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1.
Proc Natl Acad Sci U S A ; 121(41): e2406956121, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39356663

RESUMO

Many of the relevant electrochemical processes in the context of catalysis or energy conversion and storage, entail the production of gases. This often implicates the nucleation of bubbles at the interface, with the concomitant blockage of the electroactive area leading to overpotentials and Ohmic drop. Nanoelectrodes have been envisioned as assets to revert this effect, by inhibiting bubble formation. Experiments show, however, that nanobubbles nucleate and attach to nanoscale electrodes, imposing a limit to the current, which turns out to be independent of size and applied potential in a wide range from 3 nm to tenths of microns. Here we investigate the potential-current response for disk electrodes of diameters down to a single-atom, employing molecular simulations including electrochemical generation of gas. Our analysis reveals that nanoelectrodes of 1 nm can offer twice as much current as that delivered by electrodes with areas four orders of magnitude larger at the same bias. This boost in the extracted current is a consequence of the destabilization of the gas phase. The grand potential of surface nanobubbles shows they can not reach a thermodynamically stable state on supports below 2 nm. As a result, the electroactive area becomes accessible to the solution and the current turns out to be sensitive to the electrode radius. In this way, our simulations establish that there is an optimal size for the nanoelectrodes, in between the single-atom and ∼3 nm, that optimizes the gas production.

2.
Artigo em Inglês | MEDLINE | ID: mdl-39382655

RESUMO

The present work focused on inline Raman spectroscopy monitoring of SARS-CoV-2 VLP production using two culture media by fitting chemometric models for biochemical parameters (viable cell density, cell viability, glucose, lactate, glutamine, glutamate, ammonium, and viral titer). For that purpose, linear, partial least square (PLS), and nonlinear approaches, artificial neural network (ANN), were used as correlation techniques to build the models for each variable. ANN approach resulted in better fitting for most parameters, except for viable cell density and glucose, whose PLS presented more suitable models. Both were statistically similar for ammonium. The mean absolute error of the best models, within the quantified value range for viable cell density (375,000-1,287,500 cell/mL), cell viability (29.76-100.00%), glucose (8.700-10.500 g/), lactate (0.019-0.400 g/L), glutamine (0.925-1.520 g/L), glutamate (0.552-1.610 g/L), viral titer (no virus quantified-7.505 log10 PFU/mL) and ammonium (0.0074-0.0478 g/L) were, respectively, 41,533 ± 45,273 cell/mL (PLS), 1.63 ± 1.54% (ANN), 0.058 ± 0.065 g/L (PLS), 0.007 ± 0.007 g/L (ANN), 0.007 ± 0.006 g/L (ANN), 0.006 ± 0.006 g/L (ANN), 0.211 ± 0.221 log10 PFU/mL (ANN), and 0.0026 ± 0.0026 g/L (PLS) or 0.0027 ± 0.0034 g/L (ANN). The correlation accuracy, errors, and best models obtained are in accord with studies, both online and offline approaches while using the same insect cell/baculovirus expression system or different cell host. Besides, the biochemical tracking throughout bioreactor runs using the models showed suitable profiles, even using two different culture media.

3.
Molecules ; 29(18)2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39339383

RESUMO

Ceiba aesculifolia is an important species in Mexico that generates significant amounts of biomass waste during its exploitation, which can be utilized to produce energy. This study presents the characterization of this waste based on chemical (proximal and elemental) and thermal analyses (TGA-DTG) at different heating rates (ß = 10-30 °C/min (283-303 K/min)) in the presence of nitrogen and in a temperature range of 25-900 °C. Kinetic parameters were calculated and analyzed as well. Activation energy (Ea) and the pre-exponential factor (A) were determined using the Friedman (132.03 kJ/mol, 8.11E + 10 s -1), FWO (121.65 kJ/mol, 4.30E + 09), KAS (118.14 kJ/mol, 2.41E + 09), and Kissinger (155.85 kJ/mol, 3.47E + 11) kinetic methods. Variation in the reaction order, n (0.3937-0.6141), was obtained by Avrami's theory. We also calculated the thermodynamic parameters (ΔH, ΔG, ΔS) for each kinetic method applied. The results for Ea, A, n, ΔH, ΔG, and ΔS show that this biomass waste is apt for use in pyrolysis. Moreover, the moisture (<10%), ash (<2%), volatile material (>80%), and HHV (>19%) contents of C. aesculifolia allowed us to predict acceptable performance in generating energy and fuels. Finally, infrared spectroscopy analysis (FT-IR) allowed us to identify important functional groups, including one that belongs to the family of the aliphatic hydrocarbons.


