首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   193317篇
  免费   14900篇
  国内免费   4337篇
耳鼻咽喉   1365篇
儿科学   2644篇
妇产科学   3063篇
基础医学   23657篇
口腔科学   3363篇
临床医学   15435篇
内科学   32566篇
皮肤病学   2189篇
神经病学   12247篇
特种医学   6664篇
外国民族医学   2篇
外科学   15029篇
综合类   25611篇
现状与发展   21篇
一般理论   8篇
预防医学   14753篇
眼科学   2210篇
药学   26253篇
  61篇
中国医学   12659篇
肿瘤学   12754篇
  2024年   151篇
  2023年   2508篇
  2022年   3423篇
  2021年   7598篇
  2020年   6844篇
  2019年   6804篇
  2018年   6850篇
  2017年   7303篇
  2016年   7329篇
  2015年   6863篇
  2014年   8299篇
  2013年   12252篇
  2012年   9694篇
  2011年   11603篇
  2010年   7464篇
  2009年   7700篇
  2008年   9235篇
  2007年   10255篇
  2006年   9733篇
  2005年   8936篇
  2004年   7632篇
  2003年   6896篇
  2002年   5356篇
  2001年   4843篇
  2000年   4060篇
  1999年   3398篇
  1998年   2527篇
  1997年   2602篇
  1996年   2342篇
  1995年   2196篇
  1994年   2139篇
  1993年   1790篇
  1992年   1687篇
  1991年   1553篇
  1990年   1363篇
  1989年   1105篇
  1988年   1060篇
  1987年   957篇
  1986年   885篇
  1985年   1258篇
  1984年   1013篇
  1983年   758篇
  1982年   781篇
  1981年   640篇
  1980年   610篇
  1979年   493篇
  1978年   309篇
  1977年   269篇
  1976年   252篇
  1975年   191篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
《Motricité Cérébrale》2020,41(3-4):78-81
The Halliwick method, created in England in 1949 by J. McMillan, engineer, who offered his services at the Halliwick swimming school for young girls cp, is based on the physical properties of water and consists of a program in ten points (TPP) for swimming initiation; WSTH is a learning engine in water which facilitates the management of the movements and activities of daily life on earth. It's in agreement with the normal motor development of the child, the levels of motor evolution (NEM), International Classification of Functioning, disability and health (ICF) proposed by the WHO in 2001 as well as with Huber's positive health (2011). Several scientific studies attest to the efficientness of the Halliwick method and of the WSTH on motor skills. Four field studies, published, compared WSTH to conventional aquatic therapy (CAT), randomized, in children with cp: (1) on spasticity (elbow/wrist/knee/ankle measurement), WSTH shows a decrease HS specifically on the wrist and ankle after WSTH; S results for CAT; (2) on the range of motion, the measurements show a S increase proximally, especially on the UE after WSTH; (3) on the active trunk recovery, the WSTH shows an action THS in th12, S in th8 and c7; NS in CAT; (4) on the head control, the results are, after WSTH, HS in flexion/extension/inclinations and S in rotations; they are NS for CAT.ConclusionThe Halliwick method and the WSTH have been proven to be efficient on motor skills; our 4 field studies show significantly better effects with WSTH – probably thanks to “its rotation points” – than with CAT.  相似文献   
992.
Microglial polarization to the anti-inflammatory M2 phenotype is essential in resolving neuroinflammation, making it a promising therapeutic strategy for stroke intervention. The actin cytoskeleton is known to be important for the physiological functions of microglia, including migration and phagocytosis. Profilin 1 (PFN1), an actin-binding protein, is involved in the dynamic transformation and reorganization of actin. However, the role of PFN1 in microglial polarization and ischemia/reperfusion injury is unclear. The role of PFN1 on microglial polarization was examined in vitro in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGDR) and in vivo in male mice after transient middle cerebral artery occlusion (MCAO). Knockdown of PFN1 inhibited M1 microglial polarization and promoted M2 microglia polarization 48 hr after OGDR stimulation in BV2 cells and 7 days after MCAO-induced injury in male mice. RhoA/ROCK pathway was involved in the regulation of PFN1 during microglial polarization. Knockdown of PFN1 also significantly attenuated brain infarcts and edema, improved cerebral blood flow and neurological deficits in MCAO-injured mice. Inhibition of PFN1 effectively protected the brain against ischemia/reperfusion injuries by promoting M2 microglial polarization in vitro and in vivo.  相似文献   
993.
