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   24463篇
  免费   2348篇
  国内免费   1150篇
耳鼻咽喉   284篇
儿科学   336篇
妇产科学   213篇
基础医学   2270篇
口腔科学   404篇
临床医学   3204篇
内科学   2853篇
皮肤病学   467篇
神经病学   936篇
特种医学   923篇
外国民族医学   9篇
外科学   1516篇
综合类   5120篇
现状与发展   5篇
一般理论   2篇
预防医学   2639篇
眼科学   575篇
药学   2965篇
  51篇
中国医学   1704篇
肿瘤学   1485篇
  2024年   71篇
  2023年   337篇
  2022年   1168篇
  2021年   1549篇
  2020年   1203篇
  2019年   739篇
  2018年   805篇
  2017年   953篇
  2016年   747篇
  2015年   1329篇
  2014年   1619篇
  2013年   1672篇
  2012年   2496篇
  2011年   2555篇
  2010年   1786篇
  2009年   1488篇
  2008年   1584篇
  2007年   1421篇
  2006年   1181篇
  2005年   936篇
  2004年   581篇
  2003年   452篇
  2002年   295篇
  2001年   247篇
  2000年   208篇
  1999年   113篇
  1998年   50篇
  1997年   49篇
  1996年   28篇
  1995年   39篇
  1994年   28篇
  1993年   16篇
  1992年   35篇
  1991年   39篇
  1990年   19篇
  1989年   17篇
  1988年   11篇
  1987年   14篇
  1986年   5篇
  1985年   11篇
  1983年   5篇
  1979年   5篇
  1978年   4篇
  1976年   4篇
  1974年   4篇
  1972年   4篇
  1971年   5篇
  1969年   4篇
  1968年   4篇
  1966年   4篇
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
41.
目的:构建颈部三维有限元模型(finite element model,FEM),初步分析脊髓型颈椎病(cervical spondylotic myelopathy,CSM)患者与对照者颈部生物力学的差异,为CSM发病机制的研究提供生物力学依据。方法:以1名CSM患者作为力学模拟实验对象进行三维CT扫描,并构建颈部三维FEM依照患者的年龄、性别、身高、体重等参数选取本团队已有的健康颈部三维FEM作为对照,比较患者和对照者在颈椎正常受力情况下椎体、椎间盘、韧带及脊髓的应力差异,以及后仰伸运动后最大应力的差异。结果:成功构建CSM患者及对照者FEM模型,并进行力学分析,CSM患者颈椎椎体受力差异C5~C6节段最明显,对照者和患者的最大应力部位均在椎体前缘,CSM患者椎体前缘的最大应力小于对照者;CSM患者椎间盘应力分布不均匀,最大应力部位集中在椎间盘底部后缘的两侧;CSM患者各韧带的应力分布不均匀,其中后纵韧带应力最大。CSM患者颈椎在后仰伸运动时范围受限。结论:CSM患者相对于对照者可能存在颈部椎体、椎间盘及韧带受力平衡的改变和颈椎运动范围的受限,这可能与CSM力学发病机制相关。  相似文献   
42.
孙娜  袁雪梅 《循证护理》2022,(1):124-127
目的:探讨护理风险预警机制在慢性乙型肝炎肝衰竭病人护理中的应用效果。方法:选取2018年1月—2019年12月我院收治的104例慢性乙型肝炎肝衰竭病人,按照病人入院顺序,并采用单双号抽签方式分为对照组和观察组,各52例。对照组给予常规护理干预,观察组临床护理中引入护理风险预警机制,对比两组肝功能指标、并发症发生情况、护理满意度、护理质量评分、护理缺陷评分及住院时间。结果:干预后,两组肝功能指标均有所改善,且观察组下降幅度较对照组大(P<0.001);观察组与对照组并发症发生率分别为7.69%、25.00%,观察组与对照组总满意度分别为96.15%、76.92%,观察组病人护理质量评分高于对照组,护理缺陷评分及住院时间低于对照组,差异均有统计学意义(P<0.05)。结论:将护理风险预警机制用于慢性乙型肝炎肝衰竭病人的临床护理中,有利于改善病人肝功能指标,减少并发症及护理缺陷,提高护理满意度,提升护理质量,缩短病人住院时间。  相似文献   
43.
Although tacrolimus (TAC) has remarkable effects in ulcerative colitis (UC) patients when given as remission induction therapy, some can develop renal dysfunction during TAC administration, resulting in withdrawal, though related details remain poorly understood. This study was conducted to determine the impact of oral TAC on renal function for remission induction therapy in UC patients. Fifty-five patients (10 elderly, 45 non-elderly) with UC and treated with oral TAC at our hospital were retrospectively evaluated. Renal function was assessed using estimated glomerular filtration rate (eGFR). Although a high clinical response to TAC was seen in both elderly and non-elderly, a decline in eGFR was noted in nearly all patients regardless of age, with a maximum change of −34.4% from the baseline value at week 11. Furthermore, eGFR decline recovered quickly after TAC discontinuation, though did not return to the baseline at two years following cessation. The rate of eGFR change at week 12 was significantly associated with patient age (β = −0.3242, p = 0.0103) and peak serum trough level during TAC treatment (β = 0.3563, p = 0.0051). Furthermore, the rate of decline in eGFR was significantly greater during treatment with TAC in the elderly as compared to non-elderly, with a large difference in eGFR decline rate between those groups also noted at two years after withdrawal of treatment. Careful attention to renal function when administering oral TAC for UC is important and changes in eGFR should be monitored closely in elderly patients even after treatment cessation.  相似文献   
44.
