Datasets:

BASF-AI

/

WikipediaEasy2GreenhouseVsEnantiopureClassification

like 0

Follow

BASF 18

The most common side effects patients experience are a headache or a chronic cough. The chronic cough develops in about 20% of people treated.

Enantiopure drugs

Levocetirizine was first launched in 2001 by the Belgian pharmaceutical company UCB (Union Chimique Belge).

Enantiopure drugs

Flutamide has also been associated with interstitial pneumonitis (which can progress to pulmonary fibrosis). The incidence of interstitial pneumonitis with flutamide was found to be 0.04% (4 per 10,000) in a large clinical cohort of 41,700 prostate cancer patients. A variety of case reports have associated flutamide with photosensitivity. Flutamide has been associated with several case reports of methemoglobinemia. Bicalutamide does not appear to share this risk with flutamide. Flutamide has also been associated with reports of sulfhemoglobinemia and neutropenia.

Enantiopure drugs

Levetiracetam is effective for treatment of generalized tonic-clonic epilepsy. It has been approved in the United States as add-on treatment for myoclonic, and tonic-clonic seizures. Levetiracetam has been approved in the European Union as a monotherapy treatment for epilepsy in the case of partial seizures or as an adjunctive therapy for partial, myoclonic, and tonic-clonic seizures. Levetiracetam is sometimes used off label to treat status epilepticus.

Enantiopure drugs

Flutamide has been studied in the treatment of bulimia nervosa in women. Flutamide was found to be effective in the treatment of obsessive–compulsive disorder (OCD) in men with comorbid Tourette's syndrome in one small randomized controlled trial. Conversely, it was ineffective in patients with OCD in another study. More research is necessary to determine whether flutamide is effective in the treatment of OCD.

Enantiopure drugs

Oxacillin is a penicillinase-resistant β-lactam. It is similar to methicillin, and has replaced methicillin in clinical use. Other related compounds are nafcillin, cloxacillin, dicloxacillin, and flucloxacillin. Since it is resistant to penicillinase enzymes, such as that produced by Staphylococcus aureus, it is widely used clinically in the US to treat penicillin-resistant Staphylococcus aureus. However, with the introduction and widespread use of both oxacillin and methicillin, antibiotic-resistant strains called methicillin-resistant and oxacillin-resistant Staphylococcus aureus (MRSA/ORSA) have become increasingly prevalent worldwide. MRSA/ORSA can be treated with vancomycin or other new antibiotics.

Enantiopure drugs

Gestonorone caproate is a potent, long-acting, and pure progestogen, possessing no androgenic, anabolic, antiandrogenic, estrogenic, antiestrogenic, glucocorticoid, mineralocorticoid, or teratogenic effects. It is approximately 20 to 25 times more potent than progesterone or hydroxyprogesterone caproate in animal bioassays when all are given by subcutaneous injection. In humans, 100 or 200 mg intramuscular gestonorone caproate has been said to be equivalent to 1,000 mg intramuscular hydroxyprogesterone caproate. Hence, gestonorone caproate is approximately 5- to 10-fold more potent than hydroxyprogesterone caproate in humans. The biological effects of gestonorone caproate in women have been studied. Like other potent progestins, gestonorone caproate possesses potent antigonadotropic activity and is capable of markedly suppressing the gonadal production and circulating levels of sex hormones such as testosterone and estradiol. A clinical study found that 400 mg/week intramuscular gestonorone caproate suppressed testosterone levels by 75% in men, while orchiectomy as a comparator reduced testosterone levels by 91%. Levels of luteinizing hormone, conversely, remained unchanged. In general, progestogens can maximally suppress testosterone levels by about 70 to 80%. In accordance with its lack of glucocorticoid activity, gestonorone caproate has no anticorticotropic effects, and does not influence the secretion of adrenocorticotropic hormone. 17α-Hydroxyprogesterone has weak progestogenic activity, but C17α esterification results in higher progestogenic activity. Of a variety of different esters, the caproate (hexanoate) ester was found to have the strongest progestogenic activity, and this formed the basis for the development of gestonorone caproate, as well as other caproate progestogen esters such as hydroxyprogesterone caproate. Gestonorone caproate has been found to decrease the weights of the prostate gland and seminal vesicles by 40 to 70% in adult male rats. It has been shown in canines to mediate these effects both via its antigonadotropic effects and by direct actions in these tissues. Gestonorone caproate decreases the uptake of testosterone into the prostate gland. It has also been found to have direct antiproliferative effects on human ovarian cancer cells in vitro. Gestonorone caproate has been reported to act to some extent as a 5α-reductase inhibitor, similarly to progesterone.

Enantiopure drugs

It is a moderate-spectrum, bacteriolytic, β-lactam antibiotic in the aminopenicillin family used to treat susceptible Gram-positive and Gram-negative bacteria. It is usually the drug of choice within the class because it is better-absorbed, following oral administration, than other β-lactam antibiotics. In general, Streptococcus, Bacillus subtilis, Enterococcus, Haemophilus, Helicobacter, and Moraxella are susceptible to amoxicillin, whereas Citrobacter, Klebsiella and Pseudomonas aeruginosa are resistant to it. Some E. coli and most clinical strains of Staphylococcus aureus have developed resistance to amoxicillin to varying degrees.

Enantiopure drugs

Aside from its environmental impacts, R12, like most chlorofluoroalkanes, forms phosgene gas when exposed to a naked flame.

Greenhouse Gases

Escitalopram was developed in cooperation between Lundbeck and Forest Laboratories. Its development was initiated in 1997, and the resulting new drug application was submitted to the US FDA in March 2001. The short time (3.5 years) it took to develop escitalopram can be attributed to the previous experience of Lundbeck and Forest with citalopram, which has similar pharmacology.

Enantiopure drugs

Dexmethylphenidate is used as a treatment for ADHD, usually along with psychological, educational, behavioral or other forms of treatment. It is proposed that stimulants help ameliorate the symptoms of ADHD by making it easier for the user to concentrate, avoid distraction, and control behavior. Placebo-controlled trials have shown that once-daily dexmethylphenidate XR was effective and generally well tolerated. Improvements in ADHD symptoms in children were significantly greater for dexmethylphenidate XR versus placebo. It also showed greater efficacy than osmotic controlled-release oral delivery system (OROS) methylphenidate over the first half of the laboratory classroom day but assessments late in the day favoured OROS methylphenidate.

Enantiopure drugs

Levomilnacipran was developed by Forest Laboratories and Pierre Fabre Group, and was approved by the Food and Drug Administration in July 2013.

Enantiopure drugs

Trichlorofluoromethane can be obtained by reacting carbon tetrachloride with hydrogen fluoride at 435 °C and 70 atm, producing a mixture of trichlorofluoromethane, tetrafluoromethane and dichlorodifluoromethane in a ratio of 77:18:5. The reaction can also be carried out in the presence of antimony(III) chloride or antimony(V) chloride: Trichlorofluoromethane is also formed as one of the byproducts when graphite reacts with chlorine and hydrogen fluoride at 500 °C. Sodium hexafluorosilicate under pressure at 270 °C, titanium(IV) fluoride, chlorine trifluoride, cobalt(III) fluoride, iodine pentafluoride, and bromine trifluoride are also suitable fluorinating agents for carbon tetrachloride. Trichlorofluoromethane was included in the production moratorium in the Montreal Protocol of 1987. It is assigned an ozone depletion potential of 1.0, and U.S. production was ended on January 1, 1996.

Greenhouse Gases

If taken together with drugs that induce the CYP3A4 cytochrome P450 liver enzyme, levonorgestrel may be metabolized faster and may have lower effectiveness. These include, but are not limited to barbiturates, bosentan, carbamazepine, felbamate, griseofulvin, oxcarbazepine, phenytoin, rifampin, St. John's wort and topiramate.

