基于中国和中东欧十六国贸易面板数据,运用双重差分模型分析中欧班列开行对中国-中东欧国家贸易及贸易结构(包括进出口结构和商品种类结构)产生的影响.结果表明:中欧班列的通行对中国-中东欧国家贸易总体上产生了显著的促进作用,但贸易效应主要体现在中国对中东欧国家的出口贸易上,对进口贸易的影响较弱;在商品种类结构方面,中欧班列有利于中国-中东欧制成品贸易,且对制成品出口贸易的影响更大,而对初级产品贸易影响相对较小;此外,中欧班列对机械产品贸易尤其出口贸易产生了显著的正效应.这说明,中欧班列的开通并没有改变现阶段中国-中东欧国家贸易的结构特征,而是进一步强化了现有结构特征.

结核病由结核分枝杆菌感染引起,是我国面临的重大传染病,严重危害人民健康.而近年来日益增长的耐药结核病疫情使我国结核病防控工作面临严峻挑战.对氨基水杨酸(PAS)是治疗耐多药结核病的重要药物,其机制是抑制结核分枝杆菌叶酸的合成.随着其广泛运用,目前部分临床菌株已形成对PAS的耐药性.结核分枝杆菌叶酸代谢通路相关基因fo1C、thyA和ribD突变导致对PAS耐药的分子机制已较为明确.此外,近期有研究揭示了一些新的PAS潜在作用靶标及耐药位点.本文综述了PAS作用机制及结核分枝杆菌对PAS耐药机制的研究进展,旨在为研究新的PAS耐药机制提供参考.

利用Landsat系列遥感影像对四川湿地进行遥感制图,通过GIS空间叠加分析获取2000-2015年间2期(2000-2010年和2010-2015年)湿地变化时空数据库,选取平均风速、降雨量、平均气温、平均日照时间、平均相对湿度、国内生产总值、人均国内生产总值、农业生产总值和人口数量9个自然和社会经济影响因子,采用典型相关分析(CCA)方法,对四川省湿地类型变化的驱动力进行研究.(1)从2000年到2015年,四川省湿地变化面积705374 hm2,沼泽和河流湿地是每期湿地面积变化的主体,库塘是变化最大的湿地类型,湖泊湿地最为稳定,主要的湿地变化类型是沼泽转化为非湿地、河流和非湿地转变为库塘.(2)平均气温、国内生产总值和人口数量分别解释湿地类型变化的16.6％、30.7％和2.1％,而降雨量和平均相对湿度仅能解释0.6％和0.3％,表明国内生产总值、平均气温和人口数量是四川省湿地类型变化的主要驱动因子.(3)四川不同湿地类型变化的驱动因子存在差异.具体表现为,随着国内生产总值的增加,沼泽湿地转化为非湿地的量减少,而且国内生产总值越高,非湿地和河流湿地转变为库塘的量越多;随着平均气温的增加,沼泽湿地转化为非湿地的面积增加.研究结果说明社会经济的快速发展对四川湿地面积的保护和增加起到了积极作用,但全球变暖仍然导致沼泽湿地在不断减少,因此在全球变化的背景下,加强对沼泽湿地的保护和恢复,对于稳定四川湿地资源具有重要的作用.

In typical forest community of Zuojia region,growth adaptability and spatial patterns of four common tree species was studied.The results show that Larix gmelini population is stable;Acer serrulatum and Quecus mongolica population is growing,however Fraxinus mandshurica has powerful growth property.In sample plot,Larix gmelini and Quecus mongolica population had a regular distribution,Acer serrulatum population had a random distribution,Fraxinus mandshurica population had a clumped distribution.

In order to establish the mature pigtail-tip fibroblast cell isolation system and to evaluate its susceptibility to classical swine fever virus(CSFV) was Shimen strain,2-day-old newborn Landrace pigs pigtail tip as the tissue material,and obtained primary fibroblasts of the pig tail-tip by organization digestion method,then used indirect immunofluorescence method to determine the fibroblasts susceptibility to the virus(105.2TCID50/mL) in a gradient dilution testing.Our results showed that organization digestion method can able to obtain pig tail tip fibroblast cells grow in good condition and it is proper susceptibility to CSFV Shimen strain with 10-3 fold dilution of virus stock solution.

The objective of this study is to construct a targeting vectors for knocking-out porcine MSTN gene and get MSTN knock-out porcine fetal fibroblast.Construction of targeting vector:puromycin gene was used as positive-selecting gene,diphtheria toxin gene A fragment was used as negative-selecting gene.Homologous arms were inserted into the two sides of puromycin gene,respectively.The homologous arms are 4 294 bp and 1 015 bp which can knock out partial intron2 and exon3 of myostatin.Targeting vector was introduced into the 37 d porcine fetal fibroblast by FugeneHD transfection methods,after transfection,selected with puromycin.PCR analysis of clones was done using the lysate of pig fetal fibroblast after transfection.The vector was successfully constructed,which can knock out partial intron2 and exon3 of myostatin.Forty eights resistance cell strains were obtained,two strains took place correct homologous recombination through PCR identification.

