全文获取类型
收费全文 | 304篇 |
免费 | 23篇 |
专业分类
林业 | 7篇 |
农学 | 23篇 |
基础科学 | 1篇 |
16篇 | |
综合类 | 61篇 |
农作物 | 5篇 |
水产渔业 | 16篇 |
畜牧兽医 | 181篇 |
园艺 | 2篇 |
植物保护 | 15篇 |
出版年
2023年 | 4篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 15篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 11篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 9篇 |
2003年 | 10篇 |
2002年 | 12篇 |
2001年 | 21篇 |
2000年 | 13篇 |
1999年 | 9篇 |
1998年 | 3篇 |
1997年 | 8篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1991年 | 7篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1969年 | 3篇 |
1967年 | 5篇 |
1935年 | 2篇 |
1932年 | 2篇 |
1925年 | 2篇 |
1908年 | 2篇 |
排序方式: 共有327条查询结果,搜索用时 593 毫秒
111.
P Hedenqvist DVM HE Orr† BVMS Cert LAS JV Roughan† BSc PhD LM Antunes† MSc DVM & PA Flecknell† M.A Vet MB PhD DLAS Dip ECVA MRCVS 《Veterinary anaesthesia and analgesia》2002,29(1):14-19
Objective To compare the characteristics of anaesthesia induced with ketamine/medetomidine administered by the subcutaneous and intramuscular routes and to assess the effects of the addition of butorphanol to this combination. Study design Prospective randomised study. Animals Six female New Zealand White rabbits. Methods Rabbits were given one of four combinations of ketamine and medetomidine (K/M) either subcutaneously (SC) or intramuscularly (IM) on four successive occasions with a 7‐day interval between treatments. The dose combinations were; 15/0.25 mg kg?1 SC; 15/0.25 mg kg?1 IM; 15/0.5 mg kg?1 SC, and 15/0.25 mg kg?1 together with 0.4 mg kg?1 butorphanol (K/M/B) SC. The effects of anaesthesia on arterial blood gas values and cardiovascular variables were recorded at predetermined time points. Toe and ear pinch reflexes were judged to determine the duration of surgical anaesthesia. Loss of the righting reflex was used to measure the duration of sleep time. Analyses used repeated measures analysis of variance. Results All groups lost the righting reflex and ear pinch response. Three animals in the groups that received K/M alone lost their toe pinch reflex, whereas four lost this reflex when given K/M/B. Time of onset of loss of the righting, toe and ear pinch reflexes did not differ significantly among the groups. The higher dose combination of medetomidine with ketamine and the combination of K/M/B produced a greater duration of loss of the ear pinch response than the lower dose of K/M administered by either route. No significant differences were found among the groups in the duration of loss of the toe pinch reflex. All animals developed a moderate bradycardia (mean heart rate <166 beats minute?1) and moderate hypoxaemia (mean PaO2 < 6.0 kPa). Animals given butorphanol showed the greatest reduction in respiratory rate (31 ± 13 breaths minute?1, p < 0.05) but this was not reflected in any significant differences in arterial PCO2, PO2 or pH among the groups. Conclusions Administration of K/M by the SC route produced equivalent effects in comparison to intramuscular administration. The addition of butorphanol increased the duration of anaesthesia, but produced a slight increase in the degree of respiratory depression. All dose rates resulted in hypoxaemia so oxygen should be administered when these combinations are used in rabbits. Clinical relevance Subcutaneous administration is both technically simpler and may cause less discomfort to the animal than IM injection, and so is preferred. The combination of K/M with butorphanol has relatively minor effects on the depth and duration of anaesthesia, so offers little advantage to the use of K/M alone. 相似文献
112.
J. Häggström A. Boswood M. O'Grady O. Jöns S. Smith S. Swift M. Borgarelli B. Gavaghan J.‐G. Kresken M. Patteson B. Åblad C.M. Bussadori T. Glaus A. Kovačević M. Rapp R.A. Santilli A. Tidholm A. Eriksson M.C. Belanger M. Deinert C.J.L. Little C. Kvart A. French M. Rønn‐Landbo G. Wess A. Eggertsdottir M. Lynne O'Sullivan M. Schneider C.W. Lombard J. Dukes‐McEwan R. Willis A. Louvet R. DiFruscia 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2013,27(6):1441-1451
113.
114.
115.
