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   19508篇
  免费   1570篇
  国内免费   71篇
耳鼻咽喉   169篇
儿科学   628篇
妇产科学   535篇
基础医学   2951篇
口腔科学   287篇
临床医学   2252篇
内科学   3863篇
皮肤病学   593篇
神经病学   1947篇
特种医学   492篇
外科学   1882篇
综合类   164篇
一般理论   20篇
预防医学   2237篇
眼科学   345篇
药学   1170篇
中国医学   36篇
肿瘤学   1578篇
  2024年   41篇
  2023年   280篇
  2022年   506篇
  2021年   963篇
  2020年   588篇
  2019年   765篇
  2018年   825篇
  2017年   624篇
  2016年   707篇
  2015年   721篇
  2014年   884篇
  2013年   1140篇
  2012年   1647篇
  2011年   1686篇
  2010年   853篇
  2009年   748篇
  2008年   1157篇
  2007年   1174篇
  2006年   1000篇
  2005年   971篇
  2004年   887篇
  2003年   791篇
  2002年   681篇
  2001年   118篇
  2000年   92篇
  1999年   109篇
  1998年   132篇
  1997年   110篇
  1996年   77篇
  1995年   84篇
  1994年   66篇
  1993年   48篇
  1992年   46篇
  1991年   54篇
  1990年   59篇
  1989年   31篇
  1988年   35篇
  1987年   32篇
  1986年   24篇
  1985年   34篇
  1984年   34篇
  1983年   28篇
  1982年   22篇
  1981年   37篇
  1980年   24篇
  1979年   18篇
  1978年   28篇
  1976年   14篇
  1973年   16篇
  1971年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Recently, it has been reported that ingenol mebutate (IM) is an effective treatment option for anogenital warts (AGW), inducing fast wart necrosis within 24 hours in vivo. With regard to its mode of action, IM is thought to act both as an inducer of direct cytotoxic effects and immunologic mechanisms. To distinguish whether the wart necrosis is mainly caused by cytotoxic effects, or whether immune mechanisms are leading, we used time‐lapse imaging to analyse IM‐treated warts ex vivo over 24 hours. Ex vivo IM‐treated warts, which have been detached from the immune system, did not show destructive necrosis, pointing towards a primarily immune‐driven mode of action of IM in the treatment of AGW.  相似文献   
992.
This study examined associations between three parent–child engagement states and social communication, expressive language, and receptive language at 8 month follow-up, in 63 preschool-age children with autism spectrum disorder. We extend the literature on supported joint engagement by dividing this state into higher order (HSJE) and lower order types, with HSJE involving greater reciprocity in toy play. We also examined parents’ follow-in utterances that co-occurred with each state. We found that only HSJE predicts later social communication and expressive language, while object engagement predicts receptive language. HSJE combined with follow-in utterances (HSJE+FI) predicts all three outcomes when controlling for HSJE+FI in other engagement states. When controlling for total HSJE, HSJE+FI is predictive of receptive language.  相似文献   
993.
994.
We evaluated the efficacy of a peer-educator network intervention as a strategy to reduce HIV acquisition among injection drug users (IDUs) and their drug and/or sexual networks. A randomized controlled trial was conducted in St. Petersburg, Russia among IDU index participants and their risk network participants. Network units were randomized to the control or experimental intervention. Only the experimental index participants received training sessions to communicate risk reduction techniques to their network members. Analysis includes 76 index and 84 network participants who were HIV uninfected. The main outcome measure was HIV sero-conversion. The incidence rates in the control and experimental groups were 19.57 (95 % CI 10.74–35.65) and 7.76 (95 % CI 3.51–17.19) cases per 100 p/y, respectively. The IRR was 0.41 (95 % CI 0.15–1.08) without a statistically significant difference between the two groups (log rank test statistic X2 = 2.73, permutation p value = 0.16). Retention rate was 67 % with a third of the loss due to incarceration or death. The results show a promising trend that this strategy would be successful in reducing the acquisition of HIV among IDUs.  相似文献   
995.
