全文获取类型
收费全文 | 242篇 |
免费 | 15篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 11篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 6篇 |
2014年 | 12篇 |
2013年 | 9篇 |
2012年 | 23篇 |
2011年 | 20篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 14篇 |
2007年 | 13篇 |
2006年 | 14篇 |
2005年 | 17篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 13篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1974年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有257条查询结果,搜索用时 406 毫秒
91.
Takagi Y Akada R Kumagai H Yamamoto K Tamaki H 《Applied microbiology and biotechnology》2008,77(5):1073-1082
Candida albicans is a human fungal pathogen and has been extensively studied because of its clinical importance. Comprehensive gene analyses
have, however, made little progress. This is because of the diploid and asexual characteristics of the fungus that hamper
gene disruptions. In this study, we found that ultraviolet (UV) irradiation, as well as mutagen treatment, strongly stimulated
loss of heterozygosity (LOH) in strains harboring artificially constructed heterozygosity. UV-induced LOH occurred more frequently
in cells within the logarithmic phase of growth compared to those within the stationary phase of growth. This was observed
at all loci tested on chromosome 7, except for a locus neighboring the centromere. C. albicans RAD52, whose orthologue in Saccharomyces cerevisiae was reported to be involved in DNA repair by homologous recombination, was shown to be required for UV-induced LOH. These
results suggest that high efficiency LOH caused by UV irradiation could be a prominent tool for gene analyses in C. albicans. 相似文献
92.
93.
Extracorporeal shock waves: from lithotripsy to anti-inflammatory action by NO production. 总被引:8,自引:0,他引:8
Sofia Mariotto Elisabetta Cavalieri Ernesto Amelio Anna Rosa Ciampa Alessandra Carcereri de Prati Ernst Marlinghaus Sergio Russo Hisanori Suzuki 《Nitric oxide》2005,12(2):89-96
At low energy density (0.03 mJ/mm2), extracorporeal shock waves (ESW), originally developed for clinical lithotripsy, have successfully been used for anti-inflammatory treatment of soft tissues. Since nitric oxide plays a critical role in inflammation, we hypothesized for ESW to increase NO production in cells. Using human umbilical vein endothelial cells as a model system, we observed that ESW, at low energy density, rapidly induced an enhancement of eNOS activity. In these cells, eNOS activity is modulated by tyrosine- and serine-phosphorylation. ESW shifted eNOS to a less-tyrosine-phosphorylated form, without affecting its serine-phosphorylation, thus accounting for its rapid enzyme activation. LPS/IFN-gamma treatment of human umbilical vein endothelial cells induced a rapid inhibition of eNOS activity and concomitant NF-kappaB activation which were efficiently counteracted by ESW treatment. Therefore, the present results indicate that the molecular mechanism of clinically observed anti-inflammatory action of ESW should include tyrosine-dephosphorylation of eNOS, a successive increase in NO production and suppression of NF-kappaB activation. 相似文献
94.
Hideo Ezoe 《Theoretical Ecology》2017,10(1):105-115
Many plants produce excessive flowers and several hypotheses have been proposed for adaptive significances of this behavior. Here, I develop a simple resource allocation model for plants in a mutualism with pollinating seed-predators to examine a novel hypothesis that excessive flower production can be favored to “dilute” seed predation by the pollinators. Pollinators visit flowers to deposit pollen and oviposit on them, and their offspring feed on a portion of the seeds, leaving the remainder intact. Further pollinator visits increase seed mortality by over-oviposition. Excessive flower production is favored if it decreases pollinator-visit frequency per flower, while it incurs decrease in seed production because of the resource trade-off. I examine three plant strategies: (1) no abortion, the plant allocates resource to all pollinated flowers to mature; (2) selective abortion, the plant aborts flowers depending on how many times they were visited by pollinators; and (3) random abortion, the plant indiscriminately aborts a fraction of pollinated flowers irrespective of how many times they were visited. I show that the random abortion strategy can perform much more effectively than the no-abortion strategy when the amount of resource is small, the production cost per flower is low, and the pollinator density is high, although the selective abortion strategy is always the best. This “predator dilution” effect has not been considered with regard to previous excessive flower production hypotheses. 相似文献
95.
