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   2398篇
  免费   157篇
  国内免费   3篇
耳鼻咽喉   16篇
儿科学   51篇
妇产科学   18篇
基础医学   414篇
口腔科学   67篇
临床医学   184篇
内科学   498篇
皮肤病学   46篇
神经病学   253篇
特种医学   51篇
外科学   303篇
综合类   3篇
预防医学   185篇
眼科学   20篇
药学   196篇
中国医学   6篇
肿瘤学   247篇
  2024年   1篇
  2023年   21篇
  2022年   38篇
  2021年   70篇
  2020年   36篇
  2019年   82篇
  2018年   80篇
  2017年   51篇
  2016年   55篇
  2015年   100篇
  2014年   102篇
  2013年   150篇
  2012年   204篇
  2011年   224篇
  2010年   111篇
  2009年   130篇
  2008年   182篇
  2007年   176篇
  2006年   156篇
  2005年   155篇
  2004年   139篇
  2003年   119篇
  2002年   73篇
  2001年   11篇
  2000年   9篇
  1999年   19篇
  1998年   18篇
  1997年   10篇
  1996年   4篇
  1995年   5篇
  1994年   4篇
  1993年   2篇
  1992年   5篇
  1991年   2篇
  1990年   2篇
  1987年   1篇
  1985年   3篇
  1984年   2篇
  1983年   1篇
  1981年   3篇
  1977年   1篇
  1976年   1篇
排序方式: 共有2558条查询结果,搜索用时 15 毫秒
91.
BACKGROUND: DSM-IV criteria for mixed states may be too restrictive and may actually exclude patients who do not meet the full criteria for a manic and depressive state. Using this DSM-IV definition, many patients who are considered depressed may have mixed features, which can explain why some bipolar depressive states can worsen with antidepressants and can be improved by mood stabilizers or atypical antipsychotics. A dimensional approach not exclusively focused on the tonality of affect would help to define a broader entity of mixed states. The aim of this study was to apply a dimensional model to bipolar episodes and to assess the overlap between the groups defined using this model and using categorical diagnosis. METHOD: We assessed 139 DSM-IV acutely ill bipolar I patients with MAThyS (Multidimensional Assessment of Thymic States by Henry et al. in press), a scale that assesses five quantitative dimensions exploring excitatory and inhibition processes, and that is not focused on tonality of mood but on emotional reactivity. We studied the relationship between clusters defined by statistical analyses and DSM-IV bipolar mood states. RESULTS: This study showed the existence of three clusters. Cluster 1 was characterized by an inhibition in all dimensions and corresponded to the depressive cluster (more than 90% of patients met the criteria for DSM-IV Major Depressive Episode (MDE)). Cluster 2 showed a general excitation and was mainly DSM-IV manic or hypomanic patients (90%). Cluster 3 (Mixed) was more complex and the diagnosis included MDE (56%) in most of the cases associated with manic or hypomanic symptoms, mixed states (18%) defined by DSM-IV criteria, and manic or hypomanic states (25%). Emotional reactivity was relevant to distinguish Cluster 1 (Depressive), exhibiting emotional hypo-reactivity, from Cluster 2 (Manic) and 3 (Mixed), characterized by emotional hyper-reactivity. Sadness was reported equally in all three clusters. CONCLUSION: A dimensional approach using the concept of emotional reactivity seems appropriate to define a broad mixed state entity in patients who would be diagnosed with MDE according to DSM-IV. Further studies are needed to test the relevance of this model in therapeutic strategies.  相似文献   
92.
Metallo-beta-lactamase enzymes (MbetaL) are encoded by transferable genes, which appear to spread rapidly among gram-negative bacteria. The objective of this study was to develop a multiplex real-time PCR assay followed by a melt curve step for rapid detection and identification of genes encoding MbetaL-type enzymes based on the amplicon melting peak. The reference sequences of all genes encoding IMP and VIM types, SPM-1, GIM-1, and SIM-1 were downloaded from GenBank, and primers were designed to obtain amplicons showing different sizes and melting peak temperatures (Tm). The real-time PCR assay was able to detect all MbetaL-harboring clinical isolates, and the Tm-assigned genotypes were 100% coincident with previous sequencing results. This assay could be suitable for identification of MbetaL-producing gram-negative bacteria by molecular diagnostic laboratories.  相似文献   
93.

