全文获取类型
收费全文 | 19337篇 |
免费 | 1488篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 163篇 |
儿科学 | 626篇 |
妇产科学 | 534篇 |
基础医学 | 2911篇 |
口腔科学 | 286篇 |
临床医学 | 2208篇 |
内科学 | 3836篇 |
皮肤病学 | 591篇 |
神经病学 | 1938篇 |
特种医学 | 487篇 |
外科学 | 1854篇 |
综合类 | 159篇 |
一般理论 | 20篇 |
预防医学 | 2180篇 |
眼科学 | 338篇 |
药学 | 1165篇 |
中国医学 | 36篇 |
肿瘤学 | 1566篇 |
出版年
2024年 | 41篇 |
2023年 | 279篇 |
2022年 | 504篇 |
2021年 | 964篇 |
2020年 | 586篇 |
2019年 | 763篇 |
2018年 | 826篇 |
2017年 | 622篇 |
2016年 | 706篇 |
2015年 | 719篇 |
2014年 | 879篇 |
2013年 | 1133篇 |
2012年 | 1643篇 |
2011年 | 1677篇 |
2010年 | 845篇 |
2009年 | 743篇 |
2008年 | 1150篇 |
2007年 | 1163篇 |
2006年 | 992篇 |
2005年 | 965篇 |
2004年 | 880篇 |
2003年 | 783篇 |
2002年 | 673篇 |
2001年 | 106篇 |
2000年 | 81篇 |
1999年 | 102篇 |
1998年 | 128篇 |
1997年 | 110篇 |
1996年 | 76篇 |
1995年 | 80篇 |
1994年 | 65篇 |
1993年 | 48篇 |
1992年 | 44篇 |
1991年 | 51篇 |
1990年 | 47篇 |
1989年 | 26篇 |
1988年 | 24篇 |
1987年 | 28篇 |
1986年 | 20篇 |
1985年 | 31篇 |
1984年 | 30篇 |
1983年 | 26篇 |
1982年 | 20篇 |
1981年 | 30篇 |
1980年 | 21篇 |
1979年 | 11篇 |
1978年 | 24篇 |
1977年 | 11篇 |
1976年 | 11篇 |
1973年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
91.
92.
Julia F. Bodle Sean R.G. Duffy 《International journal of gynaecology and obstetrics》2008,103(2):116-120
Objective
To investigate the effect of the introduction of nurse hysteroscopists on patient satisfaction at an outpatient hysteroscopy clinic in the United Kingdom.Methods
Satisfaction with outpatient hysteroscopy performed in a University Teaching Hospital was measured using an anonymous structured questionnaire in 2000 and 2005. The unpaired t test, Mann-Whitney U test, or χ2 test was used depending on the level of measurement.Results
A total of 102 women surveyed in 2005 were compared with 139 women surveyed in 2000. Age, ethnicity, perceived health status, previous satisfaction with outpatient appointments, and expectations of the appointment did not differ between the groups. Waiting time for an appointment and once at the clinic fell during the study period (P < 0.001); satisfaction increased with the former (P < 0.001), but not the latter (P = 0.25). Satisfaction with the professional skills of healthcare providers and overall satisfaction was 95% or greater in both years.Conclusion
High levels of patient satisfaction with outpatient hysteroscopy were maintained after the introduction of nurse hysteroscopists. 相似文献93.
Regulation of NK cell cytotoxicity during pregnancy 总被引:1,自引:0,他引:1
Szekeres-Bartho J 《Reproductive biomedicine online》2008,16(2):211-217
Uterine and peripheral natural killer (NK) cells represent phenotypically and functionally distinct populations. Decidual NK cells resemble the CD56(bright) peripheral NK subset in their CD56(bright) CD16(neg) phenotype but, unlike the peripheral population, they contain cytotoxic granules. The activity of NK cells is regulated by the expression of activating or inhibitory receptors on NK cells and by that of major histocompatibility complex class I molecules on target cells. The embryonic trophoblast that forms the interface between the maternal and fetal compartments expresses non-classical human leukocyte antigens that serve as ligands for NK receptors. Decidual NK cells fulfil dual tasks. During normal conditions they contribute to creating a favourable environment for placentation, but at the same time they are equipped with cytotoxic potential to fight intrauterine infections. Decidual NK activity is regulated by a complex, mutually interacting network of cytokines and hormones. 相似文献
94.
