全文获取类型
收费全文 | 18474篇 |
免费 | 1397篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 172篇 |
儿科学 | 633篇 |
妇产科学 | 499篇 |
基础医学 | 2524篇 |
口腔科学 | 202篇 |
临床医学 | 2274篇 |
内科学 | 3436篇 |
皮肤病学 | 342篇 |
神经病学 | 1937篇 |
特种医学 | 503篇 |
外国民族医学 | 5篇 |
外科学 | 1996篇 |
综合类 | 144篇 |
一般理论 | 14篇 |
预防医学 | 2268篇 |
眼科学 | 270篇 |
药学 | 1196篇 |
中国医学 | 13篇 |
肿瘤学 | 1488篇 |
出版年
2024年 | 23篇 |
2023年 | 215篇 |
2022年 | 384篇 |
2021年 | 841篇 |
2020年 | 446篇 |
2019年 | 800篇 |
2018年 | 865篇 |
2017年 | 611篇 |
2016年 | 656篇 |
2015年 | 705篇 |
2014年 | 940篇 |
2013年 | 1083篇 |
2012年 | 1679篇 |
2011年 | 1671篇 |
2010年 | 829篇 |
2009年 | 709篇 |
2008年 | 1158篇 |
2007年 | 1134篇 |
2006年 | 1020篇 |
2005年 | 958篇 |
2004年 | 869篇 |
2003年 | 685篇 |
2002年 | 624篇 |
2001年 | 74篇 |
2000年 | 76篇 |
1999年 | 72篇 |
1998年 | 131篇 |
1997年 | 88篇 |
1996年 | 73篇 |
1995年 | 57篇 |
1994年 | 54篇 |
1993年 | 42篇 |
1992年 | 30篇 |
1991年 | 28篇 |
1990年 | 20篇 |
1989年 | 20篇 |
1988年 | 18篇 |
1987年 | 15篇 |
1986年 | 16篇 |
1985年 | 14篇 |
1984年 | 11篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1980年 | 13篇 |
1979年 | 13篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 15篇 |
1972年 | 11篇 |
1970年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 656 毫秒
131.
The purpose of this study was to quantify to what extent relative and absolute bladder dose-volume and dose-surface histograms of the planning CT scan were representative for the actual treatment. We used data of 17 patients, who each received 11 repeat CT scans and a planning CT scan. The repeat CT scans were matched on the planning CT scan by the bony anatomy. Clinical treatment plans were used to evaluate the impact of bladder filling changes on the four histogram types. The impact was quantified by calculating for this patient group the correlation coefficient between the planning histogram and the treatment histogram. We found that the absolute dose-surface histogram was the most representative one for the actual treatment. 相似文献
132.
Stephanie L. Santoro Karen Donelan Kelsey Haugen Nicolas M. Oreskovic Amy Torres Brian G. Skotko 《American journal of medical genetics. Part C, Seminars in medical genetics》2021,187(1):70-82
The COVID‐19 pandemic necessitated a rapid transition from in‐person office visits to virtual visits in the Down syndrome specialty program at Massachusetts General Hospital (MGH DSP). We describe the clinic transition to virtual visits in April 2020 and reflect on our six‐month experience in virtual visits. Clinic metrics were tracked. Electronic survey responses were collected from caregivers attending virtual visits. Input from the MGH DSP team was collected. From April to September 2020, we maintained patient volume (45 visits per month) and overall satisfaction score (6.7 out of 7) following a sudden, unanticipated transition to virtual visits. Survey of 17 caregivers attending virtual visits found that most were equipped with technology, had access to a private location, and most were able to access visit without any limitations. Caregivers appreciated the convenience of virtual visits but sometimes missed the personal connection of an in‐person visit. Overall, though, virtual visits were frequently viewed as no different than office visits. Team members identified benefits and challenges of virtual visits, as well as lessons learned from this transition. We were able to maintain multidisciplinary, specialty care with optimal caregiver feedback and sustained number of patient visits. 相似文献
133.
Wong Jasin Ezeife Nnaemezie Kudla Angelika Crown Deborah Trierweiler Robert Capraro Pamela Tomazin Stephanie Su Han Pham Tri Heinemann Allen W. 《Journal of occupational rehabilitation》2022,32(3):464-472
Journal of Occupational Rehabilitation - Purpose The COVID-19 pandemic has disproportionately affected the lives of people with disabilities (PWD). How the pandemic affects the employment of PWD... 相似文献
134.