Purpose

Frequent Emergency Department users are likely to experience poor quality of life (QOL). Case management interventions are efficient in responding to the complex needs of this population, but their effects on QOL have not been tested yet. Therefore, the aim of our study was to examine to what extent a case management intervention improved frequent Emergency Department users’ QOL in a universal health coverage system.

Methods

Data were part of a randomized controlled trial designed to improve frequent Emergency Department users’ QOL at the Lausanne University Hospital, Switzerland. A total of 250 frequent Emergency Department users (≥?5 attendances during the previous 12 months) were randomly assigned to the control (n?=?125) or the intervention group (n?=?125). The latter benefited from case management intervention. QOL was evaluated using the WHOQOL-BREF at baseline, two, five and a half, nine, and twelve months later. It included four dimensions: physical health, psychological health, social relationship, and environment. Linear mixed-effects models were used to analyze the change in the patients’ QOL over time.

Results

Patients’ QOL improved significantly (p?<?0.001) in both groups for all dimensions after two months. However, environment QOL dimension improved significantly more in the intervention group after 12 months.

Conclusions

Environment QOL dimension was the most responsive dimension for short-term interventions. This may have been due to case management’s assistance in obtaining income entitlements, health insurance coverage, stable housing, or finding general health care practitioners. Case management in general should be developed to enhance frequent users’ QOL.Trial registration: http://www.clinicaltrials.gov, Unique identifier: NCT01934322
  相似文献   
94.

Purpose

Accurate estimates of disease incidence in children are required to support pediatric drug development. Analysis of electronic health care records (EHR) may yield such estimates but pediatric‐specific methods are lacking. We aimed to understand the impact of assumptions regarding duration of disease episode and length of run‐in period on incidence estimates from EHRs.

Methods

Children aged 0 to 17 years (5–17 years for asthma) registered in the Integrated Primary Care Information database between 2002 and 2014 were studied. We tested the impact of the following: maximum duration of disease episode (0, 14, 30, 60, and 90 days) on recurrent diseases (acute otitis media [common] and acute pyelonephritis [rare]); and database run‐in period on chronic diseases—asthma (common) and type 1 diabetes (DM) (rare). We calculated incidence rate ratios with 95% confidence intervals and stratified using 1‐year age categories.

Results

Altogether, 503 495 children were registered. The incidence of acute otitis media was highest in <2‐year‐old children; using 30 days disease duration as reference, the rate increased with 8% if the duration was 14 days and decreased with 8% when extended to 60 days. Disease duration did not impact acute pyelonephritis (rare). No run‐in (to exclude prevalent cases) versus 24‐month run‐in period overestimated the incidence rate for asthma and DM by a factor of 2.

Conclusions

Analysis of EHR allows for estimation of disease incidence in children, but assumptions regarding episode length and run‐in period impact the incidence estimates. Such assumptions may be routinely explored.  相似文献   
95.
96.
Background

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) leads to prolonged survival for selected patients with colorectal (CRC) peritoneal metastases (PM). This study aimed to analyze the prognostic role of micro-satellite (MS) status and RAS/RAF mutations for patients treated with CRS.

Methods

Data were collected from 13 Italian centers with PM expertise within a collaborative group of the Italian Society of Surgical Oncology. Clinical and pathologic variables and KRAS/NRAS/BRAF mutational and MS status were correlated with overall survival (OS) and disease-free survival (DFS).

Results

The study enrolled 437 patients treated with CRS-HIPEC. The median OS was 42.3 months [95% confidence interval (CI), 33.4–51.2 months], and the median DFS was 13.6 months (95% CI, 12.3–14.9 months). The local (peritoneal) DFS was 20.5 months (95% CI, 16.4–24.6 months). In addition to the known clinical factors, KRAS mutations (p = 0.005), BRAF mutations (p = 0.01), and MS status (p = 0.04) were related to survival. The KRAS- and BRAF-mutated patients had a shorter survival than the wild-type (WT) patients (5-year OS, 29.4% and 26.8% vs 51.5%, respectively). The patients with micro-satellite instability (MSI) had a longer survival than the patients with micro-satellite stability (MSS) (5-year OS, 58.3% vs 36.7%). The MSI/WT patients had the best prognosis. The MSS/WT and MSI/mutated patients had similar survivals, whereas the MSS/mutated patients showed the worst prognosis (5-year OS, 70.6%, 48.1%, 23.4%; p = 0.0001). In the multivariable analysis, OS was related to the Peritoneal Cancer Index [hazard ratio (HR), 1.05 per point], completeness of cytoreduction (CC) score (HR, 2.8), N status (HR, 1.6), signet-ring (HR, 2.4), MSI/WT (HR, 0.5), and MSS/WT-MSI/mutation (HR, 0.4). Similar results were obtained for DFS.

