Principal Channel Research Articles

Microstructural response of coal fracture surface induced by ScCO2 injection measured with AFM

Fractures in coal serve as the principal channels for the migration of coalbed methane (CBM). The microscopic traits of coal fracture surface are of significance for evaluating reservoir permeability and directly influence the outcome of CO2 storage and displacement. To comprehend the impact of CO2 on the coal fracture surface, the alterations in the coal fracture surface before and after CO2 injection are investigated vis atomic force microscopy. As CO2 gradually transforms into a supercritical state, the fracture density and aperture on the coal fracture surface gradually escalate. The mean pore size and porosity of the coal fracture surfaces rose from 5.45 nm to 6.55 nm and from 4.66% to 6.85%, respectively. The proportion of micropores (<2 nm) gradually diminished. The proportions of mesopores (2–50 nm) and macropores (>50 nm) proportions gradually. Swelling, extraction and mineral dissolution are the predominant reasons for the alteration in the pore structure of the coal fracture surface. CO2 injection modifies the roughness and fractal characteristics of the coal fracture surface. The mean roughness Ra dropped from 6.54 nm to 4.03 nm, and the fractal dimension Ds declined from 2.45 to 2.28. With the fixed scanning range, the injection of CO2 has been shown to reduce the roughness of coal fracture surface and lower their fractal dimension, thereby has a positive influencing permeability enhancement. Therefore, in CO2-ECBM engineering, it is essential not only to analyze the physical properties of the target reservoir, but also to conduct a comprehensive evaluation of permeability with a suitably defined area of the reservoir.

Inhibitors of Intracellular RyR2 Calcium Release Channels as Therapeutic Agents in Arrhythmogenic Heart Diseases.

Ryanodine receptor type 2 (RyR2) is the principal intracellular calcium release channel in the cardiac sarcoplasmic reticulum (SR). Pathological RyR2 hyperactivity generates arrhythmia risk in genetic and structural heart diseases. RYR2 gain-of-function mutations cause catecholaminergic polymorphic ventricular tachycardia. In structural heart diseases (i.e., heart failure), posttranslation modifications render RyR2 channels leaky, resulting in pathologic calcium release during diastole, contributing to arrhythmogenesis and contractile dysfunction. Hence, RyR2 represents a therapeutic target in arrhythmogenic heart diseases. We provide an overview of the structure and function of RyR2, and then review US Food and Drug Administration-approved and investigational RyR2 inhibitors. A therapeutic classification of RyR2 inhibitors is proposed based on their mechanism of action. Class I RyR2 inhibitors (e.g., flecainide) do not change SR calcium content and are primarily antiarrhythmic. Class II RyR2 inhibitors (e.g., dantrolene) increase SR calcium content, making them less effective as antiarrhythmics but preferable in conditions with reduced SR calcium content such as heart failure.

Activating Ecocentrism: How Young Women Environmental Activists Produce Identity on Instagram

ABSTRACT The fresh face of much of today’s environmental activism is young and female, particularly visible through movements such as School Strike for Climate (SS4C). Given the pressing need for embracing and broadcasting ecocentric ways of communicating, identifying, and behaving in these times – when impacts of anthropogenic climate and environmental crises are increasingly apparent – the ecocultural discourses such activists produce for public audiences are of utmost importance. The present study illuminates ways leading young women activists produce ecocentric identities within their principal online channel of public communication, the social media platform Instagram. We identify six predominant values central to these activists’ ecocentric identities: collective over individual action, intersectionality, climate optimism, corporate and political responsibility, ethics of care, and more-than-human connection. We also illustrate ways activists operationalize these values via three main material-symbolic identity activations: holding governments and industries accountable and responsible for their role in the climate crisis; creating inclusive, diverse communities; and fostering emotional responses to the more-than-human world. While activists under study also produce their ecocentric identities in the physical world – for instance, through on-the-ground protest leadership – their online identity production communicates shared values and actions in intimate, powerful, and potentially transformative ways to mass global audiences.

Individuals and Families Affected by RYR1-Related Diseases: The Patient/Caregiver Perspective.

