Polarity Of Medium Research Articles

Induced charges in a Thomas–Fermi metal: insights from molecular simulations

We study the charge induced in a Thomas–Fermi metal by an ion in vacuum, using an atomistic description employed in constant-potential molecular dynamics simulations, and compare the results with the predictions from continuum electrostatics. Specifically, we investigate the effects of the Thomas–Fermi screening length l TF and the position d of the ion with respect to the surface on the induced charge distribution in a graphite electrode. The continuum predictions capture most of the features observed with the atomistic description (except the oscillations due to the atomic sites of the graphite lattice), provided that d and l TF are larger than the inter-atomic distances within the electrode. At large radial distance from the ion, the finite l TF case can be well approximated by the solution for a perfect metal using an effective distance d + l TF . This requires a careful definition of the effective interface between the metal and vacuum for the continuum description. Our atomistic results support in particular an early analytical prediction (Vorotyntsev and Kornyshev, Sov. J. Exp. Theor. Phys. 51, 509 (Mar., 1980)) for a single charge at the interface between a Thomas–Fermi metal and a polarisable medium, which remains to be tested in atomistic simulations with an explicit solvent.

Social Media and Political Polarization: A Panel Study of 36 Countries from 2014 to 2020

Social Media and Political Polarization: A Panel Study of 36 Countries from 2014 to 2020

Optical feedback-induced spatiotemporal patterns with power law spectra in a liquid crystal light valve.

Pattern formation can be induced by coupling electromagnetic fields to a polarizable and lossy medium. Increasing energy injection patterns can exhibit aperiodic behaviors. We investigate the self-organization of unidimensional aperiodic patterns. Based on a liquid crystal light valve (LCLV) with optical feedback, we observed aperiodic one-dimensional patterns with power laws in the temporal and spatial spectrum density of the light intensity, and their pseudo envelope and phase characteristic of spatiotemporal complexity. Theoretically, a local model describes the system close to nascent bistability and spatial instability. Numerical simulations of this model show chaotic spatiotemporal patterns whose temporal and spatial spectra have exponents similar to those observed experimentally.

Biradicals based on PROXYL containing building blocks for efficient dynamic nuclear polarization in biotolerant media

A versatile strategy for synthesizing tailored peptide based biradicals is presented. By labeling the protected amino acid hydroxyproline with PROXYL via the OH functionality and using this building block in solid phase peptide synthesis (SPPS), the obtained peptides become polarization agents for DNP enhanced solid-state NMR in biotolerant media. To analyze the effect of the radical position on the enhancement factor, three different biradicals are synthesized. The PROXYL spin-label is inserted in a collagen inspired artificial peptide sequence by binding through the OH group of the hydroxyproline moieties at specific position in the chain. This labeling strategy is universally applicable for any hydroxyproline position in a peptide sequence since solid-phase peptide synthesis is used to insert the building block. High performance liquid chromatography (HPLC) and mass spectrometry (MS) analyses show the successful introduction of the spin label in the peptide chain and electron paramagnetic resonance (EPR) spectroscopy confirms its activity. Dynamic nuclear polarization (DNP) enhanced solid-state nuclear magnetic resonance (NMR) experiments performed on frozen aqueous glycerol-d8 solutions containing these peptide radicals show significantly higher enhancement factors of up to 45 in 1H→13C cross polarization magic angle spinning (CP MAS) experiments compared to an analogous mono-radical peptide including this building block (ε ≈ 14). Compared to commercial biradicals such as AMUPol for which enhancement factors > 100 have been obtained in the past and which have been optimized in their structure, the obtained enhancement up to 45 for our biradicals presents a significant progress in radical design.

