全文获取类型
收费全文 | 16176篇 |
免费 | 928篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 116篇 |
儿科学 | 454篇 |
妇产科学 | 297篇 |
基础医学 | 2077篇 |
口腔科学 | 459篇 |
临床医学 | 1721篇 |
内科学 | 3481篇 |
皮肤病学 | 195篇 |
神经病学 | 1431篇 |
特种医学 | 500篇 |
外科学 | 2562篇 |
综合类 | 126篇 |
一般理论 | 9篇 |
预防医学 | 1036篇 |
眼科学 | 358篇 |
药学 | 1178篇 |
中国医学 | 20篇 |
肿瘤学 | 1113篇 |
出版年
2023年 | 115篇 |
2022年 | 152篇 |
2021年 | 270篇 |
2020年 | 254篇 |
2019年 | 359篇 |
2018年 | 374篇 |
2017年 | 327篇 |
2016年 | 374篇 |
2015年 | 361篇 |
2014年 | 497篇 |
2013年 | 790篇 |
2012年 | 1028篇 |
2011年 | 1048篇 |
2010年 | 563篇 |
2009年 | 555篇 |
2008年 | 944篇 |
2007年 | 977篇 |
2006年 | 936篇 |
2005年 | 824篇 |
2004年 | 827篇 |
2003年 | 780篇 |
2002年 | 715篇 |
2001年 | 234篇 |
2000年 | 230篇 |
1999年 | 253篇 |
1998年 | 203篇 |
1997年 | 181篇 |
1996年 | 159篇 |
1995年 | 135篇 |
1994年 | 140篇 |
1993年 | 111篇 |
1992年 | 155篇 |
1991年 | 162篇 |
1990年 | 168篇 |
1989年 | 163篇 |
1988年 | 145篇 |
1987年 | 142篇 |
1986年 | 135篇 |
1985年 | 134篇 |
1984年 | 124篇 |
1983年 | 106篇 |
1982年 | 115篇 |
1981年 | 81篇 |
1980年 | 72篇 |
1979年 | 84篇 |
1978年 | 59篇 |
1976年 | 56篇 |
1975年 | 55篇 |
1974年 | 62篇 |
1973年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
Jan Lycke Bo Svennerholm Anders Svenningsson Walter Muranyi Rolf M. Flügel Oluf Andersen 《Journal of neurology》1994,241(4):204-209
The role of human spumaretrovirus (HSRV) infections in the pathogenesis of multiple sclerosis (MS) was investigated with recombinant HSRV env-specific enzyme-linked immunosorbent assay. The presence of HSRV antibodies was determined in pairs of serum and cerebrospinal fluid (CSF) samples from 60 MS patients. In 7 of these patients serial serum and CSF samples were obtained in relation to the clinical activity of the disease during a period of 2 years. No increased antibody reactivity was demonstrable in the MS population compared with 14 aseptic meningitis patients, 50 blood donors and 16 healthy controls. Slightly elevated levels of antibodies were demonstrable in serum and/or CSF in 4 MS patients but also in 1 patient with aseptic meningitis, 1 blood donor and 1 child. No marked serum or CSF HSRV antibody fluctuation was observed in the MS patients followed longitudinally. Thus, this study does not support the involvement of HSRV in the pathogenesis of MS. 相似文献
24.