Enantiopure drugs

Amoxicillin may interact with these drugs: * Anticoagulants (dabigatran, warfarin). * Methotrexate (chemotherapy and immunosuppressant). * Typhoid, Cholera and BCG vaccines. * Probenecid reduces renal excretion and increases blood levels of amoxicillin. * Oral contraceptives potentially become less effective. * Allopurinol (gout treatment). * Mycophenolate (immunosuppressant)

Enantiopure drugs

Dexmethylphenidate, sold under the brand name Focalin among others, is a potent central nervous system (CNS) stimulant used to treat attention deficit hyperactivity disorder (ADHD) in those over the age of five years. It is taken by mouth. The immediate release formulation lasts up to five hours while the extended release formulation lasts up to twelve hours. It is the more active enantiomer of methylphenidate. Common side effects include abdominal pain, loss of appetite, and fever. Serious side effects may include abuse, psychosis, sudden cardiac death, mania, anaphylaxis, seizures, and dangerously prolonged erection. Safety during pregnancy and breastfeeding is unclear. Dexmethylphenidate is a central nervous system (CNS) stimulant. How it works in ADHD is unclear. Dexmethylphenidate was approved for medical use in the United States in 2001. It is available as a generic medication. In 2021, it was the 121st most commonly prescribed medication in the United States, with more than 4million prescriptions.

Enantiopure drugs

In contrast to most other neuroleptics which block both D and D receptors, levosulpiride is more selective and acts primarily as a D antagonist. Levosulpiride appears to lack effects on norepinephrine, acetylcholine, serotonin, histamine, and gamma-aminobutyric acid (GABA) receptors.

Enantiopure drugs

Estradiol with levonorgestrel in the form of a skin patch is used under the brand name Climara Pro for hormone replacement therapy in postmenstrual women, treating symptoms such as hot flashes or osteoporosis. The simultaneous delivery of a progestogen such as levonorgestrel is necessary for the protection of the endometrium.

Enantiopure drugs

R-22 is often used as an alternative to the highly ozone-depleting CFC-11 and CFC-12, because of its relatively low ozone depletion potential of 0.055, among the lowest for chlorine-containing haloalkanes. However, even this lower ozone depletion potential is no longer considered acceptable. As an additional environmental concern, R-22 is a powerful greenhouse gas with a GWP equal to 1810 (which indicates 1810 times as powerful as carbon dioxide). Hydrofluorocarbons (HFCs) are often substituted for R-22 because of their lower ozone depletion potential, but these refrigerants often have a higher GWP. R-410A, for example, is often substituted, but has a GWP of 2088. Another substitute is R-404A with a GWP of 3900. Other substitute refrigerants are available with low GWP. Ammonia (R-717), with a GWP of <1, remains a popular substitute on fishing vessels and large industrial applications. Ammonia's toxicity in high concentrations limit its application in small-scale refrigeration applications. Propane (R-290) is another example, and has a GWP of 3. Propane was the de facto refrigerant in systems smaller than industrial scale before the introduction of CFCs. The reputation of propane refrigerators as a fire hazard kept delivered ice and the ice box the overwhelming consumer choice despite its inconvenience and higher cost until safe CFC systems overcame the negative perceptions of refrigerators. Illegal to use as a refrigerant in the US for decades, propane is now permitted for use in limited mass suitable for small refrigerators. It is not lawful to use in air conditioners or larger refrigerators because of its flammability and potential for explosion.

Greenhouse Gases

Concomitant or recent (previous fourteen days) monoamine oxidase inhibitor use can lead to hypertensive reactions, including hypertensive crises. The antihypertensive effects of methyldopa, mecamylamine, reserpine, and veratrum alkaloids may be reduced by sympathomimetics. Beta-adrenergic antagonists may also interact with sympathomimetics. Increase of ectopic pacemaker activity can occur when pseudoephedrine is used concomitantly with digitalis. Antacids increase the rate of pseudoephedrine absorption, while kaolin decreases it.

Enantiopure drugs

From 1996 to 2004, researchers in the European Project for Ice Coring in Antarctica (EPICA) project were able to drill and analyze gases trapped in the ice cores in Antarctica to reconstruct GHG concentrations in the atmosphere over the past 800,000 years". They found that prior to approximately 900,000 years ago, the cycle of ice ages followed by relatively short warm periods lasted about 40,000 years, but by 800,000 years ago the time interval changed dramatically to cycles that lasted 100,000 years. There were low values of GHG in ice ages, and high values during the warm periods. This 2016 EPA illustration above is a compilation of paleoclimatology showing methane concentrations over time based on analysis of gas bubbles from EPICA Dome C, Antarcticaapproximately 797,446 BCE to 1937 CE, Law Dome, Antarcticaapproximately 1008 CE to 1980 CE Cape Grim, Australia1985 CE to 2015 CE Mauna Loa, Hawaii1984 CE to 2015 CE and Shetland Islands, Scotland: 1993 CE to 2001 CE The massive and rapid release of large volumes of methane gas from such sediments into the atmosphere has been suggested as a possible cause for rapid global warming events in the Earth's distant past, such as the Paleocene–Eocene Thermal Maximum, and the Great Dying. In 2001, NASAs Goddard Institute for Space Studies and Columbia Universitys Center for Climate Systems Research scientists confirmed that other greenhouse gases apart from carbon dioxide were important factors in climate change in research presented at the annual meeting of the American Geophysical Union (AGU). They offered a theory on the 100,000-year long Paleocene–Eocene Thermal Maximum that occurred approximately 55 million years ago. They posited that there was a vast release of methane that had previously been kept stable through "cold temperatures and high pressure...beneath the ocean floor". This methane release into the atmosphere resulted in the warming of the earth. A 2009 journal article in Science, confirmed NASA research that the contribution of methane to global warming had previously been underestimated. Early in the Earths history carbon dioxide and methane likely produced a greenhouse effect. The carbon dioxide would have been produced by volcanoes and the methane by early microbes. During this time, Earths earliest life appeared. According to a 2003 article in the journal Geology, these first, ancient bacteria added to the methane concentration by converting hydrogen and carbon dioxide into methane and water. Oxygen did not become a major part of the atmosphere until photosynthetic organisms evolved later in Earth's history. With no oxygen, methane stayed in the atmosphere longer and at higher concentrations than it does today.

Greenhouse Gases

Perindopril shares the indications of ACE inhibitors as a class, including essential hypertension, stable coronary artery disease (reduction of risk of cardiac events in patients with a history of myocardial infarction and/or revascularization), treatment of symptomatic coronary artery disease or heart failure, and diabetic nephropathy.

Enantiopure drugs

* The French writer René Daumal intoxicated himself by inhalation of carbon tetrachloride which he used to kill the beetles he collected, to "encounter other worlds" by voluntarily plunging himself into intoxications close to comatose states. * Carbon tetrachloride is listed (along with salicylic acid, toluene, sodium tetraborate, silica gel, methanol, potassium carbonate, ethyl acetate and "BHA") as an ingredient in Peter Parkers (Spider-Man) custom web fluid formula in the book The Wakanda Files: A Technological Exploration of the Avengers and Beyond'. * Australian YouTuber Tom of Explosions&Fire and Extractions&Ire made a video on extracting carbon tetrachloride from an old fire extinguisher in 2019, and later experimenting with it by mixing it with sodium, and the chemical gained a fan base called "Tet Gang" on social media (especially on Reddit). The channel owner later used carbon tetrachloride-themed designs in the channel's merch. * In the Ramones song "Carbona Not Glue" released in 1977, the narrator says that huffing the vapours of Carbona, a carbon tetrachloride-based stain remover, was better than huffing glue. They later removed the song from the album as Carbona was a corporate trademark.

Greenhouse Gases

It is one of the most commonly used volatile anesthetic agents, particularly for outpatient anesthesia, across all ages, as well as in veterinary medicine. Together with desflurane, sevoflurane is replacing isoflurane and halothane in modern anesthesia practice. It is often administered in a mixture of nitrous oxide and oxygen.

Greenhouse Gases

The antitubercular agent Ethambutol contains two constitutionally symmetrical stereogenic centers in its structure and exists in three stereoisomeric forms. An enantiomeric pair (S,S)- and (R,R)-ethambutol, along with the achiral stereoisomer called meso-form, it holds a diastereomeric relationship with the optically active stereoisomers. The activity of the drug resides in the (S,S)-enantiomer which is 500 and 12 fold more potent than the (R,R)-ethambutol and the meso-form. The drug had initially been introduced for clinical use as the racemate and was changed to the (S,S)-enantiomer, as a result of optic neuritis leading to blindness. Toxicity is related to both dose and duration of treatment. All the three stereoisomers were almost equipotent with respect to side effects. Hence the use of S,S)-enantiomer greatly enhanced the risk/benefit ratio.