Grape seed is an important natural bioactive product with various health benefits. Interstitial cells of Cajal (ICCs) are pacemaker cells in the gastrointestinal (GI) tract. The present study investigated the effects of grape seed powder (GSP) on ICC properties and GI motility. GSP depolarized the pacemaker potentials of ICCs in a dose‑dependent manner. Y25130 or SB269970 slightly inhibited GSP‑induced effects. However, Y25130 and SB269970 together completely blocked GSP-induced effects. In the presence of inhibitors of protein kinase C, protein kinase A, or mitogen-activated protein kinase, GSP‑induced ICC depolarization was inhibited. GSP increased the intestinal transit rate in normal mice and in mice with acetic acid-induced GI motility disorder. In addition, the levels of motilin and substance P were elevated after GSP dosing. These results demonstrate that GSP can regulate GI motility, and therefore, it is a potential therapeutic agent for treating GI motility disorders.  相似文献   
45.
AimWhite matter damage (WMD) is the main cause of cerebral palsy and cognitive impairment in premature infants. Although caffeine has been shown to possess neuroprotective effects in neonatal rats with hypoxic‐ischemic WMD, the mechanisms underlying these protective effects are unclear. Herein, proteins modulated by caffeine in neonatal rats with hypoxic‐ischemic WMD were evaluated.MethodsWe identified differential proteins and performed functional enrichment analyses between the Sham, hypoxic‐ischemic WMD (HI), and HI+caffeine‐treated WMD (Caffeine) groups. Confirmed the changes and effect of proteins in animal models and determined cognitive impairment via water maze experiments.ResultsIn paraventricular tissue, 47 differential proteins were identified between the Sham, HI, and Caffeine groups. Functional enrichment analyses showed that these proteins were related to myelination and axon formation. In particular, the myelin basic protein (MBP), proteolipid protein, myelin‐associated glycoprotein precursor, and sirtiun 2 (SIRT2) levels were reduced in the hypoxic‐ischemic WMD group, and this effect could be prevented by caffeine. Caffeine alleviated the hypoxic‐ischemic WMD‐induced cognitive impairment and improved MBP, synaptophysin, and postsynaptic density protein 95 protein levels after hypoxic‐ischemic WMD by preventing the HI‐induced downregulation of SIRT2; these effects were subsequently attenuated by the SIRT2 inhibitor AK‐7.ConclusionCaffeine may have clinical applications in the management of prophylactic hypoxic‐ischemic WMD; its effects may be mediated by proteins related to myelin development and synapse formation through SIRT2.  相似文献   
46.
47.
Follicular dendritic cell sarcoma (FDCS) of the nasopharynx is a rare malignant tumor that has been described in only a few case reports, and its differential diagnoses include diverse clinicopathologic entities. FDCS is often initially misdiagnosed, especially when examining small biopsy specimens. We herein report a case of FDCS arising in the nasopharynx that was initially misdiagnosed as a nerve sheath tumor. A 44-year-old woman presented with persistent obstruction of the left nasal cavity and underwent an excisional biopsy. The specimen demonstrated morphologic and immunohistochemical features of FDCS. In situ hybridization for Epstein–Barr virus-encoded RNA was negative. The patient was treated with chemotherapy and radiotherapy. The sarcoma recurred near the original site more than 3 years after the initial treatment and was completely resected. At the time of this writing, the patient had remained disease-free for 1 year after resection. This case is being reported to improve the clinical recognition of FDCS.  相似文献   
48.
肝胆管结石是肝胆外科较常见的急腹症之一,做好患者术前、术后护理对减轻患者心理负担,减少手术后并发症,提高治疗效果有非常重要意义.自2005年12月至2006年12月我科共收治肝内外胆管结石手术患者142例,取得了良好的治疗效果,现将术前、术后护理体会总结如下.  相似文献   
49.
促渗剂对白头翁素体外经皮渗透的影响   总被引:2,自引:0,他引:2  
目的:考察几种常用促渗剂对白头翁素体外经皮渗透性能的影响,为白头翁素经皮给药系统的开发提供参考。方法:采用TK-6A型透皮扩散仪,供应室加含不同促进剂的白头翁素样品,用人皮进行体外经皮渗透实验;以HPLC测定一定时间点接受室中药物浓度,求算累积渗透量及稳态透皮速率。结果:白头翁素饱和水溶液的稳态渗透速率为(1.17±0.03) μg·cm-2·h-1,含30%、50%乙醇和3%月桂氮酮-5%聚山梨酯20、30%乙醇-3%月桂氮酮-5%聚山梨酯20的白头翁素溶液稳态渗透速率为(9.30±0.32),(18.56±0.58),(7.29±0.35),(13.77±0.16) μg·cm-2·h-1,分别使白头翁素的经皮渗透速率提高了7.9,15.9,6.2,11.8倍。结论:乙醇和月桂氮酮能显著促进白头翁素的经皮渗透,白头翁素有望开发成经皮给药制剂。  相似文献   
50.
黄莪胶囊治疗良性前列腺增生症疗效分析   总被引:3,自引:0,他引:3  
目的探讨黄莪胶囊治疗良性前列腺增生症的疗效和安全性。方法采用随机、开放、平行对照的多中心II、III期临床试验及补充临床试验,869例入选病例为经确诊的良性前列腺增生患者。试验组516例,服用黄莪胶囊,每日3次,每次4粒;II、III期临床试验对照组患者分别有117、162例,均服用癃闭舒胶囊,每日2次,每次3粒;补充临床试验对照组患者74例,服用安慰剂,每日3次,每次4粒,疗程均为42 d。结果黄莪胶囊对良性前列腺增生患者气虚血瘀、湿热阻滞证的主要疗效指标IPSS积分、终点尿流率的改善均有临床意义。结论黄莪胶囊是一种治疗良性前列腺增生症气虚血瘀、湿热阻滞证安全有效的中药。  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