全文获取类型
收费全文 | 34613篇 |
免费 | 3329篇 |
国内免费 | 2392篇 |
专业分类
耳鼻咽喉 | 281篇 |
儿科学 | 500篇 |
妇产科学 | 387篇 |
基础医学 | 3705篇 |
口腔科学 | 719篇 |
临床医学 | 4520篇 |
内科学 | 5202篇 |
皮肤病学 | 325篇 |
神经病学 | 1358篇 |
特种医学 | 1153篇 |
外国民族医学 | 15篇 |
外科学 | 3655篇 |
综合类 | 6079篇 |
现状与发展 | 7篇 |
一般理论 | 2篇 |
预防医学 | 2488篇 |
眼科学 | 1010篇 |
药学 | 3941篇 |
24篇 | |
中国医学 | 2109篇 |
肿瘤学 | 2854篇 |
出版年
2024年 | 162篇 |
2023年 | 607篇 |
2022年 | 1521篇 |
2021年 | 1911篇 |
2020年 | 1488篇 |
2019年 | 1191篇 |
2018年 | 1255篇 |
2017年 | 1221篇 |
2016年 | 1105篇 |
2015年 | 1688篇 |
2014年 | 2106篇 |
2013年 | 1963篇 |
2012年 | 2750篇 |
2011年 | 2885篇 |
2010年 | 1993篇 |
2009年 | 1607篇 |
2008年 | 1955篇 |
2007年 | 1832篇 |
2006年 | 1760篇 |
2005年 | 1410篇 |
2004年 | 1108篇 |
2003年 | 944篇 |
2002年 | 821篇 |
2001年 | 671篇 |
2000年 | 649篇 |
1999年 | 640篇 |
1998年 | 422篇 |
1997年 | 403篇 |
1996年 | 352篇 |
1995年 | 334篇 |
1994年 | 301篇 |
1993年 | 173篇 |
1992年 | 210篇 |
1991年 | 160篇 |
1990年 | 123篇 |
1989年 | 108篇 |
1988年 | 116篇 |
1987年 | 114篇 |
1986年 | 95篇 |
1985年 | 70篇 |
1984年 | 28篇 |
1983年 | 25篇 |
1982年 | 12篇 |
1981年 | 16篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1978年 | 2篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
991.
目的探讨腮腺炎致无精症患者两种睾丸活检取精(TESA)即开放性睾丸活检和显微切割睾丸活检取精的优劣。方法每组24例患者,分别用开放性睾丸活检和显微切割睾丸活检取精,观察取精成功率、术后并发症发生率,术后并发症包括术后血肿的形成,术后3月睾丸萎缩、睾酮下降。结果开放性睾丸活检取精组,能找到活动的精子14例,取精成功率58.3%,术后并发症10例,约41.7%,分别为血肿2例、三月后睾丸萎缩3例、睾酮下降5例;显微切割睾丸活检取精组,能找到活动的精子18例,取精成功率75%,术后并发症5例,约20.8%,分别为血肿0例、三月后睾丸萎缩1例、睾酮下降4例。取精成功率和开放性睾丸活检取精组比较(P〈0.05),术后并发症和开放性睾丸活检取精组此较(P〈0.01)。结论显微切割睾丸活检取精较开放手术睾丸活检取精成功率高、术后并发症少,值得推广。 相似文献
992.
Hyun Wook Chae Il Suh Ah Reum Kwon Ye Jin Kim Yong Hyuk Kim Dae Ryong Kang Ha Yan Kim Sun Min Oh Hyeon Chang Kim Duk Hee Kim Ho-Seong Kim 《Journal of Korean medical science》2013,28(10):1512-1517
Longitudinal standards for height and height velocity are essential to monitor for appropriate linear growth. We aimed to construct standards in Korean children and adolescents through the population-based longitudinal Kangwha study. Our study was a part of a community-based prospective cohort study from 1986 to 1999 with 800 school children. Height and height velocity were recorded annually from age 6 until final height. Results were compared with cross-sectional data from the 2007 Korean National Growth Charts. Final height was 173.5 cm in boys and 160.5 cm in girls. Although final height was similar between longitudinal and cross-sectional standards, the mean height for age was higher in the longitudinal standard by 1-4 cm from age 6 until the completion of puberty. Using the longitudinal standard, age at peak height velocity (PHV) was 12 in boys and 10 in girls; height velocity at PHV was 8.62 cm/yr in boys and 7.07 cm/yr in girls. The mean height velocity was less than 1 cm/yr at age 17 in boys and 15 in girls. Thus, we have presented the first report of longitudinal standards for height and height velocity in Korean children and adolescents by analyzing longitudinal data from the Kangwha cohort. 相似文献
993.
994.