Assuntos
Pirólise , Termodinâmica , Cinética , Biomassa , Biocombustíveis/análise , Temperatura
4.
Heliyon ; 10(17): e36587, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39281627

RESUMO

Due to the electrical nature of the cell, it is possible to modulate its behavior through the application of non-lethal external electric fields to improve fermentation processes. In this work, a microbial cell system with a chamber and two electrodes inside and connected to a voltage source was used. One of the electrodes was kept isolated to create an electric field without the flow of current. Cultures with two ethanol-producing microbial strains (Saccharomyces cerevisiae and Zymomonas mobilis) were conducted in this device. The application of voltages between 0 and 18 V was evaluated to determine the impact of the generated electric field on ethanol production. To analyze the possible effect of the field on the central carbon metabolism in each strain, biochemical-based kinetic models were formulated to describe the experimental fermentation kinetics obtained. It was found that low applied voltages did not have significant effects on growth rate in either strain, but all voltages evaluated increased substrate consumption and ethanol production rate in Z. mobilis, while only 18 V affected these rates in S. cerevisiae, indicating that Z. mobilis was the most sensitive to the electric field. At the end of the fermentation, significant increases in ethanol yields of 10.7% and 19.5% were detected for S. cerevisiae and Z. mobilis, respectively. The proposed mathematical models showed that substrate transport through the membrane catalyzed by the phosphotransferase system (PTS) for Z. mobilis and hexose transport proteins mechanism and hexokinase (HK) activity for S. cerevisiae and the transformation of pyruvate to ethanol, catalyzed by the decarboxylase (PDC) and alcohol dehydrogenase (ADH) enzymes, were the reactions most affected by the application of the external field.

5.
Environ Sci Pollut Res Int ; 31(45): 56482-56498, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39271609

RESUMO

This study aims to conduct an applied and innovative investigation to enhance the energy quality of wood residues through hydrothermal carbonization pretreatment. For this purpose, the treatment was carried out at three different temperatures: 180, 220, and 240 °C under autogenous pressure. The in natura material and the hydrochars were characterized, and thermogravimetric analyses were performed in an O2 atmosphere with heating rates of 2.5, 5, 10, and 20 °C min-1. The global activation energy for natura biomass combustion was determined to be 112.49 kJ.mol-1. On the other hand, the hydrothermal carbonization process promoted a reduction in this value for the 94.85 kJ.mol-1. The conversion function for the in natura biomass was characterized as 1 - α , order 1, while the hydrochars was 2(1-α) [-ln(1-α)] (1/2), Avrami-Erofe'ev I. Triple kinetic parameters were ascertained, and the conversion curves along with their respective derivatives were modeled, exhibiting minimal deviations between theoretical and experimental data. This facilitated the mathematical representation of the reaction processes and allowed for a comprehensive comparison of the results.


Assuntos
Termogravimetria , Cinética , Biomassa , Madeira/química , Carvão Vegetal/química
6.
Heliyon ; 10(15): e34813, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39157401

RESUMO

In this study, a kinetic model of the heterogeneous photocatalytic degradation of acetaminophen and its main transformation products is presented. Kinetic photocatalytic modeling and photon absorption rate modeling were included. Monte Carlo method was used to model the photon absorption process. Experiments were carried out in a reactor operated in batch mode and TiO2 nanotubes were used as photocatalyst irradiated with 254 nm UVC. Kinetic parameters were estimated from the experiments data by applying a non-linear regression procedure. Intrinsic expressions to the kinetics of acetaminophen degradation and its main transformation products were derived. Model, kinetics and photon absorption formulations and parameters proved to be affordable for describing the photocatalytic degradation of acetaminophen, but improvements should be done for better description of formation and oxidation kinetics of main transformation products. The model should be tested with other pharmaceuticals and emergent pollutants to calibrate it and evaluate its applicability in a wide range of compounds.

