全文获取类型
| 收费全文 | 1800627篇 |
| 免费 | 131452篇 |
| 国内免费 | 3971篇 |
专业分类
| 耳鼻咽喉 | 22757篇 |
| 儿科学 | 58488篇 |
| 妇产科学 | 48360篇 |
| 基础医学 | 257466篇 |
| 口腔科学 | 51613篇 |
| 临床医学 | 160364篇 |
| 内科学 | 354514篇 |
| 皮肤病学 | 40411篇 |
| 神经病学 | 141222篇 |
| 特种医学 | 68263篇 |
| 外国民族医学 | 251篇 |
| 外科学 | 270429篇 |
| 综合类 | 39394篇 |
| 现状与发展 | 5篇 |
| 一般理论 | 628篇 |
| 预防医学 | 136865篇 |
| 眼科学 | 41912篇 |
| 药学 | 130016篇 |
| 7篇 | |
| 中国医学 | 4654篇 |
| 肿瘤学 | 108431篇 |
出版年
| 2021年 | 14418篇 |
| 2019年 | 15192篇 |
| 2018年 | 22006篇 |
| 2017年 | 16969篇 |
| 2016年 | 18578篇 |
| 2015年 | 21112篇 |
| 2014年 | 29196篇 |
| 2013年 | 41945篇 |
| 2012年 | 58858篇 |
| 2011年 | 61623篇 |
| 2010年 | 36073篇 |
| 2009年 | 34087篇 |
| 2008年 | 57042篇 |
| 2007年 | 60549篇 |
| 2006年 | 60807篇 |
| 2005年 | 57811篇 |
| 2004年 | 55271篇 |
| 2003年 | 52405篇 |
| 2002年 | 50265篇 |
| 2001年 | 95193篇 |
| 2000年 | 96972篇 |
| 1999年 | 80026篇 |
| 1998年 | 21053篇 |
| 1997年 | 18390篇 |
| 1996年 | 18550篇 |
| 1995年 | 17698篇 |
| 1994年 | 16166篇 |
| 1993年 | 14879篇 |
| 1992年 | 59580篇 |
| 1991年 | 57278篇 |
| 1990年 | 54856篇 |
| 1989年 | 52550篇 |
| 1988年 | 47804篇 |
| 1987年 | 46412篇 |
| 1986年 | 43631篇 |
| 1985年 | 41315篇 |
| 1984年 | 30307篇 |
| 1983年 | 25734篇 |
| 1982年 | 14366篇 |
| 1981年 | 12793篇 |
| 1979年 | 26277篇 |
| 1978年 | 18023篇 |
| 1977年 | 15276篇 |
| 1976年 | 14160篇 |
| 1975年 | 14879篇 |
| 1974年 | 18019篇 |
| 1973年 | 17310篇 |
| 1972年 | 16002篇 |
| 1971年 | 14775篇 |
| 1970年 | 13679篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
71.
K.-C. Sung D.-C. Seo S.-J. Lee M.-Y. Lee S.H. Wild C.D. Byrne 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(5):489-495
Background and aims
It is not known whether non alcoholic fatty liver disease (NAFLD) is a risk factor for diabetes in non obese, non centrally-obese subjects. Our aim was to investigate relationships between fatty liver, insulin resistance and a biomarker score for liver fibrosis with incident diabetes at follow up, in subjects who were neither obese nor centrally-obese.Methods and results
As many as 70,303 subjects with a body mass index (BMI) < 25 kg/m2 and without diabetes were followed up for a maximum of 7.9 years. At baseline, fatty liver was identified by liver ultrasound, insulin resistance (IR) by homeostatic model assessment of insulin resistance (HOMA-IR) ≥2.0, and central obesity by waist circumference (waist circumference ≥90 cm (men) and ≥85 cm (women). The Fibrosis-4 (FIB-4 score) was used to estimate extent of liver fibrosis. Cox proportional hazards models adjusted for confounders were used to estimate hazard ratios (aHRs) for incident diabetes. As many as 852 incident cases of diabetes occurred during follow up (median [IQR] 3.71 [2.03] years). Mean ± SD BMI was 22.8 ± 1.8 and 21.7 ± 2.0 kg/m2 in subjects with and without diabetes at follow up. In subjects without central obesity and with fatty liver, aHRs (95% CI) for incident diabetes at follow up were 2.17 (1.56, 3.03) for men, and 2.86 (1.50,5.46) for women. Similar aHRs for incident diabetes occurred with fatty liver, IR and the highest quartile of FIB-4 combined, in men; and there was a non significant trend toward increased risk in women.Conclusions
In normal weight, non-centrally obese subjects NAFLD is an independent risk factor for incident diabetes. 相似文献72.
73.
