全文获取类型
收费全文 | 19435篇 |
免费 | 1682篇 |
国内免费 | 539篇 |
专业分类
耳鼻咽喉 | 188篇 |
儿科学 | 415篇 |
妇产科学 | 353篇 |
基础医学 | 1546篇 |
口腔科学 | 592篇 |
临床医学 | 3185篇 |
内科学 | 2647篇 |
皮肤病学 | 297篇 |
神经病学 | 1661篇 |
特种医学 | 877篇 |
外国民族医学 | 2篇 |
外科学 | 3619篇 |
综合类 | 2041篇 |
预防医学 | 1474篇 |
眼科学 | 363篇 |
药学 | 1019篇 |
35篇 | |
中国医学 | 506篇 |
肿瘤学 | 836篇 |
出版年
2024年 | 71篇 |
2023年 | 425篇 |
2022年 | 663篇 |
2021年 | 980篇 |
2020年 | 927篇 |
2019年 | 833篇 |
2018年 | 806篇 |
2017年 | 727篇 |
2016年 | 800篇 |
2015年 | 700篇 |
2014年 | 1242篇 |
2013年 | 1273篇 |
2012年 | 967篇 |
2011年 | 1038篇 |
2010年 | 835篇 |
2009年 | 789篇 |
2008年 | 764篇 |
2007年 | 831篇 |
2006年 | 716篇 |
2005年 | 594篇 |
2004年 | 555篇 |
2003年 | 526篇 |
2002年 | 422篇 |
2001年 | 445篇 |
2000年 | 311篇 |
1999年 | 258篇 |
1998年 | 250篇 |
1997年 | 254篇 |
1996年 | 241篇 |
1995年 | 201篇 |
1994年 | 199篇 |
1993年 | 197篇 |
1992年 | 185篇 |
1991年 | 180篇 |
1990年 | 162篇 |
1989年 | 151篇 |
1988年 | 180篇 |
1987年 | 115篇 |
1986年 | 132篇 |
1985年 | 127篇 |
1984年 | 110篇 |
1983年 | 90篇 |
1982年 | 82篇 |
1981年 | 65篇 |
1980年 | 87篇 |
1979年 | 33篇 |
1978年 | 25篇 |
1977年 | 17篇 |
1976年 | 20篇 |
1974年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 515 毫秒
91.
We have developed a simple instrument for pressure algometry. It can be made easily using components found in most anaesthetic rooms. Ten students were able to make the device using written instructions. All the resulting algometers performed within 10% accuracy limits for values up to 4 kgcm−2 . 相似文献
92.
Sidestream versus mainstream carbon dioxide analyzers 总被引:1,自引:0,他引:1
93.
94.
回顾性分析了22例少见部位的脑膜瘤,22例CT表现不典型及8例CT误诊脑膜瘤的CT表现,以确定脑膜瘤不典型表现与CT误诊的关系。结果显示脑膜瘤的CT误诊多数缘于经验不足与疏忽,少数为极不典型表现所致。若检查全面、阅片仔细.术前CT定性率可由90%提高至96.25%。 相似文献
95.
The extensometer is a new device with potential in the field of respiratory pattern analysis. This paper describes the physical principles upon which the extensometer depends and also assesses its performance as a noninvasive respiratory monitor in respect of its ability to measure tidal volume and to determine obstructive breathing patterns in awake volunteers in the supine position over a limited time period. Further developments of the device are outlined and the current status of torso transducers in anaesthesia and intensive care are discussed. 相似文献
96.
The relationship between internal jugular vein diameter as measured with an ultrasound imaging machine (SiteRite, Dymax) and external jugular vein diameter was studied in 50 anaesthetised patients undergoing elective cardiac surgery. There was an inverse correlation between external jugular vein diameter and internal jugular vein diameter ( r = −0.47, p < 0.001). All patients with an external jugular vein diameter of 7 mm or greater had an internal jugular vein diameter of less than 15 mm. No patient with an external jugular vein diameter of less than 7 mm had an internal jugular vein diameter of less than 20 mm. No other patient dimension (height, weight, body mass index, neck circumference) predicted internal jugular vein size. These results suggest that a large external jugular vein (i.e. 7 mm or greater in external diameter) may be associated with a small internal jugular vein. A size 5.0-mm internal diameter tracheal tube may be used to provide a rapid assessment of external jugular vein diameter. 相似文献
97.
