全文获取类型
收费全文 | 19413篇 |
免费 | 1427篇 |
国内免费 | 460篇 |
专业分类
耳鼻咽喉 | 415篇 |
儿科学 | 245篇 |
妇产科学 | 309篇 |
基础医学 | 2964篇 |
口腔科学 | 329篇 |
临床医学 | 1718篇 |
内科学 | 3352篇 |
皮肤病学 | 510篇 |
神经病学 | 1284篇 |
特种医学 | 1167篇 |
外科学 | 2471篇 |
综合类 | 1215篇 |
现状与发展 | 5篇 |
一般理论 | 10篇 |
预防医学 | 1014篇 |
眼科学 | 466篇 |
药学 | 1784篇 |
9篇 | |
中国医学 | 609篇 |
肿瘤学 | 1424篇 |
出版年
2024年 | 31篇 |
2023年 | 154篇 |
2022年 | 409篇 |
2021年 | 836篇 |
2020年 | 425篇 |
2019年 | 509篇 |
2018年 | 625篇 |
2017年 | 513篇 |
2016年 | 713篇 |
2015年 | 1042篇 |
2014年 | 1145篇 |
2013年 | 1270篇 |
2012年 | 1946篇 |
2011年 | 1755篇 |
2010年 | 1181篇 |
2009年 | 1049篇 |
2008年 | 1209篇 |
2007年 | 1236篇 |
2006年 | 1057篇 |
2005年 | 871篇 |
2004年 | 658篇 |
2003年 | 603篇 |
2002年 | 485篇 |
2001年 | 374篇 |
2000年 | 322篇 |
1999年 | 197篇 |
1998年 | 79篇 |
1997年 | 66篇 |
1996年 | 42篇 |
1995年 | 42篇 |
1994年 | 27篇 |
1993年 | 33篇 |
1992年 | 39篇 |
1991年 | 43篇 |
1990年 | 37篇 |
1989年 | 37篇 |
1988年 | 30篇 |
1987年 | 36篇 |
1986年 | 21篇 |
1985年 | 16篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 15篇 |
1980年 | 8篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
口服异维A酸是目前临床上最为有效的抗痤疮药物,可同时作用于痤疮发病的4个主要环节。异维A酸在皮脂腺细胞内独特的分子作用机制使其具有强大的抑制皮脂腺分泌活性,近来其对痤疮免疫和炎症反应的拮抗作用也越来越受到重视。口服异维A酸主要用于治疗结节囊肿型重度痤疮以及其他治疗效果不好的中、重度寻常痤疮,使用剂量应根据患者的体重、疗效、依从性及不良反应进行综合判定。小剂量[0.25~0.5 mg/(kg·d)]治疗可以显著降低药物的不良反应及增加患者依从性;累积剂量达60~120 mg/kg可以明显降低痤疮复发率。异维A酸不良反应大多以皮肤黏膜为主要表现,严重不良反应罕见,致畸是其最严重的不良反应。口服异维A酸能快速改善痤疮皮损,有效预防痤疮瘢痕形成,改善患者生活质量。 相似文献
3.
4.
5.
Cheong-Il Shin Sang Joon Park Ji-Hyun Kim Yeonyee Elizabeth Yoon Eun-Ah Park Bon-Kwon Koo Whal Lee 《Korean journal of radiology》2021,22(5):688
ObjectiveTo compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS).Materials and MethodsThe Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods. Bland-Altman plots were used to evaluate the agreement between the measurements.ResultsLumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 mm3; 95% confidence interval [CI], 4.9–24.3 mm3); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, −0.7 mm3; 95% CI, −9.1–7.7 mm3). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 mm2; 95% CI, 0.89–1.25 mm2) but not in the larger lumen area group (mean of difference, −0.07 mm2; 95% CI, −0.22–0.08 mm2). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 mm2; 95% CI, 0.27–0.65 mm2) than in that of IVUS and SATM (1.53 mm2; 95% CI, 1.27–1.79 mm2).ConclusionSATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM. 相似文献
6.
7.
8.
Clinical usefulness of intraductal ultrasonography for the management of acute biliary pancreatitis
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
9.
Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case–control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan–Meier analysis with log-rank test (P = 0.008). The AF group''s adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16–1.57; P = 0.009) according to Cox''s proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF. 相似文献
10.
目的:探讨吉西他滨联合西妥昔单抗对三阴乳腺癌细胞增殖、迁移、侵袭的影响,并对可能的机制进行初步的探究。方法:将实验分为西妥昔单抗组(150 μg · mL-1)、吉西他滨联合用药组(西妥昔单抗150 μg · mL-1,吉西他滨2.8 μg·mL-1)。通过MTT、Transwell实验检测联合用药对MDA-MB-231细胞增殖、迁移、侵袭能力的影响,Western blotting实验检测合用药对MDA-MB-231细胞MMP-9、TIMP-1、p-IkB、NF-kB-p65表达水平的影响。结果:吉西他滨联合西妥昔单抗作用MDA-MB-231细胞后,其生长被不同程度的抑制,抑制率随吉西他滨浓度的增加而增高(P<0.05);联合用药组MDA-MB-231细胞迁移、侵袭数目明显减少(P<0.05),同时MMP-9、p-IkB、NF-kB-p65的表达含量降低,TIMP-1表达含量增加。结论:吉西他滨联合西妥昔单抗对三阴乳腺癌细胞增殖、侵袭、迁移具有抑制作用,并明显抑制MMP-9的表达,其机制可能是通过抑制NF-kB通路实现。 相似文献