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   4376篇
  免费   236篇
  国内免费   15篇
耳鼻咽喉   40篇
儿科学   149篇
妇产科学   110篇
基础医学   645篇
口腔科学   75篇
临床医学   388篇
内科学   1189篇
皮肤病学   160篇
神经病学   372篇
特种医学   71篇
外科学   363篇
综合类   22篇
一般理论   1篇
预防医学   447篇
眼科学   31篇
药学   316篇
中国医学   14篇
肿瘤学   234篇
  2024年   17篇
  2023年   30篇
  2022年   78篇
  2021年   161篇
  2020年   88篇
  2019年   134篇
  2018年   153篇
  2017年   95篇
  2016年   96篇
  2015年   129篇
  2014年   179篇
  2013年   215篇
  2012年   310篇
  2011年   363篇
  2010年   186篇
  2009年   163篇
  2008年   295篇
  2007年   291篇
  2006年   270篇
  2005年   237篇
  2004年   245篇
  2003年   228篇
  2002年   220篇
  2001年   36篇
  2000年   41篇
  1999年   32篇
  1998年   39篇
  1997年   27篇
  1996年   14篇
  1995年   21篇
  1994年   15篇
  1993年   14篇
  1992年   30篇
  1991年   17篇
  1990年   15篇
  1989年   15篇
  1988年   11篇
  1987年   11篇
  1986年   14篇
  1985年   21篇
  1984年   14篇
  1983年   15篇
  1982年   6篇
  1981年   4篇
  1979年   5篇
  1978年   3篇
  1977年   4篇
  1976年   4篇
  1974年   4篇
  1972年   3篇
排序方式: 共有4627条查询结果,搜索用时 15 毫秒
91.
G-CSF administration after high-dose chemotherapy and autologous stem cell transplantation (ASCT) has been shown to expedite neutrophil recovery. Several studies comparing filgrastim and pegfilgrastim in the post-ASCT setting concluded that the two are at least equally effective. Lipegfilgrastim (LIP) is a new long-acting, once-per-cycle G-CSF. This multicentric, prospective study aimed to describe the use of LIP in multiple myeloma patients receiving high-dose melphalan and autologous stem cell transplantation (ASCT) and compare LIP with historic controls of patients who received short-acting agent (filgrastim [FIL]). Overall, 125 patients with a median age of 60 years received G-CSF after ASCT (80 patients LIP on day 1 post-ASCT and 45 patients FIL on day 5 post-ASCT). The median duration of grade 4 neutropenia (absolute neutrophil count [ANC] < 0.5 × 10 [9]/L) was 5 days in both LIP and FIL groups, whereas the median number of days to reach ANC ≥ 0.5 × 10 [9]/L was 10% lower in the LIP than in the FIL group (10 vs 11 days), respectively. Male sex was significantly associated with a faster ANC ≥ 0.5 × 10 [9] L response (p = 0.015). The incidence of FN was significantly lower in the LIP than in the FIL group (29% vs 49%, respectively, p = 0.024). The days to discharge after ASCT infusion were greater in patients with FN (p < 0.001). The study indicates that LIP had a shorter time to ANC recovery and is more effective than FIL for the prevention of FN in the ASCT setting.  相似文献   
92.
93.
94.
95.

Objective

The assessment of prognostic biomarkers in monoclonal gammopathies of uncertain significance (MGUS) requires using large cohorts and long follow-ups, due to the low rate of conversion to multiple myeloma (MM). The aim of this article is to develop a model that allows smaller cohorts and shorter follow-ups to be used with high reliability.

Patients and methods

A total of 64 MGUS patients were studied and followed-up prospectively for 6 ± 0.24 years. Patients were classified as evolving or non-evolving, depending on whether the monoclonal protein levels increased or not over time. The risk of conversion to MM was tested based on these phenotypes, and whether the factors that predict conversion to MM are also associated with the appearance of an evolving phenotype.

Results

Eleven patients showed an evolving phenotype, and 53 a non-evolving one. All patients who converted to MM previously showed evolving phenotype (P = .003). At diagnosis, evolving phenotype associated with monoclonal gammopathies of IgA isotype (27 vs. 9%), monoclonal IgG levels above 1,500 mg/dl (P = .007, OR 9.8) and altered kappa/lambda ratios (P = .001, OR 11.7).

Conclusions

Risk factors for developing an evolving phenotype in MGUS patients are the same as those already described for the development of MM. These data show the validity of the evolving/non-evolving model to study markers to predict the outcome of MGUS patients, and confirm the role of the levels of monoclonal IgG and the light chains ratio in the prognosis of this disease.  相似文献   
96.
97.
98.
Advances in imaging acquisition techniques allow multiple imaging modalities to be collected from the same subject. Each individual modality offers limited yet unique views of the functional, structural, or dynamic temporal features of the brain. Multimodal fusion provides effective ways to leverage these complementary perspectives from multiple modalities. However, the majority of current multimodal fusion approaches involving functional magnetic resonance imaging (fMRI) are limited to 3D feature summaries that do not incorporate its rich temporal information. Thus, we propose a novel three‐way parallel group independent component analysis (pGICA) fusion method that incorporates the first‐level 4D fMRI data (temporal information included) by parallelizing group ICA into parallel ICA via a unified optimization framework. A new variability matrix was defined to capture subject‐wise functional variability and then link it to the mixing matrices of the other two modalities. Simulation results show that the three‐way pGICA provides highly accurate cross‐modality linkage estimation under both weakly and strongly correlated conditions, as well as comparable source estimation under different noise levels. Results using real brain imaging data identified one linked functional–structural–diffusion component associated to differences between schizophrenia and controls. This was replicated in an independent cohort, and the identified components were also correlated with major cognitive domains. Functional network connectivity revealed visual–subcortical and default mode‐cerebellum pairs that discriminate between schizophrenia and controls. Overall, both simulation and real data results support the use of three‐way pGICA to identify multimodal spatiotemporal links and to pursue the study of brain disorders under a single unifying multimodal framework.  相似文献   
99.
100.
Interpersonal dysfunction contributes to significant disability in the schizophrenia spectrum. Schizotypal Personality Disorder (SPD) is a schizophrenia-related personality demonstrating social cognitive impairment in the absence of frank psychosis. Past research indicates that cognitive dysfunction or schizotypy may account for social cognitive dysfunction in this population. We tested SPD subjects and healthy controls on the Empathic Accuracy (EA) paradigm and the Reading of the Mind in the Eyes Test (RMET), assessing the impact of EA on social support. We also explored whether EA differences could be explained by intelligence, working memory, trait empathy, or attachment avoidance. SPD subjects did not differ from controls in RMET, but demonstrated lower EA during negative valence videos, associated with lower social support. Dynamic, multimodal EA paradigms may be more effective at capturing interpersonal dysfunction than static image tasks such as RMET. Schizotypal severity, trait empathy, and cognitive dysfunction did not account for empathic dysfunction in SPD, although attachment avoidance is related to empathic differences. Empathic dysfunction for negative affect contributes to decreased social support in the schizophrenia spectrum. Future research may shed further light on potential links between attachment avoidance, empathic dysfunction, and social support.  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