7.
Food Res Int ; 192: 114809, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39147506

RESUMO

Legumes are abundant sources of proteins, and white common bean proteins play an important role in air-water interface properties. This study aims to investigate the technical-functional properties of white common bean protein isolate (BPI) as a function of pH, protein concentration, and guar gum (GG) presence. BPI physicochemical properties were analyzed in terms of solubility, zeta potential, and mean particle diameter at pH ranging from 2 to 9, in addition to water-holding capacity (WHC), oil-holding capacity (OHC), and thermogravimetric analysis. Protein dispersions were evaluated in terms of dynamic, interfacial, and foam-forming properties. BPI showed higher solubility (>80 %) at pH 2 and above 7. Zeta potential and mean diameter ranged from 15.43 to -34.08 mV and from 129.55 to 139.90 nm, respectively. BPI exhibited WHC and OHC of 1.37 and 4.97 g/g, respectively. Thermograms indicated decomposition temperature (295.81 °C) and mass loss (64.73 %). Flow curves indicated pseudoplastic behavior, with higher η100 values observed in treatments containing guar gum. The behavior was predominantly viscous (tg δ > 1) at lower frequencies, at all pH levels, shifting to predominantly elastic at higher frequencies. Equilibrium surface tension (γeq) ranged from 43.87 to 41.95 mN.m-1 and did not decrease with increasing protein concentration under all pH conditions. All treatments exhibited ϕ < 15°, indicating predominantly elastic surface films. Foaming properties were influenced by higher protein concentration and guar gum addition, and the potential formation of protein-polysaccharide complexes favored the kinetic stability of the system.


Assuntos
Galactanos , Mananas , Phaseolus , Gomas Vegetais , Proteínas de Plantas , Solubilidade , Propriedades de Superfície , Gomas Vegetais/química , Galactanos/química , Mananas/química , Concentração de Íons de Hidrogênio , Proteínas de Plantas/química , Phaseolus/química , Tamanho da Partícula , Água/química
8.
Sci Rep ; 14(1): 19968, 2024 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-39198560

RESUMO

Orange II, an azo dye used in textile and leather industries, is toxic and contributes to reducing dissolved oxygen in water. In this sense, agri-food waste adsorbents offer efficient, cost-effective dye removal. In this study, potato surpluses were evaluated as adsorbents for the removal of Orange II at 22 °C and pH values between 4 and 9. The adsorbents were characterized by their morphology, elemental composition, infrared spectra, and point of zero charge. Adsorption isotherms were analysed using Langmuir and Freundlich models, revealing that the Langmuir equation (0.933 < r2 > 0.882) better described the adsorption process compared to the Freundlich model (0.909 < r2 > 0.852). The maximum adsorption capacity at pH 4 was 1.1 and 2.3 times higher than at pH 7 and 9, respectively. This increased capacity at pH 4 was due to favourable electrostatic interactions between the cationic adsorbent surface and the anionic dye. A kinetic model was developed to understand the adsorption dynamics of Orange II, demonstrating high accuracy with coefficients of determination (r2) exceeding 0.99 across various pH values. The predictions of the kinetic model aligned well with the Langmuir isotherm results, indicating a strong theoretical foundation. The critical contact time required to achieve the minimum adsorbent concentration necessary for meeting a discharge limit of 14.7 mg L-1 was determined using both the Langmuir and kinetic models. Simulation profiles showed that when the adsorbent concentration was increased from 12 to 40 g L-1, the contact time necessary to achieve the discharge limit decreased from 26 to 3.35 h, highlighting the trade-off between contact time and cost. This study offers a cost-effective solution for wastewater treatment and presents a robust model for optimizing batch adsorption processes, marking a significant advancement in using potato surpluses for dye removal.


