The behavior against temperature and thermal stability of enzymes is a topic of importance for industrial biocatalysis. This study focuses on the kinetics and thermodynamics of the thermal ...inactivation of Lipase PS from B. cepacia and Palatase from R. miehei. Thermal inactivation was investigated using eight inactivation models at a temperature range of 40–70 °C. Kinetic modeling showed that the first-order model and Weibull distribution were the best equations to describe the residual activity of Lipase PS and Palatase, respectively. The results obtained from the kinetic parameters, decimal reduction time (D and tR), and temperature required (z and z’) indicated a higher thermal stability of Lipase PS compared to Palatase. The activation energy values (Ea) also indicated that higher energy was required to denature bacterial (34.8 kJ mol−1) than fungal (23.3 kJ mol−1) lipase. The thermodynamic inactivation parameters, Gibbs free energy (ΔG#), entropy (ΔS#), and enthalpy (ΔH#) were also determined. The results showed a ΔG# for Palatase (86.0–92.1 kJ mol−1) lower than for Lipase PS (98.6–104.9 kJ mol−1), and a negative entropic and positive enthalpic contribution for both lipases. A comparative molecular dynamics simulation and structural analysis at 40 °C and 70 °C were also performed.
The work carried out in this paper consists of the classification of the physiological signal generated by eye movement called Electrooculography (EOG). The human eye performs simultaneous movements, ...when focusing on an object, generating a potential change in origin between the retinal epithelium and the cornea and modeling the eyeball as a dipole with a positive and negative hemisphere. Supervised learning algorithms were implemented to classify five eye movements; left, right, down, up and blink. Wavelet Transform was used to obtain information in the frequency domain characterizing the EOG signal with a bandwidth of 0.5 to 50 Hz; training results were obtained with the implementation of K-Nearest Neighbor (KNN) 69.4%, a Support Vector Machine (SVM) of 76.9% and Decision Tree (DT) 60.5%, checking the accuracy through the Jaccard index and other metrics such as the confusion matrix and ROC (Receiver Operating Characteristic) curve. As a result, the best classifier for this application was the SVM with Jaccard Index.
•Solvent-free glycerolysis catalyzed by Lipase PS-DI produces MAG rich in PUFA.•For the first time, oxidative stability is considered during glycerolysis design.•Simultaneous optimization of MAG ...yield and oxidative stability in glycerolysis design.•Optimized glycerolysis conditions improved end-product oxidative stability by 68%.
The production of mono- and diacylglycerols rich in polyunsaturated fatty acids is achieved in this study, by solvent-free glycerolysis of anchovy oil with lipase PS-DI from Burkholderia cepacia. Attention is focused on the oxidative stability of the reaction products, determined in terms of induction time (It). The effects of glycerol/triacylglycerol molar ratio, enzyme concentration, and reaction temperature on mono- and diacylglycerol production and It are all assessed. The operating conditions that optimized monoacylglycerol yields and oxidative stability were a glycerol/triacylglycerol ratio of 3/1, 9.0% (w/w) Lipase PS-DI, a stirring rate of 200 rpm, and a reaction time of 4 h, at 45.8 °C, producing a content of 24.8% and 51.9% of mono- and diacylglycerols, respectively, over an It of 1.41 h. The glycerolysis conditions determined by simultaneous optimization strategy increased the oxidative stability of the glycerolysis products by 68%, which rose from 0.84 h (individual optimization) to 1.41 h.
