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   9645篇
  免费   715篇
  国内免费   204篇
耳鼻咽喉   27篇
儿科学   287篇
妇产科学   178篇
基础医学   954篇
口腔科学   75篇
临床医学   1993篇
内科学   892篇
皮肤病学   89篇
神经病学   962篇
特种医学   62篇
外国民族医学   1篇
外科学   277篇
综合类   1210篇
现状与发展   2篇
一般理论   1篇
预防医学   2040篇
眼科学   24篇
药学   606篇
  3篇
中国医学   615篇
肿瘤学   266篇
  2024年   28篇
  2023年   200篇
  2022年   379篇
  2021年   507篇
  2020年   505篇
  2019年   471篇
  2018年   447篇
  2017年   382篇
  2016年   340篇
  2015年   343篇
  2014年   726篇
  2013年   775篇
  2012年   594篇
  2011年   621篇
  2010年   441篇
  2009年   467篇
  2008年   472篇
  2007年   428篇
  2006年   378篇
  2005年   266篇
  2004年   226篇
  2003年   201篇
  2002年   148篇
  2001年   131篇
  2000年   125篇
  1999年   87篇
  1998年   92篇
  1997年   74篇
  1996年   85篇
  1995年   69篇
  1994年   70篇
  1993年   66篇
  1992年   45篇
  1991年   40篇
  1990年   37篇
  1989年   20篇
  1988年   35篇
  1987年   21篇
  1986年   26篇
  1985年   35篇
  1984年   34篇
  1983年   19篇
  1982年   17篇
  1981年   16篇
  1980年   20篇
  1979年   16篇
  1978年   11篇
  1977年   9篇
  1976年   10篇
  1975年   5篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
71.
We have developed a microarray (DotScan) that enables rapid immunophenotyping and classification of leukaemias and lymphomas by measuring the capture of cells by immobilized dots of 82 CD antibodies [Belov, L., de la Vega, O., dos Remedios, C.G., Mulligan, S.P., 2001. Immunophenotyping of leukemia using a cluster of differentiation antibody microarray. Cancer Res. 61, 4483; Belov, L., Huang, P., Barber, N., Mulligan, S.P., Christopherson, R.I., 2003. Identification of repertoires of surface antigens on leukemias using an antibody microarray. Proteomics 3, 2147]. The DotScan technology has been used to investigate the properties of 498 new antibodies submitted to the HLDA8 Workshop. These antibodies have been applied as 10 nl dots to a film of nitrocellulose on a microscope slide to make an HLDA8 microarray. After blocking the remaining nitrocellulose surface, individual arrays were incubated with each of 7 cell types from a human leukaemia cell panel consisting of three cell lines, CCRF-CEM (a T-cell acute lymphocytic leukaemia), MEC-1 (derived from B-cell chronic lymphocytic leukaemia) and HL-60 (a promyelocytic leukaemia), and four leukaemias from patients: a T-cell prolymphocytic leukaemia, a B-cell chronic lymphocytic leukaemia, and two acute myeloid leukaemias. Leukaemia cells were captured by those immobilized antibodies for which they expressed the corresponding surface molecule. Unbound cells were gently washed off, bound cells were fixed to the arrays and dot patterns were recorded using a DotScan array reader and quantified using DotScan data analysis software. The data obtained show the unique expression profiles of the 7 cell types in the leukaemia cell panel obtained with the DotScan microarray, and the differential capture patterns for these 7 cell types screened against the 498 antibodies in the HLDA8 microarray constructed for this study.  相似文献   
72.
目的:研究葛根素(Pur)对脂多糖(LPS)诱导的小鼠急性感染性脑损伤的保护作用及机制。方法:36只清洁级雄性ICR小鼠随机分为正常对照组(NS)、LPS感染组(LPS)和葛根素组(Pur+LPS)。LPS腹腔注射建立急性脑损伤模型,立即腹腔注射给予葛根素注射液治疗,6和24h后旷场。暗场实验检测各组小鼠的自发活动,WesternBlot检测脑组织白细胞分化抗原14(CD14)和环氧化酶2(C0X-2)蛋白表达量,Nisl染色观察神经元存活情况。结果:与NS组相比,LPS组6和24 h旷场实验自主活动距离和穿格次数显著减少,海马神经元的存活数目显著减少,脑组织CD14和C0X-2蛋白表达量显著升高(P<0.05);与LPS组比较,Pur+LPS组6和24 h时海马神经元的存活率明显提高,且CD14和C0X-2蛋白表达量明显下降(P<0.05)。结论:葛根素注射液对LPS所致小鼠急性感染性脑损伤具有一定保护作用,其作用机制可能与抑制脑组织CD14和C0X-2表达有关。  相似文献   
73.
