全文获取类型
收费全文 | 3079篇 |
免费 | 263篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 126篇 |
妇产科学 | 45篇 |
基础医学 | 314篇 |
口腔科学 | 729篇 |
临床医学 | 304篇 |
内科学 | 152篇 |
皮肤病学 | 7篇 |
神经病学 | 293篇 |
特种医学 | 36篇 |
外科学 | 161篇 |
综合类 | 219篇 |
一般理论 | 1篇 |
预防医学 | 535篇 |
眼科学 | 20篇 |
药学 | 165篇 |
中国医学 | 53篇 |
肿瘤学 | 198篇 |
出版年
2024年 | 3篇 |
2023年 | 50篇 |
2022年 | 56篇 |
2021年 | 95篇 |
2020年 | 129篇 |
2019年 | 125篇 |
2018年 | 123篇 |
2017年 | 121篇 |
2016年 | 110篇 |
2015年 | 103篇 |
2014年 | 177篇 |
2013年 | 284篇 |
2012年 | 177篇 |
2011年 | 141篇 |
2010年 | 127篇 |
2009年 | 138篇 |
2008年 | 154篇 |
2007年 | 160篇 |
2006年 | 122篇 |
2005年 | 107篇 |
2004年 | 102篇 |
2003年 | 100篇 |
2002年 | 82篇 |
2001年 | 75篇 |
2000年 | 53篇 |
1999年 | 34篇 |
1998年 | 43篇 |
1997年 | 58篇 |
1996年 | 37篇 |
1995年 | 22篇 |
1994年 | 29篇 |
1993年 | 29篇 |
1992年 | 33篇 |
1991年 | 21篇 |
1990年 | 29篇 |
1989年 | 22篇 |
1988年 | 18篇 |
1987年 | 6篇 |
1986年 | 14篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1974年 | 3篇 |
排序方式: 共有3370条查询结果,搜索用时 15 毫秒
1.
2.
《Drug metabolism and pharmacokinetics》2020,35(6):563-570
Minesapride is a novel 5-hydroxytryptamine 4 (5-HT4) receptor partial agonist that is expected to show efficacy in patients with irritable bowel syndrome with predominant constipation and functional constipation. An open-label study was conducted to evaluate pharmacokinetics (PK) and safety of minesapride. Japanese subjects, 12 elderly and 12 young, received a single oral dose of minesapride 40 mg/day in the fasted state. Metabolite profiles were also investigated in this clinical study and in an in vitro study using cryopreserved hepatocytes. Clinical results showed that minesapride was rapidly absorbed (Cmax: 2302.1 ng/mL in the elderly group, 2117.5 ng/mL in the young group), and the plasma concentration then decreased with half-life of approximately 7 h. There were no notable PK differences between elderly and young groups. No serious adverse events (AEs) were observed. The only AE that occurred in 2 or more subjects was diarrhea. Metabolite profiles in plasma and urine were similar between elderly and young groups. No major metabolites exceeded 10% of unchanged minesapride, and results of the in vitro study suggested that there were no human-specific metabolites. From the viewpoints of PK and metabolite profiling, no dose adjustment of minesapride is warranted in elderly population without renal or hepatic impairment. 相似文献
3.
目的:对比不同矫治器对错[牙合]畸形患者面高度及前后牙咬合关系的影响。方法:选取于笔者医院接受矫治的83例错[牙合]畸形患者,根据患者矫治器类型分为直丝弓组和Begg组,分别为42例和41例。比较并分析两组患者治疗前后牙咬合关系、硬组织、磨牙及面高度的变化情况。结果:矫治后,两组患者OJ-PPV、OB-PP、LMA-MPV、LMA-MPV均降低,Begg矫治组OJ-PPV水平显著高于直丝弓矫治组,OB-PP、LMA-MPV、LMA-MPV水平显著低于直丝弓矫治组,差异均具有统计学意义(P<0.05);两组患者LAFH、LAFH/TAFH、PFH/TAFH水平均升高,其中Begg矫治组患者LAFH水平显著低于直丝弓矫治组,差异均具有统计学意义(P<0.05);两组患者LMA-MP、LMC-MP水平均升高,差异具有统计学意义(P<0.05);矫治前后,两组患者SNA、SNA、ANB水平均无统计学差异(P>0.05)。结论:两种矫治器对错[牙合]畸形患者硬组织变化均无明显影响,其中Begg矫治对患者前后牙咬合关系改善作用更强,直丝弓对患者面高度的改善能力更强。 相似文献
4.