Louisa Sims 《Early child development and care》1994,98(1):79-96
This study examines young children's perceptions of work through a specific example. Reception class children at an inner city school were shown pictures of the same figure washing in four different contexts, ranging from housework to paid employment, in order to examine early classifications and conceptual systems relating to the concept of work and to ascertain whether these were gender related. Individual children varied in the complexity of their ideas, but the majority had not yet began to form hierarchical classifications of work which favour paid employment. There was evidence however that some children were beginning to devalue traditional women's work, suggesting that gender stereotypes are still prevalent amongst this age group, despite efforts by the educational system to counter this. 相似文献
98.
The effect of thoracic (T7-8) epidural etidocaine 1.5%, 9 ml, and continuous per- and postoperative epidural infusion of etidocaine 1.5%, 4 ml/h, on early (less than 500 ms) somatosensory evoked potentials (SEPs), and cortisol and glucose in plasma during cholecystectomy, was examined in ten patients. Spread of analgesia (pin-prick) was T3 (T1-T3) to L2 (T11-L3) 35 min after injection of etidocaine, and T3 (T2-T4) to T12 (T8-L4) 3 h after surgical incision (median (range)). Before operation, epidural etidocaine had no significant effects on peak-to-peak amplitude of SEPs to electrical stimulation at the L1, T10 or T6 dermatomal level (P greater than 0.09). SEPs were abolished in only two patients at T6, and no patient had SEPs abolished at T10 or L1. The plasma concentrations of cortisol and glucose were significantly increased 20 min after surgical incision and remained increased throughout the study. No correlation was found between the block-induced decrease in the peak-to-peak amplitude at T6 or T10 and increase in plasma cortisol, except for a negative correlation at T10 and the initial increase in cortisol (Rs = 0.72, P = 0.03). In conclusion, thoracic epidural administration of 9 ml of etidocaine 1.5% does not provide total afferent somatic blockade assessed by SEP and the stress response to cholecystectomy. 相似文献
99.
H. H. LUTTROPP R. THOMASSON S. DAHM J. PERSSON O. WERNER 《Acta anaesthesiologica Scandinavica》1994,38(2):121-125
Xenon is a more potent anesthetic than nitrous oxide, and gives more profound analgesia. This investigation was performed to assess the potential of xenon for becoming an anesthetic inspite of its high manufacturing cost. Seven ASA I—-II patients undergoing cholecystectomy (n = 4), hernia repair (n = 2), or mammoplasty (n=l) were studied. Denitrogenation by 15–20 min of oxygen breathing under propofol anesthesia was followed by fentanyl–supplemented xenon anesthesia administered via an automatic minimal flow system which held the oxygen concentration at 30%. Xenon anesthesia lasted 76–228 min and 8–14 1 of xenon (ATPD) was used, of which 5.6–8.1 1 was expended during the first 15 min. Anesthesia appeared to be satisfactory, and the patients woke up rapidly after xenon was discontinued. The automatic system made minimal flow xenon anesthesia easy to administer, but nitrogen accumulation is still a problem. Assuming a xenon price of 10 US $ per litre, the average cost for xenon was about 65 US $ for the first 15 min and then about 25 USS for each subsequent hour of anesthesia. 相似文献
100.
目的 探索LDH实验检测细胞活力的可行性。方法 原代培养骨髓细胞和软骨细胞,用LDH实验测定上述两组细胞的活力,并与镜下活体观察到细胞的生长状况相比较。与目前比较成熟的测定细胞活力的MTS实验的测得的值相比较。结果 LDH实验对上述两组细胞的活力的测定结果与镜下活体观察到的结果相符合。与MTS实验的测得的结果经统计学处理无显著差异。结论 LDH实验可用于细胞活力的直接测定,而对活细胞的生存、繁殖无影响。 相似文献