全文获取类型
收费全文 | 413084篇 |
免费 | 58502篇 |
国内免费 | 23789篇 |
专业分类
耳鼻咽喉 | 5277篇 |
儿科学 | 5837篇 |
妇产科学 | 7126篇 |
基础医学 | 41693篇 |
口腔科学 | 10384篇 |
临床医学 | 70118篇 |
内科学 | 72636篇 |
皮肤病学 | 6199篇 |
神经病学 | 29767篇 |
特种医学 | 15267篇 |
外国民族医学 | 213篇 |
外科学 | 49795篇 |
综合类 | 49909篇 |
现状与发展 | 116篇 |
一般理论 | 20篇 |
预防医学 | 32249篇 |
眼科学 | 11548篇 |
药学 | 33505篇 |
334篇 | |
中国医学 | 17399篇 |
肿瘤学 | 35983篇 |
出版年
2024年 | 1657篇 |
2023年 | 9641篇 |
2022年 | 14007篇 |
2021年 | 18713篇 |
2020年 | 17010篇 |
2019年 | 12610篇 |
2018年 | 17899篇 |
2017年 | 16916篇 |
2016年 | 16878篇 |
2015年 | 21956篇 |
2014年 | 27721篇 |
2013年 | 26901篇 |
2012年 | 26071篇 |
2011年 | 28838篇 |
2010年 | 22341篇 |
2009年 | 20932篇 |
2008年 | 20107篇 |
2007年 | 19056篇 |
2006年 | 20259篇 |
2005年 | 18573篇 |
2004年 | 11875篇 |
2003年 | 10671篇 |
2002年 | 9279篇 |
2001年 | 9223篇 |
2000年 | 9352篇 |
1999年 | 10628篇 |
1998年 | 7458篇 |
1997年 | 7321篇 |
1996年 | 6243篇 |
1995年 | 5577篇 |
1994年 | 4273篇 |
1993年 | 2988篇 |
1992年 | 3549篇 |
1991年 | 3031篇 |
1990年 | 2611篇 |
1989年 | 2363篇 |
1988年 | 2052篇 |
1987年 | 1668篇 |
1986年 | 1431篇 |
1985年 | 1195篇 |
1984年 | 769篇 |
1983年 | 664篇 |
1982年 | 461篇 |
1981年 | 430篇 |
1980年 | 304篇 |
1979年 | 281篇 |
1978年 | 201篇 |
1977年 | 203篇 |
1976年 | 152篇 |
1974年 | 172篇 |
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
991.
作者利用交流电弧和光栅摄谱仪组装了能够绘制谱线轮廓曲线和准确测定谱线宽度的记录仪,用线宽增量法对生物材料(拟血清)中的主要成分Ca和微量元素Cu进行了测定。与黑度法相比,本实验结果的线性好,误差小,再现性有所提高。这些结果表明,用上述仪器装置和线宽增量法进行生物材料含量分析优于黑度法。 相似文献
992.
运用人力资源管理策略 改革病房护理管理 总被引:3,自引:0,他引:3
从发展成功管理的共同文化,创建优质服务病房;建立有效的护理人力资源管理支持系统,创建适合于专业护理的工作环境,确保护理质量;以病人为中心,以病人满意度作为衡量护理工作优劣的标准三个方面介绍了乐山市人民医院运用护理人力资源管理策略,改革病房护理管理,创建优质服务病房的实践经验及其效果。 相似文献
993.
994.
995.
Manoussos M. Konstadoulakis MD Michael Vezeridis MD Emi Hatziyianni MD Constantine P. Karakousis MD PhD Bernard Cole PhD Kirby I. Bland MD Harold J. Wanebo MD 《Annals of surgical oncology》1998,5(3):253-260
Background: Oncogenes and other molecular tumor markers that predict tumor aggressiveness may allow individualization and optimization of surgical therapy of intermediate-thickness malignant melanoma. We examined the expression of selected markers, including the HLA-DR antigen, the heat shock protein-70 (HSP-70), and the c-myc oncogene in primary melanoma and regional nodes and related these findings to metastatic potential and survival.
Methods: Forty patients with primary melanoma (1.5–4.0 mm) were studied, all of whom had prophylactic lymph node dissection and were followed for 18 months to 7 years. The primary tissue and nodes were examined using immunohistochemical techniques for the presence of HLA-DR antigen and HSP-70 protein and the expression of the c-myc oncogene.
Results: Of 40 patients, there were 23 with lesions 1 to 2.9 mm thick and 17 with lesions 3 to 4 mm thick. Nodal metastases were present in 25 of the 40 patients who had elective node dissection. HLA-DR antibody stained the primary tumor in 10 patients (25%), but there was no correlation with survival in this group. HLA-DR antibody stained the stroma and cellular infiltrates surrounding the primary tumor in 28 of 40 patients; in this group there was a correlation of HLA-DR staining of the peritumoral stroma with improved survival overall. HLA-DR staining of the peritumoral stroma also influenced survival when patients were stratified by tumor thickness groups 1 to 2.9 mm and 3 to 4 mm and presence of nodal metastases. HSP-70 was demonstrated in the primary tumor in 25% of patients, who were also shown to have significantly improved survival when compared with those whose primary tumor did not stain with HSP-70. C-myc was expressed in the primary tumor in 25%, but showed no correlation with survival. None of these proteins correlated with or predicted the presence of nodal metastases.