Anders Persson Stefan Pauli Christer Halldin Sharon Stone-Elander Lars Farde Irene Sjgren Gran Sedvall 《Human psychopharmacology》1989,4(1):21-31
The 11C-labelled benzodiazepine antagonist Ro 15–1788 (flumazenil) and positron emission tomography (PET) were used to determine quantitative characteristics of benzodiazepine receptor binding in the neocortex of healthy young men. Saturating doses of unlabelled flumazenil administered i.v., before or together with the ligand-reduced 11C-flumazenil accumulation in the neocortex by about 90 per cent. Saturating doses of unlabelled flumazenil had little effect on the accumulation of radioactivity in the benzodiazepine receptor-poor regions such as pons or white matter. By giving graded doses of unlabelled flumazenil together with the tracer, saturation isotherms were obtained allowing the calculation of receptor density (Bmax) and equilibrium dissociation constant (Kd) values on the basis of certain assumptions Bmax values were in the order of 90 pmol/g and Kd values in the order of 10 nM in the neocortex. Scatchard and Hill plots of the radioactivity data indicated that 11C-flumazenil binds to saturable sites of a homogeneous population. The data indicate that intravenous doses of 1 or 2 mg flumazenil result in a benzodiazepine receptor occupancy of about 50 per cent. The method described should be useful for studying regional differences in benzodiazepine receptor characteristics in the living human brain in healthy subjects and neuropsychiatric disorders, and also in relation to treatment with drugs interacting with benzodiazepine receptors. 相似文献
25.
Domestic violence continues to be a subject of public interest and media presence, especially when it involves spectacular cases ranging from abuse of children to fatal violence in the family. Although domestic violence has been the subject of scientific research for the last three decades, there is still no clear evidence of prevalence and etiology of this particular kind of violence. Since the introduction of the German Violence Protection Act which came into force in January 2002, domestic violence has been met with severe societal and legal sanctions. The consequences for culprits are not only theoretical but also include an increase in criminal proceedings and improved civil court protection. Therefore medical staff, particularly legal medicine, is more than ever confronted with the need to standardize documentation of injuries resulting from domestic violence. In addition, legal medical specialists are often confronted with the victims’ personal and social problems. This paper gives an insight into the historical background and recent law reforms which have created legal sanctions and protection against domestic violence. 相似文献
26.
Anette M.C. Fransson DDS A
ke Tegelberg DDS PhD Anders Johansson DDS PhD Bengt Wenneberg DDS PhD 《American journal of orthodontics and dentofacial orthopedics》2004,126(6):687-693
The aim was to identify the incidence and types of possible adverse events in the masticatory system after treatment with a mandibular protruding device (MPD) during a 2-year period in patients with obstructive sleep apnea (OSA) or snoring. The subjects comprised 65 middle-aged patients (44 OSA patients, 21 snorers). A clinical examination and a questionnaire concerning signs and symptoms from the masticatory system were performed before, after 6 months, and after 2 years of MPD use. The frequencies of registered signs from the masticatory system, such as muscle and joint tenderness, palpation, and pain during mandibular movement, decreased significantly between baseline and the 2-year follow-up. There were significant changes in the mandibular range of protrusion (+0.7 mm, P < .001), overjet (-0.5 mm, P < .001), and overbite (-0.6 mm, P < .001) compared with the initial examination. Nine patients developed a lateral open bite during treatment, and 2 of them experienced subjective symptoms related to the altered occlusion but still used the MPD every night. No patient reported pain on opening the mouth wide or during jaw movements. Two reported tiredness on jaw function. The reported frequency of headaches was also significantly reduced (P < .01). The high compliance rate in MPD use showed that the therapy is well tolerated, but there is a risk of minor alterations in the occlusion during MPD treatment. 相似文献
27.
Michael V. Hansen Helen Holmgren Anders Spberg Andrej Warycha 《Neurourology and urodynamics》1990,9(3):257-268
EMG responses in the external anal sphincter (EAS), the rectus abdominis muscle (RA), and the anterior tibial muscle (TA) were recorded following single magnetic transcranial cortical stimulations (TCCS) in seven healthy volunteers. The responses in the EAS differed from the responses in the other muscles. They had comparatively long durations ranging from 1 to 2 seconds, no inhibitory periods were observed, and there was no tendency for habituation to occur following a limited number of stimuli. The responses recorded in the EAS were used as test responses in order to evaluate the excitability changes in the EAS motoneurons occurring during bladder filling. Cystometries with filling rates of 15, 50 and 200 ml/min were done. During these cystometries TCCS were applied repeatedly, with constant strength, after each 50 ml of filling up to bladder capacity. The responses following TCCS changed in a highly reproducible way during bladder filling. After 100–200 ml of filling, the responses had longer latencies, diminished sizes, and shorter durations. When the filling reached a level 50–150 ml below capacity, the responses in most subjects again became greater and the latencies shorter. The changes were believed to be physiological. It was concluded that the EAS motoneurons are under both inhibitory and facilitatory influence during bladder filling in intact healthy humans. Facilitatory influences are often observed when the bladder is filled close to capacity. At lower bladder volumes the observed influence is always inhibitory. A decrease in the EMG activity of the EAS during filling cystometry should consequently not be regarded as a pathological response. 相似文献
28.
