Padrão de realce tardio não descrito na cardiomiopatia hipertrófica: subendocárdico circunferencial / Delayed enhancement pattern not described in hypertrophic cardiomyopathy: circumferential subendocardial

INTRODUÇÃO: Na cardiomiopatia hipertrófica (CMH) o achado mais típico na ressonância magnética é o realce tardio do mesocárdico, localizado principalmente na parede inferosseptal. Este realce não está presente em todos os casos e ocorre preferencialmente em paredes onde há maior hipertrofia. Apresentamos dois casos com fenótipo típico de CMH e padrão atípico de realce tardio. RELATO DE CASO: CASO 1-Assintomático, confirmou o diagnóstico de CMH durante a investigação de quadro recorrente de acidente vascular encefálico isquêmico. CASO 2- Histórico familiar de morte súbita, assintomático, feito diagnóstico de CMH por cascata familiar. Demais detalhes das características e achados podem ser avaliados na tabela 1. Na ressonância cardíaca: 1: hipertrofia ventricular esquerda com predomínio septal, com espessura máxima de 20 mm em septo ínfero-medial associado a presença de realce tardio miocárdico com predomínio subendocárdico difuso nos segmentos apicais. (Figura A/B). 2- aumento significativo da espessura do ápice do ventrículo direito causando redução da sua cavidade efetiva e dilatação do átrio direito. Função sistólica do ventrículo direito preservadas com presença de realce tardio subendocárdico no ápice. Espessura normal das paredes do ventrículo esquerdo com a presença de áreas de realce tardio subendocárdico circunferencial envolvendo as porções basal, médio e apical com pontos de infiltração gordurosa esparsos predominantemente na porção apical e média (Figura C/D). DISCUSSÃO E CONCLUSÃO: Na CMH, o padrão de realce tardio mais prevalente é o mesocárdico, geralmente nas paredes ventriculares onde há maior hipertrofia, e é puntiforme. Na presença de aneurisma apical na CMH, tem sido descrito o padrão transmural de realce. O realce subendocárdico circunferencial evidenciado no presente estudo, representa um achado radiológico atípico e infrequente da CMH. Suscitando amplo debate quanto a sua fisiopatologia. Após discussão, sua ocorrência foi atribuída a um possível infarto tipo 2, relacionado à isquemia na CMH por desproporção entre oferta e demanda. Assim sendo, propomos a consideração do realce tardio subendocárdico circunferencial como uma potencial apresentação da CMH e concluímos ser de suma importância clínica o reconhecimento dos diversos padrões de realce tardio, ainda que atípicos, para uma abordagem propedêutica mais precisa e eficaz.

Impact of Different Mineral Reinforcements on HDPE Composites: Effects of Melt Flow Index and Particle Size on Physical and Mechanical Properties.

The use of mineral reinforcements in polymer matrix composites has emerged as an alternative for sustainable production, reducing waste and enhancing the physical and mechanical properties of these materials. This study investigated the impact of the melt flow index (MFI) of HDPE and the particle size of two mineral reinforcements, Bahia Beige (BB) and Rio Grande do Norte Limestone (CRN), on the composites. All composites were processed via extrusion, followed by injection, with the addition of 30 wt.% reinforcement. Chemical analyses revealed similar compositions with high CaO content for both minerals, while X-ray diffraction (XRD) identified predominantly calcite, dolomite, and quartz phases. Variations in the MFI, reinforcement type, and particle size showed a minimal influence on composite properties, supported by robust statistical analyses that found no significant differences between groups. Morphological analysis indicated that composites with lower MFI exhibited less porous structures, whereas larger particles of BB and CRN formed clusters, affecting impact resistance, which was attributed to poor interfacial adhesion.

Dose-response and efficacy of 904 nm photobiomodulation on diabetic foot ulcers healing: a randomized controlled trial.

