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   3834篇
  免费   178篇
  国内免费   28篇
耳鼻咽喉   11篇
儿科学   63篇
妇产科学   31篇
基础医学   595篇
口腔科学   102篇
临床医学   267篇
内科学   936篇
皮肤病学   250篇
神经病学   403篇
特种医学   197篇
外国民族医学   5篇
外科学   525篇
综合类   15篇
预防医学   148篇
眼科学   39篇
药学   193篇
中国医学   7篇
肿瘤学   253篇
  2023年   10篇
  2022年   35篇
  2021年   60篇
  2020年   33篇
  2019年   39篇
  2018年   46篇
  2017年   46篇
  2016年   53篇
  2015年   89篇
  2014年   103篇
  2013年   155篇
  2012年   214篇
  2011年   198篇
  2010年   132篇
  2009年   135篇
  2008年   259篇
  2007年   267篇
  2006年   264篇
  2005年   248篇
  2004年   239篇
  2003年   241篇
  2002年   204篇
  2001年   72篇
  2000年   54篇
  1999年   67篇
  1998年   57篇
  1997年   46篇
  1996年   32篇
  1995年   40篇
  1994年   19篇
  1993年   29篇
  1992年   29篇
  1991年   45篇
  1990年   24篇
  1989年   40篇
  1988年   30篇
  1987年   32篇
  1986年   35篇
  1985年   34篇
  1983年   18篇
  1982年   20篇
  1980年   15篇
  1979年   19篇
  1978年   13篇
  1977年   10篇
  1976年   12篇
  1974年   9篇
  1973年   10篇
  1970年   11篇
  1969年   12篇
排序方式: 共有4040条查询结果,搜索用时 15 毫秒
41.
Zusammenfassung In Mannheim wurde im Jahre 1968 mit dem schrittweisen Aufbau eines gemeindenahen psychiatrischen Versorgungssystems begonnen. Bestandteil dieses Versorgungskonzepts sind Absprachen zwischen den beteiligten stationären Einrichtungen, die die Zuweisung der Patienten zur stationären Behandlung regeln. Eine modellgestützte, multivariate Analyse von Inanspruchnahmedaten einer Kohorte von 126 schizophrenen Patienten weist nach, daß die Ungleichverteilung der Geschlechter auf die Institutionen das Ergebnis dieser Absprache ist; dabei sind Krankheitsdauer und die Art der Zuweisung von entscheidender Bedeutung.Die vorliegende Arbeit entstand im Rahmen eines von der Deutschen Forschungsgemeinschaft geförderten Projekts im Sonderforschungsbereich 116 Psychiatrische Epidemiologie der Universität Heidelberg (Sprecher: Prof. Dr. Dr. M. Schmidt)  相似文献   
42.
目的:分析胰腺切除术后出血(postpancreatectomy hemorrhage,PPH)的临床病程及预后。背景:PPH是最致命的胰腺术后并发症,但目前仍缺少其标准治疗规程。方法:1992年至2006年,对1524例施行胰腺手术的患者进行了前瞻性研究。根据以下指标进行PPH危险分级:PPH严重程度(轻度,即血红蛋白浓度下降〈3g/dL;重度,即血红蛋白浓度下降〉3g/dL),PPH出现时间(早期,即术后1~5天;晚期,术后第6天),合并胰瘘,肠道内或肠道外出血表现以及存在“复杂的”血管病理变化(腐蚀、假性动脉瘤)。  相似文献   
43.
Oral ulcerations associated with disseminated cytomegalovirus (CMV) infection were observed in four patients with AIDS manifestations showing low CD4 counts. Virus cultures of urine and saliva samples were positive for CMV in all cases. The lesions were characterized by a punched-out appearance, non-indurated borders, low bleeding tendency and lack of inflammatory wall. Light microscopy revealed granulation tissue containing "owl's eye" like cells in all specimens. Presence of CMV was confirmed by immunohistochemistry and in situ hybridization. The ulcerations were infiltrated with T-lymphocytes of the helper, suppressor and cytotoxic subset, most were positive for HLA DR. Despite the local invasion with immunocytes and high serum titers of serum antibodies the patients experienced progressive CMV disease.  相似文献   
44.
Some dietary fibers reduce the absorption of carotenoids in women   总被引:3,自引:0,他引:3  
Dietary fiber may be partly responsible for the lower bioavailability of carotenoids from food than from purified supplements. Due to the lack of detailed information available, we investigated the effects of different kinds of dietary fiber on the absorption of carotenoids and alpha-tocopherol. Six healthy young women received an antioxidant mixture consisting of beta-carotene, lycopene, lutein, canthaxanthin and alpha-tocopherol together with a standard meal. The meal did not contain additional dietary fiber or was enriched with pectin, guar, alginate, cellulose or wheat bran (0. 15 g. kg body weight(-1)). The increases in plasma carotenoid and alpha-tocopherol concentrations were followed over 24 h, and the areas-under-curves (AUC(24h)) were calculated. The mean AUC(24h) of beta-carotene was significantly (P < 0.05) reduced by the water-soluble fibers pectin, guar and alginate with a mean decrease of 33-43%. All tested fibers significantly reduced the AUC(24h) of lycopene and lutein by 40-74% (P < 0.05). The dietary fiber effect on the AUC(24h) of canthaxanthin was almost significant (P = 0.059) and there was no effect on the AUC(24h) of alpha-tocopherol. We conclude that the bioavailability of beta-carotene, lycopene and lutein given within a mixed supplement is markedly reduced by different kinds of dietary fiber.  相似文献   
45.
