全文获取类型
收费全文 | 15472篇 |
免费 | 1177篇 |
国内免费 | 427篇 |
专业分类
耳鼻咽喉 | 219篇 |
儿科学 | 286篇 |
妇产科学 | 264篇 |
基础医学 | 868篇 |
口腔科学 | 365篇 |
临床医学 | 1761篇 |
内科学 | 985篇 |
皮肤病学 | 208篇 |
神经病学 | 637篇 |
特种医学 | 268篇 |
外科学 | 1663篇 |
综合类 | 2727篇 |
一般理论 | 5篇 |
预防医学 | 3508篇 |
眼科学 | 348篇 |
药学 | 1452篇 |
36篇 | |
中国医学 | 1053篇 |
肿瘤学 | 423篇 |
出版年
2024年 | 26篇 |
2023年 | 201篇 |
2022年 | 278篇 |
2021年 | 492篇 |
2020年 | 518篇 |
2019年 | 492篇 |
2018年 | 442篇 |
2017年 | 508篇 |
2016年 | 597篇 |
2015年 | 547篇 |
2014年 | 885篇 |
2013年 | 1083篇 |
2012年 | 885篇 |
2011年 | 945篇 |
2010年 | 728篇 |
2009年 | 678篇 |
2008年 | 779篇 |
2007年 | 854篇 |
2006年 | 751篇 |
2005年 | 620篇 |
2004年 | 547篇 |
2003年 | 460篇 |
2002年 | 431篇 |
2001年 | 355篇 |
2000年 | 297篇 |
1999年 | 286篇 |
1998年 | 235篇 |
1997年 | 197篇 |
1996年 | 159篇 |
1995年 | 164篇 |
1994年 | 155篇 |
1993年 | 118篇 |
1992年 | 128篇 |
1991年 | 133篇 |
1990年 | 111篇 |
1989年 | 116篇 |
1988年 | 92篇 |
1987年 | 86篇 |
1986年 | 112篇 |
1985年 | 73篇 |
1984年 | 76篇 |
1983年 | 71篇 |
1982年 | 77篇 |
1981年 | 59篇 |
1980年 | 59篇 |
1979年 | 54篇 |
1978年 | 32篇 |
1977年 | 20篇 |
1976年 | 28篇 |
1975年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
影响肝外伤手术死亡的危险因素分析 总被引:3,自引:1,他引:2
目的分析影响肝外伤手术死亡的危险因素,探讨其临床意义。方法根据AAST和ISS标准,回顾性分析90例肝外伤手术病例,对影响手术死亡的危险因素进行单因素比较和Logistic回归分析。结果死亡15例,其中Ⅲ级2例、Ⅳ级4例、Ⅴ级9例,总体手术死亡率17%。Ⅳ~Ⅴ级肝外伤手术方式的单因素比较提示:清创性肝切除术的相对危险度是0.73;而规则性肝切除术、肝静脉或肝后下腔静脉修补术相对危险度分别是1.32、1.52。Logistic回归分析提示:ISS分会和术中失血量是影响手术死亡率的2个独立因素。结论ISS分值、术中失出血量和手术方式是影响肝外伤手术死亡的3个重要因素,娴熟的手术技能和合理的手术方式可以减少术中出血量和降低手术死亡率。 相似文献
72.
目的 :改进斑点免疫金渗滤法的渗滤装置 ,降低成本 ,使之更适用于现场操作。方法 :用自制的圆形渗滤片替代塑料渗滤盒 ,并比较二者的效果。结果 :自制的渗滤片体积更小 ,成本更低 ,为一次性使用材料 ;检测抗体的效果与塑料渗滤盒法一致。结论 :自制的渗滤片优于常用的塑料渗滤盒 相似文献
73.
D. I. NEWBLE 《Medical education》1988,22(3):200-204
A structured clinical examination has been an integral component of the final-year examinations conducted by the Departments of Medicine and Surgery at the University of Adelaide for the last 8 years. It has been used as an alternative to the traditional clinical examination. This paper describes the results of ongoing student and examiner surveys carried out to determine their views and satisfaction with this new approach. It also briefly discusses the feasibility of introducing such an examination into a conventional medical school environment. The surveys showed a remarkable level of acceptance and support by both students and examiners. This positive reaction has been maintained over the 8-year period. The main reasons seem to be its perceived relevance and fairness. Students also appear to be directing their learning in a direction thought desirable by teachers. No significant problems have been encountered with the practical implementation of the method. 相似文献
74.
75.
This study investigated a discrete-trial, titration duration discrimination procedure in behavioral pharmacology. Pentobarbital and d-amphetamine, measured with this procedure, selectively affected discrimination more than response tendencies. Pentobarbital also tended to affect selectively discrimination of longer durations, whereas d-amphetamine did not. Further experiments showed that (1) other algorithms for modulating stimulus duration are useful in behavioral pharmacology and toxicology, (2) threshold estimates are similar with the method of constant stimuli and the method of titration, and (3) this titration procedure permits the separate examination of drug effects upon discrimination and upon response tendencies; the fixed-interval procedure does not. Baseline variability was an important correlate of drug effects in that the endpoints with more variable baselines were also more sensitive to drugs. 相似文献
76.
Validation of a self-administered diet history questionnaire using multiple diet records 总被引:25,自引:0,他引:25
Gladys Block Margo Woods Arnold Potosky Carolyn Clifford 《Journal of clinical epidemiology》1990,43(12):1327-1335
The validity of a self-administered diet history questionnaire has been estimated using as the reference data the mean of three 4-day diet records collected over the year prior to the administration of the questionnaire, in 1985–1986. Subjects were women ages 45–70 years, participants in the Women's Health Trial Feasibility Study, a multi-center clinical trial in which some women were randomized to be taught to adopt and maintain a low-fat diet, while others maintained their usual diet. The questionnaire produced group mean nutrient estimates closely approximating the values obtained by three 4-day records, e.g. in the usual-diet group, 37.7% of calories from fat by both food records and by questionnaire, and in the low-fat, group, 21.3% of calories from fat by food records and 23.7% of calories from fat by questionnaire. Correlations between questionnaire and diet records for per cent of calories from fat were 0.67 and 0.65 respectively in the two groups; most correlations were in the 0.5–0.6 range, and were similar to those achievable by a single 4-day food record. 相似文献
77.
A peer tutorial programme which is available to all first- and second-year medical students has been in operation at Case Western Reserve University School of Medicine since 1972. A retrospective study of the classes of 1982, 1983 and 1984 was undertaken to assess the participation levels in the tutorial programme and to compare the participation level to available performance parameters. The analysis revealed that 54% of the first-year classes and 22% of the second-year classes participated in the peer tutorial programme. X2 analysis of the data demonstrated that the relationship between participation in the tutorial programme and performance on examinations reached statistical significance. The results suggested that an open peer tutorial programme responded to the needs, both cognitive and affective, of medical students. 相似文献
78.
Michael Nelson† Gillian F. Hague† Cyrus Cooper‡ Valda W. Bunker§ 《Journal of human nutrition and dietetics》1988,1(2):115-127
Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly. 相似文献
79.
80.
This paper describes a teaching programme for final- (sixth-) year undergraduate medical students during their 10-week term in child health. Students attend schools on two occasions and are actively involved in the physical, educational and emotional assessment of children. The advantages of the programme include active participation by the students, contact with children in a less threatening environment, learning new skills in the assessment of children, and knowledge of common screening procedures. Student evaluation of the programme has been positive. 相似文献