酶辅助提取纯化芹菜总黄酮的工艺研究

目的:筛选纤维素酶辅助提取芹菜总黄酮的最优提取工艺。方法:采用单因素试验方法分别考察乙醇浓度、料液比、提取时间、提取次数以及酶用量、pH值、酶解时间、酶解温度对芹菜总黄酮提取率的影响,同时对以上因素分别进行L_9(3~4)正交试验,得到酶辅助提取芹菜总黄酮的最佳提取工艺。结果:最佳工艺条件是纤维素酶用量7.0%、pH值4.4、酶解温度45℃、酶解时间1 h、乙醇浓度60%、料液比1∶20、提取时间2 h、提取次数1次。在此工艺下,芹菜总黄酮的提取率为4.17%。结论:加入纤维素酶可以有效提高芹菜总黄酮的提取率。     

响应面法优化超声辅助提取佛手瓜总黄酮的工艺研究

本试验研究了超声辅助提取佛手瓜中总黄酮的工艺。在单因素试验基础上,考察乙醇浓度、超声温度、液料比和超声时间对佛手瓜总黄酮提取率的影响。根据Box-Benhnken中心组合试验设计原理,采用响应面法对佛手瓜总黄酮提取的关键参数进行了优化,建立了佛手瓜总黄酮提取率的数学模型。结果表明:4个因素对佛手瓜总黄酮提取率影响的大小顺序是超声温度超声时间液料比乙醇浓度。佛手瓜总黄酮的最佳提取工艺条件为:乙醇浓度69%、超声温度71℃、液料比25 m L/g、超声时间31 min,在此条件下总黄酮提取率为3.402%,与理论预测值相对误差为0.526%。与传统热水浸提法相比,提取率提高了12.69%。     

微波辅助提取茄子根中总黄酮工艺条件研究

以烘干茄子根为原料,以茄子根中总黄酮提取率为指标,利用微波辅助提取茄子根中总黄酮。选取乙醇浓度、微波时间、微波温度、微波功率、料液比为单因素试验,在单因素试验基础上,以正交试验设计方法优化提取工艺。结果表明,最佳工艺条件为:乙醇浓度为80%、微波时间为4min、微波温度为60℃、微波功率为300W、料液比1∶20(g/mL),在此最佳条件下,茄子根总黄酮的提取率达1.652%。     

响应面法优化紫苏叶总黄酮提取工艺

文章以紫苏叶为研究对象，采用响应面分析法优化紫苏叶总黄酮的提取工艺。通过醇提法对紫苏叶总黄酮进行提取，首先对提取时间、提取温度、乙醇浓度和料液比4个单因素条件进行研究，然后进行响应面试验设计，优化分析紫苏叶总黄酮的提取工艺。结果表明，此方法提取紫苏叶中总黄酮的最佳工艺为：提取时间4.5 h，乙醇浓度68%，提取温度65℃，料液比1:55(g/mL)，其理论提取率为7.48%，实际提取率为7.43%，提取温度、乙醇浓度、料液比、提取时间4个单因素对提取率的影响程度由大到小。验证试验结果表明，其结果与响应面分析预测的结果一致，该模型可靠，该研究为提高紫苏叶总黄酮提取率提供了参考。     

正交试验优选鸡血藤总黄酮提取工艺

为对鸡血藤总黄酮的提取工艺方法进行优化选择,以单因素考察为试验基础,选用四因素三水平的正交试验方案,对乙醇浓度、提取时间、提取温度、料液比四个因素对鸡血藤总黄酮提取率的影响进行了研究。结果表明:试验条件范围内鸡血藤总黄酮的最佳提取工艺为:乙醇提取液浓度60%、提取温度70℃、提取时间2.5 h、提取料液比1:20,此条件下鸡血藤总黄酮的提取率为34.90%。同时试验分析结果表明,四个影响因素中提取时间对提取率影响最大。综上,此提取工艺方法绿色、简单,可为鸡血藤在饲料添加剂中的应用提供参考。     

响应面法优化酸藤子叶总黄酮的超声提取工艺

为了利用响应面法优化酸藤子叶中总黄酮的超声提取工艺,以总黄酮提取率为评价指标,在单因素试验的基础上,根据Box-Behnken响应面分析法确定最佳工艺条件。结果表明:各因素对总黄酮提取率的影响大小依次为乙醇浓度液料比提取时间;提取酸藤子叶总黄酮的最佳工艺条件为乙醇浓度58%,液料比21∶1,提取时间40 min,根据此条件酸藤子叶总黄酮的提取率为1.009%。说明采用响应面法优化酸藤子叶总黄酮提取工艺切实可行。     

野菊花中总黄酮不同提取方法工艺研究

以野菊花为原料,在单因素实验基础上,分别采用超声波辅助和微波辅助提取野菊花中总黄酮,并对提取工艺进行优化。结果表明:超声波提取的最佳工艺条件为超声时间30 min、料液比1∶15、乙醇浓度50%、超声温度60℃。微波辅助提取的最佳工艺条件为:料液比1∶25、微波时间2 min、乙醇浓度70%、微波温度60℃。在最佳提取工艺条件下,超声波法的总黄酮提取率(8.984%)高于微波法的总黄酮提取率(8.482%)。     

刺槐种子中黄酮类化合物的提取工艺研究

以刺槐种子为原料,对黄酮类化合物提取工艺进行了研究,采用单因素试验对影响总黄酮提取率的主要因素进行了分析,利用正交试验优化了提取总黄酮的最佳工艺条件。研究表明,刺槐种子中提取黄酮类化合物的最佳工艺条件为:乙醇浓度45%,提取温度90℃,料液比1:40,回流2次,每次2h。在最佳条件下总黄酮的提取率为2.033%。     

正交试验法优化紫荆果总黄酮提取工艺的研究

为了筛选紫荆果总黄酮的最佳提取工艺,试验采用乙醇浸提法提取紫荆果中总黄酮,初步探究乙醇浓度、料液比、浸提温度、浸提时间这4个单因素对紫荆果中总黄酮提取率的影响,并设计L9(34)正交试验确定紫荆果中总黄酮提取的较佳试验条件。结果表明:在料液比为1.5∶60、浸提时间为2.5 h、浸提温度为80℃、乙醇浓度为75%的条件下,总黄酮提取率可高达2.910%。说明优化的提取工艺简单、易行、稳定,可作为开发紫荆果药材的依据。     

酶法提取蓖麻叶总黄酮工艺优化

以蓖麻叶为原料,利用酶法协同超声提取蓖麻叶总黄酮,通过正交试验设计优化提取工艺。考察酶的添加量、p H、酶解温度、料液比和酶解时间对总黄酮提取率的影响,在单因素试验基础上进行正交试验,结果显示,酶添加量0.5%、p H 4.5、酶解温度50℃和酶解时间80 min为最佳工艺条件,此时蓖麻叶中的总黄酮提取率为3.98%。     

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。     

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。     

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.