Assuntos
Compostos Azo , Benzenossulfonatos , Solanum tuberosum , Poluentes Químicos da Água , Purificação da Água , Solanum tuberosum/química , Compostos Azo/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Benzenossulfonatos/química , Purificação da Água/métodos , Corantes/química
9.
Int. j. morphol ; 42(4): 1033-1038, ago. 2024. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-1569258

RESUMO

SUMMARY: The objective was measure quadricep strength after Total Hip Arthroplasty (THA) and kinetic treatment and then determine its impact on the functional recovery of patients with hip osteoarthritis. A total of 79 (25 were male and 54 were female) patients with THA. Exclusion criteria were previous extra-system kinetic treatment, operated on for hip fracture, not completing the treatment. Maximum Isometric Strength (MIS), Time Up and Go (TUG), Modified Harris Hip Score. There was a significant increase in the MIS of the post-treatment operated knee extension in both men and women (p < 0.0001 SE = 0.43; p < 0.0001 SE = 1.22, respectively). In the TUG, the execution time was significantly lower post-treatment in both men and women (p < 0.0001 SE = 0.77; p < 0.0001 SE = 0.94, respectively). The final Harris score increased significantly post-treatment in male and female (p < 0.0001 SE = 2.90; p < 0.0001 SE = 1.96, respectively). the association between MIS and the Harris score, it was noted that, for a 1 kg increase in this measure compared to the initial assessment, the Harris score, after 12 weeks of treatment, increased by 0.179 points (β = 0.179; p = 0.050). The conclusions were Indicate an increase in knee extension MIS of the operated hip after treatment in both sexes. At the same time, functionality increased post-treatment in both male and female.


El objetivo del estudio fue medir la fuerza del músculo cuádriceps femoral después de la artroplastia total de cadera (THA, por sus siglas en inglés) y el tratamiento kinésico, para determinar su impacto en la recuperación funcional de pacientes con osteoartritis de cadera. En el estudio participaron 79 pacientes con THA (25 hombres y 54 mujeres). Se excluyeron quienes tuvieron tratamiento Kinésico previo fuera del hospital, operación por fractura de cadera y no completar el tratamiento. Las principales medidas tomadas fueron: Fuerza Máxima Isométrica (MIS), Time UP and GO (TUG), Puntuación Modificada de Harris de Cadera. Hubo un aumento significativo en la MIS de la extensión de rodilla del lado operado después del tratamiento tanto en hombres (p<0,0001, EE=0,43) como en mujeres (p<0,0001, EE=1,22). En el TUG, el tiempo de ejecución fue significativamente menor después del tratamiento en hombres (p<0,0001, EE=0,77) y mujeres (p<0,0001, EE=0,94). La puntuación final de Harris aumentó significativamente después del tratamiento en hombres (p<0,0001, EE=2,90) y mujeres (p<0,0001, EE=1,96). En cuanto a la asociación entre MIS y la puntuación de Harris, se observó que por cada aumento de 1 kg en esta medida en comparación con la evaluación inicial, la puntuación de Harris aumentó en 0,179 puntos después de 12 semanas de tratamiento (β=0,179; p=0,050). En conclusión se observó un aumento en la MIS de la extensión de rodilla del lado operado después del tratamiento en ambos sexos. Al mismo tiempo, la funcionalidad aumentó después del tratamiento tanto en hombres como en mujeres.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Modalidades de Fisioterapia , Artroplastia de Quadril/reabilitação , Músculo Quadríceps/fisiologia , Modelos Logísticos , Estudos Retrospectivos , Força Muscular , Contração Isométrica
10.
Sports Biomech ; : 1-17, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38979762

