Search Results (32)

Halogenated flame retardants have been amongst the most widely used and effective solutions for enhancing fire resistance. However, their use is currently strictly regulated due to serious health and environmental concerns. In this context, phosphorus-based and mineral flame retardants have emerged as promising alternatives. Despite this, their combined use is neither straightforward nor guaranteed to be effective. This study scrutinizes the interactions between these two classes of flame retardants (FR) through a systematic analysis aimed at elucidating the antagonistic pathways that arise from their coexistence. Specifically, this study focuses on two inorganic fillers, mineral huntite and chemically precipitated magnesium hydroxide, both of which produce basic oxides upon thermal decomposition. These fillers were incorporated into a poly(butylene terephthalate) (PBT) matrix to be utilized as advanced-mattress FR coating fabric and were subjected to a series of flammability tests. The pyrolysis products of the prepared polymeric composite compounds were isolated and thoroughly characterized using a combination of analytical techniques. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (dTGA) were employed to monitor decomposition behavior, while the char residues collected at different pyrolysis stages were examined spectroscopically, using FTIR-ATR and Raman spectroscopy, to identify their structure and the chemical reactions that led to their formation. X-ray diffraction (XRD) experiments were also conducted to complement the spectroscopic findings in the chemical composition of the resulting char residues and to pinpoint the different species that constitute them. The morphological changes of the char’s structure were monitored by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). Finally, the Limited Oxygen Index (LOI) and UL94 (vertical sample mode) methods were used to assess the relative flammability of the samples, revealing a significant drop in flame retardancy when both types of flame retardants are present. This reduction is attributed to the neutralization of acidic phosphorus species by the basic oxides generated during the decomposition of the basic inorganic fillers, as confirmed by the characterization techniques employed. These findings underscore the challenge of combining organophosphorus with popular flame-retardant classes such as mineral or basic metal flame retardants, offering insight into a key difficulty in formulating next-generation halogen-free flame-retardant composite coatings. Full article

Fetal alcohol spectrum disorder (FASD) is a preventable cause of developmental disabilities linked to prenatal alcohol exposure (PAE). Congenital heart defects (CHDs) are frequently observed in FASD, with a notable association between PAE and dextro-type transposition of the great arteries (d-TGA). A potential pathogenetic mechanism of d-TGA in FASD, involving retinoic acid (RA) deficiency due to the interference of ethanol with RA biosynthesis, is proposed. Further investigation is required to understand the timing and impact of alcohol exposure on congenital anomalies, particularly in the context of CHDs. Full article

This work presents a comprehensive evaluation of the heat-sealability of films developed from chañar brea gum (CBG), a biopolymer with potential for packaging applications. Heat sealability is a critical property in the packaging industry, as it directly determines the integrity and functionality of the final product. The films were prepared by the 10% casting method with the addition of glycerin, and heat sealing was performed at 140 °C using a heat sealer. Heat sealing was performed on 2 cm × 10 cm strips of chañar brea gum in the horizontal (CBG-H) and vertical (CBG-V) directions. This study employs a joint determination to explore the fundamental properties of the films, including proximate analysis, antioxidant capacity, FTIR, DSC, TGA-DTGA, XRD, mechanical testing, water vapor permeability, sorption, and biodegradability. By integrating the results of all these determinations, this study seeks to evaluate and explain the “intimate relationships”—i.e., the complex interconnections among the molecular structure, composition, thermal behavior, mechanical properties, and barrier properties of chañar brea gum films—and how these fundamental properties dictate and control their heat sealability. The thermal stability of CBG is up to 200 °C, with a melting point of 152.48 °C. The interstrand spacing was very similar at 4.88 nm for CBG and 4.66 nm for CBG-H. The SEM images of the heat seal show rounded shapes on the surface, while in the cross section, it is homogeneous and almost without gaps. The WVP decreased from 1.7 to 0.37 for CBG and CBG-H, respectively. The Young’s modulus decreased from 132 MPa for CBG to 96.5 MPa for CBG-H. The heat sealability is 656 N/m, with a biodegradability of 4 days. This comprehensive approach is crucial for optimizing the sealing process and designing functional and efficient biodegradable packages. Full article

