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31.
OBJECTIVE: To determine whether particular antimicrobial susceptibility profiles of bovine mastitis-causing Staphylococcus aureus isolates were associated with specific S aureus genotypes. SAMPLE POPULATION:357 S aureus isolates recovered from milk samples submitted for diagnostic bacteriologic testing from 24 dairy herds. PROCEDURES: Antimicrobial susceptibility of S aureus isolates was assessed by determining minimum inhibitory concentrations (MICs) to 14 antimicrobial agents. After digestion of S aureus genomic DNA by SmaI, electrophoretic patterns were obtained via pulsed-field gel electrophoresis (PFGE) and used to classify isolates into types. Gels were analyzed, and data were used to prepare dendrograms. RESULTS: 308 of 357 (86%) S aureus isolates were susceptible to all antimicrobials evaluated. Forty-nine S aureus isolates were resistant to 1 or more antimicrobials; of these isolates, 37 were resistant only to penicillin, 9 were resistant to penicillin and erythromycin, 2 were resistant to tetracycline, and 1 was resistant to erythromycin. Isolates were assigned to 7 PFGE types. An association was found between PFGE type and antimicrobial susceptibility profile. Organisms with resistance to at least one of the tested antimicrobial agents were identified in only 4 of the 7 types of S aureus. CONCLUSIONS AND CLINICAL RELEVANCE: Antimicrobial resistance was uncommon among the mastitis-causing S aureus isolates identified in the milk samples. A limited number of genotypes were associated with mastitis in these herds. Antimicrobial resistance phenotypes were associated with particular S aureus PFGE types; this association may have implications for future treatment and control of S aureus-associated mastitis in cattle.  相似文献   
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In this study, a rhamnose-binding lectin from the roe of chinook salmon (Oncorhynchus tshawytscha) was purified and characterized, and its biological activities were examined in several model systems. Chinook salmon roe lectin had a molecular mass of 30 kDa and agglutinated rabbit and bovine erythrocytes. The hemagglutination activity of the lectin was not affected by metal ions. The lectin was stable up to 70 °C and between pH 4 and pH 11. Chinook salmon roe lectin did not exert antifungal activity toward the fungal species tested and did not exhibit mitogenic response toward mouse splenocytes up to a concentration of 5 mg/mL. The lectin had selective antiproliferative activity toward human breast cancer MCF-7 cells and hepatoma Hep G2 cells. It also induced the production of nitric oxide from mouse peritoneal macrophages. This is the first report that demonstrates these biological activities from chinook salmon roe lectin.  相似文献   
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Western flower thrips, Frankliniella occidentalis (Pergande), is a major pest of strawberry and other horticultural and ornamental crops. Biological control of F. occidentalis with predatory mites is recommended as an additional management strategy to chemical control in glasshouse and protected crops. However, it is not known whether multiple (two or three) species releases of predatory mites are more effective than single species releases. The effect of an application of spinosad followed by mite releases could further increase suppression of F. occidentalis. In a series of trials in the glasshouse, we evaluated three commercially available predatory mite species, Typhlodromips montdorensis (Schicha), Neoseiulus cucumeris (Oudemans) and Hypoaspis miles (Berlese). Strawberry plants were sprayed once with either spinosad at the recommended rate or with water. F. occidentalis adults were released onto plants 24 h after spraying, and mites were released six days later. Spinosad significantly reduced F. occidentalis compared to the control (water). T. montdorensis, N. cucumeris and H. miles significantly reduced F. occidentalis compared to the ‘no mite’ treatment. Spinosad had no effect on T. montdorensis and N. cucumeris, as their numbers did not differ between the spinosad and control treatments; H. miles was not recovered. When mites were released after an application of spinosad, greater suppression of F. occidentalis was achieved than with releases of predatory mites alone. When released as a double species combination, ‘T. montdorensis and H. miles’ was the most effective combination. There was no difference in efficacy between releases of ‘T. montdorensis and H. miles’ or ‘T. montdorensis, N. cucumeris and H. miles’. We conclude that multiple species releases are more effective than single species releases, and that biological control of F. occidentalis with predatory mites can be used together with spinosad.  相似文献   
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ObjectivesReport the effect of carvedilol administration on clinical and echocardiographic parameters and outcome in dogs with preclinical (ACVIM Stage B) chronic valvular heart disease (CVD).Animals, materials and methodsRetrospective case series of 38 client-owned dogs.Demographic, physical examination and diagnostic imaging findings, blood pressure (BP), administration details and outcome were obtained from medical records of dogs receiving carvedilol for preclinical CVD. When possible, additional follow-up information was obtained through telephone interviews with referring veterinarians and owners.ResultsBaseline data and follow-up were evaluated. Median and interquartile range (IQR) for age and weight were 8.6 (7.2–10.8) years and 8.5 (7.6–9.6) kg. 14/38 were male; 33/38 were Cavalier King Charles Spaniels; 33/38 had Stage B2 CVD. The initial dose of carvedilol was 0.31 (0.26–0.35) mg/kg PO twice daily. The carvedilol dose achieved following up titration was 1.11 (0.81–1.32) mg/kg twice daily. No adverse effects were recorded during up titration. Median survival for all dogs was 48.5 months with a 95% CI of 38.3–58.6.ConclusionsThis study suggests that carvedilol at the dose reported herein is well tolerated in small breed dogs with preclinical CVD. Prospective studies to evaluate efficacy are warranted.  相似文献   
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ObjectiveTo identify risk factors for first-onset congestive heart failure (CHF) in dogs with degenerative mitral valve disease (DMVD).AnimalsEighty-two dogs with and without CHF secondary to DMVD were retrospectively assigned to a derivation cohort. Sixty-five dogs with asymptomatic DMVD were recruited into a prospective validation cohort.MethodsVariables associated with risk of CHF in dogs were identified in a derivation cohort and used to construct a predictive model, which was then prospectively tested through longitudinal examination of a validation cohort.ResultsLogistic regression analysis of the derivation cohort yielded a predictive model that included the left atrial to aortic root dimension ratio (LA:Ao) and plasma concentration of N-terminal pro-B-type natriuretic peptide (NT-proBNP). When this model was prospectively applied to the validation cohort, it correctly predicted first-onset of CHF in 69.2% of cases. Analysis of the validation cohort revealed that plasma NT-proBNP concentration and indexed left ventricular end-diastolic diameter (LVIDd:Ao) were independent risk factors for development of first-onset CHF in dogs with DMVD (NT-proBNP ≥1500 pmol/L, odds ratio (OR), 5.76, 95% confidence interval (CI), 1.37–24.28, P = 0.017; LVIDd:Ao ≥3, OR, 6.11, 95% CI, 1.09–34.05, P = 0.039).ConclusionsMeasures of left heart size and plasma NT-proBNP concentration independently estimate risk of first-onset of CHF in dogs with DMVD. These parameters can contribute to the management of dogs with DMVD.  相似文献   
37.

