首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   77篇
  免费   10篇
林业   1篇
  2篇
综合类   17篇
农作物   1篇
水产渔业   2篇
畜牧兽医   59篇
植物保护   5篇
  2020年   3篇
  2019年   1篇
  2018年   3篇
  2017年   2篇
  2016年   3篇
  2015年   2篇
  2014年   2篇
  2013年   3篇
  2012年   2篇
  2011年   3篇
  2010年   5篇
  2009年   3篇
  2008年   3篇
  2007年   6篇
  2006年   1篇
  2005年   3篇
  2002年   2篇
  2001年   4篇
  2000年   2篇
  1999年   2篇
  1998年   5篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1982年   1篇
  1979年   1篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1974年   5篇
  1959年   2篇
  1939年   1篇
  1909年   1篇
排序方式: 共有87条查询结果,搜索用时 15 毫秒
71.
72.
Secretion of gastric mucins plays an essential role in host protection, and modifications in mucus properties are characteristic of the protective immune responses to pathogens. This study describes the purification and characterisation of sheep gastric mucins, and identification of those proteins that co-purify with mucins, with the potential to modify mucus properties. Gastric mucus was collected and pooled from four abattoir sheep and separated by CsCl density gradient centrifugation. Proteomic analysis of the mucin-containing fraction indicated the presence of gastric mucin (Muc5ac) and several co-purifying proteins, including intelectin-2 (Itln2). Further experimentation indicated that a combination of denaturation and reduction was required to fully release Itln2 from gastric mucin. A putative correlation was found between mucin-bound intelectin concentration and rheological properties in further sheep gastric mucus samples. In conclusion, this study provides the first characterisation of sheep gastric mucins and their purification partners, revealing potentially important mucin-intelectin interactions.  相似文献   
73.
Translocation of Tasmanian devils (Sarcophilus harrisii) is a common strategy for recovery of the species as carried out by the Save the Tasmanian Devil Program. Dasyurids including the endangered Tasmanian devil are well known to asymptomatically harbour the zoonotic bacteria Salmonella enterica in their intestinal tracts. Testing for Salmonella is a routine component of pretranslocation health testing, so a statewide microbiological survey of captive and wild devils was implemented in order to understand prevalence and common Salmonella serotypes, and inform decision-making when positive cultures are identified. This preliminary study identified a significantly higher proportion of Salmonella isolations in wild compared with captive devils. Mississippi and Typhimurium were the most common serotypes, followed by Lexington, Bovismorbificans, Kottbus and Amsterdam. Given the common finding of Salmonella in wild devils and the range of serotypes involved, in addition to numerous isolations in domestic species and humans, it is unlikely that the release of small numbers of captive devils to the wild in Tasmania poses a significant risk to the destination ecosystem. Ongoing monitoring of devils is required as the stress of acclimatisation could predispose devils to clinical disease. Appropriate personal protective attire is pertinent to protect personnel handling animals from this zoonotic infection.  相似文献   
74.
This study was designed to investigate the impact of buserelin acetate (BA) or human chorionic gonadotropin (hCG) administration on the day of first artificial insemination (AI) on subsequent luteal profile (diameter of corpus luteum (CL) and plasma progesterone) and conception rate in Murrah buffalo. The present experiment was carried out at two locations in 117 buffalo that were oestrus‐synchronized using cloprostenol (500 μg) administered (i.m.) 11 days apart followed by AI during standing oestrus. Based on treatment (i.m.) at the time of AI, buffalo were randomly categorized (n = 39 in each group) into control (isotonic saline solution, 5 ml), dAI‐BA (buserelin acetate, 20 μg) and dAI‐hCG (hCG, 3000 IU) group. Out of these, 14 buffalo of each group were subjected to ovarian ultrasonography on the day of oestrus to monitor the preovulatory follicle and on days 5, 12, 16 and 21 post‐ovulation to monitor CL diameter. On the day of each sonography, jugular vein blood samples were collected for the estimation of progesterone concentrations. All the buffalo (n = 117) were confirmed for pregnancy on day 40 post‐ovulation. The conception rate was better (p < 0.05) in dAI‐BA (51.3%) and dAI‐hCG (66.7%) groups as compared to their control counterparts (30.8%). Furthermore, the buffalo of dAI‐hCG group had improved (p < 0.05) luteal profile, whereas the buffalo of dAI‐BA group failed (p > 0.05) to exhibit stimulatory impact of treatment on luteal profile when compared to control group. In brief, buserelin acetate or hCG treatment on the day of first AI leads to an increase in conception rate; however, an appreciable impact on post‐ovulation luteal profile was observed only in hCG‐treated Murrah buffalo.  相似文献   
75.
76.
Abstract

A production management and planning system has been developed for large‐scale hanging culture operations. The relational database was designed to provide a fast, reliable and versatile tool for managing large volumes of production data at a scallop aquaculture site. The application development process is described, starting with the set of management decisions to be supported by the software. Best practices used for data structure design included normalization and entity‐relationship diagramming. The process‐based design resulted in visually consistent and user‐friendly interfaces which minimize data entry errors. An integrated forecasting model, based on seasonal exponential smoothing, extrapolates stagewise mortalities and flows calculated from the database. Typical simulation results demonstrate how forecasts provide insight into the grow‐out dynamics for capacity planning, manpower planning, and dealing with seasonal fluctuations in the yields. The software generates daily production reports, weekly harvesting schedules and long‐range planning information.  相似文献   
77.
Plant fungal pathogens can have devastating effects on a wide range of crops, including cereals and fruit (such as wheat and grapes), causing losses in crop yield, which are costly to the agricultural economy and threaten food security. Azole antifungals are the treatment of choice; however, resistance has arisen against these compounds, which could lead to devastating consequences. Therefore, it is important to understand how these fungicides are used and how the resistance arises in order to tackle the problem fully. Here, we give an overview of the problem and discuss the mechanisms that mediate azole resistance in agriculture (point mutations in the CYP51 amino acid sequence, overexpression of the CYP51 enzyme and overexpression of genes encoding efflux pump proteins). © 2015 Society of Chemical Industry  相似文献   
78.
The aim of this study was to explore the feasibility of cryopreservation of inter‐subspecies cloned embryos in buffalo. In our experiment, river buffalo ear fibroblast nucleus was fused into swamp buffalo oocyte cytoplasm. The blastocyst formation rate for nuclear transfer of freshly thawed cells was not different from those of growing cells, confluent or serum‐starved cells. A total of 122 cloned blastocysts derived from cryopreserved fibroblasts were cryopreserved and thawed, 37 were survived, the cryosurvival rate was 30.3%. The survived blastocysts were transferred into 15 recipient buffalos. Five of the recipients established pregnancy, but four of them aborted on day 53, 59, 145 and 179 of gestation respectively. One cross‐bred buffalo (Murrah × Swamp buffalo (2n = 49) received three embryos delivered a 40.5 kg female calf by natural delivery on day 320 of gestation. Up to now (13‐month old), the cloned calf has been growing well with no abnormity observed. These results demonstrated that cryopreservation of inter‐subspecies cloned embryos is feasible to produce buffalo offspring.  相似文献   
79.
80.
We have discovered numerous borings of Trypanites penetrating skeletons and synsedimentary cemented limestones in archaeocyathid reefs of the Forteau formation in southern Labrador. These are, to date, the oldest known macroborings. The discovery of these structures extends the record of large endolithic organisms 100 million years from the Lower Ordovician to the Lower Cambrian. This immediately postdates the appearance of metazoans with hard parts and confirms that endoliths have played a role in reef formation since the early Cambrian.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号