Pathogenic variants of RYR1, the gene encoding the principal sarcoplasmic reticulum calcium release channel (RyR1) with a crucial role in excitation-contraction coupling, are among the most common genetic causes of non-dystrophic neuromuscular disorders. We recently conducted a questionnaire study focusing on functional impairments, fatigue, and quality of life (QoL) in patients with RYR1-related diseases (RYR1-RD) throughout the recognized disease spectrum. In this previous questionnaire study the medical perspective was taken, reflective of a study protocol designed by neurologists and psychologists. With this present study we wanted to specifically address the patient perspective. Together with affected individuals, family members, and advocates concerned with RYR1-RD, we developed an online patient survey that was completed by 227 patients or their parents/other caretakers (143 females and 84 males, 0-85 years). We invited 12 individuals, representing most of the patient group based on age, sex, race, and type and severity of diagnosis, to share their personal experiences on living with a RYR1-RD during an international workshop in July 2022. Data were analyzed through a mixed-methods approach, employing both a quantitative analysis of the survey results and a qualitative analysis of the testimonials. Data obtained from the combined quantitative and qualitative analyses provide important insights on six topics: 1) Diagnosis; 2) Symptoms and impact of the condition; 3) Physical activity; 4) Treatment; 5) Clinical research and studies; and 6) Expectations. Together, this study provides a unique patient perspective on the RYR1-RD spectrum, associated disease impact, suitable physical activities and expectations of future treatments and trials, and thus, offers an essential contribution to future research.

Microstructure evolution of coal undergoing in situ demineralization and ensued impacts on seepage characteristics

The natural fracture system present in coal provides the principal channel for transporting coalbed methane. Dissolving or modifying mineral occlusions has the potential to enhance the permeability of highly mineralized coal seams. In this study, low-rank mineralized coal was examined using x-ray computed tomography (CT) scanning. A novel in situ demineralization method based on coal CT images was developed using an improved pore-scale three-dimensional morphological modeling algorithm to further investigate the effect of mineral alteration on the dynamic evolution of microstructure and seepage characteristics. The results indicate that the development of pore-fracture and the alteration of mineralogical properties affect the demineralization work. Demineralization increases the connected porosity from 4.16% to 15.42%, significantly increasing the interconnected pore space of the coal. Meanwhile, permeability improved from 0.73 to 2.15 μm2, and a 194.5% increase after the completion of the demineralization work. A higher demineralization degree can develop the preferential flow channels well, resulting in a more rapid pore pressure drop. As demineralization progresses, the flow streamline distribution becomes more homogeneous, and new flow channels emerge. The proposed method shows superior performance in poorly connected areas, with a 69.29% higher permeability compared to previous methods.

Transverse crack micromechanisms in high-strength steel weld metal with microstructure heterogeneity under hydrogen-containing environment

The transverse crack susceptibility for high-strength steel weld metal with microstructure heterogeneity was investigated under various environment. Transverse cracking probability (C%) increases with increasing microstructure heterogeneity and diffusible hydrogen content. The dominant transverse crack initiation are soft massive pre-eutectic ferrite (PF), the deformation-uncoordinated acicular ferrite (AF)-PF interface and inclusions aggregation. PF, AF-PF interface and inclusions acts as the principal crack extension channel during crack propagation. Transverse cracks pass AF mainly extend along {100} plane while only along {110} when passing PF. MAGBs and HAGBs impede crack propagation. The Ʃ3 boundaries promote the crack propagation, while Ʃ11, Ʃ13b and Ʃ17b hinder the crack propagation. The transverse crack of weld metal under hydrogen-containing environment is attributed to the combination of HEDE and HELP mechanisms in the presence of microstructure heterogeneity and inclusions.

