全文获取类型
收费全文 | 967篇 |
免费 | 100篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 47篇 |
妇产科学 | 10篇 |
基础医学 | 212篇 |
口腔科学 | 21篇 |
临床医学 | 127篇 |
内科学 | 173篇 |
皮肤病学 | 17篇 |
神经病学 | 40篇 |
特种医学 | 155篇 |
外科学 | 53篇 |
综合类 | 14篇 |
预防医学 | 78篇 |
眼科学 | 2篇 |
药学 | 52篇 |
中国医学 | 1篇 |
肿瘤学 | 56篇 |
出版年
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 8篇 |
2016年 | 13篇 |
2015年 | 25篇 |
2014年 | 23篇 |
2013年 | 33篇 |
2012年 | 21篇 |
2011年 | 17篇 |
2010年 | 35篇 |
2009年 | 38篇 |
2008年 | 19篇 |
2007年 | 21篇 |
2006年 | 27篇 |
2005年 | 32篇 |
2004年 | 38篇 |
2003年 | 25篇 |
2002年 | 18篇 |
2001年 | 21篇 |
2000年 | 25篇 |
1999年 | 17篇 |
1998年 | 34篇 |
1997年 | 32篇 |
1996年 | 36篇 |
1995年 | 29篇 |
1994年 | 28篇 |
1993年 | 24篇 |
1992年 | 20篇 |
1991年 | 28篇 |
1990年 | 20篇 |
1989年 | 28篇 |
1988年 | 33篇 |
1987年 | 30篇 |
1986年 | 26篇 |
1985年 | 22篇 |
1984年 | 18篇 |
1983年 | 14篇 |
1982年 | 12篇 |
1981年 | 21篇 |
1980年 | 5篇 |
1979年 | 21篇 |
1978年 | 16篇 |
1977年 | 18篇 |
1976年 | 14篇 |
1975年 | 12篇 |
1974年 | 4篇 |
1973年 | 7篇 |
1972年 | 7篇 |
排序方式: 共有1067条查询结果,搜索用时 62 毫秒
61.
AE Scaramuzza A De Palma C Mameli D Spiri L Santoro GV Zuccotti 《Acta paediatrica (Oslo, Norway : 1992)》2010,99(8):1237-1241
Aim: The aim of the student is to assess whether adolescents with type 1 diabetes mellitus (T1DM) in Italy differ from their healthy peers in regard to risky behaviour. Methods: Data were collected from 215 patients, aged 14 ± 2 years with a mean disease duration of 7 ± 5 years. The control group was comprised of 464 healthy adolescents recruited among high school students. Each patient completed an anonymous confidential questionnaire to determine the prevalence of sexual behaviour, alcohol and tobacco consumption, illicit drug use, and, among patients with diabetes and frequency of mismanagement related to diabetes care. Results: Compared with controls, subjects with diabetes showed a similar rate of sexual intercourse among males and lower rates among females (34.8% vs 35.5%, p NS and 29.4% vs 41.4%, p < 0.05, respectively). Males in the diabetes group reported a higher rate of tobacco use, whereas females showed similar or higher rates of use for every illicit drug studied. Among patients with diabetes, those who are engaged in risky behaviour showed a higher rate of treatment mismanagement (76% vs 34%, p < 0.01). Conclusion: Adolescents with T1DM are as likely as their healthy peers to engage in risky behaviour, indicating the potential benefit of anticipatory guidance concerning glycaemic control and increased risk of acute and chronic complications. 相似文献
62.
F. L. Nowrouzian A. E. Östblom A. E. Wold I. Adlerberth 《Clinical microbiology and infection》2009,15(5):466-472
Escherichia coli strains of phylogenetic group B2 obtained from Western human hosts are enriched in virulence-associated genes and have a superior capacity to persist in the colonic microbiota. Here, E . coli strains from 22 infants born in Pakistan whose rectal flora was sampled regularly over the first 6 months of life were examined. B2 strains did not carry the virulence-associated genes sfaD/E , papC , neuB or hlyA more often than strains of other phylogenetic groups . B2 origin was not associated with persistence in the bowel microbiota. As compared with B2 strains from Swedish infants, Pakistani B2 strains carried significantly less often the virulence genes fimH (p 0.04), papC (p 0.02), papG class III (p 0.01), sfaD / E (p ≤0.0001), neuB (p ≤0.0001), and hlyA (p 0.005), and also the high-pathogenicity island (p ≤0.0001). A minority of Pakistani B2 strains belonged to recognized uropathogenic O-groups, which are common among 'Western' B2 strains. Thus, extra-intestinal pathogenicity may be the foremost characteristic of B2 strains colonizing Western populations. 相似文献
63.
64.
65.
66.
A Corbet R Bucciarelli S Goldman M Mammel D Wold W Long 《The Journal of pediatrics》1991,118(2):277-284
To determine whether a single prophylactic dose of synthetic surfactant would reduce mortality and morbidity rates, we performed a randomized, controlled trial of Exosurf Neonatal at 19 hospitals in the United States. The Exosurf preparation (5 ml/kg) was instilled into the endotracheal tube of premature infants weighing 700 to 1100 gm during mechanical ventilation, as soon as practical after birth. Control infants were treated with air (5 ml/kg). Dose administration was performed in secrecy by clinicians who did not reveal for 2 years what they had instilled. A total of 222 infants received air and 224 received the synthetic surfactant; 36 infants with congenital pneumonia or malformations were excluded from the primary efficacy analysis. By the age of 28 days, there were 44 deaths in the air group and 27 deaths in the surfactant group (p = 0.022). By the age of 1 year after term there were 61 deaths in the air group and 35 deaths in the surfactant group (p = 0.002). Although there was no reduction in the incidence of respiratory distress syndrome, a significant reduction in the number of deaths attributed to respiratory distress syndrome, a significant reduction in the incidence of pulmonary air leaks, and significantly lower requirements for oxygen and mean airway pressure indicated that lung disease was less severe in the Exosurf-treated infants. There were no significant differences in the incidence of complications such as bronchopulmonary dysplasia, intraventricular hemorrhage, patent ductus arteriosus, necrotizing enterocolitis, and infection. The results indicate that a single prophylactic dose of Exosurf, in high-risk premature infants treated soon after birth, reduces the number of deaths from respiratory distress syndrome and the overall mortality rate. 相似文献
67.
