全文获取类型
收费全文 | 135529篇 |
免费 | 9633篇 |
国内免费 | 629篇 |
专业分类
耳鼻咽喉 | 1649篇 |
儿科学 | 3414篇 |
妇产科学 | 2443篇 |
基础医学 | 17362篇 |
口腔科学 | 2894篇 |
临床医学 | 13260篇 |
内科学 | 27906篇 |
皮肤病学 | 1751篇 |
神经病学 | 11931篇 |
特种医学 | 5396篇 |
外科学 | 21813篇 |
综合类 | 1915篇 |
现状与发展 | 1篇 |
一般理论 | 173篇 |
预防医学 | 12367篇 |
眼科学 | 2912篇 |
药学 | 9602篇 |
2篇 | |
中国医学 | 179篇 |
肿瘤学 | 8821篇 |
出版年
2023年 | 617篇 |
2022年 | 894篇 |
2021年 | 2571篇 |
2020年 | 1466篇 |
2019年 | 2395篇 |
2018年 | 2924篇 |
2017年 | 2112篇 |
2016年 | 2229篇 |
2015年 | 2714篇 |
2014年 | 4015篇 |
2013年 | 6056篇 |
2012年 | 8870篇 |
2011年 | 9436篇 |
2010年 | 5253篇 |
2009年 | 4806篇 |
2008年 | 8385篇 |
2007年 | 8989篇 |
2006年 | 8559篇 |
2005年 | 8711篇 |
2004年 | 8370篇 |
2003年 | 7868篇 |
2002年 | 7679篇 |
2001年 | 1276篇 |
2000年 | 1054篇 |
1999年 | 1396篇 |
1998年 | 1627篇 |
1997年 | 1303篇 |
1996年 | 1252篇 |
1995年 | 1216篇 |
1994年 | 1031篇 |
1993年 | 1004篇 |
1992年 | 838篇 |
1991年 | 863篇 |
1990年 | 753篇 |
1989年 | 731篇 |
1988年 | 753篇 |
1987年 | 737篇 |
1986年 | 760篇 |
1985年 | 836篇 |
1984年 | 907篇 |
1983年 | 867篇 |
1982年 | 1130篇 |
1981年 | 1156篇 |
1980年 | 964篇 |
1979年 | 631篇 |
1978年 | 668篇 |
1977年 | 598篇 |
1976年 | 519篇 |
1975年 | 468篇 |
1974年 | 471篇 |
排序方式: 共有10000条查询结果,搜索用时 921 毫秒
181.
182.
183.
Ying-Ying Huang Aaron C.-H. Chen James D. Carroll Michael R. Hamblin 《Dose-response》2009,7(4):358-383
The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing cell death and tissue damage has been known for over forty years since the invention of lasers. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial in mainstream medicine. The biochemical mechanisms underlying the positive effects are incompletely understood, and the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. A biphasic dose response has been frequently observed where low levels of light have a much better effect on stimulating and repairing tissues than higher levels of light. The so-called Arndt-Schulz curve is frequently used to describe this biphasic dose response. This review will cover the molecular and cellular mechanisms in LLLT, and describe some of our recent results in vitro and in vivo that provide scientific explanations for this biphasic dose response. 相似文献
184.
185.
186.
Mohammed N Islam Indraneel Bhattacharyya Junu Ojha Karen Bober Donald M Cohen James G Green 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(4):501-509
Hemifacial hypertrophy (HFH) is rare and characterized by unilateral enlargement of the head and teeth. Hemifacial hypertrophy is classified as true HFH (THFH) with unilateral enlargement of the viscerocranium, and partial HFH (PHFH) in which not all structures are enlarged. We present a case of THFH and compare and contrast it with a case of PHFH. Hemifacial hypertrophy may cover a wide spectrum of defects or may involve only muscle or bone. Myohyperplasia, reported previously as a separate syndrome, may actually represent a forme fruste of PHFH or THFH. The PHFH patient lead a healthy, normal life without significant psychosocial problems and was reluctant to accept his deformity. Contrastingly, the THFH patient had significant social stigma and compromised health together with major aesthetic morbidity. Treatment planning in THFH is arduous and involves multiple modalities. Therefore, it is imperative to differentiate THFH and PHFH for better understanding and management of the condition. 相似文献
187.
