Flexural Behavior of Unbounded Pre-stressed Beams Modified With Carbon Nanotubes under Elevated Temperature

Since fire is one of the common reasons for rehabilitation and reconstructions during the service life of a building, it is necessary to assess the elements structural and technical conditions. The objective of the present paper is to investigate the flexural behavior in bending for unbounded full pre-stressed beams with and without the incorporation of carbon nanotubes (CNTs) under the exposure to elevated temperature in comparison with non-pre-stressed beams. The test Method was divided into two major stages where the principal stage’s goal was considering the flexural behavior of fully and non-prestressed concrete beams containing CNT of 0 and 0.04% as cement replacement at ambient temperature. In the second stage, a typical group of beams was prepared and the flexural behavior was explored under the exposure to temperature of 400ºC, for 120 minutes. The major findings upon monitoring the failure mechanisms, ultimate load capacity, and deflection at critical sections, was that the CNT had shown a significant impact on the behavior and extreme resistance of fully and non-prestressed normal concrete. With CNT beams also exhibited higher imperviousness to high-temperature than that of the normal beams. Finally the significant Improvement was that the ultimate load of the non-pre-stressed beam with the presence of the CNT at the lower 50mm in the tension zone showed a gain of 13%, while the ultimate load of the fully pre-stressed beam with the presence of the CNT at the lower 50mm in the tension zone showed a gain of 21% as compared to the same beam without CNT, respectively. For the non-pre-stressed beams, the load capacity of the beam with CNT after exposure had a similar load capacity as the beam without CNT before exposure to high temperature

Expression of Notch 2 and ABCC8 genes in patients with type 2 diabetes mellitus and their association with diabetic kidney disease

Background. The incidence of type 2 diabetes mellitus (T2DM) has increased over the past years and early identification and management of its complications especially diabetic kidney disease (DKD) is of great importance. T2DM and DKD are of multifactorial etiology with contribution of genetic and environmental factors. We aimed to study the expression of ABCC8 and Notch 2 genes in patients with T2DM and to find their association with DKD. Methods. The present work was carried on 80 patients with T2DM (40 with DKD and 40 without DKD) and 40 healthy subjects as a control group. Real time polymerase chain reaction was used to assess gene expression. Results. Altered expression of ABCC8 and Notch 2 genes were found in patients with T2DM compared to control group. ABCC8 expression had significant positive correlation with HbA1c while Notch 2 expression had significant positive correlation with fasting plasma glucose and HbA1c. Notch 2 expression was significantly higher in patients with DKD compared to those without DKD. Multivariate regression analysis showed that Notch 2 expression had independent relation with increased urinary albumin excretion and reduced estimated glomerular filtration rate. ABCC8 gene expression did not show significant difference between diabetic patients with DKD compared to those without DKD. Conclusion. Increased expression of ABCC8 and Notch 2 genes may play a role in pathogenesis of T2DM. Overexpression of Notch 2 gene may have a role in the development of albuminuria and DKD in patients with T2DM which may represent a possible diagnostic tool and a possible therapeutic target

Factors Affecting Outcomes of COVID-19 Infection among Older Adults with Type 2 Diabetes: A Single Center, Cross-Sectional Study

Objective: COVID-19 infection and the factors affecting it are major concerns worldwide. This retrospective study aimed to investigate clinical, laboratory and radiological characteristics associated with disease severity and hospitalization among older adults with type 2 diabetes mellitus (T2D) with COVID-19. Materials and methods: A retrospective case series study was conducted to review the records of older adults with T2D infected with COVID-19. Sociodemographic, COVID-19-related data, laboratory tests at the time of COVID-19 diagnosis and CT findings were collected. Bivariate and multivariate regression analysis were done to determine the predictors of the studied outcome, either hospitalization or complete recovery. Results: A total of 343 patients’ records were reviewed, with a mean age of 73.6 ± 6.4 years. Most of patients had fever and cough at the time of diagnosis and ground glass opacities was found on CT in 62.1% of patients. Hospitalized patients had higher duration of diabetes, suffered more from dyspnea, body aches and chest pain, had higher HbA1c, CRP and ferritin and lower lymphocytes and hemoglobin. Fasting plasma glucose and HbA1c positively affected the duration from onset of symptoms till resolution, while hemoglobin level negatively affected it. Logistic regression analysis revealed that duration of diabetes, HbA1c, ferritin and dyspnea were significant predictors of hospitalization. Conclusions: Among older adults with T2D infected with COVID-19, poor glycemic control is associated with higher risk of hospitalization and longer duration till recovery of symptoms. Longer duration of diabetes, high serum ferritin and the presence of dyspnea are associated with higher risk for hospitalization among these patients

Wood sawdust waste-derived nano-cellulose as a versatile reinforcing agent for nano silica cement composites: a systematic study on its characterization and performance

Abstract The development of sustainable construction materials is a pressing concern for researchers worldwide, as the cement industry is a major contributor to environmental degradation. The incorporation of nano-materials with cement composites has emerged as a promising solution to sustainable materials production. In this study, the effect of the addition of nano cellulose produced from wood sawdust waste on the performance of cement-based nano-silica composite was investigated. The nano-materials were incorporated at low concentrations and in gel form to eliminate the need for any advanced dispersion techniques. The results indicated that the addition of even low concentrations of nano cellulose significantly enhanced the compactness and mechanical properties of the cement matrix. The crack propagation was observed to be arrested with better adherence to the cement hydration product, which resulted from the presence of nano-silica. The nano cellulose fibers were found to bridge the calcium silicate hydrate products, arresting the propagation of cracks at their initial condition. The high pozzolanic reactivity of nano-silica ensured a minimal amount of calcium hydroxide, which is a significant contributor to the carbon footprint of cement production. Overall, the findings of this study suggest that the incorporation of nano cellulose from wood sawdust waste with cement-based nano-silica composite can lead to the development of sustainable and high-performance building materials with improved mechanical properties and reduced environmental impact