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   579篇
  免费   33篇
  国内免费   6篇
耳鼻咽喉   3篇
儿科学   22篇
妇产科学   15篇
基础医学   73篇
口腔科学   16篇
临床医学   42篇
内科学   94篇
皮肤病学   14篇
神经病学   11篇
特种医学   46篇
外科学   71篇
综合类   82篇
预防医学   68篇
眼科学   6篇
药学   23篇
中国医学   2篇
肿瘤学   30篇
  2023年   5篇
  2022年   5篇
  2021年   12篇
  2020年   4篇
  2019年   6篇
  2018年   9篇
  2017年   6篇
  2016年   15篇
  2015年   13篇
  2014年   19篇
  2013年   29篇
  2012年   32篇
  2011年   23篇
  2010年   29篇
  2009年   26篇
  2008年   29篇
  2007年   34篇
  2006年   24篇
  2005年   15篇
  2004年   19篇
  2003年   17篇
  2002年   12篇
  2001年   14篇
  2000年   6篇
  1999年   19篇
  1998年   23篇
  1997年   16篇
  1996年   17篇
  1995年   7篇
  1994年   11篇
  1993年   10篇
  1992年   6篇
  1991年   6篇
  1990年   7篇
  1989年   17篇
  1988年   6篇
  1987年   4篇
  1986年   7篇
  1985年   6篇
  1984年   3篇
  1983年   5篇
  1980年   2篇
  1979年   3篇
  1978年   2篇
  1977年   2篇
  1976年   3篇
  1973年   7篇
  1972年   2篇
  1971年   2篇
  1967年   9篇
排序方式: 共有618条查询结果,搜索用时 15 毫秒
1.
Background and aimsWorldwide the COVID-19 pandemic has accelerated sufferings of mental health and behaviour attitudes of people. Many countries, including Bangladesh, reported suicide as extreme consequences of the psychological burden influenced by COVID-19. The present study explores human stress and its factor influenced by COVID-19 in Bangladesh, which significantly affect the quality of life.MethodsAn online-based questionnaire survey was conducted among 651 adult Bangladeshi populations by capturing socio-demographic information, possible human stress, and consequences of the pandemic. A set of statistical tools such as Pearson's Correlation Matrix (PCM), T-test, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were applied to identify the relationship between different factors and influential factors increasing human stress.ResultsMore than 83% of the participants are facing COVID-19 related mental stress, which results in short temper, sleep disorder, and family chaos. PCA and HCA outcomes indicated a significant relationship between the respondents' opinions and human stress factors, which harmonized with the country's existing scenario. PCM results enlighten the relationship between human stress factors and found financial hardship, cutting back daily spending, and food crisis are interconnected together causes stress. Also, hampering students' formal education and future career plans significantly contribute to mental stress.ConclusionBased on the above findings, it's crucial to introduce a time-oriented strategy and implement precaution monitoring plans for Bangladesh. The rescue plan will help people to manage the pandemic and improve mental health to fight against psychological challenges related to COVID-19 and future pandemics.  相似文献   
2.
3.
Between 1986–1990, 290 patients with squamouscell carcinoma of the hypopharynx were assessed at the S. S. K. M. Hospital Calcutta, out of the total of 1460 number of Head Neck cancer, (19.8%). The most frequent initial symptom was a foreign body sensation in the throat (70%), and males were affected more than females (9.8 : 1.2). The peak age incidence was found between 40 and 50 years (24%). Most of the patients came in advanced stages with cervical lymph node metastases (60%). One interesting fact that came out from the present study is the Right pyriform fassa was more commonly affected than the left in righthanded persons (56.9%). Though the reason is not clear it could be due to right — sided swallow, as one side may be predominant in funtion.  相似文献   
4.
5.
Needle core biopsy guided with mammography: a study of cost- effectiveness   总被引:2,自引:0,他引:2  
Lindfors  KK; Rosenquist  CJ 《Radiology》1994,190(1):217
  相似文献   
6.
7.
