首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   18836篇
  免费   2191篇
  国内免费   357篇
耳鼻咽喉   392篇
儿科学   939篇
妇产科学   1093篇
基础医学   1793篇
口腔科学   185篇
临床医学   1966篇
内科学   2678篇
皮肤病学   161篇
神经病学   868篇
特种医学   473篇
外国民族医学   3篇
外科学   1234篇
综合类   1309篇
现状与发展   2篇
预防医学   2782篇
眼科学   501篇
药学   1914篇
  13篇
中国医学   369篇
肿瘤学   2709篇
  2024年   72篇
  2023年   444篇
  2022年   727篇
  2021年   960篇
  2020年   941篇
  2019年   945篇
  2018年   853篇
  2017年   860篇
  2016年   916篇
  2015年   867篇
  2014年   1324篇
  2013年   1849篇
  2012年   1057篇
  2011年   1115篇
  2010年   900篇
  2009年   856篇
  2008年   873篇
  2007年   815篇
  2006年   699篇
  2005年   595篇
  2004年   498篇
  2003年   491篇
  2002年   343篇
  2001年   314篇
  2000年   231篇
  1999年   236篇
  1998年   204篇
  1997年   187篇
  1996年   140篇
  1995年   134篇
  1994年   121篇
  1993年   100篇
  1992年   108篇
  1991年   76篇
  1990年   81篇
  1989年   53篇
  1988年   57篇
  1987年   50篇
  1986年   41篇
  1985年   55篇
  1984年   36篇
  1983年   30篇
  1982年   29篇
  1981年   27篇
  1980年   16篇
  1979年   11篇
  1978年   11篇
  1977年   8篇
  1976年   9篇
  1973年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
BACKGROUND: Since the introduction of the Pap smear screening, the incidence of squamous cell carcinoma (SCC) has decreased significantly, but the incidence of adenocarcinoma (AC) relative to SCC has increased. AIM: To compare the Pap smear history of patients with AC and SCC of the cervix. METHODS: Patients for the study were identified from the database of Queensland Centre for Gynaecological Cancer. Patients with AC and SCC were matched for age at diagnosis and International Federation of Gynecology and Obstetrics stage. The final population included 188 matched pairs, being 376 patients in total. Data were collected upon the histological type of cancer, result of the most recent Pap smear, date and result of the Pap smear prior to the most recent Pap smear and symptoms. Chi-squared tests and Fisher's exact test were used to compare the two patient groups for several variables. RESULTS: Patients with AC had significantly more false-negative results on their most recent Pap smear (P<0.0001) than patients with SCC. The incidence of symptoms such as bleeding and/or vaginal discharge was comparable in patients with AC and SCC. The time between the most recent Pap smear and the diagnosis of cervical cancer was significantly shorter for patients with AC (P=0.01). CONCLUSIONS: Patients with AC had Pap smears more regularly than those with SCC, and their most recent Pap smear was significantly more likely to be normal. Thus, Pap smear prior to a diagnosis of AC is more likely than SCC false-negative and therefore not indicative of cervical cancer.  相似文献   
102.
康利克  郑红雨  李燕  邬华  沈桂新 《医学综述》2011,17(14):2197-2199
目的探讨时间-空间相关成像技术(STIC)在胎儿产前心脏筛查的应用价值。方法分别使用常规超声及STIC技术检查孕21~28周心脏正常的胎儿200例,分析STIC的图像质量、图像信息及扫查时间与常规超声之间的差异。结果使用STIC技术下200例胎儿心脏均获得满意的容积数据。脱机分析所获得的心脏各切面图像质量与常规超声图像质量无显著性差异(P>0.05),并且能获得常规超声不能显示的图像资料。采集STIC容积信息的平均扫描时间(5.12±2.56)min,采集常规超声所需各切面的平均扫描时间(6.78±3.11)min。结论 STIC扫描可以缩短检查时间,减低对检查者的经验依赖,减少对胎儿的超声照射,能提供与常规超声一致的图像质量及更多的心脏切面图像和信息。  相似文献   
103.
目的:检测试剂和手持式光电比色仪联用的方法,实现对污染食品中氰化物的现场快速定量检测。方法:通过氰化物在碱性条件下,CN-可催化茚三酮自身氧化还原反应,迅速生成红棕色产物(485 nm),其呈色深浅与氰化物含量成一定相关性,于手持式光电比色仪实现定量测定。结果:氰化物浓度在0.0~0.5 mg/L范围内线性关系良好(r=0.9957);方法的检出限为0.05 mg/kg、加标回收率为84%~106%。并与国家标准方法检测结果一致。结论:试剂-光电比色仪方法用于氰化物的现场定量检测具有简便、快速、携带方便等特点,值得推广应用。  相似文献   
104.
