Search

Abstract Extracellular vesicles (EVs) play a pivotal role in various biological pathways, such as immune responses and the progression of diseases, including cancer. However, it is challenging to isolate EVs at high purity from blood plasma and other biofluids due to their low abundance compared to more predominant biomolecular species such as lipoprotein particles and free protein complexes. Ultracentrifugation‐based EV isolation, the current gold standard technique, cannot overcome this challenge due to the similar biophysical characteristics of such species. We developed several novel approaches to enrich EVs from plasma while depleting contaminating molecular species using multimode chromatography‐based strategies. On average, we identified 716 ± 68 and 1054 ± 35 protein groups in EV isolates from 100 µL of plasma using multimode chromatography‐ and ultracentrifugation‐based techniques, respectively. The developed methods resulted in similar EV isolates purity, providing significant advantages in simplicity, throughput, scalability, and applicability for various downstream analytical and potential clinical applications.

Necessary and sufficient conditions for the exactness (in the algebraic sense) of certain sequences of bounded group homomorphisms are established.

The order Diptera is constituted of insects that possess numerous varieties of habitats, these winged, commonly called mosquitoes, comprise a monophyletic group. Malaria transmitters in Brazil are represented by mosquitoes of the Anopheles genus, being it principal vector species Anopheles (Nyssorhynchus) darlingi Root. Collectings were accomplished in the rural area of Cuiabá in the region of Coxipó do Ouro/MT, and a total 4,773 adult mosquitoes of the genus Anopheles were obtained. The prevailing species in the collectings where An. (Nys.) darlingi with 3,905 (81.8%), considered the vector of major epidemiological expression in the region, followed by Anopheles (Nyssorhynchus) argyritarsis (Robineau-Desvoidy) 267 (5.6%) and Anopheles (Nyssorhynchus) triannulatus (Neiva & Pinto) 226 (4.7%). This report might be useful to entomological surveillance, demonstrating that the Coxipó do Ouro/MT locality might be elected as an area to be monitored, once the presence of such vector in this type of environment indicates a potential malaria transmission risk for the neighbouring regions in the state of Mato Grosso.

For the first time, the behavior of LiF-added alumina-niobia ceramics was quasi-static and dynamically analyzed in ballistic tests. Different compositions were investigated for the compound Al2O3–4 wt%Nb2O5–nLiF, with n ranging from 0 to 1.50 wt%, processed at three different sintering temperatures (1300, 1350 and 1400 °C). Elastic properties, elastic wave velocities, Vickers microhardness and ballistic tests were performed according to standards. The results showed that the LiF addition benefits the Al2O3–4 wt%Nb2O5 ceramic properties, allowing to reduce by approximately 100 °C the sintering temperature without impairing the ballistic performance. The Al2O3–4 wt%Nb2O5–0.5 wt%LiF ceramics exhibit comparable properties to the commonly used Al2O3–4 wt%Nb2O5 ceramics. Keywords: Alumina, Niobia, Lithium fluoride, Mechanical properties, Elastic properties, Ballistic test

This paper presents results obtained through ballistic tests on multilayered armor system (MAS) using polyester composite reinforced with jute non-woven mat as second layer. Following international standard tests are carried out with ammunition 7.62 × 51 mm, with a velocity above of 800 m/s. The MAS is composed of a front layer with hexagonal ceramic tile (alumina doped with 4 wt% of niobia), the second layer of polyester matrix composite reinforced with 30 vol% of jute non-woven mat and the third layer an aluminum alloy plate. The utilization of polymeric composites reinforced with natural fibers to replace the aramid fabric (Kevlar™) is of interest because their performances are similar in the armor system but the composite is less expensive. Scanning electron microscopy analyses show that the polyester/jute non-woven mat composite captured ceramic fragments through mechanic incrustation. Moreover the replacement of aramid fabric for polyester matrix composites reinforced with jute non-woven mat provides weight reduction of the MAS by 5.4% and a cost reduction of 474%. Keywords: Jute non-woven, Polyester composite, Multilayered armor, Ballistic performance, Economical advantage