RESUMO

The Force-velocity (F-v) and Power-velocity (P-v) relationships quantify athlete's horizontal force production capacities during sprinting. Efforts are underway to enhance ecological validity for practitioners and sports coaches. This study provides detailed data comparison of a low frames per second setup (30 Hz; FPSlow) with splits from a high FPS camera to derive F-v and P-v relationships. Sixty-six sprints performed by 11 university track and field athletes (6 male, 5 female) were evaluated. Data were recorded using FPSlow, photocells, and a high-speed camera (240 Hz; MySprint). In the FPSlow setup, bias was 0.17s, and Limits of agreement was 0.09s compared to photocells. ICC was 1.00, and the coefficient of variation (CV) was 1.0% [0.8-1.1%]. Time acquisition comparison between MySprint and FPSlow setups revealed high consistency (ICC = 0.99) and low CV (2.9% [2.8-3.1%]). F-v profile variables exhibited biases from trivial to small, with ICC ranging from moderate to nearly perfect. CV ranged from 2.7% to 11.8%, and improved using the average of three sprints (CV between 1.8% and 8.6%). The 'simple method' applied to data from the low FPS video setup yielded kinetic and kinematic parameters comparable to those obtained by the validated previous method and photocells.

11.
Environ Technol ; : 1-16, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38972300

RESUMO

Calotropis procera fibres have been proposed for free-phase diesel removal in case of spillage into groundwater. For this, characterizations were carried out using Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FEG-SEM), wettability and contact angle measurements. Sorption oil capacity, kinetic, isothermal and recycling behaviour were evaluated. For initial optimization of the oil sorption capacity, an experimental design (DOE) was applied, with the optimized condition being 60 g L-1 of diesel in water and 0.01 g of fibre. Then, the results clearly indicated that the fibres have a hydrophobic and oleophilic character, quickly reaching more than 71.43 g g-1 of diesel sorption, according to the adjustment (R² > 0.99) of the pseudo-second order and Langmuir models, governed by absorption mechanisms. It should also be noted that at the end of 8 reuse cycles, the fibre presented a total accumulated sorption capacity of about 252.6 g g-1 of diesel. Furthermore, a laboratory-scale experiment was carried out to remove diesel from groundwater in gas station areas, the fibre removed 98.55% to 99.97% of removal efficiencies were achieved of the free phase over time. Therefore, the material demonstrates excellent characteristics for removing diesel spills in groundwater due to its fast, high and stable removal capacity.

12.
J Mol Model ; 30(8): 262, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990414

RESUMO

CONTEXT: The debate over whether kinetic energy (KE) or potential energy (PE) are the fundamental energy components that contribute to forming covalent bonds has been enduring and stimulating over time. However, the supremacy of these energy components in reactions where multiple bonds are simultaneously formed or broken has yet to be explored. In this study, we use the reaction electronic flux (REF), an effective tool for investigating changes in driving electronic activity when bond formation or dissociation occurs in a chemical reaction, to examine the fluctuations in the KE and PE in a multi-bond reaction. To that end, the activation of CO 2 by low-valent group 14 catalysts through a concerted σ -bond metathesis mechanism is analyzed. The findings of this preliminary study suggest that the REF can be utilized as a tool to rationalize alterations in the KE and PE in a multi-bond reaction. Specifically, analyses across the reaction coordinate reveal that changes in the KE and PE precede activation in the REF, stimulating the electronic activity where bond formation or dissociation processes dominate. METHODS: The activation of CO 2 by the low-valent LEH catalysts (L = N,N'-bis(2,6-diisopropyl phenyl)- ß -diketiminate; E = Si, Ge, Sn, and Pb) was studied along the reaction coordinate at the M06-2X/6-31 G(d,p)-LANL2DZ(E) level of theory. The respective minimum energy path calculations were obtained using the intrinsic reaction coordinate (IRC) procedure. The reaction electronic flux (REF) was calculated through the computation of the electronic chemical potential using the frontier molecular orbital approximation. Mayer bond orders along the reaction coordinate have been determined using the NBO 3.1 program in Gaussian16. Most of the reaction coordinate quantities reported in this study (REF, KE, PE, among others) have been determined using the Kudi program and custom Python scripts.

