全文获取类型
收费全文 | 226108篇 |
免费 | 20243篇 |
国内免费 | 12696篇 |
专业分类
耳鼻咽喉 | 2542篇 |
儿科学 | 3393篇 |
妇产科学 | 3550篇 |
基础医学 | 22836篇 |
口腔科学 | 3995篇 |
临床医学 | 26728篇 |
内科学 | 31842篇 |
皮肤病学 | 3093篇 |
神经病学 | 10339篇 |
特种医学 | 8736篇 |
外国民族医学 | 74篇 |
外科学 | 25193篇 |
综合类 | 39533篇 |
现状与发展 | 55篇 |
一般理论 | 21篇 |
预防医学 | 17438篇 |
眼科学 | 5004篇 |
药学 | 22570篇 |
212篇 | |
中国医学 | 14254篇 |
肿瘤学 | 17639篇 |
出版年
2024年 | 710篇 |
2023年 | 2790篇 |
2022年 | 7194篇 |
2021年 | 9766篇 |
2020年 | 7433篇 |
2019年 | 6185篇 |
2018年 | 6978篇 |
2017年 | 6633篇 |
2016年 | 6369篇 |
2015年 | 9987篇 |
2014年 | 12278篇 |
2013年 | 13132篇 |
2012年 | 18927篇 |
2011年 | 19842篇 |
2010年 | 14484篇 |
2009年 | 12217篇 |
2008年 | 14287篇 |
2007年 | 13831篇 |
2006年 | 13001篇 |
2005年 | 11293篇 |
2004年 | 8599篇 |
2003年 | 8094篇 |
2002年 | 6809篇 |
2001年 | 5230篇 |
2000年 | 4230篇 |
1999年 | 3335篇 |
1998年 | 1705篇 |
1997年 | 1552篇 |
1996年 | 1275篇 |
1995年 | 1157篇 |
1994年 | 940篇 |
1993年 | 614篇 |
1992年 | 1108篇 |
1991年 | 899篇 |
1990年 | 824篇 |
1989年 | 709篇 |
1988年 | 612篇 |
1987年 | 614篇 |
1986年 | 498篇 |
1985年 | 405篇 |
1984年 | 284篇 |
1983年 | 234篇 |
1982年 | 147篇 |
1981年 | 159篇 |
1980年 | 117篇 |
1979年 | 247篇 |
1978年 | 177篇 |
1977年 | 122篇 |
1976年 | 127篇 |
1974年 | 121篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
MRI同层动态增强对垂体微腺瘤的诊断价值 总被引:3,自引:0,他引:3
目的:分析垂体微腺瘤的MPd同层动态增强特征。方法:对40例临床怀疑为垂体微腺瘤的病人行同层动态增强MPd扫描,并绘出时间一信号强度曲线图。结果:40例病人中共检出垂体微腺瘤26例。同层动态增强后垂体微腺瘤的MPd表现为圆或椭圆形的低或稍低信号,似“充盈缺损”;垂体微腺瘤的最大信号强度多出现在注入造影剂后32~96s,以64s最明显。结论:同层MPd动态增强对垂体微腺瘤的诊断有较高价值。 相似文献
42.
结肠癌伴糖尿病病人的围手术期护理 总被引:2,自引:0,他引:2
[目的]探讨结肠癌伴糖尿病围手术期的最佳护理措施。[方法]对41例患有糖尿病的结肠癌围手术期病人,采取术前心理护理、控制血糖、清洁肠道、术后安置合适体位、加强引流管护理、积极预防并发症、良好的营养支持。针对易发生感染性并发症的特点,加强对呼吸道、皮肤、泌尿系、伤口感染预防的护理。[结果]发生与感染有关的并发症5例,其中肺部感染2例、切口感染2例、尿路感染1例。[结论]通过以上方法护理,使围手术期并发症明显减少,而且方法简便易行,容易做到。 相似文献
43.
Gastrointestinal dysfunction among intensive care unit patients 总被引:3,自引:0,他引:3
This study used the Acute Physiological and Chronic Health Evaluation (APACHE II) system to select two groups of ICU patients with comparable risk of hospital death to evaluate the importance of GI dysfunction, defined as failure to tolerate enteral nutrition (EN), as a prognostic factor. In our ICU, patients who have not undergone recent bowel surgery are treated by EN. Those patients who cannot tolerate EN are treated by total parenteral nutrition (TPN). One hundred and eleven patients who tolerated EN (functioning gut) and 97 TPN patients who failed to tolerate EN (GI dysfunction) were studied. The mean APACHE II scores of the two groups were 17.7 +/- 6.5 (SD) and 17.7 +/- 5.1, respectively. The observed mortality of patients with GI dysfunction (51%) was significantly higher (p less than .0005) than that of patients with a functioning gut (25%). This was associated with significantly poorer APACHE II mean BP, oxygenation, and creatinine scores among the GI dysfunction patients. Our results suggest that shock, ischemia, and hypoxemia, in addition to causing impairment of renal function, may bring about changes in the GI tract, evident clinically only as a failure to tolerate EN, which have an adverse effect on the prognosis of ICU patients so affected. 相似文献
44.
Biosynthesis of the antibiotic actinorhodin. Analysis of blocked mutants of Streptomyces coelicolor 总被引:6,自引:0,他引:6
From two types of class V act mutants of Streptomyces coelicolor two monomeric precursors of actinorhodin have been isolated and their structures determined. One is the known antibiotic kalafungin and the other a new compound. Their relationship to actinorhodin biosynthesis is discussed. 相似文献
45.
