Analysis Of Activation Research Articles

Identification of Human Ventricular Tachycardia Demarcated by Fixed Lines of Conduction Block in a 3-Dimensional Hyperboloid Circuit.

The circuit boundaries for reentrant ventricular tachycardia (VT) have been historically conceptualized within a 2-dimensional (2D) construct, with their fixed or functional nature unresolved. This study aimed to examine the correlation between localized lines of conduction block (LOBs) evident during baseline rhythm with lateral isthmus boundaries that 3-dimensionally constrain the VT isthmus as a hyperboloid structure. A total of 175 VT activation maps were correlated with isochronal late activation maps during baseline rhythm in 106 patients who underwent catheter ablation for scar-related VT from 3 centers (42% nonischemic cardiomyopathy). An overt LOB was defined by a deceleration zone with split potentials (≥20 ms isoelectric segment) during baseline rhythm. A novel application of pacing within deceleration zone (≥600 ms) was implemented to unmask a concealed LOB not evident during baseline rhythm. LOBs identified during baseline rhythm or pacing were correlated with isthmus boundaries during VT. Among 202 deceleration zones analyzed during baseline rhythm, an overt LOB was evident in 47%. When differential pacing was performed in 38 deceleration zones without overt LOBs, an underlying concealed LOB was exposed in 84%. In 152 VT activation maps (2D=53, 3-dimensional [3D]=99), 69% of lateral boundaries colocalized with an LOB in 2D activation patterns, and the depth boundary during 3D VT colocalized with an LOB in 79%. In VT circuits with isthmus regions that colocalized with a U-shaped LOB (n=28), the boundary invariably served as both lateral boundaries in 2D and 3D. Overall, 74% of isthmus boundaries were identifiable as fixed LOBs during baseline rhythm or differential pacing. The majority of VT circuit boundaries can be identified as fixed LOBs from intrinsic or paced activation during sinus rhythm. Analysis of activation while pacing within the scar substrate is a novel technique that may unmask concealed LOBs, previously interpreted to be functional in nature. An LOB from the perspective of a myocardial surface is frequently associated with intramural conduction, supporting the existence of a 3D hyperboloid VT circuit structure. Catheter ablation may be simplified to targeting both sides around an identified LOB during sinus rhythm.

Time-Dependent Analysis of Human Neurophysiological Activities during an Ecological Olfactory Experience.

It has been demonstrated that odors could affect humans at the psychophysiological level. Significant research has been done on odor perception and physiological mechanisms; however, this research was mainly performed in highly controlled conditions in order to highlight the perceptive phenomena and the correlated physiological responses in the time frame of milliseconds. The present study explored how human physiological activity evolves in response to different odor conditions during an ecological olfactory experience on a broader time scale (from 1 to 90 s). Two odors, vanilla and menthol, together with a control condition (blank) were employed as stimuli. Electroencephalographic (EEG) activity in four frequency bands of interest, theta, alpha, low beta, and high beta, and the electrodermal activity (EDA) of the skin conductance level and response (SCL and SCR) were investigated at five time points taken during: (i) the first ten seconds of exposure (short-term analysis) and (ii) throughout the entire exposure to each odor (90 s, long-term analysis). The results revealed significant interactions between the odor conditions and the time periods in the short-term analysis for the overall frontal activity in the theta (p = 0.03), alpha (p = 0.005), and low beta (p = 0.0067) bands, the frontal midline activity in the alpha (p = 0.015) and low beta (p = 0.02) bands, and the SCR component (p = 0.024). For the long-term effects, instead, only one EEG parameter, frontal alpha asymmetry, was significantly sensitive to the considered dimensions (p = 0.037). In conclusion, the present research determined the physiological response to different odor conditions, also demonstrating the sensitivity of the employed parameters in characterizing the dynamic of such response during the time. As an exploratory study, this work points out the relevance of considering the effects of continuous exposure instead of short stimulation when evaluating the human olfactory experience, providing insights for future studies in the field.

