CAS Registry Number

A CAS Registry Number referred to as CASRN or CAS Number, is a unique numerical identifier assigned by the Chemical Abstracts Service to every chemical substance described in the open scientific literature, including organic and inorganic compounds, isotopes and nonstructurable materials. The registry maintained by CAS is an authoritative collection of disclosed chemical substance information, it identifies more than 158 million unique organic and inorganic substances and 67 million protein and DNA sequences, plus additional information about each substance. It is updated with around 15,000 additional new substances daily. Chemicals have been identified by a wide variety of synonyms; these are arcane and constructed according to regional naming conventions relating to chemical formulae, structures or origins. Well-known chemicals may additionally be known via multiple generic, commercial, and/or -market names. CAS Registry Numbers are convenient for database searches, they offer a reliable and international link to every specific substance across the various nomenclatures and disciplines used by branches of science and regulatory bodies.

All molecule databases today allow searching by CAS Registry Number. On the other hand, CASRNs are not related to chemistry, are proprietary and unrelated to any previous systems, do not form phonetic analogs or synonyms. A CAS Registry Number has no inherent meaning but is assigned in sequential, increasing order when the substance is identified by CAS scientists for inclusion in the CAS REGISTRY database. A CASRN is separated by hyphens into three parts, the first consisting from two up to seven digits, the second consisting of two digits, the third consisting of a single digit serving as a check digit; this current format gives CAS a maximum capacity of 1,000,000,000 unique identifiers. The check digit is found by taking the last digit times 1, the preceding digit times 2, the preceding digit times 3 etc. adding all these up and computing the sum modulo 10. For example, the CAS number of water is 7732-18-5: the checksum 5 is calculated as = 105. Stereoisomers and racemic mixtures are assigned discrete CAS Registry Numbers: L-epinephrine has 51-43-4, D-epinephrine has 150-05-0, racemic DL-epinephrine has 329-65-7 Different phases do not receive different CASRNs, but different crystal structures do Commonly encountered mixtures of known or unknown composition may receive a CASRN.

Some metals are discerned by their oxidation state, e.g. the element chromium has 7440-47-3, the trivalent Cr has 16065-83-1 and the hexavalent Cr ion has 18540-29-9. Whole classes of molecules receive a single CASRN: the class of enzymes known as alcohol dehydrogenases has 9031-72-5. CHEMINDEX Search via Canadian Centre for Occupational Health and Safety ChemIDplus Advanced via United States National Library of Medicine Common Chemistry via Australian Inventory of Chemical Substances European chemical Substances Information System via the website of Royal Society of Chemistry HSNO Chemical Classification Information Database via Environmental Risk Management Authority Search Tool of Australian Inventory of Chemical Substances Academic publishing Beilstein Registry Number Chemical database Chemical file format Dictionary of chemical formulas EC# EC number Identifier International Chemical Identifier International Union of Pure and Applied Chemistry List of CAS numbers by chemical compound MDL number PubChem Registration authority SMILES UN number CAS registry description, by Chemical Abstracts ServiceTo find the CAS number of a compound given its name, formula or structure, the following free resources can be used: NLM,NIH ChemIDplus NIST Chemistry WebBook NCI/CADD Chemical Identifier Resolver ChemSub Online NIOSH Pocket Guide to Chemical Hazards, index of CAS numbers


Regret is a conscious negative emotional reaction to an undesirable situation. Regret is related to perceived opportunity, its intensity varies over time after the decision, in regard to action versus inaction, in regard to self-control at a particular age. The self-recrimination which comes with regret is thought to spur corrective adaptation. In Western societies adults have the highest regrets regarding choices of their education. Regret has been defined by psychologists in the late 1990s as a "negative emotion predicated on an upward, self-focused, counterfactual inference". Another definition is "an aversive emotional state elicited by a discrepancy in the outcome values of chosen vs. unchosen actions". Regret differs from remorse in that people can regret things beyond their control, but remorse indicates a sense of responsibility for the situation. For example, a person can feel regret that people die during natural disasters, but cannot feel remorse for that situation. However, a person who intentionally harms someone should feel remorse for those actions.

Agent regret is the idea that a person could be involved in a situation, regret their involvement if those actions were innocent, unintentional, or involuntary. For example, if someone decides to die by stepping in front of a moving vehicle, the death is not the fault of the driver, but the driver may still regret that the person died. Regret is distinct from disappointment. Both are negative emotional experiences relating to a loss outcome, both have similar neuronal correlates. However, they differ in regard to feedback about the outcome, comparing the difference between outcomes for the chosen vs. unchosen action. They differ in regard to agency. There are conceptual models of regret in regret in theoretical economics and finance under a field called behavioral economics. Anticipated regret, or how much regret one thinks one will feel in the future, appears to be overestimated for actions and choices; this appears to be, in part, due to a tendency to underestimate the extent to which people attribute bad outcomes to external factors rather than to internal factors.

It can lead to omission bias. Existential regret has been defined as "a profound desire to go back and change a past experience in which one has failed to choose consciously or has made a choice that did not follow one’s beliefs, values, or growth needs". Instruments to measure regret in people having to make medical decisions have failed to address current concepts of regret and failed to differentiate regret from disappointment, they have not looked for positive impacts of regret. Process regret may occur, if a person does not consider information about all available choices before making a decision. A 2005 meta-analysis of 9 studies about what adults regret most concluded, that overall adults regret choices regarding their education the most. Subsequent rankings included decisions about career and parenting. Education has been the forerunner of regret in the U. S. per Gallup surveys in 1949, 1953, 1965. Education was the forerunner of regret because it is seen as something where circumstances could be changed: "In contemporary society, education is open to continual modification throughout life.