目的 讨论2型糖尿病肾病(DKD)与中心性肥胖的关系.方法 随机选取并回顾性分析自2012.02--2012.06于我院就诊的2型糖尿病患者85例.根据尿微量白蛋白排泄量分为A、B两组,A组45例糖尿病肾病患者,B组40例糖尿病非肾病患者.比较两组患者体重指数(BMI)、腰臀比(WHR)、血脂以及糖尿病肾病等相关指标.结果 两组患者各指标均存在明显统计学差异(P＜0.05),且B组各项指标均优于A组.结论 中心性肥胖与糖尿病肾病的发病和发展有密切联系.对肥胖的糖尿病患者进行早期干预,控制血糖、血脂水平,可以减低DKD的发病率,延缓2型糖尿病患者肾损害.

The birth of animals produced by somatic cell nuclear transfer（SCNT） is one of major breakthroughs in life sciences in recent decades.The SCNT technology has aroused wide concern.However,due to the low efficiency of mammalian clone and the abnormal development of cloned offspring,its development and application has been restricted greatly.Large offspring syndrome（LOS） is one of abnormal developments in the cloned animals,which leads to premature delivery,dystocia and easy to die.LOS is similar to the BO-Wei syndrome（BWS） in human.BWS is also known as Wlims＇ tumor（WT）,which performs for the giant tongue,swelling of visceral organ and other symptoms.It was found that the pathogenesis of BWS was associated with abnormal expression of WT1 gene.This review briefly describes the progress of somatic cell nuclear reprogramming and epigenetic regulation of cell reprogramming in past years.Also,it describes the relationship between the WT1 modification of histone acetylation and somatic cell reprogramming in order to provide the clue for further investigations.

Niemann-Pick C1 Like 1 NPC1L1 has recently become a research emphasis in hyperlipidemia.It has been identified as an essential protein in the intestinal cholesterol absorption and bile secretion.NPC1L1can maintain the whole body cholesterol homeostasis by regulating cholesterol biosynthesis and it is the target of ezetimibe.

<正>RNAi是由内源或人为转染进入细胞的小干扰双链RNA诱导产生的一种转录水平的基因沉默(TGS)或转录后水平的基因沉默(PTGS)现象。在随后线虫发育调控基因的研究中,人们又发现一种新的内源性小RNA分子——microRNA(miRNA),与siRNA大小相似,并且它们的产生和功能依赖于相似的细胞机制。

[Objective] The aim was to generate transgenic pig specifically expressing Cre recombinase controlled by PIWIL1 promoter and make basic contribution for research on piRNA and its related genes' function and mechanism.[Method] The promoter of pig PIWIL1 gene was amplified by PCR method.Replace the MHC promoter of pig specific Cre recombinase expression plasmid(pET28a-MHC-Cre-BGHpo1yA-FRT2neor) with PIWIL1 promoter and specific Cre recombinase plasmid(pPIWIL1-Cre) was obtained.Transfect the plasmid to mini-pig fetal fibroblast cells and screen for positive clones with drug and do nuclear transfer.[Result] Two transgenic pigs of specific expressing Cre recombinase controlled by PIWILI promoter were got.[Conclusion] We generate transgenic pigs that specifically express Cre recombinase successfully and make possible tools for piRNA and related gene function and mechanism research.

The primer of this study was designed according to Lp-PLAz mRNA sequence of procine published by NC- t3I. Take small pig lung cDNA as template for PCR,then link it to plRES2-EGFP eukaryotic expression vector with the promoter of EFla and identify the function of the compound. Afterwards, transfect it into fetus fibroblasts of small pig, selecting and evaluating with the resistant of G418, we successfully get 5 strains fiber cells of pig with gene Lp-PLAz. This study lays a foundation for the further construction of Lp-PLAz transgenic pig and provides a new i- dea for the research on Lp-PLAz function.

As an important source of adult stem cells,mesenchymal stem cells(MSC) had the ability to differentiate.And there was extensive application in medicine and muscle disease treatment.Both of MyoD and Myf6 were family members of myogenic factors,which controled the proliferation and differentiation of muscle cells.Mef2c was an important transcription factor,which could be used as a specific sign in the myocardial differentiation process.The combination of MyoD and Mef2c could induce a large numbers of muscle-specific target gene expression,thereby inducing the cells differentiated into myoblasts.In this study,MyoD,Myf6 and Mef2c lentiviral expression vector were constructed and successfully over-expressed in pMSC.Important myoblast factors,such as MyoG and CKM were increased in MyoD,Myf6 and Mef2c over-expressed pMSC.The results demonstrated that MyoD,Myf6 and Mef2c play an important role in the transition of MSC cells to myoblasts cells.

