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   138130篇
  免费   16729篇
  国内免费   2515篇
耳鼻咽喉   510篇
儿科学   3762篇
妇产科学   2686篇
基础医学   8180篇
口腔科学   4212篇
临床医学   32475篇
内科学   16343篇
皮肤病学   1513篇
神经病学   6825篇
特种医学   1472篇
外国民族医学   14篇
外科学   11410篇
综合类   16845篇
现状与发展   9篇
一般理论   84篇
预防医学   20989篇
眼科学   1368篇
药学   13435篇
  590篇
中国医学   7390篇
肿瘤学   7262篇
  2024年   526篇
  2023年   4295篇
  2022年   5680篇
  2021年   8644篇
  2020年   9129篇
  2019年   7766篇
  2018年   7227篇
  2017年   7079篇
  2016年   6741篇
  2015年   6209篇
  2014年   10615篇
  2013年   11723篇
  2012年   8511篇
  2011年   8608篇
  2010年   6416篇
  2009年   6170篇
  2008年   5772篇
  2007年   5918篇
  2006年   4951篇
  2005年   4140篇
  2004年   3472篇
  2003年   2894篇
  2002年   2194篇
  2001年   1895篇
  2000年   1576篇
  1999年   1331篇
  1998年   1121篇
  1997年   960篇
  1996年   827篇
  1995年   621篇
  1994年   608篇
  1993年   494篇
  1992年   441篇
  1991年   377篇
  1990年   327篇
  1989年   290篇
  1988年   260篇
  1987年   237篇
  1986年   188篇
  1985年   223篇
  1984年   193篇
  1983年   136篇
  1982年   132篇
  1981年   111篇
  1980年   94篇
  1979年   59篇
  1978年   35篇
  1977年   36篇
  1976年   34篇
  1975年   29篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
Platelet α-granules release growth factors (GFs) that promote healing and tissue regeneration. Platelet-rich plasma (PRP) is shown to be beneficial in treating alopecia, and however, clinical response can be inconsistent. Due to several fold enrichment of platelets secreting large quantities of GFs following PRP injections, heterogeneity in amounts of GFs secreted by platelets may contribute to inconsistent clinical responses. Herein, we evaluated factors that could potentially contribute to heterogeneous secretion of GFs by platelets. We measured platelet secretion of transforming growth factor beta1 (TGFβ1), platelet-derived growth factor (PDGF-BB), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF2) in aliquots of de-identified PRP samples from female patients undergoing therapy in the hair disease clinic. Although secretion of GFs by platelets was comparable in PRP samples of patients with non-cicatricial and cicatricial alopecia, a Shapiro-Wilk test for normal distribution indicated significant variability across all patient samples. The amount of GF secreted by platelets was comparable when PRP prepared from two FDA-cleared devices with distinct techniques were compared. We provide evidence of platelets secreting heterogeneous amounts of GFs within each sample as high and low secretion of random factors could be simultaneously detected. These results suggest inherent heterogeneity in secretion of GFs by platelets in patient samples that are not influenced by the device used to prepare PRP. Since some GFs could have antagonistic effects on hair growth, a balance between amounts of growth promoting and inhibiting factors may be crucial in determining clinical response to PRP therapy.  相似文献   
142.
143.
Sessile serrated adenoma/polyps (SSA/Ps) are early precursor lesions in the serrated neoplasia pathway, which results in BRAF‐mutated colorectal carcinomas with not only high levels of microsatellite instability but also microsatellite stable. SSA/Ps with advanced histology, including cytological dysplasia or minimally invasive carcinomas, are important lesions because SSA/Ps are considered major contributors to “interval cancers” and these lesions can rapidly become dysplastic or invasive carcinomas. Clinicopathologically, SSA/Ps with dysplasia or invasive carcinoma were associated with advanced age, female sex, and proximal colon. Although SSA/Ps with submucosal invasive carcinoma were smaller and invaded less deeply into the submucosal layer than conventional tubular adenomas with submucosal invasive carcinoma, SSA/Ps with submucosal invasive carcinoma frequently had a mucinous component and exhibited a higher potential for lymphatic invasion and lymph node metastasis. In an SSA/P series, endoscopic characteristics, including (semi)pedunculated morphology, double elevation, central depression, and reddishness, may help accurately diagnose SSA/Ps with advanced histology. Removal of SSA/Ps with dysplasia or invasive carcinoma was recommended. Endoscopic treatment such as endoscopic mucosal resection or endoscopic submucosal dissection is useful for those lesions. However, surgical resection with lymph node dissection might be indicated when SSA/Ps with invasive carcinoma are endoscopically suspected, because these have the high risk of lymph node metastasis. Greater awareness may promote further research into improving the detection, recognition, and complete resection rates of SSA/Ps with dysplasia or invasive carcinoma and reduce the interval cancer rates.  相似文献   
144.
145.
