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   3921篇
  免费   251篇
  国内免费   46篇
耳鼻咽喉   45篇
儿科学   88篇
妇产科学   43篇
基础医学   316篇
口腔科学   167篇
临床医学   506篇
内科学   561篇
皮肤病学   82篇
神经病学   243篇
特种医学   127篇
外科学   455篇
综合类   421篇
预防医学   345篇
眼科学   191篇
药学   337篇
中国医学   34篇
肿瘤学   257篇
  2023年   23篇
  2022年   14篇
  2021年   65篇
  2020年   62篇
  2019年   82篇
  2018年   117篇
  2017年   97篇
  2016年   77篇
  2015年   240篇
  2014年   306篇
  2013年   269篇
  2012年   260篇
  2011年   399篇
  2010年   178篇
  2009年   212篇
  2008年   204篇
  2007年   284篇
  2006年   234篇
  2005年   137篇
  2004年   146篇
  2003年   106篇
  2002年   74篇
  2001年   60篇
  2000年   44篇
  1999年   44篇
  1998年   25篇
  1997年   34篇
  1996年   31篇
  1995年   29篇
  1994年   24篇
  1993年   29篇
  1992年   29篇
  1991年   35篇
  1990年   25篇
  1989年   24篇
  1988年   36篇
  1987年   28篇
  1986年   24篇
  1985年   11篇
  1984年   9篇
  1983年   9篇
  1982年   11篇
  1981年   9篇
  1980年   6篇
  1979年   11篇
  1977年   4篇
  1976年   6篇
  1975年   8篇
  1974年   4篇
  1968年   3篇
排序方式: 共有4218条查询结果,搜索用时 15 毫秒
1.
Graefe's Archive for Clinical and Experimental Ophthalmology - Ophthalmic trauma is a leading cause of preventable monocular blindness worldwide. The prevalence of ophthalmic trauma varies...  相似文献   
2.
The Dutch Drug Rediscovery Protocol (DRUP) and the Australian Cancer Molecular Screening and Therapeutic (MoST) Program are similar nonrandomized, multidrug, pan-cancer trial platforms that aim to identify signals of clinical activity of molecularly matched targeted therapies or immunotherapies outside their approved indications. Here, we report results for advanced or metastatic cancer patients with tumors harboring cyclin D-CDK4/6 pathway alterations treated with CDK4/6 inhibitors palbociclib or ribociclib. We included adult patients that had therapy-refractory solid malignancies with the following alterations: amplifications of CDK4, CDK6, CCND1, CCND2 or CCND3, or complete loss of CDKN2A or SMARCA4. Within MoST, all patients were treated with palbociclib, whereas in DRUP, palbociclib and ribociclib were assigned to different cohorts (defined by tumor type and alteration). The primary endpoint for this combined analysis was clinical benefit, defined as confirmed objective response or stable disease ≥16 weeks. We treated 139 patients with a broad variety of tumor types; 116 with palbociclib and 23 with ribociclib. In 112 evaluable patients, the objective response rate was 0% and clinical benefit rate at 16 weeks was 15%. Median progression-free survival was 4 months (95% CI: 3-5 months), and median overall survival 5 months (95% CI: 4-6 months). In conclusion, only limited clinical activity of palbociclib and ribociclib monotherapy in patients with pretreated cancers harboring cyclin D-CDK4/6 pathway alterations was observed. Our findings indicate that monotherapy use of palbociclib or ribociclib is not recommended and that merging data of two similar precision oncology trials is feasible.  相似文献   
3.
4.
Colorectal cancer (CRC) is the third most common cancer worldwide after lung and breast cancers, and ranks second in terms of cancer mortality globally. Brunei Darussalam reports high incidence of CRC in the Southeast Asian region and has no formal national screening programme for CRC. Screening for CRC in Brunei Darussalam is offered in an opportunistic fashion for individuals with average or above average risks for CRC, that is, the individual has a positive family history of CRC or neoplasms and is more than 50 years old. Opportunistic screening is widely practiced but this is not standardised. The Ministry of Health in Brunei Darussalam is currently in the process of implementing a CRC screening programme as part of a larger national health screening based on the increasing incidence of non-communicable diseases (NCDs). This review article assesses the situation of CRC in Brunei Darussalam from the 1980s to present day, including incidence of CRC in different age groups, ethnicities and genders; relevant non-modifiable and modifiable risk factors of CRC in Brunei Darussalam setting; and common CRC screening techniques used in Brunei Darussalam as well as other Asia-Pacific countries. The review also discusses the merits of a national CRC screening programme. With the increasing incidence of CRC worldwide and in Brunei Darussalam, national screening for CRC in Brunei Darussalam is an important strategy to lower morbidity and mortality rates. A review of the progress and outcome of the national screening programme will be available a few years after rollout.  相似文献   
5.
6.
7.
8.
ObjectivesOlder adults constitute the majority of patients with lung cancer. However, they are under-represented in clinical trials as eligibility criteria often restrict enrolment based on comorbidities that are common with aging. We aimed to describe comorbidities relating to trial exclusion criteria in older adults with lung cancer, determine the proportion that would typically be excluded from trials, and examine the impact on treatment uptake.Materials and MethodsWe conducted a population-based study of people aged ≥65 years diagnosed with metastatic lung cancer using linked data for clients of the Australian Government Department of Veterans' Affairs (2005–2015). We defined trial-typical patients based on the absence of comorbidities related to the following: inadequate organ (cardiac, renal, hepatic, marrow) function; cognitive dysfunction; poor performance status (PS); prior malignancy within 5 years. We report systemic therapy uptake within 3 months of diagnosis.ResultsOur study included 677 patients (median age 84). Over half (53.4%) were not trial-typical, with the most common reasons being poor PS (37.5%), cardiac disease (19.2%), and prior cancer (12.9%). Eighty-two (12.1%) received systemic therapy. Patients with poor PS, cardiac disease, and dementia had lower treatment uptake rates. However, there was no significant difference in treatment uptake between trial-typical and non-trial-typical patients (13.4 vs 11.0%).ConclusionMore than half of older adults with advanced lung cancer would be typically excluded from trial participation. Future clinical trials of older adults need to consider broader eligibility criteria to better reflect this population to gain the best evidence for their care.  相似文献   
9.
10.

