CuO SENTEZİ, rGO/CuO/PEDOT NANOKOMPOZİTLERİNİN SÜPERKAPASİTÖR VE EŞDEĞER DEVRE MODEL UYGULAMALARI

rGO, CuO, PEDOT ve rGO/CuO nanokompozitinin [rGO]o/[CuO]o= 1:1; 1:1.5; 1:2 ve rGO/CuO/PEDOT nanokompozitinin [rGO]o/[CuO]o/[EDOT]o= 1:1:1; 1:1:3; ve 1:1:5 oranlarında GO'nun kimyasal indirgenmesi ve in-situ polimerizasyon işlemi ile araştırılmıştır. Nanokompozit sentezleri Taramalı elektron mikroskobu (SEM) ve enerji dağılımlı X-ışınları analizi (EDX), yüksek çözünürlüklü geçirgenlik elektron mikroskobu (HR-TEM), Brunauer-Emmett-Teller (BET) yüzey alan analizi gibi yöntemlerle karakterize edilmiştir. Nanokompozit malzemeler spektroskopik ve termo-gravimetrik analizlerde (FTIR-ATR, Raman ve TGA-DTA) incelenmiştir. Elektrokimyasal performansları galvanostatik yükleme / boşalma (GCD), döngülü voltametri (DV) ve elektrokimyasal empedans spektroskopisi (EES) ile ölçülmüştür. En yüksek spesifik kapasitans rGO/CuO/PEDOT nanokompozitinin [rGO]o/[CuO]o/[EDOT]o =1:1:5 oranlarında 2 mV/s tarama hızında Csp= 156.7 F/g olarak elde edilmiştir. rGO/CuO/PEDOT nanokompoziti için [rGO]o/[CuO]o/[EDOT]o=1:1:5 oranında 2 elektrotlu süperkapasitör cihazın maksimum, spesifik enerji (E= 14.15 Wh/kg, 20 mA) ve speifik güç (P= 24730 W/kg, 50 mA), elektrik seri direnci (ESR= 13.33 ?) ile 3000 döngüde kapasitif kayıp fazla olmadan elde edilmiştir. LR1(CR2)(QR3) eşdeğer devre modeli EES verilerle incelenmiştir. rGO/CuO/PEDOT nanokompozit elektrodunun süperkapasitör performansı hibrid süperkapasitör olarak sinerjik etki oluştururSupercapacitor properties of rGO, CuO, PEDOT and rGO/CuO at [rGO]o/[CuO]o= 1:1; 1:1.5; 1:2 and rGO/CuO/PEDOT nanocomposite at [rGO]o/[CuO]o/[EDOT]o= 1:1:1; 1:1:3; 1:1:5 were investigated using chemical reduction of GO and in- situ polymerization process. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) surface area analysis confirm the nanocomposite formations. Nanocomposite materials are also analyzed through spectroscopic and thermo-gravimetric analysis (FTIR-ATR, Raman and TGA-DTA). Electrochemical performance were studied by galvonanostatic charge/discharge (GCD), cyclic voltametry (CV) and electrochemical impedance spectroscopy (EIS). The highest specific capacitance of Csp= 156.7 F/g at 2 mV/s is determined as rGO/CuO/PEDOT at [rGO]o/[CuO]o/[EDOT]o =1:1:5. In addition, two electrode supercapacitor device for rGO/CuO/PEDOT at [rGO]o/[CuO]o/[EDOT]o=1:1:5 are found to provide a maximum specific energy (E= 14.15 Wh/kg at 20 mA) and specific power (P= 24730 W/kg at 50 mA), electrical serial resistance (ESR= 13.33 ?) with good capacity retention after 3000 cycles. An equivalent circuit model of LR1(CR2)(QR3) is proposed to interpret the EIS data. The supercapacitor performance of the rGO/CuO/PEDOT nanocomposite electrode indicates the synergistic effect of hybrid supercapacitors

rGO/CuO/PEDOT nanocomposite formation, its characterisation and electrochemical performances for supercapacitors

