全文获取类型
收费全文 | 877篇 |
免费 | 41篇 |
国内免费 | 2篇 |
专业分类
林业 | 25篇 |
农学 | 12篇 |
基础科学 | 2篇 |
58篇 | |
综合类 | 129篇 |
农作物 | 34篇 |
水产渔业 | 20篇 |
畜牧兽医 | 600篇 |
园艺 | 13篇 |
植物保护 | 27篇 |
出版年
2021年 | 13篇 |
2020年 | 11篇 |
2019年 | 12篇 |
2018年 | 15篇 |
2017年 | 15篇 |
2016年 | 13篇 |
2014年 | 18篇 |
2013年 | 43篇 |
2012年 | 15篇 |
2011年 | 36篇 |
2010年 | 29篇 |
2009年 | 31篇 |
2008年 | 29篇 |
2007年 | 25篇 |
2006年 | 32篇 |
2005年 | 23篇 |
2004年 | 25篇 |
2003年 | 15篇 |
2002年 | 21篇 |
2001年 | 28篇 |
2000年 | 26篇 |
1999年 | 18篇 |
1998年 | 21篇 |
1997年 | 18篇 |
1996年 | 16篇 |
1995年 | 17篇 |
1994年 | 15篇 |
1993年 | 14篇 |
1992年 | 29篇 |
1991年 | 15篇 |
1990年 | 11篇 |
1989年 | 22篇 |
1988年 | 12篇 |
1987年 | 8篇 |
1986年 | 8篇 |
1985年 | 14篇 |
1984年 | 15篇 |
1983年 | 9篇 |
1979年 | 15篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1974年 | 15篇 |
1973年 | 6篇 |
1972年 | 10篇 |
1971年 | 11篇 |
1970年 | 10篇 |
1969年 | 8篇 |
1967年 | 7篇 |
1966年 | 6篇 |
排序方式: 共有920条查询结果,搜索用时 109 毫秒
31.
32.
Preliminary clinical observations on the use of piroxicam in the management of rectal tubulopapillary polyps 总被引:2,自引:0,他引:2
Knottenbelt CM Simpson JW Tasker S Ridyard AE Chandler ML Jamieson PM Welsh EM 《The Journal of small animal practice》2000,41(9):393-397
Rectal tubulopapillary polyps were diagnosed in eight dogs following proctoscopy and mucosal pinch biopsy. Histological examination of the pinch biopsies revealed evidence of malignant transformation in three of the cases. The remaining cases were diagnosed as benign polyps. Inflammatory changes were observed in four cases. Seven dogs were treated with piroxicam suppositories and one with oral piroxicam. All dogs were re-examined after four to six weeks of piroxicam therapy and the extent of haematochezia, tenesmus and faecal mucus production was reduced in all cases. The owners of seven of the dogs considered the improvement in clinical signs to be good or excellent. Cases with and without evidence of inflammation responded equally well. This finding supports the hypothesis that piroxicam has an antineoplastic effect due to apoptosis and alteration in the cell cycle. Medical management with piroxicam may provide a non-invasive treatment option for dogs with rectal polyp formation in which surgical treatment is likely to be associated with complications such as incontinence, infection and wound breakdown, or where the owner declines such treatment. 相似文献
33.
34.
Scott I Khalaf S Simcock DC Knight CG Reynolds GW Pomroy WE Simpson HV 《Veterinary parasitology》2000,89(1-2):79-94
Disturbances in the physiology of the abomasa of sheep infected with either adult Ostertagia circumcincta given via abomasal cannulae, or larvae (L3) given intraruminally were matched by pathological changes in tissues collected by repeated mucosal biopsy. Within 2-3 days of the transplant of adult worms, abomasal pH had increased markedly in five out of six animals, and there also had been rapid increases in serum gastrin and pepsinogen concentrations in all animals. Reductions in parietal cell number were recorded as early as 1 day after the transplant of adults and were associated with the rapid accumulation of many neutrophils and eosinophils. Mucosal hyperplasia, with increased numbers of cells closer in appearance to mucous/mucous neck cells, was a relatively late development, being most pronounced in the latter part of the infection. In sheep given larvae, changes in secretory physiology were again matched by a concurrent fall in parietal cell number and by the accumulation of inflammatory cells. Changes became maximal when most worms could be expected to be present as adults, confirming the role of adults in the natural disease. Some abnormalities were detected in biopsies collected from animals maintained free of parasites and, although milder in degree, there were similarities to those observed in parasitised tissues, there being fewer parietal cells, a modest degree of mucous cell hyperplasia and inflammatory infiltrates of predominantly neutrophils. These changes were the likely result of trauma to the tissues in the immediate vicinity of the cannula, due either to the presence of the cannula itself or to the frequent collection of biopsy material from areas close to it. 相似文献
35.
