862 resultados para HIGH-INTENSITY LASER


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AIM The effect of long-term high-intensity statin therapy on coronary atherosclerosis among patients with acute ST-segment elevation myocardial infarction (STEMI) is unknown. The aim of this study was to quantify the impact of high-intensity statin therapy on plaque burden, composition, and phenotype in non-infarct-related arteries of STEMI patients undergoing primary percutaneous coronary intervention (PCI). METHODS AND RESULTS Between September 2009 and January 2011, 103 STEMI patients underwent intravascular ultrasonography (IVUS) and radiofrequency ultrasonography (RF-IVUS) of the two non-infarct-related epicardial coronary arteries (non-IRA) after successful primary PCI. Patients were treated with high-intensity rosuvastatin (40 mg/day) throughout 13 months and serial intracoronary imaging with the analysis of matched segments was available for 82 patients with 146 non-IRA. The primary IVUS end-point was the change in per cent atheroma volume (PAV). After 13 months, low-density lipoprotein cholesterol (LDL-C) had decreased from a median of 3.29 to 1.89 mmol/L (P < 0.001), and high-density lipoprotein cholesterol (HDL-C) levels had increased from 1.10 to 1.20 mmol/L (P < 0.001). PAV of the non-IRA decreased by -0.9% (95% CI: -1.56 to -0.25, P = 0.007). Patients with regression in at least one non-IRA were more common (74%) than those without (26%). Per cent necrotic core remained unchanged (-0.05%, 95% CI: -1.05 to 0.96%, P = 0.93) as did the number of RF-IVUS defined thin cap fibroatheromas (124 vs. 116, P = 0.15). CONCLUSION High-intensity rosuvastatin therapy over 13 months is associated with regression of coronary atherosclerosis in non-infarct-related arteries without changes in RF-IVUS defined necrotic core or plaque phenotype among STEMI patients.

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OBJECTIVES Levels of inflammatory biomarkers associate with changes of coronary atheroma burden in statin-treated patients with stable coronary artery disease. This study sought to determine changes of plaque composition in vivo in relation to high-sensitivity C-reactive protein (hs-CRP) levels in patients with ST-elevation myocardial infarction (STEMI) receiving high-intensity statin therapy. METHODS The IBIS-4 study performed serial (baseline and 13-month), 2-vessel intravascular ultrasound (IVUS) and radiofrequency-IVUS of the non-infarct-related arteries in patients with STEMI treated with high-intensity statin therapy. The present analysis included 44 patients (80 arteries) with serial measurements of hs-CRP. RESULTS At follow-up, median low-density lipoprotein cholesterol (LDL-C) levels decreased from 126 to 77 mg/dl, HDL-C increased from 44 to 47 mg/dl, and hs-CRP decreased from 1.6 to 0.7 mg/L. Regression of percent atheroma volume (-0.99%, 95% CI -1.84 to -0.14, p = 0.024) was accompanied by reduction of percent fibro-fatty (p = 0.04) and fibrous tissue (p < 0.001), and increase in percent necrotic core (p = 0.006) and dense calcium (p < 0.001). Follow-up levels of hs-CRP, but not LDL-C, correlated with changes in percent necrotic core (p = 0.001) and inversely with percent fibrous tissue volume (p = 0.008). Similarly, baseline-to-follow-up change of hs-CRP correlated with the change in percent necrotic core volume (p = 0.02). CONCLUSIONS In STEMI patients receiving high-intensity statin therapy, stabilization of VH-IVUS-defined necrotic core was confined to patients with lowest on-treatment levels and greatest reduction of hs-CRP. Elevated CRP levels at follow-up may identify progression of high-risk coronary plaque composition despite intensive statin therapy and overall regression of atheroma volume.