Patrick N Smith Jeffrey R Balzer Mustafa H Khan Rick A Davis Donald Crammond William C Welch Peter Gerszten Robert J Sclabassi James D Kang William F Donaldson 《The spine journal》2007,7(1):83-87
BACKGROUND CONTEXT: Intraoperative somatosensory evoked potential (SSEP) monitoring has been shown to reduce the incidence of new postoperative neurological deficits in scoliosis surgery. However, its usefulness during cervical spine surgery remains a subject of debate. PURPOSE: To determine the utility of intraoperative SSEP monitoring in a specific patient population (those with cervical radiculopathy in the absence of myelopathy) who underwent anterior cervical discectomy and fusion (ACDF) surgery. STUDY DESIGN: Retrospective review. PATIENT SAMPLE: A total of 1,039 nonmyelopathic patients who underwent single or multilevel ACDF surgery. The control group (462 patients) did not have intraoperative SSEP monitoring, whereas the monitored group (577 patients) had continuous intraoperative SSEP monitoring performed. OUTCOME MEASURE: A new postoperative neurological deficit. METHODS: SSEP tracings were reviewed for all 577 patients in the monitored group and all significant signal changes were noted. Medical records were reviewed for all 1,039 patients to determine if any new neurological deficits developed in the immediate postoperative period. RESULTS: None of the patients in the control group had any new postoperative neurological deficits. In the monitored group there were six instances of transient SSEP changes (1 due to suspected carotid artery compression; 5 thought to be due to transient hypotension) which resolved with the appropriate intraoperative intervention (repositioning of retractors; raising the arterial blood pressure). Upon waking up from anesthesia, one patient in the monitored group had a new neurological deficit (partial central cord syndrome) despite normal intraoperative SSEP signals. CONCLUSIONS: ACDF appears to be a safe surgical procedure with a low incidence of iatrogenic neurological injury. Transient SSEP signal changes, which improved with intraoperative interventions, were not associated with new postoperative neurological deficits. An intraoperative neurological deficit is possible despite normal SSEP signals. 相似文献
188.
Dwight Dickinson Virginia N Iannone Christopher M Wilk James M Gold 《Neuropsychopharmacology》2004,55(8):826-833
BACKGROUND: It is controversial whether the cognitive deficit in schizophrenia is better characterized as generalized or as reflecting relatively independent deficits in different cognitive domains. The issue has implications for assessment practice, intervention design, and the exploration of schizophrenia genetics. METHODS: We used a specialized structural equation modeling approach, single common factor analysis, to explore the relative importance of generalized versus independent cognitive deficits in schizophrenia. Eighteen subtest scores from the Wechsler Adult Intelligence Scale-III and the Wechsler Memory Scale-III were included in the analysis. We analyzed these data for 97 schizophrenia or schizoaffective disorder outpatients and 87 healthy control subjects. RESULTS: Approximately two thirds of the overall effect of a schizophrenia diagnosis on cognitive performance was mediated through a single common factor. The Wechsler subtest scores showed almost uniformly strong relationships with this factor. The independent associations of group status with the subtest scores were smaller in magnitude and only selectively significant. CONCLUSIONS: The relatively greater magnitude of illness effects mediated through the common factor in this analysis, compared with the specific, independent effects, suggests that a generalized cognitive deficit is a core feature of schizophrenia. 相似文献
189.
Alfred Philip James Lake BSc MBBS FFARCS ; Kathiravelpillai Puvanachandra MBBS DO FRCS FRCOphth 《Pain practice》2004,4(2):130-131
Abstract: Stellate ganglion block is commonly used to treat the sympathetically maintained pain which may occur in one‐third of patients with complex regional pain syndrome type 1. A complication that followed a single block and presented a diagnostic dilemma for the ophthalmologist is reported. 相似文献
190.
Eric Lim Ziad Ali Ayyaz Ali Reza Motalleb-Zadeh Christopher Jackson Seok Ling Ong James Halstead Linda Sharples Jayan Parameshwar John Wallwork Stephen R Large 《The Journal of heart and lung transplantation》2005,24(8):983-989
BACKGROUND: To ascertain survival of ischemic advanced heart failure patients by treatment allocation, we examined the outcome of transplant assessment patients allocated to medical therapy, high-risk conventional surgery, or transplantation. METHODS: Patients were identified from the Papworth transplant database and excluded if primary etiology was not ischemic. Grouping was undertaken according to treatment allocation at initial assessment, and analysis was performed by intention to treat. Survival was computed from the time of assessment and Cox regression used to stratify patients according risk with the Heart Failure Survival Score. RESULTS: From May 1993 to September 2001, a total of 755 patients were admitted for transplant assessment, with 348 (46.1%) identified as having heart failure of ischemic origin. Variables required for calculation of the Heart Failure Survival Score was available in 273 patients (78.4%), and 20 patients (7.3%) were lost to follow-up. Of the remaining 253 patients, 89 (35.2%) were allocated to medical therapy, 32 (12.6%) to surgery, and 132 (52.2%) to transplantation. The relative risk (95% confidence limit) of death compared with medical therapy was 0.62 (0.28, 1.40) for surgery and 0.38 (0.24, 0.61) for transplantation in medium- to high-risk patients. For low-risk patients, the relative risks for death compared with medical therapy were 1.87 (0.63, 5.60) for surgery and 1.97 (0.79, 4.96) for transplantation. CONCLUSIONS: Transplantation improved survival of medium- and high-risk patients compared with medical therapy. In the low-risk group, this was not evident. However, repeated assessment of risk is required because the hazard for death rises steadily after the third year in these patients. 相似文献