Cotton bud art conservation

Cotton Bud SamplingA simple Q tip is all it takes to grab a microscopic sample from a work of art for laboratory testing, according to Canadian analytical chemists. They’ve used the approach to sample darkening pigments from an ancient map and from a piece of modern art as proof of principle.

They then used a range of standard spectroscopic techniques to identify components of the pigments. This particular work will provide art conservators with important clues as to how to prevent further degradation of these important cultural objects, but more widely the successful demonstration of cotton bud sampling shows that analysis of artworks needn’t be invasive and destructive.

I interviewed research leader Douglas Goltz of the University of Winnipeg who told me that, “For conservators this approach gives them another tool for identifying pigments…Certainly not every museum or art gallery has immediate access to sophisticated techniques, such as XRF – this approach can be used by anyone. The Q-tip can be carried easily and then stored for later analysis of metals in the lab.”

Read on at SpectroscopyNOW.com

Parkinson and statins

New research points to a possible link between the LDL cholesterol-lowering statin drugs (HMG-CoA reductase inhibitors) and Parkinson’s disease. Such is the concern that a study involving thousands of people is planned to assess the risk, according to a report in Chemistry & Industry today.

Earlier research had hinted at a putative link between Parkinson’s disease and statins, but the latest results from a study linking low LDL cholesterol itself to PD provides the strongest evidence to date that the link could be real.

Researchers at the University of North Carolina say that patients with low LDL cholesterol levels are more than three and a half times as likely to develop Parkinson’s disease as those with higher LDL levels.

Study leader Xuemei Huang told C&I: “I am very concerned by these findings, which is why I am planning a 16000-patient prospective study to examine the possible role of statins.” Huang was quick to point out, however, that a causal link with statins had not yet been proven. Huang adds that the well-established link between PD and apoE2, a gene associated with lower LDL cholesterol, supports her theory that low LDL is the culprit in many cases of PD.

Yoav Ben-Shlomo, a professor of clinical epidemiology at the University of Bristol suggests a contrary explanation. It could be that low LDL cholesterol levels are a consequence rather than a cause of PD, he says.

Nevertheless, statins have been in common use for more than a decade and Huang worries that if proved right we will see a big surge in the number of diagnoses of PD during the next five years.

Pfizer’s statin Lipitor is the world’s best-selling drug with $12.2 billion in sales in 2005.

Libyan death sentence

On December 19, 2006 six foreign medical workers, Kristiyana Valtcheva, Nasya Nenova, Valentina Siropulo, Valya Chervenyashka, Snezhana Dimitrova and Ashraf al-Hajuj were convicted and sentenced to death by firing squad by a Libyan court.

Their crime?

The six health workers were accused of conspiring to deliberately infect 426 Libyan children with the HIV virus.

This is the second sentencing, as an earlier death sentence was overturned by the Libyan Supreme Court in 2005.

Now, Euroscience, a pressure group promoting the responsible use of science and the conduct of researchers is calling on academic and scientific organizations to protest the sentence in the hope that the convictions can be quashed.

Enric Banda, Euroscience President, stated that “It is a tragedy that children have been infected by HIV virus at a hospital in Libya, but it is against justice to accuse a group of health workers for this incident when strong scientific evidence shows that they could not be responsible for the origin of this infection.” As Sciencebase reported previously, incontrovertible evidence suggests that the infections began long before the six Bulgarian nurses and Palestinian doctor had ever entered the hospital.

Euroscience is among several organizations appealing to Libyan leader Mu’ammar al-Gaddafi to overturn the latest sentence. The European Parliament has initiated a petition, while the Belgian Foreign Minister Karel De Gucht has called on the EU to impose sanctions on Libya over the case.

Icy blast from the past

Cerro HudsonWhat’s the connection between Antarctic ice, old volcanic eruptions and global warming? US researchers think they know.

Volcanic activity can have serious consequences for climate change as particles and gases spewed out by volcanoes enter the upper atmosphere and change its chemical balance altering how Solar radiation is absorbed or reflected. Now, French and US researchers have devised a technique for determining how past volcanic eruptions could have affected this delicate chemical balance. Their findings could reduce significantly the uncertainty in current models of global climate change and so provide more accurate predictions of future global temperatures.

Joël Savarino of the National Center for Scientific Research (CNRS) and the University of Grenoble in France together with colleagues at the University of California San Diego have reported the pattern of sulphur isotopes of volcanic fallout from past eruptions. They also determined how far into the upper atmosphere the volcanic material reached, and what chemical reactions might have occurred there.

More…

Hewlett Packard to Dell again

Sciencebase is not a gadget-fixated site, as regular readers will by now have realized. We leave that to the likes of gizmodo and techcrunch who bring their thousands of subscribers the latest and greatest in carbon-dioxide generating machines and energy-drains as fast as you can say LG chocolate and USB toothbrush. Nevertheless, we are a science and tech site, and we do like to keep up with some of the more techy developments, such as wireless USB and the latest developments in blogging software.

In the spirit of Alex Lifeson’s tourbook instruments page, I was going to provide readers with a list of the gadgets that help keep Sciencebase on its feet, but I changed my mind, there are so few. One thing that I do rely heavily on is a widescreen laptop, although I regret opting for a lower resolution than usual version for the sake of price recently. My previous 17″ widescreen with almost 2000 pixels width was much easier to use than this 15 incher.

LED chips

LED ChipsLight-emitting diodes almost ubiquitously provide the illumination in electronics and potentially will provide energy-efficient brightness in our homes. However, the LED material of choice, gallium nitride, and its method of processing and manufacture into working devices is relatively expensive. Now, US engineers have developed a novel semiconducting material based on zinc oxide that could be used in a new type of LED that is just as effective but could reduce costs for a wide range of applications.

