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   339篇
  免费   27篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   1篇
妇产科学   6篇
基础医学   47篇
口腔科学   3篇
临床医学   23篇
内科学   127篇
皮肤病学   2篇
神经病学   32篇
特种医学   21篇
外科学   49篇
综合类   3篇
预防医学   12篇
眼科学   3篇
药学   16篇
肿瘤学   21篇
  2024年   1篇
  2023年   14篇
  2022年   18篇
  2021年   15篇
  2020年   11篇
  2019年   13篇
  2018年   21篇
  2017年   10篇
  2016年   13篇
  2015年   12篇
  2014年   16篇
  2013年   21篇
  2012年   32篇
  2011年   38篇
  2010年   13篇
  2009年   7篇
  2008年   12篇
  2007年   13篇
  2006年   14篇
  2005年   15篇
  2004年   15篇
  2003年   13篇
  2002年   8篇
  2001年   4篇
  2000年   3篇
  1999年   2篇
  1998年   1篇
  1997年   7篇
  1993年   1篇
  1991年   1篇
  1987年   1篇
  1969年   1篇
  1967年   1篇
排序方式: 共有367条查询结果,搜索用时 265 毫秒
31.
Context: Dabigatran etexilate (dabigatran) is a direct thrombin inhibitor anticoagulant agent. There is limited information about the changes in coagulation profile and outcomes in overdose. A monoclonal antibody has been developed to neutralize the anticoagulant effect of dabigatran. Case reports describe enhanced clearance of dabigatran by haemodialysis as an intervention to prevent haemorrhagic complications – however, the threshold for initiating haemodialysis is not well defined in an asymptomatic patient with normal renal function. Case details: Two patients presented following deliberate dabigatran overdoses. A 55-year-old woman ingested 10?×?150?mg dabigatran. A 21-year-old woman with a history of systemic lupus erythematosus and pulmonary embolus ingested 100?×?110?mg dabigatran. Both were admitted to the intensive care unit and managed expectantly. Serial coagulation tests normalized over 60 h. The half-life of dabigatran was not prolonged following overdose, being calculated between 7 and 11 h in each case. There was positive correlation between international normalized ratio (INR), prothrombin time (PT) and activated partial thromboplastin time (aPTT) with plasma dabigatran levels. Conclusion: There is limited experience with dabigatran overdoses. Normal aPTT, PT and INR assays 12 h following deliberate ingestion indicate that the drug concentration is not high. Individual risk assessment of bleeding risk needs to be formulated for each patient and expectant management is reasonable in the presence of normal renal function and absent risk factors for bleeding.  相似文献   
32.
ObjectiveSignificant progress was made in the understanding etiopathogenic factors related to MDD, including through research on the role of micro RNAs (miRs). We investigated plasma miRs as potential markers for MDD in patients treated with antidepressants.MethodsAt the initiation and at the end of twelve weeks of treatment, blood samples were collected and a structured diagnostic interview and a standardized depression rating scale for the presence and severity of major depression were done. The average decrease in HAMD score was 76.89%. Plasma miR expression profiling was performed by real time PCR. The lists of up-regulated (cut-off=2) and down-regulated miRs were imported into the miRWalk2.0 algorithm and used for target predictions. KEGG database pathways analysis was used to retrieve the pathways significantly targeted by at least two of the miRs.ResultsOf the 222 miRs detected in plasma samples of MDD patients, 40 were differentially expressed after treatment. Twenty-three miRs were significantly overexpressed with fold changes between 1.85 and 25.42, and 17 miRs were significantly downregulated with fold changes from 0.28 to 0.68. Pathway analysis revealed a list of 29 pathways for up-regulated miRs, and 20 pathways for down-regulated miRs. Six dysregulated miRs are common to all the top five pathways (Wnt signaling, Cancer, Endocytosis, Axon guidance, MAPK signaling): miR-146a-5p, miR-146b-5p, miR-221-3p, miR-24-3p, miR-26a-5p.ConclusionOverall, our miRWalk analysis of changes in plasma microRNAs after treatment of patients with major depression might open a new avenue for the understanding of Escitalopram mode of action and for its side effects.  相似文献   
33.
34.