Radiant Floor Cooling Systems: A Critical Review of Modeling Methods

Radiant floor heating systems have become a reference technology, but their use for cooling purposes has proven inconvenient in many applications due to their reduced cooling capacity and condensation issues. Nonetheless, potentialities and drawbacks of radiant floor cooling systems have been frequently addressed and simulated, given the large potential advantages of employing a single emissive system for all seasons. This paper aims to provide a comprehensive review of the modeling methods for radiant floor cooling systems proposed in scientific papers and also used in simulation software and technical standards. Models are classified according to their characterizing features, and the distinctive contributions of each method are discussed. Additionally, the modeling of the most relevant phenomena affecting floor performance is further discussed. The review revealed the presence of two main modeling classes, one only focusing on the floor’s conductive heat transfer and the other integrating active floor analysis within the building’s energy model of the thermal zone. Despite the presence of many modeling methods that are able to consider the most important effects in the radiant cooling system operation, not all the phenomena present in a practical application are fully described. Therefore, there is an ongoing need for more comprehensive, possibly easily characterizable, modeling approaches.

Abnormal Lymphatic Sphingosine-1-Phosphate Signaling Aggravates Lymphatic Dysfunction and Tissue Inflammation.

Lymphedema is a global health problem with no effective drug treatment. Enhanced T-cell immunity and abnormal lymphatic endothelial cell (LEC) signaling are promising therapeutic targets for this condition. Sphingosine-1-phosphate (S1P) mediates a key signaling pathway required for normal LEC function, and altered S1P signaling in LECs could lead to lymphatic disease and pathogenic T-cell activation. Characterizing this biology is relevant for developing much needed therapies. Human and mouse lymphedema was studied. Lymphedema was induced in mice by surgically ligating the tail lymphatics. Lymphedematous dermal tissue was assessed for S1P signaling. To verify the role of altered S1P signaling effects in lymphatic cells, LEC-specific S1pr1-deficient (S1pr1LECKO) mice were generated. Disease progression was quantified by tail-volumetric and -histopathologic measurements over time. LECs from mice and humans, with S1P signaling inhibition, were then cocultured with CD4 T cells, followed by an analysis of CD4 T-cell activation and pathway signaling. Last, animals were treated with a monoclonal antibody specific to P-selectin to assess its efficacy in reducing lymphedema and T-cell activation. Human and experimental lymphedema tissues exhibited decreased LEC S1P signaling through S1P receptor 1 (S1PR1). LEC S1pr1 loss-of-function exacerbated lymphatic vascular insufficiency, tail swelling, and increased CD4 T-cell infiltration in mouse lymphedema. LECs, isolated from S1pr1LECKO mice and cocultured with CD4 T cells, resulted in augmented lymphocyte differentiation. Inhibiting S1PR1 signaling in human dermal LECs promoted T-helper type 1 and 2 (Th1 and Th2) cell differentiation through direct cell contact with lymphocytes. Human dermal LECs with dampened S1P signaling exhibited enhanced P-selectin, an important cell adhesion molecule expressed on activated vascular cells. In vitro, P-selectin blockade reduced the activation and differentiation of Th cells cocultured with shS1PR1-treated human dermal LECs. P-selectin-directed antibody treatment improved tail swelling and reduced Th1/Th2 immune responses in mouse lymphedema. This study suggests that reduction of the LEC S1P signaling aggravates lymphedema by enhancing LEC adhesion and amplifying pathogenic CD4 T-cell responses. P-selectin inhibitors are suggested as a possible treatment for this pervasive condition.