Due to the absence of easily applicable cut‐off points to determine high blood pressure or hypertension in children, as in the adult population, blood pressure is rarely measured in the pediatrician''s clinical routine. This has led to an underdiagnosis of high blood pressure or hypertension in children. For this reason, the present study evaluate the utility of five equations for the screening of high blood pressure in children: blood pressure to height ratio, modified blood pressure to height ratio, new modified blood pressure to height ratio, new simple formula and height‐based equations. The authors evaluated 1599 children between 5 and 18 years. The performance of the five equations was analyzed using the receiver‐operating characteristics curves for identifying blood pressure above P90th according to the American Academy of Pediatrics Clinical Practice Guideline 2017. All equations showed an area under the curve above 0.882. The new modified blood pressure to height ratio revealed a high sensitivity whereas the height‐based equations showed the best performance, with a positive predictive value above 88.2%. Finally, all equations showed higher positive predictive values in children with overweight or obesity. The height‐based equation obtained the highest PPV values above 71.1% in children with normal weight and above 90.2% in children with overweight or obesity. In conclusions, the authors recommend the use of the height‐based equations equation because it showed the best positive predictive values to identify children with elevated blood pressure, independently of their sex, pubertal and weight status.  相似文献   
105.
106.
107.
Purpose:Anemia is common in adolescent girls. Apprehension while drawing blood to estimate hemoglobin concentration is a barrier for confirming anemia. ToucHb, a noninvasive instrument that estimates the hemoglobin by taking an image of the exposed conjunctiva, was used during eye screening to help diagnose and treat anemia.Methods:ToucHb was used during secondary school eye screening and during house-to-house eye screening to estimate the hemoglobin concentration in the body. Each of the girls was distributed a packet of 60 tablets of ferrous and folate and a tablet of albendazole. They were followed up after 3 months.Results:Exactly 1511 municipal school girls aged 10-19 years (mean 12.9; standard deviation [SD] 1.64) were examined. Of them, 949 (62.8%) had hemoglobin of ≤9 mg%. Among those girls with hemoglobin ≤9 mg%, the mean (SD) during the initial and follow-up examinations was 6.1 (1.4) and 9.6 (1.03), respectively, by paired t-test (P < 0.001). Another 588 girls (average age 14.4 years, SD 1.2) had their eyes examined and hemoglobin estimated during a house-to-house eye screening. Of them, 116 (19.7%) had hemoglobin level of ≤9 mg%. Their pre-Hb was 7.9 (SD 1.05) on average and after 3 months, it was 9.6 (SD 1.02). Among those girls with hemoglobin ≤9 mg%, the mean (SD) during the initial and follow-up examinations was 6.2 (1.4) and 7.9 (1.1), respectively, by paired t-test (P < 0.001)Conclusion:ToucHb was useful to diagnose anemia while doing eye screening and to ensure its treatment. Anemia diagnosis and management would enhance the health of adolescent girls.  相似文献   
108.
Purpose:To understand/assess ocular and functional vision impairment in children with multiple disabilities with a functional vision assessment battery in addition to standard ophthalmic examinations in an outreach setting.Methods:Seven schools for children with special needs, 243 children in total, were screened for ocular disorders and functional vision impairment through school camps.Results:Among them, 37% had refractive errors needing spectacle correction. With standard ocular testing methods, the visual impairment was around 32%, but when functional vision was assessed, the functional vision impairment amounted to 70% in these children. The presence of functional vision impairment was found to be independent of the associated disability. Assessment of visual capacities such as visual closure, saccade pursuits, optic ataxia, and developmental milestones early on can help in suspecting the presence of CVIConclusion:Children with multiple disabilities are more at risk of functional vision impairment, which significantly impairs their ability to function in daily life. A complete functional vision assessment becomes essential to plan early intervention for these children. The significant proportion of vision impairment and functional vision loss in our study indicates the need for coordinated structured programs to address vision-related problems in children with multiple disabilities.  相似文献   
109.
正交法筛选莪术油微球制备工艺   总被引:3,自引:0,他引:3  
目的通过正交设计法筛选出制备符合肝动脉栓塞要求的莪术油明胶微球的最佳工艺。方法以微球粒径、分布、栽药量、包封率等为指标,采用正交设计法优化微球的制备工艺。结果按优化工艺参数制备的微球外观形态良好,粒径符舍肝动脉栓塞的要求,平均载药量为9.45%,包封率为32.34%,平均收率为85,19%,重现性良好。结论确立的莪术油微球的制备工艺切实可行。   相似文献   
110.
Self-collection may provide an opportunity for innovation within population-based human papillomavirus (HPV) cervical cancer screening programs by providing an alternative form of engagement for all individuals. The primary objective was to determine willingness to self-collect a vaginal sample for primary HPV screening and factors that impact willingness in individuals who participated in the Human Papillomavirus For Cervical Cancer (HPV FOCAL) screening trial, a large randomized controlled cervical screening trial. A cross-sectional online survey was distributed between 2017 and 2018 to 13,176 eligible participants exiting the FOCAL trial. Bivariate and multivariable logistic regression assessed factors that influence willingness to self-collect on 4945 respondents. Overall, 52.1% of respondents indicated willingness to self-collect an HPV sample. In multivariable analysis, the odds of willingness to self-collect were significantly higher in participants who agreed that screening with an HPV test instead of a Pap test was acceptable to them (odds ratio (OR): 1.45 (95% confidence interval (CI): 1.15, 1.82), those who indicated that collecting their own HPV sample was acceptable to them (p < 0.001), and those with higher educational ascertainment (OR: 1.31, 95% CI: 1.12, 1.54). The findings offer insight into the intentions to self-collect in those already engaged in screening, and can inform cervical cancer screening programs interested in offering alternative approaches to HPV-based screening.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号