13.
Artigo em Inglês | MEDLINE | ID: mdl-38936832

RESUMO

d-Xylose is a metabolizable carbon source for several non-Saccharomyces species, but not for native strains of S. cerevisiae. For the potential application of xylose-assimilating yeasts in biotechnological processes, a deeper understanding of pentose catabolism is needed. This work aimed to investigate the traits behind xylose utilization in diverse yeast species. The performance of 9 selected xylose-metabolizing yeast strains was evaluated and compared across 3 oxygenation conditions. Oxygenation diversely impacted growth, xylose consumption, and product accumulation. Xylose utilization by ethanol-producing species such as Spathaspora passalidarum and Scheffersomyces stipitis was less affected by oxygen restriction compared with other xylitol-accumulating species such as Meyerozyma guilliermondii, Naganishia liquefaciens, and Yamadazyma sp., for which increased aeration stimulated xylose assimilation considerably. Spathaspora passalidarum exhibited superior conversion of xylose to ethanol and showed the fastest growth and xylose consumption in all 3 conditions. By performing assays under identical conditions for all selected yeasts, we minimize bias in comparisons, providing valuable insight into xylose metabolism and facilitating the development of robust bioprocesses. ONE-SENTENCE SUMMARY: This work aims to expand the knowledge of xylose utilization in different yeast species, with a focus on how oxygenation impacts xylose assimilation.


Assuntos
Etanol , Fermentação , Oxigênio , Xilose , Xilose/metabolismo , Etanol/metabolismo , Oxigênio/metabolismo , Leveduras/metabolismo , Leveduras/crescimento & desenvolvimento , Cinética , Saccharomycetales/metabolismo , Saccharomycetales/crescimento & desenvolvimento , Aerobiose
14.
Int J Food Microbiol ; 420: 110783, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-38851046

RESUMO

Despite the wide variety of native and exotic fruits in Brazil, there is limited understanding of their ability to support pathogens during storage. This study aimed to evaluate the behavior of Salmonella enterica and Listeria monocytogenes inoculated into the pulp of eight fruits native and exotic to Brazil: Jenipapo (Genipa americana L.), Umbu (Spondias tuberosa Arruda), Maná (Solanum sessiliflorum), Cajá-manga (Spondias dulcis), Physalis (Physalis angulata L.), Feijoa (Acca sellowiana), Cupuaçu (Theobroma grandiflorum) (average pH < 3.3) and in a low acidy fruit: Abiu (Pouteria caimito) (pH 6.11). The pathogens were inoculated into the different fruits and stored at 10, 20, 30 and 37 °C for up to 12 h and 6 days, respectively. Among the fruits evaluated, Abiu was the only one that allowed Salmonella growth, showing higher δ-values at 20 and 30 °C (5.6 log CFU/g for both temperatures). For Physalis and Feijoa, there was a small reduction in the pathogen concentration (<1 log-cycle), mainly at 10 and 20 °C, indicating its ability to remain in the matrices. For the other fruits, notable negative δ-values were obtained, indicating a tendency towards microbial inactivation. The survival potential was significantly affected by temperature in Abiu, Maná, Cupuaçu, and Cajá-manga (p < 0.05). The same phenomena regarding δ-value were observed for L. monocytogenes population, with the greatest survival potential observed at 20 °C in Abiu (3.3 log CFU/g). Regarding the exponential growth rates in Abiu, the highest values were observed at 30 and 37 °C, both for Salmonella (4.6 and 4.9 log (CFU/g)/day, respectively) and for L. monocytogenes (2.8 and 2.7 log (CFU/g)/day, respectively), with no significant difference between both temperatures. Regarding microbial inactivation, L. monocytogenes showed greater resistance than Salmonella in practically all matrices. Jenipapo and Umbu were the pulps that, in general, had the greatest effect on reducing the population of pathogens. Furthermore, the increase in storage temperature seems to favor the increase on inactivation rates. In conclusion, Salmonella and L. monocytogenes can grow only in Abiu pulp, although they can survive in some acidic tropical fruits kept at refrigeration and abusive temperatures.


