523 research outputs found

    Wetspun polymeric fibrous systems as potential scaffolds for tendon and ligament repair, healing and regeneration

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    Tendon and ligament traumatic injuries are among the most common diagnosed musculoskeletal problems. Such injuries limit joint mobility, reduce musculoskeletal performance, and most importantly, lower people’s comfort. Currently, there are various treatments that are used to treat this type of injury, from surgical to conservative treatments. However, they’re not entirely effective, as reinjures are frequent and, in some cases, fail to re-establish the lost functionality. Tissue engineering (TE) approaches aim to overcome these disadvantages by stimulating the regeneration and formation of artificial structures that resemble the original tissue. Fabrication and design of artificial fibrous scaffolds with tailored mechanical properties are crucial for restoring the mechanical function of the tissues. Recently, polymeric nanofibers produced by wetspinning have been largely investigated to mimic, repair, and replace the damaged tissue. Wetspun fibrous structures are extensively used due to their exceptional properties, such as the ability to mimic the native tissue, their biodegradability and biocompatibility, and good mechanical properties. In this review, the tendon and ligament structure and biomechanics are presented. Then, promising wetspun multifunctional fibrous structures based on biopolymers, more specifically polyhydroxyalkanoates (PHA), polycaprolactone (PCL), and polyethylenes, will be discussed, as well as reinforcing agents such as cellulose nanocrystals (CNC), nanoparticles, and growth factors.The authors are thankful to project UID/CTM/00264/2022 of 2C2T—Centro de Ciência e Tecnologia Têxtil, funded by National Founds through FCT/MCTES and to the FCT-Fundação para a Ciência e a Tecnologia Ph.D. Scholarship (grant number SFRH/BD/147812/2019) of Joana C. Araújo. Diana P. Ferreira is thankful to CEECIND/02803/2017

    Heuristic evaluation of the usability of a mechanical ventilator Interface through a simulator

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    Determining the usability of mechanical ventilator interfaces is vital in ensuring correct usage under critical procedures that can place patients’ health in danger. Heuristic evaluation has been used to evaluate usability in many different areas, including medical devices. The objective of this study is to evaluate the usability of a mechanical ventilator using the heuristic evaluation method. The evaluation of a mechanical ventilator simulator (Drager's Evita V500) was performed using the Heuristic Evaluation System Checklist (HESC). Three evaluators took part in the experiment in assessing the usability through HESC. The results show that of the 292 checklist sub-heuristics included in the HESC Checklist, 127 were compliant (had no flaws), 75 were not compliant (had flaws) and 95 were not applicable. The results point out that the mechanical ventilator interfaces should be improved to avoid human error due to usability issues. The results also show that heuristic evaluation generates a large quantity of objective information, which provides an exhaustive identification of aspects that should be improved.publishe

    B cells Can Modulate the CD8 Memory T Cell after DNA Vaccination Against Experimental Tuberculosis

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    Abstract\ud \ud \ud \ud Background\ud \ud Although B cells are important as antigen presenting cells (APC) during the immune response, their role in DNA vaccination models is unknown.\ud \ud \ud \ud Methods\ud \ud In this study in vitro and in vivo experiments were performed to evaluate the ability of B cells to protect mice against Mycobacterium tuberculosis challenge.\ud \ud \ud \ud Results\ud \ud \ud In vitro and in vivo studies showed that B cells efficiently present antigens after naked plasmid pcDNA3 encoding M. leprae 65-kDa heat shock protein (pcDNA3-Hsp65) internalization and protect B knock-out (BKO) mice against Mycobacterium tuberculosis infection. pcDNA3-Hsp65-transfected B cells adoptively transferred into BKO mice rescued the memory phenotypes and reduced the number of CFU compared to wild-type mice.\ud \ud \ud \ud Conclusions\ud \ud These data not only suggest that B cells play an important role in the induction of CD8 T cells but also that they improve bacterial clearance in DNA vaccine model.We are thankful to Ana Paula Masson and Izaíra T Brandão for providing the DNA vaccine and recombinant protein. This study was supported by a FAPESP fellowship (05/030873) to LPA.We are thankful to Ana Paula Masson and Izaíra T Brandão for providing the DNA vaccine and recombinant protein. This study was supported by a FAPESP fellowship (05/03087-3) to LPA

    Shaping the scientific future of environmental sciences in times of multiple crises: a summary of the 12th SETAC Young Environmental Scientists Meeting in Landau in der Pfalz 2023 -

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    SETAC has a long‑standing history of supporting students and early career scientists in the fields of ecotoxicol‑ ogy and environmental chemistry. The Student Advisory Council (SAC) advocates for the diverse interests of young SETAC members offering guidance to peers and serving as a resounding voice for aspiring scientists in dialogues with the SETAC Europe Council. Founded and shaped by a rewarding liaison between SETAC Europe and its German Language Branch, the SAC now has a strong international representation, with its members being distributed all over Europe. With this publication, we want to build upon the relationship between the SETAC Europe students and the SETAC German Language Branch. The Young Environmental Scientists (YES) Meeting, which was first held as a regular conference 14 years ago, is a key‑ stone event organized by the students of SETAC and the SAC. This year, in 2023, the 12th YES meeting took place in Landau in der Pfalz, Germany. Not only has it been the first European in-person YES Meeting since the COVID‑19 pandemic, but with this year’s iteration, the YES meeting returned to its roots in Landau, where 2009 the very first YES meeting was hosted. From August 28th to September 1st, 107 participants from 37 countries and five continents had the opportunity to show‑ case their research in seven thematic sessions, engage in four workshops, listen to six expert/career talks, and two keynotes from established scientists. In reference to the meeting‑motto science through crises, this comment pays special emphasis on topical program points in touching the ongoing multiple crises. We are convinced that sharing our experience from hosting this conference will underline the importance of continuing this unique meeting format and hopefully inspire future scientific events organized by students for students

