Activation Parameters Research Articles

Подход к твёрдотельному моделированию геометрических объектов в точечном исчислении

The development of computer-aided design systems involves a combination of fundamental and applied research. The conceptual foundation of the mathematical framework for such systems lies in the notion of a complete geometric body—a geometric set of points where the number of active parameters matches the dimensionality of the space, with the geometric body represented as a distinct part of that space. The analytical representation of these point sets is achieved through the mathematical apparatus of point calculus, which can be generalized to multidimensional spaces. The article compares this proposed approach to solid modeling of geometric objects with existing methods. Examples demonstrating the modeling of geometric bodies using the new approach are provided. The advantages of this ap-proach are emphasized, including the compactness of the analytical description, the elimination of transformation ma-trices, the facilitation of parallel computations within the mathematical framework, and more. Additionally, the article explores the capabilities of modeling geometric bodies in point calculus, such as the representation of isotropic and ani-sotropic bodies as solid geometric objects with a functionally controlled linear or nonlinear spatial structure.

Revisiting secondary model features for describing the shoulder and lag parameters of microbial inactivation and growth models.

The Baranyi and Geeraerd models are two of the most reliable models for the description of, respectively, microbial growth and inactivation. They are defined as a system of differential equations, whose algebraic solution can describe the microbial response during isothermal conditions, especially when combined with suitable secondary models. However, there are still large uncertainties regarding the best functions to use as secondary models for the lag phase duration (λ) and the shoulder length (Sl). In this article, we revisit these models, focusing on the implications related to the assumption of an ideal substance whose dynamics define bacterial adaptation. We demonstrate that their link with the isothermal lag and shoulder leads to unique secondary models for the effect of temperature changes on λ and Sl. Namely, a log-linear relationship for Sl and a reverse cuadratic relationship for λ (considering a Ratkowsky model for μ). Furthermore, we observe a coupling between both secondary models (k and Sl for Geeraerd; λ and μ for Baranyi), reducing the number of unknown model parameters from four to three. Using data from the scientific literature, we illustrate the applicability of these results, being able to improve the robustness of parameter estimates. The identification of these links are of great relevance for the field of predictive microbiology, as they resolve the uncertainty regarding the functional form of secondary models. Our results also provide a way to assess the validity of those dynamic hypotheses using data gathered under isothermal conditions, something that was hardly possible using data gathered under dynamic conditions. Although this study is limited to the effect of temperature, the general approach and methodology are also applicable to other type of secondary models, so this article can be a blueprint for future studies.

Robust Spray Combustion Enabling Hierarchical Porous Carbon-Supported FeCoNi Alloy Catalyst for Zn-Air Batteries.

Rechargeable Zn-air batteries (RZABs) are poised for industrial application, yet they require low-cost, high-performance catalysts that efficiently facilitate both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The pivotal challenge lies in designing multimetal active sites and optimizing the carbon skeleton structure to modulate catalyst activity. In this study, we introduce a novel hierarchical porous carbon-supported FeCoNi bifunctional catalyst, synthesized via a spray combustion method. The carbon, derived from sucrose, was tailored into a hierarchical porous morphology through etching with NO3- ions and NaCl, thereby significantly increasing the surface area for the interaction of the O2 and electrolyte interaction. The in situ formation of FeCoNi alloy nanoparticles ensures their uniform dispersion and anchoring, facilitating electron transport. The strong interaction and charge transfer at the heterogeneous FeCoNi alloy interfaces, along with nitrogen doping, which enhances the OER/ORR activity, endow the FeCoNi/N-PC catalyst with exceptional bifunctional catalytic properties, characterized by an activity parameter of 0.73 V. Furthermore, the RZAB assembled with this catalyst demonstrates outstanding cycling stability and reversibility, with a minimal round-trip efficiency decay of 7.6% over 1380 cycles (460 h) at 10 mA cm-2.

