Correction: Chen et al. Hemodynamic Effects of Subaortic Stenosis on Blood Flow Characteristics of a Mechanical Heart Valve Based on OpenFOAM Simulation. Bioengineering 2023, 10, 312.

In the original publication [...].

Hemodynamic Effects of Subaortic Stenosis on Blood Flow Characteristics of a Mechanical Heart Valve Based on OpenFOAM Simulation.

Subaortic stenosis (SAS) is a common congenital heart disease that can cause significant morbidity and mortality if not treated promptly. Patients with heart valve disease are prone to complications after replacement surgery, and the existence of SAS can accelerates disease progression, so timely diagnosis and treatment are required. However, the effects of subaortic stenosis on mechanical heart valves (MHV) are unknown. This study aimed to investigate flow characteristics in the presence of subaortic stenosis and computationally quantify the effects on the hemodynamics of MHV. Through the numerical simulation method, the flow characteristics and related parameters in the presence of SAS can be more intuitively observed. Based on its structure, there are three types of SAS: Tunnel-type SAS (TSS); Fibromuscular annulus SAS (FSS); Discrete SAS (DSS). The first numerical simulation study on different types of SAS found that there are obvious differences among them. Among them, the tunnel-type SAS formed a separated vortex structure on the tunnel-type narrow surface, which exhibits higher wall shear force at a low obstacle percentage. However, discrete SAS showed obvious differences when there was a high percentage of obstacles, forming high peak flow, high wall shear stress, and a high-intensity complex vortex. The presence of all three types of SAS results in the formation of high-velocity jets and complex vortices in front of the MHV, leading to increased shear stress and stagnation time. These hemodynamic changes significantly increase the risk of MHV dysfunction and the development of complications. Despite differences between the three types of SAS, the resultant effects on MHV hemodynamics are consistent. Therefore, early surgical intervention is warranted in SAS patients with implanted MHV.

A randomised controlled trial on the effects of a structural education module among women with polycystic ovarian syndrome on nutrition and physical activity changes.

BACKGROUND: Polycystic ovarian syndrome (PCOS) is a complex metabolic, endocrine and reproductive disorder that has a huge impact on the life of women. To ascertain the effectiveness of health education module among women with PCOS. METHODS: This single-centre, randomised controlled trial was conducted on female staff of the University Putra Malaysia who were diagnosed with PCOS. Subjects were randomly assigned into intervention (n = 34) and control group (n = 35). In the intervention group, they need to take part in 8 education sessions in total over 6 months, and feedback was collected at the end of the session. RESULTS: Primary outcome was changes in knowledge, attitude and practise of nutrition. Secondary outcomes were eating attitude and behaviour as well as knowledge, attitude and practise towards physical activity. After 6-months of intervention, there was a significant difference observed in nutrition knowledge 1 score (p < 0.001) and nutrition knowledge 2 score (p = 0.01) between intervention and control groups. Similarly, there was a significant difference observed in international physical activity questionnaire score (p = 0.02) between intervention and control groups. However there was no significant changes for attitude and practice of nutrition, eating attitude as well as knowledge, attitude and practise of physical activity. CONCLUSIONS: Our study showed that 6-months of education intervention can improve nutrition and physical activity knowledge. Based on this study, the education module may be considered an effective intervention for women with PCOS. TRIAL REGISTRATION: Name of the registry: Australian New Zealand Clinical Trials Registry (ANZCTR). TRIAL REGISTRATION NUMBER: ACTRN12617000135314. Date of registration: 24/01/2017. URL of trial registry record: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372037.

Simulation of Mechanical Heart Valve Dysfunction and the Non-Newtonian Blood Model Approach.

The mechanical heart valve (MHV) is commonly used for the treatment of cardiovascular diseases. Nonphysiological hemodynamic in the MHV may cause hemolysis, platelet activation, and an increased risk of thromboembolism. Thromboembolism may cause severe complications and valve dysfunction. This paper thoroughly reviewed the simulation of physical quantities (velocity distribution, vortex formation, and shear stress) in healthy and dysfunctional MHV and reviewed the non-Newtonian blood flow characteristics in MHV. In the MHV numerical study, the dysfunction will affect the simulation results, increase the pressure gradient and shear stress, and change the blood flow patterns, increasing the risks of hemolysis and platelet activation. The blood flow passes downstream and has obvious recirculation and stagnation region with the increased dysfunction severity. Due to the complex structure of the MHV, the non-Newtonian shear-thinning viscosity blood characteristics become apparent in MHV simulations. The comparative study between Newtonian and non-Newtonian always shows the difference. The shear-thinning blood viscosity model is the basics to build the blood, also the blood exhibiting viscoelastic properties. More details are needed to establish a complete and more realistic simulation.

Particulate Matter-Induced Acute Coronary Syndrome: MicroRNAs as Microregulators for Inflammatory Factors.

The most prevalent cause of mortality and morbidity worldwide is acute coronary syndrome (ACS) and its consequences. Exposure to particulate matter (PM) from air pollution has been shown to impair both. Various plausible pathogenic mechanisms have been identified, including microRNAs (miRNAs), an epigenetic regulator for gene expression. Endogenous miRNAs, average 22-nucleotide RNAs (ribonucleic acid), regulate gene expression through mRNA cleavage or translation repression and can influence proinflammatory gene expression posttranscriptionally. However, little is known about miRNA responses to fine PM (PM2.5, PM10, ultrafine particles, black carbon, and polycyclic aromatic hydrocarbon) from air pollution and their potential contribution to cardiovascular consequences, including systemic inflammation regulation. For the past decades, microRNAs (miRNAs) have emerged as novel, prospective diagnostic and prognostic biomarkers in various illnesses, including ACS. We wanted to outline some of the most important studies in the field and address the possible utility of miRNAs in regulating particulate matter-induced ACS (PMIA) on inflammatory factors in this review.

Association of ATP-Binding Cassette Transporter A1 Gene Polymorphisms in Type 2 Diabetes Mellitus among Malaysians.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a complex polygenic disorder characterized by impaired insulin resistance, insulin secretion, and dysregulation of lipid and protein metabolism with environmental and genetic factors. ATP-binding cassette transporter A1 (ABCA1) gene polymorphisms are reported as the one of the genetic risk factors for T2DM in various populations with conflicting results. This study was conducted based on PCR-HRM to determine the frequency of ABCA1 gene by rs2230806 (R219K), rs1800977 (C69T), and rs9282541 (R230C) polymorphisms Malaysian subjects. METHODS: A total of 164 T2DM and 165 controls were recruited and their genotypes for ABCA1 gene polymorphisms were determined based on the real time high resolution melting analysis. RESULTS: There was a significant difference between the subjects in terms of age, BMI, FPG, HbA1c, HDL, LDL, and TG (P < 0.05). There was a significant association between HOM of R219K (P = 0.005), among Malaysian subjects; moreover, allele frequency revealed the significant difference in A allele of R219K (P = 0.003). But, there was no significant difference in genotypic and allelic frequencies of C69T and R230C polymorphism. CONCLUSION: R219K polymorphism of ABCA1 gene can be considered as a genetic risk factor for T2DM subjects among Malaysians.