ObjectiveWe aimed to iteratively refine an implementation model for managing cloud-based longitudinal care plans (LCPs) for children with medical complexity (CMC).Materials and MethodsWe conducted iterative 1-on-1 design sessions with CMC caregivers (ie, parents/legal guardians) and providers between August 2017 and March 2019. During audio-recorded sessions, we asked participants to walk through role-specific scenarios of how they would create, review, and edit an LCP using a cloud-based prototype, which we concurrently developed. Between sessions, we reviewed audio recordings to identify strategies that would mitigate barriers that participants reported relating to 4 processes for managing LCPs: (1) taking ownership, (2) sharing, (3) reviewing, and (4) editing. Analysis informed iterative implementation model revisions.ResultsWe conducted 30 design sessions, with 10 caregivers and 20 providers. Participants emphasized that cloud-based LCPs required a team of owners: the caregiver(s), a caregiver-designated clinician, and a care coordinator. Permission settings would need to include universal accessibility for emergency providers, team-level permission options, and some editing restrictions for caregivers. Notifications to review and edit the LCP should be sent to team members before and after clinic visits and after hospital encounters. Mitigating double documentation barriers would require alignment of data fields between the LCP and electronic health record to maximize interoperability.DiscussionThese findings provide a model for how we may leverage emerging Health Insurance Portability and Accountability Act–compliant cloud computing technologies to support families and providers in comanaging health information for CMC.ConclusionsUtilizing these management strategies when implementing cloud-based LCPs has the potential to improve team-based care across settings.  相似文献   
996.
997.
998.
999.
BACKGROUND: The aim of the study was to derive a donor arm disinfection technique that was rapid, but with a disinfection efficacy equivalent to a previous "best-practice" technique. This method consisted of a two-stage procedure with an initial application of 70% isopropyl alcohol and then 2% tincture of iodine (IATI). The total time for the IATI method was 2 minutes in duration. A rapid technique (1 min in duration) was needed to obviate potential problems due to increased donor waiting time, had the IATI method been implemented at blood donation sessions.
STUDY DESIGN AND METHODS: A direct swabbing and plating technique was used to enumerate bacteria present before and after disinfection. In total, seven methods were evaluated.
RESULTS: The chlorhexidine/alcohol applicator (CAA) disinfection device containing 1.5 mL of 2% chlorhexidine gluconate and 70% isopropyl alcohol (99.91% reduction; confidence limits, 99.55%, 99.98%) was shown to have equivalent disinfection efficacy as the IATI method (99.89% reduction; confidence limits, 99.36%, 99.98%; p = 0.86). Procedural time for the 1.5-mL CAA method was 1 minute thereby avoiding potential problems of increased donor waiting time, inherent in the IATI 2-minute procedure at blood donation sessions.
CONCLUSIONS: The 1.5-mL CAA disinfection method offers blood services a rapid and effective donor arm disinfection procedure. In 2006, the 1.5-mL CAA procedure was implemented throughout the entire English blood service for all donations.  相似文献   
1000.
X-ray fluorescence tomography promises to map elemental distributions in unstained and unfixed biological specimens in three dimensions at high resolution and sensitivity, offering unparalleled insight in medical, biological, and environmental sciences. X-ray fluorescence tomography of biological specimens has been viewed as impractical—and perhaps even impossible for routine application—due to the large time required for scanning tomography and significant radiation dose delivered to the specimen during the imaging process. Here, we demonstrate submicron resolution X-ray fluorescence tomography of a whole unstained biological specimen, quantifying three-dimensional distributions of the elements Si, P, S, Cl, K, Ca, Mn, Fe, Cu, and Zn in the freshwater diatom Cyclotella meneghiniana with 400-nm resolution, improving the spatial resolution by over an order of magnitude. The resulting maps faithfully reproduce cellular structure revealing unexpected patterns that may elucidate the role of metals in diatom biology and of diatoms in global element cycles. With anticipated improvements in data acquisition and detector sensitivity, such measurements could become routine in the near future.  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