全文获取类型
收费全文 | 4596篇 |
免费 | 353篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 152篇 |
妇产科学 | 108篇 |
基础医学 | 526篇 |
口腔科学 | 319篇 |
临床医学 | 570篇 |
内科学 | 1058篇 |
皮肤病学 | 35篇 |
神经病学 | 265篇 |
特种医学 | 282篇 |
外科学 | 552篇 |
综合类 | 76篇 |
一般理论 | 2篇 |
预防医学 | 403篇 |
眼科学 | 69篇 |
药学 | 350篇 |
中国医学 | 3篇 |
肿瘤学 | 143篇 |
出版年
2021年 | 56篇 |
2020年 | 29篇 |
2019年 | 52篇 |
2018年 | 68篇 |
2017年 | 50篇 |
2016年 | 52篇 |
2015年 | 59篇 |
2014年 | 135篇 |
2013年 | 151篇 |
2012年 | 206篇 |
2011年 | 202篇 |
2010年 | 115篇 |
2009年 | 119篇 |
2008年 | 200篇 |
2007年 | 189篇 |
2006年 | 150篇 |
2005年 | 194篇 |
2004年 | 219篇 |
2003年 | 195篇 |
2002年 | 164篇 |
2001年 | 154篇 |
2000年 | 162篇 |
1999年 | 136篇 |
1998年 | 80篇 |
1997年 | 71篇 |
1996年 | 61篇 |
1995年 | 70篇 |
1994年 | 61篇 |
1993年 | 49篇 |
1992年 | 93篇 |
1991年 | 83篇 |
1990年 | 108篇 |
1989年 | 95篇 |
1988年 | 93篇 |
1987年 | 94篇 |
1986年 | 79篇 |
1985年 | 83篇 |
1984年 | 81篇 |
1983年 | 70篇 |
1982年 | 45篇 |
1981年 | 40篇 |
1980年 | 40篇 |
1979年 | 39篇 |
1978年 | 31篇 |
1977年 | 37篇 |
1976年 | 42篇 |
1975年 | 28篇 |
1974年 | 35篇 |
1971年 | 28篇 |
1968年 | 27篇 |
排序方式: 共有4955条查询结果,搜索用时 15 毫秒
41.
Chlamydia trachomatis infection in prelabour amniorrhexis 总被引:2,自引:0,他引:2
Y. Ville Senior Lecturer S. G Carroll Senior Registrar P. Watts Professor M. Ward Professor K. H. Nicolaides Professor 《BJOG : an international journal of obstetrics and gynaecology》1997,104(9):1091-1093
The prevalence of Chlamydia trachomatis in the lower genital tract and amniotic fluid of women with preterm prelabour amniorrhexis was assessed by DNA amplification for C. trachomatis performed in cervical swabs and amniotic fluid obtained by amniocentesis. C. trachomatis was present in the cervix of 20 (23%) of the cases and in six (30%) of those the organism was also present in the amniotic fluid. There was no association with other pathogens in the lower genital tract or amniotic fluid. The presence of C. trachomatis was not associated with a significant decrease in the amniorrhexis to delivery interval or with an increase in perinatal mortality or morbidity. 相似文献
42.
Initial multicenter experience with double nucleoside therapy for human immunodeficiency virus infection during pregnancy. 总被引:3,自引:0,他引:3 下载免费PDF全文
N S Silverman D H Watts J Hitti D M Money E Livingston J Axelrod J M Ernest D Robbins M M DiVito 《Infectious diseases in obstetrics and gynecology》1998,6(6):237-243
OBJECTIVE: To study maternal and neonatal effects of combination nucleoside analog therapy administered to human immunodeficiency virus (HIV)-infected pregnant women for maternal indications. METHODS: A multicenter, prospective observational study was undertaken at six perinatal centers in the United States and Canada that supported regional referral programs for the treatment of HIV-infected pregnant women. Demographic, laboratory, and pregnancy outcome data were collected for 39 women whose antiretroviral treatment regimens were expanded to include more than one nucleoside analog for maternal indications. The 40 newborns were monitored at pediatric referral centers through at least three months of age to ascertain their HIV infection status. RESULTS: For all 39 women, zidovudine (ZDV) therapy was instituted at 13.4 +/- 8.2 weeks, with a second agent (lamivudine [3TC] in 85% of cases) being added at a mean gestational age of 17.6 weeks. Duration of therapy with two agents was 20.6 +/- 10.4 weeks overall, with no women stopping medications because of side effects or toxicity. No significant changes in maternal laboratory values were seen, except for an increase in mean corpuscular volume, over the course of pregnancy. No clinically significant adverse neonatal outcomes were noted, with all but the three preterm newborns leaving hospital with their mothers. Neonatal anemia (hematocrit < 50%) was seen in 62% of newborns, with no children needing transfusion; mild elevations of liver function tests, primarily aspartate aminotransferase, were noted in 58% of newborns tested, though none were clinically jaundiced. Overall rate of neonatal HIV infection was 2.5% (95% confidence interval: 0.1-13.2%). CONCLUSION: Combination antiretroviral therapy during pregnancy with two nucleoside analogs was well-tolerated by mothers and newborns, with no significant short-term toxicities or side effects noted. Surveillance of exposed newborns' hematologic and liver function appears warranted. 相似文献
43.