Summary To obtain information about the role of local proliferation in the pathogenesis of dermal infiltrate in malignant cutaneous lymphomas, we determined the percentage of 3H-thymidine-labeled infiltrating cells (3H-index).A linear correlation was found between proliferative activity and clinical stage in mycosis fungoides, i.e., the 3H-index is moderately elevated in stage I and high in stage III.The 3H-index is within normal range in dermal infiltrate of Sézary syndrome, diffuse lymphocytic lymphoma, as well as in lymphocytoma benigna cutis.In parapsoriasis en plaques two groups can be distinguished: in the smallplaque variant (chronic superficial dermatitis) the 3H-index is low, whereas the large-plaque variant (prereticulotic poikiloderma) shows strong proliferative activity.Thus, determination of proliferative activity seems to give new insights into the pathogenesis of dermal infiltrate in cutaneous lymphomas.Zusammenfassung Um die Bedeutung der lokalen Zellproliferation im dermalen Infiltrat bei cutanen malignen Lymphomen zu untersuchen, bestimmten wir den Prozentsatz der 3H-Thymidin-markierten Infiltratzellen (3H-Index.Zwischen dem klinischen Stadium der Mycosis fungoides und der Proliferationsaktivität des dermalen Infiltrats besteht eine lineare Beziehung; im Stadium I ist die Proliferation niedrig, im Stadium III sehr hoch.Nicht erhöht ist der 3H-Index im dermalen Infiltrat beim Sézary-Syndrom, diffusen lymphocytischen Lymphom sowie bei Lymphocytoma benigna cutis.Bei der Parapsoriasis en plaques müssen zwei Formen unterschieden werden: bei der kleinfleckigen Form (chronic superficial dermatitis) ist der 3H-Index niedrig, während die großfleckige Form (Präretikulotisches Poikiloderm) eine starke Proliferationsaktivität aufweist.Die Untersuchung des Proliferationsverhaltens gibt neue Einblicke in die Pathogenese des dermalen Infiltrats cutaner Lymphome.  相似文献   
46.
47.
Hereditable predisposition to papillary thyroid carcinoma (PTC) and multinodular goiter (MNG) without evidence of an association with other malignancies as a distinct entity was recognized only recently. A meta-review of the literature on familial PTC (FPTC) was undertaken, and characteristics of families with frequent occurrence of PTC or MNG (or both) were summarized. A database on thyroid cancer patients maintained in our institution was searched for potential FPTC families. Clinical examinations were performed in 6 of 12 Hannover kindreds identified, and blood samples of all family members were collected for genetic analyses. Clinical presentations and histopathologic features of the FPTC cases were compiled. Based on the FPTC meta-review and own experience, predictive criteria to identify families at risk were developed: Exclusion criteria were previous radiation exposure and coincidence with neoplasia syndromes. Primary criteria for susceptibility to FPTC are (1) PTC in two or more first-degree relatives and (2) MNG in at least three first- or second-degree relatives of a PTC patient. Secondary criteria are diagnosis in a patient younger than 33 years, multifocal or bilateral PTC, organ-exceeding tumor growth (T4), metastasis (N1, M1), and familial accumulation of adolescent-onset thyroid disease. A hereditary predisposition to PTC is considered if both primary criteria or one primary criterion plus three secondary criteria are present. Family history-taking is recommended for all PTC patients to identify FPTC kindreds at risk. Blood relatives of FPTC index patients who harbor MNG should undergo thorough and regular clinical screening. Suspicious lesions should prompt early surgical intervention.  相似文献   
48.
Her-2/neu is a tumor-associated antigen that is expressed on several adenocarcinomas and correlates with poor prognosis. In a previous study (H. J. Bühring et al., Blood, 86: 1916-1923, 1995), it has been demonstrated that Her-2/neu expression can be detected on blast cells from patients with hematological malignancies including acute lymphoblastic leukemia (ALL). Here, we show that Her-2/neu-specific CTLs induced in vitro using peptide-pulsed dendritic cells efficiently lyse primary ALL blasts constitutively expressing both Her-2/neu and human leukocyte antigen A2 in an antigen-specific and MHC-restricted manner. Furthermore, we analyzed the feasibility of this approach in an autologous setting and induced Her-2/neu-specific CTLs using dendritic cells generated from peripheral blood mononuclear cells from an ALL patient that were pulsed with peptides or transfected with in vitro-transcribed Her-2/neu mRNA. Our data demonstrate that Her-2/neu could be used as a potential target for the application of Her-2/neu-directed treatment strategies in ALL including vaccination approaches.  相似文献   
49.
50.
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