全文获取类型
收费全文 | 454篇 |
免费 | 30篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 13篇 |
2015年 | 24篇 |
2014年 | 23篇 |
2013年 | 28篇 |
2012年 | 27篇 |
2011年 | 22篇 |
2010年 | 12篇 |
2009年 | 17篇 |
2008年 | 31篇 |
2007年 | 24篇 |
2006年 | 23篇 |
2005年 | 26篇 |
2004年 | 22篇 |
2003年 | 23篇 |
2002年 | 20篇 |
2001年 | 4篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1993年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1968年 | 2篇 |
1965年 | 2篇 |
1960年 | 2篇 |
1959年 | 2篇 |
1936年 | 2篇 |
1933年 | 2篇 |
排序方式: 共有484条查询结果,搜索用时 46 毫秒
451.
Abstract Production of volatiles was stimulated by the infection of Penicillium digitatum in 'Shamouti oranges. During 7 days of disease development, there was a progressive increase in the emanations of the anaerobic metabolites acetaldehyde, ethanol and ethyl acetate. There was also an increase in other volatiles including methanol, acetone, and ethylene, accompanied by a high production of CO2 . The production of acetaldehyde, ethanol and CO2 in cultures of P. digitatum was, highest on the first day after inoculation, and decreased as the fungus developed. Ethyl acetate and ethylene increased when sporulation had already begun. Neither acetone nor methanol was found in P. digitatum in vitro. The increase of the volatiles in the infected oranges was due to the host-pathogen interaction and peel lesion. 相似文献
452.
Tobacco necrosis virus (TNV) was found occasionally in roots of indicator plants such as UC-4, UC-5 and alpine, commonly used for screening of strawberry virus diseases. The virus was purified and identified as TNV by its host-range, physical properties, electron microscopy and serological tests. The implication of the possible occurrence of TNV in indicator plants on reliable diagnosis of virus disease in strawberry is discussed. 相似文献
453.
Sally P. Mendoza Edna L. Lowe Julian M. Davidson Seymour Levine 《Hormones and behavior》1978,11(3):295-303
The relationship between seasonal sexual activity, endogenous testosterone, and weight changes (fatting) in the squirrel monkey (Saimiri sciureus) was assessed. Adult males were shown to have an annual rhythm in testosterone levels which coincides with peak sexual activity. Fatting was shown to occur in both adult males and adult females seasonally. However, fatting preceded both heightened sexual activity and increases in endogenous testosterone concentrations. In addition the frequency of eating and drinking do not show a consistent correlation with weight change in males and females. Therefore, the seasonal fatting response in squirrel monkeys must be due to mechanisms other than altered rate of consumption or increased production of testosterone. 相似文献
454.
455.
Francisco J. Cervantes Edna R. Meza-Escalante Anne-Claire Texier Jorge Gómez 《Journal of industrial microbiology & biotechnology》2009,36(11):1417-1424
The aim of this study was to evaluate the capacity of a denitrifying consortium to achieve the simultaneous removal of nitrate,
sulfide and p-cresol and elucidate the rate-limiting steps in the mixotrophic process. Nitrite reduction appeared as the most evident rate-limiting
step in the denitrifying respiratory process. The nitrite reduction rate achieved was up to 57 times lower than the nitrate
reduction rate during the simultaneous removal of sulfide and p-cresol. Negligible accumulation of N2O occurred in the denitrifying cultures corroborating that nitrite reduction was the main rate-limiting step of the respiratory
process. A synergistic effect of nitrate and sulfide is proposed to explain the accumulation of nitrite. The study also points
at the oxidation of S0 as another rate-limiting step in the denitrifying process. Different respiratory rates were achieved with the distinct electron
donors provided (p-cresol and sulfide). The oxidation rate of p-cresol (qCRES) was generally higher (up to 2.6-fold in terms of reducing equivalents) than the sulfide oxidation rate (qS2−), except for the experiments performed at 100 mg S2− L−1 in which qS2− was slightly (~1.4-fold in terms of reducing equivalents) higher than qCRES. The present study provides kinetic information, which should be considered when designing and operating denitrifying reactors
to treat industrial wastewaters containing large amounts of sulfurous, nitrogenous and phenolic contaminants such as those
generated from petrochemical refineries. 相似文献
456.
457.
458.
Nancy Yaneth Flrez Stefany Alejandra Arvalo Edna Catering Rodríguez Jaime Guerrero Kelly Paola Valverde Paula Lucía Díaz Lucy Angeline Montao Doris Mabel Gartner Carolina Duarte Jaime Enrique Moreno 《Biomédica : revista del Instituto Nacional de Salud》2021,41(1):41
IntroducciónSalmonella enterica subsp. enterica serovar Give se encuentra en mamíferos rumiantes, cerdos, aves y ambientes acuáticos, pero rara vez en humanos. En Colombia este serotipo ocupó el decimoprimer lugar en frecuencia en la vigilancia por laboratorio de la enfermedad diarreica aguda entre el 2000 y el 2013.ObjetivoCaracterizar el fenotipo y el genotipo de S. Give en aislamientos relacionados con un brote de enfermedad transmitida por alimentos en el departamento de Vichada en la quinta semana epidemiológica del 2015.Materiales y métodosSe buscó Salmonella spp. en 37 muestras de materia fecal con el método de estudio del Instituto Nacional de Salud. La muestra de sardinas enlatadas fue procesada según la norma ISO6579:2002 Cor.1:2004. Se determinó el serotipo en los aislamientos confirmados mediante serología o PCR en tiempo real, y se hicieron pruebas de sensibilidad a antimicrobianos y electroforesis en gel de campo pulsado con las enzimas Xbal y BlnI.ResultadosTodos los aislamientos de origen humano (11) y el aislamiento del alimento (1), se identificaron como S. Give y este último presentó resistencia a la tetraciclina. El análisis por PFGE-XbaI agrupó bajo el patrón COIN15JEXX01.0005 diez aislamientos de origen humano y a los restantes bajo el COIN15JEXX01.0006, con un 96,3% de similitud. Los resultados de todos los aislamientos se confirmaron con la enzima BlnI; cuatro de ellos (tres humanos y el del alimento) se agruparon bajo el patrón COIN15JEXA26.002, con un porcentaje de similitud del 95,65%.ConclusiónEl estudio confirmó que las sardinas enlatadas se relacionaron con la transmisión de S. Give en el brote, que es el tercero ocasionado por este serotipo en Colombia.Palabras clave: Salmonella, brotes de enfermedades, enfermedades transmitidas por los alimentos, vigilancia epidemiológica, Colombia 相似文献
459.
460.
The content of free sulfhydryl (SH) groups in tomato (Lycopersiconesculentum Mill.) fruits was determined. The levels of thesegroups in different cultivars increased as the fruit ripened,either on the vine or in storage. The compounds containing theseSH groups were dialyzable and were ascribed to be cysteine andglutathione. The possible significance of these findings isdiscussed. (Received January 5, 1981; Accepted March 20, 1981) 相似文献