全文获取类型
收费全文 | 477篇 |
免费 | 26篇 |
专业分类
林业 | 41篇 |
农学 | 24篇 |
基础科学 | 3篇 |
98篇 | |
综合类 | 34篇 |
农作物 | 38篇 |
水产渔业 | 51篇 |
畜牧兽医 | 168篇 |
园艺 | 7篇 |
植物保护 | 39篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 41篇 |
2020年 | 26篇 |
2019年 | 31篇 |
2018年 | 16篇 |
2017年 | 22篇 |
2016年 | 24篇 |
2015年 | 18篇 |
2014年 | 28篇 |
2013年 | 36篇 |
2012年 | 41篇 |
2011年 | 31篇 |
2010年 | 25篇 |
2009年 | 16篇 |
2008年 | 16篇 |
2007年 | 17篇 |
2006年 | 20篇 |
2005年 | 17篇 |
2004年 | 12篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有503条查询结果,搜索用时 0 毫秒
91.
Saa LR Perea A Jara DV Arenas AJ Garcia-Bocanegra I Borge C Carbonero A 《Tropical animal health and production》2012,44(7):1423-1427
A cross-sectional study was carried out to determine the seroprevalence and risk factors associated with bovine respiratory syncytial virus (BRSV) infection in non-vaccinated dairy and dual-purpose cattle herds from Ecuador. A total of 2,367 serum samples from 346 herds were collected from June 2008 to February 2009. A questionnaire, which included variables related to cattle, health, management measures, and the environment, was filled out in each herd. Presence of antibodies against BRSV was analyzed using a commercial indirect ELISA test. A logistic regression model was used to determine risk factors associated with BRSV at herd level. The individual seroprevalence against BRSV in non-vaccinated herds in Ecuador was 80.48% [1,905/2,367; 95% confidence interval (CI)?=?78.9-82.1]. The herd prevalence was 91.3% (316/346; 95% CI?=?88.3-94.3), and the intra-herd prevalence ranged between 25% and 100% (mean, 90.47%). The logistic regression model showed that the existence of bordering cattle farms, the dual-purpose farms, and the altitude of the farm (more than 2,338?m above sea level) were risk factors associated with BRSV infection. This is the first study about BRSV prevalence in Ecuador. It shows the wide spread of the BRSV infection in the country. The risk factors found will help to design effective control strategies. 相似文献
92.
Eleonora Barilli Josefina C. Sillero Mnica Fernndez-Aparicio Diego Rubiales 《Field Crops Research》2009,114(2):198-203
A germplasm collection of 2759 pea accessions was screened for resistance against Uromyces pisi (Pers.) Wint. All accessions displayed a compatible interaction (high infection type) both in adult plants under field conditions and in seedlings under growth chamber conditions, but with varying levels of disease reduction. The identified resistance was based on reduction of disease severity with no associated host cell necrosis, which fits the definition of Partial Resistance. No complete resistance or incomplete resistance based on hypersensitivity was observed. 相似文献
93.
M Alonso E Camus J Rodriguez Diego L Bertaudière J C Tatareau J M Liabeuf 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1992,45(1):9-14
A serological survey using indirect immunofluorescence (IFAT) for bovine babesiosis (Babesia bovis and B. bigemina) and card test for anaplasmosis, indicates that these haemoparasites are widespread in Martinique. The high prevalences (62% for B. bovis, 52% for B. bigemina and 43% for Anaplasma marginale) lead to the hypothesis of an unstable epizootic situation for these three haemoparasitic diseases. However, the number of smears examined was too low to evaluate their clinical incidence. Both the American and Cuban card tests gave similar results in the detection of antibodies to A. marginale. Theileria mutans is described for the first time in Martinique. Trypanosomosis (Trypanosoma vivax) has disappeared from Martinique, on clinical and serological evidence. 相似文献
94.
95.
96.
Diego F. Varela-Ortiz José E. Barboza-Corona Joaquín González-Marrero Ma. Fabiola León-Galván Mauricio Valencia-Posadas Alma A. Lechuga-Arana Cynthia G. Sánchez-Felipe Fernanda Ledezma-García Abner J. Gutiérrez-Chávez 《Veterinary research communications》2018,42(3):243-250
Staphylococcus aureus is an opportunistic pathogen that may cause severe infections in livestock, and represents the major cause of mastitis in dairy cows. Currently, instead of using antibiotics, new strategies are sought to reduce this clinical health problem. The aim of this study was to determine the efficacy of phage therapy to kill S. aureus strains obtained from farms located at the State of Guanajuato, México. Thirty-six S. aureus strains from cow milk with subclinical mastitis were isolated and identified, and the susceptibility to antibiotics and four phages also isolated in this work was tested. It was found that more of 90% of S. aureus isolates were not susceptible to six or more antibiotics, and 100% were resistant to penicillin, dicloxacillin, cefotaxime, ampicillin and cephalothin, and 81 and 77%, to tetracycline and cefuroxime, respectively. Fortunately, 100% of S. aureus isolates were susceptible to phages used in this work, which was detected as clear zones using specific phage. It was shown for the first time, that phages used in this study are active against pathogenic S. aureus and might be incorporated into the therapy as an important tool for the control of staphylococcal bovine mastitis, specially to antibiotic-resistant S. aureus strains isolated in farm located at the state of Guanajuato, México; and its use might be extended to other regions inside or outside the country. 相似文献
97.
