全文获取类型
收费全文 | 1237篇 |
免费 | 53篇 |
专业分类
林业 | 58篇 |
农学 | 45篇 |
基础科学 | 17篇 |
246篇 | |
综合类 | 40篇 |
农作物 | 140篇 |
水产渔业 | 126篇 |
畜牧兽医 | 421篇 |
园艺 | 46篇 |
植物保护 | 151篇 |
出版年
2023年 | 16篇 |
2022年 | 49篇 |
2021年 | 59篇 |
2020年 | 56篇 |
2019年 | 82篇 |
2018年 | 52篇 |
2017年 | 78篇 |
2016年 | 59篇 |
2015年 | 42篇 |
2014年 | 48篇 |
2013年 | 90篇 |
2012年 | 78篇 |
2011年 | 77篇 |
2010年 | 52篇 |
2009年 | 40篇 |
2008年 | 47篇 |
2007年 | 36篇 |
2006年 | 42篇 |
2005年 | 46篇 |
2004年 | 31篇 |
2003年 | 21篇 |
2002年 | 31篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有1290条查询结果,搜索用时 15 毫秒
11.
Mohamed A.M. Alsafy Mahmoud H. El-Kammar Mostafa M. Kassem Samir A.A. El-Gendy Ahmad N. EL-Khamary 《Journal of Equine Veterinary Science》2013
The purpose of this study was to provide a detailed laparoscopic anatomy of the caudal abdominal region of mare in a standing position and to evaluate and modify a technique for standing laparoscopic ovariectomy using combination between hand-tied ligating loop and electrocoagulation techniques, as the ligating loops, electrocoagulation, and modified electroligation laparoscopic ovariectomy were applied using nine adult mares. Laparoscopy was practical and effective for direct visual examination of internal abdominal organs in the mare. Ventral dislocation of abdominal viscera after pneumoperitoneum was established with the mare in standing position, which provided an excellent inspection of the dorsal and ventral structures in the peritoneal cavity on the right and left sides. Standing laparoscopic ovariectomy using an electroligation modified method was considered a safe and effective method for hemostasis of the mesovarium, technically easy, time saving, and economical. The mean surgical time for bilateral ovariectomy was 40 ± 7.63, 60 ± 5.25, and 85 ± 6.43 minutes for electroligation-modified technique, ligating loops technique, and electrocoagulation technique, respectively. 相似文献
12.
Ahmed M Kimura K Soliman M Yamaji D Okamatsu-Ogura Y Makondo K Inanami O Saito M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(2):125-131
Leptin, a pleiotropic hormone regulating food intake and energy expenditure, has been shown to directly modulate human polymorphonuclear neutrophil (PMN) functions or indirectly through the action of tumor necrosis factor-alpha (TNF-alpha). Bovine PMN have considerable different characteristics from human PMN. For example, it does not respond to N-formyl-Methionyl-Leucyl-phenylalanine, a well known human PMN activator. In the present study, we tested the effects of leptin and TNF-alpha on superoxide production and degranulation of bovine peripheral PMN, in which both long isoform of leptin receptor (Ob-Rb) and TNF receptor 1 were expressed. Human leptin, human TNF-alpha, phorbol myristate acetate (PMA) and opsonized zymosan particles (OZP) did not stimulate degranulation responses, while zymosan-activated serum (ZAS) did. Neither leptin nor TNF-alpha enhanced the ZAS-induced degranulation responses. TNF-alpha, PMA, OZP and ZAS increased superoxide production in different magnitudes, whereas leptin did not. TNF-alpha, but not leptin, enhanced OZP- and ZAS-induced superoxide production, possibly, in part due to facilitating translocation of p47(phox), a component of NADPH oxidase. These results indicate that, unlike in human PMN, leptin does not have any direct effect on degranulation and superoxide production in bovine PMN, although TNF-alpha influences superoxide production. 相似文献
13.
Mohamed M. A. Abumandour Raafat M. A. El-Bakary 《Veterinary research communications》2013,37(3):229-238
This study was carried out on the tongues of 12 adult normal healthy Egyptian fruit bats of both sexes. The tongue is protrusible, elongated flat with a rounded apex and its wide and thickness increase gradually toward the lingual root. There are four types of lingual papillae; two mechanical and two gustatory. The tongue divided into three parts (anterior, middle and posterior), each part subdivides into three regions; two lateral regions and median region, in addition to the lingual apex to the anterior region. The lingual papillae close to the median region of the tongue were posteriorly directed toward the pharynx, while theses present on the lateral regions of the tongue are directed medioposteriorly. There are sex subtypes of the filiform papillae; three on the anterior part (small, conical and giant), two on the middle part (cornflower and leaf-like papillae) while the posterior part contain rosette shape filiform papillae, in addition to transitional papillae and conical papillae. Two gustatory papillae represented by; small number of fungiform papillae which scattered among the filiform papillae on lingual apex and two lateral regions of the anterior and middle part of tongue, while the three circumvallate papillae on the posterior part were arranged in a triangle form. 相似文献
14.
Kirsten Büsing Mohamed Elhensheri Kristin Entzian Udo Meyer Annette Zeyner 《Research in veterinary science》2014
Humic acids are used to prophylactically treat intestinal diseases in a wide number of species, yet the mechanism of action remains unknown. The general assumption has been that humic acids act locally; however studies using young piglets show orally supplemented humic acids can penetrate the intestinal wall, and thus potentially act systemically. The objective of this study was to determine if humic acids could also cross the intestinal barrier in adult pigs and be detected in other organs. Adult minipigs (>18 months old) orally received either 1 g humic acids/kg body weight (verum, n = 3) or placebo (control, n = 3), for 2 weeks. At the end of the feeding period tissue samples were harvested from the intestine, various glands and organs. Unstained tissue samples were examined by light microscopy for the presence of humic acid particles. No humic acid particles were detected in any of the unstained tissues from verum or control pigs. 相似文献
15.
