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   3129篇
  免费   236篇
  国内免费   15篇
耳鼻咽喉   42篇
儿科学   95篇
妇产科学   85篇
基础医学   426篇
口腔科学   104篇
临床医学   363篇
内科学   739篇
皮肤病学   52篇
神经病学   244篇
特种医学   64篇
外科学   301篇
综合类   11篇
预防医学   386篇
眼科学   64篇
药学   210篇
中国医学   8篇
肿瘤学   186篇
  2024年   1篇
  2023年   31篇
  2022年   35篇
  2021年   102篇
  2020年   77篇
  2019年   104篇
  2018年   126篇
  2017年   79篇
  2016年   110篇
  2015年   122篇
  2014年   151篇
  2013年   194篇
  2012年   291篇
  2011年   279篇
  2010年   147篇
  2009年   136篇
  2008年   208篇
  2007年   223篇
  2006年   189篇
  2005年   182篇
  2004年   187篇
  2003年   146篇
  2002年   124篇
  2001年   14篇
  2000年   6篇
  1999年   12篇
  1998年   13篇
  1997年   13篇
  1996年   6篇
  1995年   9篇
  1994年   9篇
  1993年   6篇
  1992年   4篇
  1991年   4篇
  1990年   6篇
  1989年   4篇
  1988年   3篇
  1987年   6篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1983年   3篇
  1982年   1篇
  1981年   3篇
  1980年   3篇
  1979年   1篇
  1978年   3篇
  1976年   1篇
  1973年   1篇
排序方式: 共有3380条查询结果,搜索用时 203 毫秒
1.
Objective: To perform a scoping review of the applicability of the Gail model in different countries for different ethnicities. Methods: The review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist and search strategies based on the PICOS approach. The reviewed articles were included if they were published between 2013 and 2018 in English, Portuguese, or Spanish; were original articles available in full online; and described the use of the Gail model. The PubMed, Embase, and Web of Science data bases were searched. Results: A total of 38 articles eligible for analysis were identified, of which 16 used the Gail model to assess breast cancer risk in women, eight analyzed the applicability of this tool in their population, seven compared the tool and/or modified it according to the specific risk factors of their population, and seven cited the model in determining eligibility for chemoprevention. Conclusion: The Gail model has different applicabilities Greater effectiveness and breast cancer risk are found in developed countries.  相似文献   
2.
Objective: This study aimed to analyze the trend in cervical cancer (ICD C53) mortality in Brazilian regions in women who are who are screened and not screened from 1996 to 2015. Methods: An epidemiological study, of time series of mortality from cervical cancer performed in 90,856 women under 24 years old (343 women), between 25 and 64 years old (32,703 women), and over 65 years old (10,909 women). The data from this research were collected from the DATASUS, from the SIM Health Surveillance Secretariat files, captured through TABNET selecting the resident population by gender and age group and ICD 10 C53 from 1996 to 2015. Results: Among women, 43.8% were white, and 76% had less than eight years of formal education. Polynomial regression showed an increasing trend in cervical cancer mortality in Brazil for women aged 15 - 24 years (p=0.01). Between 25 - 64 and 65 years or older it remained constant, but high (p=0.07; 0.99). The Northeast region pointed a growing trend in women aged 15 to 24 (p=0.01), 25 to 64 years (p=0.01) and 65 or older (p=0.001). The Northeast presented the highest average growth per year. In the Southeast, South and Midwest regions, decreasing trends were observed despite the high rates. The Joinpoint regression showed a 95% confidence interval, and that mortality from cervical cancer in the North region increased throughout the period analyzed. an increasing trend was observed from 1996 to 1998, whereas in the Midwest region, the trend remained stable throughout the period analyzed. The Federal District presented an upward trend from 1996 to 2015. In Brazil, an upward trend was observed throughout the whole period analyzed. Conclusions: Cervical cancer mortality in younger women is becoming more predominant, in addition to the high rate observed for women aged 65 or older.  相似文献   
3.
Harinakshi Sanikini  David C. Muller  Marisa Sophiea  Sabina Rinaldi  Antonio Agudo  Eric J. Duell  Elisabete Weiderpass  Kim Overvad  Anne Tjønneland  Jytte Halkjær  Marie-Christine Boutron-Ruault  Franck Carbonnel  Iris Cervenka  Heiner Boeing  Rudolf Kaaks  Tilman Kühn  Antonia Trichopoulou  Georgia Martimianaki  Anna Karakatsani  Valeria Pala  Domenico Palli  Amalia Mattiello  Rosario Tumino  Carlotta Sacerdote  Guri Skeie  Charlotta Rylander  María-Dolores Chirlaque López  Maria-Jose Sánchez  Eva Ardanaz  Sara Regnér  Tanja Stocks  Bas Bueno-de-Mesquita  Roel C.H. Vermeulen  Dagfinn Aune  Tammy Y.N. Tong  Nathalie Kliemann  Neil Murphy  Marc Chadeau-Hyam  Marc J. Gunter  Amanda J. Cross 《International journal of cancer. Journal international du cancer》2020,146(4):929-942
Obesity has been associated with upper gastrointestinal cancers; however, there are limited prospective data on associations by subtype/subsite. Obesity can impact hormonal factors, which have been hypothesized to play a role in these cancers. We investigated anthropometric and reproductive factors in relation to esophageal and gastric cancer by subtype and subsite for 476,160 participants from the European Prospective Investigation into Cancer and Nutrition cohort. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models. During a mean follow-up of 14 years, 220 esophageal adenocarcinomas (EA), 195 esophageal squamous cell carcinomas, 243 gastric cardia (GC) and 373 gastric noncardia (GNC) cancers were diagnosed. Body mass index (BMI) was associated with EA in men (BMI ≥30 vs. 18.5–25 kg/m2: HR = 1.94, 95% CI: 1.25–3.03) and women (HR = 2.66, 95% CI: 1.15–6.19); however, adjustment for waist-to-hip ratio (WHR) attenuated these associations. After mutual adjustment for BMI and HC, respectively, WHR and waist circumference (WC) were associated with EA in men (HR = 3.47, 95% CI: 1.99–6.06 for WHR >0.96 vs. <0.91; HR = 2.67, 95% CI: 1.52–4.72 for WC >98 vs. <90 cm) and women (HR = 4.40, 95% CI: 1.35–14.33 for WHR >0.82 vs. <0.76; HR = 5.67, 95% CI: 1.76–18.26 for WC >84 vs. <74 cm). WHR was also positively associated with GC in women, and WC was positively associated with GC in men. Inverse associations were observed between parity and EA (HR = 0.38, 95% CI: 0.14–0.99; >2 vs. 0) and age at first pregnancy and GNC (HR = 0.54, 95% CI: 0.32–0.91; >26 vs. <22 years); whereas bilateral ovariectomy was positively associated with GNC (HR = 1.87, 95% CI: 1.04–3.36). These findings support a role for hormonal pathways in upper gastrointestinal cancers.  相似文献   
4.
Background: Primary progressive aphasia (PPA) is a neurodegenerative dementia in which language decline is the first and most prominent symptom. Among several interventions for PPA, language rehabilitation has been the most frequently used.

