Articles in 2012

Bolaform amphiphiles are surfactants with two hydrophilic end groups, known to form stable micelles. Polarz et al.have synthesized dipolar bolaform surfactants with polyoxometallate head groups, which have a very low self-organization concentration and form nanoscale monolayer vesicles.

The functioning of bacterial communities is affected by selection, but the role of predation by single or multiple predators is unclear. In a study of 465 bacterial microcosms, Saleem et al.find that multiple predation causes positive bacterial diversity effects due to increased evenness among bacterial species.

Acetylenes can be covalently linked by oxidative coupling reactions. Zhanget al. report terminal alkyne C_sp-H bond activation and concomitant homo-coupling on a silver surface, yielding polymeric networks with a conjugated backbone.

Tuberous sclerosis complex is an autosomal dominant cognitive disorder caused by mutations affecting TSCgenes. Sato and colleagues examine tuberous sclerosis complex mutant mice and find that the behavioural and anatomical abnormalities can be reversed by inhibiting rapamycin-sensitive signalling pathways, even in adulthood.

Selected reaction monitoring mass spectrometry (SRM-MS) can quantify dynamic changes in protein expression with high sensitivity. Karlsson et al. define optimal detection parameters for 10,412 distinct group A Streptococcus pyogenespeptides, which facilitates proteome-wide SRM-MS studies in this bacterium.

Colloidal quantum dots may be used in a variety of emerging technologies, particularly if charged states can be stabilized. Here, cadmium selenide core-shell nanocrystals are engineered for trion emission at low temperatures, and their finite size introduces an acoustic phonon bottleneck, inhibiting spin relaxation.

Host–pathogen relationships can be mediated by polyvalent glycan ligand–protein interactions. Here well-defined highly valent glycodendrimeric constructs are synthesized that can mimic pathogens, and can inhibit a model of infection by the Ebola virus.

NFκB/p65 and PPARγ are both transcription factors that perform distinct but overlapping roles in cellular regulation. Hou et al. report that PPARγ acts as an E3 ubiquitin ligase and promotes Lys48-linked ubiquitination and degradation of p65, terminating NFκB-mediated inflammation and tumorigenesis.

Selective inhibitors of protein methyltransferases are anticancer drug candidates. Yu et al. report the structural changes that occur when selective inhibitors bind to the protein methyltransferase DOT1L.

The proteome of the malarial parasite Plasmodium falciparum has an overabundance of aggregation-prone asparagine repeat-containing proteins. Muralidharan et al. show that PlasmodiumHsp110 protein potently prevents aggregation of asparagine-rich proteins, thereby allowing the parasite to survive febrile episodes.

TatA, B and C act together to translocate folded proteins across bacterial and chloroplast membranes, however the precise mechanism remains unclear. Fröbel and colleagues discover that TatC has unforeseen membrane insertase activity, while TatB prevents premature cleavage before translocation.

Genetic modification in insects mostly involves the use of fluorescent markers to identify successful transformation. Here Osanai-Futahashi et al.report a marker system based on changes in melanin pigmentation that allows the identification of genetically modified insects with the naked eye.

Tumorigenesis has been likened to a form of cellular reversion to the embryonic state. Ma et al.identify a foetal miRNA as an oncogenic activator of the Wnt/β-catenin pathway in colorectal cancer, whose expression is negatively correlated with survival but is positively correlated with response to adjuvant chemotherapy.

Microparticles are small vesicular structures that are shed from cellular plasma membranes. Tang and colleagues show that cells treated with chemotherapeutic drugs produce drug-containing microparticles, which can be used as anticancer agents in mice.

Diagnostic microfluidic devices often require complicated optical systems and computers to quantify results. Here, Qin and colleagues link enzymatic biomarker detection with the displacement of ink, resulting in a device that displays quantitative results as bar graphs directly on the device.

Reading requires accurate and rapid distinction between similar visual stimuli. Thesen and colleagues use human intracranial electrophysiology and brain imaging to show that letter-selective responses, in an area of the brain immediately posterior to the visual word-form area, occur before word selection.

Demand for crops is increasing, but it is not clear whether the yields can meet this demand. Using crop yield observations, this study analyses global trends and finds that while yields continue to increase in some areas, across 24–39% of crop-growing regions, yields have stagnated or declined over the past 50 years.

Phylogenetic bat studies suggest that powered flight is evolutionarily conserved. Tokita et al.find that bat wing muscles are derived from multiple myogenic sources with different embryonic origins, and that spatiotemporal correlations exist between outgrowth of wing membranes and expansion of wing muscles.

Knowledge of how a disease spreads can lead to useful predictions to help manage and contain it. Here, Maher et al.model white-nose syndrome spreading in North American bats, and show that concentrated habitat distribution and longer winters can mediate pathogen dispersal, matching the ecological traits of bats.

The mislocalization and downregulation of the proteins TDP-43 and ADAR2, respectively, are implicated in amyotrophic lateral sclerosis pathology. Yamashita et al. find that downregulation of ADAR2 results in calcium-permeable AMPA receptor-mediated calpain activation and subsequent aberrant cleavage of TDP-43.