Enantiopure drugs

Earths natural greenhouse effect makes life as we know it possible and carbon dioxide plays a significant role in providing for the relatively high temperature on Earth. The greenhouse effect is a process by which thermal radiation from a planetary atmosphere warms the planets surface beyond the temperature it would have in the absence of its atmosphere. Without the greenhouse effect, the Earths average surface temperature would be about compared to Earths actual average surface temperature of approximately 14 °C (57.2 °F). Water is responsible for most (about 36–70%) of the total greenhouse effect, and the role of water vapor as a greenhouse gas depends on temperature. On Earth, carbon dioxide is the most relevant, direct anthropologically influenced greenhouse gas. Carbon dioxide is often mentioned in the context of its increased influence as a greenhouse gas since the pre-industrial (1750) era. In 2013, the increase in CO was estimated to be responsible for 1.82 W m of the 2.63 W m change in radiative forcing on Earth (about 70%). The concept of atmospheric CO increasing ground temperature was first published by Svante Arrhenius in 1896. The increased radiative forcing due to increased CO in the Earths atmosphere is based on the physical properties of CO and the non-saturated absorption windows where CO absorbs outgoing long-wave energy. The increased forcing drives further changes in Earths energy balance and, over the longer term, in Earth's climate.

Greenhouse Gases

Unsaturated fluorocarbons are far more reactive than fluoroalkanes. Although difluoroacetylene is unstable (as is typical for related alkynes, see dichloroacetylene), hexafluoro-2-butyne and related fluorinated alkynes are well known.

Greenhouse Gases

The mean lifespan of methane in the atmosphere was estimated in a range between 9.6 years and twelve years. These differences are caused by the uncertainties about hydroxyl radical (-OH) concentrations and formation processes. When -OH reacts with methane, it is removed from the atmosphere, so changes in its concentration would also affect the concentration of methane. An increase in methane emissions greater than the regeneration rate of OH radicals would reduce their concentrations and so increase methane's mean atmospheric lifetime. The reaction of methane and chlorine atoms acts as a primary sink of Cl atoms and is a primary source of hydrochloric acid (HCl) in the stratosphere. CH + Cl → CH + HCl The HCl produced in this reaction leads to catalytic ozone destruction in the stratosphere.

Greenhouse Gases

Drospirenone is an antimineralocorticoid with potassium-sparing properties, though in most cases no increase of potassium levels is to be expected. In women with mild or moderate chronic kidney disease, or in combination with chronic daily use of other potassium-sparing medications (ACE inhibitors, angiotensin II receptor antagonists, potassium-sparing diuretics, heparin, antimineralocorticoids, or nonsteroidal anti-inflammatory drugs), a potassium level should be checked after two weeks of use to test for hyperkalemia. Persistent hyperkalemia that required discontinuation occurred in 2 out of around 1,000 women (0.2%) with 4 mg/day drospirenone alone in clinical trials.

Enantiopure drugs

The density of saltwater depends on the dissolved salt content as well as the temperature. Ice still floats in the oceans, otherwise, they would freeze from the bottom up. However, the salt content of oceans lowers the freezing point by about 1.9 °C (due to freezing-point depression of a solvent containing a solute) and lowers the temperature of the density maximum of water to the former freezing point at 0 °C. This is why, in ocean water, the downward convection of colder water is not blocked by an expansion of water as it becomes colder near the freezing point. The oceans' cold water near the freezing point continues to sink. So creatures that live at the bottom of cold oceans like the Arctic Ocean generally live in water 4 °C colder than at the bottom of frozen-over fresh water lakes and rivers. As the surface of saltwater begins to freeze (at −1.9 °C for normal salinity seawater, 3.5%) the ice that forms is essentially salt-free, with about the same density as freshwater ice. This ice floats on the surface, and the salt that is "frozen out" adds to the salinity and density of the seawater just below it, in a process known as brine rejection. This denser saltwater sinks by convection and the replacing seawater is subject to the same process. This produces essentially freshwater ice at −1.9 °C on the surface. The increased density of the seawater beneath the forming ice causes it to sink towards the bottom. On a large scale, the process of brine rejection and sinking cold salty water results in ocean currents forming to transport such water away from the Poles, leading to a global system of currents called the thermohaline circulation.

Greenhouse Gases

Esketamine is approximately twice as potent an anesthetic as racemic ketamine. In mice, the rapid antidepressant effect of arketamine was greater and lasted longer than that of esketamine. The usefulness of arketamine over esketamine has been supported by other researchers. Esketamine inhibits dopamine transporters eight times more than arketamine. This increases dopamine activity in the brain. At doses causing the same intensity of effects, esketamine is generally considered to be more pleasant by patients. Patients also generally recover mental function more quickly after being treated with pure esketamine, which may be a result of the fact that it is cleared from their system more quickly. This is however in contradiction with arketamine being devoid of psychotomimetic side effects. Unlike arketamine, esketamine does not bind significantly to sigma receptors. Esketamine increases glucose metabolism in the frontal cortex, while arketamine decreases glucose metabolism in the brain. This difference may be responsible for the fact that esketamine generally has a more dissociative or hallucinogenic effect while arketamine is reportedly more relaxing. However, another study found no difference between racemic ketamine and esketamine on the patient's level of vigilance. Interpretation of this finding is complicated by the fact that racemic ketamine is 50% esketamine.

Enantiopure drugs

An interesting alternative synthesis of azlocillin involves activation of the substituted phenylglycine analogue 1 with 1,3-dimethyl-2-chloro-1-imidazolinium chloride (2) and then condensation with 6-APA.

Enantiopure drugs

Generally, levosalbutamol is well tolerated. Common mild side-effects include an elevated heart rate, muscle cramps, and gastric upset (including heartburn and diarrhea). Symptoms of overdose in particular include: collapse into a seizure; chest pain (possible precursor of a heart attack); fast, pounding heartbeat, which may cause raised blood pressure (hypertension); irregular heartbeat (cardiac arrhythmia), which may cause paradoxical lowered blood pressure (hypotension); nervousness and tremor; headache; dizziness and nausea/vomiting; weakness or exhaustion (medical fatigue); dry mouth; and insomnia. Rarer side effects may indicate a dangerous allergic reaction. These include: paradoxical bronchospasm (shortness of breath and difficulty breathing); skin itching, rash, or hives (urticaria); swelling (angioedema) of any part of the face or throat (which can lead to voice hoarseness), or swelling of the extremities.

Enantiopure drugs

Very common effects (>10% incidence) include: * Headache (24%) * Nausea (18%) * Ejaculation disorder (9–14%) * Somnolence (4–13%) * Insomnia (7–12%)

Enantiopure drugs

Atmospheric methane removal is a category of potential approaches being researched to accelerate the breakdown of methane that is in the atmosphere, for the purpose of mitigating some of the impacts of climate change. Atmospheric methane has increased since pre-industrial times from 0.7 ppm to 1.9 ppm. From 2010 to 2019, methane emissions caused 0.5 °C (about 30%) of observed global warming. Global methane emissions approached a record 600 Tg CH per year in 2017.

Greenhouse Gases

Amoxicillin (α-amino-p-hydroxybenzyl penicillin) is a semisynthetic derivative of penicillin with a structure similar to ampicillin but with better absorption when taken by mouth, thus yielding higher concentrations in blood and in urine. Amoxicillin diffuses easily into tissues and body fluids. It will cross the placenta and is excreted into breastmilk in small quantities. It is metabolized by the liver and excreted into the urine. It has an onset of 30 minutes and a half-life of 3.7 hours in newborns and 1.4 hours in adults. Amoxicillin attaches to the cell wall of susceptible bacteria and results in their death. It is effective against streptococci, pneumococci, enterococci, Haemophilus influenzae, Escherichia coli, Proteus mirabilis, Neisseria meningitidis, Neisseria gonorrhoeae, Shigella, Chlamydia trachomatis, Salmonella, Borrelia burgdorferi, and Helicobacter pylori. As a derivative of ampicillin, amoxicillin is a member of the penicillin family and, like penicillins, is a β-lactam antibiotic. It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the bacterial cell wall. It has two ionizable groups in the physiological range (the amino group in alpha-position to the amide carbonyl group and the carboxyl group).

Enantiopure drugs

Moexipril is generally well tolerated in elderly patients with hypertension. Hypotension, dizziness, increased cough, diarrhea, flu syndrome, fatigue, and flushing have been found to affect less than 6% of patients who were prescribed moexipril.

