Polyhexamethylene Biguanide: Polyurethane Blend Nanofibrous Membranes for Wound Infection Control

Polyhexamethylene biguanide (PHMB) is a broad-spectrum antiseptic which avoids many efficacy and toxicity problems associated with antimicrobials, in particular, it has a low risk of loss of susceptibility due to acquired antimicrobial resistance. Despite such advantages, PHMB is not widely used in wound care, suggesting more research is required to take full advantage of PHMB’s properties. We hypothesised that a nanofibre morphology would provide a gradual release of PHMB, prolonging the antimicrobial effects within the therapeutic window. PHMB:polyurethane (PU) electrospun nanofibre membranes were prepared with increasing PHMB concentrations, and the effects on antimicrobial activities, mechanical properties and host cell toxicity were compared. Overall, PHMB:PU membranes displayed a burst release of PHMB during the first hour following PBS immersion (50.5–95.9% of total released), followed by a gradual release over 120 h (≤25 wt % PHMB). The membranes were hydrophilic (83.7–53.3°), gradually gaining hydrophobicity as PHMB was released. They displayed superior antimicrobial activity, which extended past the initial release period, retained PU hyperelasticity regardless of PHMB concentration (collective tensile modulus of 5–35% PHMB:PU membranes, 3.56 ± 0.97 MPa; ultimate strain, >200%) and displayed minimal human cell toxicity (<25 wt % PHMB). With further development, PHMB:PU electrospun membranes may provide improved wound dressings

Socially-augmented argumentation tools: rationale, design and evaluation of a debate dashboard

Collaborative Computer-Supported Argument Visualization (CCSAV) is a technical methodology that offers support for online collective deliberation over complex dilemmas. As compared with more traditional conversational technologies, like wikis and forums, CCSAV is designed to promote more critical thinking and evidence-based reasoning, by using representations that highlight conceptual relationships between contributions, and through computational analytics that assess the structural integrity of the network. However, to date, CCSAV tools have achieved adoption primarily in small-scale educational contexts, and only to a limited degree in real world applications. We hypothesise that by reifying conversations as logical maps to address the shortcomings of chronological streams, CCSAV tools underestimate the importance of participation and interaction in enhancing collaborative knowledge-building. We argue, therefore, that CCSAV platforms should be socially augmented in order to improve their mediation capability. Drawing on Clark and Brennan’s influential Common Ground theory, we designed a Debate Dashboard, which augmented a CCSAV tool with a set of widgets that deliver meta-information about participants and the interaction process. An empirical study simulating a moderately sized collective deliberation scenario provides evidence that this experimental version outperformed the control version on a range of indicators, including usability, mutual understanding, quality of perceived collaboration, and accuracy of individual decisions. No evidence was found that the addition of the Debate Dashboard impeded the quality of the argumentation or the richness of content

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Echocardiographic parameters for differentiation of balanced from unbalanced forms of complete atrioventricular septal defect

Диагнозата на пълния атриовентрикуларен септален дефект (ПАВСД) е изцяло ехокардиографска. При разграничаването на балансираните от дебалансираните форми се използват различни измервания, но всяко от тях има ограничения и не може да се използва самостоятелно. Липсва установен алгоритъм, който да позволява прецизно класифициране на ПАВСД като балансиран или дебалансиран, особено при граничните форми. На базата на протокол, включващ измерване на редица използвани от други изследователи ехокардиографски показатели, ние успяхме да идентифицираме 4 измервания, които приложени в предиктивен модел позволяват правилно определяне на формата на ПАВСД в 97% от случаите. Тези показатели са: ъгъл на входящия кръвоток на дясна и лява камера, входящ кръвоток през лявата атриовентрикуларна клапа, атриовентрикуларен клапен индекс и съотношение между дългите оси на камерите. The diagnosis of complete atrioventricular septal defect (CAVSD) relies completely on echocardiography. Different measurements can be used for the differentiation of the balanced from the unbalanced forms of the defect but each of them has limitations and cannot be applied separately. There is no established algorithm ensuring precise classifi cation of the CAVSD as balanced or unbalanced, especially in borderline forms. Based on a protocol, including measurements of a series of echocardiographic parameters used by other investigators, we have managed to identify 4 measurements which when applied in a predictive model allow for correct determination of the form of the CAVSD in 97% of the cases. These parameters are: infl ow angle right ventricle/left ventricle, left atrioventricular valve infl ow, atrioventricular valve index, and ratio between the long axes of the two ventricles

Echocardiographic parameters for differentiation of balanced from unbalanced forms of complete atrioventricular septal defect

