全文获取类型
收费全文 | 49245篇 |
免费 | 2444篇 |
国内免费 | 1158篇 |
专业分类
耳鼻咽喉 | 269篇 |
儿科学 | 1402篇 |
妇产科学 | 227篇 |
基础医学 | 2466篇 |
口腔科学 | 93篇 |
临床医学 | 7544篇 |
内科学 | 9283篇 |
皮肤病学 | 263篇 |
神经病学 | 2258篇 |
特种医学 | 1453篇 |
外科学 | 4548篇 |
综合类 | 9887篇 |
预防医学 | 3314篇 |
眼科学 | 238篇 |
药学 | 5862篇 |
48篇 | |
中国医学 | 2214篇 |
肿瘤学 | 1478篇 |
出版年
2024年 | 70篇 |
2023年 | 601篇 |
2022年 | 1507篇 |
2021年 | 1991篇 |
2020年 | 1748篇 |
2019年 | 1352篇 |
2018年 | 1424篇 |
2017年 | 1554篇 |
2016年 | 1810篇 |
2015年 | 1724篇 |
2014年 | 4228篇 |
2013年 | 4013篇 |
2012年 | 3582篇 |
2011年 | 3668篇 |
2010年 | 2872篇 |
2009年 | 2489篇 |
2008年 | 2389篇 |
2007年 | 2425篇 |
2006年 | 2147篇 |
2005年 | 1771篇 |
2004年 | 1398篇 |
2003年 | 1148篇 |
2002年 | 872篇 |
2001年 | 821篇 |
2000年 | 687篇 |
1999年 | 590篇 |
1998年 | 472篇 |
1997年 | 446篇 |
1996年 | 376篇 |
1995年 | 323篇 |
1994年 | 316篇 |
1993年 | 222篇 |
1992年 | 198篇 |
1991年 | 196篇 |
1990年 | 183篇 |
1989年 | 148篇 |
1988年 | 138篇 |
1987年 | 96篇 |
1986年 | 90篇 |
1985年 | 124篇 |
1984年 | 108篇 |
1983年 | 53篇 |
1982年 | 80篇 |
1981年 | 69篇 |
1980年 | 62篇 |
1979年 | 51篇 |
1978年 | 43篇 |
1977年 | 36篇 |
1976年 | 28篇 |
1975年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
The Hemodynamic Mechanisms of Lung Injury and Systemic Inflammatory Response Following Brain Death in the Transplant Donor 总被引:7,自引:2,他引:5
Vassilios S. Avlonitis Christopher H. Wigfield John A. Kirby John H. Dark 《American journal of transplantation》2005,5(4):684-693
Brain-dead donors are the major source of lungs for transplantation. Brain death is characterized by two hemodynamic phases. Initially, massive sympathetic discharge results in a hypertensive crisis. This is followed by neurogenic hypotension. Up-regulation of pro-inflammatory mediators occurs in all organs and lung injury develops; this can adversely affect graft function post-transplantation. The mechanisms of the systemic and lung inflammation are unknown. We hypothesized that the hemodynamic changes are responsible for these inflammatory phenomena. Brain death was induced by intra-cranial balloon inflation in rats. This resulted in hypertensive crisis, followed by hypotension. There was a significant increase in blood neutrophil CD11b/CD18 expression and pro-inflammatory cytokine levels in serum and bronchoalveolar lavage, compared with control animals. Rupture of the capillary-alveolar membrane was demonstrated by electron microscopy. Elimination of the hypertensive response by α-adrenergic antagonist pre-treatment prevented inflammatory lung injury, reduced the systemic inflammatory markers and preserved capillary-alveolar membrane integrity. Correction of the neurogenic hypotension with noradrenaline ameliorated the systemic inflammatory response and improved oxygenation. We conclude that the sympathetic discharge triggers systemic and lung inflammation, which can be further enhanced by neurogenic hypotension. Management of the brain-dead donor with early anti-inflammatory treatment and vasoconstrictors is warranted. 相似文献
32.