Remote retrieval of dissolved organic carbon in rivers using a hyperspectral drone system

ABSTRACT Rivers act as the principal channels for transporting terrigenous dissolved organic carbon (DOC) to lakes and reservoirs. Satellite remote sensing-based river monitoring is difficult due to the narrow river form and high spatiotemporal heterogeneity of DOC components. The unique advantages of unmanned aerial vehicles (UAVs) facilitate river DOC concentration monitoring. The DOC concentration in 8 major tributaries (average width: 109.62 m) and shoreside of the Lake Chaohu Basin were retrieved via a hyperspectral UAV. The results showed that (1) the DOC concentration was significantly correlated with the water remote sensing reflectance ( R rs ) of 402, 429-438, 440–451 and 458–462 nm in the blue band (r2: 0.11 to 0.13; p<0.05), and 620–621 and 623–693 nm in the red band (r2: 0.12 to 0.20; p<0.05). The water quality parameters chlorophyll-a (Chl-a) and suspended particulate matter (SPM) and environmental parameters wind speed and temperature 3 days delay sampling date, also showed a significant correlation. (2) The random forest regression (RFR) model attained the best performance (r2: 0.64; RMSE: 0.30 mg/L; MAPE: 7.02%). (3) DOC concentration in Lake Chaohu Basin was highest in the northeast (8.19 mg/L), followed by the northwest and west (7.13 mg/L), and it was lowest in the south (6.70 mg/L).

Application of one-dimensional hierarchical network assisted screening for cervical cancer based on Raman spectroscopy combined with attention mechanism

Cervical cancer is one of the most common malignant tumors among women, and its pathological change is a relatively slow process. If it can be detected in time and treated properly, it can effectively reduce the incidence rate and mortality rate of cervical cancer, so the early screening of cervical cancer is particularly critical and significant. In this paper, we used Raman spectroscopy technology to collect the tissue sample data of patients with cervicitis, Low-grade Squamous Intraepithelial Lesion, High-grade Squamous Intraepithelial Lesion, Well differentiated squamous cell carcinoma, Moderately differentiated squamous cell carcinoma, Poorly differentiated squamous cell carcinoma and cervical adenocarcinoma. A one-dimensional hierarchical convolutional neural network based on attention mechanism was constructed to classify and identify seven types of tissue samples. The attention mechanism Efficient Channel Attention Networks module and Squeeze-and-Excitation Networks module were combined with the established one-dimensional convolutional hierarchical network model, and the results showed that the combined model had better diagnostic performance. The average accuracy, F1, and AUC of the Principal Component Analysis-Squeeze and Excitation-hierarchical network model after 5-fold cross validations could reach 96.49%±2.12%, 0.97±0.03, and 0.98±0.02, respectively, which were 1.58%, 0.0140, and 0.008 higher than those of hierarchical network. The recall rate of the Principal Component Analysis-Efficient Channel Attention-hierarchical network model was as high as 96.78%±2.85%, which is 1.47% higher than hierarchical network. Compared with the classification results of traditional CNN and ResNet for seven types of cervical cancer staging, the accuracy of the Principal Component Analysis-Squeeze and Excitation-hierarchical network model is 3.33% and 11.05% higher, respectively. The experimental results indicate that the model established in this study is easy to operate and has high accuracy. It has good reference value for rapid screening of cervical cancer, laying a foundation for further research on Raman spectroscopy as a clinical diagnostic method for cervical cancer.

Myosin Va: Capturing cAMP for synaptic plasticity.

The plus-end directed actin-dependent motor protein, myosin Va, is of particular relevance for outward vesicular protein trafficking and for restraining specific cargo vesicles within the actin cortex. The latter is a preferred site of cAMP production, and the specificity of cAMP signaling is largely mediated through the formation of microdomains that spatially couple localized metabotropic receptor activity and cAMP production to selected effectors and downstream targets. This review summarizes the core literature on the role of myosin Va for the creation of such a cAMP microdomain at the mammalian nerve-muscle synapse that serves the activity-dependent recycling of nicotinic acetylcholine receptors (nAChRs)-a principal ligand-gated ion channel which is imperative for voluntary muscle contraction. It is discussed that i) the nerve-muscle synapse is a site with a unique actin-dependent microstructure, ii) myosin Va and protein kinase A regulatory subunit Iα as well as nAChR and its constitutive binding partner, rapsyn, colocalize in endocytic/recycling vesicles near the postsynaptic membrane, and iii) impairment of myosin Va or displacement of protein kinase A regulatory subunit Iα leads to the loss of nAChR stability. Regulation of this signaling process and underlying basic pieces of machinery were covered in previous articles, to which the present review refers.