Aims: This narrative review aimed to evaluate existing standardised language tests used in the assessment of PPA, in order to determine whether they are appropriate and psychometrically adequate to detect change over time in the treatment of anomia.

Main Contribution: The present findings highlight the scarcity of psychometrically robust instruments used to measure therapy-induced gains in PPA. Additionally, most of these instruments were not validated for use with the PPA population, which consequently might bias the results. There is a need for population-based norms for existing instruments.

Conclusions: The accurate assessment of lexico-semantic deficits in PPA should rely on objective, reliable, valid, and responsive outcome measures. Psychometric studies are needed to evaluate and eventually improve the quality of language tests used in clinical practice.  相似文献   

5.
Although combined spin‐ and gradient‐echo (SAGE) dynamic susceptibility‐contrast (DSC) MRI can provide perfusion quantification that is sensitive to both macrovessels and microvessels while correcting for T1‐shortening effects, spatial coverage is often limited in order to maintain a high temporal resolution for DSC quantification. In this work, we combined a SAGE echo‐planar imaging (EPI) sequence with simultaneous multi‐slice (SMS) excitation and blipped controlled aliasing in parallel imaging (blipped CAIPI) at 3 T to achieve both high temporal resolution and whole brain coverage. Two protocols using this sequence with multi‐band (MB) acceleration factors of 2 and 3 were evaluated in 20 patients with treated gliomas to determine the optimal scan parameters for clinical use. ΔR2*(t) and ΔR2(t) curves were derived to calculate dynamic signal‐to‐noise ratio (dSNR), ΔR2*‐ and ΔR2‐based relative cerebral blood volume (rCBV), and mean vessel diameter (mVD) for each voxel. The resulting SAGE DSC images acquired using MB acceleration of 3 versus 2 appeared visually similar in terms of image distortion and contrast. The difference in the mean dSNR from normal‐appearing white matter (NAWM) and that in the mean dSNR between NAWM and normal‐appearing gray matter were not statistically significant between the two protocols. ΔR2*‐ and ΔR2‐rCBV maps and mVD maps provided unique contrast and spatial heterogeneity within tumors.  相似文献   
6.
Study ObjectiveTo assess the efficacy of Tissucol Duo (Baxter AG, Vienna, Austria) fibrin sealant in decreasing the incidence of lymphocele (LC) after pelvic laparoscopic lymph node dissection using harmonic shears.DesignRandomized controlled trial (Canadian Task Force classification level I).SettingTertiary referral and educational center.PatientsSeventy-four patients randomized to the use of sealant per hemipelvis.InterventionFibrin sealant.Measurements and Main ResultsAfter bilateral pelvic lymphadenectomy a fibrin sealant was used in 1 hemipelvis but not the other, applied in 41 patients (55.4%) to the left and 33 patients (44.6%) to the right hemipelvis. The primary outcome was the incidence of LC after surgery in symptomatic and asymptomatic patients. Imaging (ultrasound, computed tomography, and magnetic resonance) was performed to detect LC at 3, 6, and 12 months after surgery. Overall, 26 patients (35.1%) developed LC, and 4 were symptomatic (5.4%). Allowing patients to serve as their own treatment group and control, the hemipelvis treated with Tissucol Duo corresponding to the treatment group and that not treated to the control group, LCs were found in 17 (23%) and 14 (19%) cases, respectively, but the difference was not significant. The mean initial LC maximum diameter was 27.1 mm (standard deviaiotn, 35.2), and LCs tended to decrease in size during the first year to a mean of 8.7 mm.ConclusionApplication of Tissucol Duo fibrin sealant after laparoscopic pelvic lymphadenectomy using ultrasonic shears does not decrease the occurrence of symptomatic or asymptomatic LC.  相似文献   
7.
8.
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