Computational study of charge transfer iso-surface in first three excited states, electron-hole transition effects, chemical nature and bond order analysis investigations of chrysogine

This work presents the theoretical DFT (Density Functional Theory) studies and the biological application of chrysogine, a marine alkaloid. Energy minimisation and additional DFT evaluations were performed for vacuum and solvent media. It has been observed that solvation with polar solvents has resulted in a slight variation in the molecule’s properties. The Multiwfn software was employed to carry out various topological analyses. Among these, the charge transfer studies show that the second and third excited states are the most significant. From the reactivity analysis, the least energy gap (4.9624 eV) is obtained in water, indicating that chrysogine is most reactive in aqueous media. Theoretical UV studies show that the trends in λmax values correspond to n -->π* and n -->σ* electronic transitions within the molecule. An increase in medium polarity has demonstrated in the MEP (Molecular Electrostatic Potential) maps an increase in the potential range from −6.619 × 10−2 a.u. to 6.619 × 10−2 a.u. in the gas phase, to a sharp rise to −8.036 × 10−2 a.u. to 8.036 × 10−2 a.u. in ethanol, −8.098 × 10−2 a.u. to 8.098 × 10−2 a.u. in methanol, −8.130 × 10−2 a.u. to 8.130 × 10−2 a.u. in DMSO, and −8.127 × 10-2 a.u. to 8.127 × 10−2 a.u. in water. The most significant transition contributing to molecular stability from NBO (Natural Bond Orbital) analysis is: (O2-C9) π* → π* (C7-C8) with the energy of 258.13 kcal mol−1. The ADMET profile for the molecule was assimilated with the help of online servers. The molecule was docked against lung cancer target proteins (PDB ID: 1NTK, 3QFB) using software such as AutoDock Tools and PyMOL. The respective illustrations and data were visualised using Discovery Studio Visualizer. Good binding affinities (−5.69 kcal mol−1 for 1NTK and −6.64 kcal mol−1 for 3QFB proteins) and interactions were achieved with the selected targets.

Ionic liquid-functionalized pillar[6]arene: A novel stationary phase of high selectivity towards a wide range of isomers

In this work, a novel pillar[6]arene bonded with octyl-imidazolium ionic liquids (IMP6A-C4) as a stationary phase for gas chromatographic (GC) separations was designed, synthesized, and characterized. The IMP6A-C4 capillary column, prepared by the static coating method, had medium polarity (133) and relatively high column efficiency of 4982 plates/m determined by n-dodecane at 120 ℃. As demonstrated, through the separation of the mixture of 17 aliphatic analytes and the mixture of 20 analytes with different polarities, the IMP6A-C4 column exhibited privileged retention and high resolving capacity for H-bonded and aromatic analytes, suggesting advantages over the P6A-C4 column and common polysiloxane HP-5 and HP-35 columns. Strikingly, it implemented high resolutions with good peak shapes for isomer mixtures of phenols, anilines, and benzaldehydes. These findings demonstrated that the excellent resolving performance of the IMP6A-C4 column can be attributed to the comprehensive interactions of its rigid 3D aromatic cavities and polar imidazolium ionic liquids, including π-π, ion-π, H-bonding, dipole–dipole interactions. On the other hand, the IMP6A-C4 capillary column exhibited good repeatability and reproducibility with the RSD% values in the range of 0.01–0.03% for run-to-run, 0.09–0.32% for day-to-day, and 2.72–5.23% for column-to-column. The satisfactory separation performance reveals the promising prospects of the IMP6A-C4 stationary phase in separation science.

Construction of lignosulphonate-containing polymersomes and prospects for their use for elemental sulfur encapsulation

The renewable nature and natural origin of sulfite lignin (lignosulfonate) allow considering it as a potential raw material for the synthesis of valuable environmentally friendly polymer nanomaterials. To create them, a deep understanding of the relationship between the structure of the lignosulfonate macromolecule and the nature of intramolecular and intermolecular interactions is necessary, which would make it possible to control self-assembly processes and obtain nanostructures of specified sizes and morphology. The work discusses the structure formation processes occurring in the lignosulfonate – water – acetone system during the spontaneous formation of polymer nanostructures and submicrostructures. The electrostatic effects of sulfo groups and counterions under conditions of changing the medium polarity and their contribution to self-associations of lignosulfonates have been established. A state diagram was plotted for the ternary lignosulfonate – water – acetone system under conditions of induced phase separation at T = 298 K and under atmospheric pressure. The size and ζ-potential of these nanostructures and submicrostructures of lignosulfonates were estimated depending on the composition of the medium of their formation. The morphology of the resulting nanostructures and submicrostructures of lignosulfonates has been established. The vesicular nature of the aggregates (polymersomes) was confirmed, their shape being close to ideal spheroids with one hole, ranging in size from 40 to 500 nm. A multi-stage mechanism for the formation of lignosulfonate nanoassociates and submicroassociates is proposed. The encapsulating ability of our polymersomes with respect to elemental sulfur from the instant of its inception until the loss of aggregative and sedimentation stability was assessed. Lignosulfonate polymersomes can be recommended as additives to prevent the occluding effect of sulfur melts during hydrometallurgical processing of sulfide ores.