Ciaramella P Corona M Cortese L Piantedosi D Santoro D Di Loria A Rigato R 《Veterinary parasitology》2004,123(1-2):11-15
One hundred and fifty horses from Italy were tested for serum antibodies to Neospora caninum by indirect fluorescence antibody test (IFAT). Antibodies were present in 42 horses (28%). The positive titres were: 1:50 (16/150-10.5%), 1:100 (26/150-17%), 1:200 (8/150-5.3%) and 1:800 (1/150-0.6%). No neurological anomalies were observed in the seropositive horses. This is the first serologic survey for Neospora spp. antibodies performed on horses born and raised in Italy. 相似文献
98.
Diego E. Gomez Catherine L. Radtke Lauren A. Russell Alfonso Lopez Maureen W. Wichtel 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(10):1049-1052
Acute pancreatitis is a rare disease in horses and is often associated with gastrointestinal disorders. Accurate diagnosis is challenging due to the presence of nonspecific clinical signs. This case represents the first documentation of acute pancreatitis in a horse following surgery of the reproductive tract. 相似文献
99.
Pablo E Otero Natali Verdier Martin R Ceballos Lisa Tarragona Myriam Flores Diego A Portela 《Veterinary anaesthesia and analgesia》2014,41(5):543-547
ObjectiveTo determine the minimal electrical threshold (MET) necessary to elicit appropriate muscle contraction when the tip of an insulated needle is positioned epidurally or intrathecally at the L5-6 intervertebral space (phase-I) and to determine whether the application of a fixed electrical current during its advancement could indicate needle entry into the intrathecal space (phase-II) in dogs.Study designProspective, blinded study.AnimalsThirteen (phase-I) and seventeen (phase-II) dogs, scheduled for a surgical procedure where L5-6 intrathecal administration was indicated.MethodsUnder general anesthesia, an insulated needle was first inserted into the L5-6 epidural space and secondly into the intrathecal space and the MET necessary to obtain a muscular contraction of the pelvic limb or tail at each site was determined (phase-I). Under similar conditions, in dogs of phase-II an insulated needle was inserted through the L5-6 intervertebral space guided by the use of a fixed electrical current (0.8 mA) until muscular contraction of the pelvic limb or tail was obtained. Intrathecal needle placement was confirmed by either free flow of cerebrospinal fluid (CSF) or myelography.ResultsThe current required to elicit a motor response was significantly lower (p < 0.0001) when the tip of the needle was in the intrathecal space (0.48 ± 0.10 mA) than when it was located epidurally (2.56 ± 0.57). The use of a fixed electrical stimulation current of 0.8 mA resulted in correct prediction of intrathecal injection, corroborated by either free flow of CSF (n = 12) or iohexol distribution pattern (n = 5), in 100% of the cases.Conclusion and clinical relevanceNerve stimulation may be employed as a tool to distinguish epidural from intrathecal insulated needle position at the L5-6 intervertebral space in dogs. This study demonstrates the feasibility of using an electrical stimulation test to confirm intrathecal needle position in dogs. 相似文献
100.
Camilo Jaramillo David L. Renaud Luis G. Arroyo Daniel G. Kenney Lisa Gamsjaeger Diego E. Gomez 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2022,36(2):812
BackgroundIncreased concentration of haptoglobin (Hp) in serum is associated with survival of critically ill humans and horses. High serum activity of liver‐derived enzyme is associated with sepsis in children and foals.Hypothesis/ObjectivesInvestigate whether admission serum Hp and glutamic dehydrogenase (GLDH) are associated with systemic inflammatory response syndrome (SIRS) and survival of sick calves.AnimalsOne hundred two calves.MethodsRetrospective cross‐sectional study. Electronic medical records from all calves <30 days of age admitted to a teaching hospital for 8 years were reviewed. The signalment, clinicopathological findings, the presence of SIRS, final diagnosis, hospitalization time and outcome were recorded. A Cox proportional hazard ratio (HzR) were calculated to assess the association between clinicopathological variables and survival to discharge.ResultsSerum Hp concentrations were similar between SIRS (0.29 g/L; range, 0.05‐3.6) and non‐SIRS calves (0.22 g/L; range, 0‐4.2; P = .62). GLDH activity was similar between SIRS (12 U/L; range, 1‐1025) and non‐SIRS calves (9 U/L; range, 2‐137; P = .2). Absent suckle reflex (HzR: 6.44, 95% CI: 1.44‐28.86), heart rate (HR) < 100 beats per minute (bpm; HzR: 12.2; 95% CI: 2.54‐58.62), HR > 140 bpm (HzR: 3.59, 95% CI: 1.05‐12.33), neutrophil count <1.7 × 109/L (HzR: 7.36; 95% CI: 2.03‐26.66) and increased gamma‐glutamyl transferase activity (every 50‐unit, HzR: 1.12; 95% CI: 1.03‐1.21) were predictive of nonsurvival.Conclusions and Clinical ImportanceThe use of Hp and GLDH for prediction of survival in sick calves cannot be recommended at this time. 相似文献