D-transposition of the great arteries (D-TGA) is a common cyanotic critical congenital heart disease. An arterial switch operation (ASO) with/without a ventricular septal defect (VSD) closure is the preferred surgical approach, with an added challenge when an intramural coronary artery (IMC) is present (1), with a reported increased incidence of postoperative complications and mortality (2,3). We present our recent D-TGA with intramural coronary artery (TGA-IMC) experience, focusing on the salient features identified on echocardiography, computed tomography (CT) angiography, and invasive angiograms, as well as variations in ASO surgical techniques for repair. Diagnostic imaging evaluation allowed for identification of the lesion, as well as planning for and undertaking of two different surgical approaches. While the two patients had differing immediate postoperative courses, both were asymptomatic at discharge, with normal biventricular systolic function. Our experience demonstrates that the suspicion for a coronary anomaly in TGA can be raised prenatally and confirmed postnatally with focused trans-thoracic echocardiography and ECG-gated CT angiogram evaluation while also aiding in operative planning. Moreover, suggesting further exploration of the optimal surgical technique for the repair of TGA-IMC. Full article

Background: Pregnancy in women with biventricular circulation and a systemic right ventricle (sRV) is considered high risk, with limited data available on pregnancy outcomes. This study aimed to investigate pregnancy outcomes in this population. Materials and Methods: A systematic review was conducted using four major electronic databases. Pregnant women with a complete transposition of great arteries (d-TGA) after an atrial switch operation or a congenitally corrected transposition of the great arteries (ccTGA) were included. Results: In total, 15 studies including 632 pregnancies in 415 women with an sRV and biventricular circulation were identified, of whom 299 (72%) had d-TGA and 116 (28%) ccTGA. Maternal mortality or cardiac transplantation occurred in 0.8% of pregnancies. The most frequent maternal complications were the worsening of systemic atrioventricular valve regurgitation [pooled estimate (PE): 16%, 95% CI: 5;26], the deterioration of sRV function (PE: 15%, 95% CI: 2;27), the worsening of the NYHA class (PE: 13%, 95% CI: 6;20), all-cause hospitalization (PE): 10%, 95% CI: 7;12), arrhythmias (PE: 8%, 95% CI: 5;11), and symptomatic heart failure (PE: 6%, 95% CI: 3;10). Stillbirth occurred in 0.7% of pregnancies and neonatal death in 0.4%. Small-for-gestational-age neonates were encountered in 36% (95% CI: 21;52) of pregnancies and preterm delivery in 22% (95% CI: 14;30). A subgroup analysis showed no significant difference in outcomes between women with d-TGA and those with ccTGA, except for the worsening of the NYHA class, which occurred more often in d-TGA (18%, 95% CI: 12;27 vs. 6%, 95% CI: 3;15, respectively, p = 0.03). Conclusions: Maternal and fetal/neonatal mortality are low among pregnant women with biventricular circulation and an sRV. However, significant maternal morbidity and poor neonatal outcomes are frequently encountered, rendering management in specialized centers imperative. Full article

Dextro-transposition of the great arteries (D-TGA) is a critical congenital heart defect that can impact neurodevelopment due to cerebral perfusion and oxygenation disorders followed by alterations in synaptogenesis, gyrification, sulcation, and the microstructure. Brain injuries can occur both pre-operatively and postoperatively, especially white matter injuries, neuronal loss, and stroke. Materials and Methods: In a retrospective study conducted at a tertiary center between 2016 and 2023, we investigated the early effects of Prostaglandin E1 (PGE1) administration and balloon atrial septostomy (BAS) on cerebral blood flow and oxygenation in inborn neonates with D-TGA. Cerebral Doppler Ultrasound in the anterior cerebral artery (ACA) was performed to assess the resistive index (RI), Peak Systolic Velocity (PSV), and End-Diastolic Velocity (EVD) before PGE1, before the BAS procedure, and 24 h after birth. Cerebral regional saturations of oxygen (crSO₂) and cerebral fractional tissue oxygen extraction (cFTOE) were evaluated. D-TGA patients were divided into the PGE1 group and the PGE1 + BAS group. Age-matched healthy controls were used for comparison. Results: All 83 D-TGA newborns received PGE1 within two hours after delivery, of whom 46 (55.42%) underwent BAS. In addition, 77 newborns composed the control group. PGE1 administration increased crSO₂ from 47% to 50% in the PGE1 group, but lower than in controls at 24 h of life, while cFTOE remained elevated. The RI increased 24 h after delivery (0.718 vs. 0.769; p = 0.000002) due to decreased EDV (10.71 vs. 8.74; p < 0.0001) following PGE1 treatment. The BAS procedure resulted in a significant increase in crSO₂ from 42% to 51% at 24 h of life in the PGE1 + BAS group. Doppler parameters exhibited a similar trend as observed in the PGE1 group. Conclusions: PGE1 treatment and BAS are lifesaving interventions that may improve cerebral perfusion and oxygenation in newborns with D-TGA during the transition period, as reflected by increasing SpO₂ and crSO₂. Full article

