June 2006 – Page 3 – David Bradley

Anaerobics class

A QSPR (quantitative structure-property relationship) study of the anaerobic biodegradation of chlorophenols could lead to an improvement in the disposal of these potentially carcinogenic industrial waste products.

Youzhi Dai, Dasen Yang, Fei Zhu, Lanyan Wu, Xiangzheng Yang, and Jianhua Li of the Department of Environmental Engineering, at Xiangtan University, People’s Republic of China have based their analysis on quantum chemical and physicochemical descriptors, using partial least squares analysis to obtain a good prediction of the QSPR for the disappearance rate constant (logK) of chlorophenols (CPs) in an anaerobic microbial culture.

More…

Sonic laser

The ultrasound equivalent of a laser could lead to important new discoveries in materials science by providing researchers with a non-destructive way to detect even the subtlest of changes, such as phase transitions deep in their samples. Now, researchers at the University of Illinois at Urbana-Champaign and at the University of Missouri-Rolla have built just such an ultrasound analogue of the laser – the uaser, pronounced way-zer.

Light amplification by stimulated emission of radiation devices, lasers, are well known, but a sonic analogue had until now not been developed. Richard Weaver and his colleagues set out to change that and to develop a device that would induce ultrasound amplification by stimulated emission of radiation to produce coherent ultrasonic waves of a single frequency. “A sonic laser has been possible for some time now,” Weaver told us, “our method could have been done earlier. I tend to think it wasn’t for two reasons: first no-one saw an application and second few people are expert at both laser physics and ultrasonics.”

More…

Gates and Windows

It always seemed odd that a guy called Gates would fill his life with windows but today Microsoft Corp. announced that as of summer 2008 chairman Bill Gates will drop out of his transition day-to-day role in the company and begin to focus on his global health and education work through the Bill & Melinda Gates Foundation. Apparently, it’s going to take two years for the “transition” to happen, which is about right really, and no doubt they’ll give the process a code name like BigBone, and then when the marketing people get a hold of it they’ll change it to Scheista. It’s nice that he’s going to go through this transition at a time when the next version of Windows will be hitting the torrent networks.

True blue electric blue

polymer-led-mullen Wide angle X-ray scattering, photoluminescence, polarizing optical microscopy, differential calorimetry, and dielectric spectroscopy have been used to study the optical properties of a range of blue-light emitting organic compounds. The mechanism of the self-assembly of these oligoindenofluorenes up to the polymer, their thermal properties, and associated molecular dynamics also reveal important clues about their behaviour and potential for applications in organic light-emitting diodes (OLEDS) and other devices.

More…

H5N1 Vaccine Available

cockerel Elena Govorkova and colleagues at St. Jude Children’s Research Hospital in Memphis, Tennessee, have developed a vaccine against the potential lethal H5N1 strain of avian influenza. The vaccine protects, it seems, without triggering antibody production as is normally the case.

While lab tests show the vaccine to be effective, there is a problem with this preliminary study. It was not carried out on humans, so we shall not know whether it would be of any use should a pandemic arise. But, at least the laboratory ferrets, will be protected.

A peak you reach

Rather than relying on MRI and follow-up biopsy to provide information about a suspect abnormality in the breast, researchers at the Memorial Sloan-Kettering Cancer Center in New York have demonstrated in preliminary trials that NMR spectroscopy could be used to significantly reduce the number of biopsies required to detect the early stages of breast cancer. NMR can lock on to the choline peak associated with malignancy during the MRI scan.

Lia Bartella MD and her colleagues found that NMR could reduce the need for biopsy by 58%. They demonstrated that 23 of 40 suspicious lesions could have been spared biopsy, and none of the resultant cancers would have been missed, in a study group. “All cancers in this study were identified with MR spectroscopy,” explains Bartella, “There were no false-negative results. These results should encourage more women to take this potentially life-saving test.”

More…

Owl pellet dissection

A friend of mine is into nature conservation in a big way and one of the tools of the trade, which to the outsider may seem rather odd, is owl pellet dissection. I had a go at dissecting an owl pellet myself, here you can see the results

Owl pellets are the regurgitated remains (bones, feathers and other indigestibles) that accumulate in this bird of prey’s gizzard after it dines on small rodents and other critters. The dessicated pellets are to be found lying where they are discarded by the owl and can provide important information about what critters are being preyed on in owl territory.

