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   1802篇
  免费   120篇
  国内免费   21篇
耳鼻咽喉   11篇
儿科学   39篇
妇产科学   42篇
基础医学   277篇
口腔科学   36篇
临床医学   126篇
内科学   453篇
皮肤病学   46篇
神经病学   113篇
特种医学   62篇
外科学   334篇
综合类   8篇
预防医学   110篇
眼科学   55篇
药学   91篇
中国医学   4篇
肿瘤学   136篇
  2024年   1篇
  2023年   27篇
  2022年   99篇
  2021年   145篇
  2020年   77篇
  2019年   67篇
  2018年   70篇
  2017年   58篇
  2016年   67篇
  2015年   69篇
  2014年   65篇
  2013年   97篇
  2012年   130篇
  2011年   161篇
  2010年   85篇
  2009年   60篇
  2008年   71篇
  2007年   113篇
  2006年   108篇
  2005年   98篇
  2004年   86篇
  2003年   82篇
  2002年   70篇
  2001年   2篇
  2000年   1篇
  1999年   5篇
  1998年   3篇
  1996年   4篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1990年   1篇
  1989年   1篇
  1986年   1篇
  1983年   2篇
  1981年   2篇
  1976年   2篇
  1975年   3篇
  1974年   1篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有1943条查询结果,搜索用时 15 毫秒
91.
Direct electrical stimulation (DES) is considered to be the gold standard for mapping cortical function. A careful mapping of the eloquent cortex is key to successful resective or ablative surgeries, with a minimal postoperative deficit, for treatment of drug‐resistant epilepsy. There is accumulating evidence suggesting that not only local, but also remote activations play an equally important role in evoking clinical effects. By introducing a new intracranial stimulation paradigm and signal analysis methodology allowing to disambiguate EEG responses from stimulation artifacts we highlight the spatial extent of the networks associated with clinical effects. Our study includes 26 patients that underwent stereoelectroencephalographic investigations for drug‐resistant epilepsy, having 337 depth electrodes with 4,351 contacts sampling most brain structures. The routine high‐frequency electrical stimulation protocol for eloquent cortex mapping was altered in a subtle way, by alternating the polarity of the biphasic pulses in a train, causing the splitting the spectral lines of the artifactual components, exposing the underlying tissue response. By performing a frequency‐domain analysis of the EEG responses during DES we were able to capture remote activations and highlight the effect''s network. By using standard intersubject averaging and a fine granularity HCP‐MMP parcellation, we were able to create local and distant connectivity maps for 614 stimulations evoking specific clinical effects. The clinical value of such maps is not only for a better understanding of the extent of the effects'' networks guiding the invasive exploration, but also for understanding the spatial patterns of seizure propagation given the timeline of the seizure semiology.  相似文献   
92.
Globally, COVID-19 vaccines are currently being used to prevent transmission and to reduce morbidity and death associated with SARS-CoV-2 infection. Current research reveals that vaccines such as BNT162b2 and Ad26.COV2.S are highly immunogenic and have high short-term effectiveness for most of the known viral variants. Clinical trials showed satisfying results in the general population, but the reluctance in testing and vaccinating pregnant women left this category with little evidence regarding the safety, efficacy, and immunogenicity following COVID-19 vaccination. With the worldwide incidence of COVID-19 remaining high and the possibility of new transmissible SARS-CoV-2 mutations, data on vaccination effectiveness and antibody dynamics in pregnant patients are critical for determining the need for special care or further booster doses. An observational study was developed to evaluate pregnant women receiving the complete COVID-19 vaccination scheme using the BNT162b2 and Ad26.COV2.S, and determine pregnancy-related outcomes in the mothers and their newborns, as well as determining adverse events after vaccination and immunogenicity of vaccines during four months. There were no abnormal findings in pregnancy and newborn characteristics comparing vaccinated versus unvaccinated pregnant women. COVID-19 seropositive pregnant women had significantly higher spike antibody titers than seronegative patients with similar characteristics, although they were more likely to develop fever and lymphadenopathy following vaccination. The same group of pregnant women showed no statistically significant differences in antibody titers during a 4-month period when compared with case-matched non-pregnant women. The BNT162b2 and Ad26.COV2.S vaccines are safe to administer during the third trimester of pregnancy, while their safety, efficacy, and immunogenicity remain similar to those of the general population.  相似文献   
93.
94.
The identification of targetable molecules in cellular signaling pathways represents a milestone in the treatment of melanoma. Selective inhibitors of these molecules, known as phosphokinases, allow for individual signaling pathways to be “switched off”. This is of particular importance for tumors in which these pathways are constitutively activated by mutations in genes encoding said molecules. Especially patients with BRAF‐mutated melanomas significantly benefit from kinase inhibitor therapies, with the current standard of combined BRAF and MEK inhibition providing very good long‐term disease control. Such regimens have been shown to achieve a progression‐free survival of more than ten months and an overall survival of more than two years, along with good quality of life. Given that the majority of patients develop secondary resistance during long‐term kinase inhibitor therapy, current clinical trials are geared towards finding suitable drug combinations including inhibitors of other signaling pathways as well as immune checkpoint inhibitors. The present review highlights targeted therapies for melanoma currently available as well as potential future options presently under clinical investigation.  相似文献   
95.
96.

