全文获取类型
收费全文 | 3119篇 |
免费 | 243篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 83篇 |
妇产科学 | 55篇 |
基础医学 | 554篇 |
口腔科学 | 73篇 |
临床医学 | 267篇 |
内科学 | 557篇 |
皮肤病学 | 65篇 |
神经病学 | 240篇 |
特种医学 | 75篇 |
外科学 | 300篇 |
综合类 | 58篇 |
一般理论 | 2篇 |
预防医学 | 227篇 |
眼科学 | 186篇 |
药学 | 250篇 |
中国医学 | 15篇 |
肿瘤学 | 287篇 |
出版年
2024年 | 6篇 |
2023年 | 28篇 |
2022年 | 59篇 |
2021年 | 95篇 |
2020年 | 71篇 |
2019年 | 89篇 |
2018年 | 81篇 |
2017年 | 80篇 |
2016年 | 112篇 |
2015年 | 113篇 |
2014年 | 140篇 |
2013年 | 168篇 |
2012年 | 266篇 |
2011年 | 219篇 |
2010年 | 140篇 |
2009年 | 148篇 |
2008年 | 208篇 |
2007年 | 188篇 |
2006年 | 155篇 |
2005年 | 147篇 |
2004年 | 141篇 |
2003年 | 153篇 |
2002年 | 126篇 |
2001年 | 40篇 |
2000年 | 25篇 |
1999年 | 43篇 |
1998年 | 24篇 |
1997年 | 22篇 |
1996年 | 19篇 |
1995年 | 15篇 |
1994年 | 16篇 |
1993年 | 12篇 |
1992年 | 20篇 |
1991年 | 14篇 |
1990年 | 19篇 |
1989年 | 14篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 15篇 |
1984年 | 18篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1979年 | 7篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1974年 | 11篇 |
1970年 | 6篇 |
1966年 | 4篇 |
排序方式: 共有3373条查询结果,搜索用时 772 毫秒
1.
Lauren Tingey Britta Mullany Rachel Chambers Ranelda Hastings Angelita Lee Anthony Parker 《AIDS care》2015,27(9):1087-1097
Potential for widespread transmission of HIV/AIDS among American Indian (AI) adolescents exists, yet no evidence-based interventions (EBIs) have been adapted and evaluated with this population. Intensive psychoeducation may improve knowledge and decision-making which could potentially translate to reductions in HIV risk behaviors. A peer group randomized controlled comparison of an adapted EBI vs. control was delivered over an eight-day summer basketball camp in one reservation-based tribal community to adolescents ages 13–19. Outcome data were gathered immediately post-camp and at 6 and 12 months follow-up. Self-selected peer groups were randomized to intervention (n = 138) or control (n = 129) conditions for a total sample of 267 participants (56.2% female), mean age 15.1 years (SD = 1.7). Intervention participants had better condom use self-efficacy post-camp (Adjusted Mean Difference [AMD] = ?0.75, p < 0.005) and at 6 (AMD = ?0.44, p < 0.005) and 12 months (AMD = ?0.23, p < 0.05) follow-up. Intervention participants also had higher HIV prevention and transmission knowledge (post-camp: AMD = 0.07, p < 0.01; 6 months: AMD = 0.06, p < 0.01) were more likely to believe condoms prevent sexually transmitted infections (post-camp: RR = 1.41, p < 0.005; 6 months: RR = 1.34, p < 0.05), to talk with an adult about HIV/AIDS (post-camp: RR=1.78, p < 0.005; 6 months: RR = 1.14, p < 0.005), had higher partner negotiation efficacy related to substance use during sex (post-camp: AMD = 0.37, p < 0.01), and were more likely to intend to use a condom (post-camp: RR = 1.39, p < 0.01). The adapted intervention had short- and medium-term impacts on AI adolescent risk for HIV/AIDS, but attenuated at 12 months. Intervention delivery through a community-based camp is feasible and acceptable with strong retention. Additional study is needed to evaluate the adapted intervention's impact on sexual risk behaviors and if booster sessions and parent involvement translate to long-term impacts. 相似文献
2.
Interprofessional collaboration and communication in nursing homes: a qualitative exploration of problems in medical care for nursing home residents – study protocol
下载免费PDF全文
![点击此处可从《Journal of advanced nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
3.
Low myocardial glucose uptake in Turner syndrome is unaffected by growth hormone: a randomized,placebo‐controlled FDG‐PET study
下载免费PDF全文
![点击此处可从《Clinical endocrinology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
4.