Eduardo H. Umeoka Matheus C. Eiras Iara G. Viana Vanessa S. Giorgi Aline Bueno Débora C. Damasceno 《Systems biology in reproductive medicine》2019,65(1):87-94
Wistar Audiogenic Rat (WAR) strain is an animal model for epilepsy studies, the chronic multifactorial disease that affects millions of people worldwide. The animals of this strain are genetically predisposed to sound-induced seizures, called audiogenic seizures, and have been used for many years in studies to understand the mechanisms involved in the epilepsies and their neuropsychiatric comorbidities, as well as the screening of potential anti-convulsant agents. Nevertheless, little is known about the reproductive characteristics of these animals. The main goal of this study was to characterize the female reproductive performance and the fetal growth of WARs in comparison to the Wistar rats, obtaining important information for physiology and behavioral studies, as well as for the preservation of the strain. The results indicated few differences between WAR and Wistar regarding the female reproductive performance. There was no significant difference in the number of pregnant females by mating, number of live births per female, number of cells per blastocyst, and several characteristics related to reproductive performance, such as pre- and post-implantation losses. However, significant differences were observed in birth weight and weight gain until weaning, with WAR animals presenting a body weight below Wistar at birth and reduced body weight gain during the lactation period. In addition, the WAR females showed lower body weight on the day 20 of pregnancy and a larger number of corpora lutea, when compared with those of Wistar animals. Thus, we conclude that although Wistar and WAR strains have few differences in their reproductive performance, which might impact future physiological life challenges or others experimentally induced procedures, it still is a very viable strain regarding reproduction.
Abbreviations: CONCEA: National Council for the Control of Animal Experimentation; GEPR: genetically epilepsy-prone rats; WAR: Wistar Audiogenic Rat. 相似文献
74.
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75.
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76.
Aim: The aim of study was to investigate the opportunities of local phlebectomy in the elimination of isolated pelvic-perineal reflux (PPR), as well as to determine the feasibility of endovascular embolization of the tributaries of internal iliac veins in PPR. Clinical trial no. NCT01598051.
Materials and methods: The work is based on the results of examination and treatment of 43 female patients with varicose veins of the pelvis, perineum, and lower extremities. Patients had no signs of pelvic congestion syndrome (PCS). All patients underwent duplex ultrasound scanning (DUS) and ovariography with pelvic phlebography (OPP). For the elimination of PPR, local phlebectomy was performed in the major labia and perineal area, with maximal possible mobilization of the vessel within the operative wound (33 patients). In 10 patients with isolated varicose transformation of the superficial veins on the posterior thigh, mini-phlebectomy was performed using the Varady phlebectomy extractors.
Results and discussion: The varicose syndrome of the external genitalia, perineum, and posterior thigh was successfully treated in 100% of patients. Findings suggest that thorough mobilization and excision of the veins of the pudendal labia, perineum, and subcutaneous veins of the thigh is a reliable method for eliminating the pathological reflux from the intrapelvic veins to the superficial veins of the perineum and lower extremities. No recurrences of vulvar, perineal varices or dilation of the veins of the lower extremities were observed in 100% of patients over the 3-year follow-up period.
Conclusion: Local phlebectomy is an effective technique for eliminating the isolated PPR in patients with varicose transformation of intrapelvic, vulvar, or perineal veins. Endovascular embolization of the tributaries of the internal iliac veins is not an essential component in the treatment of PPR. The present study has a limitation due to the absence of patients with PCS. The effectiveness of phlebectomy in the treatment of isolated PPR was studied. 相似文献
77.
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78.
A. Glahn P. J. Proskynitopoulos S. Bleich T. Hillemacher 《Expert opinion on pharmacotherapy》2020,21(9):1083-1092
ABSTRACT
Introduction
Alcohol withdrawal syndrome is a common and life-threatening condition in patients suffering from alcohol use disorder. Treatment of this syndrome is challenging, especially in patients that are critically ill, either because of withdrawal symptoms or underlying conditions. For the treatment, several pharmacological agents exist, such as benzodiazepines, barbiturates, or dexmedetomidine. Nonetheless, as alcohol withdrawal syndromes can occur in every clinical setting, it is necessary to provide a guideline for clinicians confronted with this syndrome in varying clinical contexts. 相似文献79.
80.
Sarah J. Schrauben Haochang Shou Xiaoming Zhang Amanda Hyre Anderson Joseph V. Bonventre Jing Chen Steven Coca Susan L. Furth Jason H. Greenberg Orlando M. Gutierrez Joachim H. Ix James P. Lash Chirag R. Parikh Casey M. Rebholz Venkata Sabbisetti Mark J. Sarnak Michael G. Shlipak Sushrut S. Waikar Paul L. Kimmel Ramachandran S. Vasan Harold I. Feldman Jeffrey R. Schelling 《Journal of the American Society of Nephrology : JASN》2021,32(1):115