The basal ganglia have a local renin–angiotensin system and it has been shown that the loss of dopaminergic neurons induced by neurotoxins is amplified by local angiotensin II (AII) via angiotensin type 1 receptors (AT1) and nicotinamide adenine dinucleotide phosphate (NADPH) complex activation. Recent studies have revealed a high degree of counter‐regulatory interactions between dopamine and AII receptors in non‐neural cells such as renal proximal tubule cells. However, it is not known if this occurs in the basal ganglia. In the striatum and nigra, depletion of dopamine with reserpine induced a significant increase in the expression of AT1, angiotensin type 2 receptors (AT2) and the NADPH subunit p47phox, which decreased as dopamine function was restored. Similarly, 6‐hydroxydopamine‐induced chronic dopaminergic denervation induced a significant increase in expression of AT1, AT2 and p47phox, which decreased with L‐dopa administration. A significant reduction in expression of AT1 mRNA was also observed after administration of dopamine to cultures of microglial cells. Transgenic rats with very low levels of brain AII showed increased AT1, decreased p47 phox and no changes in AT2 expression, whereas mice deficient in AT1 exhibited a decrease in the expression of p47 phox and AT2. The administration of relatively high doses of AII (100 nm ) decreased the expression of AT1, and the increased expression of AT2 and p47phox in primary mesencephalic cultures. The results reveal an important interaction between the dopaminergic and local renin–angiotensin system in the basal ganglia, which may be a major factor in the progression of Parkinson’s disease.  相似文献   
35.
Organophosphate (OP) poisoning continues to represent an important medical issue through its high prevalence among toxic pathologies and through its severity. In diagnosing this toxicological disorder, the most frequently utilized and available laboratory test remains the assessment of plasma cholinesterase - butyrylcholinesterase (BChE) - activity. Despite the reluctance of many researchers on the usefulness of serum BChE for kinetic analysis in OP intoxications, we have tested a recently proposed protocol, which is safe, non-expensive, easy to perform, appropriate to distinguish between an aged cholinesterase and a still reactivable one. Our aim was to validate the usefulness of this protocol, studying a series of 23 consecutive patients acutely intoxicated with OP, admitted in a regional Emergency Hospital, over a 1-year period. Introducing the proposed test in the routine of monitoring OP-intoxicated patients has resulted in the identification of a pattern with a funnel aspect, consequence of the initial possibility to increment the degree of BChE activity. This funnel shape defines the presence of reactivability, while its absence demonstrates the lack of obidoximes effect, due to cholinesterase's ageing process. This method consisted in an advantage for the diagnosis, having the potential of improving prognostic evaluation and therapeutic orientation in OP intoxications.  相似文献   
36.
37.
We report the differential clinicopathologic and immunophenotypical features of 2 pure ovarian ependymomas of extra-axial type with a predominant microcystic, anaplastic pattern occurring in patients aged 22 and 32 years and a unique myxopapillary pigmented ependymoma that originated within an ovarian mature cystic teratoma in a 35-year-old woman. The latter had a central nervous system phenotype different from that previously reported in ovarian ependymomas of extra-axial types, being negative for estrogen and progesterone receptors, epithelial membrane antigen and cytokeratin 34βE12, cell adhesion molecule 5.2, and cytokeratin 7. Furthermore, its benign behavior contrasted with the aggressive course of the other 2 ependymomas of extra-axial types, in which peritoneal invasion was present at the time of diagnosis. These findings illustrate that both central and extra-axial types of ependymoma show phenotypic variations that may point to either a derivation from different precursors or differentiation along diverse pathways. Thus, whereas ependymomas of extra-axial types would represent neometaplastic phenomena, those originated from the nervous tissue of teratomas resemble central nervous system ependymomas. Moreover, the dissimilarities between central and peripheral types of ependymoma would parallel the phenotypic differences present in primitive neural tumors of the female genital tract.  相似文献   
38.
