水牛脾切除术的研究     

陈东仁  丁明星 《华中农业大学学报》1993,12(1):53-55

近3年来成功地作了20例水牛的脾切除术,没有1例因手术而招致死亡。成功地探索出适合于水牛脾切除术的麻醉方法、切口部位和大小、手术操作方法。  相似文献   

A Novel Gelatinase from Marine Flocculibacter collagenilyticus SM1988: Characterization and Potential Application in Collagen Oligopeptide-Rich Hydrolysate Preparation     

Jian Li  Jun-Hui Cheng  Zhao-Jie Teng  Xia Zhang  Xiu-Lan Chen  Mei-Ling Sun  Jing-Ping Wang  Yu-Zhong Zhang  Jun-Mei Ding  Xin-Min Tian  Xi-Ying Zhang 《Marine drugs》2022,20(1)

Although the S8 family in the MEROPS database contains many peptidases, only a few S8 peptidases have been applied in the preparation of bioactive oligopeptides. Bovine bone collagen is a good source for preparing collagen oligopeptides, but has been so far rarely applied in collagen peptide preparation. Here, we characterized a novel S8 gelatinase, Aa2_1884, from marine bacterium Flocculibacter collagenilyticus SM1988^T, and evaluated its potential application in the preparation of collagen oligopeptides from bovine bone collagen. Aa2_1884 is a multimodular S8 peptidase with a distinct domain architecture from other reported peptidases. The recombinant Aa2_1884 over-expressed in Escherichia coli showed high activity toward gelatin and denatured collagens, but no activity toward natural collagens, indicating that Aa2_1884 is a gelatinase. To evaluate the potential of Aa2_1884 in the preparation of collagen oligopeptides from bovine bone collagen, three enzymatic hydrolysis parameters, hydrolysis temperature, hydrolysis time and enzyme-substrate ratio (E/S), were optimized by single factor experiments, and the optimal hydrolysis conditions were determined to be reaction at 60 ℃ for 3 h with an E/S of 400 U/g. Under these conditions, the hydrolysis efficiency of bovine bone collagen by Aa2_1884 reached 95.3%. The resultant hydrolysate contained 97.8% peptides, in which peptides with a molecular weight lower than 1000 Da and 500 Da accounted for 55.1% and 39.5%, respectively, indicating that the hydrolysate was rich in oligopeptides. These results indicate that Aa2_1884 likely has a promising potential application in the preparation of collagen oligopeptide-rich hydrolysate from bovine bone collagen, which may provide a feasible way for the high-value utilization of bovine bone collagen.  相似文献   

竹材采运机械发展探究     

费叶琦  刘英  陈甲伟  丁奉龙  王争光 《世界林业研究》2021,34(1):31-36

采伐、剔枝、打捆、转运及竹根处理作为竹产业链中采运环节的主要工序,直接影响着竹产业后端加工竹材的供应和竹产业的发展.文中对近年来这几道工序的竹工机械现状进行梳理,总结目前存在的主要问题及后续改进措施,并对未来竹工机械发展方向进行预测,以期为后续我国相关研究提供理论和技术参考.  相似文献   

第三次全国农作物种质资源调查与收集行动湖南茶树专项总结报告     

黄飞毅  段继华  康彦凯  雷雨  邓晶  陈宇宏  丁玎  罗意  刘振  李赛君 《茶叶通讯》2020,(1):32-36

2015年10月至2018年12月,项目组参与第三次全国农作物种质资源调查与收集行动,对湖南省茶树种质资源进行普查、调查和征集、收集,共普查、调查和征集、收集茶树种质资源165份,涉及45个农业县(市、区),范围为东经109.176821°~114.005865°、北纬24.943720°~29.819774°、海拔31.33~1469.00m,并对湖南茶树种质资源的保护和合理开发利用提出了建议。  相似文献   

Mitochondrial genes associated with pyrethroid resistance revealed by mitochondrial genome and transcriptome analyses in the malaria vector Anopheles sinensis (Diptera: Culicidae)     

Yi‐Ran Ding  Zhen‐Tian Yan  Feng‐Ling Si  Xu‐Dong Li  Qi‐Meng Mao  Sana Asghar  Bin Chen 《Pest management science》2020,76(2):769-778

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Application method affects pesticide efficiency and effectiveness in wheat fields     

Jinjing Xiao  Li Chen  Fan Pan  Yajing Deng  Chenchun Ding  Min Liao  Xianyan Su  Haiqun Cao 《Pest management science》2020,76(4):1256-1264

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Evolution of spatial structure patterns of city networks in the Yangtze River Economic Belt from the perspective of corporate pledge linkage     

Xingxing Jin  Guojian Hu  Hailong Ding  Shilin Ye  Yuqi Lu  Jinhuang Lin 《Growth and change》2020,51(2):833-851