Dextro-transposition of the great arteries (D-TGA) is the second most common cyanotic heart disease, accounting for 5–7% of all congenital heart defects (CHDs). It is characterized by ventriculoarterial (VA) connection discordance, atrioventricular (AV) concordance, and a parallel relationship with D-TGA. As a result, the pulmonary and systemic circulations are separated [the morphological right ventricle (RV) is connected to the aorta and the morphological left ventricle (LV) is connected to the pulmonary artery]. This anomaly is included in the group of developmental disorders of embryonic heart conotruncal irregularities, and their pathogenesis is multifactorial. The anomaly’s development is influenced by genetic, epigenetic, and environmental factors. It can occur either as an isolated anomaly, or in association with other cardiac defects. The typical concomitant cardiac anomalies that may occur in patients with D-TGA include ventriculoseptal defects, patent ductus arteriosus, left ventricular outflow tract obstruction (LVOTO), mitral and tricuspid valve abnormalities, and coronary artery variations. Correction of the defect during infancy is the preferred treatment for D-TGA. Balloon atrial septostomy (BAS) is necessary prior to the operation. The recommended surgical correction methods include arterial switch operation (ASO) and atrial switch operation (AtrSR), as well as the Rastelli and Nikaidoh procedures. The most common postoperative complications include coronary artery stenosis, neoaortic root dilation, neoaortic insufficiency and neopulmonic stenosis, right ventricular (RV) outflow tract obstruction (RVOTO), left ventricular (LV) dysfunction, arrhythmias, and heart failure. Early diagnosis and treatment of D-TGA is paramount to the prognosis of the patient. Improved surgical techniques have made it possible for patients with D-TGA to survive into adulthood. Full article

This study utilizes a brain—computer interface (BCI)—based deep neural network (DNN) and genetic algorithm (GA) method. This research explores the interaction design of the main control human-machine interaction interfaces (HMIs) for intelligent electric vehicles (EVs) by integrating neural network predictions with genetic algorithm optimizations. Augmented reality (AR) was incorporated into the experimental setup to simulate real driving conditions, providing participants with an immersive and realistic experience. A comparative analysis of several models including the support vector machines-genetic algorithm (SVMs-GA), decision trees-genetic algorithm (DT-GA), particle swarm optimization-genetic algorithm (PSO-GA), and deep neural network-genetic algorithm (DNN-GA) was conducted. The results indicate that the DNN-GA model exhibited superior prediction accuracy with the lowest mean squared error (MSE) of 0.22 and mean absolute error (MAE) of 0.31. Additionally, the DNN-GA model demonstrated the shortest training time of 69.93 s, making it 4.5% more efficient than the PSO-GA model and 51.8% more efficient compared to the SVMs-GA model. This research focuses on promoting an innovative and efficient machine learning hybrid model with the goal of improving the efficiency of the human-machine interaction interfaces (HMIs) interface of intelligent electric vehicles. By optimizing the accuracy and response speed, the aim is to enhance the control interface and significantly improve user experience and usability. Full article

