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   106817篇
  免费   9796篇
  国内免费   4289篇
耳鼻咽喉   1818篇
儿科学   1987篇
妇产科学   831篇
基础医学   13782篇
口腔科学   11231篇
临床医学   11341篇
内科学   11716篇
皮肤病学   1273篇
神经病学   4280篇
特种医学   4290篇
外国民族医学   30篇
外科学   16656篇
综合类   15963篇
现状与发展   9篇
一般理论   1篇
预防医学   6187篇
眼科学   1123篇
药学   7189篇
  71篇
中国医学   6139篇
肿瘤学   4985篇
  2024年   105篇
  2023年   1867篇
  2022年   2339篇
  2021年   4338篇
  2020年   4399篇
  2019年   3878篇
  2018年   3906篇
  2017年   3766篇
  2016年   3910篇
  2015年   4038篇
  2014年   7465篇
  2013年   9210篇
  2012年   6283篇
  2011年   6933篇
  2010年   5637篇
  2009年   5278篇
  2008年   5234篇
  2007年   5320篇
  2006年   4681篇
  2005年   4333篇
  2004年   3790篇
  2003年   3411篇
  2002年   2561篇
  2001年   2365篇
  2000年   1866篇
  1999年   1646篇
  1998年   1187篇
  1997年   1137篇
  1996年   1028篇
  1995年   955篇
  1994年   904篇
  1993年   660篇
  1992年   696篇
  1991年   606篇
  1990年   523篇
  1989年   482篇
  1988年   415篇
  1987年   369篇
  1986年   324篇
  1985年   463篇
  1984年   355篇
  1983年   300篇
  1982年   345篇
  1981年   283篇
  1980年   281篇
  1979年   202篇
  1978年   209篇
  1977年   148篇
  1976年   159篇
  1975年   82篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Pancreatology》2022,22(8):1175-1180
BackgroundHepatic steatosis has been described as a common finding in adults following total pancreatectomy with islet autotransplantation (TPIAT) but it is unknown if this occurs in children and adolescents.ObjectivesTo define the frequency of post-TPIAT hepatic steatosis in a sample of children and adolescents and to identify clinical predictors of incident steatosis post-TPIAT.MethodsIn this prospective study, consecutive participants at least 1-month post-TPIAT underwent a liver MRI with proton density fat fraction (PDFF) and blood draw at our pediatric academic medical center between April 2021 and January 2022. Comparison clinical pre-TPIAT liver MRI or ultrasound and insulin use and graft function data were extracted from the medical record. T-tests were used for the comparison of means across continuous variables between participants with and without post-TPIAT steatosis.ResultsA total of 20 participants (mean: 13 ± 4 years; 12 female) were evaluated. Mean liver PDFF at research MRI was 7.4 ± 6.2% (range: 2–25%). Seven participants (35%) had categorical hepatic steatosis (PDFF>5%) post-TPIAT, five of whom had pre-TPIAT steatosis, reflecting a 13% (2/15; 95% CI: 2–40%) incidence of post-TPIAT steatosis. Participant characteristics were not significantly different between subgroups with and without post-TPIAT steatosis. Mean PDFF at research MRI was not different between graft function subgroups (7.5% optimal/good vs. 7.3% marginal/failure; p = .96).ConclusionOur study shows a moderate prevalence but low incidence of hepatic steatosis in a small sample of children and adolescents post-TPIAT. This study raises questions about a causal relationship between TPIAT and hepatic steatosis.  相似文献   
2.
