1-(2-吡啶偶氮)-2-萘酚分光光度法测饲料中的钒

基于pH为3.6的HAc-NaAc缓冲溶液中,钒与1-(2-吡啶偶氮)-2-萘酚(PAN)反应形成红色络合物,建立分光光度法测定饲料中钒的方法.配合物的最大吸收波长为570 nm,摩尔吸光系数为3.5万L/(mol·cm),钒的质量浓度在0～3.5 μg/mL符合比尔定律.将该法用于饲料中微量钒的测定,其加标回收率为102.5％～103.4％,相对标准偏差为2.6％～3.9％(n=5).效果令人满意.     

2,6-二甲苯胺噻嗪对大鼠血液中离子的影响

为探讨2,6-二甲苯胺噻嗪麻醉对大鼠机体的影响,本试验对30只wistar大鼠腹腔50mg/kg注射2,6-二甲苯胺噻嗪,检测单纯使用2,6-二甲苯胺噻嗪麻醉时,血液中钙离子、钾离子和钠离子的浓度变化.分别于麻醉前,麻醉诱导期、麻醉期、麻醉恢复期Ⅰ、麻醉恢复期Ⅱ断头取血,使用分光光度计测定离子的浓度变化.结果证明,2,6-二甲苯胺噻嗪麻醉对大鼠血液中离子的含量存在影响.     

固相萃取-高效液相色谱-二极管阵列检测器测定牛奶中土霉素、金霉素的残留量

土霉素、金霉素均属于四环素类药物，为广谱抗生素，对革兰氏阳性和阴性细菌、立克次氏体等均有抑制作用，在兽医临床上，这两种药物被广泛用于治疗奶牛乳房炎，因此极易残留于牛奶中，牛奶中残留的原型药物能与人体中的钙结合，导致人体钙流失，影响人体健康”。并且由于四环素类药物价格低廉，所以在畜禽饲养中被广泛用作饲料添加剂来预防动物疾病和提高饲料利用率，但食品动物中的药物残留会对消费者的健康造成危害，长期用药会产生耐药菌株。因此许多国家都对这两种药物实施例行监控，我国和欧盟规定牛奶中的四环素类药物总量不得超过100μg／l。笔者采用同相萃取、高效液相色谱法测定土霉素、金霉素残留量。     

2,3,7,8-四氯二苯并-对-二噁英对鱼类胚胎发育影响的研究进展

二噁英(dioxin)所以被称为"世纪之毒",因之是危害极大的环境激素,致畸、致癌和突变性强,可通过食物链富集进入鱼、人和其他动物体内,并在脂肪中积蓄,对机体健康构成严重威胁。其中尤以2,3,7,8-四氯二苯并-对-二噁英(2,3,7,8-tetrachlorodibenzo-p-dioxin,TCDD)的毒性最强,引起了全球的高度关注。文中着重综述TCDD对鱼类胚胎发育的影响、机理及目前预防TCDD对鱼类胚胎发育影响的研究进展,旨在更好地为研究TCDD对鱼类胚胎发育的影响、机理及预防措施提供参考。     

气相色谱法测定2-二乙氨基乙硫醇的含量

为建立2-二乙氨基乙硫醇含量检测的气相色谱法,采用氢火焰离子检测器,分流进样,分流比25∶1,设定程序升温,用面积归一化法进行计算。2-二乙氨基乙硫醇在浓度0.1~0.6 g/mL范围内与峰面积具有良好的线性关系,线性方程为Y=2.0×107 X-3.1×105,相关系数R2为0.9981,精密度测试中重复性的RSD为0.03%,中间精密度的RSD为0.30%。本方法简便、准确,重现性好,可用于2-二乙氨基乙硫醇的含量测定。     

二氢杨梅素-镍配合物的合成及其细胞毒性初探北大核心CSCD

本试验在合成二氢杨梅素-镍配合物(DMY-Ni)的基础上探讨其作为饲料添加剂的饲用安全性。以二氢杨梅素(DMY)和乙酸镍为原料,采用加热回流法合成DMY-Ni,通过紫外光谱、红外光谱对其进行表征。采用噻唑蓝(MTT)法,研究不同浓度(10、20、40、80和160μg/m L)、不同作用时间(12、24、36和48 h)下,DM Y与DM Y-Ni对小鼠正常肝实质细胞AM L12增殖的影响。结果显示:DM Y与镍离子配合后可生成DM Y-Ni。10、20和40μg/m L DM Y或DM Y-Ni分别作用AM L12细胞48 h后,AM L12细胞的存活率与空白对照组差异不显著(P>0.05);80μg/m L及以上浓度的DMY-Ni作用AML12细胞48 h后,AML12细胞的存活率显著低于空白对照组(P<0.01或P<0.001),160μg/m L的DMY作用AML12细胞48 h后,AM L12细胞的存活率显著低于空白对照组(P<0.01)。随DM Y或DM Y-Ni浓度的增加和作用时间的延长,AML12细胞的存活率逐渐降低。DMY与DMY-Ni对AML12细胞的半数抑制浓度(IC50)分别为285.10、222.84μg/m L。由此得出,DMY与DMY-Ni对AML12细胞都具有相对低毒性,且DMY-Ni对AML12细胞的毒性较DMY稍有增加。     

