全文获取类型
收费全文 | 26006篇 |
免费 | 1735篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 878篇 |
妇产科学 | 713篇 |
基础医学 | 3212篇 |
口腔科学 | 524篇 |
临床医学 | 3989篇 |
内科学 | 4628篇 |
皮肤病学 | 299篇 |
神经病学 | 2677篇 |
特种医学 | 535篇 |
外科学 | 2126篇 |
综合类 | 280篇 |
一般理论 | 64篇 |
预防医学 | 3706篇 |
眼科学 | 340篇 |
药学 | 1546篇 |
1篇 | |
中国医学 | 26篇 |
肿瘤学 | 2040篇 |
出版年
2023年 | 105篇 |
2022年 | 156篇 |
2021年 | 437篇 |
2020年 | 304篇 |
2019年 | 460篇 |
2018年 | 561篇 |
2017年 | 443篇 |
2016年 | 455篇 |
2015年 | 503篇 |
2014年 | 792篇 |
2013年 | 1258篇 |
2012年 | 1842篇 |
2011年 | 1906篇 |
2010年 | 1039篇 |
2009年 | 905篇 |
2008年 | 1759篇 |
2007年 | 1841篇 |
2006年 | 1832篇 |
2005年 | 1864篇 |
2004年 | 1781篇 |
2003年 | 1692篇 |
2002年 | 1567篇 |
2001年 | 214篇 |
2000年 | 160篇 |
1999年 | 283篇 |
1998年 | 344篇 |
1997年 | 248篇 |
1996年 | 243篇 |
1995年 | 231篇 |
1994年 | 197篇 |
1993年 | 186篇 |
1992年 | 143篇 |
1991年 | 134篇 |
1990年 | 114篇 |
1989年 | 122篇 |
1988年 | 107篇 |
1987年 | 102篇 |
1986年 | 104篇 |
1985年 | 109篇 |
1984年 | 123篇 |
1983年 | 125篇 |
1982年 | 144篇 |
1981年 | 136篇 |
1980年 | 119篇 |
1979年 | 76篇 |
1978年 | 74篇 |
1977年 | 73篇 |
1976年 | 57篇 |
1975年 | 45篇 |
1974年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
Abstract A previous study of the sensitivity and accuracy of a standardized radiographic technique for the disclosure of root cavities in a cadaver material indicated that it was not possible to perceive small artificial “resorption” cavities. Using the same material, the aim of the present study was to evaluate whether the use of subtraction radiography would improve the detection of root cavities. In an autopsy material of five mandibular blocks each containing two premolars, small, medium, and large cavities were drilled in the cervical, middle, and apical thirds of the proximal and oral root surfaces. Each jaw block was radiographed before (B) and after (A) cavity preparation with three different exposure times resulting in light, medium, and dark film densities. The radiographs were digitized. Digital subtraction was performed between the A- and B images of varying densities by a computer program developed for dental subtraction radiography. Conventional and reverse contrast modes of the subtraction image were assessed independently by four observers. The results showed small inter- and intraobserver differences in diagnostic accuracy for assessment of total number of root cavities. Original film density did not influence the diagnostic performance in the resulting subtraction image. Contrast mode in the subtraction image influenced diagnostic performance as the majority of observers did best with the reverse contrast mode (p<0.05). Some of the small root cavities were disclosed by the subtraction technique, but overall accuracy was not increased compared to conventional radiography. 相似文献
65.
66.
Nancy D. Brener Etienne G. Krug Linda L. Dahlberg Kenneth E. Powell 《The Journal of school health》1997,67(5):171-174
ABSTRACT: Programs for preventing violence among youth should be evaluated to determine if they are effective. Nurses' logs appear to be a useful tool for evaluating school-based violence prevention programs. The logs provide a record of students' visits to the school nurse that can be used to determine if a violence prevention program is associated with a reduction in fighting—and other injury-related nurse visits. This method has many strengths: it is simple and inexpensive, it does not interrupt the school routine, it permits school-level rather than student-level data collection, it provides a ready "baseline," and it allows continuous data collection. However, potential limitations do exist. For example, the method may provide insufficient information and may be affected by factors unrelated to the intervention. School officials can increase the usefulness of the logs by encouraging standardization and providing training in their use. 相似文献
67.
Stuart Sherman MD Nancy S. Nieland MD David H. Van Thiel MD 《Digestive diseases and sciences》1988,33(3):368-374
Summary An unusual case of a woman with primary biliary cirrhosis and cutaneous sarcoidosis is described. The factors that allow a specific diagnosis of each condition are presented and the literature pertaining to such complex and unusual cases is presented.This work was supported in part by a grant from the Gastroenterology Medical Research Foundation of Southwestern Pennsylvania. 相似文献
68.
Lynn Rew Margaret Taylor-Seehafer Nancy Thomas 《Journal for specialists in pediatric nursing》2000,5(3):131-138
ISSUES AND PURPOSE. To identify the ethical and legal implications of conducting research with homeless adolescents and to discuss guidelines for conducting research without parental consent.
CONCLUSIONS. Ethical principles of capacity, risk, postponement, and truthful disclosure within the context of the rights of minors to consent to healthcare treatment form the basis of the argument for allowing adolescents to consent to participate in research without parental consent when there is minimal risk or when such consent could place them at increased risk for harm.