Study of regional hemodynamics and neuromuscular activity in patients with intra-articular fracture of the distal tibia

Evaluation of regional hemodynamis and functional condition of the lower extremity muscles of the lower leg, motor activity of two periphery nerves in patients who sustained the intra-articular fractures of the distal tibia was performed at 8–10 days; 1,5–2, 3–4 and 6–12 months after the surgical treatment with open reduction and plate fixation. Physiological analysis of the restoration of natural and evoked neuro-muscular activity, regional blood supply in cases with good adaptation of the boney fragments allowed to perform quantitative evaluation of the muscular activity level, degree of revascularization and the compensation of the initial and secondary circulatory disorders of the blood supply during different phases of reparative osteogenesis. During stages of fracture union and remodeling all patients demonstrated disorders of muscular and peripheral nerves function, hyperperfusion on main arteries with increased vascularization of the injured segment. Normalization of the parameters of neuro-muscular activity and regional blood supply was not yet completed by the time of boney union (by radiological data). Significant or moderate degree of disorders of muscular function with moderate of insignificant decrease of motor conduction of n.peroneus in the dustal segment (level of the forefoot) with insignificant decrease or normal level of motor conduction of n.tibialis, hyperperfusion on main arteries with normal vascularization of the injured segment. The received data build the basis for the definition of the criteria of anatomical-functional compliance between boney union and restoration of the motor activity of the muscles.

Antifungal Potential of Biogenic Zinc Oxide Nanoparticles for Controlling Cercospora Leaf Spot in Mung Bean.

Agricultural growers worldwide face significant challenges in promoting plant growth. This research introduces a green strategy utilizing nanomaterials to enhance crop production. While high concentrations of nanomaterials are known to be hazardous to plants, this study demonstrates that low doses of biologically synthesized zinc oxide nanoparticles (ZnO NPs) can serve as an effective regulatory tool to boost plant growth. These nanoparticles were produced using Nigella sativa seed extract and characterized through UV-Vis spectroscopy, FT-IR, X-ray diffraction, and scanning electron microscopy (SEM). The antifungal properties of ZnO NPs were evaluated against Cercospora canescens, the causative agent of Cercospora leaf spot in mung bean. Application of ZnO NPs significantly improved plant metrics, including shoot, root, pod, leaf, and root nodule counts, as well as plant length, fresh weight, and dry weight-all indicators of healthy growth. Moreover, low-dose ZnO NPs positively influenced enzymatic activity, physicochemical properties, and photosynthetic parameters. These findings suggest that biologically synthesized ZnO NPs offer a promising approach for enhancing crop yield and accelerating plant growth.

Models for plasmasphere and plasmatrough density and average ion mass including dependence on L, MLT, geomagnetic activity, and phase of the solar cycle

Using observations of mass density inferred from standing Alfvén wave frequencies and electron density inferred from plasma wave frequencies, predominantly for the Combined Release and Radiation Effects Satellite (CRRES) and Van Allen Probes spacecraft, we used symbolic nonlinear regression to find analytical formulas for the equatorial electron density, ne, mass density, ρm, and average ion mass, M≡ρm/ne. We separate the data into plasmasphere and plasmatrough populations based on the observed values of ne in order to find formulas for plasmasphere, plasmatrough, and both plasmasphere and plasmatrough. Our models depend on position, the solar extreme ultraviolet (EUV) F10.7 flux, geomagnetic activity parameters such as Kp, AE, Dst, and the solar wind dynamic pressure. Formulas for M are presented with or without ne as an input parameter. By examining formulas of varying complexity, we are able to determine the relative importance of the various dependencies. The most important dependencies for ne and ρm are that they decrease with respect to L shell and geomagnetic activity as specified by parameters such as Kp. The most important dependence of M is that M increases with respect to increasing F10.7. The value of M is close to unity within the plasmasphere, but can be significantly above 1 in the plasmatrough. Although ne and ρm have maximum value at dusk local time, M has maximum value at dawn local time. The O+ concentration is larger at dawn local time, but the O+ density can be comparable at dawn and dusk because of larger ne at dusk.

Identification of Key Amino Acids in the A Domains of Polymyxin Synthetase Responsible for 2,4-Diaminobutyric Acid Adenylation in Paenibacillus polymyxa NBRC3020 Strain.