A novel channel setup for capturing tire wear particles: Principle, numerical investigation, and experimental verification

Tire wear particles (TWPs) are an important source of microplastic pollutants, but no feasible technologies have been developed to limit emissions. In this study, a novel and practical approach was proposed to capture tire wear particles. A principal channel and an auxiliary channel were set up and investigated by an aerodynamic vehicle model with patterned tires. The results showed that the TWP concentration is the dominant factor of the capture entrance setup for obtaining a high capture ratio. With the use of this approach, the highest capture ratio reached 48.5%. The principal channel could capture approximately 2–3 times more TWPs than the auxiliary channel. The TWP capture ratio of the front channel was higher than that of the rear channel due to the wheel cover structure and higher wind pressure. The obtained findings could help develop and enrich the capturing methodology for fresh TWPs to reduce the induced pollution.

Caracterización química y faunística de canales de drenaje del valle inferior del Río Colorado (Partido de Villarino y Patagones, provincia de Buenos Aires)

This is a contribution to the study o f the salty soil degradation, produced by outcrop of underground salt water, in the Lower Colorado River Valley. The process is made worse by the excesive growth of submerged aquatic weeds in the drainage System. The macroscopic aspect of the problem is shown in a nonquatizated flow diagram.&#x0D; On the basis of fortnightly water analysis, main chemical features of four principal channels are reported. For each month and channel Schoeller’s graphs are added and ionic variation through the year is pointed out.&#x0D; The meiofauna related to aquatic weeds was identified and some observations on alimentary habits were made. Bafon-benthos complex is a low diversity community with unispecific dominance of the gastropod Littorina parchappii (Hydrobiidae). Trophic relationships of this fauna are graphically displayed.&#x0D; The lack of an effective predation on weeds may be a factor of their exuberant development and the introduction of the macrophytophagous snail Ampollaría canaliculata Lamarck, 1801, as a potential biocontrol agent, is proposed.

A comprehensive numerical investigation of a branch-inspired channel in roll-bond type PVT system using design of experiments approach

In this research, a branch-inspired design of RB in a PVT system is vastly numerically investigated. The cooling channels of RB are based on hexagonal grids inspired by the branch structures. The design variables that have been taken into consideration are the three principal channel geometric parameters of the RB structure. Using the design of experiments, 15 different RB configurations are modeled, and consequently, the thermal and electrical performance analyses are implemented using ANSYS Fluent software; Notably, the numerical simulation is validated by performing an experimental investigation. Furthermore, the influence of these geometric parameters on the average PV surface temperature, the temperature difference between hot and cold regions of the PV surface as well as PVT efficiency are obtained. Interestingly, an ingenious method to determine the average PV surface temperature was introduced to obtain the PV electrical efficiency. In addition, the optimization of the PVT system was conducted with 40 scenarios, exploring the thermal and electrical efficiency, as well as the PV temperature uniformity index. According to the obtained results, the best scenario system can increase PV electrical efficiency by 20.4 %. The optimal system's electrical, thermal, and overall PVT efficiency are 17.75 %, 61.86 %, and 79.56 % respectively at 1000 W/m2 irradiation.

Impact of Servant Leadership and Narcissism on Firm Performance: A Comparative Analysis of U.S. and Chinese International Strategic Distribution Channel Alliances

ABSTRACT An integrative conceptual model developed tested the relative influence of servant leadership and narcissism in relation to strategic variables including adaptation and cooperation on competitive advantage and firm performance. Data were collected using structured on-site interviews conducted with 140 and 95 key respondents of randomly selected manufactuarer-export houses located in U.S. and China, respectively. Empirical results revealed that both strategic variables and leadership variables were positively related to competitive advantage, which, in turn, influenced firm performance. The influence of societal culture was evident in our results in that relationships among antecedents of firm performance were denser for U.S. than they were for Chinese firms. Based on these findings, insights for administrative guidance and implications for influencing and managing a firms ISA between manufacturers and their principal international distribution channel alliance partners were discussed. Research drawbacks are identified and directions for future studies are proffered.

