全文获取类型
收费全文 | 26194篇 |
免费 | 2763篇 |
国内免费 | 571篇 |
专业分类
耳鼻咽喉 | 315篇 |
儿科学 | 533篇 |
妇产科学 | 261篇 |
基础医学 | 2055篇 |
口腔科学 | 540篇 |
临床医学 | 2351篇 |
内科学 | 3132篇 |
皮肤病学 | 963篇 |
神经病学 | 1183篇 |
特种医学 | 2514篇 |
外国民族医学 | 17篇 |
外科学 | 1734篇 |
综合类 | 3218篇 |
现状与发展 | 4篇 |
一般理论 | 1篇 |
预防医学 | 2254篇 |
眼科学 | 1275篇 |
药学 | 1866篇 |
7篇 | |
中国医学 | 482篇 |
肿瘤学 | 4823篇 |
出版年
2024年 | 39篇 |
2023年 | 342篇 |
2022年 | 474篇 |
2021年 | 995篇 |
2020年 | 881篇 |
2019年 | 882篇 |
2018年 | 874篇 |
2017年 | 882篇 |
2016年 | 1047篇 |
2015年 | 1113篇 |
2014年 | 1799篇 |
2013年 | 2218篇 |
2012年 | 1654篇 |
2011年 | 1698篇 |
2010年 | 1326篇 |
2009年 | 1212篇 |
2008年 | 1280篇 |
2007年 | 1218篇 |
2006年 | 1108篇 |
2005年 | 986篇 |
2004年 | 869篇 |
2003年 | 747篇 |
2002年 | 617篇 |
2001年 | 577篇 |
2000年 | 459篇 |
1999年 | 414篇 |
1998年 | 382篇 |
1997年 | 341篇 |
1996年 | 317篇 |
1995年 | 242篇 |
1994年 | 215篇 |
1993年 | 206篇 |
1992年 | 184篇 |
1991年 | 180篇 |
1990年 | 156篇 |
1989年 | 167篇 |
1988年 | 148篇 |
1987年 | 133篇 |
1986年 | 136篇 |
1985年 | 190篇 |
1984年 | 165篇 |
1983年 | 121篇 |
1982年 | 109篇 |
1981年 | 93篇 |
1980年 | 86篇 |
1979年 | 72篇 |
1978年 | 48篇 |
1977年 | 38篇 |
1976年 | 30篇 |
1975年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
《Cancer radiothérapie》2022,26(4):611-615
In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3 Gy), then ultra (dose/fraction: 5.2 to 6.1 Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20 Gy/fraction), the use of a single fraction of 19 to 23 Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors. 相似文献
2.
Background:We aim to evaluate the efficiency of Raman spectroscopy (RS) in diagnosing suspected patients with intrahepatic cholangiocarcinoma (ICC), manifested by diagnostic sensitivity, specificity, and accuracy.Methods:We will research widely the articles concerning the use of RS in ICC through authenticated database including PubMed/Medline, EMBASE, Web of Science, Ovid, Web of Knowledge, Cochrane Library, and CNKI between January 2012 and November 2020, retrieving at least 1500 spectra with strict criteria. This study will be carried out in accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We are going to summarize the test performance using random effects models.Results:Based on the pooled sensitivity, specificity, and diagnostic accuracy, we intend to provide the relative diagnostic efficiency in ICC through RS.Conclusion:Through this systematic review and meta-analysis, we intend to provide the pooled sensitivity, specificity and diagnostic accuracy of RS in the diagnosis of suspected ICC. Other parameters like positive likelihood ratios (LR), negative LR, diagnostic odds ratio (DOR), and area under curve (AUC) of the summary receiver operating characteristics (SROC) curve will also be calculated and related figures will be drawn to help illustrate the efficacy of RS in the diagnosis of ICC. 相似文献
3.
4.
5.
《Obesity research & clinical practice》2020,14(2):158-163
Although an inverse relationship between body mass index (BMI) and baroreflex sensitivity (BRS) was found, the effect of waist circumference (WC) on BRS is still inconclusive. The contradictory results of previous studies may be related to the heterogeneity and relatively small sample size of the subjects examined. The aim of this population-based study was to investigate whether the influence of increased WC is more detrimental to BRS than BMI. A total of 760 community dwellers were recruited and they were classified into Q1 (n = 189), Q2 (n = 183), Q3 (n = 192) and Q4 (n = 196) groups, based on WC quartiles. Spontaneous BRS was determined by spectral α coefficient method. Valsalva ratio was the longest RR interval after release of Valsalva maneuver divided by the shortest RR interval during maneuver. Cardiac autonomic function was calculated by power spectrum of heart rate in low and high frequency (LF, 0.04–0.15 Hz; HF, 0.15–0.40 Hz), and LF/HF ratio in supine position for five minutes. There were significant differences in spontaneous BRS and Valsalva ratio among different WC groups. In multivariate analysis, obesity was inversely associated with spontaneous BRS and Valsalva ratio. However, these inverse relationships became insignificant after further adjustment for WC quartiles. In contrast, Q4 vs. Q1, Q3 vs. Q1 and Q2 vs. Q1 of WC were inversely related to spontaneous BRS. Q4 vs. Q1 and Q3 vs. Q1 of WC were negatively associated with the Valsalva ratio. In conclusion, increased and even high-normal WC had a stronger adverse effect on BRS than BMI, independent of cardio-metabolic risk factors. 相似文献
6.
