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   11009篇
  免费   552篇
  国内免费   59篇
耳鼻咽喉   103篇
儿科学   584篇
妇产科学   153篇
基础医学   1260篇
口腔科学   223篇
临床医学   843篇
内科学   2262篇
皮肤病学   294篇
神经病学   720篇
特种医学   275篇
外科学   1753篇
综合类   294篇
一般理论   3篇
预防医学   555篇
眼科学   394篇
药学   1046篇
  2篇
中国医学   76篇
肿瘤学   780篇
  2023年   68篇
  2022年   188篇
  2021年   389篇
  2020年   199篇
  2019年   265篇
  2018年   310篇
  2017年   228篇
  2016年   295篇
  2015年   344篇
  2014年   471篇
  2013年   620篇
  2012年   868篇
  2011年   836篇
  2010年   487篇
  2009年   412篇
  2008年   663篇
  2007年   633篇
  2006年   638篇
  2005年   553篇
  2004年   503篇
  2003年   408篇
  2002年   355篇
  2001年   168篇
  2000年   177篇
  1999年   148篇
  1998年   86篇
  1997年   67篇
  1996年   46篇
  1995年   43篇
  1994年   40篇
  1993年   37篇
  1992年   95篇
  1991年   84篇
  1990年   82篇
  1989年   80篇
  1988年   71篇
  1987年   63篇
  1986年   61篇
  1985年   61篇
  1984年   43篇
  1983年   24篇
  1982年   26篇
  1979年   39篇
  1977年   31篇
  1975年   33篇
  1974年   29篇
  1973年   25篇
  1972年   32篇
  1971年   25篇
  1968年   21篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Variable levels of essential polyunsaturated fatty acids (EPUFAs) reported in schizophrenia are likely due to differences in age, sex, ethnicity, diet, life style and treatments. The present study examined the EPUFAs levels in plasma, RBC and CSF in never-medicated first-episode psychotic patients and normal controls matched for ethnicity, diet and life style. The plasma EPUFAs levels were similar in both groups. Among the EPUFAs enriched in the brain, predominantly docosahexaenoic acid (DHA) levels were lower in RBC (p=<0.01) whereas higher in CSF (p=<0.01) in male>female patients. This altered DHA metabolism may provide clues for neuropathology and treatment of schizophrenia.  相似文献   
992.
993.
Endomyocardial fibrosis is a rare condition that occurs primarily in tropical countries. It can often mimick a variety of other common cardiac conditions such as apical hypertrophic cardiomyopathy and Ebstein anomaly. We report a case of a left ventricular mass that at histologic examination was found to be endomyocardial fibrosis.  相似文献   
994.
Identification of new foci of cutaneous leishmaniasis (CL), along with reports of Leishmania donovani causing the disease, is an issue of concern. Clinico-epidemiologic analysis of 98 cases in the endemic regions of Rajasthan state, India, suggested the preponderance of infection in men (62.24%) compared with women (37.75%). Species characterization by internal transcribed spacer 1 (ITS1) polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP), kDNA-PCR, and immunofluorescence assay established L. tropica as the causative organism. When applied directly to 32 clinical samples, kDNA PCR had a sensitivity of 96.6%, whereas ITS1 PCR had a sensitivity of 82.75%, thus facilitating diagnosis and species identification. Either parasite culture or direct microscopy alone detected 48.2% and 65.5% of the positive samples, respectively, whereas culture and microscopy together improved overall sensitivity to 89.3% (25/28). Except for the kDNA PCR, all other assays were 100% specific. This study provides the first comprehensive molecular and immunologic studies of CL in India.  相似文献   
995.
