全文获取类型
收费全文 | 11398篇 |
免费 | 573篇 |
国内免费 | 284篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 219篇 |
妇产科学 | 56篇 |
基础医学 | 1192篇 |
口腔科学 | 280篇 |
临床医学 | 1555篇 |
内科学 | 1528篇 |
皮肤病学 | 31篇 |
神经病学 | 1660篇 |
特种医学 | 739篇 |
外科学 | 1128篇 |
综合类 | 1090篇 |
现状与发展 | 1篇 |
预防医学 | 582篇 |
眼科学 | 51篇 |
药学 | 1041篇 |
6篇 | |
中国医学 | 666篇 |
肿瘤学 | 255篇 |
出版年
2024年 | 18篇 |
2023年 | 155篇 |
2022年 | 446篇 |
2021年 | 620篇 |
2020年 | 494篇 |
2019年 | 474篇 |
2018年 | 468篇 |
2017年 | 419篇 |
2016年 | 377篇 |
2015年 | 383篇 |
2014年 | 876篇 |
2013年 | 1005篇 |
2012年 | 687篇 |
2011年 | 787篇 |
2010年 | 524篇 |
2009年 | 574篇 |
2008年 | 588篇 |
2007年 | 507篇 |
2006年 | 489篇 |
2005年 | 374篇 |
2004年 | 292篇 |
2003年 | 205篇 |
2002年 | 170篇 |
2001年 | 162篇 |
2000年 | 149篇 |
1999年 | 141篇 |
1998年 | 121篇 |
1997年 | 94篇 |
1996年 | 75篇 |
1995年 | 64篇 |
1994年 | 56篇 |
1993年 | 59篇 |
1992年 | 54篇 |
1991年 | 43篇 |
1990年 | 34篇 |
1989年 | 38篇 |
1988年 | 33篇 |
1987年 | 18篇 |
1986年 | 21篇 |
1985年 | 19篇 |
1984年 | 16篇 |
1983年 | 13篇 |
1982年 | 24篇 |
1981年 | 17篇 |
1980年 | 11篇 |
1979年 | 7篇 |
1978年 | 13篇 |
1977年 | 12篇 |
1976年 | 8篇 |
1975年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
1.
《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
2.
目的:探讨温针灸对功能性便秘(FC)患者临床症状及焦虑抑郁的改善作用。方法:选取2017年1月至2017年12月中国中医科学院广安门医院南区收治的FC患者70例作为研究对象,随机分为观察组和对照组,每组35例。对照组采用常规针刺治疗,观察组采用温针灸治疗,比较治疗前后2组患者便秘临床症状积分、首次排便时间、中医证候评分、焦虑自评量表(SAS)、抑郁自评量表(SDS)评分。结果:观察组有效率96. 00%,对照组有效率68. 00%,差异有统计学意义(P0. 05)。治疗后2组患者的周排便次数、粪便性状积分和排便困难程度均改善,中医证候评分、SAS和SDS评分下降,较治疗前差异有统计学意义(P 0. 05)。治疗后,观察组患者的周排便次数、粪便性状积分高于对照组,中医证候评分、SDS和SAS评分、首次排便时间以及排便困难程度积分小于对照组,差异有统计学意义(P 0. 05)。结论:温针灸治疗能调节胃肠道运动、润湿肠道、显著改善便秘等临床症状,对FC患者有显著临床效果。 相似文献
3.
《Sleep medicine》2020
ObjectivesTo determine the prevalence of restless legs syndrome (RLS) and RLS-mimic conditions, the risk factors for RLS, and whether RLS contributes to functional impairment in children and adolescents with attention-deficit/hyperactivity disorder (ADHD).MethodsADHD children and adolescents were prospectively studied at the outpatient psychiatric clinic. A trained registered nurse used the 2012 Revised International Restless Legs Syndrome Study Group diagnostic criteria to diagnose RLS. Sociodemographic data and medical records were reviewed. Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P) Thai version was used to identify association between RLS and 6 domains of function [family, school (learning), school (behavior), life skills, child self-concept, social activities, and risky activities].ResultsA total of 217 patients were included. Of those, 23 (11%) patients met the criteria for RLS, and 49 (23%) had RLS-mimic conditions. Those conditions included myalgia (30/49), habitual foot tapping (23/49), positional discomfort (20/49), leg ulcer/bruise (1/49), and arthralgia/arthritis (1/49). Binary logistic regression revealed first-degree relative having RLS symptom to be significantly associated with RLS in study patients (OR: 5.06, p < 0.01). Multivariate linear regression showed RLS to be independently associated with school (behavior) (Β = 1.18, p = 0.05) and life skills (Β = 2.36, p = 0.05) impairment.ConclusionsRLS was found to be common in ADHD children and adolescents. RLS-mimic conditions were found in two-thirds of patients who previously met 4 essential RLS criteria. First-degree relative with RLS symptom was associated with RLS, and RLS was associated with functional impairment in the life skills and school (behavior) domains. 相似文献
4.
5.
6.
