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   108篇
  免费   7篇
林业   7篇
农学   3篇
  13篇
综合类   6篇
农作物   10篇
水产渔业   15篇
畜牧兽医   53篇
园艺   1篇
植物保护   7篇
  2023年   2篇
  2022年   5篇
  2021年   9篇
  2020年   11篇
  2019年   4篇
  2018年   3篇
  2017年   7篇
  2016年   8篇
  2015年   1篇
  2014年   9篇
  2013年   7篇
  2012年   4篇
  2011年   9篇
  2010年   5篇
  2009年   2篇
  2008年   4篇
  2007年   9篇
  2006年   2篇
  2005年   1篇
  2003年   3篇
  2002年   2篇
  2000年   2篇
  1998年   3篇
  1993年   1篇
  1990年   1篇
  1974年   1篇
排序方式: 共有115条查询结果,搜索用时 9 毫秒
111.
The aims of this study were to characterize EGF protein expression in ovine ovaries and to verify the effect of EGF on the in vitro development of isolated pre‐antral follicles. After collection, ovarian tissue was fixed for immunohistochemical analysis. Additional pairs of ovaries were collected, and secondary follicles were cultured for 18 days in α‐MEM+ (control) alone or supplemented with EGF (1, 10 or 50 ng/ml). The immunostaining for EGF was observed in oocytes from pre‐antral and antral follicles, in granulosa cells of primary and secondary follicles, as well as in cumulus and mural cells of antral follicles. After 18 days, the results showed that treatment with 50 ng/ml EGF significantly increased the percentage of morphologically normal follicles compared with the control group (α‐MEM+) and significantly reduced the precocious extrusion of oocytes and increased the percentage of antral follicles compared with the control and 1 ng/ml EGF. All the treatments induced a progressive and significant increase of the follicular diameter throughout the period of culture. However, there were no significant differences in follicular diameter or in the daily growth rate among treatments. In conclusion, this study demonstrated the presence of EGF in ovine ovaries. Moreover, 50 ng/ml EGF increased the percentage of normal follicles and improved antrum formation in isolated ovine follicles after 18 days of in vitro culture.  相似文献   
112.
ObjectiveTo determine the effect of intravenous (IV) buprenorphine on the isoflurane (ISO) minimum alveolar concentration (ISOMAC) in dogs.Study designRandomized, crossover, design.AnimalsSix healthy, adult (2–3 years old), intact dogs (two males and four females) weighing 7.4–11.0 kg.MethodsEach dog was studied on three occasions, 1 week apart, and baseline ISOMAC (MACB) was determined on each occasion. ISOMAC was defined as the mean of the end-tidal ISO concentrations that prevented and allowed purposeful movement in response to a noxious stimulus. After MACB determination, dogs were randomly given buprenorphine (BUP) at either 0.01, 0.05 or 0.1 mg kg?1 IV, and ISOMAC was determined at two time periods after BUP administration. The first post-treatment determination (MACT1) was initiated 45 minutes after BUP administration and the second determination (MACT2) was initiated 4 hours after BUP administration. MAC values were determined in duplicate and the mean values were used for statistical analysis.ResultsIsoflurane minimum alveolar concentration was decreased at 141 minutes (the time of MACT1 determination) by 25%, 35%, and 27% after administration of BUP at 0.01, 0.05, and 0.1 mg kg?1, respectively (p ≤ 0.05). The MAC reductions were not statistically different among doses. The reductions in ISOMAC at 342 minutes (the time of MACT2 determination) ranged from 13 to 16%, and were not statistically different among doses.Conclusions and clinical significanceBuprenorphine at 0.01, 0.05, and 0.1 mg kg?1 significantly decreased ISOMAC in dogs at 141 minutes but not at 342 minutes. When using BUP for MAC reduction re-dosing may be required for procedures of long duration, and there may be no advantage to using the 0.1 mg kg?1 dose.  相似文献   
113.
The aim of this study was to evaluate different ionic adjustment strategies in oligohaline water on the growth of Litopenaeus vannamei and C:N:P stoichiometric ratios of the floc microbial community (MC) in synbiotic nursery system. A 35-day culture (2000 PL's/m3) was carried out in 60 L units in a completely randomized experimental design, with three treatments: T1—seawater diluted to a salinity of 2.5 g/L (control), T2—water with a salinity of 2.5 g/L with potassium (K?) adjusted and T3—water at a salinity of 2.5 g/L with its Ca:Mg:K ratio adjusted to 1:3:1, each treatment in triplicates. The MC of flocs and the dissolved fraction (DF) was separated by filtration, where MC >1.6 µm and DF <1.6 µm. The juveniles reached a final weight of 0.40 ± 0.09–0.49 ± 0.04 g, survival above 80% and an average yield of 0.69 ± 0.18–0.81 ± 0.02 kg/m3, without significant differences among the treatments. A stabilizing trend of C:P, C:N and N:P ratios of MC was observed considering the variations of C:N:P in the DF, indicating a homeostatic behaviour of the floc MC, as occurs in systems with high nutrient availability. Our results indicate that the major ions initial concentrations (Ca2+: 25.07 mg/L, Mg2+: 89.75 mg/L and K?: 25.00 mg/L), total alkalinity 100.00 mg/L and total hardness 433.30 mg/L provide conditions that do not limit shrimp growth in oligohaline water synbiotic nursery system.  相似文献   
114.
European Journal of Plant Pathology - The fungus Colletotrichum lindemuthianum has genes that encode different enzymes involved in plant cell wall degradation such as pectinases, which are...  相似文献   
115.
Effects of a Bacterial Inoculum in Channel Catfish Ponds   总被引:9,自引:0,他引:9  
A commercial bacterial Inoculum cultured on site called Biostart was applied to three channel catfish Ictalurus punctatus ponds at Auburn, Alabama, USA, three times per week from May until October 1996. There were few significant differences (P × 0.1) in concentrations of water quality variables between ponds treated with bacteria and control ponds. In addition, bottom soil carbon and nitrogen did not differ between treated and control ponds. However, survival and net production of fish was significantly (P × 0.1) greater in ponds that received the bacterial inoculum than in controls. The mechanism by which the bacterial treatment influenced fish survival cannot be explained from data collected in this study. Further studies of probiotics are needed to define the potential benefits of these treatments to aquacultural production and to determine their mechanisms of action in pond ecosystems.  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