全文获取类型
收费全文 | 11277篇 |
免费 | 654篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 229篇 |
妇产科学 | 162篇 |
基础医学 | 1891篇 |
口腔科学 | 140篇 |
临床医学 | 1043篇 |
内科学 | 2591篇 |
皮肤病学 | 287篇 |
神经病学 | 1215篇 |
特种医学 | 649篇 |
外科学 | 1766篇 |
综合类 | 79篇 |
一般理论 | 2篇 |
预防医学 | 438篇 |
眼科学 | 182篇 |
药学 | 564篇 |
中国医学 | 9篇 |
肿瘤学 | 613篇 |
出版年
2023年 | 69篇 |
2022年 | 90篇 |
2021年 | 220篇 |
2020年 | 141篇 |
2019年 | 197篇 |
2018年 | 219篇 |
2017年 | 216篇 |
2016年 | 287篇 |
2015年 | 299篇 |
2014年 | 344篇 |
2013年 | 418篇 |
2012年 | 666篇 |
2011年 | 765篇 |
2010年 | 465篇 |
2009年 | 464篇 |
2008年 | 683篇 |
2007年 | 732篇 |
2006年 | 649篇 |
2005年 | 703篇 |
2004年 | 670篇 |
2003年 | 619篇 |
2002年 | 630篇 |
2001年 | 144篇 |
2000年 | 150篇 |
1999年 | 165篇 |
1998年 | 158篇 |
1997年 | 139篇 |
1996年 | 109篇 |
1995年 | 96篇 |
1994年 | 71篇 |
1993年 | 80篇 |
1992年 | 78篇 |
1991年 | 71篇 |
1990年 | 50篇 |
1989年 | 56篇 |
1988年 | 61篇 |
1987年 | 38篇 |
1986年 | 41篇 |
1985年 | 57篇 |
1984年 | 41篇 |
1983年 | 41篇 |
1982年 | 30篇 |
1981年 | 28篇 |
1979年 | 25篇 |
1978年 | 33篇 |
1977年 | 25篇 |
1975年 | 21篇 |
1972年 | 24篇 |
1971年 | 26篇 |
1969年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Martin R. Späth Malte P. Bartram Nicolàs Palacio-Escat K. Johanna R. Hoyer Cedric Debes Fatih Demir Christina B. Schroeter Amrei M. Mandel Franziska Grundmann Giuliano Ciarimboli Andreas Beyer Jayachandran N. Kizhakkedathu Susanne Brodesser Heike Göbel Jan U. Becker Thomas Benzing Bernhard Schermer Martin Höhne Markus M. Rinschen 《Kidney international》2019,95(2):333-349
3.
4.
Stefan Scholz Florian Koerber Kinga Meszaros Rosa Maya Fassbender Bernhard Ultsch Robert R. Welte Wolfgang Greiner 《Vaccine》2019,37(12):1692-1701
Introduction
Invasive meningococcal disease (IMD) is a severe disease mainly affecting infants and young children. The most common serogroup causing IMD in Germany is the serogroup type B Neisseria meningitidis (MenB). The aim of the present study is to estimate the economic burden of MenB-related IMD in Germany.Method
A bottom-up, model-based costing approach has been used to calculate the diagnose- and age-specific yearly lifetime costs of a hypothetical cohort of MenB-related IMD cases. Direct costs contain the treatment cost for the acute phase of the disease, long-term sequelae, costs for rehabilitation, and public health response. Indirect costs are calculated for the human-capital approach and the friction-cost approach considering productivity losses of patients or parents for the acute phase and long-term sequelae. Publicly available databases from the Federal Statistical Office, the SOEP panel data set, literature, and expert opinion were used as data sources. All future costs beyond the reference year of 2015 were discounted at 3%.Results
The total costs for the hypothetical cohort (343 patients) from a societal perspective are €19.6 million (€57,100/IMD case) using the friction-cost approach and €58.8 million (€171,000/IMD case) using the human-capital approach. Direct costs amount to €18.6 million or €54,300 €/case. Sequelae are responsible for 81% of the direct costs/case.Discussion
The elevated costs/MenB-related IMD case reflect the severity of the disease. The total costs are sensitive to the productivity-loss estimation approach applied. MenB is an uncommon but severe disease; The costs/case reflect the severity of the disease and is within the same magnitude as for human papilloma virus infections. The available literature on sequelae is due to the uncommonness limited and heterogeneous. 相似文献5.