Developing novel nonribosomal peptides (NRPs) requires a comprehensive understanding of the enzymes involved in their biosynthesis, particularly the substrate amino acid recognition mechanisms in the adenylation (A) domain. This study focused on the A domain responsible for adenylating l-2,4-diaminobutyric acid (l-Dab) within the synthetase of polymyxin, an NRP produced by Paenibacillus polymyxa NBRC3020. To date, investigations into recombinant proteins that selectively adenylate l-Dab─exploring substrate specificity and enzymatic activity parameters─have been limited to reports on A domains found in enzymes synthesizing l-Dab homopolymers (pldA from S. celluloflavus USE31 and pddA from S. hindustanus NBRC15115), which remain exceedingly rare. The polymyxin synthetase in NBRC3020 contains five A domains specific to l-Dab, distributed across five distinct modules (modules 1, 3, 4, 5, 8, and 9). In this study, we successfully obtained soluble A domain proteins from modules 1, 5, 8, and 9 by preparing module-specific recombinant proteins. These proteins were expressed in E. coli BAP-1, purified via Ni-affinity chromatography, and demonstrated high specificity for l-Dab. Through sequence homology analysis, three-dimensional structural modeling, docking simulations to estimate substrate-binding sites, and functional validation using alanine mutants, we identified Glu281 and Asp344 as critical residues for recognizing the side chain amino group of l-Dab, and Asp238 as essential for recognizing its main chain amino group in the A domain. Notably, these key residues were conserved not only across the A domains in modules 1, 5, 8, and 9 of P. polymyxa NBRC3020 but also in those of the P. polymyxa PKB1 strain, as confirmed by sequence homology analysis. Interestingly, in pldA and pddA, the key residues involved in recognizing the side-chain amino group of l-Dab, which are conserved among polymyxin synthetases of NBRC3020 and PKB1 strain, were not observed. This suggests a potentially different mechanism for l-Dab recognition.

Dehydrogenase: A key soil health indicator for Thar Desert, India

A field study was conducted to identify a potential fertility indicator for the soils of the Thar Desert. The study area included eight districts, covering a total of 156,580 km². This region experiences a wide range of climatic conditions, with annual rainfall varying from 177 mm to 409 mm and temperatures fluctuating between 8°C and 46°C. Surface soil samples (0-10 cm depth) were collected from agricultural fields across the region, representing various soil properties and cropping patterns. The soil texture varied from sandy loam to loamy sand, and the wet colour ranged from dark reddish-brown to dark yellowish-brown. The physicochemical and biological properties of the soil samples from different areas of the Thar Desert were as follows: moisture content ranged from 2.19% to 8.73%, bulk density from 1.18 to 1.33 Mg/m³, particle density from 1.82 to 4.11 Mg/m³, pore space percentage from 26.74% to 68.53%, solid space percentage from 31.47% to 73.26%, pH values from 7.69 to 8.43, and electrical conductivity from 0.12 to 0.17 dS/m. Furthermore, the soil organic carbon content ranged from 0.82% to 1.21%, while organic matter content varied between 1.41% and 2.09%. The available nitrogen was found to be between 285.69 and 365.87 kg/ha, phosphorus ranged from 19.84 to 24.77 kg/ha, potassium levels ranged from 214.29 to 314.72 kg/ha, and sulfur levels varied between 16.08 and 23.62 ppm. Additionally, nitrogenase retention time was recorded at 1.391 to 1.547 minutes, phosphatase activity ranged from 269.44 to 343.15 µg p-nitrophenol g⁻¹ h⁻¹, and dehydrogenase enzyme activity ranged from 250.33 to 309.34 µg TPF/g/24 h. The results demonstrated that soil properties varied across the Thar Desert. This study provided valuable insights into the physicochemical and biological characteristics of the soil in the Thar Desert of Rajasthan, India. Notably, a significant positive correlation (r² value of 0.95) was found between dehydrogenase enzyme activity and various soil fertility parameters, suggesting that dehydrogenase could serve as a potential biological indicator of soil fertility.

Effect of prophylactic doses of enoxaparin on antifactor Xa activity confirmed by rotational thromboelastometry in critically ill patients: a preliminary prospective cohort study.