MHC—I类抗原加工途径异常与肿瘤关系的研究进展 总被引:1,自引:0,他引:1
随着免疫学研究的不断深入,MHC-I类抗原呈递细节已逐渐明晰,全面认识肿瘤细胞MHC-I类相关抗原加工途径缺陷或改变与肿瘤生物学及肿瘤临床的关系,将有助于肿瘤的诊治和预防。 相似文献
46.
Kuo-Sheng Hung MD Phd Chung-Ling Liang MD Cheng-Haung Wang MD Hsueh-Wen Chang PhD Naeun Park MS Suh-Hang Hank Juo MD PhD 《Journal of clinical neuroscience》2004,11(8):849-853
Frontal intracerebral haemorrhage (ICH) is a common result of cranial trauma. Outcome differences between bilateral and unilateral frontal ICH are not well studied but would be valuable to predict prognosis in clinical practice. Two aims are proposed in this study: first to compare the risk of developing delayed ICH after bilateral or unilateral frontal ICH, and second to determine the variables helpful to predict outcome according to the Glasgow Outcome Scale (GOS). Between January 1993 and December 1997, 694 consecutive patients with traumatic ICH were admitted to the Chang Gung Medical Center within 24 h of the trauma. Patients with ICH in sites other than the frontal lobes were excluded. A total of 161 cases (mean age 46.3+/-20.3 years), including 57 bilateral (mean age 52.5+/-18.7 years) and 104 unilateral (mean age 42.9+/-20.5 years) traumatic frontal ICH were studied. Twenty-eight of 57 patients (49%) with bifrontal ICH versus 17 of 104 patients (16%) with unilateral frontal ICH had a further, delayed ICH. In 42 of 45 patients (93%) with delayed ICH, this occurred within 5 days of the initial trauma. Multivariate logistic regression was used to select significant predictors of outcome. We found that delayed ICH (p<0.001), age (p=0.004) and mechanism of injury (p=0.001) explained the worse outcome in patients with bifrontal ICH. The best-fitting logistic regression model included three variables: delayed ICH (p=0.011), initial GCS (p=0.023), and a sum score of clinical and radiological variables (p=0.003). Bifrontal ICH tended to occur in older patients after a fall and was associated with a higher risk of developing delayed ICH or brain stem compression compared to unilateral ICH damage. Using these three variables - delayed ICH, initial GCS, and the sum score - in a logistical regression model is useful to predict outcome in patients with traumatic frontal ICH and may aid patient management. 相似文献
47.
目的 为构建生物人工肝进行肝细胞的准备。方法 采用胶原酶半原位灌流法分离单个乳猪肝细胞,并对其活力及单层和聚集培养后的白蛋白、尿素合成功能进行检测。结果 采用本方法从每头乳猪中分离到的单个肝细胞数为(3.1±1.5)×10~(10),活性超过95%。在加入激素和生长因子的培养基中单层培养时,肝细胞功能良好,可维持2周左右。而在未加入激素和生长因子的培养中肝细胞虽能存活1周,但功能于24h后即丧失。球形聚集培养可实现肝细胞的大量培养,且生物学活性较单层培养显著提高。结论 采用胶原酶半原位灌注法所得单个乳猪肝细胞基本能满足构建生物人工肝对肝细胞数量的要求。聚集培养接种密度大,细胞生物学活性高,可用于构建生物人工肝。 相似文献
48.
A randomly selected sample of 662 12-year-old Hong Kong children, 529 of whom were Southern Chinese and 133 non-Chinese, was clinically examined for dental caries. The DMFT values were 2.76 and 1.66 for the Chinese and non-Chinese children, respectively. The D component for the Chinese children was 2.12, while for the non-Chinese children it was only 0.45. Approximately 24.0% of the Chinese children had attended the dentist because they were in pain. Only 3.8% of the Chinese children had sought orthodontic or preventive treatment, compared with 24.0% of the non-Chinese children. Although these findings indicate the caries experience to be well below the FDI/WHO global goal for the year 2000, there is a great need to increase the level of dental awareness among Chinese children. 相似文献
49.
Infusions made from 15 Chinese, 11 Ceylon/Indian and 6 herb teas (1 g/100 ml deionized water at 85 degrees C) were analyzed for F, P, Ca, Al, Mg, Mn and Zn. Chinese teas continued to release F throughout the first hour of infusion, whereas release of F from Ceylon/Indian teas was essentially completed after 5 minutes. After a 15-minute infusion, the mean F concentration in Chinese teas was 1.73 ppm, and in Ceylon/Indian teas it was 1.24 ppm. Herb teas contained a negligible amount of F (0.02-0.05 ppm). Phosphorus and Mg were the most abundant of the other elements with an average of 12.5 and 9.1 ppm, respectively. A high correlation (r = 0.81) was found between the released F and Al. The total F content in tea leaves ranged from 82 to 371 ppm. The addition of milk to tea infusions did not appreciably reduce the F concentration. The estimated daily F intake from tea infusion made with fluoridated water at 0.7 ppm is 1.05 mg. 相似文献
50.
随着医院信息化程度的提高,建立有效的医院信息网络系统安全体系成了重要的课题.在充分认识到病毒危害的前提下,本文阐述了医院信息系统内软件和硬件的防病毒策略. 相似文献