全文获取类型
收费全文 | 8538篇 |
免费 | 515篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 264篇 |
妇产科学 | 265篇 |
基础医学 | 878篇 |
口腔科学 | 139篇 |
临床医学 | 780篇 |
内科学 | 2228篇 |
皮肤病学 | 80篇 |
神经病学 | 836篇 |
特种医学 | 327篇 |
外科学 | 940篇 |
综合类 | 93篇 |
一般理论 | 6篇 |
预防医学 | 986篇 |
眼科学 | 157篇 |
药学 | 557篇 |
中国医学 | 2篇 |
肿瘤学 | 415篇 |
出版年
2024年 | 7篇 |
2023年 | 35篇 |
2022年 | 58篇 |
2021年 | 174篇 |
2020年 | 83篇 |
2019年 | 167篇 |
2018年 | 190篇 |
2017年 | 159篇 |
2016年 | 145篇 |
2015年 | 170篇 |
2014年 | 279篇 |
2013年 | 389篇 |
2012年 | 629篇 |
2011年 | 689篇 |
2010年 | 377篇 |
2009年 | 372篇 |
2008年 | 568篇 |
2007年 | 686篇 |
2006年 | 639篇 |
2005年 | 612篇 |
2004年 | 576篇 |
2003年 | 526篇 |
2002年 | 463篇 |
2001年 | 97篇 |
2000年 | 64篇 |
1999年 | 78篇 |
1998年 | 103篇 |
1997年 | 75篇 |
1996年 | 59篇 |
1995年 | 68篇 |
1994年 | 47篇 |
1993年 | 46篇 |
1992年 | 47篇 |
1991年 | 29篇 |
1990年 | 36篇 |
1989年 | 60篇 |
1988年 | 35篇 |
1987年 | 23篇 |
1986年 | 21篇 |
1985年 | 17篇 |
1984年 | 30篇 |
1983年 | 20篇 |
1982年 | 23篇 |
1981年 | 18篇 |
1980年 | 16篇 |
1979年 | 7篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1971年 | 6篇 |
排序方式: 共有9079条查询结果,搜索用时 15 毫秒
1.
2.
Xinran Liu James Anstey Ron Li Chethan Sarabu Reiri Sono Atul J. Butte 《Applied clinical informatics》2021,12(2):407
Background Machine learning (ML) has captured the attention of many clinicians who may not have formal training in this area but are otherwise increasingly exposed to ML literature that may be relevant to their clinical specialties. ML papers that follow an outcomes-based research format can be assessed using clinical research appraisal frameworks such as PICO (Population, Intervention, Comparison, Outcome). However, the PICO frameworks strain when applied to ML papers that create new ML models, which are akin to diagnostic tests. There is a need for a new framework to help assess such papers. Objective We propose a new framework to help clinicians systematically read and evaluate medical ML papers whose aim is to create a new ML model: ML-PICO (Machine Learning, Population, Identification, Crosscheck, Outcomes). We describe how the ML-PICO framework can be applied toward appraising literature describing ML models for health care. Conclusion The relevance of ML to practitioners of clinical medicine is steadily increasing with a growing body of literature. Therefore, it is increasingly important for clinicians to be familiar with how to assess and best utilize these tools. In this paper we have described a practical framework on how to read ML papers that create a new ML model (or diagnostic test): ML-PICO. We hope that this can be used by clinicians to better evaluate the quality and utility of ML papers. 相似文献
3.
4.
Kevin L Taylor Rhonda K Oates Ron Grane Douglas W Leaman Ernest C Borden Daniel J Lindner 《Journal of interferon & cytokine research》2006,26(5):353-361
Interferon-alpha (IFN-alpha) has proved effective in the treatment of hemangiomas, hemangioblastomas, and Kaposi's sarcoma. To investigate the ability of IFNs to inhibit angiosarcoma, we used two transformed murine endothelial cell lines that form angiosarcomas in vivo. SVR and MS1-VEGF cell lines express oncogenic H-ras or vascular endothelial growth factor (VEGF), respectively. IFN-alpha1,8, which is active against murine and human cells, inhibited SVR and MS1-VEGF proliferation in vitro by 40% at 10(3) U/mL (p = 0.028). In vivo, IFN-alpha1,8 inhibited SVR tumor volume by 71% (p = 0.047) and MS1-VEGF volume by 79% (p = 0.003). Tumor-induced angiogenesis was decreased in SVR tumors by 52% (p = 0.005) and in MS1-VEGF tumors by 58% (p = 0.001). Sera from IFN-alpha1,8-treated mice bearing either SVR or MS1-VEGF tumors demonstrated a 5-fold increase in IP-10/CXCL10 (p = 0.001), an IFN-induced antiangiogenic protein. Both recombinant IP-10 and IFN-alpha1,8 inhibited human umbilical vein endothelial cell (HUVEC) vessel formation in the fibrin gel assay, a three-dimensional culture model of angiogenesis, by 56% at 25 ng/mL and 50% at 1.2 ng/mL, respectively (p < 0.001). An IP-10 blocking antibody restored vessel formation to 80% of untreated controls (p = 0.001). Given the magnitude of the in vivo response, these data suggested that the antitumor effects of IFN-alpha1,8 were likely mediated through angiogenesis inhibition rather than solely by direct inhibition of tumor cell proliferation. 相似文献
5.
