全文获取类型
| 收费全文 | 3932720篇 |
| 免费 | 293944篇 |
| 国内免费 | 6716篇 |
专业分类
| 耳鼻咽喉 | 56541篇 |
| 儿科学 | 124495篇 |
| 妇产科学 | 105522篇 |
| 基础医学 | 565252篇 |
| 口腔科学 | 112436篇 |
| 临床医学 | 361609篇 |
| 内科学 | 751820篇 |
| 皮肤病学 | 83451篇 |
| 神经病学 | 319931篇 |
| 特种医学 | 151387篇 |
| 外国民族医学 | 1277篇 |
| 外科学 | 590491篇 |
| 综合类 | 89549篇 |
| 现状与发展 | 13篇 |
| 一般理论 | 1601篇 |
| 预防医学 | 317460篇 |
| 眼科学 | 93905篇 |
| 药学 | 294267篇 |
| 89篇 | |
| 中国医学 | 7553篇 |
| 肿瘤学 | 204731篇 |
出版年
| 2018年 | 42162篇 |
| 2017年 | 31981篇 |
| 2016年 | 35713篇 |
| 2015年 | 40330篇 |
| 2014年 | 57663篇 |
| 2013年 | 87688篇 |
| 2012年 | 119239篇 |
| 2011年 | 126769篇 |
| 2010年 | 75403篇 |
| 2009年 | 71368篇 |
| 2008年 | 119350篇 |
| 2007年 | 127166篇 |
| 2006年 | 128374篇 |
| 2005年 | 124773篇 |
| 2004年 | 120041篇 |
| 2003年 | 115495篇 |
| 2002年 | 113128篇 |
| 2001年 | 175008篇 |
| 2000年 | 180521篇 |
| 1999年 | 152748篇 |
| 1998年 | 45571篇 |
| 1997年 | 40420篇 |
| 1996年 | 40004篇 |
| 1995年 | 38314篇 |
| 1994年 | 35718篇 |
| 1993年 | 33534篇 |
| 1992年 | 121568篇 |
| 1991年 | 118595篇 |
| 1990年 | 115261篇 |
| 1989年 | 111028篇 |
| 1988年 | 102908篇 |
| 1987年 | 101057篇 |
| 1986年 | 95410篇 |
| 1985年 | 91685篇 |
| 1984年 | 69236篇 |
| 1983年 | 59072篇 |
| 1982年 | 35782篇 |
| 1981年 | 32034篇 |
| 1979年 | 64951篇 |
| 1978年 | 46067篇 |
| 1977年 | 38660篇 |
| 1976年 | 36862篇 |
| 1975年 | 39072篇 |
| 1974年 | 47645篇 |
| 1973年 | 45357篇 |
| 1972年 | 42867篇 |
| 1971年 | 40111篇 |
| 1970年 | 37346篇 |
| 1969年 | 35145篇 |
| 1968年 | 32280篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
61.
P. Mendogni S. Henchi L.C. Morlacchi D. Tosi M. Nosotti P. Tarsia A.I. Gregorini L. Rosso 《Transplantation proceedings》2019,51(1):194-197
Background
Solid organ transplantation is associated with a higher risk of Epstein-Barr virus (EBV)–related lymphoproliferative disease due to immunosuppressive regimen. Little evidence is currently available on post-transplant lymphoproliferative disorders (PTLDs) in the lung transplant (LuTx) setting, particularly in cystic fibrosis (CF) recipients.Methods
We retrospectively analyzed all the cases of PTLDs that occurred in our LuTx center between January 2015 and December 2017. We reviewed clinical and radiologic data, donor and recipient EBV serostatus, immunosuppressive therapy, histologic data, and follow-up of these patients.Results
A total of 77 LuTxs were performed at our center in the study period; 39 (50.6%) patients had CF; 4 developed EBV-related PTLDs. They were all young (17–26 years) CF patients with high serum EBV DNA load. Disease onset was within the first 3 months after LuTx. In 3 cases presentation was associated with fever and infection-like symptoms, whereas in 1 case radiologic suspicion arose unexpectedly from a CT scan performed for different clinical reasons. Diagnosis was reached through lung biopsy in all cases. All patients received rituximab,?cyclophosphamide, doxorubicin hydrochloride (hydroxydaunomycin), vincristine sulfate (Oncovin), and prednisone with variable response and complications.Conclusion
In our experience, the early development of EBV-related PTLD was a highly aggressive, life-threatening condition, which exclusively affected young CF patients in the early post-transplant period. The rate of this complication was relatively high in our population.Diagnosis with lung biopsy is crucial in all suspected cases and regular monitoring of EBV DNA levels is of utmost importance given the high correlation with PTLDs in patients at increased risk. 相似文献62.
