曼陀罗毒性的研究进展

茄科植物曼陀罗是一种有毒杂草,全世界约16种。本文主要从曼陀罗的化学成分、致毒机理、毒性、生物活性生物碱成分的检测方法等方面综述了曼陀罗毒性的研究进展。     

进境粮谷中截获的检疫性杂草种子生活力测定

[目的]测定进境粮谷中截获的检疫性杂草种子的生活力,为研究进境检疫性杂草种子的灭活方法提供基础理论数据.[方法]采用四唑染色测定方法(TTC)测定.[结果]测定出进境粮谷中截获的7种检疫性杂草种子的生活力.其中豚革(Ambrosia artemisifolia L.)72.0%,三裂叶豚草(Ambrosia trifida L.)73.2%,法国野燕麦(Avena ludoviciana Dur)22.0%,刺蒺藜草(Cenchrus echinatus L.)89.0%,锯齿大戟(Euphorbia dentata Michx.)30.5%,假高粱(Sorghum halepense Pers.)美国产100.0%,阿根廷产81.0%,苍耳属(Xanthium spp.)53.0%.[结论]采用种子四唑染色方法测定杂草种子的生活力,不受种子休眠限制,不需摸索其萌发所需最适宜的温湿度条件,方法简便快捷,结果准确.     

基于ITS序列的DNA条形码技术鉴定罂粟科种子

采用基于ITS4/ITS5序列的DNA条形码分子生物学技术,结合形态学和地理分布信息,对满洲里口岸进境俄罗斯粮食中检出的2种未知种子进行检疫鉴定.结果表明,2种未知种子分别为红花疆罂粟[Roemeria refracta(Stev.)DC.]和长荚罂粟(Papaver dubium L.).本方法具有快速、简便、准确的...     

LC-MS测定鸡肉中的24种β-受体激动剂的研究

采用LCMS联用方法测定鸡肉中的24种β-受体激动剂,结果表明:24种β-受体激动剂在0.100~10.000μg/L范围内线性良好;方法检出限和方法定量限分别介于0.004~0.025μg/kg和0.014~0.082μg/kg。     

马鹿茸胶囊缓解体力疲劳作用的研究

目的:研究以马鹿茸、淫羊藿、黄精、枸杞为主要原料的保健食品的缓解体力疲劳作用。方法:将小鼠按体重随机分为0.15、0.30、0.90 g/kg.BW剂量组和对照组4个组,连续灌胃给予受试物30 d,根据《保健食品检验与评价技术规范》观察小鼠负重游泳时间,检测血清尿素、肝糖原、血乳酸含量。结果:在连续给予马鹿茸胶囊30 d后,0.90 g/kg.BW剂量组能明显延长小鼠的负重游泳时间,增加小鼠肝糖原储备量,降低小鼠运动后血清尿素水平,与对照组比较差异有显著性(P0.05)。结论:马鹿茸胶囊作为保健食品具有缓解体力疲劳功能。     

出口欧鳗中噁喹酸残留痕量检测新技术研究

以出口欧鳗样品为实验材料,探索了只需经样品均化,40%甲醇(含15mmol/L高氯酸和25mmol/L磷酸)提取溶液提取、离心、过滤,高效液相色谱-荧光检测器检测等步骤的噁喹酸残留快速检测方法.试验表明,该方法技术操作步骤少,检测限低,检测效率高,能满足输韩欧鳗产品噁喹酸残留限量低至1μg/kg的超痕量检测监控要求.方法的添加浓度为5μg/kg时,回收率55%～82%,检测限0.5μg/kg.     

