全文获取类型
| 收费全文 | 5499773篇 |
| 免费 | 363740篇 |
| 国内免费 | 12047篇 |
专业分类
| 耳鼻咽喉 | 79281篇 |
| 儿科学 | 176215篇 |
| 妇产科学 | 149159篇 |
| 基础医学 | 768099篇 |
| 口腔科学 | 161769篇 |
| 临床医学 | 514956篇 |
| 内科学 | 1030074篇 |
| 皮肤病学 | 120792篇 |
| 神经病学 | 447729篇 |
| 特种医学 | 207754篇 |
| 外国民族医学 | 1941篇 |
| 外科学 | 811554篇 |
| 综合类 | 128304篇 |
| 现状与发展 | 16篇 |
| 一般理论 | 2475篇 |
| 预防医学 | 452218篇 |
| 眼科学 | 131364篇 |
| 药学 | 404909篇 |
| 148篇 | |
| 中国医学 | 10545篇 |
| 肿瘤学 | 276258篇 |
出版年
| 2018年 | 59069篇 |
| 2017年 | 44813篇 |
| 2016年 | 50989篇 |
| 2015年 | 57411篇 |
| 2014年 | 81239篇 |
| 2013年 | 124712篇 |
| 2012年 | 166430篇 |
| 2011年 | 177780篇 |
| 2010年 | 107013篇 |
| 2009年 | 100968篇 |
| 2008年 | 166219篇 |
| 2007年 | 177010篇 |
| 2006年 | 178475篇 |
| 2005年 | 173483篇 |
| 2004年 | 167111篇 |
| 2003年 | 160662篇 |
| 2002年 | 156210篇 |
| 2001年 | 234615篇 |
| 2000年 | 241629篇 |
| 1999年 | 205304篇 |
| 1998年 | 64260篇 |
| 1997年 | 56221篇 |
| 1996年 | 55409篇 |
| 1995年 | 53503篇 |
| 1994年 | 49649篇 |
| 1993年 | 46736篇 |
| 1992年 | 164169篇 |
| 1991年 | 160429篇 |
| 1990年 | 156144篇 |
| 1989年 | 150981篇 |
| 1988年 | 139972篇 |
| 1987年 | 137837篇 |
| 1986年 | 130826篇 |
| 1985年 | 126128篇 |
| 1984年 | 95612篇 |
| 1983年 | 82007篇 |
| 1982年 | 49655篇 |
| 1981年 | 44932篇 |
| 1979年 | 89923篇 |
| 1978年 | 64285篇 |
| 1977年 | 54544篇 |
| 1976年 | 51603篇 |
| 1975年 | 54994篇 |
| 1974年 | 66648篇 |
| 1973年 | 63917篇 |
| 1972年 | 60710篇 |
| 1971年 | 56874篇 |
| 1970年 | 52856篇 |
| 1969年 | 50267篇 |
| 1968年 | 46440篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
61.
M. Corral-Blanco V.C. Prudencio-Ribera M.E. Jarrín-Estupiñán R. Alonso-Moralejo V. Pérez-González J.C. Meneses-Pardo A. Hermira-Anchuelo A. De Pablo-Gafas 《Transplantation proceedings》2019,51(2):380-382
Background
Pulmonary hypertension (PH) is a comorbidity associated with interstitial lung disease (ILD). The purpose of this study was to evaluate the influence of PH on intrahospital mortality in lung transplantation (LT) for ILD.Methods
We conducted a retrospective cohort study of 66 patients who underwent LT for ILD at the 12 de Octubre University Hospital (Madrid, Spain) from October 2008 to June 2014. PH was defined as mean pulmonary arterial pressure (mPAP) ≥25 mmHg on right-sided heart catheterization and intrahospital mortality as any death taken place after the transplantation of patients not being discharged.Results
We retrospectively analyzed data of 66 patients; they were stratified by the presence or absence of PH before LT. Twenty-seven patients (41%) had PH. The PH group had a lower diffusing capacity of carbon monoxide (DLCO), carbon monoxide transfer coefficient (KCO), and 6-minute walk distance test (6MWT) and a higher total lung capacity (TLC), modified medical research council dyspnea scale (mMRC), and lung allocation score (LAS) than the non-PH group. Patients with PH more often underwent double lung transplantation (DLT; 59%) than single lung transplantation (SLT).Intrahospital mortality was 13% (9/66). No significant differences were observed in Kaplan-Meier survival curves for the PH and non-PH groups with a median survival time of 46 days versus 33 days (IQR 26–74; log-rank P = .056); however, the postoperative length of stay in the hospital was greater in the PH group.Conclusions
In our cohort, pulmonary hypertension was not related to early mortality in lung transplantation recipients for interstitial lung diseases. 相似文献62.
