Comparative study on structural and optical features of undoped and Eu3+ doped Pr6O11 synthesized via sol-gel and flame spray pyrolysis

© 2020 The AuthorsHerein, it was aimed to differentiate features of undoped and europium (Eu3+) doped Pr6O11 particles fabricated via the sol-gel (SG) and flame spray pyrolysis (FSP) methods. The crystal phase structure, morphological, chemical, and optical features of synthesized Pr6O11 particles were characterized using an X-ray diffractometer (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), photoluminescence spectroscopy (PL), and UV–vis spectrophotometer. The results show that, compared with SG-based samples, Eu-doped Pr6O11 synthesized by FSP has excellent structural integrity, optical and electrical features, and morphology. This study outlines the development of a compatibility strategy between the production method and the final Pr6O11 powders, and that the optical, and electrical features may be controlled by selecting the proper dopant

Synthesis, structural and optical characterization of Nd: YAG powders via flame spray pyrolysis

In this study, undoped Y3Al5O12 (YAG) and neodymium (Nd3+) doped (Nd: YAG) powders were synthesized by Flame Spray Pyrolysis (FSP) for the first time in literature. The synthesized powders were investigated about structural, morphological, elemental and optical properties by using Thermogravimetric - Differential Thermal Analysis (DTA-TG), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Fourier Transformed Infrared Spectroscopy (FTIR), and photoluminescence spectroscopy (PL). The particle size range of undoped and Nd doped YAG powders produced by the FSP method was determined around 200-1100 nm. After calcination at 1000 degrees C, cubic YAG crystalline phases were successfully observed. The luminescence results as excitation, emission, and upconversion properties have been investigated for both undoped YAG (YG) and Nd3+ doped YAG with different dopant ratios as 1% (YG1), 3% (YG3) and %5 (YG5). When synthesized powders excited at 460 nm, the emission maxima observed at 540 nm and 808 nm. All YAG powders yielded bi-exponential decay curves. The highest decay time value was 1% Nd: YAG particle at 277 mu s. Furthermore, these powder

The predictors of COVID-19 mortality in a nationwide cohort of Turkish patients

© 2021 Elsevier LtdThe COVID-19-related death rate varies between countries and is affected by various risk factors. This multicenter registry study was designed to evaluate the mortality rate and the related risk factors in Turkey. We retrospectively evaluated 1500 adults with COVID-19 from 26 centers who were hospitalized between March 11 and July 31, 2020. In the study group, 1041 and 459 cases were diagnosed as definite and highly probable cases, respectively. There were 993 PCR-positive cases (66.2%). Among all cases, 1144 (76.3%) were diagnosed with non-severe pneumonia, whereas 212 (14.1%) had severe pneumonia. Death occurred in 67 patients, corresponding to a mortality rate of 4.5% (95% CI:3.5–5.6). The univariate analysis demonstrated that various factors, including male sex, age ≥65 years and the presence of dyspnea or confusion, malignity, chronic obstructive lung disease, interstitial lung disease, immunosuppressive conditions, severe pneumonia, multiorgan dysfunction, and sepsis, were positively associated with mortality. Favipiravir, hydroxychloroquine and azithromycin were not associated with survival. Following multivariate analysis, male sex, severe pneumonia, multiorgan dysfunction, malignancy, sepsis and interstitial lung diseases were found to be independent risk factors for mortality. Among the biomarkers, procalcitonin levels on the 3rd-5th days of admission showed the strongest associations with mortality (OR: 6.18; 1.6–23.93). This study demonstrated that the mortality rate in hospitalized patients in the early phase of the COVID-19 pandemic was a serious threat and that those patients with male sex, severe pneumonia, multiorgan dysfunction, malignancy, sepsis and interstitial lung diseases were at increased risk of mortality; therefore, such patients should be closely monitored

The predictors of COVID-19 mortality in a nationwide cohort of Turkish patients

© 2021 Elsevier LtdThe COVID-19-related death rate varies between countries and is affected by various risk factors. This multicenter registry study was designed to evaluate the mortality rate and the related risk factors in Turkey. We retrospectively evaluated 1500 adults with COVID-19 from 26 centers who were hospitalized between March 11 and July 31, 2020. In the study group, 1041 and 459 cases were diagnosed as definite and highly probable cases, respectively. There were 993 PCR-positive cases (66.2%). Among all cases, 1144 (76.3%) were diagnosed with non-severe pneumonia, whereas 212 (14.1%) had severe pneumonia. Death occurred in 67 patients, corresponding to a mortality rate of 4.5% (95% CI:3.5–5.6). The univariate analysis demonstrated that various factors, including male sex, age ≥65 years and the presence of dyspnea or confusion, malignity, chronic obstructive lung disease, interstitial lung disease, immunosuppressive conditions, severe pneumonia, multiorgan dysfunction, and sepsis, were positively associated with mortality. Favipiravir, hydroxychloroquine and azithromycin were not associated with survival. Following multivariate analysis, male sex, severe pneumonia, multiorgan dysfunction, malignancy, sepsis and interstitial lung diseases were found to be independent risk factors for mortality. Among the biomarkers, procalcitonin levels on the 3rd-5th days of admission showed the strongest associations with mortality (OR: 6.18; 1.6–23.93). This study demonstrated that the mortality rate in hospitalized patients in the early phase of the COVID-19 pandemic was a serious threat and that those patients with male sex, severe pneumonia, multiorgan dysfunction, malignancy, sepsis and interstitial lung diseases were at increased risk of mortality; therefore, such patients should be closely monitored

The association of antiviral drugs with COVID-19 morbidity: The retrospective analysis of a nationwide COVID-19 cohort

