全文获取类型
收费全文 | 1903149篇 |
免费 | 135116篇 |
国内免费 | 3957篇 |
专业分类
耳鼻咽喉 | 27466篇 |
儿科学 | 59903篇 |
妇产科学 | 52722篇 |
基础医学 | 278497篇 |
口腔科学 | 56043篇 |
临床医学 | 165801篇 |
内科学 | 366295篇 |
皮肤病学 | 43346篇 |
神经病学 | 145703篇 |
特种医学 | 73850篇 |
外国民族医学 | 503篇 |
外科学 | 290996篇 |
综合类 | 43254篇 |
现状与发展 | 8篇 |
一般理论 | 583篇 |
预防医学 | 135651篇 |
眼科学 | 45274篇 |
药学 | 144169篇 |
7篇 | |
中国医学 | 4954篇 |
肿瘤学 | 107197篇 |
出版年
2018年 | 18187篇 |
2016年 | 16135篇 |
2015年 | 17972篇 |
2014年 | 25023篇 |
2013年 | 37902篇 |
2012年 | 49776篇 |
2011年 | 52737篇 |
2010年 | 31300篇 |
2009年 | 30013篇 |
2008年 | 50033篇 |
2007年 | 54372篇 |
2006年 | 55044篇 |
2005年 | 52751篇 |
2004年 | 51411篇 |
2003年 | 49578篇 |
2002年 | 48763篇 |
2001年 | 90324篇 |
2000年 | 92531篇 |
1999年 | 77827篇 |
1998年 | 20997篇 |
1997年 | 18739篇 |
1996年 | 18362篇 |
1995年 | 17390篇 |
1994年 | 16241篇 |
1992年 | 60428篇 |
1991年 | 59178篇 |
1990年 | 58085篇 |
1989年 | 56905篇 |
1988年 | 52661篇 |
1987年 | 51779篇 |
1986年 | 49481篇 |
1985年 | 46968篇 |
1984年 | 34950篇 |
1983年 | 29743篇 |
1982年 | 17474篇 |
1981年 | 15892篇 |
1979年 | 33382篇 |
1978年 | 23833篇 |
1977年 | 20510篇 |
1976年 | 18964篇 |
1975年 | 21502篇 |
1974年 | 25342篇 |
1973年 | 24533篇 |
1972年 | 23338篇 |
1971年 | 21812篇 |
1970年 | 20815篇 |
1969年 | 19765篇 |
1968年 | 18427篇 |
1967年 | 16537篇 |
1966年 | 15233篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
151.
152.
Denise Lee Marcella D. Walker Hsin Yi Chen John A. Chabot James A. Lee Jennifer H. Kuo 《Surgery》2019,165(1):107-113
Background
Bone mineral density (BMD) has been found to improve after parathyroidectomy (PTX) in patients with primary hyperparathyroidism. There are few data on the effect of PTX on BMD in normocalcemic and normohormonal primary hyperparathyroidism.Methods
A retrospective analysis of 92 primary hyperparathyroidism patients who underwent PTX between 2004 and 2012 with pre- and post-PTX dual-energy x-ray absorptiometry was performed. Within-person changes in BMD pre- and post-PTX were analyzed using log linear mixed models, stratified by biochemical status.Results
Bone mineral density increased post-PTX in the whole cohort at the lumbar spine (+2.5%), femoral neck (+2.1%), and total hip (+1.9%) and decreased at the one-third radius (–0.9%). On comparison of BMD changes by profile, BMD increased in those with the typical profile at the lumbar spine (3.2%), femoral neck (2.9%), and total hip (2.9%) but declined at the one-third radius (–1.5%). In contrast, BMD improved only at the femoral neck (4.3%) in the normohormonal group and did not change at any site in the normocalcemic group. The typical group had a greater increase in BMD over time at the femoral neck and total hip compared with normocalcemic patients.Conclusion
Our results indicate that the skeletal benefit of PTX was attenuated in normocalcemic and normohormonal patients, suggesting that skeletal changes after PTX may depend on biochemical profile. 相似文献153.
