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   26970篇
  免费   2793篇
  国内免费   2306篇
耳鼻咽喉   275篇
儿科学   297篇
妇产科学   236篇
基础医学   2734篇
口腔科学   389篇
临床医学   3443篇
内科学   3504篇
皮肤病学   295篇
神经病学   1568篇
特种医学   1075篇
外国民族医学   7篇
外科学   2753篇
综合类   5819篇
现状与发展   8篇
一般理论   1篇
预防医学   2179篇
眼科学   597篇
药学   3163篇
  20篇
中国医学   1696篇
肿瘤学   2010篇
  2024年   112篇
  2023年   449篇
  2022年   1210篇
  2021年   1403篇
  2020年   1081篇
  2019年   922篇
  2018年   934篇
  2017年   899篇
  2016年   795篇
  2015年   1208篇
  2014年   1613篇
  2013年   1557篇
  2012年   2133篇
  2011年   2316篇
  2010年   1745篇
  2009年   1401篇
  2008年   1569篇
  2007年   1651篇
  2006年   1529篇
  2005年   1309篇
  2004年   994篇
  2003年   1115篇
  2002年   894篇
  2001年   699篇
  2000年   627篇
  1999年   454篇
  1998年   296篇
  1997年   240篇
  1996年   170篇
  1995年   143篇
  1994年   126篇
  1993年   85篇
  1992年   68篇
  1991年   68篇
  1990年   57篇
  1989年   53篇
  1988年   46篇
  1987年   25篇
  1986年   27篇
  1985年   18篇
  1984年   17篇
  1983年   3篇
  1982年   1篇
  1981年   5篇
  1980年   1篇
  1976年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
目的 比较不同特异性抗原和不同输注途径诱导免疫耐受的强度及探讨其可能机理。方法 建立大鼠颈部异位心脏移植模型 ,采用供体特异性全血、供体特异性脾细胞和骨髓细胞 (DSBM) ,通过外周、门静脉和胸腺三种不同途径输注以诱导免疫耐受的产生和维持。结果 供体特异性抗原诱导免疫耐受以 DSBM及通过胸腺接种途径效果最佳。结论 供者特异性抗原能诱导受体免疫耐受并促进移植物存活 ,可望成为较理想的临床免疫耐受诱导方法。  相似文献   
102.
目的 :评价毒毛旋花子K间歇疗法 (简称ISKT)治疗保持窦性心律的冠心病心力衰竭的疗效及可行性。方法 :2 0 0例窦性心律的冠心病心力衰竭患者分为两组 :A组 98例采用维持量地高辛治疗 ;B组 10 2例采用ISKT。结果 :心率 (HR)、左室射血分数 (LVET)及血压 (BP)治疗前与治疗后 3个月比较 ,在A组分别为 :88± 12及 6 8± 12 (次 /min ,P <0 .0 1) ;0 32± 12及 0 40± 12 (P <0 .0 1) ;12 6± 2 1/ 90± 6及 12 8± 2 1/ 80± 15 ,(mmHg,P >0 .0 5 ) ;在B组分别为 :90± 10及 70± 11(次 /min ,P <0 .0 1) ;0 .32± 0 .10及 0 48± 0 10 (P <0 .0 1) ;12 8± 2 0 / 91± 7及 110± 10 / 76± 10(mmHg ,P <0 .0 1)。治疗 3个月后两组间比较 :HR(P >0 .0 5 ) ;LVEF(P <0 .0 5 ) ,Bp(P <0 .0 0 1)。B组的心功能有较好的改善 ,因心绞痛而服用的硝酸甘油量较少 ,两组洋地黄中毒或过量发生率的差别无显著性的意义。结论 :对窦性心律的冠心病心力衰竭 ,ISKT是安全、有效、可行的一种治疗方法。  相似文献   
103.
104.
