全文获取类型
收费全文 | 573篇 |
免费 | 22篇 |
专业分类
林业 | 15篇 |
农学 | 5篇 |
60篇 | |
综合类 | 92篇 |
农作物 | 57篇 |
水产渔业 | 17篇 |
畜牧兽医 | 295篇 |
园艺 | 20篇 |
植物保护 | 34篇 |
出版年
2019年 | 12篇 |
2018年 | 10篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 27篇 |
2012年 | 26篇 |
2011年 | 26篇 |
2010年 | 16篇 |
2009年 | 20篇 |
2008年 | 23篇 |
2007年 | 24篇 |
2006年 | 16篇 |
2005年 | 26篇 |
2004年 | 11篇 |
2003年 | 13篇 |
2002年 | 14篇 |
2001年 | 11篇 |
2000年 | 19篇 |
1999年 | 13篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1995年 | 7篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 11篇 |
1990年 | 19篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 9篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 12篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1973年 | 6篇 |
1972年 | 9篇 |
1971年 | 4篇 |
1970年 | 6篇 |
1967年 | 7篇 |
1958年 | 3篇 |
1957年 | 3篇 |
1955年 | 4篇 |
排序方式: 共有595条查询结果,搜索用时 31 毫秒
131.
An adult dog with a persistent elevation in alkaline phosphatase enzyme activity was started on mitotane for suspected hyperadrenocorticism. One month later, the dog was presented for intermittent anorexia and acute icterus. The dog's liver enzyme activities and total bilirubin were markedly elevated, prothrombin time was prolonged, and blood urea nitrogen and glucose were low. Histopathology revealed marked, centrilobular, hepatocellular loss. After discontinuation of the mitotane, the dog recovered with supportive care and was normal 3 months later, which was consistent with mitotane-associated hepatic failure. 相似文献
132.
133.
Webb C Bedwell C Guth A Avery P Dow S 《Veterinary immunology and immunopathology》2006,112(3-4):129-140
Oxidative stress and abnormal glutathione metabolism is thought to play an important role in various diseases of cats. However, current assays for the reduced form of glutathione (GSH) are time-consuming and semi-quantitative and do not allow assessment of GSH concentrations in individual cell populations. Therefore, we developed a flow cytometric assay for rapid determination of intracellular GSH concentrations in feline blood leukocytes. The assay was based on the ability of the non-fluorescent substrate monochlorobimane (mBCl) to form fluorescent adducts with GSH in a reaction catalyzed by the enzyme glutathione-S-transferase. Using flow cytometry, we found that mBCl was sensitive and specific for intracellular detection of the reduced form of GSH in feline leukocytes. Intracellular GSH concentrations were also stable for at least 24h in EDTA preserved whole blood samples stored at 4 degrees C. Neutrophils and monocytes from normal cats had significantly higher intracellular concentrations of GSH than T cells and B cells. The effects of FIV infection on intracellular GSH concentrations in cats were assessed using flow cytometry. We found that neutrophils from FIV-infected cats had significantly increased GSH concentrations, whereas intracellular GSH concentrations were significantly decreased in CD4(+) and CD8(+) lymphocytes from FIV-infected cats, compared to age-matched control animals. We conclude that a flow cytometric assay based on mBCl may be used to accurately and rapidly assess the effects of various disease states and treatments on GSH concentration in cat leukocytes and to help assess intracellular oxidative stress. 相似文献
134.
Popmintchev T Chen MC Popmintchev D Arpin P Brown S Alisauskas S Andriukaitis G Balciunas T Mücke OD Pugzlys A Baltuska A Shim B Schrauth SE Gaeta A Hernández-García C Plaja L Becker A Jaron-Becker A Murnane MM Kapteyn HC 《Science (New York, N.Y.)》2012,336(6086):1287-1291
High-harmonic generation (HHG) traditionally combines ~100 near-infrared laser photons to generate bright, phase-matched, extreme ultraviolet beams when the emission from many atoms adds constructively. Here, we show that by guiding a mid-infrared femtosecond laser in a high-pressure gas, ultrahigh harmonics can be generated, up to orders greater than 5000, that emerge as a bright supercontinuum that spans the entire electromagnetic spectrum from the ultraviolet to more than 1.6 kilo-electron volts, allowing, in principle, the generation of pulses as short as 2.5 attoseconds. The multiatmosphere gas pressures required for bright, phase-matched emission also support laser beam self-confinement, further enhancing the x-ray yield. Finally, the x-ray beam exhibits high spatial coherence, even though at high gas density the recolliding electrons responsible for HHG encounter other atoms during the emission process. 相似文献
135.