Keyath Nisar Jitendra Kumar MB Arun Kumar Suresh Walia Najam A Shakil Rajender Parsad Balraj S Parmar 《Pest management science》2009,65(2):175-182
BACKGROUND: Infestation of seeds by pests during storage leads to deterioration in quality. Seed coating is an effective option to overcome the menace. Unlike synthetic fungicidal seed coats, little is known of those based on botanicals. This study aims at developing azadirachtin‐A‐based pesticidal seed coats to maintain seed quality during storage. RESULTS: Polymer‐ and clay‐based coats containing azadirachtin‐A were prepared and evaluated for quality maintenance of soybean seed during storage. Gum acacia, gum tragacanth, rosin, ethyl cellulose, hydroxyethyl cellulose, polyethyl methacrylate, methyl cellulose, polyethylene glycol, polyvinyl chloride, polyvinyl acetate, polyvinyl pyrrolidone and Agrimer VA 6 polymers and the clay bentonite were used as carriers. The time for 50% release (t1/2) of azadirachtin‐A into water from the seeds coated with the different coats ranged from 8.02 to 21.36 h. The half‐life (T1/2) of azadirachtin‐A in the coats on seed ranged from 4.37 to 11.22 months, as compared with 3.45 months in azadirachtin‐A WP, showing an increase by a factor of nearly 1.3–3.3 over the latter. The coats apparently acted as a barrier to moisture to reduce azadirachtin‐A degradation and prevented proliferation of storage fungi. Polyethyl methacrylate, polyvinyl acetate and polyvinyl pyrrolidone were significantly superior to the other polymers. Azadirachtin‐A showed a significant positive correlation with seed germination and vigour, and negative correlation with moisture content. CONCLUSION: Effective polymeric carriers for seed coats based on azadirachtin‐A are reported. These checked seed deterioration during storage by acting as a barrier to moisture and reduced the degradation of azadirachtin‐A. Copyright © 2008 Society of Chemical Industry 相似文献
116.
117.
Jens Gebauer Yahia O. Adam Aida Cuní Sanchez Dietrich Darr Muneer E. S. Eltahir Kamal E. M. Fadl Gabriele Fernsebner Michael Frei Tsige-Yohannes Habte Karl Hammer Mauricio Hunsche Henry Johnson Maha Kordofani Michael Krawinkel Florian Kugler Eike Luedeling Tarig E. Mahmoud Anthony Maina Dagmar Mithöfer Chimuleke R. Y. Munthali Georg Noga Rabea North Willis O. Owino Kathleen Prinz Freda K. Rimberia Amina Saied Martin Schüring Anne Sennhenn Martin A. Späth Mohamed E. N. Taha Andreas Triebel Florian Wichern Martin Wiehle Nicole Wrage-Mönnig Katja Kehlenbeck 《Genetic Resources and Crop Evolution》2016,63(3):377-399
118.
Serum testosterone,sperm quality,cytological, physicochemical and biochemical characteristics of the prostatic fraction of dogs with prostatomegaly 下载免费PDF全文
A Aquino‐Cortez BQ Pinheiro HVR Silva DBC Lima TFP Silva MB Souza DA Viana FAF Xavier Júnior JSAM Evangelista FZ Brandão LDM Silva 《Reproduction in domestic animals》2017,52(6):998-1003
Prostatomegaly is a common finding in older non‐neutered dogs. This study compared the serum testosterone, sperm quality and characteristics of the prostatic fraction between healthy dogs and dogs with prostatomegaly. Blood samples of ten dogs (five dogs from each group) were taken for serum testosterone measurement. Sperm motility, vigour, concentration, viability, membrane functionality and morphology were analysed in sperm‐rich fraction. Osmolality, pH, cell types, and albumin, haemoglobin, acid phosphatase, alkaline phosphatase, glucose, triglycerides, cholesterol, calcium, phosphorus, magnesium and chloride were analysed in prostatic fraction. Dogs with prostatomegaly have the lowest sperm motility, vigour, concentration and functional membrane. Dogs with prostatomegaly have the highest glucose, triglycerides and cholesterol. Glucose was the only constituent positively correlated with serum testosterone and prostate volume. It can be concluded that dogs with prostatomegaly have poorer sperm quality, and glucose, triglycerides and cholesterol in prostatic fraction can be used as prostatomegaly biomarkers. 相似文献
119.
