全文获取类型
收费全文 | 400篇 |
免费 | 15篇 |
国内免费 | 2篇 |
出版年
2022年 | 4篇 |
2021年 | 14篇 |
2020年 | 4篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 15篇 |
2014年 | 16篇 |
2013年 | 30篇 |
2012年 | 22篇 |
2011年 | 27篇 |
2010年 | 11篇 |
2009年 | 15篇 |
2008年 | 16篇 |
2007年 | 21篇 |
2006年 | 13篇 |
2005年 | 25篇 |
2004年 | 16篇 |
2003年 | 19篇 |
2002年 | 12篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1964年 | 2篇 |
排序方式: 共有417条查询结果,搜索用时 171 毫秒
51.
The goal of this study was to determine the acute effects of permanent denervation on the length density of the capillary
network in rat slow soleus (SOL) and fast extensor digitorum longus (EDL) muscles and the effect of short-lasting reinnervation
in slow muscle only. Denervation was performed by cutting the sciatic nerve. Both muscles were excised 2 weeks later. Reinnervation
was studied 4 weeks after nerve crush in SOL muscle only. Capillaries and muscle fibres were visualised by triple immunofluorescent
staining with antibodies against CD31 and laminin and with fluorescein-labelled Griffonia (Bandeira) simplicifolia lectin. A recently developed stereological approach allowing the estimation of the length of capillaries adjacent to each
individual fibre (Lcap/Lfib) was employed. Three-dimensional virtual test grids were applied to stacks of optical images captured with a confocal microscope
and their intersections with capillaries and muscle fibres were counted. Interrelationships among capillaries and muscle fibres
were demonstrated with maximum intensity projection of the acquired stacks of optical images. The course of capillaries in
EDL seemed to be parallel to the fibre axes, whereas in SOL, their preferential direction deviated from the fibre axes and
formed more cross-connections among neighbouring capillaries. Lcap/Lfib was clearly reduced in denervated SOL but remained unchanged in EDL, although the muscle fibres significantly atrophied in
both muscle types. When soleus muscle was reinnervated, capillary length per unit fibre length was completely restored. The
physiological background for the different responses of the capillary network in slow and fast muscle is discussed.
This study was supported by the Slovenian Research Agency and the Ministry of Education, Youth and Sport of the Czech Republic
(KONTAKT grant no. 19/2005). 相似文献
52.
53.
Aberrant interaction of carcinoma cells with basement membranes (BM) is a fundamental pathophysiological process that initiates a series of events resulting in cancer cell invasion and metastasis. In this report, we describe the results of our investigations pertaining to the events triggered by the adhesion of normal (PNT1A) and highly metastatic (PC-3) prostate cells onto BM proteins. Unlike PNT1A, PC-3 cells adhered avidly to Matrigel BM matrix as well as to isolated collagen type IV, laminin, and heparan sulfate proteoglycan perlecan, main BM components. This aberrantly increased cancer cell adhesion resulted in sustained BRCA2 protein depletion and vigorous cell proliferation, a cascade triggered by beta1 integrin-mediated phosphatidylinositol 3-kinase activation leading to BRCA2 degradation in the proteasome. This latter effect was orchestrated by phosphatidylinositol 3-kinase-dependent up-regulation of Skp2, a subunit of the Skp1-Cul1-F-box protein ubiquitin complex that directly associates with BRCA2 as demonstrated by coimmunoprecipitation assays, determines its ubiquitination, and ultimately targets it for proteasomal degradation. Inhibition of Skp2 expression by small interference RNA prevented BRCA2 depletion and inhibited the trophic effect upon cell proliferation. These results provide additional evidence on the role of BRCA2 as a modulator of cancer cell growth and elucidate the molecular mechanisms involved in its down-regulation in cancer cells when interacting with BM, a crucial step in the biology of metastasis. Furthering the understanding of this molecular pathway may prove valuable in designing new therapeutic strategies aimed at modifying the natural history of prostate carcinoma. 相似文献
54.
