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   3035篇
  免费   172篇
  国内免费   16篇
耳鼻咽喉   49篇
儿科学   199篇
妇产科学   96篇
基础医学   272篇
口腔科学   52篇
临床医学   192篇
内科学   547篇
皮肤病学   73篇
神经病学   149篇
特种医学   173篇
外科学   376篇
综合类   325篇
一般理论   1篇
预防医学   117篇
眼科学   149篇
药学   156篇
中国医学   3篇
肿瘤学   294篇
  2023年   20篇
  2022年   30篇
  2021年   64篇
  2020年   28篇
  2019年   51篇
  2018年   82篇
  2017年   61篇
  2016年   65篇
  2015年   84篇
  2014年   116篇
  2013年   91篇
  2012年   149篇
  2011年   165篇
  2010年   130篇
  2009年   109篇
  2008年   140篇
  2007年   149篇
  2006年   161篇
  2005年   121篇
  2004年   115篇
  2003年   98篇
  2002年   108篇
  2001年   76篇
  2000年   91篇
  1999年   96篇
  1998年   59篇
  1997年   63篇
  1996年   68篇
  1995年   45篇
  1994年   35篇
  1993年   16篇
  1992年   41篇
  1991年   48篇
  1990年   39篇
  1989年   35篇
  1988年   33篇
  1987年   31篇
  1986年   19篇
  1985年   26篇
  1984年   22篇
  1983年   20篇
  1981年   14篇
  1977年   18篇
  1976年   18篇
  1975年   14篇
  1973年   13篇
  1972年   16篇
  1971年   12篇
  1968年   15篇
  1967年   12篇
排序方式: 共有3223条查询结果,搜索用时 15 毫秒
91.
The rapid introduction of Internet of Things (IoT) Technology has boosted the service deliverance aspects of health sector in terms of m-health, and remote patient monitoring. IoT Technology is not only capable of sensing the acute details of sensitive events from wider perspectives, but it also provides a means to deliver services in time sensitive and efficient manner. Henceforth, IoT Technology has been efficiently adopted in different fields of the healthcare domain. In this paper, a framework for IoT based patient monitoring in Intensive Care Unit (ICU) is presented to enhance the deliverance of curative services. Though ICUs remained a center of attraction for high quality care among researchers, still number of studies have depicted the vulnerability to a patient’s life during ICU stay. The work presented in this study addresses such concerns in terms of efficient monitoring of various events (and anomalies) with temporal associations, followed by time sensitive alert generation procedure. In order to validate the system, it was deployed in 3 ICU room facilities for 30 days in which nearly 81 patients were monitored during their ICU stay. The results obtained after implementation depicts that IoT equipped ICUs are more efficient in monitoring sensitive events as compared to manual monitoring and traditional Tele-ICU monitoring. Moreover, the adopted methodology for alert generation with information presentation further enhances the utility of the system.  相似文献   
92.
93.
Rheologic predictors of the severity of the painful sickle cell crisis   总被引:4,自引:0,他引:4  
Ballas  SK; Larner  J; Smith  ED; Surrey  S; Schwartz  E; Rappaport  EF 《Blood》1988,72(4):1216-1223
Deformable sickle erythrocytes have been reported by Mohandas and Evans to be more adherent to vascular endothelium than rigid irreversibly sickled cells (ISC). To define the clinical implications of this finding we have determined genetic, hematological, clinical, and rheological characteristics of sickle erythrocytes obtained from 65 patients with sickle cell anemia and fetal hemoglobin (Hb F) levels less than 15%. The alpha-globin gene number had a significant effect on the hematological parameters, the percentage of dense cells, ISC number, and HB A2 levels. The presence or absence of alpha thalassemia, however, had no effect on the frequency and severity of the sickle cell painful crisis (r = 0.06, P greater than .05). RBC deformability, determined by an ektacytometer, showed great heterogeneity among patients with three or four alpha-globin genes. Linear regression analyses of the data showed significant positive correlation of the frequency and severity of the painful crisis with RBC deformability (r = 0.49, P less than .001), and negative correlations with the percentage of dense cells (r = -0.37, P = .002), and the percentage of ISC (r = -0.46, P less than .001). We propose that the more deformable the sickle RBC are, the greater their adherence to vascular endothelium, and the more they cause vaso-occlusive crises, RBC deformability and the percentage of dense cells (or ISC) seem to have a predictive value of the frequency and severity of painful crises in sickle cell anemia.  相似文献   
94.
OBJECTIVES: Transjugular intrahepatic portosystemic shunt (TIPS) is frequently used to treat patients with refractory ascites, but its role is controversial. We sought to determine from the literature the efficacy, morbidity, and mortality associated with TIPS for refractory ascites. METHODS: We searched MEDLINE and identified studies published in English from January, 1985, to March, 2003, that evaluated the effect of TIPS in patients with refractory ascites. Outcomes that were analyzed included complete resolution of ascites, reduction in ascites, mortality, encephalopathy, stenosis, and renal function. Data were analyzed on an intention to treat basis. RESULTS: Of 25 studies identified, 16 were included in the analysis. The pooled estimate for complete response at 6 months was 45% and for any response (complete and partial) was 63%. Pooled 6-month mortality after TIPS was 36%. Risk factors for mortality included renal insufficiency (serum creatinine >1.5 mg/dl), hyperbilirubinemia (total bilirubin >3 mg/dl), advanced age (>60 yr), and poor response to TIPS. The pooled rate of new or worsening encephalopathy after TIPS was 32%. In most cases, encephalopathy was managed medically or by reduction in shunt size; however, refractory cases were associated with 100% mortality in most studies. Studies reporting the effect of TIPS on kidney function showed improvement in creatinine clearance and urinary sodium excretion. CONCLUSIONS: TIPS is effective in eliminating ascites or substantially reducing ascites in cases refractory to medical therapy. Renal insufficiency, refractory encephalopathy, and hyperbilirubinemia were consistently associated with mortality after TIPS. In individuals with risk factors for mortality, alternative strategies should be recommended.  相似文献   
95.
96.
Prompt serum copper and zinc in addition to vitamin B12 levels should be measured in patients suffering from refractory anemia with neurological symptoms. A timely copper supplementation can help revert the hematological and possibly the neurological manifestations.  相似文献   
97.
The risk of type 2 diabetes mellitus (T2DM) varies by ethnicity, but ethnic differences in response to diabetes prevention interventions remain unclear. This systematic review and meta-analysis assessed ethnic differences in the effects of lifestyle interventions on T2DM incidence, glycemic outcomes (fasting glucose, 2-h glucose, HbA1c), anthropometric measures (weight, BMI, waist circumference), and lifestyle behaviors (physical activity, energy intake, energy from fat, fiber intake). MEDLINE, EMBASE, and other databases were searched (to June 15, 2020) for randomized and non-randomized controlled trials on lifestyle interventions (diet and/or physical activity) in adults at risk of T2DM. Ethnicity was categorized into European, South Asian, East and Southeast Asian, Middle Eastern, Latin American, and African groups. Forty-four studies were included in meta-analyses. Overall, lifestyle interventions resulted in significant improvement in T2DM incidence, glycemic outcomes, anthropometric measures, physical activity, and energy intake (all P < 0.01). Significant subgroup differences by ethnicity were found for 2-h glucose, weight, BMI, and waist circumference (all P < 0.05) but not for T2DM incidence, fasting glucose, HbA1c, and physical activity (all P > 0.05). Few studies in non-European groups reported dietary intake. Lifestyle interventions in different ethnic groups may have similar effects in reducing incidence of T2DM although this needs to be confirmed in further studies.  相似文献   
98.

