莫能菌素微生物检测法的比较研究

用微生物法测定莫能菌素并筛选出合适的工作菌,分别选用短小芽孢杆菌和枯草芽孢杆菌作为工作菌摸索条件、制备标准曲线、测定最低检测限。结果表明,采用枯草芽孢杆菌的最低检测限为1μg/ml,较短小芽孢杆菌的1.25μg/ml要低;枯草芽孢杆菌标准曲线的相关系数为0.9983,较短小芽孢杆菌的0.994要高,说明实验有良好的线形关系;五组工作曲线的变异系数分别为5.1%和1.7%,说明本方法重现性较好。因此,应提倡采用枯草芽孢来检测莫能菌素。     

微生物抑制法检测饲料中盐霉素含量的研究

从几种标准工作菌株中筛选出对盐霉素敏感的菌株,以敏感菌株为工作菌株测定饲料中盐霉素的含量。结果显示:枯草芽孢杆菌、藤黄微球菌对盐霉素不敏感,地衣芽孢杆菌、嗜热脂肪芽孢杆菌对盐霉素敏感。以嗜热脂肪芽孢杆菌敏感菌株为工作菌株测定饲料中盐霉素含量,最低检出浓度为0.25μg/ml,饲料中最低检出限为1.0mg/kg,标准曲线相关系数为0.99,回收率在60%～80%,均高于标准中规定的参数。试验结果表明:微生物抑制法检测饲料中盐霉素含量,灵敏度高,快速,简便。     

UPLC-MS／MS法同时测定鸡肉中的莫能菌素和盐霉素残留

建立了同时测定鸡肉中莫能菌素和盐霉素残留检测方法。在国内外已有研究的基础上,对样品前处理和仪器条件进行了改进,采用乙腈提取鸡肉中莫能菌素和盐霉素残留,石墨化碳黑SPE小柱对提取液进行净化,然后用Waters ACQUITY UPLCTMTQD超高效液相色谱-串联质谱仪测定。结果表明,莫能菌素和盐霉素的检测限为0.2μg/kg,最低定量限为0.5μg/kg。选取0.5、1.0、2.0μg/kg三个浓度进行空白添加回收率实验,回收率为71.9%~95.1%,批内变异系数和批间变异系数均小于15%,适合大量鸡肉样品中莫能菌素和盐霉素的残留检测。     

庆大霉素ELISA检测方法的建立与应用

本实验利用戊二醛法合成抗原,进行动物免疫,制备特异性强的单克隆抗体。建立了庆大霉素ELISA检测方法,方法灵敏度为0.1μg/L,半数抑制浓度IC50为0.295μg/kg,将建立的庆大霉素ELISA检测方法应用于肌肉组织的检测中,得到最低检测限为7.91μg/kg,样本添加回收率在70%～120%之间,变异系数小于15%,该方法的建立为庆大霉素的残留检测提供了可靠的分析检测手段。     

饲料中恩拉霉素的微生物学含量测定方法研究

研究并建立了微生物学法测定饲料中恩拉霉素含量的方法.饲料样品经酸性甲醇溶液提取,大孔吸附树脂层析柱吸附洗脱后,饲料中的恩拉霉素得到很好的分离纯化.本方法采用枯草芽孢杆菌为检验菌,饲料中恩拉霉素的最低定量限为0.5 mg/kg,标准曲线的线性范围为0.4～12.8 u/mL,相关系数R为0.999 1,回收率大于85%,RSD小于15%.该方法适用于饲料中恩拉霉素的检测.     

高效液相色谱-串联质谱法检测牛肌肉组织中加米霉素残留

建立一种测定牛肌肉组织中加米霉素残留的高效液相色谱-串联质谱方法。均质后的样品经0.1 mol/L磷酸二氢钾溶液提取,正己烷脱脂,HLB固相萃取柱净化,反相C 18色谱柱分离,采用多反应监测正离子模式测定。结果显示,该方法检测限为0.5μg/kg,定量限为2μg/kg;在2-400μg/kg范围内线性良好,相关系数r均大于0.999;平均回收率范围为91.6%-118.7%,批内变异系数在2.06%-11.06%之间（n=6）,批间变异系数在3.86%-7.98%之间（n=18）。该方法灵敏、准确、重复性好,适用于牛肌肉组织中加米霉素残留量的测定。     

蜂蜜中聚醚类抗生素的一次性快速检测方法研究

研究建立了高效液相色谱串联荧光检测器和二极管阵列紫外可见检测器,并配置柱后衍生系统,一次性快速测定蜂蜜样品中莫能菌素、盐霉素、甲基盐霉素和拉沙洛菌素药物残留。在各聚醚类抗生素浓度5~100(拉沙洛菌素:80)μg/mL范围内,检测峰面积和浓度呈良好线性关系。回收率试验:在空白蜂蜜中添加莫能菌素、盐霉素、甲基盐霉素和拉沙洛菌素浓度分别为5、20、60μg/mL时,总体平均回收率为73%~99%,变异系数为0.2%~1.52%。最低检测限为2.5μg/mL。方法简单、快速、准确。     

微生物检测法测定安来霉素发酵液生物效价

根据安来霉素对革兰阳性细菌能产生有效抑制的原理,采用微生物抑制法试验,做出抑菌圈直径对应安来霉素效价的标准曲线。试验以枯草芽孢杆菌为工作菌,用杯碟法测定安来霉素的效价。结果表明:标准曲线的工作范围为1700～1.33万μg/mL,安来霉素的最低检出限为21.47μg/mL,平均回收率均超过97.5%,并且检测时间仅需16h。该法能快速检测安来霉素效价且灵敏度高,操作简便,回收率高。     

高效液相色谱法检测鱼肉中甲砜霉素残留的研究

用高效液相色谱法检测鱼肉中甲砜霉素残留。采用乙酸乙脂超声波提取鱼肉中残留的甲砜霉素,紫外检测波长225nm,流动相为甲醇:水[60:40(V/V)],流速1.2ml/min,进样量10μl,用色谱柱分离后在高效液相色谱仪上进行检测。在以上色谱条件下,内标物氟苯尼考的均保留时间为1.970min;甲砜霉素的均保留时间为2.239min,在鱼肉中的最低检测限为0.05μg/g,标准曲线的线性范围为0.02～16μg/ml,线性相关系数为0.9998。甲砜霉素浓度为0.05、0.5、40μg/g时鱼肉回收药物的均回收率为92.08%～105.38%;批间变异系数分别为3.61%、2.33%、3.56%。结果表明,高效液相色谱法是一种快速、灵敏、可靠的检测鱼肉中甲砜霉素残留的分析方法。     

超高效液相色谱-串联质谱法测定水产品中群勃龙残留方法研究

建立了牛奶中苯并咪唑类药物及代谢物残留的超高效液相色谱-串联质谱检测方法。水产样品经乙酸乙酯提取,C18固相萃取柱净化,采用超高效液相色谱-串联质谱多反应监测模式检测,外标法定量。不同基质中,群勃龙在2-100 ng/mL的浓度范围内呈现良好的线性相关,相关系数为0.994以上;本方法对群勃龙群勃龙在鱼、虾、鳖、蟹类产品中的检测限为0.5μg/kg,定量限为1μg/kg;在贝类产品中的检测限为1μg/kg,定量限2μg/kg;不同水产品的基质中添加1-10μg/kg浓度范围内,其回收率为74.2%-119%,批内变异系数在1.0%-9.0%之间,批间变异系数在0.3%-8.5%之间。本方法分析速度快,灵敏度高,重现性好,各项技术指标均满足国内外相关法规要求,可用于水产品中群勃龙的残留检测。     

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。