全文获取类型
收费全文 | 18306篇 |
免费 | 1955篇 |
国内免费 | 574篇 |
专业分类
耳鼻咽喉 | 141篇 |
儿科学 | 535篇 |
妇产科学 | 280篇 |
基础医学 | 1826篇 |
口腔科学 | 418篇 |
临床医学 | 1776篇 |
内科学 | 3765篇 |
皮肤病学 | 423篇 |
神经病学 | 1510篇 |
特种医学 | 348篇 |
外国民族医学 | 1篇 |
外科学 | 1551篇 |
综合类 | 2584篇 |
预防医学 | 815篇 |
眼科学 | 357篇 |
药学 | 2351篇 |
26篇 | |
中国医学 | 1669篇 |
肿瘤学 | 459篇 |
出版年
2024年 | 121篇 |
2023年 | 568篇 |
2022年 | 1011篇 |
2021年 | 1344篇 |
2020年 | 1273篇 |
2019年 | 1027篇 |
2018年 | 919篇 |
2017年 | 968篇 |
2016年 | 879篇 |
2015年 | 765篇 |
2014年 | 1200篇 |
2013年 | 1557篇 |
2012年 | 982篇 |
2011年 | 979篇 |
2010年 | 750篇 |
2009年 | 750篇 |
2008年 | 730篇 |
2007年 | 695篇 |
2006年 | 639篇 |
2005年 | 580篇 |
2004年 | 447篇 |
2003年 | 416篇 |
2002年 | 339篇 |
2001年 | 309篇 |
2000年 | 257篇 |
1999年 | 166篇 |
1998年 | 164篇 |
1997年 | 139篇 |
1996年 | 127篇 |
1995年 | 95篇 |
1994年 | 96篇 |
1993年 | 59篇 |
1992年 | 62篇 |
1991年 | 64篇 |
1990年 | 53篇 |
1989年 | 50篇 |
1988年 | 31篇 |
1987年 | 36篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 28篇 |
1983年 | 16篇 |
1982年 | 23篇 |
1981年 | 16篇 |
1980年 | 14篇 |
1979年 | 13篇 |
1978年 | 14篇 |
1976年 | 6篇 |
1974年 | 2篇 |
1972年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
S Rombouts† T Nijsten†‡ J Lambert† 《Journal of the European Academy of Dermatology and Venereology》2007,21(3):326-333
BACKGROUND: Previous studies on the association between smoking and acne have reported conflicting results. OBJECTIVE: To investigate the association between smoking and acne among school-going adolescents. METHODS: A cross-sectional study was conducted. Smoking was defined as smoking > 3 cigarettes daily for 6 months or more. We defined acne as having > 20 retentional and/or inflammatory facial acne lesions. Multivariate (proportional) logistic regression models were used to adjust for confounding variables. RESULTS: Of the 594 participants, 36.2% had acne. Acne sufferers were less likely to smoke (18.1 vs. 23.7%, P = 0.10). In girls, smoking was significantly associated with lower prevalence of acne (adjusted OR = 0.41, 95% CI = 0.13, 0.82). Smoking, daily cigarette consumption and duration of smoking appeared to be protective in the development of inflammatory acne in girls. No significant associations between acne and smoking variables were detected among boys. Limitations: although this study suggests a significant negative association between smoking and inflammatory acne in girls, it does not prove causality. This association did show a trend for linear relationship. Because of the unexpected differences between boys and girls, sample size may have affected our results. CONCLUSION: The anti-inflammatory effects of smoking may inhibit the development of papulopustular acne in girls more than in boys. However, smoking should not be considered a therapeutic option for acne. Additional studies that consider possible differences across age, gender and type of acne are needed to clarify the association between smoking and acne. 相似文献
62.
