中国国家粮食安全战略演进及前瞻

粮食安全始终是关系中国国民经济发展、社会稳定和国家安全的全局性战略问题。自新中国成立以来,通过多次粮食战略的调整,已经形成了相对完善的粮食安全保障体系。中国的粮食产量总体上呈现的是波动式增长的趋势,这种增长与中央粮食战略的调整均有一定关系。国家粮食战略经过了20世纪50年代的从互助组到统购统销、60年代的进口粮食缓解粮食危机、70和80年代的家庭联产承包责任制直至21世纪初期至今的从取消农业税到严防死守18亿亩耕地红线这样一个过程。中国粮食安全面临粮农种粮的相对收益较低的结构性矛盾,要解决这一矛盾,必须从国家层面加大投入资本和提高基础设施建设能力,大力推动农业科技创新,努力在提高粮食生产能力上挖掘新潜力,在优化农业结构上开辟新途径,在转变农业发展方式上寻求新突破,在促进农民增收上获得新成效。自2004年以来,中共中央、国务院"一号文件"多次聚焦"三农"问题,始终强调粮食安全的重要性,这凸显了国家在协调粮食政策运转过程中的重要作用及中共中央对粮食安全的高度重视。只有保住"安全口粮和放心粮",才能保证中国到21世纪中叶顺利达到中等发达国家水平。     

柔嫩艾美耳球虫DF-1细胞培养体系的建立及应用

为了建立柔嫩艾美耳球虫的鸡胚成纤维传代细胞(DF-1)培养体系,并应用于柔嫩艾美耳球虫子孢子的细胞入侵活力检测,将CFDA-SE标记的子孢子接入DF-1细胞,利用流式细胞仪测定子孢子的细胞入侵活力。比较了37℃和41℃培养温度下,子孢子对DF-1、MDBK、Vero、BHK、MDCK五种细胞的入侵活力。优化了在子孢子入侵活力检测时,DF-1细胞最佳培养条件。结果表明,柔嫩艾美耳球虫子孢子在DF-1细胞中可发育为第一代裂殖子。在不同培养温度下,子孢子对DF-1细胞的入侵活力均高于其他细胞。优化后的DF-1细胞培养体系的培养程序为:用含100mL/L胎牛血清的DMEM稀释DF-1细胞,以每孔1×105个细胞铺被24孔板,37℃、50mL/L CO2培养24h后,用含50mL/L胎牛血清的DMEM换液后,每孔接入3×105个子孢子,41℃、50mL/L CO2培养8～12h,收集细胞进行检测。     

猪PD-1分子及其配体的实时荧光定量RT-PCR检测方法的建立

根据猪程序性死亡因子PD-I及其配体PD-LI和PD-L2的基因序列,分别设计了特异性引物和TaqMan探针,以10倍系列稀释的重组质粒pMD-PD-1、pMD-PD-L1和pMD-PD-L2为标准品,对实时荧光定量PCR的条件进行优化,以建立定量检测这3个基因的方法.结果表明,建立的方法在1×10~2～1×10~8copies/μL模板范围内具有良好的线性关系(r~2>0.99),扩增效率均高于96%,可检测至少100 copies的阳性标准品.利用该方法对猪外周血单核细胞中这3个基因的表达情况进行了检测,结果也表明该方法具有良好的敏感性、特异性和重复性,可应用于临床样品的检测.     

重庆地区部分牛和猪外周血博尔纳病病毒自然感染的调查

采用荧光定量巢式实时逆转录聚合酶链反应检测了重庆地区牛和猪各50例外周血单核细胞中博尔纳痛病毒(Borna disease virus,BDV)p24基因片段,并对其进行BDV p40基因片段的检测以确保结果的可靠性.检出的阳性序列与GenBank中5个国家4个动物种属25例BDV p24基因序列进行比对,分析其核苷酸和氨基酸序列的同源性,重建基因系统发生树.结果显示,3例牛和2例猪血标本BDV p24检测呈阳性,阳性率分别为6.00%和4.00%;5例标本BDV p40片段检测均为阳性,其余标本均为阴性;BDVp24扩增产物序列与BDV标准病毒株He/80的同源性为100%,与H1766和Strain V相比,变异程度小,所编码的氨基酸序列亦无变化;从发生树可以看出,5例BDV p24片段序列汇聚德国-瑞士-奥地利-日本-重庆混合支系.提示,重庆地区牛和猪中可能存在BDV的自然感染,其流行株可能源于外来疫病病原的传入.     

三个柔嫩艾美球虫虫株线粒体cox 1基因部分序列的比较分析

为研究柔嫩艾美球虫不同毒力株的线粒体细胞色素c氧化酶第1亚基(cox1)基因与球虫种群之间的遗传关系,应用聚合酶链反应扩增柔嫩艾美球虫3个不同毒力株的cox1序列,并与GenBank上登录的鸡柔嫩艾美球虫、巨型艾美球虫、毒害艾美球虫和堆形艾美球虫虫株的相应序列进行比对分析.结果显示,每个虫株都获得659 bp的cox1部分有效序列(pcox1).柔嫩艾美球虫不同虫株的pcox1序列完全相同,但与其他种的艾美球虫相应的pcox1序列有不同程度的差异.表明柔嫩艾美球虫的cox1序列可作为艾美球虫不同种虫株之间遗传变异研究的标记.     

Determinants and Evaluation of Local Energy‐Efficiency Initiatives from the American Recovery and Reinvestment Act

This article examines variation in local‐level energy‐efficiency grants and corresponding initiatives from the American Reinvestment and Recovery Act (ARRA) in the United States. The analysis is based upon a hurdle model of counts of energy‐efficiency grants received by 348 local governments that received these grants from 2009 to 2013, as well as 348 matched local governments that did not receive such funds. City‐level characteristics including amount of federal financial support, per capita income, signaling of preferences for sustainability policies, manufacturing, and political influences are shown to be empirically important determinants of variation in local energy‐efficiency initiatives. The evidence suggests that all else held equal, the $21.8 billion in ARRA funds expended with the intent of increasing local energy‐efficiency programs and policies successfully led to this end.     

Prodrugs of New Psychoactive Substances (NPS): A New Challenge

The concept of a substance acting as a prodrug for an intended drug is not new and has been known and utilized with particular benefits within medicine for efficacy and patient safety. Prodrugs of psychoactive substances are also not particularly new but this has also extended to considerations of prodrugs of new psychoactive substances (NPS). The continuing evolution of NPS has been a constant forensic challenge. In some countries, this constant evolution has led to the introduction of various alternative methods of drug control. Whether for this reason or in the pursuit of user experimentation, prodrugs of NPS have been discussed, developed, and exploited, posing some distinct forensic challenges. This is especially the case within toxicological analysis of biological fluids and for some substances, also forensic chemical analysis, through inherent instability of the prodrug or metabolism in the body. Particular examples of NPS prodrugs include 1-propanoyl-LSD, 1-butanoyl-LSD, 1-acetyl-LSD, and 2C-B-AN. This is in addition to associated substances and medicines that may be used for an intended pharmacological effect. Various prodrugs for stimulant and hallucinogenic substances in particular have appeared in the literature and have been discussed within drug user forums and made available for purchase online. Presently, drug monitoring data from national and international systems indicate that prodrugs are not widely available or problematic. Nevertheless, it is important that there is sufficient awareness of the prodrug concept and potential impact and associated forensic implications, not just for chemical analysis but also for toxicological considerations when a substance has been used.