目的分析同型半胱氨酸(Hcy)、溶血磷脂酸(LPA)及转化生长因子-β1(TGF-β1)在创伤性骨折下肢静脉栓塞中的预测价值。方法选取2019年3月至2020年2月商丘市第一人民医院收治的104例创伤性骨折者(观察组),根据有无DVT:有DVT组33例,无DVT组71例;根据创伤严重程度:轻度组61例,重度组43例。另选取本院同期92例健康体检者设为对照组。比较不同人群、不同病情程度以及有无DVT者血浆Hcy、LPA及血清TGF-β1水平,分析Hcy、LPA及TGF-β1对DVT的预测价值。结果观察组Hcy、LPA及TGF-β1表达水平均明显高于对照组,差异均有统计学意义(P<0.05)。重度组Hcy、LPA及TGF-β1表达水平明显高于轻度组,差异均有统计学意义(P<0.05)。有DVT组者Hcy、LPA及TGF-β1表达水平明显高于无DVT组,差异均有统计学意义(P<0.05)。依据ROC曲线分析可知,Hcy+LPA+TGF-β1三者联合预测创伤性骨折后发生DVT敏感度和特异度分别为88.90%、8130%,明显高于三者单独检测(P<0.05)。结论Hcy、LPA及TGF-β1在创伤性骨折发生下肢静脉栓塞时水平均明显升高,三者联合检测对下肢静脉栓塞早期诊断有重要的临床价值。  相似文献   
3.
特纳综合征(TS)是女性常见的性染色体异常疾病,与多种疾病共存。越来越多的证据表明TS患者有较高的骨质疏松患病率,本文就近年来TS中骨质疏松的危险因素及管理治疗的相关研究进展做一综述。  相似文献   
4.
5.
目的探讨经皮椎体后凸成形术(PKP)术中不同注入量高粘度骨水泥治疗骨质疏松性腰椎骨折(OLVF)的疗效及安全性。 方法前瞻性收集2016年9月至2018年9月本院OLVF患者150例,男84例,女66例,年龄(60±8)岁。依据随机数字表分为高量组、中量组、低量组,每组50例,高量组、中量组、低量组PKP术中高粘度骨水泥注入量分别为5.0~7.0 ml、3~4.9 ml、<3.0 ml,比较三组疗效及安全性。 结果150例患者获得满意随访,随访时间(19±7)个月。高量组、中量组、低量组手术时间、术中出血量比较,差异无统计学意义(P>0.05);高量组和中量组术后3、6个月椎体前缘高度[(27.3±3.1)mm、(26.0±2.7)mm和(26.9±3.0)mm、(25.7±2.8)mm]明显高于低量组[(23.8±2.8)mm、(21.3±2.5)mm],高量组和中量组术后3、6个月Cobb角及疼痛视觉模拟评分法(VAS)、Oswestry功能障碍指数问卷表(ODI)评分[(40.2±4.7)°、(41.5±4.8)°、(2.6±0.4)分、(1.6±0.3)分、(25.8±3.5)分、(26.9±3.5)分和(40.9±4.8)°、(42.1±4.8)°、(2.6±0.4)分、(1.6±0.3)分、(26.2±3.5)分、(27.2±3.7)分]明显低于低量组[(46.3±5.3)°、(47.8±5.6)°、(3.3±0.4)分、(2.3±0.4)分、(33.3±4.1)分、(34.3±4.2)分],差异有统计学意义(F=25.371、18.914、29.334、22.457、34.276、30.217、29.364、20.071,均P<0.001);高量组骨水泥渗漏率(28.00%)明显高于中量组和低量组(8.00%和4.00%),差异有统计学意义(χ2=10.241,P=0.005)。 结论PKP术中不同注入量高粘度骨水泥治疗OLVF的疗效及安全性存在一定的差异,其中注入中量(3~4.9 ml)高粘度骨水泥可获得良好的疗效及安全性,值得临床推广。  相似文献   
6.
