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   86515篇
  免费   7288篇
  国内免费   2156篇
耳鼻咽喉   332篇
儿科学   1135篇
妇产科学   907篇
基础医学   6607篇
口腔科学   1208篇
临床医学   12549篇
内科学   9254篇
皮肤病学   978篇
神经病学   16444篇
特种医学   1797篇
外国民族医学   5篇
外科学   5064篇
综合类   11789篇
现状与发展   10篇
一般理论   4篇
预防医学   6490篇
眼科学   489篇
药学   10868篇
  54篇
中国医学   5766篇
肿瘤学   4209篇
  2024年   128篇
  2023年   1357篇
  2022年   1856篇
  2021年   3377篇
  2020年   3079篇
  2019年   5428篇
  2018年   5059篇
  2017年   3820篇
  2016年   3210篇
  2015年   3183篇
  2014年   6092篇
  2013年   6784篇
  2012年   4802篇
  2011年   4864篇
  2010年   4403篇
  2009年   4725篇
  2008年   3790篇
  2007年   4615篇
  2006年   4092篇
  2005年   3224篇
  2004年   2034篇
  2003年   2020篇
  2002年   1745篇
  2001年   1376篇
  2000年   1118篇
  1999年   846篇
  1998年   730篇
  1997年   636篇
  1996年   546篇
  1995年   564篇
  1994年   554篇
  1993年   412篇
  1992年   410篇
  1991年   351篇
  1990年   275篇
  1989年   282篇
  1988年   238篇
  1987年   292篇
  1986年   257篇
  1985年   551篇
  1984年   572篇
  1983年   407篇
  1982年   403篇
  1981年   307篇
  1980年   311篇
  1979年   216篇
  1978年   124篇
  1977年   123篇
  1976年   104篇
  1974年   85篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
1.
2.
何金娜  谭建勋  梁霞 《全科护理》2022,20(7):939-941
目的:探讨增进积极体验为目标的健康干预对抑郁症病人抑郁情绪及生活质量的影响。方法:选择2019年9月—2021年3月在医院就诊的68例抑郁症病人为研究对象,按照随机数字表法分为观察组与对照组,每组34例。对照组予以常规护理,观察组在常规护理基础上予以增进积极体验为目标的健康干预。干预前后分别采用汉密尔顿抑郁量表(HAMD)、世界卫生组织生存质量测定量表简表(WHOQOL-BREF)评估病人的抑郁情绪和生活质量,同时对两组病人的护理满意度进行比较。结果:干预后观察组病人抑郁评分低于对照组(P<0.05);两组病人的生理功能、心理功能、社会功能及环境功能指标均较干预前有明显改善,且观察组评分均高于对照组(P<0.05);观察组病人对护理干预的总满意度为97.06%,高于对照组的61.76%(P<0.05)。结论:增进积极体验为目标的健康干预可明显缓解抑郁症病人的抑郁情绪,提高病人的生活质量。  相似文献   
3.
轻度认知障碍(Mild cognition impairment, MCI)是尚未达到阿尔兹海默病(Alzheimer’s disease, AD)的诊断标准且可逆转为正常脑老化状态的最佳窗口期。情志异常、肝失疏泄(肝失疏泄日久致肝郁)已被证实为MCI的重要情志病机,且“长期负性情绪积累肝失疏泄致衰加速脑老化”的科学假说已在本课题组前期研究中得到初步证实,疏肝法干预肝郁型MCI患者疗效显著,但以上作用机制尚未得到完全阐述。因此本研究系统总结了中医学对MCI的认识,长期情绪不调肝失疏泄对MCI的影响及可能机制,疏肝解郁方药及其成分改善肝郁型MCI的可行性,并提出使用无束缚性设计的眼动技术以探索疏肝法改善肝郁型MCI的可行性,为MCI的中医药干预及其神经机制探讨提供新思路,为中医情志衰老学说增添新内涵。  相似文献   
4.
