A Review of Biomaterials and Scaffold Fabrication for Organ-on-a-Chip (OOAC) Systems

Copyright: © 2021 by the authors. Drug and chemical development along with safety tests rely on the use of numerous clinical models. This is a lengthy process where animal testing is used as a standard for pre-clinical trials. However, these models often fail to represent human physiopathology. This may lead to poor correlation with results from later human clinical trials. Organ-on-a-Chip (OOAC) systems are engineered microfluidic systems, which recapitulate the physiochemical environment of a specific organ by emulating the perfusion and shear stress cellular tissue undergoes in vivo and could replace current animal models. The success of culturing cells and cell-derived tissues within these systems is dependent on the scaffold chosen; hence, scaffolds are critical for the success of OOACs in research. A literature review was conducted looking at current OOAC systems to assess the advantages and disadvantages of different materials and manufacturing techniques used for scaffold production; and the alternatives that could be tailored from the macro tissue engineering research field.EPSRC studentship

Automatic solid-phase extraction by programmable flow injection coupled to chromatographic fluorimetric determination of fluoroquinolones

Fluoroquinolones are broad-spectrum bactericidal agents applied for the treatment of human and veterinary diseases. Their common use and their incorrect disposal foster environmental contamination, namely in water resources, increasing the risk of antimicrobial resistance. Hence, a method based on automatic solid-phase extraction coupled to liquid chromatography and fluorimetric detection is proposed for the determination of fluoroquinolones in environmental waters. For the solid-phase extraction procedure, a commercially available molecularly imprinted polymer targeting fluoroquinolones was trapped inside a flow-through extraction column, integrated into a programmable flow injection system using multisyringe flow injection analysis, where all steps concerning sorbent conditioning, sample loading, matrix removal, and analyte elution were performed under computer control. The eluate resulting from the sample preparation was collected and transferred at-line to chromatographic analysis using a reversed-phase monolithic column coupled to a fluorimetric detector, and isocratic elution with methanol-phosphoric acid (pH 3.0; 5.0 mM) (17.5:82.5, v/v) at a flow rate of 3.5 mL min-1. Sample treatment and chromatographic analysis were performed in tandem, with sample throughput limited by the sample treatment step. Calibration curves based on fluorescence intensity vs. analyte mass were obtained in the range of 10 to 1000 pg for norfloxacin, ciprofloxacin, and enrofloxacin with LOD values of 6-19 ng L-1 for a sample volume of 100 mL, and RSD < 11% at 0.7 ¿g L-1. The method was successfully applied to estuarine river water analysis.info:eu-repo/semantics/publishedVersio

All-fiber broadband spectral acousto-optic modulation of a tubular-lattice hollow-core optical fiber

We demonstrate a broadband acousto-optic notch filter based on a tubular-lattice hollow-core fiber for the first time. The guided optical modes are modulated by acoustically induced dynamic long-period gratings along the fiber. The device is fabricated employing a short interaction length (7.7 cm) and low drive voltages (10 V). Modulated spectral bands with 20 nm half-width and maximum depths greater than 60 % are achieved. The resonant notch wavelength is tuned from 743 to 1355 nm (612 nm span) by changing the frequency of the electrical signal. The results indicate a broader tuning range compared to previous studies using standard and hollow-core fibers. It further reveals unique properties for reconfigurable spectral filters and fiber lasers, pointing to the fast switching and highly efficient modulation of all-fiber photonic devices

Stakeholders da bovinocultura de corte sustentável no Brasil.

