全文获取类型
收费全文 | 215篇 |
免费 | 11篇 |
专业分类
林业 | 33篇 |
农学 | 3篇 |
基础科学 | 3篇 |
17篇 | |
综合类 | 15篇 |
农作物 | 5篇 |
水产渔业 | 5篇 |
畜牧兽医 | 140篇 |
植物保护 | 5篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 14篇 |
2012年 | 11篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 12篇 |
2007年 | 13篇 |
2006年 | 12篇 |
2005年 | 8篇 |
2004年 | 13篇 |
2003年 | 8篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1940年 | 2篇 |
1939年 | 1篇 |
1937年 | 1篇 |
1936年 | 2篇 |
1934年 | 2篇 |
1930年 | 2篇 |
1927年 | 2篇 |
1926年 | 1篇 |
1925年 | 6篇 |
1916年 | 4篇 |
1915年 | 1篇 |
1903年 | 1篇 |
1899年 | 2篇 |
排序方式: 共有226条查询结果,搜索用时 0 毫秒
31.
32.
Incidence of clinical mastitis is highest at drying off and during the periparturient period. Intramammary Escherichia coli infection in high-yielding cows can show a severe clinical response during the early post-partum period. Severe clinical mastitis is mainly determined by cow factors, in particular the functionality of the circulating polymorphonuclear leukocytes (PMN) which are recruited to the mammary gland during the inflammatory reaction. There is a co-incidence between the periods of highest incidence of clinical mastitis and specific structural changes in the mammary gland. During the periparturient period, marked changes in various systemic and local hormones are related to the secretory state of the mammary gland epithelium (lactogenesis). Estrogen and progesterone induce proliferation of the mammary epithelium throughout gestation and act as survival factors in different tissues, although conflicting data have been reported on their effect on PMN oxidative burst. Somatotropin (STH), responsible for maintenance of lactation in ruminants, has been shown to positively influence innate immunity and a more rapid recovery in milk production of severely affected animals. The concentration of STH, and as a result also IGF-I levels is, however, quite low during early lactation. IGF-I and its regulating binding proteins are associated with cell survival, modulation of apoptosis and functionality of PMN in humans. During early lactation, bio-availability of IGF-I is decreased, which might reduce its stimulating effects on PMN quality and functionality. PRL, concomitantly known as a lactogenic hormone and an immunoregulatory cytokine, has also been associated with modulation of the immune system. It is expected that in periparturient animals, hormone changes could interfere with the immune response and the clinical response of mastitis. 相似文献
33.
Hunt GB Kummeling A Tisdall PL Marchevsky AM Liptak JM Youmans KR Goldsmid SE Beck JA 《Veterinary surgery : VS》2004,33(1):25-31
OBJECTIVE : To report outcomes after cellophane banding of single congenital portosystemic shunts in dogs and cats. STUDY DESIGN : Retrospective study of sequential cases. ANIMALS : One hundred and six dogs and five cats. METHODS : Medical records were reviewed for breed, sex, age at surgery, shunt anatomy, results of pre- and postoperative biochemical analysis, development of postligation neurologic dysfunction, portal hypertension or other serious complications, and the owners' perception of their animal's response to surgery. RESULTS : Ninety-five dogs and all 5 cats had extrahepatic shunts. Eleven dogs had intrahepatic shunts. Six dogs (5.5%) died as a result of surgery from portal hypertension (2 dogs), postligation neurologic dysfunction (2), splenic hemorrhage (1) and suspected narcotic overdose (1). Serious complications were more common in dogs with intrahepatic shunts than those with extrahepatic shunts (P=.002). Postligation neurologic dysfunction necessitated treatment in 10 dogs and 1 cat; 8 dogs and the cat survived. Clinical signs attributed to portosystemic shunting resolved or were substantially attenuated in all survivors. Postoperative serum bile acid concentrations or results of ammonia tolerance testing were available for 88 animals; 74 (84%) were normal and 14 (16%) were abnormal. Multiple acquired shunts were documented in two animals. CONCLUSIONS : Cellophane banding is a safe and effective alternative to other methods of attenuation. CLINICAL RELEVANCE : Slow occlusion of portosystemic shunts using a variety of methods is being evaluated world wide. Cellophane banding is a relatively simple procedure with comparable safety and efficacy to previously reported techniques. 相似文献
34.
35.
36.
Edwige Gaby Nkouaya Mbanjo Fran?ois Tchoumbougnang Albert Sone Mouelle Julius Enyong Oben Moses Nyine Carine Dochez Morag Elizabeth Ferguson James Lorenzen 《Euphytica》2012,188(3):369-386
A well-saturated genetic linkage map is valuable for fundamental and applied genetic research. Genetic linkage maps of two half-sib diploid banana populations were constructed using allele-specific-polymerase chain reactions (AS-PCRs), diversity array technology (DArT), and simple sequence repeat (SSR) markers. Molecular maps were produced for each parent using the pseudo-testcross mapping strategy. The first maternal map (6142-1, 81 individuals) consisted of 231 markers divided as followed: 121 DArT, 106 SSR and 4 AS-PCR markers in 15 linkage groups (LGs) covering 670?cM. The second maternal map (6142-1-S, 58 individuals) contained a total of 152 markers including 71 DArTs, 79 SSRs, and 2 AS-PCRs mapped to 16 LGs that spanned 698?cM. The combined paternal map (139 individuals) comprised 316 markers (196 DArTs, 117 SSRs and 3 AS-PCRs) distributed over 15 LGs with a total map length of 1,004?cM. While distorted segregation of some markers was observed in all maps, this was much more frequent for the male parent. Homology between maps was assessed using common markers. While there was generally good congruity with regard to marker order across maps, incongruity in other cases may reflect chromosomal rearrangement events such as inversions, translocations, or deletions. The new banana map can provide a better understanding of the Musa genome and could be used for the identification of economically important traits and improvement of breeding strategies. 相似文献
37.
38.
Mordecai A Liptak JM Hofstede T Stalker M Kruth S 《Journal of the American Animal Hospital Association》2008,44(2):90-94
A 6-year-old, male castrated domestic shorthair cat was presented for evaluation of lethargy, vomiting, anorexia, and constipation. Physical examination revealed an elevated body temperature and an extramural colonic mass. Abdominal ultrasonography demonstrated a hypoechoic mass measuring 2.2 cm in maximum dimension immediately caudal to the bladder. Cytological evaluation of a fine-needle aspirate confirmed the mass was a prostatic abscess. Abdominal celiotomy and prostatic omentalization were successful in resolving clinical abnormalities. Feline prostatic abscessation is a rare condition that has not been previously reported and may have a good outcome if treated early and appropriately. 相似文献
39.