Month: February 2005

Dr Myriam Sarachik

Dr Myriam Sarachik (of City College in New York City) escaped the Holocaust from Belgium to become a prominent physicist and educator.

She will be honoured on 28th February in Paris as the recipient of the L’Oreal-UNESCO’s Women in Science Prize as a laureate.

The selection of five laureates representing five regions of the world, by a jury of world class scientists that includes some Nobel Prize winners, and the award of 15 Fellowships to aspiring young women scientists, has attracted the attention of the scientific community. The prize which has now recognized 91 women from 45 different countries has enabled young women to continue their education and scientific research as they enter the field and has promoted the groundbreaking research of senior women scientists.

Sarachik’s career in experimental condensed matter physics has included work on superconductivity, disordered metallic alloys, metal-insulator transitions, hopping transport in solids, and the behavior of molecular magnets. In particular, she has made seminal contributions to Kondo physics, metal-insulator transitions, and quantum spin dynamics. In her low temperature laboratory, she and her team are pursuing the study of condensed matter properties at low temperatures, with particular focus on two areas: molecular nano-magnets and the novel behavior of two-dimensional electron systems.

US Consumers and Vitamins

Friends and I were discussing the claim that US consumers are about to lose the right to purchase vitamins, minerals, and dietary supplements, and one member of the clan pointed out a Snopes page that debunks the news as a hoax:

Urban Legends Reference Pages: Politics (Vitamin See). However, there is a claim from cynical skeptics that Snopes is not so righteous as it claims…

Anyway, while this CODEX issue might very well be an urban legend, I’m afraid the truth is that here in the EU, they really are intending to stifle vitamins and supplements. Whether that’s a good or a bad thing I don’t know. Personally, I try to avoid supplements, but I realise millions of people have a use for them.

There are, however, lots of problems with certain supplements (natural cadmium levels associated with zinc, mean that zinc tablets are high enough to cause problems with long-term use, mega-doses of any vitamin cause toxicity, calcium bodies (kidney
stones) for instance with vitamin C, many herbal remedies need not necessarily be contaminated to be harmful, although contamination of Chinese herbal medicines with mercury and arsenic have been reported on many separate occasions here and
in the US), and wasn’t there a fairly recent problem with a contaminant in taurine?

Long-term use of echinacea can cause health problems, while the use of St John’s Wort is contraindicated for several prescription medicines. Even drinking too much grapefruit juice can interfere deliteriously with liver enzymes and cause heart
problems for users of certain antibiotics and antihistamines.

Dose is always the issue in toxicity, whether that’s dose of the active or a contaminant.

There may be a place for vitamins and supplements, but perhaps it is about time these were brought under more strict regulations so that benefit-risk management (BRM) can be considered in a more logical manner than it currently is. BRM is after all at the top of all pharmaceutical company agendas and adverse drug reactions (ADRs) feature prominently in the minutes.

http://tinyurl.com/6da7l – PDF from EU on the directive set to be enforced 1 August 2005

http://news.bbc.co.uk/1/hi/health/3831931.stm – WHO warnings on supplements and vitamins

http://news.bbc.co.uk/1/hi/health/3443651.stm – EU rule change attacked.

Ranitidine and other molecules

Occasionally, I get queries from students asking me where they can find the structure of this or that compound, usually it’s something like sildenafil (Viagra), ranitidine (Zantac), or rofecoxib (Vioxx) and is pertinent to their current chemistry homework assignment.

There are lots of databases on the web that contain great swathes of molecular structures including some that I wrote about for Nature recently, such as PubChem. But, another place to start your search might be Molecular Heaven or ChemSpider.com

But, what I don’t understand is why students cannot use the search engines, surely the easiest option would be to type in “molecular model” or structure and the name of the compound. When I tried molecular model ranitidine, the first hit had a molecular structure and loads of other information on the anti-ulcer drug. Of course, with ChemSpider you will likely get more curated data together with more detailed information, so perhaps I’ve answered my own question in that regard.

POST UPDATED: ChemSpider information added September 16, 2008

Oak Aged Mythology

Oak aged mythology – According to recent research at the Public University of Navarre, wine makers get no benefit to their product from leaving wines to mature in oak casks for more than a year. In fact, chemical analysis showed that levels of aromatics in the wine from the oak casks begin to decrease if the wine is left to mature for too long. Legislation insists that Gran Reserva wines be kept for 18 months, but science shows that this isn’t based on sound chemical principles.

Michael Dino

Michael Dino got in touch to tell me about his gallery of space shuttle main engine photos at Dino’s Gallery (You’ll need to login to Photobucket to view the gallery). Apparently, the Shuttle’s solid rocket boosters (SRBs) burn two million pounds of fuel in about 2 minutes, which is about as long as it takes to heat your food in a microwave oven…think about how many pizzas that much fuel could defrost (in an instant)!

Congenital Arthur Miller

According to many of the media reports of the death of Arthur Miller he apparently died of congenital heart failure. Wouldn’t “congenital” imply he had heart failure at birth? Presumably, they meant to say “congestive”, he may have had a congenital heart problem of course that led to heart failure in later life. Meanwhile, one of my chums on the NASW discussion lists explained that in the US, “congestive heart failure” is not an acceptable cause of death for entry on a death certificate. Maybe they should have just said he died of a “dodgy ticker”, makes more sense than congenital.

Rational Drug Design

Science Writer David Bradley is currently working on an RSS newsfeed for Simulated Biomolecular Systems, better known as SimBioSys Inc, a Canadian company that specialises in chemistry software with a difference.

UPDATE: Keen-eyed readers will probably have noticed that Sciencebase is no longer working on this project with the chemistry software company. However, I can point you to some exciting developmental work between my co-workers at Chemspider.com and Symbiosis.

Symbiosis is working with ChemSpider on the LASSO project with ChemSpider. Indeed, LASSO descriptor is now available for almost all 18+ million structures in the Chemspider structure database. They have also added the virtual screening results for all ligands against 40 target families, from the DUD database of decoys.

Chemspider recently revealed the preliminary results of this very large cross screening work and the two businesses are now working together to clean up the interface and more powerful search capabilities.

Images Reveal Titan’s Secrets

Images reveal Titan’s secrets: “Spacecraft is 8.9 feet in diameter and 703 pounds (317 kg).”

Those significant figures fascinate me! Why do news agencies insist on giving us such levels of alleged precision. 8.9 feet! That’s 106.8 inches as opposed to 108 inches. Who cares about that 1.2 when you’ve travelled 2 billion miles from home? And, where did they get that 703 pounds, 317kg? Presumably, thes figures have been converted back and forth as I reckon the craft was more than likely given as 700 pounds and someone turned that into kg somewhere and then turned it back again using different conversion factors…but, who cares. 700 lbs, 300 kg, it’s not like anyone is going back to Titan to check.

Jonathan Goodman

Jonathan Goodman tells me that “Most highly strained molecules have small rings, and most explosive molecules have nitrogen and oxygen atoms close to carbon and each other so they can rearrange easily.” However, when he asks chemists if they can think of a molecule which would spontaneously fall apart, even though it contains only carbon and hydrogen, there are four bonds to every carbon and one to each hydrogen, there are only single bonds, and there are no rings, the usual response is that all such molecules should be stable. His paper shows that this is incorrect, even for rather simple molecules.” Check out his paper on this in J. Chem. Inf. Model. 2005, 45, 81-87 (DOI: 10.1021/ci0497657) You can access the paper by pasting the DOI into the sciencebase DOI lookup tool