全文获取类型
收费全文 | 75018篇 |
免费 | 8014篇 |
国内免费 | 4947篇 |
专业分类
耳鼻咽喉 | 511篇 |
儿科学 | 1127篇 |
妇产科学 | 851篇 |
基础医学 | 7372篇 |
口腔科学 | 1564篇 |
临床医学 | 10579篇 |
内科学 | 9634篇 |
皮肤病学 | 836篇 |
神经病学 | 3196篇 |
特种医学 | 2391篇 |
外国民族医学 | 41篇 |
外科学 | 5709篇 |
综合类 | 15312篇 |
现状与发展 | 23篇 |
一般理论 | 8篇 |
预防医学 | 7033篇 |
眼科学 | 1839篇 |
药学 | 8617篇 |
106篇 | |
中国医学 | 5926篇 |
肿瘤学 | 5304篇 |
出版年
2024年 | 338篇 |
2023年 | 1276篇 |
2022年 | 2997篇 |
2021年 | 3803篇 |
2020年 | 3121篇 |
2019年 | 2406篇 |
2018年 | 2427篇 |
2017年 | 2564篇 |
2016年 | 2273篇 |
2015年 | 3477篇 |
2014年 | 4300篇 |
2013年 | 4470篇 |
2012年 | 6080篇 |
2011年 | 6532篇 |
2010年 | 4936篇 |
2009年 | 4250篇 |
2008年 | 4609篇 |
2007年 | 4430篇 |
2006年 | 4164篇 |
2005年 | 3696篇 |
2004年 | 2524篇 |
2003年 | 2346篇 |
2002年 | 2012篇 |
2001年 | 1488篇 |
2000年 | 1361篇 |
1999年 | 1088篇 |
1998年 | 632篇 |
1997年 | 629篇 |
1996年 | 443篇 |
1995年 | 443篇 |
1994年 | 373篇 |
1993年 | 206篇 |
1992年 | 280篇 |
1991年 | 258篇 |
1990年 | 243篇 |
1989年 | 209篇 |
1988年 | 198篇 |
1987年 | 179篇 |
1986年 | 149篇 |
1985年 | 111篇 |
1984年 | 72篇 |
1983年 | 69篇 |
1982年 | 32篇 |
1981年 | 43篇 |
1980年 | 42篇 |
1979年 | 44篇 |
1977年 | 27篇 |
1973年 | 44篇 |
1972年 | 28篇 |
1969年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 26 毫秒
41.
Estrogen receptors in the external anal sphincter 总被引:1,自引:0,他引:1
K Haadem L Ling M Fern? H Graffner 《American journal of obstetrics and gynecology》1991,164(2):609-610
Inasmuch as anal competence in women is reduced after the age of 50 years, it may be dependent on effects of estrogens. In this study, samples of the external anal sphincter were analyzed for the presence of estrogen receptors and were found to be present at a median concentration of 5.0 fmol per milligram of protein (range, 1.9 to 13) in women (n = 7), and 1.1 fmol per milligram of protein (range, 0 to 3.2) in men (n = 7). These findings are of interest with regard to the treatment of idiopathic anal incontinence. 相似文献
42.
Duane A. Sewell Daqing Li Ling Duan Mary R. Schwartz Bert W. O'Malley 《The Laryngoscope》1997,107(11):1490-1495
An effective “suicide gene” therapy strategy in experimental studies has been the use of the herpes simplex virus thymidine kinase gene(HSV-tk) to sensitize tumors to the cytotoxic effects of ganciclovir administration. Previous studies using this model have focused on utilizing maximal viral titers and high levels of ganciclovir that are not compatible with human dosing. Because of the high ganciclovir doses and the maximal viral titers, this strategy has limited application to actual clinical scenarios. In the following studies the authors investigate tumor regression in an oral squamous cell carcinoma animal model as a function of variable adenoviral titers and more physiologic ganciclovir dosing. Using adenoviral titers ranging from 1 × 108 to 2 × 109 plaque forming units(pfu) to treat oral tumors, they found no statistical difference in tumor regression among the different viral doses, despite differences in mitotic activity. Each treatment group, however, demonstrated a significant effect on tumor regression when compared with controls. Furthermore, the authors were able to reduce the level of ganciclovir administration to 10 mg/kg twice daily from established levels of 100 to 150 mg/kg twice daily while maintaining significant tumor responses to the HSV-tk therapy. Mean survival of animals treated with this lower ganciclovir dose was significantly higher than in controls and was equal to established means based on previous studies using higher ganciclovir doses. The optimization of this suicide gene therapy strategy is imperative in order to minimize theoretical and known viral and ganciclovir toxicities while establishing a foundation upon which to design appropriate and effective clinical trials. 相似文献
43.
BTA在膀胱癌诊断中的应用 总被引:2,自引:1,他引:1
为了探求对膀胱肿瘤诊断及术后复发监测的理想手段,从1995年9月~1996年6月,采用BTA试剂检测方法对202例血尿患者及71例膀胱肿瘤术后的患者进行了诊断检测,诊断膀胱癌的敏感度为96%、特异度为83%、准确度为86%,26例膀胱肿瘤患者中仅6例(23%)尿脱落细胞阳性,正常对照均为阴性。认为BTA试剂是一种快速、有效、无创性诊断膀胱肿瘤的方法。 相似文献
44.
