全文获取类型
收费全文 | 8584篇 |
免费 | 655篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 385篇 |
妇产科学 | 205篇 |
基础医学 | 1206篇 |
口腔科学 | 172篇 |
临床医学 | 829篇 |
内科学 | 1749篇 |
皮肤病学 | 126篇 |
神经病学 | 898篇 |
特种医学 | 292篇 |
外科学 | 907篇 |
综合类 | 64篇 |
一般理论 | 2篇 |
预防医学 | 898篇 |
眼科学 | 203篇 |
药学 | 538篇 |
中国医学 | 5篇 |
肿瘤学 | 748篇 |
出版年
2023年 | 85篇 |
2022年 | 122篇 |
2021年 | 245篇 |
2020年 | 184篇 |
2019年 | 235篇 |
2018年 | 229篇 |
2017年 | 204篇 |
2016年 | 205篇 |
2015年 | 236篇 |
2014年 | 303篇 |
2013年 | 435篇 |
2012年 | 561篇 |
2011年 | 623篇 |
2010年 | 326篇 |
2009年 | 288篇 |
2008年 | 519篇 |
2007年 | 524篇 |
2006年 | 493篇 |
2005年 | 477篇 |
2004年 | 410篇 |
2003年 | 346篇 |
2002年 | 377篇 |
2001年 | 123篇 |
2000年 | 144篇 |
1999年 | 118篇 |
1998年 | 89篇 |
1997年 | 69篇 |
1996年 | 55篇 |
1995年 | 40篇 |
1994年 | 42篇 |
1993年 | 36篇 |
1992年 | 80篇 |
1991年 | 70篇 |
1990年 | 77篇 |
1989年 | 78篇 |
1988年 | 62篇 |
1987年 | 59篇 |
1986年 | 57篇 |
1985年 | 56篇 |
1984年 | 50篇 |
1983年 | 39篇 |
1982年 | 27篇 |
1979年 | 31篇 |
1978年 | 25篇 |
1977年 | 27篇 |
1974年 | 28篇 |
1973年 | 27篇 |
1970年 | 25篇 |
1969年 | 25篇 |
1968年 | 26篇 |
排序方式: 共有9261条查询结果,搜索用时 15 毫秒
61.
Rachael W Taylor Kirsten A Mcauley Sheila M Williams Wyn Barbezat Glen Nielsen Jim I Mann 《International journal of pediatric obesity》2006,1(3):146-152
OBJECTIVE: Community-based lifestyle intervention may offer the best means of reducing the global epidemic of childhood obesity and its consequences, yet few successful interventions have been reported. The objective was to determine whether increasing extra-curricular levels of activity could reduce weight gain in children. METHODS: A controlled intervention study was conducted using standardised methods to assess outcomes. Two comparable relatively rural communities in Otago, New Zealand formed intervention and control settings. Height, weight, waist circumference and participation in physical activity (by accelerometry) were measured at baseline and at 1 year in 384 children aged 5 to 12 years representing the majority of children in this age group in intervention and control communities. Community Activity Co-ordinators were employed at each school in the intervention area. Their brief was to widen exposure to activity and engage children not interested in traditional sporting activities by encouraging lifestyle-based activities (e.g. walking) and non-traditional sports (e.g. golf and taekwondo) during extra-curricular time at school, after school and during vacations. Simple dietary advice was offered and the wider community was encouraged to participate. RESULTS: Average accelerometry counts at 1 year were 28% (95% CI: 11 to 47%) higher in intervention compared with control children after adjusting for age, sex, baseline values and school. Intervention children spent less time in sedentary activity (ratio 0.91, p = 0.007) and more time in moderate (1.07, p = 0.001) and moderate/vigorous (1.10, p = 0.01) activity. Adjusted mean BMI Z-score was lower in intervention relative to control children by -0.12 units (95% CI: -0.22 to -0.02). CONCLUSION:. An intervention designed to maximise opportunities for physical activity during extra-curricular time at school and during leisure time through the provision of community-based Activity Co-ordinators significantly increased participation in physical activity and slowed unhealthy weight gain in primary school-aged children. 相似文献
62.
