全文获取类型
收费全文 | 2082篇 |
免费 | 120篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 60篇 |
妇产科学 | 59篇 |
基础医学 | 281篇 |
口腔科学 | 27篇 |
临床医学 | 265篇 |
内科学 | 366篇 |
皮肤病学 | 52篇 |
神经病学 | 185篇 |
特种医学 | 54篇 |
外科学 | 209篇 |
综合类 | 31篇 |
预防医学 | 214篇 |
眼科学 | 36篇 |
药学 | 149篇 |
中国医学 | 9篇 |
肿瘤学 | 170篇 |
出版年
2023年 | 19篇 |
2022年 | 39篇 |
2021年 | 67篇 |
2020年 | 31篇 |
2019年 | 49篇 |
2018年 | 62篇 |
2017年 | 42篇 |
2016年 | 61篇 |
2015年 | 64篇 |
2014年 | 100篇 |
2013年 | 135篇 |
2012年 | 157篇 |
2011年 | 156篇 |
2010年 | 90篇 |
2009年 | 84篇 |
2008年 | 109篇 |
2007年 | 110篇 |
2006年 | 120篇 |
2005年 | 86篇 |
2004年 | 112篇 |
2003年 | 96篇 |
2002年 | 85篇 |
2001年 | 35篇 |
2000年 | 38篇 |
1999年 | 27篇 |
1998年 | 17篇 |
1997年 | 13篇 |
1996年 | 14篇 |
1995年 | 9篇 |
1994年 | 16篇 |
1993年 | 6篇 |
1992年 | 16篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1980年 | 12篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1971年 | 6篇 |
1970年 | 5篇 |
1966年 | 5篇 |
1927年 | 3篇 |
排序方式: 共有2210条查询结果,搜索用时 15 毫秒
81.
Test‐retest reliability of the default mode network in a multi‐centric fMRI study of healthy elderly: Effects of data‐driven physiological noise correction techniques 下载免费PDF全文
Rocco Marchitelli Ludovico Minati Moira Marizzoni Beatriz Bosch David Bartrés‐Faz Bernhard W. Müller Jens Wiltfang Ute Fiedler Luca Roccatagliata Agnese Picco Flavio Nobili Oliver Blin Stephanie Bombois Renaud Lopes Régis Bordet Julien Sein Jean‐Philippe Ranjeva Mira Didic Hélène Gros‐Dagnac Pierre Payoux Giada Zoccatelli Franco Alessandrini Alberto Beltramello Núria Bargalló Antonio Ferretti Massimo Caulo Marco Aiello Carlo Cavaliere Andrea Soricelli Lucilla Parnetti Roberto Tarducci Piero Floridi Magda Tsolaki Manos Constantinidis Antonios Drevelegas Paolo Maria Rossini Camillo Marra Peter Schönknecht Tilman Hensch Karl‐Titus Hoffmann Joost P. Kuijer Pieter Jelle Visser Frederik Barkhof Jorge Jovicich 《Human brain mapping》2016,37(6):2114-2132
Understanding how to reduce the influence of physiological noise in resting state fMRI data is important for the interpretation of functional brain connectivity. Limited data is currently available to assess the performance of physiological noise correction techniques, in particular when evaluating longitudinal changes in the default mode network (DMN) of healthy elderly participants. In this 3T harmonized multisite fMRI study, we investigated how different retrospective physiological noise correction (rPNC) methods influence the within‐site test‐retest reliability and the across‐site reproducibility consistency of DMN‐derived measurements across 13 MRI sites. Elderly participants were scanned twice at least a week apart (five participants per site). The rPNC methods were: none (NPC), Tissue‐based regression, PESTICA and FSL‐FIX. The DMN at the single subject level was robustly identified using ICA methods in all rPNC conditions. The methods significantly affected the mean z‐scores and, albeit less markedly, the cluster‐size in the DMN; in particular, FSL‐FIX tended to increase the DMN z‐scores compared to others. Within‐site test‐retest reliability was consistent across sites, with no differences across rPNC methods. The absolute percent errors were in the range of 5–11% for DMN z‐scores and cluster‐size reliability. DMN pattern overlap was in the range 60–65%. In particular, no rPNC method showed a significant reliability improvement relative to NPC. However, FSL‐FIX and Tissue‐based physiological correction methods showed both similar and significant improvements of reproducibility consistency across the consortium (ICC = 0.67) for the DMN z‐scores relative to NPC. Overall these findings support the use of rPNC methods like tissue‐based or FSL‐FIX to characterize multisite longitudinal changes of intrinsic functional connectivity. Hum Brain Mapp 37:2114–2132, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
82.