Enantiopure drugs

One major use of CFCs has been as propellants of aerosols, including metered-dose inhalers for drugs used to treat asthma. The conversion of these devices and treatments from CFC to propellants that do not deplete the ozone layer is almost complete. Production and import is now banned in the United States.

Greenhouse Gases

The refrigerant naming system is mainly used for fluorinated and chlorinated short alkanes used as refrigerants. In the United States, the standard is specified in ANSI/ASHRAE Standard 34–1992, with additional annual supplements. The specified ANSI/ASHRAE prefixes were FC (fluorocarbon) or R (refrigerant), but today most are prefixed by a more specific classification: *CFC—list of chlorofluorocarbons *HCFC—list of hydrochlorofluorocarbons *HFC—list of hydrofluorocarbons *FC—list of fluorocarbons *PFC—list of perfluorocarbons (completely fluorinated) The decoding system for CFC-01234a is: *0 = Number of double bonds (omitted if zero) *1 = Carbon atoms -1 (omitted if zero) *2 = Hydrogen atoms +1 *3 = Fluorine atoms *4 = Replaced by Bromine ("B" prefix added) *a = Letter added to identify isomers, the "normal" isomer in any number has the smallest mass difference on each carbon, and a, b, or c are added as the masses diverge from normal. Other coding systems are in use as well.

Greenhouse Gases

Atmospheric carbon dioxide plays an integral role in the Earth's carbon cycle whereby is removed from the atmosphere by some natural processes such as photosynthesis and deposition of carbonates, to form limestones for example, and added back to the atmosphere by other natural processes such as respiration and the acid dissolution of carbonate deposits. There are two broad carbon cycles on Earth: the fast carbon cycle and the slow carbon cycle. The fast carbon cycle refers to movements of carbon between the environment and living things in the biosphere whereas the slow carbon cycle involves the movement of carbon between the atmosphere, oceans, soil, rocks, and volcanism. Both cycles are intrinsically interconnected and atmospheric facilitates the linkage. Natural sources of atmospheric include volcanic outgassing, the combustion of organic matter, wildfires and the respiration processes of living aerobic organisms. Man-made sources of include the burning of fossil fuels for heating, power generation and transport, as well as some industrial processes such as cement making. It is also produced by various microorganisms from fermentation and cellular respiration. Plants, algae and cyanobacteria convert carbon dioxide to carbohydrates by a process called photosynthesis. They gain the energy needed for this reaction from absorption of sunlight by chlorophyll and other pigments. Oxygen, produced as a by-product of photosynthesis, is released into the atmosphere and subsequently used for respiration by heterotrophic organisms and other plants, forming a cycle with carbon. Most sources of emissions are natural, and are balanced to various degrees by similar sinks. For example, the decay of organic material in forests, grasslands, and other land vegetation - including forest fires - results in the release of about 436 gigatonnes of (containing 119 gigatonnes carbon) every year, while uptake by new growth on land counteracts these releases, absorbing 451 Gt (123 Gt C). Although much in the early atmosphere of the young Earth was produced by volcanic activity, modern volcanic activity releases only 130 to 230 megatonnes of each year. Natural sources are more or less balanced by natural sinks, in the form of chemical and biological processes which remove from the atmosphere. Overall, there is a large natural flux of atmospheric into and out of the biosphere, both on land and in the oceans. In the pre-industrial era, each of these fluxes were in balance to such a degree that little net flowed between the land and ocean reservoirs of carbon, and little change resulted in the atmospheric concentration. From the human pre-industrial era to 1940, the terrestrial biosphere represented a net source of atmospheric (driven largely by land-use changes), but subsequently switched to a net sink with growing fossil carbon emissions. In 2012, about 57% of human-emitted , mostly from the burning of fossil carbon, was taken up by land and ocean sinks. The ratio of the increase in atmospheric to emitted is known as the airborne fraction. This ratio varies in the short-term and is typically about 45% over longer (5-year) periods. Estimated carbon in global terrestrial vegetation increased from approximately 740 gigatonnes in 1910 to 780 gigatonnes in 1990.

Greenhouse Gases

Carbon tetrachloride was briefly used as a volatile inhalation anaesthetic and analgesic for intense menstruation pains and headaches in the mid-19th century. Its anaesthetic effects were known as early as 1847 or 1848. It was introduced as a safer alternative to Chloroform by Doctor Protheroe Smith in 1864. In December 1865, the Scottish obstetrician who discovered the anaesthetic effects of chloroform on humans, James Young Simpson, had experimented with carbon tetrachloride as an anaesthetic. Simpson named the compound "Chlorocarbon" for its similarity to chloroform. His experiments involved injecting carbon tetrachloride into two women's vaginas. Simpson orally consumed carbon tetrachloride and described it as having "the same effect as swallowing a capsule of chloroform". Because of the higher amount of chlorine atoms (compared to chloroform) in its molecule, carbon tetrachloride has a stronger anaesthetic effect than chloroform and required a smaller amount. Its anaesthetic action was likened to ether, rather than the related chloroform. It is less volatile than chloroform, therefore it was more difficult to apply and needed warm water to evaporate. Its smell has been described as "fruity", quince-like and "more pleasant than chloroform", and had a "pleasant taste". Carbon tetrachloride for anaesthetic use was made by the chlorination of carbon disulfide. It was used on at least 50 patients, of which most were women in labour. During anaesthesia, carbon tetrachloride has caused violent muscular contractions and negative effects on the heart in some patients that it had to be substituted with chloroform or ether. Such use was experimental and the anaesthetic use of carbon tetrachloride never gained popularity due to its potential toxicity.

Greenhouse Gases

In the UK, pseudoephedrine is available over the counter under the supervision of a qualified pharmacist, or on prescription. In 2007, the MHRA reacted to concerns over diversion of ephedrine and pseudoephedrine for the illicit manufacture of methamphetamine by introducing voluntary restrictions limiting over the counter sales to one box containing no more than 720 mg of pseudoephedrine in total per transaction. These restrictions became law in April 2008. No form of ID is required.

Enantiopure drugs

R-410A replaced R-22 as the preferred refrigerant for use in residential and commercial air conditioners in Japan, Europe, and the United States. Parts designed specifically for R-410A must be used, as R-410A operates at higher pressures than other refrigerants. R-410A systems thus require service personnel to use different tools, equipment, safety standards, and techniques. Equipment manufacturers are aware of these changes and require the certification of professionals installing R-410A systems. In addition, the AC&R Safety Coalition has been created to help educate professionals about R-410A systems.

Greenhouse Gases

In Australia, and the United States, Armodafinil is considered to be a Schedule 4 prescription-only medicine or prescription animal remedy. Schedule 4 is defined as "Substances, the use or supply of which should be by or on the order of persons permitted by State or Territory legislation to prescribe and should be available from a pharmacist on prescription."

Enantiopure drugs

Sevoflurane was discovered by Ross Terrell and independently by Bernard M Regan. A detailed report of its development and properties appeared in 1975 in a paper authored by Richard Wallin, Bernard Regan, Martha Napoli and Ivan Stern. It was introduced into clinical practice initially in Japan in 1990 by Maruishi Pharmaceutical Co., Ltd. Osaka, Japan. The rights for sevoflurane worldwide were held by AbbVie. It is now available as a generic drug.

Greenhouse Gases

Mecillinam (INN) or amdinocillin (USAN) is an extended-spectrum penicillin antibiotic of the amidinopenicillin class that binds specifically to penicillin binding protein 2 (PBP2), and is only considered to be active against Gram-negative bacteria. It is used primarily in the treatment of urinary tract infections, and has also been used to treat typhoid and paratyphoid fever. Because mecillinam has very low oral bioavailability, an orally active prodrug was developed: pivmecillinam.

Enantiopure drugs

In accordance with terms and agreement reached in the Montreal Protocol (The Montreal Protocol on Substances That Deplete the Ozone Layer), the United States Environmental Protection Agency has mandated that production or import of R-22 along with other hydrochlorofluorocarbons (HCFCs) be phased out in the United States. In the E.U. and the U.S., R-22 cannot be used in the manufacture of new air conditioning or similar units from 1 January 2010. In other parts of the world, the phase-out date varies from country to country. All newly manufactured window air conditioners and mini split air conditioners in the United States come with R-410A. Since 1 January 2020, the production and importation of R-22 has been banned; the only available sources of R-22 include that which has been stockpiled or recovered from existing devices. R-410A use expanded globally and rapidly as it replaced R-22.

