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   45404篇
  免费   2308篇
  国内免费   202篇
耳鼻咽喉   170篇
儿科学   1354篇
妇产科学   655篇
基础医学   3208篇
口腔科学   725篇
临床医学   6033篇
内科学   5866篇
皮肤病学   394篇
神经病学   2002篇
特种医学   536篇
外科学   2342篇
综合类   4527篇
现状与发展   1篇
一般理论   5篇
预防医学   16033篇
眼科学   223篇
药学   2261篇
  19篇
中国医学   533篇
肿瘤学   1027篇
  2024年   46篇
  2023年   904篇
  2022年   1491篇
  2021年   2198篇
  2020年   2142篇
  2019年   3018篇
  2018年   2618篇
  2017年   1753篇
  2016年   1240篇
  2015年   1420篇
  2014年   3344篇
  2013年   3198篇
  2012年   2836篇
  2011年   3099篇
  2010年   2379篇
  2009年   2206篇
  2008年   2123篇
  2007年   2011篇
  2006年   1533篇
  2005年   997篇
  2004年   821篇
  2003年   641篇
  2002年   527篇
  2001年   462篇
  2000年   395篇
  1999年   338篇
  1998年   278篇
  1997年   228篇
  1996年   142篇
  1995年   135篇
  1994年   111篇
  1993年   104篇
  1992年   92篇
  1991年   64篇
  1990年   50篇
  1989年   41篇
  1988年   32篇
  1985年   260篇
  1984年   374篇
  1983年   303篇
  1982年   310篇
  1981年   304篇
  1980年   249篇
  1979年   244篇
  1978年   207篇
  1977年   152篇
  1976年   139篇
  1975年   119篇
  1974年   103篇
  1973年   78篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
BackgroundDuring their training, students in osteopathy regularly undergo spinal manipulation exercises. This exposes the students’ spine to unskilled gestures performed by their colleagues learning spinal manipulation. Discomfort, muscle soreness or moderate pain following spinal manipulations lasting two or three days are commonly reported. In addition, some students may have ongoing spinal musculoskeletal disease (SMSD) during their studies. The purpose of this study was to evaluate the prevalence of SMSDs and their maximum intensity in a population of osteopathy students and to determine whether individual differences exist.MethodAn exploratory cross-sectional study took place over three years. Data were collected by means of a self-administrated standardised questionnaire screening for MSD: the Nordic questionnaire.ResultsThere were 733 exploitable questionnaires, giving an average response rate of 91.5%. Average prevalence of SMSD was 98.4% during the last 12 months. Average maximum intensity perceived was 6/10 and 45% of students experienced an intense SMSD (scored between 7 and 10/10). Variation of the maximum intensity of SMSD between “before osteopathy studies” and “the last 12 months” was 1.2/10. This variation was influenced by the number of days students were manipulated during a week (p < 0.0001). On average, students underwent manipulation three days a week.ConclusionThis study confirms the important prevalence of SMSD among osteopathy students. This result led us to carry out a qualitative study for exploring students’ conceptions in health and spinal manipulative practices.  相似文献   
32.
《Vaccine》2020,38(46):7372-7378
BackgroundTheories of health behavior change are being inadequately adopted to understand the reasons behind low influenza vaccination rates among healthcare workers (HCWs). The Theory of Planned Behavior (TPB) is being used to predict intention-behavior relationship while the Health Belief Model (HBM) is being employed to predict actual behavior. The purpose of this study was to test a conceptual model based on the HBM’s constructs to predict Jordanian HCWs’ intentions for influenza vaccine uptake as an alternative to the TPB.MethodA cross-sectional questionnaire-based study was conducted in 2016 in a tertiary teaching hospital in Amman-Jordan including a convenience sample of 477 HCWs with direct patient contact. The study instrument was tested for validity and reliability. A conceptual regression model was proposed incorporating the constructs of the primary HBM with some modifications in the threat construct as well as an additional variable about explicit past vaccination behavior (in the past year and/or any previous history of influenza vaccine uptake).ResultsAlmost all the constructs of the HBM demonstrated significant differences between participants intending and those who did not intend to vaccinate against influenza. After adjusting for the confounding variables in the final conceptual regression model, past vaccination behavior (OR= 4.50, 95%Confidence Interval 3.38–6.00, P< 0.0005) and the perceived benefit scale (OR= 1.19, 95% Confidence Interval 1.11–1.28, P< 0.0005) were the only significant predictors of intentions to vaccinate against influenza in the next season.ConclusionTaking into consideration the altruistic beliefs of HCWs and their explicit past vaccination history augments the utility of the original HBM tool in predicting HCWs’ intentions to vaccinate against influenza in a way that is consistent with the predictive ability of the Theory of Planned Behavior.  相似文献   
33.
《Vaccine》2016,34(43):5155-5158
BackgroundGrowing conflict and insecurity played a major role in precipitating polio outbreaks in the Horn of Africa and the Middle East. In Angola, the early post-conflict situation was characterized by the presence of many inaccessible zones and districts due to insecurity and poor infrastructure. Partnership with the Angolan Army health service (AAHS) was one of the innovative strategies that the Polio Eradication Initiative (PEI) introduced into the country to support the polio vaccination campaigns in insecure and hard to reach zones.MethodsBefore embarking on creating a partnership with Angolan military it was essential to make high-level advocacy with top military decision makers to engage the leadership in the process for better and sustainable support to the strategy. The principal supports provided by the AAHS were the administration of oral polio vaccine, vitamin A, deworming agents, social mobilization, monitoring campaign quality, and surveillance. Distribution of logistics using military vehicles and helicopters to hard to reach and insecure zones was also part of the support.ResultsUsing this partnership it was possible to reach a significant number of children in insecure and hard to reach areas with polio vaccine and other child survival interventions. The military partnership also contributed in increasing the demand and addressing rejection for the polio vaccine.ConclusionMilitary is a potentially productive force that can be used for any development activities in any country. The Angolan experience has demonstrated that it is possible to form a partnership with the military for basic health intervention activities with little training and investment.  相似文献   
34.

