全文获取类型
收费全文 | 738篇 |
免费 | 68篇 |
专业分类
806篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 10篇 |
2019年 | 13篇 |
2018年 | 14篇 |
2017年 | 20篇 |
2016年 | 22篇 |
2015年 | 39篇 |
2014年 | 39篇 |
2013年 | 45篇 |
2012年 | 55篇 |
2011年 | 58篇 |
2010年 | 35篇 |
2009年 | 43篇 |
2008年 | 37篇 |
2007年 | 48篇 |
2006年 | 40篇 |
2005年 | 47篇 |
2004年 | 35篇 |
2003年 | 41篇 |
2002年 | 25篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1970年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有806条查询结果,搜索用时 0 毫秒
91.
V Castro-Leyva A Espejel-Nuñez G Barroso V Zaga-Clavellina A Flores-Pliego I Morales-Mendez S Giono-Cerezo SW Walsh G Estrada-Gutierrez 《PloS one》2012,7(8):e43605
Objective
To compare the inflammatory response preserved ex vivo by decidual cells isolated from women who experienced preterm labor with and without subclinical intrauterine infection.Methods
Fetal membranes were obtained after cesarean section from 35 women who delivered before 37 weeks of gestation following spontaneous preterm labor, with no clinical evidence of intrauterine infection. Decidua was microbiologically tested and cultured. Concentrations of anti-inflammatory cytokines (IL-2, IL-4, IL-10), pro-inflammatory cytokines (IL-6, IL-8, IL-1β and TNF-α), and matrix metalloproteinases (MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9) were measured in the supernatants using Bio-Plex, and prostaglandin E2 (PGE2) was measured by enzyme immunoassay.Results
Subclinical infection was confirmed in 10 women (28.5%). Microorganisms isolated were Ureaplasma urealyticum (4), group B streptococci (3), Gardnerella vaginalis (1), and Escherichia coli (2). We found a significant increase of pro-inflammatory cytokines and a significant decrease of anti-inflammatory cytokines in supernatants from decidual cells obtained from women with preterm labor and subclinical intrauterine infection compared to women without infection. Secretion of MMP-1, MMP-8, MMP-9 and PGE2 was significantly higher in infected women. Secretion of IL-8 by decidual cells from infected women persisted upon repeated in vitro culture passages.Conclusions
Almost 30% of idiopathic preterm labor cases were associated with subclinical intrauterine infection, and decidual cells isolated from these cases preserved an ex vivo inflammatory status after in vivo bacterial exposure. 相似文献92.
Many important questions in biology are, fundamentally, comparative, and this extends to our analysis of a growing number of sequenced genomes. Existing genomic analysis tools are often organized around literal views of genomes as linear strings. Even when information is highly condensed, these views grow cumbersome as larger numbers of genomes are added. Data aggregation and summarization methods from the field of visual analytics can provide abstracted comparative views, suitable for sifting large multi-genome datasets to identify critical similarities and differences. We introduce a software system for visual analysis of comparative genomics data. The system automates the process of data integration, and provides the analysis platform to identify and explore features of interest within these large datasets. GenoSets borrows techniques from business intelligence and visual analytics to provide a rich interface of interactive visualizations supported by a multi-dimensional data warehouse. In GenoSets, visual analytic approaches are used to enable querying based on orthology, functional assignment, and taxonomic or user-defined groupings of genomes. GenoSets links this information together with coordinated, interactive visualizations for both detailed and high-level categorical analysis of summarized data. GenoSets has been designed to simplify the exploration of multiple genome datasets and to facilitate reasoning about genomic comparisons. Case examples are included showing the use of this system in the analysis of 12 Brucella genomes. GenoSets software and the case study dataset are freely available at http://genosets.uncc.edu. We demonstrate that the integration of genomic data using a coordinated multiple view approach can simplify the exploration of large comparative genomic data sets, and facilitate reasoning about comparisons and features of interest. 相似文献
93.
Ruiz-Herrera A Robinson TJ 《BioEssays : news and reviews in molecular, cellular and developmental biology》2008,30(11-12):1126-1137
In this review, we focus on the evolutionary and biomedical aspects of the architecture of human chromosome 3 (HSA3) by analyzing chromosomal regions that have been conserved during the evolutionary process, compared to those that have been involved in the genomic restructuring of different placental lineages. Given that the organization of human chromosome 3 is derived when compared to the ancestral primate karyotype, and is an autosome that is commonly implicated in human tumour formation, we examined the patterns of change and the genomic consequences that have resulted from its complex evolutionary history. The data show four discrete chromosomal regions that are frequently implicated in chromosomal rearrangements (3p25, 3p22, 3p12 and 3q21). These are rich in repetitive elements and are commonly implicated in structural rearrangements that underpin human genomic disorders and neoplasias. Additional Supporting Information may be found in the online version of this article. 相似文献
94.
