Molecular determinants of improved cathepsin B inhibition by new cystatins obtained by DNA shuffling

Background: Cystatins are inhibitors of cysteine proteases. The majority are only weak inhibitors of human cathepsin B, which has been associated with cancer, Alzheimer's disease and arthritis. Results: Starting from the sequences of oryzacystatin-1 and canecystatin-1, a shuffling library was designed and a hybrid clone obtained, which presented higher inhibitory activity towards cathepsin B. This clone presented two unanticipated point mutations as well as an N-terminal deletion. Reversing each point mutation independently or both simultaneously abolishes the inhibitory activity towards cathepsin B. Homology modeling together with experimental studies of the reverse mutants revealed the likely molecular determinants of the improved inhibitory activity to be related to decreased protein stability. Conclusion: A combination of experimental approaches including gene shuffling, enzyme assays and reverse mutation allied to molecular modeling has shed light upon the unexpected inhibitory properties of certain cystatin mutants against Cathepsin B. We conclude that mutations disrupting the hydrophobic core of phytocystatins increase the flexibility of the N-terminus, leading to an increase in inhibitory activity. Such mutations need not affect the inhibitory site directly but may be observed distant from it and manifest their effects via an uncoupling of its three components as a result of increased protein flexibility.State of Sao Paulo Research Foundation (FAPESP)[1998/14138-2]State of Sao Paulo Research Foundation (FAPESP)[05/59833-5]State of Sao Paulo Research Foundation (FAPESP)[08/58316-5

Differential expression of exosomal microRNAs in prefrontal cortices of schizophrenia and bipolar disorder patients

Exosomes are cellular secretory vesicles containing microRNAs (miRNAs). Once secreted, exosomes are able to attach to recipient cells and release miRNAs potentially modulating the function of the recipient cell. We hypothesized that exosomal miRNA expression in brains of patients diagnosed with schizophrenia (SZ) and bipolar disorder (BD) might differ from controls, reflecting either disease-specific or common aberrations in SZ and BD patients. The sources of the analyzed samples included McLean 66 Cohort Collection (Harvard Brain Tissue Resource Center), BrainNet Europe II (BNE, a consortium of 18 brain banks across Europe) and Boston Medical Center (BMC). Exosomal miRNAs from frozen postmortem prefrontal cortices with well-preserved RNA were isolated and submitted to profiling by Luminex FLEXMAP 3D microfluidic device. Multiple statistical analyses of microarray data suggested that certain exosomal miRNAs were differentially expressed in SZ and BD subjects in comparison to controls. RT-PCR validation confirmed that two miRNAs, miR-497 in SZ samples and miR-29c in BD samples, have significantly increased expression when compared to control samples. These results warrant future studies to evaluate the potential of exosome-derived miRNAs to serve as biomarkers of SZ and BD

Losses Analysis of Induction Motors under Ambient and Cryogenic Conditions

Cryogenic induction machines have been re-emerging as a potential solution to increase the current power density for challenging specific power applications. Compared with an ambient temperature operation, cryogenic conditions allow higher power density and increased efficiency due to the decrease of electric resistivity of conducting materials and increased cooling capability. This work focuses on the losses analysis of induction machines immersed in liquid nitrogen. Under ambient and cryogenic conditions, experimental tests are performed and presented for two induction machines, a 90 W 40 V induction machine, and a 550 W 400 V induction machine, to evaluate the mechanical, iron and residual losses, and the change of their equivalent circuit parameters

Antifungal activity of a new derivative of 5-aminoimidazole-4-carbohydrazonamide

[Excerpt] Fungal infections, as recognized by the World Health Organization (WHO), are among the most worrying challenges for the medical community due to their high incidence, recurrence, and the emergence of resistance to the few available drugs and therapies. The discovery of new molecules with antifungal activity, exhibiting new mechanisms of action and less side effects, thus represents an important step forward in the development of alternative treatments [1]

Osteosynthesis metal plate system for bone fixation using bicortical screws: numerical–experimental characterization