A high-density consensus map of A and B wheat genomes 总被引:1,自引:0,他引:1
Daniela Marone Giovanni Laidò Agata Gadaleta Pasqualina Colasuonno Donatella B. M. Ficco Angelica Giancaspro Stefania Giove Giosué Panio Maria A. Russo Pasquale De Vita Luigi Cattivelli Roberto Papa Antonio Blanco Anna M. Mastrangelo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,125(8):1619-1638
A durum wheat consensus linkage map was developed by combining segregation data from six mapping populations. All of the crosses were derived from durum wheat cultivars, except for one accession of T. ssp. dicoccoides. The consensus map was composed of 1,898 loci arranged into 27 linkage groups covering all 14 chromosomes. The length of the integrated map and the average marker distance were 3,058.6 and 1.6?cM, respectively. The order of the loci was generally in agreement with respect to the individual maps and with previously published maps. When the consensus map was aligned to the deletion bin map, 493 markers were assigned to specific bins. Segregation distortion was found across many durum wheat chromosomes, with a higher frequency for the B genome. This high-density consensus map allowed the scanning of the genome for chromosomal rearrangements occurring during the wheat evolution. Translocations and inversions that were already known in literature were confirmed, and new putative rearrangements are proposed. The consensus map herein described provides a more complete coverage of the durum wheat genome compared with previously developed maps. It also represents a step forward in durum wheat genomics and an essential tool for further research and studies on evolution of the wheat genome. 相似文献
55.
Iaffaldano P Viterbo RG Paolicelli D Lucchese G Portaccio E Goretti B Direnzo V D'Onghia M Zoccolella S Amato MP Trojano M 《PloS one》2012,7(4):e35843
Background and Objectives
Natalizumab reduces the relapse rate and magnetic resonance imaging activity in patients with Relapsing-Remitting Multiple Sclerosis (RRMS). So far the influence of natalizumab on cognitive functions and fatigue in MS remains uncertain. The aim of this prospective, open-label, observational study was to evaluate the possible effects of natalizumab on cognition and fatigue measures in RRMS patients treated for up to two years.Methods
Cognitive performances were examined by the Rao''s Brief Repeatable Battery (BRB), the Stroop test (ST) and the Cognitive Impairment Index (CII), every 12 months. Patients who failed in at least 3 tests of the BRB and the ST were classified as cognitively impaired (CI). Fatigue Severity Scale (FSS) was administered every 12 months to assess patient''s self-reported fatigue. One hundred and 53 patients completed 1 and 2 year-natalizumab treatment, respectively.Results
After 1 year of treatment the percentage of CI patients decreased from 29% (29/100) at baseline to 19% (19/100) (p = 0.031) and the mean baseline values of CII (13.52±6.85) and FSS (4.01±1.63) scores were significantly reduced (10.48±7.12, p<0.0001 and 3.61±1.56, p = 0.008). These significant effects were confirmed in the subgroup of patients treated up to two years.Conclusions
These results demonstrate that a short-term NTZ treatment may significantly improve cognitive performances and fatigue in RRMS patients. 相似文献56.
Daniele A De Rosa A Nigro E Scudiero O Capasso M Masullo M de Laurentiis G Oriani G Sofia M Bianco A 《The international journal of biochemistry & cell biology》2012,44(3):563-569
Adiponectin (Acrp30) shows several beneficial properties and circulates as different oligomers. The role of Acrp30 in lung is not fully clear, but a link with chronic obstructive pulmonary disease (COPD) has been highlighted. In this study, we analyzed the anthropometrical and biochemical features and evaluated total Acrp30 levels of a COPD cohort without metabolic complications compared to healthy controls. In addition, being the oligomerization state critical for its biological activities, we characterized the pattern of Acrp30 circulating oligomers focusing on the high molecular weight (HMW) oligomers to verify whether it correlates to COPD. Finally, we investigated AdipoR1 and AdipoR2 expression in lung from COPD. Interestingly, we found for the first time that the oligomerization state of Acrp30 is altered in COPD; particularly, we observed that the higher levels of Acrp30 are associated with a significant and specific increase of HMW. In addition, we demonstrated the presence of AdipoRs with a lower expression of AdipoR2 compared to AdipoR1. In conclusion, we demonstrated that in COPD, the higher levels of Acrp30 are associated with the significantly increase of HMW representing the most biologically active forms. The important role of Acrp30 in pathophysiological conditions of lung is supported also by the modulation of AdipoRs with the down regulation of AdipoR2. The low expression of AdipoR2 could suggest a specific role of this receptor, mainly implicated in Acrp30 effects on inflammation and oxidative stress. Thus, total Acrp30, HMW and its receptors could be considered critical targets to improve diagnostic and therapeutic strategies for lung diseases. 相似文献
57.