Endometrial metaplasias and changes (EMCs) are conditions frequently overlooked and misdiagnosed. The aim of this review is to update current issues and provide a classification with a practical clinicopathological approach. Hormonal or irritative stimuli are the main inducing factors of EMCs, although some metaplasias have a mutational origin. EMCs vary from reactive, degenerative lesions to those able to associate with malignancy or those having a preneoplastic potential. The most common types of EMCs are ciliated tubal metaplasia (CTM) and mucinous metaplasia (MM), which occur in simple and complex glands, and possibly these architectural changes hold the same prognostic significance as they do in hyperplastic endometrioid lesions. Immunohistochemically, CTM is positive for LhS28, bcl-2, PAX2 and p16(INK4A). Complex CTM is likely to be a precursor of ciliated endometrioid-type carcinomas. MMs should be evaluated architecturally, taking into account that their atypicality is minimal. The differentiation between complex MM and mucinous carcinoma may be extremely difficult. Surface complex, papillary MM in endometrial polyps can be considered as benign. Intestinal-type endometrial MM is rare and its presence should prompt further investigation of associated lesions in the endocervix. Endometrial squamous metaplasia (ESS) is often linked to chronic irritative situations. It should be differentiated from secondary involvement by a human papilomavirus-related cervical lesion. Morular metaplasia is a mutational phenomenon with a distinct phenotype that helps to differentiate it from ESS. Morules are benign, hormonally inert structures that are often markers of complex endometrioid glandular architecture, and they are associated with an attenuated malignancy. Endometrial reactive changes are commonly associated with desquamation or hormonal imbalance. The frequent, p16(INK4A) positive, benign surface papillary syncytial change may be misdiagnosed, in some cases, as surface serous adenocarcinoma. Eosinophilic, oxyphilic, oncocytic and clear cell changes are non-specific. Rare stromal metaplasias have little clinical significance and should be differentiated from implanted fetal or embryonal tissues.  相似文献   
39.
Strategic modulation of cognitive control   总被引:1,自引:0,他引:1  
The neural substrate of cognitive control is thought to comprise an evaluative component located in the anterior cingulate cortex (ACC) and an executive component in the prefrontal cortex (PFC). The control mechanism itself is mainly local, triggered by response conflict (monitored by the ACC) and involving the allocation of executive resources (recruited by the PFC) in a trial-to-trial fashion. However, another way to achieve control would be to use a strategic mechanism based on long-term prediction of upcoming events and on a chronic response strategy that ignores local features of the task. In the current study, we showed that such a strategic control mechanism was based on a functional dissociation or complementary relationship between the ACC and the PFC. When information in the environment was available to make predictions about upcoming stimuli, local task features (e.g., response conflict) were no longer used as a control signal. We suggest that having separate control mechanisms based on local or global task features allows humans to be persistent in pursuing their goals, yet flexible enough to adapt to changes in the environment.  相似文献   
40.
Marco Metra  Marianna Adamo  Daniela Tomasoni  Alexandre Mebazaa  Antoni Bayes-Genis  Magdy Abdelhamid  Stamatis Adamopoulos  Stefan D. Anker  Johann Bauersachs  Yuri Belenkov  Michael Böhm  Tuvia Ben Gal  Javed Butler  Alain Cohen-Solal  Gerasimos Filippatos  Finn Gustafsson  Loreena Hill  Tiny Jaarsma  Ewa A. Jankowska  Mitja Lainscak  Yuri Lopatin  Lars H. Lund  Theresa McDonagh  Davor Milicic  Brenda Moura  Wilfried Mullens  Massimo Piepoli  Marija Polovina  Piotr Ponikowski  Amina Rakisheva  Arsen Ristic  Gianluigi Savarese  Petar Seferovic  Rajan Sharma  Thomas Thum  Carlo G. Tocchetti  Sophie Van Linthout  Cristiana Vitale  Stephan Von Haehling  Maurizio Volterrani  Andrew J.S. Coats  Ovidiu Chioncel  Giuseppe Rosano 《European journal of heart failure》2023,25(7):1115-1131
Acute heart failure is a major cause of urgent hospitalizations. These are followed by marked increases in death and rehospitalization rates, which then decline exponentially though they remain higher than in patients without a recent hospitalization. Therefore, optimal management of patients with acute heart failure before discharge and in the early post-discharge phase is critical. First, it may prevent rehospitalizations through the early detection and effective treatment of residual or recurrent congestion, the main manifestation of decompensation. Second, initiation at pre-discharge and titration to target doses in the early post-discharge period, of guideline-directed medical therapy may improve both short- and long-term outcomes. Third, in chronic heart failure, medical treatment is often left unchanged, so the acute heart failure hospitalization presents an opportunity for implementation of therapy. The aim of this scientific statement by the Heart Failure Association of the European Society of Cardiology is to summarize recent findings that have implications for clinical management both in the pre-discharge and the early post-discharge phase after a hospitalization for acute heart failure.  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