全文获取类型
收费全文 | 1978篇 |
免费 | 272篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 50篇 |
妇产科学 | 33篇 |
基础医学 | 268篇 |
口腔科学 | 113篇 |
临床医学 | 196篇 |
内科学 | 393篇 |
皮肤病学 | 7篇 |
神经病学 | 127篇 |
特种医学 | 116篇 |
外科学 | 260篇 |
综合类 | 103篇 |
一般理论 | 1篇 |
预防医学 | 206篇 |
眼科学 | 25篇 |
药学 | 238篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 107篇 |
出版年
2021年 | 29篇 |
2020年 | 15篇 |
2019年 | 20篇 |
2018年 | 42篇 |
2017年 | 32篇 |
2016年 | 28篇 |
2015年 | 22篇 |
2014年 | 53篇 |
2013年 | 89篇 |
2012年 | 82篇 |
2011年 | 109篇 |
2010年 | 35篇 |
2009年 | 38篇 |
2008年 | 82篇 |
2007年 | 91篇 |
2006年 | 97篇 |
2005年 | 89篇 |
2004年 | 91篇 |
2003年 | 77篇 |
2002年 | 67篇 |
2001年 | 73篇 |
2000年 | 50篇 |
1999年 | 54篇 |
1998年 | 23篇 |
1997年 | 15篇 |
1996年 | 22篇 |
1995年 | 27篇 |
1994年 | 22篇 |
1993年 | 25篇 |
1992年 | 40篇 |
1991年 | 45篇 |
1990年 | 65篇 |
1989年 | 57篇 |
1988年 | 39篇 |
1987年 | 49篇 |
1986年 | 55篇 |
1985年 | 48篇 |
1984年 | 31篇 |
1983年 | 30篇 |
1982年 | 13篇 |
1981年 | 28篇 |
1980年 | 12篇 |
1979年 | 38篇 |
1978年 | 20篇 |
1977年 | 26篇 |
1976年 | 13篇 |
1975年 | 16篇 |
1972年 | 12篇 |
1969年 | 12篇 |
1968年 | 14篇 |
排序方式: 共有2255条查询结果,搜索用时 31 毫秒
101.
102.
Behavioral clusters and coronary heart disease risk. 总被引:2,自引:0,他引:2
The purpose of the present study was to empirically identify individuals who differed in their patterns of components derived from the structured interview (SI), and to evaluate whether individuals characterized by the different patterns varied in terms of their risk for coronary heart disease (CHD). The present study represents a reanalysis of data from the Western Collaborative Group Study in which components of Type A were individually related to risk for CHD. Subgroups of individuals who differed in the patterns of their component scores were identified by means of cluster analytic techniques and were found to vary in their risk of CHD. As expected, a pattern of characteristics in which hostility was salient was found to be predictive of CHD. Moreover, another pattern of characteristics that appears to reflect pressured, controlling, socially dominant behavior in which hostility was not salient also was found to be predictive of CHD. Further, two patterns of characteristics were identified that were unrelated to CHD risk. Finally, two patterns of characteristics were identified that were related to reduced risk of CHD. Overall, these results suggest that future research should investigate variables in addition to hostility in regard to risk for and protection from CHD. 相似文献
103.
The incidence of acute gastroenteritis and self suspected food poisoning in general practice populations was compared with consultation rates in four group practices during a 3-month winter period and a 2-month autumn period. The average monthly consultation rate for acute gastroenteritis and self suspected food poisoning was 0.3% and 0.06% respectively. However, over the same period, on average, an estimated 7% of the practice population per month reported an acute gastroenteritis illness, and 0.7% suspected a food poisoning illness. Only about one in 26 people who suffer an acute episode of gastroenteritis consult their general practitioner (GP). In two practices, faecal samples were sought from all patient cases; the isolation rate for salmonellas was 2% (3/191) and for campylobacters it was 12% (23/191). In the other two practices following routine management, the isolation rate for salmonellas was 9% (6/64) and for campylobacters it was 2% (1/64). Isolation of faecal pathogens was not associated with patients'' suspicion of food poisoning. A history of eating out in the week before onset was associated with a significantly increased yield of salmonellas and campylobacters. 相似文献
104.
105.
Studies were performed to evaluate the anti-tumor activity of mafosfamid, a new synthetic derivative of cyclophosphamide. We tested its ability to eliminate lymphoblastic leukemia cells from autologous bone marrow grafts following a 30 min preincubation in a highly sensitive clonogenic assay. Treatment with 50-100 micrograms mafosfamid/ml eliminated more than 4 logs of contaminating clonogenic tumor cells from a 200-fold excess of normal bone marrow. Flow cytometric studies showed differences in cell cycle kinetics between mafosfamid-resistant and mafosfamid-susceptible tumor cell clones. Compared to drug susceptible clonogenic tumor cells, clones that resisted treatment with 100 micrograms mafosfamid/ml exhibited a smaller percentage of cells in S-phase, indicating that mafosfamid is mostly cytotoxic to rapidly cycling tumor cells. The combination of mafosfamid and a target cell selective immunotoxin containing pokeweed anti-viral protein was superior to mafosfamid alone or immunotoxin alone for purging mafosfamid-resistant leukemic cells from human marrow. 相似文献
106.
107.
The kinetics of cell-mediated immunity to simian virus 40 (SV40) tumor-specific transplantation antigen (TSTA) were compared to the kinetics of tumor-unrelated parameters of immune responsiveness in the assessment of the immune statuses of inbred MHA/SsLAK hamsters during the course of progressive syngeneic SV40 tumor growth and after tumor excision. With the use of the tumor cell neutralization test in vivo and the macrophage migration inhibition assay in vitro, specific cellular immunity to SV40 TSTA was detected by 4 days after tumor cell inoculation, when the tumor was small. This tumor-specific immune response was no longer detected at 7 days after tumor cell inoculation, when the tumor had reached a mean diameter of 12.5 mm, but it returned by 14 days after surgical excision of the tumor. The patterns of host responsiveness to mitogens in spleen cells derived from tumor-bearing animals or from tumor-excised animals generally showed little or no correlation with the kinetics of tumor-specific cellular immunity. The kinetics of the humoral immune response to murine erythrocytes, as determined by hemagglutination assays, correlated much more closely with the kinetics of tumor-specific immunity than did the responses to mitogens. IgG antibody (T-dependent) responses were more affected by progressive tumor growth than were IgM antibody (T-independent) responses. The data suggest that results of tests with the use of tumor-unrelated parameters of immune responsiveness for the assessment of the immune status of cancer patients should be interpreted with caution. 相似文献
108.
Neonatal blood tyrosine elevations 总被引:1,自引:0,他引:1
109.
The 11th case of Kaposi's sarcoma of the glans penis is reported. Aetiology and treatment are discussed and evidence adduced to support a conservative surgical approach by local excision, supplemented if necessary by low dosage irradiation and possibly methotrexate infusion. 相似文献
110.