This study reports the numerical and experimental characterization of a standard immobilization system currently being used to treat simple oblique bone fractures of femoral diaphyses. The procedure focuses on the assessment of the mechanical behavior of a bone stabilized with a dynamic compression plate (DCP) in a neutralization function, associated to a lag screw, fastened with surgical screws. The non-linear behavior of cortical bone tissue was revealed through four-point bending tests, from which damage initiation and propagation occurred. Since screw loosening was visible during the loading process, damage parameters were measured experimentally in independent pull-out tests. A realistic numerical model of the DCP-femur setup was constructed, combining the evaluated damage parameters and contact pairs. A mixed-mode (I+II) trapezoidal damage law was employed to mimic the mechanical behavior of both the screw–bone interface and bone fractures. The numerical model replicated the global behavior observed experimentally, which was visible by the initial stiffness and the ability to preview the first loading peak, and bone crack satisfactorily.This research was funded by the Portuguese Foundation for Science and Technology (FCT), grant numbers SFRH/BD/143736/2019, UIDB/CVT/00772/2020, LA/P/0059/2020, UIDB/04033/2020, PTDC/EME-SIS/28225/2017, UID/EEA/04436/2019 and Laboratório Associado de Energia, Transportes e Aeronáutica (LAETA), grant number UID/EMS/50022/2020

Restricción alimentaria, desinhibición alimentaria y percepción de hambre de mujeres con peso normal y con sobrepeso

Background: Eating behavior is a strong predictor of weight gain in adults. Research characterizing differences in components of dietary restraint, disinhibition and hunger between overweight and normal weight subjects is insuffi cient.Objective: To evaluate and to compare scores of dietary restraint (DR), disinhibition (DD), and hunger (H) between women at normal weight (NW, n=32) and overweight (WW, n=32). We evaluated correlations between these scores with adiposity and food intake variables.Material and methods: It was a cross-sectional comparison of two groups (overweight and normal weight women), at ages between 20 and 40 years. We measured body mass index (BMI), waist circumference (WC), body composition (BC), energy and macronutrient intake (EMI), DR, DD and H. The differences between groups were analyzed using Student’s T or Mann-Whitney tests. Correlations among DR, DD or H and all other variables in each group were also evaluated.Results: Mean values of BMI, CC, BC, EMI, DR, DD and H were higher for WW (P<.05). Half or more of WW women had moderate or high levels of DR, DD or H. Mean scores of these variables were higher for this group (P<.05) and tended to “high level”. There was a positive correlation between the H and the EMI (P<.05) in the WW group.Conclusions: Eating behavior was associated with weight and body composition in these women, especially for WW. Strategies that address changes in cognitive control of food intake can become useful tools in controlling body weight.Introducción: El comportamiento alimentario es un factor de predicción del peso en adultos. Son escasos los estudios sobre diferencias en la restricción, la desinhibición y el hambre entre personas de peso normal y con sobrepeso.Objetivo: Evaluar la restricción dietética (RD) y desinhibición (DD) y la percepción del hambre (H) entre mujeres con peso normal (PN, n = 32) y con sobrepeso (SP, n = 32) y evaluar su correlación con la adiposidad y la ingesta.Material y métodos: Estudio transversal que midió el índice de masa corporal (IMC), la circunferencia de la cintura (CC), la composición corporal, la ingesta de energía y los macronutrientes (IEM), RD, DD y H de mujeres de edades entre 20 y 40 años. Las diferencias entre los grupos se analizaron mediante la prueba de la t de Student o la de Mann-Whitney. Se analizaron las correlaciones entre RD, DD o H y las demás variables.Resultados: Los valores medios del IMC, CC, composición corporal, IEM, RD, DD y H fueron mayores para SP (p < 0,05). La mitad o más de las mujeres con SP tenían valores moderados o altos de RD, DD o H. Las puntuaciones medias de estas variables fueron más altas en este grupo (p < 0,05) y tendieron a “altas”. Se observó una correlación positiva entre H e IEM (p < 0,05) en el SP.Conclusiones: El comportamiento alimentario está asociado con el peso y la composición corporal, especialmente en las mujeres con sobrepeso. Las estrategias que cambien el control cognitivo de la ingesta pueden ser útiles para el control del peso corporal

Organization of plastid genomes in the freshwater red algal order Batrachospermales (Rhodophyta)