Does Gender Moderate the Mediating Effects of Public Opinion on Relationships Between Media Polarization and Voter Intention? A Simple Question and a Complex Answer

Purpose: The purpose of this study is to identify whether there is a moderating effect of gender on the mediating effects of public opinion on the relationship between media polarization and voter intention in Sri Lanka. Method: To achieve the research objectives, this study used the quantitative survey method with a self-administered closed-end questionnaire with a 5-point Likert scale. The sample size was 500, and the sample was selected from registered voters in the Western Province of Sri Lanka. Results and Conclusion: In the data analysis, it was found that the government news media and privately owned news media do not have a direct effect on voter intention. However, the government and privately owned news media shaped public opinion toward voter intentions. The data analysis of this study also revealed that public opinion also negatively affects voter intention. This effect is also moderated by gender, as the results showed. However, this study found that gender does not moderate the mediating effect of public opinion on the relationship between media polarization and voter intention. Implication of the research: The findings of this study highlight the importance of controlling the biased political behavior of media owners during elections by minimizing media cross-ownership and encouraging media horizontal ownership. This study further emphasizes that increasing the voter's political literacy can prevent the negative effects of factors such as gender on voter intention. Originality/value: This study provides insight into how media affects voter intention through public opinion according to its ownership interests and agendas. This study also highlights that public opinion is a mediating variable in the electoral context. This study confirms that there is no moderating effect of gender on the mediating effect of public opinion. It adds new knowledge to the public opinion research literature.

Aerosol collection efficiency enhancement in HVAC systems through electrical field-Induced filter media polarization

Electrically enhanced media filters improve filtration efficiency in heating, ventilation, and air conditioning (HVAC) systems. Enhancement is accomplished by placing a uniquely formulated media material which can be polarized between arrays of wire electrodes. We explore the implementation of an electrically enhanced filtration system to both quantify the level of enhancement in filtration efficiency achievable in conditions representative of HVAC systems, and to determine the mechanism of collection enhancement. Measurements were carried out on a system comprised of a MERV 11 base filter, two arrays of upstream electrodes, and one array of downstream electrodes. Collection efficiency measurements reveal a strong dependency on the applied voltage across all examined face velocities. At a particle diameter of 0.3 μm, the collection efficiencies showed marked increases of 51.6%, 47.2%, and 30.7% from the zero-field level to a voltage of 10 kV at flow rates of 850, 1700, and 2550 m3 hr−1, respectively. Notably, this enhancement in collection efficiency is maintained even after particle loading on the filter. Charge state examinations revealed minimal changes in particle charge levels within the filter unit, demonstrating that the enhancement of filter performance is driven by dielectrophoretic motion and to a lesser extent electrophoretic motion.

Energy loss of heavy quarks in the presence of magnetic field

We study the heavy quark energy loss in the presence of a background magnetic field. The analysis considers the high magnetic field generated by spectators from initial hard collisions that were incorporated using the medium-modified Debye mass, determined from quark condensates at finite temperature and magnetic field via recent lattice quantum chromodynamics calculations. We analyse the impact of medium polarization on the heavy quark propagation in a quark–gluon plasma formed in relativistic heavy-ion colliders like relativistic heavy ion collider and large hadron collider. For simplification, we considered the static medium with constant temperature and magnetic field values. Then, we explore the nuclear modification factor (R AA) at different magnitudes of magnetic field strengths at fixed temperatures. The energy loss of heavy quarks significantly increases, leading to R AA suppression at higher magnetic field values.

Development of a Versatile Lipid Core for Nanostructured Lipid Carriers (NLCs) Using Design of Experiments (DoE) and Raman Mapping.