Conclusion: We conclude that the use of specific molecular-oncogene markers in intermediate-thickness primary melanoma may identify patients at high risk for conventional treatment failure and reduced survival who may profit from more aggressive surgery, adjuvant therapy, or both.Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995. 相似文献
996.
Methylmercury is a ubiquitous environmental pollutant and potent neurotoxin. Treatment of methylmercury poisoning relies almost exclusively on the use of chelating agents to accelerate excretion of the metal. The present study demonstrates that oral administration of N-acetylcysteine (NAC), a widely available and largely nontoxic amino acid derivative, produces a profound acceleration of urinary methylmercury excretion in mice. Mice that received NAC in the drinking water (10 mg/ml) starting at 48 hr after methylmercury administration excreted from 47 to 54% of the 203Hg in urine over the subsequent 48 hr, as compared to 4-10% excretion in control animals. When NAC-containing water was given from the time of methylmercury administration, it was even more effective at enhancing urinary methylmercury excretion and at lowering tissue mercury levels. In contrast, excretion of inorganic mercury was not affected by oral NAC administration. The ability of NAC to enhance methylmercury excretion when given orally, its relatively low toxicity, and is wide availability in the clinical setting indicate that it may be an ideal therapeutic agent for use in methylmercury poisoning. 相似文献
997.
Juraj Sprung MD PhD David Distel CRNA Jeffrey Grass MD Eric L. Bloomfield MD Ian C. Lavery MD 《Journal of clinical anesthesia》1996,8(8):662-665
We describe a patient in whom long-term monoamine oxidase (MAO) inhibitor therapy was discontinued 20 days before surgery with general anesthesia. This patient developed severe perioperative hypotension after administration of 10 mg of bupivacaine through an epidural catheter, which was corrected only after potent vasopressor therapy. We attribute this hemodynamic instability to attenuation of this patient's sympathetic tone based on several mechanisms: (1) residual effect of long-term administration of MAO inhibitor that caused a decrease in the number of β-adrenergic receptors (adrenergic subsensitivity due to receptor down-regulation), (2) recovered MAO activity causing effective degradation of sympathetic amines, and (3) combined attenuating effects of general and epidural anesthesia on sympathetic tone. 相似文献
998.
Peter Schnider MD Joachim Maly PhD Josef Grünberger PhD Susanne Aull MD Karl Zeiler MD Peter Wessely MD 《Headache》1995,35(5):269-272
A considerable proportion of headache patients fulfill the criteria of "drug abuse" (definition according to the International Headache Society [IHS] criteria). These patients exhibit markedly reduced vigilance and continuous performance, as shown by the results of critical flicker frequency (CFF) analysis.
The present study deals with the question whether this impairment of vigilance and continuous performance is reversible. Forty-eight headache patients with drug abuse were investigated three times by means of CFF analysis: immediately before (A), immediately after (B), and 3 weeks after having finished (C) inpatient drug withdrawal.
Immediately after withdrawal, a significant decrease of headache intensity was observed. The CFF values, however, remained unchanged at a depressed level, probably due to withdrawal medication and the initial sedative side effects of thymoleptic agents (given as prophylaxis).
Three weeks after withdrawal, however, the CFF values were significantly improved, and were now within a range not far from the normal values known from a healthy general population. Thus, even after many years of drug abuse, headache patients have a good chance to improve their vigilance and continuous performance and to reach normal or close to normal levels. 相似文献
The present study deals with the question whether this impairment of vigilance and continuous performance is reversible. Forty-eight headache patients with drug abuse were investigated three times by means of CFF analysis: immediately before (A), immediately after (B), and 3 weeks after having finished (C) inpatient drug withdrawal.
Immediately after withdrawal, a significant decrease of headache intensity was observed. The CFF values, however, remained unchanged at a depressed level, probably due to withdrawal medication and the initial sedative side effects of thymoleptic agents (given as prophylaxis).
Three weeks after withdrawal, however, the CFF values were significantly improved, and were now within a range not far from the normal values known from a healthy general population. Thus, even after many years of drug abuse, headache patients have a good chance to improve their vigilance and continuous performance and to reach normal or close to normal levels. 相似文献
999.
1000.
Christopher Griffin MRACOG Michael John Peek PhD FRACOG DDU 《The Australian & New Zealand journal of obstetrics & gynaecology》1997,37(2):235-237
EDITORIAL COMMENT": The editorial committee found this case report irresistible as an example of triumph over misfortune and disability. Iatrogenic, accidental, prolonged and complete amnioreduction is unique in the editor's clinical experience and knowledge of the literature. Importantly the case also illustrates that conservative management of 'premature rupture of the membranes'can be successful. The favourable outcome may have been related to the abdominal rather than the usual cervical route of amnioreduction, and the restoration of normal liquor volume after the amnioreduction was discontinued. Moreover, in spontaneous rupture of the membranes the cause of the problem is likely to be persistent.
Summary: A successful outcome for an infant following complete iatrogenic amnioreduction at 20 weeks gestation is possible without any invasive medical treatment. 相似文献
Summary: A successful outcome for an infant following complete iatrogenic amnioreduction at 20 weeks gestation is possible without any invasive medical treatment. 相似文献