Supercapacitor properties of rGO, CuO, PEDOT and rGO/CuO at [rGO](o)/[CuO](o) = 1:1; 1:1.5; 1:2 and rGO/CuO/PEDOT nanocomposite at [rGO](o)/[CuO](o)/[EDOT](o) = 1:1:1; 1:1:3; 1:1:5 were investigated using chemical reduction of GO and in-situ polymerisation process. SEM-EDX, HRTEM, BET surface area analysis confirm the nanocomposite formations. Nanocomposite materials are also analysed through FTIR-ATR, Raman, TGA-DTA, GCD, CV and EIS. The highest specific capacitance of C-sp = 156.7 F/g at 2 mV/s is determined as rGO/CuO/PEDOT at [rGO](o)/[CuO](o)/[EDOT](o) = 1:1:5. In addition, two-electrode supercapacitor device for rGO/CuO/PEDOT at [rGO](o)/[CuO](o)/[EDOT](o) = 1:1:5 are found to provide a maximum specific energy (E = 14.15 Wh/kg at 20 mA) and specific power (P = 24730 W/kg at 50 mA), electrical serial resistance (ESR = 13.33 omega) with good capacity retention after 3000 cycles. An equivalent circuit model of LR1(CR2)(QR3) is proposed to interpret the EIS data. The supercapacitor performance of the rGO/CuO/PEDOT nanocomposite electrode indicates the synergistic effect of hybrid supercapacitors.Namik Kemal Uni., Scientific Research Project UnitNamik Kemal University [NKUBAP.01, YL.18.151]This work was supported by Namik Kemal Uni., Scientific Research Project Unit [grant number: NKUBAP.01.YL.18.151]

Mortality analysis of COVID-19 infection in chronic kidney disease, haemodialysis and renal transplant patients compared with patients without kidney disease: a nationwide analysis from Turkey

Background. Chronic kidney disease (CKD) and immunosuppression, such as in renal transplantation (RT), stand as one of the established potential risk factors for severe coronavirus disease 2019 (COVID-19). Case morbidity and mortality rates for any type of infection have always been much higher in CKD, haemodialysis (HD) and RT patients than in the general population. A large study comparing COVID-19 outcome in moderate to advanced CKD (Stages 3-5), HD and RT patients with a control group of patients is still lacking. Methods. We conducted a multicentre, retrospective, observational study, involving hospitalized adult patients with COVID-19 from 47 centres in Turkey. Patients with CKD Stages 3-5, chronic HD and RT were compared with patients who had COVID-19 but no kidney disease. Demographics, comorbidities, medications, laboratory tests, COVID-19 treatments and outcome [in-hospital mortality and combined in-hospital outcome mortality or admission to the intensive care unit (ICU)] were compared. Results. A total of 1210 patients were included [median age, 61 (quartile 1-quartile 3 48-71) years, female 551 (45.5%)] composed of four groups: Control (n = 450), HD (n = 390), RT (n = 81) and CKD (n = 289). The ICU admission rate was 266/ 1210 (22.0%). A total of 172/1210 (14.2%) patients died. The ICU admission and in-hospital mortality rates in the CKD group [114/289 (39.4%); 95% confidence interval (CI) 33.9-45.2; and 82/289 (28.4%); 95% CI 23.9-34.5)] were significantly higher than the other groups: HD = 99/390 (25.4%; 95% CI 21.3-29.9; P<0.001) and 63/390 (16.2%; 95% CI 13.0-20.4; P<0.001); RT = 17/81 (21.0%; 95% CI 13.2-30.8; P = 0.002) and 9/81 (11.1%; 95% CI 5.7-19.5; P = 0.001); and control = 36/450 (8.0%; 95% CI 5.8-10.8; P<0.001) and 18/450 (4%; 95% CI 2.5-6.2; P<0.001). Adjusted mortality and adjusted combined outcomes in CKD group and HD groups were significantly higher than the control group [hazard ratio (HR) (95% CI) CKD: 2.88 (1.52- 5.44); P = 0.001; 2.44 (1.35-4.40); P = 0.003; HD: 2.32 (1.21- 4.46); P = 0.011; 2.25 (1.23-4.12); P = 0.008), respectively], but these were not significantly different in the RT from in the control group [HR (95% CI) 1.89 (0.76-4.72); P = 0.169; 1.87 (0.81-4.28); P = 0.138, respectively]. Conclusions. Hospitalized COVID-19 patients with CKDs, including Stages 3-5 CKD, HD and RT, have significantly higher mortality than patients without kidney disease. Stages 3-5 CKD patients have an in-hospital mortality rate as much as HD patients, which may be in part because of similar age and comorbidity burden. We were unable to assess if RT patients were or were not at increased risk for in-hospital mortality because of the relatively small sample size of the RT patients in this study

