Author: David Bradley

Disease Mongering

I was a bit tardy covering the recent conference on disease mongering, but to make up for it have posted a new poll on the SciScoop site to give visitors a chance to voice their opinion.

A conference held April 11-13, in Newcastle, Australia, raised some serious questions about the motives of the pharmaceutical industry. The patents on drugs for old-fashioned diseases that were originally making a $1billion a year are almost all expired and new avenues of research under the umbrella of biotech have yet to make the same level of return for other diseases. As such, there is a feeling among some observers that “new” conditions, such as restless legs syndrome, attention deficit hyperactivity disorder (ADHD), and sexual dysfunction are being hyped by the industry as the serious ills of our time that need new (lucrative) treatments. Is this the case or can we simply not do without the chemical fix of those repeat prescriptions? A collection of freely accessible essays on the subject of disease mongering is available on the PLOS Medicine site.

Visit SciScoop to vote in the poll and help us answer the question – “Are we drug company puppets?”

Bremelanotide MSDS

Readers interested in sexual chemistry will have spotted the recent item on bremelanotide (Sex Gets Up Women’s Noses, April 24, 2006), which is soon to enter Phase III clinical trials for female sexual dysfunction (see also PLoS Medicine on the subject of disease mongering).

Anyway, recent sciencebase visitors have been trying to locate the material data safety sheet (MSDS) for this compound (judging from the recent spate of searches on the site for that term). Anyway, ChemSpy.com has excellent access to several MSDS sources here. If it’s listed anywhere you should be able to find the bremelanotide MSDS there.

A blogger on another site discussing my short bremelanotide article, suggested that the fact this drug is odourless and colourless represented a serious risk in terms of men spiking a woman’s drink, but I wonder…this drug doesn’t knock you out or give you amnesia it just makes you horny, so if Mr B. Nomates can’t score under normal circumstances when any number of potential mates may be horny or not, it won’t seriously boost his chances will it?

Da Vinci de Leonardo

A letter in Physics Today this month discusses the archetypal renaissance man and his impact or otherwise on science, engineering and art…

Who is he?

According to the letter head, some fella by the name of Da Vinci. Perhaps he’s the same guy to whom Dan Brown is referring in his eponymous code book. I assume so. Either way, surely they don’t mean the Italian polymath born in Vinci in 1452 known to his mum as L’il Leonardo. I bet they do you know…

Periodic Table History

UPDATE: June 2011 – debate is raging as to what format the Periodic Table should ultimately take and indeed whether there is an ultimate, fundamental structure or whether it is merely a convenience. Check out the periodic table debate here.

Here’s a book no chemist, or indeed no scientist, should miss – The Periodic Table: Its Story and Its Significance, by UCLA chemical philosopher Eric Scerri. Older readers will recall my Alchemist interview with Eric Scerri.

The book has already had some excellent advance reviews, one in particular from my good friend John Emsley, of Cambridge U says: “Written to a high standard of scholarship, ‘The Periodic Table’ is the only book of its kind currently on the market, giving both an historical and philosophical perspective to the development of this key to the elements. The philosophical discussion Scerri weaves through its pages is rarely found in chemistry books, giving it a special quality that will appeal to the scientific community at large. In years to come it will be seen as essential reading for all who aspire to lecture and write on the subject.”

Peter Atkins, who I have never met admittedly, had this to say: “Few concepts are more important in chemistry than the periodic table, and Eric Scerri’s book offers a wonderfully thorough, lucid, and provocative introduction for both chemists and the scientifically literate to this major cultural contribution. Anyone interested in the foundations of chemistry will take delight, inspiration, and information from this highly approachable book.”

You can place an advance order via amazon, the book hits the shelves September 15 at $35 hardcover.

The Periodic Table

Turning Sperm Heads

Size really does matter! In fact a micro device that can analyse even the smallest of the small could help solve one of “man’s” greatest mysteries – what turns a sperm’s head and sends it in the direction of the egg for that fertilizatory encounter?

Sperm are well-known for turning their microscopic heads and changing direction (at least to those with a microscope who like to view such tiny events). Previous research (about which I wrote in 1991 under the heading “Not every sperm is sacred”) revealed that sperm turn in response to chemical signals, a process termed chemotaxis, and even have their own olfactory receptors. Such chemical messages may play key roles in the fertilization process. Defects in sperm chemotaxis may be a cause of infertility, and sperm chemotaxis could potentially be used as a diagnostic tool to determine sperm quality to treat male infertility.

However, Milos Novotny and Stephen Jacobson of Indiana University have developed a new tool to probe exactly how sperm chemotaxis occurs. In the current issue of Anal Chem, they describe the initial tests on their microfluidic device for studying sperm chemotaxis: “An advantage of the microfluidic platform over conventional chemotaxis assays is the ability to create chemical gradients with temporal and spatial stability, leading to greater repeatability in the experimental conditions.”

They add that microfluidic devices provide a convenient, disposable platform for conducting chemotaxis assays.

http://dx.doi.org/10.1021/ac052087i

Two-faced Electronic Paper

Janus

Two-faced microscopic beads that rotate through a half turn when an electric field is applied to them could be the key to creating electronic paper, according to Japanese scientists. Takasi Nisisako and his team in the Department of Precision Engineering at the University of Tokyo have developed a new technique that allows them to produce these “Janus” particles much more efficiently and with uniform size.

Other researchers have previously developed two-colored beads of between 30 and 150 micrometers diameter (a micrometer is a thousandth of a millimeter) for experimental electronic paper applications. A thin film of these particles is sandwiched between a control grid and a protective surface. Applying a voltage to specific regions of the layer through the control grid can make clusters of individual particles flip over so that they appear black against a background of un-flipped white particles. Such technology could allow a device to display an image, words or pattern that is retained using no additional power until an erase voltage is applied making the particles flip back to white.

