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   2591567篇
  免费   190153篇
  国内免费   7601篇
耳鼻咽喉   34408篇
儿科学   85527篇
妇产科学   71770篇
基础医学   364772篇
口腔科学   70000篇
临床医学   235021篇
内科学   517072篇
皮肤病学   62824篇
神经病学   213926篇
特种医学   100254篇
外国民族医学   744篇
外科学   388102篇
综合类   50458篇
现状与发展   5篇
一般理论   971篇
预防医学   196704篇
眼科学   56855篇
药学   188683篇
  8篇
中国医学   5378篇
肿瘤学   145839篇
  2021年   20413篇
  2019年   21076篇
  2018年   29837篇
  2017年   22990篇
  2016年   26636篇
  2015年   29867篇
  2014年   40975篇
  2013年   61123篇
  2012年   81071篇
  2011年   85388篇
  2010年   51574篇
  2009年   49651篇
  2008年   79604篇
  2007年   84423篇
  2006年   86079篇
  2005年   82146篇
  2004年   79091篇
  2003年   76295篇
  2002年   73569篇
  2001年   128523篇
  2000年   131438篇
  1999年   110574篇
  1998年   31312篇
  1997年   27955篇
  1996年   28258篇
  1995年   27406篇
  1994年   25094篇
  1993年   23434篇
  1992年   85173篇
  1991年   81580篇
  1990年   78793篇
  1989年   76067篇
  1988年   69484篇
  1987年   68006篇
  1986年   63545篇
  1985年   60525篇
  1984年   44967篇
  1983年   37980篇
  1982年   22480篇
  1981年   19997篇
  1979年   38973篇
  1978年   27459篇
  1977年   23266篇
  1976年   21513篇
  1975年   22829篇
  1974年   26790篇
  1973年   25376篇
  1972年   23753篇
  1971年   21957篇
  1970年   20185篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
ABSTRACT

Close observation of the interactions between a traumatised mother and her infant son provides information on the modes of transmission of psychic trauma in the mother–infant dyad. Following the presentation of a current literature review on the theme, the subject of “radioactive residue” and counter-transference in the transmission of psychic trauma from mother to infant will be illustrated through a clinical case study that focuses on a Haitian mother and her two-year-old infant son who has been referred to a “transitional care nursery” in urban Paris. The encounter with this mother–infant dyad is analysed through observing the quality of the interactions that take place between the mother and infant in order to determine how a particularly traumatic narrative impacts the mother–infant relationship, in addition to relations with the clinician. Mother and infant respond to one another through the emission and reception of “radioactive residues” as hypothesized by Gampel. This clinical case study shows that there is a need to consider transcultural factors and collective experience and history when analysing traumatic events. Additionally, the case study shows that counter-transference can be an effective clinical tool for gaining access to an infant's experience as the recipient of a traumatic narrative.  相似文献   
54.
55.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
56.

Purpose

Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy.

Methods

Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24 hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.< 8) and PMI (≥3vs.< 3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate.

Results

CTASI pc-ASPECTS, dichotomized at < 8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived.

Conclusion

PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.  相似文献   
57.
58.
Purpose: To use polymerase chain reaction (PCR) and Goldmann-Witmer coefficient (GWC) calculation to diagnose infectious uveitis.

Methods: Prospective cross-sectional study.

Results: Twenty-seven of 106 patients had positive PCR and/or GWC results on aqueous humor (AH) sampling and 15 of 27 (55.6%) were HIV-positive. Patients with non-anterior uveitis (NAU) were more likely to be HIV+ (p = 0.005). More than 1 possible pathogen was identified in 9 of 27 patients of whom 7 were HIV+. The final clinical diagnosis was discordant with AH findings in 9 of 27 cases. A positive EBV PCR result was associated with a discordant diagnosis (p = 0.001). All cases of herpetic anterior uveitis (42.9% HIV+) tested PCR-/GWC+ while all cases of herpetic NAU tested PCR+/GWC- (83.3% HIV+). All rubella virus cases were PCR+/GWC+.

Conclusion: PCR is useful to diagnose herpetic NAU in HIV+ patients while GWC is useful to diagnose herpetic anterior uveitis.  相似文献   

59.
To determine percent of patients without malignancy and ≤ 40 years of age with high cumulative radiation doses through recurrent CT exams and assess imaging appropriateness. From the cohort of patients who received cumulative effective dose (CED) of ≥ 100 mSv over a 5-year period, a sub-set was identified with non-malignant disease. The top 50 clinical indications leading to multiple CTs were determined. Clinical decision support (CDS) system scores were analyzed using a widely adopted standard of 1–3 (red) as “not usually appropriate,” 4–6 (yellow) “may or may not be appropriate,” and 7–9 (green) “usually appropriate.” Clinicians reviewed patient records to assess compliance with appropriate use criteria (AUC). 9.6% of patients in our series were with non-malignant conditions and 1.4% with age ≤ 40 years. CDS scores (rounded) were 2% red, 38% yellow, 27% green, and 33% unscored CTs. Clinical society guidelines for CT exams, wherever available, were followed in 87.5 to 100% of cases. AUCs were not available for several clinical indications as also referral guidelines for serial CT imaging. More than half of CT exams were unrelated to follow-up of a primary chronic disease. We are faced with a situation wherein patients in age ≤ 40 years require or are thought to require many CT exams over the course of a few years but the radiation risk creates concern. There is a fair number of conditions for which AUC are not available. Suggested solutions include development of CT scanners with lesser radiation dose and further development of appropriateness criteria.  相似文献   
60.
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