Regulatory Mechanisms That Guide the Fetal to Postnatal Transition of Cardiomyocytes.

Heart disease remains a global leading cause of death and disability, necessitating a comprehensive understanding of the heart's development, repair, and dysfunction. This review surveys recent discoveries that explore the developmental transition of proliferative fetal cardiomyocytes into hypertrophic postnatal cardiomyocytes, a process yet to be well-defined. This transition is key to the heart's growth and has promising therapeutic potential, particularly for congenital or acquired heart damage, such as myocardial infarctions. Although significant progress has been made, much work is needed to unravel the complex interplay of signaling pathways that regulate cardiomyocyte proliferation and hypertrophy. This review provides a detailed perspective for future research directions aimed at the potential therapeutic harnessing of the perinatal heart transitions.

Effect of fetuin-A on adenine-induced chronic kidney disease model in male rats.

Objectives: This study aimed to investigate the possible effects of fetuin-A on an adenine-induced chronic kidney disease (CKD) model in male rats. Materials and Methods: Rats were divided into three groups: group A included rats fed a normal diet; group B included rats fed a normal diet with 220 mg/kg adenine daily for 21 days; group C included rats fed a normal diet with 220 mg/kg adenine daily for 21 days and intraperitoneally administered with 5 mg\kg fetuin-A every other day for 2 weeks. Serum samples were assayed for serum creatinine, urea, sodium, potassium, calcium, phosphorus, tumor necrosis factor (TNF), interleukin-6 (IL-6), and estimated glomerular filtration rate (eGFR), and immunohistochemical staining was performed. Results: Group B showed a significant increase in serum creatinine, urea, phosphorus, potassium, TNF, and IL-6 and a significant decrease in serum sodium, calcium, and eGFR compared with group A. Regarding immunohistochemistry, group B showed increased apoptosis. In group C, fetuin-A reduced the urea, creatinine, and phosphorus levels, and in group C, fetuin-A decreased inflammation and apoptosis by reduction of caspase-3 staining. Conclusion: Fetuin-A improved kidney function in CKD due to its anti-inflammatory and anti-fibrotic role.

Evaluation of the Infill Design on the Tensile Response of 3D Printed Polylactic Acid Polymer.

The current study explores the effects of geometrical shapes of the infills on the 3D printed polylactic acid (PLA) plastic on the tensile properties. For this purpose, by utilizing an accessible supply desktop printer, specimens of diamond, rectangular, and hexagonal infill patterns were produced using the fused filament fabrication (FFF) 3D printing technique. Additionally, solid samples were printed for comparison. The printed tensile test specimens were conducted at environmental temperature, Ta of 23 °C and crosshead speed, VC.H of 5 mm/min. Mainly, this study focuses on investigating the percentage infill with respect to the cross-sectional area of the investigated samples. The mechanical properties, i.e., modulus of toughness, ultimate tensile stress, yield stress, and percent elongation, were explored for each sample having a different geometrical infill design. The test outcomes for each pattern were systematically compared. To further validate the experimental results, a computer simulation using finite element analysis was also performed and contrasted with the experimental tensile tests. The experimental results mainly suggested a brittle behavior for solidly infilled specimen, while rectangular, diamond, and hexagonal infill patterns showed ductile-like behavior (fine size and texture of infills). This brittleness may be due to the relatively higher infill density results that led to the high bonding adhesion of the printed layers, and the size and thickness effects of the solid substrate. It made the solidly infilled specimen structure denser and brittle. Among all structures, hexagon geometrical infill showed relative improvement in the mechanical properties (highest ultimate tensile stress and modulus values 1759.4 MPa and 57.74 MPa, respectively) compared with other geometrical infills. Therefore, the geometrical infill effects play an important role in selecting the suitable mechanical property's values in industrial applications.

Experimental Behavior of Cracked Reinforced Concrete Columns Strengthened with Reinforced Concrete Jacketing.

Reinforced concrete (RC) columns often need to be strengthened or rehabilitated to allow them to carry the loads applied to them. In previous studies, RC columns have been strengthened by jacketing, without considering the occurrence of cracking. In this study, the behavior of RC columns strengthened externally by jacketing after cracking is analyzed. The accuracy of the existing models was verified by analyzing the performance of fifteen RC columns with different cross-sections to determine the effect of new variables, such as the column size, amount of steel reinforcement, and whether the column was cracked or not, on the effectiveness of strengthening. The analysis demonstrated that this strengthening technique could effectively improve both the ductility and strength of RC column cross-sections. The results indicate that the model suggested by the ACI-318 code can predict the ultimate load capacity of RC columns without strengthening, or strengthened by RC jacketing before or after cracking, with higher accuracy and material efficiency. The RC columns without strengthening met the safety limit of the ACI-318 model. However, for strengthened columns, a reduction coefficient must be used to enable the columns to meet the safety limit, with values of 94% and 76% for columns strengthened before and after cracking, respectively. Furthermore, strengthening after cracking affects the ultimate load capacity of the column, with 15.7%, 14.1%, and 13.5% lower loads for square, rectangular, and circular columns than those strengthened before cracking, respectively.