Critically ill patients present multiple risk factors for venous thromboembolism (VTE). Underdosing of antithrombotic medications can result in VTE even as bleeding remains a significant concern for critically ill patients. On the other hand bleeding, remaining a significant concern for the critically ill, can be worsend by overdosing of antithrombotic medications. The present study aimed to assess the effects of prophylactic doses of enoxaparin on antifactor Xa activity (anti-Xa) and rotational thromboelastometry (ROTEM) parameters in critically ill patients. In this prospective single-center cohort study, the effects of enoxaparin were assessed via anti-Xa monitoring. Standard laboratory coagulation and ROTEM parameters were also determined using the same blood samples. A total of 61 patients (42.6% women) were enrolled in this study, whose median age was 59.0 (interquartile range: 43.0-70.0) years. Based on anti-Xa, the effects of enoxaparin were normal in 35 subjects (57.4%); in 17 patients (27.9%), the anti-Xa troughs and/or peaks were higher than the prophylactic range; in 9 patients (14.7%), the anti-Xa peak was lower than the prophylactic range. There were differences among the anti-Xa groups with respect to some ROTEM parameters. No VTE was detected among the study subjects. In 3 subjects (4.9%), there were signs of bleeding, and these patients presented with longer thrombin times. Anti-Xa values may be within the prophylactic range in slightly more than half of the critically ill patients receiving enoxaparin at prophylactic doses. The dosing of low-molecular-weight heparin (LMWH) in critically ill patients may require individualization based on anti-Xa. Further studies are therefore required to establish a universal anti-Xa prophylactic range for LMWH, the timing of anti-Xa determination, and management of LMWH dosing.

Chloride‐Assisted Transfer Hydrogenation of Ketones by Half‐Sandwich Rhodium Iminophosphonamide Complexes

Half‐sandwich 18e rhodium iminophosphonamide complexes [Сp*RhCl(NPN)] with NPN = Ph2P(N‐p‐Tol)2 (1a), Ph2P(N‐p‐Tol)(NMe) (1b) and 16e cationic [Сp*Rh(NPN)](PF6) (2a+PF6‐) were found to catalyze transfer hydrogenation of carbonylic substrates (acyclic and cyclic alkyl ketones, aromatic ketones and aldehydes) with the activity strongly enhanced by the presence of chloride ligand. Kinetic studies including KIE and activation parameters measurements carried out for two model ketones (acetophenone and cyclohexanone) as well as model spectroscopic investigation accompanied with the DFT calculations allowed to propose unconventional chloride‐assisted mechanism of transfer hydrogenation to account for different behavior of 18e chloride complexes vs their less active 16e cationic counterparts. The key species initiating the catalytic cycle is the solvate complex [Cp*Rh(NPN)(iPrOH)]Cl, which does not result from direct coordination of iPrOH to 2a+PF6‐ rather forms via the Cl‐ dissociation in 1 promoted by specific interactions with alcohol, namely by H‐bonding with the Cl ligand, Cp*Rh(NPN)Cl···HOR.

Understanding Dioxygen Activation in the Fe(III)-Promoted Oxidative Dehydrogenation of Amines: A Computational Study

Hydrogenation and dehydrogenation reactions are fundamental in chemistry and essential for all living organisms. We employ density functional theory (DFT) to understand the reaction mechanism of the oxidative dehydrogenation (ODH) of the pyridyl-amine complex [FeIIIL3]3+ (L3, 1,9-bis(2′-pyridyl)-5-[(ethoxy-2″-pyridyl)methyl]-2,5,8-triazanonane) to the mono-imine complex [FeIIL4]2+ (L4, 1,9-bis(2′-pyridyl)-5-[(ethoxy-2″-pyridyl)methyl]-2,5,8-triazanon-1-ene) in the presence of dioxygen. The nitrogen radical [FeIIL3N8•]2+, formed by deprotonation of [FeIIIL3]3+, plays a crucial role in the reaction mechanism derived from kinetic studies. O2 acts as an oxidant and is converted to H2O. Experiments with the deuterated ligand L3 reveal a primary C-H kinetic isotope effect, kCH/kCD = 2.30, suggesting C-H bond cleavage as the rate-determining step. The DFT calculations show that (i) 3O2 abstracts a hydrogen atom from the α-pyridine aliphatic C-H moiety, introducing a double bond regio-selectively at the C7N8 position, via the hydrogen atom transfer (HAT) mechanism, (ii) O2 does not coordinate to the iron center to generate a high-valent Fe oxo species observed in enzymes and biomimetic complexes, and (iii) the experimental activation parameters (ΔH≠ = 20.38 kcal mol−1, ΔS≠ = −0.018 kcal mol−1 K−1) fall within in the range of values reported for HAT reactions and align well with the computational results for the activated complex [FeIIL3N8•]2+···3O2.

