阿司匹林增加胰岛素抵抗大鼠胰岛素敏感性的实验研究

目的　观察阿司匹林对高脂饮食大鼠胰岛素敏感性的影响。方法　灌服阿司匹林前后采用腹腔注射胰岛素耐量试验 (IITT)观察大鼠胰岛素的敏感性 ,并测定空服胰岛素、血糖和血脂等。结果　高脂饮食 4月、阿司匹林治疗 4周后 ,IITT发现高脂组腹腔注射胰岛素后 1h、1 5h和 2h的血糖及空腹胰岛素和甘油三酯水平显著高于正常对照组 (P <0 0 5或P <0 0 1 ) ;而阿司匹林治疗组腹腔注射胰岛素后 1h、1 5h和 2h的血糖及空腹胰岛素和甘油三酯水平显著低于高脂组 (P <0 0 5或P <0 0 1 ) ,与正常对照组差异无显著性。结论　大剂量阿司匹林有增加胰岛素敏感性和改善脂代谢紊乱的作用     

High‐Performance and Uniform 1 cm2 Polymer Solar Cells with D1‐A‐D2‐A‐Type Random Terpolymers

For the commercial development of organic photovoltaics (OPVs), laboratory‐scale OPV technology must be translated to large area modules. In particular, it is important to develop high‐efficiency polymers that can form thick (>100 nm) bulk heterojunction (BHJ) films over large areas with optimal morphologies for charge generation and transport. Here, D₁‐A‐D₂‐A random terpolymers composed of 2,2′‐bithiophene with various proportions of 5,6‐difluoro‐4,7‐bis(thiophen‐2‐yl)‐2,1,3‐benzothiadiazole and 5,6‐difluoro‐2,1,3‐benzothiadiazole (FBT) are synthesized. It is found that incorporating small proportions of FBT into the polymer not only conserves the high crystallinity and favorable face‐on orientation of the D‐A copolymer FBT‐Th4 but also improves the nanoscale phase separation of the BHJ film. Consequently, the random terpolymer PDT2fBT‐BT10 exhibits a much improved solar cell efficiency of 10.31% when compared to that of the copolymer FBT‐Th4 (8.62%). Moreover, due to this polymer's excellent processability and suppressed overaggregation, OPVs with 1 cm² active area based on 351 nm thick PDT2fBT‐BT10 BHJs exhibit high photovoltaic performance of 9.42%, whereas rapid efficiency decreases arise for FBT‐Th4‐based OPVs for film thicknesses above 300 nm. It is demonstrated that this random terpolymer can be used in large area and thick BHJ OPVs, and guidelines for developing polymers that are suitable for large‐scale printing technologies are presented.     

Shared ancestral polymorphisms and chromosomal rearrangements as potential drivers of local adaptation in a marine fish

Gene flow has tremendous importance for local adaptation, by influencing the fate of de novo mutations, maintaining standing genetic variation and driving adaptive introgression. Furthermore, structural variation as chromosomal rearrangements may facilitate adaptation despite high gene flow. However, our understanding of the evolutionary mechanisms impending or favouring local adaptation in the presence of gene flow is still limited to a restricted number of study systems. In this study, we examined how demographic history, shared ancestral polymorphism, and gene flow among glacial lineages contribute to local adaptation to sea conditions in a marine fish, the capelin (Mallotus villosus). We first assembled a 490‐Mbp draft genome of M. villosus to map our RAD sequence reads. Then, we used a large data set of genome‐wide single nucleotide polymorphisms (25,904 filtered SNPs) genotyped in 1,310 individuals collected from 31 spawning sites in the northwest Atlantic. We reconstructed the history of divergence among three glacial lineages and showed that they probably diverged from 3.8 to 1.8 million years ago and experienced secondary contacts. Within each lineage, our analyses provided evidence for large N_e and high gene flow among spawning sites. Within the Northwest Atlantic lineage, we detected a polymorphic chromosomal rearrangement leading to the occurrence of three haplogroups. Genotype–environment associations revealed molecular signatures of local adaptation to environmental conditions prevailing at spawning sites. Our study also suggests that both shared polymorphisms among lineages, resulting from standing genetic variation or introgression, and chromosomal rearrangements may contribute to local adaptation in the presence of high gene flow.     