Radon transport carried by geogas: prediction model.

This paper provides an overview and information on radon migration in the crust. In the past several decades, numerous studies on radon migration have been published. However, there is no there is no comprehensive review of large-scale radon transport in the earth crust. A literature review was conducted to present the research on the mechanism of radon migration, geogas theory, investigation of multiphase flow, and modeling method of fractures. Molecular diffusion was long considered the primary mechanism for radon migration in the crust. However, a molecular diffusion mechanism cannot explain the understanding of anomalous radon concentrations. In contrast with early views, the process of radon migration and redistribution within the Earth may be determined by geogas (mainly CO2 and CH4). Microbubbles rising in fractured rocks may be a rapid and efficient way of radon migration, as reported by recent studies. All these hypotheses on the mechanisms of geogas migration are summarized into a theoretical framework, defined as "geogas theory." According to geogas theory, fractures are the principal channel of gas migration. The development of the discrete fracture network (DFN) method is expected to supply a new tool for fracture modeling. It is hoped that this paper will contribute to a deeper understanding of radon migration and fracture modeling.

Pharmacological Evidence Suggests That Slo3 Channel Is the Principal K+ Channel in Boar Spermatozoa.

Sperm ion channels are associated with the quality and type of flagellar movement, and their differential regulation is crucial for sperm function during specific phases. The principal potassium ion channel is responsible for the majority of K+ ion flux, resulting in membrane hyperpolarization, and is essential for sperm capacitation-related signaling pathways. The molecular identity of the principal K+ channel varies greatly between different species, and there is a lack of information about boar K+ channels. We aimed to determine the channel identity of boar sperm contributing to the primary K+ current using pharmacological dissection. A series of Slo1 and Slo3 channel modulators were used for treatment. Sperm motility and related kinematic parameters were monitored using a computer-assisted sperm analysis system under non-capacitated conditions. Time-lapse flow cytometry with fluorochromes was used to measure changes in different intracellular ionic concentrations, and conventional flow cytometry was used to determine the acrosome reaction. Membrane depolarization, reduction in acrosome reaction, and motility parameters were observed upon the inhibition of the Slo3 channel, suggesting that the Slo3 gene encodes the main K+ channel in boar spermatozoa. The Slo3 channel was localized on the sperm flagellum, and the inhibition of Slo3 did not reduce sperm viability. These results may aid potential animal-model-based extrapolations and help to ameliorate motility and related parameters, leading to improved assisted reproductive methods in industrial livestock production.

Theoretical Study on Mechanism for the Reaction of 2-propargyl radical (C3H3) with ammonia (NH3)

A theoretical study of the mechanism and kinetics of the reaction of 2-propargyl radical, H2CCCH, with ammonia, NH3, has been carried out by ab initio molecular orbital theory based on CCSD(T)/6-311++G(3df,2p)//B3LYP/6-311++(3df,2p) method. The potential energy surface (PES) for the C3H3 + NH3 reaction was established, showing that the reaction has four principal entrance channels. Two H-abstraction reactions from NH3, leading to propyne or allene + NH2. The addition reactions start by formation of two intermediates H2CCCHNH3 and H2CC(NH3)CH. From these two intermediate states, many other transition states and intermediate states can be accessed, leading to 21 possible products. The reaction has sizable entrance energy barriers, though the H-abstraction entrance channels might contribute significantly at high temperatures, where formation of HCCCH3 + NH2 is more energetically favorable.

Coherent-Phonon-Driven Hot-Carrier Effect in a Superlattice Solar Cell

Carrier thermalization in a superlattice solar cell made of polar semiconductors is studied theoretically by considering a minimal model where electron-phonon scattering is the principal channel of carrier energy loss. Importantly, the effect of an intrinsic quantum mechanical property; the phonon coherence, on carrier thermalization is investigated, within semiclassical picture in terms of phonon wave packet. It turns out that coherent longitudinal optical (LO) phonons weaken the effective electron-phonon coupling, thus supposedly lowering the carrier energy loss rate in solar cell. The resulting thermalization power is indeed significantly reduced by the coherent phonons, resulting in enhanced hot carrier effect, particularly for thin enough well layer where carrier confinement is also strong. A recent experiment on superlattice solar cell prototype is shown to manifest the coherent phonons-driven phenomenon. Our results demonstrate the practical implications of the fundamental quantum coherence property of phonons in semiconductors for improving superlattice solar cell performance, via hot carrier effect.

