全文获取类型
收费全文 | 995943篇 |
免费 | 76686篇 |
国内免费 | 2613篇 |
专业分类
耳鼻咽喉 | 12961篇 |
儿科学 | 34464篇 |
妇产科学 | 28460篇 |
基础医学 | 145275篇 |
口腔科学 | 27713篇 |
临床医学 | 90266篇 |
内科学 | 193542篇 |
皮肤病学 | 22913篇 |
神经病学 | 79105篇 |
特种医学 | 38386篇 |
外国民族医学 | 305篇 |
外科学 | 149483篇 |
综合类 | 23738篇 |
一般理论 | 385篇 |
预防医学 | 77819篇 |
眼科学 | 22607篇 |
药学 | 71859篇 |
3篇 | |
中国医学 | 2029篇 |
肿瘤学 | 53929篇 |
出版年
2018年 | 10556篇 |
2017年 | 8235篇 |
2016年 | 9373篇 |
2015年 | 10594篇 |
2014年 | 14415篇 |
2013年 | 22001篇 |
2012年 | 28980篇 |
2011年 | 30824篇 |
2010年 | 18488篇 |
2009年 | 17435篇 |
2008年 | 28786篇 |
2007年 | 30459篇 |
2006年 | 30960篇 |
2005年 | 29637篇 |
2004年 | 28924篇 |
2003年 | 27796篇 |
2002年 | 26813篇 |
2001年 | 46924篇 |
2000年 | 48034篇 |
1999年 | 40261篇 |
1998年 | 11177篇 |
1997年 | 10095篇 |
1996年 | 10160篇 |
1995年 | 9775篇 |
1994年 | 9091篇 |
1993年 | 8480篇 |
1992年 | 32248篇 |
1991年 | 31458篇 |
1990年 | 31006篇 |
1989年 | 29874篇 |
1988年 | 27167篇 |
1987年 | 27325篇 |
1986年 | 25434篇 |
1985年 | 24601篇 |
1984年 | 18397篇 |
1983年 | 15515篇 |
1982年 | 9288篇 |
1981年 | 8375篇 |
1979年 | 16859篇 |
1978年 | 12217篇 |
1977年 | 10314篇 |
1976年 | 9754篇 |
1975年 | 10178篇 |
1974年 | 12317篇 |
1973年 | 11843篇 |
1972年 | 10884篇 |
1971年 | 10113篇 |
1970年 | 9375篇 |
1969年 | 8724篇 |
1968年 | 8104篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
X Dong M He X Song B Lu Y Yang S Zhang N Zhao L Zhou Y Li X Zhu R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks. 相似文献
992.
G Anita Heeren John B Jemmott Andrew Mandeya Joanne C Tyler 《AIDS education and prevention》2007,19(1):1-12
This study compared the predictive value of the theory of planned behavior in university students in South Africa (N = 251) and the United States (N = 160) who completed an anonymous self-administered questionnaire. Multiple regression analyses revealed that condom use and intention were significantly predicted by positive condom attitude, subjective norm, self-efficacy, and attending university in South Africa. Significant interactions between country and predictors indicated that subjective norm predicted condom use and intention more strongly in the American sample than in the South African sample; attitude predicted intention more strongly in the American sample than in the South African sample; but self-efficacy predicted intention more strongly in the South African sample than in the American sample. The theory of planned behavior may provide a useful framework for interventions to reduce South African students' risk of HIV/and sexuality transmitted diseases. Such interventions should especially focus on building self-efficacy to use condoms. 相似文献
993.
B Gerdts AFPM Vloemans RW Kreis 《Journal of the European Academy of Dermatology and Venereology》2007,21(6):781-788
BACKGROUND: Toxic epidermal necrolysis (TEN) is a severe and potentially fatal drug reaction characterized by an extensive skin rash with blisters and exfoliation, frequently accompanied by mucositis. The wounds caused by TEN are similar to second-degree burns and severe cases may involve large areas of skin loss. OBJECTIVES: Analysis of our results in patients with TEN and evaluation of the variety of therapeutic interventions that has been studied and suggested in TEN. PATIENTS/METHODS: Retrospective analysis of 19 consecutive patients with TEN treated in our burns centre between 1989 and 2004. RESULTS: Immediate withdrawal of any potentially fatal drug, maximum supportive care, and a restricted and tailored antibiotic, medical and surgical treatment regimen confined mortality to 21%, whereas prognosis scores like APACHE II and SCORTEN predicted mortality of 22 and 30%, respectively. A positive contribution of selective digestive decontamination is suggested but has yet to be established. CONCLUSIONS: Because of a potentially fatal outcome, fast referral of a patient suspected of TEN to a specialized centre (mostly a burns unit or specialized dermatology centre) for expert wound management and tailored comprehensive care is strongly advised and contributes to survival. 相似文献
994.
