Author: David Bradley

Tamiflu Molecular Structure

molecular structure of TamifluRoche is allegedly struggling to keep up with unprecedented demand for its antiviral Tamiflu in light of the massive media scaremongering that is going on globally thanks to the emergence of the H5N1 strain of bird flu. Taiwan already intends to stockpile a generic version of the drug oseltamivir with or without Roche’s permission. Currently, oseltamivir is synthesised from shikimic acid, which is obtained from the star anise fruit. The total synthesis takes at least ten steps, but chemists are working on simpler approaches.

That aside, Nature just reported a case of a girl with a strain of H5N1 that is resistant to this drug. If prevalence is high, then the media will have even more scare-mongering to do.

Flu Resistance

The international science journal Nature has lifted the media embargo on an important paper due for publication next week – The paper raises the possibility that the current prophylactic regimen for Tamiflu (oseltamivir) may have contributed to the emergence of partial resistance to the drug in a Vietnamese patient.

This paper provides an analysis of an H5N1 virus — isolated from a
patient in Vietnam earlier this year (1) – that is partially resistant to
oseltamivir.

The potential emergence of a resistant virus is a continuing concern of
health agencies, although evidence to date suggests that viruses with
mutations giving rise to resistance have reduced fitness, making them less
transmissible and of lower pathogenicity.

The paper highlights the fact that the current recommended
prophylactic treatment regimen may involve suboptimal doses and
durations of oseltamivir treatment that could contribute to the emergence
of resistant virus. It also raises the possibility that a larger arsenal
of influenza antivirals may need to be developed. Stockpiling zanamivir
(sold as Relenza) in addition to oseltamivir may be warranted.

Although the case described in this paper was part of a family cluster,
the paper does not directly address the issue of human-to-human
transmission of H5N1.

Nobel Prize for Literature 2005

Is it any surprise there is a gulf between science and arts?

This is what the art world seemingly considers important: Harold Pinter "in his plays uncovers the precipice under everyday prattle and forces entry into oppression’s closed rooms"

Whereas science renders discoveries in chemistry that offer “Fantastic opportunities have been created for producing many new molecules – pharmaceuticals, for example. Imagination will soon be the only limit to what molecules can be built!”

Earthquake Refusal

It’s the news that should set the press a tremble, but fellow science journalist Natasha Loder has had to resort to posting an item about the refusal of Pakistan to grant leading Himalayan earthquake expert Roger Bilham an entry visa on her blog. At a time when one would expect intellectual activity in this field to be desperately needed, apparently scientists are not allowed into the country because this is not a time for “intellectual activities”, reports Loder.

Bilham and his colleagues at the University of Colorado have been forewarning of a major Himalayan earthquake for years, but the Kashmir earthquake released only a tenth of the potential energy stored in the region and Bilham further expects geological unrest.

His expertise could provide critical clues to when and where that pent up energy might be released…surely such intellectual activity is not just desirable but essential.

Research into magnetic materials and frustrated magnets

Some time ago I wrote a feature article for EPSRC Newsline about frustrated magnets, the article is available on sciencebase.com and has attracted the attention of a fair few web surfers. Interestingly, the most recent of them hit the page in question while searching for “picture of a frustrated parent”. Odd, I thought. So, I did the search myself on the SE they’d used and found that very page at #3 in the search engine results page (SERP)!

Now, I know websurfing can be a frantic occupation, but surely the text that was displayed in the SERP didn’t point to any photographic evidence of parental frustration…

“The conventional picture of a magnet says each atom in a material … Harrison. In such a ‘frustrated’ lattice, the conventional forces … Harrison spotted the parent compound, potassium hydroxy …”

Whatever. I hope the surfer in question found their picture in the end. I could provide one of a frustrated webmaster easily…

Toxic Aftermath

The floodwaters that engulfed New Orleans after Katrina turned out to be less toxic than scientists predicted. But, the same floodwaters pumped back into Lake Pontchartrain nevertheless carried with them high levels of various metals, including copper and zinc. Researchers at Louisiana State University writing in the October 11 issue of ES&T suggest this might pose a long-term risk to the area’s aquatic life.

Genetic Google

Google is fast, you have to agree…it can somehow narrow down a search of billions of webpages and bring you a list of the “most relevant” within fractions of a second. Admittedly, sometimes that list can be long, but it’s still quite astounding how it does it. Anyway, it occurred to me that maybe its indexing method and algorithm might be useful to those who search DNA databases.

Chemists are slowly beginning to recognise how Google can be used to search for unique chemical structures using the INChI format, so maybe there is potential for DNA searching. Maybe DNA searching is already fast enough, but I somehow doubt it.

Nobel Prize for Physics 2005

This year’s Nobel Prize for Physics has been awarded to Roy J. Glauber “for his contribution to the quantum theory of optical coherence” and to John L. Hall and Theodor W. H�nsch “for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique”. You can see a complete list of all Nobel Prize Physicists on the sciencebase site as well find links to their Nobel work.

Nobel Prize for Medicine 2005

The Nobel committee today announced the winner of the Nobel Prize in Physiology or Medicine for 2005: Barry J. Marshall and J. Robin Warren for their discovery of “the bacterium Helicobacter pylori and its role in gastritis and peptic ulcer disease”

The winners made the unexpected discovery that inflammation in the stomach (gastritis) as well as ulceration of the stomach or duodenum (peptic ulcers) are the result, not of endogenous factors but of infection with a “corkscrew-shaped” bacterium H. pylori

What does hydrophobic mean?

In chemistry, hydrophobicity (from the combining form of water in Greek hydros and for fear phobos) is the physical property of a molecule that is repelled from water. Hydrophobic molecules tend to be non-polar and thus have a greater affinity for other neutral molecules and non-polar solvents. Hydrophobic molecules in water often cluster together forming tiny bubble-like structures known as micelles.

The opposite of hydrophobic is hydrophilic. A hydrophilic substance, from the Greek hydros for water and philia love, is a molecule or other molecular entity that is attracted to, and tends to be dissolved by, water. A hydrophilic molecule is one that has a tendency to interact with or be dissolved by water and other polar substances including solvents; the interactions are more thermodynamically favourable.

Water always was a slippery character. Now, scientists at Pacific Northwest National Laboratory have made an incredible thin layer of water, just a single molecule thick, that sits on a slab of platinum metal and refuses to freeze. Strictly speaking, the monolayer held at just 60 Kelvin becomes hydrophobic and will not allow ice crystallites to form on its surface.

What’s that you say, “hydrophobic water”?

Denial doesn’t get any more profound than that, even if we are talking about molecules.

According to Physics News Update: “Weaker bonding results in a “classic” hydrophobic state, in which the water merely balls up immediately.” So, it’s a balls up, is it? That explains a lot.