胰腺脂肪含量及分布与2型糖尿病发生的关系

目的:应用磁共振Dixon技术测量胰腺脂肪含量,观察胰腺脂肪含量及脂肪分布对2型糖尿病(T2DM)发生的影响,并探讨胰腺脂肪含量及其分布情况对T2DM发生的预测价值。方法:回顾性分析147例接受腹部MRI和T1加权Dixon成像检查的病人,分为T2DM组59例、风险组病人38例及对照组50例,获得胰头、胰体、胰尾脂肪分数,收集病人的年龄、性别、吸烟及饮酒史、空腹血糖(FPG)、总胆固醇(TC)、高密度脂蛋白(HDL-C)、三酰甘油(TG)、低密度脂蛋白(LDL-C)、肝功能、血清肌酐(Cr)、体质量指数(BMI),比较各组数值差异。同时按BMI水平分为BMI正常组46例、超重组79例及肥胖组22例,分析T2DM组、风险组及对照组的胰腺各部位脂肪分数的差异。并进一步做logistic回归分析,以确定胰腺脂肪分布对T2DM发生的影响。结果:T2DM组、风险组与对照组之间的年龄、吸烟及饮酒比例、BMI、ALT、AST、Cr、TC、TG、HDL-C、LDL-C差异均无统计学意义(P>0.05)。3组病人的胰腺头、体、尾部及平均脂肪分数差异均有统计学意义(P<0.05~P<0.01),T2DM组的腺头、体和平均脂肪分数均高于对照组(P<0.05~P<0.01),T2DM和风险组胰尾的脂肪分数均高于对照组(P<0.01)。在BMI正常组中,T2DM组的胰头、体、尾及平均脂肪分数均为高于对照组(P<0.05);超重组中,T2DM组胰尾和平均脂肪分数高于对照组(P<0.05);在肥胖组中,3组不同部位及平均脂肪分数差异均无统计学意义(P>0.05)。多因素logistic结果显示,胰腺尾部的脂肪分数高是T2DM的独立危险因素(OR=1.685,95%CI:1.174~2.419,P<0.01),胰头、胰体脂肪分数、BMI、TC、TG及LDL-C水平与T2DM间关联无统计学意义(P>0.05)。结论:胰腺脂肪含量增加与T2DM相关,而胰尾脂肪含量的增加也会增加T2DM的发生风险。

基于自适应t分布与动态权重的樽海鞘群算法

针对樽海鞘群算法寻优精度低、收敛速度慢和易陷入局部最优等缺点,提出一种基于自适应t分布与动态权重的樽海鞘群算法。首先,在领导者位置更新中引入蝴蝶优化算法中的全局搜索阶段公式,以此来增强全局探索能力;然后,在追随者位置更新中引入自适应动态权重因子来加强精英个体的引导作用,从而增强局部开发能力;最后,为了避免算法陷入局部最优,引入自适应t分布变异策略对最优个体进行变异。通过对12个基准测试函数进行求解,根据平均值、标准差、求解成功率、Wilcoxon检验和收敛曲线分析,表明所提出的算法要优于标准樽海鞘群算法,以及参与比较的其他改进樽海鞘群算法和其他群智能算法,说明了其在寻优精度和收敛速度方面都有显著提升,并且具备跳出局部最优的能力。通过将其应用在脱硝入口浓度最低点寻找上,验证了算法的有效性。

三种扇贝种间血液生理指标比较及热胁迫对栉孔扇贝血液生理指标的影响

为了比较3种扇贝血液中的K^(+)、Na^(+)、Ca^(2+)和Cl−浓度,血氧(pO_(2))和血二氧化碳(pCO_(2))气体分压及血液酸碱度(pH)的差异情况,实验利用血气分析仪对栉孔扇贝、虾夷扇贝和海湾扇贝的血液生理指标进行测定。结果显示,扇贝的血液生理指标呈现显著的物种差异,其中栉孔扇贝血液的K^(+)浓度[(15.74±1.47)mmol/L]、Na^(+)浓度[(388.07±11.38)mmol/L]、Cl^(−)浓度[(462.43±6.88)mmol/L]和pO_(2)[(140.13±15.35)mmHg]最高。此外,栉孔扇贝和虾夷扇贝的Ca2+浓度和pCO_(2)含量较高,而海湾扇贝的pH最高。对相同月龄不同大小栉孔扇贝血液指标进行比较,发现栉孔扇贝的血液pH值与其壳高呈正相关(r=0.611),而生理指标与壳高呈负相关。随着温度的升高,栉孔扇贝血液的Ca2+浓度显著增加,而pO_(2)显著下降,K^(+)、Na^(+)和Cl^(−)浓度先升高后恢复到初始水平,而pH和pCO_(2)保持相对稳定。研究结果为贝类血液生理研究提供参考,也为贝类生理状态的评估提供了一种新的思路与方法。