Neuroinflammation is initiated as a result of traumatic brain injury and can exacerbate evolving tissue pathology. Immune cells respond to acute signals from damaged cells, initiate neuroinflammation, and drive the pathological consequences over time. Importantly, the mechanism(s) of injury, the location of the immune cells within the brain, and the animal species all contribute to immune cell behavior following traumatic brain injury. Understanding the signals that initiate neuroinflammation and the context in which they appear may be critical for understanding immune cell contributions to pathology and regeneration.Within this paper, we review a number of factors that could affect immune cell behavior acutely following traumatic brain injury. 相似文献
63.
S. Fatahi M. Pezeshki S.M. Mousavi A. Teymouri J. Rahmani H. Kord Varkaneh E. Ghaedi 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(5):432-439
Background and aim
Given the contradictory results of previous randomized controlled trials (RCTs), we performed a systematic review and meta-analysis to quantify and summarize the effects of folic acid supplementation on C-reactive protein (CRP).Methods and results
We performed a systematic search of all available RCTs conducted up to October 2018 in the following databases: PubMed, Scopus, and Cochrane. RCTs that investigated the effect of folate on CRP were included in the present study. Data were combined with the use of generic inverse-variance random-effects models. Statistical heterogeneity between studies was evaluated using Cochran's Q-test. Ten RCTs (1179 subjects) were included in the present meta-analysis. Pooled analysis results showed that folate supplementation significantly lowered the serum CRP level (weighted mean difference (WMD): ?0.685 mg/l, 95% CI: ?1.053, ?0.318, p < 0.001). However, heterogeneity was significant (I2 = 96.7%, p = 0.000). Stratified analyses indicated that sex, intervention period, and type of study population were sources of heterogeneity. Following analysis, results revealed that the greatest impact was observed in women (WMD: ?0.967 mg/l, 95% CI: ?1.101, ?0.833, p = 0.000), patients with type 2 diabetes mellitus (WMD: ?1.764 mg/l, 95% CI: ?2.002, ?1.526, p = 0.000), and intervention period less than 12 weeks (WMD: ?0.742 mg/l, 95% CI: ?0.834, ?0.650, p = 0.000).Conclusion
This meta-analysis suggested that folic acid supplementation could significantly lower the serum CRP level. Folic acid leads to greater CRP lowering effect in women, patients with T2DM, and those with less than 12-week intervention. 相似文献64.