正确编制“本年盈余与预算结余差异调节表”是公立医院执行《政府会计制度》的一大难点,现有的几种差异调节方法存在诸多不足,核算正确与否依赖会计人员的基本素质,而且工作量巨大。以财务会计与预算会计差异产生的基本原理为基础,利用计算机软件实时校验并自动登记差异,是简便、高效、准确编制“本年盈余与预算结余差异调节表”的方法,本文对此进行了举例说明。 相似文献
5.
《Journal of infection and chemotherapy》2020,26(1):23-27
IntroductionAlthough peak C-reactive protein (CRP) levels are correlated with the prognosis of some diseases, there have been no reports regarding the association between peak CRP levels and mortality in patients with bacteremia. The present study aimed to determine the association between peak CRP levels and prognosis in patients with bacteremia.MethodsThis retrospective cohort study was conducted in a single tertiary hospital and included patients with bacteremia admitted to the emergency department from November 2012 to March 2017. Cox regression analysis was performed to examine the association between peak CRP levels and 30-day mortality. We also performed propensity score adjustment using potential confounding factors.ResultsOne hundred fifty-nine patients were included in the study. Peak CRP levels were significantly higher in the β-hemolytic streptococci (P = 0.001) and Streptococcus pneumoniae (P = 0.003) groups. The C-statistic of the multivariate logistic regression model for the propensity score was 0.88. For 30-day mortality, peak CRP levels >20 mg/dL did not show significance in the Cox regression analysis (hazard ratio, 0.866; 95% confidence interval, 0.489–1.537; P = 0.62). Even after propensity score adjustment, no significance was noted (hazard ratio, 0.865; 95% confidence interval, 0.399–1.876; P = 0.71).ConclusionsPeak CRP levels were not an independent predictor of mortality in patients with bacteremia in the emergency department. Clinicians should consider that patients with extremely high peak CRP levels do not necessarily have high mortality and vice versa. 相似文献
6.
Thomas Benner Andr J.W. van der Kouwe John E. Kirsch A. Gregory Sorensen 《Magnetic resonance in medicine》2006,56(1):204-209
Although the magnetic field of an MR scanner is very stable under little or no load, it can become less stable under heavy‐duty cycle conditions, such as in diffusion tensor imaging (DTI). Uncorrected, such field drifts lead to an apparent image shift along the phase‐encoding direction and decreasing effectiveness of fat saturation pulses. A method is presented to adjust the center frequency of all RF pulses and the receiver in real time during the acquisition. No data postprocessing or changes to the sequence timing are necessary. In vivo acquisitions were performed to assess the prolonged effectiveness of fat saturation. Field drifts of approximately 2.5 Hz/min were measured and corrected during DTI acquisitions at b‐values of up to 3000 s/mm2. The effectiveness of fat saturation diminished over the duration of an 18‐min acquisition when the drift was left uncorrected. The proposed method corrects for apparent image shift and ensures continuously effective fat saturation over the duration of an acquisition. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc. 相似文献
7.
目的:研究紧咬、叩齿运动中松动牙牙合力的动态变化特征。方法:选择19例单侧下颌第一磨牙松动的患者,用PVDF动态牙合力仪测量健侧和患侧下颌第一磨牙节律性叩齿和紧咬运动中牙合力动态变化曲线,分析最大牙合力峰值和到达峰值的时间,对两侧的测量结果进行分析。结果:叩齿运动中健侧下颌第一磨牙牙合力峰值平均为25kg,到达峰值的时间为108ms;患侧的分别为21kg和126ms;紧咬运动中健侧下颌第一磨牙牙合力峰值平均为27kg,到达峰值的时间为768ms;患侧的分别为23kg和1023ms;经配对t检验,健侧与患侧的峰值及到达峰值的时间差异均有显著性。结论:牙齿松动导致咀嚼功能降低,牙合力值和牙合力上升的速度均降低。 相似文献
8.