Stephanie Andraos Beatrix Jones Clare Wall Eric Thorstensen Martin Kussmann David Cameron-Smith Katherine Lange Susan Clifford Richard Saffery David Burgner Melissa Wake Justin OSullivan 《Nutrients》2021,13(3)
Scope: B vitamers are co-enzymes involved in key physiological processes including energy production, one-carbon, and macronutrient metabolism. Studies profiling B vitamers simultaneously in parent–child dyads are scarce. Profiling B vitamers in parent–child dyads enables an insightful determination of gene–environment contributions to their circulating concentrations. We aimed to characterise: (a) parent–child dyad concordance, (b) generation (children versus adults), (c) age (within the adult subgroup (age range 28–71 years)) and (d) sex differences in plasma B vitamer concentrations in the CheckPoint study of Australian children. Methods and Results: 1166 children (11 ± 0.5 years, 51% female) and 1324 parents (44 ± 5.1 years, 87% female) took part in a biomedical assessment of a population-derived longitudinal cohort study: The Growing Up in Australia’s Child Health CheckPoint. B vitamer levels were quantified by UHPLC/MS-MS. B vitamer levels were weakly concordant between parent–child pairs (10–31% of variability explained). All B vitamer concentrations exhibited generation-specificity, except for flavin mononucleotide (FMN). The levels of thiamine, pantothenic acid, and 4-pyridoxic acid were higher in male children, and those of pantothenic acid were higher in male adults compared to their female counterparts. Conclusion: Family, age, and sex contribute to variations in the concentrations of plasma B vitamers in Australian children and adults. 相似文献
135.
136.
Sosa Sylvia Kogan Michael D. Garcia Stephanie Strobino Donna M. Minkovitz Cynthia S. 《Maternal and child health journal》2021,25(2):221-229
Maternal and Child Health Journal - The Health Resources and Services Administration’s Maternal and Child Health Bureau (HRSA MCHB) developed a three-tiered performance measure framework for... 相似文献
137.
Maternal and Child Health Journal - The maternal health field has recently focused on the importance of interpersonal quality of care and continues to cite structural deficits as a contributor to... 相似文献
138.
139.
Beomyoung Cho Jana L. Hirschtick Bukola Usidame Rafael Meza Ritesh Mistry Stephanie R. Land David T. Levy Theodore Holford Nancy L. Fleischer 《The Journal of adolescent health》2021,68(4):750-757
PurposeThis study examines sociodemographic patterns of exclusive/dual/polytobacco use among U.S. high school students using multiple national surveys.MethodsUsing three national youth surveys (Population Assessment of Tobacco and Health [PATH] Wave 4 [2016–2017], 2017 Youth Risk Behavior Survey, and 2017 National Youth Tobacco Survey), we classified tobacco products into four groups: (1) electronic nicotine delivery systems (ENDS), (2) conventional cigarettes (CCs), (3) other combustible tobacco products, and (4) smokeless tobacco products. We created 16 categories of non/exclusive/dual/polytobacco use within the past 30 days using the four product groups and calculated weighted population prevalence by sex and race/ethnicity (all surveys) and parental education and income (PATH), based on variable availability.ResultsThe results from 9,331, 12,407, and 9,699 high school students in PATH, Youth Risk Behavior Survey, and National Youth Tobacco Survey, respectively, largely agreed and pointed to similar conclusions. ENDS was the most prevalent exclusive use product (3.8%–5.2% across surveys), with CCs falling to second or third (1.2%–2.0% across surveys). By sex, exclusive, dual, and poly smokeless tobacco product use were more common for males, whereas exclusive CC use was more common for females. By race/ethnicity, non-Hispanic Whites had a higher prevalence of exclusive ENDS use and ENDS/CC dual use than non-Hispanic Blacks. As income and parental education levels increased from low to high, the prevalence of exclusive CC use decreased, whereas the prevalence of exclusive ENDS use increased.ConclusionUnderstanding sociodemographic patterns of tobacco use can help identify groups who may be at greater risk for tobacco-related health outcomes. 相似文献
140.
PurposeTexting is used by many adolescents and has the potential to improve well-being, as youth can reach out for support immediately after experiencing a stressful situation. Many studies have examined whether texting is associated with well-being, but few have used experimental designs, preventing causal claims.MethodsIn this experimental study, 130 adolescents (Mage = 12.41) participated with a same-gender friend whom they texted regularly. Both adolescents completed a task that elicited stress and then engaged in one of the following randomly assigned activities: texting their friend, watching a video on a cellphone (passive-phone condition), or sitting quietly (no activity condition). Participants reported their mood and stress levels after the stress task and again after the activity. Heart rate variability was measured throughout.ResultsParticipants who texted their friend reported higher moods (b = ?.80, standard error [SE] = .24, p < .001, ηp2 = .09) and lower stress at the end of the study than those in the no activity condition (b = .51, SE = .25, p = .046, ηp2 = .04) and higher moods than adolescents in the passive-phone condition (b = ?.74, SE = .25, p = .004, ηp2 = .08). No differences were noted between the passive-phone and no activity conditions. There were no differences in heart rate variability between the three conditions. The effects of texting on mood, self-reported stress, and heart rate variability did not differ by gender.ConclusionsBoth boys and girls may benefit from texting a friend after experiencing a stressful event. 相似文献