首页 | 官方网站   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   186526篇
  免费   1638篇
  国内免费   66篇
医药卫生   188230篇
  2023年   116篇
  2022年   67篇
  2021年   295篇
  2020年   245篇
  2019年   324篇
  2018年   22204篇
  2017年   17644篇
  2016年   19797篇
  2015年   1293篇
  2014年   1241篇
  2013年   1402篇
  2012年   7855篇
  2011年   21899篇
  2010年   19283篇
  2009年   11965篇
  2008年   20316篇
  2007年   22491篇
  2006年   1327篇
  2005年   2866篇
  2004年   3972篇
  2003年   4902篇
  2002年   3003篇
  2001年   366篇
  2000年   458篇
  1999年   231篇
  1998年   279篇
  1997年   278篇
  1996年   141篇
  1995年   154篇
  1994年   143篇
  1993年   112篇
  1992年   85篇
  1991年   143篇
  1990年   162篇
  1989年   117篇
  1988年   92篇
  1987年   65篇
  1986年   40篇
  1985年   53篇
  1984年   39篇
  1983年   52篇
  1982年   51篇
  1980年   61篇
  1974年   30篇
  1969年   26篇
  1938年   60篇
  1937年   26篇
  1934年   31篇
  1932年   58篇
  1930年   49篇
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
1.
2.
Intratumor heterogeneity is a main cause of the dismal prognosis of glioblastoma (GBM). Yet, there remains a lack of a uniform assessment of the degree of heterogeneity. With a multiscale approach, we addressed the hypothesis that intratumor heterogeneity exists on different levels comprising traditional regional analyses, but also innovative methods including computer-assisted analysis of tumor morphology combined with epigenomic data. With this aim, 157 biopsies of 37 patients with therapy-naive IDH-wildtype GBM were analyzed regarding the intratumor variance of protein expression of glial marker GFAP, microglia marker Iba1 and proliferation marker Mib1. Hematoxylin and eosin stained slides were evaluated for tumor vascularization. For the estimation of pixel intensity and nuclear profiling, automated analysis was used. Additionally, DNA methylation profiling was conducted separately for the single biopsies. Scoring systems were established to integrate several parameters into one score for the four examined modalities of heterogeneity (regional, cellular, pixel-level and epigenomic). As a result, we could show that heterogeneity was detected in all four modalities. Furthermore, for the regional, cellular and epigenomic level, we confirmed the results of earlier studies stating that a higher degree of heterogeneity is associated with poorer overall survival. To integrate all modalities into one score, we designed a predictor of longer survival, which showed a highly significant separation regarding the OS. In conclusion, multiscale intratumor heterogeneity exists in glioblastoma and its degree has an impact on overall survival. In future studies, the implementation of a broadly feasible heterogeneity index should be considered.  相似文献   
3.
Objectives

Air-polishing has been used in the treatment of periodontitis and gingivitis for years. The introduction of low-abrasive powders has enabled the use of air-polishing devices for subgingival therapy. Within the last decade, a wide range of different low-abrasive powders for subgingival use has been established. In this study, the effects of a glycine powder and a trehalose powder on human gingival fibroblasts (HGF) were investigated.

Methods

HGF were derived from three systemically and periodontally healthy donors. After 24 h and 48 h of incubation time, mRNA levels, and after 48 h, protein levels of TNFα, IL-8, CCL2, and VEGF were determined. In addition, NF-κB p65 nuclear translocation and in vitro wound healing were assessed. Statistical analysis was performed by ANOVA and post hoc Dunnett’s and Tukey’s tests (p?<?0.05).

Results

Glycine powder significantly increased the expression of proinflammatory genes and showed exploitation of the NF-κB pathway, albeit trehalose powder hardly interfered with cell function and did not trigger the NF-κB pathway. In contrast to trehalose, glycine showed a significant inhibitory effect on the in vitro wound healing rate.

Conclusion

Subgingivally applicable powders for air-polishing devices can regulate cell viability and proliferation as well as cytokine expression. Our in vitro study suggests that the above powders may influence HGF via direct cell effects. Trehalose appears to be relatively inert compared to glycine powder.

Clinical relevance

With the limitations of an in vitro design, our study suggests that in terms of cell response, trehalose-based air-polishing powders show a reduced effect on inflammation.