A method which optimizes on global properties of sample recordings is proposed for the definition of and the discrimination between electroencephalogram (EEG) classes. The sample was drawn from students at the University of Heidelberg from 1974 to 1978 and consists of 15 healthy index cases clinically ascertained as belonging to the low voltage EEG group. In addition, the three clinically defined groups: diffuse β (18 index cases), borderline α (12 index cases) and monomorphous α (18 index cases) have been included in the study, as well as the first degree relatives of the index cases, thus providing a clinical classification into four groups. The proposed method provides an automatic and reliable classification algorithm using discriminant and cluster analysis. The relation between such an automatized classification and clinical classification schemes is investigated. In particular, the inheritance of the low voltage, EEG, the question on sex differences and the question of a simple Mendelian mechanism had been examined. The method of random splittings had been applied for discriminant and cluster analysis. Our findings can be summarized as follows: (1) except for the monomorphous α EEG group, the clinical classification shows rather marginal separation (discriminating performance 60% to 75%), while a new and more reliable grouping scheme improves the discriminating performance up to 87% to 91%. The latter scheme leads to the concept of personal channel pattern (PCP) and was compared to the clinical classification scheme by means of contingency tables; (2) only a weak correlation between the clinically and PCP-based groups could be found (Cramér Index: 0.27). Accordingly, we continued to investigate the extent to which the proposed EEG classification scheme can nevertheless explain the genetic mechanisms apparently involved in the low voltage EEG. We thus considered the role of sex differences manifest in our proposed new grouping scheme; (3) males occurred more frequently in the new group 3 and females more frequently in the new group 1. In this regard, a much better correlation of the new groups between mothers and children than between fathers and children was observed; and (4) with help of our new PCP scheme, we have been able to reproduce a simple two gene Mendelian scheme to explain inheritance of the clinical low voltage EEG group. In this PCP-based scheme, the low voltage property does not occur when dominance of a certain gene (called gene A) is absent. © 1996 Wiley-Liss, Inc.  相似文献   
74.
精神分裂症恢复期患者及家属家庭干预的对照研究   总被引:3,自引:1,他引:3  
目的:以康复期出院精神分裂症患者和家属为对象,定期复诊进行家庭干预并对照研究。方法:干预组68例,对照组52例,采用BPRS评定;干预组家属74人,对照组家属65人,采用SCL-90评定。结果:6个月后干预组患者BPRS和入组时对照比较均有显著性差异(P<0.01),说明干预组患者的精神症状,不良情绪及社会功能明显好转,入组时两组家属SCL-90评定与常模对照比较,均有明显差异(P<0.05或0.01),经干预后干预组与全国常规比较无显著性差异(P>0.05),说明患者家属普遍存在心理障碍,经干预后家属心理状况明显改善。结论:对康复期病人及家属进行门诊家庭干预,是有效的康复方法,值得推广应用。  相似文献   
75.
Cluster analysis of the MMPI has been utilized widely in the chronic low back pain literature to try to identify reliable patient subtypes predictive of treatment outcome. We extended this methodology to patients with heterogeneous chronic medical conditions by replicating prototypic MMPI cluster group profiles and by relating cluster groups to clinical baseline and outcome data. Subjects were two independent samples (n=254 and n=263) of chronically ill patients admitted to an inpatient medicine/psychiatry unit. Using a four-cluster solution, similar cluster profile groups were replicated in both samples. Consistent differences emerged between cluster groups on functional impairment, psychiatric diagnoses, depression, and psychosomatic symptoms. Cluster group membership also predicted changes in functional impairment and depression six months after treatment. Results are discussed in terms of similarities between chronic low back pain and chronic illness and tailoring treatment to different patient types.This research was supported in part by a grant from the Henry J. Kaiser Family Foundation.  相似文献   
76.
We calculated a Research Diagnostic Criteria (RDC) endogenous score for 257 depressed inpatients based on the number of endogenous criteria present. The distribution of RDC endogenous scores was unimodal. There was no association between endogenous scores and results of the Dexamethasone Suppression Test, or morbid risk for depression in the patients' first-degree relatives. The morbid risk for a family history of alcoholism tended to decrease with increasing endogenous scores, although a consistent steady decline was not observed. The results suggest that the RDC criteria do not fit either the categorical or dimensional model of endogenous classification. Potential sources of difficulty with the RDC endogenous criteria are discussed.  相似文献   
77.