With the rise of community colleges and student aid programs in recent decades, education of some sort is accessible to nearly all socioeconomic groups."This finding can be attributed to the principle of perceived opportunity. "People's biggest regrets are a reflection of. In other cultures, regrets may be ranked differently depending on the perceived opportunity in a particular society. A 2016 review of past studies found risk factors for people to develop "decision regret" regarding their health care were: higher decisional conflict, lower satisfaction with the decision, adverse outcomes in physical health, greater anxiety levels. A 2018 study found that people were more to express "ideal-related regrets", such as failing to follow their dreams and live up to their full potential; this was found to correlate with the anecdotal accounts of palliative care nurse Bronnie Ware about the most common regrets she had heard expressed by those nearing death, which included: "I wish I’d had the courage to live a life true to myself, not the life others expected of me."

"I wish I hadn’t worked so hard." "I wish I’d had the courage to express my feelings." "I wish I had stayed in touch with my friends." "I wish that I had let myself be happier." There is an interplay between action versus time. Regrets of an action are more intense in the short term, whereas regrets of inaction are more intense over the long term. In a 2001 study, high intensity of regret and intrusive thoughts in older adults was related to self-control, low internal control was expected to be self-protective and help to decrease regret. In younger adults, internal-control facilitated active change and was associated with low intensity of regret. People's biggest regrets occur where they perceive the greatest and most important opportunity for corrective action; when no opportunity exists to improve conditions, thought processes mitigate the cognitive dissonance caused by regret, e.g. by rationalization, reconstrual. Regret pushes people toward revised decision making and corrective action as part of learning that may bring improvement in life circumstances.

A 1999 study measured regret in accordance to negative reviews with service providers. Regret was an accurate p

Trading fund

A trading fund is an executive agency, government department or simply a part of a department, that enables the department to handle its own revenues and expenses separately from overall government finances and more like a business, as opposed to having to obtain funding from the government's legislature and feeding income back into its treasury. A Hong Kong governmental study of trading funds in the UK and Hong Kong describes their nature and purpose as follows: A trading fund is a financial and accounting framework established by law to enable a government department, or part of a department, to adopt certain accounting and management practices common in the private sector. Operates on a self-financing basis and does not need to seek funding from the legislature to finance its daily operations after its establishment... the intention an institutional change would provide the appropriate flexibility in resource management and nurture a new working culture to improve services in terms of both quality and cost-effectiveness.

Each country has its own specific laws and regulations controlling the establishment and use of trading funds. The significance of a UK trading fund is that it has standing authority under the 1973 Act to use its receipts to meet its expenses or outgoings; some trading funds have, as their main function, the collection and supply of information to both public and private sectors. In the UK, a trading fund can only be established with the agreement of HM Treasury. To establish a fund, more than 50% of the trading fund's revenue will consist of receipts for goods and services provided by the department, where the responsible minister and the Treasury are satisfied that the setting up of the trading fund will lead to "improved efficiency and effectiveness in management of operations". Trading funds in the UK were established through the Government Trading Funds Act 1973, modified by the Government Trading Act 1990, along with other modifications through finance legislation. In 1993, Hong Kong followed suit with its Trading Funds Ordinance of that year.

Establishment and operation of a Hong Kong trading fund is subject to decisions made by the Legislative Council on the recommendation of the Financial Secretary. Date of establishment as trading fund is shown: Companies House - 1 October 1991 Crown Commercial Service - 1 April 1991 Driver & Vehicle Agency - 1 April 2007 Driver and Vehicle Standards Agency - 1 April 2015 FCO Services - 1 April 2008 HM Land Registry - 1 April 1993 Intellectual Property Office - 1 October 1991 Medicines and Healthcare Products Regulatory Agency - 1 April 2003 Meteorological Office - 1 April 1996 Ordnance Survey - 1 April 1999 Queen Elizabeth II Conference Centre - 1 April 1997 Registers of Scotland - 1 April 1996 Royal Mint - 1 April 1975 United Kingdom Hydrographic Office - 1 April 1996 Defence Science and Technology Laboratory - 1 July 2001 Driver and Vehicle Licensing Agency - 1 April 2004 Army Base Repair Organisation – 1 April 2002 Central Office of Information – 1 April 1991 Chessington Computer Centre – 1 April 1993 Crown Suppliers - 1 April 1976 Defence Aviation Repair Agency - 1 April 2001 Defence Evaluation and Research Agency - 1 April 1995 Defence Research Agency - 1 April 1993 Defence Support Group - 1 April 2008 Driver and Vehicle Testing Agency - 1 April 1996 Driving Standards Agency - 1 April 1997 Fire Service College - 1 April 1992 Forensic Science Service - 1 April 1999 HM Stationery Office - 1 April 1980 Medicines Control Agency - 1 April 1993 NHS Estates - 1 April 1999 Royal Ordnance Factories - 1 July 1974 Vehicle and Operator Services Agency - 1 April 2003 Vehicle Inspectorate - 1 April 1991 Companies Registry – 1 August 1993 Electrical and Mechanical Services - 1 August 1996 Hongkong Post - 1 August 1995 Land Registry - 1 August 1993 Office of the Telecommunications Authority - 1 June 1995 Sewage Services - 11 March 1994