bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural, dielectric and electrical characteristics of manganese modified (Bi0.5Ba0.25Sr0.25) (Ti0.5Fe0.5)O3 relaxor
Authors: Auromun Krishna , Choudhary R N P 
Published: January 2021

Abstract
In this communication, detailed studies of the structural, microstructural, dielectric, and electrical properties of polycrystalline materials, (Bi0.5Ba0.25Sr0.25) (Ti0.5Fe0.5)O3 and (Bi0.5Ba0.25Sr0.25) (Ti0.25Mn0.25Fe0.5)O3, synthesized by using a high–temperature solid-state-reaction method, have been reported. X-ray structural and scanning electron micrograph studies exhibit phase pure tetragonal system and surface morphology (size and distribution of grains and grain boundaries) of the samples respectively. Analysis of the temperature and frequency dependence of dielectric and electrical (impedance, modulus, and conductivity) data reveals the ferroelectric relaxor behavior, relaxation mechanism, and semiconductor (negative temperature coefficient of resistance) properties of the bulk BFBST and Mn modified BFBST electro-ceramics. The relaxation time and activation energy (Ea) were calculated from the above data. The characteristics of Mn modified BFBST have been compared to that of it’s parent (BFBST) compound. The different inherent conduction mechanisms, such as Ohmic, hopping, space charge limited (SCLC) have been analyzed. The bulk- and interface-limited conduction processes were evidently found in the materials by the Poole–Frenkel (PF) and Schottky (SEmen modified BFBST have been compared to that of its parent (BFBST) compound) emission fitting of the J ∼ E characteristic data. The leakage data of BFBST-Mn (Mn modified Mn) quantified the average energy gap (Eg) in the range of 0.83–0. 87 eV for different applied voltages and in a wide range of temperature (25 °C–300 °C). With the increase in voltage, Eg decreases. This work suggests that Mn-substitution (Mn4+) at B (Ti4+) site keeping the stoichiometry undisturbed enhances structural, dielectric response (higher dielectric constant) and reduce the leakage behavior especially at low temperature and high-frequency range.
Atomic and electronic structure of two-dimensional Mo(1−

x
)W
x
S2 alloys
Authors: Xia Xue , Loh Siow Mean , Viner Jacob , Teutsch Natalie C , Graham Abigail J , Kandyba Viktor , Barinov Alexei , Sanchez Ana M , Smith David C , Hine Nicholas D M , Wilson Neil R 
Published: January 2021

Abstract
Alloying enables engineering of the electronic structure of semiconductors for optoelectronic applications. Due to their similar lattice parameters, the two-dimensional semiconducting transition metal dichalcogenides of the MoWSeS group (MX2 where M = Mo or W and X = S or Se) can be grown as high-quality materials with low defect concentrations. Here we investigate the atomic and electronic structure of Mo(1−x)W
x
S2 alloys using a combination of high-resolution experimental techniques and simulations. Analysis of the Mo and W atomic positions in these alloys, grown by chemical vapour transport, shows that they are randomly distributed, consistent with Monte Carlo simulations that use interaction energies determined from first-principles calculations. Electronic structure parameters are directly determined from angle resolved photoemission spectroscopy measurements. These show that the spin–orbit splitting at the valence band edge increases linearly with W content from MoS2 to WS2, in agreement with linear-scaling density functional theory predictions. The spin–orbit splitting at the conduction band edge is predicted to reduce to zero at intermediate compositions. Despite this, polarisation-resolved photoluminescence spectra on monolayer Mo0.5W0.5S2 show significant circular dichroism, indicating that spin-valley locking is retained. These results demonstrate that alloying is an important tool for controlling the electronic structure of MX2 for spintronic and valleytronic applications.
Evidence of Reduced Efferent Renal Sympathetic Innervation After Chemical Renal Denervation in Humans
Authors: Hearon Christopher M , Howden Erin J , Fu Qi , Yoo Jeung-Ki , Dias Katrin A , Roberts-Reeves Monique A , Samels Mitchel , Sarma Satyam , Nesbitt Shawna , Vongpatanasin Wanpen , Goldstein David S , Addo Tayo , Levine Benjamin D 
Published: January 2021

Abstract

BACKGROUND
Renal denervation (RDN) is effective at lowering blood pressure. However, it is unknown if ablative procedures elicit sympathetic denervation of the kidneys in humans. The aim of this investigation was to assess sympathetic innervation of the renal cortex following perivascular chemical RDN, which may be particularly effective at ablating perivascular efferent and afferent nerves.