《中国现代医生》2020,58(20):178-180+184
目的 探讨临床护理路径用于ICU重症颅脑损伤患者护理中的价值。方法 选择2017年11月~2018年10月进行ICU重症颅脑损伤治疗的患者100例作为对象,随机数字表法分为对照组(n=50)和观察组(n=50)。对照组给予常规护理,观察组在其基础上应用临床护理路径,15 d护理后比较患者依从性情况、对患者护理前后心理状态进行评分,对不良并发症产生情况进行比较。结果 观察组康复锻炼依从、按时用药依从及饮食依从高于对照组(P0.05)。护理前两组SDS与SAS评分比较差异无统计学意义(P0.05),护理后,观察组SDS与SAS评分低于对照组(P0.05)。观察组出现压疮、泌尿感染、以及发热的发生率显著低于对照组(P0.05)。结论 将临床护理路径用于ICU重症颅脑损伤患者的护理中,提高了患者的护理依从性,减少了不良情绪以及不良并发症的产生,有助于患者整体治疗,值得推广应用。  相似文献   
146.
147.
148.
Caring is typically constructed as a feminised practice, resulting in women shouldering the burden of care-related work. Health-seeking behaviours are also constructed as feminine and men have poorer health outcomes globally. Employing men as carers may not only improve the health of the men they assist but also be transformative with regards to gendered constructions of caring. Using semi-structured interviews and observational home visits, this study explored the techniques that community care workers employ when working with male clients. The empirical analysis draws on the perspectives of eight care workers and three of their male clients from the Cape Town area. Interviews reveal how care workers and clients perform and negotiate masculinities as they navigate hegemonic masculine norms that require men to act tough, suppress emotions and deny weakness and sickness. Both parties bump up against ideals of what it means to be a man as they strive to provide care and receive support. Community care workers avoid rupturing client performances of hegemonic masculinities which inhibit confession and support. To do this, they use techniques of indirectly broaching sensitive subjects, acting in a friendly way and being clear about the intention of their work.  相似文献   
149.
Helicobacter pylori (H. pylori) is a main risk factor for gastric cancer (GC). Epithelial-mesenchymal transition (EMT) is involved in the development and progression of H. pylori-associated GC. However, the exact molecular mechanism of this process remains unclear. The AKT/GSK3β signaling pathway has been demonstrated to promote EMT in several types of cancer. The present study investigated whether H. pylori infection induced EMT, and promoted the development and metastasis of cancer in the normal gastric mucosa, and whether this process was dependent on AKT activation. The expression levels of the EMT-associated proteins, including E-cadherin and N-cadherin, were determined in 165 gastric mucosal samples of different disease stages by immunohistochemical analysis. The expression levels of E-cadherin, N-cadherin, AKT, phosphorylated (p-)AKT (Ser473), GSK3β and p-GSK3β (Ser9) were further determined in H. pylori-infected Mongolian gerbil gastric tissues and cells co-cultured with H. pylori by immunohistochemical analysis and western blotting. The results indicated that the expression levels of the epithelial marker E-cadherin were decreased, whereas the expression levels of the mesenchymal marker N-cadherin were increased during gastric carcinogenesis. Their expression levels were associated with H. pylori infection. Furthermore, H. pylori infection resulted in downregulation of E-cadherin expression and upregulation of N-cadherin expression in Mongolian gerbils and GES-1 cells. In addition, an investigation of the associated mechanism of action revealed that p-AKT (Ser473) and p-GSK3β (Ser9) were activated in GES-1 cells following co-culture with H. pylori. Furthermore, following pretreatment of the cells with the AKT inhibitor VIII, the expression levels of E-cadherin, N-cadherin, p-AKT and p-GSK3β did not show significant differences between GES-1 cells that were co-cultured with or without H. pylori. The levels of p-AKT and p-GSK3β were increased in H. pylori-infected Mongolian gerbils. In conclusion, the present study demonstrated that H. pylori infection activated AKT and resulted in the phosphorylation and inactivation of GSK3β, which in turn promoted early stage EMT. These effects were AKT-dependent. This mechanism may serve as a prerequisite for GC development.  相似文献   
150.
目的探讨工作坊模式在护生压疮护理带教中的应用效果,为临床护理带教提供参考。方法选取2018年7月—2019年6月在医院实习的120名护生作为研究对象,随机分为对照组和观察组,各60名护生。对照组采用传统带教法进行压疮培训,观察组采用工作坊教学模式进行培训。培训结束后比较两组护生压疮知识的掌握程度即理论考核、技能操作成绩,教学效果满意度。结果观察组护生对压疮知识的掌握程度即理论考核成绩、技能操作考核成绩远远高于对照组,两组差异具有统计学意义(P<0.05)。95%的观察组护生对工作坊教学模式的效果表示满意,认为工作坊教学模式能够提高学习的兴趣、主动性和临床实践能力,对临床工作有很大帮助。结论工作坊教学模式应用于压疮护理的临床带教,能让护生亲身体验压疮护理的过程,并参与其中,将理论与实践相结合,更好地活跃课堂气氛,启发护生思考,提高护生对压疮理论和技能的掌握,为临床实际工作中压疮护理质量的提高奠定基础。  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