BackgroundThe incidence of heterotopic ossification (HO) after total knee arthroplasty (TKA) varies and is of unclear clinical significance. This study aimed to identify the incidence of HO in patients undergoing revision TKA for either stiffness or aseptic loosening/instability and determine if the presence of HO is associated with inferior absolute range of motion (ROM) and ROM gains.MethodsEighty-seven patients were prospectively enrolled and separated into 2 cohorts to evaluate ROM after revision TKA (2017-2019). Group 1 (N = 40) patients were revised for stiffness, while group 2 (N = 47) patients were revised for either aseptic loosening or instability. Goniometer-measured ROM values were obtained preoperatively and at 6 weeks, 6 months, and 1 year postoperatively. Statistical analysis included a Fisher’s exact test to assess for an association between preoperative HO and final ROM at 1 year after revision TKA.ResultsHO was identified on preoperative radiographs in 17 patients (20%). There was a significantly higher rate of preoperative HO in patients revised for stiffness compared to patients revised for instability or loosening (30% vs 11%; P = .03). Five cases of HO qualitatively identified as most clinically severe were associated with lower ROM at each time point compared to the remainder of HO cases in this study cohort (P < .02).ConclusionThe presence of HO is greater in patients undergoing revision TKA for stiffness. Additionally, HO severity appears to have a major effect on preoperative and postoperative ROM trajectory. This information should help guide patient expectations and highlight the need for a comprehensive, standardized classification system for HO.  相似文献   
105.
BackgroundMacroscopic hematuria after wasp sting has been reported in Asia to occur before acute kidney injury (AKI), and is often used by clinicians as a sign indicating the need for intensive care and blood purification therapy. However, there is no study on the clinical characteristics and prognosis of this symptom.MethodsThe clinical data of 363 patients with wasp sting admitted to Suining Central Hospital from January 2016 to December 2018 were retrospectively analyzed. At admission, the poisoning severity score (PSS) was used as the criterion for severity classification. According to the presence of macroscopic hematuria, the patients were divided into macroscopic hematuria and non-macroscopic hematuria group.ResultsOf the 363 wasp sting patients, 219 were male and 144 were female, with a mean age of 55.9 ± 16.3 years. Fifty-one (14%) had macroscopic hematuria, 39 (10.7%) had AKI, 105 (28.9%) had rhabdomyolysis, 61 (16.8%) had hemolysis, 45 (12.4%) went on to received hemodialysis, and 14 (3.9%) died. The incidence of AKI in macroscopic hematuria group was 70.6%, and oliguric renal failure accounted for 72.2%. Patients with macroscopic hematuria had significantly higher PSS (2.2 ± 0.5 vs. 1.1 ± 0.3, p < .001).ConclusionMacroscopic hematuria can be regarded as a surrogate marker of deteriorating clinical outcome following wasp stings. In wasp sting patients with symptoms of macroscopic hematuria or serum LDH higher than 463.5 u/L upon admission, the risk of AKI increases significantly, therefore hemodialysis should be considered. The PSS is helpful in early assessment of the severity of wasp sting patients.  相似文献   
106.
Patients with diabetes often experience visual defects before any retinal pathologies are detected. The molecular mechanism for the visual defects in early diabetes has not been elucidated. Our previous study reported that in early diabetic retinopathy (DR), rhodopsin levels were reduced due to impaired 11-cis-retinal regeneration. Interphotoreceptor retinol-binding protein (IRBP) is a visual cycle protein and important for 11-cis-retinal generation. IRBP levels are decreased in the vitreous and retina of DR patients and animal models. To determine the role of IRBP downregulation in the visual defects in early DR, we induced diabetes in transgenic mice overexpressing IRBP in the retina. IRBP overexpression prevented diabetes-induced decline of retinal function. Furthermore, IRBP overexpression also prevented decreases of rhodopsin levels and 11-cis-retinal generation in diabetic mice. Diabetic IRBP transgenic mice also showed ameliorated retinal oxidative stress, inflammation, apoptosis, and retinal degeneration compared with diabetic wild-type mice. These findings suggest that diabetes-induced IRBP downregulation impairs the regeneration of 11-cis-retinal and rhodopsin, leading to retinal dysfunction in early DR. Furthermore, increased 11-cis-retinal–free opsin constitutively activates the phototransduction pathway, leading to increased oxidative stress and retinal neurodegeneration. Therefore, restored IRBP expression in the diabetic retina may confer a protective effect against retinal degeneration in DR.  相似文献   
107.
