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   93457篇
  免费   5407篇
  国内免费   2208篇
耳鼻咽喉   707篇
儿科学   1789篇
妇产科学   1089篇
基础医学   7001篇
口腔科学   671篇
临床医学   13027篇
内科学   21400篇
皮肤病学   274篇
神经病学   5820篇
特种医学   5974篇
外国民族医学   4篇
外科学   12358篇
综合类   14091篇
现状与发展   6篇
预防医学   3625篇
眼科学   2964篇
药学   7303篇
  47篇
中国医学   2186篇
肿瘤学   736篇
  2024年   95篇
  2023年   1384篇
  2022年   1924篇
  2021年   3727篇
  2020年   3307篇
  2019年   2978篇
  2018年   3047篇
  2017年   2729篇
  2016年   2794篇
  2015年   2884篇
  2014年   6133篇
  2013年   6411篇
  2012年   5004篇
  2011年   5623篇
  2010年   4519篇
  2009年   4558篇
  2008年   4758篇
  2007年   4777篇
  2006年   4364篇
  2005年   3589篇
  2004年   2979篇
  2003年   2525篇
  2002年   2134篇
  2001年   2054篇
  2000年   1584篇
  1999年   1451篇
  1998年   1377篇
  1997年   1352篇
  1996年   1063篇
  1995年   1108篇
  1994年   957篇
  1993年   844篇
  1992年   826篇
  1991年   694篇
  1990年   615篇
  1989年   543篇
  1988年   546篇
  1987年   488篇
  1986年   421篇
  1985年   481篇
  1984年   458篇
  1983年   261篇
  1982年   369篇
  1981年   288篇
  1980年   249篇
  1979年   221篇
  1978年   188篇
  1977年   112篇
  1976年   95篇
  1975年   61篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
81.
BackgroundDistal radial access (DRA) has been proposed to improve procedure ergonomics and favor radial artery patency. Although promising data, nothing is known on evolving hand function after DRA.ObjectivesThis study sought to comprehensively evaluate hand function in patients undergoing DRA.MethodsReal-world patients undergoing DRA undertook a thorough multimodality assessment of hand function implementing multidomain questionnaires (Disabilities of the Arm, Shoulder and Hand and Levine-Katz), and motor (pinch grip test) and sensory (Semmes-Weinstein monofilaments test) examinations of both hands. All assessments were performed at preprocedural baseline and planned at 1-, 6-, and 12-month follow-up (FU). Adverse clinical and procedural events were documented too.ResultsData of 313 patients (220 men, age 66 ± 10 years) from 9 international centers were analyzed. The Disabilities of the Arm, Shoulder and Hand and the Levine-Katz scores slightly improved from baseline to FU (P = 0.008 and P = 0.029, respectively). Pinch strength mildly improved from baseline to FU (P < 0.001 for both the left and right hands). Similarly, touch pressure threshold appeared to faintly improve in both the left and right hands (P < 0.012 for all the sites). For both motor and sensory function tests, comparable findings were found for the DRA hand and the contralateral one, with no significant differences between them. Repeated assessment of all tests over all FU time points similarly showed lack of worsening hand function. Access-related adverse events included 19 harmless bleedings and 3 forearm radial artery and 3 distal radial artery occlusions. None affected hand function at FU.ConclusionsIn a systematic multidimensional assessment, DRA was not associated with hand function impairment. Moreover, DRA emerges as a safe alternative vascular access.  相似文献   
82.
《中国现代医生》2020,58(13):97-99+104
目的考察休克指数(shock index,SI)和舒张压(diastolic blood pressure,DBP)对女性产后出血的风险预测效果。方法选取2016年1月~2018年12月在我院行产检并分娩的320例产后出血孕妇作为研究组,另外选取同期进行正常分娩的健康孕妇240例作为对照组,比较两组患者的一般临床资料、血红蛋白(hemoglobin,Hb)、舒张压(diastolic blood pressure,DBP)、收缩压(systolic blood pressure,SBP)、心率(heart rate,HR)及休克指数(shock index,SI),并采用Ordinal逻辑回归分析各参数对产后出血的风险预警。结果两组患者在年龄、孕周、BMI及新生儿体重相比,差异无统计学意义(P0.05),而孕次相比,差异具有统计学意义(P0.05);与对照组产后24 h相比,研究组产后24 h患者的DBP、SBP及Hb均显著降低,而HR和SI显著升高(P0.05);与对照组产前相比,产后24 h患者的SBP、HR及SI显著降低(P0.05);与研究组产前相比,产后24 h患者的DBP、SBP、HR及Hb均显著降低,而SI显著升高,差异具有统计学意义(P0.05);Ordinal逻辑回归分析结果显示,休克指数和舒张压对产后出血具有预警作用(P0.05)。结论休克指数和舒张压可作为评估女性产后出血的风险预测指标,临床应密切监护。  相似文献   
83.