Arck PC Rücke M Rose M Szekeres-Bartho J Douglas AJ Pritsch M Blois SM Pincus MK Bärenstrauch N Dudenhausen JW Nakamura K Sheps S Klapp BF 《Reproductive biomedicine online》2008,17(1):101-113
Many pregnancies are lost during early gestation, but clinicians still lack tools to recognize risk factors for miscarriage. Thus, the identification of risk factors for miscarriage during the first trimester in women with no obvious risk for a pregnancy loss was the aim of this prospective cohort trial. A total of 1098 women between gestation weeks 4 and 12 in whom no apparent signs of a threatened pregnancy could be diagnosed were recruited. Demographic, anamnestic, psychometric and biological data were documented at recruitment and pregnancy outcomes were registered subsequently. Among the cases with sufficiently available data, 809 successfully progressing pregnancies and 55 subsequent miscarriages were reported. In this cohort, risk of miscarriage was significantly increased in women at higher age (>33 years), lower body mass index (< or =20 kg/ m(2)) and lower serum progesterone concentrations (< or =12 ng/ml) prior to the onset of the miscarriage. Women with subsequent miscarriage also perceived higher levels of stress/demands (supported by higher concentrations of corticotrophin-releasing hormone) and revealed reduced concentrations of progesterone-induced blocking factor. These risk factors were even more pronounced in the subcohort of women (n = 335) recruited between gestation weeks 4 and 7. The identification of these risk factors and development of an interaction model of these factors, as introduced in this article, will help clinicians to recognize pregnant women who require extra monitoring and who might benefit from therapeutic interventions such as progestogen supplementation, especially during the first weeks of pregnancy, to prevent a miscarriage. 相似文献
95.
The objective of this study was to assess the validity and observed effect size of a new instrument, the Optimality Index-United States (OI-US), for use in perinatal clinical research. Using a large, hospital-based, midwifery service clinical database that included complete obstetric data for 3425 women, we examined discriminant validity and the effects of two different scoring methods used with the OI-US. Discriminant validity was confirmed by comparing OI scores for women who remained low risk and did not require physician involvement in their care (OI score mean = 84%; standard deviation [SD] = 8%) compared to those whose condition changed to require physician involvement in their care (mean = 71%; SD = 10%; P < .001). Two methods of scoring the OI-US were compared, finding no significant difference and suggesting that the types of data available and the research question can drive this decision. Finally, effect size was calculated by two methods: Cohen's d (-1.4) and the effect size correlation (r = -0.548), the latter of which corresponds to a d of -1.3, both resulting in a similarly large effect size estimation. The OI-US is a new instrument that shows promise for use in perinatal clinical research, particularly when assessing more subtle clinical differences in outcomes between study groups. 相似文献
96.
Our objective was to address the gap in knowledge about the extent to which perinatal mental health and risk behaviors are associated with childhood and adult experiences of abuse that arises because of barriers to screening and disclosure about past and current abuse. Survey data from an ongoing study of the effects of posttraumatic stress on childbearing were used to describe four groups of nulliparous women: those with no abuse history, adult abuse only, childhood abuse only, and abuse that occurred during both periods. The rates of abuse history disclosure were higher in the research context than in the clinical settings. Mental health morbidity and risk behaviors occurred in a dose-response pattern with cumulative abuse exposure. Rates of current posttraumatic stress disorder ranged from 4.1% among those never abused to 11.4% (adult only), 16.0% (childhood only), and 39.2% (both periods). Women abused during both periods also were more likely to be using tobacco (21.5%) and drugs (16.5%) during pregnancy. We conclude that mental health and behavioral risk sequelae affect a significant portion of both childhood and adult abuse survivors in prenatal care. The integration into the maternity setting of existing evidence-based interventions for the mental health and behavioral sequelae of abuse is needed. 相似文献
97.
98.
99.
100.
Schmid M Schneitter A Hinterberger S Seeber J Reinthaller A Hefler L 《Obstetrics and gynecology》2007,110(6):1231-1236
OBJECTIVE: To evaluate whether C-reactive protein (CRP) serum levels are associated with prognosis in surgically treated endometrial cancer. METHODS: In the present multicenter study, CRP serum levels were measured preoperatively in 403 surgically staged patients with endometrioid endometrial cancer. Results were correlated to clinical data. RESULTS: The mean (standard deviation) serum CRP level in patients with endometrial cancer was 1.0 (1.8) mg/dL. Serum CRP levels were associated with tumor stage (P=.01), but not with tumor grade (P=.8), lymph node involvement (P=.8), and age at diagnosis (P=.9). In a univariable survival analysis, serum CRP levels, tumor stage, tumor grade, and age at diagnosis were associated with disease-free and overall survival (all P <.001). In a multivariable Cox regression model, serum CRP levels (P=.001, P=.004), tumor stage (P <.001, P <.001), tumor grade (P=.02, P=.009), and age at diagnosis (P=.002, P=.001) were independent prognostic factors for disease-free and overall survival. CONCLUSION: Our results suggest that elevated serum CRP levels are associated with a less favorable prognosis in patients with surgically treated endometrial cancer. LEVEL OF EVIDENCE: II. 相似文献