Author: David Bradley

Penggunaan Eceng Gondok

Eceng gondok

I was intrigued by a rash of searches on the Sciencebase site from people looking for the phrase “Penggunaan Eceng Gondok”. A quick Google revealed that Eceng Gondok is the water hyacinth, although “gondok” itself is actually the Indonesian word for goitre.

A scan of three Indonesian-English dictionaries then revealed that “penggunaan” means employing or using, so visitors searching for “Penggunaan Eceng Gondok” were presumably looking for mentions of the uses of water hyacinth. Now, not having much experience of this aquatic plant, I did a little more searching and found that it is a common raw material in Indonesia for making sandals and woven goods, such as table mats it seems. As ever with artisanal and traditional crafts emerging from the developing regions of the world there is an “environmental” and “eco-friendly” tag associated with this material.

Blood Group Test

red-blood-cellsA, B, AB, or O?

A blood type (also called a blood group) is a classification of blood based on the presence or absence of inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system, and some of these antigens are also present on the surface of other types of cells of various tissues. Several of these red blood cell surface antigens, that stem from one allele (or very closely linked genes), collectively form a blood group system.

The ABO system is the most important blood group system in human blood transfusion. The associated anti-A antibodies and anti-B antibodies are usually “Immunoglobulin M”, abbreviated IgM, antibodies. ABO IgM antibodies are produced in the first years of life by sensitization to environmental substances such as food, bacteria and viruses. The “O” in ABO is often called “0” (zero/null) in other languages.

A quite literally vital question when a blood transfusion is required and normally blood type is determined using an antibody and optical examination. However, Austrian researchers at the University of Vienna have developed a novel approach that is much simpler and side-steps expensive antibodies. Their technique is based on the blood-type-specific adsorption of red blood cells (erythrocytes) on a plastic surface “embossed” on the molecular scale.

Production of the analytical chips needed for this method is a simple and inexpensive process: quartz microbalances (tiny piezoelectric quartz crystals) are coated with a wafer-thin film of polyurethane. Erythrocytes of a specific blood type in liquid are placed on a slide and stick to its surface, forming the embossing “stamp”. The polymer is cured to harden it and the cells washed off. The ebmossed plastic surface now contains a large number of tiny impressions with indentations shaped like the antigens on the surface of the blood cells.

If a sample of blood is then placed on the chip, the erythrocytes will preferentially settle into those impressions with a matching shape. The resulting increase in mass is measured with the incredibly sensitive quartz microbalance.

The shape and size of the erythrocytes are the same for all blood types, so how can they be differentiated by these indentations? ‘The outer form is not the deciding factor,’ says team leader Franz Dickert, ‘instead, it is the differences in the surfaces of the different blood types.’ There are sugar-like molecular fragments on the surface of the cells that differentiate the blood types.

‘Despite a noticeable cross-sensitivity for the other blood types, determination of the blood type by the embossed plastic films is unambiguous,’ says Dickert, ‘because the strongest sensor signal comes from the microbalance that carries the impressions corresponding to the blood type of the sample.’

Dickert and colleagues publish details of their technique in Angew Chem, 2006, 45, 2626-2629

Robots in the Military

The idea of robots in the military brings about thoughts of a sci-fi nightmare, probably starring Arnie and most definitely not R2. The military does, nevertheless, already use robotics to help members of the armed forces protect themselves against a wide range of dangers. But, the idea of a robot fighter shooting at the enemy is not that far from reality.

Read about this and the latest robotics news on our scenta robots news page.

Spam Flood

Isn’t web spam wonderful? The Sciencebase blog received a dozen new “comments” to posts overnight, all from a single source in China and all listing chemical compounds a company over there is trying to sell.

Here are just a few, 2,2-Bis(hydroxymethyl) propionic acid, Morpholine, Pelargonic Acid, 2,2-Dimethylbutyric acid (without the links to the spammer’s site, of course). The first person to give me a run-down of what these materials are used for can award themselves a gold star!