Conclusion

For patients affected by CRC-PM who are eligible for CRS, clinical and pathologic criteria need to be integrated with molecular features (KRAS/BRAF mutation). Micro-satellite status should be strongly considered because MSI confers a survival advantage over MSS, even for mutated patients.

  相似文献   
97.
Since the mechanisms by which specific immunity destroys Her-2/neu carcinoma cells are highly undetermined, these were assessed in BALB/c mice vaccinated with plasmids encoding extracellular and transmembrane domains of the protein product (p185(neu)) of the rat Her-2/neu oncogene shot into the skin by gene gun. Vaccinated mice rejected a lethal challenge of TUBO carcinoma cells expressing p185(neu). Depletion of CD4 T cells during immunization abolished the protection, while depletion of CD8 cells during the effector phase halved it, and depletion of polymorphonuclear granulocytes abolished all protection. By contrast, Ig mu-chain gene KO mice, as well as Fcgamma receptor I/III, beta-2 microglobulin, CD1, monocyte chemoattractant protein 1 (MCP1), IFN-gamma, and perforin gene KO mice were protected. Only mice with both IFN-gamma and perforin gene KOs were not protected. Although immunization also cured all BALB/c mice bearing established TUBO carcinomas, it did not cure any of the perforin KO or perforin and IFN-gamma KO mice. Few mice were cured that had knockouts of the gene for Ig mu-chain, Fcgamma receptor I/III, IFN-gamma, or beta-2 microglobulin. Moreover, vaccination cured half of the CD1 and the majority of the MCP1 KO mice. The eradication of established p185(neu) carcinomas involves distinct mechanisms, each endowed with a different curative potential.  相似文献   
98.
Synaptic function is central to brain function. Understanding the synapse is aided by studies of patients lacking individual synaptic proteins. Common neurological diseases are genetically complex. Their understanding is likewise simplified by studies of less common monogenic forms. We detail the disease caused by absence of the synaptic protein CNKSR2 in 8 patients ranging from 6 to 62 years old. The disease is characterized by intellectual disability, attention problems, and abrupt lifelong language loss following a brief early childhood epilepsy with continuous spike‐waves in sleep. This study describes the phenotype of CNKSR2 deficiency and its involvement in systems underlying common neurological disorders. Ann Neurol 2014;76:758–764  相似文献   
99.
100.

Purpose

Extended-duration thromboprophylaxis (EDTPPX) is the practice of prescribing antithrombotic therapy for 21 days after discharge, commonly used in surgical patients who are at high risk for venothromboembolism (VTE). While guidelines recommend EDTPPX, criteria are vague due to a paucity of data. The criteria can be further informed by cost-effectiveness thresholds. This study sought to determine the VTE incidence threshold for the cost-effectiveness of EDTPPX compared to inpatient prophylaxis.

Methods

A decision tree was used to compare EDTPPX for 21 days after discharge to 7 days of inpatient prophylaxis with base case assumptions based on an abdominal oncologic resection without complications in an otherwise healthy individual. Willingness to pay was set at $50,000/quality-adjusted life year (QALY). Sensitivity analyses were performed to assess uncertainty within the model, with particular interest in the threshold for cost-effectiveness based on VTE incidence.

Results

EDTPPX was the dominant strategy when VTE probability exceeds 2.39 %. Given a willingness to pay threshold of $50,000/QALY, EDTPPX was the preferred strategy when VTE incidence exceeded 1.22 and 0.88 % when using brand name or generic medication costs, respectively.

Conclusions

EDTPPX should be recommended whenever VTE incidence exceeds 2.39 %. When post-discharge estimated VTE risk is 0.88–2.39 %, patient preferences about self-injections and medication costs should be considered.  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