Recent evidence implicates endogenous pituitary adenylyl cyclase activating polypeptide (PACAP) in the aversive effect of nicotine. In the present study, we assessed if nicotine-induced conditioned place preference (CPP) or affective signs of nicotine withdrawal would be altered in the absence of PACAP and if there were any sex-related differences in these responses. Male and female mice lacking PACAP and their wild-type controls were tested for baseline place preference on day 1, received conditioning with saline or nicotine (1 mg/kg) on alternate days for 6 days and were then tested for CPP the next day. Mice were then exposed to four additional conditioning and were tested again for nicotine-induced CPP 24 hr later. Controls were conditioned with saline in both chambers and tested similarly. All mice were then, 96 hr later, challenged with mecamylamine (3 mg/kg), and tested for anxiety-like behaviors 30 min later. Mice were then, 2 hr later, forced to swim for 15 min and then tested for depression-like behaviors 24 hr later. Our results showed that male but not female mice lacking PACAP expressed a significant CPP that was comparable to their wild-type controls. In contrast, male but not female mice lacking PACAP exhibited reduced anxiety- and depression-like behaviors compared to their wild-type controls following the mecamylamine challenge. These results suggest that endogenous PACAP is involved in affective signs of nicotine withdrawal, but there is a sex-related difference in this response.  相似文献   
994.
IntroductionSchool-based education is a potentially effective approach for improving mental health literacy (MHL) in adolescents. This study evaluated the effects of the “Short MHL Program (SMHLP)”, a brief (50 min), school teacher-led program, on MHL in adolescents in a quasi-cluster randomized controlled trial.MethodsA total of 975 high school first graders (age 15–16) in Japan were allocated to classes such that gender and academic achievement ratios were almost equivalent at the time of admission to the high school. They were assigned at the class level to the SMHLP (n = 364 from 10 classes) or a control group (n = 611 from 17 classes). The program consisted of a 50-minute session and was delivered by a school teacher. The students completed a self-report questionnaire at 3 time points: pre-, (immediately) post- and 2-month follow-up. Outcomes included “Knowledge about mental health/illnesses”, “Recognition of the necessity to seek help”, “Intention to seek help”, and “Intention of helping peers”. Mixed effects modeling was employed for analyses.ResultsScores of all outcomes were significantly improved in the intervention group compared to the control group post-intervention (p < .001). These improvements were maintained at 2-months follow-up for all outcomes (p < .001–.05). Questionnaire scores did not differ between groups at baseline.ConclusionsThe effect of the SMHLP was confirmed in grade 10 students. Brief, yet effective programs can be a viable option to promote understanding of mental health problems and have the potential to be incorporated into regular school curriculum. "  相似文献   
995.
Purpose and backgroundThis study retrospectively compares diagnostic performance of 1.5 T versus 3 T non-echo planar diffusion weighted imaging with or without additional T1 and T2 sequences in the detection of residual and/or recurrent cholesteatoma.MethodsPatients with clinically suspected recurrent cholesteatoma or postoperative routine survey MR who subsequently underwent surgical procedure were retrospectively included (135 patients, 164 operated ears) from a large database. Patients underwent 1.5 T (128 ears) or 3 T MRI (36 ears), with non-echo planar DWI, T1 and T2 acquisitions. Two radiologists independently reassessed the images. Definitive surgical diagnosis was used as gold standard. Sensitivity, specificity and diagnostic odds ratio were evaluated.ResultsAccording to surgical diagnosis a cholesteatoma was present in 124 of 164 ears, corresponding with a prevalence of 75%. Sensitivity and specificity were lower for 3 T compared to 1.5 T, irrespective of whether additional T1 and T2-weighted sequences were used or not. Diagnostic odds ratios were higher for 1.5 T (34 and 12 for reader 1 and 2, respectively) compared to 3 T (3 and 4 for reader 1 and 2, respectively). Adding T1 and T2 sequences lowers sensitivity but increases specificity.ConclusionNon-epi DWI for the detection of residual/recurrent cholesteatoma is preferably performed on 1.5 T scanners over 3 T. The use of additional sequences regarding detection of cholesteatoma is debatable as it lowers sensitivity but increases specificity. However, these sequences may also be of use in diagnosing complications and planning surgical procedures in some hospitals.  相似文献   
996.