Andr ia Kist Fernandes Felipe Mallmann Ana Maria Pasquali Steinhorst Fernando Lopes Nogueira Eduardo Mü ller vila Dumitriu Zunino Saucedo Francisco Juchem Machado Marcelo Greg rio Raymundi S rgio Saldanha Menna Barreto Paulo de Tarso Roth Dalcin 《The Journal of asthma》2003,40(6):683-690
Asthma patients that depend on emergency department (ED) services are generally considered to have extremely poor disease control and prognosis. It is important to identify characteristics related to poor disease control and frequent visits to the ED to apply appropriate clinical management. This study comprised a cross-sectional survey of consecutive patients with asthma exacerbation (age ≥12 years) presenting at the adult ED of a large, tertiary care, university-affiliated hospital over a 2-month period. The frequent visitors (FV) were defined by ≥3 visits to the ED in the preceding year, and the occasional visitors (OV) by ≤2 visits. Eighty-six patients (61 females and 25 males) were included in the study (mean age 38 ± 18 years). Of these patients, 51.2% were FV and 48.8% were OV. Sixty-nine percent had annual income lower than A$3000 and 66.3% had ≤8 years of the formal education. Only 18.6% had used inhaled corticosteroids, 79.1% identified the asthma attack severity, 70.9% increased or initiated inhaled β-agonist, 20.9% increased or initiated steroid therapy, and 55.8% had an asthma action plan for attack. The number of hospital admissions in past year (OR 4.3, P = .02), use of home nebulizer (OR 3.6, P = .05) and the lack of a written asthma action plan (OR 3.3, P = .03) were independently associated with frequent visits to the ED. We conclude that a substantial proportion of the patients that visit the ED are FV. These patients are more likely to have hospital admission in the past year, to use a home nebulizer, and to lack a written asthma action plan. They should be considered the most important target for asthma education. 相似文献
33.
34.
综合医院医务人员感染SARS情况对比分析 总被引:3,自引:1,他引:2
目的:分析在防治SARS工作初期、后期医务人员感染SARS的差异和采取的对策,为减少综合医院内医务人员SARS的感染提供参考。方甚:对本院自2003年3月24日至6月2日SARS诊断治疗任务中发生的医务人员的感染原因和采取的对策进行回顾性分析。结果:防治SARS工作初期,急诊科交叉感染和在SARS隔离病房等与SARS患者密切接触的工作岗位,共有17名医务人员感染,及时隔离治疗,均已痊愈,未造成医护人员的进一步交叉感染:经加强防护培训,改善工作条件,在防治SARS工作后期,仅发生2名护工感染,亦已痊愈,派出非典医疗队实现零感染。结论:综合医院内医务人员感染SARS的问题严峻,加强医院内的全员防护培训,按岗分区管理,改善医务人员的工作条件和病人的隔离观察环境,做好监督检查,积极应对,可以减少医务人员的SARS感染。 相似文献
35.
沾染液体火箭推进剂时的个人洗消技术进展 总被引:3,自引:0,他引:3
岳茂兴 《中华航空航天医学杂志》2003,14(3):189-192
目的 回顾与分析国内外有关沾染液体火箭推进剂时个人洗消技术和方法的研究资料,提出有效的个人洗消技术和方法,以尽可能地避免染毒或减轻染毒伤员的伤害程度。资料来源与选择 结合我们已进行的有关研究和参加抢救的临床救治体会,并引用国内外公开发表的相关论文及著作。资料引用 论文28篇及3部专著。资料综合主要针对个人洗消技术的有效性与安全性对文献作者采用的方法和指标进行分析和综合。结论 迅速及时地进行有效的洗消,以尽早彻底清除沾染的毒物,是防治液体火箭推进剂中毒的首要措施,可以明显避免或减轻染毒伤员的伤害程度。 相似文献
36.
应用不同浓度TPA诱发血小板聚集,观察20名正常人血小板的聚集率。结果显示:TPA从5ng/ml到10ng/ml之间,随着浓度的增加,血小板聚集率逐渐增加,最佳浓度为10ng/ml。当TPA浓度〉10mg/ml时,继续增加TPA浓度,血小板聚集率将不再升高,且于20mg/ml时出现明显的解聚现象。 相似文献
37.
