全文获取类型
收费全文 | 227篇 |
免费 | 25篇 |
国内免费 | 1篇 |
专业分类
林业 | 6篇 |
农学 | 3篇 |
基础科学 | 1篇 |
9篇 | |
综合类 | 16篇 |
农作物 | 14篇 |
水产渔业 | 12篇 |
畜牧兽医 | 187篇 |
植物保护 | 5篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 15篇 |
2012年 | 11篇 |
2011年 | 10篇 |
2010年 | 10篇 |
2009年 | 19篇 |
2008年 | 18篇 |
2007年 | 15篇 |
2006年 | 10篇 |
2005年 | 15篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 4篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有253条查询结果,搜索用时 15 毫秒
231.
In vivo quantification of muscle damage in dogs after general anaesthesia with halothane andpropofol
B. M. Aktas P. Vinclair A. Autefage H. P. Lefebvre P. L. Toutain J. P. Braun 《The Journal of small animal practice》1997,38(12):565-569
Muscle damage in dogs anaesthetised with halothane and propofol was quantified by measurement of the area under the curve of plasma creatine kinase (CK) versus time. Plasma CK remained unchanged during anaesthesia for two and a half and five hours. Following halothane anaesthesia of dogs (resting on one side directly on the surgical table or on cushions, and with or without rotation of the body every 30 minutes), plasma CK was elevated in some animals to 10 000 U/litre by the 12th hour (baseline value ≤100 u/litre), whereas it remained almost unchanged in other animals. Plasma CK then returned to reference values on day 2 or 3. The mean equivalent of muscle damaged ranged from 0–6 to 0–9 g/kg bodyweight. No muscle damage could be demonstrated in animals anaesthetised with propofol. It is therefore concluded that plasma CK should not be used as a diagnostic aid following halothane anaesthesia because of false positives due to the halothane anaesthesia itself and that propofol Is best suited for the investigation of muscle damage due to surgical procedures. 相似文献
232.
Infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) are now increasingly being reported in animals and people who work with animals, including horses and horse personnel. The objectives of this study were to evaluate the prevalence of MRSA colonization in veterinary personnel attending an international equine veterinary conference, and to identify risk factors for MRSA colonization in this group. Volunteers were recruited at the conference to provide a single nasal swab and complete a questionnaire regarding contact with the human health care system, contact with horses, and personal hand hygiene. Colonization with MRSA was found in 26/257 (10.1%) of study participants. Multivariable analysis showed an increased risk of MRSA colonization associated with having been diagnosed with or having treated a patient diagnosed with MRSA colonization or infection in the last year (odds ratio [OR] 8.41, 95% confidence interval [CI] 1.51–49.92, P = 0.015; OR 3.27, 95% CI 1.05–10.11, P = 0.039, respectively), whereas hand washing between infectious cases (OR 0.27, 95% CI 0.11–0.72, P = 0.009) and hand washing between farms (OR 0.35, 95% CI 0.14–0.98, P = 0.047) were protective. The prevalence of MRSA colonization among equine veterinary personnel found in this study was high compared to that of other studies of the general population. These data support previous suggestions that equine veterinary personnel are at increased risk of colonization with MRSA. This is the first study to demonstrate a statistically significant association between hand hygiene practices and a measurable clinical outcome in veterinary medicine. 相似文献
233.
234.
235.
KA BETTELHEIM 《Australian veterinary journal》1996,73(1):20-26
All mammals are colonised by Escherichia coli generally at birth and these organisms become part of their intestinal flora for the rest of their lives. New types are acquired generally by an oral route. Some E coli are pathogenic and some may have a far more enhanced ability to colonise the human intestine than most others. Recently enterohaemorrhagic E coli have emerged. They can cause a number of intestinal illnesses in humans including bloody diarrhoea and haemolytic uraemic syndrome. These organisms produce a number of virulence factors particularly the Shiga-like toxins (verotoxins). The intestines of animals may be the reservoir of these organisms for human infection, and cattle particularly have been shown to harbour them. Food, especially undercooked meat products, have been associated with a number of outbreaks throughout the world. While a certain serotype O157.H7 has been associated with many outbreaks throughout the world, other serotypes, particularly 0111.H-, have also been reported. This latter serotype appears to be more common in Australia. 相似文献
236.