Purpose

This study aimed to investigate 3 planning target volume (PTV) margin expansions and determine the most appropriate volume to be used in bladder preservation therapy when using daily cone beam computed tomography (CBCT). We aimed to establish whether a smaller PTV expansion is feasible without risking geographical miss.

Methods and materials

The study included patients with bladder cancer who were treated with a hypofractionated course of radiation therapy delivered with intensity modulated radiation therapy. The clinical target volume (CTV) was the whole empty bladder, and the PTV consisted of a 1.5-cm margin around the bladder (PTV1.5 cm). Patients underwent daily CBCT imaging before treatment to assess the bladder volume and ensure accurate positioning. We investigated 2 additional smaller PTV margin expansions to determine the most appropriate volume to be used with CBCT as a daily image guided radiation therapy modality. These margins were created retrospectively on every CBCT. The first additional volume was a uniform PTV margin of the surrounding 1 cm (PTV1 cm). When considering that the majority of the internal bladder movement was due to the variation in filling that occurs in the superior and anterior directions, a second volume of an anisotropic PTV margin with a 1.5-cm superior/anterior and 1 cm in other directions (PTV1/1.5 cm) was created. We recorded the frequency and measured the volume of bladder falling out of each PTV based on the daily CBCT.

Results

For the purpose of this study, we considered an arbitrary 5 cm3 of CTV falling out of the designated PTV as a clinically significant volumetric miss. The frequency of such a miss when applying the uniform PTV1 cm was 1%. However, when applying the uniform PTV1.5 cm and anisotropic PTV1/1.5 cm margins, the frequency was 0.5% and 0.5%, respectively.