PRACTICE IMPLICATIONS. Adolescents who are the target population for clinical research or who are intended recipients of nursing care should be involved in setting priorities, purposes, and protocols. Parents and other adults from their communities should be included in developing strategies to protect their confidentiality and privacy while helping them achieve autonomy in making informed health-related decisions. 相似文献
CONCLUSIONS. Ethical principles of capacity, risk, postponement, and truthful disclosure within the context of the rights of minors to consent to healthcare treatment form the basis of the argument for allowing adolescents to consent to participate in research without parental consent when there is minimal risk or when such consent could place them at increased risk for harm.
PRACTICE IMPLICATIONS. Adolescents who are the target population for clinical research or who are intended recipients of nursing care should be involved in setting priorities, purposes, and protocols. Parents and other adults from their communities should be included in developing strategies to protect their confidentiality and privacy while helping them achieve autonomy in making informed health-related decisions. 相似文献
69.
Nancy Morabito Agostino Gaudio Antonino Lasco Antonino Catalano Marco Atteritano Aldo Trifiletti Giuseppina Anastasi Darwin Melloni Nicola Frisina 《Journal of bone and mineral research》2004,19(11):1766-1770
Today, androgen deprivation therapy is a cornerstone of treatment for advanced prostate cancer, although it presents important complications such as osteoporosis. Neridronate, a relatively new bisphosphonate, is able to prevent bone loss in patients with prostate cancer during androgen ablation. INTRODUCTION: Androgen-deprivation therapy (ADT) is a cornerstone of treatment for advanced prostate cancer. This therapy has iatrogenic complications, such as osteoporosis. The aim of our study was to evaluate the efficacy of neridronate, a relatively new bisphosphonate, to prevent bone loss during androgen ablation. MATERIALS AND METHODS: Forty-eight osteoporotic patients with prostate cancer, treated with 3-month depot triptorelina, were enrolled and randomly assigned to two different treatment groups: group A (n = 24) was treated with a daily calcium and cholecalciferol supplement (500 mg of elemental calcium and 400 IU cholecalciferol), and group B (n = 24) received in addition to the same daily calcium and cholecalciferol supplement, 25 mg of neridronate given intramuscularly every month. All patients also received bicalutamide for 4 weeks. Lumbar and femoral BMD was evaluated by DXA at baseline and after 1 year of therapy; moreover, deoxypyridinoline (DPD) and bone alkaline phosphatase (BALP) were determined at the beginning, midway through, and at the end of the study. RESULTS: After 6 and 12 months, whereas patients treated only with calcium and cholecalciferol (group A) showed a marked bone loss, with increased levels of DPD and BALP compared with baseline values, patients treated also with neridronate (group B) had substantially unchanged levels of these markers. After 1 year of treatment, lumbar and total hip BMD decreased significantly in patients treated only with calcium and cholecalciferol (group A), whereas it did not change significantly at any skeletal site in patients treated also with neridronate (group B). No relevant side effects were recorded during our study. CONCLUSIONS: Neridronate is an effective treatment in preventing bone loss in the hip and lumbar spine in men receiving ADT for prostate cancer. 相似文献
70.
Reductions in depressed mood and denial coping during cognitive behavioral stress management with hiv-positive gay men treated with haart 总被引:1,自引:1,他引:0
Adam W. Carrico M.S. Michael H. Antoni Ph.D. Ron E. Durán Ph.D. Gail Ironson M.D. Ph.D. Frank Penedo Ph.D. Mary Ann Fletcher Ph.D. Nancy Klimas M.D. Neil Schneiderman Ph.D. 《Annals of behavioral medicine》2006,31(2):155-164
Background: Stress management interventions for HIV-positive persons have been designed to enhance coping skills and encourage health-promoting
behaviors with the hope of decreasing distress and slowing disease progression.Purpose: We examined the efficacy of a cognitive behavioral stress management (CBSM) intervention in combination with medication
adherence training (MAT) in 130 gay and bisexual men living with HIV infection.Methods: Participants were randomized to either a 10-week CBSM+MAT intervention (n = 76) or a MAT-only condition (n = 54). Measures
of self-reported adherence, active cognitive coping (i.e., acceptance and positive reinterpretation), avoidant coping (i.e.,
denial and behavioral disengagement), and depressed mood were examined over the 10-week intervention period.Results: Men in CBSM+MAT reported reductions in depressed mood and denial coping during the 10-week intervention period, but no changes
in active cognitive coping or self-reported adherence were observed. Using path analysis, greater reliance on denial coping
at baseline was associated with decreased depressed mood at 10 weeks. We also determined that CBSM+MAT may decrease depressed
mood by reducing reliance on denial coping over the 10-week intervention period.Conclusions: Although denial may be an effective means of distress reduction in the short term, reliance on this coping strategy may
result in a decreased capacity to effectively manage a variety of disease-related stressors in the long term. CBSM+MAT addresses
this potentially detrimental pattern by teaching stress reduction skills that may decrease depressed mood via reduced reliance
on denial coping.
This research was supported by National Institute of Mental Health Grants P01 MH49548 and T32 MH18917. 相似文献