Cherie A. Motti Piers Ettinger-Epstein Richard H. Willis Dianne M. Tapiolas 《Marine drugs》2010,8(1):190-199
The viviparous Great Barrier Reef sponge Luffariella variabilis (Poléjaeff 1884) contains a range of secondary metabolites, including manoalide (1) and manoalide monoacetate (3). ESI (+) FTICR-MS accurate mass determination has, for the first time, been used to detected the presence of 3 only in an organic extract of a single L. variabilis larva showing that the parentally produced 3 is sequestered in the larva. As 3 has previously been shown to have antibacterial and quorum sensing inhibition activity, and readily converts to 1, which also exhibits similar activity, it may provide a chemical defence against predation and microbial attack. 相似文献
120.
Effect of Ischemia and Reperfusion on Neutrophil Accumulation in Equine Microvascular Tissue Flaps 总被引:1,自引:0,他引:1
W. Michael Scott DVM MVSc Diplomate ACVS J. David Fowler DVM MVSc Diplomate ACVS Gilbert Matte PhD rew L. Allen DVM MVSc PhD A. A. Wilkinson MA MB BChir MSc FRCPC Jeremy V. Bailey BVSc MVSc Diplomate ACVS Peter B. Fretz VMD Diplomate ACVS 《Veterinary surgery : VS》1999,28(3):180-187
Objective— To investigate neutrophil accumulation after ischemia and reperfusion (IR) in microvascular tissue flaps in horses.
Study Design— Randomized controlled experiment.
Sample Population— A total of 8 horses between 1 and 10 years of age, 4 of each sex.
Methods— Control and experimental myocutaneous island flaps based on the superficial branch of the deep circumflex iliac vessels were dissected on each horse. Atraumatic vascular clamps were applied to the pedicle of the experimental flap for 90 minutes and then removed to allow reperfusion. Based on the assumption that rapid infiltration of neutrophils into affected tissues is a hallmark of IR injury, radiolabeled autogenous leukocytes were used to indirectly quantify neutrophil accumulation in flap tissues. Labeled leukocytes were administered through a jugular catheter 30 minutes before flap reperfusion. Biopsies were collected from each flap over a 6 hour postischemia time period; in group 1 ( n = 4 ) from 0 to 6 hours postischemia, and in group 2 ( n = 4 ) from 24 to 30 hours postischemia. Biopsies were examined scintigraphically and histologically for evidence of neutrophil infiltration.
Results— All control flaps survived and 6 of 8 experimental flaps survived. There was no significant evidence of acute neutrophil infiltration into flap tissues after reperfusion in either group.
Conclusions— The results of this study suggest that equine myocutaneous flap tissues can survive a 90-minute ischemic period and reperfusion. No significant evidence of the occurrence of IR injury in flap tissues was found.
Clinical Relevance— The reasons for the previously reported failures of equine free tissue transfer remain uncertain, but they do not appear to be caused by neutrophil mediated injury associated with ischemia and reperfusion. 相似文献
Study Design— Randomized controlled experiment.
Sample Population— A total of 8 horses between 1 and 10 years of age, 4 of each sex.
Methods— Control and experimental myocutaneous island flaps based on the superficial branch of the deep circumflex iliac vessels were dissected on each horse. Atraumatic vascular clamps were applied to the pedicle of the experimental flap for 90 minutes and then removed to allow reperfusion. Based on the assumption that rapid infiltration of neutrophils into affected tissues is a hallmark of IR injury, radiolabeled autogenous leukocytes were used to indirectly quantify neutrophil accumulation in flap tissues. Labeled leukocytes were administered through a jugular catheter 30 minutes before flap reperfusion. Biopsies were collected from each flap over a 6 hour postischemia time period; in group 1 ( n = 4 ) from 0 to 6 hours postischemia, and in group 2 ( n = 4 ) from 24 to 30 hours postischemia. Biopsies were examined scintigraphically and histologically for evidence of neutrophil infiltration.
Results— All control flaps survived and 6 of 8 experimental flaps survived. There was no significant evidence of acute neutrophil infiltration into flap tissues after reperfusion in either group.
Conclusions— The results of this study suggest that equine myocutaneous flap tissues can survive a 90-minute ischemic period and reperfusion. No significant evidence of the occurrence of IR injury in flap tissues was found.
Clinical Relevance— The reasons for the previously reported failures of equine free tissue transfer remain uncertain, but they do not appear to be caused by neutrophil mediated injury associated with ischemia and reperfusion. 相似文献