Dual institution experience of extranodal marginal zone lymphoma reveals excellent long‐term outcomes 下载免费PDF全文
Adam G. Starr Paolo F. Caimi PingFu Fu Mira R. Massoud Howard Meyerson Eric D. Hsi David B. Mansur Sheen Cherian Arun D. Singh Brenda W. Cooper Marcos J.G. De Lima Hillard M. Lazarus Stanton L. Gerson Deepa Jagadeesh Mitchell R. Smith Robert M. Dean Brad L. Pohlman Brian T. Hill Basem M. William 《British journal of haematology》2016,173(3):404-412
Extranodal marginal zone lymphoma (EMZL) is a B‐cell lymphoma arising from mucosa‐associated lymphoid tissue (MALT). The disease characteristics, clinical course and treatment vary considerably based on site of involvement. Because long‐term outcome data for EMZL are limited, we sought to describe the clinical details of a large number of patients with EMZL evaluated at the Case Comprehensive Cancer Center over a 12‐year period to identify prognostic markers including the impact of site of involvement. We identified 211 cases of EMZL involving the stomach (30%), ocular adnexa (19%), lungs (16%) and intestines (9%). Initial treatment included antibiotics (18%), radiation (21%), rituximab (20%), chemotherapy (3%), rituximab + chemotherapy (7%), surgery (17%) or observation (8%). After a median follow‐up of 44·3 months (range 2·2–214·9), median progression‐free survival (PFS) was 68·2 months (95% confidence interval [CI] 54·5–111·3) and median overall survival (OS) has not been reached. Age >60 years, elevated lactate dehydrogenase level (LDH), ≥4 lymph node groups involvement, and high follicular lymphoma international prognostic index (FLIPI) were associated with inferior PFS/OS. In summary, patients with EMZL have excellent prognosis with median OS in excess of 10 years. Age, elevated LDH, advanced disease, and high FLIPI score are associated with worse outcomes. 相似文献
83.
Sarah Jorgensen Mira Zurayk Samantha Yeung Jill Terry Maureen Dunn Paul Nieberg Annie Wong-Beringer 《The American journal of emergency medicine》2018,36(1):12-17
Background
Optimal management of urinary tract infections (UTIs) in the emergency department (ED) is challenging due to high patient turnover, decreased continuity of care, and treatment decisions made in the absence of microbiologic data. We sought to identify risk factors for return visits in ED patients treated for UTI.Methods
A random sample of 350 adult ED patients with UTI by ICD 9/10 codes was selected for review. Relevant data was extracted from medical charts and compared between patients with and without ED return visits within 30 days (ERVs).Results
We identified 51 patients (15%) with 59 ERVs, of whom 6% returned within 72 h. Nearly half of ERVs (47%) were UTI-related and 33% of ERV patients required hospitalization. ERVs were significantly more likely (P < 0.05) in patients with the following: age ≥ 65 years; pregnancy; skilled nursing facility residence; dementia; psychiatric disorder; obstructive uropathy; healthcare exposure; temperature ≥ 38 °C heart rate > 100; and bacteremia. Escherichia coli was the most common uropathogen (70%) and susceptibility rates to most oral antibiotics were below 80% in both groups except nitrofurantoin (99% susceptible).Cephalexin was the most frequently prescribed antibiotic (51% vs. 44%; P = 0.32). Cephalexin bug-drug mismatches were more common in ERV patients (41% vs. 15%; P = 0.02). Culture follow-up occurred less frequently in ERV patients (75% vs. 100%; P < 0.05).Conclusions
ERV in UTI patients may be minimized by using ED-source specific antibiogram data to guide empiric treatment decisions and by targeting at-risk patients for post-discharge follow-up. 相似文献84.
