全文获取类型
收费全文 | 1499篇 |
免费 | 62篇 |
国内免费 | 4篇 |
专业分类
林业 | 58篇 |
农学 | 33篇 |
基础科学 | 10篇 |
285篇 | |
综合类 | 269篇 |
农作物 | 81篇 |
水产渔业 | 101篇 |
畜牧兽医 | 507篇 |
园艺 | 36篇 |
植物保护 | 185篇 |
出版年
2023年 | 9篇 |
2022年 | 15篇 |
2021年 | 32篇 |
2020年 | 21篇 |
2019年 | 28篇 |
2018年 | 20篇 |
2017年 | 22篇 |
2016年 | 29篇 |
2015年 | 31篇 |
2014年 | 33篇 |
2013年 | 56篇 |
2012年 | 71篇 |
2011年 | 92篇 |
2010年 | 49篇 |
2009年 | 44篇 |
2008年 | 74篇 |
2007年 | 105篇 |
2006年 | 99篇 |
2005年 | 74篇 |
2004年 | 81篇 |
2003年 | 75篇 |
2002年 | 75篇 |
2001年 | 24篇 |
2000年 | 17篇 |
1999年 | 19篇 |
1998年 | 20篇 |
1997年 | 10篇 |
1996年 | 17篇 |
1995年 | 18篇 |
1994年 | 12篇 |
1993年 | 23篇 |
1992年 | 11篇 |
1991年 | 22篇 |
1990年 | 14篇 |
1989年 | 7篇 |
1988年 | 13篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 13篇 |
1984年 | 16篇 |
1983年 | 13篇 |
1982年 | 13篇 |
1981年 | 5篇 |
1980年 | 10篇 |
1979年 | 13篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1975年 | 9篇 |
1973年 | 6篇 |
1966年 | 6篇 |
排序方式: 共有1565条查询结果,搜索用时 0 毫秒
11.
12.
13.
OBJECTIVE: To describe a modified ventral stabilization technique for surgical management of atlantoaxial subluxation in dogs and to evaluate the outcome. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Nineteen client-owned dogs. METHODS: Medical records of 19 dogs with a radiographic diagnosis of atlantoaxial subluxation surgically managed by a modified ventral fixation technique (cortical screws, Kirschner wires, polymethylmethacrylate) were reviewed. Data on pre- and post-operative neurologic status, surgical technique, and complications were retrieved. Follow-up evaluation was performed at approximately 1 month. Telephone interview of the owner was used for long-term assessment (median follow-up for 17 surviving dogs was 10.5 months). RESULTS: Adequate reduction and stabilization was achieved in all dogs based on radiographic assessment immediately after surgery. Improved neurologic outcome occurred in 16 dogs at 1 month and in 15 dogs at follow-up; 2 dogs died of post-operative complications within 24 hours of surgery. One dog was euthanatized at the owners' request because of recurrent neck pain associated with implant failure after 1 month. Two dogs required surgery to remove broken and migrated implants, but further stabilization was not necessary. CONCLUSIONS: Adequate stabilization and improved neurologic outcome was achieved in most dogs. However, on account of the small size of the study and the variable neurologic signs of the dogs on admission, the surgical technique described could not be compared to those previously reported. CLINICAL RELEVANCE: The surgical technique described is an effective means of surgical treatment for atlantoaxial subluxation. 相似文献
14.
McCally RE Kim SE Bacon NJ Winter MD Cords AA Conway JA 《Journal of the American Animal Hospital Association》2012,48(3):198-202
A 2 yr old dog presented for dysphagia and coughing secondary to a 4 cm × 4 cm turgid subepiglottic mass. Cervical radiographs, an esophagram, and computed tomography confirmed the presence of a cystic mass that was not intimately associated with any surrounding structures. An incisional biopsy confirmed the cystic nature of the mass and helped to rule out a malignancy. A marginal surgical excision was performed via a ventral approach. Histopathology of the mass was consistent with a thyroglossal duct cyst. This is the first report of a thyroglossal duct cyst in this location in a dog. There was no recurrence of clinical signs 14 mo after surgery. 相似文献
15.
Anthony Claes Barry A. Ball Cynthia J. Corbin Alan J. Conley 《Journal of Equine Veterinary Science》2014
Cryptorchidism is a developmental disorder which can be diagnosed by a variety of different tests. Still, equine field veterinarians often rely on endocrine markers to detect retained testicular tissue. This report describes the value of anti-Müllerian hormone (AMH) as a diagnostic marker for cryptorchidism in three stallions suspected of cryptorchidism, with equivalent serum testosterone concentrations. A single measurement of AMH identified cryptorchidism, with inconclusive testosterone concentrations as either gelding or stallion. Furthermore, a human chorionic gonadotropin (hCG) stimulation test or surgery was performed to support the diagnostic value of AMH. To conclude, the endocrine panel for cryptorchidism should be expanded to include determination of serum AMH, as this determination can increase the diagnostic accuracy of a single blood sample. 相似文献
16.
Ignacio Raggio Réjean C. Lefebvre Pierre Poitras Denis Vaillancourt Alan K. Goff 《The Canadian veterinary journal. La revue veterinaire canadienne》2008,49(11):1093-1098
Multiple pregnancies are still an important cause of noninfectious abortion, stillbirth, neonatal mortality, and significant delays in reproductive performance in mares. Despite new management techniques, reduction in multiple pregnancies is an ongoing preoccupation and challenge for the equine veterinarian. The aim of the present study was to establish a twin pregnancy experimental model in the mare to study the effectiveness of a transvaginal ultrasound-guided embryonic vesicle injection. Mares in heat were inseminated and then received an embryo at day 7 of the estrous cycle. At days 14 and 30, 53.5% (n = 23) and 23% (n = 10) of the mares, respectively, were carrying twins. Twin pregnancies were reduced at day 30 by transvaginal ultrasound-guided puncture of the embryonic vesicle (control, n = 5) or by transvaginal ultrasound-guided injection (TVUEVI) of 25 mg of amikacin into the embryonic vesicle (n = 5). The TVUEVI treatment had a 40% success rate and no significant variations in progesterone and prostaglandin metabolite were observed. Even though the technique does not seem very effective, the experimental model could be useful for clinical research in embryo reduction and early embryonic loss. 相似文献
17.
18.
19.
Kelly AM Kahn GS 《Journal of the American Veterinary Medical Association》2005,226(11):1798; author reply 1798
20.
Carlson JC Linz GM Ballweber LR Elmore SA Pettit SE Franklin AB 《Veterinary parasitology》2011,180(3-4):340-343
To investigate the relationship between European starlings and bovine coccidiosis we collected samples from European starlings, cattle feed bunks, cattle water troughs, and cattle feces within concentrated animal feeding operations (CAFOs). These samples were screened for coccidia spp. to investigate (i) the prevalence of coccidia in starlings using CAFOs; (ii) if there is a relationship between bovine coccidiosis and starling numbers; (iii) if coccidia contamination of cattle feed and water is related to the number of starlings observed on CAFOs. Coccidia belonging to the genus Eimeria were detected in cattle feces and one water sample but no Eimeria spp. were detected in European starlings or cattle feed. However, many European starling samples were positive for Isospora. Starling use of CAFOs did not appear to be associated with coccidia spp. shedding by cattle and there was no correlation between starling numbers and contamination of cattle feed and water, suggesting that starling do not contribute to the amplification and spread of Eimeria in CAFOs. 相似文献