全文获取类型
收费全文 | 530篇 |
免费 | 27篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 42篇 |
妇产科学 | 71篇 |
基础医学 | 67篇 |
口腔科学 | 6篇 |
临床医学 | 55篇 |
内科学 | 80篇 |
皮肤病学 | 5篇 |
神经病学 | 21篇 |
特种医学 | 133篇 |
外国民族医学 | 1篇 |
外科学 | 14篇 |
综合类 | 7篇 |
预防医学 | 26篇 |
药学 | 24篇 |
1篇 | |
肿瘤学 | 13篇 |
出版年
2021年 | 7篇 |
2020年 | 1篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 19篇 |
2011年 | 16篇 |
2010年 | 5篇 |
2009年 | 15篇 |
2008年 | 13篇 |
2007年 | 20篇 |
2006年 | 15篇 |
2005年 | 8篇 |
2004年 | 11篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 9篇 |
2000年 | 15篇 |
1999年 | 15篇 |
1998年 | 22篇 |
1997年 | 17篇 |
1996年 | 29篇 |
1995年 | 17篇 |
1994年 | 22篇 |
1993年 | 17篇 |
1992年 | 12篇 |
1991年 | 11篇 |
1990年 | 16篇 |
1989年 | 22篇 |
1988年 | 18篇 |
1987年 | 23篇 |
1986年 | 16篇 |
1985年 | 15篇 |
1984年 | 10篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 6篇 |
1976年 | 9篇 |
1975年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有567条查询结果,搜索用时 15 毫秒
1.
2.
R Seifer A J Sameroff C P Baldwin A Baldwin 《Journal of the American Academy of Child and Adolescent Psychiatry》1992,31(5):893-903
Protective processes in at-risk children between 4 and 13 years of age were examined in a longitudinal study. A multiple risk index was used at 4 years to identify 50 high-risk children and 102 who were at low risk. Cognitive and social-emotional status were measured at each time point. The following indicators of protective processes were related to positive change in cognitive and/or social-emotional function in the high-risk children between 4 and 13 years: mother-child interaction; child perceived competence, locus of control, life events, and social support; and maternal parenting values, social support, depression, and expressed emotion. Many of these factors were also related to improvement in the low-risk children. Some variables showed an interaction effect, where impact was substantially higher in the high-risk group compared with the low-risk group. The utility of multiple risk constructs and process oriented approaches to protective factors are discussed. 相似文献
3.
Yifat Cohen Anthony Spirito Cheryl Sterling Deidre Donaldson Ronald Seifer Barry Plummer Ruscinda Avila Kathy Ferrer 《Journal of child psychology and psychiatry, and allied disciplines》1996,37(8):989-993
Adolescents who were psychiatrically hospitalized ( N = 105) were classified as sexually abused, physically abused, both sexually and physically abused, or not abused, and studied to determine the prevalence of suicidal behavior and psychiatric disorders. Self-reports of hopelessness, depression, coping, and self-concept were also examined. No difference in suicidal behavior or psychiatric disorder, based on abuse history, was found, with one exception. Adolescents who were sexually abused, particularly those who experienced the most severe sexual abuse, used negative coping strategies more often than those not sexually abused. Findings suggest that symptomatology of adolescents who are psychiatrically hospitalized does not differ markedly based on history of abuse. 相似文献
4.
进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml ̄(-1)诱导HL-60细胞发生凋亡,而阻断HR20细胞于G_1期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml ̄(-1)处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G_1期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关 相似文献
5.
B Nurcombe R Seifer A Scioli M G Tramontana W L Grapentine H C Beauchesne 《Journal of the American Academy of Child and Adolescent Psychiatry》1989,28(3):333-342
The concept of major depressive disorder in childhood and adolescence is reviewed and it is suggested that contemporary enthusiasm for this diagnosis may have outrun the evidence that it is a distinct categorical entity. To test the hypothesis that major depression is not a qualitatively distinct disorder in adolescence, but rather a continuously distributed, noncategorical syndrome, the behavioral rating scales (CBCL-P) of 216 hospitalized adolescent patients were analyzed first by principal components analysis and then by cluster analysis. Three behavioral syndromes were isolated by principal components analysis. Of three groups of patients identified by a subsequent cluster analysis, one was consistent with the concept of a categorically distinct "nuclear" depression. However, a noncategorical continuously distributed depressive syndrome appears to affect a larger number of patients in this age group, and the "nuclear" disorder may be less prevalent than is currently assumed. One explanation of these findings would combine a categorical model of nuclear depression with a dimensional model of dysthymia. 相似文献
6.
