丝素蛋白作为药物载体的研究进展

丝素蛋白作为一种具有优良性能的天然高分子材料,在生物医学领域被深入研究。丝素蛋白材料形态易塑,生物相容性良好,生物降解性可控且降解产物无毒,因此是理想的药物载体。本文综述了丝素膜、丝素凝胶、丝素纳米纤维和丝素微球等不同类型的药物载体,并展望了其研究和应用前景。     

二型花柱植物红蓼的繁殖生物学研究

本研究发现了红蓼的异型花柱现象,红蓼野外居群存在长柱型花和短柱型花。研究表明长/短柱花型具有精确的交互式异位特征,其花大小,柱头形态,乳突大小,花粉粒数目、大小都表现出两型性(P<0.01)。与长柱型花相比,短柱型花较大,有短且排列紧密的柱头乳突细胞,花药产生较少且大的花粉。长/短柱型花花瓣长度无显著差异(P>0.01)。扫描电镜显示两型花的花粉均具有散孔,孔近似圆形,边缘形状不规则。野外调查发现蓟马、蚂蚁、食蚜蝇为主要访花者。人工授粉,红蓼长/短柱型花自交、型内异交以及型间异交花粉管均萌发,0.5 h花粉管已萌发至子房,只有部分花粉管能萌发至子房且沿花柱壁及子房壁生长,说明其受精方式为合点受精。长/短柱型花型内异交座果率分别为14.00%和13.33%,自交座果率分别为4.62%和2.86%,型间异交的座果率分别为43.33%和44.61%,表明红蓼长/短柱型花自交表现出一定的亲和性,但座果率低,仍以异交为主。     

西南喀斯特地区草地生态系统面临的问题及对策

本文系统阐述了西南喀斯特地区草地生态系统的重要性,并分析了西南喀斯特地区草地生态系统面临的问题,主要为水土流失、土壤贫瘠、土地石漠化、生物多样性减少以及人类不合理利用等,针对上述问题提出了增加栽培草地面积、提高公众环保意识、调整农村产业结构、保持水土、防治石漠化、建立完善的监测评价体系等一系列相应对策,以期为喀斯特地区草地生态系统健康、稳定、持续发展提供一定的科学依据。     

蒸汽爆破参数对菜籽粕中总硫苷脱毒效果的影响

本试验旨在研究蒸汽爆破参数(水料比、蒸汽压强、维压时间)对菜籽粕中总硫苷脱毒效果的影响,并用体外仿生法对脱毒菜籽粕的营养物质消化率进行评价。试验均采用单因素试验设计,分别筛选出最适的水料比、维压时间与蒸汽压强,每个试验处理设4个水平,每个水平3个重复。结果表明:蒸汽爆破处理对菜籽粕中总硫苷的脱毒效果明显,总硫苷脱毒率达73.71%~86.98%。以总硫苷脱毒率为筛选指标,按单因素试验设计,分别筛选出最适的水料比为25%,最适的维压时间为60 s,最适的蒸汽压强为2.0 MPa。以菜籽粕营养物质消化率筛选指标时发现,与未处理组相比,1.0、1.5 MPa(固定水料比为25%、维压时间为60 s)蒸汽压强对菜籽粕营养物质消化率无显著影响(P0.05),2.0 MPa蒸汽压强时可显著或极显著降低粗蛋白质、赖氨酸、精氨酸的消化率(P0.05或P0.01),提高蒸汽压强可极显著降低总硫苷、异硫氰酸酯的含量(P0.01)。综合考虑总硫苷脱毒率与营养物质消化率指标,当固定水料比为25%、维压时间为60 s时,适宜的蒸汽压强以不大于2.0 MPa为宜。     