<正>目前,肝病是威胁我国人民健康的重大疾病之一,传统的治疗方法总体治疗效果不理想,而基因治疗为肝病治疗提供了新的手段。基因治疗的缺陷在于不能限制转录的基因在特定的组织中发挥作用,可能对其他正常组织起到很大的副作用,降低治疗效果。因此,采用肝脏特异性启动子是解决基因治疗特异性问题的关键。本研究根据NCBI上公布的Alb基因序列设计引物,

<正>目前位点特异性重组酶系统在基因打靶中获得广泛应用,是条件性基因打靶、诱导性基因打靶、时空特异性基因打靶策略的技术核心。该系统目前主包括Cre/LoxP系统,FLP/FRT系统,该系统可以使某个基因在特定的细胞类型、特定时间表达或被沉默,进而研究该基因的特定功能。本研究应用FLP/FRT重组酶系统将FLP基因连接到可以游离于染色体外的载体PCEP4上获

<正>MSTN基因是TGF-B超家族的一员,又被成为GDF-8,该基因通过调控肌卫星细胞的活化和自我更新来调控肌肉生长发育,该基因失活时表现出双肌症状。MSTN基因共含有3个外显子和2个内含子,外显子3序列及其编码的氨基酸变异程度小,MSTN基因表达产物的功能区主要由109个氨基酸组成,编码这一段氨基酸的核苷酸主要集中在外显子3上,其中9个半胱氨酸对该因

<正>提高动物胴体瘦肉率一直是动物遗传育种学家、动物繁殖学家和动物营养学家最关注的问题之一。肌肉生长抑制素(Myostatin,MSTN)是近年来发现的一种生长分化因子,主要在动物骨骼肌中表达,它对动物肌肉的发生和发育以及再生都有重要调控作用。该基因缺失会导致动物骨骼肌肌纤维数量增多或肌细胞肥大等现象并且引起肉用动物的"双肌"表型,从而提高产

Parthenogenetic oocyte activation is an effective method for studies of mechanisms of mammalian fertilization and development,and an important part for studies of nuclear transfer,microinjection fertilization techniques,parthenogenetic embryonic stem cell research as well.Effects of ethanol,SrCl2 and Ca-A23187 on parthenogenetic activation rate and diploid rate of mouse oocytes,either individually or in combination with the use of 6-DMAP were investigated in this study.Our results showed：activation rates of mouse oocytes treated with either single or joint activators presented significant differences（P0.05）.Activation rate of oocytes treated with SrCl2 was the highest（92%-94%）;blastocyst rates of oocytes treated with the SrCl2 alone or combination with 6-DMAP were significant differences（P0.05） between single group（18%） and that（53%） in joint group.3.There were significant differences（P0.05） of diploid rates between single group（21%） and joint group（77%） when oocytes were treated with Ca-A23187 or combined with 6-DMAP.Our results demonstrate：the SrCl2 has significant effects on parthenogenetical activation of mouse oocytes;the parthenogenetical blastocyst rates are significantly improved in the joint groups with 6-DMAP;the 6-DMAP can inhibit the extrusion of second polar body,and significantly increase diploid rate of parthenogenetic activation mouse oocytes.

Three-year-old plants of'Applo'were used to study the effect of low temperature on bud break and changes of endogenous hormones in bud of asparagus(Asparagus officinalis Linn).The results showed that asparagus plant showed rapid bud break and spear growth when it was incubated on Oct.30.But when it was incubated on Nov.14 or 29,bud break and spear harvest decreased.While when it was incubated on Dec.14 or later,the bud break had no difference with that incubated on Oct.30,but spear harvest increased.These results suggested that once asparagus plants underwent the period of dormancy induced by the chilling in winter,they needed sufficient chilling duration to restore the activity of bud break and spear growth.The experiment of different low temperature treatment revealed that 2 ℃ 30 d or 5 ℃ 45 d could sastify the chilling duration o'fApplo'.During natural or treated chilling period,the content of GA3,IAA and ZR in bud of asparagus was relatively stable,but the content of ABA increased during dormancy stage,and then decreased rapidly to a lower level.The changes of ABA content had close relationship with dormancy and dormancy-breaking of asparagus.

The V13KL is a kind of antimicrobial peptides through optimal design and artificial synthesis,which it is characteristic of stronger antimicrobial activity and weaker hemolytic activity.This study was conducted to examine expression of this peptide in COS-7 cells and detect the effect of this peptide on early development of mouse embryos.The eukaryotic expression vector pIRES2-EGFP-V13KL was constructed,and transfected into the COS-7 cells and injected into the pronucleus of the mouse embryos.The results showed that V13KL and EGFP could co-express in COS-7 cells,and the transfection efficiency is 75.8%.About 10% of the mouse embryos injected with the vector developed into blastula.This study may be the basis of large-scale application and the cultivation of transgenic animals in the future.