Specific inhibition of human leukocyte elastase by substituted alpha-pyrones

Several a-pyrones have been synthesized and investigated for their in vitro inhibitory activity using a-chymotrypsin (a-CT), porcine pancreatic elastase (PPE) and human leukocyte elastase (HLE). 4-Hydroxy-6-undecyl-2H-pyran-2-one 4, 4-Hydroxy-6-[(1-butyl)heptyl]-2H-pyran-2-one 5 and 4-Methoxy-6-[(1-butyl) heptyl]-2H-pyran-2-one 6 were found to be specific inhibitors of HLE. These compounds constitute a promising new class of HLE inhibitors.     

Loci on 20q13 and 21q22 are associated with pediatric-onset inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common inflammatory disorder with complex etiology that involves both genetic and environmental triggers, including but not limited to defects in bacterial clearance, defective mucosal barrier and persistent dysregulation of the immune response to commensal intestinal bacteria. IBD is characterized by two distinct phenotypes: Crohn's disease (CD) and ulcerative colitis (UC). Previously reported GWA studies have identified genetic variation accounting for a small portion of the overall genetic susceptibility to CD and an even smaller contribution to UC pathogenesis. We hypothesized that stratification of IBD by age of onset might identify additional genes associated with IBD. To that end, we carried out a GWA analysis in a cohort of 1,011 individuals with pediatric-onset IBD and 4,250 matched controls. We identified and replicated significantly associated, previously unreported loci on chromosomes 20q13 (rs2315008[T] and rs4809330[A]; P = 6.30 x 10(-8) and 6.95 x 10(-8), respectively; odds ratio (OR) = 0.74 for both) and 21q22 (rs2836878[A]; P = 6.01 x 10(-8); OR = 0.73), located close to the TNFRSF6B and PSMG1 genes, respectively.     

Theoretical mechanics: crowd synchrony on the Millennium Bridge

Soon after the crowd streamed on to London's Millennium Bridge on the day it opened, the bridge started to sway from side to side: many pedestrians fell spontaneously into step with the bridge's vibrations, inadvertently amplifying them. Here we model this unexpected and now notorious phenomenon--which was not due to the bridge's innovative design as was first thought--by adapting ideas originally developed to describe the collective synchronization of biological oscillators such as neurons and fireflies. Our approach should help engineers to estimate the damping needed to stabilize other exceptionally crowded footbridges against synchronous lateral excitation by pedestrians.     

The RNA-binding protein FCA is an abscisic acid receptor

The phytohormone abscisic acid (ABA) regulates various physiological processes in plants. The molecular mechanisms by which this is achieved are not fully understood. Genetic approaches have characterized several downstream components of ABA signalling, but a receptor for ABA has remained elusive. Although studies indicate that several ABA response genes encode RNA-binding or RNA-processing proteins, none has been found to be functional in binding ABA. Here we show that FCA, an RNA-binding protein involved in flowering, binds ABA with high affinity in an interaction that is stereospecific and follows receptor kinetics. The interaction between FCA and ABA has molecular effects on downstream events in the autonomous floral pathway and, consequently, on the ability of the plant to undergo transition to flowering. We further show that ABA binding exerts a direct control on the FCA-mediated processing of precursor messenger RNA. Our results indicate that FCA is an ABA receptor involved in RNA metabolism and in controlling flowering time.     

汽相生长的碲锡铅单晶的质量评价

碲锡铅(Pb_1-xSn_xTe)是一种禁带宽度可调的三元化合物半导体,用它不仅可制备814μm的高灵敏度的红外探测器,而且可以制备长波红外可调谐激光器.