目的探讨胫前动脉踝上穿支皮瓣修复足踝部软组织缺损的临床疗效。方法回顾性研究2018年4月至2019年6月采用胫前动脉踝上穿支皮瓣修复足踝部软组织缺损19例的资料,其中男11例,女8例;年龄为21~75岁,平均39岁。根据前踝上穿支皮瓣解剖学基础,按照足踝部软组织缺损大小和形状,在小腿下端前外侧设计并切取皮瓣转位修复创面。切取胫前动脉踝上穿支皮瓣面积为6.0 cm×5.0 cm^14.0 cm×8.0 cm,均为带蒂皮瓣转位。根据皮瓣成活、感染控制、弹性色泽、外观形态、供区瘢痕、皮肤感觉、患者认可等情况,对患者足踝部软组织缺损的修复情况进行综合评价。结果本组19例皮瓣全部成活,软组织缺损、肌腱、骨质及钢板外露均得以修复。供区均I期愈合。术后门诊随访2~16个月,皮瓣血运良好,颜色接近周围正常皮肤,臃肿不明显,患者对外观表示满意;供区皮片愈合良好,无明显增生、挛缩及溃疡,踝关节功能良好。结论胫前动脉踝上穿支皮瓣是修复足踝部软组织缺损较为理想的方法之一,手术操作简便,穿支较恒定,血供可靠,具有一定的临床应用价值。  相似文献   
84.
85.
Background and aimsCoronary artery disease (CAD) is the principal cause of death in individuals with non-alcoholic fatty liver disease (NAFLD). The aim of this study was to use genetic epidemiology to study the association between de novo lipogenesis (DNL), one of the major pathways leading to NAFLD, and CAD risk.Methods and resultsDNL susceptibility genes were used as instruments and selected using three approaches: 1) genes that are associated with both high serum triglycerides and low sex hormone-binding globulin, both downstream consequences of DNL (unbiased approach), 2) genes that have a known role in DNL (biased approach), and 3) genes that have been associated with serum fatty acids, used as a proxy of DNL. Gene-CAD effect estimates were retrieved from the meta-analysis of CARDIoGRAM and the UK Biobank (~76014 cases and ~264785 controls). Effect estimates were clustered using a fixed-effects meta-analysis. Twenty-two DNL susceptibility genes were identified by the unbiased approach, nine genes by the biased approach and seven genes were associated with plasma fatty acids. Clustering of genes selected in the unbiased and biased approach showed a statistically significant association with CAD (OR:1.016, 95%CI:1.012; 1.020 and OR:1.013, 95%CI:1.007; 1.020, respectively), while clustering of fatty acid genes did not (OR:1.004, 95%CI:0.996–1.011). Subsequent exclusion of potential influential outliers did reveal a statistically significant association (OR:1.009, 95%CI:1.000; 1.018).ConclusionsDNL susceptibility genes are associated with an increased risk of CAD. These findings suggest that DNL may be involved in the pathogenesis of CAD and favor further development of strategies that target NAFLD through DNL.  相似文献   
86.
目的:探究风池穴不同刺法对椎动脉型颈椎病的临床疗效。方法:选择2018年4月—2019年1月北京中医药大学东直门医院针灸科门诊就诊的84例椎动脉型颈椎病患者作为研究对象,分为观察组43例、对照组41例。观察组采用短刺法针刺风池穴治疗,对照组采用平补平泻法针刺风池穴治疗,1个疗程后比较两组患者的ESCV、颈椎病症状分级量化表评分以及TCD相关指标,TCD指标观察基底动脉和双侧椎动脉的平均血流速度(Vm)、收缩期血流速度峰值(Vs)、血管搏动指数(PI)和血管阻力指数(RI)的变化。结果:治疗前后两组ESCV、颈椎病症状分级量化表评分比较,差异有统计学意义(P<0.05),且椎动脉、基底动脉的Vs、Vm较治疗前明显减慢,且观察组治疗效果优于对照组(P<0.05)。结论:针刺风池穴治疗椎动脉型颈椎病临床效果显著,且短刺法优于平补平泻法。  相似文献   
87.
