全文获取类型
收费全文 | 407178篇 |
免费 | 25777篇 |
国内免费 | 10453篇 |
专业分类
耳鼻咽喉 | 3689篇 |
儿科学 | 12160篇 |
妇产科学 | 4828篇 |
基础医学 | 32552篇 |
口腔科学 | 8889篇 |
临床医学 | 45179篇 |
内科学 | 68191篇 |
皮肤病学 | 6345篇 |
神经病学 | 20158篇 |
特种医学 | 15830篇 |
外国民族医学 | 32篇 |
外科学 | 53888篇 |
综合类 | 39875篇 |
现状与发展 | 41篇 |
一般理论 | 9篇 |
预防医学 | 33493篇 |
眼科学 | 7309篇 |
药学 | 61098篇 |
183篇 | |
中国医学 | 10970篇 |
肿瘤学 | 18689篇 |
出版年
2023年 | 4369篇 |
2022年 | 11146篇 |
2021年 | 16845篇 |
2020年 | 11415篇 |
2019年 | 18824篇 |
2018年 | 14554篇 |
2017年 | 12615篇 |
2016年 | 12588篇 |
2015年 | 15500篇 |
2014年 | 27449篇 |
2013年 | 28752篇 |
2012年 | 28189篇 |
2011年 | 25528篇 |
2010年 | 22252篇 |
2009年 | 20931篇 |
2008年 | 19358篇 |
2007年 | 19414篇 |
2006年 | 16903篇 |
2005年 | 12424篇 |
2004年 | 8136篇 |
2003年 | 7186篇 |
2002年 | 5603篇 |
2001年 | 5009篇 |
2000年 | 4157篇 |
1999年 | 3319篇 |
1998年 | 3373篇 |
1997年 | 3078篇 |
1996年 | 2563篇 |
1995年 | 2526篇 |
1994年 | 2327篇 |
1993年 | 1917篇 |
1992年 | 2159篇 |
1991年 | 1883篇 |
1990年 | 1729篇 |
1989年 | 1662篇 |
1988年 | 1515篇 |
1987年 | 1372篇 |
1985年 | 4598篇 |
1984年 | 5112篇 |
1983年 | 4029篇 |
1982年 | 4607篇 |
1981年 | 4247篇 |
1980年 | 3577篇 |
1979年 | 3392篇 |
1978年 | 2783篇 |
1977年 | 2239篇 |
1976年 | 2617篇 |
1975年 | 1901篇 |
1974年 | 1720篇 |
1973年 | 1644篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
941.
B. Berthelsen 《European radiology》1992,2(5):452-458
The results of embolisation of dural arteriovenous fistulas draining into the transverse or sigmoid sinus were evaluated in 20 patients. Tinnitus was the main symptom in all patients although one also suffered from vertigo and sudden deafness. Nine patients were treated with PVA (polyvinylalcohol) alone and 11 with combined PVA and bucrylate (isobutyl-2-cyanoacrylate) in 1–9 procedures. Recurrence of symptoms, requiring repeated procedures was common but at subsequent clinical follow up 10 patients had no tinnitus, 5 were improved and only 5 experienced no change. Complications occured in six patients: four had transient neurological symptoms and one of these also developed a necrotic wound which later healed. One patient suffered from a cranial nerve palsy and one had an intracranial haemorrhage after a transvenous embolisation. This last patient recovered completely. The best clinical results were achieved in small fistulas and fistulas treated with combined bucrylate and PVA. 相似文献
942.
Peter Reimer Sanjay Saini Ken K. Kwong Mark S. Cohen Ralph Weissleder Thomas J. Brady 《Journal of magnetic resonance imaging : JMRI》1994,4(3):331-335
To develop guidelines for clinical magnetic resonance imaging of the liver, the authors undertook an animal study to investigate the effect of dose and pulse sequence on liver signal intensity in gadopentetate dimeglumine—enhanced echo-planar imaging. Serial imaging of the liver was performed in anesthetized rats after intravenous administration of five different doses (0.01, 0.05, 0.1, 0.2, and 0.5 mmol/kg) of contrast agent, with six different pulse sequences. The results show that gadopentetate dimeglumine—enhanced echo-planar images obtained during the perfusion phase can yield either positive (due to increased T1 relaxation rates) or negative (due to susceptibility-induced increased T2 relaxation rates) liver enhancement depending on choice of pulse sequence and dose. At the current clinically recommended dose of 0.1 mmol/kg, maximal liver signal enhancement was seen with a T1-weighted inversion-recovery sequence, while maximal liver signal diminution was seen with a T2*-weighted gradient-echo sequence. The authors conclude that gadopentetate dimeglumine—enhanced echo-planar imaging can provide T1, T2, and T2* contrast that may be exploited for both lesion detection and lesion characterization. 相似文献
943.