Matthew E. Modes Ruth A. Engelberg Lois Downey Elizabeth L. Nielsen J. Randall Curtis Erin K. Kross 《Journal of pain and symptom management》2019,57(2):251-259
Context
Goals-of-care discussions are associated with improved end-of-life care for patients and therefore may be used as a process measure in quality improvement, research, and reimbursement programs.Objectives
To examine three methods to assess occurrence of a goals-of-care discussion—patient report, clinician report, and documentation in the electronic health record (EHR)—at a clinic visit for seriously ill patients and determine whether each method is associated with patient-reported receipt of goal-concordant care.Methods
We conducted a secondary analysis of a multicenter cluster-randomized trial, with 494 patients and 124 clinicians caring for them. Self-reported surveys collected from patients and clinicians two weeks after a clinic visit assessed occurrence of a goals-of-care discussion. Documentation of a goals-of-care discussion was abstracted from the EHR. Patient-reported receipt of goal-concordant care was assessed by survey two weeks after the visit.Results
Fifty-two percent of patients reported occurrence of a goals-of-care discussion at the clinic visit; clinicians reported occurrence of a discussion at 66% of visits. EHR documentation occurred in 42% of visits (P < 0.001 for each compared with other two). Patients who reported occurrence of a goals-of-care discussion at the visit were more likely to report receipt of goal-concordant care than patients who reported no discussion (β 0.441, 95% CI 0.190–0.692; P = 0.001). Neither occurrence of a discussion by clinician report nor by EHR documentation was associated with goal-concordant care.Conclusion
Different approaches to assess goals-of-care discussions give differing results, yet each may have advantages. Patient report is most likely to correlate with patient-reported receipt of goal-concordant care. 相似文献65.
Alison Connolly Kate Jones Ioannis Basinas Karen S. Galea Laura Kenny Padraic McGowan Marie A. Coggins 《International journal of hygiene and environmental health》2019,222(2):205-210
Background
The International Agency for Research on Cancer (IARC) has recently classified glyphosate as a Group 2A ‘probably carcinogenic to humans’. Due to this carcinogenic classification and resulting international debate, there is an increased demand for studies evaluating human health effects from glyphosate exposures. There is currently limited information on human exposures to glyphosate and a paucity of data regarding glyphosate's biological half-life in humans.Objective
This study aims to estimate the human half-life of glyphosate from human urine samples collected from amenity horticulture workers using glyphosate based pesticide products.Methods
Full void urine spot samples were collected over a period of approximately 24?h for eight work tasks involving seven workers. The elimination time and estimation of the half-life of glyphosate using three different measurement metrics: the unadjusted glyphosate concentrations, creatinine corrected concentrations and by using Urinary Excretion Rates (UER) (μg L?1, μmol/mol creatinine and UER μg L?1) was calculated by summary and linear interpolation using regression analysis.Results
This study estimates the human biological half-life of glyphosate as approximately 5 ½, 10 and 7 ¼ hours for unadjusted samples, creatinine corrected concentrations and by using UER (μg L?1, μmol/mol creatinine, UER μg L?1), respectively. The approximated glyphosate half-life calculations seem to have less variability when using the UER compared to the other measuring metrics.Conclusion
This study provides new information on the elimination rate of glyphosate and an approximate biological half-life range for humans. This information can help optimise the design of sampling strategies, as well as assisting in the interpretation of results for human biomonitoring studies involving this active ingredient. The data could also contribute to the development or refinement of Physiologically Based PharmacoKinetic (PBPK) models for glyphosate. 相似文献66.
Elizabeth A. Schoenfeld Kate Bennett Katy Manganella Gage Kemp 《Child Care in Practice》2019,25(1):112-125
ABSTRACTEach year, over 600 youth under the age of 25 experience literal homelessness in Austin, Texas. Of these youth, 76% have a history of involvement with foster care or the juvenile justice system—far exceeding the rates of system involvement observed among homeless youth in other large communities in the United States (approximately 54%; Voices of Youth Count, 2017). Recently, Austin was selected by the U.S. Department of Housing & Urban Development as one of ten communities nationwide to participate in the Youth Homelessness Demonstration Program (YHDP), a federal initiative designed to effectively end youth homelessness by 2020. Youth with lived experience are central players in the development and implementation of Austin's response to the youth homelessness crisis. A group of twelve of these youth (the “Austin Youth Collective to End Youth Homelessness,” or AYC) serve as key decision-making partners within the Austin YHDP team. Representatives of the AYC are deeply involved at every level of the community planning process, from the development of youth-centric housing options to system redesign efforts to ensure that youth do not exit the foster care or juvenile justice systems to homelessness. The article provides an overview of the development and contributions of the AYC—including their programmatic recommendations and advocacy work—as well as key recommendations for communities looking to leverage youth voice at the systems level. 相似文献
67.