Assuntos
Microbiologia de Alimentos , Frutas , Listeria monocytogenes , Salmonella enterica , Salmonella enterica/crescimento & desenvolvimento , Listeria monocytogenes/crescimento & desenvolvimento , Frutas/microbiologia , Brasil , Temperatura , Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Armazenamento de Alimentos
15.
Foods ; 13(10)2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38790797

RESUMO

This study focuses on optimizing the ultrasound-assisted extraction (UAE) of bioactive compounds from purple-fleshed sweet potatoes (PFSP) for potential use as natural colorants. Factors such as time, temperature, and solid-to-liquid ratio were varied using a Box-Behnken Design. The optimal conditions were determined as 75 min, 70 °C, and a 1:15 m/v solid-to-liquid ratio, resulting in 18.372 mg/100 g total anthocyanin (TA) and 151.160 mg GAE/100 g total phenolic content (TPC). The validation yielded 18.822 mg/100 g for total anthocyanin and 162.174 mg GAE/100 g for total phenolic content, showing a 7% difference from predictions. UAE significantly increased TA extraction by 81% and TPC by 93% compared with the conventional method, with a notable reduction in process time from 24 h to 75 min. Additionally, three kinetic models were tested to compare extraction mechanisms, confirming the efficiency of UAE for PFSP bioactive compound recovery. This study proposes the UAE technique as a highly effective means of extracting bioactive compounds from PFSP, offering promising applications across multiple industries.

16.
Int J Biol Macromol ; 269(Pt 1): 132036, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38697429

RESUMO

Alpha-glucosidase inhibitors play an important role in Diabetes Mellitus (DM) treatment since they prevent postprandial hyperglycemia. The Glycoside Hydrolase family 13 (GH13) is the major family of enzymes acting on substrates containing α-glucoside linkages, such as maltose and amylose/amylopectin chains in starch. Previously, our group identified glycoconjugate 1H-1,2,3-triazoles (GCTs) inhibiting two GH13 α-glycosidases: yeast maltase (MAL12) and porcine pancreatic amylase (PPA). Here, we combined kinetic studies and computational methods on nine GCTs to characterize their inhibitory mechanism. They all behaved as reversible inhibitors, and kinetic models encompassed noncompetitive and various mechanisms of mixed-type inhibition for both enzymes. Most potent inhibitors displayed Ki values of 30 µM for MAL12 (GPESB16) and 37 µM for PPA (GPESB15). Molecular dynamics and docking simulations indicated that on MAL12, GPESB15 and GPESB16 bind in a cavity adjacent to the active site, while on the PPA, GPESB15 was predicted to bind at the entrance of the catalytic site. Notably, despite its putative location within the active site, the binding of GPESB15 does not obstruct the substrate's access to the cleavage site. Our study contributes to paving the way for developing novel therapeutic strategies for managing DM-2 through GH13 α-glycosidases inhibition.


Assuntos
Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Cinética , Ligantes , Suínos , Inibidores de Glicosídeo Hidrolases/farmacologia , Inibidores de Glicosídeo Hidrolases/química , Animais , Domínio Catalítico , alfa-Glucosidases/metabolismo , alfa-Glucosidases/química , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/metabolismo , Glicosídeo Hidrolases/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Triazóis/química , Triazóis/farmacologia , Modelos Moleculares
17.
Int J Legal Med ; 138(5): 1977-1983, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38658410

RESUMO

The use of less lethal weapons aims to mitigate civilian casualties caused by firearm use. However, due to numerous cases in which these weapons caused serious injuries, even lethal injuries, both legislation and the forensic field are interested in characterizing and regulating them better. In the forensic field, there is a lack of strong research about injury patterns of these weapons which makes it difficult to identify the type of weapon employed. In this study, the main objective was to characterize the injury pattern produced by the impact of the 9 mm P.A.K. projectile. A porcine model was used. Four different distances were studied: firm contact, 10 cm, 60 cm and 110 cm, using 3 of the more representative anatomical sites: the head, the hind leg and the ribs. The average measurement of the entrance orifice varied according to the anatomical site, being 6.67 mm wide and 6.25 mm long in the thorax, 7.3 mm wide and 8.8 mm long in the hind legs, and 7.62 mm wide and 7.54 mm long in the head. The variation in width and length measurements was not found to be directly related to the shot distance. The gunshot residues had similar characteristics to those of conventional lead projectiles, however there was more unburned powder deposit near the wounds, with a less dense soot and more dense powder tattoo. Depth varied widely regardless of tissue and firing distance, although loss of penetrating power and injury is observed as one moves away from the target.


