Forebrain peptides modulate sexually polymorphic vocal circuitry

The peptide arginine-vasopressin (mammals) and its evolutionary precursor arginine-vasotocin (non-mammals) modulate reproductive physiology and numerous related social behaviours, as do oxytocin (mammals) and its homologues mesotocin and isotocin (fish). The distributions in the brain and/or the behavioural functions of these peptides often differ between the sexes, and between species with divergent social structures. Here we present neurophysiological evidence that males with vocal characteristics typical of females share a pattern of neuropeptide function with females rather than conspecific males. The plainfin midshipman fish (Porichthys notatus) has two male morphs with different reproductive tactics and vocalizations (a key species-typical behaviour which varies in its physical attributes and contextual usage, depending on the morph's social strategy). Forebrain-evoked, rhythmic vocal-motor activity that precisely mimics natural vocalizations was modulated by arginine-vasotocin, isotocin and their antagonists delivered to the preoptic area-anterior hypothalamus, a primary site for behavioural integration in all vertebrates. Peptides had different effects in males that acoustically court females (arginine-vasotocin-sensitive) than in females and sneak-spawning males (isotocin-sensitive), showing that the neuromodulatory mechanisms that establish reproduction-related behaviour can be dissociated from gonadal sex.     

A microRNA polycistron as a potential human oncogene

To date, more than 200 microRNAs have been described in humans; however, the precise functions of these regulatory, non-coding RNAs remains largely obscure. One cluster of microRNAs, the mir-17-92 polycistron, is located in a region of DNA that is amplified in human B-cell lymphomas. Here we compared B-cell lymphoma samples and cell lines to normal tissues, and found that the levels of the primary or mature microRNAs derived from the mir-17-92 locus are often substantially increased in these cancers. Enforced expression of the mir-17-92 cluster acted with c-myc expression to accelerate tumour development in a mouse B-cell lymphoma model. Tumours derived from haematopoietic stem cells expressing a subset of the mir-17-92 cluster and c-myc could be distinguished by an absence of apoptosis that was otherwise prevalent in c-myc-induced lymphomas. Together, these studies indicate that non-coding RNAs, specifically microRNAs, can modulate tumour formation, and implicate the mir-17-92 cluster as a potential human oncogene.     

GC/MS法追踪摇头丸杂质体系

本文运用GS/MS的总离子流法,选择离子法,对南京地区常见的几种摇头丸进行全面分析,找出与合成途径相关的痕量杂质,根据杂质情况初步确定其合成途径.     

鲁克沁构造带稠油成藏机制研究

吐哈盆地台南凹陷鲁克沁构造带中的北西走向断层受挤压强烈 ,封闭性好 ;而北东走向断层封闭性差 ,常成为油气运移的良好通道。由于本区断块圈闭的有效性差 ,故不具备大规模聚集稀油的条件 ,但对稠变到一定程度的稠油能起较好的封堵作用。鲁克沁构造带高粘重质油的形成是原油运移和成藏阶段双重稠变作用的结果 ,并且油气的聚集是一个动态的过程。随着原油的逐渐稠变 ,所需要的封堵条件逐渐降低 ,油气的聚集过程才趋于稳定。鲁克沁构造带构造后期变革主要表现在构造幅度的增大 ,而未发生强烈的断裂作用 ,因此 ,前侏罗系油藏得以完好地保存     

Effects of the virulence plasmid ColV, I-K94 on the sensitivity of Escherichia coli to putative environmental inhibitory agents

Derivatives of Escherichia coli carrying the virulence plasmid, ColV, I-K94 were more resistant than the ColV- parents to phage Mel but were more sensitive to the hydrophobic inhibitors deoxycholate, erythromycin and lysozyme. The basis for these changes in sensitivity has been examined in ColV+ mutants with altered colicin or VmpA protein levels and in ColV+ strains with repressed transfer properties.     

Structure of recombinant human rheumatoid arthritic synovial fluid phospholipase A2 at 2.2 A resolution

Phospholipases A2 (PLA2s) may be grouped into distinct families of proteins that catalyse the hydrolysis of the 2-acyl bond of phospholipids and perform a variety of biological functions. The best characterized are the small (relative molecular mass approximately 14,000) calcium-dependent, secretory enzymes of diverse origin, such as pancreatic and venom PLA2s. The structures and functions of several PLA2s are known. Recently, high-resolution crystal structures of complexes of secretory PLA2s with phosphonate phospholipid analogues have provided information about the detailed stereochemistry of transition-state binding, confirming the proposed catalytic mechanism of esterolysis. By contrast, studies on mammalian nonpancreatic secretory PLA2s (s-PLA2s) have only recently begun; s-PLA2s are scarce in normal cells and tissues but large amounts are found in association with local and systemic inflammatory processes and tissue injury in animals and man. Such s-PLAs have been purified from rabbit and rat inflammatory exudate, from synovial fluid from patients with rheumatoid arthritis and from human platelets. Cloning and sequencing shows that the primary structure of the human s-PLA2 has about 37% homology with that of bovine pancreatic PLA2 and 44% homology with that of Crotalus atrox PLA2. The human s-PLA2 is an unusually basic protein, yet contains most of the highly conserved amino-acid residues and sequences characteristic of the PLA2s sequenced so far. Here we report the refined, three-dimensional crystal structure at 2.2 A resolution of recombinant human rheumatoid arthritic synovial fluid PLA2. This may aid the development of potent and specific inhibitors of this enzyme using structure-based design.     

求取剩余油饱和度的一种实用方法

分析了水驱油田地质、测井及开发动态特征，提出了用生产井含水率资料结合测井资料求取产层平均剩余油饱和度的方法。阐述了该方法的基本模型和计算过程，并以实例计算说明了这种方法的实际应用效果。结果表明，该方法操作简便、实用性强、计算结果可靠，且能准确反映储层的剩余油分布特征。这种方法也避免了水淹层混合液电阻率、岩电系数和水淹层电阻率求取值失真的影响。     

Sequence-based characterization of structural variation in the mouse genome

Structural variation is widespread in mammalian genomes and is an important cause of disease, but just how abundant and important structural variants (SVs) are in shaping phenotypic variation remains unclear. Without knowing how many SVs there are, and how they arise, it is difficult to discover what they do. Combining experimental with automated analyses, we identified 711,920 SVs at 281,243 sites in the genomes of thirteen classical and four wild-derived inbred mouse strains. The majority of SVs are less than 1?kilobase in size and 98% are deletions or insertions. The breakpoints of 160,000 SVs were mapped to base pair resolution, allowing us to infer that insertion of retrotransposons causes more than half of SVs. Yet, despite their prevalence, SVs are less likely than other sequence variants to cause gene expression or quantitative phenotypic variation. We identified 24 SVs that disrupt coding exons, acting as rare variants of large effect on gene function. One-third of the genes so affected have immunological functions.     

松辽盆地南部低渗透砂岩储层裂缝特征及其对油田开发的影响

松辽盆地南部的低渗透砂岩储层中普遍存在受断层和沉积微相控制的４组高角度构造裂缝,其中以近东西向裂缝渗透性最好,北西向和北东向两组裂缝对储层中流体的渗流也起着相当重要作用,这３组裂缝是油田开发井网布置时应考虑的主要因素。在泥岩夹层中,除了高角度构造裂缝外,还发育有低角度顺层滑脱裂缝,因此,该区泥岩的吸水能力普遍较强,对注水效果有重要影响,因而在注水时应严格控制注入压力。