目的 探讨台州市功能性消化不良的流行病学现状及影响因素。方法 回顾性选取2020年1月至2022年2月浙江省台州医院收治的功能性消化不良患者200例,统计患者的一般资料,分析该病的流行病学现状,对功能性消化不良的影响因素进行单因素分析,然后将差异有统计学意义的因素再进一步纳入多因素Logistic回归分析。结果 200例功能性消化不良患者中,女性发病率高于男性;30~60岁年龄段群体,患病率最高;存在暴饮暴食、喜食烫食、挑食、多食酸制品、未准时进食、常食宵夜、睡眠时间<6h、有药物过敏史、有功能性消化不良家族史、存在便秘情况者的患病率均高于未存在以上情况者,差异均有统计学意义(P<0.05)。多因素Logistic回归分析显示,性别、年龄、暴饮暴食、喜食烫食、挑食、多食酸制品、未准时进食、宵夜摄取情况、每天睡眠时间、药物过敏史、家族史、便秘是该病患病率升高的主要影响因素。结论 性别、年龄、暴饮暴食、喜食烫食、挑食、酸制品、未准时进食情况、宵夜摄取情况、每天睡眠时间、药物过敏史、家族史、便秘是功能性消化不良的主要影响因素。 相似文献
7.
In this study, the carbonic anhydrase (CA) enzyme was purified from Black Sea trout (Salmo trutta Labrax Coruhensis) kidney with a specific activity of 603.77 EU/mg and a yield of 35.5% using Sepharose-4B-l-tyrosine- sulphanilamide affinity column chromatography. For determining the enzyme purity and subunit molecular mass, sodiumdodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was performed and single band was observed. The molecular mass of subunit was found approximately 29.71 kDa. The optimum temperature, activation energy (Ea), activation enthalpy (ΔH) and Q10 values were obtained from Arrhenius plot. Km and Vmax values for p-nitrophenyl acetate of the purified enzyme were calculated from Lineweaver-Burk graphs. In addition, the inhibitory effects of different heavy metal ions (Fe2+, Pb2+, Co2+, Ag+ and Cu2+) on Black Sea trout kidney tissue CA enzyme activities were investigated by using esterase method under in vitro conditions. The heavy metal concentrations inhibiting 50% of enzyme activity (IC50) were obtained. Finally Ki values and inhibition types were calculated from Lineweaver-Burk graphs. 相似文献
8.
《Brain stimulation》2021,14(1):161-169
BackgroundThe prediction violation account of automatic or pre-attentive change detection assumed that the inferior frontal cortex (IFC) is involved in establishing a prediction model for detecting unexpected changes. Evidence supporting the IFC’s contribution to prediction model is mainly based on the Mismatch Negativity (MMN) to deviants violating predictions that are established based on the frequently presented standard events. However, deviant detection involves processes, such as events comparison, other than prediction model establishment.ObjectiveThe current study investigated the critical role of the IFC in establishing a prediction model during standards processing for subsequent deviant detection.MethodsTranscranial Magnetic Stimulation (TMS) was applied at the IFC to disrupt the processing of the initial 2 or 5 standards of a 3-, 6-, or 9-standard train, while the MMN responses to pitch deviant presented after the standard trains were recorded and compared.ResultsAn abolishment of MMN was only observed when TMS was delivered to the IFC at the initial 2 standards of the 3-standard train, but not at the initial 5 standards, or when TMS at the vertex or TMS sound recording was applied. The MMNs were also preserved when IFC TMS, vertex TMS, or TMS sound recording was applied at the initial 2 or 5 standards of longer trains.ConclusionThe IFC plays a critical role in processing the initial standards of a short standard train for subsequent deviant detection. This result is consistent with the prediction violation account that the IFC is important for establishing the prediction model. 相似文献
9.
《Allergologia et immunopathologia》2019,47(4):357-364
IntroductionAmaranthus retroflexus (Redroot Pigweed) is one of the main sources of allergenic pollens in temperate areas. Polcalcin is a well-known panallergen involved in cross-reactivity between different plants. The aim of this study was the molecular cloning and expression of polcalcin, as well as evaluating its IgE-reactivity with A. retroflexus sensitive patients’ sera.MethodsAllergenic extract was prepared from A. retroflexus pollen and the IgE-reactivity profile was determined by ELISA and immunoblotting using sera from twenty A. retroflexus sensitive patients. Polcalcin-coding sequence was amplified by conventional PCR method and the product was inserted into pET-21b(+) vector. The recombinant protein was expressed in E. coli BL21 and purified by metal affinity chromatography. The IgE-binding capability of the recombinant protein was analyzed by ELISA and immunoblotting assays, and compared with crude extract.ResultsOf 20 skin prick test positive patients, 17 patients were positive in IgE-specific ELISA. Western blotting confirmed that approximately 53% of ELISA positive patients reacted with 10 kDa protein in crude extract. The A. retroflexus polcalcin gene, encoding to 80 amino acid residues was cloned and expressed as a soluble protein and designated as Ama r 3. The recombinant polcalcin showed rather identical IgE-reactivity in ELISA and western blotting with 10 kDa protein in crude extract. These results were confirmed by inhibition methods, too.ConclusionThe recombinant form of A. retroflexus polcalcin (Ama r 3) could be easily produced in E. coli in a soluble form and shows rather similar IgE-reactivity with its natural counterpart. 相似文献
10.