Statement of problem

Components have been introduced that allow the screw channel of an implant crown to be angled lingually and the screws to be tightened in a non-axial direction to the implant. Information is lacking as to how the removal torque value (RTV) and force to failure (FTF) of these components compare with those of conventional screws.

Purpose

The purpose of this in vitro study was to evaluate and compare the RTV and FTF values of cyclically loaded implant-supported restorations. Specifically, values for conventional axially tightened gold screws were compared with those for non-axially tightened screws aligned at 3 different angulations.

Material and methods

A total of 28 external hexagon implants were embedded in acrylic resin and divided into 4 groups. Simulated restorations were fabricated on abutments capable of different screw channel angulations. Dynamic abutments (DA) were waxed at different angulations and then cast. Simulated restorations were placed on the implants and tightened: group 0GS: 0-degree angulation gold screw tightened to 35 Ncm (control group); group 0DAS, 0-degree angulation with dynamic abutment (DAS) screw; group 20DAS: 20-degree angulation with DA screw; group 28DAS: 28-degree angulation with DAS screw. In groups 0DAS, 20DAS, and 28DAS, the DAS screw was used and tightened to 25 Ncm. Screw removal torque values were recorded by using a digital torque gauge at baseline and, after reaching cyclic fatigue, by using a dual-axis mastication simulator for 1 200 000 cycles. The fracture strength (FS) of the implant restorations was tested under compression until failure by using a universal testing machine. Differences between baseline and removal torque (ΔRT) were calculated. Statistical analysis was performed by using 1-way ANOVA for ΔRT and FS separately (α=.05).

Results

ΔRT and FS values were not significantly different among the groups (P>.05). The screw fractured in 5 of 28 specimens (17.8%); the remaining specimens failed with fracture of the implant.

Conclusions

The removal torque and FS values of the angulated abutment screw were comparable to those of the gold screw. Angulation of the abutment had no significant influence on the screw removal torque values.  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