Anna C. Rienmüller Sandro M. Krieg Franziska A. Schmidt Elias L. Meyer Bernhard Meyer 《The spine journal》2019,19(1):113-120
Background Context
The concept of dynamic stabilization (DS) of the lumbar spine for treatment of degenerative instability has been introduced almost two decades ago. Dynamic stabilization follows the principle of controlling movement in the coronal plane by providing load transfer of the spinal segment without fusion and, at the same time, reducing side effects such as adjacent segment disease (ASD). So far, only little is known about revision rates after DS due to ASD and screw loosening (SL).Purpose
The present study aimed to evaluate the longitudinal revision rates following dynamic pedicle screw stabilization in the lumbar spine and to determine specific risk factors predictive for ASD, SL, and overall reoperation in a large cohort with considerable follow-up.Design
We carried out a post hoc analysis of a prospectively collected database in a level I spine center.Patients Example
The patient sample comprised 283 (151 female/132 male) consecutive patients suffering from painful degenerative lumbar segmental instability with or without spinal stenosis who underwent DS of the lumbar spine (Ulrich Cosmic, Ulrich Medical, Ulm, Germany) between January 2008 and December 2011.Outcome Measures
Longitudinal reoperation rate and risk factors predictive for revision surgery were evaluated.Methods
We analyzed the longitudinal reoperation rate due to ASD and SL and overall reoperation. Risk factors such as age, gender, body mass index, lumbar lordosis (LL), number of segments, and number of previous surgeries were taken into account. Regular and mixed model logistic regressions were performed to determine risk factors for revision surgery on a patient and on a screw level.Results
The mean age was 65.7±10.2 years (range 31–88). One hundred thirty-two patients were stabilized in 1 segment, 134 in 2 segments, 15 in 3 segments, and 2 patients in 4 segments. Reoperation rate for ASD and SL after 1 year was 7.4 %, after 2 years was 15.0%, and after a mean follow-up of 51.4±15 months was 22.6%. Reasons for revision were SL in 19 cases (6.6%), ASD in 39 cases (13.7%), SL and ASD in 6 cases, hematoma in 2 cases (0.7%), cerebrospinal fluid fistulae in 3 cases (1.1%), infection in 6 cases (2.1%), and implant failure in 1 case (0.4%). The patients' age, the number of stabilized segments, and the number of previous surgeries and postoperative LL had a significant influence on the probability for revision surgery.Conclusions
Reoperation rates after DS of the lumbar spine are comparable with rigid fixations. The younger the patient and the more segments are involved, the lower the LL and the more previous surgeries were found, the higher was the risk of revision. Risk of revision was almost twice as high in men compared with women. We therefore conclude that for clear clinical indication and careful evaluation of preoperative imaging data, DS using the Cosmic system seems to be a possible option. The presented data will help to further tailor indication and patient selection. 相似文献6.
Marco Maruzzo Umberto Basso Eugenio Borsatti Laura Evangelista Filippo Alongi Orazio Caffo Francesca Maines Sara Galuppo Rocco De Vivo Fable Zustovich Dario Palleschi Andrea Zivi Teodoro Sava Mariella Sorarù Roberto Iacovelli Maurizio Nicodemo Susanne Baier Lucia Fratino Vittorina Zagonel 《Clinical genitourinary cancer》2019,17(1):e187-e194
Background
Radium 223 was introduced for metastatic castration-resistant prostate cancer based on the results of a randomized controlled trial showing risk reduction for death and skeletal events. Our aim was to evaluate the outcome of patients receiving radium 223 in a real-world setting.Patients and Methods
We conducted a multicenter retrospective analysis in the Triveneto region of Italy.Results
One hundred fifty-eight patients received radium 223 in our region. After a median follow-up of 9.5 months, 75 patients died. The median overall survival (OS) was 14.2 months, and the median progression-free survival (PFS) was 6.2 months. Seventy-one (45%) patients achieved progression as best response. Thirty-seven (23%) patients stopped the treatment early because of progression. Eastern Cooperative Oncology Group performance status was prognostic for OS (18.4 vs. 12.3 vs. 7.5 months; 0 vs. 1, P = .0062; 0 vs. 2, P = .0002), whereas previous prostatectomy or docetaxel exposure were not. A neutrophil to lymphocytes ratio ≥ 3 significantly impacted OS (18.1 vs. 9.7 months; P < .001) and slightly impacted PFS (6.6 vs. 5.6 months; P = .05). Patients with a baseline alkaline phosphatase (ALP) value ≥ 220 U/L had worse OS and PFS (24.1 vs. 10.5 months; 7.2 vs. 5.5 months; P < .001). Patients with changes in ALP value achieved better OS (P = .029) and PFS (P = .002). There was no difference according to the line of therapy (0 vs. ≥ 1; P = .490). The main grade 3/4 toxicities were anemia, asthenia, and thrombocytopenia.Conclusion
This large real-world report confirms comparable OS and PFS data when compared with the pivotal study, as well as the predictive role of ALP and neutrophil to lymphocytes ratio. The definition of the optimal position of radium 223 in the treatment of metastatic castration-resistant prostate cancer has still to be defined. 相似文献7.
8.
Intramedullary nailing implants have now assumed the first place in the treatment of pertrochanteric fractures.The reasons for their popularity are their high fatigue strength and the minimally invasive surgical technique required for their use.These advantages are of great benefit to the mainly geriatric and frequently multitraumatized patients concerned.The main device in this implant group is the gamma nail, which was originally developed by Grosse and Kempf. The gamma nail yielded results superior to those obtained with the dynamic hip screw, which had been the standard so far, especially when it was used in the treatment of unstable fractures.Although there was some vigorous debate over the original principles of the gamma nail, the current system is widely accepted and is available in different variants.However,owing to the high complication rate when the system was first introduced, the original gamma nail acquired the reputation of being an implant whose use made high demands.The critical analysis of implant-specific problems associated with the original gamma nail resulted in improvements to the implant and the instruments, with a noticeably reduced complication rate and better surgical technique.This article describes its current state of development.The various components are discussed individually. The results of our own investigation appear at the end of the report, reflecting this development process. 相似文献
9.
10.