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   1255篇
  免费   80篇
  国内免费   4篇
儿科学   26篇
妇产科学   66篇
基础医学   188篇
口腔科学   20篇
临床医学   98篇
内科学   313篇
皮肤病学   52篇
神经病学   110篇
特种医学   35篇
外科学   126篇
综合类   9篇
预防医学   77篇
眼科学   8篇
药学   98篇
中国医学   8篇
肿瘤学   105篇
  2023年   14篇
  2022年   28篇
  2021年   36篇
  2020年   26篇
  2019年   24篇
  2018年   43篇
  2017年   20篇
  2016年   21篇
  2015年   41篇
  2014年   43篇
  2013年   58篇
  2012年   109篇
  2011年   113篇
  2010年   59篇
  2009年   64篇
  2008年   83篇
  2007年   76篇
  2006年   70篇
  2005年   61篇
  2004年   81篇
  2003年   80篇
  2002年   55篇
  2001年   14篇
  2000年   8篇
  1999年   3篇
  1998年   7篇
  1997年   3篇
  1996年   3篇
  1995年   7篇
  1994年   4篇
  1993年   3篇
  1992年   5篇
  1991年   5篇
  1990年   2篇
  1989年   6篇
  1988年   5篇
  1987年   13篇
  1986年   7篇
  1985年   3篇
  1984年   5篇
  1983年   3篇
  1982年   3篇
  1976年   5篇
  1974年   4篇
  1973年   4篇
  1970年   4篇
  1968年   1篇
  1966年   2篇
  1965年   1篇
  1963年   1篇
排序方式: 共有1339条查询结果,搜索用时 15 毫秒
21.

Purpose

In Parkinson’s disease (PD) patients, REM sleep behavior disorder (RBD) might precede PD or develop with or after the onset of PD. No previous study has explored differences between these two groups. The aim of this study was therefore to compare clinical features and REM sleep chin electromyographic patterns between patients in whom RBD heralded PD and those in whom RBD occurrence coincided with or followed the clinical manifestations of PD.

Method

Twenty-seven consecutive PD patients (mean age 67.9 years) were enrolled. Detailed clinical, laboratory, and polysomnographic studies were obtained in all participants.

Results

Sixteen of the 27 patients were affected by RBD. These had a significantly higher stage of PD and took significantly higher doses of dopaminergic therapy; their disease duration tended to be longer, and their cognitive status tended to be lower. PD patients in whom RBD preceded PD (n?=?6) did not differ from PD patients without RBD in disease parameters, while PD patients in whom RBD developed with or after PD (n?=?10) showed a significantly higher disease stage, took significantly higher dopaminergic therapy, and had a longer disease duration.

