Background
Crowd surfing, vaping and Doggerland
Thursday 27 October 2016

Crowd surfing

Leiden chemists have made a layer of graphene go crowd surfing on a layer of phospholipids. In terms of physics, graphene is a miracle substance: it’s one molecule thick and has all sorts of special electrical properties which make it suitable for building things like sensors. Phospholipids are molecules that can have their cake and eat it: they a have fatty, water-resistant side and a phosphate side that is soluble in water. The membrane surrounding every living cell consists of phospholipids and the pharmaceutical industry uses them for administering substances that don’t dissolve well in water.

PhD candidate Lia Lima and her fellow researchers describe, in the science journal Nanoscale, how graphene, when it covers lipids, compresses them and protects them from being washed away – the scientists call it “crowd surfing”. The benefits are mutual: the fatty layer improves the electric conductivity of the graphene layer. By combining graphene with phospholipids, you can, in theory, easily administer tiny sensors to a human body.

Vaping

In Respiratory Research, LUMC Professor Pieter Hiemstra and a German colleague present a literature retrospective on electronic cigarettes. These cigarettes are rapidly gaining in popularity, raising the question as to how healthy they really are. However, e-cigarettes are difficult to study, even when test animals or cell cultures are used. So far, no one has drawn up any reliable standardisation for research strategy. There are different kinds of e-cigarettes; they all have different ignition temperatures and contain all sorts of different potions. Although it’s reasonably evident that you can safely eat those flavourings, how safe is it to smoke them?

The available studies are not sufficient to predict how bad vaping could be in the long term. Nonetheless, it has emerged that, although e-smoke is better for you than cigarette smoke, it too has adverse effects on your lung cells. Studies conducted on test animals reveal that smoke from e-cigarettes increases your chances of contracting an infectious disease and can cause COPD-like tissue damage, just like ordinary cigarettes. Oh, and that nicotine is extremely addictive, even if you don’t burn the rest of the tobacco plant.

Doggerland

During the last ice age, much of Earth’s water was trapped in the glacial caps, so the sea level was much lower than it is now. You could have walked from Holland to England. In fact, the dry area of the Southern North Sea was populated by mammoths, lions, deer - and people. Archaeologists can’t tell us very much about those people just yet. Usually, archaeologists work with sites of which they know how they were dug; that produces more information than a piece of bone found in a fishing net or in a sand bank thrown up as coastal protection.

In the Journal for Archaeological Science, Leiden/Groningen Professor Hans van der Plicht describes an isotope study on human remains from this Doggerland. Isotopes are versions of atoms with a different number of neutrons than the usual sort. “Ordinary” nitrogen has 14 neutrons but there is also a heavier version that has 15. The proportions between the two in a bone can tell you something about the owner of the bone’s diet. Van der Plicht and his colleagues draw the conclusion that the inhabitants of what is now sea mostly ate freshwater fish. So archaeologists have managed to obtain at least a little bit of information.