首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   90篇
  免费   17篇
林业   1篇
  14篇
综合类   8篇
水产渔业   5篇
畜牧兽医   71篇
植物保护   8篇
  2021年   2篇
  2020年   1篇
  2018年   1篇
  2017年   4篇
  2016年   8篇
  2015年   5篇
  2014年   4篇
  2013年   4篇
  2012年   2篇
  2011年   3篇
  2010年   3篇
  2009年   4篇
  2008年   2篇
  2007年   1篇
  2006年   3篇
  2005年   1篇
  2003年   1篇
  2000年   3篇
  1999年   3篇
  1998年   2篇
  1993年   1篇
  1992年   5篇
  1991年   2篇
  1990年   3篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   7篇
  1983年   2篇
  1982年   2篇
  1980年   2篇
  1977年   2篇
  1976年   4篇
  1974年   2篇
  1973年   1篇
  1972年   2篇
  1970年   3篇
  1967年   1篇
  1963年   1篇
  1903年   1篇
  1900年   1篇
排序方式: 共有107条查询结果,搜索用时 31 毫秒
31.
32.
33.
Summary Between April 1985 and August 1986, 89 Jamaican dairy herds with 10 or more cows were visited, 1, 645 lactating cows were examined using the CMT test and 254 composite milk samples collected for bacteriological examination. Widespread management faults were noted, especially of milking machine usage and maintenance and the abuse of antibiotics. Fifty-six per cent of all quarters were found to have CMT scores of one or higher, 0·8% showed clinical mastitis and 3·2% were blind. The most common bacterial pathogenStaphylococcus aureus, was recovered from 31% of sampled cows. The resultant milk loss from clinical and subclinical mastitis was estimated to be 20% of the potential national production.
Resumen Se visitaron 89 hatos lecheros con 10 o más, vacas en Jamaica, entre abril 1985 y agosto 1986. Se examinaron un total ede 1·645 vacas lactantes, por medio de la prueba California para mastitis, colectando a la vez 254 muestras compuestas de leche, para exámenes, bacteriológicos. Se detectaron un sinnúmero de fallas en el manejo, especialmente relacionados con el uso y mantenimeiento de las máquinas de orde?o, y con el abuso de antibióticos. Cincuenta y seis por ciento de todos los cuartos tenían mastitis clínica y 3·2% estaban ciegos. El patógeno más común fue elStaphylococcus aureus, el cual se recuperó de 31% de las vacas examinadas. La pérdida de leche resultante de mastitis clínica o subclínica, se calculó en un 20% de la producción nacional potencial.

Résumé Entre avril 1985 et ao?t 1986, 89 troupeaux laitiers jama?cains de 10 vaches et plus, ont fait l'objet d'une enquête. 1645 vaches en lactation ont été contr?lées à l'aide du test californien pour le dépistage de la mammite (CMT) et 254 prélèvements de lait de mélange ont été récoltés pour un examen bactériologique. Des erreurs fréquentes de conduite du troupeau ont été notées particulièrement dans l'emploid des machines à traire et dans leur entretien ainsi que dans l'abus des antibiotiques. 56 p. 100 des quartiers avaient un résultat égal ou supérieur à 1 ou plus au test californien (CMT), 0,8 p. 100 étaient atteints d'une mammite clinique et 3,2 p. 100 étaient “secs”. Le germe pathogène le plus fréquent,Staphylococcus aureus a été trouvé chez 31 p. 100 des vaches examinées. On estime a 20 p. 100 du potential national de production la perte de lait résultant de ces mammites cliniques et subcliniques.
  相似文献   
34.
The objective was to compare plasma lidocaine concentrations when a commercially available 5% lidocaine patch was placed on intact skin vs. an incision. Our hypothesis was that greater absorption of lidocaine would occur from the incision site compared to intact skin. Ten dogs were used in a crossover design. A patch was placed over an incision, and then after a washout period, a patch was placed over intact skin. Plasma lidocaine concentrations were measured at patch placement; 20, 40 and 60 min; and 2, 4, 6, 12, 24, 36, 48, 72 and 96 h after patch placement. After patch removal, the skin was graded using a subjective skin reaction system. No dogs required rescue analgesia, and no toxicity or skin reaction was noted. Mean ± SD AUC and CMAX were 3054.29 ± 1095.93 ng·h/mL and 54.1 ± 15.84 ng/mL in the Incision Group, and 2269.9 ± 1037.08 ng·h/mL and 44.5 ± 16.34 ng/mL in the No‐Incision Group, respectively. The AUC was significantly higher in the Incision Group. The results of the study demonstrate that the actual body exposure to lidocaine was significantly higher when an incision was present compared to intact skin. No adverse effects were observed from either treatment. Efficacy was not evaluated.  相似文献   
35.