Ceramic armors are frequently used for protection against high energy projectiles, such as the 7.62 mm and 5.56 mm. Recently, it has been demonstrated that a modification in the geometry of the impact face, from flat to convex, enlarges the stress distribution zone created by the projectile-target interaction. This effect raises the projectile's energy absorption and might improve the user's safety. In the present work, the objective is to characterize ceramic armor plates with convex impact face, by means of the NIJ-0101.06 (2008) standard methodology, aiming to provide an eventual application in armor vests. The characterization is based on the measurement of the backface signature, a deformation behind armor imprinted in a reference material that simulates the consistency of the human body. The results showed significant improvement in the ballistic performance after the impact geometry modification. Keywords: Ballistic test, Ceramic armor, Multilayered armor system, Impact geometry

The ballistic protection against high-energy projectiles, such as the 7.62 mm, is more efficiently performed by means of multilayered armor systems (MAS). A MAS might be composed of a ceramic front, followed by a fiber/fabric composite as intermediate layer, and a ductile metal back layer. In a previous investigation, a MAS with intermediate layer of epoxy composite reinforced with 30 vol.% of ramie fabric was ballistic tested against 7.62 mm ammunition and compared to MAS with Kevlar® (aramid fabric laminate) as intermediate layer. Both MAS met the standard requirements, but a significant cost reduction favored the ramie fabric composite. In the present work, two other related epoxy composites, one reinforced with raw ramie fibers and other with aramid fabric layers, are investigated as MAS intermediate layer. The objective is to achieve similar ballistic performance with more economical and/or environmentally friendly materials. The results indicate that both new composites met the requirements with comparable ballistic performance as the previously investigated ramie fabric and Kevlar®. Moreover, the ramie fiber composite MAS was the least expensive, among all of them, being 14% cheaper than the previously studied ramie fabric composite MAS. Keywords: Ballistic test, Natural ramie fiber, Aramid fiber, Epoxy composite

El análisis paramétrico usado en la determinación de los efectos de los parámetros geométricos y los asociados al dieléctrico en Superficies Selectivas en Frecuencia (SSF), es una herramienta de uso generalizado debido a la ausencia de formulaciones que permitan evaluar este tipo de efectos. El objetivo de esta clase de análisis es determinar la influencia en la frecuencia de resonancia de un parámetro en particular, bien sea asociado al soporte dieléctrico o a los parámetros geométricos de la superficie selectiva, con la finalidad de orientar el proceso de diseño de la superficie. En este artículo se presenta la aplicación del Modelo de Circuito Equivalente (MCE) actuando en conjunto con una novedosa formulación de la permitividad efectiva del dieléctrico en SSF tipo bucle cuadrado, el cual permite determinar los efectos de los parámetros geométricos y los asociados al dieléctrico en la frecuencia de resonancia de la superficie selectiva, haciendo innecesario el uso de análisis de tipo paramétrico. Los resultados obtenidos muestran una exactitud aceptable cuando se comparan con los arrojados por las simulaciones electromagnéticas realizadas en un software basado en el Método de los Elementos Finitos (MEF).

This paper presents the implementation outcomes of the Equivalent Circuit Model (ECM) acting in conjunction with the Matrix Cascading Method (MCM) for bandwidth calculation in cross dipole Frequency Selective Surfaces (FSSs). Dielectric layers are used as a support of resonant elements in FSSs. Models of effective permittivity of the dielectric layers in FSSs allow to determine the effect of the material used as insulating support of the resonant elements, in relation to the resonant frequency and bandwidth, as a function of the thickness of the dielectric material. However, in this approach, the insulating support is considered as thin dielectric, and therefore, it is modeled as a lumped parameter. This consideration may lead to unsuitable results in calculating the bandwidth for thick dielectric supports. The novelty of the paper is the implementation of the Equivalent Circuit Model together with the Matrix Cascading Method to determine the frequency response of the cross dipole selective surface for any dielectric thickness and configuration. It is notable the low computational time as well as the acceptable accuracy obtained with the proposed approach, compared to Ansys-HFSS simulations.

