共查询到17条相似文献,搜索用时 171 毫秒
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采用挤出滚圆法制备盐酸沃尼妙林微丸,将含不同比例丙烯酸树脂Ⅱ和Ⅲ及不同包衣增重的几种微丸进行体外释放度试验,选择合适的丙烯酸树脂Ⅱ和Ⅲ比例及包衣增重,同时对制剂的稳定性进行考察,以对自行研制的盐酸沃尼妙林质量进行初步评价.结果显示:丙烯酸树脂Ⅱ和丙烯酸树脂Ⅲ的比例为2∶1、包衣增重为15%时,包衣样品具有典型的肠溶特征,在模拟胃部环境中前2h累积释放量均小于标示量10%,进入肠道内45min的累积释放量大于70%,具有明显的定位释放功能.稳定性试验结果表明,在模拟市售包装的条件下,本品外观、含量等指标均保持稳定,说明微丸具有良好的稳定性、制备工艺可靠. 相似文献
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替米考星微丸肠溶包衣的处方筛选 总被引:2,自引:1,他引:1
采用挤出滚圆方法制备替米考星载药丸芯,以丙烯酸树脂Ⅱ和Ⅲ为材料利用离心造粒包衣设备对丸芯进行包衣。结果显示,所制备的替米考星肠溶微丸在pH=1盐酸溶液中2 h内累积释放度小于10%,用0.2 mol/L的磷酸钠溶液将溶出介质pH调至6.8,继续运转45 min后累积释放度达80%以上,符合《中国药典》对肠溶制剂的要求。 相似文献
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乳化凝聚法制备维生素B_1微胶囊工艺的研究 总被引:1,自引:0,他引:1
以维生素B1为研究对象,利用正交回归分析法探讨一种能有效降低水溶性营养素从饲料中溶出的微胶囊生产工艺,主要考察了相体积比(X1,20%~40%)、乳化剂Span80添加量(X2,0~10g/l)、芯材与壁材百分比(X3,25%~100%)以及分散剂添加量(X4,0~4g/l)4种工艺参数。不同工艺条件下制备的微胶囊产品性能指标为颗粒粒径(Y1)44.3~168.5μm、包埋率(Y2)4.3%~31.8%、溶失率(Y3)1.1%~43.6%。正交回归分析表明,最佳工艺参数X1、X2、X3分别为20%、6.74g/l、100%,在该工艺条件下所制备的微胶囊能显著降低维生素B1的溶失(P<0.05)。 相似文献
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综述了近年来国内外对草坪硝态氮淋溶问题的研究现状与进展,以及国内草坪施肥管理的研究现状,对有效的减少我国草坪硝酸盐淋失的途径和方法进行了探讨。影响草坪硝酸盐淋溶的因子主要包括:氮肥种类、施氮水平、施肥时间、灌溉、土壤状况等。减少硝态氮淋溶的合理途径有:合理确定施肥量;选择合适的氮肥种类和施肥方式,如使用缓释氮肥,碳/氮比高的有机肥;施用硝化抑制剂;合理的灌溉等。目前,国内有关草坪硝酸盐的研究与国外相比,还较为欠缺,研究适合我国草坪的长效氮肥,制定舍理、有效、安全的草坪施肥制度已成为研究发展的趋势。 相似文献
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小鼠动情周期与超排效果 总被引:1,自引:0,他引:1
通过对25只小鼠用两种阴道涂片方法进行动情周期的观察,筛选出最佳涂片方法观察到的具有明显动情周期变化的小鼠进行超数排卵。根据不同生理周期将小鼠分组,分别为发情期(第1组)、发情后期(第2组)及间情期(第3组),而13只未知周期的小鼠作为对照组,比较各组间超排效果。结果表明:(1)用方法2涂片效果最好,方法2较方法1各时期阴道上皮细胞变化明显,对小鼠正常的生理周期影响相对较小,可观察到小鼠正常动情周期的变化规律。(2)不同生理周期小鼠的超排效果,以间情期可用胚百分率和平均每只小鼠获得胚胎数极显著高于发情期、发情后期及未知周期。 相似文献
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氮磷耦合效应对新建果岭草坪硝态氮淋溶的影响 总被引:2,自引:2,他引:0
在北京地区采用二次饱和D最优设计,研究了氮磷耦合效应对新建果岭草坪硝态氮淋溶的影响。结果表明:淋溶水中硝酸盐质量浓度的关键因子是氮肥施用量,其次是施磷量。硝酸盐淋溶质量浓度关键取决于施氮量,但当年施氮量大于33 g/m2时,增加施磷量也能减少硝酸盐的淋溶。从环境保护的角度讲,在北京的气候条件下,新建果岭年纯氮施用量低于20 g/m2,月纯氮施用量控制在5.2 g/m2以内,不会发生硝酸盐淋溶污染水环境。 相似文献
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不同环境温度下沼液养分在土壤中的淋失模拟研究 总被引:4,自引:0,他引:4
沼液因其养分利用率高,被广泛应用于农业生产中,而环境温度可通过影响土壤的物理化学性质,影响沼液养分的淋溶损失。试验采用土柱模拟法,研究了不同环境温度对土壤沼液养分淋溶的影响,旨在揭示不同季节土壤养分淋溶可能存在的差异,为生产中合理施用沼液提供理论依据。土柱规格为内径7.5 cm、高20 cm的聚氯乙烯(PVC)管,按每公顷施入0,130和260 kg N,设置每土柱沼液灌溉总量为0,200和400 mL。按当地年平均降雨量的70%计算实际浇灌量为1500 mL,分5次每隔6 d模拟不同降雨次数进行浇灌。沼液浇灌前用清水补足不足部分并混匀。土柱放置于20和30℃的温室培养,每次淋溶后收集土壤淋溶液,测定其全氮、硝态氮、铵态氮、全钾、全磷、速效磷和电导率。结果表明,施用沼液后淋溶液中氮、磷、钾淋失量较清水对照显著增大,其中40 mL沼液水平下,全氮含量平均增加73%,全磷含量增加880%,全钾含量增加388%,且随着沼液用量的增加淋溶液中的养分浓度呈增加趋势。环境温度的提高增加了沼液养分在土壤中的淋溶损失,30℃时淋溶液中的硝态氮、全氮、全钾、全磷、速效磷含量及电导率整体高于20℃,其中全氮平均提高14.68%,全磷平均提高33.59%,全钾平均提高24.08%。整体而言,30℃下沼液养分较20℃时更易发生淋失。因此,在农业生产中,应适当减少夏季高温时的沼液施用次数,增加春秋季节施用次数,但沼液用量不要超过130 kg N/hm2,防止沼液养分大量流失,污染周边环境。 相似文献
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不同方法制备的中草药原液对抑菌试验的影响 总被引:3,自引:0,他引:3