Jianhua Chen Qiaogan Liao Gang Ye Dan He Xiaoyan Du Weiguo Zhu Jianhe Liao Zuo Xiao Liming Ding 《Macromolecular chemistry and physics.》2013,214(18):2054-2060
Two electron‐deficient tetracyclic monomers, 6,9‐dibromo‐7,8‐bis(octyloxy)‐11H‐indeno[2,1‐b] quinoxalin‐11‐one ( M1 ) and 1,3‐bis(5′‐bromo‐4′‐hexylthiophen‐2‐yl)‐9H‐indeno[1,2‐b]thieno[3,4‐e]pyrazin‐9‐one ( M2 ), are synthesized through condensation of ninhydrin with aromatic diamines in good yields. Copolymerization of M1 with thiophene (Th) and dithieno[3,2‐b:2′,3′‐d]silole (DTS), and M2 with DTS affords three new D–A conjugated copolymers, P1 – P3, respectively . The optical, electrochemical, and photovoltaic properties of P1–P3 are investigated. P3 exhibits a broad absorption (300–1100 nm) and a low bandgap of 1.24 eV. Solar cells based on P3 /[6,6]‐phenyl C71 butyric acid methyl ester (PC71BM) blends afford a power conversion efficiency of 1.93% and a very broad spectral response (300–1020 nm).
995.
Ye Zhao Tian-xiang Gu Guang-wei Zhang Hua-gang Liu Chun Wang 《Cardiovascular pathology》2013,22(5):383-388
BackgroundAtrial fibrosis causes abnormal conduction through the atria, creating a substrate for atrial fibrillation (AF). In a rabbit model, rapid atrial pacing produces significant atrial fibrosis and the substrate for AF maintenance. This atrial remodeling is a potential therapeutic target.ObjectiveTo evaluate the effects of the losartan on atrial fibrosis.MethodsThirty rabbit AF models were produced by rapid atrial stimulation. They were randomly divided into three groups: sham group, rapid atrial pacing group, and rapid atrial pacing with losartan group. We performed AF vulnerability studies, atrial histologic, and molecular analyses after 4 weeks.ResultsOnly rabbits in the rapid atrial pacing group developed sustained AF (30 min, 4of 10 rabbits). Treatment with losartan resulted in a significant reduction in left atrial fibrosis and AF duration (P<.01). real-time polymerase chain reaction analyses demonstrated the drug's effects on the expression of Collagen I, Collagen III, and TGF-β/Smads signaling pathway.ConclusionsThe treatment of losartan results in significantly reduced atrial fibrosis and AF vulnerability. Pharmacological therapy targeted at the fibrotic substrate itself may play an important role in the management of AF. 相似文献
996.
997.
998.
As a critical enzyme for the uric acid production, xanthine oxidase (XO) has emerged as a primary drug target for antihyperuricemic therapy. A hierarchical virtual screening integrating both ligand-based and structure-based approaches was applied herein to identify potent XO inhibitors. Four compounds, which were previously reported as XO inhibitors, were recognized through the virtual screening protocol, and compound H3, which is distinct from the structures of known XO inhibitors, was identified as a new chemotype inhibitor with IC50 of 2.6 μM. The binding mode of H3 was further investigated by molecular docking and molecular dynamics (MD) simulation. The results suggested the feasibility to discover new chemotypes of XO inhibitors via integrated virtual screening strategies.A new chemotype of XO inhibitor with the IC50 of 2.6 μM was identified by a hierarchical virtual screening strategy. 相似文献
999.
目的观察不同的碳水化合物肠内营养液[肠内营养乳剂(TPF-D)和肠内营养混悬液(TPF)]用于早期肠内营养对应激性高血糖患者血糖水平与预后的影响,探讨其作为应激性高血糖患者早期肠内营养制剂的临床可行性。
方法选入2020年6至10月徐州医科大学附属医院急诊ICU收治的合并应激性高血糖的患者为研究对象。根据入排标准,最终71例患者纳入研究,随机数字表法将其分为观察组(35例,鼻饲TPF-D)和对照组(36例,鼻饲TPF)。收集患者一般资料,包括性别、年龄、急性生理与慢性健康状况(APACHE Ⅱ)评分;记录患者第1、3、7天每4小时一次血糖数据,并计算平均血糖值(GLUAVE)、平均血糖波动幅度(GLUMAGE);计算治疗后3、7 d胰岛素应用总量;监测患者第1、7天相关营养指标变化,如总蛋白(TP)、白蛋白(ALB)、前白蛋白(PA);记录胃肠道并发症(如反流、呕吐、腹泻、腹胀等)、ICU住院时间及28 d病死率。
结果(1)2组性别比例、年龄、APACHE Ⅱ评分比较,差异均无统计学意义(P>0.05)。(2)2组第1、3、7天GLUAVE及第1、3天GLUMAGE比较,差异均无统计学意义(P>0.05);观察组第7天GLUMAGE显著低于对照组,差异有统计学意义[(0.72±0.08)mmol/L vs(1.56±0.10)mmol/L,t=6.22,P=0.02]。(3)观察组治疗3、7 d胰岛素应用总量显著低于对照组,差异均有统计学意义[(60.40±39.80)U vs(102.70±49.60)U,t=0.17,P=0.02;(110.50±43.30)U vs(202.80±56.40)U,t=2.52,P=0.01]。(4)2组第1、7天TP、PA、ALB比较,差异均无统计学意义(P>0.05)。(5)2组胃肠道并发症、ICU住院时间、28 d病死率比较,差异均无统计学意义(P>0.05)。
结论应激性高血糖患者早期营养中,TPF-D较TPF能更好地降低血糖变异性,控制血糖波动幅度,并减少临床中胰岛素用量,但不影响预后。 相似文献
1000.