OBJECTIVE: The aim of this study was to establish whether radiation treatment planning using MRI alone could replace CT-based planning for brain tumors while retaining the dosimetric accuracy. This would help to provide a single imaging modality for both target delineation as well as treatment planning, thus saving time and resources. METHODS: Twenty-five patients with brain tumors were scanned on a spiral CT scanner and 1.5 T MRI scanner. Three treatment plans were generated for all patients. The first plan was generated using the CT scan images with inhomogeneity correction (CT + IC); the second plan used the CT scan without inhomogeneity correction (CT-IC) and the third plan was generated using the MRI scan (MRI alone). RESULTS: The maximum distortion in the MRI phantom study was less than 1 mm. There were no statistically significant differences in any of the target coverage parameters analysed in this study. Similarly, the maximum antero-posterior and lateral dimensions for the CT-based and MRI-based planning did not show any statistical difference. CONCLUSION: MRI-based treatment planning for brain lesions is feasible and gives equivalent dosimetric results compared to CT-based treatment planning.  相似文献   
996.
The incidence of 5-fluorouracil (5-FU)-related cardiotoxicity seems to be dosage and schedule dependent. Although various other cardiac events have been reported in literature, a series of patients having transient asymptomatic bradycardia has not been reported in the literature as yet. We report such a series of patients who had transient asymptomatic bradycardia after being treated with continuous infusion 5-FU. We plan to do a Holter study during the period of bradycardia in subsequent patients and this may throw more light on the issue.  相似文献   
997.
Somatic mutations in the epidermal growth factor receptor (EGFR) gene are associated with clinical response and prolonged survival in patients with non-small cell lung cancer (NSCLC) treated with EGFR tyrosine kinase inhibitors (TKIs). We began screening patients for somatic EGFR mutations by DNA sequencing as part of clinical care in 2004. We performed a retrospective cohort study of 278 patients with NSCLC referred for EGFR testing over a 10-month period. Tumor samples underwent direct DNA sequence analyses of EGFR exons 18 through 24. We determined the clinical characteristics and EGFR mutation status of the patients and analyzed their response to therapy and survival. EGFR somatic mutations were identified in 68 (24%) of patients. A minimal smoking history was the strongest clinical predictor of harboring a mutation. In multivariable analyses, each pack-year of smoking corresponded to a 5% decreased likelihood of having an EGFR mutation. Among 92 patients with unresectable disease undergoing subsequent systemic therapy, EGFR mutations were associated with an increased response rate to EGFR TKIs (p < .0001) but not chemotherapy. Overall survival was significantly prolonged in EGFR mutation-positive patients (p = .001), with a median survival of 3.1 years compared with 1.6 years in mutation-negative patients, after adjusting for age, gender, and stage at diagnosis. Integrating molecular profiling into clinical care is feasible in NSCLC patients and provides useful clinical information.  相似文献   
998.
999.
ObjectiveThe prevalence of social media for sharing personal thoughts makes it a viable platform for the assessment of suicide risk. However, deep learning models are not able to capture the diverse nature of linguistic choices and temporal patterns that can be exhibited by a suicidal user on social media and end up overfitting on specific cues that are not generally applicable. We propose Adversarial Suicide assessment Hierarchical Attention (ASHA), a hierarchical attention model that employs adversarial learning for improving the generalization ability of the model.Material and MethodsWe assess the suicide risk of a social media user across 5 levels of increasing severity of risk. ASHA leverages a transformer-based architecture to learn the semantic nature of social media posts and a temporal attention-based long short-term memory architecture for the sequential modeling of a user’s historical posts. We dynamically generate adversarial examples by adding perturbations to actual examples that can simulate the stochasticity in historical posts, thereby making the model robust.ResultsThrough extensive experiments, we establish the face-value of ASHA and show that it significantly outperforms existing baselines, with the F1 score of 64%. This is a 2% and a 4% increase over the ContextBERT and ContextCNN baselines, respectively. Finally, we discuss the practical applicability and ethical aspects of our work pertaining to ASHA, as a human-in-the-loop framework.Discussion and ConclusionsAdversarial samples can be helpful in capturing the diverse nature of suicidal ideation. Through ASHA, we hope to form a component in a larger human-in-the-loop infrastructure for suicide risk assessment on social media.  相似文献   
1000.
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