全文获取类型
收费全文 | 132篇 |
免费 | 23篇 |
出版年
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 9篇 |
2012年 | 6篇 |
2011年 | 6篇 |
2010年 | 7篇 |
2009年 | 2篇 |
2008年 | 7篇 |
2007年 | 10篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1993年 | 2篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 156 毫秒
31.
David Ochoa Mindaugas Jonikas Robert T Lawrence Bachir El Debs Joel Selkrig Athanasios Typas Judit Villén Silvia DM Santos Pedro Beltrao 《Molecular systems biology》2016,12(12)
The coordinated regulation of protein kinases is a rapid mechanism that integrates diverse cues and swiftly determines appropriate cellular responses. However, our understanding of cellular decision‐making has been limited by the small number of simultaneously monitored phospho‐regulatory events. Here, we have estimated changes in activity in 215 human kinases in 399 conditions derived from a large compilation of phosphopeptide quantifications. This atlas identifies commonly regulated kinases as those that are central in the signaling network and defines the logic relationships between kinase pairs. Co‐regulation along the conditions predicts kinase–complex and kinase–substrate associations. Additionally, the kinase regulation profile acts as a molecular fingerprint to identify related and opposing signaling states. Using this atlas, we identified essential mediators of stem cell differentiation, modulators of Salmonella infection, and new targets of AKT1. This provides a global view of human phosphorylation‐based signaling and the necessary context to better understand kinase‐driven decision‐making. 相似文献
32.
33.
Variations among cell lines in the synthesis of sphingolipids in de novo and recycling pathways 总被引:1,自引:0,他引:1
There are several pathways for the incorporation of sugars into
glycosphingolipids (GSL). Sugars can be added to ceramide that contains
sphinganine (dihydrosphingosine) synthesized de novo (pathway 1), to
ceramide synthesized from sphingoid bases produced by hydrolysis of
sphingolipids (pathway 2), and into GSL recycling from the endosomal
pathway through the Golgi (pathway 3). We reported previously the
surprising observation that SW13 cells, a human adrenal carcinoma cell
line, synthesize most of their GSL in pathway 2. We now present data on the
synthesis of GSL in four additional cell lines. Approximately 90% of sugar
incorporation took place in pathway 2, and 10% or less in pathway 1, in
human foreskin fibroblasts and NB41A3 neuroblastoma cells. In contrast,
approximately 50-90% of sugar incorporation took place in pathway 1 in
C2C12 myoblasts. The C2C12 cells divide more rapidly and synthesize 10-14
times as much GSL as the other three cell lines. In C6 glioma cells,
approximately 30% of sugar incorporation occurred in pathway 1 and 60% in
pathway 2. There was no relation between the utilization of pathways for
GSL and sphingomyelin synthesis in foreskin fibroblasts and C2C12 cells. In
both cells pathways 1 and 2 each accounted for 50% of incorporation of
choline into sphingomyelin. In five of the six cell lines that we have
studied, most GSL synthesis takes place in pathway 2. We suggest that when
the need for synthesis is relatively low, as in slowly dividing cells, GSL
are synthesized predominantly from sphingoid bases salvaged from the
hydrolytic pathway. When cells are dividing more rapidly, the need for
increased synthesis is met by upregulating the de novo pathway.
相似文献
34.
Zeki Bahadir Eric Tisdell Arturo A Arce Esquivel Devon A Dobrosielski Michael A Welsch 《Dynamic medicine : DM》2007,6(1):3
Background
Previous research indicates that venous emptying serves as a stimulus for vasodilation in the human forearm. This suggests the importance of recognizing the potential influence of venous volume on reactive hyperemic blood flow (RHBF) following occlusion. The purpose of this study was to examine the influence of venous emptying on forearm vascular function.Methods
Forearm RHBF, venous capacitance and venous outflow were examined in 35 individuals (age = 22 ± 2 years), using mercury in-Silastic strain gauge plethysmography, at rest and following five minutes of upper arm occlusion using standard procedures (Control). In addition, the same measures were obtained following five minutes of upper arm occlusion preceded by two minutes of passive arm elevation (Pre-elevation).Results
Average resting arterial inflow was 2.42 ± 1.11 ml·100 ml-1·min-1. RHBF and venous capacitance were significantly greater during Pre-elevation compared to Control (RHBF; Pre-elevation: 23.76 ± 5.95 ml·100 ml-1 ·min-1 vs. Control: 19.33 ± 4.50; p = 0.001), (venous capacitance; Pre-elevation: 2.74 ± 0.89 % vs. Control: 2.19 ± 0.97, p = 0.001). Venous outflow did not differ between the two conditions.Conclusion
Venous emptying prior to upper arm occlusion results in a significant greater RHBF response and venous capacitance. Recognition of the influence of venous volume on RHBF is particularly important in studies focusing on arterial inflow, and also provides further evidence for the interplay between the venous and arterial system.35.