Neiger R Simpson KW 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2000,14(2):125-133
The discovery of the spiral bacterium Helicobacter pylori and its causative role in gastric disease in humans has brought a dramatic change to gastroenterology. Although spiral bacteria have been known for more than a century to infect the stomachs of dogs and cats, recent research has been conducted mainly in the wake of interest in H. pylori. H. pylori has not been found in dogs and only very rarely in cats and zoonotic risk is minimal. A variety of other Helicobacter spp. can infect the stomach of pets; however, their pathogenic role is far from clear, and they have a small but real zoonotic potential. The prevalence of gastric Helicobacter spp. in dogs and cats is high, irrespective of clinical signs, and as in human medicine, mode of transmission is unclear. The relationship of Helicobacter spp. to gastric inflammation in cats and dogs is unresolved, with inflammation, glandular degeneration, and lymphoid follicle hyperplasia accompanying infection in some but not all subjects. Circulating anti-Helicobacter immunoglobulin G antibodies have been detected in 80% of dogs with naturally acquired infection and most dogs and cats with experimental infection. The gastric secretory axis is similar in infected and uninfected cats and dogs and no relationship of infection to gastrointestinal ulcers has been found. Differences in the pathogenicity of Helicobacter spp. are apparent, because infection with H pylori is associated with a more severe gastritis than infection with other Helicobacter spp. in both cats and dogs. Rapid urease test, histopathology, and touch cytology are all highly accurate invasive diagnostic tests for gastric Helicobacter-like organisms in dogs and cats, whereas culture and polymerase chain reaction are the only means to identify them to the species level. Urea breath and blood tests or serology can be used to diagnose Helicobacter spp. noninvasively in dogs and cats. Most therapeutic studies in pets have not shown long-term eradication of Helicobacter spp. Whether this is due to reinfection or recrudescence has not been established. 相似文献
36.
FJ Pena JA Gines J Duque V Vieitez R Martinez –Pérez L Madejón I Nuñez Martinez JM Moran S Fernández-García 《Reproduction in domestic animals》2006,41(2):189-190
A 6-year-old female Alaska Malamute dog was presented for evaluation of abdominal enlargement referred by a local veterinarian. On the history, the owner complained of chronic abdominal enlargement initiated more than 4 months ago, reduced appetite, occasional vomiting and general dullness. He also complained of greenish mucous intermittent vaginal discharge starting 10 days ago. The bitch was chronically treated with medroxiprogesterone acetate. A laparatomy was performed and fluid in the abdomen was found and aspirated during the surgery. Also a very fluid-filled distended uterus and a mass in the distal part of the left uterine horn were found. The mass was encapsulated by the omentum, but areas of necrosis and calcification were identified. Histopathological diagnosis was endometrial adenocarcinoma. 相似文献
37.
The number of people keeping reptiles in captivity has markedly increased, and widespread inappropriate husbandry will result in an increasing incidence of the diagnosis of hepatic lipidosis(HL). It may become apparent that some species of snake have predisposition to develop HL. In the specific instance of the genus Aspidites, alterations to the usual husbandry that limit feeding and thereby body weight should markedly lessen the chance of the animal's developing HL. It is important for clinicians to develop a more aggressive approach to these cases and to build a bank of data with which to promote understanding of this common malady. 相似文献
38.
S Ikeda JM Prendes C Alonso-Montes A Rodríguez C Díez M Kitagawa H Imai E Gómez 《Reproduction in domestic animals》2006,41(5):383-385
In multiple ovulation and embryo transfer (MOET) programmes in cattle, a considerable number of morphologically poor-quality embryos continue to be produced; this is one of the limiting factors of the technique. Apoptosis has often been implicated in developmental arrest and fragmentation; these are regarded as poor traits of embryonic quality in mammalian pre-implantation embryos. In the present study, apoptosis was assessed in morphologically poor-quality embryos in comparison with good-quality embryos that were recovered from a MOET programme. Retarded embryos (two to 16 cell stage), morulae with severe fragmentation and morphologically good-quality morulae recovered from superstimulated cows at day 7 post-insemination were subjected to TdT-mediated dUTP nick-end labelling (TUNEL) and Hoechst staining. Cell nuclei that showed both TUNEL staining and apoptotic morphology were considered to be apoptotic. Apoptotic index (AI) was calculated as the percentage of apoptotic cells per embryo. Fifteen of 17 retarded embryos and 10 of 15 morphologically poor-quality morulae did not show signs of apoptosis. The mean AIs in the morphologically poor-quality embryos (two to 16 cell stage, 2.2%; poor morulae, 1.3%) were as low as that in the good-quality embryos (2.9%). These results suggest that another mode of developmental arrest and/or fragmentation that is independent of apoptosis occurs in morphologically poor-quality embryos recovered from MOET programmes. 相似文献
39.
40.