Michael P. Recht Josef Kramer Cheryl A. Petersilge Joseph Yu Mini Pathria Debra Trudell David J. Sartoris Donald Resnick 《Journal of magnetic resonance imaging : JMRI》1994,4(2):173-177
Although magnetic resonance (MR) images of the glenohumeral joint frequently demonstrate intraarticular fluid, no specific criteria have, to the authors' knowledge, been published that allow accurate assessment of the amount of fluid present. Also, despite the increasing use of MR arthrography of the shoulder, the optimal amount of intra-articular fluid that should be used with this technique has not been determined. The authors progressively distended the glenohumeral joint in six cadaveric shoulder specimens with a dilute gadopentetate dimeglumine solution and obtained MR images after injection of 2, 5, 10, 15, and 20 mL of the solution. The pattern of fluid distribution was evaluated, and these results were then used to estimate the amount of fluid that was present in the glenohumeral joint on MR images of 20 shoulders obtained in 12 asymptomatic volunteers. In 14 of these shoulders, intraarticular fluid was present; however, in none was more than 2 mL evident. Results of the cadaveric study also indicated that 15 mL of intraarticular fluid appears to be the optimal amount for MR arthrography. 相似文献
944.
945.
Dr Andrzej Sapinski MD 《Journal of clinical monitoring and computing》1994,10(6):373-376
Objective. The objective of this study was to compare blood pressure (BP) measured by the sphygmooscillographic method with that measured by the direct and auscultatory methods.Methods. In 15 adult patients undergoing cardiac surgery, blood pressure was measured by the sphygmooscillographic and direct methods simultaneously on the same upper extremity. In another group of 86 children and 11 adults, blood pressure was measured by the sphygmooscillographic and auscultatory methods simultaneously, with one cuff. For the sphygmooscillographic measurement, we used sphygmomanometer-S, which measures blood pressure on the basis of the amplitude height (oscillometric) and the morphology (sphygmographic) of pulse waves recorded by a transducer placed in the cuff.Results. The systolic and diastolic blood pressure measured by the sphygmooscillographic method were both 2 mm Hg higher than those from the direct method; the mean blood pressure was 0.6 mm Hg higher. These differences were not significant. Compared with the auscultatory method, sphygmooscillographic systolic values were higher by 7 mm Hg, while diastolic values were lower by 9 mm Hg. These differences were significant.Conclusions. Blood pressure measurements obtained by the sphygmooscillographic method correlate well with the direct method for measuring blood pressure in children and adults; but, they do not correlate well with the auscultatory method. 相似文献
946.
The yeast spectrum of the 'tea fungus Kombucha' 总被引:1,自引:0,他引:1
947.
30例肝硬化食管静脉曲张破裂大出血患者,用垂体后叶素0.2~0.4U/min连续静脉滴注和硝酸甘油含服联合治疗。结果表明,近期止血有效申达80%,死亡率10%;无一例出现严重心绞痛和心电图异常。 相似文献
948.
下尿路梗阻性肾积水患者逼尿肌功能变化 总被引:1,自引:1,他引:0
目的:探讨下尿路梗阻性肾积水患者逼尿肌功能变化。方法:对20例(3.5-73岁)下尿路梗阻导致的肾积水组和10例(13-67岁)无肾积水的对照组进行膀胱压力容积测定与压力-流率测定,并记录不同膀胱灌注量的逼尿肌基础压力。结果:下尿路梗阻性肾积水组逼尿肌-括约肌协同失调(DSD)11例(55%),逼尿肌功能过度活跃5例;而对照组仅发现1例(10%)DSD,未发现有逼尿肌功能过度活跃。下尿路梗阻性肾积水组平均膀胱顺应性显著低于对照组(P<0.05),而下尿路梗阻性肾积水组平均逼尿肌基础压力,平均逼尿肌最大收缩压和残余尿量均显著高于对照组(P<0.05),且下尿路梗阻性肾积水组在灌注量逐渐增加时高逼尿肌基础压力发生率逐渐增加。结论:下尿路梗阻性肾积水多伴有逼尿肌功能异常,提示膀胱逼尿肌功能改变与下尿路梗阻性肾积水的形成及发展有一定的相关性。 相似文献
949.
人大肠癌细胞体外常温及温热环境中药物敏感性试验 总被引:1,自引:0,他引:1
用MTT比色法对20例大肠癌患者术后标本在常温及温热环境中进行体外药物敏感性试验,结果显示,某些药物在温热环境中,对癌细胞的杀伤作用有显著提高,此项试验为临床温热化疗法提供了理论依据。 相似文献
950.
Endovascular stent implantation in patients with stenotic aortoarteriopathies: early and medium-term results. 总被引:1,自引:0,他引:1
Ernest S Siwik Stanton B Perry James E Lock 《Catheterization and cardiovascular interventions》2003,59(3):380-386
Data regarding stent implantation for stenotic aortoarteriopathy (SAA) are incomplete. We report on nine patients with this rare syndrome who underwent arterial stent implantation. Indications, results, and complications for patients with SAA were reviewed. Nine patients underwent 11 procedures. Twenty-two stents were implanted in the aorta or brachiocephalic vessels. Five patients had diffuse stenoses, three patients had middle aortic syndrome, and one patient had thoracic and abdominal coarctation. Associated diagnoses included Williams syndrome (2), neurofibromatosis (2), Takayasu's (1), and congenital rubella (1). Median gradient was 60 mm Hg (20-140 mm Hg). Poststent gradient was 15 mm Hg (0-60 mm Hg; P < 0.001). Additional stents were implanted in two patients and five underwent stent redilation. Two patients (22%) were found to have aneurysm formation. Stent implantation effectively provides gradient relief in SAA. Gradient reduction persists or is amenable to redilation. Importantly, however, uncomplicated stent implantation does not preclude aneurysm formation and may be more common than in traditional patient groups. 相似文献