Unveiling Intramolecular [3+2] Cycloaddition Reactions Leading to Functionalized Heterocycles in the Light of Molecular Electron Density Theory.

The relative reactivity andcis/transselectivity of the intramolecular [3+2] cycloaddition (IM32CA) reactionsof nitrile oxide (NO), azide (AZ), nitrile sulfide (NS) and nitrile ylide (NY),leading to functionalized heterocycles are studied within the Molecular Electron Density Theory. The kinetically controlled IM32CA reactions are predicted to becisstereospecific, while the reaction feasibility follows the order NY > NS > NO > AZ with the respective activation Gibbs free energies of 13.7, 17.8, 21.1 and 27.3 kcal·mol-1in benzene at 353 K. The decreased activation energy of NY could be correlated with its carbenoid character, relative to the zwitterionic one predicted for the other species. The AZ reaction showed relatively higher activation parameter, and accordingly higher than that of the NO one, in conformity with the experimental outcomes. Topological analysis of the electronic structure of the transition state structure shows that the formation of the new single bonds has not yet started on any of them according to a non-concerted mechanism. Analysis of the kinetic parameters of the intermolecular [3+2] cycloaddition reactions of NOs and AZs shows that the low activation entropies associated with the intramolecular processes are the factor responsible for the feasibility of these non-polarzw-typeIM32CA reactions.

Dynamics of HDL-Cholesterol Following a Post-Myocardial Infarction Cardiac Rehabilitation Program.

Exercise-based cardiac rehabilitation programs (CRP) are recommended for patients following acute coronary syndrome to potentially improve high-density lipoprotein cholesterol (HDL-C) levels and prognosis. However, not all patients reach target HDL-C levels. Here we analyze the dynamics and predictors of HDL-C increase during CRP in patients following ST-segment elevation myocardial infarction or occlusion myocardial infarction. We conducted a prospective study of myocardial infarction patients who completed exercise-based Phase 2 CRP. Data was collected on clinical variables, cardiovascular risk factors, treatment goals, pharmacological therapy, and health outcomes through questionnaires at the beginning and at the end of Phase 2 CRP. Lipid profile analysis was performed before discharge, 4 to 6 weeks after discharge, and at the end of Phase 2 CRP. Changes in lipid profiles were evaluated, and predictors of failure to increase HDL-C levels were identified by binary logistic regression analysis. Our cohort comprised 121 patients (mean age 61.67 ± 10.97 years, 86.8% male, and 47.9% smokers before admission). A significant decrease in total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) were noted, along with an increase in HDL-C (43.87 ± 9.18 vs. 39.8 ± 10.03 mg/dL, p < 0.001). Patients achieving normal HDL-C levels (>40 mg/dL in men and >50 mg/dL in women) significantly increased from 34.7% at admission to 52.9% the end of Phase 2. Multivariable analysis revealed smoking history (hazard ratio [HR] = 0.35, 95% confidence interval [CI], 0.11-0.96, p = 0.04), increased reduction in total cholesterol (HR = 0.94, 95% CI, 0.89-0.98, p = 0.004), and increased reduction in LDL-C (HR = 0.94, 95% CI, 0.89-0.99, p = 0.01) were inversely associated with failure to increase HDL-C levels. Conversely, higher HDL-C before CRP (HR = 1.15, 95% CI, 1.07-1.23, p < 0.001) and increased lipoprotein (a) (HR = 1.01, 95% CI, 1-1.02, p = 0.04) predicted failure to increase HDL-C levels. No significant correlations were found with Mediterranean diet adherence, weekly physical activity, training modalities, or physical fitness parameters. Participation in an exercise-based Phase 2 CRP led to mild but significant increases in HDL-C. Smoking history and patients experiencing substantial reductions in total cholesterol and LDL-C were more likely to experience HDL-C increases, unlike those with higher HDL-C and lipoprotein (a) levels before CRP.