136.
Hart ML Suchodolski JS Steiner JM Webb CB 《Journal of Feline Medicine and Surgery》2012,14(4):240-245
This study was designed to test the hypothesis that in cats with chronic diarrhea the daily administration of a proprietary synbiotic (Proviable-DC) would result in an improvement in stool character, as assessed by the owner. Adult cats with chronic diarrhea were recruited for the study and screened for systemic diseases. Fecal flotation, wet mount, immunofluorescence assay (IFA) for Giardia and Cryptosporidium species, and Tritrichomonas species polymerase chain reactions (PCRs) were used to screen for intestinal parasitism. The synbiotic was administered for 21 days; otherwise, no changes were made to ongoing treatment(s) or diet. The severity of the diarrhea was assessed using a standardized fecal scoring system and the owner's subjective perception before, and after, supplementation. The mean fecal score for the 53 cats completing the study decreased from 6.0 to 4.4, representing a significantly (P <0.001) firmer stool character. Seventy-two percent of owners perceived an improvement in their cat's diarrhea following a 21-day course of synbiotic supplementation. 相似文献
137.
Mesenchymal stem cells (MSC) are increasingly being proposed as a therapeutic option for a variety of different diseases in human and veterinary medicine. At present, MSC are most often collected from bone marrow (BM) or adipose tissue (AT) and enriched and expanded in vitro before being transferred into recipients. However, little is known regarding the culture characteristics of feline BM-derived (BM-MSC) versus AT-derived MSC (AT-MSC). We compared BM-MSC and AT-MSC from healthy cats with respect to in vitro growth and cell surface phenotype. Mesenchymal stem cells isolated from AT proliferated significantly faster than BM-MSC. Phenotypic differences between BM-MSC and AT-MSC were not present in the surface markers assessed. We conclude that BM-MSC and AT-MSC are similar phenotypically but that cultures of AT-MSC are easier to generate because of their higher intrinsic proliferative rate. Thus, AT-MSC may be the preferred MSC for clinical applications where rapid and efficient generation of MSC is important. 相似文献
138.
Three ejaculates were collected from four stallions and used to compare the effects of three centrifugation methods on post-storage motility and recovery of available sperm. Two aliquots per ejaculate were diluted with skim milk-glucose (SKMG) extender to 50×106 sperm/mL, placed in 50-mL conical bottom tubes, and centrifuged at either 700g for 15 minutes (700g) or 600g for 12 minutes (600g). A third aliquot was diluted 1:1 with SKMG, placed in 15-mL conical tubes, and centrifuged at 400g for 7 minutes (400g). Subsamples from each pre-treated diluted ejaculate were held at room temperature and evaluated for motility at the same time as the post-centrifugation pre-storage motility evaluation was made for treated aliquots. After centrifugation, samples from each aliquot were stored at 5°C for evaluation after 24 and 48 hours or frozen in liquid nitrogen. Percentage of available sperm harvested was higher (P ≤ .05) for aliquots centrifuged in 15-mL tubes at 400g versus 600g in 50-mL tubes. After centrifugation, total but not progressive motility of aliquots centrifuged at 700g was lower than that for noncentrifuged controls and sperm from aliquots centrifuged at 400g in 15-mL tubes. After cold storage, values for total but not progressive motility or velocity were higher (P ≤ .05) for aliquots centrifuged in 15-mL tubes at 400g compared with those centrifuged in 50-mL tubes at both 600g and 700g. Postthaw motility of frozen sperm was not different between centrifugation treatments. Poststorage percentages of intact acrosomes and detached heads did not differ because of centrifugation treatment. 相似文献
139.
Jinelle A. Webb Julius M. Liptak Saundra A. Hewitt Andrew R. Vince 《The Canadian veterinary journal. La revue veterinaire canadienne》2009,50(1):81-84
Multilobular osteochondrosarcoma (MLO) of the os penis was diagnosed in a dysuric dog. Recurrence was confirmed or suspected twice over a 22-month period. This is the first reported case of MLO occurring in the os penis, and the 5th reported case of neoplasia of the os penis in the dog. 相似文献
140.