PURPOSE: This study aimed to examine the impact of a 904 nm photobiomodulation (PBM) on diabetic ulcers using varying dosages. METHODS: The study was a randomized, double-blind, placebo-controlled clinical trial that compared treatments using PBM (GaAs 904 nm 30w) with three different energy densities (4 J/cm2; 8 J/cm2; 10 J/cm2) in the healing process of non-infected diabetic foot ulcers. Eighty volunteers (48.75% female; 58.5 ± 11.1 years) were randomized into three intervention groups treated with PBM and one control group (PBM placebo). Volunteers performed up 20 interventions with PBM, either placebo or actual, in conjunction with conventional therapy, which involved dressing the wound with Helianthus annuus vegetable oil. The primary variable was the ulcer size reduction rate. RESULTS: GaAs 904 nm PBM yielded a clinically and significant ulcer size rate reduction of diabetic foot ulcers, independently of energy density range (p < 0.05). However, 10 J/cm² had 60% of completely healed ulcers and the highest proportion of patients reaching 50% of ulcer reduction rate after 5 weeks of treatment. In addition, only 10 J/cm² showed a significant difference between control group after a 10-week follow-up (p < 0.05). CONCLUSION: GaAs 904 nm PBM was effective in treating diabetic foot ulcers in this study and a dosage of 10 J/cm², after a 10-week follow-up, proved to be the most effective compared to the other groups. CLINICAL TRIAL REGISTRATION NUMBER: NCT04246814.

Impacto do estudo genético negativo na cardiomiopatia hipertrófica: relato de caso / Impact of negative genetic study on hypertrophic cardiomyopathy: case report

TÍTULO: Impacto do estudo genético negativo na cardiomiopatia hipertrófica: relato de caso. INTRODUÇÃO: A realização do painel genético na cardiomiopatia hipertrófica (CMH) tem importância tanto para confirmação diagnóstica, investigação de familiares e também para afastar fenocópias, algumas delas com tratamento específico e outras que requerem tratamento individualizado. Na CMH, em cerca de 60% dos casos, não se consegue isolar uma mutação responsável. Pretendemos ressaltar, neste relato de caso, um resultado negativo de painel molecular com implicações diagnósticas e prognósticas. RELATO DE CASO: masculino, 35 anos, portador de transtorno cognitivo importante, iniciou investigação cardiológica devido histórico familiar - irmão, com diagnóstico de CMH e também portador de transtorno cognitivo, falecido aos 21 anos em decorrência de complicações de CMH. Realizou eletrocardiograma sendo evidenciado intervalo PR curto e onda delta, padrão de Wolff-Parkinson-White (WPW); ecocardiograma transtorácico (ECOTT) demonstrou hipocontratilidade difusa de ventrículo esquerdo (VE), fração de ejeção de 45%, septo interventricular e parede posterior medindo 30mm/18mm; exames laboratoriais normais. A ressonância magnética além dos achados já flagrados pelo ECOTT, demonstrou extensa fibrose miocárdica de padrão não-coronariano em VE e porção apical de ventrículo direito. Pela evolução para disfunção ventricular, grande magnitude de hipertrofia do ventrículo esquerdo, WPW, sexo masculino, transtorno cognitivo e história familiar, foi aventada a hipótese de doença de Danon, uma lisossomopatia de herança ligada ao cromossomo X. O painel genético com pesquisa dos principais genes implicados em CMH, incluindo o gene LAMP2, foi negativo para todos os genes testados, inclusive sem evidência de variantes de significado indeterminado. COMENTÁRIOS E CONCLUSÃO: o painel genético negativo neste caso teve importância crucial para afastar a doença de Danon, já que vários aspectos clínicos apontavam para este diagnóstico. Se o painel genético fosse positivo, haveria uma implicação terapêutica e quanto à orientação genética no que diz respeito à questão reprodutiva. Vale a pena ressaltar também a importância dos exames laboratoriais de enzimas hepáticas e creatinofosfoquinase que costumam estar alterados na doença de Danon e estavam normais no presente caso. Além de afastar fenocópias, o painel molecular pode ajudar a delimitar novos espectros de CMH com seus respectivos prognósticos e propiciar aconselhamento genético preciso, além de, no futuro, auxiliar nas terapias de edição gênica.