Improved outcome at 28 days of age for very low birth weight infants treated with a single dose of a synthetic surfactant 总被引:1,自引:0,他引:1
C Bose A Corbet G Bose J Garcia-Prats L Lombardy D Wold D Donlon W Long 《The Journal of pediatrics》1990,117(6):947-953
Two identical double-blind, controlled, randomized trials were initiated to determine whether the administration of a single 5 ml/kg dose of a synthetic surfactant (Exosurf Neonatal), soon after the delivery of infants with birth weights 700 to 1350 gm, would improve rates of survival without bronchopulmonary dysplasia. Both trials were terminated before enrolling their planned sample sizes because of the availability of Exosurf under the provisions of a Treatment Investigational New Drug program. We report the combined results of these trials. Study infants were stratified according to birth weight and gender before random assignment to a treatment regimen. One hundred ninety-two infants received Exosurf and 193 received an air placebo. The study groups were similar when a variety of demographic features describing the mothers, their pregnancies, the circumstances of the births, and the infants were compared. Exosurf-treated infants required significantly less oxygen and respiratory support during the first 3 days of life in comparison with the air-treated infants. Fewer infants in the Exosurf group had pulmonary interstitial emphysema (26 vs 13; p = 0.028). In the Exosurf group, there was a significant reduction in the combined outcome, neonatal death or survival with bronchopulmonary dysplasia (57 vs 39; p = 0.042), and there was a significant increase in rates of survival without this disease (128 vs 137; p = 0.042). There were no differences between treatment groups in the incidences of a variety of complications of prematurity, including apnea, patent ductus arteriosus, intraventricular hemorrhage, and necrotizing enterocolitis. We conclude that improvements in respiratory physiology after a single prophylactic dose of Exosurf result in an increased likelihood of neonatal survival without bronchopulmonary dysplasia. 相似文献
68.
A mail campaign to promote mammography screening was tested with 3,887 Medicare recipients in North Dakota who had not had a mammogram in 2
years. Three types of mailings were compared: (1) a simple reminder message, (2) a reminder accompanied by a persuasive communication emphasizing personal risk, and (3) a reminder accompanied by a message tailored to the participants' chief barrier to having a mammogram. Overall, subsequent mammography rates for women in these conditions did not differ from the rate observed among women who did not receive any mailing. However, post-hoc analyses suggested that women who reported a barrier to having a mammogram were more likely to have a mammogram. Population-wide mail campaigns of the kinds tested here may be generally ineffective for Medicare recipients who are obtaining screenings infrequently. Tailoring messages may be one potentially effective intervention, if investigators can develop ways to increase responses to inquiries about barriers. 相似文献
69.
Habib NA Mitry R Seth P Kuppuswamy M Doronin K Toth K Krajcsi P Tollefson AE Wold WS 《Cancer gene therapy》2002,9(8):651-654
The successful clinical application of adenovirus (Ad) in cancer control has been of limited success because of the current inability to infect the majority of cancer cells with a large amount of vector. In this study, we show that when human lung tumors growing in immunodeficient nude mice were coinfected with a replication-defective (RD) Ad vector expressing green fluorescent protein and a replication-competent (RC) Ad vector named KD3, KD3 enhanced the expression of green fluorescent protein throughout the tumor. Also, KD3 and another RC vector named KD1 complemented the expression of luciferase from a RD vector in a human liver tumor xenotransplant in nude mice. Altogether, these results suggest that the combination of a RD vector with a RC vector might be a more effective treatment for cancer than either vector alone due to more widespread dissemination of the virus. 相似文献
70.
Phorbol ester-sensitive EL4 murine thymoma cells respond to phorbol 12-
myristate 13-acetate with activation of ERK mitogen-activated protein
kinases, synthesis of interleukin-2, and death, whereas phorbol ester-
resistant variants of this cell line do not exhibit these responses.
Additional aspects of the resistant phenotype were examined, using a
newly-established resistant cell line. Phorbol ester induced morphological
changes, ERK activation, calcium-dependent activation of the c-Jun
N-terminal kinase (JNK), interleukin-2 synthesis, and growth inhibition in
sensitive but not resistant cells. A series of protein kinase C activators
caused membrane translocation of protein kinase C's (PKCs) alpha, eta, and
theta in both cell lines. While PKC eta was expressed at higher levels in
sensitive than in resistant cells, overexpression of PKC eta did not
restore phorbol ester-induced ERK activation to resistant cells. In
sensitive cells, PKC activators had similar effects on cell viability and
ERK activation, but differed in their abilities to induce JNK activation
and interleukin-2 synthesis. PD 098059, an inhibitor of the mitogen
activated protein (MAP)/ERK kinase kinase MEK, partially inhibited ERK
activation and completely blocked phorbol ester-induced cell death in
sensitive cells. Thus MEK and/or ERK activation, but not JNK activation or
interleukin-2 synthesis, appears to be required for phorbol ester-induced
toxicity. Alterations in phorbol ester response pathways, rather than
altered expression of PKC isoforms, appear to confer phorbol ester
resistance to EL4 cells.
相似文献