Summary During the period 1980 through 1989 a total of 1029 cases of fatal poisoning (638 men and 391 women) were examined at the Department of Forensic Medicine, Aarhus University, Denmark. In 68% of the cases death had been caused by drugs, whereas acute alcohol poisoning and carbon monoxide accounted for 15% and 14% of the cases, respectively. Alcohol was detected in more than half of the 1029 fatal poisoning cases, and in 42% of all cases the blood alcohol concentration was above 0.8 g/kg. In 57% of the cases death was categorized as accidental, only in 31% of the cases as suicide. Accidental deaths were especially predominant amongst drug and/or alcohol abusers. Propoxyphene was the drug found to have caused most fatal poisonings during the decade (30% of the drug-related deaths). Most of the propoxyphene-related deaths occurred during the early and mid-eighties. Barbiturate poisonings were quite frequent during the first half of the eighties. However, the number of deaths caused by barbiturates decreased significantly after 1986, when most barbiturates were withdrawn from the market. The number of deaths caused by narcotics and analgesics increased during the survey period, while no specific tendency was observed concerning antidepressants. 相似文献
38.
他汀类药物早期干预对急性冠脉综合征患者血脂、高敏C反应蛋白和纤维蛋白原的影响 总被引:5,自引:0,他引:5
目的 比较他汀类药物和阿司匹林联合用药与单用阿司匹林对急性冠脉综合征患者血脂、高敏C反应蛋白及纤维蛋白原的影响。方法 所有患者均在急性冠脉综合征发病后72h内开始接受药物治疗,他汀组(40例)应用他汀类药物加阿司匹林治疗8周,对照组(16例)单用阿司匹林治疗,观察两组总胆固醇、低密度脂蛋白胆固醇、高敏C反应蛋白和纤维蛋白原水平的变化。结果 治疗8周后,他汀组各指标显著降低,面对照组仅高敏C反应蛋白水平显著下降。他汀类药物降低高敏C反应蛋白、纤维蛋白原的程度与其降脂作用无关。结论 他汀类药物与阿司匹林联合用药降低高敏C反应蛋白和纤维蛋白原的作用可能优于单用阿司匹林,并与其抗炎作用有关。 相似文献
39.
目的:探讨急性肾功能衰竭的治疗。方法:复习有关急性肾功能衰竭的治疗文献,作一总结。结果:使用人工合成三肽序列(RGD)的多肽、生长因子、心房利钠因子和人工肾小管治疗急性肾功能衰竭都取得了较好的疗效。结论:这些新的治疗可望改善急性肾衰的预后和降低死亡率。 相似文献
40.
Early laparoscopic cholecystectomy for acute cholecystitis 总被引:4,自引:0,他引:4
Background: The timing of laparoscopic cholecystectomy for acute cholecystitis remains controversial.
Methods: One hundred ninety-four patients with acute cholecystitis were reviewed. The conversion rates for the various number of days
of symptoms before surgery were analyzed. The conversion rate dramatically increased from 3.6% for those patients with 4 days
of symptoms to 26% for those patients with 5 days of symptoms. The mean number of days of symptoms prior to surgery in those
patients who underwent successful laparoscopic cholecystectomy was 4.1 as compared to 8.0 in those patients who required open
cholecystectomy (p < 0.0001). Based on this data the patients were divided into two groups. Group 1 consisted of 109 patients who underwent
laparoscopic cholecystectomy within 4 days of onset of symptoms and group 2 consisted of 85 patients who underwent laparoscopic
cholecystectomy after more than 4 days following onset of symptoms.
Results: The conversion rate from laparoscopic to open cholecystectomy was 15%. The conversion rate for group 1 was 1.8% as compared
to 31.7% for group 2 (p < 0.0001). Indications for conversion were inability to identify the anatomy secondary to inflammatory adhesions (68%), cholecystoduodenal
fistula (18%), and bleeding (14%). The major complication rate for group 1 was 2.7% as compared to 13% for group 2 (p= 0.007). The mortality rate for all patients with attempted laparoscopic cholecystectomy for acute cholecystitis was 1.5%.
The average procedure time for group 1 was 100 ± 37 min vs 120 ± 55 min in group 2. The average number of postoperative hospital
days in group 1 was 5.5 ± 2.7 days as compared to 10.8 ± 2.7 days in group 2.
Conclusions: We advocate early laparoscopic cholecystectomy within 4 days of onset of symptoms to decrease major complications and conversion
rates. This decreased conversion rate results in decreased length of procedure and hospital stay.
Received: 28 March 1996/Accepted: 12 September 1996 相似文献