FTP1.7 Critical decision analysis of pre-hospital major haemorrhage protocol activation

Abstract Aims Major haemorrhage protocol activation (MHPA) facilitates immediate blood product availability and institutional capacity readiness for bleeding trauma patients. MHPA is a difficult decision pre-hospital, where two thirds of MHPAs occur. We aimed to identify the determinants and influences of the pre-hospital MHPA decision. Methods This prospective qualitative study had Health Research Authority approval (REC 22/PR/0089). Physicians from one helicopter emergency medical service (HEMS) were purposively sampled. Written informed consent was obtained. Cases representing difficult MHPA decisions within the previous six months were included. Semi-structured interviews were conducted via Microsoft Teams, following the critical decision analysis method. Interviews were transcribed and analysed using a 6-step inductive thematic analysis method on NVivo. Results Twelve interviews were conducted with nine participants: median age 37 years (range 34-45), median post-graduate experience 12 years (IQR 10.5-14.8), and median HEMS experience 1 year (IQR 0.5-4.9). Cues for (and against) the MHPA decision included: hard evidence of bleeding (or bleeding judged to be non-severe); initial information fit their mental model of a bleeding patient (or did not); patient deterioration (or response to resuscitation); acknowledgement that injuries and bleeding can be missed (or uncertainty of clinical findings); and alternative diagnoses were considered less likely (or more likely). Other influences of the MHPA decision were heuristics (especially anchoring bias), situational awareness, previous experience, colleagues on-scene, time- and task-pressure, and the desire for diagnostic accuracy and professional reputation. Conclusions Multiple determinants and influences affect the pre-hospital MHPA decision. Acknowledging these cognitive processes will inform efforts to improve decision-making in trauma.

Submillimeter fMRI Acquisition Techniques for Detection of Laminar and Columnar Level Brain Activation.

Since the first demonstration in the early 1990s, functional MRI (fMRI) has emerged as one of the most powerful, noninvasive neuroimaging tools to probe brain functions. Subsequently, fMRI techniques have advanced remarkably, enabling the acquisition of functional signals with a submillimeter voxel size. This innovation has opened the possibility of investigating subcortical neural activities with respect to the cortical depths or cortical columns. For this purpose, numerous previous works have endeavored to design suitable functional contrast mechanisms and dedicated imaging techniques. Depending on the choice of the functional contrast, functional signals can be detected with high sensitivity or with improved spatial specificity to the actual activation site, and the pertaining issues have been discussed in a number of earlier works. This review paper primarily aims to provide an overview of the subcortical fMRI techniques that allow the acquisition of functional signals with a submillimeter resolution. Here, the advantages and disadvantages of the imaging techniques will be described and compared. We also summarize supplementary imaging techniques that assist in the analysis of the subcortical brain activation for more accurate mapping with reduced geometric deformation. This review suggests that there is no single universally accepted method as the gold standard for subcortical fMRI. Instead, the functional contrast and the corresponding readout imaging technique should be carefully determined depending on the purpose of the study. Due to the technical limitations of current fMRI techniques, most subcortical fMRI studies have only targeted partial brain regions. As a future prospect, the spatiotemporal resolution of fMRI will be pushed to satisfy the community's need for a deeper understanding of whole-brain functions and the underlying connectivity in order to achieve the ultimate goal of a time-resolved and layer-specific spatial scale. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

Quality evaluation of Keteling capsules based on fingerprinting, multicomponent quantification, and quantitative prediction

The Keteling capsule (KC) is a traditional Chinese medicine (TCM) made from the dried extract of Ficus microphylla and an appropriate amount of chlorpheniramine maleate. It is widely used to treat cough and relieve asthma. Despite its extensive usage, a rapid and comprehensive quality evaluation strategy for KC remains a challenge. This study introduces an electrochemical fingerprint analysis technique, in addition to the commonly employed HPLC fingerprints, for efficient and convenient quality evaluation. Moreover, a cost-effective, rapid, and accurate multi-component quantification technique known as the “Multi-markers assay by the monolinear method (MAML)” and the “FT-IR quantitative model” were explored. The HPLC fingerprints were evaluated using a systematically quantified fingerprint method, while the electrochemical fingerprints, based on the Belousov-Zhabotinsky oscillation reaction principle, were effectively analyzed and characterized using oxidation induction times and oscillation lifetimes. Multi-component quantitative analysis was carried out through the MAML and FT-IR quantitative models. The HPLC fingerprint successfully classified the 22 samples into eight grades with excellent discrimination. Active ingredient content analysis was achieved using reliable parameters obtained from electrochemical fingerprinting. The no significant difference in the quantitative results proves the accuracy of the MAML method. Additionally, successful FT-IR quantitative prediction models were developed for chlorogenic acid, isovitexin, and chlorpheniramine maleate. This study offers a dependable and effective approach for enhancing the quality control of KC, and it can provide new insights for improving the quality analysis methods in the field of TCM.

