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The push for new anti-inflammatory drugs has pharmaceutical companies flocking to a previously abandoned therapy. Heidi Ledford reports on the resurrection of interleukin-1 blockers.
Hanging bright in the morning sky, Venus's allure is obvious; but its blasted surface looks too hot to handle. Eric Hand investigates the difficulties of returning to the closest planet - and new plans to reap the rewards of doing so.
Occasionally science makes procedures possible that are so radical that those at the interface between science and politics are called on to define moral standards for society.
The Venus Express mission has returned its first findings on the harsh atmosphere of our sister planet. It's another step towards explaining how Venus turned out so differently from our balmy home.
The p53 protein is widely studied for its function as a tumour suppressor, preventing cancer. It emerges that this protein also has an essential physiological role in regulating embryo implantation in mice.
Where would you start in trying to work out the structure of a macromolecular machine consisting of 456 proteins? Taking a combined experimental and computational approach is one answer.
The atoms and bonds that make up complex solids can be identified chemically — a feat made possible by cleverly combining spectroscopic and structural information conveyed by electrons scattered through a thin sample.
Synaptic communication is triggered by action potentials, but neurons also talk to each other in between action potentials. Specific intracellular-calcium sensors regulate these conversations.
The motor protein kinesin 'walks' by alternately advancing its two motor structural domains. A cutting-edge, single-molecule fluorescence technique reveals further details of this stepping mechanism.
Venus is Earth's near twin in mass and radius, yet its atmosphere, mostly composed of carbon dioxide, has a surface temperature and pressure far higher than those of the Earth. This paper discusses the first year of observations by Venus Express, which bring into focus the evolutionary paths by which the climates of two similar planets diverged from common beginnings to such extremes.
Venus is completely covered by a thick cloud layer, with the cloud tops in fast retrograde rotation. Global and small scale properties of these clouds and their temporal and latitudinal variations are investigated, and the wind velocities are derived. The southern polar region is highly variable and can change dramatically on time scales as short as one day, perhaps arising from the injection of SO2 into the mesosphere.
Venus has a bright 'dipole' double-eye feature at the centre of a vast vortex that rotates around the north pole, and is surrounded by a cold 'collar'. Observations of Venus' south polar region are reported, where clouds with morphology much like those around the north pole are seen, but rotating somewhat faster.
Observations of infrared emission from CO2, O2 and NO established that photochemical and dynamic activity controls the structure of the upper atmosphere of Venus, but were unable to identify the altitude of the emission. But it is reported here that day-side CO2 emission extends from 90–120 km altitude, with a peak at ∼115 km. Night-side O2 emission peaks at 96 km and is visible over the range 95–100 km.
Venus' mesosphere is a transition region between the retrograde super rotation at the top of the thick clouds and the solar-antisolar circulation in the thermosphere. The mesospheric distributions of HF, HCl, H2O and HDO are reported, and an unexpected extensive layer of warm air at altitudes 90–120 km on the nightside is found.
On Venus, the bulk of O and O2 are gravitationally bound, but heavy ions have been observed to escape, though their composition could not be determined. Venus Express measurements report that the dominant escaping ions are O+, He+ and H+. The escape of H+ and O+, together with the estimated neutral hydrogen and oxygen escape, currently takes place near the stoichometric ratio corresponding to water.
Radio-sounding results from the first Venus Express Radio Science (VeRa) occultation season are reported, which determine the fine structure in temperatures at upper cloud-deck altitudes, detect a distinct day–night temperature difference in the southern middle atmosphere, and track day-to-day changes in Venus' ionosphere.
Observations of Venus' ionosphere reveal strong, circularly-polarized, electromagnetic waves with frequencies near 100 Hz. The waves appear as bursts of radiation lasting 0.25 to 0.5 s and have the expected properties of whistler-mode signals generated by lightning discharges in Venus' clouds.
A study of endocytosis of Shigella toxin shows that it enters cells via narrow tubular membrane invaginations, with similar properties on cell and model membranes. The toxin induces membrane reorganisation before the formation of tubular invaginations.
A combination of genetics and electrophysiology is used to tease apart synchronous and asynchronous releases of neurotransmitter at nerve terminals, and the existence of independent calcium sensors is proposed. The first quantitative model to account for the full range of calcium-dependence of synaptic transmission is also provided.
This paper reports the solving of a number of difficulties, such as instrumentation instabilities and delocalization in inelastic scattering, to visualize the atomic columns of La, Mn and O in the layered manganite La1.2Sr1.8Mn2O7 as two-dimensional images.
Electron microscopy is combined with optical single-molecule tracking to visualize molecular diffusion in a nanoporous material. For the first time, guest molecules can be 'seen' changing speed or direction in response to structural features of the host.
Experimental results from a study of grain-boundary diffusion of siderophile ('iron-loving') elements through polycrystalline MgO are reported. The diffusivities computed are high enough to allow transport of a number of siderophile elements over geologically significant length scales (tens of kilometres) over the age of the Earth.
This work describes the identification and characterization of novel small molecule activators of SIRT1, an NAD+-dependent deacetylase that mediates the beneficial effects of caloric restriction. These small molecules are structurally unrelated to, and much more potent than, resveratrol, and improve metabolic function in animal models of diabetes and obesity.
Understanding morphogen activity is one of the longest standing problems in developmental biology. Both the duration of exposure to the secreted morphogen Sonic hedgehog (Shh) and the concentration of Shh are important in determining the fate of cells in the neural tube and in the limb bud. This paper clarifies the relationship between time and concentration in Shh signalling during patterning of the neural tube.
The p53 gene has been extensively studied for its role in tumour prevention but little is known about its normal physiological function. A crucial role of this factor in fecundity and reproduction is now reported.
Conventional antibiotics, which target the infectious agent, are subject to the development of antibiotic resistance. An alternative approach is to focus on host factors that support pathogen growth. A kinase inhibitor screen identified AKT1 as a central molecule essential for intracellular survival of Salmonella typhimurium and Mycobacterium tuberculosis and thus presenting a putative drug target.
Immature thymic T cells receive signals through the T cell receptor which determine whether they undergo positive or negative selection. Calcineurin/NFAT signalling in preselection thymocytes produces a temporal window with enhanced signalling sensitivity paving the way for positive selection.
The nutrient sensor mTOR controls mitochondrial gene expression and oxidative function via an interaction between the transcriptional regulators PGC-1α and YY1.
Crystal structures of complexes between the epidermal growth factor receptor (EGFR) kinase domain and a fragment of its feedback inhibitor MIG6 reveal an allosteric inhibition mechanism. MIG6 binds the cyclin/CDK-like asymmetric dimer interface of EGFR and blocks formation of the activating dimer.
This paper addresses the question of how centromere architecture affects spindle formation, and presents evidence supporting the claim that centromeres are malleable with respect to tangential forces. Once deformed, they remain in this position until they are straightened by external forces applied along microtubules.
Two different single-molecule fluorescence resonance energy transfer (smFRET) sensors are developed to detect whether kinesin is bound to its microtubule track by one or two heads. It is found that at physiological concentrations of ATP, kinesin waits in-between steps in a two-headed bound state, whereas at lower ATP concentrations, a one-head bound state predominates.