目的:探讨特发性脊柱侧凸PUMC(协和)分型系统的一致性,并对影响分型一致性的因素进行分析.方法:随机选取南京鼓楼医院2004年~2006年治疗的80例特发性脊柱侧凸患者,其中男性15例,女性65例,平均年龄14.6岁(10~18岁),均有完整的术前站立位正侧位X线片及仰卧位左右Bending片共四张.由4名脊柱外科专科医生分别根据PUMC(协和)分型标准进行分型,2周后此4位医生分别对这些患者的X线片再次进行分型,收集分型结果分别作可信度和可重复性分析,计算Kappa值检验一致性并对影响分型一致性的因素进行统计分析,结果:80例患者均可用PUMC分型,分型可信度平均Kappa值为0.801,可重复性Kappa值为0.878.PUMC分型不一致中包括上胸弯的界定18次;胸弯明显时,代偿性与结构性腰弯的界定15次;腰弯明显时,代偿性与结构性胸弯的界定18次;单弯顶点的判断20次;测量角度的差异18次.结论:PUMC(协和)分型学习曲线相对较短,易于掌握且具有良好的可信度和可重复性. 相似文献
63.
急性脑梗死诱发全身炎症反应综合征致多器官功能障碍综合征的临床研究 总被引:15,自引:2,他引:13
目的 探讨急性脑梗死 (ACI)诱发全身炎症反应综合征 (SIRS)致多器官功能障碍综合征(MODS)的发病机制 ,以及血清肿瘤坏死因子 (TNF α)、白细胞介素 (IL 1) β含量变化在ACI诱发SIRS发生、发展并向MODS转化的临床意义。方法 6 8例ACI患者根据病情变化分为 3组 ,其中单纯性ACI(SACI组 ) 36例 ,ACI致SIRS(SIRS组 ) 32例 ,ACI致SIRS后发展为MODS(MODS组 ) 2 4例 ;应用酶联免疫吸附法 (ELISA法 )分别测定患者不同病程中血清TNF α、IL 1β值 ,并与对照组 (为 2 8名同期健康体检者 )比较。 结果 (1) 6 8例ACI中 4 7.0 6 %发生SIRS;SIRS时 75 %发生MODS。 (2 )血清TNF α、IL 1β的含量MODS 组 >SIRS组 >SACI组 >对照组 ,各组间比较 ,差异具有极显著性 (均P <0 0 1)。MODS重症者 (积分≥ 9分 )血清TNF α、IL 1β含量高于轻症者 (积分 <9分 ) (均P <0 0 1) ;MODS死亡者血清TNF α、IL 1β含量高于存活者 (均 P <0 0 1)。结论 (1)ACI后出现SIRS可导致MODS的发生。 (2 )患者血清TNF α、IL 1β水平异常变化可作为判断ACI致SIRS、MODS病情进展、预后及转归的一项指标 相似文献
64.
33例肝占位性病变MRI误诊的分析 总被引:1,自引:0,他引:1
我院1988年以来4000余例腹部MRI中,发现肝占位性病变误诊33例。所用机型为美国Disonics公司0.5T超导MRI,自旋回波序列(SE序列)、常规T1加权(T1WI)、质子加权(PDWI)、T2加权(T2WI),覆盖全肝。其中,PHC误诊为MHC5例、MHC误诊为PHC6例、PHC误为HHE5例、MHC误诊为HHE2例、HHE误诊为PHC6例、肝硬化结节误诊为PHC2例、炎性假瘤误诊为PHC3例、肝结核误诊为PHC1例、HCY误诊为HHE3例。本文从病变的影像学特征和扫描技术方面详细探讨了误诊的原因和鉴别诊断要点。 相似文献
65.
Giuseppe Giuffre’ Vincenzo Schifano Maria Vadala’ 《Documenta ophthalmologica. Advances in ophthalmology》1995,91(3):255-263
We report on a case of idiopathic uveal effusion syndrome complicated by AION. To our knowledge such an association hasn't been previously described. We suggest that scleral thickening caused obstruction of vortex veins followed by uveal effusion and compression of posterior ciliary arteries within their intrascleral tract, leading to AION. Nevertheless it can't be excluded that AION was the result of mechanical compression on ciliary vessels of optic disc by choroidal detachment. 相似文献
66.
