全文获取类型
收费全文 | 625篇 |
免费 | 24篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 56篇 |
妇产科学 | 4篇 |
基础医学 | 72篇 |
口腔科学 | 11篇 |
临床医学 | 78篇 |
内科学 | 138篇 |
皮肤病学 | 21篇 |
神经病学 | 13篇 |
特种医学 | 140篇 |
外科学 | 17篇 |
综合类 | 9篇 |
预防医学 | 7篇 |
眼科学 | 6篇 |
药学 | 15篇 |
肿瘤学 | 62篇 |
出版年
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 9篇 |
2013年 | 14篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 25篇 |
2009年 | 21篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 36篇 |
1997年 | 47篇 |
1996年 | 48篇 |
1995年 | 38篇 |
1994年 | 21篇 |
1993年 | 26篇 |
1992年 | 8篇 |
1991年 | 16篇 |
1990年 | 8篇 |
1989年 | 21篇 |
1988年 | 27篇 |
1987年 | 24篇 |
1986年 | 23篇 |
1985年 | 15篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 15篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1975年 | 12篇 |
1971年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有651条查询结果,搜索用时 0 毫秒
91.
Our study of 16 normal term, breast-fed infants documents real-time ultrasound as a technique for evaluating the oral portion of the sucking mechanism in infants. We also describe the mechanics of sucking used by the infants during breast-feeding. 相似文献
92.
93.
Mullerian duct cyst: diagnosis with MR imaging 总被引:1,自引:0,他引:1
94.
The effect of purified human fibroblast interferon on primary and secondary colony formation by blast progenitors from the peripheral blood of patients with acute myelogenous leukemia was examined. Interferon inhibited blast progenitors and normal granulocyte/macrophage progenitors (CFU-C) in a dose-dependent manner. The magnitude of this effect on blast progenitors and CFU was similar. Interferon also inhibited secondary plating of blast progenitors (self- renewal). This effect was in marked contrast to the effect of adriamycin, which reduced primary plating efficiency of blast progenitors but did not affect self-renewal. Inhibition of blast progenitor proliferation by interferon was markedly reduced when interferon was added after 24 hr of culture and was absent when added after 72 hr. Inhibition of self-renewal was observed even when interferon was added at 72 hr. We conclude that interferon inhibits both primary proliferation and self-renewal of blast progenitors and that this effect is not due to reduction in the number of primary colonies. These experiments provide an example of how cell culture techniques may be used to test antitumor agents for effects on important cellular events other than general cytotoxicity. 相似文献
95.
96.
97.
J L Millar T J McElwain R D Clutterbuck E A Wist 《American journal of clinical oncology》1982,5(3):321-328
The toxicity of melphalan in mice was reduced by the injection of S-2-(3-aminopropylamino)-ethylphosphorothioic acid (WR2721). This was seen in terms of reduced toxicity to the stem cells of the bone marrow and intestinal epithelium as well as improved animal survival. Using human melanoma xenografts and growth delay as an end-point, it was demonstrated that WR2721 did not protect this tumor from melphalan. With radio-labelled WR2721, it was shown that WR2721 was rapidly cleared from the blood and actively accumulated by all normal tissues except the CNS. Intact human tumor xenografts and Lewis lung tumors were less able to accumulate WR2721 than normal tissues, but in vitro studies showed that tissue fragments or single cell suspensions of tumors were as efficient as liver fragments or bone marrow cells in accumulating the drug. The rapid clearance of WR2721 and poor vascularity of the intact tumors were thought to be responsible for the differential uptake and protection of normal tissues by WR2721. 相似文献
98.
MP Busch ; EA Operskalski ; JW Mosley ; CE Stevens ; ER Schiff ; SH Kleinman ; H Lee ; M Lee ; M Harris 《Transfusion》1994,34(10):858-864
BACKGROUND: The long-term course of human immunodeficiency virus type 1 (HIV-1)-related disease among seropositive blood donors has not been described. The enrollment and epidemiologic background of HIV-1- infected donors in the Transfusion Safety Study and their immunologic and clinical progression are described. STUDY DESIGN AND METHODS: Through the testing of approximately 200,000 sera from donations made in late 1984 and early 1985, 146 anti-HIV-1-positive donors and 151 uninfected matched donors were enrolled. These two cohorts were followed with 6-month interval histories and laboratory testing. RESULTS: Seropositive donors detected before the institution of routine anti-HIV-1 screening disproportionately were first-time donors and men with exclusively male sexual contacts. The actuarial probability of a person's developing AIDS within 7 years after donation was 40 percent; the probability of a person's dying of AIDS was 28 percent. AIDS developed more often when the donor was p24 antigen-positive at donation. Over a 3-year period, significant decreases occurred in CD4+, CD2+CD26+, CD4+CD29+, and CD20+CD21+ counts, but not in CD8+ subsets, CD20+, or CD14+. CONCLUSION: The high proportions of first-time donations and exclusively homosexual men among seropositive donors suggest that test-seeking may have contributed to the high HIV-1 prevalence in the repository. Implementation of alternative test sites when routine donor screening began in 1985 may have averted many high- risk donations. The disease course in HIV-1-infected donors had the same wide spectrum of immunologic and clinical manifestations as were reported for other cohorts. 相似文献
99.
Lene?ThorsenEmail author Wenche?Nystad Hein?Stigum Olav?Dahl Olbj?rn?Klepp Roy?M.?Bremnes Erik?Wist Sophie?D.?Foss? 《Supportive care in cancer》2005,13(8):637-646
Goals of work Physical activity is claimed to have a beneficial influence on a persons mental health, though its impact may be different in cancer patients and individuals in the general population. The objective of this cross-sectional study was (1) to estimate the associations between the level of self-reported physical activity as a lifestyle factor (LPA) and the prevalence of depression and anxiety disorder in testicular cancer survivors (TCSs) and in men of similar age from the general population (GenPop), and (2) to examine whether these associations differ in the two groups.Patients and method A total of 1260 TCSs and 20,207 men from the GenPop completed a questionnaire that assessed LPA, and depression and anxiety disorder on the Hospital Anxiety and Depression Scale (HADS).Main results The prevalence of HADS-defined depression was lower among those who were physically active than in those who were physically inactive (TCSs 9% vs 17%, P<0.001; GenPop 8% vs 15%, P<0.001). Among physically inactive TCSs there was a trend towards higher a prevalence of HADS-defined anxiety disorder compared to physically active TCSs (P=0.07). In the GenPop this difference was statistically significant (P<0.001). Multivariate analysis confirmed the association between LPA and HADS-defined depression in both the TCSs [adjusted odds ratio (aOR)=0.56; 95% confidence interval (CI) (0.31, 1.02)] and the GenPop [aOR=0.58; 95% CI (0.51, 0.65)], but not the association between LPA and HADS-defined anxiety disorder. The associations between LPA and HADS-defined depression and HADS-defined anxiety disorder did not differ between the TCSs and the GenPop.Conclusion In both the TCSs and the GenPop, the prevalence of HADS-defined depression was higher among those who were physically inactive than among those who were physically active, with no intergroup difference. There was no association between LPA and prevalence of HADS-defined anxiety disorder in either of the groups after adjusting for background variables. Prospective studies are needed to allow causal inferences to be drawn. 相似文献
100.
C Oliveira RA Navarro-Xavier EA Anjos-Vallota JO Martins VLF Silveira LRC Gon?alves MS Araújo G Motta P Sannomiya MLV Oliva 《British journal of pharmacology》2010,161(4):899-910