The Influence of Ceramsite and Superphosphate on Humification in the Composting Process of Garden Wastes

This study used ceramsite and superphosphate as exogenous additives for composting garden wastes. It investigated the changes in temperature, pH, lignocellulose, enzyme activity, humic substrates, and humification parameters during the composting process. A total of four treatments—T0 (CK), T1 (ceramsite), T2 (superphosphate), and T3 (superphosphate + ceramsite)—were tested in a 50-day composting experiment. It was found that the formation of the compost humic substrate could be increased to 14.69% under the action of ceramsite. In addition, ceramsite promoted lignocellulose degradation, improved enzyme activity, and enhanced the material conversion in the composting process. At the same time, superphosphate also promoted the formation of humic substrates in compost but was less effective than ceramsite. Ceramsite is the best additive in promoting compost maturation.

Day-to-day variability in sleep and activity predict the onset of a hypomanic episode in patients with bipolar disorder.

Detecting transitions in bipolar disorder (BD) is essential for implementing early interventions. Our aim was to identify the earliest indicator(s) of the onset of a hypomanic episode in BD. We hypothesized that objective changes in sleep would be the earliest indicator of a new hypomanic or manic episode. In this prospective, observational, contactless study, participants used wearable technology continuously to monitor their daily activity and sleep parameters. They also completed weekly self-ratings using the Altman Self-Rating Mania Scale (ASRM). Using time-frequency spectral derivative spike detection, we assessed the sensitivity, specificity, and balanced accuracy of wearable data to identify a hypomanic episode, defined as at least one or more weeks with consecutive ASRM scores ≥10. Of 164 participants followed for a median (IQR) of 495.0 (410.0) days, 50 experienced one or more hypomanic episodes. Within-night variability in sleep stages was the earliest indicator identifying the onset of a hypomanic episode (mean ± SD) sensitivity: 0.94 ± 0.19; specificity: 0.80 ± 0.19; balanced accuracy: 0.87 ± 0.13), followed by within-day variability in activity levels: sensitivity: 0.93 ± 0.18; specificity: 0.84 ± 0.13; balanced accuracy: 0.89 ± 0.11. Limitations of our study includes a small sample size. Strengths include the use of densely sampled data in a well-characterized cohort followed for over a year, as well as the use of a novel approach using time-frequency analysis to dynamically assess behavioral features at a granular level. Detecting and predicting the onset of hypomanic (or manic) episodes in BD is paramount to implement individualized early interventions.

Effectiveness of Using a Digital Wearable Plantar Pressure Device to Detect Muscle Fatigue: Within-Subject, Repeated Measures Experimental Design.

Muscle fatigue, characterized by reduced force generation during repetitive contractions, impacts older adults doing daily activities and athletes during sports activities. While various sensors detect muscle fatigue via muscle activity, biochemical markers, and kinematic parameters, a real-time wearable solution with high usability remains limited. Plantar pressure monitoring detects muscle fatigue through foot loading changes, seamlessly integrating into footwear to improve the usability and compliance for home-based monitoring. This study aimed to investigate the effects of muscle fatigue on plantar pressure measurements using a self-developed wearable plantar pressure system. Twelve healthy participants completed a 5-minute calf muscle fatigue protocol. The plantar pressures and surface electromyography (sEMG) activity of the gastrocnemius muscles were recorded before and after exercise. The plantar pressures at 6 regions and the median frequency (MDF) of sEMG were analyzed to quantify fatigue. The self-developed foot pressure system showed a significant decrease in plantar pressure peak values at the heel of the left (P=.003) and right feet (P=.001) and at the lateral toe of the left (P=.001) and right feet (P=.026). A significant increase was observed at the metatarsal head of both the left foot (P=.001) and the right foot (P=.017). The MDF of sEMG signals significantly decreased in the left (P=.001) and right gastrocnemius (P<.001). Plantar pressure changes and sEMG signals effectively detect gastrocnemius muscle fatigue using the proposed wearable system, supporting the development of a wearable solution for detecting muscle fatigue suitable for home-use.