The Combined Deletion of S6K1 and Akt2 Deteriorates Glycemic Control in a High-Fat Diet

Signaling downstream of mechanistic target of rapamycin complexes 1 and 2 (mTORC1 and mTORC2) controls specific and distinct aspects of insulin action and nutrient homeostasis in an interconnected and as yet unclear way. Mice lacking the mTORC1 substrate S6 kinase 1 (S6K1) maintain proper glycemic control with a high-fat diet. This phenotype is accompanied by insulin hypersensitivity, Akt- and AMP-activated kinase upregulation, and increased lipolysis in adipose tissue and skeletal muscle. Here, we show that, when S6K1 inactivation is combined with the deletion of the mTORC2 substrate Akt2, glucose homeostasis is compromised due to defects in both insulin action and β-cell function. After a high-fat diet, the S6K1(-/-) Akt2(-/-) double-mutant mice do not become obese, though they are severely hyperglycemic. Our data demonstrate that S6K1 is required for pancreatic β-cell growth and function during adaptation to insulin resistance states. Strikingly, the inactivation of two targets of mTOR and phosphatidylinositol 3-kinase signaling is sufficient to reproduce major hallmarks of type 2 diabetes.     

Comparative analysis of intermuscular bones in fish of different ploidies

We documented the number, morphology, and distribution of intermuscular bones in five fishes of different ploidy: Carassius auratus (Abbr.WCC, 2n=100), Carassius auratus variety PengZe (Abbr.PZCC, 3n=150), improved triploid crucian carp (Abbr.ITCC, 3n=150), improved red crucian carp (Carassius auratus red var., Abbr.IRCC, ♀, 2n=100), and improved allotetraploids (Abbr.G×AT, ♂, 4n=200). The number of intermuscular bones in WCC, PZCC, and G×AT ranged from 78 to 83 ( $\bar x$ =81), 80 to 86 ( $\bar x$ =84), and 77 to 84 ( $\bar x$ =82), respectively. The numbers in ITCC and IRCC were significantly lower, ranging from 77 to 82 ( $\bar x$ =79) and 58 to 77 ( $\bar x$ =71), respectively. The average number of intermuscular bones in each sarcomere, ranked in order from highest to lowest, was 0.721 (WCC), 0.673 (PZCC), 0.653 (G×AT), 0.633 (ITCC), and 0.608 (IRCC). There was no difference between ITCC and G×AT or between G×AT and PZCC. However, the average number of intermuscular bones in the sarcomeres of ITCC, WCC, and PZCC differed significantly, as did that of IRCC and the four other kinds of fish. The intermuscular bone of these five fishes was divided into seven shape categories, non-forked (卜), one-end-unequal-bi-fork (卜), one-end-equal-bi-fork (Y), one-end-multi-fork, two-end-bi-fork, two-end-multi-fork, and tree-branch types. Generally, the morphological complexity was higher in the anterior intermuscular bones than in the posterior body. The number of intermuscular bones was similar but not equal between the left and right sides of the body. ITCC had significantly fewer intermuscular bones than either WCC or PZCC, making it of greater commercial value. Additionally, IRCC and ITCC had fewer intermuscular bones than WCC. Our observations are significant in both fish bone developmental biology and genetic breeding.     