The objective of this study was to develop a versatile lipid core for the 'brick-dust type of drugs' (poorly water-soluble and poorly lipid-soluble drugs). In the first step, excipients of different polarities were classified according to their behavior in aqueous solutions. Subsequently, binary mixtures were prepared with cetyl palmitate (Crodamol™ CP pharma, Campinas, São Paulo, Brazil) as the solid lipid, and its miscibility with other excipients was evaluated using Raman mapping and classical least squares (CLS). Based on the results, the excipients Crodamol™ CP pharma (hydrophobic), Super Refined™ DMI (dimethyl isosorbide; hydrophilic, Mill Hall, PA, USA), and Super Refined™ Lauryl Lactate (lauryl lactate, medium polarity, Mill Hall, PA, USA) were chosen to compose the lipid core. The ideal proportion of these excipients was determined using a mixture design and the standard deviation (STD) of image histograms as the response variables. After statistical evaluation of the DoE results, the final composition was determined, and drugs with different logP (0 to 10) and physicochemical characteristics were evaluated in the optimized mixture. The drugs butamben (Sigma-Aldrich Co., Spruce Street, St. Louis, MO, USA), tacrolimus (NutriFarm, São Paulo, Brazil), atorvastatin calcium, and resveratrol (Botica da Terra, Campinas, Brazil) presented a homogeneous distribution in the optimized lipid core, indicating that this is a promising system to be used in nanostructured lipid carrier (NLC) formulations of such types of drugs.

Navigating Political Polarization in News Production: The Case of Italy

This study looks at political polarization from Italian political journalists’ perspectives and investigates (a) how they conceive political polarization and (b) how they navigate it in their daily work. Empirical data shed light on a number of main factors shaping journalists’ perceptions of political polarization, pinpointing the existence of “media polarization.” The findings also revealed five ideal-typical strategies adopted to deal with a polarized environment: mitigating, aligning, nurturing, creating, and ignoring polarization. The reflections proposed throughout the article suggest new perspectives through which to analyze the topic, fostering a debate beyond the case study.

The Origin of Dual-Emission in PLICT Compounds - an Empirical Approach.

Fluorescence spectroscopy proves to be a powerful and versatile tool in scientific research, demanding ongoing advancements of fluorescence probes to cater to a broad range of applications. The particular interest lies in the development of fluorophores with multiplexing capability, emitting from more than one excited state depending on the polarity and viscosity of the surrounding medium. Here, we present a variety of novel dual planarized intramolecular charge transfer (PLICT) emitters based on cyano-1-aminoindole structures. We have chosen a combination of experimental studies, theoretical calculations and the creation of a unique fluorophore cataloging map. This map serves as a useful tool for empirically determining the origin of both fluorescence bands.

Journalism and social-political conflict in contemporary society

This study delves into the intricate dynamics between journalism and contemporary social-political conflicts. It aims to comprehend the challenges journalists face when reporting on such conflicts, encompassing physical risks in conflict zones, ethical dilemmas arising from portraying sensitive issues, and economic pressures influencing media coverage decisions. Grounded in the theoretical framework of Peace Journalism, the study adopts principles emphasizing accuracy, fairness, and the promotion of dialogue over sensationalism. Utilizing the descriptive research method, the study consults and analyzes relevant literatures, documents, and records to interrogate media ethics and power in multicultural Nigeria. Findings reveal challenges in conflict reporting, including threats to physical safety, ethical quandaries, and economic constraints shaping narratives. Social-political conflicts trigger shifts in the media landscape, influencing news consumption patterns, contributing to media polarization, and fostering the rise of citizen journalism facilitated by social media platforms. Hence, the study offers a set of recommendations to address identified challenges. These encompass safeguarding press freedom, implementing media literacy programs, providing comprehensive journalist training and support, diversifying news sources, establishing ethical reporting guidelines, promoting peace journalism initiatives, fostering international collaboration, launching public awareness campaigns, investing in conflict reporting, and advocating for ongoing research and continuous monitoring.