Background

The Heartmate 3 (HM3) is a Conformiteé Européenne mark–approved left ventricular (LV) assist device (LVAD) with fully magnetically levitated rotor and features consisting of a wide range operational speeds, wide flow paths, and artificial pulse. We performed a hemodynamic-echocardiographic speed optimization evaluation in HM3-implanted patients to achieve optimal LV- and right ventricular (RV) shape.

Methods and Results

Sixteen HM3 patients underwent pump speed ramp tests with right heart catheterization. Three-dimensional echocardiographic (3DE) LV and RV datasets (Philips) were acquired, and volumetric (Tomtec) and shape (custom software) analyses were performed (LV: sphericity, conicity; RV: septal and free-wall curvatures). Data were recorded at up to 13 speed settings. Speed changes were in 100-rpm steps, starting at 4600 rpm and ramping up to 6200 rpm. 3DE was feasible in 50% of the patients. Mean original speed was 5306 ± 148 rpm. LV end-diastolic (ED) diameter (?0.15 ± 0.09 cm/100 rpm) and volumes (ED: 269 ± 109 mL to 175 ± 90 mL; end-systolic [ES]: 234 ± 111 mL to 146 ± 81 mL) progressively decreased as the shape became less spherical and more conical; RV volumes initially remained stable, but at higher speeds increased (ED: from 148 ± 64 mL to 181 ± 92 mL; ES: 113 ± 63 mL to 130 ± 69 mL). On average, the RV septum became less convex (bulging toward the LV) at the highest speeds.

Conclusions

LV and RV shape changes were noted in HM3-supported patients. Although a LV volumetric decrease and shape improvement was consistently noted, RV volumes grew in response to increase in speed above a certain point. A next concern would be whether understanding of morphologic and function changes in LV and RV during LVAD speed change assessed with the use of 3DE helps to optimize LVAD speed settings and improve clinical outcomes.  相似文献   
99.
Ocular manifestations of Mycoplasma pneumoniae infection, other than conjunctivitis, are uncommon. Optic disk swelling, optic nerve atrophy, retinal exudates and hemorrhages, and cranial nerve palsies have been infrequently reported. We describe a 15-year-old patient who developed bilateral optic disk edema and iritis during an acute infection with M. pneumoniae and review the world literature on findings associated with ocular manifestations of infection with this pathogen. Although our patient experienced complete resolution of iritis and optic disk edema after 6 weeks, several patients described in the literature have experienced permanent sequelae as a result of optic neuropathy.  相似文献   
100.
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