6 research outputs found

    Structural and Optical Properties of Varies Thickness of Znte Nanoparticle

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    ZnTe thin films of different thicknesses were deposited onto glass substrates for optical devices applications. Xray diffractogram of different thicknesses for ZnTe films are measured and their patterns exhibits polycrystalline nature with a preferential orientation along the (111) plane. X-ray diffraction techniques have been employed to determine the microstructure parameters, both crystallite size and microstrain. Film thickness and the optical constants of ZnTe films were calculated based on the measured transmittance spectral data using Swanepole’s method in the wavelength range 400–2500 nm. The refractive index n and absorption index k were calculated, and the refractive index exhibits a normal dispersion. The refractive index could be extrapolated by Cauchy dispersion relationship over the whole spectra range, which extended from 400 to 2500 nm. The optical band gap can be calculated in strong absorption region and displays an allowed direct transition. Both the refractive index and the band gap increase with the increase film thickness, thus ZnTe/glass substrates are good candidates in optoelectronic devices

    Structural and Optical Properties of Varies Thickness of Znte Nanoparticle

    Get PDF
    ZnTe thin films of different thicknesses were deposited onto glass substrates for optical devices applications. Xray diffractogram of different thicknesses for ZnTe films are measured and their patterns exhibits polycrystalline nature with a preferential orientation along the (111) plane. X-ray diffraction techniques have been employed to determine themicrostructure parameters, both crystallite size and microstrain. Film thickness and the optical constants of ZnTe films were calculated based on the measured transmittance spectral data using Swanepole’s method in the wavelength range 400–2500 nm. The refractive index n and absorption index k were calculated and the refractive index exhibits a normal dispersion. The refractive index could be extrapolated by Cauchy dispersion relationship over the whole spectra range, which extended from 400 to 2500 nm. The optical band gap can be calculated in strong absorption region and displays an allowed direct transition. Both the refractive index and the band gap increase with the increase film thickness, thus ZnTe/glass substrates are good candidates in optoelectronic devices.Keywords: ZnTe, thin film, cry crystallitze size; microstrain; optical constants

    Characterization of Myocardial Injury in Patients With COVID-19

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    Background: Myocardial injury is frequent among patients hospitalized with coronavirus disease-2019 (COVID-19) and is associated with a poor prognosis. However, the mechanisms of myocardial injury remain unclear and prior studies have not reported cardiovascular imaging data. Objectives: This study sought to characterize the echocardiographic abnormalities associated with myocardial injury and their prognostic impact in patients with COVID-19. Methods: We conducted an international, multicenter cohort study including 7 hospitals in New York City and Milan of hospitalized patients with laboratory-confirmed COVID-19 who had undergone transthoracic echocardiographic (TTE) and electrocardiographic evaluation during their index hospitalization. Myocardial injury was defined as any elevation in cardiac troponin at the time of clinical presentation or during the hospitalization. Results: A total of 305 patients were included. Mean age was 63 years and 205 patients (67.2%) were male. Overall, myocardial injury was observed in 190 patients (62.3%). Compared with patients without myocardial injury, those with myocardial injury had more electrocardiographic abnormalities, higher inflammatory biomarkers and an increased prevalence of major echocardiographic abnormalities that included left ventricular wall motion abnormalities, global left ventricular dysfunction, left ventricular diastolic dysfunction grade II or III, right ventricular dysfunction and pericardial effusions. Rates of in-hospital mortality were 5.2%, 18.6%, and 31.7% in patients without myocardial injury, with myocardial injury without TTE abnormalities, and with myocardial injury and TTE abnormalities. Following multivariable adjustment, myocardial injury with TTE abnormalities was associated with higher risk of death but not myocardial injury without TTE abnormalities. Conclusions: Among patients with COVID-19 who underwent TTE, cardiac structural abnormalities were present in nearly two-thirds of patients with myocardial injury. Myocardial injury was associated with increased in-hospital mortality particularly if echocardiographic abnormalities were present

    Safety of hospital discharge before return of bowel function after elective colorectal surgery

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    Background: Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function. Methods: A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien\u2013Dindo classification system. Results: A total of 3288 patients were included in the analysis, of whom 301 (9\ub72 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4\u20137) and 7 (6\u20138) days respectively (P < 0\ub7001). There were no significant differences in rates of readmission between these groups (6\ub76 versus 8\ub70 per cent; P = 0\ub7499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0\ub790, 95 per cent c.i. 0\ub755 to 1\ub746; P = 0\ub7659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34\ub77 versus 39\ub75 per cent; major 3\ub73 versus 3\ub74 per cent; P = 0\ub7110). Conclusion: Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients
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