Greenhouse Gases

Atmospheric Methane Removal is a category of potential approaches being researched to accelerate the breakdown of methane once in the atmosphere to mitigate some of the impacts of climate change. Different methods to remove methane from the atmosphere include thermal-catalytic oxidation, photocatalytic oxidation, biological methanotrophic methane removal, concentration with zeolites or other porous solids, and separation by membranes.

Greenhouse Gases

Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. What distinguishes them from other gases is that they absorb the wavelengths of radiation that a planet emits, resulting in the greenhouse effect. The Earth is warmed by sunlight, causing its surface to radiate heat, which is then mostly absorbed by greenhouse gases. Without greenhouse gases in the atmosphere, the average temperature of Earth's surface would be about , rather than the present average of . The five most abundant greenhouse gases in Earth's atmosphere, listed in decreasing order of average global mole fraction, are: water vapor, carbon dioxide, methane, nitrous oxide, ozone. Other greenhouse gases of concern include chlorofluorocarbons (CFCs and HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons, sulfur hexafluoride|, and nitrogen trifluoride|. Water vapor causes about half of the greenhouse effect, but humans are not directly adding to its amount, so it is not a driver of climate change. Carbon dioxide is causing about three-quarters of global warming and can take thousands of years to be fully absorbed by the carbon cycle. Methane causes most of the remaining warming and lasts in the atmosphere for an average of 12 years. Human activities since the beginning of the Industrial Revolution (around 1750) have increased carbon dioxide by over 50%, up to a level not seen in over 3 million years. The atmospheric methane concentrations have increased by over 150% during the same time period. Without human influence, the natural flows of carbon between the atmosphere, terrestrial ecosystems, the ocean, and sediments would be fairly balanced. The vast majority of carbon dioxide emissions by humans come from the burning of fossil fuels. Further contributions come for example from cement manufacturing and deforestation. Methane emissions originate from agriculture, fossil fuel production, waste, and other sources. If current emission rates continue then temperature rises will surpass sometime between 2040 and 2070. This is a level which the Intergovernmental Panel on Climate Change (IPCC) says is "dangerous".

Greenhouse Gases

Alogliptin, sold under the brand names Nesina and Vipidia, is an oral anti-diabetic drug in the DPP-4 inhibitor (gliptin) class. Like other members of the gliptin class, it causes little or no weight gain, exhibits relatively little risk of hypoglycemia, and has relatively modest glucose-lowering activity. Alogliptin and other gliptins are commonly used in combination with metformin in people whose diabetes cannot adequately be controlled with metformin alone. In April 2016, the U.S. Food and Drug Administration (FDA) added a warning about increased risk of heart failure. It was developed by Syrrx, a company which was acquired by Takeda Pharmaceutical Company in 2005. In 2020, it was the 295th most commonly prescribed medication in the United States, with more than 1million prescriptions.

Enantiopure drugs

The action of water on rock over long periods of time typically leads to weathering and water erosion, physical processes that convert solid rocks and minerals into soil and sediment, but under some conditions chemical reactions with water occur as well, resulting in metasomatism or mineral hydration, a type of chemical alteration of a rock which produces clay minerals. It also occurs when Portland cement hardens. Water ice can form clathrate compounds, known as clathrate hydrates, with a variety of small molecules that can be embedded in its spacious crystal lattice. The most notable of these is methane clathrate, 4 , naturally found in large quantities on the ocean floor.

Greenhouse Gases

Levonorgestrel is marketed alone or in combination with an estrogen (specifically ethinylestradiol, estradiol, or estradiol valerate) under a multitude of brand names throughout the world, including Alesse, Altavera, Alysena, Amethia, Amethyst, Ashlyna, Aviane, Camrese, Chateal, Climara Pro, Cycle 21, Daysee, Emerres, Enpresse, Erlibelle, Escapelle, Falmina, Introvale, Isteranda, Jadelle, Jaydess, Jolessa, Klimonorm, Kurvelo, Kyleena, Lessina, Levlen, Levodonna, Levonelle, Levonest, Levosert, Levora, Liletta, Loette, Logynon, LoSeasonique, Lutera, Lybrel, Marlissa, Microgynon, Microlut, Microvlar, Min-Ovral, Miranova, Mirena, My Way, Myzilra, Next Choice, Nordette, Norgeston, NorLevo, Norplant, One Pill, Option 2, Orsythia, Ovima, Ovranette, Plan B, Plan B One-Step, Portia, Postinor, Postinor-2, Preventeza, Ramonna, Rigevidon, Quartette, Quasense, Seasonale, Seasonique, Skyla, Sronyx, Tri-Levlen, Trinordiol, Triphasil, Triquilar, Tri-Regol, Trivora, and Upostelle, among many others. These formulations are used as emergency contraceptives, normal contraceptives, or in menopausal hormone therapy for the treatment of menopausal symptoms. As an emergency contraceptive, levonorgestrel is often referred to colloquially as the "morning-after pill".

Enantiopure drugs

Rain is generally mildly acidic, with a pH between 5.2 and 5.8 if not having any acid stronger than carbon dioxide. If high amounts of nitrogen and sulfur oxides are present in the air, they too will dissolve into the cloud and raindrops, producing acid rain.

Greenhouse Gases

Eslicarbazepine acetate (ESL), sold under the brand names Aptiom and Zebinix among others, is an anticonvulsant medication approved for use in Europe and the United States as monotherapy or as additional therapy for partial-onset seizures epilepsy. Similarly to oxcarbazepine, ESL behaves as a prodrug to (S)-(+)-licarbazepine. As such, their mechanisms of action are identical.

Enantiopure drugs

In the electronics industry, octafluoropropane is mixed with oxygen and used as a plasma etching material for SiO layers in semiconductor applications, as oxides are selectively etched versus their metal substrates. In medicine, octafluoropropane may compose the gas cores of microbubble contrast agents used in contrast-enhanced ultrasound. Octafluoropropane microbubbles reflect sound waves well and are used to improve the ultrasound signal backscatter. It is used in eye surgery, such as pars plana vitrectomy procedures where a retina hole or tear is repaired. The gas provides a long-term tamponade, or plug, of a retinal hole or tear and allows re-attachment of the retina to occur over the several days following the procedure. Under the name R-218, octafluoropropane is used in other industries as a component of refrigeration mixtures. It has been featured in some plans for terraforming Mars. With a greenhouse gas effect 24,000 times greater than carbon dioxide (CO), octafluoropropane could dramatically reduce the time and resources it takes to terraform Mars. It is the active liquid in PICO-2L dark matter bubble detector (joined PICASSO and COUPP collaborations).

Greenhouse Gases

Chloromethane and bromomethane are used to introduce methyl groups in organic synthesis. Chlorodifluoromethane is the main precursor of tetrafluoroethylene, which is the monomeric precursor to Teflon.

Greenhouse Gases

The elimination half-life of levomethamphetamine is between 13.3 and 15 hours, whereas dextromethamphetamine has a half-life of about 10.5 hours.

Enantiopure drugs

Dexpramipexole is the (D)-enantiomer of pramipexole. Enantiopure dexpramipexole has essentially no dopamine agonist activity and shares no other pharmacologic similarity to pramipexole. In contrast, pramipexole the (S)-enantiomer is a dopamine agonist and is an approved drug (Mirapex) used in Parkinson’s disease. Dexpramipexole is a low molecular weight, orally bioavailable, water-soluble small molecule with linear pharmacokinetics and linear dose proportionality.

Enantiopure drugs

Common side effects include headache, dizziness, feeling tired, cough, nausea, and rash. Serious side effects may include low blood pressure, liver problems, hyperkalemia, and angioedema. Use is not recommended during the entire duration of pregnancy as it may harm the baby.

Enantiopure drugs

Dexketoprofen belongs to a class of medicines called NSAIDs. It works by blocking the action of a substance in the body called cyclo-oxygenase, which is involved in the production of chemicals in the body called prostaglandins. Prostaglandins are produced in response to injury or certain diseases and would otherwise go on to cause swelling, inflammation and pain. By blocking cyclo-oxygenase, dexketoprofen prevents the production of prostaglandins and therefore reduces inflammation and pain. Along with peripheral analgesic action, it possesses central analgesic action.

