April 1, 2013

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X-ray crystallography made easy

Sixty years ago this month Nature published the famous paper by Watson and Crick solving the structure of DNA. At the time many researchers pursued this goal, made difficult by the complexity of the DNA itself. A key contribution to the solution of the puzzle was the x-ray diffraction data provided by Rosalind Franklin. Indeed, without x-ray diffraction experiments this discovery would have been almost impossible at the time.

X-ray diffraction image of DNA. (c) Nature Magazine. Franklin, R. & Gosling, R. G. Nature 171, 740-741 (1953) - doi:10.1038/171740a0

Rosalind Franklin’s x-ray diffraction image of DNA. (c) Nature Magazine. Franklin, R. & Gosling, R. G. Nature 171, 740-741 (1953) – doi:10.1038/171740a0

The way x-ray crystallography works is that a beam of x-rays is directed at a crystal, where the x-rays bounce off the atoms. Because the atoms in a crystal are periodically arranged, the x-rays form complex but regular patterns (such as the one seen for DNA). A detailed analysis of these patterns enables the precise determination of the crystal structure.

To this day such experiments aren’t easy. They require relatively large crystals and typically are done at major facilities such as electron synchrotrons. The synthesis of the crystals for these experiments can often be very difficult.

Yasuhide Inokuma, Makoto Fujita and colleagues from the University of Tokyo in Japan  and the University of Jyväskylä in Finland have now developed a clever method that does away with many limitations of x-ray crystallography. Their method works with tiny amounts of material, only about a half to 5 micrograms are enough. This is around a millionth of a gram – truly tiny. The difference between a microgram and a gram is the same as that between a gram and a metric ton. In addition, another major advance of their method is that the target molecules don’t even need to be in a crystalline state. Continue reading…

February 5, 2013

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The curse of the obsession with doctorate degrees

Today the University of Düsseldorf in Germany has revoked the doctorate of the German Federal Minister of Education and Research, Annette Schavan, following accusations of plagiarism.  She denies the accusations and has announced to continue the fight for her degree in court. This is the second case in two years of a German federal minister losing their doctorate based on accusations of plagiarism, the other being Karl-Theodor zu Guttenberg, the former Minister of Defence.

I don’t want to comment on these specific cases, but focus on the broader issues here. To me these cases are a reminder that in some countries (such as Germany…) doctorate degrees mean far too much, and in some cases are sought after also because they give considerable social recognition. They are used to advance careers in completely unrelated careers, and in this way create entrance barriers based on unnecessary criteria. This is very wrong. Continue reading…

January 19, 2013

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Lithium-ion batteries and the Boeing 787 Dreamliner

The Boeing 787 Dreamliner is the most recent major new aircraft design from Boeing, and the manufacturer’s most fuel-efficient plane. I have never had the pleasure of being passenger on one of these, but the design is certainly very modern. Composite materials are widely used in the aircraft, which is key to the plane’s fuel efficiency and explains the popularity of the plane. With more than 800 orders in the books, Boeing was also on a good track to break even commercially.

Then, on January 16 the FAA grounded all 787, following a number of technical problems. Earlier, the Japanese airlines ANA and JAL had already suspended all 787 flights, which was a significant signal because combined these two airlines operate almost half of the 787 delivered to date. Aside from a number of other technical issues such as a fuel leak, a key reason to ground the entire fleet has been two incidences where the back-up batteries overcharged and overheated such that there was the danger of fire on board. But how big a deal are these battery incidents? Continue reading…