薛俊梅 《国外畜牧学(猪与禽)》2010,30(5)
多种肠道紊乱会威胁家禽的健康,并引起发病和死亡,造成经济损失.抗生素生长促进剂的禁用,使肠道细菌受到诱发因素的影响后而使肠道内腔遭到破坏,提高了本病的发生率.你如何认识这一问题并会采取什么措施呢? 相似文献
16.
Dkhil MA Abdel-Maksoud MA Al-Quraishy S Abdel-Baki AA Wunderlich F 《Veterinary parasitology》2012,186(3-4):222-228
Eimeria coecicola causes intestinal coccidiosis in rabbits and, thereby, enormous economic losses in rabbit farms. Here, we investigate the final target site of E. coecicola, the appendix of rabbits, at the level of gene expression. Rabbits, orally infected with E. coecicola, begin to shed parasitic oocysts with their feces on day 5 p.i., and approximately 1.1 million oocysts are maximally shedded on day 7 p.i. At maximal shedding, the appendix has increased in size by about 2-3-folds and reveals increased hemorrhage which is associated with increases in nitrite/nitrate, malondialdehyde and catalase activity and a decrease in glutathione. Agilent 2-color oligo whole rabbit genome microarray, in combination with quantitative real-time PCR, detects 45 and 36 genes whose expression is more than 2-fold up- and down-regulated, respectively, by E. coecicola infection on day 7 p.i. The most dramatic increase by approximately 50-fold reveals the mRNA of the pro- and anti-inflammatory pleiotropic cytokine interleukin 6 (IL-6), whereas the largest decrease by approximately 13-fold is detected for mRNAs encoding for DBP, SULT3A1, CRP and glutathione-S transferase. Also, there are up- and down-regulations in the expression of genes encoding diverse regions of antibodies. Our data suggest that IL-6 plays a central role in the infection of the appendix of rabbits by E. coecicola, presumably involved in both pathological injuries, host defences and healing processes. 相似文献
17.
Kittelberger R Reichel MP Jenner J Heath DD Lightowlers MW Moro P Ibrahem MM Craig PS O'Keefe JS 《Veterinary parasitology》2002,110(1-2):57-76
The aim of this study was to develop an immunological method for the identification of sheep infected with Echinococcus granulosus which would allow the monitoring of animals imported into countries free from hydatidosis and as an aid to countries where control schemes for the disease are in operation. Three enzyme-linked immunosorbent assays (ELISAs) were developed and validated, using as antigen either a purified 8 kDa hydatid cyst fluid protein (8kDaELISA), a recombinant EG95 oncosphere protein (OncELISA) or a crude protoscolex preparation (ProtELISA). Sera used for the assay validations were obtained from 249 sheep infected either naturally or experimentally with E. granulosus and from 1012 non-infected sheep. The highest diagnostic sensitivity was obtained using the ProtELISA at 62.7 and 51.4%, depending on the cut-off. Assay sensitivities were lower for the 8kDaELISA and the OncELISA. Diagnostic specificities were high, ranging from 95.8 to 99.5%, depending on the ELISA type and cut-off level chosen. A few sera from 39 sheep infected with T. hydatigena and from 19 sheep infected with T. ovis were recorded as positive. Western immunoblot analysis revealed that the dominant antigenic components in the crude protoscolex antigen preparation were macromolecules of about 70-150 kDa, most likely representing polysaccharides. This study demonstrated that the ProtELISA was the most effective immunological method of those assessed for detection of infection with E. granulosus in sheep. Because of its limited diagnostic sensitivity of about 50-60%, it should be useful for the detection of the presence of infected sheep on a flock basis and cannot be used for reliable identification of individual animals infected with E. granulosus. 相似文献
18.
Sedqyar M Weng Q Watanabe G Kandiel MM Takahashi S Suzuki AK Taneda S Taya K 《The Journal of reproduction and development》2008,54(1):52-57
To clarify the cellular source and secretory pattern of inhibin in the Japanese quail during follicular development, the plasma concentrations of immunoreactive (ir) inhibin were measured from 1 to 7 weeks after hatching. Localization of the inhibin/activin alpha, beta A and beta B subunits was investigated by immunohistochemistry. To monitor development of the pituitary and ovarian functions, the plasma luteinizing hormone (LH) and progesterone concentrations were also measured. Ovarian weight increased gradually until 6 weeks of age and then abruptly increased at 7 weeks of age just at the onset of egg production. Plasma concentrations of LH increased significantly at 6 weeks of age. The plasma concentrations of ir-inhibin and progesterone and the pituitary contents of LH also increased significantly at 7 weeks of age. Immunohistochemically, the inhibin/activin alpha, beta A and beta B subunits were localized in the granulosa cells of all follicles during different stages of development from 1 to 7 weeks after hatching. The inhibin alpha, beta A and beta B subunits were also found in the interstitial cells but not theca cells of all follicles. These results demonstrated that the plasma concentrations of ir-inhibin of the female Japanese quails rose with ovarian development. The immunohistochemical results suggested that granulosa and interstitial cells are the major source of ovarian inhibins in female Japanese quails. 相似文献
19.
20.
Abdilatif Mohamed Haji Onono Joshua Orungo Mutua Florence Kanini 《Tropical animal health and production》2018,50(7):1701-1710
Tropical Animal Health and Production - Small ruminants’ production contributes to livelihood of pastoral communities, but this faces myriad constraints. This study aimed at identifying... 相似文献