Kerstin Schmidt Johannes Hoffend Annette Altmann Ludwig G Strauss Antonia Dimitrakopoulou-Strauss Britta Engelhardt Dirk Koczan J?rg Peter Thomas J Dengler Walter Mier Michael Eisenhut Uwe Haberkorn Ralf Kinscherf 《Journal of nuclear medicine》2006,47(3):543-551
Growth of malignant tumors is dependent on sufficient blood supply. Thus, inhibition of tumor angiogenesis is emerging as a promising target in the treatment of malignancies. Human angiostatin (hANG) is one of the most potent inhibitors of endothelial cell proliferation, angiogenesis, and tumor growth in vivo. However, its mechanisms operating in vivo are not well understood. METHODS: To obtain more information about functional changes in the angiogenic process, we established Morris hepatoma (MH3924A) cell lines expressing hANG (hANG-MH3924A). The effects of hANG expression on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs) were measured in coculture experiments in vitro. To evaluate changes in tumor perfusion and blood volume, H2 15O and 68Ga-DOTA-albumin (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N',N'-tetraacetic acid) were used for PET studies in vivo. Additionally, immunohistologic quantification of vascularization, apoptosis, and proliferation as well as gene array analyses were performed. RESULTS: Our in vitro experiments demonstrate reduced proliferation and increased apoptosis in HUVECs when being cocultured with hANG-MH3924A. In support, tumor growth of hANG-MH3924A is diminished by 95% in vivo. However, tumor perfusion and blood volume are increased in hANG-MH3924A corresponding to an increased microvessel density. Furthermore, hANG-transfected tumors show changes in expression of genes related to apoptosis, stress, signal transduction, and metabolism. CONCLUSION: hANG expression leads to inhibition of tumor growth, increased apoptosis, and changes in the expression of multiple genes involved in stress reactions, signal transduction, and apoptosis, which indicates a multifactorial reaction of tumors. An enhanced microvessel density is seen as part of these reactions and is associated with increased perfusion as measured by PET. 相似文献
5.
Mark L. Laudenslager Maria L. Boccia Christy L. Berger Mary M. Gennaro-Ruggles Britta McFerran Martin L. Reite 《Developmental psychobiology》1995,28(4):199-211
Many behavioral, immunological, and physiological consequences of brief maternal separation in bonnet (Macaca radiata) and pigtail monkeys (Macaca nemistrina) have been documented. However, the impact of social separation on plasma cortisol and growth hormone is unknown for these particular species. In the present study, the behavioral and endocrinological consequences of a 2-week maternal separation in socially housed infant bonnet and pigtail monkeys were followed. In seven pairs (separated and matched control) of bonnet and six pairs of pigtail infants, plasma was obtained under baseline, separated, and reunion conditions twice weekly for the duration of the study. Blood samples were obtained from both infants of the pair in approximately 10 min. Plasma total cortisol, free cortisol, and growth hormone were measured in these samples. Focal animal behavioral observations were made on all subjects twice daily throughout the study period. In both species, total cortisol and free cortisol rose immediately following maternal separation in comparison to the matched nonseparated controls and returned to basal levels (e.g., that of matched non-separted controls) following reunion with the mother. In contrast, plasma growth hormone rose only in the pigtail infants over a time course that peaked around the time of reunion. Multiple regression techniques indicated for the first week of separation, in the separated but not control subjects, that mean plasma free and total cortisol was positively related to distress behaviors (vocalization and postural slouch) observed during this week and negatively related to social behaviors (play and proximity to others) noted during the same period. In contrast, plasma growth hormone was related to both species and sex of the subjects but unrelated to behavioral variables. © 1995 John Wiley & Sons, Inc. 相似文献
6.
N. K. Panda Y. N. Mehra S. B. S. Mann 《Indian journal of otolaryngology and head and neck surgery》1993,45(3):125-127
The efficacy of local application of Nitrobid oinment in the treatment of idiopathic sudden sensorineural hearing loss has
been presented Overall good to fair recovery occured in 40% of the patients, important prognostic indicators were found to
be severity of initial hearing loss, time from onset to initial visit, age of the patient and hearing status of the opposite
ear. 相似文献
7.
A retrospective longitudinal study of 105 penetrating keratoplasties for vascularized corneal opacities was done. The results of cases with an etiology of healed trachoma or healed corneal ulcers were compared. The vascularization was graded from Grade I to V depending on the quadrant and type of vascularization. Graft clarity of 2+ or more in cases of trachomatous opacity was achieved in 93% of cases and that after postinfectious opacity in 71.8%. Prognosis was poor in cases where deep vascularization was present in more than two quadrants or more than 180 degrees. 相似文献
8.
A case of congenital erythropoietic porphyria, with corneoscleral ulceration, a rare association in this disorder, was reported. Anterior segment ischemia is believed to play an important role in the etiopathogenesis of corneoscleral ulceration. Remarkable improvement occurred with use of topical heparin drops (500 units/ml). 相似文献
9.
10.
Lutz Liefeldt Martin Buhl Britta Schweickert Elisabeth Engelmann Orhan Sezer Peter Laschinski Lothar Preuschof Hans-H Neumayer 《Nephrology, dialysis, transplantation》2002,17(10):1840-1842