AM Rao E Richter S Bandow B Chase PC Eklund KA Williams S Fang KR Subbaswamy M Menon A Thess RE Smalley G Dresselhaus MS Dresselhaus 《Science (New York, N.Y.)》1997,275(5297):187-191
Single wall carbon nanotubes (SWNTs) that are found as close-packed arrays in crystalline ropes have been studied by using Raman scattering techniques with laser excitation wavelengths in the range from 514.5 to 1320 nanometers. Numerous Raman peaks were observed and identified with vibrational modes of armchair symmetry (n, n) SWNTs. The Raman spectra are in good agreement with lattice dynamics calculations based on C-C force constants used to fit the two-dimensional, experimental phonon dispersion of a single graphene sheet. Calculated intensities from a nonresonant, bond polarizability model optimized for sp2 carbon are also in qualitative agreement with the Raman data, although a resonant Raman scattering process is also taking place. This resonance results from the one-dimensional quantum confinement of the electrons in the nanotube. 相似文献
237.
RÉKA DOMOKOS 《Fisheries Oceanography》2009,18(6):419-438
The South Equatorial Counter Current (SECC) strongly influences the American Samoa Exclusive Economic Zone (EEZ) and changes strength on a seasonal and ENSO cycle. A strong SECC is associated with a predominantly anticyclonic eddy field as well as increased micronekton biomass and catch-per-unit-effort (CPUE) for albacore tuna, the economically important target species of the local longline fishery. A strong SECC carries chlorophyll a -rich waters from upwelling regions at the north coast of New Guinea towards the EEZ, most likely resulting in the observed increase in micronekton biomass, forage for albacore. Relatively stable anticyclonic eddies show a further increase in micronekton biomass, apparently advected from neighboring SECC waters. The presence of forage presumably concentrates albacore, thus resulting in the observed increase in CPUE. High shear regions of neither anticyclonic nor cyclonic eddies correlate with increased micronekton biomass. Areas characterized by South Equatorial Current (SEC) waters correspond to areas with the lowest micronekton biomass and the highest number of aggregative structures, which are most likely small pelagic fish shoals. Micronekton composition in SEC waters differs from that in the SECC. During El Niños, the seasonal signals at the north shore of New Guinea and in the SECC are exceptionally strong and correspond to higher albacore CPUE in the EEZ. My results suggest that the strength of upwelling and the resulting increase in chlorophyll a at New Guinea, as well as the Southern Oscillation Index, could be used to predict the performance of the local longline fishery for albacore tuna in the American Samoa EEZ. 相似文献
238.
【目的】利用表达模式分析、转基因过表达和细胞学观察等策略,解析TaCYP78A5调控花器官大小的功能和机制,为作物遗传改良提供基因资源和理论基础。【方法】根据EnsemblPlants基因组数据库中不同物种CYP78A家族成员的序列信息,对小麦TaCYP78A5和其他物种中的同源基因进行序列比对和进化分析;利用生物信息学分析小麦TaCYP78A5的基因和蛋白结构,以及不同器官的表达模式;通过在拟南芥中组成型过表达和生殖器官局部特异性过表达TaCYP78A5的策略,明确TaCYP78A5具有调控花器官大小的功能;利用显微镜观察不同转基因拟南芥花器官的细胞学特征,解析TaCYP78A5调控花器官大小的细胞学机制;利用小麦转基因过表达策略,明确TaCYP78A5调控小麦穗部大小等其他穗部性状的功能;利用323份小麦品种的单倍型数据与穗部表型数据进行关联分析,探析不同小麦品种TaCYP78A5表达量的高低对穗部大小等其他穗部性状的影响。【结果】小麦TaCYP78A5与拟南芥AtCYP78A5的基因和蛋白序列相似性较低,但基因和蛋白结构相似性较高。小麦TaCYP78A5和拟南芥AtCYP78A5... 相似文献
239.
240.
Chetboul V Athanassiadis N Concordet D Nicolle A Tessier D Castagnet M Pouchelon JL Lefebvre HP 《Journal of veterinary pharmacology and therapeutics》2004,27(1):49-56
The objective of this study was to determine the intra- and inter-observer variability of echocardiographic measurements in dogs. Four observers with different levels of experience in echocardiography performed 192 echocardiographic examinations of six dogs on four different days. The lowest within- and between-day coefficients of variation (CV) (%) were 13.8 and 5.2 for the right ventricle in diastole, 8.9 and 4.5 for the interventricular septal thickness in diastole (6.3 and 7.0 in systole), 7.7 and 9.4 for the left ventricular free-wall thickness in diastole (8.1 and 5.2 in systole), 3.1 and 5.0 for the left ventricular end-diastolic diameter (6.2 and 7.0 for end-systolic diameter), 10.2 and 10.8 for the left ventricular shortening fraction, and 8.2 and 9.8 for the left atrium/aorta ratio, respectively. Most of these lowest CVs were observed by the two most experienced observers. Conversely, all maximum values were obtained with the two less experienced observers. These differences in observer-dependent variability may considerably influence the minimum number of animals required to detect a treatment-associated change in echocardiographic variables. 相似文献