首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11292篇
  免费   993篇
  国内免费   40篇
耳鼻咽喉   67篇
儿科学   358篇
妇产科学   260篇
基础医学   1613篇
口腔科学   152篇
临床医学   1477篇
内科学   2267篇
皮肤病学   184篇
神经病学   1258篇
特种医学   203篇
外国民族医学   1篇
外科学   1242篇
综合类   153篇
一般理论   14篇
预防医学   1348篇
眼科学   220篇
药学   730篇
中国医学   17篇
肿瘤学   761篇
  2024年   23篇
  2023年   174篇
  2022年   268篇
  2021年   515篇
  2020年   376篇
  2019年   450篇
  2018年   440篇
  2017年   348篇
  2016年   367篇
  2015年   373篇
  2014年   470篇
  2013年   617篇
  2012年   882篇
  2011年   884篇
  2010年   433篇
  2009年   427篇
  2008年   639篇
  2007年   698篇
  2006年   606篇
  2005年   544篇
  2004年   474篇
  2003年   395篇
  2002年   367篇
  2001年   113篇
  2000年   109篇
  1999年   93篇
  1998年   71篇
  1997年   51篇
  1996年   38篇
  1995年   38篇
  1994年   38篇
  1993年   27篇
  1992年   74篇
  1991年   76篇
  1990年   74篇
  1989年   64篇
  1988年   50篇
  1987年   51篇
  1986年   50篇
  1985年   51篇
  1984年   33篇
  1983年   46篇
  1982年   19篇
  1981年   25篇
  1979年   34篇
  1978年   31篇
  1974年   30篇
  1973年   28篇
  1972年   21篇
  1969年   18篇
排序方式: 共有10000条查询结果,搜索用时 906 毫秒
991.
992.
Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.  相似文献   
993.
Objective: To systematically identify factors associated with participation in social and community activities for adult wheelchair users (WCUs). Data sources: PubMed/MEDLINE, CINAHL, PsycINFO and EMBASE. Study selection: Quantitative and qualitative peer-reviewed publications were included, which were written in English, reported original research and investigated factors associated with social and community participation in adult WCUs. Data extraction: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used. Factors were organized using the International Classification of Functioning, Disability and Health (ICF). Data synthesis: Thirty-five studies were selected: two of power WCUs, 10 of manual WCUs and 23 of both. Six qualitative studies, ranging in quality from 8/10 to 9/10 and 29 quantitative studies were included, ranging in quality from 4/15 to 11/15. Fifteen body function, 4 activity, 5 participation, 15 environmental and 14 personal factors were found to be associated with social and community participation. Conclusions: Social and community participation of WCUs is associated with factors from all ICF domains. Wheelchair factors, accessibility, skills with wheelchair use, pain, finances and education are modifiable factors frequently reported to be associated with participation. Experimental research focusing on modifiable factors is needed to further our understanding of factors influencing participation among WCUs.
  • Implications for Rehabilitation
  • Wheelchair factors, including comfort and durability, are associated with participation and may be targeted in clinical intervention.

  • Wheelchair skills are clinically modifiable and have been shown to improve participation in manual wheelchair users.

  • Body functions (e.g. confidence, depression and fatigue) and personal factors (e.g. finances and level of education) may be considered for clinical intervention.