Introduction

To determine the biologic variability of N-terminal pro-brain natriuretic peptide (NTproBNP) in healthy dogs and dogs with various stages of myxomatous mitral valve disease (MMVD).

Animals

Thirty-eight privately owned dogs: 28 with MMVD and 10 healthy controls.

Materials and methods

Prospective clinical study with comprehensive evaluation used to group dogs as healthy or into three stages of MMVD based on current guidelines. NTproBNP was measured hourly, daily, and weekly. For each group, analytical (CVA), within-subject (CVI), and between-subject (CVG) coefficients of variability were calculated in addition to percent critical change value (CCV) and index of individuality (IoI).

Results

For healthy dogs, calculated NTproBNP values were: CVA = 4.2%; CVI = 25.2%; CVG = 49.3%; IoI = 0.52, and CCV = 70.8%. For dogs with MMVD, calculated NTproBNP values were: CVA = 6.2%; CVI = 20.0%; CVG = 61.3%; IoI = 0.34, and CCV = 58.2%.

Conclusions

Biologic variability affects NTproBNP concentrations in healthy dogs and dogs with MMVD. Monitoring serial individual changes in NTproBNP may be clinically relevant in addition to using population-based reference ranges to determine changes in disease status.  相似文献   
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A commercial methylcellulose culture medium, with and without the addition of recombinant bovine granulocyte colony-stimulating factor (rbG-CSF), was utilized for culturing bovine bone marrow cells in a colony-forming unit assay. Bone marrow mononuclear cells were isolated and cultured in a commercial methylcellulose-based medium containing several recombinant human cytokines. Cultures were prepared with and without 100 ng/mL of rbG-CSF. The size and mean number of colonies per plate from culture days 3 to 9 were compared. We concluded that bovine bone marrow colony growth was supported by this culture medium. The addition of rbG-CSF yielded larger and more numerous colonies. There were significantly more colonies on day 3 (P < 0.001), day 4 (P < 0.001), and day 5 (P = 0.03) with rbG-CSF. Both culture media had the highest colony counts on day 5.  相似文献   
40.
The purpose of this study was to investigate the effects of isolates of noncytopathic type 2 Bovine viral diarrhea virus (ncpBVDV-2) of high and low virulence on the proliferation of bone marrow progenitor cells. Holstein calves 6 to 7 mo old and BVDV-na?ve were inoculated intranasally with a BVDV isolate of high virulence (HV24515), a BVDV isolate of low virulence (LV11Q), or uninfected cell culture medium. Serial bone marrow and peripheral blood samples were collected before and after inoculation. Bone marrow mononuclear cells (BMMCs) were isolated and cultured for 5 d, and the mean number of colony-forming unit-granulocyte-macrophage (CFU-GM) colonies was determined. Tritiated (3H)-thymidine uptake by BMMCs was determined to indicate overall proliferative capacity. Virus isolation was done on concurrent samples of BMMCs and peripheral blood. Virus was isolated from BMMCs and peripheral blood buffy-coat cells as early as day 2 or 3 after inoculation. Neutropenia developed in both groups inoculated with a BVDV isolate. However, in the calves given LV11Q, neutrophil counts rebounded earlier in response to increased proliferation of BMMCs, whereas the response was delayed in calves given HV24515. Thymidine uptake was significantly increased (P = 0.0047) in BMMCs after inoculation compared with before inoculation in the calves given LV11Q but not in those given HV24515 or in the control calves. The median number of CFU-GM colonies was significantly decreased (P = 0.0164) after inoculation compared with before inoculation in the calves given HV24515, whereas there was no significant difference in the calves given LV11Q or in the control calves. The data support the hypothesis that the prolonged neutropenia observed in calves given HV24515 results at least in part from decreased proliferative capacity of bone marrow progenitor cells.  相似文献   
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