全文获取类型
收费全文 | 20904篇 |
免费 | 1122篇 |
国内免费 | 300篇 |
专业分类
耳鼻咽喉 | 133篇 |
儿科学 | 518篇 |
妇产科学 | 562篇 |
基础医学 | 863篇 |
口腔科学 | 310篇 |
临床医学 | 5405篇 |
内科学 | 1375篇 |
皮肤病学 | 144篇 |
神经病学 | 486篇 |
特种医学 | 2001篇 |
外科学 | 1934篇 |
综合类 | 3886篇 |
一般理论 | 1篇 |
预防医学 | 2116篇 |
眼科学 | 352篇 |
药学 | 1246篇 |
59篇 | |
中国医学 | 348篇 |
肿瘤学 | 587篇 |
出版年
2024年 | 31篇 |
2023年 | 258篇 |
2022年 | 633篇 |
2021年 | 842篇 |
2020年 | 793篇 |
2019年 | 635篇 |
2018年 | 681篇 |
2017年 | 728篇 |
2016年 | 598篇 |
2015年 | 666篇 |
2014年 | 1611篇 |
2013年 | 1378篇 |
2012年 | 1406篇 |
2011年 | 1355篇 |
2010年 | 1115篇 |
2009年 | 1088篇 |
2008年 | 1108篇 |
2007年 | 1010篇 |
2006年 | 965篇 |
2005年 | 740篇 |
2004年 | 626篇 |
2003年 | 513篇 |
2002年 | 355篇 |
2001年 | 333篇 |
2000年 | 302篇 |
1999年 | 287篇 |
1998年 | 215篇 |
1997年 | 235篇 |
1996年 | 182篇 |
1995年 | 163篇 |
1994年 | 151篇 |
1993年 | 119篇 |
1992年 | 109篇 |
1991年 | 99篇 |
1990年 | 71篇 |
1989年 | 75篇 |
1988年 | 66篇 |
1987年 | 62篇 |
1986年 | 78篇 |
1985年 | 73篇 |
1984年 | 45篇 |
1983年 | 55篇 |
1982年 | 91篇 |
1981年 | 74篇 |
1980年 | 42篇 |
1979年 | 50篇 |
1978年 | 70篇 |
1977年 | 32篇 |
1976年 | 45篇 |
1975年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
A mesenteric cyst with milk of calcium in an adult patient is presented. Preoperative evaluation included plain film, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). To our knowledge, the presence of milk of calcium in a mesenteric cyst has not been previously described. 相似文献
82.
H. Brändström P. Gerdhem F. Stiger K. J. Obrant H. Melhus Ö. Ljunggren A. Kindmark K. Åkesson 《Calcified tissue international》2003,74(1):18-24
Osteoprotegerin (OPG), a secreted member of the tumor necrosis factor receptor family, is a potent inhibitor of osteoclast activation and differentiation. In animal models OPG prevents bone loss, and in humans bone resorption can be reduced by injections of OPG. OPG may also play a role in cardiovascular disease since mice lacking the OPG gene display arterial calcification. In a screening effort of the OPG gene, we recently discovered a single nucleotide polymorphism in the promoter region of OPG (T950C), and reported an association with vascular morphology and function in 59 healthy individuals. Due to the pronounced effect of OPG on bone turnover, the present study was conducted to investigate whether OPG polymorphisms are also associated with bone mineral density or with fracture. The relationship between single nucleotide polymorphisms in the promoter region of OPG (T950C) and the first intron (C1217T), and bone mineral density, measured by DXA in the hip or spine or ultrasound of the heel, was investigated in the Malmö OPRA-study of 1044 women, all 75 years old. The possible relation to fracture incidence was also analyzed. Among the 858 and 864 individuals respectively, genotyped, no significant associations between the investigated single nucleotide polymorphisms and bone mineral density measurements (T950C P = 0.50–0.64, C1217T P = 0.51–1.00), quantitative ultrasound measurements of the calcaneus, or fractures (T950C P = 0.61–0.66, C1217T P = 0.14–0.33) were found. Thus, our results show that polymorphisms in the OPG gene, one of which has previously been found to be associated with cardiovascular morphology and function, are not associated with bone mineral density in elderly Swedish women. 相似文献
83.
医科院校师生对考试现状看法的调查与分析 总被引:2,自引:0,他引:2
医科院校的考试主要是学科考试。调查显示,教师和学生对目前的学科考试模式评价均不高,存在的最主要弊端是考试方法单一,考试管理不够科学、严谨,考风不好;认为作弊的主要原因在于学生自己学习不努力、社会风气影响以及学校对教师和学生要求不够严格。因此,要搞好考试改革,提高考试质量,必须着重从改革考试方法、加强考试管理的改革与研究、整顿考风、制定科学的成绩评定方法、加强能力考核、实施教考分离等方面进行探索与实践。 相似文献
84.