地塞米松对电光性眼炎防治作用的实验研究 总被引:3,自引:1,他引:2
本文对电光性眼炎家兔角膜上皮的超氧化物歧化酶(SOD)活性及脂质过氧化反应主要代谢产物丙二醛(MDA)含量进行测量。发现紫外线照射后3小时SOD活性降低,伴随上述改变,MDA含量增高。用地塞米松在照射前、后滴眼,3小时检测SOD和MDA,发现其可保护SOD,并降低MDA含量。透射电镜下显示,角膜上皮细胞的变化主要在其底部细胞,以水肿性改变为主。实验结果提示自由基损伤在急性电光性眼炎的发生、发展过程中起了重要作用,地塞米松可减轻这种变化。 相似文献
46.
目的 探讨超声刀在腹腔镜胆囊切除术中的应用价值。方法 将 86例腹腔镜胆囊切除术患者随机分为超声刀组 ( 3 4例 )与电刀组( 5 2例 ) ,分别使用超声刀与单极电刀完成手术 ,比较术中及术后的效果。结果 86例手术顺利完成 ,无中转开腹。手术时间分别为 ( 4 5±7)min和 ( 62± 9)min(P <0 0 1) ,术中出血量分别为 ( 5± 0 .8)ml和 ( 2 0± 5 )ml(P <0 .0 1) ,术后肠道功能恢复时间分别为 ( 2 0± 4)h和 ( 2 4±6)h(P <0 0 1) ,两组均无胆瘘发生。结论 超声刀在腹腔镜胆囊切除术中较电刀更快捷 ,出血更少 ,术后恢复更快 相似文献
47.
Summary Using acetylcholinesterase histochemical and choline acetyltransferase immunocytochemical localization methods, this study has provided conclusive evidence for the existence of cholinergic neurons in the external cuneate nucleus of gerbils. By light microscopy, both acetylcholinesterase and choline acetyltransferase labelling was confined to the rostral portion of the external cuneate nucleus. Ultrastructurally, acetylcholinesterase reaction products were found in the nuclear envelope, cisternae of rough endoplasmic reticulum and Golgi saccules of some somata and large dendrites as well as in the membranes of small dendrites, myelinated axons and axon terminals. These neuronal elements were also stained for choline acetyltransferase; immunoreactivity was associated with nuclear pores, nuclear envelope, perikaryal membrane and all the membranous structures within the cytoplasm. Of the total choline acetyltransferase-labelled neuronal profiles analysed, 79% were myelinated axons, 15% dendrites, 4% somata and 2% axon terminals. The immunostained axon terminals consisted of two types containing either round (Rd type; 62.5%) or pleomorphic (Pd type; 37.5%) vesicles. Both were associated directly with choline acetyltransferase-positive dendrites. In contrast to the paucity of choline acetyltransferase-labelled axon terminals, numerous choline acetyltransferase-positive myelinated axons were present. It may thus be hypothesized that most, if not all, of the external cuneate nucleus cholinergic neurons are projection cells; such cells may give rise to axonal collaterals which synapse onto their own dendrites for possible feedback control. Choline acetyltransferase-positive dendrites were contacted by numerous unlabelled presynaptic boutons, 60% of which contained round or spherical synaptic vesicles (Rd boutons) and 40% flattened vesicles (Fd boutons), suggesting that these neurons are under strong inhibitory control. The preferential concentration of cholinergic components in the rostral external cuneate nucleus may be significant in the light of the highly organized somatotopy in the external cuneate nucleus and its extensive efferent projections to medullary autonomic-related nuclei. Our results suggest that the cholinergic neurons may be involved in somatoautonomic integration. 相似文献
48.
J L Wright C Coppin B J Mullen J A Pare T F Rutherford H Ling A N Gerein R T Miyagishima J C Hogg 《Canadian journal of surgery》1986,29(3):205-208
Recent studies have shown that the survival of patients with lung cancer is improved if the tumour is resected before it becomes larger than 3 cm in diameter and before it spreads to lymph nodes. While this suggests a positive benefit from early detection, recent mass-screening studies have claimed that the benefit obtained from this procedure is illusory because it relates to a lead-time bias. This study reports the results of surgical resection of 143 primary lung cancers. The data confirmed that the predicted 5-year survival was greatest (74%) following resection of lesions that were less than 3 cm in diameter without node involvement. Analysis showed that the age of these patients was 63 +/- 8 years, the same as in patients with larger tumours and more extensive node involvement. This suggests that tumours progress rapidly from a stage at which resection is beneficial to stages at which it is not. Although it is desirable that tests predict the presence of small tumours, the high requirements for sensitivity and specificity at current prevalence rates for lung cancer make this goal impractical. 相似文献
49.
A double-blinded study was conducted to compare the effects of mupirocin and tetracycline ointments in the treatment of skin infections. 111 patients were available for clinical assessment, of which 53 were treated with mupirocin and 58 treated with tetracycline. Clinically, both groups were improved, and there was no significant difference. Bacteriological assessment however revealed a better response to mupirocin. Staphylococcus aureus and Streptococcus pyogenes were the most common organisms isolated. 99% of Staphylococci were sensitive to mupirocin compared with 61% to tetracycline and 29% to penicillin G. 57% of Group A beta haemolytic Streptococci were resistant to tetracycline compared to 14% to mupirocin. Gram-negative organisms were mostly resistant to both preparations. No side effects were observed in both treatment groups. This study suggests that mupirocin is a safe and effective topical preparation for treating most of our common skin infections. 相似文献
50.
Amiodarone is an iodinated antiarrhythmic agent that is effective in the treatment of atrial and ventricular arrhythmias. A number of side effects are seen, including pulmonary toxicity and thyroid dysfunction. A patient with both amiodarone-induced pneumonitis and hyperthyroidism who exhibited abnormal gallium activity in the lungs, as well as diffuse gallium uptake in the thyroid gland is presented. The latter has not been previously reported and supports the concept of iodide-induced "thyroiditis" with gallium uptake reflecting the inflammatory response. 相似文献