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   238篇
  免费   7篇
林业   40篇
农学   13篇
  23篇
综合类   9篇
农作物   6篇
水产渔业   25篇
畜牧兽医   118篇
园艺   1篇
植物保护   10篇
  2022年   5篇
  2021年   4篇
  2020年   1篇
  2019年   2篇
  2018年   2篇
  2017年   4篇
  2016年   4篇
  2015年   2篇
  2014年   7篇
  2013年   18篇
  2012年   15篇
  2011年   18篇
  2010年   3篇
  2009年   4篇
  2008年   11篇
  2007年   13篇
  2006年   14篇
  2005年   11篇
  2004年   7篇
  2003年   16篇
  2002年   13篇
  2001年   9篇
  2000年   10篇
  1999年   6篇
  1998年   5篇
  1997年   1篇
  1996年   2篇
  1994年   1篇
  1992年   3篇
  1991年   6篇
  1990年   3篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1984年   2篇
  1983年   2篇
  1981年   2篇
  1979年   1篇
  1978年   2篇
  1974年   3篇
  1973年   2篇
  1972年   1篇
  1971年   2篇
  1969年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有245条查询结果,搜索用时 15 毫秒
1.
Bovine granulosa cells (GC) vary in their morphological aspect during different stages of folliculogenesis. In this study, 10 morphologically normal bovine ovaries were collected to study the structural aspects of different stages of GC using intermediate filament protein antibodies including cytokeratin AE1/AE3 (AE1/AE3), vimentin, nectin‐4 and desmin. Hormonal immunolocalization was assessed using the immunomarkers anti‐Müllerian hormone (AMH) and inhibin alpha. In addition, tumour markers and proliferation markers using c‐erbB‐2 oncoprotein and proliferating cell nuclear antigen, respectively, were investigated. The immunolabelling of AE1/AE3 in GC was strongest in the early follicle stage and gradually decreased when reaching the Graafian follicle stage. Its immunolabelling increased again as the stage progressed from stage I to stage III. The immunolabelling of inhibin alpha was inversely proportional to that of AE1/AE3 in the developing ovarian follicles as their immunolabelling is opposite to each other during folliculogenesis. AMH was immunopositive in almost all GC stages in different intensities and percentages, except for some negative staining in the atretic IV follicles. The atretic IV follicle is a unique type of atretic follicle that shows Call‐Exner body formation, which was mainly found in older cows in this study. The distinct patterns of immunoreactivity for various types of immunomarkers in the different GC stages will play an important role in diagnostic assistance of various follicle conditions, including cystic ovaries and GC tumours.  相似文献   
2.
Assessment of spleen size using the ultrasonography has become a standard practice in human. However, the assessment is not established method in experimental animals. To establish the index to assess the spleen size using ultrasonography, we measured the cross-section image of rabbit spleen during endotoxin shock. The image of the cross-section was appeared as triangle, and the height of the triangular image was defined as the spleen index. This spleen index showed strong correlation with the spleen weight. In conclusion, this method is suitable for observation of changes in rabbit spleen size and may reduce the number of rabbit in the longitudinal studies.  相似文献   
3.
Combined effects of treatment with trientine, a copper-chelating agent, and X-irradiation on development of fibrosarcoma using a murine transplantation model in vivo and on cellular survival in vitro were examined. Copper contents in the tumors and serum of trientine-treated mice were significantly lower than those of untreated mice. The tumor volumes of mouse fibrosarcoma QRsp-11 cells increased more slowly in the trientine-treated and the X-irradiated mice than in the control mice from 10 to 24 days postinoculation. The extent of inhibition of tumor growth by X-irradiation at 3 Gy was similar to that obtained by treatment with trientine. A combination of trientine and X-irradiation at 3 Gy showed inhibitory effects on tumor growth similar to those obtained by X-irradiation at 6 Gy. The results showed that trientine and X-irradiation interacted additively in inhibition of tumor growth. When QRsp-11 cells and mouse and bovine endothelial cells were treated with trientine after X-irradiation, the surviving fractions of the cells with combined treatments were essentially consistent with the products of the surviving fractions of trientine-treated cells and those of X-irradiated cells. When the cells were pretreated with trientine and X-irradiated, the surviving fractions of the pretreated cells were lower than those of cells without treatment.  相似文献   
4.
