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   45568篇
  免费   2994篇
  国内免费   251篇
耳鼻咽喉   394篇
儿科学   1319篇
妇产科学   1235篇
基础医学   6052篇
口腔科学   981篇
临床医学   4677篇
内科学   9884篇
皮肤病学   908篇
神经病学   4909篇
特种医学   1533篇
外科学   6005篇
综合类   194篇
一般理论   24篇
预防医学   3377篇
眼科学   775篇
药学   2837篇
  2篇
中国医学   84篇
肿瘤学   3623篇
  2023年   482篇
  2022年   393篇
  2021年   1787篇
  2020年   1067篇
  2019年   1509篇
  2018年   1741篇
  2017年   1217篇
  2016年   1357篇
  2015年   1577篇
  2014年   2153篇
  2013年   2696篇
  2012年   4007篇
  2011年   3998篇
  2010年   2024篇
  2009年   1880篇
  2008年   3167篇
  2007年   3078篇
  2006年   2791篇
  2005年   2751篇
  2004年   2305篇
  2003年   2059篇
  2002年   1836篇
  2001年   273篇
  2000年   231篇
  1999年   267篇
  1998年   315篇
  1997年   235篇
  1996年   153篇
  1995年   187篇
  1994年   173篇
  1993年   137篇
  1992年   119篇
  1991年   91篇
  1990年   77篇
  1989年   72篇
  1988年   65篇
  1987年   54篇
  1986年   49篇
  1985年   48篇
  1984年   43篇
  1983年   26篇
  1982年   43篇
  1981年   32篇
  1980年   29篇
  1979年   21篇
  1978年   16篇
  1976年   16篇
  1974年   17篇
  1972年   19篇
  1971年   16篇
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
1.
2.
Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges.  相似文献   
3.
We present data from patients with advanced biliary tract cancer (BTC) receiving pembrolizumab in the KEYNOTE-158 (NCT02628067; phase 2) and KEYNOTE-028 (NCT02054806; phase 1b) studies. Eligible patients aged ≥18 years from both studies had histologically/cytologically confirmed incurable BTC that progressed after standard treatment regimen(s), measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, Eastern Cooperative Oncology Group performance status 0/1, and no prior immunotherapy. Programmed death ligand 1 (PD-L1)-positive tumors were required for eligibility in KEYNOTE-028 only. Patients received pembrolizumab 200 mg every three weeks (KEYNOTE-158) or 10 mg/kg every two weeks (KEYNOTE-028) for ≤2 years. Primary efficacy endpoint was objective response rate (ORR) by RECIST v1.1. Response assessed by independent central review is reported. KEYNOTE-158 enrolled 104 patients and KEYNOTE-028 enrolled 24 patients. Median (range) follow-up was 7.5 months (0.6-34.3) in KEYNOTE-158 and 5.7 months (0.6-55.4) in KEYNOTE-028. In KEYNOTE-158, ORR was 5.8% (6/104; 95% CI, 2.1%-12.1%); median duration of response (DOR) was not reached (NR) (range, 6.2-26.6+ months). Median (95% CI) OS and PFS were 7.4 (5.5-9.6) and 2.0 (1.9-2.1) months. Among PD-L1-expressers (n = 61) and PD-L1-nonexpressers (n = 34), respectively, ORR was 6.6% (4/61) and 2.9% (1/34). In KEYNOTE-028, ORR was 13.0% (3/23; 95% CI, 2.8%-33.6%); median DOR was NR (range, 21.5-53.2+ months). Median (95% CI) OS and PFS were 5.7 (3.1-9.8) and 1.8 (1.4-3.1) months. Grade 3 to 5 treatment-related adverse events occurred in 13.5% of patients in KEYNOTE-158 (no grade 4; grade 5 renal failure, n = 1) and 16.7% in KEYNOTE-028 (no grade 4/5). In summary, pembrolizumab provides durable antitumor activity in 6% to 13% of patients with advanced BTC, regardless of PD-L1 expression, and has manageable toxicity.  相似文献   
4.
5.
Context: Treatment of primary spinal syringomyelia is still controversial. Among others, shunting syrinx fluid to the subarachnoid, peritoneal or pleural space has been utilized with varying success. Shunt obstruction, migration, and infection represent the most common complications of these procedures.

Findings: The authors present the case of an 81-year-old woman who developed an unusual neurological deterioration resembling a subacute posttraumatic ascending myelopathy (SPAM) after the insertion of a syringosubarachnoid shunt for the treatment of slow-growing D10 syringomyelia.

Conclusion/Clinical Relevance: To date, no cases of SPAM secondary to the insertion of a syringosubarachnoid shunt for the treatment of syringomyelia have been reported. The potential pathogenesis related to this phenomenon is discussed.  相似文献   
6.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
7.
8.
Colorectal cancer (CRC) screening programs help diagnose cancer precursors and early cancers and help reduce CRC mortality. However, currently recommended tests, the fecal immunochemical test (FIT) and colonoscopy, have low uptake. There is therefore a pressing need for screening strategies that are minimally invasive and consequently more acceptable to patients, most likely blood based, to increase early CRC identification. MicroRNAs (miRNAs) released from cancer cells are detectable in plasma in a remarkably stable form, making them ideal cancer biomarkers. Using plasma samples from FIT-positive (FIT+) subjects in an Italian CRC screening program, we aimed to identify plasma circulating miRNAs that detect early CRC. miRNAs were initially investigated by quantitative real-time PCR in plasma from 60 FIT+ subjects undergoing colonoscopy at Fondazione IRCCS Istituto Nazionale dei Tumori, then tested on an internal validation cohort (IVC, 201 cases) and finally in a large multicenter prospective series (external validation cohort [EVC], 1121 cases). For each endoscopic lesion (low-grade adenoma [LgA], high-grade adenoma [HgA], cancer lesion [CL]), specific signatures were identified in the IVC and confirmed on the EVC. A two-miRNA-based signature for CL and six-miRNA signatures for LgA and HgA were selected. In a multivariate analysis including sex and age at blood collection, the areas under the receiver operating characteristic curve (95% confidence interval) of the signatures were 0.644 (0.607–0.682), 0.670 (0.626–0.714) and 0.682 (0.580–0.785) for LgA, HgA and CL, respectively. A miRNA-based test could be introduced into the FIT+ workflow of CRC screening programs so as to schedule colonoscopies only for subjects likely to benefit most.  相似文献   
9.
10.
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