The occurrence of iron-rich rocks in some areas makes possible the formation of duricrusts in positions from the relief tops to the slopes and valley bottoms, as is the case of the Quadrilátero Ferrífero (QF--'Iron Quadrangle') in the Brazilian Atlantic Plateau. This study aimed to analyse these materials in the Late Pleistocene fluvial archives of the QF to contribute to the understanding of the complex processes involved in the evolution of surface coverage in tropical regions. The results showed an essential external iron source for the Fe-cemented alluvium, that is, they are ferricretes. Two ferricrete facies were identified: plate-shaped and conglomeratic. They are characterised by the infilling of a primary porous system with crystalline and amorphous ferruginous phases or grain coatings by ferruginous materials. In plate-shaped ferricretes, the size of the cemented grains differentiates the identified subtypes. Conglomeratic ferricretes can be subdivided into ferruginous and aluminous, and feature two types of cementing microstructures: septary and microlaminar. The results of the X-ray diffraction analysis of the conglomeratic ferricretes highlight the strong presence of goethite (more common) and hematite. The chemical composition corroborated the mineralogical analysis, with the septa having an average iron-rich composition. Aluminous conglomeratic ferricretes also occur and are the oldest in the area; their cement is composed mainly of gibbsite. Thus, it can be considered (i) a possible past source area of aluminous sediments or (ii) the in situ deferruginisation of a first level of ferricretes. A certain granulometric control in both ferricrete facies reinforces the importance of transport and deposition during ferricrete genesis. However, the cementing of sediments under supergene conditions and their microstructural variety suggest that their formation and evolution also occurred as a result of lateritic processes. Furthermore, the ferricretes revealed integration with the regional relief evolution, and the conglomeratic ones may be associated with lower rates of drainage incisions in some valleys. [ABSTRACT FROM AUTHOR]

The urban violence and the different types of global armed conflicts demand efficient protective systems against high energy ammunition. Multilayered Armor Systems (MAS) provide efficient protection by making use of lighter and more efficient materials. A typical MAS may be composed of three layers: a front ceramic followed by a composite, backed by a ductile metal. Polymer composites reinforced with natural fibers have proven to be effective second layers, being also lighter, low-cost and environmentally friendly as compared to conventional composites like KevlarTM. The present work evaluates MAS using as second layer polyester composites reinforced with 10, 20, and 30 vol. % of sisal fibers. Ballistic tests were performed using class III 7.62x51 mm ammunition, based on the NIJ 0101.06 backface signature methodology. Both the 30 vol.% sisal fiber composite and the conventional aramid laminates were equally efficient in terms of MAS second layer. The explanation might be the similar capacity of the different composites to retain the fragments generated by the interaction of the projectile with the front ceramic, independently of the percentage of sisal fibers.

Due to increasing improvement of weaponry and ammunition, attention is being given to the development of new materials that could more effectively resist to ballistic impact. In order to stop high energy bullets, with speed above 800 m/s, a high strength material is necessary. However, if just one material is used, then a relatively thick piece is required, which might affect negatively the wearer mobility. The objective of this work is to investigate the effect of thickness on the ballistic behavior of aramid fabric laminates, Kevlar®, hit by high energy bullet. The purpose is to find the minimum thickness to avoid perforation. Ballistic tests using conventional 7.62 mm ammunition were performed according to standard procedures. The macro and microscopic aspects of the target specimens were evaluated. The results showed a change in the ballistic behavior of the laminates as their thickness increased. It was found that until the laminate was able to capture the bullet, 96 layers (~50 mm) were required. This is significantly higher than the necessary thickness for a multilayered armor to stop the same 7.62 mm bullet.

The mechanical behavior and the strengthening mechanism of stainless steel welded joints at 600 °C have been investigated. The welds were composed of AISI 304 stainless steel, as base metal, and niobium containing AISI 347 stainless steel, as weld metal. The investigation was conducted by means of creep tests. The welded specimens were subjected to both high temperature (600 °C) and long periods (up to 2000 h) under constant load, and both mechanical properties and microstructural changes in the material were monitored. It was found that the exposure of the material at 600 °C under load contributes to a strengthening effect on the weld. The phenomenon might be correlated with an accelerated process of second phase precipitation hardening. Keywords: Stainless steel, Weld, AISI 304, Precipitation hardening

For personal protection against high kinetic energy projectiles, multilayered armor systems (MAS) are usually the best option. They combine synergistically the properties of different materials such as ceramics, composites and metals. In the present work, ballistic tests were performed to evaluate multilayered armor systems (MAS) using curaua non-woven fabric epoxy composites as second layer. A comparison to a MAS using aramid (Kevlarâ¢) fabric laminates was made. The results showed that the curaua non-woven fabric composites are suitable to the high ballistic applications, and are promising substitutes for aramid fabric laminates. Keywords: Composite, Natural fiber, Curaua fiber, Non-woven fabric, Aramid laminate, Ballistic test

