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   8840篇
  免费   503篇
  国内免费   39篇
耳鼻咽喉   55篇
儿科学   253篇
妇产科学   404篇
基础医学   1183篇
口腔科学   230篇
临床医学   668篇
内科学   2019篇
皮肤病学   276篇
神经病学   718篇
特种医学   264篇
外科学   1166篇
综合类   40篇
一般理论   4篇
预防医学   690篇
眼科学   126篇
药学   666篇
中国医学   29篇
肿瘤学   591篇
  2023年   66篇
  2022年   52篇
  2021年   179篇
  2020年   166篇
  2019年   246篇
  2018年   275篇
  2017年   198篇
  2016年   197篇
  2015年   197篇
  2014年   310篇
  2013年   387篇
  2012年   591篇
  2011年   530篇
  2010年   303篇
  2009年   307篇
  2008年   491篇
  2007年   460篇
  2006年   414篇
  2005年   398篇
  2004年   410篇
  2003年   300篇
  2002年   299篇
  2001年   195篇
  2000年   251篇
  1999年   201篇
  1998年   73篇
  1997年   62篇
  1996年   77篇
  1995年   69篇
  1994年   51篇
  1993年   52篇
  1992年   153篇
  1991年   161篇
  1990年   137篇
  1989年   124篇
  1988年   112篇
  1987年   92篇
  1986年   81篇
  1985年   85篇
  1984年   70篇
  1983年   66篇
  1982年   28篇
  1981年   35篇
  1979年   44篇
  1976年   29篇
  1975年   40篇
  1974年   33篇
  1973年   27篇
  1972年   27篇
  1966年   27篇
排序方式: 共有9382条查询结果,搜索用时 15 毫秒
1.
2.
3.
Shaving and other modes of epilation can cause undue anxiety, pain, or skin irritation in children. Here, we present hair trimming as a safe, painless, and cost‐effective alternative for patients with unwanted hair which may be performed indefinitely or until the child is old enough to direct management. In select cases, removing unwanted hair using this technique may facilitate dermatologic surveillance.  相似文献   
4.
5.
6.
Our objectives were to assess sperm alteration and adipose tissue (AT) genes expression related to steroid metabolism subsequent to fatty acids consumption. Twenty‐nine mature male mice were divided into: fat diet (FD; n = 15) and the control group (n = 14). FD group was fed with low level of trans and saturated fatty acids source for 60 days. Sperm parameters, levels of hormones and the mRNA abundance of the target genes in AT were assessed. The sperm concentration, total and progressive motilities were lower in FD group compared to that of control (p < 0.01). Blood estradiol levels increased in FD (p < 0.001), whereas no significant difference was observed in testosterone. The mRNA levels of StAR, CYP11A1, CYP17A1, 17βHSD7 and 17βHSD12 in AT of FD were higher than those of the control (p < 0.05). In contrast, mRNA level of Cyp19a1 in FD was significantly (p < 0.05) lower than that of control. 17βHSD12 and 17βHSD7 (as oestrogenic genes) increased, while 17βHSD5 and 17βHSD3 (as androgenic genes) remained unchanged, indicating that dietary trans/saturated fatty acids affect AT genes expression. Probably, sperm parameters were altered by increment of expression level of genes involved in oestrogenic metabolism rather than those engaged in androgenic metabolism after fatty acids consumption.  相似文献   
7.
8.
Autozygosity mapping (AM) is a technique utilised for mapping homozygous autosomal recessive (AR) traits and facilitation of genetic diagnosis. We investigated the utility of AM for the molecular diagnosis of heterogeneous AR disorders, using epidermolysis bullosa (EB) as a paradigm. We applied this technique to a cohort of 46 distinct EB families using both short tandem repeat (STR) and genome‐wide single nucleotide polymorphism (SNP) array‐based AM to guide targeted Sanger sequencing of EB candidate genes. Initially, 39 of the 46 cases were diagnosed with homozygous mutations using this method. Independently, 26 cases, including the seven initially unresolved cases, were analysed with an EB‐targeted next‐generation sequencing (NGS) panel. NGS identified mutations in five additional cases, initially undiagnosed due to the presence of compound heterozygosity, deep intronic mutations or runs of homozygosity below the set threshold of 2 Mb, for a total yield of 44 of 46 cases (95.7%) diagnosed genetically.  相似文献   
9.
Background: As professionals, social workers have a special position in relation to considering the needs ofchildren with cancer and their families. Hence, it is important to recognize the experiences and challenges of socialworkers to improve care of their clients. Method: This study was a qualitative content analysis that aimed to determinea comprehensive understanding of pediatric oncology social workers’ experiences in Iran. In total, 19 social workersparticipated in the study. A purposeful sampling method was applied until reaching data saturation. Data were collectedusing semi-structured interviews and field observations. Then, the gathered data were analyzed through face contentanalysis. The study lasted from 2015 to 2017. Finding: Concepts extracted from social workers’ experiences consistedof the nature of oncology work, lack of professional competence, low organizational support and professional inferioritythat were related to main concept of “exhausting and stressful service”. The results indicated that social workers’involvement in stressful and emotionally demanding situations and facing with professional and organizationalchallenges caused personal exhaustion. Conclusion: In addition to explaining the social workers’ experiences andrelated factors, the results emphasize the importance of taking care of service providers to prevent them becomingstressed and exhausted. It is also important to protect patients from the consequences of stressed and exhausted careproviders so further research is recommended to develop specific intervention.  相似文献   
10.
Calcium supplementation (1,200 mg/day) did not significantly reduce colorectal adenomas in our recent randomized, controlled trial (Vitamin D/Calcium Polyp Prevention Study, VCPPS, 2004–2013) in contrast to our previous trial (Calcium Polyp Prevention Study, CPPS, 1988–1996). To reconcile these findings, we identified participant characteristics that differed between the study populations and modified the effect of calcium supplementation on adenomas or high-risk findings (advanced or multiple adenomas). Compared to the CPPS, more participants in the VCPPS were obese (body mass index (BMI) ≥30 kg/m2; 37.5% vs. 24.4%) and fewer had normal BMI (BMI <25 kg/m2; 18.5% vs. 31%). BMI appeared to modify the effect of calcium supplementation on adenomas and especially on high risk-findings: in the VCPPS, there was a 44% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.56, 95% CI = 0.26–1.23), but not among overweight (RR = 1.09, 95% CI = 0.62–1.91) or obese (RR = 1.54, 95% CI = 0.92–2.57) individuals (pinteraction = 0.03). Similarly, in the CPPS, there was a 56% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.44, 95% CI = 0.26–0.74), but not among overweight (RR = 0.87, 95% CI = 0.55–1.39) or obese (RR = 1.02, 95% CI = 0.57–1.82) individuals (pinteraction = 0.02). Standardization of each trial's findings to the BMI distribution in the other attenuated calcium's protective effect on adenomas in the CPPS but enhanced it in the VCPPS. In conclusion, 1,200 mg/day calcium supplementation may reduce risk of colorectal adenomas among those with normal BMI but not in overweight or obese individuals; and differences in BMI distribution partially account for the apparent difference in calcium efficacy between the two trials.  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