Effect of extraction method on antioxidant activity and phytochemical content of purple okra extract supplements

This study analyzed the effects of extraction methods on the antioxidant activity and phytocemical content of purple okra extract supplements. The extraction methods used in the preparation of the supplements were maceration and digestion. The purple okra extract supplement showed antioxidant capacity expressed as % inhibition of 99.73±0.17% and 83.46±0.90%, with an AEAC of 12.50±0.32 and 9.43±0.17 mg AEAC g⁻¹. The antioxidant activity, expressed as IC50, was measured at 233.01±61.69 and 391.05±8.90 ppm, indicating weak antioxidant activity. The purple okra extract supplement showed total phenols of 72.80±18.55 and 62.65±22.85 mg GAE g⁻¹, and total flavonoid content of 90.73±6.11 and 75.62±7.06 mg QE g⁻¹. Based on the statistical analysis using an independent t-test, it was found that the extraction method significantly affected the parameters of antioxidant activity and capacity, as well as total flavonoid content. By elucidating the influence of extraction methods on the activity, capacity, and phytochemical content of purple okra extract supplements, this study enhances our understanding of the importance of using appropriate extraction methods to maximize the extraction of active compounds. Future research is expected to optimize extraction methods, exploring solvent combinations, conducting in vivo studies on the therapeutic potential of purple okra, and examining its molecular mechanisms.

Synchronization in spiking neural networks with short and long connections and time delays.

Synchronization is fundamental for information processing in oscillatory brain networks and is strongly affected by time delays via signal propagation along long fibers. Their effect, however, is less evident in spiking neural networks given the discrete nature of spikes. To bridge the gap between these different modeling approaches, we study the synchronization conditions, dynamics underlying synchronization, and the role of the delay of a two-dimensional network model composed of adaptive exponential integrate-and-fire neurons. Through parameter exploration of neuronal and network properties, we map the synchronization behavior as a function of unidirectional long-range connection and the microscopic network properties and demonstrate that the principal network behaviors comprise standing or traveling waves of activity and depend on noise strength, E/I balance, and voltage adaptation, which are modulated by the delay of the long-range connection. Our results show the interplay of micro- (single neuron properties), meso- (connectivity and composition of the neuronal network), and macroscopic (long-range connectivity) parameters for the emergent spatiotemporal activity of the brain.

Rapid microfluidic perfusion system enables controlling dynamics of intracellular pH regulated by Na+/H+ exchanger NHE1.

pH regulation of eukaryotic cells is of crucial importance and influences different mechanisms including chemical kinetics, buffer effects, metabolic activity, membrane transport and cell shape parameters. In this study, we develop a microfluidic system to rapidly and precisely control a continuous flow of ionic chemical species to acutely challenge the intracellular pH regulation mechanisms and confront predictive models. We monitor the intracellular pH dynamics in real-time using pH-sensitive fluorescence imaging and establish a robust mathematical tool to translate the fluorescence signals to pH values. By varying flow rate across the cells and duration for the rinsing process, we manage to tweak the dynamics of intracellular pH from a smooth recovery to either an overshooting state, where the pH goes excitedly to a maximum value before decreasing to a plateau, or an undershooting state, where the pH is unable to recover to ∼7. We believe our findings will provide more insight into intracellular regulatory mechanisms and promote the possibility of exploring cellular behavior in the presence of strong gradients or fast changes in homogeneous conditions.

The association between serum zinc level and clinical features in patients with inflammatory bowel disease

Zinc is an essential element and important for inflammatory bowel disease patients. Herein, we aimed to elucidate the correlation between serum zinc concentration and various parameters, especially the disease activity index and endoscopic scores, in these patients. We measured serum zinc concentrations in 37 patients with Crohn's disease and 64 with ulcerative colitis and retrospectively analyzed patient characteristics, blood test values, disease activity, and endoscopic scores. Hypozincemia (<80 ‍μg/dl) was observed in 45.9% and 29.7% of patients with Crohn's disease and ulcerative colitis, respectively. Serum zinc concentration showed a weak negative correlation with Crohn's Disease Activity Index and C-reactive protein levels in Crohn's disease patients, and a weak negative correlation with white blood cell count in ulcerative colitis patients. The zinc concentrations in ulcerative colitis patients were significantly lower in Mayo endoscopic sub-score grade 2 than in grades 0 and 1. The simple endoscopic score for Crohn's disease moderately correlated with zinc concentration. In addition, serum zinc concentration showed a moderate correlation with serum albumin and Onodera's prognostic nutritional index in both Crohn's disease and ulcerative colitis patients. Serum zinc concentration clearly correlated with inflammatory bowel disease activity, endoscopy scores, and immunonutritional parameters, suggesting the importance of monitoring zinc levels.