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   22542篇
  免费   1853篇
  国内免费   499篇
耳鼻咽喉   175篇
儿科学   339篇
妇产科学   225篇
基础医学   1970篇
口腔科学   273篇
临床医学   2861篇
内科学   2334篇
皮肤病学   116篇
神经病学   2257篇
特种医学   1646篇
外科学   1417篇
综合类   4095篇
一般理论   2篇
预防医学   2505篇
眼科学   415篇
药学   2663篇
  21篇
中国医学   942篇
肿瘤学   638篇
  2024年   23篇
  2023年   281篇
  2022年   477篇
  2021年   789篇
  2020年   847篇
  2019年   699篇
  2018年   689篇
  2017年   838篇
  2016年   863篇
  2015年   886篇
  2014年   1783篇
  2013年   1613篇
  2012年   1754篇
  2011年   1719篇
  2010年   1336篇
  2009年   1166篇
  2008年   1102篇
  2007年   1076篇
  2006年   975篇
  2005年   787篇
  2004年   672篇
  2003年   584篇
  2002年   480篇
  2001年   376篇
  2000年   357篇
  1999年   335篇
  1998年   254篇
  1997年   246篇
  1996年   200篇
  1995年   197篇
  1994年   161篇
  1993年   125篇
  1992年   120篇
  1991年   103篇
  1990年   98篇
  1989年   86篇
  1988年   80篇
  1987年   68篇
  1986年   62篇
  1985年   88篇
  1984年   84篇
  1983年   46篇
  1982年   57篇
  1981年   52篇
  1980年   61篇
  1979年   37篇
  1978年   36篇
  1977年   39篇
  1976年   24篇
  1975年   19篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
目的探讨脑状态指数(CSI)联合中枢神经系统(CNS)感染评分表在重型脑外伤并发颅内感染患者病情监测中的应用。方法选取2018年6月至2019年6月开封市中心医院神经外科收治的重型脑外伤患者78例,采用CSI评分及CNS评分对患者病情进行评估。结果CSI评分10~30分组、31~50分组、51~80分组、CNS评分0~13分组、14~26分组、27~39分组在性别、年龄、脑挫裂伤、颅内血肿等方面比较差异均无统计学意义(均P>0.05),而CSI评分10~30分组、31~50分组、51~80分组在颅内感染发生率、死亡率、格拉斯哥预后评分(GOS)、Barthel指数差异均有统计学意义(均P<0.05)。CNS评分0~13分组、14~26分组、27~39分组颅内感染发生率及死亡率差异均有统计学意义(均P<0.05)。经Pearson单因素分析可知,CSI评分与CNS评分呈负相关(P<0.05)。结论CSI评分联合CNS评分对重型脑外伤并发颅内感染患者病情判断及预后有重要的价值,可为患者实施预见性护理提供指导,从而降低重型脑外伤患者颅内感染率及死亡率,提高患者临床治疗效果。  相似文献   
62.
Objectives: Previous research has shown a decline in Theory of mind (ToM) associated with normal aging. However, very few studies have investigated older people’s ToM using an ecological approach. The present study was designed to fill this gap and examine older people’s frequency of mental state talk (MST) in describing their best friend, together with their performance on a traditional ToM task. In addition, the study examined the association between these two ToM indices and relationships with friends and family members.

Method: Seventy-two healthy older adults (age range 60–79) participated in the study. We measured ToM ability with a classic measure, the Faux Pas task, and selected the Describe-a-friend task to measure MST frequency; social relationships were investigated with the Lubben Social Network Scale. Correlation and regression analyses were performed.

Results: No significant association between MST and scores on the Faux Pas task emerged. In addition, MST (but not Faux Pas scores) significantly predicted friendships (but not family relationships) over and above general cognitive functioning.