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AIMS/HYPOTHESIS To investigate exercise-related fuel metabolism in intermittent high-intensity (IHE) and continuous moderate intensity (CONT) exercise in individuals with type 1 diabetes mellitus. METHODS In a prospective randomised open-label cross-over trial twelve male individuals with well-controlled type 1 diabetes underwent a 90 min iso-energetic cycling session at 50% maximal oxygen consumption ([Formula: see text]), with (IHE) or without (CONT) interspersed 10 s sprints every 10 min without insulin adaptation. Euglycaemia was maintained using oral (13)C-labelled glucose. (13)C Magnetic resonance spectroscopy (MRS) served to quantify hepatocellular and intramyocellular glycogen. Measurements of glucose kinetics (stable isotopes), hormones and metabolites complemented the investigation. RESULTS Glucose and insulin levels were comparable between interventions. Exogenous glucose requirements during the last 30 min of exercise were significantly lower in IHE (p = 0.02). Hepatic glucose output did not differ significantly between interventions, but glucose disposal was significantly lower in IHE (p < 0.05). There was no significant difference in glycogen consumption. Growth hormone, catecholamine and lactate levels were significantly higher in IHE (p < 0.05). CONCLUSIONS/INTERPRETATION IHE in individuals with type 1 diabetes without insulin adaptation reduced exogenous glucose requirements compared with CONT. The difference was not related to increased hepatic glucose output, nor to enhanced muscle glycogen utilisation, but to decreased glucose uptake. The lower glucose disposal in IHE implies a shift towards consumption of alternative substrates. These findings indicate a high flexibility of exercise-related fuel metabolism in type 1 diabetes, and point towards a novel and potentially beneficial role of IHE in these individuals. TRIAL REGISTRATION ClinicalTrials.gov NCT02068638 FUNDING: Swiss National Science Foundation (grant number 320030_149321/) and R&A Scherbarth Foundation (Switzerland).

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The intensity of care for patients at the end-of-life is increasing in recent years. Publications have focused on intensity of care for many cancers, but none on melanoma patients. Substantial gaps exist in knowledge about intensive care and its alternative, hospice care, among the advanced melanoma patients at the end of life. End-of-life care may be used in quite different patterns and induce both intended and unintended clinical and economic consequences. We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked databases to identify patients aged 65 years or older with metastatic melanoma who died between 2000 and 2007. We evaluated trends and associations between sociodemographic and health services characteristics and the use of hospice care, chemotherapy, surgery, and radiation therapy and costs. Survival, end-of-life costs, and incremental cost-effectiveness ratio were evaluated using propensity score methods. Costs were analyzed from the perspective of Medicare in 2009 dollars. In the first journal Article we found increasing use of surgery for patients with metastatic melanoma from 13% in 2000 to 30% in 2007 (P=0.03 for trend), no significant fluctuation in use of chemotherapy (P=0.43) or radiation therapy (P=0.46). Older patients were less likely to receive radiation therapy or chemotherapy. The use of hospice care increased from 61% in 2000 to 79% in 2007 (P =0.07 for trend). Enrollment in short-term (1-3 days) hospice care use increased, while long-term hospice care (≥ 4 days) remained stable. Patients living in the SEER Northeast and South regions were less likely to undergo surgery. Patients enrolled in long-term hospice care used significantly less chemotherapy, surgery and radiation therapy. In the second journal article, of 611 patients identified for this study, 358 (59%) received no hospice care after their diagnosis, 168 (27%) received 1 to 3 days of hospice care, and 85 (14%) received 4 or more days of hospice care. The median survival time was 181 days for patients with no hospice care, 196 days for patients enrolled in hospice for 1 to 3 days, and 300 days for patients enrolled for 4 or more days (log-rank test, P < 0.001). The estimated hazard ratios (HR) between 4 or more days hospice use and survival were similar within the original cohort Cox proportional hazard model (HR, 0.62; 95% CI, 0.49-0.78, P < 0.0001) and the propensity score-matched model (HR, 0.61; 95% CI, 0.47-0.78, P = 0.0001). Patients with ≥ 4 days of hospice care incurred lower end-of-life costs than the other two groups ($14,298 versus $19,380 for the 1- to 3-days hospice care, and $24,351 for patients with no hospice care; p < 0.0001). In conclusion, Surgery and hospice care use increased over the years of this study while the use of chemotherapy and radiation therapy remained consistent for patients diagnosed with metastatic melanoma. Patients diagnosed with advanced melanoma who enrolled in ≥ 4 days of hospice care experienced longer survival than those who had 1-3 days of hospice or no hospice care, and this longer overall survival was accompanied by lower end-of-life costs.^