Enantiopure drugs

Hexafluoroethane is used as a versatile etchant in semiconductor manufacturing. It can be used for selective etching of metal silicides and oxides versus their metal substrates and also for etching of silicon dioxide over silicon. The primary aluminium and the semiconductor manufacturing industries are the major emitters of hexafluoroethane using the Hall-Héroult process. Together with trifluoromethane it is used in refrigerants R508A (61%) and R508B (54%). It is used as a tamponade to assist in retinal reattachment following vitreoretinal surgery.

Greenhouse Gases

In September 2023, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion, recommending the granting of a pediatric use marketing authorization for the medicinal product Aqumeldi, intended for the treatment of heart failure in children from birth to less than 18 years of age. The applicant for this medicinal product is Proveca Pharma Limited. Aqumeldi was approved for medical use in the European Union in November 2023.

Enantiopure drugs

Levomethamphetamine can register on urine drug screens as either methamphetamine, amphetamine, or both, depending on the subject's metabolism and dosage. L-methamphetamine metabolizes completely into L-amphetamine after a period of time.

Enantiopure drugs

Dexketoprofen is the (S)-enantiomer of ketoprofen. Technically it is a chiral switch of (±)-ketoprofen. The switch was done for a faster onset of action, a better therapeutic value. Dexketoprofen consists of a propionic acid moiety connected to a benzophenone molecule by its second carbon.

Enantiopure drugs

Zofenopril (INN) is a medication that protects the heart and helps reduce high blood pressure. It is an angiotensin-converting enzyme (ACE) inhibitor. In small studies, zofenopril appeared significantly more effective in reducing hypertension than two older antihypertensive drugs, atenolol and enalapril, and was associated with fewer adverse effects. Zofenopril is a prodrug with zofenoprilat as the active metabolite. It was patented in 1978 and approved for medical use in 2000.

Enantiopure drugs

1,1-Dichloro-1-fluoroethane is mainly used as a solvent and foam blowing agent under the names R-141b and HCFC-141b. It is a class 2 ozone depleting substance undergoing a global phaseout from production and use under the Montreal Protocol since the late 1990s. It is being replaced by HFCs within some applications.

Greenhouse Gases

Levonorgestrel-containing emergency contraception is available over-the-counter in some countries, such as the United States. On some college campuses, Plan B is available from vending machines. A policy update in 2015, required all pharmacies, clinics, and emergency departments run by Indian Health Services (for Native Americans) to have Plan B One-Step in stock, to distribute it to any woman (or her representative) who asked for it without a prescription, age verification, registration or any other requirement, to provide orientation training to all staff regarding the medication, to provide unbiased and medically accurate information about emergency contraception, and to make someone available at all times to distribute the pill in case the primary staffer objected to providing it on religious or moral grounds.

Enantiopure drugs

Within the Earth's atmosphere and surface, the liquid phase is the most common and is the form that is generally denoted by the word "water". The solid phase of water is known as ice and commonly takes the structure of hard, amalgamated crystals, such as ice cubes, or loosely accumulated granular crystals, like snow. Aside from common hexagonal crystalline ice, other crystalline and amorphous phases of ice are known. The gaseous phase of water is known as water vapor (or steam). Visible steam and clouds are formed from minute droplets of water suspended in the air. Water also forms a supercritical fluid. The critical temperature is 647 K and the critical pressure is 22.064 MPa. In nature, this only rarely occurs in extremely hostile conditions. A likely example of naturally occurring supercritical water is in the hottest parts of deep water hydrothermal vents, in which water is heated to the critical temperature by volcanic plumes and the critical pressure is caused by the weight of the ocean at the extreme depths where the vents are located. This pressure is reached at a depth of about 2200 meters: much less than the mean depth of the ocean (3800 meters).

Greenhouse Gases

Unlike the majority of ACE inhibitors, captopril is not administered as a prodrug (the only other being lisinopril). About 70% of orally administered captopril is absorbed. Bioavailability is reduced by presence of food in stomach. It is partly metabolised and partly excreted unchanged in urine. Captopril also has a relatively poor pharmacokinetic profile. The short half-life necessitates dosing two or three times per day, which may reduce patient compliance. Captopril has a short half-life of 2–3 hours and a duration of action of 12–24 hours.

Enantiopure drugs

A 5-step process to synthesise levobupivacaine from N-CBZ (S)-lysine, published in 1996, is depicted in Scheme 1. The key steps in this process include oxidative de-animation and stereospecific ring closure to form the pipecolamide core structure. This method is claimed to be efficient, but showed to be dangerous for mass production due to the high risk of explosion of the diazonium salt intermediates. A more recent patent from 2008, consists of a 3-step process (see Scheme 2) to synthesise levobupivacaine hydrochloride of an optical purity of at least 99%. (S)-2,6-pipecocholxylide (I) is reacted with 1-bromobutane and a base (a), such as potassium carbonate, to obtain a solution of (S)-bupivacaine (II) and its enantiomers. Recrystallisation of this solution with a solvent (b), preferably cyclohexane, can lead to an optical purity of at least 98% levobupivacaine. Lastly, the addition of hydrochloride (c) is possible.

Enantiopure drugs

Possible adverse effects in the central nervous system caused by levobupivacaine usage are light-headedness, tinnitus, tongue numbness and convulsions, which may be due to the blockade of sodium, potassium and calcium channels in tissues that were not intended as targets. Cardiotoxicity may be a result of indirect effects of the drug, such as the blockade of myocardial sympathetic nerves, thus leading to contractile delay, or by direct effects, such as the blockade of potassium channels. Effects of this nature lead to lowered contractile function and arrhythmogenic effects, which can potentially cause cardiovascular collapse and death. It is to note that the drug also has vasoconstrictive activity, thereby increasing the duration of sensory blockage with a relatively low risk of central nervous system toxicity on one hand, and on the other, it can have the same effect on uteroplacental blood flow, which can harm the foetus. Ultimately, levobupivacaine has been shown to have a lower risk of cardiovascular and central nervous system toxicity compared to bupivacaine in animal studies, not at the expense of potency and efficacy, and should be therefore considered as an alternative.

Enantiopure drugs

Levetiracetam is effective as single-drug treatment for newly diagnosed focal epilepsy in adults. It reduces focal seizures by 50% or more as an add-on medication.

Enantiopure drugs

The use of racemic amlodipine is commonly associated with adverse events like peripheral edema and other side effects like headache, dizziness, flushing and abdominal pain. Controlled clinical trials showed that levamlodipine is rarely associated with these side effects. No controlled clinical study of levamlodipine has been performed in patients with hepatic impairment and renal impairment. Clinical studies in patients with normal liver function have shown that there is no elevation in the hepatic enzymes with the use of levamlodipine. However, caution should be taken while administering levamlodipine to such patients. In a postmarketing surveillance study, levamlodipine (2.5/5 mg) was found to be well tolerated (n = 1859) in patients with hypertension. Out of 314 patients, who reported peripheral edema with conventional amlodipine were switched over to levamlodipine and edema was resolved in 310 patients (98.72%) at the end of 4 weeks. Only in 4 patients was edema sustained. Only 30 patients (out of 1859) reported side effects. These side effects included vertigo, tachycardia, cough, headache, fever, mild difficulty in breathing and edema. Adverse events were mild in nature and no serious adverse events were reported.

Enantiopure drugs

Perfluoro(2-methyl-3-pentanone) is a fluorinated ketone with the structural formula CFCFC(=O)CF(CF), a fully-fluorinated analog of ethyl isopropyl ketone. It is used as an electronics coolant liquid and fire protection fluid sold commercially by 3M under brand names such as Novec 1230, Novec 649, and FK-5-1-12. It is also known as “waterless water” or “dry water”.

Greenhouse Gases

In New Zealand, pseudoephedrine is currently classified as a Class B Part II controlled drug in the Misuse of Drugs Act 1975, making it illegal to supply or possess except on prescription. Pseudoephedrine, ephedrine, and any product containing these substances, e.g. cold and flu medicines, were first classified in October 2004 as Class C Part III (partially exempted) controlled drugs, due to being the principal ingredient in methamphetamine. New Zealand Customs and police officers continued to make large interceptions of precursor substances believed to be destined for methamphetamine production. On 9 October 2009, Prime Minister John Key announced pseudoephedrine-based cold and flu tablets would become prescription-only drugs and reclassified as a class B2 drug. The law was amended by The Misuse of Drugs Amendment Bill 2010, which passed in August 2011. On 24 November 2023, the recently-formed National-led coalition government announced that the sale of cold medication containing pseudoephedrine would be allowed (as part of the coalition agreement between the National and ACT parties).

