全文获取类型
收费全文 | 3554622篇 |
免费 | 248725篇 |
国内免费 | 6764篇 |
专业分类
耳鼻咽喉 | 50050篇 |
儿科学 | 112489篇 |
妇产科学 | 94823篇 |
基础医学 | 497344篇 |
口腔科学 | 103429篇 |
临床医学 | 322421篇 |
内科学 | 684320篇 |
皮肤病学 | 75159篇 |
神经病学 | 287810篇 |
特种医学 | 136908篇 |
外国民族医学 | 1094篇 |
外科学 | 532373篇 |
综合类 | 84167篇 |
现状与发展 | 5篇 |
一般理论 | 1412篇 |
预防医学 | 279877篇 |
眼科学 | 84769篇 |
药学 | 263477篇 |
87篇 | |
中国医学 | 7497篇 |
肿瘤学 | 190600篇 |
出版年
2018年 | 37864篇 |
2017年 | 28990篇 |
2016年 | 32087篇 |
2015年 | 36209篇 |
2014年 | 51421篇 |
2013年 | 77268篇 |
2012年 | 105188篇 |
2011年 | 111216篇 |
2010年 | 65838篇 |
2009年 | 62164篇 |
2008年 | 104479篇 |
2007年 | 111305篇 |
2006年 | 112267篇 |
2005年 | 108902篇 |
2004年 | 104963篇 |
2003年 | 100679篇 |
2002年 | 98450篇 |
2001年 | 166980篇 |
2000年 | 172220篇 |
1999年 | 144987篇 |
1998年 | 41226篇 |
1997年 | 36770篇 |
1996年 | 36423篇 |
1995年 | 35231篇 |
1994年 | 32893篇 |
1993年 | 30485篇 |
1992年 | 114964篇 |
1991年 | 111299篇 |
1990年 | 107404篇 |
1989年 | 103760篇 |
1988年 | 95824篇 |
1987年 | 94116篇 |
1986年 | 88966篇 |
1985年 | 84888篇 |
1984年 | 63932篇 |
1983年 | 54502篇 |
1982年 | 32285篇 |
1981年 | 28844篇 |
1979年 | 58902篇 |
1978年 | 41188篇 |
1977年 | 34963篇 |
1976年 | 32728篇 |
1975年 | 34548篇 |
1974年 | 42517篇 |
1973年 | 40556篇 |
1972年 | 37969篇 |
1971年 | 35074篇 |
1970年 | 32959篇 |
1969年 | 30639篇 |
1968年 | 28143篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
M. Tobias Heinrichs George L. Drusano David L. Brown Michael S. Maynard Sherwin K.B. Sy Kenneth H. Rand Charles A. Peloquin Arnold Louie Hartmut Derendorf 《International journal of antimicrobial agents》2019,53(3):275-283
Introduction
There is an urgent need for new anti-tuberculosis (TB) drugs and optimization of current TB treatment. Moxifloxacin and linezolid are valuable options for the treatment of drug-resistant TB; however, it is crucial to find a dose at which these drugs not only show high efficacy but also suppress the development of further drug resistance.Methods
Activity of moxifloxacin and linezolid against Mycobacterium tuberculosis was studied in the hollow-fiber infection model system in log-phase growth under neutral pH and slow growth in an acidic environment. Doses that achieved maximum bacterial kill while suppressing the emergence of drug resistance were determined. Through Monte Carlo simulations the quantitative output of this in vitro study was bridged to the human patient population to inform optimal dosage regimens while accounting for clinical minimum inhibitory concentration (MIC) distributions.Results and Discussion
Moxifloxacin activity was significantly decreased in an acidified environment. The loss of activity was compensated by accumulation of the drug in TB lung lesions; therefore, moderate efficacy can be expected. Moxifloxacin 800 mg/day is the dose that most likely leads to resistance suppression while exerting maximum bacterial kill. Linezolid demonstrated very good activity even at a reduced pH. Linezolid 900 mg once-daily (QD) is likely to achieve a maximum killing effect and prevent the emergence of drug resistance; 600 mg QD in a robust drug regimen may have similar potential. 相似文献102.
