兽药产品批准文号申报核发及管理有关问题探讨

兽药产品批准文号管理是我国控制兽药市场准入的前置性管理模式,本文就目前兽药产品批准文号申报、核发及管理中存在的一些问题进行了分析,对企业申报兽药产品批准文号时的注意事项进行了阐述。     

Effect of preparation conditions on protein secondary structure and biofilm formation of kafirin

Various extraction and drying conditions for the isolation of kafirin from dry-milled, whole grain sorghum have been investigated, with a view to optimizing extraction of the protein for commercial food coatings and packaging films. The addition of sodium hydroxide to an aqueous ethanol extractant increased the yield and solubility of kafirin. Subsequent heat drying at 40 degrees C was shown to cause the kafirin to aggregate as indicated by an increase in intermolecular beta-sheets. Extraction of the flour using ethanol (70%, w/w) with 0.5% (w/w) sodium metabisulfite and 0.35% (w/w) sodium hydroxide at 70 degrees C followed by freeze-drying of the protein was found to produce a yield of 54% kafirin with good film-forming properties. The kafirin films were assessed for their sensory properties, tensile strength, strain, and water vapor permeability. Fourier transform infrared spectroscopy was used to study the secondary structure of the extracted kafirins. The best films were made with kafirin containing a large proportion of nativelike alpha-helical structures with little intermolecular beta-sheet content as indicated by the Fourier transform infrared reflectance peak intensity ratios associated with these secondary structures. The principal factor affecting the secondary structure of the protein appeared to be the temperature at which the protein was dried. Heat drying resulted in a greater proportion of intermolecular beta-sheets. Any industrial-scale extraction must therefore minimize protein aggregation and maximize native alpha-helical structures to achieve optimal film quality.     

恩拉霉素的研究进展

概述了恩拉霉素的理化特性、药效学、毒理学和临床应用研究进展,展望了今后恩拉霉素的研究方向.     

部分国家和地区猪链球菌的耐药性及耐药机制研究进展

猪链球菌病作为一种具有重要公共卫生意义的疾病,其防治一直是人们关注的焦点。为了了解猪链球菌对于各种抗生素的耐药情况以及耐药机制的研究进展,作者查阅了相关资料,对部分国家和地区进行的相关研究进行综述,以期对耐药性和耐药机制的研究以及临床用药有所帮助。     

猪细小病毒基因组结构及检测技术研究进展

猪细小病毒是引起母猪繁殖障碍性疾病的主要病原体之一,对猪细小病毒的基因组、转录、编码的结构蛋白和非结构蛋白、转录的调控及血清学诊断、分子生物学检测技术方面的研究进展予以综述,以期对其进一步研究有参考价值。     

关于加强我国兽药监管体系建设的思考

《农产品质量安全法》的颁布和实施，标志着我国农产品质量安全监管工作进入新阶段，兽药作为保障动物性产品安全的农产品生产过程中的重要投入品，其监管工作尤其令人关注。作者曾在基层挂职从事兽药监管工作，对我国兽药监管体系建设，尤其是市县级兽药监管现状十分担忧。特撰文阐述了兽药及兽药监管工作的重要性，分析了目前我国兽药及监督管理体系现状、面临的任务及存在问题，指出了我国市县级兽药监管系统存在监管主体不明确、监管体系不健全、行政管理和执法能力较弱、经费保障机制不到位、队伍素质不高、宣传培训不够等问题，并对此提出了解决问题的建议与对策。各级农牧部门应借兽医管理体制改革的东风，加强监督管理体系建设，进一步加强兽药监督队伍建设，加大兽药监督工作的经费支持力度，切实加强兽药监督管理工作。[编者按]     

Alteration of kafirin and kafirin film structure by heating with microwave energy and tannin complexation

Heating with microwave energy and tannin complexation of kafirin both increase the tensile strength of cast kafirin bioplastic films. The effects of these treatments on the molecular structure of kafirin and of kafirin in the film were investigated. SDS-PAGE of heated wet kafirin showed an increase in kafirin oligomers. Disulfide groups increased in heated kafirin and in films made from the heated kafirin. Fourier transform infrared (FTIR) spectroscopy of heated kafirin and films made from the heated kafirin indicated an increase in beta-sheet conformation. In contrast, kafirin complexation with tannic acid (TA) and sorghum condensed tannin (SCT) resulted in a slight decrease in beta-sheet conformation in the kafirin and a larger decrease in the kafirin in the films. Raman spectroscopy showed that, with TA, there was a shift in peak from 1710 to 1728 cm(-1) for kafirin-tannic acid complexes, indicating kafirin and tannic acid interaction. The protein conformational changes presumably facilitated cross-linking between kafirin molecules and/or between kafirin and the tannins. Thus, although both heating with microwave energy and tannin complexation cause cross-linking of kafirin to increase film tensile strength, their effects on kafirin structure appear to be different.     

我国兽用转基因微生物产品的安全评价

转基因生物是指通过基因操作技术对遗传物质（DNA）进行重组、修饰,从而改变基因组构成的动物、植物、微生物。动物用转基因微生物产品主要是指经过人工修饰基因的疫苗、诊断试剂和饲料添加微生物。转基因技术打破了异种微生物之间天然杂交的屏障,实现了微生物间的基因转移,获得了新的生物学性状。基因重组技术为人类有效的利用微生物的遗传特性,     

Effect of Microwave Heating of Kafirin on the Functional Properties of Kafirin Films

To improve the functional properties of cast kafirin films, dry kafirin, extracted with an aqueous ethanol‐based solvent at 70°C, was microwave‐heated. No effect on film tensile properties was found. Two strategies were employed to improve the effect of microwaving: extraction of kafirin using an aqueous tert‐butanol‐based solvent at ambient temperature to minimize temperature‐induced denaturation and wetting the kafirin to increase its dielectric properties. Microwave heating this kafirin to 90 or 96°C and holding for 1–2 min more than doubled maximum tensile strength and Young's modulus, and decreased strain by about one‐third compared with films made from nonmicrowaved kafirin. Film water vapor permeability was reduced by at least one‐third. Digestibility of microwaved kafirin and films was also substantially decreased, and film biodegradability was slowed slightly. Microwave heating gave a film microstructure with fewer and smaller size pores. SDS‐PAGE showed microwave‐induced intermolecular cross‐linking of the kafirin monomers, which was possibly responsible for the modification of film properties. Microwave heating of kafirin can be used to modify kafirin film properties, but the kafirin must be microwaved wet and be as close as possible to its native state.