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   99篇
  免费   6篇
  3篇
综合类   15篇
农作物   1篇
水产渔业   1篇
畜牧兽医   84篇
园艺   1篇
  2023年   1篇
  2019年   3篇
  2018年   2篇
  2017年   2篇
  2016年   3篇
  2015年   2篇
  2014年   2篇
  2013年   6篇
  2012年   3篇
  2011年   1篇
  2010年   5篇
  2009年   7篇
  2008年   2篇
  2007年   2篇
  2006年   6篇
  2005年   6篇
  2004年   1篇
  2003年   5篇
  2002年   1篇
  2001年   3篇
  1999年   2篇
  1998年   8篇
  1997年   4篇
  1996年   10篇
  1995年   3篇
  1994年   2篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1990年   2篇
  1988年   6篇
  1985年   1篇
排序方式: 共有105条查询结果,搜索用时 62 毫秒
61.
Incubation of dog spermatozoa in a medium without glucose and in the presence of lactate and pyruvate (l-CCM) for 4 h at 38.5 degrees C in a 5% CO(2) atmosphere induced in vitro capacitation of these cells. This was verified after the combined specific capacitation-like changes in percentages of viability and altered acrosomes, motility characteristics, sperm location of reactivity against Pisum sativum, Arachis hypogaea and Helix pomatia lectins and the tyrosine phosphorylation pattern. Furthermore, a feasible acrosome reaction (AR) was induced when spermatozoa incubated in l-CCM for 4 h were further co-incubated for 1 h with canine oocytes. This was demonstrated by AR-like changes in percentages of viability, altered acrosomes, motility characteristics and sperm location of reactivity against P. sativum, A. hypogaea and H. pomatia lectins. All these results clearly indicate that in vitro capacitation, and subsequent AR, can be feasibly achieved without the presence of sugars. This ability can be related to the specific characteristics of energy-metabolism regulation reported in dog spermatozoa.  相似文献   
62.
VCARS, the Veterinary Computerized Anesthetic Record System, has been developed to capture pre-, peri- and post-anesthetic data using Tablet PCs, 802.11b wireless networks, and a web-based database. Patient demographics, anticipated procedures and anesthetist, service information and hematologic and chemistry values are imported from the Veterinary Medical Teaching Hospital patient information system. Using a wireless Tablet PC, pre-anesthetic examination findings are recorded and an anesthetic plan including anesthetic drugs and anesthetic and monitoring equipment is developed. During induction and maintenance of anesthesia, physiologic variables, drug, fluid, anesthetic gas and oxygen administration, laboratory values, patient location, and important events can be charted with the simplicity of a paper anesthetic record. This information can be manipulated for display in a variety of ways depending on the specific needs of the case. Tools for calculating optimal fluid rates and drug dosages are incorporated into the design. The anesthetic records from multiple cases can be viewed simultaneously using a centrally-located monitor. Detailed audit trails ensure data integrity. A high-end search engine will allow rapid and complete retrieval of patient and anesthetic information. Macromedia flash is used to allow temporary disconnection from the wireless network without losing the ability to view, add, or edit data. The initial stages of software development are nearing completion, a wireless network is in place and hardware is being purchased. A pilot study will be conducted using manual entry of physiologic data prior to integration of automatically captured patient physiological variables. It is anticipated that this system will drastically improve the accuracy of data collection and retrieval and will provide important information about anesthetic management allowing improvement in overall patient care.  相似文献   
63.
64.
In order to determine the injure produced in boar spermatozoa through cryopreservation process, we analyzed the expression of the hexose transporters Glut‐3 and Glut‐5 and the zona pellucida binding protein As‐A (P68) in three different steps of the freezing‐thawed protocol: at 17°C (fresh BTS‐diluted semen, 1 : 2 v/v, step 1), at 5°C (after glycerol addition; step 2), and post‐thawing (step 3). All sperm analyses were carried out with immunogold techniques under electronic microscopy. For this study eight healthy post‐pubertal Iberian boars were submitted to a collection of twice per week through 3 months, evaluating two ejaculates from each boar. Glut‐3 maintains the expression in the acrosome region post‐thawing but not along the tail where is reduced. The expression of Glut‐5 and As‐A is majority located at the post‐acrosome region of the spermatozoa at step 1, but in step 2 and step 3 this expression is relocated to sperm tail area. In conclusion, while cryopreservation affects the localization and the expression of Glut‐3 and Glut‐5, its fertilizing capacity is not significantly reduced. The stabilization of boar semen at 5°C was found to be the most crucial step for sperm survival.  相似文献   
65.
Anthelmintic resistance (AR) is a well-recognized challenge in farmed ruminants. The use of anthelmintics in combination is one of the strategies recommended to slow the rate of AR development. Two studies were undertaken in 2017 and 2019 to assess the efficacy of single-dose macrocyclic lactone (ML) anthelmintic and ML combination drenches. In total, 11 Faecal Egg Count Reduction Trials (FECRTs) were set up in 10 different beef herds, with results available from 10 of those FECRTs (9 herds). AR to a single ML anthelmintic was detected in all 9 herds, with resistance to Cooperia and Haemonchus spp on 9 farms, and resistance to Ostertagia and Trichostrongylus spp on 2 farms. In contrast, for the ML combination anthelmintics, all FECRTs resulted in efficacies of 99%–100%. The results suggest that cattle producers should strongly consider using combination drenches in their herds in preference to single actives.  相似文献   
66.
