全文获取类型
收费全文 | 375篇 |
免费 | 23篇 |
专业分类
398篇 |
出版年
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 15篇 |
2014年 | 16篇 |
2013年 | 26篇 |
2012年 | 14篇 |
2011年 | 16篇 |
2010年 | 24篇 |
2009年 | 25篇 |
2008年 | 16篇 |
2007年 | 12篇 |
2006年 | 14篇 |
2005年 | 16篇 |
2004年 | 11篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 11篇 |
1997年 | 11篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1991年 | 4篇 |
1989年 | 3篇 |
1988年 | 11篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 19篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1966年 | 1篇 |
1965年 | 2篇 |
1932年 | 1篇 |
1931年 | 1篇 |
排序方式: 共有398条查询结果,搜索用时 15 毫秒
331.
Shahnaz Shahidi‐Noghabi Els JM Van Damme Kamran Mahdian Guy Smagghe 《Archives of insect biochemistry and physiology》2010,75(3):207-220
In this project, the toxicity and mechanism of action of the ricin‐B‐related lectin SNA‐I from elderberry (Sambucus nigra) in the pea aphid (Acyrthosiphon pisum) and the beet armyworm (Spodoptera exigua), two important pest insects in agriculture, were studied. SNA‐I is a chimeric lectin belonging to the class of ribosome‐inactivating proteins and consists of an A‐chain with N‐glycosidase activity and a carbohydrate‐binding B‐chain. Incorporation of 2 mg/ml of SNA‐I in the diet of neonates and adults of A. pisum caused 40–46% mortality within 2 days, while in third instars of S. exigua, the larval biomass was significantly reduced by 12% after feeding for 3 days on a diet containing 5 mg/g of SNA‐I. Interestingly, extracts of the (mid)gut of treated A. pisum and S. exigua demonstrated DNA fragmentation and this was accompanied with an increase in caspase‐3‐like activity. The involvement of cell death or apoptosis in the entomotoxicity of SNA‐I through induction of caspase‐3‐like activity was also confirmed by addition of the permeable caspase‐3 inhibitor III in the diet, leading to a rescue of the treated aphid neonates. Finally, similar to the chimeric lectin SNA‐I, the hololectin SNA‐II, consisting of two carbohydrate‐binding B‐chains caused high mortality to neonate A. pisum aphids with an LC50 of 1.59 mg/ml, suggesting that the entomotoxic action of the lectins under study mainly relies on their carbohydrate‐binding activity. © 2010 Wiley Periodicals, Inc. 相似文献
332.
Alireza Babaei Seyed Reza Tabaei-Aghdaei Morteza Khosh-Khui Reza Omidbaigi Mohammad Reza Naghavi Gerhard D Esselink Marinus JM Smulders 《BMC plant biology》2007,7(1):12
Background
Damask roses (Rosa damascena Mill.) are mainly used for essential oil production. Previous studies have indicated that all production material in Bulgaria and Turkey consists of only one genotype. Nine polymorphic microsatellite markers were used to analyze the genetic diversity of 40 accessions of R. damascena collected across major and minor rose oil production areas in Iran. 相似文献333.
Arco J Teske Bart WL De Boeck Paul G Melman Gertjan T Sieswerda Pieter A Doevendans Maarten JM Cramer 《Cardiovascular ultrasound》2007,5(1):1-19
Recent developments in the field of echocardiography have allowed the cardiologist to objectively quantify regional and global myocardial function. Regional deformation (strain) and deformation rate (strain-rate) can be calculated non-invasively in both the left and right ventricle, providing information on regional (dys-)function in a variety of clinical settings. Although this promising novel technique is increasingly applied in clinical and preclinical research, knowledge about the principles, limitations and technical issues of this technique is mandatory for reliable results and for implementation both in the clinical as well as the scientific field. In this article, we aim to explain the fundamental concepts and potential clinical applicability of strain and strain-rate for both tissue Doppler imaging (TDI) derived and speckle tracking (2D-strain) derived deformation imaging. In addition, a step-by-step approach to image acquisition and post processing is proposed. Finally, clinical examples of deformation imaging in hypertrophic cardiomyopathy (HCM), cardiac resynchronization therapy (CRT) and arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) are presented. 相似文献
334.
Manon JM van Oosten Radboud JEM Dolhain Jan W Koper Elisabeth FC van Rossum Marieke Emonts Khik H Han Jacques MGW Wouters Johanne MW Hazes Steven WJ Lamberts Richard A Feelders 《Arthritis research & therapy》2010,12(4):R159
Introduction
The glucocorticoid receptor (GR) plays an important regulatory role in the immune system. Four polymorphisms in the GR gene are associated with differences in glucocorticoid (GC) sensitivity; the minor alleles of the polymorphisms N363 S and BclI are associated with relative hypersensitivity to GCs, while those of the polymorphisms ER22/23EK and 9β are associated with relative GC resistance. Because differences in GC sensitivity may influence immune effector functions, we examined whether these polymorphisms are associated with the susceptibility to develop Rheumatoid Arthritis (RA) and RA disease severity. 相似文献335.