外泌体在眼科疾病中的研究进展

外泌体(exosome)是直径30 nm~150 nm的纳米级囊泡,由脂质双分子层、蛋白质和遗传物质组成。人体内几乎所有类型的细胞都能分泌外泌体。它们在细胞通信、免疫调节、炎症反应和新生血管形成中起着关键作用。目前,外泌体已在肿瘤、心血管及泌尿系统中得到广泛研究。近年来,外泌体在眼科疾病中的作用受到越来越多的关注。外泌体在角膜病变、年龄相关性黄斑病变、糖尿病视网膜病变、青光眼等常见眼科疾病的发生、发展中发挥重要作用。不同间充质干细胞来源的外泌体在眼科疾病中的治疗潜力是当下的热点。间充质干细胞来源的外泌体具有与间充质干细胞相似的抗炎、抗凋亡、神经保护和组织修复的作用,因此外泌体可能是多种眼科疾病无细胞疗法治疗研究的新方向。进一步了解外泌体的生物学特性以及外泌体在眼科疾病的最新研究进展,将为相关眼病的发生机制和防治策略提供参考依据。

双壳贝类积累转化麻痹性贝毒的研究进展

麻痹性贝毒(Paralytic shellfish toxins,PST)是一类分布广、危害大的海洋毒素。滤食性双壳贝类在摄食、消化产毒单胞藻和细菌等过程中积累代谢PST,并通过食物链进行传递,给人类生命健康和水产业带来不利影响。随着贝类基础生物学和养殖产业的发展,以及基因组学和毒素检测技术的不断进步,近年来,各国学者对贝类吸收、转运和代谢PST的规律有了更深入的认识,为养殖贝类食品安全风险防控提供了理论参考。为更全面了解贝类积累和利用PST的研究进展,本文从PST在双壳贝类中的分布、积累转化特征与分子机制等方面进行了综述。

仿刺参疣足数量SNP遗传力评估

随着测序技术的发展,基于单核苷酸多态性(SNP)分子标记的遗传力估计比传统法准确性更高,已被广泛应用于动植物育种中。本研究对不同地理仿刺参(Apostichopusjaponicus)群体的疣足数量进行重测序全基因组水平的SNP遗传力估计,结果显示,次等位基因频率(Minorallele frequency,MAF)>0.05时,在50K SNP基础上均匀抽样,不同SNP密度的仿刺参疣足数量SNP遗传力估计均值范围为(0.566±0.022)~(0.612±0.003);MAF>0.1时,SNP遗传力估计均值范围为(0.586±0.015)~(0.615±0.016),说明50K低密度SNP标记足够捕获数量性状基因座(QTL)大效应和小效应;同时,染色体水平SNP遗传力估计值显示,单个染色体对遗传力的贡献和其长度显著相关,暗示仿刺参疣足数量是一个复杂的数量性状,与该性状相关的基因效应位点散布在各染色体,并由多基因共同作用。本研究结果可为海参低密度SNP芯片的设计开发及海参遗传参数评估提供一定的理论依据。

AFLP analysis revealed differences in genetic diversity of four natural populations of Manila clam (Ruditapes philippinarum) in China

The amplified fragment length polymorphism （AFLP） technology was used to analyze the genetic diversities in four natural populations of Manila clam （ Ruditapes philippinarum）, distributed in four sea areas of China, i.e. , the Bohai Sea, the Huanghai Sea, the East China Sea and the South China Sea. Two hundred and sixty-four AFLP loci were analysed in 195 individuals and revealed high levels of genetic diversity. The percentage of polymorphic loci ranged from 92.13% to 96.06% and the Shannon＇ s information index was from 0.256 8 to 0. 275 6. By analyzing molecular variance （ AMOVA）, it was found that there were high levels of genetic differentiation between populations of Qingdao and the other three sea areas. Cluster analysis by Nei＇ s pairwise distances grouped specimens by geographical origin, except the population of Qingdao. A conclusion can be drawn that there are high genetic diversities in the four natural populations of Manila clam in China and some distinct differences existed among and between the four populations. The results also indicated that human cultivation activities will have great influence on the genetic structure of the population of Qingdao.

Development and Characterization of Microsatellite Markers for the Pacific Abalone (Haliotis discus) via EST Database Mining

The EST database of the Pacific abalone (Haliotis discus) was mined for developing microsatellite markers. A total of 1476 EST sequences were registered in GenBank when data mining was performed. Fifty sequences (approximately 3.4%) were found to contain one or more microsatellites. Based on the length and GC content of the flanking regions, cluster analysis and BLASTN, 13 microsatellite-containing ESTs were selected for PCR primer design. The results showed that 10 out of 13 primer pairs could amplify scorable PCR products and showed polymorphism. The number of alleles ranged from 2 to 13 and the values of Ho and He varied from 0.1222 to 0.8611 and 0.2449 to 0.9311, respectively. No significant linkage disequilibrium (LD) between any pairs of these loci was found, and 6 of 10 loci conformed to the Hardy-Weinberg equilibrium (HWE). These EST-SSRs are therefore potential tools for studies of intraspecies variation and hybrid identification.