2,3,7,8-四氯二苯并-对-二噁英对鱼类生长的影响及投喂调控

二噁英(dioxin)可通过多种途径进入鱼、人和其他动物体,并在脂肪中积蓄,使机体畸形、突变和致癌等。其中2,3,7,8-四氯二苯并-对-二噁英(2,3,7,8-tetrachlorodibenzo-p-dioxin,TCDD)被称为"地球上毒性最强的物质"。文中主要综述TCDD对鱼类生长的影响及其机理,同时提出通过投喂无污染或抗污染毒害的饲料,积极地预防TCDD对鱼类生长的影响。旨在更好的研究TCDD对鱼类和其他水生生物的影响、机制与预防,控制TCDD对水环境的污染,保护鱼类和其他水生生物,生产健康、卫生和安全的渔业产品。     

两广二号小蚕对微量吡丙醚耐受性研究

吡丙醚是一种苯醚类农药，在防治果蔬害虫方面起到重要的作用，但在喷洒时常会发生漂移现象污染桑叶，进而对养蚕产生影响。本研究通过给两广二号小蚕（1～3龄）添食含不同浓度吡丙醚的桑叶，调查龄期经过、结茧率、死笼率、茧层率及丝质成绩等指标。结果表明，两广二号小蚕对不同浓度吡丙醚耐受性差异较大。与对照组相比，吡丙醚添食浓度为0.005 mg/kg时，小蚕蚕期延长1.67 d，吡丙醚添食浓度为0.010 mg/kg和0.015 mg/kg时，小蚕蚕期延长2 d，表明添食吡丙醚浓度和小蚕蚕期延长时间呈正相关关系，添食浓度越大，熟蚕时间推迟越长；处理组的病蚕率、上蔟率、结茧率、死笼率均与对照组无显著差异；处理组家蚕全茧量、茧层量显著高于对照组，吡丙醚浓度为0.005 mg/kg和0.010 mg/kg时表现为显著差异，浓度为0.015 mg/kg时表现为极显著差异；处理组中蚕的解舒光折、丝量和纤度三个指标显著高于对照组，丝质成绩中其他指标则与对照组无显著差异。结果可为进一步研究该农药使用的安全性提供参考。     

磺胺氯吡嗪钠-二甲氧苄啶混悬液对鸡的靶动物安全性试验

为评价磺胺氯吡嗪钠-二甲氧苄啶混悬液对靶动物鸡的安全性,选择40只15日龄健康黄羽肉鸡,随机分成4组,每组10只.各组分别以0 mg/L、推荐剂量(300 mg/L)、3倍推荐剂量(900 mg/L)、5倍推荐剂量(1 500 mg/L)的磺胺氯吡嗪钠-二甲氧苄啶溶液饮水给药,连用5d.试验期间观察临床表现和体重变化,试验结束后进行病理学检查,并测定血液学和血液相关生化指标的变化.结果表明,磺胺氯吡嗪钠-二甲氧苄啶溶液在鸡以3倍以下推荐剂量用药,连用5d是安全的,在炎热季节可适当降低混饮时药物的浓度.     

木聚糖酶和果胶酶对小麦-玉米-豆粕型日粮的体外酶解研究

该试验旨在通过透析袋体外酶解的方法,研究木聚糖酶和果胶酶对小麦-玉米-豆粕型日粮还原糖生成量、干物质和粗蛋白体外酶解效果的影响。试验采用单因子试验设计,木聚糖酶的添加浓度分别为10、30、50、70、90 U/g,果胶酶的添加浓度分别为3、6、9、12、15 U/g,每个添加水平分别设5个重复。试验结果表明:当木聚糖酶添加量为50、70、90 U/g时,还原糖生成量显著高于对照组和其它低剂量添加组(P0.05);果胶酶添加量为12 U/g时,还原糖生成量显著高于对照组和3 U/g添加组(P0.05);木聚糖酶添加浓度由10 U/g提高至90 U/g时,提高了还原糖生成量(线性和二次,P0.05)和粗蛋白质酶解率(线性和二次,P0.05);果胶酶添加浓度由3 U/g提高至15 U/g时,提高了还原糖生成量(二次,P0.05)。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。