44.
45.
Benoit R Watts DD Dwyer K Kaufmann C Fakhry S 《The Journal of trauma》2000,49(3):477-81; discussion 481-2
BACKGROUND: Falls from windows in urban areas cause a significant number of pediatric injuries. Window falls have not been well described in the nonurban setting. We describe the epidemiology of window falls from residential homes among pediatric patients at a suburban Level I trauma center. METHODS: A review of patients admitted from January 1991 through November 1999 to a center serving a rapidly growing suburban area was performed. RESULTS: A total of 2,322 children, ages 0-14 years, were admitted during the study period. Falls comprised 41% of these admissions, and 11% of falls were from windows, greater than twice the national average. More than 39% of children who fell from windows were admitted directly to the intensive care unit. Overall mortality rate was 4%. Ages 0 to 4 years comprised the largest percentage (83%), and all children who died were in this age group. Children < or = 4 years were more likely to have an Abbreviated Injury Score > or = 2 (head injury) than those ages 10 to 14 years (p = 0.032). More than 31% of all children injured in window falls seen at the study institution between 1991 and 1999 were admitted in the last 2 years. CONCLUSION: Pediatric falls from windows in this suburban area appear to be increasing, with an incidence greater than the national average. Children at greatest risk are less than 4 years old. Further research in injury prevention at the national level aimed at suburban areas may be warranted. 相似文献
46.
47.
The influence of children's self-report trait anxiety and depression on visual search for emotional faces 总被引:2,自引:0,他引:2
Hadwin JA Donnelly N French CC Richards A Watts A Daley D 《Journal of child psychology and psychiatry, and allied disciplines》2003,44(3):432-444
BACKGROUND: This study presents two experiments that investigated the relationship between 7- and 10-year-olds' levels of self-report trait anxiety and depression and their visual search for threatening (angry faces) and non-threatening (happy and neutral faces) stimuli. METHOD: In both experiments a visual search paradigm was used to measure participants' reaction times to detect the presence or absence of angry, happy or neutral schematic faces (Experiment 1) or cartoon drawings (Experiment 2). On target present trials, a target face was displayed alongside three, five or seven distractor items. On target absent trials all items were distractors. RESULTS: Both experiments demonstrated that on target absent (but not present) trials, increased levels of anxiety produced significantly faster search times in the angry face condition, but not in the neutral condition. In Experiment 2 there was some trend towards significance between anxiety and searches for happy faces in absent trials. There were no effects of depression on search times in any condition. CONCLUSION: The results support previous work highlighting a specific link between anxiety and attention to threat in childhood. 相似文献
48.
49.
Robbins J Aragaki AK Kooperberg C Watts N Wactawski-Wende J Jackson RD LeBoff MS Lewis CE Chen Z Stefanick ML Cauley J 《JAMA》2007,298(20):2389-2398
Context The 329 000 hip fractures that annually occur in the United States are associated with high morbidity, mortality, and cost. Identification of those at high risk is a step toward prevention. Objective To develop an algorithm to predict the 5-year risk of hip fracture in postmenopausal women. Design, Setting, and Participants A total of 93 676 women who participated in the observational component of the Women's Health Initiative (WHI), a multiethnic longitudinal study, were used to develop a predictive algorithm based on commonly available clinical features. Selected factors that predicted hip fracture were then validated by 68 132 women who participated in the clinical trial. The model was tested in a subset of 10 750 women who had undergone dual-energy x-ray absorptiometry (DXA) scans for bone mass density assessment. Main Outcome Measure The prediction of centrally adjudicated hip fracture, measured by the area under the receiver operator characteristic (ROC) curves. Results During a mean (SD) follow-up of 7.6 (1.7) years, 1132 hip fractures were identified among women participating in the observational study (annualized rate, 0.16%), whereas during a mean follow-up of 8.0 (1.7) years, 791 hip fractures occurred among women participating in the clinical trial (annualized rate, 0.14%). Eleven factors predicted hip fracture within 5 years: age, self-reported health, weight, height, race/ethnicity, self-reported physical activity, history of fracture after age 54 years, parental hip fracture, current smoking, current corticosteroid use, and treated diabetes. Receiver operating characteristic curves showed that the algorithm had an area under the curve of 80% (95% confidence interval [CI], 0.77%-0.82%) when tested in the cohort of different women who were in the clinical trial. A simplified point score was developed for the probability of hip fracture. Receiver operating characteristic curves comparing DXA-scan prediction based on a 10% subset of the cohort and the algorithm among those who participated the clinical trial were similar, with an area under the curve of 79% (95% CI, 73%-85%) vs 71% (95% CI, 66%-76%). Conclusion This algorithm, based on 11 clinical factors, may be useful to predict the 5-year risk of hip fracture among postmenopausal women of various ethnic backgrounds. Further studies are needed to assess the clinical implication of the algorithm in general and specifically to identify treatment benefits. 相似文献
50.