Genome-Wide Identification, Characterization, and Expression Profiling of the Glutaredoxin Gene Family in Tea Plant (Camellia sinensis)

Glutaredoxins (GRXs) are a widely distributed group of small oxidoreductases that play an important role in responding to oxidative stress and maintaining redox homeostasis in living organisms. However, there has been no report on the GRX gene family in tea plants (Camellia sinensis). In this study, we conducted a systematic analysis of the CsGRX gene family in tea plants and identified a total of 86 CsGRX genes. Based on phylogenetic and conserved active site analyses, these genes were classified into four categories: CC-type, CPYC-type, CGFS-type, and GRL-type. These subtypes showed distinct characteristics in terms of gene structure, conserved motif, chromosome distribution, subcellular localization, cis-regulatory elements, and expression pattern, indicating functional differences among CsGRX family members. Collinearity analysis showed that the CsGRX family may have undergone member expansion using tandem and segmental duplication along with overwhelmingly strict purifying selection. Protein tertiary structure analysis supported the conserved site-specific binding of CsGRX family members to glutathione. Protein interaction network analysis revealed that CsGRX may interact with glutathione reductase (GR), 2-Cys Peroxiredoxin BAS1, TGA3, and others to participate in the oxidative stress response in tea plants. GO and KEGG enrichment analyses also supported the important role of the CsGRX family in maintaining intracellular redox homeostasis. Expression analysis based on RNA-seq revealed differential expression patterns of CsGRX genes under drought, cold stress, and in different tissues, which were further confirmed by RT-qPCR analysis, indicating their broad-spectrum functionality. This study provides a new perspective for further exploring the evolution and molecular functions of specific CsGRX genes.

Hypospadias prevalence by severity and associated risk factors: A population-based active surveillance analysis

Hypospadias is one of the most common congenital anomalies. Trends of hypospadias prevalence by severity are not well reported. Most prevalence studies consist of pooled data from different countries or states suffer from low data quality due to inconsistent methodologies, limited variables, and lack of categorization of hypospadias severity. The objective of this study is to examine the prevalence of hypospadias by degrees of severity and associated risk factors using combined data sources from a stable and well-defined population. The study population includes infants born with hypospadias to mothers residing in Arkansas from 1997 to 2016. Cases were identified from an active population-based surveillance program of birth defects. Identified hypospadias cases from surveillance data were linked to birth certificate and to a clinical database. These two data sources provide more details on the location of the defect and maternal and infant characteristics. The prevalence and 95% confidence intervals were calculated using total male live births as denominator. Chi-square test was used to assess the association of nominal variables. Logistic regression was used to calculate adjusted odds ratio. A total 3230 hypospadias cases were identified from 1997 to 2016. The overall prevalence is 83.0 per 10,000 male births. A majority of cases (56.7%) were classified as first degree with the others having second degree (22.8%), third degree (4.7%) or not otherwise specified (15.6%). The highest prevalence of hypospadias was observed among Non-Hispanic whites. Higher prevalence also was observed among mothers in the older age group with no prenatal care in the first trimester and with gestational hypertension or diabetes. Premature or small for gestational age infants tend to have higher prevalence across all levels of severity. The number of hypospadias cases increased over time. After maternal age, race and education were adjusted, higher risk persisted for infants of restricted fetal growth, mothers with gestational hypertension or diabetes and the cohort of 2013-2016. There is an increase of hypospadias cases in Arkansas. Several maternal and infant characteristics associated with higher prevalence for all levels of severity are worth further investigation.