Amiloidose de cadeias leves: quando biópsia de língua tem rendimento maior do que a de gordura abdominal / Light chain amyloidosis: when tongue biopsy has a higher yield than abdominal fat biopsy

INTRODUÇÃO: a amiloidose de cadeias leves (AL) é uma doença causada pela produção exagerada pelos plasmócitos de cadeias leves kappa ou lambda e posterior deposição tecidual de agregados proteicos fibrilares e insolúveis em diferentes órgãos, incluindo o coração. O diagnóstico de AL dever ser confirmado através de biópsia. Deve-se dar preferência, inicialmente, à biópsia de gordura abdominal, sendo a coloração de vermelho congo com birrefringência sob a luz polarizada o método usado na determinação de proteína amiloide tecidual. RELATO DE CASO: masculino, 57 anos, passou a manifestar quadro de dispneia aos esforços, hipotensão sintomática, macroglossia, intolerância a drogas vasodilatadores, síndrome do túnel do carpo bilateral e disfunção autonômica. O eletrocardiograma evidenciava baixa voltagem e fibrilação atrial. O ecocardiograma evidenciava fenótipo infiltrativo, fração de ejeção de 60% e aumento da espessura do septo interventricular de 14mm. Relação kappa/lambda de 475 (valor de referência até 1,65) e imunofixação sérica com pico monoclonal de kappa. A biopsia de gordura abdominal foi negativa. Como apresentava macroglossia, foi indicada biopsia de língua, órgão afetado, que no anátomo patológico evidenciou depósito amiloide. Posteriormente foi realizada espectrometria de massa que confirmou que a proteína do depósito amiloide era a cadeia leve kappa. COMENTÁRIOS E CONCLUSÕES: a biopsia de gordura abdominal, apresenta sensibilidade de 60% a 80% e especificidade de 90% a 100% no diagnóstico de amiloidose. Portanto costuma ser o local inicial preferencial das biopsias extracardíacas para pesquisa de amiloidose. No entanto, um resultado negativo não deve excluir o diagnóstico. Isto ocorreu no presente caso, que apresentava clínica muito sugestiva de amiloidose e biopsia de gordura abdominal negativa. O passo seguinte seria a realização de biopsia endomiocárdica, porém optou-se em realizar biopsia de língua, já que havia macrogossia, sabendo-se que a biopsia de órgão acometido tem rendimento de 100%, o que se confirmou neste caso. Concluimos que havendo macroglossia, a língua deve ser o local preferencial da biopsia para diagnóstico de AL.

Babassu Coconut Fibers: Investigation of Chemical and Surface Properties (Attalea speciosa.).

To complement previous results, an analysis of the chemical and morphological properties of babassu fibers (Attalea speciosa Mart. ex Spreng.) was conducted in order to evaluate their potential as reinforcements in the production of composites with epoxy matrix. The diameter distribution was analyzed in a sample of one hundred fibers, allowing the verification of its variation. The determination of the chemical properties involved experimental analyses of the constituent index and X-ray diffraction. The diffractogram was used to calculate the crystallinity index and the microfibril angle, which are crucial parameters that indicate the consistency of the mechanical properties of babassu fibers and the feasibility of their use in composites. The results revealed that babassu fiber has a chemical composition, with contents of 28.53% lignin, 32.34% hemicellulose, and 37.97% cellulose. In addition, it showed a high crystallinity index of 81.06% and a microfibril angle of 7.67°. These characteristics, together with previous results, indicate that babassu fibers have favorable chemical and morphological properties to be used as reinforcements in composites, highlighting its potential as an important material for applications in technology areas.

Ballistic Performance, Thermal and Chemical Characterization of Ubim Fiber (Geonoma baculifera) Reinforced Epoxy Matrix Composites.