Background

Epithelial ovarian cancer (EOC) remains the main cause of mortality due to gynecological malignancies. Optimal tumor debulking and platinum response are the most important prognostic factors for overall survival (OS) in primary EOC. In the setting of recurrence, the role of cytoreduction is not clear. A critical point is to predict preoperatively the subgroup of patients with optimal surgical outcome. The aim of the study was to analyze the predictive role of HE4 for surgical outcome and platinum response in EOC patients experiencing a first relapse. Secondary aims were the prognostic role of HE4 for OS and progression-free survival (PFS).

Methods

Plasma was obtained before secondary cytoreduction from 73 EOC patients. A total of 66.7 % underwent a total macroscopic tumor clearance; 86.3 % of the patients had disease that responded to platinum therapy. HE4 was detected by enzyme-linked immunosorbent assay. For statistical analysis, the chi-square test, Fisher’s exact test, Kendall’s tau b, and Mann-Whitney U test were used. OS, PFS rates, and respective 95 % confidence intervals (CI) were estimated according to the Kaplan–Meier method.

Results

At a HE4 cutoff value of 250 pMk, a sensitivity of 52 % and a specificity of 93.8 % (p = 0.001, 95 % CI 0.601–0.861) were reached in predicting total macroscopic tumor clearance. Plasma HE4 concentrations together with platinum response were the only independent prognostic factors for OS (p < 0.001, hazard ratio [HR] 18.77, 95 % CI 4.68–75.25; and p = 0.044, HR 3.33, 95 % CI 1.03–10.7, respectively). Together with ascites, HE4 was the only independent predictive factor for surgical outcome (p = 0.029, odds ratio [OR] 7.2, 95 % CI 1.22–42.19 and p = 0.036, OR 10.18, 95 % CI 1.16–88.69, respectively).

Conclusions

HE4 is an independent predictive marker for surgical outcome and OS in patients with recurrent EOC. Larger population studies are needed to validate these results.  相似文献   
97.
Capsule endoscopy (CE) revolutionized the small bowel examination. We emphasize the role of CE in suspected Crohn's disease, studying 24 investigations performed in the Institute of Gastroenterology and Hepatology. The global diagnostic yield was 54%, the specific diagnostic yield for Crohn's disease was 37.5%, the specificity was 100% and the retention rate was 4.1%. For maximum accuracy and efficiency, unitary administration and diagnostic criteria are needed, and for minimising the risk of complications, specific prior investigations would be suitable.  相似文献   
98.
Knowledge regarding the influence of the microbial community in cancer promotion or protection has expanded even more through the study of bacterial metabolic products and how they can modulate cancer risk, which represents an extremely challenging approach for the relationship between intestinal microbiota and colorectal cancer (CRC). This review discusses research progress on the effect of bacterial dysbiosis from a metabolic point of view, particularly on the biochemical mechanisms of butyrate, one of the main short chain fatty acids (SCFAs) with anti-inflammatory and anti-tumor properties in CRC. Increased daily intake of omega-3 polyunsaturated fatty acids (PUFAs) significantly increases the density of bacteria that are known to produce butyrate. Omega-3 PUFAs have been proposed as a treatment to prevent gut microbiota dysregulation and lower the risk or progression of CRC.  相似文献   
99.
The study aimed to evaluate lifestyle factors among Information Technology (IT) workers from Romania before and during the pandemic. We used an online applied questionnaire, filled in by 1638 respondents, that assessed nutrition status-Body Mass Index (BMI), weight and diet change, physical activity, alcohol consumption, number of hours working in front of the computer, stress, and sleep. Multivariate logistic regression was used to establish the lifestyle factors that lead to weight gain. Although the level of physical activity (PA) was low before the pandemic, the results of our study showed a further decrease in physical activity. In total, 61.1% of men and 71.1% of women performed PA for less than 30 min per day. Weight gain was reported in 50.5% of men and 45.3% of women (mean weight gain was 5.11 ± 3.52 kg) as a result of increased screen time (with a mean of 3.52 ± 4.29 for females and 3.05 ± 2.09 for males, p > 0.05 h per day) and the reported changes in diet. Despite the popularity of home-cooked foods, the intake of vegetables and fruit remained low. The quality of sleep was poor for 55.7% of the respondents. Public health and corporation policies are required to encourage a healthy lifestyle and avoid chronic diseases.  相似文献   
100.
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