Alan. B. Franklin Sarah N. Bevins Jeremy W. Ellis Ryan S. Miller Susan A. Shriner J. Jeffrey Root Daniel P. Walsh Thomas J. Deliberto 《Transboundary and Emerging Diseases》2019,66(2):705-714
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for clade 2.3.4.4 viruses in waterfowl as an early warning for the US poultry industry during the outbreak . After surveillance sampling of waterfowl, we tested whether there was greater detection of clade 2.3.4.4 viruses inside hotspots. We found that hotspots defined using kernel density estimates of waterfowl band recoveries worked well in predicting areas with higher prevalence of the viruses in waterfowl. This approach exemplifies the value of ecological knowledge in predicting risk to agricultural security. 相似文献
154.
155.
156.
K. Miura S. Yamaoka K. Arizono S. Ohba T. Koga T. Kawasaki N. Yoshida I. Asahina 《The British journal of oral & maxillofacial surgery》2019,57(6):529-535
Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism. 相似文献
157.
M. Iachina P.M. Ljungdalh R.G. Sørensen L. Kaerlev J. Blaakær O. Trosko N. Qvist B.M. Nørgård 《Clinical oncology (Royal College of Radiologists (Great Britain))》2019,31(2):115-123
Aims
To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.Materials and methods
The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.Results
In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).Conclusions
We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis. 相似文献158.
159.
Yinong Young-Xu Julia Thornton Snider Robertus van Aalst Salaheddin M. Mahmud Edward W. Thommes Jason K.H. Lee David P. Greenberg Ayman Chit 《Vaccine》2019,37(11):1484-1490
Background
Observational studies of the relative effectiveness of influenza vaccines are essential for public health decision making. Their estimates, however, are subject to bias due to unmeasured confounders. Instrumental variable (IV) methods can control for observed and unobserved confounders.Methods
We used linked electronic medical record databases in the Veterans Health Administration (VHA) as well as Medicare administrative files to examine the relative vaccine effectiveness (rVE) of high-dose influenza vaccine (HD) versus standard-dose influenza vaccines (SD) in preventing hospitalizations among VHA-enrolled Veterans ≥65?years of age during 5 influenza seasons (2010–2011 through 2014–2015). Using multivariable IV Poisson regression modeling to address unmeasured confounding and bias, we analyzed the data by each season and through longitudinal analysis of all five seasons.Findings
We included 3,638,924 person–influenza seasons of observation where 158,636 (4%) were among HD vaccine recipients and 3,480,288 (96%) were among SD vaccine recipients. Of the 1,728,562 Veterans, 1,702,824 (98.5%) were male and 1,299,412 (75%) were non-Hispanic white. Based on the longitudinal analysis of all five seasons, the IV-adjusted rVE estimate of HD vs. SD was 10% (95% CI, 8–12%) against all-cause hospitalization; 18% (95% CI, 15–21%) against cardiorespiratory-associated hospitalization; and 14% (95% CI, 6–22%) against influenza/pneumonia-associated hospitalization. The findings by season were similar.Interpretation
Our analysis of VHA clinical data collected from approximately 1.7 million Veterans 65?years and older during five seasons demonstrates that high-dose influenza vaccine is more effective than standard-dose influenza vaccines in preventing influenza- or pneumonia-associated hospitalizations, cardiorespiratory hospitalizations, and all-cause hospitalizations. 相似文献160.
Gudrun Aspelund Elaa M Mahdi David H Rothstein Derek S Wakeman 《Journal of gastroenterology and hepatology》2019,34(6):966-974
Choledochal cysts (CDCs) and biliary atresia (BA) are rare pediatric hepatobiliary anomalies that require surgical intervention due to increased risk of malignancy and liver failure, respectively. The underlying disease and operative procedures place patients at risk for long‐term complications, which may continue to affect them into adulthood. Lack of a transitional care model in the health‐care system potentiates the challenges they will face following aging out of their pediatric providers' care. We sought to elucidate the long‐term complications and challenges patients with CDCs and BA face, review the current literature regarding transitioning care, and propose guidelines aiding adult providers in continued care and surveillance of these patients. A literature review was performed to assess short‐term and long‐term complications after surgery and the current standards for transitioning care in patients with a history of CDCs and BA. While transitional programs exist for patients with other gastrointestinal diseases, there are few that focus on CDCs or BA. Generally, authors encourage medical record transmission from pediatric to adult providers, ensuring accuracy of information and compliance with treatment plans. Patients with CDCs are at risk for developing biliary malignancies, cholangitis, and anastomotic strictures after resection. Patients with BA develop progressive liver failure, necessitating transplantation. There are no consensus guidelines regarding timing of follow up for these patients. Based on the best available evidence, we propose a schema for long‐term surveillance. 相似文献