Boosted water electrolysis capability of NixCoyP via charge redistribution and surface activation

Water electrolysis for efficiently generating hydrogen is a key chemistry to realize the hydrogen economy. Transition metal phosphides (TMPs) have become promising catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under alkaline conditions. But their widespread application is still limited due to the intermediates’ adsorption/desorption energy to be improved and the rare analysis of activation. Herein, we demonstrate a bifunctional catalyst, bimetallic phosphide (NixCoyP) supported by Ni foam (NF), towards HER and OER. X-ray photoelectron spectra demonstrate that the synergy between nickel and cobalt regulates the electron redistribution around active sites, which optimizes reaction intermediates’ adsorption/desorption kinetics on active sites. Post-stability analysis further reveals the surface activation phenomenon, that NixCoyP can transform into hydroxides for HER and oxyhydroxides for OER. Such behaviors allow the surface of catalysts to form new heterostructures with reorganized electronic structures to sustain the low voltage of water electrolysis and excellent stability. Density functional theory analysis proves that the NiCoP/M-OH heterostructure significantly enhances the HER properties through the optimized adsorption/desorption capacities for H* intermediates. Remarkably, this catalyst exhibits an outstanding overall water electrolysis performance.

Through-Space, Lone-Pair Promoted Aromatic Substitution: A Relay Mechanism Can Beat Out Direct Activation.

We report a detailed experimental and theoretical analysis of through-space arene activation with halogens, tetrazoles and achiral esters and amides. Contrary to previously assumed direct activation through σ-complex stabilization, our results suggest that these reactions proceed by a relay mechanism wherein the lone pair-containing activators form exothermic π-complexes with electrophilic nitronium ion before transferring it to the probe ring through low barrier transition states. Noncovalent interactions (NCI) plots and Quantum Theory of Atoms in Molecules (QTAIM) analyses depict favorable interactions between the Lewis base (LB) and the nitronium ion in the precomplexes and the transition states, suggesting directing group participation throughout the mechanism. The regioselectivity of substitution also comports with a relay mechanism. In all, these data pave the way for an alternate platform of electrophilic aromatic substitution (EAS) reactions.

A BRIEF VIEW ON THE EFFECTIVE ASPECTS OF THE HISTORIAN IN THE PROCESS OF HISTORICAL RESEARCH

It must be acknowledged that the effects of the characteristics and qualities of successful historians in scientific historical research are important and sensitive in every aspect. Because a successful researcher always looks at the phenomena around him with curiosity and truth-seeking plans. Because he has a sensitive, dynamic and searching mind toward what is happening around him. In order to prove historical facts, experienced researchers are constantly trying to identify the authenticity of historical events and phenomena through active methods, especially criticism and analysis, controversy and debate, and make them accessible to the lovers of science and knowledge and human societies.
 In the same way, the significance of the research is as the followings: it identifies the characteristics of the researcher with its positive and negative aspects, such as the good ethics of authorship, honesty, maintaining trustworthiness, having professional and specialized literacy, the authority of impartiality towards writing and the truthful expression of the content. However, regarding the negative aspects of the researcher, issues such as: bias, non-personality, biased expression and illegal betrayals of the researcher have been mentioned. Accordingly, the mentioned issues have added to the importance of this scientific research. In addition, more attention has been paid to its positive aspects and avoid its negative aspects.
 Furthermore, in general the purpose of study is to include the issues of introducing the main features of researchers in the field of history. Particularly, the purpose of this study is to express the positive and negative aspects of the researcher, keeping in mind the requirements of time and maintaining trustworthiness. Last but not least, a library research method was applied to analyze and discuss the materials.

Judicial Activism — the Enforcement of Human Rights in India

The most conspicuous feature of the Indian legal system is judicial activism and almost institutionalization of government by the judiciary. This activism is often assisted by activist lawyers, social activists, journalists and several others. The Supreme Court of India through innovative exercise of judicial power was fairly successful in protecting and promoting human rights and this process of creative exercise of judicial power is termed as judicial activism. The means and methods by which the judiciary expands its role is through public interest litigation (PIL). This paper is aimed at incisive analysis of judicial activism and PIL in promoting human rights of the weak and the vulnerable.