Gulf War Illness (GWI) affects 30% of veterans from the 1991 Gulf War (GW), who suffer from symptoms that reflect ongoing mitochondria dysfunction. Brain mitochondria bioenergetics dysfunction in GWI animal models corresponds with astroglia activation and neuroinflammation. In a pilot study of GW veterans (n = 43), we observed that blood nicotinamide adenine dinucleotide (NAD) and sirtuin 1 (Sirt1) protein levels were decreased in the blood of veterans with GWI compared to healthy GW veterans. Since nicotinamide riboside (NR)-mediated targeting of Sirt1 is shown to improve mitochondria function, we tested whether NR can restore brain bioenergetics and reduce neuroinflammation in a GWI mouse model. We administered a mouse diet supplemented with NR at 100μg/kg daily for 2-months to GWI and control mice (n = 27). During treatment, mice were assessed for fatigue-type behavior using the Forced Swim Test (FST), followed by euthanasia for biochemistry and immunohistochemistry analyses. Fatigue-type behavior was elevated in GWI mice compared to control mice and lower in GWI mice treated with NR compared to untreated GWI mice. Levels of plasma NAD and brain Sirt1 were low in untreated GWI mice, while GWI mice treated with NR had higher levels, similar to those of control mice. Deacetylation of the nuclear-factor κB (NFκB) p65 subunit and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) was an increase in the brains of NR-treated GWI mice. This corresponded with a decrease in pro-inflammatory cytokines and lipid peroxidation and an increase in markers of mitochondrial bioenergetics in the brains of GWI mice. These findings suggest that targeting NR mediated Sirt1 activation restores brain bioenergetics and reduces inflammation in GWI mice. Further evaluation of NR in GWI is warranted to determine its potential efficacy in treating GWI.  相似文献   
997.
目的探讨胺碘酮治疗心脏瓣膜置换术后心房颤动患者的临床效果,旨在为提高瓣膜置换术后心房颤动患者疗效提供参考依据。方法计算机检索PubMed、Web of Science、WILEY医学及护理学科库、Cochrane Library、CNKI、万方数据库、维普数据库、中国生物医学文献数据库,查找自建库至2019年9月24日有关胺碘酮治疗心脏瓣膜置换术后心房颤动患者临床疗效的随机对照试验(RCT)。经过2名研究员独立文献筛选、文献质量评价后提取相关数据,采用Revman 5.3软件进行定量综合分析。结果共纳入7篇文献,其中中文文献6篇,英文文献1篇;累计710例患者,试验组363例,对照组347例。采用Revman 5.3软件行定量合成,结果显示,使用胺碘酮治疗瓣膜置换术后心房颤动能够提高心房颤动转复率(RR=1.36,95%CI:1.20~1.54,P<0.05),且窦性心律维持率提高(RR=1.41,95%CI:1.16~1.72,P=0.002),其可以缩短ICU监护时间(MD=-1.09,95%CI:-1.32^-0.86,P<0.05)和总住院天数(MD=-3.92,95%CI:-4.25^-3.59,P<0.05)。结论胺碘酮治疗瓣膜置换术后心房颤动可以提高心房颤动转复率和窦性心律维持率,缩短ICU监护时间和总住院天数,值得临床推广应用。  相似文献   
998.
Alzheimer?s disease (AD) is a neurodegenerative disease characterised by neurocognitive impairments, especially memory impairment, as core symptoms linked to reductions in activities of daily life. As marginal symptoms, neuropsychiatric symptoms (NPSs) appear during the progressive course of the disease. A lack of self‐awareness (anosognosia) of cognitive and functional impairments is often seen in patients with AD, and associations between anosognosia and other NPSs have been previously reported. To account for anosognosia pathogenesis neurocognitively, the cognitive awareness model (CAM) has been helpful for explaining the stream of events from sensory input to behavioural/affective and metacognitive outputs. According to CAM, there are three types of anosognosia: (i) primary anosognosia, (ii) executive anosognosia, and (iii) mnemonic anosognosia. These types of anosognosia are generated from different neurocognitive modulations leading to metacognitive outputs or behavioural/affective regulations. Primary anosognosia is considered to be caused by deficits in the metacognitive awareness system (MAS). While preserved MAS function is associated with milder depression and anxiety in AD, a severer depressive mood in patients with mild AD can inversely cause self‐underestimation. The modulation of executive anosognosia is thought to be associated with dangerous/disinhibition behaviours and apathy among NPS sub‐symptoms, via impairments of comparator mechanism (Cm) within the central executive system. Other neurobehavioral reactions linked to self‐awareness include ‘denying’ and ‘confabulation’, and each of these reactions is thought to be affected by the MAS and a Cm. Denial of one?s own memory impairments appears as a defensive reaction to protect against dysphoric feelings, and the confabulatory comment is instantly reaction constructed by fabrications according to misinterpretations of memory information about oneself. Similarly, the innovative development of a theoretical model (CAM) has contributed to explaining the mechanism of anosognosia and some neurobehavioral outputs from a neurocognitive perspective.  相似文献   
999.