Assuntos
Balística Forense , Modelos Animais , Ferimentos por Arma de Fogo , Animais , Suínos , Balística Forense/métodos , Ferimentos por Arma de Fogo/patologia , Costelas/lesões , Costelas/patologia , Armas de Fogo
18.
J Imaging ; 10(2)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38392087

RESUMO

This study aims to evaluate non-invasive PET quantification methods for (R)-[11C]PK11195 uptake measurement in multiple sclerosis (MS) patients and healthy controls (HC) in comparison with arterial input function (AIF) using dynamic (R)-[11C]PK11195 PET and magnetic resonance images. The total volume of distribution (VT) and distribution volume ratio (DVR) were measured in the gray matter, white matter, caudate nucleus, putamen, pallidum, thalamus, cerebellum, and brainstem using AIF, the image-derived input function (IDIF) from the carotid arteries, and pseudo-reference regions from supervised clustering analysis (SVCA). Uptake differences between MS and HC groups were tested using statistical tests adjusted for age and sex, and correlations between the results from the different quantification methods were also analyzed. Significant DVR differences were observed in the gray matter, white matter, putamen, pallidum, thalamus, and brainstem of MS patients when compared to the HC group. Also, strong correlations were found in DVR values between non-invasive methods and AIF (0.928 for IDIF and 0.975 for SVCA, p < 0.0001). On the other hand, (R)-[11C]PK11195 uptake could not be differentiated between MS patients and HC using VT values, and a weak correlation (0.356, p < 0.0001) was found between VTAIF and VTIDIF. Our study shows that the best alternative for AIF is using SVCA for reference region modeling, in addition to a cautious and appropriate methodology.

19.
Mol Pharm ; 21(4): 1861-1871, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38416030

RESUMO

This study aims to investigate key variables affecting the dissolution of amorphous pharmaceuticals. We examined sample treatment methods (centrifugation vs syringe filtration), time delays between sample collection and processing (immediate, 2, or 24 h), and different sample preparations (bare powder, capsules, or tablets). These factors were evaluated through both sink and nonsink dissolution experiments, using controlled supersaturation conditions (sink index ≈ 0.1) with amorphous solid dispersions (ASDs) containing low-substituted hydroxypropyl cellulose (L-HPC) and either indomethacin or posaconazole as model drugs. Our results highlighted the significant impact of syringe filtration on nonsink dissolutions, particularly the notable reduction in dissolved drug concentration, possibly due to filtration-induced precipitation. Moreover, introducing a delay of 2 or 24 h between sample collection and quantitation under nonsink conditions led to substantial concentration changes. This effect was not as pronounced when samples underwent centrifugation, and only the analysis was delayed for 2 h. The findings also emphasize the importance of accounting for delays introduced by pharmaceutical formulations, particularly in assessing the kinetic-solubility profiles of ASDs. This research offers valuable insights into the field of ASDs, enhancing our understanding of how these variables can influence dissolution results.


Assuntos
Cristalização , Solubilidade , Liberação Controlada de Fármacos
20.
Environ Sci Pollut Res Int ; 31(14): 21291-21301, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38383932

RESUMO

In this work, iron-bearing mining reject was employed as an alternative and potential low-cost catalyst to degrade phenol in water by photo-Fenton strategy. Various techniques, including SEM-EDS, BET, FTIR, and XRD, were applied to evaluate the material's properties. Process parameters such as hydrogen peroxide concentration, catalyst dosage, and pH were studied to determine the optimum reaction conditions ([catalyst] = 0.75 g L-1, [H2O2] = 7.5 mM, and pH = 3). Phenol degradation and mineralization efficiencies at 180 and 300 min were 96.5 and 78%, respectively. These satisfactory results can be associated with the iron amount present in the waste sample. Furthermore, the material showed high catalytic activity and negligible iron leaching even after the fourth reuse cycle. The degradation behavior of phenol in water was well represented by a kinetic model based on the Fermi function. The iron-bearing mining reject can be considered a potential photo-Fenton catalyst for phenol degradation in wastewater.

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