A multilayered armor system (MAS) is intended to personal protection against high kinetic energy ammunition. MAS layers are composed of materials such as a front ceramic and a back composite that must show both high impact resistance and low weight, usually conflicting characteristics. Synthetic fiber fabrics, such as Kevlar⢠and Dyneemaâ¢, are the favorite materials to back the front ceramic, due to their high strength, high modulus and relatively low weight. Recently, composites reinforced with natural fibers have been considered as MAS second layer owing to their good performance associated with other advantages as being cheaper and environmentally friendly. Among the natural fibers, those extracted from the leaves of the Ananas erectifolius plant, known as curaua, stand out due to its exceptional high strength and high modulus. Thus, the objective of the present work is to evaluate the performance of curaua fiber-reinforced polyester composites subjected to ballistic impact of high energy 7.62 mm ammunition. Composites reinforced with 0, 10, 20 and 30 vol.% of curaua fibers were produced and stand-alone tested as armor target to evaluate the absorbed energy. Analysis of variance (Anova) and Tukey's honest significant difference test (HSD) made it possible to compare the results to Kevlar⢠laminates. Among the tested materials, the 30 vol.% fiber composites were found to be the best alternative to Kevlarâ¢. Keywords: Composite, Natural fiber, Curaua fiber, Ballistic test

Abstract. This study describes ecological data obtained in a rural area in the State of Mato Grosso, including the insects belonging to the family Culicidae, especially those framed as potential vectors of tropical diseases. In 2015, we collected adult mosquitoes in fragments of forest in a rural area located in Mato Grosso Central West of Brazil. We captured 18,256 mosquitoes of the sub-families Culicinae and Anophelinae and have identified 34 species belonging to 12 genera: Aedes (1 species), Anopheles (8 species), Coquillettidia (1 species), Haemagogus (1 species), Culex (5 species), Psorophora (5 species), Ochlerotatus (4 species), Deinocerites (1 species), Mansonia (4 species), Sabethes (2 species), Limatus (1 species), Wyeomyia (1 species). The family Culicidae presented high richness and abundance, established by diversity indexes (Margalef α =3.26; Shannon H' = 2.09; Simpson D = 0.19) with dominance of the species Anopheles (Nyssorhyncus) darlingi Root (89.8%). This species has considerable epidemiological value, considered the main vector of malaria in Mato Grosso. Many species of mosquitoes are vectors of pathogens that cause disease in humans and domestic animals, transmitting pathogens including viruses (arboviruses), filaria worms (helminths) and protozoa. Composição de espécies e distribuição da fauna de mosquitos (Diptera: Culicidae) e sua importância para doenças transmitidas por vetores em uma área rural do centro-ocidental - Mato Grosso, Brasil Resumo. Este estudo descreve dados ecológicos de uma área rural do Estado de Mato Grosso e dos insetos da família Culicidae especialmente aqueles enquadrados como vetores potenciais de doenças tropicais. Em 2015, coletamos mosquitos adultos em fragmentos de floresta em localidades de áreas rurais no Mato Grosso região Centro Oeste do Brasil. Foram capturados 18.256 exemplares alados de mosquitos das subfamílias Culicinae e Anophelinae e identificadas 34 espécies pertencentes a 12 gêneros: Aedes (1 espécie), Anopheles (8 espécies), Coquillettidia (1 espécie), Haemagogus (1 espécie), Culex (5 espécies), Psorophora (5 espécies), Ochlerotatus (4 espécies), Deinocerites (1 espécie), Mansonia (4 espécies), Sabethes (2 espécies), Limatus (1 espécie), Wyeomyia (1 espécie). A família Culicidae apresentou alta riqueza e abundância, estabelecida por índices de diversidade (Margalef α = 3.26, Shannon H' = 2.09, Simpson D = 0.19) com predominância da espécie Anopheles (Nyssorhyncus)darlingi Root (89.8%). Esta espécie tem considerável valor epidemiológico, sendo considerada o principal vetor de malária em Mato Grosso. Muitas espécies de mosquitos são vetores de patógenos que causam doenças em humanos e animais domésticos, transmitindo patógenos incluindo vírus (arboviroses), filárias (helmintos) e protozoários.