Enantiopure drugs

Octafluoropropane can be produced either by electrochemical fluorination or by the Fowler process using cobalt fluoride.

Greenhouse Gases

With the codename FL 1060, mecillinam was developed by the Danish pharmaceutical company Leo Pharmaceutical Products (now LEO Pharma). It was first described in the scientific literature in a 1972 paper.

Enantiopure drugs

It is a precursor to trifluoromethyltrimethylsilane, a popular trifluoromethylating reagent in organic synthesis.

Greenhouse Gases

Orbiting Carbon Observatory-2 (OCO-2) is an American environmental science satellite which launched on 2 July 2014. A NASA mission, it is a replacement for the Orbiting Carbon Observatory which was lost in a launch failure in 2009. It is the second successful high-precision (better than 0.3%) observing satellite, after GOSAT.

Greenhouse Gases

Studies in female pregnant rats have shown minor fetal skeletal abnormalities when given maximum recommended human doses of levetiracetam orally throughout pregnancy and lactation. Studies were conducted to look for increased adverse effects in the elderly population as compared to younger patients. One such study published in Epilepsy Research showed no significant increase in incidence of adverse symptoms experienced by young or elderly patients with central nervous system (CNS) disorders.

Enantiopure drugs

Dexpramipexole is a first-in-class oral investigational medicine that lowers blood and tissue eosinophils before they can cause damage in the target organ. Dexpramipexole is being developed by [https://areteiatx.com/ Areteia Therapeutics] and has the potential to be the first oral treatment ever approved for eosinophilic asthma. The eosinophil-targeting effects of oral dexpramipexole were discovered during its clinical development. Across five clinical trials, dexpramipexole has consistently been shown to significantly reduce blood eosinophil counts.

Enantiopure drugs

CFC-113 can be prepared from hexachloroethane and hydrofluoric acid: This reaction may require catalysts such as antimony, chromium, iron and alumina at high temperatures. Another synthesis method uses HF on tetrachloroethylene instead.

Greenhouse Gases

Greenhouse gas monitoring involves the direct measurement of atmospheric concentrations and direct and indirect measurement of greenhouse gas emissions. Indirect methods calculate emissions of greenhouse gases based on related metrics such as fossil fuel extraction. There are several different methods of measuring carbon dioxide concentrations in the atmosphere, including infrared analyzing and manometry. Methane and nitrous oxide are measured by other instruments, such as the range-resolved infrared differential absorption lidar (DIAL). Greenhouse gases are measured from space such as by the Orbiting Carbon Observatory and through networks of ground stations such as the Integrated Carbon Observation System. The Annual Greenhouse Gas Index (AGGI) is defined by atmospheric scientists at NOAA as the ratio of total direct radiative forcing due to long-lived and well-mixed greenhouse gases for any year for which adequate global measurements exist, to that present in year 1990. These radiative forcing levels are relative to those present in year 1750 (i.e. prior to the start of the industrial era). 1990 is chosen because it is the baseline year for the Kyoto Protocol, and is the publication year of the first IPCC Scientific Assessment of Climate Change. As such, NOAA states that the AGGI "measures the commitment that (global) society has already made to living in a changing climate. It is based on the highest quality atmospheric observations from sites around the world. Its uncertainty is very low."

Greenhouse Gases

Dexpramipexole was originally identified as a candidate therapy for amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease by James Bennett, M.D., Ph.D., then of the University of Virginia. The drug was initially investigated in ALS by Knopp Biosciences and Biogen Idec. A 2010 Phase II clinical trial showed a slowing of ALS disease progression and mortality benefits. In January 2013, Biogen Idec discontinued its development of dexpramipexole in ALS due to lack of efficacy in the Phase III study. As a result of observing eosinophil lowering in the ALS trials, Knopp pivoted dexpramipexole clinical development to eosinophil associated diseases. In subsequent clinical trials, dexpramipexole significantly reduced eosinophil counts and glucocorticoid requirements in patients with hypereosinophilic syndrome and significantly reduced blood and tissue eosinophil counts in patients with chronic rhinosinusitis with nasal polyps.

Enantiopure drugs

Levetiracetam is a Schedule 4 substance in Australia under the Poisons Standard (February 2020). A Schedule 4 substance is classified as "Prescription Only Medicine, or Prescription Animal Remedy – Substances, the use or supply of which should be by or on the order of persons permitted by State or Territory legislation to prescribe and should be available from a pharmacist on prescription."

Enantiopure drugs

Because it is biologically inert and chemically stable, perfluorohexane has attracted attention in medicine. Like other fluorocarbons, perfluorohexane dissolves gases, including oxygen from the air, to a higher concentration than ordinary organic solvents. This effect is attributed to the weak intermolecular forces between perfluorohexane molecules, which allows "space" for gas molecules to partition into the liquid. Animals can be submerged in a bath of oxygenated perfluorohexane without drowning, as there is sufficient oxygen available in the solvent to allow respiration to continue. This effect has led to the experimental use of perfluorohexane in treating burn victims, as their lungs can be filled with either perfluorohexane vapor or in extreme cases liquid perfluorohexane, allowing breathing to continue without the problems normally seen with pulmonary edema that sometimes occur when the inside of the lungs have been burnt e.g. by inhalation of hot smoke. Research was particularly active on the topic of partial liquid ventilation (PLV) in the 1990s and early 2000s, however, perfluorohexane and other perfluorocarbons showed no significant improvement of patient outcomes in clinical trials.

Greenhouse Gases

1,1,1-Trichloroethane was one of the volatile organochlorides that have been tried as alternatives to chloroform in anaesthesia. In the 1880s, it was found to be a safe and strong substitute for chloroform but its production was expensive and difficult. In 1880, 1,1,1-Trichloroethane was suggested as an anaesthetic. It was first referred to as "methyl-chloroform" in the same year. At the time, the narcotic effects of chloral hydrate were owed to a hypothetical metabolic pathway to chloroform in "alkaline blood". Trichloroethane was studied for its structural similarity to chloral and potential anaesthetic effects. However, trichloroethane did not exhibit any conversion to chloroform in laboratory experiments. The 1,1,2-trichloroethane isomer, which lacked a trichloromethyl group, exhibited anaesthetic effects even stronger than the 1,1,1 isomer.

Greenhouse Gases

On long timescales, atmospheric concentration is determined by the balance among geochemical processes including organic carbon burial in sediments, silicate rock weathering, and volcanic degassing. The net effect of slight imbalances in the carbon cycle over tens to hundreds of millions of years has been to reduce atmospheric . On a timescale of billions of years, such downward trend appears bound to continue indefinitely as occasional massive historical releases of buried carbon due to volcanism will become less frequent (as earth mantle cooling and progressive exhaustion of internal radioactive heat proceed further). The rates of these processes are extremely slow; hence they are of no relevance to the atmospheric concentration over the next hundreds or thousands of years.

Greenhouse Gases

About 20 million kg per year are produced industrially as both a by-product of and precursor to the manufacture of Teflon. It is produced by reaction of chloroform with HF: It is also generated biologically in small amounts apparently by decarboxylation of trifluoroacetic acid.

Greenhouse Gases

As at 2017, the company operated the following stations: *Alexandria Station, Northern Territory * Boomarra Station, Queensland * Coolullah Station, Queensland *Coorabulka Station, Queensland * Cungelella Station, Queensland *Glenormiston Station, Queensland * Goldsborough Station, Queensland *Kynuna Station (includes Dagworth Station), Queensland * Landsborough Station, Queensland *Marion Downs Station, Queensland *Mittiebah Station, Northern Territory *Monkira Station, Queensland *Portland Downs Station, Queensland * Wainui Feedlot and Farm, Queensland Other properties that the company has owned include: *Gordon Downs, Queensland

Greenhouse Gases

Major greenhouse gases are well mixed and take many years to leave the atmosphere. The atmospheric lifetime of a greenhouse gas refers to the time required to restore equilibrium following a sudden increase or decrease in its concentration in the atmosphere. Individual atoms or molecules may be lost or deposited to sinks such as the soil, the oceans and other waters, or vegetation and other biological systems, reducing the excess to background concentrations. The average time taken to achieve this is the mean lifetime. This can be represented through the following formula, where the lifetime of an atmospheric species X in a one-box model is the average time that a molecule of X remains in the box. can also be defined as the ratio of the mass (in kg) of X in the box to its removal rate, which is the sum of the flow of X out of the box chemical loss of X and deposition of X (all in kg/s): If input of this gas into the box ceased, then after time , its concentration would decrease by about 63%. Changes to any of these variables can alter the atmospheric lifetime of a greenhouse gas. For instance, methanes atmospheric lifetime is estimated to have been lower in the 19th century than now, but to have been higher in the second half of the 20th century than after 2000. Carbon dioxide has an even more variable lifetime, which cannot be specified down to a single number. Scientists instead say that while the first 10% of carbon dioxides airborne fraction (not counting the ~50% absorbed by land and ocean sinks within the emission's first year) is removed "quickly", the vast majority of the airborne fraction – 80% – lasts for "centuries to millennia". The remaining 10% stays for tens of thousands of years. In some models, this longest-lasting fraction is as large as 30%.