Lancet Calls for Open Access to TGN-1412 Trial Investigation

British medical journal, The Lancet, has called for an open and independent investigation of what went wrong with the small phase I clinical trial of TGN-1412 that had six men in intensive care within hours of the trial beginning.

“Commercial confidentiality should not obstruct independent scrutiny of the drug trial that led to six men becoming seriously ill in Northwick Park Hospital in London, UK,” states an Editorial in the Journal, “Both TeGenero and The Medicines and Healthcare products Regulatory Agency (MHRA) – who authorised the trial – denied The Lancet’s request to see the protocol stating that it is ‘commercially sensitive’.”

News has been terse to say the least since the initial media frenzy regarding the trial. Quite bizarrely, Northwick Park Hospital in north west London, is where eccentric UK medical comedy Green Wing is recorded.

Password Sitter

P30%_gha! or p0%3ghA!?

If you’ve ever resorted to scribbling your assigned computer password on a Post-It and sticking it to the side of your monitor because it was too cryptic to remember, then research at the Fraunhofer Institute for Secure Information Technology in Germany, could be just what you’ve been waiting for.

The scientists there have developed a new program — PasswordSitter. “Using it, you only need to remember a single password. The program provides all the other passwords on any device, whenever you need them”, explains team leader Markus Schneider, “A special procedure based on state-of-the-art encryption technology provides the necessary security.”

Despite new security mechanisms, requesting a password is the most common method of checking a user’s identity. Most of us have so many passwords for websites, databases, email etc, that remembering which one goes with what is a major headache. The problem is doubled by company IT managers who often force users (quite sensibly) not only to choose non-obvious passwords with mixed alphanumerics and even punctuation marks but also to change it on a regular basis.

According to the annual Safenet survey, half of all professional computer users write down their passwords, and around a third even divulge their passwords to colleagues. It almost defeats the object of having a password in the first place. A lot of people go for weak passwords, such as the name of a spouse, or don’t think twice about using the same password for everything. “These kinds of practices harbour potential security risks”, says Schneider, “On the other hand, it’s virtually impossible for you to follow the security advice from the experts without any help.”

PasswordSitter bolsters security because it generates strong passwords, while the level of security can be set to allow different password guidelines to be followed and passwords can be changed quickly and easily.

But, you may be wondering why not opt for one of those neat USB fingerprint reader? gadgets? Well, they’re fine if you’re at your own PC, but what happens if you’re working at someone else’s workstation or in a cybercafe?

PasswordSitter provides users with access to their passwords from any device at any time they need them.

So, how does it work? Well, it seems that Fraunhofer aren’t so keen to reveal details, although Schneider told Sciencebase that, “PasswordSitter is available as signed Java applet. If you are in a cybercafe in Peru, then you can download PasswordSitter, type in your Master Password and PasswordSitter generates your ebay password for you every time you need it. Note that your ebay password is not stored in the PasswordSitter system.”

There are other password-minding systems out there – including PassPack and LastPass and if you’re stuck for ideas for how to come up with a password try my passwords for scientists idea.

Polymeric Hydrogen Storage

UK chemists have devised a new approach hydrogen gas storage that could power fuel-cell cars and vehicles without the need to carry hazardous cylinders of compressed gas. The approach is base on a highly porous polymer that can trap huge numbers of gas molecules allowing hydrogen gas to be stored in a compact container in a safe form.

You can read the full story in the March issue of Spotlight, the physical sciences magazine from PSIgate and David Bradley

Swell Gels

A new type of microscopic particle that has a hard shell and a soft core that changes structure depending on the temperature has been developed by Walter Richtering and graduate student Ingo Berndt of the University of Aachen, Germany, and Jan Skov Pedersen of the University of Ã…rhus, Denmark, and their colleagues. The particles might have industrial and biomedical applications. For instance, they could be used for the controlled release of substances held within the shell.