Theresa H M Keegan Sally L Glaser Christina A Clarke Margaret L Gulley Fiona E Craig Joseph A Digiuseppe Ronald F Dorfman Risa B Mann Richard F Ambinder 《Journal of clinical oncology》2005,23(30):7604-7613
PURPOSE: Epstein-Barr virus (EBV) in Hodgkin's lymphoma (HL) cells has been considered as a prognostic marker for this heterogeneous disease, but studies have yielded mixed findings, likely because of selected patient series and failure to acknowledge an effect of age on outcome. This study assessed survival after HL in a population-based cohort large enough to examine the joint effects of EBV with other factors including age, sex, and histologic subtype. PATIENTS AND METHODS: Included were 922 patients with classical HL diagnosed between mid-1988 and 1997 in the Greater San Francisco Bay Area, with archived biopsy specimens assayed for EBV with immunohistochemistry and in situ hybridization. Vital status was followed through December 30, 2003 (median follow-up time, 97 months). Overall and disease-specific survival were analyzed with the Kaplan-Meier method and Cox proportional hazards regression models. RESULTS: In children less than 15 years old, EBV presence was suggestively associated (P = .07) with favorable survival. In adults aged 15 to 44 years, EBV did not affect HL outcome, although a protective effect was suggested. In older adults (45 to 96 years), EBV presence nearly doubled the risk of overall and HL-specific mortality but only for patients with nodular sclerosis (NS) histologic subtype (hazard ratio for death = 2.5; 95% CI, 1.5 to 4.3). CONCLUSION: In HL, EBV tumor cell presence is associated with better survival in young patients and poorer survival in older patients with NS, independent of other factors. Variation in outcome by age and histology could indicate biologically distinct disease entities. Evidence that EBV is a meaningful prognostic marker may have therapeutic relevance. 相似文献
63.
Kirsten H. Leng Amy L. Yaroch Nadine Budd Nugent Sarah A. Stotz James Krieger 《Nutrients》2022,14(10)
Increased fruit and vegetable (FV) intake is associated with decreased risk of nutrition-related chronic diseases. Sociodemographic disparities in FV intake indicate the need for strategies that promote equitable access to FVs. The United States Department of Agriculture’s Gus Schumacher Nutrition Incentive Program (GusNIP) supports state and local programs that offer nutrition incentives (NIs) that subsidize purchase of FVs for people participating in the Supplemental Nutrition Assistance Program (SNAP). While a growing body of research indicates NIs are effective, the pathways through which GusNIP achieves its results have not been adequately described. We used an equity-focused, participatory process to develop a retrospective Theory of Change (TOC) to address this gap. We reviewed key program documents; conducted a targeted NI literature review; and engaged GusNIP partners, practitioners, and participants through interviews, workshops, and focus groups in TOC development. The resulting TOC describes how GusNIP achieves its long-term outcomes of increased participant FV purchases and intake and food security and community economic benefits. GusNIP provides NIs and promotes their use, helps local food retailers develop the capacity to sell FVs and accept NIs in accessible and welcoming venues, and supports local farmers to supply FVs to food retailers. The TOC is a framework for understanding how GusNIP works and a tool for improving and expanding the program. 相似文献
64.
65.
B M Glaser 《Ophthalmology》1986,93(9):1193-1197
Giant retinal tears with foreshortened and stiffened retina secondary to advanced proliferative vitreoretinopathy (PVR) pose a complex problem for the retinal surgeon. In the past, tractional forces on the retina in these eyes have been counteracted temporarily by retinal sutures, retinal incarceration, or retinal tacks, often combined with fluid-gas exchange in the prone position. These techniques are complex and add multiple additional maneuvers to the surgical procedure. The current report describes the use of a simple, stepwise fluid-gas exchange technique with the patient in the supine position in which the expanding gas bubble traps the edge of the stiffened and foreshortened retina against the pigment epithelium. Long-term counteraction of tractional forces was achieved by the use of intraocular silicone oil. Using this technique, 18 of 19 eyes with giant retinal tears and PVR Grade D1 to D3 could be successfully reattached. Four of these successfully reattached eyes had 360 degrees giant retinal tears. The most common and significant complication in our series was the recurrence of periretinal membranes. All 18 eyes that were initially reattached suffered the recurrence of significant periretinal membranes. Four of those 18 eyes developed recurrent interior traction detachments on to four months postoperatively. 相似文献
66.
