全文获取类型
收费全文 | 4704篇 |
免费 | 259篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 272篇 |
妇产科学 | 229篇 |
基础医学 | 508篇 |
口腔科学 | 139篇 |
临床医学 | 416篇 |
内科学 | 950篇 |
皮肤病学 | 159篇 |
神经病学 | 577篇 |
特种医学 | 252篇 |
外科学 | 568篇 |
综合类 | 67篇 |
一般理论 | 1篇 |
预防医学 | 125篇 |
眼科学 | 215篇 |
药学 | 236篇 |
中国医学 | 7篇 |
肿瘤学 | 195篇 |
出版年
2024年 | 6篇 |
2023年 | 46篇 |
2022年 | 81篇 |
2021年 | 132篇 |
2020年 | 103篇 |
2019年 | 129篇 |
2018年 | 159篇 |
2017年 | 106篇 |
2016年 | 176篇 |
2015年 | 203篇 |
2014年 | 210篇 |
2013年 | 257篇 |
2012年 | 360篇 |
2011年 | 362篇 |
2010年 | 161篇 |
2009年 | 166篇 |
2008年 | 370篇 |
2007年 | 350篇 |
2006年 | 366篇 |
2005年 | 288篇 |
2004年 | 258篇 |
2003年 | 186篇 |
2002年 | 166篇 |
2001年 | 39篇 |
2000年 | 44篇 |
1999年 | 44篇 |
1998年 | 19篇 |
1997年 | 11篇 |
1996年 | 11篇 |
1995年 | 13篇 |
1994年 | 13篇 |
1992年 | 23篇 |
1991年 | 17篇 |
1990年 | 20篇 |
1989年 | 10篇 |
1988年 | 13篇 |
1987年 | 21篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1965年 | 1篇 |
排序方式: 共有5006条查询结果,搜索用时 15 毫秒
81.
82.
Hakan Tüzün Ka?an Karakaya Emine Baran Deniz 《Environmental health and preventive medicine》2015,20(5):325-331
Objectives
This study is aimed to find out the handwashing habits and their relations to the socio-economic variables.Methods
The sampling is determined regarding the address-based population registration system of the country. The multi-staged stratified cluster sampling method was used. It is conducted by a face to face questionnaire with 6854 persons. 22 questions are asked whether they are washing their hands or not related to different situations, the results are graded and the “Handwashing Habits Score” (HHS) is obtained. The reasons for not handwashing were evaluated by categorizing as individual, environmental and combined reasons.Results
The HHS is increasing in the older age groups (β = 0.148, p < 0.001), females (β = 0.306, p < 0.001), citizens of urban settlement (β = 0.061, p < 0.001), higher education levels (β = 0.191, p < 0.001). The reasons for not handwashing were found as 53.3 % individual, 39.2 % environmental, 7.5 % combined. The frequency of mentioning not washing hands because of the environmental reasons is getting higher in the older age groups, in the urban side, and in the higher education level (p < 0.001).Conclusions
The handwashing habits are shaped by the determinant networks which form a complex structure by intertwining individual, socio-economic and environmental factors in different sub-groups with various weights. This result might contribute to the efforts of conceptualizing the health behaviors with ecological model. 相似文献83.
Theodore D Satterthwaite Joseph W Kable Lillie Vandekar Natalie Katchmar Danielle S Bassett Claudia F Baldassano Kosha Ruparel Mark A Elliott Yvette I Sheline Ruben C Gur Raquel E Gur Christos Davatzikos Ellen Leibenluft Michael E Thase Daniel H Wolf 《Neuropsychopharmacology》2015,40(9):2258-2268
Unipolar and bipolar depressive episodes have a similar clinical presentation that suggests common dysfunction of the brain’s reward system. Here, we evaluated the relationship of both dimensional depression severity and diagnostic category to reward system function in both bipolar and unipolar depression. In total, 89 adults were included, including 27 with bipolar depression, 25 with unipolar depression, and 37 healthy comparison subjects. Subjects completed both a monetary reward task and a resting-state acquisition during 3T BOLD fMRI. Across disorders, depression severity was significantly associated with reduced activation for wins compared with losses in bilateral ventral striatum, anterior cingulate cortex, posterior cingulate cortex, and right anterior insula. Resting-state connectivity within this reward network was also diminished in proportion to depression severity, most notably connectivity strength in the left ventral striatum. In addition, there were categorical differences between patient groups: resting-state connectivity at multiple reward network nodes was higher in bipolar than in unipolar depression. Reduced reward system task activation and resting-state connectivity therefore appear to be a brain phenotype that is dimensionally related to depression severity in both bipolar and unipolar depression. In contrast, categorical differences in reward system resting connectivity between unipolar and bipolar depression may reflect differential risk of mania. Reward system dysfunction thus represents a common brain mechanism with relevance that spans categories of psychiatric diagnosis. 相似文献
84.
Akaltun Mazlum Serdar Altindag Ozlem Turan Neytullah Gursoy Savas Gur Ali 《Clinical rheumatology》2021,40(5):1989-1995
Clinical Rheumatology - The aim of this study is to investigate the effectiveness of high intensity laser therapy on pain, functionality, flexion range of motion (FROM), and ultrasonographic... 相似文献
85.
86.