广西合浦儒艮国家级自然保护区及邻近水域鱼类种数及保护对策

2003年6月至2004年5月,通过底拖网作业收集鱼类标本对广西合浦儒艮国家级自然保护区及其邻近水域鱼类种数进行了调查,并走访当地鱼市进行实地调查.共记录到保护区及其邻近水域的鱼类14目41科57种,其中55种为硬骨鱼类,占总数的96.49%,另有2种软骨鱼类,占总数的3.51%.有41种为暖水性鱼类,占总数的71.93%.生态类型中底层鱼类共37种,占总数64.91%.区系特征以北太平洋和印度太平洋区系为主.掠夺性获取和开发以及环境污染是目前这一水域鱼类资源面临的最大威胁,针对以上威胁提出了相应的保护对策.     

鲍曼不动杆菌感染的呼吸机相关肺炎20例

目的 了解我院NICU内鲍曼氏不动杆菌感染呼吸机相关肺炎的情况,探讨有效预防和控制的该类感染的措施。方法 收集我院NICU内2006.1-2007.2之间发生呼吸相关肺炎病通过细菌培养确定为鲍曼氏不动杆菌感染的患儿的临床资料以及该菌的药敏试验结果进行分析。结果 鲍曼氏不动杆菌是呼吸机相关肺炎的主要致病菌之一,其流行情况复杂,并且出现了耐碳青酶烯类的菌株感染,可造成严重的不良后果。结论 预防该菌在NICU内导致感染需要引起临床工作者更多的重视,加强对其定植情况的监测是预防其感染和流行的重要措施,对该菌开展及分子流行病学的深入研究将有助于指导NICU内NI防治。     

Affinity purification and characterization of the Escherichia coli molecular chaperones

The molecular chaperones are a group of proteins that are effective in vitro and in vivo folding aids and show a well-documented affinity for proteins lacking tertiary structure. The molecular chaperones were induced from lon(-) Escherichia coli mutants, affinity purified with an immobilized beta-casein column, and assayed for refolding activity with thermally and chemically denatured carbonic anhydrase B (CAB). Chaperones were induced with three treatments: heat shock at 39 degrees C, heat shock 42 degrees C, and alcohol shock with 3% ethanol (v/v). Lysates were applied to an immobilized beta-casein (30 mg/g beads) column. After removing nonspecifically bound proteins with 1 M NaCl, the molecular chaperones were eluted with cold water or 1 mM Mg-ATP. The cold water and Mg-ATP eluates were analyzed by SDS-PAGE. Western analysis identified five E. coli molecular chaperones including DnaK, DnaJ, GrpE, GroEL, and GroES. The purity of eluted chaperones was 58% with cold water and 100% with Mg-ATP. Refolding denatured CAB in the presence of Mg-ATP resulted in a 97% recovery of heat-denatured CAB and a 68% recovery of chemically denatured CAB. The use of affinity matrices for the chaperone purification which are effective as in vitro folding aids will be presented.     

宁夏黄土丘陵区不同生态恢复生境地表甲虫多样性

为了解宁夏黄土丘陵区不同生境地表甲虫群落多样性变化规律及与环境因子的关系, 并探讨不同生态恢复措施对维持地表甲虫群落多样性的影响, 2013年7-8月, 作者利用陷阱法调查了该区6种生境内的地表甲虫群落多样性。结果表明: 灌草混交林地、乔灌混交林地、生态薪炭林地中地表甲虫物种丰富度和个体数量均较高, 天然封育草地、生态经济林地和水平农田中物种丰富度较低, 生态经济林地和水平农田中甲虫个体数量显著高于天然封育草地。不同生境间, 灌草混交林地、乔灌混交林地与生态薪炭林地之间、生态经济林地与水平农田之间甲虫群落组成相似性较高。多元回归分析表明, 草本层生物量、灌木层盖度及土壤含水量是影响甲虫物种丰富度的决定因素, 林冠层盖度和枯落物厚度是决定地表甲虫个体数量的重要因素。CCA分析表明, 枯落物盖度、枯落物厚度、林冠层盖度及草本层盖度是影响地表甲虫群落组成的重要环境因子。研究表明, 灌草混交林地为地表甲虫群落多样性维持较好的生境类型, 是宁夏黄土丘陵区典型生态恢复的最优模式。