85.
Izbicki G Rudensky B Na'amad M Hershko C Huerta M Hersch M 《Critical care medicine》2004,32(2):439-442
OBJECTIVE: We observed that many critically ill patients developed leukocytosis following blood transfusions. To validate this observation and to explore a possible mechanism, a prospective study was designed. DESIGN: Prospective, non-interventional study. SETTING: Surgical/medical intensive care unit in a university-affiliated community hospital. PATIENTS: Consecutive patients who required packed red blood cells transfusion. INTERVENTIONS: White blood cell count (mean +/- SD) x 10(9)/L before and 2, 4, 6, 12, and 24 hrs following transfusion of non-filtered packed red cells was measured in 96 patients. MEASUREMENTS AND MAIN RESULTS: Twenty patients were septic at the time of transfusion, whereas 76 were not. The incidence of post-transfusion leukocytosis in septic vs. nonseptic patients was 15% vs. 76%, respectively (p <.001). The white blood cell count in nonseptic patients increased from 14.3 +/- 4.8 before transfusion to 19.5 +/- 7.0 2 hrs following transfusion (p <.001) and returned to baseline in 24 hrs. In the septic group, no significant post-transfusion leukocytosis occurred. In 11 nonseptic patients requiring more than one unit of packed red cells, a significant increase in mean white blood cell count occurred 2 hrs after transfusion with non-filtered packed red cells, whereas transfusion with pre-storage-filtered packed red cells did not result in such an increase. Interleukin-8 concentrations (pg/mL) in stored non-filtered packed red cells were significantly higher after 4 wks of storage (745.5 +/- 710, p =.02) than at weeks 1 (61.2 +/- 21.6) and 2 (59.3 +/- 29). In the last 16 nonseptic patients, the units of non-filtered packed red cells were assayed for interleukin-8 immediately before transfusion. Interleukin-8 concentrations were higher in units that caused leukocytosis in the recipients compared with those that did not (408.4 +/- 202 vs. 65.1 +/- 49, p =.02). CONCLUSIONS: Transfusion of non-filtered packed red cells, but not of pre-storage-filtered packed red cells, may frequently cause an acute and transient leukocytosis in critically ill nonseptic patients. Interleukin-8 accumulating in stored non-filtered packed red cells may play a role in this phenomenon. Recognition of post packed red cell transfusion leukocytosis may avoid unnecessary investigations and therapies in false suspicion of sepsis. 相似文献
86.
Susan Tsai Hugo P Marques Mechteld C de Jong Paulo Mira Vasco Ribeiro Michael A Choti Richard D Schulick Eduardo Barroso Timothy M Pawlik 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2010,12(4):262-269
Background:
Two-stage hepatectomy has been proposed for patients with bilateral colorectal liver metastases. The present study assesses the feasibility and outcome of two-stage hepatectomy for the treatment of colorectal liver metastases.Methods:
From January 1994 to December 2008, 720 patients underwent liver resections at two institutions for colorectal liver metastases. The feasibility and outcomes of two-staged hepatectomies were evaluated.Results:
Forty-five patients were eligible for the two-stage approach and both stages were completed in 35 patients (78%). Reasons for failure included disease progression (n= 7), poor performance status (n= 1) and death after the first stage (n= 2). Patients who completed both stages had significantly fewer lesions than patients who failed to complete the second stage (5 vs. 8; P= 0.02). No differences between the two groups were observed with regard to lesion size, receipt of radiofrequency ablation (RFA) or presence of extrahepatic disease. Post-operative morbidity (24% vs. 26%; P= 0.9) and mortality (4% vs. 5%; P= 0.8) was similar between the first and second stages. Median overall survival was 16 months. Three-year survival was significantly worse for patients failing to complete both stages (18%) compared with patients completing both stages (58%) (P < 0.001). Similar survival rates were observed between patients who completed two-stage vs. patients treated with a planned single-stage hepatectomy (58% vs. 53%; P= 0.34).Conclusion:
The two-stage strategy for colorectal liver metastases can be performed with acceptable morbidity and mortality. The second stage will not be feasible in 20–25% of patients.Patients who are able to complete the two-stage approach, however, may have long-term survival comparable to patients treated with a planned single-stage hepatectomy. 相似文献87.