辣木叶保护肝脏的功能研究

目的:研究辣木叶的保护动物肝脏的功能。方法:以辣木叶咀嚼片0.4、0.8、2.4 g·(kg·d)~(-1)3个剂量组给予小鼠31 d后,将各组动物隔夜禁食16 h,模型对照组及各剂量组灌胃一次给予CCl_4,空白对照组给玉米油。给CCl_4后24 h处死动物,取血清测定ALT、AST,并取肝脏进行病理组织学检查。结果:0 g·(kg·d)~(-1)组(模型对照)的ALT、AST酶活力高于0 g·(kg·d)~(-1)组(空白对照),0 g·(kg·d)~(-1)组(模型对照)的肝细胞水样变性及肝细胞坏死评分高于0 g·(kg·d)~(-1)组(空白对照),且差异有统计学意义(P 0.05),表明化学性肝损伤模型成立。2.4 g·(kg·d)~(-1)组的AST酶活力低于0 g·kg~(-1)·d~(-1)组(模型对照),0.4、0.8、2.4 g·(kg·d)~(-1)组的ALT酶活力低于0 g·(kg·d)~(-1)组(模型对照),差异均有统计学意义(P 0.05)。2.4 g·(kg·d)~(-1)组的肝细胞水样变性及肝细胞坏死评分低于0 g·(kg·d)~(-1)组(模型对照),差异均有统计学意义(P 0.05)。结论:在本实验条件下,辣木叶对小鼠化学性肝损伤具有辅助保护功能。     

出口工业产品企业分类管理合格评定电子化浅析

随着经济全球化进程的加快和改革开放的不断深化,我国外贸事业迅猛发展,出口企业多、货值大,但管理水平参差不齐,同时国际技术性贸易壁垒高筑,贸易摩擦时有发生。而原有检验监管模式过于关注微观的产品质量,使得检验检疫把关显得格外繁重,地处外贸大省的广东检验检疫局尤甚。目前,广东检验检疫局大概以占全国检验检疫系统1/8的人员,承担了超过全国1/3的检验检疫业务。因而,转变职能,创新检验检疫模式,提高通关效     

对化癌灵胶囊小鼠经口急性毒性试验的研究

本试验采用ICR小鼠对化癌灵胶囊进行小鼠经口一次给药急性毒性试验。给药后发现动物出现活动减少，嗜睡直至死亡，测定LD50为11.02g／kg体重，95％可信区间为10.09~12.23 g/kg体重。     

液相色谱-串联质谱法检测蜂王浆中7种糖皮质激素的残留

采用液相色谱-串联质谱在多反应监测模式下测定蜂王浆中7种糖皮质激素残留。试样中加入p H 5.2的乙酸铵缓冲盐溶液和β-葡萄糖醛酸甙酶/芳基硫酸酯酶,37℃恒温箱中放置16 h。甲醇超声提取,去除部分蛋白质,依次经HLB柱和氨基柱净化,液相色谱-串联质谱仪检测。该方法在0~80μg/kg范围内具有良好的线性关系。实验中添加水平为10、20和40μg/kg时,回收率范围为84.7%~100%;相对标准偏差小于9.9%;方法检出限(LOQ)均为10μg/kg。     

Consumer acceptance and physicochemical quality of osmodehydrated carambola (Averrhoa carambola L.) slices

Consumer acceptability and physicochemical properties of candied osmodehydrated (OD) carambola were evaluated in an effort to increase consumption of the fruit. Fresh carambola slices (Averrhoa carambola L.) were soaked in either 15% or 20% or 25% NaCl brine for 18 h, then in 40 °Brix sucrose for 18 h, followed by 60 °Brix sucrose for 18 h and dried at 55°C for 18 h. Slices soaked in 15% NaCl were most preferred by a focus group. Decreases in pH, total soluble solids (TSS) and increase in salinity were recorded in sucrose solutions after soaking carambola. During osmosis, carambola became less green and more orange‐yellow (P < 0.05). The pH of candied OD products varied between 3.62 and 4.16, salinity 16–28 ppt, TSS of 67–70 °Brix and 18.8–20.8% moisture. There were no differences (P > 0.05) in flavour or texture for products brined in 15% NaCl and soaked in either refined white sucrose (RS) solutions or brown unrefined sucrose (URS) syrups, but differences (P < 0.05) in appearance, colour and overall acceptability. Candied RS carambola had higher (P < 0.05) overall acceptability (6.2 – liked slightly to moderately) to products from URS (5.6 – neither liked nor disliked to liked slightly), which was also supported by paired preference testing. Flavour was most liked (P < 0.05) of all sensory attributes.     

