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   550篇
  免费   37篇
  国内免费   10篇
耳鼻咽喉   1篇
儿科学   38篇
基础医学   43篇
口腔科学   7篇
临床医学   47篇
内科学   159篇
皮肤病学   5篇
神经病学   43篇
特种医学   134篇
外科学   31篇
综合类   7篇
预防医学   35篇
药学   31篇
  1篇
肿瘤学   15篇
  2021年   4篇
  2019年   2篇
  2018年   6篇
  2017年   4篇
  2015年   2篇
  2013年   7篇
  2012年   10篇
  2011年   5篇
  2010年   6篇
  2009年   9篇
  2008年   8篇
  2007年   15篇
  2006年   14篇
  2005年   10篇
  2004年   12篇
  2003年   12篇
  2002年   9篇
  2001年   8篇
  2000年   7篇
  1999年   11篇
  1998年   19篇
  1997年   16篇
  1996年   27篇
  1995年   17篇
  1994年   27篇
  1993年   20篇
  1992年   10篇
  1991年   14篇
  1990年   23篇
  1989年   25篇
  1988年   19篇
  1987年   25篇
  1986年   14篇
  1985年   21篇
  1984年   15篇
  1983年   16篇
  1982年   12篇
  1981年   14篇
  1980年   13篇
  1979年   11篇
  1978年   12篇
  1977年   8篇
  1976年   10篇
  1975年   7篇
  1974年   6篇
  1973年   8篇
  1970年   5篇
  1967年   2篇
  1966年   3篇
  1965年   2篇
排序方式: 共有597条查询结果,搜索用时 46 毫秒
1.
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   
2.
Hydrolysis of peptides within lumen of small intestine   总被引:2,自引:0,他引:2  
  相似文献   
3.
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   
4.
Differential pattern of DNA-aneuploidy in human malignancies   总被引:5,自引:0,他引:5  
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   
5.
6.
Osteosarcomatosis   总被引:10,自引:0,他引:10  
A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.  相似文献   
7.
India's Integrated Child Development Services (ICDS) was established in 33 projects in 1975 and is spread over 22 states; 67 additional projects were begun in 1977, and over the next 2 years; 100 additional projects were added. By 1991=92, coverage was almost 50% of the country with 2696 projects; the expectation is for 100% coverage by the year 2000. An infrastructure chart identifies the organization and integration between level and social welfare and health departments. Objectives are clearly identified and the departments functionally linked. Linkages are achieved by shared space and activities at various levels. Over the past 17 years, services have included minimum needs programs, integrated rural development and poverty alleviation, national health policy and education policy, universal immunization, and the development of women and children in rural areas. ICDS is sponsored 100% by the status and uniquely relies on the honorary anganwadi worker (AWW), who is a woman, recruited and chosen by the community, aged 21-45 years and middle-school educated. The AWW was responsibility for 2000 households or 1000 persons in rural areas and 700 persons in tribal areas. The AWW is crucial to the functioning of the program and receives an honorarium of Rs. 225-275/month for implementing the ICDs program; AWWs have helpers who are paid Rs. 110/month. Training over a 3-year period is conducted at the Bal Sevika Training Institute by the Indian Council of Child Welfare. Additional health personnel and their role and the number of persons/per area AWWS are responsible for, equipment, and functions are also described. The AWW is responsible for nonformal preschool education, organization of supplementary nutrition feeding, health and nutrition education of women and families, immunization of women and children, treatment and referral of common illnesses, growing monitoring, and community participation. Presently, there are 2506 central sector projects and 190 state sector projects and 250,000 AWWs. The preschool education, health, and nutrition programs are summarized. Future directions will encompass future child and mother development and expansion to cover all 90 districts having a birth rate higher than 39/1000. Lessons learned from the past will be integrated and may involve cost containment, acceleration of development of services, alternative services, and giving mothers more responsibility for improving health and nutrition.  相似文献   
8.
The study aim was to examine the effect on birth spacing of a prior female child's birth. The study site was a rural health center under observation by staff from the Dayanand Medical College in Ludhiana, India. The sample included 73 pregnant women who were grouped by the sex of the preceding child. The results showed that the average birth interval was significantly shorter for women with a preceding birth of a female child. The average interval in weeks was 90.73 weeks + or - 54.46 weeks for the 41 women who had a prior girl child compared to 133.68 weeks for the male child. When the female child was at a parity of one the birth interval averaged 73.36 weeks, compared to 137.2 weeks for a prior parity of one male child. At parity of two, the average birth interval was 106.2 for a prior girl child and 144.38 for a prior male child. At a parity of three, the average birth interval was 88.22 weeks for a prior girl child and 96.5 weeks for a prior male child. At a parity of four, the average birth interval was 87.66 weeks for a prior girl child and 46.0 weeks for a prior male child. The significant effect of having a prior girl child was evident only at a parity of one. The intervals at a parity of two and three were shorter for girls but not significantly different. The recommendation was that young women and women with low parity be targeted for family planning in order to lengthen the birth interval, regardless of the desire for sons.  相似文献   
9.
In India, interviews were conducted with 250 couples who had at least 2 living children and at least 1 son so researchers could examine the effect of child loss on contraceptive usage. The interviewees lived in the area served by the rural health center in Pohir. 67 couples had lost a child. The child loss group had an acceptance rate for contraception of 41.7% compared to 44.8% for the group who had not experienced child loss. The difference was insignificant. Caste, literacy, and parity did not affect contraceptive usage. These findings suggest that child loss does not play a crucial role in contraception acceptance. On the other hand, some studies show that it is a barrier to fertility limitation. Additional studies are needed to resolve the issue of child loss and fertility.  相似文献   
10.
Given the increasing advocacy for the use of inhaled corticosteroids as a treatment of choice for persistent asthma, growing numbers of children are being exposed to the possible growth-suppressing effects of glucocorticoids. Recent evidence strongly suggests that, when consistently administered at moderate doses, inhaled corticosteroids (IC) are capable of slowing growth in children. Whether such growth suppression would persist and ultimately affect final adult height remains unknown. Therapeutic goals which aim for uninterrupted inflammatory disease control rather than periodic symptom control may increase the occurrence of growth failure in children treated with IC. In this article, current information about the mechanisms of growth suppression by glucocorticoids and the effects of IC on growth is reviewed, and recommendations for designing studies to investigate the effects of drugs on growth are presented.  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