The search for unexplored natural materials as an alternative to synthetic components has driven the development of novel polymeric composites reinforced with environmentally-friendly materials. Natural lignocellulosic fibers (NLFs) have been highlighted as potential reinforcement in composite materials for engineering applications. In this work, a less known Amazonian fiber, the ubim fiber (Geonoma baculifera), is investigated as a possible reinforcement in epoxy composites and was, for the first time, thermally characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Additionally, its chemical structure was elucidated by Fourier transform infrared spectroscopy (FTIR). Ballistic tests were also performed against the threat of a 7.62 mm high-speed lead projectile. The results were statistically analyzed by the Weibull statistical analysis method. FTIR analysis showed the functional groups normally found for NLFs highly rich in cellulose, hemicellulose, and lignin. The TGA/DTG results showed the onset of thermal degradation for the composites (325~335 °C), which represents better thermal stability than isolated ubim fiber (259 °C), but slightly lower than that of pure epoxy (352 °C). The DSC results of the composites indicate endothermic peaks between 54 and 56 °C, and for the ubim fibers, at 71 °C. Ballistic tests revealed higher energy absorption in composites with lower fiber content due to the more intense action of the brittle fracture mechanisms of the epoxy resin, which tended to dissipate more energy. These failure mechanisms revealed the presence of river marks, cracks, and broken fibers with a detachment interface. These results may contribute to the production of ubim fiber-reinforced composites in engineering applications, such as ballistic armors.

Characterization of Thermo-Mechanical and Chemical Properties of Polypropylene/Hemp Fiber Biocomposites: Impact of Maleic Anhydride Compatibilizer and Fiber Content.

This article presents a comprehensive study on the physical, mechanical, thermal, and chemical properties of polypropylene (PP) composites reinforced with hemp fibers (HF) and compatibilized with maleic anhydride (MAPP). The composites were processed using a twin-screw extruder, followed by hot compression at 190 °C. Subsequently, the composites were analyzed using Izod impact and Shore D hardness tests to evaluate their mechanical properties. Thermal properties were investigated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), while X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) were employed to study their chemical properties. Additionally, a statistical analysis was conducted to compare the average results of the impact and hardness tests. XRD analysis revealed that the addition of HF and MAPP led to the disappearance of peaks corresponding to the beta phase in pure PP. Hemp fibers exhibited an impressive crystallinity of 82.10%, surpassing other natural fibers, and had a significant molecular orientation angle (MFA) of 6.06°, making them highly desirable for engineering applications. The crystallite size was observed to be relatively large, at 32.49 nm. FTIR analysis demonstrated strong interactions between the fiber, compatibilizing agent, and polymer matrix. TGA tests showed that the addition of 5 and 10 wt.% MAPP resulted in complete degradation of the composites, similar to pure PP. DSC analyses indicated a reduction in crystallinity (Xc) due to the incorporation of HF and MAPP. Shore D hardness tests revealed an increase in hardness with the addition of 5 wt.% MAPP, while a steep decline in this property was observed with 10 wt.% MAPP. In terms of impact resistance, fractions of 3 and 5 wt.% MAPP in the composites exhibited improved performance compared to the pure polymer. Analysis of variance (ANOVA) was employed to ensure the statistical reliability of the mechanical test results. This comprehensive study sheds light on the diverse properties of PP composites reinforced with hemp fibers and compatibilized with MAPP, emphasizing their potential as sustainable materials for engineering applications. The results contribute to the understanding of the structural and functional aspects of these composites, guiding future research and developments in the field.

Polymeric nanoparticles containing babassu oil: A proposed drug delivery system for controlled release of hydrophilic compounds.