Correlation between cerebral hemodynamic functional near-infrared spectroscopy and positron emission tomography for assessing mild cognitive impairment and Alzheimer's disease: An exploratory study.

This study was performed to investigate the usefulness of functional near-infrared spectroscopy (fNIRS) by conducting a comparative analysis of hemodynamic activation detected by fNIRS and positron emission tomography (PET) and magnetic resonance imaging (MRI) in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Participants were divided into four groups: the subjective memory impairment (SMI), amnestic MCI (aMCI), non-amnestic MCI (naMCI), and AD groups. We recorded the hemodynamic response during the semantic verbal fluency task (SVFT) using a commercial wireless continuous-wave NIRS system. The correlation between the parameters of the neuroimaging assessments among the groups was analyzed. Region of interest-based comparisons showed that the four groups had significantly different hemodynamic responses during SVFT in the bilateral dorsolateral prefrontal cortex (DLPFC). The linear mixed effect model result indicates that the mean ΔHbO2 from the bilateral DLPFC regions showed a significant positive correlation to the overall FDG-PET after controlling for age and group differences in the fNIRS signals. Amyloid PET signals tended to better differentiate the AD group from other groups, and fNIRS signals tended to better differentiate the SMI group from other groups. In addition, a comparison between the group pairs revealed a mirrored pattern between the hippocampal volume and hemodynamic response in the DLPFC. The hemodynamic response detected by fNIRS showed a significant correlation with metabolic and anatomical changes associated with disease progression. Therefore, fNIRS may be considered as a screening tool to predict the hemodynamic and metabolic statuses of the brain in patients with MCI and AD.

Climate Change-related Counter-attitudinal Fake News Exposure and its Effects on Search and Selection Behavior

ABSTRACT Disinformation in today’s high-choice media environment, particularly regarding environment- and science-related issues, poses threats to individuals and society. It is argued that online users turn primarily to attitude-confirming content (selective exposure effects) which amplifies existing opinions and societal polarization. However, with the increasing prevalence of online disinformation and fake news, it is also likely that people will be exposed to disinformation that contradicts their current beliefs. Regarding the controversial issue of anthropogenic climate change, we elucidate how users react when they are (incidentally) exposed to counter-attitudinal anthropogenity-denying fake news by investigating their search and selection behavior after the exposure. The innovative research design of our case study includes pre- and post-surveys, stimulus exposure, and content analyses of web activities (n = 39). Importantly, the exposure to climate-change-denying fake news decreased acceptance of climate change and its human causes. Selection behavior was mainly attitude-confirming, while search behavior was more diverse. Journalistic sources were used most often and for longest. Individual characteristics affected searches and selections. KEY POLICY HIGHLIGHTS In the information-saturated online environment comprising scientifically correct and incorrect information, users are frequently exposed to counter-attitudinal fake news, e.g. videos denying anthropogenic climate change. After exposure to an attitude-opposing fake news video, participants’ climate change acceptance decreased. In a free internet search after stimulus exposure, attitude-confirming anthropogenity-accepting positions and journalistic content dominated users’ selection but not search behavior. Future climate change-related communication activities should note that participants who stated they knew little about climate change knowledge were mainly interested in solution-oriented websites. The higher participants’ willingness to take personal responsibility or acknowledge others’ responsibility, the more they searched for anthropogenity-opposing content.

Multi-Active/Passive-IRS Enabled Wireless Information and Power Transfer: Active IRS Deployment and Performance Analysis

Intelligent reflecting surfaces (IRSs), active and/or passive, can be densely deployed in complex environments to significantly enhance wireless network coverage for both wireless information transfer (WIT) and wireless power transfer (WPT). In this letter, we study the downlink WIT/WPT from a multi-antenna base station to a single-antenna user over a multi-active/passive IRS (AIRS/PIRS)-enabled wireless link. In particular, we derive the location of the AIRS with those of the other PIRSs being fixed to maximize the received signal-to-noise ratio (SNR) and signal power at the user in the cases of WIT and WPT, respectively. The derived solutions reveal that the optimal AIRS deployment is generally different for WIT versus WPT due to the different roles of AIRS-induced amplification noise. Furthermore, both analytical and numerical results are provided to show the conditions under which the proposed AIRS deployment strategy yields superior performance to other baseline deployment strategies as well as the conventional all-PIRS enabled WIT/WPT.

