Material modeling and recent findings in transcatheter aortic valve implantation simulations.

BACKGROUND AND OBJECTIVE: Transcatheter aortic valve implantation (TAVI) has significantly transformed the management of aortic valve (AV) diseases, presenting a minimally invasive option compared to traditional surgical valve replacement. Computational simulations of TAVI become more popular and offer a detailed investigation by employing patient-specific models. On the other hand, employing accurate material modeling procedures and applying basic modeling steps are crucial to determining reliable numerical results. Therefore, this review aims to outline the basic modeling approaches for TAVI, focusing on material modeling and geometry extraction, as well as summarizing the important findings from recent computational studies to guide future research in the field. METHODS: This paper explains the basic steps and important points in setting up and running TAVI simulations. The material properties of the leaflets, valves, stents, and tissues utilized in TAVI simulations are provided, along with a comprehensive explanation of the geometric extraction methods employed. The differences between the finite element analysis, computational fluid dynamics, and fluid-structure interaction approaches are pointed out and the important aspects of TAVI modeling are described by elucidating the recent computational studies. RESULTS: The results of the recent findings on TAVI simulations are summarized to demonstrate its powerful potential. It is observed that the material properties of aortic tissues and components of implanted valves should be modeled realistically to determine accurate results. For patient-specific AV geometries, incorporating calcific deposits on the leaflets is essential for ensuring the accuracy of computational findings. The results of numerical TAVI simulations indicate the significance of the selection of optimal valves and precise deployment within the appropriate anatomical position. These factors collectively contribute to the effective functionality of the implanted valve. CONCLUSIONS: Recent studies in the literature have revealed the critical importance of patient-specific modeling, the selection of accurate material models, and bio-prosthetic valve diameters. Additionally, these studies emphasize the necessity of precise positioning of bio-prosthetic valves to achieve optimal performance in TAVI, characterized by an increased effective orifice area and minimal paravalvular leakage.

Latest Developments in Adapting Deep Learning for Assessing TAVR Procedures and Outcomes.

Aortic valve defects are among the most prevalent clinical conditions. A severely damaged or non-functioning aortic valve is commonly replaced with a bioprosthetic heart valve (BHV) via the transcatheter aortic valve replacement (TAVR) procedure. Accurate pre-operative planning is crucial for a successful TAVR outcome. Assessment of computational fluid dynamics (CFD), finite element analysis (FEA), and fluid-solid interaction (FSI) analysis offer a solution that has been increasingly utilized to evaluate BHV mechanics and dynamics. However, the high computational costs and the complex operation of computational modeling hinder its application. Recent advancements in the deep learning (DL) domain can offer a real-time surrogate that can render hemodynamic parameters in a few seconds, thus guiding clinicians to select the optimal treatment option. Herein, we provide a comprehensive review of classical computational modeling approaches, medical imaging, and DL approaches for planning and outcome assessment of TAVR. Particularly, we focus on DL approaches in previous studies, highlighting the utilized datasets, deployed DL models, and achieved results. We emphasize the critical challenges and recommend several future directions for innovative researchers to tackle. Finally, an end-to-end smart DL framework is outlined for real-time assessment and recommendation of the best BHV design for TAVR. Ultimately, deploying such a framework in future studies will support clinicians in minimizing risks during TAVR therapy planning and will help in improving patient care.

The protective role of the opioid antagonist LY255582 in the management of high fat diet-induced obesity in adult male albino rats.

OBJECTIVES: The involvement of the opioid system in energy balance has been known for several decades but many questions remain unanswered. Therefore, this study was designed to investigate the effect of the non-selective opioid receptor antagonist (LY255582) on high fat diet (HFD)-induced obesity. METHODS: Twenty-four adult male albino rats were divided into 4 groups: Control, HFD non-treated, HFD+LY255582 treated during the first 4 weeks and Obese-LY255582- treated groups during the following 4 weeks after the induction of obesity. LY255582 (0.31 mg/kg, s.c.) was administrated daily with HFD feeding. Blood samples were collected for measurement of lipid profile, glucose, insulin, and leptin. Body weight, body mass index (BMI), and food intake were also measured. RESULTS: Consumption of HFD resulted in a significant increase in body weight, body mass index (BMI), glucose, insulin, leptin levels, and induced a state of dyslipideamia. Opioid antagonist LY255582 administration with HFD decreased food intake, body weight and BMI, in addition to the improvement of HFD related metabolic abnormalities (dyslipidemia and insulin resistance) during the dynamic phase of obesity development than in animals with already developed dietary obesity. CONCLUSION: The use of opioid antagonist may be a promising approach in treatment of HFD-induced obesity.