Conclusions

The anisotropic PTV expansion of 1.5 cm superiorly and anteriorly and 1 cm in all other directions around the bladder (CTV) provides a safe PTV approach when daily CBCT imaging is used to localize an empty bladder.  相似文献   
35.
36.
ObjectiveTo measure incidence and main risk factors related to sexually transmitted infections (STIs) in Daroca Prison (Zaragoza, Spain).MethodA retrospective cohort study (2005-2013) to measure the incidence of STI and a cross-sectional study to measure risk factors.ResultsOf the 203 inmates, 79 developed an STI, 37 had a previous STI, 55.2% lacked knowledge on STI prevention, and 28.9% showed behaviours unfavourable for STI prevention. The incidence rate was 6.5 STIs per 1,000 inmates-year. The most frequent STIs were hepatitis B (39.7%), Ureaplasma urealyticum (19.1%), herpes simplex (16.2%) and HIV (8.8%). The risk (hazard ratio, HR) of acquiring a new STI was significantly higher in inmates with a history of previous STI (HR = 2.61; 95%CI: 1.01 to 6.69), and was at the limit of significance for non-preventive behaviour (HR = 2.10; 95%CI: 0.98 to 4.53), but not in knowledge related to STIs (HR = 1.33; 95%CI: 0.58 to 3.07).ConclusionThe most important risk factors in prison are behaviours related to STIs and previous history of STIs. Other factors are being a repeat offender, injecting drug use, or being in a methadone programme. Health personnel and peer education can facilitate prevention and control.  相似文献   
37.
目的 探讨聚焦解决护理模式结合健康教育对银屑病患者心理状态、应对方式的影响。方法 选取2020年2月至2021年2月我院收治的100例银屑病患者,随机分为观察组(聚焦解决护理模式结合健康教育)与对照组(常规健康教育)。比较两组的心理状态及应对方式。结果 干预后,观察组的焦虑自评量表(SAS)、抑郁自评量表(SDS)评分低于对照组(P<0.05)。干预后,观察组的面对评分高于对照组,屈服、回避评分低于对照组(P<0.05)。干预后,观察组的病耻感评分低于对照组(P<0.05)。结论 聚焦解决护理模式结合健康教育可有效改善银屑病患者的不良情绪,减轻病耻感,转变疾病应对方式。  相似文献   
38.
《Vaccine》2019,37(35):5059-5066
Background: Hepatitis B virus (HBV) infection is highly endemic in most low income countries including Cambodia. This nationwide serosurvey was conducted to assess the impact of hepatitis B vaccination and to determine whether Cambodia met the WHO regional 2017 target of hepatitis B surface antigen (HBsAg) seroprevalence less than 1% in five-year-old children.Methods: A cross-sectional multi-stage cluster survey was conducted among children born during 2010–2012 and their mothers in Cambodia. HBsAg prevalence was estimated by rapid point-of-care testing, and demographic data, including vaccination history, was collected. Vaccine coverage in children and the prevalence of HBsAg among children and mothers was calculated taking into account the complex survey design. Factors associated with children’s failure to receive timely (within 24 h) vaccination were analysed by multivariate logistic analysis.Findings: A total of 2,520 children 5–7 years old and 2,028 mothers were recruited. In total, 78.4% of children received hepatitis B vaccination birth-dose (HepB-BD); of these, 58.7% were administered ≤ 24 h. Birth at home or “other” location were independent risk factors for children’s failure to receive timely HepB-BD. Overall HBsAg seroprevalence was 4.39% (95%CI: 3.53%–5.45%) among mothers and 0.56% (95%CI: 0.32%–0.98%) among children. The prevalence among children without hepatitis B vaccination was 4.62% (95%CI: 1.31%–14.97%). Among children with a HBsAg-positive mother, prevalence was 10.11% (95%CI: 5.41%–18.11%).Interpretation: Having achieved the 2017 target of less than 1% HBsAg prevalence among 5 years old children, Cambodia can now focus on eliminating mother-to-child transmission of HBV. Moreover, the high HBsAg prevalence among mothers suggests that routine screening with proper linkage to care and treatment is needed. Strengthening measures to improve vaccination coverage further and eliminate mother-to-child transmission by coordinated programming with other services offering additional HBV interventions will help move towards the global goal of hepatitis B elimination by 2030.Funding: As per sources of funding.  相似文献   
39.
ImportanceImmunotherapy has emerged as an effective treatment option for the management of advanced cancers. The effects of these immune checkpoint inhibitors in the older patient population has not been adequately assessed.ObjectiveTo understand the impact of aging on CTLA-4 and PDL-1 inhibitors efficacy and immune-related adverse events (irAE) in the context of real-world management of advanced solid cancers.Design, Setting, and ParticipantsThis retrospective study involved all non-study patients with histologically-confirmed metastatic or inoperable solid cancers receiving immunotherapy at Kingston Health Sciences Centre. We defined ‘older patient’ as age ≥ 75. All statistical analyses were conducted under SPSS IBM for Windows version 24.0.Main Outcomes and MeasuresStudy outcomes included immunotherapy treatment response, survival, as well as number, type, and severity of irAEs.ResultsOur study (N = 78) had 29 (37%) patients age <65, 26 (33%) patients age 65–74, and 23 (30%) patients age ≥75. Melanoma, non-small cell lung cancer, and renal cell carcinoma accounted for 70%, 22%, and 8% of the study population, respectively. Distributions of ipilimumab (32%), nivolumab (33%), and pembrolizumab (35%) were similar in the study. The response rates were 28%, 27%, and 39% in the age <65, age 64–74, age ≥75 groups, respectively (P = 0.585). Kaplan-Meier curve showed a median survival of 28 months (12.28–43.9, 95% CI) and 17 months (0–36.9, 95% CI) in the age <65 and age 64–74 groups, respectively; the estimated survival probability did not reach 50% in the age ≥75 group (P = 0.319). There were no statistically significant differences found in terms of irAEs, multiple irAEs, severity of grade 3 or higher, types of irAEs, and irAEs resolution status when comparing between different age groups.Conclusion and RelevanceOur results suggest that patients age ≥75 are able to gain as much benefit from immunotherapy as younger patients, without excess toxicity. Our findings suggest that single agent immunotherapy is generally well-tolerated across different age groups with no significant difference in the type, frequency or severity of irAEs. Future studies evaluating aging and combination immunotherapy are warranted.  相似文献   
40.
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