用煎煮法、加水研磨法、乙醇浸提法制取大蒜、苦参、白头翁、蒲公英原液,以金黄色葡萄球菌和鼠伤寒沙门氏菌为试验菌株做抑菌试验。结果:加水研磨法制备的四种中草药原液都没有抑菌作用;大蒜原液以乙醇浸提法制备最好,与煎煮法相比,对金黄色葡萄球菌抑菌作用差异极显著(P<0.05),对鼠伤寒沙门氏菌抑菌作用差异极显著(P<0.01);苦参原液对金黄色葡萄球菌的抑制作用以乙醇浸提法制备最好,与煎煮法相比差异极显著(P<0.01),对鼠伤寒沙门氏菌的抑菌作用两者差异不显著(P>0.05);乙醇浸提法、煎煮法制备的白头翁及蒲公英原液对两种细菌的抑菌作用均差异不显著(P>0.05)。 相似文献
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Hiwasa M Kohno H Togari T Okabe K Fukui Y 《The Journal of reproduction and development》2009,55(1):50-54
The present study aimed to investigate the fertility of ewes artificially inseminated with three different methods using a synthetic semen extender, AndroMed. The three methods of artificial insemination (AI) were cervical AI with fresh-diluted or frozen-diluted semen at observed estrus, and an intrauterine AI with frozen-thawed semen. A total of 80 ewes were treated with a controlled internal drug release (CIDR) containing 0.3 g progesterone per device for 12 days. In Experiment 1 (26 Suffolk ewes), superovulation was induced with 20 mg follicle-stimulating hormone and 250 IU equine chorionic gonadotropin (eCG) two days and one day before CIDR removal, respectively, during the non-breeding season. In Experiment 2 (54 Suffolk and Suffolk crossbred ewes), an intramuscular injection of 500 IU eCG was administered one day before CIDR removal to synchronize estrus and ovulation during the breeding season. In Experiment 1, fresh-diluted or frozen-thawed semen was deposited into the cervical orifice after estrus detection, and an intrauterine AI with frozen-thawed semen was performed by laparoscopy at a fixed-time basis without estrus detection. Embryos were recovered by uterine flushing 6 days after AI, and the rates of recovered, fertilized (cleaved) ova and embryos at the morula or blastocyst stage were compared among the three AI methods. In Experiment 2, the pregnancy rates after the three AI methods were compared. In Experiment 1, the rates of recovered ova were not significantly different among the three AI methods (52.5-56.7%). The rate of fertilized ova (81.0%) by laparoscopic AI with frozen-thawed semen was significantly higher compared with cervical AI of fresh-diluted (25.5%) or frozen-thawed (3.5%) semen, but the rate of embryos at the morula or blastocyst stage (17.6%) was significantly lower than that of the cervical AI with fresh-diluted semen (69.2%). The rates of ewes yielding fertilized ova were not significantly different among the three groups (44.4, 11.1 and 62.5% for cervical AI with fresh-diluted and frozen-thawed semen and intrauterine AI with frozen-thawed semen). In Experiment 2, the pregnancy rate of ewes intrauterinally inseminated with frozen-thawed semen (72.2%) was significantly higher than those of ewes inseminated cervically with fresh-diluted (5.5%) or frozen-thawed (0.0%) semen. The present results showed that acceptable fertilization and pregnancy rates could be obtained by an intrauterine AI with frozen-thawed semen using a synthetic semen extender (AndroMed), but not sufficient by the cervical AI with either fresh or frozen semen. 相似文献