全文获取类型
收费全文 | 42003篇 |
免费 | 4203篇 |
国内免费 | 1037篇 |
专业分类
耳鼻咽喉 | 471篇 |
儿科学 | 936篇 |
妇产科学 | 1525篇 |
基础医学 | 3223篇 |
口腔科学 | 562篇 |
临床医学 | 9855篇 |
内科学 | 5468篇 |
皮肤病学 | 435篇 |
神经病学 | 2217篇 |
特种医学 | 2445篇 |
外国民族医学 | 6篇 |
外科学 | 4601篇 |
综合类 | 6518篇 |
现状与发展 | 3篇 |
预防医学 | 2967篇 |
眼科学 | 922篇 |
药学 | 2638篇 |
60篇 | |
中国医学 | 753篇 |
肿瘤学 | 1638篇 |
出版年
2024年 | 37篇 |
2023年 | 726篇 |
2022年 | 1121篇 |
2021年 | 1721篇 |
2020年 | 2043篇 |
2019年 | 1866篇 |
2018年 | 1811篇 |
2017年 | 1854篇 |
2016年 | 1817篇 |
2015年 | 1807篇 |
2014年 | 3394篇 |
2013年 | 3237篇 |
2012年 | 2407篇 |
2011年 | 2736篇 |
2010年 | 2126篇 |
2009年 | 1930篇 |
2008年 | 2012篇 |
2007年 | 1963篇 |
2006年 | 1674篇 |
2005年 | 1450篇 |
2004年 | 1159篇 |
2003年 | 1129篇 |
2002年 | 900篇 |
2001年 | 786篇 |
2000年 | 617篇 |
1999年 | 573篇 |
1998年 | 467篇 |
1997年 | 430篇 |
1996年 | 397篇 |
1995年 | 363篇 |
1994年 | 328篇 |
1993年 | 244篇 |
1992年 | 240篇 |
1991年 | 218篇 |
1990年 | 178篇 |
1989年 | 164篇 |
1988年 | 139篇 |
1987年 | 134篇 |
1986年 | 124篇 |
1985年 | 189篇 |
1984年 | 177篇 |
1983年 | 92篇 |
1982年 | 129篇 |
1981年 | 78篇 |
1980年 | 70篇 |
1979年 | 48篇 |
1978年 | 35篇 |
1977年 | 33篇 |
1976年 | 29篇 |
1975年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
翟洪漫 《中国医疗器械信息》2022,(1)
目的:给予不同年龄结节性甲状腺肿合并甲状腺癌患者实施甲状腺超声检查,对相应的超声检查特征展开分析。方法:选择2018年6月~2019年6月的114例患者为对象,所有患者均被确诊为结节性甲状腺肿合并甲状腺癌,并且利用甲状腺二维超声及多普勒超声对患者进行检查,依据患者年龄阶段均分为两组,每组中各纳入57例患者,年龄超过60岁以上的患者为老年组;年龄在60岁以下的患者为中青年组,对比两组患者的血流相关指标与钙化情况数据。结果:老年组中的平均收缩期流速、阻力指数等数据明显低于中青年组,且比较后P<0.05,具有临床可比较意义。老年组中钙化的总例数为21例,总钙化率占比为36.84%,中青年组中钙化的总例数为38例,总钙化率占比为66.67%,前者数据显著低于后者钙化率,P<0.05。结论:在对结节性甲状腺肿合并甲状腺癌患者实施超声检查后,中青年组患者的病灶呈现低回声、高回声以及伴微小钙化、血流分布以内部血流为主、血流阻力大的特点明显高于老年组,能够显著提升诊断效果,为日后的临床治疗提供了图像依据。 相似文献
3.
4.
目的探讨多元化联合教学模式在超声引导下疼痛介入治疗教学中的应用效果。方法选择2018年1月至2020年12月在北京大学第三医院疼痛科进修的30名医师作为研究对象,将其分为对照组与观察组;对照组采用常规教学模式;观察组采用多元化联合教学模式,比较两组医师技能考核成绩、教学质量评分和满意度评分。结果观察组医师技能考核成绩优良率为93.3%,高于对照组的73.3%(P<0.05);观察组医师对基础理论知识掌握、临床思维能力的提高、学习兴趣的激发、疾病诊治能力的提高4个方面的评分均高于对照组(P<0.01)。结论多元化联合教学模式可促进超声引导下疼痛介入治疗技能的提高,有利于提高学员的综合临床能力。 相似文献
5.
6.
《Zeitschrift für medizinische Physik》2022,32(2):209-217
This work describes a measurement method for assessing dose-related image-quality of CT scans based on the difference detail curve (DDC) method, and showcases its use in a low contrast setting. The method is based on a phantom consisting of elliptical slices of different sizes into which contrast object modules can be inserted. These modules contain contrast objects based on (synthetic) resin mixtures with sucrose (native) or sodium iodine (contrast medium). Mixing ratios are provided to achieve a range of clinically relevant CT-numbers with these materials. The phantom is characterized in terms of contrast accuracy, energy dependency and long-term drift with satisfying results. Contrast accuracy and energy dependency are similar to that of water or soft tissue. Image quality of 655 scans of the phantom acquired at 30 different clinical institutions and with 16 different CT scanner models from 4 manufacturers was assessed by calculating a difference detail curve (DDC) from evaluation of up to 5 human observers using a custom-made software (RadiVates) described in this work. Based on these measurements, inter-observer variability was quantified using a bootstrap method and was shown to be a large contributor to the overall variability. This work demonstrates that assessment of CT image quality is feasible with the aforementioned phantom and DDC method. 相似文献
7.