29.
J. L. Frederiksen H. B. W. Larsson P. Christiansen J. Olesen 《European journal of neurology》1997,4(6):561-566
To evaluate various MRI criteria we studied a representative group of 149 consecutive patients below 50 years with acute monosymptomatic optic neuritis (AMON), a frequent first manifestation of multiple sclerosis (MS). The presence, number, size, and localization of areas of increased signal (AIS) on T2-weighted brain MRIs obtained at 1.5 T were described and compared with findings in 71 healthy persons aged 21–50 years without diabetes, cerebrovascular or neurologic diseases. MRI was performed within 2–145 days, median 16 days from onset of AMON and showed from 0 to 26 AIS, sized 2–30 mm, in 79 of 149 (53%) patients compared to 0–18 AIS, sized 2–12 mm, in 31 of 71 (44%) healthy persons. In patients, AIS were significantly more frequent in women than in men (χ2 = 4.67, p > 0.05). Periventricular AIS were revealed in 70 (47%) patients and in 14 (20%) healthy persons. Subcortical AIS were present in 5 (3%) patients and in 18 (25%) healthy persons. Infratentorial AIS were present in only 3 (2%) patients. The sensitivity and specificity of previously proposed diagnostic MRI criteria for MS were unsatisfactory in our group of patients and have previously only been validated in definite MS. We therefore constructed and tested four new sets of criteria. The set with the best relation between sensitivity (e.g. 41%) and specificity (e.g. 93%) was the following: presence of two or more AIS, of which at least one is periventricular or infratentorial, combined with the absence of subcortical AIS. These criteria are recommended for patients with AMON and might be used in other patients with possible or probable MS. 相似文献
30.
Shinichi Suzuki Cornelius A Davis Charles C Miller Tam T T Huynh Anthony L Estrera Eyal E Porat Anders Vinnerkvist Hazim J Safi 《European journal of cardio-thoracic surgery》2003,24(1):119-24; discussion 124
OBJECTIVE: Previous studies have identified age, renal failure and aneurysm extent as predictors of mortality following thoracoabdominal and descending thoracic aortic aneurysm (TAA) repair. We studied the impact of coronary artery disease (CAD) and cardiac function on 30-day mortality following TAA repair. METHODS: Between February 1991 and May 2001, we performed 854 TAA repairs. Two hundred ninety-one patients (34%) had a history of coronary artery disease. One hundred forty-one/291 (49%) had undergone coronary artery bypass surgery (CAB) prior to TAA repair. We conducted multivariable analyses of known risk factors along with the left ventricular ejection fraction (EF) and prior CAB to determine the adjusted effect of CAD on outcome. RESULTS: Mortality in patients with CAD was 54/291 (18%) compared to 75/563 (13%) without CAD (P<0.05). In patients who had prior CAB, mortality was 31/141 (22%) compared to 98/713 (14%) patients without prior CAB, (P<0.02). In multivariable analysis, the effects of CAD and CAB on mortality were eliminated by consideration of a low EF (defined as less than 50%). CONCLUSION: Impaired left ventricular function appears to be the strongest cardiac predictor of mortality for TAA repair, independent of the presence of coronary artery disease or coronary artery bypass revascularization. 相似文献