RESUMEN

This study compares the workability, mechanical, and thermal characteristics of structural self-compacting lightweight concrete (SCLWC) formulations using pumice aggregate (PA), expanded perlite aggregate (EPA), fly ash (FA), and silica fume (SF). FA and SF were used as partial substitutes for cement at a 10% ratio in various mixes, impacting different aspects: According to the obtained results, FA enhanced the workability but SF reduced it, while SF improved the compressive and splitting tensile strengths more than FA. EPA, used as a fine aggregate alongside PA, decreased the workability, compressive strength, and splitting tensile strength compared to the control mix (K0). The thermal properties were altered by FA and SF similarly, while EPA notably reduced the thermal conductivity coefficients. The thermal conductivity coefficients (TCCs) of the K0-K4 SCLWC mixtures ranged from 0.275 to 0.364 W/mK. K0 had a TCC of 0.364 W/mK. With 10% FA, K1 achieved 0.305 W/mK; K2 with 10% SF reached 0.325 W/mK. K3 and K4, using EPA instead of PA, showed significantly lower TCC values: 0.275 W/mK and 0.289 W/mK, respectively. FA and SF improved the thermal conductivity compared to K0, while EPA further reduced the TCC values in K3 and K4 compared to K1 and K2. The compressive strength (CS) values of the K0-K4 SCLWC mixtures at 7 and 28 days reveal notable trends. Using 10% FA in K1 decreased the CS at both 7 days (12.16 MPa) and 28 days (22.36 MPa), attributed to FA's gradual pozzolanic activity. Conversely, K2 with SF showed increased CS at 7 days (17.88 MPa) and 28 days (29.89 MPa) due to SF's rapid pozzolanic activity. Incorporating EPA into K3 and K4 reduced the CS values compared to PA, indicating EPA's lower strength contribution due to its porous structure.

RESUMEN

OBJECTIVE: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection might have a higher mortality rate in patients with end-stage renal disease due to immunosuppression. This study investigates the mortality rates of SARS-CoV-2 infection and the factors affecting mortality among patients who were on maintenance hemodialysis and continuous ambulatory peritoneal dialysis. MATERIALS AND METHODS: A total of 200 patients, including 157 maintenance hemodialysis and 43 continuous ambulatory peritoneal dialysis patients followed in our hospital, were included in the study. The patients' sociodemographic characteristics, comorbidities, history of SARS-CoV-2 infection in the previous year, death event, source of death (SARS-CoV-2 or not), presence of hospitalization due to SARS-CoV-2 infection, need for intensive care unit, need for ventilatory support in intensive care unit were obtained from the clinical file records. RESULTS: 85 of the 200 patients had a history of SARS-Cov-2 infection during the last 12 months. Forty-two (49.5%) patients with SARS-CoV-2 infection were hospitalized. Patients with SARS-CoV-2 had longer dialysis time, increased mortality, and significantly higher comorbidities such as coronary artery disease, congestive heart failure. Besides, heart failure and hypertension were the determining factors in the risk factor analysis for SARS-CoV-2 infection. In dialysis patients, the mortality rate in the last year, due to all causes, including SARS-CoV-2 infection, was 23% while the mortality rate due to "SARS-CoV-2 infection only" was 13%) (p > 0.05). Our findings are important in guiding clinical decision-making and informing the public and health authorities about the risk of death associated with COVID-19 in this patient group.

Asunto(s)

RESUMEN

Background/aim: Deficient levels of vitamin D are an important factor in the pathogenesis of some neurodegenerative diseases. The aim of this study is to determine the relationship between vitamin D deficiency and depression status and sleep disorders of patients on dialysis. Materials and methods: In this cross-sectional study, 121 hemodialysis patients were enrolled. All patients had been on hemodialysis for at least six months at the time of the study. Sleep quality and depression status were measured by using specific inventories. All the patients filled out Pittsburg Sleep Quality Index (PSQI) and Beck Depression Inventory (BDI), and gave blood samples. Vitamin D levels were measured for 121 patients, and statistical analysis was done by using SPSS. Results: Regression analyses demonstrated that low levels of 25(OH)D and high BDI score were independent risk factors for poor sleep quality [ORs were 0.668 (0.566­0.789), 1.080 (1.001­1.164), and 1.080 (1.001­1.164), respectively]. Conclusion: Our results suggest that deficiency of 25(OH)D is an important independent risk factor for poor sleep quality in hemodialysis patients.

Asunto(s)

RESUMEN

INTRODUCTION: Free triiodothyronine (FT3) is a marker of comorbidity in end-stage renal disease and in many acute and chronic diseases. There is lack of data about the link between FT3 levels and malnutrition and inflammation in hemodialysis patients. The objective of the present study was to investigate the link between FT3 and malnutrition and inflammation in hemodialysis patients. MATERIALS AND METHODS: A total of 84 patients were included in the study (38 men and 46 women; mean age, 56.2 +/- 14.8 years; hemodialysis duration, 95.72 +/- 10.35 months). Serum FT3, free thyroxin, and thyroid-stimulating hormone concentrations were determined. Demographic data and laboratory values were evaluated. Patients' comorbidity status was determined using the Charlson Comorbidity Index (CCI), and malnutrition-inflammation status was determined by Malnutrition-Inflammation Score (MIS). RESULTS: Serum FT3 concentration inversely correlated with age (r = -0.328, P = .002), CCI (r = -0.591, P = .001), C-reactive protein (r = -0.299, P = .01), and MIS (r = -0.671, P = .001), and positively correlated with serum albumin (r = 0.389, P = .001). In multivariate linear regression analysis, FT3 was independently associated with MIS (beta;, -0.14; 95% confidence interval, -0.175 to 0.063, P = .003), adjusted for CCI, C-reactive protein level, serum albumin level, and MIS. CONCLUSIONS: The results of this study indicate that FT3 is negatively correlated with inflammatory markers, namely C-reactive protein, and it is independently related with MIS in hemodialysis patients. Therefore, we suggest that FT3 can be accepted as an inflammatory marker in hemodialysis patients.

Asunto(s)