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Laser Shock Processing is developing as a key technology for the improvement of surface mechanical and corrosion resistance properties of metals due to its ability to introduce intense compressive residual stresses fields into high elastic limit materials by means of an intense laser driven shock wave generated by laser with intensities exceeding the 109 W/cm2 threshold, pulse energies in the range of 1 Joule and interaction times in the range of several ns. However, because of the relatively difficult-to-describe physics of shock wave formation in plasma following laser-matter interaction in solid state, only limited knowledge is available in the way of full comprehension and predictive assessment of the characteristic physical processes and material transformations with a specific consideration of real material properties. In the present paper, an account of the physical issues dominating the development of LSP processes from a moderately high intensity laser-matter interaction point of view is presented along with the theoretical and computational methods developed by the authors for their predictive assessment and new experimental contrast results obtained at laboratory scale.

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Outline: • Introduction • Process Experimental Setup • Experimental Procedure • Experimental Results for Al2024-T351 and Ti6Al4V - Residual stresses - Tensile Strength - Fatigue Life • Discussion and Outlook - Prospects for technological applications of LSP

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In the work, the results of an investigation of GaInP/GaInAs/Ge MJ SCs intended for converting concentrated solar radiation, when operating at low temperatures (down to -190 degrees C) are presented. A kink of the cell I-V characteristic has been observed in the region close to V-oc starting from -20 degrees C at operation under concentrated sunlight. The causes for its occurrence have been analyzed and the reasons for formation of a built-in potential barrier for majority charge carriers at the n-GaInP/n-Ge isotype hetero-interface are discussed. The effect of charge carrier transport in n-GaInP/n-p Ge heterostructures on MJ SC output characteristics at low temperatures has been studied including EL technique.

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Trata de una conferencia invitada que ganó premio a la mejor comunicación científica.

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CPV receivers are made of materials with very different lineal expansion coefficients. Strong variations in DNI due to the passage of clouds can cause sudden temperature changes that creates mechanical stress. For common solder and metal filled polymers the plastic limit could be reached causing substantial fatigue. The best forecast of receiver reliability is therefore achieved by applying an intermittent light source with nominal irradiance level and a number of cycles equal to the expected cloud passages for a given site. The UPM has developed specialized equipment, dubbed the LYSS (Light cYcling Stressing Source), for carrying out such experiments. The small thermal capacity of receivers allows simulating more than 25000 cycles per week. The number of deep transients expected for Madrid in 30 years operation, based on available data, is about 45000. We are currently using the system to cycle a ?Ge/Ag Epoxy/aluminum? receiver, which shows no degradation after 20000 cycles. The equipment can cast up to 200 and 70 W/cm2 on 0.1 and 1 cm2 cells, respectively.

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After construction of the LYSS (Light cYcling Stressing Source) in early 2014, several CPV receivers, with and without secondary optical element (SOE) have been aged under fast transient illumination cycling,. The test plan for Madrid consisted of 50000 cycles. Receivers with poor heat spreaders showed low reliability but those with thicker metal layers passed the test well. The operation of LYSS along 8 months, after more than 250000 cycles, did not show any significant failure, except lamp reposition every 120 hours, in average. The equipment seems valid for unveiling weak receiver designs with respect to intensive illumination, in steady and transient modes.