刘晓加 《南方医科大学学报》1995,(3)
根据汉语文字的特点,书写行为的相关因素及我国文化背景的具体情况,设计了一套用于评定汉语失写症患者书写能力的方法,包括自动书写、抄写、听写、看图书写、主动书写及书写相关能力检查6个部分。通过临床应用,初步显示了该检查法在失写症评估中的可靠性和实用性。 相似文献
85.
372���Ǽ��Լ�״��������������� 总被引:14,自引:0,他引:14
目的 探讨辅助检查在诊断亚急性甲状腺炎中的作用。方法 回顾分析372例亚急性甲状腺炎病人所做的各项辅助检查结果。结果 血沉,B超,彩色多普勒,甲状腺核素扫描,甲状腺吸^131I率测定,细针穿刺细胞学,TMA,TGA等项检查诊断本病的阳性率分别为93.75%,81.63%,95.62%,89.66%,69.70%,89.41%,13.46%和9.62%。T3,T4,TSH检查结果随着病程的进展变化较大。结论 血沉检查对诊断本病缺乏特异性;彩色多普勒,细针穿刺细胞学检查诊断率高,特异性强,是首选的检查手段;甲状腺核素扫描可以准确地反映甲状腺功能状态;检测血清中T3,T4,TSH水平可以协助诊断本病,判断疾病所处时期。 相似文献
86.
87.
D.R. Pina S.B. Duarte J. Morceli T. Ghilardi Netto 《Applied radiation and isotopes》2006,64(12):1623-1630
We present the construction of a homogeneous phantom to be used in simulating the scattering and absorption of X-rays by a standard patient chest and skull when irradiated laterally. This phantom consisted of lucite and aluminium plates with their thickness determined by a tomographic exploratory method applied to the anthropomorphic phantom. Using this phantom, an optimized radiographic technique was established for chest and skull of standard sized patient in lateral view. Images generated with this optimized technique demonstrated improved image quality and reduced radiation doses. 相似文献
88.
M. Amgwerd M. Röthlin D. Candinas R. Schimmer H. P. Klotz F. Largiadèr 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1994,379(6):335-340
A number of studies have shown that ultrasound has an advantage over physical examination in the diagnosis of acute appendicitis. Most of these studies were conducted by experts in the field of ultrasonography. In this study the influence of experience on the results of the sonography of actue appendicitis were evaluated. All 203 patients admitted to our unit between December 1990 and December 1992 were examined physically and sonographically by a team of surgeons consisting of one experienced sonographer and six inexperienced surgical trainees. Laparotomy was performed in 136 patients (46%). Appendicitis was demonstrated histologically in 119 cases (39.4%). Initial clinical findings were positive in 87 (28.8%). Sonography was positive in 119 patients (39.4%). The 163 patients not operated on demonstrated other pathology on ultrasound in 60 cases (19.9%). The rate of negative laparotomies amounted to 7.2% in our study. Sensitivity and specificity for the sonographic diagnosis were 92% and 95%, respectively. They were only 81% and 80% for physical examination. Overall accuracy was 92% for sonography. Sensitivity and specificity for the inexperienced surgeons were 87% and 93%, respectively, while the experienced surgeon reached values of 97% and 98%, respectively. The results of both groups are comparable with values in the literature, suggesting that ultrasound evaluation of appendicitis is not a diagnostic tool limited to a few experienced sonographers. 相似文献
89.
Ultrasonography in the detection of cervical incompetency 总被引:2,自引:0,他引:2
Mario Podobnik Milan Buli Nikola Smiljanic Josip Bistri
ki 《Journal of clinical ultrasound : JCU》1988,16(6):383-391
In 80 pregnancies with clinical and ultrasonic signs of cervical incompetency, the length of the cervix and the thickness of the anterior wall of a lower uterine segment have been evaluated ultrasonically. We have also measured the width of the endocervical canal and studied the prolapse of fetal membranes (with fetal parts) into the endocervical canal. We evaluated these same parameters in 80 healthy pregnancies. The length of the cervix, the thickness of the anterior wall of a lower uterine segment, and the width of the endocervical canal were followed longitudinally in the patients from the 10th to the 36th gestation week. No statistically significant differences between age groups were found. In four age groups at risk for cervical incompetency, cervical lengths and wall thickness were significantly different (p less than 0.001) from those in comparable controls. Forty-five percent of the patients in the at-risk group, with cervical cerclage, delivered at 37.3 (range: 32 to 41) weeks and 6.25% of pregnancies ended in abortion when the amniotic membrane herniated into the cervical canal, with or without some part of the fetus. 相似文献
90.
目的:探讨B超对异位妊娠的诊断价值。方法:对2004年1月~2009年1月的86例异位妊娠患者,采用超声诊断仪进行检查、分析。结果:超声检查的86例异位妊娠患者,诊断符合84例,确诊率为97.6%,误诊2例,误诊率为2.4%。结论:超声检查有着无创性、可重复性等不可比拟的优越性,为异位妊娠患者的诊断及治疗提供了可靠的依据。 相似文献