Introduction Timely and accurate diagnosis of the earliest manifestations of Alzheimer’s disease (AD) is critically important. Cognitive challenge tests such as the Loewenstein Acevedo Scales for ...Semantic Interference and Learning (LASSI-L) have shown favorable diagnostic properties in a number of previous investigations using amyloid or FDG PET. However, no studies have examined LASSI-L performance against cerebrospinal fluid biomarkers of AD, which can be affected before the distribution of fibrillar amyloid and other changes that can be observed in brain neuroimaging. Therefore, we aimed to evaluate the relationship between LASSI-L scores and CSF biomarkers and the capacity of the cognitive challenge test to detect the presence of amyloid and tau deposition in patients with subjective cognitive decline and amnestic mild cognitive impairment (MCI). Methods One hundred and seventy-nine patients consulting for memory loss without functional impairment were enrolled. Patients were examined using comprehensive neuropsychological assessment, the LASSI-L, and cerebrospinal fluid (CSF) biomarkers (Aβ1-42/Aβ1-40 and ptau181). Means comparisons, correlations, effect sizes, and ROC curves were calculated. Results LASSI-L scores were significantly associated with CSF biomarkers Aβ1-42/Aβ1-40 in patients diagnosed with MCI and subjective cognitive decline, especially those scores evaluating the capacity to recover from proactive semantic interference effects and delayed recall. A logistic regression model for the entire sample including LASSI-L and age showed an accuracy of 0.749 and an area under the curve of 0.785 to detect abnormal amyloid deposition. Conclusion Our study supports the biological validity of the LASSI-L and its semantic interference paradigm in the context of the early stages of AD. These findings emphasize the utility and the convenience of including sensitive cognitive challenge tests in the assessment of patients with suspicion of early stages of AD.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is associated with psychological/emotional disturbances. This study aimed to assess internal consistency, reliability, and construct ...validity of the Hospital Anxiety and Depressive Scale (HADS), as a patient-reported outcome measure (PROM) for evaluating emotional consequences of SARS-CoV-2 in hospitalized COVID-19 survivors with long COVID. The LONG-COVID-EXP-CM is a multicenter cohort study including patients hospitalized by COVID-19 during the first wave of the pandemic in five hospitals in Madrid. A total of 1969 (age: 61 ± 16 years, 46.5% women) COVID-19 survivors experiencing post-COVID symptoms a mean of 8.4 ± 1.5 months after hospital discharge completed HADS. Internal consistency (Cronbach α), reliability (item-internal consistency, item-discriminant validity), construct validity (confirmatory factor analysis), and floor effect and ceiling effect were calculated. The mean time for fulfilling HADS was 65 ± 12 s. A ceiling effect ranging from 1.99% to 13.74% and a floor effect ranging from 43.05% to 77.77% was observed. Based on the item-scale correlation coefficients, the Cronbach’s alpha values reflecting the internal consistency reliability were 0.890 for the anxiety scale (HADS-A) and 0.856 for the depressive scale (HADS-D) The correlation coefficient between HADS-A and HADS-D scores was excellent (r: 0.878). The confirmatory factor analysis revealed that five out of the seven fitness indexes were excellent: CFI = 0.969, NNFI = 0.963; TLI = 0.963; AGFI = 0.951; GFI = 0.972), supporting good construct validity. In conclusion, this study indicates that both anxiety and depressive symptoms scales of HADS had overall good psychometric properties to be used for assessing psychological and emotional stress in COVID-19 survivors with long COVID.
Background and Objectives: Metabolic-dysfunction-associated steatotic liver disease or MASLD is the main cause of chronic liver diseases in children, and it is estimated to affect 35% of children ...living with obesity. This study aimed to identify metabolic phenotypes associated with two advanced stages of MASLD (hepatic steatosis and hepatic steatosis plus fibrosis) in Mexican children with obesity. Materials and Methods: This is a cross-sectional analysis derived from a randomized clinical trial conducted in children and adolescents with obesity aged 8 to 16 years. Anthropometric and biochemical data were measured, and targeted metabolomic analyses were carried out using mass spectrometry. Liver steatosis and fibrosis were estimated using transient elastography (Fibroscan® Echosens, Paris, France). Three groups were studied: a non-MASLD group, an MASLD group, and a group for MASLD + fibrosis. A partial least squares discriminant analysis (PLS-DA) was performed to identify the discrimination between the study groups and to visualize the differences between their heatmaps; also, Variable Importance Projection (VIP) plots were graphed. A VIP score of >1.5 was considered to establish the importance of metabolites and biochemical parameters that characterized each group. Logistic regression models were constructed considering VIP scores of >1.5, and the receiver operating characteristic (ROC) curves were estimated to evaluate different combinations of variables. Results: The metabolic MASLD phenotype was associated with increased concentrations of ALT and decreased arginine, glycine, and acylcarnitine (AC) AC5:1, while MASLD + fibrosis, an advanced stage of MASLD, was associated with a phenotype characterized by increased concentrations of ALT, proline, and alanine and a decreased Matsuda Index. Conclusions: The metabolic MASLD phenotype changes as this metabolic dysfunction progresses. Understanding metabolic disturbances in MASLD would allow for early identification and the development of intervention strategies focused on limiting the progression of liver damage in children and adolescents.