目的 评价美国国家电器制造协会(National Electrical Manufactures Association, NEMA)最新标准(NU 2-2018)在正电子发射型计算机断层显像/电子计算机断层显像(positron emission tomography/computed tomography, PET/CT)设备性能检测中的作用。 方法 依据最新的NEMA NU 2-2018标准,检测西门子Biograph Vision PET/CT的空间分辨率、灵敏度、散射分数、计数丢失、随机符合、飞行时间分辨率、计数丢失率和随机符合校正精度、图像质量、衰减和散射校正精度及PET与CT配准精度指标。 结果 距视野中心1 cm处横向和轴向空间分辨率分别为3.75 mm和3.76 mm;在视野中心和轴向10 cm处的灵敏度分别为16.83 kcps/MBq和16.67 kcps/MBq;放射性浓度为27.37 kBq/mL时,最大等效噪声计数率为258.26 kcps,散射分数为38.58%;系统时间分辨率为209.82 ps;图像质量模型的对比度恢复系数范围为88.9%~96.2%,背景变异系数范围为2.05%~6.80%,平均肺插件残余误差为2.43%;计数丢失和随机符合校正最大误差为3.9%;距离床板末端 5 cm 和 100 cm处,在距视野中心Y轴1 cm处,PET和CT的配准精度分别为0.46 mm和1.07 mm,在距视野中心X轴20 cm处,PET和CT的配准精度分别为1.06 mm和1.45 mm,在距视野中心Y轴20 cm处PET和CT的配准精度分别为0.85 mm和1.15 mm。 结论 NEMA NU 2-2018标准检测条件更加接近临床,能更好地反映PET/CT设备的系统性能。  相似文献   
5.
6.
《Value in health》2022,25(6):1018-1029
ObjectivesThis study aimed to explore quality-adjusted life-year (QALY) and subsequent cost-effectiveness estimates based on the more physical health–focused EQ-5D 5-level version (EQ-5D-5L) value set for England or cross-walked EQ-5D 3-level version UK value set scores or more mental health recovery-focused Recovering Quality of Life Utility Index (ReQoL-UI), when using alternative within-trial statistical methods. We describe possible reasons for the different QALY estimates based on the interaction between item scores, health state profiles, preference-based scores, and mathematical and statistical methods chosen.MethodsQALYs are calculated over 8 weeks from a case study 2:1 (intervention:control) randomized controlled trial in patients with anxiety or depression. Complete case and with missing cases imputed using multiple-imputation analyses are conducted, using unadjusted and regression baseline-adjusted QALYs. Cost-effectiveness is judged using incremental cost-effectiveness ratios and acceptability curves. We use previously established psychometric results to reflect on estimated QALYs.ResultsA total of 361 people (241:120) were randomized. EQ-5D-5L crosswalk produced higher incremental QALYs than the value set for England or ReQoL-UI, which produced similar unadjusted QALYs, but contrasting baseline-adjusted QALYs. Probability of cost-effectiveness <£30 000 per QALY ranged from 6% (complete case ReQoL-UI baseline-adjusted QALYs) to 64.3% (multiple-imputation EQ-5D-5L crosswalk unadjusted QALYs). The control arm improved more on average than the intervention arm on the ReQoL-UI, a result not mirrored on the EQ-5D-5L nor condition-specific (Patient-Health Questionnaire-9, depression; Generalized Anxiety Disorder-7, anxiety) measures.ConclusionsReQoL-UI produced contradictory cost-effectiveness results relative to the EQ-5D-5L. The EQ-5D-5L’s better responsiveness and “anxiety/depression” and “usual activities” items drove the incremental QALY results. The ReQoL-UI’s single physical health item and “personal recovery” construct may have influenced its lower 8-week incremental QALY estimates in this patient sample.  相似文献   
7.