METHODS
Seven hypertensive patients (4F:3M; 50–65 years) completed PET–CT sympathetic neuroimaging of the renal cortex using 11C-methylreboxetine (11C-MRB, norepinephrine transporter ligand) and 6-[18F]-fluorodopamine (18F-FDA; substrate for the cell membrane norepinephrine transporter) before and 8 weeks after chemical RDN (Peregrine System Infusion Catheter, Ablative Solutions; n = 4; 2F:2M) or control renal angiography (n = 3; 2F:1M). Patients completed physiological phenotyping including 24-hour ambulatory blood pressure, hemodynamics, muscle sympathetic nerve activity, and 24-hour urine collection.

RESULTS
RDN decreased 11C-MRB-derived radioactivity by ~30% (Δ  11C-MRB/chamber: −0.95 a.u. confidence interval (CI): −1.36 to −0.54, P = 0.0002), indicative of efferent RDN. In contrast, 18F-FDA-derived radioactivity increased (Δ  18F-FDA/chamber: 2.72 a.u. CI: 0.73–4.71, P = 0.009), consistent with reduced vesicular turnover. Controls showed no change in either marker. Ambulatory systolic pressure decreased in 3 of 4 patients (−9 mm Hg CI: −27 to 9, P = 0.058), and central systolic pressure decreased in all patients (−23 mm Hg CI: −51 to 5, P = 0.095).

CONCLUSIONS
These results are the first to show efferent sympathetic denervation of the renal cortex following RDN in humans. Further studies of mechanisms underlying variable blood pressure lowering in the setting of documented RDN may provide insights into inconsistencies in clinical trial outcomes.

CLINICAL TRIALS REGISTRATION
Trial Number NCT03465917.
Male fetal sex affects uteroplacental angiogenesis in growth restriction mouse model†
Authors: Hebert Jessica F , Millar Jess A , Raghavan Rahul , Romney Amie , Podrabsky Jason E , Rennie Monique Y , Felker Allison M , O’Tierney-Ginn Perrie , Morita Mayu , DuPriest Elizabeth A , Morgan Terry K 
Published: January 2021

Abstract
Abnormally increased angiotensin II activity related to maternal angiotensinogen (AGT) genetic variants, or aberrant receptor activation, is associated with small-for-gestational-age babies and abnormal uterine spiral artery remodeling in humans. Our group studies a murine AGT gene titration transgenic (TG; 3-copies of the AGT gene) model, which has a 20% increase in AGT expression mimicking a common human AGT genetic variant (A[−6]G) associated with intrauterine growth restriction (IUGR) and spiral artery pathology. We hypothesized that aberrant maternal AGT expression impacts pregnancy-induced uterine spiral artery angiogenesis in this mouse model leading to IUGR. We controlled for fetal sex and fetal genotype (e.g., only 2-copy wild-type [WT] progeny from WT and TG dams were included). Uteroplacental samples from WT and TG dams from early (days 6.5 and 8.5), mid (d12.5), and late (d16.5) gestation were studied to assess uterine natural killer (uNK) cell phenotypes, decidual metrial triangle angiogenic factors, placental growth and capillary density, placental transcriptomics, and placental nutrient transport. Spiral artery architecture was evaluated at day 16.5 by contrast-perfused three-dimensional microcomputed tomography (3D microCT). Our results suggest that uteroplacental angiogenesis is significantly reduced in TG dams at day 16.5. Males from TG dams are associated with significantly reduced uteroplacental angiogenesis from early to late gestation compared with their female littermates and WT controls. Angiogenesis was not different between fetal sexes from WT dams. We conclude that male fetal sex compounds the pathologic impact of maternal genotype in this mouse model of growth restriction.
The Spatial Politics of Nation-Building: Minority Women Writers in Anglophone Malaysian and Singapore Literatures
Authors: Poon Angelia 
Published: January 2021

AbstractThis article considers the spatial politics of nation-building in two novels by ethnic minority women writers from Malaysia and Singapore. Preeta Samarasan’s Evening Is the Whole Day depicts the claustrophobic Rajasekharan household, showing how the perversion of the patriarchal heteronormative family is linked to the restrictive ethno-nationalism of a new Malaysian nation and its betrayal of its ethnic minority subjects. In Balli Kaur Jaswal’s Inheritance, ethnic minority subjects have a place in the fast-developing new nation of Singapore because of its official multiracialism but only if they are quiescent, conform to sexual norms, and are not hampered by disability. Both writers question the historical building of national norms, arguing for a remapping of the nation’s spaces in the name of more equitable and inclusive futures.
Dental anomalies frequency in submucous cleft palate versus complete cleft palate
Authors: Schwartz João Paulo , Garib Daniela Gamba 
Published: January 2021

Summary

Background/Objectives
This retrospective study evaluated the prevalence of dental anomalies of number in different subphenotypes of isolated cleft palate.