Mortality analysis of COVID-19 infection in chronic kidney disease, haemodialysis and renal transplant patients compared with patients without kidney disease: A nationwide analysis from Turkey

© The Author(s) 2020.Background. Chronic kidney disease (CKD) and immunosuppression, such as in renal transplantation (RT), stand as one of the established potential risk factors for severe coronavirus disease 2019 (COVID-19). Case morbidity and mortality rates for any type of infection have always been much higher in CKD, haemodialysis (HD) and RT patients than in the general population. A large study comparing COVID-19 outcome in moderate to advanced CKD (Stages 3-5), HD and RT patients with a control group of patients is still lacking. Methods. We conducted a multicentre, retrospective, observational study, involving hospitalized adult patients with COVID-19 from 47 centres in Turkey. Patients with CKD Stages 3-5, chronic HD and RT were compared with patients who had COVID-19 but no kidney disease. Demographics, comorbidities, medications, laboratory tests, COVID-19 treatments and outcome [in-hospital mortality and combined in-hospital outcome mortality or admission to the intensive care unit (ICU)] were compared. Results. A total of 1210 patients were included [median age, 61 (quartile 1-quartile 3 48-71) years, female 551 (45.5%)] composed of four groups: Control (n = 450), HD (n = 390), RT (n = 81) and CKD (n = 289). The ICU admission rate was 266/ 1210 (22.0%). A total of 172/1210 (14.2%) patients died. The ICU admission and in-hospital mortality rates in the CKD group [114/289 (39.4%); 95% confidence interval (CI) 33.9-45.2; and 82/289 (28.4%); 95% CI 23.9-34.5)] were significantly higher than the other groups: HD = 99/390 (25.4%; 95% CI 21.3-29.9; P<0.001) and 63/390 (16.2%; 95% CI 13.0-20.4; P<0.001); RT = 17/81 (21.0%; 95% CI 13.2-30.8; P = 0.002) and 9/81 (11.1%; 95% CI 5.7-19.5; P = 0.001); and control = 36/450 (8.0%; 95% CI 5.8-10.8; P<0.001) and 18/450 (4%; 95% CI 2.5-6.2; P<0.001). Adjusted mortality and adjusted combined outcomes in CKD group and HD groups were significantly higher than the control group [hazard ratio (HR) (95% CI) CKD: 2.88 (1.52- 5.44); P = 0.001; 2.44 (1.35-4.40); P = 0.003; HD: 2.32 (1.21- 4.46); P = 0.011; 2.25 (1.23-4.12); P = 0.008), respectively], but these were not significantly different in the RT from in the control group [HR (95% CI) 1.89 (0.76-4.72); P = 0.169; 1.87 (0.81-4.28); P = 0.138, respectively]. Conclusions. Hospitalized COVID-19 patients with CKDs, including Stages 3-5 CKD, HD and RT, have significantly higher mortality than patients without kidney disease. Stages 3-5 CKD patients have an in-hospital mortality rate as much as HD patients, which may be in part because of similar age and comorbidity burden. We were unable to assess if RT patients were or were not at increased risk for in-hospital mortality because of the relatively small sample size of the RT patients in this study