The only way to get at that information, however, is to tease apart the pellet with tweezers and other implements to extract the bones from the tangle of hair and other detritus. It needs a steady hand, a keen eye, and a lot of patience. What you will find within is quite amazing though, tiny jaw bones and skulls, femurs, tibias pelvic bones and more.

Identifying which bone belongs to which creature takes even more patience, but it is possible and provides useful insights into the prevalence or otherwise of particular small mammals in a given area where owls prey.

For more on owl pellet dissection, check out this site http://www.kidwings.com/owlpellets/.

The reason I bring it up (pardon the pun) today, is that owl pellet dissection was the hot new search phrase on the sciencebase site this last month, with dozens of visitors all flapping for information on the subject. It’s not a topic that’s been searched for here before, so I thought I’d provide some background in case we have another flutter of en-raptor-ed activity.

Alchemical musings

In my guise as ChemWeb’s Alchemist this week I report on how there may be no need for a magic bullet in cancer chemotherapy and a basic (as opposed to acidic) approach could be all that is needed. Also spotted a smashing discovery that could explains glassy substances and precludes an ideal standard for physicists.

The Alchemists all sees the swirling clouds clearing as various holes in the ozone layer finally seem to be on the mend, and we learn of a co-polymer that not only fends off barnacles but can smell nice too.

Finally, spontaneous chiral resolution with achiral ligands.

Herring Gulls fighting

These two birds I photographed in my in-law’s garden were anything but lovebirds, although they might look like they were dancing seconds before and seconds after they were tearing each other’s feathers off and spitting blood. This didn’t seem to be a bar-room brawl between chums fighting over fishy scraps, these two were at it for a good half an hour. It has to have been a territorial or mating rights argument of some sort.

Nature really is red in beak and claw.

Gardenia delight for diabetes

An extract of the gardenia fruit, which is used in traditional Chinese medicine, could provide a new lead in the search for drugs to treat the symptoms of type 2 diabetes. The extract contains a chemical that apparently reverses some of the pancreatic dysfunction that underlies the disease, according to researchers writing in the June 7 issue of Cell Metabolism.

The chemical in question is genipin. This compound was previously found to cross-link proteins, but it has also now been shown to inhibit the enzyme uncoupling protein 2 (UCP2) through another mechanism. In both animals and humans, high concentrations of UCP2 appear to inhibit insulin secretion from the pancreas and increase the risk of type 2 diabetes.

“We think the increase in UCP2 activity is an important component of the pathogenesis of diabetes,” said Bradford Lowell of Beth Israel Deaconess Medical Center and Harvard Medical School. “Our goal therefore was to discover a UCP2 inhibitor capable of working in intact cells, as such an inhibitor could theoretically represent a lead compound for agents aimed at improving beta cell function in type 2 diabetes.”

Study coauthor Chen-Yu Zhang’s familiarity with traditional Chinese medicine led the team to consider the extract of Gardenia jasminoides Ellis fruits. Pancreas cells taken from normal mice secreted insulin when treated with the extract, they found, whereas the cells of mice lacking UCP2 did not. The results suggested that the extract worked through its effects on the UCP2 enzyme.

“When I first saw the results, I was in disbelief,” Lowell said. “I didn’t think we could ever be that lucky.” However, blinded repetition of the initial experiments confirmed the results every time, he said.

Through a series of chemical analyses, the researchers then zeroed in on genipin as the active compound. Genipin, like the extract, stimulated insulin secretion in control but not UCP2-deficient pancreas cells.

They further found that acute addition of genipin to isolated pancreatic tissue reversed high glucose- and obesity-induced dysfunction of insulin-producing beta cells. A derivative of genipin that lacked the chemical’s cross-linking activity continued to inhibit UCP2, they reported.

That’s a good sign for the therapeutic potential of genipin-related compounds, according to Lowell, as such indiscriminate cross-linking would likely have adverse effects. However, further work will need to examine whether inhibition of UCP2 itself might also have some negative consequences.