995.
Seymour Solomon Brian M Grosberg Deborah I Friedman Richard B Lipton 《Journal of neuro-ophthalmology》2007,27(3):243-4; author reply 244-5
996.
997.
PD Dr. C. Wagner G. Zimmermann A. Moghaddam S. Studier-Fischer B. Vock A. Wentzensen 《Trauma und Berufskrankheit》2005,7(3):168-174
Rupture of the Achilles tendon is typically associated with sportive activities with increasing tendency; it occurs most commonly in the third to fourth decade of life with a male-to-female ratio of 5–10:1. Ruptures are caused predominantly by a sudden, unexpected overextension of the tendon while direct trauma is less frequent. The recommended treatment of the injury remains controversial. In Germany, due to the good functional results, the open surgical repair represents the standard therapy since many years. The open suture technique offers the advantage of a lower re-rupture rate but is associated with the risk of wound-related complications including infection. By percutaneous suture techniques a significant decrease in the rate of infections and complications in wound healing could be achieved by minimal-access with reduced soft tissue trauma; on the other hand an increased rate of lesions of the sural nerve is reported. Dynamic imaging assessment of ultrasound or MRI allows a more accurate localisation of the ruptured ends of the tendons which is the prerequisite for the non-operative primary functional treatment of Achilles tendon ruptures. This conservative treatment regime is recommended when adaptation of the ends of the ruptured tendon is possible in 20° plantar flexion of the foot. Moreover, the desired level of daily activity and the patients’ degree of compliance has to be considered. Operative management should be avoided in the elderly patient or patients with risk factors like immunosuppressive therapy, diabetes mellitus, steroid use or failure to comply. 相似文献
998.
Serum LH, FSH and testosterone were quantitated in 9 patients with pure motor stroke within 24-48 h of its reported onset. High circulating LH with normal or low testosterone was noted in 8 of them. In response to an intravenous bolus of GnRH, the LH responses were exaggerated in all, but the FSH responses in 7 of them were comparable to those in eugonadal age matched controls. The rise in testosterone following 2000U hCG daily for 3 consecutive days was insignificant in the patients group compared to the controls. The data suggest normally operative pituitary testicular feed-back but decreased Leydig cell response in pure motor stroke. 相似文献
999.
The clinical features and prognosis of pseudoseizures diagnosed using video-EEG telemetry 总被引:25,自引:0,他引:25
A total of 110 patients underwent diagnostic evaluation for attacks of uncertain origin by means of video-EEG telemetry and had a diagnosis of pseudoseizures confirmed. Eighty-six patients (78%) were female, mean age of onset 25 years, and mean duration of attacks was 3 years. Many of the patients had erroneously been thought to be suffering from epilepsy. The attacks could be divided into two broad categories: attacks of collapse (one-third) and attacks with prominent motor activity (two-thirds). In some patients, the attacks were associated with incontinence and injury. The differential diagnosis and clinical features of the attacks are described. Additional psychiatric features were present in 52 (47%) patients. Follow-up (for a median 5 years; range, 1 to 14 years) showed that 40% of these patients stopped having pseudoseizures. This favorable outcome was associated with being female, leading an independent life, a formal psychological approach to therapy and counseling, and the absence of coexisting epilepsy, but not with the duration of pseudoepilepsy, prior episodes of pseudostatus, the coexistence of overt psychiatric disease, or the clinical features of the attacks. 相似文献
1000.
Motor and somatosensory evoked potentials in hereditary spastic paraplegia. 总被引:7,自引:4,他引:3 下载免费PDF全文
L Pelosi B Lanzillo A Perretti L Santoro L Blumhardt G Caruso 《Journal of neurology, neurosurgery, and psychiatry》1991,54(12):1099-1102
Motor evoked potentials (MEPs) from the arms and legs to transcranial stimulation of the motor cortex and somatosensory evoked potentials (SSEPs) from stimulation of the nerves of the arms and legs, were recorded in 11 patients with hereditary spastic paraplegia. Electrophysiological abnormalities were found to be distributed differently among the systems examined; the longer the pathway, the higher the incidence and severity of impairment. MEPs from the leg were either absent or clearly reduced or prolonged in all patients. Eight patients showed abnormal cortical SSEPs on stimulation of the leg (absent or reduced responses in four, slowed central conduction velocity in seven), but only two of these patients had abnormal MEPs from the arm (absent responses). Cortical SSEPs on stimulation of the median nerve were reduced in two patients. Mean values of amplitude and central conduction velocity for MEPs and SSEPs from the leg were significantly different between patients and controls. Such differences were not found for either MEPs or SSEPs from the arm. This distribution of abnormalities, which suggests a differential involvement of the spinal pathways, parallels the reported pathological pattern in which degeneration of axons is more common and severe in the motor and sensory fibres supplying the leg. 相似文献