This study examines the axial compressive behavior of square concrete filled steel tube (CFST) short columns enhanced with steel plate reinforcement (SPR). Although CFST columns benefit from composite action, square sections exhibit reduced confinement effectiveness for the concrete core, increasing susceptibility to local buckling. While various strengthening methods are available, most of their implementation with prefabricated steel tubes is frequently impractical due to fabrication complexities that adversely affect construction efficiency. To overcome these issues, nine 100 mm × 100 mm × 300 mm square CFST short column specimens were tested experimentally under axial compression, including unreinforced, single SPR and double SPR configurations. SPR elements were spot welded internally to the steel tube walls to improve local stability with minimal fabrication complexity. Results confirm that SPR effectively delays local buckling onset, redistributes stress concentrations and enhances concrete confinement. Compared to unreinforced columns, specimens with SPR demonstrated increases in initial elastic stiffness (up to 63
Traditionally recognized for its role in calcium homeostasis and bone metabolism, vitamin D is increasingly acknowledged for its broader physiological effects, particularly in cardiovascular health. One area of growing interest is its influence on cardiac autonomic function. Cardiac autonomic dysfunction, characterized by an imbalance between sympathetic and parasympathetic activity, is a well-established predictor of adverse cardiovascular outcomes. This narrative review aims to synthesize the current literature on the association between vitamin D status and cardiac autonomic function. Accumulating observational data indicate that individuals with vitamin D deficiency exhibit poorer cardiac autonomic function, reflected by reduced heart rate variability indices, compared to vitamin D-sufficient individuals. Interventional trials, though limited, suggest that vitamin D supplementation may improve autonomic balance, especially in those with baseline deficiency. The relationship appears to be affected by factors such as glycemic control, disease state, and vitamin D binding protein levels. Vitamin D may modulate autonomic regulation largely via the vitamin D receptor, which activation influences multiple downstream pathways, including central nervous system effects, neurotrophic properties, regulation of the renin-angiotensin-aldosterone system, calcium-parathyroid hormone axis, and immune modulation. However, inconsistencies in study design, population characteristics, and assessment methods limit the strength of current evidence. Further longitudinal and interventional studies are warranted to establish causality and determine whether vitamin D repletion can reduce cardiovascular risk by restoring autonomic balance.
While continuous positive airway pressure (CPAP) reduces cardiovascular risk in obstructive sleep apnea (OSA), its effects on renin–angiotensin–aldosterone system (RAAS) modulation remain controversial. This meta-analysis investigates CPAP's differential impacts on RAAS components and identifies responsive patient subgroups. Sixteen studies were included in the systematic review and eight (231 patients) in the meta-analysis. Primary outcomes included plasma aldosterone concentration (PAC), plasma renin activity (PRA), and angiotensin II (AngII) changes. Subgroup analyses examined age, BMI, and CPAP duration thresholds, with meta-regression assessing moderating factors. CPAP significantly reduced PAC (d + of -0.72, 95
This study aimed to examine interdependencies among Chinese, Mathematics and English performance and to test for a unifying proficiency factor. It analysed longitudinal data from 27,750 students over 22 examination sessions in six years, applying Pearson correlations, multivariate general linear models, cross-lagged panel analysis, principal component analysis and confirmatory factor analysis. Results indicated moderate but significant bivariate associations and reciprocal predictive effects, most notably a leading influence of Chinese on subsequent English performance. Factor analyses consistently identified a single latent construct academic proficiency accounting for 62.9 % of score variance. This study is the first to demonstrate a general academic proficiency factor across all three Gaokao subjects using cross-lagged and factor analytic methods on largescale longitudinal data. These findings indicate that student performance across Chinese, Mathematics, and English is moderately interrelated and can be parsimoniously represented by a single latent academic proficiency factor. While the study does not directly assess underlying cognitive or motivational traits, the consistent factor loadings and strong model fit suggest the presence of a general academic dimension influencing all three subjects. This suggests that instructional designs which foster cross-subject skill transfer, such as embedding reading strategies in Mathematics or reinforcing logical reasoning in language tasks, may enhance overall academic performance. Furthermore, educational interventions aimed at strengthening general learning processes, such as metacognitive regulation and effort management, could offer broad-based support across disciplines. These insights can inform the development of more integrated and efficient curricular strategies under China's New Gaokao framework and may have relevance for other high-stakes assessment systems.
Scincidae is a speciose squamate family that is both ecologically diverse and near-cosmopolitan in distribution. The osteology of Scincidae, and particularly the dentition, remains understudied. The tooth morphology of three sympatric skink species of the genus Eutropis (E. multifasciata, E. rudis and E. rugifera), collected from Kota Samarahan, western Sarawak (Borneo), was studied using scanning electron microscopy (SEM). The primary aim was to compare gross tooth as well as fine surface morphology, and to determine possible adaptive suites vis-& agrave;-vis their respective diets. Lizards were collected during visual encounter surveys, through the use of adhesive traps, then euthanised and decapitated. Following standard protocol, the maxilla, the mandible and the palatine region were prepared using an ethanol series, critically point-dried and examined under an electron microscope. To determine the possible functions of dental features, implements used in cutting and breaking (scalpel blades, knives and drills) tools were standardised according to the literature. Inter-specific variation in tooth structure was observed, suggesting that blade-like and drill-bit forms function to reduce food bolus size through slicing and drilling, respectively. Comparisons with scalpel blade ridges and edges of commercial drills with dentitional structures, particularly on occlusal surfaces, provide examples of an interdisciplinary approach to understanding the functional application of tooth morphology and its potential for inspiring biologically informed product design.