P. Herent B. Schmauch P. Jehanno O. Dehaene C. Saillard C. Balleyguier J. Arfi-Rouche S. Jégou 《Diagnostic and interventional imaging》2019,100(4):219-225
Purpose
The purpose of this study was to assess the potential of a deep learning model to discriminate between benign and malignant breast lesions using magnetic resonance imaging (MRI) and characterize different histological subtypes of breast lesions.Materials and methods
We developed a deep learning model that simultaneously learns to detect lesions and characterize them. We created a lesion-characterization model based on a single two-dimensional T1-weighted fat suppressed MR image obtained after intravenous administration of a gadolinium chelate selected by radiologists. The data included 335 MR images from 335 patients, representing 17 different histological subtypes of breast lesions grouped into four categories (mammary gland, benign lesions, invasive ductal carcinoma and other malignant lesions). Algorithm performance was evaluated on an independent test set of 168 MR images using weighted sums of the area under the curve (AUC) scores.Results
We obtained a cross-validation score of 0.817 weighted average receiver operating characteristic (ROC)-AUC on the training set computed as the mean of three-shuffle three-fold cross-validation. Our model reached a weighted mean AUC of 0.816 on the independent challenge test set.Conclusion
This study shows good performance of a supervised-attention model with deep learning for breast MRI. This method should be validated on a larger and independent cohort. 相似文献103.
Andrew J Lindford Heikki Mäkisalo Hannu Jalanko Jouni Lauronen Veli-Jukka Anttila Susanna Juteau Antti-Jussi Ämmälä Anna Eskola Samuli Saarni Helena Isoniemi Antti Mäkitie Patrik Lassus 《Journal of plastic, reconstructive & aesthetic surgery》2019,72(2):173-180
Aim
We herein describe the establishment of the Helsinki Vascularized Composite Allotransplantation (VCA) program and its execution in the first two face transplant cases.Methods & patients
The Helsinki VCA program initially required the fulfillment of legal, hospital, financial, and ethical requirements. Thereafter, the assembling of a multidisciplinary team commenced. A team of Plastic, maxillofacial and ENT surgeons comprise the facial VCA team. The protocol involves collaboration with the Solid Organ Transplant (SOT) team, transplant immunology, immunosuppression, microbiology, psychiatric evaluation, well-defined VCA indications and informed consent. Between 2011 and 2017 two patients were selected for transplantation. Both patients had a severe composite facial deformity involving the maxilla and mandible following earlier ballistic injury.Results
Patient 1 was a 35 year-old male who underwent successful near total face transplantation in February 2016 and at 30 months he has a good aesthetic outcome with symmetrical restoration of the central face and good sensory and symmetrical motor functional outcomes. Patient 2 was a 58 year-old male who underwent full face transplantation in March 2018 and at 5 months he has recovered without major problems.Conclusion
A successful facial VCA program requires a well-prepared research protocol, experts from multiple specialties and careful patient selection. The establishment of the Helsinki VCA program required long and thorough planning and resulted in the first two Nordic face transplantation cases. This protocol now forms the platform (as a proof of concept) for other types of vascularized composite allotransplantations. 相似文献104.
105.
V. Jenkins I. Solis-Trapala H. Payne M. Mason L. Fallowfield S. May L. Matthews S. Catt 《Clinical oncology (Royal College of Radiologists (Great Britain))》2019,31(2):99-107
Aims
Delaying progression, ameliorating symptoms and maintaining quality of life (QoL) are primary aims of treatment for metastatic castrate-resistant prostate cancer (mCRPC). Real-world rather than clinical trial data about symptoms and side-effects are sparse. In EXTREQOL, patients' QoL, pain and information needs were recorded during treatment.Material and methods
Men with mCRPC from 20 UK cancer centres starting various systemic mCRPC treatments completed QoL, pain and information needs questionnaires at baseline, 3 and 6 months.Results
In total, 132 patients were recruited. Overall QoL declined significantly by 6 months (Functional Assessment of Cancer Therapy-Prostate [FACT-P] mean = –3.89, 95% confidence interval –6.7 to –1.05, P = 0.007; Trial Outcome Index [TOI] analysis mean = –3.10, 95% confidence interval –5.34 to –0.83, P = 0.007). Those who came off novel therapy and remained on luteinising hormone-releasing hormone agonist therapy alone had worse scores than patients receiving concomitant chemotherapy (Prostate Concerns Subscale mean difference = –4.45, 95% confidence interval –7.06 to –1.83, P = 0.001; TOI mean difference = –5.62, 95% confidence interval –10.97 to –0.26, P = 0.040). At 3 and 6 months, men who reported pain at baseline improved (43%, 40%), but for others pain levels remained the same (45%, 42%) or worsened (13%, 18%). Information regarding supportive care was lacking throughout the period of time on the study.Conclusion
Most mCRPC treated patients experience reduced QoL and inadequate pain control. More help with pain management and better information provision regarding supportive care is warranted. 相似文献106.
