全文获取类型
收费全文 | 295篇 |
免费 | 27篇 |
专业分类
林业 | 5篇 |
农学 | 2篇 |
18篇 | |
综合类 | 60篇 |
农作物 | 5篇 |
水产渔业 | 8篇 |
畜牧兽医 | 202篇 |
园艺 | 3篇 |
植物保护 | 19篇 |
出版年
2021年 | 4篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 5篇 |
2013年 | 20篇 |
2012年 | 16篇 |
2011年 | 15篇 |
2010年 | 13篇 |
2009年 | 5篇 |
2008年 | 19篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2005年 | 16篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 10篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1993年 | 4篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 8篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1969年 | 3篇 |
1968年 | 3篇 |
1967年 | 2篇 |
1938年 | 1篇 |
1935年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有322条查询结果,搜索用时 234 毫秒
41.
Objective The aim of this study was to describe the practices, attitudes and beliefs of Queensland veterinarians in relation to postoperative pain and perioperative analgesia in dogs. Methods One veterinarian from each of the 50 randomly selected Queensland veterinary practices was enrolled after selection by convenience sampling. Results The study response rate was 94.3%. Demeanour, vocalisation and heart rate were the most common postoperative pain assessment tools used, even though the most sensitive tools were considered to be demeanour, heart rate and respiratory rate. Only 20% of respondents used formalised pain scoring systems. Preoperative analgesic administration was always used by 72% of respondents. There was marked variability in the frequency with which analgesia was administered perioperatively for ovariohysterectomy. Only 24% of veterinarians discharged animals with ongoing analgesia even though 38% agreed that pain is still present 7 days postoperatively. Multimodal analgesia was used by 82% of respondents. Epidural and local anaesthetic analgesic techniques were not being utilised by any respondents. Conclusions These results indicate that management of postoperative pain in dogs in Queensland is frequently suboptimal and, at times, is not consistent with the veterinarian's attitudes and beliefs. Continuing education into analgesic use and pain evaluation may be effective in addressing this. 相似文献
42.
The objectives of the current study were to estimate the sensitivity and specificity of three real-time polymerase chain reaction (PCR) tests for diagnosis of feline immunodeficiency virus (FIV) infection in domestic cats, both individually and when interpreted in series with one of two serological tests, separately in populations of cats at low and high risk of being infected with FIV. One PCR test targeted the pol gene and two targeted the gag gene of FIV. For comparison, sensitivities and specificities of the individual serological tests (IDEXX SNAP(?) test and AGEN Simplify(?) test) were also estimated. The study populations consisted of domestic cats thought to be not vaccinated against FIV. Low-risk (males aged 4 years or less and females; n=128) and high-risk (males over 4 years; n=128) cats were selected from those where blood samples were submitted to a commercial clinical pathology service. Bayesian latent class models were used to obtain posterior probability distributions for sensitivity and specificity for each test, based on prior distributions obtained from three experts. Medians of the posterior sensitivity distributions for the PCR tests based on the pol gene and two regions of the gag gene tests ranged from 0.85 to 0.89, compared to 0.89-0.97 for the two serological tests. The medians of posterior specificity distributions for these PCR tests were 0.94-0.96, and 0.95-0.97 for the serological tests. In contrast, the PCR based on one region of the gag gene had lower median sensitivity. Sensitivities of combinations of these serological and PCR tests interpreted in series were low; medians of posterior sensitivity distributions ranged from 0.75 to 0.83. Relative to the low-risk population, median sensitivities in the high-risk population were lower for all tests other than the AGEN Simplify(?) test; specificities were similar in both populations. We conclude that the sensitivities of the two PCR tests based on the pol gene and two regions of the gag gene, respectively, in non-vaccinated cats are probably lower than the sensitivities of the two serological tests we assessed. We do not recommend screening cats whose FIV vaccination status is uncertain with one of these serological tests and then testing positives with one of these PCR tests because in non-vaccinates, the sensitivities of combinations of these serological and PCR tests interpreted in series are low. Assessment of the validity of these PCR assays in FIV-vaccinated cats is required. 相似文献
43.
The postprandial increase in glucose concentration is typically not considered in selecting diets to manage diabetic and pre-diabetic cats. This study describes increases in glucose and insulin concentrations in 24 clinically healthy, neutered adult cats following one meal (59 kcal/kg) of a moderate carbohydrate diet (25% of energy). Median time to return to baseline after feeding for glucose was 12.2 h (1.8-≥24 h) and for insulin was 12.3 h (1.5-≥24 h). Time to return to baseline for glucose was not different between male (10.2 h) and female (17.2 h) cats. There was evidence female cats had a longer return to baseline for insulin (18.9 h versus 9.8 h) and females had higher (0.9 mmol/l difference) peak glucose than males. This demonstrates that the duration of postprandial glycaemia in cats is markedly longer than in dogs and humans, and should be considered when managing diabetic and pre-diabetic cats. 相似文献
44.
45.
46.
47.