试论单证一致原则在可转让信用证下的缺位及完善

信用证转让后必然出现信用证内容变动,判断单证是否一致则出现了两个标准,在第二受益人直接提交的单据和转让后信用证相符的情况下,开证行却有理由宣称单据和原信用证不符。这一问题的解决需要明确第二受益人和开证行之间的关系,并明确判断单证一致的标准是转让后的信用证。     

硅灰石灼减量测试中不确定度分量贡献矢量谱的相似度分析

本文建立了对矢量谱的相似度进行评估的数学模型,并用其对硅灰石灼减量测试的不确定度评估中不确定度分量贡献矢量谱进行相似度的分析,得到的结论与实际相符。     

提单危机的法律问题探讨

提单危机随着国际贸易的不断发展而产生,其中无单放货现象较为典型。从提单的法律属性、保函的作用等层面入手,对无单放货的对策进行探讨,以期有益于法律理论和司法实务。     

信用证欺诈的民事救济——兼评最高人民法院《关于审理信用证纠纷案件若干问题的规定》

在现代国际贸易中,信用证作为最重要的收付方式,被誉为"国际商业的生命线".欺诈是对这条生命线的致命打击,它不仅严重损害了当事人的合法权益,也直接影响了国际贸易的发展和金融机构的声誉.作为法律救济方式之一,信用证欺诈的民事救济具有不可或缺的作用,加快信用证欺诈民事救济制度的建设,乃当务之急.     

信用证遭拒付的处理与应对

在出口业务中采用信用证方式支付,有时出口企业会遇到信用证被拒付的情况.由于开证行拒付信用证的原因和意图不同,有些拒付可能是不正当的.受益人应掌握判断信用证拒付成立与否的依据和标准.当遇到信用证被拒付时,首先要正确分析和判断,在此基础上寻求妥善处理的办法.     

Managerial Incentives and Durable Goods Monopoly

In many cases durable goods monopolists who sell out output do not appear to act in the competitive fashion suggested by Coase (1972). This indicates the firm‘s owners mitigate their commitment problem with buyers in some manner. This paper shows that managerial incentives provide a natural mechanism for the owner to mitigate its commitment problem without explicitly contracting with buyers. Owners will optimally shift their managers from the singular goal of profit maximization by penalizing them for sales. Additionally, the paper demonstrates that the degree to which managerial incentives and compensation diverge from pure profit maximization is in large part a function of the durability or quality of the product.     

不同类型信用证软条款的识别及应对

信用证是国际贸易常用的支付方式,近年来信用证中软条款大量出现,有的给我出口公司造成很大危害。软条款信用证的出现,既有出口企业自身的原因,也有国外开证行及进口商的原因。本文结合一些实例,论述如何识别不同类型的信用证软条款及应对方法。     

Vertical Relationships in the Automotive Industry: Do They Matter?

In this note we examine how vertical relationships are related to the efficiency of the operations in the automotive production chain. We first provide an overview of the nature of supplier arrangements by comparing current practices in the countries Japan, US, and Germany. Current best practices show that vertical linkages in the automotive industry have shifted away from simple market transactions and now involve closer long-term interactions coupled however with subtle incentive elements. We outline the economic issues which are present in vertical relationships and include a brief account of differing theoretical perspectives. Then, we use a refined methodology to measure productivity at the industry level for the supplier industries automotive parts and metalworking and for the final assembly industry. It turns out that Japanese industries achieve the highest productivity level at the supplier and at the assembly level. We interpret the empirical results and relate the differences in vertical arrangemen s with the efficiency of both parts in the relation.     

浅析信用证欺诈及其防范

信用证欺诈具有多发性、隐蔽性和高智商性等诸多特点，在国际贸易中十分常见。在我国正式融入WTO后，外贸体制将彻底转为自营进出口登记制度，国际贸易将更为活跃，预防信用证欺诈的紧迫性也日益凸显。