67.
M. J. R. C Alles M. A. der Gaag R. J. Stokroos 《European archives of oto-rhino-laryngology》2006,263(9):791-797
To evaluate the value of clinical trials on intratympanic steroid therapy in Ménière’s disease (MD), idiopathic sudden sensorineural hearing loss (ISSNHL) and rapidly progressive sensorineural hearing loss (RPSNHL). Medline and Pubmed databases from 1966 to present were searched for clinical studies on intra- or transtympanic (cortico)steroid therapy of MD, ISSNHL and RPSNHL. Results were cross-checked with additional databases to obtain a complete data set. Clinical trials were evaluated on the basis of comparability, internal and external validity. Articles were judged using the following questions: was a randomised double-blind controlled trial performed? Which criteria were used to confirm the diagnosis of MD, ISSNHL, RPSNHL? Which therapy was evaluated? How long was the follow-up? Which criteria were used to evaluate the results? Reliable evidence on the efficiency, optimum dosage and administration schedule of intratympanic steroid therapy in MD, ISSNHL and RPSNHL is lacking, therefore further investigation is required. 相似文献
68.
Stephen D Silberstein James J Corbett 《Cephalalgia : an international journal of headache》1993,13(3):212-213
Lumbar puncture is crucial in two distinct clinical situations in the diagnosis of the headache patient. The first is the patient who is suspected of having a symptomatic headache; the second is the patient with a chronic intractable or atypical headache disorder. This review discusses the usefulness of the lumbar puncture in the diagnosis of headache secondary to subarachnoid hemorrhage, meningitis, and intracranial hypotension and hypertension. The value of lumbar puncture in the presence of a normal CT/MRI scan is discussed. 相似文献
69.
S. Urien D. Morin A. Renouard I. Rocher J.-P. Tillement 《European journal of clinical pharmacology》1988,34(4):381-385
Summary The serum concentrations of 1-acid glycoprotein (AAG), albumin (HSA) and non-esterified fatty acids, and the serum binding of tertatolol were measured in four groups of individuals: healthy control subjects (n=24), and patients with inflammation (n=28), and hepatic (n=20) and renal (n=27) insufficiency.Serum binding of tertatolol was increased in patients with inflammation (94.6%), decreased in patients with hepatic insufficiency (88.8%) and it was unchanged in patients with renal insufficiency (92.8%) as compared to controls (92.7%).Multivariate analysis indicated that the changes were mainly related to concomitant changes in AAG concentration, which could account for 57% of intersubject variability in the bound/free ratio, and to a lesser extent in HSA, which accounted for only 4% of the variability in the binding.The data show that the free fraction of the basic drug tertatolol in serum is affected by pathological conditions that cause changes in AAG concentration. 相似文献
70.
目的:分析比较腓骨肌萎缩症1A型(Charcot-Marie-Tooth1A,CMT1A)患者和慢性炎性脱髓鞘性多发性神经病(chronic inflammatory demyelinating polyneuropathy, CIDP)患者F波改变的特点和原因。方法:收集自2012年1月到2018年12月在北京大学第三医院诊治的CMT1A和CIDP患者各30例,记录临床资料、电生理指标(神经传导速度和F波、H反射)、神经功能等级评分等,部分患者行臂丛和腰丛的磁共振影像检查,分析比较结果。结果:CMT1A患者的正中神经平均运动传导速度为(21.10±10.60) m/s, CIDP患者为(31.52±12.46)m/s,二者差异有统计学意义(t=-6.75,P<0.001), CMT1A患者中约43.3%(13/30)未引出尺神经F波,明显高于CIDP未引出F波的患者比例(4/30,13.3%),χ2=6.65,P=0.010。在可引出F波的患者中,CMT1A组患者的F波潜伏期为(52.40±17.56) ms, CIDP组为(42.20±12.73) ms... 相似文献