Different drug delivery systems are prepared on the nanoscale to improve performance in drug formulations, such as nanoparticles or nanoemulsions. Polymeric nanoparticles have been used to encapsulate drugs for several applications because of some characteristics of these carriers to control drug delivery, transport molecules to a specific tissue, protect the drugs, and increase drug bioavailability. When using nanocapsules, an essential parameter for encapsulating different hydrophilic or lipophilic molecules is the characteristics of the core. Babassu oil (BBS) is a natural product from Brazil, composed majoritary of short-chain saturated fatty acids. BBS has an elevated hydrophilic-lipophilic balance (HLB), which may promote interaction of the oil with hydrophilic drugs. In this study, we developed and characterized particles containing babassu oil, solely or combined with sorbitan monostearate (Span® 60) or medium chain triglycerides (MCT) in the core to test different HLB and evaluated the encapsulation of a model hydrophilic molecule. Different techniques were used to characterize all formulations in terms of size and distribution, and in vitro drug release by dialysis technique was performed. The BBS was also characterized and presented 46,05 ± 1,11% and 15,38 ± 0,06% of lauric and myristic acid, respectively; saponification index of 248.87 ± 0.64 mg of KOH per gram of BBS, and no oxidation of the oil was indicated by means of peroxide index. Evaporation of solvent carried in the room or reduced pressure influenced the particles' size; nevertheless, all had a z-average smaller than 220 nm. Nanoparticles with a ratio among aqueous phase and organic phase of 2.8 were considered adequate to encapsulate diclofenac sodium. The particles size/zeta potential were 189.83 ± 7.86 nm / - 10.39 ± 2.52 mV, 156.80 ± 4.77 nm / - 9.27 ± 4.61 mV, and 168.87 ± 5.22 nm / - 12.98 ± 4.66 mV to nanoparticles prepared with BBS + MCT, BBS, and BBS + Span® 60, respectively. All formulations exhibited an amount of drug content close to the theoretical amount (1.0 mg mL-1), and no difference was observed in the release profile among the three nanoparticles. Formulation containing only babassu oil in the core displayed 66.78 ± 15.62% of encapsulation efficiency to diclofenac sodium, the highest value among all formulations tested. Results demonstrate that the innovative nanoparticles containing BBS promote the encapsulation of a model hydrophilic molecule, and other components can be evaluated to change the core's hydrophilicity and encapsulation of molecules.

Fabric Impregnation with Shear Thickening Fluid for Ballistic Armor Polymer Composites: An Updated Overview.

As destructive power of firearms raises over the years, ballistic armors are in continuous need of enhancement. For soft armors, this improvement is invariably related to the increase of stacked layers of high-strength fiber fabrics, which potentially restrains wearer mobility. A different solution was created in the early 2000s, when a research work proposed a new treatment of the ballistic panels with non-Newtonian colloidal shear thickening fluid (STF), in view of weight decreasing with strength reinforcement and cost-effective production. Since then, databases reveal a surge in publications generally pointing to acceptable features under ballistic impact by exploring different conditions of the materials adopted. As a result, several works have not been covered in recent reviews for a wider discussion of their methodologies and results, which could be a barrier to a deeper understanding of the behavior of STF-impregnated fabrics. Therefore, the present work aims to overview the unexplored state-of-art on the effectiveness of STF addition to high-strength fabrics for ballistic applications to compile achievements regarding the ballistic strength of this novel material through different parameters. From the screened papers, SiO2, Polyethylene glycol (PEG) 200 and 400, and Aramid are extensively being incorporated into the STF/Fabric composites. Besides, parameters such as initial and residual velocity, energy absorbed, ballistic limit, and back face signature are common metrics for a comprehensive analysis of the ballistic performance of the material. The overview also points to a promising application of natural fiber fabrics and auxetic fabrics with STF fluids, as well as the demand for the adoption of new materials and more homogeneous ballistic test parameters. Finally, the work emphasizes that the ballistic application for STF-impregnated fabric based on NIJ standards is feasible for several conditions.

Curaua-Aramid Hybrid Laminated Composites for Impact Applications: Flexural, Charpy Impact and Elastic Properties.

Curaua, as a leaf-based natural fiber, appears to be a promising component with aramid fabric reinforcement of hybrid composites. This work deals with the investigation of flexural, impact and elastic properties of non-woven curaua-aramid fabric hybrid epoxy composites. Five configurations of hybrid composites in a curaua non-woven mat with an increasing quantity of layers, up to four layers, were laminated through the conventional hand lay-up method. The proposed configurations were idealized with at least 60 wt% reinforcement in the non-alternating configuration. As a result, it was observed that the flexural strength decreased by 33% and the flexural modulus by 56%. In addition, the energy absorbed in the Charpy impact also decreased in the same proportion as the replaced amount of aramid. Through the impulse excitation technique, it was possible observe that the replacement of the aramid layers with the curaua layers resulted in decreased elastic properties. However, reduction maps revealed proportional advantages in hybridizing the curaua with the aramid fiber. Moreover, the hybrid composite produced an almost continuous and homogeneous material, reducing the possibility of delamination and transverse deformation, which revealed an impact-resistant performance.