Schueller PO Meyer C Brehm M Wernet P Schannwell CM Strauer BE 《International journal of cardiology》2007,118(3):398-399
Antegrade femoral artery access is commonly used for percutaneous transluminal revascularization of ipsilateral lower limbs in patients with critical limb ischemia. While hemostasis at the end of the procedure can be achieved by manual compression, this may lead to an increase in local vascular complications. Femoral artery closure devices, such as the Angioseal collagen plug and anchor device, have been approved and shown of benefit after retrograde femoral artery catheterization. To date, there are however no data on the use of such arteriotomy closure device after antegrade femoral access. We hereby report a case series of five patients in whom Angioseal was successfully used after antegrade femoral puncture and below-the-knee percutaneous transluminal angioplasty. In all cases the device enabled immediate and complete hemostasis without major complications, despite the intense antithrombotic regimen, including heparin, aspirin, and clopidogrel in all patients, as well as glycoprotein IIb/IIIa inhibitors (in two patients) and fibrinolytic therapy (in one). 相似文献
88.
Madhubala Devi S. Subadani Devi Kaushik Debnath Th. Mira Devi H. Nabachandra Singh 《Indian journal of hematology & blood transfusion》2007,23(3-4):109-111
An autopsy finding of sudden death due to disseminated intra-vascular sickling of RBCs in a young adult male from Madhya Pradesh while undergoing army recruitment rally, is reported because of its rarity in this part of the country. 相似文献
89.
Sabine Vollstädt‐Klein Svenja Wichert Juri Rabinstein Mira Bühler Oliver Klein Gabriele Ende Derik Hermann Karl Mann 《Addiction (Abingdon, England)》2010,105(10):1741-1749
Aims During the development of drug addiction, initial hedonic effects decrease when substance use becomes habitual and ultimately compulsive. Animal research suggests that these changes are represented by a transition from prefrontal cortical control to subcortical striatal control and within the striatum from ventral to dorsal domains of the striatum, but only limited evidence exists in humans. In this study we address this hypothesis in the context of alcohol dependence. Design, setting and participants Non‐abstinent heavy social drinkers (n = 21, 5.0 ± 1.5 drinks/day, 13 of them were alcohol‐dependent according to DSM‐IV) and light social drinkers (n = 10, 0.4 ± 0.4 drinks/day) were examined. Measurements We used a cue‐reactivity functional magnetic resonance imaging (fMRI) design during which pictures of alcoholic beverages and neutral control stimuli were presented. Findings In the dorsal striatum heavy drinkers showed significant higher activations compared to light drinkers, whereas light social drinkers showed higher cue‐induced fMRI activations in the ventral striatum and in prefrontal areas compared to heavy social drinkers [region of interest analyses, P < 0.05 false discovery rate (FDR)‐corrected]. Correspondingly, ventral striatal activation in heavy drinkers correlated negatively with obsessive‐compulsive craving, and furthermore we found a positive association between cue‐induced activation in the dorsal striatum and obsessive‐compulsive craving in all participants. Conclusions In line with our hypothesis we found higher cue‐induced activation of the ventral striatum in social compared to heavy drinkers, and higher dorsal striatal activation in heavy drinkers. Increased prefrontal activation may indicate that social drinkers activate cortical control when viewing alcohol cues, which may prevent the development of heavy drinking or alcohol dependence. Our results suggest differentiating treatment research depending on whether alcohol use is hedonic or compulsive. 相似文献
90.
The use of 3D surface imaging technology is becoming increasingly common in craniofacial clinics and research centers. Due to fast capture speeds and ease of use, 3D digital stereophotogrammetry is quickly becoming the preferred facial surface imaging modality. These systems can serve as an unparalleled tool for craniofacial surgeons, proving an objective digital archive of the patient's face without exposure to radiation. Acquiring consistent high-quality 3D facial captures requires planning and knowledge of the limitations of these devices. Currently, there are few resources available to help new users of this technology with the challenges they will inevitably confront. To address this deficit, this report will highlight a number of common issues that can interfere with the 3D capture process and offer practical solutions to optimize image quality. 相似文献