Bleesing JJ Souto-Carneiro MM Savage WJ Brown MR Martinez C Yavuz S Brenner S Siegel RM Horwitz ME Lipsky PE Malech HL Fleisher TA 《Journal of immunology (Baltimore, Md. : 1950)》2006,176(11):7096-7103
In this study, we have identified an altered B cell compartment in patients with chronic granulomatous disease (CGD), a disorder of phagocyte function, characterized by pyogenic infections and granuloma formation caused by defects in NADPH activity. This is characterized by an expansion of CD5-expressing B cells, and profound reduction in B cells expressing the memory B cell marker, CD27. Both findings were independent of the age, genotype, and clinical status of the patients, and were not accompanied by altered CD5 and CD27 expression on T cells. Focusing on CD27-positive B cells, considered to be memory cells based on somatically mutated Ig genes, we found that the reduction was not caused by CD27 shedding or abnormal retention of CD27 protein inside the cell. Rather, it was determined that CD27-negative B cells were, appropriately, CD27 mRNA negative, consistent with a naive phenotype, whereas CD27-positive B cells contained abundant CD27 mRNA and displayed somatic mutations, consistent with a memory B cell phenotype. Thus, it appears that CGD is associated with a significant reduction in the peripheral blood memory B cell compartment, but that the basic processes of somatic mutation and expression of CD27 are intact. X-linked carriers of CGD revealed a significant correlation between the percentage of CD27-positive B cells and the percentage of neutrophils with normal NADPH activity, reflective of the degree of X chromosome lyonization. These results suggest a role for NADPH in the process of memory B cell formation, inviting further exploration of secondary Ab responses in CGD patients. 相似文献
336.
F. Polo M.J. Figueras I. Inza J. Sala J.M. Fleisher J. Guarro 《Antonie van Leeuwenhoek》1999,75(4):285-292
The incidence of serotypes of Salmonella in three types of environmental water (sea, river and fresh reservoirs) from north-east Spain was investigated. The study was performed at specific sampling locations during the summer for a period of five years (1992–1996). A total of 823 strains were isolated and 55 different serotypes were identified, 42 were recovered from sea water, 32 from river water and 12 from freshwater reservoirs. The most frequently isolated serotypes coincided with those involved in clinical cases in the area studied. Salmonella enteritidis was the most common (111 isolates), it was found in all types of water, although most predominantly in sea water (16.1% of the isolates). This serotype, together with S. hadar, significantly increased in frequency during the five year study period. The most frequent serotypes in river water and freshwater reservoirs were S. virchow (9.5%) and S. mikawasima (23.8%) respectively. Significant differences were assessed in the indicator organism densities between the samples with serotypes of clinical significance (S. enteritidis, S. infantis, S. typhimurium, S. virchow and S. paratyphi B) and those without clinical significance. Therefore their presence in all environmental waters may be of epidemiological significance. 相似文献
337.
Roel GW Verhaak Mathijs A Sanders Maarten A Bijl Ruud Delwel Sebastiaan Horsman Michael J Moorhouse Peter J van der Spek Bob Löwenberg Peter JM Valk 《BMC bioinformatics》2006,7(1):337-4
Background
Accurate interpretation of data obtained by unsupervised analysis of large scale expression profiling studies is currently frequently performed by visually combining sample-gene heatmaps and sample characteristics. This method is not optimal for comparing individual samples or groups of samples. Here, we describe an approach to visually integrate the results of unsupervised and supervised cluster analysis using a correlation plot and additional sample metadata. 相似文献338.
Philippe GAC Vanden Bergh Thomas Fett Laurent LM Zecchinon Anne VT Thomas Daniel JM Desmecht 《BMC veterinary research》2005,1(1):1-7
Background
Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2), the most abundant and widely expressed beta2-integrin, is required for many cellular adhesive interactions during the immune response. Many studies have shown that LFA-1 is centrally involved in the pathogenesis of several diseases caused by Repeats-in-toxin (RTX) -producing bacteria. 相似文献339.
MG Oliveira Alves CFL Carta M-E Padín-Iruegas M Pérez-Sayáns JM Suarez-Peñaranda JS Issa 《Biotechnic & histochemistry》2016,91(4):263-268
We investigated the gene and protein expressions of V-type ATPase protein subunit C1 (ATP6V1C1) in cases of oral squamous cell carcinoma (OSCC) and contralateral normal mucosa in smokers, nonsmokers and former smokers. Subjects were separated into five groups of 15: group 1, smokers with OSCC; group 2, normal contralateral mucosa of OSCC patients; group 3, chronic smokers; group 4, former smokers who had stopped smoking 1 year earlier; group 5, individuals who had never smoked. Exfoliative cytology specimens from oral mucosa of smokers, former smokers and nonsmokers showed normal gene and protein expression. We found significantly greater gene expression in the OSCC group than in the nonsmoker groups. No difference in gene expression was observed between normal contralateral mucosa and nonsmoker groups, smoker and nonsmoker groups or former smoker and nonsmoker groups. We observed intense immunostaining for ATP6V1C1 protein in all cases of OSCC and weak or no staining in smoker, former smoker and nonsmoker groups. Significantly greater expression of ATP6V1C1 protein was observed in the OSCC group compared to the other groups, which supports the role of ATP6V1C1 in effecting changes associated with oral cancer. Analysis of the mucosae of chronic smokers, former smokers and the normal contralateral mucosa of patients with OSCC showed unaltered ATP6V1C1 gene and protein expression. Early stages of carcinogenesis, represented by altered epithelium of chronic smokers, had neither gene nor protein alterations as seen in OSCC. Therefore, we infer that the changes in ATP6V1C1 occur during later stages of carcinogenesis. Our preliminary study provides a basis for future studies of using ATP6V1C1 levels for detecting early stage OSCC. 相似文献
340.
Freya KR Swinnen Paul J Coucke Anne M De Paepe Sofie Symoens Fransiska Malfait Filomena V Gentile Luca Sangiorgi Patrizia D’Eufemia Mauro Celli Ton JTM Garretsen Cor WRJ Cremers Ingeborg JM Dhooge Els MR De Leenheer 《Orphanet journal of rare diseases》2011,6(1):1-8