Novel Mutations and Deletions of the KIT (Steel Factor Receptor) Gene in Human Piebaldism 总被引:8,自引:0,他引:8
下载免费PDF全文
![点击此处可从《American journal of human genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kazuhiko Ezoe Stuart A. Holmes Lingling Ho Christopher P. Bennett Jean L. Bolognia Louise Brueton John Burn Rafael Falabella Emilia M. Gatto Norihisa Ishii Celia Moss Mark R. Pittelkow Elizabeth Thompson K. Anne Ward Richard A. Spritz 《American journal of human genetics》1995,56(1):58-66
Piebaldism is an autosomal dominant genetic disorder of pigmentation characterized by white patches of skin and hair. Melanocytes are lacking in these hypopigmented regions, the result of mutations of the KIT gene, which encodes the cell surface receptor for steel factor (SLF). We describe the analysis of 26 unrelated patients with piebaldism-like hypopigmentation—17 typical patients, 5 with atypical clinical features or family histories, and 4 with other disorders that involve white spotting. We identified novel pathologic mutations or deletions of the KIT gene in 10 (59%) of the typical patients, and in 2 (40%) of the atypical patients. Overall, we have identified pathologic KIT gene mutations in 21 (75%) of 28 unrelated patients with typical piebaldism we have studied. Of the patients without apparent KIT mutations, none have apparent abnormalities of the gene encoding SLF itself (MGF), and genetic linkage analyses in two of these families are suggestive of linkage of the piebald phenotype to KIT. Thus, most patients with typical piebaldism appear to have abnormalities of the KIT gene. 相似文献
96.
Chikako Ono Masanao Sato Hitomi Taka Shin-ichiro Asano Yoshiharu Matsuura Hisanori Bando 《PloS one》2015,10(3)
To infect their hosts, DNA viruses must successfully initiate the expression of viral genes that control subsequent viral gene expression and manipulate the host environment. Viral genes that are immediately expressed upon infection play critical roles in the early infection process. In this study, we investigated the expression and regulation of five canonical regulatory immediate-early (IE) genes of Autographa californica multicapsid nucleopolyhedrovirus: ie0, ie1, ie2, me53, and pe38. A systematic transient gene-expression analysis revealed that these IE genes are generally transactivators, suggesting the existence of a highly interactive regulatory network. A genetic analysis using gene knockout viruses demonstrated that the expression of these IE genes was tolerant to the single deletions of activator IE genes in the early stage of infection. A network graph analysis on the regulatory relationships observed in the transient expression analysis suggested that the robustness of IE gene expression is due to the organization of the IE gene regulatory network and how each IE gene is activated. However, some regulatory relationships detected by the genetic analysis were contradictory to those observed in the transient expression analysis, especially for IE0-mediated regulation. Statistical modeling, combined with genetic analysis using knockout alleles for ie0 and ie1, showed that the repressor function of ie0 was due to the interaction between ie0 and ie1, not ie0 itself. Taken together, these systematic approaches provided insight into the topology and nature of the IE gene regulatory network. 相似文献
97.
Masayuki Nakamichi Hisanori Fujii Takamasa Koyama 《Primates; journal of primatology》1983,24(1):52-66
The behavioral development of a malformed male infant in a free-ranging Japanese monkey group, whose hands were completely
missing and whose hind feet were distorted, was investigated during the first one year of life, by comparison with normal
infants. In the first few weeks of life, the malformed infant was not able to move by himself and was almost completely dependent
on his mother's help. He gradually became able to creep with his forelimb elbows and distorted hind feet at about the first
month of life, and was able to walk bipedally on his hind feet, though unstably, after the sixth month of life. His locomotor
ability, however, was essentially inferior to that of normal infants throughout the first one year of life. His social interactions
with the group members were different from those of normal infants. Normal infants increased their interactions with sameaged
infants or older juveniles through active behavior-like play, whereas the malformed infant developed relations particularly
with adults through behavior such as passive body contact. The conditions for survival of the observed malformed infant are
discussed. 相似文献
98.
99.
100.
Identification of cis-regulatory sequences in the human angiotensinogen gene by transgene coplacement and site-specific recombination
下载免费PDF全文
![点击此处可从《Molecular and cellular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Shimizu T Oishi T Omori A Sugiura A Hirota K Aoyama H Saito T Sugaya T Kon Y Engel JD Fukamizu A Tanimoto K 《Molecular and cellular biology》2005,25(8):2938-2945