Conclusion: These findings show the crucial distinction between possessing an ability and using it in daily life and suggest the need to move toward more ecological measures of older adults’ abilities. In addition, the present results indicate that the spontaneous use of ToM ability, not the ability per se, impacts on older adults’ social relationships.  相似文献   

63.
64.
Idiopathic Pulmonary Fibrosis (IPF) is a most common progressive interstitial lung disease (ILD) of unknown etiology, although majority of patients are elderly male smokers. The main pathogenesis is aberrant recovery of epithelial injury and collagen deposition. Fibrotic nonspecific interstitial pneumonia, connective tissue disease (CTD) especially rheumatoid arthritis (RA) associated ILD, and chronic hypersensitivity pneumonia(CHP) are important differential diagnosis. Main symptoms are non-productive cough and progressive exertional dyspnea. Crucial physical findings are scalene muscle hypertrophy, bibasilar fine crackles, and finger clubbing. The serum markers such as lactate dehydrogenase (LDH) and Krebs von den Lungen-6 (KL-6) are sensitive for ILD detection and activity. Both pulmonary function test (PFT) and the 6-minute walk test (6MWT) are useful tool for evaluation of disease progression of IPF. Serial changes of forced vital capacity (FVC) and 6MWT distance predict mortality in IPF effectively. Recently published international IPF guidelines highlight the importance of chest high resolution computed tomography (HRCT) findings such as honeycombing, traction bronchiectasis (TBE), and sub-pleural reticular opacity. IPF is chronic and progressive; therefore, tracking disease behavior is crucial. Unifying clinical, physiological, and imaging information over time is useful. With regard to its management, two anti-fibrotic drugs such as pirfenidone and nintedanib have been available. These drugs can slow the decline of FVC and prevent acute exacerbation (AE). In this review, I outline the clinical characteristics of IPF, physiological, imaging, pathological findings and review diagnosis process and management.  相似文献   
65.
66.
Nowadays, advanced extraction techniques and highly sensitive metabolic profiling methods are effectively employed to get new information on plant chemical constituents. Among them wild medicinal plants or their parts, with large and ancient use in folk medicine, are investigated for their potential functional use and cultivation. In this context, Inula viscosa leaves engaged our attention. A simple experimental design, based on Soxhlet extraction and chromatographic fractionation, allowed us to obtain the investigated polyphenol fraction (IvE). UHPLC-HRMS analyses revealed shikimoyl depsides of caffeic acid and unusual dihydrobenzofuran lignans as main secondary metabolites. These compounds, together with cinchonain-type phenols, and hydroxycinnamoyl flavonol glycosides, are reported for the first time in inula. Overall, forty-three secondary metabolites were identified. The extract exerted a remarkable antiradical activity towards DPPH? and ABTS+?. Furthermore, it was able to inhibit cell viability and mitochondrial redox activity of neuroblastoma, hepatoblastoma and colon carcinoma cells, whereas it did not affect cell density of HaCaT cells immortalized human keratinocytes. As detected by the oxidant-sensing probe 2′,7′-dichlorodihydrofluorescein diacetate, the inhibitory responses seemed to be related to IvE-induced increase of intracellular reactive oxygen species (ROS). The obtained results highlighted that inula leaves, nowadays even undervalued and unexplored, could be considered a renewable source of nutraceutical compounds.  相似文献   
67.
目的研究部分调节性内斜视患儿的屈光状态与双眼单视功能的相关性。 方法回顾性分析36例部分调节性内斜视患儿,对患儿裸眼视力、矫正视力、阿托品散瞳后的屈光度数、戴镜半年的远近残余斜视度及双眼单视功能等进行记录和统计学分析。左右眼等效球镜用配对秩和检验比较,右眼等效球镜与视力、斜视度和视功能的相关性采用Spearman分析。 结果36例部分调节性内斜视患儿年龄3~14岁,平均(79.39±31.21)个月,右眼等效球镜(+4.45±1.73)D,左眼等效球镜(+4.75±1.68)D;33 cm裸眼斜视度(+53.19±18.05)△,6 m裸眼斜视度(+47.50±19.00)△;33 cm残余斜视度(+30.36±12.03)△,6 m残余斜视度(+25.53±9.59)△。右眼等效球镜与同视机Ⅰ级、Ⅱ级和Ⅲ级视功能无相关性(r=-0.012,-0.058,-0.016;P>0.05)。右眼等效球镜与33 cm裸眼斜视度呈正相关(r=0.344,P<0.05),与裸眼视力呈负相关(r=-0.456,P<0.05)。33 cm裸眼斜视度与同视机Ⅰ级、Ⅱ级和Ⅲ级功能均呈负相关(r=-0.378,-0.678,-0.482;P<0.05),与Titmus立体图亦呈负相关(r=-0.477,P<0.05)。6 m裸眼斜视度与同视机Ⅰ级、Ⅱ级和Ⅲ级功能均呈负相关(r=-0.453,-0.610,-0.430;P<0.05)。33 cm残余斜视度与同视机Ⅱ和Ⅲ级功能均呈负相关(r=-0.651,-0.600;P<0.05),与Titmus立体图、立体动物和立体圆圈亦呈负相关(r=-0.688,-0.625,-0.462;P<0.05)。6 m残余斜视度与同视机Ⅱ和Ⅲ级功能均呈负相关(r=-0.587,-0.543;P<0.05),与Titmus立体图、立体动物和立体圆圈亦呈负相关(r=-0.644,-0.514,-0.492;P<0.05)。 结论部分调节性内斜视患儿的屈光状态与双眼单视功能不相关,与裸眼视力负相关。影响双眼单视功能的是残余斜视度。  相似文献   
68.
Footwear has been used to protect feet for millennia with socially exclusive population adopting stylish and fashionable shoes with expensive materials. In terms of historic timeline, only more recently footwear has been worn by all classes in the western world as an integral part of their apparel. Traditionally, footwear has been constructed from natural materials, mainly leather, but has recently benefitted from the flexibility that technology has provided with a plethora materials and new design innovations. Although it has expanded the availability for a variety of consumers, the choice and fit continue to be problematic with many individuals wearing shoes that are ill-fitting. Provision of specific footwear advice for problem feet is poorly evidenced and is heavily practitioner dependant limiting its efficacy. There is limited understanding as to the changes that can occur from regularly wearing footwear that is unsuitable in shape, style and construction which is referred to as ill-fitting. Current research on the effect that everyday footwear has on foot function and pain focuses mainly on women’s shoes, particularly high heels. Defining what is a good fitting shoe, that does not damage the foot or mechanics of walking, may need to be individualised, but best fit is based on loose historical parameters rather than research evidence. The aim of this overview is to highlight aspects of current research, establishing what is known about the effect’s shoes have on the feet as well as exploring the mythology around footwear fit and advice that is often historical in nature.  相似文献   
69.
Background: Previous genome-wide association study (GWAS) has revealed the association between MYP10 at 8p23 and MYP15 at 10q21.1 and high myopia (HM) in a French population. This study is managed to discover the connection between some single nucleotide polymorphism (located at MYP10 and MYP15) and Han Chinese HM.