Read the full story in the March issue of chemistry newsletter Reactive Reports

Chemical Closures

A press release just in from the UK’s Royal Society of Chemistry announces that HEFCE (Higher Education Funding Council for England) intends to throw £5million ($9m) into two major initiatives from the RSC and the Institute of Physics. The announcement follows an agreement last year that HEFCE would work with a group of organisations to support strategically important and vulnerable subjects.

At a time when UK chemistry and physics departments seem to be getting earmarked for closure on an almost yearly basis, this additional funding might be quite timely. Steve Egan, Acting Chief Executive of HEFCE, explains the rationale behind it, ‘We believe that the long-term health of these subjects can best be secured by ensuring that there is an increasing demand from people wishing to study them who are well informed about future career prospects. We are pleased to work with partners – including the learned societies, universities, schools, colleges and employers – to stimulate interest and excitement in these subjects and to bring them to the attention of pupils from a wide range of backgrounds.’

Exeter University, Queen Mary’s, Kings College London, Swansea, to name but a few have all closed their chemistry lab doors for the last time and at the time of writing the future of Sussex University’s chemistry department (5-rated and the source of two Nobel laureates remains in the balance. Sussex’s senate intends to hold a debate with “stakeholders” (students, staff and advisers in other words) in the near future before making the final decision to shut it down.

The plan will cripple all the chemical sciences at the university, including biochemistry, chemical biology, and medicine, Harry Kroto said in a video appeal to Sussex (http://tinyurl.com/j2qmj) where he carried out his Nobel-winning fullerene research.

Where were these initiatives when those institutions were seeing dwindling chemistry enrolment numbers? Why didn’t someone think to check how the physics and chemistry departments were doing before allowing them to close? Of course, some of these departments have been re-born as merged and rebranded subsidiaries of biology. But, where will the fundamental physics and chemistry be taught if students are more concerned with biotech applications than understanding the underlying principles?

The RSC press release tells us that “The Chemistry For Our Future programme aims to ensure a strong and sustainable chemical science community within higher education, and to provide a sound basis for continuing the success of industries that rely on chemistry.” IOP’s, on the other hand, “Stimulating Demand for Physics programme will be funded in partnership with several universities and a wide range of other organisations.” The aim is to enhance understanding between schools and universities, smoothing the transition to higher education while informing curriculum development.

Is a few million quid going to save other chemistry departments from the bio fate? One can hope so, but the recent Oxford Uni refurb that is taking that particular department forward with considerable pace cost £60m. £5m might seem too little, too late for some departments heading the way of King’s and the rest.

The Dynamic Duo of Biology

Researchers have modified a popular system for protein labelling and modification to reduce the risk of unwanted cross-reactions and so make it more accurate and effective.

With incredible specificity and powerful affinity for each other, the protein streptavidin and its small-molecule target biotin are truly the ‘Dynamic Duo’ of biological research, the researchers explain, and a perennial favourite for use in the design of biochemical experimental techniques. For example, one can easily subject biotin-linked proteins to highly specific labelling with streptavidin-linked fluorophores. Nonetheless, there is an important limitation to the system-streptavidin naturally forms tetramers (assemblies of four protein molecules) that bind up to four molecules of biotin, creating the potential for unexpected cross-linking of biotinylated targets. Efforts to engineer monomeric streptavidin variants have generally resulted in diminished biotin affinity.

Now, Alice Ting and colleagues at Massachusetts Institute of Technology, Cambridge, have developed an alternative approach that involves engineering ‘dead’ streptavidin variants that can bind to each other but not to biotin. By combining the two types of streptavidin monomers in the proper proportions and isolating tetramers that consist of three dead subunits and one active subunit, they obtain streptavidin complexes that are functionally monomeric and bind only one molecule of biotin.

They have demonstrated that the hybrid tetramers retain normal affinity for biotin but induce far less ‘clumping’ of biotinylated targets relative to wild-type streptavidin tetramers. This approach also offers the possibility of building divalent and trivalent tetramers. According to Kai Johnsson of the École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, “the existing plentitude of applications of the streptavidin-biotin interaction provides an enormous playground for streptavidins with reduced but defined valencies.”

More details can be found in April’s Nature Methods.