One-step look-ahead policy for active learning reliability analysis

One-step look-ahead policy for active learning reliability analysis

Li-Ion Battery Active Material Impedance Analysis I: Comparison of Measured NCM 111 Kinetics with Butler-Volmer Equation Based Predictions

The expression for the exchange current density to describe the intercalation kinetics of Li-ion battery materials proposed by Newman and coworkers has been used extensively for battery modeling, however its applicability to existing battery materials should be validated. Here we show an electrochemical impedance spectroscopy (EIS) analysis of the kinetic behavior of NCM 111 as a function of electrolyte salt concentration and state-of-charge (SOC) and compare it to the proposed theory. An areal capacity dependent EIS analysis first gives insights into the feasibility of measuring kinetic and transport parameters, including the solid diffusion resistance of lithium, showing that low-areal capacity electrodes are required to predominantly probe the kinetics. We then show how the charge transfer kinetics follow a Butler-Volmer type concentration dependent behavior for lower concentrated electrolytes (≤1.5 M) but deviate from the proposed theory at higher salt concentrations. A further SOC dependent analysis shows how NCM 111 generally follows the proposed theory of U-shaped symmetric kinetics, but the limited oxidative stability window leads to practically asymmetric kinetics for charging and discharging. This asymmetry is visible in NCM 111 lithiation and delithiation rate tests, where upon lithiation the kinetics generally become slower for higher degrees of lithiation, limiting the performance.

I can board, but I’d rather wait: Active boarding delay choice behaviour analysis using smart card data in metro systems

I can board, but I’d rather wait: Active boarding delay choice behaviour analysis using smart card data in metro systems

Investigation of the low-temperature exposure effect on the water activity of food products

Introduction: The activity of water is an integral characteristic of the moisture condition in a product, by which one can assess the correctness of various technological processes, as well as predict the shelf life of the product. Existing studies on the activity of water in food products were conducted mostly for the positive temperature range. Little attention was paid to the study of the effects of low-temperature exposure on water activity.Purpose: The article is devoted to the study of water activity in food products at various temperatures. Such an approach will allow predicting the shelf life of food products and optimizing the development of methods for controlling the functional and technological characteristics of food raw materials.Materials and Methods: The objects of research were: beef chilled according to GOST R 52427-2005, chilled pork, chilled mutton, fresh cucumbers, fresh carrots, fresh tomatoes, fresh parsley greens, dill greens, green onion greens. Two installations were used to analyze the water activity in the research objects: designed at the Kuzbass State Agricultural Academy, and the LabSwift-aw water activity analyzer. Experiments were conducted for fresh, chilled, and frozen products at various temperatures.Results: A design of a homemade installation that can be used to measure water activity is presented. The accuracy of this installation's measurements is experimentally proven. An analysis of water activity in fresh, chilled, and frozen products has been conducted. The water activity of fresh products was within the range of 0.954-0.995. It was found that with the same moisture content, the water activity can vary slightly, which is due to the difference in the chemical composition of the product and the salt content. It was established that chilling products from 22 to 6°C leads to a decrease in water activity by an average of 2%. Freezing to a temperature of -5°C results in a further reduction of water activity by an average of 0.03 units. Lowering the freezing temperature from -5°C to -10°C, -20°C, -30°C, and -40°C results in a reduction of water activity by an average of 0.04, 0.07, 0.06, and 0.05 units, respectively. Based on experimental data, mathematical dependencies of water activity on the freezing temperature for all studied products were derived.Conclusion: Water activity has important theoretical and practical significance, and the results of the research can be useful in predicting the shelf life of food products and developing methods to control the functional and technological characteristics of food raw materials.