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   203090篇
  免费   28550篇
  国内免费   6732篇
耳鼻咽喉   1696篇
儿科学   1482篇
妇产科学   5157篇
基础医学   14523篇
口腔科学   2161篇
临床医学   16161篇
内科学   19536篇
皮肤病学   1360篇
神经病学   724篇
特种医学   5978篇
外国民族医学   253篇
外科学   30037篇
综合类   26132篇
现状与发展   38篇
一般理论   3篇
预防医学   9519篇
眼科学   110篇
药学   14301篇
  131篇
中国医学   4879篇
肿瘤学   84191篇
  2024年   186篇
  2023年   4206篇
  2022年   6034篇
  2021年   10540篇
  2020年   10539篇
  2019年   9527篇
  2018年   9153篇
  2017年   9552篇
  2016年   10293篇
  2015年   11875篇
  2014年   17207篇
  2013年   16878篇
  2012年   13618篇
  2011年   13818篇
  2010年   10056篇
  2009年   10309篇
  2008年   10500篇
  2007年   9826篇
  2006年   8668篇
  2005年   7054篇
  2004年   5857篇
  2003年   4847篇
  2002年   4103篇
  2001年   3748篇
  2000年   3095篇
  1999年   2553篇
  1998年   1980篇
  1997年   1738篇
  1996年   1411篇
  1995年   1481篇
  1994年   1221篇
  1993年   937篇
  1992年   829篇
  1991年   753篇
  1990年   563篇
  1989年   511篇
  1988年   422篇
  1987年   379篇
  1986年   288篇
  1985年   381篇
  1984年   311篇
  1983年   198篇
  1982年   204篇
  1981年   188篇
  1980年   164篇
  1979年   114篇
  1978年   76篇
  1977年   60篇
  1976年   54篇
  1975年   34篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
61.
目的:探讨人胃癌细胞中乙酰肝素酶(HPSE)调控的差异蛋白和信号通路,为以HPSE为靶点防治胃癌提供依据。方法:利用siRNA干扰技术,在乙酰肝素酶(HPSE)基因高表达的SGC7901细胞中转入干扰HPSE的慢病毒载体(LV-HPSE-RNAi),通过嘌呤霉素筛选出稳定株,利用qPCR和Western blot分别检测HPSE mRNA和蛋白表达;利用细胞划痕实验和Transwell侵袭实验测定细胞的迁移和侵袭能力;利用同位素标记的相对和绝对定量(iTRAQ)联合二维液相色谱串联质谱(2DLC-MS/MS)技术筛查差异蛋白,并进行生物信息学分析,对差异蛋白PKCa应用Western blot进一步验证。结果:人胃癌SGC7901细胞和沉默HPSE表达的ZSGC7901细胞对比检测出98个差异蛋白,并且富集在157条信号通路上。与肿瘤发生发展关系密切的有6条:细胞外基质和受体相互作用、局灶性黏附、PI3K-Akt信号通路、癌途径、癌中microRNAs、Wnt信号通路。且上调的FAK、ITGA、PKCa等蛋白和下调的PKA、CDK6等蛋白在通路中处于重要的位置。Western blot结果证明PKCa在沉默HPSE的ZSGC7901细胞中表现为上调,差异具有统计学意义(P<0.05),与蛋白质组学筛选结果一致。结论:HPSE在人胃癌细胞中调控的蛋白,参与细胞重要生物学过程、参与重要分子功能及重要信号途径,有望可以成为防治胃癌的新靶点。  相似文献   
62.
BackgroundGiven numerous publications and clinical trials regarding axillary management in breast cancer, we sought to summarize this complex literature to help clarify this field for clinicians. This systematic review focuses on the role of irradiation of the axillary nodes (locoregional nodal irradiation [LRNI]) in the management of the axilla in patients with early-stage breast cancer in various clinical settings.MethodsWe searched MEDLINE and EMBASE databases, the Cochrane library, the proceedings of the ASCO, the ASTRO, the ESMO, the ESTRO, and the San Antonio Breast Cancer Symposium (2016–2019) meetings. The quality of the studies was assessed with design-specific tools. The study was registered in PROSPERO.ResultsWe included one systematic review, one individual patient data (IPD) meta-analysis, and five randomized controlled trials (RCTs). After axillary lymph node dissection (ALND), LRNI resulted in small benefits in breast cancer specific mortality, locoregional recurrence, and distant metastases-free survival but not overall survival. After a positive sentinel node biopsy (SLNB), LRNI may provide equivalent locoregional control and disease-free survival (DFS) compared to ALND with a lower risk of lymphedema. No randomized data is available for the neoadjuvant setting.ConclusionsThe summary of the role of radiation, is relevant to radiation oncologists for choosing the correct cohort of patient requiring LRNI and to surgeons making clinical decisions regarding the timing and type of breast reconstruction offered to patients.  相似文献   
63.