Greenhouse Gases

There are several possible potential benefits to chiral switching or chiral specific drugs. These include: #An improved (less complex, more selective) pharmacodynamic profile #A higher therapeutic index (improved safety margin) #Less complex pharmacokinetic profile, less complex drug interactions #Less complex relationship between plasma concentration and effect   #More rational therapeutic drug monitoring #Expose the patient to less body load and thus reduce metabolic/renal/hepatic drug load The chiral switching approach has sometimes resulted in failures and disappointments.

Enantiopure drugs

Adverse effects of dextromethorphan in overdose at doses 3 to 10 times the recommended therapeutic dose: At doses 11 to 75 times the recommended therapeutic dose: Episodic acute psychosis can occur when high doses of dextromethorphan are taken for recreational use, and an abundance of psychiatric symptoms can result, including dissociation and other PCP-like symptoms.

Enantiopure drugs

Water is miscible with many liquids, including ethanol in all proportions. Water and most oils are immiscible, usually forming layers according to increasing density from the top. This can be predicted by comparing the polarity. Water being a relatively polar compound will tend to be miscible with liquids of high polarity such as ethanol and acetone, whereas compounds with low polarity will tend to be immiscible and poorly soluble such as with hydrocarbons. As a gas, water vapor is completely miscible with air. On the other hand, the maximum water vapor pressure that is thermodynamically stable with the liquid (or solid) at a given temperature is relatively low compared with total atmospheric pressure. For example, if the vapor's partial pressure is 2% of atmospheric pressure and the air is cooled from 25 °C, starting at about 22 °C, water will start to condense, defining the dew point, and creating fog or dew. The reverse process accounts for the fog burning off in the morning. If the humidity is increased at room temperature, for example, by running a hot shower or a bath, and the temperature stays about the same, the vapor soon reaches the pressure for phase change and then condenses out as minute water droplets, commonly referred to as steam. A saturated gas or one with 100% relative humidity is when the vapor pressure of water in the air is at equilibrium with vapor pressure due to (liquid) water; water (or ice, if cool enough) will fail to lose mass through evaporation when exposed to saturated air. Because the amount of water vapor in the air is small, relative humidity, the ratio of the partial pressure due to the water vapor to the saturated partial vapor pressure, is much more useful. Vapor pressure above 100% relative humidity is called supersaturated and can occur if the air is rapidly cooled, for example, by rising suddenly in an updraft.

Greenhouse Gases

The synergy between the atmospheric concentration measurements, the knowledge of local ecosystem fluxes on the other hand, has shown effective in reducing the uncertainties on carbon assessments. However, in Europe, observatories are all managed differently for each country and data is not homogeneously processed. The value added impact of the infrastructure allows an enhanced visibility and dissemination of European greenhouse gas data and products that are both long-term and carefully calibrated. ICOS meets the data needs of carbon cycle and climate researchers as well as those of politicians and the general public. ICOS serves as the backbone to users engaged in developing data assimilation models of greenhouse gas sources and sinks, namely reverse modelling, which allows the deduction of surface carbon flux pattern. A common data centre, the ICOS Carbon Portal, provides free access to all ICOS data, as well as to links with inventory data, and outreach material. This portal allows the production of web based tools for the survey of sources and sinks in near real-time. ICOS delivers the information in near real-time with a quantification of the uncertainty associated with the results due to the use of several different models using different methodologies. ICOS enables Europe to be a key global player for in-situ observations of greenhouse gases, data processing and user-friendly access to data products for validation of remote sensing products, scientific assessments, modelling and data assimilation.

Greenhouse Gases

Perfluorocarbons or PFCs, are organofluorine compounds with the formula CF, meaning they contain only carbon and fluorine. The terminology is not strictly followed and many fluorine-containing organic compounds are also called fluorocarbons. Compounds with the prefix perfluoro- are hydrocarbons, including those with heteroatoms, wherein all C-H bonds have been replaced by C-F bonds. Fluorocarbons includes perfluoroalkanes, fluoroalkenes, fluoroalkynes, and perfluoroaromatic compounds.

Greenhouse Gases

While absorption and release is always happening as a result of natural processes, the recent rise in levels in the atmosphere is known to be mainly due to human (anthropogenic) activity. Anthropogenic carbon emissions exceed the amount that can be taken up or balanced out by natural sinks. Thus carbon dioxide has gradually accumulated in the atmosphere and, as of May 2022, its concentration is 50% above pre-industrial levels. The extraction and burning of fossil fuels, releasing carbon that has been underground for many millions of years, has increased the atmospheric concentration of . As of year 2019 the extraction and burning of geologic fossil carbon by humans releases over 30 gigatonnes of (9 billion tonnes carbon) each year. This larger disruption to the natural balance is responsible for recent growth in the atmospheric concentration. Currently about half of the carbon dioxide released from the burning of fossil fuels is not absorbed by vegetation and the oceans and remains in the atmosphere. Burning fossil fuels such as coal, petroleum, and natural gas is the leading cause of increased anthropogenic ; deforestation is the second major cause. In 2010, 9.14 gigatonnes of carbon (GtC, equivalent to 33.5 gigatonnes of or about 4.3 ppm in Earth's atmosphere) were released from fossil fuels and cement production worldwide, compared to 6.15 GtC in 1990. In addition, land use change contributed 0.87 GtC in 2010, compared to 1.45 GtC in 1990. In the period 1751 to 1900, about 12 GtC were released as to the atmosphere from burning of fossil fuels, whereas from 1901 to 2013 the figure was about 380 GtC. The International Energy Agency estimates that the top 1% of emitters globally each had carbon footprints of over 50 tonnes of in 2021, more than 1,000 times greater than those of the bottom 1% of emitters. The global average energy-related carbon footprint is around 4.7 tonnes of per person.

Greenhouse Gases

Levonorgestrel acetate (LNG-A), or levonorgestrel 17β-acetate, also known as 3-ketonorgestimate, is a progestin which was never marketed. It is a progestogen ester and is the C17β acetate ester and a prodrug of levonorgestrel. Norgestimate is the C3 oxime of LNG-A. The drug is a minor active metabolite of norgestimate, which is a prodrug of norelgestromin and to a lesser extent of levonorgestrel and LNG-A. LNG-A has high affinity for the progesterone receptor, about 135% of that of promegestone (relative to 150% for levonorgestrel). Along with levonorgestrel butanoate, LNG-A was investigated as a hormonal contraceptive by the Population Council.

Enantiopure drugs

Enhanced Atmospheric Methane Oxidation is the concept of enhancing the overall oxidative methane sink in the atmosphere, through generating additional hydroxyl or chlorine atmospheric radicals.

Greenhouse Gases

Esomeprazole capsules, as well as Losec/Prilosec tablets, are formulated as a "multiple-unit pellet system" (MUPS). Essentially, the capsule consists of extremely small enteric-coated granules (pellets) of the esomeprazole formulation inside an outer shell. When the capsule is immersed in an aqueous solution, as happens when the capsule reaches the stomach, water enters the capsule by osmosis. The contents swell from water absorption, causing the shell to burst, and releasing the enteric-coated granules. For most patients, the multiple-unit pellet system is of no advantage over conventional enteric-coated preparations. Patients for whom the formulation is of benefit include those requiring nasogastric tube feeding and those with difficulty swallowing (dysphagia).

Enantiopure drugs