Navarro A Ordóñez C Martínez E Pérez C Astudillo A Tolivia J 《Histology and histopathology》2008,23(8):995-1001
Apolipoprotein D (apo D), a lipocalin transporter of small hydrophobic molecules could play an important role in several neurodegenerative diseases. However, its role in those diseases remains unclear. There has been reported increments of apo D in relation with different neuropathologic diseases. Recently, we reported the absence of apo D in neurons of substantia nigra which can contribute to the lability of neurons to oxidative damage. In order to determine the relationship between apo D expression and neuronal death, we studied the expression of apo D in various regions of human brains from patients without any neurological or psychological disorders, in relation with the neuronal damage revealed by Fluoro-Jade B staining. The absence of expression for apo D in injured neurons and the negative staining for Fluoro-Jade B of neurons that express apo D was observed in all sections studied. These findings are in accordance with the role possibly played by apo D in the neuroprotection of the nervous system. 相似文献
95.
Plasmodium falciparum multi-stage proteins are involved in vital processes for parasite survival, which turns them into attractive targets for studies aimed at developing a fully effective antimalarial vaccine. MCP-1 and PfSPATR are both found in sporozoite and merozoite forms, and have been associated respectively with invasion of hepatocytes and red blood cells (RBCs). Binding assays with synthetic peptides derived from these two important proteins have enabled identifying those sequences binding with high specific activity (named High activity binding peptides-HABPs) to hepatoma-derived HepG2 cells and human RBCs. Twelve RBC HABPs were identified within the MCP-1 amino acid sequence, most of them in the C-terminal region. The MCP-1 HABPs 33387 and 33397 also presented high activity binding to HepG2 cells. PfSPATR presented four RBC HABPs and two HepG2 HABPs, but only one (32686) could bind to both cell types. RBC binding assays evidenced that binding of all HABPs was saturable and differentially affected by the enzymatic treatment of target cells. Moreover, all HABPs inhibited in vitro invasion of merozoites at 200 microM and had particular structural features when analyzed by circular dichroism. The results suggest that these synthetic peptides capable of binding to the two P. falciparum target cells could be potentially included in the design of a multi-stage, subunit-based, chemically synthesized antimalarial vaccine. 相似文献
96.
97.
Miguel Angel Pujana Monica Gratacós Jordi Corral Isabel Banchs Aurora Sánchez David Genís Carlos Cervera Víctor Volpini X. Estivill 《Human genetics》1997,101(1):18-21
Genetic anticipation – increasing severity and a decrease in the age of onset with successive generations of a pedigree –
is clearly present in autosomal dominant cerebellar ataxia (ADCA). Anticipation is correlated with expansion of the CAG/CTG
repeat sequence to sizes above those in the normal range through the generations of a pedigree. Genetic heterogeneity has
been demonstrated for ADCA, with four cloned genes (SCA1, SCA2, SCA3/MJD, and SCA6) and three mapped loci (SCA4, SCA5 and
SCA7). Another related dominant ataxia, dentatorubral-pallidoluysian atrophy (DRPLA), presents anticipation with CAG/CTG repeat
expansions. We had previously analysed ADCA patients who had not shown repeat expansions in cloned genes for CAG/CTG repeat
expansions by the repeat expansion detection method (RED) and had detected expansions of between 48 and 88 units in 17 unrelated
familial cases. We present here an analysis of 13 genes and expressed sequence tags (ESTs) containing 10 or more CAG/ CTG
repeat sequences selected from public databases in the 17 unrelated ADCA patients. Of the 13 selected genes and ESTs, 9 were
found to be polymorphic with heterozygosities ranging between 0.09 and 0.80 and 2 to 17 alleles. In ADCA patients none of
the loci showed expansions above the normal range of the CAG/CTG repeat sequences, excluding them as the mutation causing
ADCA.
Received: 28 May 1997 / Accepted: 30 June 1997 相似文献
98.
The postmortern stability of somatostatin-like immunoreactivity (SLI) has been investigated in mice cooled after death at a rate which approximates the rate of cooling of the human brain in situ under normal mortuary conditions. Significant changes in SLI levels were observed within the first few hours after death, but concentrations measured 6–24 hr after death seem to be similar to those existing at the time of death. 相似文献
99.
100.