Mechanical Properties, Critical Length, and Interfacial Strength of Seven-Islands-Sedge Fibers (Cyperus malaccensis) for Possible Epoxy Matrix Reinforcement.

The growing concern about the limitation of non-renewable resources has brought a focus on the development of environmentally sustainable and biodegradable composite materials. In this context, a trend in the development of natural fibers used as a reinforcement in composites is ever-increasing. In this work, for the first-time, fibers extracted from the seven-islands-sedge plant (Cyperus malaccensis) have been characterized by X-ray diffraction (XRD) to calculate the crystallinity index and the microfibrillar angle (MFA). Also, an evaluation of the ultimate tensile strength by diameter intervals has been investigated and statistically analyzed by both the Weibull method and the analysis of variance (ANOVA). Moreover, the maximum deformation and tensile modulus have been found from the data acquired. Pullout tests have been conducted to investigate the critical length and interfacial strength when sedge fibers, are incorporated into epoxy resin matrix. Microstructure analysis by scanning electron microscopy (SEM) was performed to observe the mechanism responsible for causing rupture of the fiber as well as the effective fiber interfacial adhesion to the epoxy matrix.

Bio-Based Composites for Light Automotive Parts: Statistical Analysis of Mechanical Properties; Effect of Matrix and Alkali Treatment in Sisal Fibers.

Composites based on virgin and recycled polypropylene (PP and rPP) reinforced with 15 wt% sisal fibers, with and without alkali treatment, were prepared by compression molding in a mat composed of a three-layer sandwich structure. The sisal was characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The composites were characterized according to physical and mechanical properties. Additionally, a factorial experimental design was used to statistically evaluate the mechanical properties of the composite. The FTIR and XRD indicated the partial removal of amorphous materials from the surface of the sisal after alkali treatment. The composites' density results varied from 0.892 to 0.927 g·cm-3, which was in the desirable range for producing lightweight automotive components. A slight decrease in the hardness of the pure rPP and rPP composites in relation to the PP was observed. The water absorption was higher in rPP composites, regardless of the chemical treatment. Moreover, the impact resistance of PP and its composites was higher than the values for rPP. Statistical analysis showed that the alkali treatment was a significant factor for the hardness of the rPP and PP composites, and that the addition of the sisal layer was relevant to improve the impact resistance of the composites.

Dynamic Mechanical Analysis and Ballistic Performance of Kenaf Fiber-Reinforced Epoxy Composites.

Several industry sectors have sought to develop materials that combine lightness, strength and cost-effectiveness. Natural lignocellulosic natural fibers have demonstrated to be efficient in replacing synthetic fibers, owing to several advantages such as costs 50% lower than that of synthetic fibers and promising mechanical specific properties. Polymeric matrix composites that use kenaf fibers as reinforcement have shown strength increases of over 600%. This work aims to evaluate the performance of epoxy matrix composites reinforced with kenaf fibers, by means of dynamic-mechanical analysis (DMA) and ballistic test. Through DMA, it was possible to obtain the curves of storage modulus (E'), loss modulus (E″) and damping factor, Tan δ, of the composites. The variation of E' displayed an increase from 1540 MPa for the plain epoxy to 6550 MPa for the 30 vol.% kenaf fiber composites, which evidences the increase in viscoelastic stiffness of the composite. The increase in kenaf fiber content induced greater internal friction, resulting in superior E″. The Tan δ was considerably reduced with increasing reinforcement fraction, indicating better interfacial adhesion between the fiber and the matrix. Ballistic tests against 0.22 caliber ammunition revealed similar performance in terms of both residual and limit velocities for plain epoxy and 30 vol.% kenaf fiber composites. These results confirm the use of kenaf fiber as a promising reinforcement of polymer composites for automotive parts and encourage its possible application as a ballistic armor component.

Evaluation of the Change in Density with the Diameter and Thermal Analysis of the Seven-Islands-Sedge Fiber.