K.A. Lee M.T.A. Sharabiani D. Tumino J. Wadsley V. Gill G. Gerrard R. Sindhu M.N. Gaze L. Moss K. Newbold 《Clinical oncology (Royal College of Radiologists (Great Britain))》2019,31(6):385-390
Aims
To obtain an overview of the management and outcomes of children aged 18 years or younger diagnosed with differentiated thyroid carcinoma of follicular cell origin across the UK, by collecting and analysing data from the limited number of centres treating these patients. This multicentre data might provide a more realistic perspective than single-institution series.Materials and methods
Six centres submitted data extracted from historical records on patients aged 18 years or younger, diagnosed between 1964 and 2017. The univariate and multivariable Cox proportional hazard model was used to identify potential predictors of progression-free survival, using national data as a control.Results
Data on 166 patients were available for analysis. Females (74%) were predominant, and the age ranged from 3 to 19 years at diagnosis, mean 14.1 years. Nodal metastases were present in 51%; 12% had distant metastases. After surgery, 95% received radioactive iodine (39% on more than one occasion) and 4% received external beam radiotherapy. With a median follow-up duration of 5 years, 69% are alive with no evidence of disease; 20% are alive with a raised thyroglobulin level as the only evidence of residual disease; 6% have residual structural disease detectable on imaging; 2% have died, from cerebral metastases.Conclusion
Despite most patients having advanced disease at presentation, outcomes are very good. A national prospective registry should allow systematic collection of good-quality data and may facilitate research to further improve outcomes. 相似文献107.
Edward J.A. Harris Steven Kao Brian McCaughan Takashi Nakano Nobuyuki Kondo Rebecca Hyland Anna K. Nowak Nicholas H. de Klerk Fraser J.H. Brims 《Journal of thoracic oncology》2019,14(2):288-293
Introduction
Malignant pleural mesothelioma (MPM) is an uncommon cancer with a poor prognosis and heterogeneous survival. Surgery for MPM is offered in some specialist centers to highly selected patients. A previously described classification and regression tree (CART) model stratified survival in unselected MPM patients using routinely collected clinical data. This study aimed to examine the performance of this CART model on a highly selected surgical population.Methods
Data were collected from subjects undergoing cytoreductive surgery for MPM from specialist centers in Hyõgo, Japan, and Sydney, Australia, between 1991 and 2016. The CART model was applied using the combination of clinical variables to stratify subjects into risk groups (1 through 4); survival characteristics were then compared.Results
Two hundred eighty-nine cases were included (205 from Australia, 84 from Japan). Overall median survival was 34.6 (interquartile range: 17.5–56.1) months; median age was 63.0 (interquartile range: 57.0–67.8) years, and 83.0% (n = 240) were male. There were no clinically meaningful differences between the two cohorts. Survival across the four risk groups was significantly different (p < 0.0001); the model stratified survival well with a Harrell's concordance statistic of 0.62 (95% confidence interval: 0.57–0.66) at 36 months. The group with the longest survival (median, 82.5 months) had: no weight loss, hemoglobin > 153 g/L and serum albumin > 43 g/L at time of referral to the surgical center.Conclusions
Using routinely available clinical variables, the CART model was able to stratify surgical patients into risk groups with statistically different survival characteristics with fair to good performance. Presence of weight loss, anemia, and low albumin should confer caution when considering surgical therapy for MPM. 相似文献108.
109.
Sabin J. Bozso Jeevan Nagendran Michael W.A. Chu Bob Kiaii Ismail El-Hamamsy Maral Ouzounian Jörg Kempfert Christoph Starck Michael C. Moon 《The Annals of thoracic surgery》2021,111(2):463-470
- Download : Download high-res image (134KB)
- Download : Download full-size image