Little is known about genome organization in members of the order Batrachospermales, and the infra-ordinal relationship remains unresolved. Plastid (cp) genomes of seven members of the freshwater red algal order Batrachospermales were sequenced, with the following aims: (i) to describe the characteristics of cp genomes and compare these with other red algal groups; (ii) to infer the phylogenetic relationships among these members to better understand the infra-ordinal classification. Cp genomes of Batrachospermales are large, with several cases of gene loss, they are gene-dense (high gene content for the genome size and short intergenic regions) and have highly conserved gene order. Phylogenetic analyses based on concatenated nucleotide genome data roughly supports the current taxonomic system for the order. Comparative analyses confirm data for members of the class Florideophyceae that cp genomes in Batrachospermales is highly conserved, with little variation in gene composition. However, relevant new features were revealed in our study: genome sizes in members of Batrachospermales are close to the lowest values reported for Florideophyceae; differences in cp genome size within the order are large in comparison with other orders (Ceramiales, Gelidiales, Gracilariales, Hildenbrandiales, and Nemaliales); and members of Batrachospermales have the lowest number of protein-coding genes among the Florideophyceae. In terms of gene loss, apcF, which encodes the allophycocyanin beta subunit, is absent in all sequenced taxa of Batrachospermales. We reinforce that the interordinal relationships between the freshwater orders Batrachospermales and Thoreales within the Nemaliophycidae is not well resolved due to limited taxon sampling

Synergistic activity of a novel class of azoimidazole dyes with polyvinylpyrrolidone-silver nanoparticles for the development of antibacterial textiles

The high demand for novel antimicrobial textiles by the medical, health care, hygiene, sportswear, personal protective equipment, and filtration sectors promoted the growth of functional textiles. However, the efficacy of antimicrobial agents against different pathogens is a considerable challenge due to the distinctive mechanisms of action and resistance. The development of novel synergistic antimicrobial agents may offer numerous opportunities to enhance antimicrobial effectiveness, namely boost the activity of individual agents, reduce dosages, minimize toxicity, and amplify the activity spectrum. On the one hand, azo dyes containing a heterocycle present good tinctorial strength and brightness of shades. In particular, the imidazole ring also has interesting antimicrobial, analgesic, and anti-inflammatory properties. On the other hand, silver nanoparticles (AgNPs) are renowned antimicrobial agents against a wide range of microorganisms, but their application is limited by the toxicity observed for effective concentrations. In this work, a novel class of azoimidazoles (AzoIz) and corresponding precursors (AmIz) were conjugated with polyvinylpyrrolidone-coated AgNPs, and their synergistic effect was assessed against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The results showed interesting antimicrobial properties of the novel AzoIz molecules when combined with a very small concentration of AgNPs. Thus, the application of these conjugates in textiles may lead to highly colored materials with remarkable antimicrobial properties, which worth to be further explored

Thermal, mechanical and chemical analysis of poly(vinyl alcohol) multifilament and braided yarns

Poly(vinyl alcohol) (PVA) in multifilament and braided yarns (BY) forms presents great potential for the design of numerous applications. However, such solutions fail to accomplish their requirements if the chemical and thermomechanical behaviour is not sufficiently known. Hence, a comprehensive characterisation of PVA multifilament and three BY architectures (6, 8, and 10 yarns) was performed involving the application of several techniques to evaluate the morphological, chem- ical, thermal, and mechanical features of those structures. Scanning electron microscopy (SEM) was used to reveal structural and morphological information. Differential thermal analysis (DTA) pointed out the glass transition temperature of PVA at 76 °C and the corresponding crystalline melt- ing point at 210 °C. PVA BY exhibited higher tensile strength under monotonic quasi-static loading in comparison to their multifilament forms. Creep tests demonstrated that 6BY structures present the most deformable behaviour, while 8BY structures are the least deformable. Relaxation tests showed that 8BY architecture presents a more expressive variation of tensile stress, while 10BY of- fered the least. Dynamic mechanical analysis (DMA) revealed storage and loss moduli curves with similar transition peaks for the tested structures, except for the 10BY. Storage modulus is always four to six times higher than the loss modulus.This work was funded by European Regional Development funds (FEDER) through the Competitiveness and Internationalization Operational Program (POCI)—COMPETE andby Na-tional Funds through Portuguese Fundação para a Ciência e Tecnologia (FCT) under the project UID/EMS/50022/2020, UID/EEA/04436/2019 andUID/ CTM/00264/2019. Andrea Zille acknowledges financial support of the FCT through the project PTDC/CTM-TEX/28295/2017,and Nuno Dourado acknowledges financial support of the FCT through the project PTDC/EME-SIS/28225/2017. M.F.S.M. de Moura acknowledges the ‘Laboratório Associado de Energia, Transportes e Aeronáutica’ (LAETA) for the financial support