36.
Southern green stink bugs, Nezara viridula (L.) (Hemiptera: Pentatomidae), are pests of cotton recently shown to ingest, retain, and introduce some pathogens of cotton into bolls. The objective of this study was to determine where pathogen colonization occurs in N. viridula after ingestion. Laboratory‐reared adult N. viridula were fed sterile green beans soaked in water (control) or beans previously soaked in a suspension of one of three opportunistic bacterial pathogens [Pantoea agglomerans (Ewing & Fife), Pantoea ananatis (Serrano) Truper & De’Clari, or Klebsiella pneumoniae (Schroeter)] or a yeast [Nematospora coryli (Peglion)]. The insect rostrum, head, and alimentary canal were subsequently processed to determine the presence of pathogenic organisms. Overall, the alimentary canal exhibited significantly more bacterial colony forming units per g tissue (mean ± SEM = 4 806.3 ± 397.2) than the head (443.4 ± 397.2) and rostrum (46.0 ± 397.2); concentrations in the head and rostrum did not differ significantly. All four pathogens were detected in the alimentary canal, but only P. agglomerans and N. coryli were detected in the rostrum and head. Although P. ananatis and K. pneumoniae were only detected in the alimentary canal, their ranges of concentrations were similar to those of P. agglomerans and N. coryli in this tissue. Non‐selective media indicated that other bacterial fauna was also detected in all study insects. Thus, N. viridula does not discriminate with regard to ingestion of pathogens. The observed distribution pattern of tested bacteria and yeast in certain tissues of N. viridula clarifies the propensity for transmission of P. agglomerans and N. coryli. Results are discussed in relation to future research avenues examining selective colonization of certain pathogens and frequency of host infection by adults harboring the pathogenic organisms. 相似文献
37.
Patr��cia F N Fa��sca Ana Nunes Rui DM Travasso Eugene I Shakhnovich 《Protein science : a publication of the Protein Society》2010,19(11):2196-2209
Systematic Monte Carlo simulations of simple lattice models show that the final stage of protein folding is an ordered process where native contacts get locked (i.e., the residues come into contact and remain in contact for the duration of the folding process) in a well‐defined order. The detailed study of the folding dynamics of protein‐like sequences designed as to exhibit different contact energy distributions, as well as different degrees of sequence optimization (i.e., participation of non‐native interactions in the folding process), reveals significant differences in the corresponding locking scenarios—the collection of native contacts and their average locking times, which are largely ascribable to the dynamics of non‐native contacts. Furthermore, strong evidence for a positive role played by non‐native contacts at an early folding stage was also found. Interestingly, for topologically simple target structures, a positive interplay between native and non‐native contacts is observed also toward the end of the folding process, suggesting that non‐native contacts may indeed affect the overall folding process. For target models exhibiting clear two‐state kinetics, the relation between the nucleation mechanism of folding and the locking scenario is investigated. Our results suggest that the stabilization of the folding transition state can be achieved through the establishment of a very small network of native contacts that are the first to lock during the folding process. 相似文献
38.
39.
Background
The statistical modeling of biomedical corpora could yield integrated, coarse-to-fine views of biological phenomena that complement discoveries made from analysis of molecular sequence and profiling data. Here, the potential of such modeling is demonstrated by examining the 5,225 free-text items in the Caenorhabditis Genetic Center (CGC) Bibliography using techniques from statistical information retrieval. Items in the CGC biomedical text corpus were modeled using the Latent Dirichlet Allocation (LDA) model. LDA is a hierarchical Bayesian model which represents a document as a random mixture over latent topics; each topic is characterized by a distribution over words. 相似文献40.