Pollen, fossil logs, and macrofossils from three high-elevation sites in the Maligne Range, Jasper National Park, Alberta, provide the first detailed record of timberline fluctuations in the Canadian Rockies during the last 8700 years. Timberlines were much higher than at present between 8700 to 5200 years ago but oscillated significantly in elevation, with a major episode of timberline recession punctuating two periods of high timberline between about 6700 to 5900 and about 8700 to 7000 years ago. Since 5200 years ago, regional timberlines have generally receded with perhaps brief reversals, reaching their lowest recorded positions sometime after 500 years ago.  相似文献   
36.
Salmonellae are Gram‐negative zoonotic bacteria that are frequently part of the normal reptilian gastrointestinal flora. The main objective of this project was to estimate the prevalence of non‐typhoidal Salmonella enterica in the nesting and foraging populations of sea turtles on St. Kitts and in sand from known nesting beaches. Results suggest a higher prevalence of Salmonella in nesting leatherback sea turtles compared with foraging green and hawksbill sea turtles. Salmonella was cultured from 2/9 and identified by molecular diagnostic methods in 3/9 leatherback sea turtle samples. Salmonella DNA was detected in one hawksbill turtle, but viable isolates were not recovered from any hawksbill sea turtles. No Salmonella was detected in green sea turtles. In samples collected from nesting beaches, Salmonella was only recovered from a single dry sand sample. All recovered isolates were positive for the wzx gene, consistent with the O:7 serogroup. Further serotyping characterized serovars Montevideo and Newport present in cloacal and sand samples. Repetitive‐element palindromic PCR (rep‐PCR) fingerprint analysis and pulsed‐field gel electrophoresis of the 2014 isolates from turtles and sand as well as archived Salmonella isolates recovered from leatherback sea turtles in 2012 and 2013, identified two distinct genotypes and four different pulsotypes, respectively. The genotyping and serotyping were directly correlated. To determine the persistence of representative strains of each serotype/genotype in these environments, laboratory‐controlled microcosm studies were performed in water and sand (dry and wet) incubated at 25 or 35°C. Isolates persisted for at least 32 days in most microcosms, although there were significant decreases in culturable bacteria in several microcosms, with the greatest reduction in dry sand incubated at 35°C. This information provides a better understanding of the epizootiology of Salmonella in free‐ranging marine reptiles and the potential public health risks associated with human interactions with these animals in the Caribbean.  相似文献   
37.
38.
A 25‐week immersion challenge was conducted exposing Oreochromis mossambicus, Oreochromis aureus and Oreochromis urolepis hornorum to Francisella noatunensis subsp. orientalis (Fno). Two populations were compared for each fish species; ‘resident fish’ were defined as fish maintained in tanks since week 0 of challenge, whereas ‘naïve fish’ were defined as fish added to tanks once temperature in water reached <26 °C at 21 weeks post‐challenge. Fno genome equivalents (GEs) in water were similar in all treatments 1 h post‐challenge; however, significantly lower Fno GEs were detected 2 weeks post‐challenge in all tanks, and the only treatment with detectable Fno GE after 4 weeks of challenge were the O. mossambicus tanks. Twenty‐one weeks post‐challenge, naïve fish were stocked with ‘resident’ cohorts. Over a 4‐week period, mortalities occurred consistently only in O. mossambicus naïve cohorts. Overall presence of granulomas in spleen of survivors was similar (>55%) in all resident populations; however, in naïve populations, only O. mossambicus presented granulomas. Similarly, only O. mossambicus presented viable Fno in the spleen of survivors, and Fno GEs were only detected in O. mossambicus, and in resident O. aureus. In conclusion, the results of this study suggest different susceptibility of tilapia species to piscine francisellosis.  相似文献   
39.
The microbial metabolism of N3,N3-diethyl 2,4-dinitro-6-trifluoromethyl-m-phenylenediamine (dinitramine), N-sec-butyl-4-tert-butyl-2,6-dinitroaniline (A-820), N-n-propyl-N-cyclopropylmethyl-4-trifluoromethyl-2,6-dinitroaniline (CGA-10832), and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) by Aspergillus fumigatus Fres., Fusarium oxysporum Schlecht and Paecilomyces sp. was investigated. The dinitrodiamine and dinitroanilines were most readily metabolized by Paecilomyces sp. The metabolism of dinitramine was examined in detail, and four metabolites were isolated: N3-ethyl 2,4-dinitro-6-trifluoromethyl-m-phenylenediamine; 2,4-dinitro-6-tri-fluoromethyl-m-phenylenediamine; 6-amino-1-ethyl-2-methyl-7-nitro-5-trifluoromethylbenzimidazole and 6-amino-2-methyl-7-nitro-5-trifluoromethylbenzimidazole. The presence of a dinitramine-degrading enzyme system in A. fumigatus was demonstrated. The enzyme dealkylates dinitramine and requires NADPH and Fe2+ as cofactors.  相似文献   
40.
Abnormal carpal configuration was observed in a litter of ten 2-month-old pups raised in a research colony. Five of the pups were exercised daily, and carpal configuration returned to normal within 7 to 10 days. The other 5 pups remained confined, and their carpal configuration returned to normal after 6 weeks. It was concluded that poor muscle tone was responsible for the carpal hyperextension.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号