《Brain stimulation》2020,13(3):858-860
Transcranial direct current stimulation (tDCS) is a type of non-invasive brain stimulation technique that is explored as an add-on treatment for the alleviation of symptoms across the diverse symptom domains in neuropsychiatric disorders. In psychiatry, data is emerging on the effects of tDCS as an add-on treatment in schizophrenia as well as obsessive-compulsive disorder (OCD). But despite high prevalence, the effectiveness of tDCS in co-morbid schizophrenia and OCD is lacking. This case report for the first time examines the clinical utility with target-specific effects of the add-on tDCS in a patient diagnosed with schizo-obsessive disorder.  相似文献   
1000.
目的探讨术前白蛋白碱性磷酸酶比值(AAPR)与根治性膀胱切除术后患者总体生存期(OS)的关系。方法回顾性分析2007年1月至2015年12月青岛大学附属医院收治的166例膀胱癌患者的临床病理资料。男148例,女18例。年龄(65.1±9.4)岁。伴高血压病31例、糖尿病14例。体质指数(BMI)(24.00±3.32)kg/m^2。肿瘤单发92例,多发74例。肿瘤直径<3 cm者43例,≥3 cm者123例。合并肾积水33例,无肾积水133例。术前AAPR(0.62±0.23)。根据AAPR的三分位点将患者分为低AAPR组55例,AAPR(0.42±0.09);中AAPR组55例,AAPR(0.58±0.05);高AAPR组56例,AAPR(0.86±0.21)。美国麻醉医师协会(ASA)分级1级4例,2级65例,3级86例,4级11例。根治术前患者均行经尿道膀胱肿瘤切除术,病理诊断均为膀胱癌,高级别144例,低级别22例。166例均行根治性膀胱切除术,其中腹腔镜手术140例,开放手术26例。术中行输尿管皮肤造口55例,回肠代膀胱96例,回肠原位新膀胱15例。将AAPR连续性变量和AAPR分组作为原始模型,调整年龄、肿瘤大小、pT分期、pN分期、肾积水、ASA分级、辅助化疗的数据作为校准模型1,在校准模型1基础上增加BMI、肿瘤数目、病理等级的数据作为校准模型2。采用趋势性检验检测不同AAPR组间危险比(HR)变化趋势。分析不同因素分层的AAPR与OS的关系。采用Kaplan-Meier法绘制生存曲线。采用基于广义相加模型的曲线拟合表示AAPR与OS的关系。结果本组166例中位随访63个月,生存95例,死亡71例。3年生存率为61%,5年生存率为50%。术后病理分期:T1期27例,T2期82例,T3期48例,T4期9例;N0期145例,N1期14例,N2期6例,N3期1例。术后52例行辅助化疗。单因素Cox回归分析结果显示,AAPR(HR=0.09,95%CI 0.022~0.391,P=0.001)、高AAPR组(HR=0.40,95%CI 0.216~0.742,P=0.003)、年龄(HR=2.42,95%CI 1.294~4.531,P=0.006)、肿瘤大小(HR=2.11,95%CI 1.112~4.014,P=0.023)、肿瘤数目(HR=0.62,95%CI 0.378~1.022,P=0.061)、pT3期(HR=8.93,95%CI 3.173~25.114,P<0.001)、pT4期(HR=10.39,95%CI 3.110~34.707,P<0.001)、N1期(HR=2.80,95%CI 1.422~5.531,P=0.003)、N3期(HR=17.06,95%CI 2.192~132.863,P=0.007)、病理分级(HR=0.30,95%CI 0.113~0.817,P=0.019)、肾积水(HR=2.36,95%CI 1.406~3.939,P=0.001)、术后辅助化疗(HR=2.66,95%CI 1.674~4.247,P<0.001)均与术后OS相关。调整年龄、肿瘤大小、pT分期、pN分期、肾积水、ASA分级、辅助化疗、BMI、肿瘤数目、病理分级后,Cox回归分析结果显示,与低AAPR组相比,高AAPR组的死亡风险降低约59%(HR=0.406,95%CI 0.200~0.822,P=0.012),AAPR每升高1个单位,死亡风险下降约80%(HR=0.199,95%CI 0.051~0.779,P=0.020)。趋势性检验结果显示,原始模型和校准模型中,AAPR不同分组间OS的HR下降趋势均有统计学意义(P=0.016),提示两者呈线性关系。调整年龄、肿瘤大小、pT分期、pN分期、肾积水、ASA分级、辅助化疗、BMI、肿瘤数目、病理分级后,曲线拟合图显示,AAPR与OS呈线性相关,随AAPR升高,术后死亡风险下降,OS延长。结论AAPR与膀胱肿瘤患者根治性膀胱切除术后的OS成线性相关,随AAPR升高,患者术后死亡风险下降,OS延长。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号