Structural and Functional Studies of a Bothropic Myotoxin Complexed to Rosmarinic Acid: New Insights into Lys49-PLA2 Inhibition

Snakebite envenoming is an important public health problem in many tropical and subtropical countries, and is considered a neglected tropical disease by the World Health Organization. Most severe cases are inflicted by species of the families Elapidae and Viperidae, and lead to a number of systemic and local effects in the victim. One of the main problems regarding viperidic accidents is prominent local tissue damage whose pathogenesis is complex and involves the combined actions of a variety of venom components. Phospholipases A2 (PLA2s) are the most abundant muscle-damaging components of these venoms. Herein, we report functional and structural studies of PrTX-I, a Lys49-PLA2 from Bothops pirajai snake venom, and the influence of rosmarinic acid (RA) upon this toxin's activities. RA is a known active component of some plant extracts and has been reported as presenting anti-myotoxic properties related to bothopic envenomation. The myotoxic activity of Lys49-PLA2s is well established in the literature and although no in vivo neurotoxicity has been observed among these toxins, in vitro neuromuscular blockade has been reported for some of these proteins. Our in vitro studies show that RA drastically reduces both the muscle damage and the neuromuscular blockade exerted by PrTX-I on mice neuromuscular preparations (by ∼80% and ∼90%, respectively). These results support the hypothesis that the two effects are closely related and lead us to suggest that they are consequences of the muscle membrane-destabilizing activity of the Lys49-PLA2. Although the C-terminal region of these proteins has been reported to comprise the myotoxic site, we demonstrate by X-ray crystallographic studies that RA interacts with PrTX-I in a different region. Consequently, a new mode of Lys49-PLA2 inhibition is proposed. Comparison of our results with others in the literature suggests possible new ways to inhibit bothropic snake venom myotoxins and improve serum therapy

On the implementation of the gamma function for image correction on a endoscopic camera

This paper describes part of project that implemented the image processing of a CMOS sensor for endoscopic purposes. The sensor is a small sized device of 1x1mm2 and the image processing has been done inside a FPGA. This part of the work describes the implementation of the Gamma function with a balance between the resources needed and the accuracy. A linear piecewise solution was used that stores the values for 31 gamma functions with values ranging from 1 to 4 with 0.1 steps. The solution developed is 10 bit based, was coded in VHDL and is implemented in a Spartan 6 FPGA. The results show that it is an accurate solution that has a small footprint in terms of used resources.info:eu-repo/semantics/publishedVersio

Full image-processing pipeline in field-programmable gate array for a small endoscopic camera

Endoscopy is an imaging procedure used for diagnosis as well as for some surgical purposes. The camera used for the endoscopy should be small and able to produce a good quality image or video, to reduce discomfort of the patients, and to increase the efficiency of the medical team. To achieve these fundamental goals, a small endoscopy camera with a footprint of 1 mm × 1 mm × 1.65 mm is used. Due to the physical prop erties of the sensors and human vision system limitations, different image-processing algorithms, such as noise reduction, demosaicking, and gamma correction, among others, are needed to faithfully reproduce the image or video. A full image-processing pipeline is implemented using a field-programmable gate array (FPGA) to accomplish a high frame rate of 60 fps with minimum processing delay. Along with this, a viewer has also been developed to display and control the image-processing pipeline. The control and data transfer are done by a USB 3.0 end point in the computer. The full developed system achieves real-time processing of the image and fits in a Xilinx Spartan-6LX150 FPGA.info:eu-repo/semantics/publishedVersio

Elemental mapping of Portuguese ceramic pieces with a full-field XRF scanner based on a 2D-THCOBRA detector

UID/FIS/04559/2020In this work, we present a novel application of the full-field energy-dispersive X-ray fluorescence (EDXRF) imaging system based on a MicroPattern Gaseous Detector (2D-THCOBRA) in the cultural heritage field. The detector has an intrinsic imaging capability with spatial resolution of 400μmFWHM, and is energy sensitive, presenting an energy resolution of approximately 1keVFWHM at 5.9keV. The full-field XRF scanner based on the 2D-THCOBRA detector allows mapping the distribution of elements in large area samples with high detection efficiency (75 % at 5.9keV), being a very promising choice for elemental mapping analysis of large area cultural heritage samples. In this work, we have demonstrated the imaging capabilities of the full-field XRF scanner and used it to assess the restoration of a Portuguese faience piece.publishersversionpublishe

Hygienisation, gentrification, and urban displacement in Brazil

This article engages recent debates over gentrification and urban displacement in the global South. While researchers increasingly suggest that gentrification is becoming widespread in “Southern” cities, others argue that such analyses overlook important differences in empirical context and privilege EuroAmerican theoretical frameworks. To respond to this debate, in this article, we outline the concept of higienização (hygienisation), arguing that it captures important contextual factors missed by gentrification. Hygienisation is a Brazilian term that describes a particular form of urban displacement, and is directly informed by legacies of colonialism, racial and class stigma, informality, and state violence. Our objective is to show how “Southern” concepts like hygienisation help urban researchers gain better insight into processes of urban displacement, while also responding to recent calls to decentre and provincialise urban theory

Determinação de fósforo biodisponível em rações de peixes utilizando extração assistida por ultra-som e espectrofotometria no visível

The aim of the present work was to develop and optimize a method for determination of bioavailable phosphorus in samples of feces and fish feed using ultrasound extraction and subsequent quantification by visible spectrophotometry. Using as extractor solution HNO3 0.50 mol L-1, the great conditions of extraction established were: sample mass - 100 mg, samples granulometry - < 60 µm, sonification time - five cycles of 40 s and ultrasound potency - 136 W. The proposed method was applied in studies of digestibility of this nutrient in different feeds used in diets of juvenile of Nile tilapia

Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin

A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1, 4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column

Triagem Inteligente: O Uso da Internet das Coisas na Classificação dos Riscos nas Emergências

Este artigo tem como objetivo apresentar a automação do processo de triagem de pacientes utilizando o atuador Arduino. O processo de triagem determina o nível de risco do paciente e sua execução pode tornar-se desnecessariamente complexa, sendo que, aproximadamente, 80% dos pacientes em serviços de emergência não necessitam de atendimento urgente. Portanto, a automatização deste processo pode provar-se bastante benéfica: os dados do paciente são analisados em tempo real, provendo um resultado seguro e em alta velocidade, garantindo prioridade a pacientes em risco e reduzindo o tempo de admissão dele

Triagem Inteligente: O Uso da Internet das Coisas na Classificação dos Riscos nas Emergências

Este artigo tem como objetivo apresentar a automação do processo de triagem de pacientes utilizando o atuador Arduino. O processo de triagem determina o nível de risco do paciente e sua execução pode tornar-se desnecessariamente complexa, sendo que, aproximadamente, 80% dos pacientes em serviços de emergência não necessitam de atendimento urgente. Portanto, a automatização deste processo pode provar-se bastante benéfica: os dados do paciente são analisados em tempo real, provendo um resultado seguro e em alta velocidade, garantindo prioridade a pacientes em risco e reduzindo o tempo de admissão dele