The pledge of stock rights is a method for measuring the external horizontal connections of enterprises, which is more suitable to represent the city network compared with the vertical connections of enterprises. Meanwhile, it is greatly significant to express the relationships of regional spaces. The paper characterizes and explores the evolution of urban spatial structure with complex network research methods to enrich the relevant works on city networks in the Yangtze River Economic Belt from 2011 to 2017. The results are as follows: First, from 2011 to 2017, the pledge of stock rights among cities was enhanced significantly, and the trend of the city networks' characteristics become strengthened and more complicated. Second, cities in the Yangtze River Delta have relatively high connection values, however, cities in the western area are holding peripheral positions within the city network. Third, due to the advantages of economic agglomeration and radiation, the provincial capital have become the core nodes in the city network. Fourth, Shanghai, Hangzhou, and Nanjing have dominant positions within city networks in the Yangtze River Economic Belt. Particularly, Shanghai, as one of the leading financial centers in China, has a growing influence on other cities and gradually evolved into a regional growth pole city and the first core city.  相似文献   

尿素类型与灌溉管理对玉米节水保肥的影响     

傅敏  丁文超  胡恒宇  韦安培 《中国农学通报》2020,36(4):15-22

水分和氮素管理对提高作物产量具有重要作用。笔者研究尿素类型与灌溉管理对玉米节水保肥的影响以达到玉米高氮肥利用效率和高产田的生产目标。本研究在2016—2017年开展2年完全随机区组设计试验,讨论了尿素类型（普通尿素和控释尿素）及灌溉对玉米土壤和氮素利用的影响。每种尿素类型设置2种氮素水平,分别为75、150 kg N/hm ²,以不施氮肥为对照。水分设置2种灌溉水平,分别为全生育期不灌水和灌浆阶段灌水85 mm。结果表明：在灌溉与施氮水平相同下,0~40 cm土层应用控释尿素处理氮含量较高,但在更深的土壤层低于普通尿素处理;相对于不灌溉,灌溉增加了硝态氮的损失,但施用控释尿素的处理硝态氮损失低于施用普通尿素处理;灌溉条件下施用控释尿素可以提高玉米氮素吸收,并使更多的氮向籽粒中转移;与普通尿素相比,控释尿素提高了氮肥利用率,降低土壤对氮需求的依赖。控释尿素低氮的释放可以减少硝态氮在土壤中的存留时间而迅速被玉米吸收,从而降低硝态氮的损失风险,提高了土壤氮肥利用效率。综上,控释尿素与少量灌溉相结合适用于华北半湿润地区达到玉米高氮肥利用效率和高产田的生产目标。  相似文献   

4个国外接骨木属种质资源引种与生物学特性研究   总被引：1，自引：1，他引：0  

丁鑫  郭巍  沈希辉  程建明  孙萌 《中国农学通报》2020,36(16):73-78

为探讨4个接骨木品种在河南省郑州地区的引种表现及适应性,2015—2019年定期观测引种的‘金叶’、‘金羽’、‘花叶’、‘紫云’4个国外接骨木品种,采用层次分析法进行性状评价。研究结果表明,露地栽培中,引种的4个接骨木品种均可在郑州地区正常生长、开花、结果。4个接骨木品种均生长健壮,枝繁叶茂,花期较长,较耐低温。以观赏性、适应性、生长特性权重分配分别为0.4、0.3、0.3进行综合分析评价,综合分值表现为‘金叶’接骨木>‘花叶’接骨木>‘金羽’接骨木>‘紫云’接骨木。由此可见,4种接骨木均具有较高的观赏价值和适应性,可广泛用于郑州地区城市园林绿化和美化。  相似文献   

高效液相色谱法测定茶叶中的5种农药残留   总被引：1，自引：1，他引：0  

丁怡  李荣玉  刘世江  赵琪君 《中国农学通报》2020,36(29):132-138

建立高效液相色谱法检测茶叶样品中5种农药残留分析方法,以期为茶叶绿色生产提供技术理论支撑。样品经水浸泡后,用正己烷和丙酮混合液(V:V=5:1)振荡提取,乙酸乙酯萃取,经弗罗里硅土和活性炭层析柱净化后,高效液相色谱检测茶叶中5种农药（高效氯氟氰菊酯、氯氰菊酯、联苯菊酯、噻虫嗪和吡虫啉）残留量。结果表明：在0.1~10.0 mg/L范围内,5种农药的色谱峰面积与其浓度均呈良好的线性关系,相关系数均大于0.9994,在0.1、0.5、1 mg/L的添加水平下,5种农药在空白茶叶样品中的平均回收率均在85%~95%之间,相对标准偏差(RSD)在0.55%~2.5%之间。该方法符合农药残留分析实验要求,灵敏度高。  相似文献