刘湘  王玉钗  张雨恬  田丽  谯茹  张伟龙  贺福元  刘平安 《中草药》2023,54(17):5530-5540
目的 基于超分子“印迹模板”的分布特征划分鱼腥草注射剂指纹图谱成分簇,进行谱热学研究探讨鱼腥草注射剂中形成超分子结构的可疑成分。方法 采用气相色谱-质谱(GC-MS)法建立11批次鱼腥草注射剂的指纹图谱,采用匹配频数法和段带总量统计矩法划分“印迹模板”成分簇并构建新指纹图谱;采用等温微量热滴定仪测定11批次鱼腥草注射剂中挥发油成分相互滴定的放热量;根据超分子“印迹模板”作用放热的叠加性原理,进行总峰面积与鱼腥草注射剂自放热量的线性回归,建立谱热学方程并分析成分簇贡献率,根据关键成分簇信息筛选关键成分结构。结果 11批次鱼腥草挥发油GC-MS指纹图谱可被划分为26个“印迹模板”成分簇,总峰面积与热量线性回归后保留10个相关性大的变量:V2、V10、V15、V17、V19、V20、V21、V22、V23、V26,其回归系数分别为-1.12×10-4、5.93×10-6、7.58×10-5、9.32×10-4、-1.14×10-5、4.97×10-4、5.26×10-5、-1.16×10-4、-5.66×10-5、-2.08×10-5,常数为24.199,r=0.958。筛选得到17个形成超分子结构的可疑成分,分别为樟烯、β-月桂烯、4-甲基-3-(1-甲基乙叉基)-环己烯、3-(4-甲基-3-戊烯基)-呋喃等。结论 以超分子“印迹模板”为理论指导,运用匹配频数法对鱼腥草注射剂挥发油进行成分簇划分;利用线性回归得到了各个成分簇对放热值的贡献度及排序,得到形成超分子结构的关键成分,为后续对鱼腥草注射剂(类)致敏研究提供方向。  相似文献   
108.
目的 探讨胆总管囊肿胆管穿孔引流术后采取二次腹腔镜行胆总管囊肿根治术的可行性。方法 回顾性分析徐州医科大学附属徐州儿童医院2012年2月至2020年2月收治的10例胆总管囊肿并胆管穿孔行外引流术、并再次行腹腔镜胆总管囊肿根治术的患儿临床资料,分析术前及术中注意事项,总结相关经验。二次手术采用四孔法,其中脐部及右侧腹切口选择原切口,没有额外增加切口;囊肿分离采取囊肿横断切除法,避免损伤门静脉和肝动脉。结果 10例患儿,其中男4例,女6例;年龄9个月至8岁,平均(3.1±0.6)岁。9例患儿在腔镜下完成二次手术,手术方式为腹腔镜下胆总管囊肿切除肝管空肠Roux-en-Y吻合术。1例因纤维增生囊壁厚,腹腔镜下操作渗血多,不易止血影响操作视野,放弃腹腔镜操作中转开腹手术。所有患儿术中未发生腹腔镜手术副损伤,术后未发生胆漏、肠瘘、腹腔感染等并发症,均康复出院,住院时间7~10 d。结论 采用腹腔镜胆总管囊肿根治术治疗既往有胆管穿孔外引流手术史的患儿是安全可行的。  相似文献   
109.
110.
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