A preocupação com a sustentabilidade, que emergiu principalmente a partir de eventos internacionais, passou a ser visível também na política em geral e nas estruturas de governo, sendo notável o esforço em vincular discursos políticos com a noção de sustentabilidade. Porém, o que a sociedade realmente anseia é pela prática do discurso, por um mundo em que as dimensões da sustentabilidade sejam reconhecidas, discutidas e respeitadas. Neste ínterim, este artigo tem como objetivo identificar as principais discussões em torno da temática da sustentabilidade e os stakeholders que as conduzem na Câmara Setorial da cadeia produtiva da carne bovina no Brasil nos últimos cinco anos. Para tal, foi realizada uma análise qualitativa em torno dos diálogos e ações na referida Câmara Setorial. Esta pesquisa lançou mão do método de análise de conteúdo (BARDIN, 2006), por meio do qual foram definidas categorias de análise a priori, à luz da literatura. Foram atas de 16 reuniões, embora tenham acontecido, no total, 18 reuniões no período considerado. Como resultados, foi percebida uma preocupação maior em torno da dimensão ecológica da sustentabilidade, enquanto que as outras dimensões foram pouco ou nada discutidas. A análise das atas e pautas, porém, indica que essa temática já estava definida em pauta, o que pode auxiliar a compreensão dos assuntos debatidos nas reuniões analisadas. Percebeu-se que as discussões em torno de todas as questões envolvendo a sustentabilidade foram, em sua maioria, conduzidas pelos mesmos stakeholders durante as reuniões, o que sinaliza baixa participação dos demais

Cross-cultural adaptation of the City Birth Trauma Scale for the Brazilian context

Background: Posttraumatic stress disorder consists of a set of symptoms that occurs in response to one or more traumatic events and can occur in postpartum, from traumatic situations related to the birth or to the baby’s health in the first days of life. It is important tracking the presence of birth trauma, but there is not available instruments in the Brazilian context for this purpose. Objectives: To present the cross-cultural adaptation of City Birth Trauma Scale (BiTS) into Brazilian portuguese. Methods: Cross-cultural adaptation involved independent translations, synthesis,back-translation, and submission to the original author’s appreciation. After the scale was subjected to face validity, followed by a pilot study with postpartum mothers. Results: All steps were performed for the cross-cultural adaptation. Regarding face validity, items evaluated concerning different types of equivalence, presented satisfactory agreement values (≥4.20). Most of the expert’s suggestions were followed, being the main ones related to adjustments in prepositions, pronouns and verbal subjects. Pilot study showed that the mothers had been able to understand and respond to the instrument without adjustments. Discussion: BiTS’s Brazilian version proved to be cross-culturally adapted, ensuring the possibility of intercultural data comparison from the semantic, idiomatic, cultural, and conceptual perspectives. New studies are being conducted to attest its psychometric adequac

Endoscopic closure of transmural bladder wall perforations

Background: Traditionally, intraperitoneal bladder perforations caused by trauma or iatrogenic interventions have been treated by open or laparoscopic surgery. Additionally, transvesical access to the peritoneal cavity has been reported to be feasible and useful for natural orifice translumenal endoscopic surgery (NOTES) but would be enhanced by a reliable method of closing the vesicotomy. Objective: To assess the feasibility and safety of an endoscopic closure method for vesical perforations using a flexible, small-diameter endoscopic suturing kit in a survival porcine model. Design, setting, and participants: This pilot study was performed at the University of Minho, Braga, Portugal, using six anesthetized female pigs. Interventions: Closure of a full-thickness longitudinal incision in the bladder dome (up to 10 mm in four animals and up to 20 mm in two animals) with the endoscopic suturing kit using one to three absorbable stitches. Measurements: The acute quality of sealing was immediately tested by distending the bladder with methylene-blue dye under laparoscopic control (in two animals). Without a bladder catheter, the animals were monitored daily for 2 wk, and a necropsy examination was performed to check for the signs of peritonitis, wound dehiscence, and quality of healing. Results and limitations: Endoscopic closure of bladder perforation was carried out easily and quickly in all animals. The laparoscopic view revealed no acute leak of methylene-blue dye after distension of the bladder. After recovery from anaesthesia, the pigs began to void normally, and no adverse event occurred. Postmortem examination revealed complete healing of vesical incision with no signs of infection or adhesions in the peritoneal cavity. No limitations have yet been studied clinically. Conclusions: This study demonstrates the feasibility and the safety of endoscopic closure of vesical perforations with an endoscopic suturing kit in a survival porcine model. This study provides support for further studies using endoscopic closure of the bladder which may lead to a new era in management of bladder rupture and adoption of the transvesical port in NOTES procedures