ObjectiveTo analyze the effects of electrolysis, through a medium frequency current, associated to aerobic physical activity in the body composition of young women.MethodsThe study was composed of 34 sedentary women (24.35 ± 4.43 years, 71.30 ± 7.08 kg, 1.61 ± 0.06 m, 27.31 ± 1.67 kg/m2) which were evaluated for their anthropometric measures and body composition. The volunteers were randomly assigned to two group: Electrolyphysis plus Aerobic Exercise (gEEA): 17 volunteers were submitted to the application, for 60 min , of the Aussie current, followed by aerobic physical activity (77% of HRmax) on the trampoline for 40 min, through video-lessons of Jump; and Aerobic Exercise group (gEA): 17 volunteers performed only physical activity following the same parameters mentioned above. Each group performed its protocols twice weekly, for 5 weeks, totaling 10 sessions. For the data analysis, measures repeated ANOVA was performed to compare the means of the variables analyzed before and after the treatment protocols using the SPSS - 21.0 software, adopting a p ≤ 0.05.ResultsAlthough gEEA decreased suprailiac skinfold (p = 0.04), abdominal skinfold (p = 0.03) and circumference at umbilical scar (p = 0.02) in an intragroup analysis, these means differences in anthropometric measures were not important between-groups (p > 0.05). Furthermore, there were no effect of treatment on body composition (p > 0.05).ConclusionTo this studied condition, our results suggested that application of medium frequency electrolysis did not enhance the losses on anthropometric measures and body composition.  相似文献   
7.
目的 观察治伤巴布剂对急性软组织损伤(acute soft tissue injury, ASTI)模型p38丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)、丝/苏氨酸蛋白激酶(AKT)信号通路的影响,探讨治伤巴布剂干预ASTI的可能作用机制。方法 将40只雄性SD大鼠按照随机数字表法分为正常对照组、模型对照组、治伤巴布剂组、p38MAPK信号通路抑制剂组、AKT信号通路抑制剂组,每组8只。除正常对照组外,其余四组均予以左侧后肢小腿ASTI造模。造模成功后,治伤巴布剂组于标记部位立即予治伤巴布剂(修剪成1.5x3cm大小)外敷,并用胶布固定;其余四组均予等剂量赋形剂(修剪成1.5×3 cm大小)外敷处理,胶布固定;持续外敷,共持续24 h。p38MAPK信号通路抑制剂组在造模前30 min予腹腔注射p38MAPK信号通路抑制剂SB203580(400 μg/kg/天)1次;AKT信号通路抑制剂组在造模前30 min予腹腔注射AKT信号通路抑制剂perifosine(20 mg/kg/天)1次。分别于0(造模前)、2h、4h、8h、12h、24h测量受伤小腿肌肉处的周长,并计算肌肉肿胀率(muscle swelling rate,MSR)。24 h药物干预结束后,采用颈椎脱臼法处死大鼠。后将左侧后肢小腿损伤中心部位进行取材,分成三份。一部分用于观察组织病理学形态变化;一部分用于逆转录聚合酶链反应(RT-PCR)检测核因子-κB(nuclear factor kappa-B,NF-κB)p65 mRNA、肿瘤坏死因子-α(TNF-α)mRNA、白细胞介素-1β(IL-1β)mRNA表达水平;剩下部分用酶联免疫吸附试验(ELISA)法检测骨骼肌组织TNF-α、IL-1β含量水平及蛋白质免疫印迹(Western-blot)法测定p38MAPK、AKT、NF-κB p65、核因子抑制蛋白α(inhibitor kappa B alpha, IκBα)表达水平。结果 与正常对照组相比,模型对照组MSR显著增加(P<0.01);病理形态学上,骨骼肌组织可见大面积肌细胞排列紊乱,肌细胞变性坏死,间质内可见红细胞聚集及大量炎症细胞浸润;骨骼肌组织TNF-α、IL-1β含量水平显著升高(P<0.01);磷酸化p38MAPK(p-p38)/总p38MAPK(t-p38),磷酸化-AKT(p-AKT)/总-AKT(t-AKT)明显升高(P<0.01),NF-κB p65及NF-κB p65mRNA表达水平明显升高(P<0.01)。与模型对照组相比,治伤巴布剂组MSR在治疗第8 h、12 h、24 h显著下降(P<0.01),且在治疗第24 h,其MSR较p38MAPK、AKT信号通路抑制剂组下降更明显(P<0.05);病理学评分显著下降(P<0.01),且较p38MAPK、AKT信号通路抑制剂组下降更显著(P<0.05);骨骼肌组织TNF-α、IL-1β含量水平明显下降(P<0.01),且较p38MAPK、AKT信号通路抑制剂组更显著(P<0.05);p-p38/t-p38及p-AKT/t-AKT明显下降(P<0.01),NF-κB p65及NF-κB p65 mRNA表达水平显著下降(P<0.01),且较p38MAPK、AKT信号通路抑制剂组在降低NF-κB p65及NF-κB p65 mRNA相对表达值方面更显著(P<0.01)。结论 治伤巴布剂可能同时对p38MAPK、AKT信号通路产生了一定的抑制作用,引起NF-κB活性下调,NF-κB p65蛋白的表达下调,进而引起骨骼肌组织TNF-α、IL-1β炎性细胞因子含量水平下调,减轻ASTI炎症反应,从而改善ASTI。  相似文献   
8.