A. Blanco G. Mangini A. Giancaspro S. Giove P. Colasuonno R. Simeone A. Signorile P. De Vita A. M. Mastrangelo L. Cattivelli A. Gadaleta 《Molecular breeding : new strategies in plant improvement》2012,30(1):79-92
Grain protein content (GPC) in durum wheat (Triticum turgidum var. durum) is negatively correlated with grain yield. To evaluate possible genetic interrelationships between GPC and grain yield per spike, thousand-kernel weight and kernel number per spike, quantitative trait loci (QTL) for GPC were mapped using GPC-adjusted data in a covariance analysis on yield components. Phenotypic data were evaluated in a segregating population of 120 recombinant inbred lines derived from crossing the elite cultivars Svevo and Ciccio. The material was tested at five environments in southern Italy. QTL were determined by composite interval mapping based on the Svevo?×?Ciccio linkage map described in Gadaleta et al. (2009) and integrated with DArT markers. The close relationship between GPC and yield components was reflected in the negative correlation between the traits and in the reduction of variance when GPC values were adjusted to yield components. Ten independent genomic regions involved in the expression of GPC were detected, six of which were associated with QTL for one or more grain yield components. QTL alleles with increased GPC effects were associated with QTL alleles with decreased effects on one or more yield component traits, or vice versa (i.e. the allelic effects were in opposite direction). Four QTL for GPC showed always significant effects, and these QTL should represent genes that influence GPC independently from variation in the yield components. Such genes are of special interest in wheat breeding since they would allow an increase in GPC without a concomitant decrease in grain yield. 相似文献
58.
Guo W Schafer S Greaser ML Radke MH Liss M Govindarajan T Maatz H Schulz H Li S Parrish AM Dauksaite V Vakeel P Klaassen S Gerull B Thierfelder L Regitz-Zagrosek V Hacker TA Saupe KW Dec GW Ellinor PT MacRae CA Spallek B Fischer R Perrot A Özcelik C Saar K Hubner N Gotthardt M 《Nature medicine》2012,18(5):766-773
59.
D Marone G Panio DB Ficco MA Russo P De Vita R Papa D Rubiales L Cattivelli AM Mastrangelo 《Molecular genetics and genomics : MGG》2012,287(9):741-753
Diversity array technology (DArT) markers are largely used for mapping, genetic diversity, and association mapping studies. For years, they have been used as anonymous genomic markers, as their sequences were not known. As the sequences of 2,000 wheat DArT clones are now available, this study was designed to analyze these sequences with bioinformatic approaches, and to study the genetic features of a subset of 291 markers positioned on the A and B genomes in three durum wheat genetic maps. A set of 1,757 non-redundant sequences was identified, and used as queries for similarity searches. Analysis of the genetic positions of markers corresponding to nearly identical sequences indicates that redundancy of sequences is one of the factors that explains the clustering of these markers in specific genomic regions. Of a total of 1,124 DArT clones (64?%) that represent putatively expressed sequences, putative functions are proposed for more than 700 of them. Of note, many clones correspond to genes that are related to disease resistance, as characterized by leucine-rich repeat domains, and 40 of these clones are positioned in the three genetic maps presented in this study. Finally, DArT markers have been used to find syntenic regions in the Brachypodium and rice genomes. In conclusion, the analyses herein presented contribute to explain the main features of DArT markers observed in genetic maps, as clustering in short chromosome regions. Moreover, the attribution of putative gene functions for more than 700 sequences makes these markers an optimal tool for collinearity studies or for the identification of candidate genes. 相似文献
60.
To investigate the role of catalase and superoxide dismutase (SOD) in the acetic acid (AA) induced yeast programmed cell death (AA-PCD), we compared Saccharomyces cerevisiae cells (C-Y) and cells individually over-expressing catalase T (CTT1-Y) and Cu,Zn-SOD (SOD1-Y) with respect to cell survival, hydrogen peroxide (H2O2) levels and enzyme activity as measured up to 200 min after AA treatment. AA-PCD does not occur in CTT1-Y, where H2O2 levels were lower than in C-Y and the over-expressed catalase activity decreased with time. In SOD1-Y, AA-PCD was exacerbated; high H2O2 levels were found, SOD activity increased early, remaining constant en route to AA-PCD, but catalase activity was strongly reduced. 相似文献