  相似文献   
4.
5.
The prospective, multicenter, noninterventional TACTIC study assessed effectiveness and safety of trifluridine/tipiracil (FTD/TPI) in patients with metastatic colorectal cancer (mCRC) in a real-world setting in Germany, thus evaluating the external validity of the findings from the pivotal RECOURSE trial. Primary endpoint was overall survival (OS). Secondary objectives included progression-free survival (PFS), safety, and quality of life (QoL). Subgroups comprised patients with good (<3 metastatic sites at inclusion, ≥18 months from diagnosis of first metastasis to inclusion) or poor (remaining patients) prognostic characteristics (GPC/PPC). GPC without liver metastases was considered best prognostic characteristics (BPC). In total, 307 eligible patients (pretreated or not suitable for other available therapies) were treated with FTD/TPI. Overall, median [95%-CI] OS was 7.4 months [6.4-8.6], median PFS was 2.9 months [2.8-3.3]. In BPC (n = 65) and GPC (n = 176) compared to PPC (n = 124) subgroup, median OS (13.3 [9.1-17.6] vs 8.9 [7.6-9.8] vs 5.1 [4.4-7.0] months) and median PFS (4.0 [3.3-5.3] vs 3.4 [3.0-3.7] vs 2.6 [2.4-2.8] months) were longer. Patient-reported QoL, assessed by validated questionnaires (EQ-5D-5L, PRO-CTCAE), was stable throughout FTD/TPI treatment. Predominant FTD/TPI-related adverse events of grades 3 or 4 were neutropenia (13.0%), leukopenia (7.5%), and anemia (5.2%). Altogether, palliative FTD/TPI therapy in patients with pretreated mCRC was associated with prolonged survival, delayed progression, maintained health-related QoL, and manageable toxicity. Low metastatic burden and indolent disease were favorable prognostic factors for survival. TACTIC confirms the effectiveness and safety of FTD/TPI, highlighting its value in routine clinical practice.  相似文献   
6.
7.
8.
Journal of Neuro-Oncology - Glioblastoma multiforme (GBM) is a highly malignant glial tumor, affecting men more often than women. The reason for this gender-specific predominance remains unclear,...  相似文献   
9.
10.
Purpose

About 20–25% of patients experience weight regain (WR) or insufficient weight loss (IWL) after bariatric metabolic surgery (BS). Therefore, we aimed to retrospectively assess the effectiveness of adjunct treatment with the GLP-1 receptor agonist semaglutide in non-diabetic patients with WR or IWL after BS.

Materials and Methods

Post-bariatric patients without type 2 diabetes (T2D) with WR or IWL (n?=?44) were included in the analysis. The primary endpoint was weight loss 3 and 6 months after initiation of adjunct treatment. Secondary endpoints included change in BMI, HbA1c, lipid profile, hs-CRP, and liver enzymes.

Results

Patients started semaglutide 64.7?±?47.6 months (mean?±?SD) after BS. At initiation of semaglutide, WR after post-bariatric weight nadir was 12.3?±?14.4% (mean?±?SD). Total weight loss during semaglutide treatment was???6.0?±?4.3% (mean?±?SD, p?<?0.001) after 3 months (3.2 months, IQR 3.0–3.5, n?=?38) and???10.3?±?5.5% (mean?±?SD, p?<?0.001) after 6 months (5.8 months, IQR 5.8–6.4, n?=?20). At 3 months, categorical weight loss was?>?5% in 61% of patients,?>?10% in 16% of patients, and?>?15% in 2% of patients. Triglycerides (OR?=?0.99; p?<?0.05), ALT (OR?=?0.87; p?=?0.05), and AST (OR?=?0.89; p?<?0.05) at baseline were negatively associated with weight loss of at least 5% at 3 months’ follow-up (p?<?0.05).

Conclusion

Treatment options to manage post-bariatric excess weight (regain) are scarce. Our results imply a clear benefit of adjunct treatment with semaglutide in post-bariatric patients. However, these results need to be confirmed in a prospective randomized controlled trial to close the gap between lifestyle intervention and revision surgery in patients with IWL or WR after BS.

Graphical abstract
  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-23

京公网安备 11010802026262号