全文获取类型
收费全文 | 161篇 |
免费 | 3篇 |
出版年
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2010年 | 14篇 |
2009年 | 13篇 |
2008年 | 13篇 |
2007年 | 12篇 |
2006年 | 11篇 |
2005年 | 9篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1953年 | 1篇 |
1952年 | 1篇 |
1951年 | 2篇 |
1950年 | 2篇 |
1920年 | 1篇 |
排序方式: 共有164条查询结果,搜索用时 15 毫秒
161.
The pressure potentials (turgor pressure) in leaves of maize(Zea mays L.) and grain sorghum (Sorghum vulgare Pers.) plantssubjected to water stress in a controlled environment were estimatedfrom measurements of water and osmotic potentials. Changes inturgor pressure were larger in sorghum than in maize duringthe development of water stress and after re-watering. It issuggested that this indicates a lower cell wall elasticity insorghum than in maize. This fact may affect some of the physiologicalactivities of sorghum 相似文献
162.
REBECA MANNING-CELA MARCO A. MERAZ J. MANUEL HERNANDEZ ISAURA MEZA 《The Journal of eukaryotic microbiology》1994,41(4):360-365
ABSTRACT. Parasitic amebas propagate among hosts through cysts, the resistant forms in their life cycle. In spite of their key role in infection, little is known about the encystation process and the mechanisms involved in reaching this stage. Two features drastically affected by encystation are motility and cell shape, both of which are determined by the cytoskeleton, composed mainly of actin in these organisms. Therefore, we studied the occurrence and relative levels of actin and actin synthesis during encystation of Entamoeba invadens. Using a cDNA actin probe obtained from a library of E. histolytica and a monoclonal antibody against actin, we found that, while the total actin levels sharply decrease as encystation proceeds, the levels of actin mRNA are reduced only in mature cysts. Moreover, actin synthesis does not take place in precysts and the later stages of cyst formation. In contrast, the levels of other proteins remain stable in trophozoites, precysts and cysts, and stage specific peptides are actively synthesized in precysts. The results indicate that encystation is accompanied by a preferential down-regulation of actin synthesis and a decrease in actin levels. The reorganization of the cytoskeleton occurring as trophozoites transform into round, quiescent cells, could be a regulatory factor in the observed changes. 相似文献
163.
APARICIO-TEJO PEDRO M.; SANCHEZ-DIAZ MANUEL F.; PENA JOSE I. 《Journal of experimental botany》1980,31(3):839-843
The relationship between transpiration measured gravimetrically,a generalized transpiration equation, and the ratio VPD/rleafwas investigated in Trifolium repens plants subjected to varyingwater potentials. Dawn leaf water potential was measured witha pressure chamber, leaf diffusion resistance with a diffusionporometer, leaf temperatures with a thermistor, and relativehumidity with an aspirated psychrometer. During drought transpirationrates determined by both methods were quite similar particularlyat the lowest water potentials. After rewatering calculatedrates were somewhat higher than measured ones. It is concludedthat transpiration calculated by the indirect method is a usefuland reasonable estimate of transpiration for single plants undervarying water potentials. 相似文献
164.
JOSE GARCIA GONZALEZ VICENTE VICENTE ORTEGA MANUEL REDONDO JOSE RODRIGUEZ VICENTE 《Pigment cell & melanoma research》1995,8(4):173-179
Objective: The aim of this work was to evaluate the behaviour of B16-F10 melanoma cell cultures implanted in the anterior chamber of the eye of New Zealand white rabbits by studying the clinical-pathological and ultrastructural characteristics of the lesions. Methods: One group (A) (consisting of 30 rabbits) was transclerally inoculated (1 mm from sclero-corneal limbus) with 4×106 melanocytes and another group (B) (also 30 animals) was inoculated once per week for 3 consecutive weeks with 5×106 cells (total 15×106); 30 animals acted as the control group (C). All the lesions were processed for optic and electronic microscopy. Results: Tumoral growth in group A was 43% (13/30) and in group B 80% (24/30). All lesions were pigmented and none perforated the eyeball. Microscopically, they were a mixture of epithelioid and fusiform cells disposed around the blood vessels. Ultrastructurally, the presence of melanosomes in different stages of maturation and aberrant melanosomes were characteristic. Conclusion: We suggest that the transcleral inoculation of 15×106 B16-F10 melanocytes into the anterior chamber of the eye of New Zealand white rabbits may be a valid and reproducible method for obtaining an experimental ocular melanoma model. 相似文献