Copyright © 2022 Babayigit, Kokturk, Kul, Cetinkaya, Atis Nayci, Argun Baris, Karcioglu, Aysert, Irmak, Akbas Yuksel, Sekibag, Baydar Toprak, Azak, Mulamahmutoglu, Cuhadaroglu, Demirel, Kerget, Baran Ketencioglu, Ozger, Ozkan, Ture, Ergan, Avkan Oguz, Kilinc, Ercelik, Ulukavak Ciftci, Alici, Nurlu Temel, Ataoglu, Aydin, Cetiner Bahcetepe, Gullu, Fakili, Deveci, Kose, Tor, Gunluoglu, Altin, Turgut, Tuna, Ozturk, Dikensoy, Yildiz Gulhan, Basyigit, Boyaci, Oguzulgen, Borekci, Gemicioglu, Bayraktar, Elbek, Hanta, Kuzu Okur, Sagcan, Uzun, Akgun, Altinisik, Dursun, Cakir Edis, Gulhan, Oner Eyuboglu, Gultekin, Havlucu, Ozkan, Sakar Coskun, Sayiner, Kalyoncu, Itil and Bayram.Background and objectives: Although several repurposed antiviral drugs have been used for the treatment of COVID-19, only a few such as remdesivir and molnupiravir have shown promising effects. The objectives of our study were to investigate the association of repurposed antiviral drugs with COVID-19 morbidity. Methods: Patients admitted to 26 different hospitals located in 16 different provinces between March 11–July 18, 2020, were enrolled. Case definition was based on WHO criteria. Patients were managed according to the guidelines by Scientific Board of Ministry of Health of Turkey. Primary outcomes were length of hospitalization, intensive care unit (ICU) requirement, and intubation. Results: We retrospectively evaluated 1,472 COVID-19 adult patients; 57.1% were men (mean age = 51.9 ± 17.7years). A total of 210 (14.3%) had severe pneumonia, 115 (7.8%) were admitted to ICUs, and 69 (4.7%) were intubated during hospitalization. The median (interquartile range) of duration of hospitalization, including ICU admission, was 7 (5–12) days. Favipiravir (n = 328), lopinavir/ritonavir (n = 55), and oseltamivir (n = 761) were administered as antiviral agents, and hydroxychloroquine (HCQ, n = 1,382) and azithromycin (n = 738) were used for their immunomodulatory activity. Lopinavir/ritonavir (β [95% CI]: 4.71 [2.31–7.11]; p = 0.001), favipiravir (β [95% CI]: 3.55 [2.56–4.55]; p = 0.001) and HCQ (β [95% CI]: 0.84 [0.02–1.67]; p = 0.046) were associated with increased risk of lengthy hospital stays. Furthermore, favipiravir was associated with increased risks of ICU admission (OR [95% CI]: 3.02 [1.70–5.35]; p = 0.001) and invasive mechanical ventilation requirement (OR [95% CI]: 2.94 [1.28–6.75]; p = 0.011). Conclusion: Our findings demonstrated that antiviral drugs including lopinavir, ritonavir, and favipiravir were associated with negative clinical outcomes such as increased risks for lengthy hospital stay, ICU admission, and invasive mechanical ventilation requirement. Therefore, repurposing such agents without proven clinical evidence might not be the best approach for COVID-19 treatment

Image_1_The association of antiviral drugs with COVID-19 morbidity: The retrospective analysis of a nationwide COVID-19 cohort.JPEG

Background and objectivesAlthough several repurposed antiviral drugs have been used for the treatment of COVID-19, only a few such as remdesivir and molnupiravir have shown promising effects. The objectives of our study were to investigate the association of repurposed antiviral drugs with COVID-19 morbidity.MethodsPatients admitted to 26 different hospitals located in 16 different provinces between March 11–July 18, 2020, were enrolled. Case definition was based on WHO criteria. Patients were managed according to the guidelines by Scientific Board of Ministry of Health of Turkey. Primary outcomes were length of hospitalization, intensive care unit (ICU) requirement, and intubation.ResultsWe retrospectively evaluated 1,472 COVID-19 adult patients; 57.1% were men (mean age = 51.9 ± 17.7years). A total of 210 (14.3%) had severe pneumonia, 115 (7.8%) were admitted to ICUs, and 69 (4.7%) were intubated during hospitalization. The median (interquartile range) of duration of hospitalization, including ICU admission, was 7 (5–12) days. Favipiravir (n = 328), lopinavir/ritonavir (n = 55), and oseltamivir (n = 761) were administered as antiviral agents, and hydroxychloroquine (HCQ, n = 1,382) and azithromycin (n = 738) were used for their immunomodulatory activity. Lopinavir/ritonavir (β [95% CI]: 4.71 [2.31–7.11]; p = 0.001), favipiravir (β [95% CI]: 3.55 [2.56–4.55]; p = 0.001) and HCQ (β [95% CI]: 0.84 [0.02–1.67]; p = 0.046) were associated with increased risk of lengthy hospital stays. Furthermore, favipiravir was associated with increased risks of ICU admission (OR [95% CI]: 3.02 [1.70–5.35]; p = 0.001) and invasive mechanical ventilation requirement (OR [95% CI]: 2.94 [1.28–6.75]; p = 0.011).ConclusionOur findings demonstrated that antiviral drugs including lopinavir, ritonavir, and favipiravir were associated with negative clinical outcomes such as increased risks for lengthy hospital stay, ICU admission, and invasive mechanical ventilation requirement. Therefore, repurposing such agents without proven clinical evidence might not be the best approach for COVID-19 treatment.</p