According to Deli Wang and colleagues at the University of California San Diego, an LED requires a positive and a negative semiconducting material. While “n-type” negative-charge carrying nanowires of inexpensive zinc oxide have been easy to make, the researchers have now synthesized nanoscale cylindrical wires of the material that can transport positive charges. These so-called “p-type ZnO nanowires” complete the circuit for making a new type of inexpensive LED.

You can read the full story in the January issue of Intute Spotlight.

Molecular speed bumps

Mark KuzykRegular readers will recall my mention of the Kuzyk Quantum Gap a few days ago and how Intute Spotlight would be covering news on how Kuzyk himself is closing the gap.

Well, here’s the spin: New organic molecules that interact with light more strongly than any other materials could provide the template for new high-speed optical switches for telecommunications and data processing, according to an international team of researchers. The same compounds could also act as the basic units of optical memory systems and be used to produce high-density holograms.

Researchers from Washington State University (WSU), the University of Leuven in Belgium and the Chinese Academy of Sciences have developed and tested an entirely new class of chromophores. The chemists in China synthesised the compounds, which were then evaluated using theoretical calculations by scientists at WSU. The optical properties were then tested by the Belgian team. ‘To our great excitement, the molecules performed better than any other molecules ever measured,’ says WSU physicist Mark Kuzyk.

Read on…

Help with total synthetic spam

Diketone structureSpam comes in all shapes and forms, so I am always suspicious when two emails identical in content and with attachments arrive that purport to be from two different correspondents. However, two such messages arrived this morning one claiming to come from a Dr Suhasini Bhatnagar, the other from Aarif Khatri. Normally, I’d let my spam filter do its job and trash such messages, but my interest was piqued by the subject line, which read “help regarding synthesis”. Often spam arrives with two random words stuck together that are supposed to beat spam filters, but three is rare and even less frequent are subject lines that make logical sense and simultaneously are pertinent to my interests.

So, I read on…

This is what Dr Bhatnagar (and presumably his chemistry supervisor, Prof Khatri) had to say:

“I was looking for help regarding the organic synthesis of a compound…I am doing My DSc from Agra University and the first part of work lasting now for past 3 years was involving Bioinformatics and its now that i need to synthesise the organic diketone type of compound [4-(2,4-dioxopentyl)benzoic acid] and I do not know how. Can you please help me design a simple reaction wherein I can get a few grams of the compound. I have very very limited resources and also knowledge in the subject. Your help would be greatly appreciated.”

Now, it is too far in the dim and distant past when I last did a retrosynthetic analysis, so I’m going to duck out of taking up his offer, but I wondered whether any Sciencebase readers could shed any light on the relevance of this compound and whether or not a total synthesis would be readily accessible. Your comments may also enlighten me as to whether these emails were nothing more than an intricate social engineering endeavour and that I’ve been duped into responding in this way.

I hope not.

Solvent abuse

Adolescent drug use has fallen overall since the late 1990s, but the “recreational” use of solvents is on the increase. Solvent, or inhalant, abuse is now the fourth most abused drug among US teens according to NIDA.

Inhalants, which include volatile organic compounds such as butane and aromatic hydrocarbons (like toluene) activate the same areas of the brain as do other drugs of abuse. However, understanding their precise mode of action has not been clarified until now.

Toluene is found in paint thinners, varnishes and even nail polish remover and is commonly abused and new research shows that it stimulates dopamine release in specific regions of the brain known as drug reward pathways. The results, obtained by Arthur Riegel and colleagues at the Vollom Institute, in Portland, Oregon, suggest that the brain interprets inhalation of toluene as a rewarding experience which can result in continued abuse and re-abuse.The findings could help in developing strategies to prevent and treat addiction to substances containing toluene.

Surprisingly, researchers also found that toluene-containing substances are most effective at low concentrations. Since toluene is rapidly absorbed by the brain, this might explain why the preferred mode of delivery is by “huffing” or “sniffing”. Sniffing is frequently considered a harmless recreational or party drug but unlike other drugs, even a single session of inhaling the compound can disrupt heart rhythms enough to cause cardiac arrest and lower oxygen levels enough to cause suffocation. Not a good thing.

The research is published today in the journal Neuropsychopharmacology.

Obesity and colon cancer link

Obesity is a major risk factor for colon cancer, but until now medical scientists were at a loss to explain why. Now, a study of on three human colon cancer cell-lines has demonstrated that the “fat hormone” leptin may enhance the growth of colonic cancer cells. The discovery not only offers an explanation as to the underlying cause of the increase colon cancer risk in obesity but could lead to a new approach to fighting this type of cancer.

The hormone leptin is released by fat cells, adipocytes, so the higher your body fat content (calculate your body fat now), the higher the concentration of leptin in your blood stream is likely to be. Leptin plays a key role in regulating metabolism, body weight and energy expenditure.

According to previous research, people who are obese are two to three times more likely to develop colon cancer than their leaner counterparts. Other research revealed that some colon cancer cells carry receptors for leptin.

Now, scientists at the University of California San Diego School of Medicine believe they have found the link.

“These results may explain why obesity increases a person’s risk of colonic cancer, and the fact that we have shown how leptin stimulates these cells means that drug companies may be in a better position to develop new treatments against the disease,’ says UCSD’s Kim Barrett.

The team grew cancer cells in the laboratory and found that leptin could stimulate their growth. In two out of three cell lines, leptin also blocked normal programmed cell death, apoptosis, which usually prevents runaway cell growth. When apoptosis fails normal cells can become cancerous.

The researchers explain that they have also found the complex chemical signalling pathways in the cell that are influenced by leptin, which reinforces their claim that leptin does indeed play a critical part in influencing cancer cell growth in the colon.

The results are published in detail in the journal BJS.