Диагнозата на пълния атриовентрикуларен септален дефект (ПАВСД) е изцяло ехокардиографска. При разграничаването на балансираните от дебалансираните форми се използват различни измервания, но всяко от тях има ограничения и не може да се използва самостоятелно. Липсва установен алгоритъм, който да позволява прецизно класифициране на ПАВСД като балансиран или дебалансиран, особено при граничните форми. На базата на протокол, включващ измерване на редица използвани от други изследователи ехокардиографски показатели, ние успяхме да идентифицираме 4 измервания, които приложени в предиктивен модел позволяват правилно определяне на формата на ПАВСД в 97% от случаите. Тези показатели са: ъгъл на входящия кръвоток на дясна и лява камера, входящ кръвоток през лявата атриовентрикуларна клапа, атриовентрикуларен клапен индекс и съотношение между дългите оси на камерите. The diagnosis of complete atrioventricular septal defect (CAVSD) relies completely on echocardiography. Different measurements can be used for the differentiation of the balanced from the unbalanced forms of the defect but each of them has limitations and cannot be applied separately. There is no established algorithm ensuring precise classifi cation of the CAVSD as balanced or unbalanced, especially in borderline forms. Based on a protocol, including measurements of a series of echocardiographic parameters used by other investigators, we have managed to identify 4 measurements which when applied in a predictive model allow for correct determination of the form of the CAVSD in 97% of the cases. These parameters are: infl ow angle right ventricle/left ventricle, left atrioventricular valve infl ow, atrioventricular valve index, and ratio between the long axes of the two ventricles

Echocardiographic preoperative evaluation of unbalanced atrioventricular septal defect

Дебалансираният атриовентрикуларен септален дефект се среща при около 10-15% от пациентите с тази сърдечна малформация, като поставя сериозно предизвикателство пред лекарите по отношение на избора на най-подходящата оперативна интервенция. Формите с умерена степен на дисбаланс между двете камери, особено когато размерът на лява камера е преценен като граничен, затрудняват значително избора между двукамерна корекция и еднокамерна циркулация. Водещо значение при определяне на дисбаланса при АВСД има не само размерът на камерите, но и нарушеното разпределение на кръвотока. Използването на различни ехокардиографски показатели би могло да допринесе за по-прецизната оценка на показанията за съответната хирургична стратегия, а оттам – и за подобряване на прогнозата за пациентите. Unbalanced atrioventricular septal defect is seen by 10-15% of the patients with this congenital heart disease and poses serious challenges for the treating physicians regarding the choice of the most suitable operative intervention. The forms with moderate degree of unbalance between the two ventricles, especially when the size of the left ventricle is considered borderline, make the choice between two-ventricle correction and single-ventricle palliation quite difficult. The most important factor when judging the degree of unbalance is not the size of the ventricles but rather the redistribution of blood flow. The use of different echocardiographic measurements could contribute to the more precise determination of the indications for one of the two surgical strategies with resulting improvement of patient outcome

Genetic diversity as a paramount factor determining wheat adaptation to drought stress

Wheat (Triticum aestivum L.) is a globally important crop for food and nutritional security that requires sufficient water supply for optimal production. All stages of wheat growth and development are adversely affected by reduced water supply, which limit productivity across large areas of Central and Southern Europe. Since drought episodes are expected to occur more frequently and with a greater intensity, the research efforts are devoted to identification of key traits associated with drought resistance that could be used as direct and indirect selection criteria for wheat drought tolerance. We evaluated and quantified several key genetic and molecular features of wheat genotypes with contrasting drought tolerance under severe dehydration triggered by the treatment of wheat with 250 mM sorbitol in hydroponic systems. Plant status was evaluated non-destructively by measuring leaf chlorophyll index, nitrogen content, and leaf relative water content. The drought-tolerant genotype displayed higher chlorophyll and nitrogen content, when grown under drought and benign conditions. Since root architecture appears to be a key trait for breeding against dehydration, we analysed the members of the DEEPER ROOTING (DRO) gene family that allow the root to penetrate deeper into soil, which could increase the yield even upon water shortage. Expression patterns of the DRO members showed genotype-specific changes under drought stress, which correlated well with plant drought tolerance. Our experiments suggest that genes affecting root system architecture could contribute to development of wheat cultivars with higher drought adaptability

LaTroncation lexicale en français contemporain (aspects linguistiques)

STRASBOURG-B.N.U.S. (674821001) / SudocSudocFranceF

Determination of selected trace elements in marine biota samples with the application of fast temperature programs and solid sampling continuous source high resolution atomic absorption spectroscopy: method validation

International audienceAnalytical procedure for the determination of As, Cd, Cu, Ni, Co and Cr in marine biota samples using solid sampling high-resolution continuum source atomic absorption spectrometry (HR CS AAS) and accelerated fast temperature programmes has been developed. Calibration technique based on the use of solid certified reference materials similar to the nature of the analysed sample and statistics of regression analysis were applied. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. Accordingly, blanks, selectivity, calibration, linearity, working range, trueness, repeatability and reproducibility, limits of detection and quantification and expanded uncertainty for all investigated elements were assessed. The major contributors to the combined uncertainty of the analyte mass fractions were found to be the homogeneity of the samples and the microbalance precision. Traceability to the SI system of units of the obtained with the proposed analytical procedure results was also demonstrated. The potential of the proposed analytical procedure based on solid sampling HR CS AAS technique was demonstrated by direct analysis of marine reference biota samples. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of selected trace elements in marine biota samples, such as straightforward calibration, a high sample throughput, sufficient precision, a suitable limit of detection and reduced risk of analyte loss and contamination