目的检测HOXD10、HOXD12、HOXD13基因内4个已知单核苷酸多态(single nucleotide poly-morphisms,SNP)rs2593778、rs847154、rs847151、rs13392701在单纯性马蹄内翻足核心家系中的分布情况,分析各个SNP位点及所构成单倍型与单纯性马蹄内翻足的相关性。方法应用限制性片段长度多态性技术结合测序,分析84个单纯性马蹄内翻足核心家系4个SNP位点基因型;应用ETDT软件统计分析各SNP位点基因型与单纯性马蹄内翻足的相关性;应用TRANSMIT软件构建单倍型并统计分析单倍型频率是否存在差异。结果位于HOXD12基因5′侧翼序列的SNP位点rs847154和位于HOXD13第1外显子的SNP位点rs13392701在单纯性马蹄内翻核心家系中存在传递不平衡(P<0.05);位于HOXD12基因第1外显子的SNP位点rs847151未检测到多态;位于HOXD10第1外显子的SNP位点rs2593778经ETDT分析无统计学意义。结论HOXD12基因5′侧翼序列的SNP位点rs847154和位于HOXD13第1外显子的SNP位点rs13392701与单纯性先天性马蹄内翻足有明显的相关性,提示HOXD12、HOXD13可能是单纯性马蹄内翻足重要的易感基因。  相似文献   
78.
Fifty-seven male chronic pain patients admitted to an inpatient multimodal pain treatment program at a Midwestern Veterans Administration hospital completed the MMPI, Profile of Mood States (POMS), Tennessee Self-Concept Scale (TSCS), Rathus Assertiveness Schedule (RAS), activity diaries, and an extensive pain questionnaire. All patients were assessed both before and after treatment, and most also were assessed 2–5 months prior to treatment. No significant changes occurred during the baseline period, but significant improvements were evident at posttreatment on most variables: MMPI, POMS, TSCS, RAS, pain severity, sexual functioning, and activity diaries. MMPI subgroup membership, based on a hierarchical cluster analysis in a larger sample, was not predictive of differential treatment outcome. Possible reasons for comparable treatment gains among these subgroups, which previously have been shown to differ on many psychological and behavioral factors, are discussed.This paper originally was presented at the Fourth World Congress on Pain, Seattle, Washington, September, 1984.  相似文献   
79.
目的探讨抑郁障碍患者与家属的家庭亲密度适应性和情绪状况,为抑郁障碍患者的健康教育及家庭干预提供科学有效的理论依据。方法选择2006年6~9月在北京大学第六医院就诊的抑郁障碍患者95例及共同陪伴的直系家属95例为调查对象。采用家庭亲密度和适应性量表中文版(FACES-CV)、Zung氏焦虑自评量表和Zung氏抑郁自评量表。结果1患者的家庭亲密度得分与国内常模一致(P>0.05),但适应性得分低于国内常模(P<0.01);焦虑、抑郁得分高于国内常模(P<0.01)。家属的家庭亲密度得分高于国内常模(P<0.01),适应性得分低于国内常模(P<0.01)。家属的焦虑得分与国内常模一致(P>0.05),但抑郁得分高于国内常模(P<0.05)。2家庭模式分型构成比:中间型47.9%,平衡性26.3%,极端型25.8%。患者的家庭"拱极模式"以"僵硬—松散型"居多,家属则以"自由—缠结型"居多。3家庭亲密度与患者的家属的文程化度有关,相关系数范围(r=0.21~0.26,P<0.05)、与家庭人数呈负相关(r=-0.21,P<0.01);与患者及家属的焦虑、抑郁情绪呈显著负相关,相关系数范围(r=-0.30~0.37,P<0.01);家庭适应性与患者的年龄(r=0.28,P<0.01)、文化程度(r=0.34,P<0.01)有关。与家属的年龄(r=0.26,P<0.05)文化程度(r=0.22,P<0.05)有关。与患者和家属的焦虑、抑郁情绪呈显著负相关,相关系数范围(r=-0.30~-0.42,P<0.01)。结论家庭亲密度适应性与患者和家属的文化程度、焦虑、抑郁情绪有关,家庭亲密度与患者的家庭人数有关,家庭适应性与患者和家属的年龄有关。  相似文献   
80.
Papillary adenoma of type II pneumocytes is a rare tumour. It is considered to be a benign neoplasm and is derived from immature cells in the bronchioloalveolar epithelium, however, its biological nature has not been elucidated. We report a case of an adenomatous tumour; a papillary adenoma of type II pneumocytes, which we regard as possessing malignant potential. Light microscopically, as well circumscribed, papillary tumour of predominantly cuboidal cells resembling type II pneumocytes was found, but Clara type and ciliated cells were also present. Immunohistochemically, the tumour cells reacted positively with antibodies to surfactant apoproteins (A, B), carcinoembryonic antigen, cytochrome P-450 1A1-2 and 2B1-2. Ultrastructurally, many osmiophilic lamellar bodies and electron-dense granules were demonstrated. Semi-serial sections revealed signs of transbronchial dissemination and vascular invasion. Morphometry using 12-dimensional cluster analysis disclosed features of the tumour cells which resembled those of pneumocyte type II adenocarcinoma. These findings suggest that the present case has some malignant characteristics and originates from immature bronchiolar or alveolar cells, with a potential to develop into both type II pneumocyte and Clara cell type adenocarcinomas.  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