BackgroundIntraabdominal and retroperitoneal sarcomas (IaRS) are malignant connective tissue tumors. Surgical resection is often the only curative treatment. The primary objective was to report the mid-term outcomes following contemporary treatment protocols and identify prognostic factors.MethodsA retrospective review of consecutive patients (n = 107) with IaRS treated at single center from 2013 until 2018 was conducted. Histological diagnosis, tumor grade, perioperative complications, mortality, and long-time survival were registered and retrieved from patient records. Primary and recurrent tumors were analyzed separately.ResultsA total of 107 patients were identified. Median follow-up time was 3.5 years. Thirty-day mortality was 3.4% and 90-day mortality was 5.6% for all tumors. The major complication rate was 18%. The 5-year estimated survival for primary and recurrent tumors was 55.4% and 48.4%, respectively. Multifocal disease was evident in 32% of the patient cohort, and 58% of patients in the recurrent group. Multivariate analysis for survival revealed a hazard ratio (HR) of 3.1 (95% CI 1.68–8.41) for multifocality, HR 2.9 (95% CI 1.28–6.98) for Clavien-Dindo grade, HR 2.3 (95% CI 1.21–4.31) for tumor grades 2 or 3, and HR 1.002 (95% CI 1.001–1.004) for surgical margins.ConclusionsOur study found overall acceptable morbidity and mortality, and identified prognostic markers for overall survival. Recurrent tumors were not associated with worse survival. Multifocality is associated with a worse overall survival. The prognostic factors identified were; tumor grade, multifocality, intralesional margins and postoperative complications.  相似文献   
9.
In the pelvis, anatomic complexity and difficulty in visualization and access make surgery a formidable task. Surgeons are prone to work-related musculoskeletal injuries from the frequently poor design and flow of their work environment. This is exacerbated by the strain of surgery in the pelvis. These injuries can result in alterations to a surgeons practice, inadvertent patient injury, and even early retirement. Human factors examines the relationships between the surgeon, their instruments and their environment. By bridging physiology, psychology, and ergonomics, human factors allows a better understanding of some of the challenges posed by pelvic surgery. The operative approach involved (open, laparoscopic, robotic, or perineal) plays an important role in the relevant human factors. Improved understanding of ergonomics can mitigate these risks to surgeons. Other human factors approaches such as standardization, use of checklists, and employing resiliency efforts can all improve patient safety in the operating theatre.  相似文献   
10.
目的 测定儿童1型糖尿病(T1DM)患者骨密度(BMD),分析探讨骨密度变化的影响因素。方法 选取于2018年1月—2021年6月于我院收治的儿童1型糖尿病患者76例,收集性别、年龄、发病年龄、身高、体重、BMI、病程等基本资料,检测空腹血糖、空腹C肽、糖化血红蛋白(HbA1c)、血碳酸氢根(HCO3-)、血清碱性磷酸酶(ALP),应用双能X线吸收测定法测定骨密度,获取Z值。结果 76例儿童1型糖尿病患者骨密度Z值为-0.93±2.14。HbA1c、病程与骨密度Z值呈负相关,差异具有统计学意义(分别B=-0.334,P<0.001;B=-0.191,P=0.017)。结论 儿童1型糖尿病患者骨密度低于健康儿童,血糖控制不良、病程长是1型糖尿病儿童骨密度减低的危险因素。  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