Repeated seismic surveys of the Landers, California, fault zone that ruptured in the magnitude (M) 7.5 earthquake of 1992 reveal an increase in seismic velocity with time. P, S, and fault zone trapped waves were excited by near-surface explosions in two locations in 1994 and 1996, and were recorded on two linear, three-component seismic arrays deployed across the Johnson Valley fault trace. The travel times of P and S waves for identical shot-receiver pairs decreased by 0.5 to 1.5 percent from 1994 to 1996, with the larger changes at stations located within the fault zone. These observations indicate that the shallow Johnson Valley fault is strengthening after the main shock, most likely because of closure of cracks that were opened by the 1992 earthquake. The increase in velocity is consistent with the prevalence of dry over wet cracks and with a reduction in the apparent crack density near the fault zone by approximately 1.0 percent from 1994 to 1996.  相似文献   
67.
浒苔和龙须菜营养成分的研究   总被引:2,自引:0,他引:2  
利用常规方法对龙须菜和浒苔的基本营养成分进行测定,并利用 GC、HPLC和GC-MS对2种藻类的脂肪酸、氨基酸和呈味物质做了具体分析.研究结果表明,龙须菜和浒苔中蛋白质含量分别为18.78%和14.26%;粗脂肪含量分别为0.68%和1.28%;纤维素含量分别为4.97%和3.94%;总糖含量分别为11.58%和12.13%.必需氨基酸含量分别占氨基酸总量34.78%、37.36%;不饱和脂肪酸总量分别占脂肪酸总含量的38.31%、55.84%;呈味物质中烷烃在龙须菜粉中含量高达44.25%,在浒苔粉中烯烃含量为51.22%.龙须菜和浒苔可作为人类和动物的理想食源.  相似文献   
68.
OBJECTIVE: To determine the efficacy of doxorubicin when used alone in inducing remission in cats with lymphosarcoma. DESIGN: Prospective multi-institutional study of naturally occurring disease. METHODS: Cases were accrued from veterinary institutions in Australia and New Zealand after obtaining consent from informed owners. Cats were treated with doxorubicin every 3 weeks for three treatments. If there was no response to the first dose of doxorubicin or if the cat relapsed during the doxorubicin regimen, the cat was withdrawn from the trial and either euthanased or treated with other agents. Age, breed, gender and anatomic site of the lymphosarcoma (multicentric, alimentary, mediastinal, extranodal) were recorded for each cat. Clinical remission was assessed before each treatment by physical examination, radiography, ultrasonography and computed tomography where appropriate. Complete remission was defined as the disappearance of all clinical signs and clinically detectable tumour. RESULTS: Twenty-one cases were accrued over a 2-year-period but only 19 were available for data analysis. Young Siamese cats were over-represented and all cats with mediastinal tumours were young Siamese. There was a significant difference between the mean ages of cats with mediastinal or multicentric lymphosarcoma (mean +/- SD: 3.5 +/- 3.0 and 4.3 +/- 2.6 years, respectively) and cats with alimentary or extranodal LSA (11.4 +/- 0.9 and 11.0 +/- 0.9 years, respectively). Of 19 cats treated with doxorubicin alone, 6 (32%) had complete remission, 6 (32%) had partial remission and 7 (36%) did not respond. CONCLUSIONS: The results suggest that doxorubicin cannot be recommended as a single agent for treatment of feline lymphosarcoma because of the rather poor remission rate achieved.  相似文献   
69.
Clinical isolates (n = 63) of Pseudomonas aeruginosa obtained from various sites in 63 horses were compared using ERIC2 RAPD PCR to determine their genetic relatedness. Resulting banding patterns (n = 24 genotypes) showed a high degree of genetic heterogeneity amongst all isolates examined, indicating a relative non-clonal relationship between isolates from these patients, employing this genotyping technique. This study characterised 63 clinical isolates into 24 distinct genotypes, with the largest cluster (genotype E) accounting for 10/63 (15.9%) of the isolates. ERIC2 RAPD PCR proved to be a highly discriminatory molecular typing tool of P. aeruginosa in isolates recovered from horses. With the adoption of several controls to aid reproducibility, this technique may be useful as an alternative to PFGE, particularly in epidemiological investigations of outbreaks where speed may be a significant parameter. This is the first report of clonal heterogeneity amongst P. aeruginosa from horses and demonstrated that ERIC RAPD PCR is a rapid method for the examination of this species in horses, which may be useful in outbreak analysis.  相似文献   
70.
Models of biogenic carbon (BC) flux assume that short herbivorous food chains lead to high export, whereas complex microbial or omnivorous food webs lead to recycling and low export, and that export of BC from the euphotic zone equals new production (NP). In the Gulf of St. Lawrence, particulate organic carbon fluxes were similar during the spring phytoplankton bloom, when herbivory dominated, and during nonbloom conditions, when microbial and omnivorous food webs dominated. In contrast, NP was 1.2 to 161 times greater during the bloom than after it. Thus, neither food web structure nor NP can predict the magnitude or patterns of BC export, particularly on time scales over which the ocean is in nonequilibrium conditions.  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