滩羊土——草——畜系统中的微量元素及其意义

甘肃景泰滩羊典型产区草地土壤中含有Ｂｅ、Ｐｂ、Ｔｉ、Ｂａ、Ｍｎ、Ｇａ、Ｃｒ、Ｎｉ、Ｖ、Ｃｕ、Ｚｒ、Ｃｏ、Ｓｒ、Ｙ、Ｙｂ等１５种微量元素。草地混合牧草吸其中的１３种,其中Ｙｂ显著减少,缺少了Ｂｅ和Ｃｏ。羊毛中微量元素的种类和含量变化很大并且复杂。滩羊成年母羊毛中只含Ｐｂ、Ｔｉ、Ｍｎ、Ｃｕ等４种元素,而二毛期即１月龄羔羊毛中含有Ｂａ、Ｐｂ、Ｔｉ、Ｍｎ、Ｃｒ、Ｎｉ、Ｃｕ、Ｚｒ、Ａｇ、Ｚｎ、Ｓｒ、Ｍｏ和Ｙ     

SONOGRAPHY OF THE MUSCULOSKELETAL SYSTEM IN DOGS AND CATS

Sonography of the musculoskeletal system in dogs and cats was undertaken to evaluate the application of this imaging procedure in orthopedics. In most of the patients a 7,5 MHz linear transducer was used because of its flat application surface and its resolving power. The evaluation of bone by sonography is limited, but sonography can provide addition information regarding the bone surface and surrounding soft tissue. Ultrasound is valuable for assessing joint disease. Joint effusion, thickening of the joint capsule and cartilage defects can be identified sonographically. It is also possible to detect bone destruction. Instabilities are often identified with the help of a dynamic examination. Soft tissue abnormalities of the musculoskeletal system lend themselves to sonographic evaluation. Partial or complete muscles or tendon tears are able to be differentiated and the healing process can be monitored. Most of the diseases that are in the area of the biceps or the achilles tendon, such as dislocation of the tendon, old injuries with scarification, free dissecates in the tendonsheath, tendinitis and/or tendosynovitis can be differentiated by sonography. In addition, with clinical and laboratory findings, it is often possible to make a correct diagnosis with ultrasound in patients with abscesses, foreign bodies, hematomas, soft tissue tumors and lipomas.     

Comparison of production systems for efficient use of indigenous pig breeds in developing countries

Conserving pig genetic resources and improving their productivity is important to increase returns over investment in developing countries. The purebred, first‐cross, rotational cross and backcross matings representing production systems based on pig breeds indigenous to the country and exotic pig breeds were investigated. The number of pigs in the nucleus and commercial herds necessary to produce a defined quantity of pork was considered. The amount of heterosis between the indigenous and exotic breeds, superiority in meat production, and degree of inferiority in reproductive performance of the exotic breed compared with that of the indigenous breed were investigated. The number of breeding pigs in the whole system was in the following order: pure breeding (PB) > first‐cross (F1) > rotational cross (RC) > backcross (BC) systems. The number of breeding pigs in the nucleus herds of the RC and BC systems was smaller than that in the nucleus herds of the PB and F1 systems. The degree of inferiority in reproductive performance of the exotic breed compared with that of the indigenous breed affected the efficiency of the production system.     

深化草业经济体制改革实行草原有偿承包制度

实行草原有偿承包制度,是草业经济体制改革的重要突破。本文在总结草原有偿承包制度产生与发展过程的基础上,阐明草原有偿承包制度的基本内容,阐述了建立草原有偿承包制度之理论、法律、现实和实践根据及其在草地畜牧业经济建设中的重大意义。     

乙脑病毒PrME基因在杆状病毒表达系统中的表达

本试验将乙型脑炎病毒（ＪＥＶ）的ＰｒＭ／Ｅ基因的ＨｉｎｄⅢ－ＢｇｌⅡ片段（２．１ｋｂ）插入到杆状病毒载体ｐＡｃＵＷ３１的ＢａｍＨＩ位点,使外源基因置于多角体蛋白启动予下游,构建成转移载体ｐＡｃＵＷ３１ＪＥ,以Ｌｉｐｏｆｅｃｔｉｎ作为共转染试剂,将纯化的ｐＡｃＵＷ３１ＪＥ与Ｂｓｕ３６Ｉ线性化的杆状病毒ＡｃＭＮＰＶ．ＬａｃＺＤＮＡ共转染昆虫ｓｆ９经病毒蚀斑纯化技术和Ｘ－ｇａｌ与中性红双重染色技术,随机     

云南肉牛生产体系建设

本文根据云南省肉牛生产现状和特点,对云南省肉牛生产体系建设作了全面论述。