全文获取类型
收费全文 | 105篇 |
免费 | 14篇 |
专业分类
林业 | 2篇 |
基础科学 | 1篇 |
8篇 | |
综合类 | 16篇 |
农作物 | 1篇 |
水产渔业 | 4篇 |
畜牧兽医 | 81篇 |
植物保护 | 6篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 1篇 |
2011年 | 5篇 |
2010年 | 9篇 |
2009年 | 5篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 2篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1930年 | 1篇 |
1893年 | 1篇 |
1892年 | 1篇 |
排序方式: 共有119条查询结果,搜索用时 578 毫秒
21.
DM Magalhães DD Fernandes MBS Mororó CMG Silva GQ Rodrigues JB Bruno MHT Matos CC Campello JR Figueiredo 《Reproduction in domestic animals》2011,46(1):134-140
The aim of the present study was to evaluate the effects of different medium replacement intervals on the viability, antral cavity formation, growth and in vitro maturation (IVM) of oocytes from caprine and ovine pre‐antral follicles. Pre‐antral ovarian follicles (≥150 μm) were isolated from the ovarian cortex of goats and sheep and were individually cultured for 24 days using two different medium replacement intervals [2 days (T1) or 6 days (T2)]. Follicle development was evaluated on the basis of antral cavity formation, increases in follicular diameter and the presence of healthy cumulus oocyte complexes and fully grown oocytes. For caprine species, results showed a higher percentage (p < 0.05) of viable follicles in T1 than T2 from day 6 until the end of the culture. In addition, when comparing both treatments after the same culture duration, the rate of antrum formation was significantly higher in T1 than in T2 from day 12 onwards. Yet, in ovines, when both treatments were compared on day 24 of the culture, there were more viable follicles in T2 than in T1 (p < 0.05). In the caprine species, percentages of fully grown oocytes (≥110 μm) acceptable for IVM after 24 days of culture were significantly higher in normal follicles cultured in T1 (30.0%) than in T2 (6.7%; p < 0.05). On the other hand, in ovines, at the end of the culture, the percentage of oocytes destined for IVM was higher in T2 than in T1 (23.5% vs 2.9%; p < 0.05). In conclusion, under the same conditions, the frequency of medium replacement significantly affected the in vitro development of caprine and ovine pre‐antral follicles. To improve the efficiency of the culture system, the medium must be replaced every 2 and 6 days for goat and sheep pre‐antral follicles, respectively. 相似文献
22.
23.
The effects of varying amounts (100.0-0.01 units/ml) of human interferon (IFN) alpha upon in vitro canine immune responses were studied. Exogenous heterologous species IFN-alpha suppressed B-cell differentiation in a dose-dependent fashion and enhanced interleukin-2 production (P less than 0.05) by activated T-lymphocytes. Interferon enhanced natural killer (NK) cytotoxicity when tested against NK-resistant target cells (less than 0.05). One hundred units IFN/ml increased interleukin-1 production by canine monocytes, but this effect was not statistically significant. Exogenous IFN had no discernible effect upon lectin-induced lymphocyte blastogenesis. The results of this study demonstrate that human IFN-alpha does affect various canine lymphocyte functions and these effects depend upon the in vitro assay system employed. 相似文献
24.
A dot-immunobinding assay, amplified with avidin and biotin (DAB assay), was used to detect serum antibodies to Mycoplasma iowae in immunized turkeys. The DAB assay was used to test serum samples from 122 commercial market turkey flocks obtained from four Iowa processing plants. The samples were pooled and tested for the presence of antibodies to four species of Mycoplasma spp. considered to be important pathogens for turkeys: M. gallisepticum (MG), M. iowae (MI), M. meleagridis (MM), and M. synoviae (MS). The occurrence of antibodies against these mycoplasmas, as determined by the DAB assay, were 5.7% for MG, 18.0% for MI, 77.9% for MM, and 9.8% for MS. 相似文献
25.
Effect of oestrous synchrony between embryo donors and recipients,embryo quality and state on the pregnancy rate in beef cattle 下载免费PDF全文
MCC Rodrigues ALM Bonotto DAV Acosta AA Boligon MN Corrêa CC Brauner 《Reproduction in domestic animals》2018,53(1):152-156
This study aimed to evaluate the effect of oestrous synchrony between donors and recipients and the embryo quality on the pregnancy rate in beef cow recipients. The experiment was performed over two years at an embryo transfer (ET ) centre in Southern Brazil. Ninety Aberdeen Angus cows were subjected to superovulation (SOV ) protocols, resulting in the recovery of 1,048 transferable embryos. Eleven groups were formed with intervals of 6 hr, from ?30 to +30 hr, with respect to recipient versus donor oestrous detection. Evaluation of embryo quality was according to the IETS guidelines. The overall pregnancy rate was 52%. Effects related to donor and recipient oestrous synchronization on pregnancy rate were observed (p = .01), ranging from 36% to 50%. The embryo quality rate affected the pregnancy rate, where Grade I resulted in 57% and Grade III in 43% of pregnancy (p < .001). The embryonic state (frozen or fresh) showed no (p > .05) effect on pregnancy rate: 53% for fresh embryos and 44% for frozen embryos. The odds ratio for explanatory variables causing pregnancy indicated that Grade III embryos had 31% less chance of conception compared to Grade I. Thus, oestrous synchrony between donor and recipient, considering ±30 hr apart, can affect the pregnancy rate along with embryo quality. 相似文献
26.
27.
DN Basov SI Woods AS Katz EJ Singley RC Dynes M Xu DG Hinks CC Homes M Strongin 《Science (New York, N.Y.)》1999,283(5398):49-52
Analysis of the interlayer infrared conductivity of cuprate high-transition temperature superconductors reveals an anomalously large energy scale extending up to midinfrared frequencies that can be attributed to formation of the superconducting condensate. This unusual effect is observed in a va- riety of materials, including Tl2Ba2CuO6+x, La2-xSrxCuO4, and YBa2Cu3O6.6, which show an incoherent interlayer response in the normal state. Midinfrared range condensation was examined in the context of sum rules that can be formulated for the complex conductivity. One possible interpretation of these experiments is in terms of a kinetic energy change associated with the superconducting transition. 相似文献
28.
29.
We report the case of a bilateral and multilocular spermatocele and sperm granuloma in a dog that was vasectomized 5 years before. Clinical examination revealed scrotal dermatitis and benign prostatic hyperplasia. Orchiectomy was performed, and gross and histological examination showed testicular degeneration associated with epididymal sperm granuloma. In relation to this case, the literature about long-term effects of vasectomy in dogs has been reviewed. On the basis of these results, a preventive sonogram and physical assessment in prostate and other reproductive structures before vasectomy is recommended. 相似文献
30.
Oestrus Expression and Ovarian Function in Repeat Breeder Cows, Monitored by Ultrasonography and Progesterone Assay 总被引:1,自引:0,他引:1
Ovarian ultrasonography and plasma progesterone levels were monitored in 37 lactating Holstein cows with a history of repeat breeding; the data obtained were analysed in conjunction with clinical and behavioural signs, to identify the aetiology of the syndrome. Differences were detected between RBCs displaying apparently normal cycles and others with irregular cycles. There were also differences in heat expression; a large number of repeat breeder cows (RBCs, 50%) displayed delayed or silent oestrus. Ovarian disorders were common in RBCs, and included ovarian cysts, mistimed AI, subluteal progesterone levels, luteal dysfunction or ovulation defects. Both ultrasonography and plasma progesterone assays are useful tools for ascertaining the aetiology of the repeat breeder syndrome. 相似文献