Sexually transmitted infections and sexual behaviour among youth clients of hotel-based female sex workers in Dhaka, Bangladesh.

A cross-sectional study was conducted among youth clients of hotel-based female sex workers (YCHBFSWs) in nine randomly selected hotels in Bangladesh to examine sexual-risk behaviour, condom use and determinants of condom use in last sex, knowledge of HIV, sexually transmitted infection (STI) prevalence and STI care-seeking behaviour. A prestructured questionnaire was used to collect sociodemographic, behavioural, clinical information; urine specimens (before sex) and blood were collected for diagnosis of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, syphilis and herpes simplex virus 2 (HSV2) infection. One thousand and thirteen participants were enroled in the study. Approximately half of them reported visiting female sex workers (FSWs) at least once a month and 25% visited FSWs at least once a week. Only 12% of participants reported regular condom use. The prevalence of N. gonorrhoeae, C. trachomatis, T. vaginalis, syphilis and HSV2 was 2.2%, 3.9%, 7.2%, 2.6% and 12.9%, respectively. Only 15.3% of the YCHBFSW sought STI care in the past year. Negotiation of condom use with FSWs was the main determinant (odds ratio = 17.95) for condom use at last sex. Male clients of FSWs, including YCHBFSW, are an important bridge population for HIV transmission in Bangladesh and HIV interventions should be designed and implemented for them.

Family planning and fertility in Bangladesh.

PIP: This study examines the trends in contraceptive use and fertility levels in Bangladesh using national-level data from 1975-97. It also considers the major factors affecting contraceptive use and fertility. Data from the 1993/94 and 1996/97 Bangladesh Demographic Health Survey were also used for the multivariate analysis of the determinants of contraceptive use and fertility. It was found that between 1975 and 1996/97 the use of family planning methods increased 5-fold, rising from 13.6% to 69.2%. Also, contraceptive prevalence rate increased by over 6 times during the same period, rising from 7.7% to 49.2%. The sharp increase in contraceptive prevalence led to an appreciable decline in fertility, with total fertility rate dropping from 6.3 during the period 1971-75 to 3.3 during the period 1994-96. Except for the 15-19 year age group, fertility declined substantially in all other age groups, especially among women aged 35 years and older. Results of the analysis indicate that six factors account for the reproductive change in Bangladesh. These include interspousal communication on family planning, desire for children, women's education and employment status, access to mass media, and program efforts. The policy and programmatic implications of the findings are discussed.^ieng

Unmet contraceptive need in Bangladesh: evidence from the 1993/94 and 1996/97 Demographic and Health Surveys.

PIP: Unmet contraceptive need is defined as the percentage of currently married women in their reproductive ages who do not want additional children and yet do not practice contraception. This analysis examined the extent of unmet need in Bangladesh and differentials in unmet need by selected characteristics of the respondents. Data were obtained from the 1993-94 and 1996-97 Bangladesh Demographic and Health Surveys (BDHS), which employed nationally representative, two-stage samples of 8842 (7510 rural ad 1332 urban) and 8306 (6995 rural and 1311 urban) currently married women of reproductive age. In this analysis, the dependent variable "unmet need" includes pregnant women whose pregnancy was mistimed, amenorrheic women whose last birth was mistimed, and women who were neither pregnant nor amenorrheic and who were not using any method of family planning. In addition, several independent variables were also considered in the analysis. According to the BDHS data, 1 out of every 6 women in Bangladesh has an unmet need--8% each for spacing and limiting the birth of children. The extent of unmet need was found to be higher in rural than in urban areas, and was higher in Sylhet and Chittagong divisions compared to the country's other divisions. The main predictors of unmet need were found to be ever use of family planning, husband-wife communication on family planning matters, number of living children, and place of residence. Furthermore, unmet need was slightly lower among women with some secondary schooling than among those with little or no education.^ieng