PurposeOptical coherence tomography angiography (OCTA) was utilized to examine changes in ocular surface squamous neoplasia (OSSN) vascular patterns over time in individuals treated with topical medical therapy.MethodsTen individuals with OSSN diagnosed by clinical examination and high resolution (HR)-optical coherence tomography (OCT) were recruited. All individuals received topical immuno- or chemotherapy. OCTA images were obtained and analyzed at three points: presentation, mid-treatment and tumor resolution. Tumor metrics including tumor area (TA), tumor volume (TV), tumor depth (TD), and total tumor density (TTD) were calculated. Vessel area density (VAD) was also quantified within the OSSN, the subepithelium under and adjacent to the OSSN and the subepithelium of the uninvolved, contralateral eye. Vascular network changes were also subjectively evaluated.ResultsTA, TV, TD and TTD all significantly decreased with time (p < 0.001). The mean VAD within the OSSN significantly decreased (p < 0.001) between visits (presentation: 26.52 ± 6.8%, mid-treatment: 7.19 ± 5.88%, tumor resolution: 0.11 ± 0.34%). The mean subepithelial VAD under the OSSN also decreased with time (23.22 ± 11.03%, 20.99 ± 5.99% and 19.58 ± 7.08%), and after resolution the sub-tumor VAD (19.58 ± 7.08%) was comparable to the subepithelial VAD in the contralateral eye (15.47 ± 4.37%, p > 0.05). The mean VAD in the subepithelium adjacent to the OSSN increased with treatment, then decreased significantly between mid-treatment and resolution (23.26 ± 4.54, 28.30 ± 7.43% and 21.68 ± 6.10%, p = 0.009). Qualitatively, the tumor subepithelial vascular network was complex and dense but with tumor resolution appeared less tortuous and similar to the uninvolved eye.ConclusionOCTA provided insight into the pathophysiology of tumor angiogenesis, showing decreased vascular density and normalization of vascular networks associated with tumor resolution.  相似文献   
8.
The importance of the left atrial appendage (LAA) as the source of thromboembolism including stroke in patients with nonvalvular atrial fibrillation is well documented, with more than 90% of ischemic strokes related to a LAA thrombus. Although oral anticoagulation has been the standard of care, approximately 50% to 60% of patients either have contraindications to oral anticoagulation or do not continue the medication beyond the first year. This led to the development of local site-specific therapy to occlude the LAA by either surgical or transcatheter means. Despite marked advancements, incomplete LAA closure with surgical and transcatheter approaches remains frequent. The etiology of incomplete LAA closure and its clinical implications remain unclear. Multiple strategies are in development including changes in deployment techniques, a new device design, and alternative approaches to leak closure.  相似文献   
9.
目的 探讨主动脉夹层术后患者心理状况、躯体症状对其生活质量的影响及作用机制,为制订干预计划提供参考。方法 采用广泛性焦虑障碍量表、患者健康问卷抑郁量表、躯体症状量表、12项简明健康状况调查表对327例主动脉夹层术后患者进行调查,根据相关性分析结果提出假设,应用AMOS软件进行结构方程模型分析。结果 主动脉夹层术后患者生活质量得分(81.56±7.36)分,焦虑得分2.00(0, 3.00)分,抑郁得分2.00(0, 3.00)分,躯体症状得分5.00(2.00, 8.00)分;焦虑、抑郁、躯体症状对生活质量有直接影响,焦虑、抑郁通过躯体症状对生活质量有间接影响(均P<0.05)。结论 主动脉夹层术后患者生活质量处于中等偏上水平,应早期对主动脉夹层术后患者的心理状况与躯体症状进行动态评估与监测,及时进行心理干预和症状管理,以改善其生活质量。  相似文献   
10.
AimsThe associations between prognostic awareness, acceptance of illness and psychological outcomes (anxiety, depression and spiritual well-being) remain unclear. This study examined the associations between prognostic awareness and various psychological outcomes and how they can be moderated by patient acceptance of illness (cancer).Materials and methodsIn total, 1184 patients with stage IV solid cancer were recruited at major public hospitals across four Asian countries (China, India, Sri Lanka, Vietnam). Prognostic awareness and acceptance of illness were assessed through self-reported understanding of treatment intent and acceptance of illness, respectively. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale, whereas spiritual well-being was measured using the Functional Assessment of Chronic Illness Therapy – Spiritual Well-Being Scale. Multivariate regressions were used to estimate the associations while controlling for patient characteristics.ResultsCompared with being unaware of their prognosis (i.e. believing that their cancer is curable), being aware or unsure of their prognosis was associated with higher anxiety and depressive symptoms, and lower spiritual well-being scores. Acceptance of illness moderated these relationships and improved the psychological outcomes.ConclusionsThe results suggest that disclosure of prognostic information should be provided in conjunction with psychological interventions that focus on acceptance of illness.  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