Ozakin C Sinirtaş M Sevgican E Kazak E Gedikoglu S 《Scandinavian journal of infectious diseases》2003,35(10):700-703
Some automated systems used in clinical microbiology laboratories are able to detect products responsible for antimicrobial resistance. In this study, 626 isolates (436 Escherichia coli, 134 Klebsiella pneumoniae and 56 Klebsiella oxytoca strains) were examined for the presumptive detection of extended-spectrum beta-lactamase (ESBL) production by 2 methods: the Sceptor system (BD, Sparks, MD, USA) and the E-test. ESBL production was detected in 26 E. coli strains (5.96%), 60 K. pneumoniae strains (44.77%) and 15 K. oxytoca strains (26.78%) by ceftazidime/ceftazidime-clavulanate E-test. Using the E-test, ESBL production was detected in 25 of 201 E. coli strains (12.43%), 55 of 75 K. pneumoniae (73.33%) and 14 of 27 K. oxytoca strains (51.85%) that were alerted as ESBL-producing strains by the Sceptor system. ESBL positivity was detected in 1 E. coli, 5 K. pneumoniae and 1 K. oxytoca strains, that were not warned as being ESBL producers by the Sceptor system. These data suggest that clinical microbiology laboratories should not only rely on these rapid automated systems but also use another method for screening ESBL producers, such as the E-test. The rates of these ESBL-producing isolates in this study were lower than those in other studies reported from other parts of Turkey, but higher than those reported from the USA and Europe. 相似文献
87.
The aim of this study was to evaluate the total antioxidant status (TAS), total oxidative status (TOS) and oxidative stress
index (OSI) in patients with postmenopausal osteoporosis. We also investigate the relation between bone mineral density and
oxidative/antioxidative parameters. Thirty-nine patients with osteoporosis and 26 healthy controls were included in the study.
Plasma TAS, TOS levels were determined by using a novel automated methods. Plasma TOS and OSI value were significantly higher,
and plasma TAS level was lower in patients than in healthy controls (P < 0.001 for all). There was a significant negative correlation between OSI and BMD in lumbar and femoral neck region (r = −0.63, P < 0.001; r = 0.40, P = 0.018). The results of this study indicated that increased osteoclastic activity and decreased osteoblastic activity may
be associated with an imbalance between oxidant and antioxidant status in postmenopausal osteoporosis. Therefore, supplementation
of antioxidant-enriched diet to the therapy might shed light on the development of novel therapeutic strategies for osteoporosis. 相似文献
88.
Summary Synovial effusions containing cholesterol crystals are uncommon. Most of the few reported cases have been found in patients with seropositive rheumatoid arthritis. In vitro studies, as well as an animal model, have suggested that cholesterol crystals could have a role in inflammation of the joints. In this report we present a case of seronegative arthritis, complicated by large carpal synovial cysts which contained numerous cholesterol crystals. The long-term presence of the cysts, without evidence of joint destruction, suggests that cholesterol crystal formation is probably a rare epiphenomenon, rather than a harbinger of inflammation. 相似文献
89.
Behçet's disease is an inflammatory disorder of unknown etiology. Genetic tendency has an important role in its pathogenesis, and HLA‐B51, a class I MHC antigen, has been recognized as the strongest susceptibility factor for Behçet's disease. Despite the confirmation of the association of HLA‐B51 with Behçet's disease in different populations, its pathogenic mechanisms remain elusive. HLA‐B51 differs in only two amino acids from HLA‐B52, other split antigen of HLA‐B5, which is not associated with Behçet's disease. These two amino acids are located in the B pocket of the antigen‐binding groove, which occupies the second amino acids of the bound peptides. To understand the nature of the HLA–peptide interactions, differences in structure and dynamics of two HLA alleles were investigated by molecular dynamics simulations using YAYDGKDYI, LPRSTVINI, and IPYQDLPHL peptides. For HLA‐B51, all bound peptides fluctuated to larger extent than HLA‐B52. Free energy profiles of unbinding process for YAYDGKDYI by steered molecular dynamics simulations showed that unbinding from HLA‐B52 results in greater free energy differences than HLA‐B51. These results suggest the possibility of an instability of HLA‐B51 associated with the repertoire of peptides, and this finding may provide significant insight to its pathogenic role in Behçet's disease. 相似文献
90.
Katrin Mueller Yoshiaki Sunami Michael Stuetzle Nurdan Guldiken Ozlem Kucukoglu Sebastian Mueller Hasan Kulaksiz Peggy Schwarz Pavel Strnad 《The Journal of pathology》2013,231(4):532-542
The liver is the central regulator of iron metabolism and accordingly, chronic liver diseases often lead to systemic iron overload due to diminished expression of the iron‐regulatory hormone hepcidin. To study the largely unknown regulation of iron metabolism in the context of hepatic disease, we used two established models of chronic liver injury, ie repeated carbon tetrachloride (CCl4) or thioacetamide (TAA) injections. To determine the impact of CCAAT/enhancer‐binding protein (C/EBP)‐homologous protein (CHOP) on hepcidin production, the effect of a single TAA injection was determined in wild‐type and CHOP knockout mice. Furthermore, CHOP and hepcidin expression was assessed in control subjects and patients with alcoholic liver disease. Both chronic injury models developed a distinct iron overload in macrophages. TAA‐, but not CCl4‐ injected mice displayed additional iron accumulation in hepatocytes, resulting in a significant hepatic and systemic iron overload which was due to suppressed hepcidin levels. C/EBPα signalling, a known hepcidin inducer, was markedly inhibited in TAA mice, due to lower C/EBPα levels and overexpression of CHOP, a C/EBPα inhibitor. A single TAA injection resulted in a long‐lasting (> 6 days) suppression of hepcidin levels and CHOP knockouts (compared to wild‐types) displayed significantly attenuated hepcidin down‐regulation in response to acute TAA administration. CHOP mRNA levels increased 5‐fold in alcoholic liver disease patients versus controls (p < 0.005) and negatively correlated with hepcidin expression. Our results establish CHOP as an important regulator of hepatic hepcidin expression in chronic liver disease. The differences in iron metabolism between the two widely used fibrosis models likely reflect the differential regulation of hepcidin expression in human liver disease. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 相似文献