朱丹 《临床超声医学杂志》2022,24(9)
冻结肩是常见的肩部疾病,传统非可视化治疗冻结肩效果欠佳。近年来,超声引导具有动态实时定位、无辐射、便携性、低成本等优点在辅助诊断和治疗冻结肩患者中得到成功应用,不仅能提供精确的诊断,也提高了患者中长期的疗效。本文就超声引导辅助诊断和治疗冻结肩的研究进展进行综述。 相似文献
8.
《Journal of vascular and interventional radiology : JVIR》2022,33(12):1476-1484.e2
PurposeTo evaluate temporal trends, practice variation, and associated outcomes with the use of intravascular ultrasound (US) during deep venous stent placement among Medicare beneficiaries.Materials and MethodsAll lower extremity deep venous stent placement procedures performed between January 1, 2017, and December 31, 2019 among Medicare beneficiaries were included. Temporal trends in intravascular US use were stratified by procedural setting and physician specialty. The primary outcome was a composite of 12-month all-cause mortality, all-cause hospitalization, or repeat target vessel intervention. The secondary outcome was a composite of 12-month stent thrombosis, embolization, or restenosis.ResultsAmong the 20,984 deep venous interventions performed during the study period, 15,184 (72.4%) utilized intravascular US. Moderate growth in intravascular US use was observed during the study period in all clinical settings. There was a variation in the use of intravascular US among all operators (median, 77.3% of cases; interquartile range, 20.0%–99.2%). In weighted analyses, intravascular US use during deep venous stent placement was associated with a lower risk of both the primary (adjusted hazard ratio, 0.72; 95% confidence interval [CI], 0.69–0.76; P < .001) and secondary (adjusted hazard ratio, 0.32; 95% CI, 0.27–0.39; P < .001) composite end points.ConclusionsIntravascular US is frequently used during deep venous stent placement among Medicare beneficiaries, with further increase in use from 2017 to 2019. The utilization of intravascular US as part of a procedural strategy was associated with a lower cumulative incidence of adverse outcomes after the procedure, including venous stent thrombosis and embolization. 相似文献
9.
This meta-analysis was designed to assess the effectiveness and safety of extracorporeal shock wave therapy (ESWT) for patients with low back pain (LBP). Pubmed, Embase, Cochrane's library, PEDro (Physiotherapy Evidence Database), China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched until December 2019 to identify studies assessing the effectiveness and safety of EPSW for LBP. The prime outcome is pain intensity measured by Visual Analog Scale (VAS) or numeric rating scale (NRS). Other outcomes included functional status, quality of life, psychological outcomes measured by Oswestry Disability Index (ODI), as well as the adverse events. Mean differences (MD) were calculated for continuous outcomes, while odd ratios (OR) were calculated for binary outcomes. Revman 5.3 software was used for statistical analysis. Five randomized controlled trials (RCTs) were finally included in this meta-analysis. The pooled mean difference in post-treatment pain scores was −2.37 (P <0.0001), indicating that post-treatment pain scores was significantly higher by 2.37 in control group than in ESWT group. At a mean follow-up time of 4–6 weeks, the pooled mean difference in ODI scores was −14.10 (P <0.00001), indicating that the pooled mean difference of post-treatment ODI scores was 14.10 higher in control group than in ESWT group. The use of ESWT is effective in alleviating pain and improving the general functional state for patients with LBP. However, more evidence was needed to verify its safety. 相似文献
10.
《Clinical neurophysiology》2021,132(9):2003-2011
ObjectiveA large N20 and P25 of the median nerve somatosensory evoked potential (SEP) predicts short survival in amyotrophic lateral sclerosis (ALS). We investigated whether high frequency oscillations (HFOs) over N20 are enlarged and associated with survival in ALS.MethodsA total of 145 patients with ALS and 57 healthy subjects were studied. We recorded the median nerve SEP and measured the onset-to-peak amplitude of N20 (N20o-p), and peak-to-peak amplitude between N20 and P25 (N20p-P25p). We obtained early and late HFO potentials by filtering SEP between 500 and 1 kHz, and measured the peak-to-peak amplitude. We followed up patients until endpoints (death or tracheostomy) and analyzed the relationship between SEP or HFO amplitudes and survival using a Cox analysis.ResultsPatients showed larger N20o-p, N20p-P25p, and early and late HFO amplitudes than the control values. N20p-P25p was associated with survival periods (p = 0.0004), while early and late HFO amplitudes showed no significant association with survival (p = 0.4307, and p = 0.6858, respectively).ConclusionsThe HFO amplitude in ALS is increased, but does not predict survival.SignificanceThe enlarged HFOs in ALS might be a compensatory phenomenon to the hyperexcitability of the sensory cortex pyramidal neurons. 相似文献