Probable gas embolism during operative hysteroscopy caused by products of combustion 总被引:8,自引:0,他引:8
Ngozi Imasogie Ron Crago Nicholas A. Leyland Frances Chung 《Journal canadien d'anesthésie》2002,49(10):1044-1047
PURPOSE: Gas embolism is a rare but well documented entity during operative hysteroscopy, with an incidence of 10-50%. Catastrophic outcomes occur at a rate of three in 17,000 procedures. The purpose of this report is to present a non-fatal case of gas embolism probably caused by the gaseous products of combustion. CLINICAL FEATURES: A 50-yr-old woman with a history of menorrhagia was scheduled for hysteroscopy and endometrial ablation and polypectomy. Fifteen minutes into the procedure, with the patient in lithotomy position, 20 degree head down tilt, and breathing spontaneously, a sudden oxygen desaturation occurred from 97% to 87%. The patient's end-tidal carbon dioxide dropped from 46 mmHg to 27 mmHg. The patient's breathing pattern remained normal, respiratory rate remained 11-12 breaths x min(-1) but amplitude of the reservoir bag movement was increased. Cardiovascular variables remained stable. She responded rapidly to 100% oxygen and made an uneventful recovery. Having ruled out other possible causes, we concluded gas embolism was responsible for the fall in oxygen saturation and end-tidal CO(2). CONCLUSION: With all the precautions in place to minimize the likelihood of fluid overload and ambient air embolism occurring, we surmised that products of combustion were the cause of the gas embolism. During endometrial ablation, gaseous products of combustion, mainly carbon dioxide, accumulate. The gases may then contribute to the rise in uterine pressure that occurs as irrigation fluid enters the uterus and this rise in pressure in turn encourages passage of gas into the open venous sinuses. 相似文献
6.
7.
Starling III John BA Patel Purvisha J. MD Rasberry Ron D. MD 《Dermatologic surgery》2005,31(4):484-485
BACKGROUND: Simple surgical excision is one of the most common treatment methods in the dermatologist's armamentarium. We describe a precise postsurgical dressing technique that can be used for wound care of those patients whose treatment involves removal of lesions via cutaneous surgery. OBJECTIVE: To devise a novel, precise, and effective dressing technique for postsurgical wound care. MATERIALS AND METHODS: We describe the technique using common in-office instruments. RESULTS AND CONCLUSION: Wound dressings for lesions located on curved areas such as the ears, nose, cheeks, and chin often exhibit less than adequate adherence and stability. The kerf-cut dressing technique optimizes pliability of dressing tape, and this maximizes efficient and stable application of postsurgical wound dressings to curved areas of the body. 相似文献
8.
9.
A Birkenfeld D Navot Y Ezra A Ron J G Schenker 《European journal of obstetrics, gynecology, and reproductive biology》1987,25(3):221-229
The effect of estradiol valerate and allylestrenol on the endometrial transformation of five hypergonadotropic hypogonadic women was evaluated. Estradiol valerate was administered throughout the whole induced cycle (28 days), while allylestrenol was added during the second half of the cycle. Endometrial biopsies were performed during allylestrenol treatment and were evaluated histologically. Samples of endometrium were also subjected to one-dimensional SDS electrophoresis. Of ten biopsies performed, only one was interpreted to be in-phase, while the others were dated proliferative (4 biopsies) or showed abortive or out-of-phase secretory transformation. The highest mean serum progesterone level, detected under allylestrenol treatment, was 1.5 ng/ml. Protein electrophoresis demonstrated relative sequential changes in the protein patterns of the 115 kDa and 150 kDa protein bands. It is concluded that allylestrenol, although having gestagen properties, may not be efficient for the induction of an adequate secretory transformation of human endometrium in the absence of ovaries. 相似文献
10.
Reeve Bryce B. Hays Ron D. Chang Chih-Hung Perfetto Eleanor M. 《Quality of life research》2007,16(1):1-8
Background Health-related quality of life (HRQL) is an accepted outcome measure in patients with mood and anxiety disorders. Yet, surprisingly
little attention has been paid to the determinants. In this paper we test the hypothesis that it is associated with personality
traits while controlling for mental disorders.
Methods A large sample of outpatients (n=640) with mood and anxiety disorders was studied. The empirically supported five factor model
of normal personality traits was assessed using the NEO-FFI and includes: neuroticism, extraversion, openness to experience,
agreeableness, and conscientiousness. Mental disorders were assessed with the CIDI, and HRQL with the SF-36.
Results Regression analyses revealed that the NEO-FFI scores, with the exception of conscientiousness, were significantly associated
with SF-36 subscales and summary scores, independently from the mental disorders. The percentage of explained variance due
to the personality traits was highest for the subscales Vitality (10.0%), Mental Health (13.3%) and the Mental Health Summary
Score (9.5%). Furthermore, specific personality traits were related to specific SF-36 subscales.
Conclusions A low HRQL of patients with mood or anxiety disorders is not only determined by the disease or the current health but is also
shaped by personality traits that are relatively stable throughout an individual's life time. 相似文献