BackgroundLymphedema is a serious complication of axillary lymph node dissection (ALND) with an incidence rate of 20%. Simplified Lymphatic Microsurgical Preventing Healing Approach (SLYMPHA) is a safe and relatively simple method, which decreases incidence of lymphedema dramatically. Our initial study showed an 88% decrease in clinical lymphedema rate. In the initial study, we used arm circumference measurement for the diagnosis of lymphedema and median follow up was 15 months. The aim of this study was to confirm these results after a long-term follow up period and by using bioimpedance spectroscopy (L-Dex) technology in detecting lymphedema.Study designAll patients, undergoing ALND with or without SLYMPHA between January 2014 and November 2020 were included in the study. Patients with no postoperative L-Dex measurements were excluded. A L-Dex score outside the normal range (±10 L-Dex unit) or ≥10 L-Dex unit increase above patient's baseline was considered as lymphedema. The incidence of lymphedema was compared between patients with and without SLYMPHA.Results194 patients were included in the study. 57% of cohort underwent SLYMPHA. Mean follow-up time was 47 ± 37 months. Patients, who underwent SLYMPHA, had a significantly lower rate of lymphedema (16% vs 32%; p = 0.01; OR 0.4 [0.2–0.8]).ConclusionSLYMPHA is a safe and relatively simple method, which continued its efficacy after a long-term follow up period. It should be considered as an adjunct procedure to ALND for all patients during initial surgery.  相似文献   
64.
AimsOligometastatic disease (OMD) represents a spectrum of clinical scenarios and various classification systems have been proposed. Bone-only OMD can occur in patients with advanced prostate cancer and validated decision-making tools are needed to assist patient selection for metastasis-directed therapy. The aim of the present study was to determine the prognostic utility of a classification system for OMD.Materials and methodsA retrospective review was conducted of all patients with bone-only oligometastatic prostate cancer treated with stereotactic body radiotherapy (SBRT) since November 2011. SBRT was delivered using CyberKnife® and gantry-based linear accelerator platforms. All patients were classified into oligometastatic states based on the European Society for Radiotherapy and Oncology/European Organisation for Research and Treatment of Cancer (ESTRO/EORTC) classification system. Kaplan–Meier and Cox regression analyses were carried out to determine the prognostic utility of this classification system.ResultsIn total, 105 patients with 145 osseous metastases were treated over 119 sessions. The median follow-up after SBRT was 23 months (interquartile range 10–39.8). Twelve patients had died after a median time of 31 months. The 3-year metastatic progression-free survival was 23% (95% confidence interval 13–32) and the 3-year overall survival was 88% (95% confidence interval 80–96). Patients in a metachronous oligometastatic state were 4.50 (95% confidence interval 1.19–17.10, P = 0.03) times more likely to experience metastatic progression compared with those with synchronous oligometastases, and 6.69 (95% confidence interval 1.05–42.50, P = 0.04) times more likely to experience any failure. Hazard ratio magnitudes increased for patients in a repeat oligometastatic state. The multivariate model for both metastatic progression-free survival and failure-free survival found prostate-specific antigen doubling time <4 months (P = 0.002; P = 0.05) to independently predict for progression.ConclusionThe ESTRO/EORTC classification of OMD predicts for progression in patients treated with SBRT for bone-only oligometastatic prostate cancer at our institution. Further validation in prospective series over multiple tumour sites is needed. These characterisation factors should be assessed in patients considered for metastasis-directed therapy together with established prognostic features.  相似文献   
65.