7.
The term “oligometastatic prostate cancer” refers to a heterogeneous group of disease states currently defined solely on the basis of clinical features. Oligorecurrent disease, de novo oligometastases, and oligoprogressive disease likely have unique biologic underpinnings and natural histories. Evidence suggesting the existence of a subset of patients who harbor prostate cancer with limited metastatic potential currently includes disparate and overwhelmingly retrospective reports. Nevertheless, emerging prospective data have corroborated the “better-than-expected,” retrospectively observed outcomes, particularly in the setting of oligorecurrent prostate cancer. Improved functional imaging with prostate-specific membrane antigen-targeted strategies may enhance the identification of patients with oligometastatic prostate cancer in the short term. In the long term, refinement of the oligometastatic case definition likely will require biologic risk-stratification schemes. To determine optimal treatment strategies and identify patients most likely to benefit from metastasis-directed therapy, future efforts should focus on conducting high-quality, prospective trials with much-needed molecular correlative studies. 相似文献
8.
《Journal of Medical Imaging and Radiation Sciences》2015,46(4):442-449
The purpose of this literature review is to investigate clinical treatment methods of total body irradiation within the context of a clinical department adopting a paediatric cohort with no existing technique. An extensive review of the literature was conducted using PubMed, Science Direct, Google Scholar, and Clinicians Knowledge Network. Articles were limited to nonhelical tomotherapy, nonparticle therapies, and those using hyperfractionated regimes. Total marrow irradiation was excluded because of national treatment and trial limitations. Of the numerous patient positioning methods present within the literature, the most comfortable and reproducible positioning methods for total body irradiation include both supine and the supine and/or prone combination. These positions increased stability and patient comfort during treatment, while also facilitating computed tomography data acquisition at the simulation stage. Ideally, dose calculations should be performed using a three-dimensional treatment planning system and quality assurance procedures that include in vivo dosimetry measurements. The available literature also suggests inhomogeneity correction factors and intensity modulation are superior to conventional open field techniques and should be implemented within developing protocols. Dynamic machine dose modulation is suggested to reduce department impact, removing the need for tissue compensators and accessory shielding devices, while providing significant improvements to treatment time and dose accuracy. Further long-term survival and intensity modulation studies are warranted, including direct comparisons of both dose modulation and treatment efficiency. 相似文献
9.
目的 分析白内障围手术期结膜囊菌群的分布及药敏试验结果。方法 选取264例白内障患者,分别在患者入院后、手术消毒前、手术消毒后、手术结束后四个时间点取样,进行细菌培养及药敏试验,比较不同时期的细菌培养结果和药敏结果。结果 入院后结膜囊细菌培养阳性率明显高于手术消毒前、手术消毒后及手术结束后;入院后结膜囊细菌培养以表皮葡萄球菌为主;革兰氏阳性球菌对头孢西丁、加替沙星、左氧氟沙星等敏感性较高。结论 表皮葡萄球菌是结膜囊最常见的细菌,术前应常规应用抗生素点眼,聚维酮碘冲洗结膜囊等来预防术后感染性眼内炎。 相似文献
10.
目的:通过对同一患者双眼不同手术方式的自身对比,了解飞秒扫描后改SBK手术的疗效差异,为不同患者屈光手术方式的选择提供临床指导依据。方法回顾分析2例右眼行飞秒激光小切口透镜取出术( SMILE),左眼SMILE术中负压环脱失和激光扫描不良透镜分离困难而改行机械刀制瓣准分子激光手术( SBK)的患者,比较术后视力、等效球镜( SE)、对比敏感度( CSF)、波前像差( HAOS)以及泪膜破裂时间( BUT)、泪液分泌功能试验( Schimer I)和SPEED、OSDI干眼症状问卷调查分析差异。结果(1)术后个月,均能达到最佳矫正视力(BSCVA),等效球镜均在±0.75 D以内,双眼比较无显著性差异。(2)CSF的比较,左右眼无显著性差异,略低于正常水平。(3)术后3个月,BUT和Schimer检查中,双眼无显著性差异。(4)HAOS比较中,总像差RMS和高阶像差这两项, SMILE眼低于SBK眼;球差(S)的比较,SMILE眼高于SBK眼。(5)SPEED和OSDI问卷评分双眼无显著差异。结论 SMILE失败眼改SBK后视觉质量与SMILE眼无显著差异,其视觉质量、疗效不受影响。 相似文献