Conclusion

Our findings are compatible with the hypothesis that patients in whom RBD precedes, or does not precede, PD might constitute two possibly distinct clinical and physiopathological groups, based on different progressive neuropathological sequences of events.  相似文献   
22.
(1) Aim: This study aims to analyze the in vitro infiltration of a silicate root canal sealer into dentinal tubules after using different endodontic irrigating solutions. (2) Methods: Twenty-nine teeth with single roots were separated into three groups according to the final irrigation protocol: G1 n = 10) = 17% EDTA (ethylenediaminetetraacetic acid) + 3.0% sodium hypochlorite (NaOCl), G2 (n = 10) = 17% EDTA + 2.0% chlorhexidine and G3 (Control group, n = 9) = 17% EDTA + saline solution. Root canals were filled using cold lateral compaction technique with MTA Fillapex sealer and gutta-percha. The sealer was labeled with rhodamine B. The teeth were segmented at the middle and third apical sections, which were visualized using 10× confocal laser microscopy to determine the sealer penetration percentage. (3) Results: In the apical section, no statistically significant differences were found between the groups regarding sealer penetration. In the middle section, Group 1 obtained the highest percentage, and Group 2 the lowest (p = 0.004). Group 1 also presented statistically significant differences in the Control Group (p = 0.031) and had close sealer penetration values. Meanwhile, the Control Group (p = 0.023) and Group 2 (p = 0.029) revealed a significant decrease of sealer penetration between the apical and middle sections. (4) Conclusion: The obtained results support that final irrigation with NaOCl promoted similar sealer penetration in the apical and middle sections. On the other hand, a significant decrease in the sealer penetration of the middle section was observed for the chlorhexidine and saline groups. Compared to other irrigant solutions, NaOCl promotes more uniform sealer penetration, which can correlate with better sealing and, consequently, higher endodontic treatment success.  相似文献   
23.
BACKGROUNDCoronavirus disease (COVID) is a new and highly contagious infectious disease caused by the coronavirus (COVID-19 or severe acute respiratory syndrome coronavirus 2). There is limited data regarding the incidence and management of COVID-19 in immunocompromised patients’ post-transplantation. In the pre-COVID-19 era, these patients were already at an increased risk of developing opportunistic infections. These often manifested with atypical symptoms.CASE SUMMARYWe report another case of uneventful COVID-19 pneumonia in a 58-year old male who was 18 mo’ post liver transplantation. He received tacrolimus monotherapy since July 2019. The clinical manifestations included only epigastric pain radiating to the right hypochondrium, nausea and vomiting. He had no fevers, cough, shortness of breath, anosmia or dysgeusia even if the chest computed tomography scan revealed an extension of the multiple patchy ground-glass density shadows to the upper lobe of the left lung too. He was hospitalised and received a course of oral chloroquine (200 mg × 3 per day) for a period of 10 d. Interestingly, the COVID 19 infection was uneventful though there were no modifications to his tacrolimus dosing. He was successfully discharged. We performed subsequent follow-up via telemedicine.CONCLUSIONIn light of the current pandemic, it is even more important to identify how the liver recipient’s patients present and are managed, especially for immunosuppression treatment.  相似文献   
24.
In recent years,a number of case reports and clinical studies have highlighted the risk of hepatitis B and C virus reactivation in patients with inflammatory bowel disease who are treated with immunosuppressive drugs.The cases of viral hepatitis reactivation that have been reported are characterized by a wide range of clinical manifestations,from viremia without clinically relevant manifestations to fulminant life-threatening hepatitis.The development and dissemination of biological immunosuppressive drugs have led to a significant increase in the number of reports of interest to physicians in a variety of clinical settings.On this topic,there have been a number of published guidelines and reviews that have collected the available evidence,providing recommendations on prophylactic and therapeutic strategies and methods for monitoring patients at risk.However,it should be noted that,to date,very few clinical studies have been published,and most of the recommendations have been borrowed from otherclinical settings.The published studies are mostly retrospective and are based on very heterogeneous populations,using different therapeutic and prophylactic regimens and obtaining conflicting results.Thus,it seems clear that it is desirable to concentrate our efforts on prospective studies,not conducting further reviews of the literature in the continued absence of new evidence.  相似文献   
25.
26.
27.
A subset of over-expressed microRNAs (miRNAs) identified in parathyroid carcinomas (Ca) compared to normal glands belongs to C19MC, a cluster on chromosome 19q13.4 involved in stem cell biology and tumourigenesis. In this study, the expression of C19MC-MIR371-3 clusters and the molecular mechanisms presiding their modulation were investigated in a series of six normal parathyroids, 24 adenomas (Ad), 15 Ca and five matched metastases. The general expression levels of C19MC or MIR371-3 clusters in Ad lesions did not differ from normal glands, while they distinguished Ad from Ca at unsupervised hierarchical cluster analysis (P=0.0008). MIR517C showed the most significant difference in expression between Ca and Ad (P=0.0003) and it positively correlated with serum calcium, parathormone and tumour weight. In regard to the molecular mechanism determining C19MC cluster activation, we could detect C19MC copy number (CN) gain in ten Ca (67%) extending distal to the MIR371-3 cluster in almost all samples. Conversely, only four Ad (16%) showed C19MC amplification, with one case presenting distal genomic aberration to MIR371-3. Globally, CN variations of 19q13.4 loci were significantly associated with MIR517C up-regulation (P=0.006). Opposite to normal glands where C19MC promoter was methylated, hypomethylation occurred in 15 out of 30 analysed tumours. Though the epigenetic status did not correlate with C19MC miRNA expression levels, loss of C19MC promoter methylation was significantly associated with Ca and metastatic disease (P=0.01). In conclusion, C19MC cluster aberrations are a characteristic of Ca with respect to Ad. Altogether, these evidences point towards a role for 19q13.4 miRNA clusters as oncogenes in parathyroid tumourigenesis.  相似文献   
28.
Multiple lines of evidence demonstrate that schizophrenia patients may perform worse than normal controls in several cognitive tasks. However, little is known on putative differences in cognitive functioning between schizophrenia patients responding to antipsychotics and those resistant to the treatment. In this cross-sectional study, 63 subjects (41 schizophrenia and schizoaffective patients and 22 age and sex-matched controls) were enrolled. Patients were divided in resistant (TRS, n=19) and non-resistant to pharmacological treatment (non-TRS, n=22) according to the American Psychiatric Association (APA) criteria for treatment resistance. The Brief Assessment of Cognition in Schizophrenia (BACS) was administered to patients and controls. The following rating scales were administered to schizophrenia patients: the Positive and Negative Syndrome Scale (PANSS), the Drug Attitude Inventory (DAI) and the Subjective Well-being under Neuroleptics (SWN). Statistically significant differences among non-TRS patients, TRS ones, and controls were detected at the BACS. TRS patients performed significantly worse than non-TRS ones on Verbal Memory task, exhibited higher PANSS total and subscales scores and were prescribed higher antipsychotic doses. Poorer performances at the BACS significantly correlated with more severe negative symptoms in TRS but not in non-TRS patients. These results may suggest that TRS patients suffer from a form of the disease with prominent cognitive impairment possibly related to negative symptoms.  相似文献   
29.
Journal of Neurology - Little is known about metabolic changes in progressive supranuclear palsy. Goals of the present study are to: (1) investigate whether early progressive supranuclear palsy is...  相似文献   
30.
Neurological Sciences - The Frontal Assessment Battery (FAB) is a neuropsychological tool largely used to assess executive functions. Prior studies found a marked ceiling effect for the prehension...  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