Fibrillin-1 and fibrillin-2, encoded by FBN1 and FBN2, respectively, play significant roles in elastic fiber assembly, with pathogenic variants causing a diverse group of connective tissue disorders such as Marfan syndrome (MFS) and congenital contractural arachnodactyly (CCD). Different genomic variations may lead to heterogeneous phenotypic features and functional consequences. Recent high-throughput sequencing modalities have allowed detection of novel variants that may guide the care for patients and inform the genetic counseling for their families. We performed clinical phenotyping for two newborn infants with complex congenital heart defects. For genetic investigations, we employed next-generation sequencing strategies including whole-genome Single-Nucleotide Polymorphism (SNP) microarray for infant A with valvular insufficiency, aortic sinus dilatation, hydronephrosis, and dysmorphic features, and Trio whole-exome sequencing (WES) for infant B with dextro-transposition of the great arteries (D-TGA) and both parents. Infant A is a term male with neonatal marfanoid features, left-sided hydronephrosis, and complex congenital heart defects including tricuspid regurgitation, aortic sinus dilatation, patent foramen ovale, patent ductus arteriosus, mitral regurgitation, tricuspid regurgitation, aortic regurgitation, and pulmonary sinus dilatation. He developed severe persistent pulmonary hypertension and worsening acute hypercapnic hypoxemic respiratory failure, and subsequently expired on day of life (DOL) 10 after compassionate extubation. Cytogenomic whole-genome SNP microarray analysis revealed a deletion within the FBN1 gene spanning exons 7–30, which overlapped with the exon deletion hotspot region associated with neonatal Marfan syndrome. Infant B is a term male prenatally diagnosed with isolated D-TGA. He required balloon atrial septostomy on DOL 0 and subsequent atrial switch operation, atrial septal defect repair, and patent ductus arteriosus ligation on DOL 5. Trio-WES revealed compound heterozygous c.518C>T and c.8230T>G variants in the FBN2 gene. Zygosity analysis confirmed each of the variants was inherited from one of the parents who were healthy heterozygous carriers. Since his cardiac repair at birth, he has been growing and developing well without any further hospitalization. Our study highlights novel FBN1/FBN2 variants and signifies the phenotype–genotype association in two infants affected with complex congenital heart defects with and without dysmorphic features. These findings speak to the importance of next-generation high-throughput genomics for novel variant detection and the phenotypic variability associated with FBN1/FBN2 variants, particularly in the neonatal period, which may significantly impact clinical care and family counseling. Full article

This paper investigates the development of fabric materials using several blends of inherently fire-resistant (FR) fibers and various knitted structures. The samples are evaluated with respect to their performance and comfort-related properties. Inherently fire-resistant fibers, e.g., Nomex, Protex, carbon and FR viscose, were used to develop different structures of knitted fabrics. Cross-miss, cross-relief, and vertical tubular structures were knitted by using optimum fiber blend proportions and combinations of stitches. Several important aspects of the fabric samples were investigated, e.g., their physical, mechanical and serviceability performance. Thermo-physiological and tactile/touch-related comfort properties were evaluated in addition to flame resistance performance. An analysis of mechanical performance indicated that the knitted structure has a significant influence on the tensile strength, bursting strength and pilling resistance. The cross-relief structure proved to be the strongest followed by the cross-miss and vertical tubular structures. The FR station suits made from 70:30 Protex/Nomex exhibited the best combination of tensile and bursting strength; therefore, this material is recommended for making a stable and durable station suit. Interestingly, it was also concluded from the experimental study that knitted samples with a cross-relief structure exhibit the best fire-resistance performance. Fiber blends of 70:30 Protex/Nomex and 70:30 Nomex/carbon were found to be optimum in terms of overall performance. The best flame resistance was achieved with Nomex:carbon fiber blends. These results were confirmed with vertical flammability tests, TGA, DTGA and cone calorimetry analysis. The optimization of blend composition as well as knitting structure/architecture is a crucial finding toward designing the best FR station suit in terms of mechanical, dimensional, thermal, thermo-physiological and flame resistance performance. Full article

Several polyurethane-formulated films with curcumin and/or chitosan additives for food packaging have been previously obtained. The study examines the effect of the additives on the film’s morphological, mechanical, barrier, and migration properties. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), water contact angle, thermogravimetric and differential thermal analysis (TGA and DTGA), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), oxygen transmission rate (OTR), water vapor transmission rate (WVTR), and the overall and specific migration tests were conducted. The results show that the presence of chitosan significantly increased the overall migration and mechanical properties, such as the elongation at break, tensile strength, and Young’s modulus of most polyurethane formulations, while curcumin had a minor influence on the mechanical performance. Based on the results, formulations with curcumin but without chitosan are suitable for food packaging. Full article

The population of patients with a systemic right ventricle (sRV) in biventricular circulation includes those who have undergone an atrial switch operation for destro-transposition of the great arteries (d-TGA) and those with congenitally corrected transposition of the great arteries (ccTGA). Despite the life expectancy of these patients is significantly increased, the long-term prognosis remains suboptimal due to late complications such as heart failure, arrhythmias, and premature death. These patients, therefore, need a close follow-up to early identify predictive factors of adverse outcomes and to implement all preventive therapeutic strategies. This review analyzes the late complications of adult patients with an sRV and TGA and clarifies which are risk factors for adverse prognosis and which are the therapeutic strategies that improve the long-term outcomes. For prognostic purposes, it is necessary to monitor sRV size and function, the tricuspid valve regurgitation, the functional class, the occurrence of syncope, the QRS duration, N-terminal pro B-type natriuretic peptide levels, and the development of arrhythmias. Furthermore, pregnancy should be discouraged in women with risk factors. Tricuspid valve replacement/repair, biventricular pacing, and implantable cardioverter defibrillator are the most important therapeutic strategies that have been shown, when used correctly, to improve long-term outcomes. Full article