In the pearl cultivation farms of the Ehime Prefecture, Japan, mass mortalities of the pearl oyster Pinctada fucata have occurred since 1994. The occurrences of mass mortality roughly coincided with a shift of the dominant phytoplankton from Skeletonema and Chaetoceros to Chaetoceros and Nitzschia all of which belong to Bacillariophyceae. Hence, we evaluated Nitzschia, together with Chaetoceros and Isocrysis, as food for the oyster. Wet weights, lengths, widths, glycogen contents, and growth rates in terms of wet weight of the oysters in all the feeding treatments were significantly higher than those in the non-feeding treatment. The highest glycogen content (2.34%) and growth rate (2.21 g month−1) were found in the Chaetoceros treatment. Growth rate in the Isocrysis treatment (1.63 g month−1) was also high, although glycogen content in this treatment (0.41%) was low. In the Nitzschia treatment, growth rate of the oyster (0.94 g month−1) was the lowest and glycogen content (0.83%) was also low relative to that in the Chaetoceros treatment. Chlorophyll a concentration in fecal pellets was lowest in the Nitzschia treatment (<2.7 μg mg−1), suggesting more complete digestion of Nitzschia by the oyster. Thus, Nitzschia was edible and digestible but not assimilated by P. fucata. We propose the following scenario for the relationship between Nitzschia dominance and mass mortality. When Nitzschia dominates in a culture area, the physiological condition of P. fucata deteriorates due to low assimilation of Nitzschia by the oyster, followed by susceptibility of the oyster to infection by agents lethal to the oyster.  相似文献   
5.
The taste and extractive components of boiled dorsal muscle and broth prepared from half-smooth golden puffer Lagocephalus spadiceus caught in Japan and from those imported from China were compared. In the sensory test, the first taste, elasticity, and saltiness of boiled muscle from Japanese (domestic) fish were higher than those of the imported fish, whereas the orthonasal fishy smell of the imported fish was higher than that of the domestic fish. The first taste, aftertaste, retronasal fishy smell, sweetness, saltiness, and umami of the broth prepared from dorsal muscle of the domestic fish were higher than those of the imported fish, whereas orthonasal fishy smell and bitterness of the imported fish were higher than those of the domestic fish. Most panelists preferred the overall taste of the domestic fish to that of the imported fish. The concentration of trimethylamine in the trichloroacetic acid extracts from boiled muscle and broth of the imported fish was higher than that of the domestic fish, suggesting that this substance contributes to the orthonasal fishy smell of the imported fish.  相似文献   
6.
This study examined the effects of calcium lactate on the development of chicken embryos in a shell-less culture system (cSLCS) up to the seventeenth day of incubation. In the presence of calcium lactate, a significant reduction in embryo viability was observed during the first week of incubation in cSLCS. On day 17 of embryo development, no significant difference was observed in the blood plasma calcium concentration or tibia bone density between cSLCS and intact control embryos, whereas the tibia length was significantly shorter in cSLCS embryos than in the intact control. These results suggest that calcium lactate supplementation in cSLCS supports bone formation in developing chicken embryos, but has adverse effects on the viability of embryos, particularly during the first week of embryo development.  相似文献   
7.
Effects of recombinant bovine granulocyte-macrophage colony-stimulating factor (rboGM-CSF) on bactericidal activity of bovine peripheral blood neutrophils in vitro and in vivo were studied. In in vitro experiment, bovine blood neutrophils were cultured for 9 hr in media containing 0.005, 0.05 or 0.5 microg/ml of rboGM-CSF. Neutrophils treated with rboGM-CSF showed significantly higher luminol-dependent chemiluminescence (LDCL) than control cells. In in vivo experiment, neutrophils isolated from cows injected 5.0 microg/kg of rboGM-CSF showed significantly higher Nitrobluetetrazolium (NBT) reduction value than that from control cows 24 hr post injection. Total leukocyte counts of cows injected rboGM-CSF sharply decreased 6 hr post injection and recovered to normal level 2 days post injection. Body temperature of these cows rose 6 hr post injection and back to normal level at 24 hr post injection. It was suggested that rboGM-CSF enhanced bactericidal activity of bovine neutrophils both in vitro and in vivo.  相似文献   
8.
9.
Electron-microscope characterization of infectious bursal disease virus   总被引:1,自引:0,他引:1  
  相似文献   
10.
A survey of Salmonella was carried out in fecal samples of 887 pigs with diarrhea collected from 235 pig farms between April 1996 and March 2001. Salmonella was isolated from 84 feces (9.5%) of 887 pigs and from 45 (19.1%) of 235 farms. The higher prevalence was found in weaned pigs (12.4%) and fattening pigs (17.3%) than in sows (4.2%) and suckling pigs (4.5%). Isolation rates of S. Typhimurium were higher from weaned and fattening pigs than from the others. Therefore, risk of horizontal infection of S. Typhimurium will increase, if no adequate health managements are practiced when weaned and fattening pigs have diarrhea.  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