Amgad El Mekabaty Monica S. Pearl Bommy Mershon Ivor Berkowitz Philippe Gailloud Thierry A.G.M. Huisman 《Journal of neuroradiology. Journal de neuroradiologie》2019,46(3):214-221
Background and purpose
The vein of Galen aneurysmal malformation (VGAM) is a rare congenital vascular malformation with a higher morbidity and mortality, especially in neonates. Ultrasound, CT and MR are usually used in diagnosis and treatment monitoring of these disorders. In this current study, we aim to examine utility of SWI in evaluation of treatment response in infants with VGAM.Materials and methods
We performed a retrospective chart analysis of children with VGAM in our institution between January 2008 and December 2016. Inclusion criteria included; confirmed VGAM on DSA; available SWI sequence at baseline and at follow up after at least a single embolization session; age at initial MR of 18?years or younger. Signal intensity and Angioarchitecture of VGAM and cerebral veins on SWI, as well as hydrocephalus and clinical outcome were evaluated.Results
Of 11 patients identified with VGAM in our institution, 5 children (3 males and 2 females) satisfied the inclusion criteria. The average age at initial MR was 29?days (range 1–120). Fourteen MRI were available for review. All children had VGAM of mural type. Intramedullary veins were dilated and SWI-hypointense in all children, while subependymal and sulcal veins were dilated and SWI-hypointense in 4 patients on initial MRI. On the first available follow up MRI, cerebral veins have mostly normalized in 4 children and remained mostly dilated and SWI-hypointense in 1 child; even after complete treatment of the VGAM.Conclusion
Our preliminary findings show that SWI seems to offer a beneficial non-invasive tool in evaluating passive venous congestion patterns in pediatric patients with VGAM. It remains to be determined in larger studies, the clinical significance of these SWI changes. 相似文献63.
64.
Birgitte Lerbæk Rikke Jørgensen Jørgen Aagaard Julie Nordgaard Niels Buus 《Archives of Psychiatric Nursing》2019,33(2):174-181
Background
Life expectancy of people with severe mental illness (SMI) is greatly shortened compared to the general population, and despite extensive research, this issue is unsolved. Although it is widely recognised that people with SMI need support from health care services to manage health related issues, profound health inequalities exist within provision of health care. The aim of this study was to examine how mental health care professionals accounted for their actions and responsibilities related to managing physical health issues among people with SMI.Methods
Three focus groups were conducted with 22 mental health care professionals, employed at three mental health care locations. Participants' situated accounts were subjected to discourse analysis.Results
Participants accounted for actions and responsibilities in three typical ways; 1) by positioning people with SMI as difficult to motivate and actively resisting intervention, 2) by positioning people with SMI as so impaired that intervention was futile, and 3) by arguing they are undertreated for physical conditions and might have physical illnesses that staff are not aware of because of prominent mental illness. These discursive strategies seemed to legitimise situations where participants described not responding to physical health issues, and to downplay potential trouble in situations where participants described not succeeding in facilitating lifestyle changes or promoting compliance to treatment of physical conditions.Discussion and conclusion
Mental health care professionals need to increase their awareness of latent discriminating attitudes towards people with SMI. Such attitudes are suggested to reinforce barriers for people with SMI receiving physical health care. 相似文献65.