The purpose of this study was to investigate the thermal stability and the decomposition kinetics of ethylene–propylene–diene monomer (EPDM) composite samples loaded with and without lead powder (50, 100, and 200 phr lead) using thermogravimetric analysis (TGA). TGA was carried out at different heating rates (5, 10, 20, and 30 °C/min) under inert conditions in the temperature range of 50–650 °C. Lead addition did not significantly change the onset temperature or peak position corresponding to the maximum decomposition rate of the first derivative of the TGA curve (DTGA) (onset at about 455 °C and T_m at about 475 °C). Peak separation for the DTGA curves indicated that the main decomposition region for EPDM, the host rubber, overlapped the main decomposition region for volatile components. The decomposition activation energy (E_a) and pre-exponent factor (A) were estimated using the Friedman (FM), Kissinger–Akahira–Sunose (KAS), and Flynn–Wall–Ozawa (FWO) iso-conversional methods. Average activation energy values of around 231, 230, and 223 kJ/mol were obtained for the EPDM host composite using the FM, FWO, and KAS methods, respectively. For a sample loaded with 100 phr lead, the average activation energy values obtained via the same three methods were 150, 159, and 155 kJ/mole, respectively. The results obtained from the three methods were compared with results obtained using the Kissinger and Augis–Bennett/Boswell methods, and strong convergence was found among the results of the five methods. A significant change in the entropy of the sample was detected with the addition of lead powder. For the KAS method, the change in entropy, ΔS, was −3.7 for EPDM host rubber and −90 for a sample loaded with 100 phr lead, α = 0.5. Full article

Evaluation and understanding of the thermal behavior of polymers is crucial for many applications, e.g., polymer processing at relatively high temperatures, and for evaluating polymer-polymer miscibility. In this study, the differences in the thermal behavior of poly(vinyl alcohol) (PVA) raw powder and physically crosslinked films were investigated using various methods, such as thermogravimetric analysis (TGA) and derivative TGA (DTGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Various strategies were adopted, e.g., film casting from PVA solutions in H₂O and D₂O and heating of samples at carefully selected temperatures, in order to provide insights about the structure-properties relationship. It was found that the physically crosslinked PVA film presents an increased number of hydrogen bonds and increased thermal stability/slower decomposition rate compared to the PVA raw powder. This is also depicted in the estimated values of specific heat of thermochemical transition. The first thermochemical transition (glass transition) of PVA film, as for the raw powder, overlaps with mass loss from multiple origins. Evidence for minor decomposition that occurs along with impurities removal is presented. The overlapping of various effects (softening, decomposition, and evaporation of impurities) has led to confusion and apparent consistencies, e.g., from the XRD, it is derived that the film has decreased crystallinity, and apparently this is in agreement with the lower value of heat of fusion. However, the heat of fusion in this particular case has a questionable meaning. Full article

One of the current challenges is to add value to agro-industrial wastes, and the cocoa industry generates about 10 tons of cocoa pod husks in Colombia for each ton of cocoa beans, which are incinerated and cause environmental damage. This study characterized the Colombian cocoa pod husk (CPH) and to isolate and characterize cellulose microfibers (tCPH) extracted via chemical treatment and pressure. Chemical and physical analyses of CPH were performed, and a pretreatment method for CPH fibers was developed, which is followed by a hydrolysis method involving high pressure in an autoclave machine with an alkaline medium (6% NaOH), and finally, bleaching of the fiber to obtain tCPH. The tCPH cellulose microfibers were also chemically and physically analyzed and characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermo-gravimetric analysis (TGA). Chemical and physical characterization showed a decrease in lignin content in tCPH. FTIR analysis showed the absence of some peaks in tCPH with respect to the CPH spectrum; XRD results showed an increase in crystallinity for tCPH compared to CPH, due to a higher presence of crystalline cellulose in tCPH. SEM images included a control fiber treated without high pressure (tCPHnpe), and agglomerated fibers were observed, whereas cellulose microfibers with a mean diameter of 10 ± 2.742 μm were observed in tCPH. Finally, with TGA and DTGA it was confirmed that in tCPH, the hemicellulose and lignin were removed more successfully than in the control fiber (tCPHnpe), showing that the treatment with pressure was effective at isolating the cellulose microfibers from cocoa pod husk. Full article