Retinoyl β-glucuronide is a naturally occurring, biologically active metabolite of vitamin A. Although retinoyl β-glucuronide is regarded as a detoxification product of retinoic acid, it plays several roles in the functions of vitamin A. It can serve as a source of retinoic acid, and it may be a vehicle for transport of retinoic acid to target tissues. Topically applied retinoyl β-glucuronide is comparable in efficacy to retinoic acid in the treatment of acne in humans, without the same side effects. Retinoyl β-glucuronide may or may not be teratogenic, depending on the mode of administration and the species in which it is used. It may be a valuable therapeutic compound for the treatment of skin disorders and certain types of cancers.  相似文献   
8.
The clinical significance of specimens with low sample-to-cutoff (S/Co) ratios in the Ortho VITROS chemiluminescence assay (CIA) for detection of antibodies to hepatitis C virus (HCV) was evaluated. In one study of 482 CIA-reactive samples, none of the 83 samples with S/Co ratios of < 5 was HCV RNA positive. In a subsequent study, 332 samples with S/Co ratios of between 1 and 20 were tested with the recombinant immunoblot assay (RIBA). None of the 163 samples with S/Co ratios of < 5 was RIBA positive, 83% were RIBA negative, and 28 samples (18%) were RIBA indeterminate. HCV RNA and/or clinical evidence of hepatitis was not found in the 27 indeterminate cases examined. These results show that over 99% of samples with very low S/Co ratios (< or = 5) have no evidence of HCV infection. Therefore, we suggest that the HCV antibody testing algorithm for the VITROS assay might be modified to eliminate supplemental testing of samples with very low S/Co ratios.  相似文献   
9.
This paper describes the tragic case of a young woman who died of cancer of the colon after successfully donating eggs to her younger sister. Although there is no direct link between her operation and the subsequent development of bowel carcinoma, this case imparts a feeling of unease when seen in conjunction with other cases reported during the last few years. It is a reminder that little is known of the long-term consequences of some aspects of assisted conception. Women undergoing ovarian stimulation for themselves or a matched recipient have the right to be advised, in an agreed format, that there is some concern about unproven potential risks from the stimulatory drugs. The safety of egg donors must assume priority over all other considerations, including lack of donors or any moral position. The recent decision by the Human Fertilisation and Embryology Authority (HFEA) to withdraw any form of payment or recompense to egg donors does not seem to us to be based on a balance of scientific advances, patient needs and the ethics of gamete supply. They state that the intention to withdraw payments was implicit in the 1990 Human Fertilisation and Embryology (HFE) Act. However the Act was based on the Warnock report made 6 years earlier. Even in 1990 ovum donation was uncommon and fertility drugs had not yet caused any unease. The Act provided the HFEA with discretionary powers to issue directions so that the future policies would be consistent with any emerging new medical evidence. It is imperative that the HFEA provide convincing evidence on how the current policy of payment to donors harms society, donors or recipients, and how in the UK the new policy will improve medical practice in assisted conception. Successful pilot studies must precede the implementation of any new policy. Failure to do this could cause irreversible harm to the practice of assisted conception using donor gametes, which will ultimately be against the basic aims of the 1990 HFE Act.   相似文献   
10.
Parathyroid hormone secretion is negatively regulated by a 7- transmembrane domain, G-protein coupled Ca(2+)-sensing receptor. We hypothesized that activating mutations in this receptor might cause autosomal dominant hypoparathyroidism (ADHP). Consistent with this hypothesis, we identified, in two families with ADHP, heterozygous missense mutations in the Ca(2+)-sensing receptor gene that cosegregated with the disorder. None of 50 normal controls had either mutation. We also identified a de novo, missense Ca(2+)-sensing receptor mutation in a child with severe sporadic hypoparathyroidism. The amino acid substitution in one ADHP family affected the N-terminal, extracellular domain of the receptor. The other mutations involved the transmembrane region. Unlike patients with acquired hypoparathyroidism, patients with these mutations had hypercalciuria even at low serum calcium concentrations. Their greater hypercalciuria presumably reflected activation of Ca(2+)-sensing receptors in kidney cells, where the receptor negatively regulates calcium reabsorption. This augmented hypercalciuria increases the risk of renal complications and thus has implications for the choice of therapy.   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