Identificar la presencia de disfonía ocupacional (DO) con base en el índice de discapacidad vocal (VHI) y el índice de perturbación vocal integrado (IPI) en un grupo de docentes de la ciudad de Cali. ...Se realizó un estudio descriptivo de corte transversal entre enero y febrero 2019. Todos los participantes completaron el cuestionario VHI y fueron sometidos a un análisis acústico de la voz para estimar el IPI. Se analizó la información de 30 docentes, de los cuales 22 eran mujeres, el 80% (24) tenían una edad mayor de 45 años. Por medio del VHI, se identificó que todos los docentes experimentaban algún grado de discapacidad vocal con una mediana de 41,5 puntos (rango intercuartílico: 33,7 a 65,7), mientras que con IPI el 40% (12) tenían valores anormales (IPI 2). No se encontró una relación entre las puntuaciones del VHI y los valores del IPI (p>0,05). Los hallazgos de este estudio resaltan el alto riesgo de DO entre los docentes a causa de su ejercicio profesional, por lo que es imprescindible generar un programa nacional de detección temprana del riesgo vocal que incluya actividades de promoción y prevención.
To identify the presence of occupational dysphonia (OD) based on the vocal disability index (VHI) and the integrated vocal disturbance index (IPI) in a group of teachers in the city of Cali. A descriptive cross-sectional study was conducted between January and February 2019. All participants completed the VHI questionnaire and underwent an acoustic voice analysis to estimate the IPI. Data from 30 teachers were analyzed, of which 22 were women, 80% (24) were over 45 years of age. By means of the VHI, it was identified that all teachers experienced some degree of vocal impairment with a median of 41.5 points (interquartile range: 33.7 to 65.7), while with IPI 40% (12) had abnormal values (IPI≥2). No relationship was found between VHI scores and IPI values (p>0.05) The findings of this study highlight the high risk of OD among teachers due to their professional practice, so it is essential to generate a national program for early detection of vocal risk that includes promotion and prevention activities.
Abstract Gaze direction and pupil dilation play a critical role in communication and social interaction due to their ability to redirect and capture our attention and their relevance for emotional ...information. The present study aimed to explore whether the pupil size and gaze direction of the speaker affect language comprehension. Participants listened to sentences that could be correct or contain a syntactic anomaly, while the static face of a speaker was manipulated in terms of gaze direction (direct, averted) and pupil size (mydriasis, miosis). Left anterior negativity (LAN) and P600 linguistic event-related potential components were observed in response to syntactic anomalies across all conditions. The speaker’s gaze did not impact syntactic comprehension. However, the amplitude of the LAN component for mydriasis (dilated pupil) was larger than for miosis (constricted pupil) condition. Larger pupils are generally associated with care, trust, interest, and attention, which might facilitate syntactic processing at early automatic stages. The result also supports the permeable and context-dependent nature of syntax. Previous studies also support an automatic nature of syntax (fast and efficient), which combined with the permeability to relevant sources of communicative information, such as pupil size and emotions, is highly adaptive for language comprehension and social interaction.
Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N) fixation by cyanobacteria in association with ...mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier) at Cordillera Darwin (Tierra del Fuego) and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N2 fixation. Pioneer moss-cyanobacteria associations showed the highest N2 fixation rates (4.60 and 4.96 µg N g-1 bryo. d-1) very early after glacier retreat (4 and 7 years) which may help accelerate soil development under wetter conditions. In drier climate, N2 fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g-1 bryo. d-1) but peaked at intermediate-aged sites (26 and 66 years). N2 fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N2 fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous). We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N2-fixation rates in post-glacial areas with very low N deposition.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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