Basic properties of sedge fibers from the seven-islands-sedge plant (Cyperus malaccensis) were investigated with possible application in reinforcing composite materials. A dimensional distribution and the effect of fiber diameter on density were investigated using gas pycnometry. The Weibull method, used to statistically analyze the acquired data from the diameter intervals, indicated an inverse dependence, where the thinnest fibers had the highest density values. The morphology of the fibers was obtained through scanning electron microscopy (SEM), in which a lower presence of defects was revealed in the thinner fibers, corroborating the inverse density dependence. In addition, the sedge fiber was characterized by differential scanning calorimetry and thermogravimetric analysis, which indicate an initial thermal degradation at around 241 °C. These results revealed for the first time that thinner sedge fibers might be promising reinforcement for polymer composites with a limit in temperature application.

Tensile Properties of Curaua-Aramid Hybrid Laminated Composites for Ballistic Helmet.

A typical ballistic protection helmet for ground military troops has an inside laminate polymer composite reinforced with 19 layers of the aramid, which are neither recyclable or biodegradable and are relatively expensive. The hybridization of synthetic aramid with a natural lignocellulosic fiber (NLF) can provide a lower cost and desirable sustainability to the helmet. In the present work, the curaua fiber, one of the strongest NLFs, is, for the first time, considered in non-woven mat layers to partially replace the aramid woven fabric layers. To investigate the possible advantage of this replacement, the tensile and impact properties of aramid/curaua hybrid laminated composites intended for ballistic helmets, in which up to four layers of curaua were substituted for the aramid, were evaluated. Tensile strength, toughness, and elastic modulus decreased with the replacement of the aramid while the deformation of rupture was improved for the replacement of nine aramid layers by two layers of curaua. Preliminary impact tests corroborate the decreasing tendency found in the tensile properties with the replacement of the aramid by curaua. Novel proposed Reduction Maps showed that, except for the replacement of four aramid layers by one layer of curaua, the decrease percentage of any tensile property value was lower than the corresponding volume percentage of replaced aramid, which revealed advantageous hybridization for the replacement of nine or more aramid layers.

Fatores relacionados ao risco de feridas em pacientes com Diabetes mellitus Tipo 2 / Factors related to wound risk in patients with Type 2 Diabetes mellitus

Poucos estudos abordam as características sociodemográficas e o risco de feridas no nordeste brasileiro. O objetivo do estudo foi determinar a prevalência de risco de feridas e os fatores relacionados em pessoas com diabetes no município de Parnaíba, estado do Piauí, Brasil. Estudo transversal realizado com 300 pessoas com diabetes. Os voluntários foram avaliados por meio de questionário sociodemográfico, monofilamento de 10 g, diapasão de 128 Hz, martelo de reflexo e escala de classificação de risco de feridas. Sexo masculino (OR 2,33; IC 95% 1,22-4,42), idade (OR 1,03; IC 95% 1,01-1,05), inatividade física (OR 2,35; IC 95% 1,26-4,38) e duração maior de diabetes (OR 3,28; IC 95% 1,56-6,91) foram associados ao risco de feridas. Este estudo demonstrou um alto risco de feridas relacionado a idade, sexo feminino, duração da diabetes e inatividade física e alta prevalência de complicações como a neuropatia periférica diabética e amputações.

Few studies have addressed the sociodemographic characteristics and risk of wound development in northeastern Brazil. The objective of the study was to determine the prevalence of wound risk and the related factors in people with diabetes in the municipality of Parnaíba, Piauí State, Brazil. A cross-sectional study was conducted with 300 people with diabetes. The volunteers were assessed using a sociodemographic questionnaire, a 10 g monofilament, a 128 Hz tuning fork, a reflex hammer, and a wound risk rating scale. Male sex (OR 2.33, 95% CI 1.22-4.42), age (OR 1.03, 95% CI 1.01-1.05), physical inactivity (OR 2.35, 95% CI 1.26-4.38), and a longer duration of diabetes (OR 3.28, 95% CI 1.56-6.91) were associated with wound risk. This study demonstrated a high wound risk related to age, male sex, duration of diabetes, and physical inactivity and a high prevalence of complications such as diabetic peripheral neuropathy and amputations.