The concentrations of trace elements in fish roes and the effect of processing conditions (karasumi-like or karashi mentaiko) were investigated in six commercial fish species from New Zealand. The studied elements were As, Cd, Cr, Cu, Hg, Pb, and Zn, and the roes were from the following species: chinook salmon ( Oncorhynchus tshawytscha), hoki ( Macruronus novaezelandiae), southern blue whiting ( Micromesistius australis), hake ( Merluccius australis), blue warehou ( Seriolella brama), and barracouta ( Thyrsites atun). The concentrations of As, Cd, Cr, Hg, and Pb in the roes were lower than literature values for fish muscles. Only Zn in barracouta roe and Cu in salmon roe and their products were relatively higher than the generally accepted levels in fish muscles and could be of safety concern. Hence, the consumption of barracouta and salmon roes among certain parts of the population needs to be monitored and assessed. Dry salting (karasumi-like) processing increased ( P < 0.001) the concentrations of the studied trace elements while salting fermentation (karashi mentaiko) processing tended to decrease the levels of trace elements. Fermentation may be a useful process to decrease the level of toxic trace elements. 相似文献
48.
REASONS FOR PERFORMING STUDY: Several therapeutic agents have been tested in models of ischaemia and reperfusion injury (IRI) in equine jejunum, with mixed results. This study was based on the use of an organ perfusion solution (OPS) designed to protect human allografts from IRI. HYPOTHESIS: A modified OPS can preserve the integrity of equine large colon during 12 h of isolated pulsatile perfusion, in the absence of oxygen and blood. METHODS: Segments of large colon were removed from anaesthetised horses, the contents removed and the mucosa rinsed with 0.9% saline. Experimental segments were perfused for 12 h with one litre modified OPS (n = 7) delivered by pulsatile flow through an extracorporeal circuit. Control segments (n = 4) were perfused on the same circuit with one litre of autologous blood. Vascular resistance, flow and pressure were measured serially, and aliquots of OPS and blood drawn hourly for routine biochemical analyses. Mucosal biopsies of the experimental and control segments were taken at 0, 6 and 12 h and in vivo mucosal tissue at 0 h for baseline comparison. All biopsies underwent histomorphometric analysis and immunohistochemical assessment of calprotectin activity. RESULTS: All colon segments were machine perfused without technical complications. Vascular and biochemical indices remained constant over 12 h in the OPS group, and were constant over 6 h in the control group, but deteriorated later. Mucosal integrity, expression of cyclooxygenases-1 and -2, and expression of mucosal calprotectin were unchanged in the OPS group compared with the baseline tissues, and mucosal integrity was superior to the control tissues. CONCLUSIONS: A modified OPS designed to target specific pathways of damage from IRI can preserve colonic mucosal integrity for 12 h in the absence of blood and oxygen. 相似文献
49.
REASON FOR PERFORMING STUDY: The cytosolic protein complex, calprotectin, is abundant in neutrophils and could be used to improve the ability to localise and assess neutrophil infiltration in the equine intestine during ischaemia and reperfusion (I/R), but further study is required. OBJECTIVES: To assess the number of calprotectin-containing cells by immunohistochemistry in correlation with direct counting and scoring of neutrophils in the equine colon during I/R. METHODS: One and 2 h ischaemia of the left dorsal colon were induced, followed by 30 min reperfusion under general anaesthesia or by 18 h reperfusion after anaesthetic recovery. Biopsies were processed for light microscopy and stained with H/E for detection of neutrophils. To identify calprotectin-containing cells, immunohistochemistry was performed on formalin-fixed tissues with the murine MAC 387 antibody and a biotin-free peroxidase staining procedure. The number of neutrophils within submucosal venules and the colonic mucosa were calculated and compared with the number of calprotectin-positive cells. RESULTS: The number of calprotectin-positive cells within submucosal venules and within the colonic mucosa correlated significantly with the accumulation of neutrophils within the corresponding tissue segments. Within the submucosal venules, both calprotectin-positive cells and H/E-stained neutrophils increased with duration of ischaemia and peaked after 30 min of reperfusion. After 18 h reperfusion the number of these cells declined within the vessels. After 2 h ischaemia, neutrophils started to migrate into the mucosa towards the epithelium, with a significant increase over time during reperfusion, and peak infiltration after 18 h reperfusion. CONCLUSIONS: Neutrophil infiltration into the colon after I/R is a time-dependent process, involving migration through the submucosa towards the epithelium. 相似文献
50.
The pharmacological effects of glargine administered once or twice daily were compared in six healthy cats. A two-way crossover study was performed with insulin and glucose concentrations measured following subcutaneous administration of glargine once daily (0.5U/kg) or twice daily (0.25U/kg, repeated after 12h). Nadir glucose concentration and mean daily glucose concentration did not differ significantly following insulin administration once daily or twice daily in divided doses. Time to reach last glucose nadir differed, with longer intervals occurring following twice daily dosing. Blood glucose failed to return to baseline concentration by 24h in three of six cats in each treatment group. Insulin variables were not significantly different following once or twice daily dosing. This study in healthy cats demonstrates that glargine has a long duration of action with carry-over effects to the next day likely, regardless of dosing regimen. A study in diabetic cats is required to determine the best dosing regimen. 相似文献