A relationship between brainstem auditory evoked potential and vagal control of heart rate in adult women

Numerous studies have investigated the connection between autonomic control of heart rate (HR) and auditory stimulus. Yet, the literature lacks evidence of a close association between auditory brainstem processing and HR autonomic control. We aimed to evaluate and verify the relationship between auditory brainstem response (ABR) and HR variability (HRV) in healthy women. Forty‑six healthy female subjects, between the ages of 18 and 30 years old participated in the study. They were subjected to an audiometry examination, followed by rest for 10 minutes for HR recording. Next, ABR evaluation was completed discretely in both ears, with I, III and V wave components. Linear regression revealed that the root‑mean square of differences between adjacent normal RR intervals (RMSSD) and the triangular interpolation of RR interval (TINN) exhibited a significant association with Wave I in the right ear. These variables contributed to 28.2% (R²) of Wave I. In conclusion, there was a significant interaction between the autonomic control of HR and auditory processing in the right ear, suggesting that vagal tone interacts with the cochlear nerve

Global Women’s Breakfast (GWB): #UnidaspelaQuímica

Global Women’s Breakfast (GWB): #BoundbyChemistry. Global Women’s Breakfast is an initiative of the International Union of Pure and Applied Chemistry, aiming to give women scientists, from all over the world, the opportunity to know each other, communicating virtually and sharing their experiences. Many countries joined this initiative and Portugal was not an exception, with its participation already at the first Networking Breakfast in 2011, celebrating the year of the centenaries of Marie Curie Nobel Prize in Chemistry, the Portuguese Chemical Society and the Faculdade de Ciências da Universidade de Lisboa as well. The success of these networking breakfasts, involving students, young researchers, and scientists, encouraged its further organization in Portugal, annually since 2019. This article describes the interventions of Portuguese women scientists, coming from Institutions throughout Portugal, in the Global Women’s Breakfast as partners in their mission as scientists, creative and open to international collaborations. Global Women's Breakfast é uma iniciativa criada pela International Union of Pure and Applied Chemistry para dar oportunidade às mulheres cientistas de todo o mundo de se conhecerem, comunicando virtualmente e compartilhando as suas experiências. A adesão dos países foi muito elevada e Portugal não foi exceção, participando já no primeiro Networking Breakfast em 2011, Ano Internacional da Química, no qual se celebraram os centenários do Prémio Nobel da Química a Marie Curie, da Sociedade Portuguesa de Química e da Faculdade de Ciências da Universidade de Lisboa. O sucesso destes pequenos-almoços em rede, que envolvem estudantes, jovens investigadoras e cientistas, encorajou a continuação da participação de Portugal anualmente, desde 2019. Este artigo descreve a intervenção de mulheres cientistas portuguesas, pertencentes a instituições de Norte a Sul do país, no Global Women’s Breakfast, cúmplices na sua missão de cientistas, criativas e abertas à colaboração internacional

Kinetic modelling for the photocatalytic degradation of phenol by using TiO2-coated glass raschig rings under simulated solar light

BACKGROUNDImmobilisation of TiO2 photocatalysts has proven to be an efficient technological approach concerning both practical and economical aspects. The efficiency of photocatalytic phenol degradation using glass raschig rings coated with TiO2 Aeroxide((R))P25 was evaluated in a recirculation reactor operating under simulated solar light irradiation, by comparing the first order reaction rate (r) as a function of several operation conditions. RESULTSThe reaction rate increases with the initial phenol concentration ([PhOH](0)), the irradiation intensity (I), the number of TiO2-coated rings (N), and the hydrogen peroxide concentration [H2O2], and is minimally affected by the solution's flow rate (Q). A kinetic model was developed for the determination of the r as a function of the operating parameters. CONCLUSIONSThe empirical model allows the prediction of the efficiency of the photocatalytic degradation process in a wide range of operation conditions, which can be considered a useful tool for the scaling-up of the water treatment process. (c) 2014 Society of Chemical Industr

Laccase immobilization over multi-walled carbon nanotubes: Kinetic, thermodynamic and stability studies

The biocatalytic performance of immobilized enzyme systems depends mostly on the intrinsic properties of both biomolecule and support, immobilization technique and immobilization conditions. Multi-walled carbon nanotubes (MWCNTs) possess unique features for enzyme immobilization by adsorption. Enhanced catalytic activity and stability can be achieved by optimization of the immobilization conditions and by investigating the effect of operational parameters. Laccase was immobilized over MWCNTs by adsorption. The hybrid material was characterized by Fourier transformed infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM and TEM, respectively). The effect of different operational conditions (contact time, enzyme concentration and pH) on laccase immobilization was investigated. Optimized conditions were used for thermal stability, kinetic, and storage and operational stability studies. The optimal immobilization conditions for a laccase concentration of 3.75 mu L/mL were a pH of 9.0 and a contact time of 30 min (522 U-lac/g(carrier)). A decrease in the thermal stability of laccase was observed after immobilization. Changes in Delta S and Delta H of deactivation were found for the immobilized enzyme. The Michaelis-Menten kinetic constant was higher for laccase/MWCNT system than for free laccase. Immobilized laccase maintained (or even increased) its catalytic performance up to nine cycles of utilization and revealed long-term storage stability

Aliivibrio fischeri L-Asparaginase production by engineered Bacillus subtilis: a potential new biopharmaceutical

L-Asparaginase (L-ASNase) is an enzyme applied in the treatment of lymphoid malignancies. However, an innovative L-ASNase with high yield and lower side effects than the commercially available preparations are still a market requirement. Here, a new-engineered Bacillus subtilis strain was evaluated for Aliivibrio fischeri L-ASNase II production, being the bioprocess development and the enzyme characterization studied. The pBS0E plasmid replicative in Bacillus sp and containing PxylA promoter inducible by xylose and its repressive molecule sequence (XylR) was used for the genetic modification. Initially, cultivations were carried out in orbital shaker, and then the process was scaled up to stirred tank bioreactor (STB). After the bioprocess, the cells were recovered and submitted to ultrasound sonication for cells disruption and intracellular enzyme recovery. The enzymatic extract was characterized to assess its biochemical, kinetic and thermal properties using L-Asparagine and L-Glutamine as substrates. The results indicated the potential enzyme production in STB achieving L-ASNase activity up to 1.539 U mL-1. The enzymatic extract showed an optimum pH of 7.5, high L-Asparagine affinity (Km = 1.2275 mmol L-1) and low L-Glutaminase activity (0.568-0.738 U mL-1). In addition, thermal inactivation was analyzed by two different Kinect models to elucidate inactivation mechanisms, low kinetic thermal inactivation constants for 25 ºC and 37 ºC (0.128 and 0.148 h-1, respectively) indicate an elevated stability. The findings herein show that the produced recombinant L-ASNase has potential to be applied for pharmaceutical purposes.publishe