Such electronic paper has not yet entered the mainstream electronic gadgetry market because making the particles all the same size and of consistent quality is difficult. Prototype devices based on these Janus particles cannot yet produce a perfect picture. Nisisako and his team have now solved the quality control problem by side-stepping the standard manufacturing approach and have instead turned to microfluidic technology.

The team built a tiny device that comprises a sliver of glass into which is etched a Y-shaped channel. The researchers then seal this beneath a second layer of glass leaving the ends of the channel open. The two starting ingredients are liquid monomers designed to produce particles that respond to an electric current and have a different color on each of their two faces. The team feeds each ingredient into the arms of the “Y” where the materials form a two-color stream at the junction, which travels down the leg of the “Y”. The emerging fluid droplets are all identical and are then “cured” to form solid microscopic particles.

By integrating any number of these microfluidic devices, Nisisako suggests it should be possible to scale-up the manufacture of Janus particles for commercial applications. He adds that their approach is not limited to polymer ingredients and making microparticles from other starting materials such as ceramics or metals should also be possible.

Advanced Materials

Science News with a Spectral Twist

Channelling toxins Novel treatments for high blood pressure and other disorders could emerge from high-resolution solid-state NMR studies that reveal how toxins affect the structure of potasssium channels in the cell.

Marc Baldus of the Max Planck Institute for Biophysical Chemistry in Göttingen and colleagues in France and Germany have exploited a special protein synthesis procedure to follow how potassium channels and toxins combine to change the structure of the channel.

Zeolites step-by-step The evolution of zeolites has been followed by University of Minnesota chemical engineer Michael Tsapatsis and colleagues using microscopy and X-ray diffraction. Their study could lead to a new approach to designing and synthesizing novel variations on the zeolite theme for use as molecular sieves, catalysts, and sensors.

Analytical raft floats organic NLOs A combination of analytical techniques has proved its worth in assessing a series of non-linear optical materials for use in future organic optoelectronics devices. Juan López Navarrete of the University of Malaga, Spain, and colleagues at the University of Zaragoza-CSIC and the University of Minnesota, Morris, USA, used UV-vis, IR, and Raman spectroscopy, nonlinear optical (NLO) measurements, X-ray diffraction, and cyclic voltammetry to assess the properties of a series of tricyanovinyl (TCV)-substituted oligothiophenes.

A particularly golden study US researchers have devised what they describe as a very efficient method for making well-defined gold nanoparticles with equal numbers of hydrophobic and hydrophilic arms. The V-shaped arms are alternately distributed across the surface of 2 nanometre gold core particles. The solubility of these nanoparticles in a wide range of solvents means that they should be amenable to further processing with various chemical modifiers. Such nanoparticles have potential in optoelectronics, catalysis, and biomedical applications.

Cool Science Experiments

Sciencebase hosts a collection of science experiments from a cool coffee experiment to how to build a homemade electric motor.

Here is a brief list of possible science experiments, although Sciencebase no longer provides these particular write-ups you can download similar science projects via the links.

  • Black Light Experiment
  • Sinking and Floating Experiment
  • Oil and water experiment
  • Cartesian Diver Experiment
  • Why is the sky blue experiment
  • Clean up tarnished silver
  • Floating Soap Bubbles Experiment
  • Bending Water Experiment

Preventing the Spread of Bird Flu

cockerelIn the week that the H7 variant of avian influenza has led to the culling of 35000 chickens in England, scientists at Imperial College London have simulated the spread of a “human” bird flu epidemic and say that rapid treatment and isolation of infected individuals not only from the public but their household contacts will be essential to prevent thousands of deaths. They also suggest that vaccine stockpiles should be gathered together in readiness for a pandemic, even if the vaccine is not very potent. However, it is strict border controls and travel restrictions that will be needed to slow an outbreak and prevent a global pandemic.

Neil Ferguson and colleagues used computer modelling to evaluate the influence of a range of anti-pandemic measures, such as treatment and prophylaxis with antiviral drugs, household quarantine, vaccination and restrictions on travel. They found that with a policy of giving antiviral drugs both as treatment to infected cases and prophylactically to the patient’s families coupled with early closure of schools hit by the outbreak, rates of disease could be cut by almost a half.

However, for this policy to be feasible, antiviral stockpiles would need to be sufficient to treat 50% of the population – twice what many countries are planning. Combining such a policy with targeted immunization of children with a stockpiled trial vaccine might reduce illness rates by two-thirds, even if the vaccine was not particularly effective in its protection. Even greater drug coverage would have a correspondingly larger protective impact. Ferguson provides more details in this week’s Nature.

Built in Code in Da Vinci Judgement

Mr Justic Peter Smith who recently presided over the alleged plagiarism UK case concerning Dan Brown’s The Da Vinci Code (it should really be The Leonardo Code, of course) and the “non-fiction” The Holy Blood and The Holy Grail turns out to be something of a wiggy wag.

Smith italicised a couple of dozen characters in his judgement which cleared Brown of the charges. So what, you might ask? Well, Smith is something of a code maker himself and confided in a Guardian journalist (once the lawyers finally spotted the wheeze) that the italics “don’t look like typos, do they?”

So here are those very letters:

j a e i e x t o s t g p s a c g r e a m q w f k a d p m q z v

The Register says Smith “will cough” as soon as someone figures it out. Be nice if it were a Sciencebase reader – let me know if you crack it!