    Resposta imune a doenças infecciosas

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    The interaction between pathogens and immune system occurs in a dynamic way with sophisticate mechanisms of evasion and immune control of infection, respectively. Therefore, it is a sine qua non condition to understand the complexity of this relationship in order to developed new strategies for infection control. Although the immune system has specialized mechanisms to control infection, different conditions involved in the interaction between immune system and pathogens can or cannot determine the development of disease. Interestingly, a protective immune response against one kind of parasite may not be protective against another. So, each pathogen presents a specific way of interaction with the immune system. The development of research in this area has contributed with a better comprehension of the immune system and pathogen relationship and opened perspective in improving the treatment with the development of new drugs and/or vaccines.A interação do sistema imune com os agentes infecciosos ocorre de uma maneira dinâmica, com mecanismos de controle da infecção e de escape sofisticados. A compreensão dessa complexidade é condição sine qua non para que se estabeleça uma ação total no controle dessas infecções. Embora a resposta imune desenvolvida para controle das diferentes infecções apresente certas particularidades, em geral, apresentam também mecanismos comuns. A priori os mecanismos podem ser redundantes, no entanto existe uma gama de sutilezas entre a interação hospedeiro-parasita que define o estabelecimento ou não de doença. Por outro lado, não se pode deixar de alertar que melhores condições de saneamento básico diminuiriam a incidência de inúmeras doenças. A classificação de uma resposta imune protetora tem que ser avaliada sempre em relação ao tipo de agente agressor, pois um mecanismo protetor conta um vírus pode não ser essencial contra uma bactéria extracelular. De qualquer forma, o avanço na pesquisa com diferentes patógenos tem contribuído para uma melhor compreensão da resposta imune decorrente da interação entre o hospedeiro e parasita o que pode resultar no desenvolvimento de novas drogas e vacinas

    Green extraction techniques as advanced sample preparation approaches in biological, food, and environmental matrices: A review

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    Green extraction techniques (GreETs) emerged in the last decade as greener and sustainable alternatives to classical sample preparation procedures aiming to improve the selectivity and sensitivity of analytical methods, simultaneously reducing the deleterious side effects of classical extraction techniques (CETs) for both the operator and the environment. The implementation of improved processes that overcome the main constraints of classical methods in terms of efficiency and ability to minimize or eliminate the use and generation of harmful substances will promote more efficient use of energy and resources in close association with the principles supporting the concept of green chemistry. The current review aims to update the state of the art of some cutting-edge GreETs developed and implemented in recent years focusing on the improvement of the main analytical features, practical aspects, and relevant applications in the biological, food, and environmental fields. Approaches to improve and accelerate the extraction efficiency and to lower solvent consumption, including sorbent-based techniques, such as solid-phase microextraction (SPME) and fabric-phase sorbent extraction (FPSE), and solvent-based techniques (μQuEChERS; micro quick, easy, cheap, effective, rugged, and safe), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), in addition to supercritical fluid extraction (SFE) and pressurized solvent extraction (PSE), are highlighted.This research was funded by FCT (Fundação para a Ciência e a Tecnologia) through the CQM Base Fund, UIDB/00674/2020, Programmatic Fund, UIDP/00674/2020, and CEB—Centre of Biological Engineering, and by ARDITI (Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação) through the project M1420-01-0145-FEDER-000005, Centro de Química da Madeira (CQM+; Madeira 14-20 Program). The authors also acknowledge FCT and the Madeira 14–20 Program to the Portuguese Mass Spectrometry Network (RNEM) through the PROEQUIPRAM program, M14-20 M1420-01-0145-FEDER-000008). ARDITI is also acknowledged for the postdoctoral fellowship granted to J.A.M.P. (Project M1420-09-5369-FSE-000001).info:eu-repo/semantics/publishedVersio

    Characterization of Systemic Disease Development and Paw Inflammation in a Susceptible Mouse Model of Mayaro Virus Infection and Validation Using X-ray Synchrotron Microtomography

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    Mayaro virus (MAYV) is an emerging arthropod-borne virus endemic in Latin America and the causative agent of arthritogenic febrile disease. Mayaro fever is poorly understood; thus, we established an in vivo model of infection in susceptible type-I interferon receptor-deficient mice (IFNAR−/−) to characterize the disease. MAYV inoculations in the hind paws of IFNAR−/− mice result in visible paw inflammation, evolve into a disseminated infection and involve the activation of immune responses and inflammation. The histological analysis of inflamed paws indicated edema at the dermis and between muscle fibers and ligaments. Paw edema affected multiple tissues and was associated with MAYV replication, the local production of CXCL1 and the recruitment of granulocytes and mononuclear leukocytes to muscle. We developed a semi-automated X-ray microtomography method to visualize both soft tissue and bone, allowing for the quantification of MAYV-induced paw edema in 3D with a voxel size of 69 µm3. The results confirmed early edema onset and spreading through multiple tissues in inoculated paws. In conclusion, we detailed features of MAYV-induced systemic disease and the manifestation of paw edema in a mouse model extensively used to study infection with alphaviruses. The participation of lymphocytes and neutrophils and expression of CXCL1 are key features in both systemic and local manifestations of MAYV disease
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