BACKGROUND: Carcinosarcomas are rare neoplasms of the female genital tract. They tend to be highly aggressive and are generally associated with a poor prognosis. Carcinosarcomas of the uterine cervix are extremely rare, with only approximately 35 cases previously reported in English. CASE: A 68-year-old woman presented with cervical carcinosarcoma. She remained without evidence of recurrent disease for 18 months after surgical resection and pelvic radiation treatment. CONCLUSION: In a review of all cases reported in the literature, it appears that cervical carcinosarcomas tend to present at an earlier stage than carcinosarcomas of the uterine corpus, therefore allowing early diagnosis and treatment. They may therefore be associated with a better overall prognosis than their counterparts in the corpus. Some studies have shown improved survival of patients of carcinosarcoma of the uterine corpus whose treatment included postoperative radiation and chemotherapy. Due to the better prognosis of cervical carcinosarcomas, we suggest studies to evaluate the role of aggressive, multimodal therapy, with the intent of obtaining a cure of cervical carcinosarcomas. 相似文献
67.
Heavey EJ Moysich KB Hyland A Druschel CM Sill MW 《Journal of Midwifery & Women's Health》2008,53(4):338-344
Our objective was to examine the relationship between pregnancy desire among female adolescents and their perception of desire for pregnancy in their male partners. This is an observational cross-sectional study which examined 92 surveys administered to adolescent women between the ages of 14 to 19 years at two obstetrical care services serving a population from limited socioeconomic backgrounds. Participants were all pregnant or awaiting pregnancy test results. Participants were asked about their levels of pregnancy happiness and desire and their partners' levels of pregnancy happiness and desire. Spearman's correlation coefficient was calculated and discordant pairs were examined with McNemar's test. Logistic regression was utilized to examine the relationship between male and female pregnancy happiness and desire. We found that there was a significant correlation between the adolescents' feelings about pregnancy and their perceptions of their male partners' feelings about pregnancy (0.326; P = .004). McNemar's test indicated that male partners were significantly more likely to be reported to feel positively about the pregnancy than female partners (P = .017). Female adolescents who reported male partners who felt positively about the pregnancy were four times as likely to report having desired their pregnancy now or sooner (odds ratio [OR] = 4.35). We conclude that male partners may impact adolescent pregnancy desire. Further prospective studies are needed and male-focused adolescent pregnancy interventions should be developed. 相似文献
68.
OBJECTIVE: to assess and investigate knowledge of labour pain management options and decision-making among primiparous women. DESIGN: a semi-structured guide was used in focus groups to gather pregnant women's knowledge concerning labour analgesia. Attitudes to labour and pain relief, knowledge of pain relief, trustworthiness of knowledge sources, and plans and expectations for labour pain relief were investigated. SETTING: a major tertiary obstetric hospital in metropolitan Sydney, Australia. PARTICIPANTS: twenty five primiparous women, who were 25 weeks or more gestation, and planning a vaginal birth. FINDINGS: although women considered themselves knowledgeable, they were unable to describe labour analgesic risks or benefits. There was a large discrepancy between perception and actual knowledge. The main source of knowledge was anecdotal information. Late in pregnancy was considered the ideal time to be given information about labour analgesia. Women described their labour pain relief plans as flexible in relation to their labour circumstances; however, most women wanted to take an active role in decision-making. KEY CONCLUSIONS: the large discrepancy between perceived knowledge and actual knowledge of the likely consequences of labour analgesia suggests that women rely too heavily on anecdotal information. IMPLICATIONS FOR PRACTICE: clinicians should be aware that some women overestimate their knowledge and understanding of analgesic options, which is often based on anecdotal information. Standardised labour analgesia information at an appropriate time in their pregnancy may benefit some women and assist health-care providers and women to practice shared decision-making. 相似文献
69.
Volkmar Glaser 《Journal of molecular medicine (Berlin, Germany)》1939,18(34):1156-1157
Ohne Zusammenfassung 相似文献
70.