目的:探讨肛肠疾病手术前后肛管直肠压力测定的应用。方法:将2018年5月-2019年5月在上海市松江区方塔中医医院及上海中医药大学附属曙光医院肛肠科行手术治疗的826例肛肠疾病患者作为研究对象,其中,选择性痔上黏膜吻合术246例、单纯外剥内扎术115例、外剥内扎结合内痔套扎术(Automatic Ligation of Hemorrhoids,RPH)153例、低位肛瘘切除术177例、高位肛瘘切开挂线术135例,分别于术前及术后1个月测定肛管直肠压力。结果:选择性痔上黏膜吻合术后直肠静息压、肛管静息压明显低于术前,肛管舒张压高于术前(P<0.05),但肛管最大收缩压与术前相比无明显差异(P>0.05);单纯外剥内扎术术后直肠静息压、肛管静息压明显低于术前,肛管舒张压、肛管最大收缩压明显高于术前(P<0.05);外剥内扎结合内痔套扎术术后直肠静息压、肛管静息压明显低于术前,肛管舒张压、肛管最大收缩压明显高于术前(P<0.05);低位肛瘘切除术术后直肠静息压、肛管静息压、肛管舒张压均高于术前(P<0.05),而肛管最大收缩压与术前相比无明显差异(P>0.05);高位肛瘘切开挂线术术后直肠静息压高于术前,肛管静息压、肛管舒张压低于术前(P<0.05),而与肛管最大收缩压术前相比无明显差异(P>0.05)。结论:肛肠疾病手术前后肛管直肠压力测定的应用效果显著,能准确判断手术效果及患者恢复情况,为医师的进一步诊治奠定了良好基础。  相似文献   
88.
目的 观察SWIM技术治疗后循环大血管闭塞所致急性缺血性卒中的有效性及安全性。 方法 回顾性分析2017年2月-2018年11月于大连市中心医院采用SWIM技术治疗的后循环大血管闭 塞所致急性缺血性卒中患者的临床资料,评价该技术的疗效和安全性,并分析影响患者预后的因素。 观察指标为术后即刻成功再通(mTICI≥2b)、90 d良好预后(mRS评分≤2分),以及术后24 h任何颅内 出血、90 d全因死亡。 结果 共纳入35例患者,平均年龄66.1±12.1岁,男性26例(74.3%),基线NIHSS评分22(15~34)分。 术后即刻成功再通率为94.3%(33/35),90 d良好预后率为45.7%(16/35),24 h颅内出血率为17.1% (6/35),90 d全因死亡率为37.1%(13/35)。单因素分析显示,基线NIHSS评分较低(P =0.001)、基 线后循环ASPECTS评分较高(P =0.016)、发病至到院时间较短(P =0.039)、发病至再通时间较短 (P =0.047)、血管成功再通率较高(P =0.036)以及饮酒比例较低(P =0.042)与良好预后相关。 结论 使用SWIM技术治疗后循环急性缺血性卒中相对安全、有效。  相似文献   
89.
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   
90.
ObjectivesSevere acute kidney injury (AKI) is a known risk factor for infection and mortality. However, whether stage 1 AKI is a risk factor for infection has not been evaluated in adults. We hypothesized that stage 1 AKI following cardiac surgery would independently associate with infection and mortality.MethodsIn this retrospective propensity score–matched study, we evaluated 1620 adult patients who underwent nonemergent cardiac surgery at the University of Colorado Hospital from 2011 to 2017. Patients who developed stage 1 AKI by Kidney Disease Improving Global Outcomes creatinine criteria within 72 hours of surgery were matched to patients who did not develop AKI. The primary outcome was an infection, defined as a new surgical-site infection, positive blood or urine culture, or development of pneumonia. Secondary outcomes included in-hospital mortality, stroke, and intensive care unit (ICU) and hospital length of stay (LOS).ResultsStage 1 AKI occurred in 293 patients (18.3%). Infection occurred in 20.9% of patients with stage 1 AKI compared with 8.1% in the no-AKI group (P < .001). In propensity-score matched analysis, stage 1 AKI independently associated with increased infection (odds ratio [OR]; 2.24, 95% confidence interval [CI], 1.37-3.17), ICU LOS (OR, 2.38; 95% CI, 1.71–3.31), and hospital LOS (OR, 1.30; 95% CI, 1.17-1.45).ConclusionsStage 1 AKI is independently associated with postoperative infection, ICU LOS, and hospital LOS. Treatment strategies focused on prevention, early recognition, and optimal medical management of AKI may decrease significant postoperative morbidity.  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