ObjectivesTo describe our robotic Y intracorporeal neobladder (ICNB) technique and to report its post-operative complications and urodynamics (UD) findings.Subjectsand Methods: In this prospective study we enrolled patients affected by MIBC (T1-T4N0–N1M0) from 01/2017 to 06/2021 at our Centers. All the patients underwent robotic radical cystectomy (RARC) with Y–ICNB reconfiguration. Early and late complications were collected and classified according to Clavien-Dindo. Continence and potency at 1, 3, 6 and 12 months were evaluated. At the 3rd month of follow-up patients underwent UD. Finally, in a retrospective match paired analysis the functional outcomes of Y RARC patients were compared with a cohort of open Y radical cystectomy.Results45 patients were enrolled. Overall 30-day complications were observed in 25 (55,5%) patients and 30 to 90-days complications in 4 (8,9%). 9 patients (20%) had Clavien ≥3 complications. UDs revealed median neobladder capacity of 268 cc, with a median compliance of 13 ml/cm H20; the voiding phase showed a voiding volume and a post void residual (PVR) of 154 cc and 105 cc respectively. At 12 months of follow-up 4.4%, 15.5% and 4.4% of the patients experienced urge, stress and mix urinary incontinence respectively. The comparison between Y RARC and Y open RC revealed a higher neobladder capacity with open approach (p = 0.049) with subsequent better findings during the voiding phase in terms of maximum flow (p = 0.002), voiding volume (p = 0.001) and PVR (p = 0.01). Focusing on continence recovery, a slight trend in favor of RARC was shown without reaching the statistical significance.ConclusionsRobotic Y–ICNB is feasible and safe as shown by the low rate of postoperative complications. Satisfying UD functional outcomes are achievable, both during filling and voiding phase.  相似文献   
66.
《Diagnostic Histopathology》2022,28(11):493-500
After decades of relative stagnation lung cancer is emerging as a disease type where rapid progress is being made in diagnosis and therapy, as well as in our understanding of disease biology. Much of this progress is of immediate impact to diagnosticians, and more is likely to affect diagnostic practice in the near future. In this review we seek to briefly summarize several key areas of active research of immediate or probable imminent value to trainee and consultant pulmonary pathologists alike. We cover some major changes in tumour classification, grading, and patient stratification, as well as considering the state of the art in machine-assisted interpretation of lung cancer histology, and the use of genetically modified lung cancer models.  相似文献   
67.
68.
  • DNA is the sequence that codes for proteins.
  • Messenger RNA is transcribed from the DNA sequence of genes and translated into protein.
  • It can be difficult to predict how a change in the DNA sequence will affect messenger RNA and protein quantity and quality.
  • DNA translocation changes can cause the joining of sequences from two different genes or different parts of the same gene.
  • DNA sequencing is often used clinically to predict how DNA changes might affect proteins.
  • Alternatively, RNA sequencing can be used as a more direct measure of the effect of DNA changes on the protein products.
  • This sequencing is important for identifying changes in cancer that may indicate response to targeted therapy, prognosis, or diagnosis.
  相似文献   
69.
Genome-scale screening experiments in cancer produce long lists of candidate genes that require extensive interpretation for biological insight and prioritization for follow-up studies. Interrogation of gene lists frequently represents a significant and time-consuming undertaking, in which experimental biologists typically combine results from a variety of bioinformatics resources in an attempt to portray and understand cancer relevance. As a means to simplify and strengthen the support for this endeavor, we have developed oncoEnrichR, a flexible bioinformatics tool that allows cancer researchers to comprehensively interrogate a given gene list along multiple facets of cancer relevance. oncoEnrichR differs from general gene set analysis frameworks through the integration of an extensive set of prior knowledge specifically relevant for cancer, including ranked gene-tumor type associations, literature-supported proto-oncogene and tumor suppressor gene annotations, target druggability data, regulatory interactions, synthetic lethality predictions, as well as prognostic associations, gene aberrations and co-expression patterns across tumor types. The software produces a structured and user-friendly analysis report as its main output, where versions of all underlying data resources are explicitly logged, the latter being a critical component for reproducible science. We demonstrate the usefulness of oncoEnrichR through interrogation of two candidate lists from proteomic and CRISPR screens. oncoEnrichR is freely available as a web-based service hosted by the Galaxy platform ( https://oncotools.elixir.no ), and can also be accessed as a stand-alone R package ( https://github.com/sigven/oncoEnrichR ).  相似文献   
70.
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