Hydrolysis of peptides within lumen of small intestine 总被引:2,自引:0,他引:2
7.
STUDY OBJECTIVES: To quantitatively assess compliance and experimental success with imposed sleep schedules among healthy children involved in an experimental comparison of optimized and restricted sleep. DESIGN: We asked children to follow assigned sleep schedules at home that created optimized (at least 10 hours time-in-bed per night) and restricted (6.5 to 8 hours time-in-bed per night) sleep conditions across 2 weeks during the school year. Self-report or parent-report of bedtime and risetime was obtained daily and continuous actigraphy was recorded. SETTING: Home. PARTICIPANTS: 78 healthy children (41 boys, 37 girls; mean age, 10.2 years; age range, 6.5 to 12.9 years) INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: We used reported time-in-bed to assess noncompliance with assigned schedules. Experimental failure was assessed with actigraphically based estimates of sleep period (time from sleep onset to sleep offset) and total sleep time (minutes of scored sleep during sleep period). Reported time-in-bed averaged 3.45 hours less per night under restricted versus optimized conditions. Sleep period and total sleep time showed similar differences (2.97 and 2.32 hours less, respectively). Four children met a priori criteria for noncompliance (3 for optimized nights and 1 for restricted). Eight children met a priori criteria for experimental failure within conditions (7 for optimized nights and 1 for restricted), but most achieved a substantial difference in sleep behavior across optimized and restricted weeks. CONCLUSIONS: In general, healthy children as young as 6 years of age can maintain substantial changes in their usual schedules across several nights at home and should be considered for inclusion in experimental studies of sleep extension and restriction. This paper offers a methodologic "road-map" for scientists interested in pursuing this goal. 相似文献
8.
Summary The relationships of VII and VIII cranial nerves and related arteries are reviewed in 26 preparations by microdissection techniques. These vessels may be grouped in large (AICA, PICA), medium (LA, SA, CSA, RPI) and small calibre (vasa nervorum, radicullar and medullar branches). The importance of these structures in acoustic neuroma surgery, vestibular neurectomy and cross-compression syndromes is discussed. Vascular loops and elongated arteries are normal structures present at birth.This work was supported by a grant from the AJ Roemmers Foundation 相似文献
9.
Differential pattern of DNA-aneuploidy in human malignancies 总被引:5,自引:0,他引:5
Th Büchner W Hiddemann B Wörmann B Kleinemeier J Schumann W Göhde J Ritter K.-M Müller DB von Bassewitz A Roessner E Grundmann 《Pathology, research and practice》1985,179(3):310-317
The differential pattern of DNA-aneuploidy, detected by flow cytometry (FCM) regarding its frequency, grade and multiclonality, was investigated and correlated to tumor type, malignancy grade, tumor stage and prognosis in a multi-institutional study at the University of Münster. High resolution measurements using admixed normal blood reference cells were undertaken in 2413 cases of 13 different malignant diseases and in 776 benign lesions or samples. The incidence of DNA-aneuploidy was highest in melanomas, carcinomas, testicular tumors, sarcomas (75%-95%) and myelomas (65%). Acute leukemias showed an intermediate DNA-aneuploidy rate of 40% with special subgroups represented by common ALL (44%), p less than 0.05) and myelomonocytic/monocytic AML (47%, p less than 0.01). The lowest DNA-aneuploidy-rate was found in basal cell skin carcinomas (19%) and congenital melanocytic nevi (9%). No case of DNA-aneuploidy was observed in the 776 benign lesions or samples.--DNA-indices giving the grade of DNA-aneuploidy with 1.0 for normal diploid G1/0 cells were found distributed predominantly between 1.0 and 2.0 in the solid tumors, except testicular tumors, clustering around a triploid maximum at 1.5. DNA-indices of myelomas and acute leukemias generally ranged below 1.25 with lower DNA-aneuploidy grades in AML than in ALL (p less than 0.01).--In melanomas the aneuploidy rate was higher (86%) in metastases than in the primary tumors (54%, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
10.