Brian Darrith Nicholas B. Frisch Matthew W. Tetreault Michael P. Fice Chris N. Culvern Craig J. Della Valle 《The Journal of arthroplasty》2019,34(2):221-227
Background
Although some prior work supports the safety of same-day arthroplasty performed in a hospital, concerns remain when these procedures are performed in a free-standing ambulatory surgery center. The purpose of this study is to compare 90-day complication rates between matched cohorts that underwent inpatient vs outpatient arthroplasty at an ambulatory surgery center.Methods
A single-surgeon cohort of 243 consecutive patients who underwent outpatient arthroplasty was matched with 243 inpatients who had the same procedure. One-to-one nearest-neighbor matching with respect to gender, age, American Society of Anesthesiologists Score, and body mass index was utilized. The 486 primary arthroplasties included 178 unicondylar knees (36.6%), 146 total hips (30.0%), 92 total knees (18.9%), and 70 hip resurfacings (14.5%). Ninety-day outcomes including reoperation, readmission, unplanned clinic or emergency department visits, and major and minor complications were compared using a 2-sample proportions test.Results
The 2 cohorts were similar in distribution of demographic variables, demonstrating successful matching. The inpatient and outpatient cohorts both had readmission rates of 2.1% (P = 1.0). With the number of subjects studied, there were no statistically significant differences in rates of major complications (2.1% vs 2.5%, P = 1.0), minor complications (7.0% vs 7.8%, P = .86), reoperations (0.4% vs 2.1%, P = .22), emergency department visits (1.6% vs 2.5%, P = .52), or unplanned clinic visits (3.3% vs 5.8%, P = .19).Conclusion
This study suggests that arthroplasty procedures can be performed safely in an ambulatory surgery center among appropriately selected patients without an increased risk of complications. 相似文献66.
Chancellor F. Gray Hernan A. Prieto Justin T. Deen Hari K. Parvataneni 《The Journal of arthroplasty》2019,34(2):206-210
Background
Revision total joint arthroplasty (TJA) is associated with increased readmissions, complications, and expense compared to primary TJA. Bundled payment methods have been used to improve value of care in primary TJA, but little is known of their impact in revision TJA patients. The purpose of this study is to evaluate the impact of a care redesign for a bundled payment model for primary TJA on quality metrics for revision patients, despite absence of a targeted intervention for revisions.Methods
We compared quality metrics for all revision TJA patients including readmission rate, use of post–acute care facility after discharge, length of stay, and cost, between the year leading up to the redesign and the 2 years following its implementation. Changes in the primary TJA group over the same time period were also assessed for comparison.Results
Despite a volume increase of 37% over the study period, readmissions declined from 8.9% to 5.8%. Use of post–acute care facilities decreased from 42% to 24%. Length of stay went from 4.84 to 3.92 days. Cost of the hospital episode declined by 5%.Conclusion
Our health system experienced a halo effect from our bundled payment-influenced care redesign, with revision TJA patients experiencing notable improvements in several quality metrics, though not as pronounced as in the primary TJA population. These changes benefitted the patients, the health system, and the payers. We attribute these positive changes to an altered institutional mindset, resulting from an invested and aligned care team, with active physician oversight over the care episode. 相似文献67.
Katherine M. Stenson Benjamin O. Patterson Matthew Joe Grima Jorg L. De Bruin Peter J.E. Holt Ian Loftus 《Journal of vascular surgery》2019,69(1):53-62.e1
Background
Endovascular aneurysm sealing (EVAS) represents a novel approach to the treatment of abdominal aortic aneurysms. It uses polymer technology to achieve an anatomic seal within the sac of the aneurysm. This cohort study reports the early clinical outcomes, technical refinements, and learning curve during the initial EVAS experience at a single institution.Methods
Results from 150 consecutive EVAS cases for intact, infrarenal abdominal aortic aneurysms are reported here. These cases were undertaken between March 2013 and July 2015. Preoperative, perioperative, and postoperative data were collected for each patient prospectively.Results
The median age of the cohort was 76.6 years (interquartile range, 70.2-80.9 years), and 87.3% were male. Median aneurysm diameter was 62.0 mm (IQR, 58.0-69.0 mm). Adverse neck morphology was seen in 69 (46.0%) patients, including aneurysm neck length <10 mm (17.3%), neck diameter >32 mm or <18 mm (8.7%), and neck angulation >60 degrees (15.3%). Median follow-up was 687 days (IQR, 463-897 days); 37 patients (24.7%) underwent reintervention. The rates of unresolved endoleak are 1.3% type IA, 0.7% type IB, and 2.7% type I. There were no type III endoleaks. There have been seven secondary ruptures in this cohort; all but one of these patients survived after reintervention. Only one rupture occurred in an aneurysm that had been treated within the manufacturer's instructions for use (IFU).Conclusions
The rate of unresolved endoleaks is satisfactorily low. The incidence of secondary rupture is of concern; however, when the IFU are adhered to, the rate is very low. The results of this study suggest that working within the IFU yields better clinical results. 相似文献68.