Diving into the divide: a systematic review of cognitive bias-based polarization on social media

PurposeThe global prevalence of social media and its potential to cause polarization are highly debated and impactful. The previous literature often assumes that the ideological bias of any media outlet remains static and exogenous to the polarization process. By studying polarization as a whole from an ecosystem approach, the authors aim to identify policies and strategies that can help mitigate the adverse effects of polarization and promote healthier online discourse.Design/methodology/approachTo investigate online polarization, the authors perform a systematic review and analysis of approximately 400 research articles to explore the connection between cognitive bias and polarization, examining both causal and correlational evidence. The authors extensively evaluate and integrate existing research related to the correlation between online polarization and crucial factors such as public engagement, selective exposure and political democracy. From doing so, the authors then develop a PolarSphere ecosystem that captures and illustrates the process of online polarization formation.FindingsThe authors' review uncovers a wide range of associations, including ideological cognition, bias, public participation, misinformation and miscommunication, political democracy, echo chambers and selective exposure, heterogeneity and trust. Although the impact of bias on social media polarization depends on specific environments and internal/external conditions, certain variables exhibit strong associations across multiple contexts. The authors use these observations as a basis from which to construct PolarSphere, an ecosystem of bias-based polarization on social media, to theorize the process of polarization formation.Originality/valueBased on the PolarSphere ecosystem, the authors argue that it is crucial for governments and civil societies to maintain vigilance and invest in further research to gain a deep comprehension of how cognitive bias affects online polarization, which could lead to ways to eliminate polarization.

Theoretical investigation of tautomerism of 2- and 4-pyridones: origin, substituent and solvent effects.

Computational investigation at the BHandHLYP/6-311+G(d,p) level of theory of the gas-phase tautomerism of 2- and 4-pyridones confirmed the slight prevalence of lactim in the case of the former, but its dominance in the case of the latter, as shown previously. Examination of aromaticity by using HOMA, EDDB, NBOdel, NICS and AICD led to the conclusion that tautomerization of 4-pyridone results in greater aromaticity gain. It is also driven by the Pauli repulsion relief, which was revealed by the tautomerization energy decomposition analysis. By contrast, in the case of 2-pyridone, lactim is favoured by orbital and electrostatic interactions and disfavoured by the Pauli repulsion. Aromaticity gain in this case is smaller. The position of the tautomeric equilibrium can be modulated by substituent inductive effects (Cl and F), inductive and resonance effects (NH2 and NO2), hydrogen bonding (NO2), and medium polarity, the increase of which increases lactam population.

The uses of the term polarisation in Swedish newspapers, 2010–2021

Abstract In this article, we investigate the rhetorical uses and media frames associated with the term polarisation in Swedish print media from 2010 to 2021. We first produce a qualitative and detailed assessment of a sample of 240 articles and then proceed to a computational (word2vec) analysis of all major Swedish newspaper articles including the term (N = 32,805). We find that the term has changed its rhetorical function over time. Initially used to describe, – that is, used as a technical descriptor of events and issues in society – this use later became increasingly vague and general. Instead, it has been rhetorically used to amplify, implying a sense of urgency, conflict, or threat. Over time, the term has been used increasingly frequently, but has been applied less to Sweden and, instead, most often associated with political actors and events in the US. Moreover, we find that, for Sweden, the term polarisation was mostly related to social and political issues, whereas for the US, it carried affective associations.

WITHDRAWN: Auditing amplification and polarization in TikTok

WITHDRAWN: Auditing amplification and polarization in TikTok

Quantifying the Ground‐State Hydrogen‐Bond Formation of a Super‐Photoacid by Inspecting Its Excited‐State Dynamics.

AbstractThe Front Cover image is provided by Ye‐Jin Choi, Ulsan National Institute of Science and Technology (Republic of Korea). The image shows the excited‐state proton transfer and proposed influence of medium polarity on the hydrogen‐bond formation between a cationic photoacid and a base in the ground state. Read the full text of the Research Article at 10.1002/cptc.202300164.

A naphthalene–phenanthro[9,10-d]imidazole-based π-conjugated molecule with a self-assembly-induced tuneable multiple fluorescence output exhibits artificial light-harvesting properties

Upon varying the medium polarity L1 can be fabricated into various self-assembled superstructures with distinct morphologies and multiple tuneable luminescence colors, which exhibit artificial light-harvesting properties.