An Efficient Procedure for Isolating Microsatellite DNAs from Sea Cucumber(Apostichopus japonicus)

The construction of enrichment library proves to be one of the efficient approaches for isolating microsatellites in this study. The genomic DNA of sea cucumber was digested with HaeIII and size-selected DNA fragments (250-700 bp) were ligated to an adaptor. Microsatellite-containing sequences were captured by using a combination of GA and CA probes, which were attached to a nylon membrane. The microsatellite enrichment library constructed in this study consisted of approximately 700 clones. Two hun-dred and thirty-two clones reacted positively after the library screening procedure. Of the 50 clones sequenced, all contained at least one microsatellite and one duplicate clone was found. Approximately 86% of the sequenced fragments permitted to design primers for sequence tagged microsatellite site (STMS).

Genetic diversity and specific markers in four scallop species, Patinopecten yessoensis, Argopecten irradians, Chlamys nobilis and C.farreri

The AFLP （amplified fragrnent length polymorphism）technique was used to analyse the genetic diversity in four scallop species, Patinopecten yessoensis, A rgopecten irradians, Chlamys nobilis and C. farreri. The genetic similarity indexes of these four species are 0.8415, 0.7863, 0.7190 and 0.6731, while Shannon diversity indexes are 43.52, 58.87, 80.16 and 92.83, respectively. As analyzed, the genetic diversities in two native species, i.e., C, farreri and C. nobilis, are higher than those in other two introduced species, A. irradians and P. yessoensis. The results also showed that C. nobilis and C, farreri shared the most common loci. The genetic distance indicated that C. nobilis and C. farreri are closely related. Moreover, out of 510 AFLP markers, 21 specific bands are found to distinguish the four species scallops and these markers may be applied to the specific germplasm characterization and molecular assistant classification in scallops.

基于视觉AI的公交客流感知关键技术

针对目前公交客流站台以及车厢内部感知不精准,导致公交服务供需不匹配的问题,研究面向车厢以及站台场景的客流实时感知与统计算法。在充分分析相关客流感知算法的理论基础上,提出基于视觉AI 的客流感知关键技术,通过半自动标注算法获取训练样本,构建深度学习客流感知模型,并对站台以及车厢内实际场景进行验证,模型精确度以及实时性满足实际应用要求,最后从乘客,监管,运营角度提出客流感知技术在公交领域的应用场景。对优化公共交通资源配置,提升乘客出行体验具有重要意义。

mRNA differential display on gene expression in settlement metamorphosis process of Ruditapes philippinarum larvae

The mRNA differential display (DDRT-PCR) technique was adopted to find out the genes related tosettlement metamorphosis development process of Ruditapes philippinarum larvae.In this study,we haveobtained three hundred and forty-six amplification bands in total from pediveliger larvae,veliger larvae,eye spot larvae and post-larvae.Sixty-five out of three hundred and forty-six bands are distinctly differen-tial display from band pattern,which can be put into four groups,standing for different expression char-acters.Sixteen differential display bands were cloned,sequenced and analyzed and nine different se-quences are obtained in the study.Three sequences have higher similarity to the cDNAs deposited indatabase and three are very similar to the rDNA of other species,considered as the rDNA of Ruditapesphilippinarum.The rest three sequences are found to be novel sequences after analyzed.Their accessionnumbers are AY916799,AY916798,and AY916797 respectively.We thought the novel sequences arepossibly relevant to the early embryo development of Ruditapes philippinarum larvae and can provide somefundamental understandings that are helpful for the improvement of scallop seed raising industry.

互联网平台封禁行为的发生机理和规制考量

互联网平台封禁行为虽然表现形式多样,但无不是平台经济领域经营者之间与流量获取、流量分发、流量变现相关的封锁或妨碍行为。互联网平台封禁行为可能是一种自卫手段或安保措施,因而具有一定的合理性。但这种行为与网络平台、信息产品互联互通的内在需求以及互联网行业高质量发展的战略追求存在冲突,因而又具有较大程度的不合理性。尽管我国《反垄断法》《反不正当竞争法》《电子商务法》《个人信息保护法》等法律法规皆具有规制互联网平台封禁行为的依据,但对其违法性评价不应一概而论,而应当区分不同平台类型、不同业务场景、特别是不同行为类别及损害机理,进而对封禁行为予以类型化的分析和个案式的处理。唯其如此,方能助力推动形成更加健康多元的平台互联互通生态。