Lindsay A. Weiner Adam C. Richardson Semhar Z. Tewelde 《The Journal of emergency medicine》2019,56(4):e43-e46
Background
Spontaneous spinal and intracranial subdural hematomas are rarely reported, especially occurring simultaneously. Anticoagulation use has been associated with spontaneous hemorrhages. Prompt diagnosis is required to prevent permanent neurological sequelae. In this case report, we describe a spontaneous spinal and intracranial subdural hematoma in a woman taking warfarin and initially presenting with severe vaginal pain.Case Report
A 42-year-old woman who had a history of mechanical valve replacement and was therefore taking warfarin, came to an emergency department for relief of severe vaginal pain. Mild concurrent lumbar pain increased concern about spinal pathology, so magnetic resonance imaging of her spine was performed. It revealed a subdural hematoma extending from L1–S1 with arachnoiditis, which suggested intracranial pathology, though the patient had no complaint of a headache. Computed tomography of her brain demonstrated a large right subdural hemorrhage with midline shift. Subsequent imaging revealed no aneurysm or source of the intracranial bleeding. We concluded that the patient experienced spontaneous anticoagulation-related intracranial hemorrhage resulting in lumbar subdural hematoma and arachnoiditis with referred vaginal pain.Why Should an Emergency Physician Be Aware of This?
Pelvic, vaginal, or perineal pain may be the presenting symptom in patients with lower spinal pathology. It is important to consider causes other than gynecological ones in the differential diagnosis of these patients, as well as to be cognizant of the relationship between spinal and intracranial subdural hemorrhages. In patients with back pain or radiating lumbar pain, especially coupled with neurological effects, clinicians should consider spinal subdural hemorrhage and arachnoiditis to expedite imaging studies and treatment of these rare entities. 相似文献69.
David C. Johnson Steven S. Raman Sohrab A. Mirak Lorna Kwan Amirhossein M. Bajgiran William Hsu Cleo K. Maehara Preeti Ahuja Izak Faiena Aydin Pooli Amirali Salmasi Anthony Sisk Ely R. Felker David S.K. Lu Robert E. Reiter 《European urology》2019,75(5):712-720
Background
Multiparametric magnetic resonance imaging (mpMRI) undoubtedly affects the diagnosis and treatment of localized prostate cancer (CaP). However, clinicians need a better understanding of its accuracy and limitations in detecting individual CaP foci to optimize management.Objective
To determine the per-lesion detection rate for CaP foci by mpMRI and identify predictors of tumor detection.Design, setting, and participants
We carried out a retrospective analysis of a prospectively managed database correlating lesion-specific results from mpMRI co-registered with whole-mount pathology (WMP) prostatectomy specimens from June 2010 to February 2018. Participants include 588 consecutive patients with biopsy-proven CaP undergoing 3-T mpMRI before radical prostatectomy at a single tertiary institution.Outcome measurements and statistical analysis
We measured mpMRI sensitivity in detecting individual CaP and clinically significant (any Gleason score ≥7) CaP foci and predictors of tumor detection using multivariate analysis.Results and limitations
The final analysis included 1213 pathologically confirmed tumor foci in 588 patients with primarily intermediate- (75%) or high-risk (12%) CaP. mpMRI detected 45% of all lesions (95% confidence interval [CI] 42–47%), including 65% of clinically significant lesions (95% CI 61–69%) and nearly 80% of high-grade tumors. Some 74% and 31% of missed solitary and multifocal tumors, respectively, were clinically significant. The majority of missed lesions were small (61.1% ≤1 cm); 28.3% were between 1 and 2 cm, and 10.4% were >2 cm. mpMRI missed at least one clinically significant focus in 34% of patients overall, and in 45% of men with multifocal lesions. On multivariate analysis, smaller, low-grade, multifocal, nonindex tumors with lower prostate-specific antigen density were more likely to be missed. Limitations include selection bias in a prostatectomy cohort, lack of specificity data, an imperfect co-registration process, and uncertain clinical significance for undetected lesions.Conclusions
mpMRI detects less than half of all and less than two-thirds of clinically significant CaP foci. The moderate per-lesion sensitivity and significant proportion of men with undetected tumor foci demonstrate the current limitations of mpMRI.Patient summary
Magnetic resonance imaging of the prostate before surgical removal for prostate cancer finds less than half of all individual prostate cancer tumors. Large, solitary, aggressive tumors are more likely to be visualized on imaging. 相似文献70.
Maryam Boumezrag Sormeh Harounzadeh Hamza Ijaz Angeline Johny Lorna Richards Yan Ma Maxine A. Le Saux Paige Kulie Caitlin Davis Andrew C. Meltzer 《The American journal of emergency medicine》2019,37(2):304-307