  相似文献   
994.
Using «consensus» primers derived from the LTR region of 15 HIV-1 isolates, a fragment of 583 bp was amplified from human DNA. Even though specificity was confirmed by Southern blot analysis with a conserved LTR oligonucleotide probe, no significant homologies were detected to either retroviral regions or human or non-human published sequences. Nevertheless, when used as a probe, the 583-bp fragment identified a unique DNA sequence in the human genome on chromosome 1, and cross-reactive sequences in monkey, but not mouse, DNA. This novel, unique and conserved sequence of 583 bp was used to isolate a human HS-1 clone in which the structural property of a viral LTR could be identified.  相似文献   
995.
996.
997.
The Revised International Staging System (R-ISS) and the International Myeloma Working Group 2014 (IMWG 2014) are newer staging systems used to prognosticate multiple myeloma (MM) outcomes. We hypothesized that these would provide better prognostic differentiation for newly diagnosed multiple myeloma (MM) compared with ISS. We analyzed the Center for International Blood and Marrow Transplant Research database from 2008 to 2014 to compare the 3 systems (N?=?628) among newly diagnosed MM patients undergoing upfront autologous hematopoietic cell transplantation (AHCT). The median follow-up of survivors was 48 (range, 3 to 99) months. The R-ISS provided the greatest differentiation between survival curves for each stage (for overall survival [OS], the differentiation was 1.74 using the R-ISS, 1.58 using ISS, and 1.60 using the IMWG 2014) . Univariate analyses at 3 years for OS showed R-ISS I at 88% (95% confidence interval [CI], 83% to 93%), II at 75% (95% CI, 70% to 80%), and III at 56% (95% CI, 3% to 69%; P < .001). An integrated Brier score function demonstrated the R-ISS had the best prediction for PFS, though all systems had similar prediction for OS. Among available systems, the R-ISS is the most optimal among available prognostic tools for newly diagnosed MM undergoing AHCT. We recommend that serum lactate dehydrogenase and cytogenetic data be performed on every MM patient at diagnosis to allow accurate prognostication.  相似文献   
998.
Purpose: High-intensity language therapy has been shown to provide greater outcomes for people with aphasia (PWA). Unfortunately, a number of issues including the ageing population and a lack of rurally-based clinicians prevent high-intensity interventions. Computer-based therapies are a potential solution to the issues of intensity and accessibility; however, this service delivery model is not commonly used. A possible reason behind the poor uptake is that current computer-based aphasia therapy (CBAT) programs may not meet the needs of speech-language pathologists (SLPs). This study investigated the preferences of SLPs with regard to the features desired in their ideal CBAT program.

Method: Phenomenological research methodology was used to explore the preferences of 10 SLPs. Data were analysed using qualitative thematic analysis.

Result: Desired features were grouped into five themes: therapy activities, stimuli, cues, access and progress data. A range of sub-themes were also identified.

Conclusion: The wide range of desirable features found in this study may reflect the extent to which current CBAT programs are considered to be useful, but perhaps do not meet the needs of users. The study’s findings provide useful information for future CBAT developers to create programs with high clinician usability.  相似文献   
999.
Skeletal dysplasias are a diverse group of rare Mendelian disorders with clinical and genetic heterogeneity. Here, we used targeted copy number variant (CNV) screening and identified intragenic exonic duplications, formed through Alu‐Alu fusion events, in two individuals with skeletal dysplasia and negative exome sequencing results. First, we detected a homozygous tandem duplication of exon 9 and 10 in IFT81 in a boy with Jeune syndrome, or short‐rib thoracic dysplasia (SRTD) (MIM# 208500). Western blot analysis did not detect any wild‐type IFT81 protein in fibroblasts from the patient with the IFT81 duplication, but only a shorter isoform of IFT81 that was also present in the normal control samples. Complementary zebrafish studies suggested that loss of full‐length IFT81 protein but expression of a shorter form of IFT81 protein affects the phenotype while being compatible with life. Second, a de novo tandem duplication of exons 2 to 5 in MATN3 was identified in a girl with multiple epiphyseal dysplasia (MED) type 5 (MIM# 607078). Our data highlights the importance of detection and careful characterization of intragenic duplication CNVs, presenting them as a novel and very rare genetic mechanism in IFT81‐related Jeune syndrome and MATN3‐related MED.  相似文献   
1000.

Background

Pediatric inflammatory bowel disease (IBD) may be associated with a higher burden of surgery and postoperative complications. This study aimed to measure the burden in pediatric IBD over a 20-year period in a large tertiary referral center.

Methods

A retrospective review was conducted of children diagnosed with IBD between 1996 and 2015, with a focus upon operative intervention (excluding endoscopy) and postoperative outcomes.

Results

Of 786 IBD patients, 121/581 (20.8%) with Crohn's disease (CD) and 22/205 (10.7%) with ulcerative colitis (UC) underwent surgery during the study period. When comparing 10-year epochs for CD, median time from diagnosis to intervention decreased from 34?months to 3?months (P?<?0.0001). Postoperative complications occurred in 16/121 (13%) CD patients (bowel obstruction: 10, anastomotic stricture: 4, stomal issues: 4, anastomotic leak: 1). Within the UC cohort, the median time from diagnosis to intervention decreased from 62?months to 6?months (P?=?0.0019). Postoperative complications occurred in 9/22 (41%) UC patients (bowel obstruction: 7, stomal issues: 3, anastomotic stricture: 1). Compared with CD, complications were more frequent in UC patients (P?=?0.004).

Conclusion

Surgery and postoperative complications are common in pediatric IBD. The timing of intervention has trended towards earlier operations in both CD and UC.

Level of evidence

Treatment study—level III (retrospective comparative study).  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号