Aldosterone: Renal Action and Physiological Effects.

Aldosterone exerts profound effects on renal and cardiovascular physiology. In the kidney, aldosterone acts to preserve electrolyte and acid-base balance in response to changes in dietary sodium (Na+ ) or potassium (K+ ) intake. These physiological actions, principally through activation of mineralocorticoid receptors (MRs), have important effects particularly in patients with renal and cardiovascular disease as demonstrated by multiple clinical trials. Multiple factors, be they genetic, humoral, dietary, or otherwise, can play a role in influencing the rate of aldosterone synthesis and secretion from the adrenal cortex. Normally, aldosterone secretion and action respond to dietary Na+ intake. In the kidney, the distal nephron and collecting duct are the main targets of aldosterone and MR action, which stimulates Na+ absorption in part via the epithelial Na+ channel (ENaC), the principal channel responsible for the fine-tuning of Na+ balance. Our understanding of the regulatory factors that allow aldosterone, via multiple signaling pathways, to function properly clearly implicates this hormone as central to many pathophysiological effects that become dysfunctional in disease states. Numerous pathologies that affect blood pressure (BP), electrolyte balance, and overall cardiovascular health are due to abnormal secretion of aldosterone, mutations in MR, ENaC, or effectors and modulators of their action. Study of the mechanisms of these pathologies has allowed researchers and clinicians to create novel dietary and pharmacological targets to improve human health. This article covers the regulation of aldosterone synthesis and secretion, receptors, effector molecules, and signaling pathways that modulate its action in the kidney. We also consider the role of aldosterone in disease and the benefit of mineralocorticoid antagonists. © 2023 American Physiological Society. Compr Physiol 13:4409-4491, 2023.

Child Abusing News: Episodic and Thematic Media Framing Adapting the Children Act and UNICEF’s Principles in Bangladesh

Media is the principal channel of communication that structures people’s consciousness. Such influence of media is often constructed through particular framing which reaches powerful organizations and encourages them to work on different social issues like child abuse. The present study is designed to assess the trend of episodic and thematic media framing on child-abusing news and its relation with the adaptation of The Children Act along with UNICEF’s reporting principles. With media framing theory this paper executed a quantitative study through content analysis. A total of 1091 news articles were studied from two broadsheets and one tabloid newspaper within a timeline of one year. Results revealed that episodic news has a higher tendency of violating reporting principles than thematic. Incidents of sexual abuse received most of the coverage in Bangladeshi newspapers where girls were found most likely to be the victims of misrepresentation. Finally, the tabloid newspaper was found guiltier of unethical reporting than the broadsheets which established a significant connection between the tendency of principles violation and newspaper type. The paper recommended policymakers, child welfare institutes, and mass media promote children’s rights to decrease the rate of abuse cases in Bangladesh. Keywords: child abuse, media framing, children act, UNICEF, Bangladesh

Application of Deep Learning Technique for the Detection of Coronary Heart Disease (CHD)

A blockage or cessation of blood flow to our heart muscle is a sign of Coronary Heart Disease (CHD), which is caused by an accumulation of fatty substances in the coronary arteries known as atheroma. The principal blood channels that deliver blood to the heart are known as coronary arteries. In this paper, the possible application of deep learning technique is explored for the detection of Coronary Heart Disease. In this study, the methodology includes infrastructure creation for the detection of CHD using supervised and unsupervised learning. The result shows the proceeding to manage the data set and process the data there, user input is appropriately gathered. The embedded system that conducts data translation is linked to the controller sensor, which regulates the CHD pulse system. The study concludes that the diagnostic accuracy of the deep learning model using Decision Tree (DT) and Naive Bayes (NB) Classification is effective and error-free. DT and NB Classification is an effective way of detecting CHD by the deep learning model. The future potential of this paper is the development of models for heart disease diagnoses in patients around the world.