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68.
Maria del Mar Bibiloni Jordi Fernández-Blanco Noemí Pujol-Plana Sònia Surià Sonet Maria Cèlia Pujol-Puyané Sílvia Mercadé Fuentes Laura Ojer Fernández de Soto Josep A. Tur 《Gaceta sanitaria / S.E.S.P.A.S》2019,33(2)
Objective
To assess a 6-month nutritional and physical activity intervention program on the nutritional status of overweight or obese and not very active 8-14 years old children by means of a controlled pre-post design (ACTIVA’T program).Method
Pre-post study in 8-14 years old overweight or obese and low active children from Vilafranca del Penedès (Barcelona, Spain) randomized in control group (n = 51, 47.1% girls, nutritional intervention and ≤3 h/wk physical activity) and ACTIVA’T group (n = 45, 37.8% girls, nutritional and physical activity ≥5 h/wk intervention). Body mass index, waist/height index, and diet quality by means of KIDMED test at the beginning and at the end of the program were assessed. During the intervention, each participant was accompanied by a relative (father or mother) who performed the same activities as the children.Results
Dietary recommendations have positively changed the habits of both ACTIVA’T and control group. The reversion in the prevalence of overweight and obesity was 93.8% and 58.6%, respectively, in the ACTIVA’T group, compared to 25.0% and 35.8% in the control group. Abdominal obesity was decreased from 42.2% to 17.8% in the ACTIVA’T group and from 47.1% to 27.5% in the control group.Conclusions
The program ACTIVA’T (nutritional education and physical activity promotion) improves the quality of diet and reverses the prevalence of overweight and obesity in the underactive child population. 相似文献69.
Trevor J. Royce Adam S. Feldman Matthew Mossanen Joanna C. Yang William U. Shipley Pari V. Pandharipande Jason A. Efstathiou 《Clinical genitourinary cancer》2019,17(1):23-31.e3
Introduction
There are limited randomized data comparing radical cystectomy (RC) with bladder-sparing tri-modality therapy (TMT) in the treatment of muscle-invasive bladder cancer (MIBC). Both strategies are thought to have similar survival outcomes with different morbidity profiles. We compare the effectiveness of TMT and RC using decision-analytic modeling and the endpoint of quality-adjusted life years (QALYs).Patients and Methods
Using a Markov model, we simulated the lifetime outcomes after TMT versus RC ± neoadjuvant chemotherapy for 67-year-old patients with clinical stage T2-T4aN0M0 MIBC. Model probabilities and utilities were extracted from the literature. The incremental effectiveness was reported in QALYs and sensitivity analyses were performed.Results
For all patients with MIBC, although the model showed identical survival, TMT was the most effective strategy with an incremental gain of 0.59 QALYs over RC (7.83 vs. 7.24 QALYs, respectively). When limiting the model to favorable, contemporary cohorts in both the TMT and RC strategies, TMT remained more effective with an incremental gain of 1.61 QALYs (9.37 vs. 7.76 QALYs, respectively). One-way sensitivity analyses demonstrated the model was sensitive to the quality of life parameters (ie, the utilities) for RC and TMT. When testing the 95% confidence interval of the RC utility parameter the model demonstrated an incremental gain with TMT from ?0.54 to 4.23 QALYs. Probabilistic sensitivity analysis demonstrated that TMT was more effective than RC for 63% of model iterations.Conclusions
This modeling study found that treatment of MIBC with organ-sparing TMT in appropriately-selected patients may result in a gain of QALYs relative to RC. 相似文献70.
Shulin Wu Sharron X. Lin Gregory J. Wirth Min Lu Jian Lu Alexander O. Subtelny Zongwei Wang Douglas M. Dahl Aria F. Olumi Chin-Lee Wu 《Clinical genitourinary cancer》2019,17(1):e44-e52