Social and psychological factors associated with adolescents'' self-acceptance of occlusal condition 总被引:1,自引:0,他引:1
D. F. Brown A. J. Spencer P. D. Tolliday 《Community dentistry and oral epidemiology》1987,15(2):70-73
Studies using plaster models of teeth and photographs simulating the full range of occlusal conditions have found high agreement between measures of adolescent social acceptability of these conditions and perceived need for orthodontic treatment. This study examined the association between adolescents' acceptability of their own occlusal condition, severity of malocclusion, and likelihood of undergoing orthodontic treatment. The factors predicting the acceptability of occlusal condition of 13-yr-olds, as assessed by the SASOC scale, were measurements of acceptability of general physical appearance, and the severity of occlusal condition. Variability in SASOC scores appeared to be independent of gender, socioeconomic status, and ethnicity. Gender, and severity of occlusal condition were important differences between subjects who had received, planned, or were undergoing orthodontic treatment, and those who had not. Neither SASOC scores nor perceived need for treatment accounted for a significant proportion of the variance between these groups. Although adolescents seeking orthodontic treatment had a greater severity of malocclusion than those not, little difference was observed between these groups in acceptance of occlusal condition. 相似文献
9.
目的:探讨MEAW技术在错He畸形固定矫治末期进行精细调整中的应用效果。方法:选取处于方丝弓固定矫治后期遗留局部小开He,上下颌牙齿尖窝交错关系未建立,中线未对齐等缺陷的病例7例,年龄14~24岁,平均年龄17.6岁,采用MEAW技术加颌间弹力牵引,进行咬合关系的精细调整。结果:经过MEAW技术3~6个月的调整,全部病例均达到预期的矫治效果,上下牙列建立了正常的覆He覆盖关系和良好的尖窝咬合关系。结论:对于固定矫治末期出现的小缺陷,通过MEAW技术加各种不同方向和力值的颌间弹力牵引,进行牙列的精细调整,能很好地恢复咬合关系,提高矫治效果。 相似文献
10.
Periklis Proussaefs 《Journal of prosthodontics》2004,13(1):36-41
PURPOSE: This study evaluated the effect of different cements on resistance to dislodgment of crowns cemented on preparations lacking geometric resistance form. MATERIALS AND METHODS: A preparation that offered no geometric resistance form, with 20 degrees total occlusal convergence (TOC), 0.9 mm wide shoulder finish line, and a 2.5 mm axial wall height was created on an ivorine tooth using a milling machine. Ten metal test specimen die replicas and 10 standardized metal crowns with recipient sites for the application of external forces through a universal testing machine were fabricated. The crowns were cemented on the dies under 5 and 10 kg external loads, the marginal openings measured, loaded to dislodgment, and cleaned of cement. The process was repeated using zinc oxide and eugenol (ZOE), zinc phosphate (ZPh), resin modified glass ionomer (RMGI), and composite resin (CR) cements. RESULTS: Marginal openings under 5 kg cementation loads were 74.63 (+/-15.04) for ZOE, 75.98 (+/-18.20) microm for ZPh, 98.58 (+/-22.62) microm for RMGI, and 105.82 (+/-20.07) microm for CR cements respectively; under 10 kg cementation loads they were 57.62 (+/-15.86) microm, 59.55 (+/-15.41) microm, 95.00 (+/-19.52) microm, 101.30 (+/-12.52) microm respectively. Oblique dislodgment forces, measured with a Universal testing machine, were 40.18 (+/- 6.76) N for ZOE, 215.65 (+/-45.79) N for ZPh, 165.43 (+/-19.53) N for RMGI, and 181.54 (+/-30.75) N for CR respectively when crowns were cemented under 5 kg loads. The corresponding values for 10 kg loads were 38.62 (+/-4.19), 274.86 (+/-54.22), 139.70 (+/-21.71), and 160.40 (+/-21.21) respectively. Only zinc phosphate cement produced statistically enhanced resistance when crowns were cemented under 10 kg force (p value = 0.035). CONCLUSIONS: Under the conditions of the present study only crowns cemented with zinc phosphate displayed increased resistance to dislodgment on preparations lacking resistance form. 相似文献