Methods and Results: This case-control association study contained 1673 samples, including 869 ophthalmic patients and 804 controls. Twelve tag SNPs have been selected from the MYP10 and MYP15 loci and genotyped by SNaPshot method. Among 12 SNPs, rs4840437 and rs6989782 in TNKS gene were found significant association with HM. Carriers of rs4840437G allele and rs4840437GG genotype created a low risk of high myopia (P = .036, OR = 0.81, 95%CI = 0.71–0.93; P = .016, OR = 0.73, 95%CI = 0.56–0.96; respectively). Carriers of rs6989782T allele and rs6989782TT+CT genotype also had a decreased risk of high myopia (P = .048, OR = 0.82, 95%CI = 0.71–0.94; P = .006, OR = 0.74, 95%CI = 0.59–0.92; respectively). Other 10 SNPs displaced nonsignificant association with HM. Additionally, the risk haplotype AC and the protective haplotype GT, generated by two SNPs in TNKS, were considerably more likely to be association with HM (for AC, P = .002 and OR = 1.26; for GT, P = .027 and OR = 0.84).

Conclusions: Our results demonstrated that some heritable variants in the TNKS gene are associated with HM in the Han population. The possible functions of TNKS in the development and pathogenesis of hereditary high myopia still require further researches to identify.  相似文献   

70.
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