Materials/Methods
The sample comprised 26 individuals with submucous cleft palate (group S) and 68 individuals with complete cleft palate (group C) aged between 9 and 12 years from a single centre. Panoramic radiographs were evaluated regarding the presence of dental anomalies of number in permanent teeth. Intergroup comparison was performed using chi-square tests (P &lt; 0.05).

Results
Tooth agenesis was found in 34.61 and 36.76 per cent of group S and group C, respectively. The most commonly missing teeth were the maxillary second premolar, maxillary lateral incisor, and mandibular second premolar. Supernumerary teeth were found in none and 1.47 per cent of the individuals with submucous and complete cleft palate, respectively. No statistically significant difference was found between groups for the frequency of tooth agenesis and supernumerary teeth.

Limitations
Only dental anomalies of number were evaluated.

Conclusions/Implications
Individuals with submucous and complete cleft palate showed similar prevalence for tooth agenesis and supernumerary teeth. Dental anomalies frequency seems not to be a discriminator for subphenotypes of cleft palate.
RAD18 mediates DNA double-strand break-induced ubiquitination of chromatin protein
Authors: Mustofa Md Kawsar , Tanoue Yuki , Chirifu Mami , Shimasaki Tatsuya , Tateishi Chie , Nakamura Teruya , Tateishi Satoshi 
Published: January 2021

Abstract
The E3 ubiquitin ligase RAD18 mono-ubiquitinates PCNA to promote bypass of replication fork-stalling DNA lesions. On the other hand, RAD18 also contributes to DNA double-strand break (DSB) repair. RAD18 is recruited to ionizing radiation (IR)-induced DSB and colocalizes with ubiquitinated chromatin proteins. RAD18 interacts with the ubiquitinated chromatin proteins via its ubiquitin-binding Zinc finger (UBZ) domain and is proposed to propagate DNA DSB signalling and recruit DNA repair proteins. We found that purified human RAD18 protein complexed with RAD6B (RAD6B–RAD18) catalyzes mono- and poly-ubiquitination of histone H2A in vitro while UBZ domain-mutated RAD18 complexed with RAD6B protein catalyzes mono- but not poly-ubiquitination of histone H2A. Human RAD18−/−cells synchronized at the G1 phase show a reduced signal of ubiquitinated protein in chromatin after IR when compared to that of wild-type control cells. The reduced signal of ubiquitinated protein in RAD18−/−cells is rescued by the introduction of RAD18 cDNA but to a lesser extent by the introduction of cDNA coding RAD18 lacking UBZ domain. Taken together, these results indicate that RAD18 mediates DSB-induced ubiquitination of chromatin protein during the G1 phase.
Need for Confirmatory Neutralization Tests for Hepatitis B Surface Antigen Tests in Populations with Intermediate Prevalence
Authors: Lee Min Young , Kang So Young , Lee Woo In , Kim Myeong Hee 
Published: January 2021

Abstract

Objective
Hepatitis B surface antigen (HBsAg) is known as the hallmark of hepatitis B virus (HBV) infection. This study aimed to determine whether an HBsAg neutralization test is necessary to accurately interpret HBsAg test results.

Methods
Initially reactive HBsAg specimens from a 5-year period, with cutoff index values between 1.0 and 2.0, were subjected to neutralization confirmatory testing using an Elecsys HBsAg Confirmatory test kit (Roche Diagnostics GmbH. Mannheim, Germany).

Results
The neutralization test showed 46.1% positive (confirmed positive group) and 53.9% negative (confirmed negative group) results from the total specimens. Among the confirmed negative group, 79.5% of patients were confirmed to be negative for the current infection, whereas 4 patients in the chronic hepatitis B subgroup showed a neutralization percentage close to 40%. More than half of patients in the confirmed positive group were considered to be in the hepatitis B e antigen-negative inactive HBsAg carrier phase.

Conclusion
In populations with intermediate HBV prevalence, a neutralization test is necessary to confirm an HBsAg result and reduce the false positive and false negative rates of initial HBsAg tests.
Are extreme asymptotic giant branch stars post-common envelope binaries?
Authors: Dell’Agli F , Marini E , D’Antona F , Ventura P , Groenewegen M A T , Mattsson L , Kamath D , García-Hernández D A , Tailo M 
Published: January 2021

ABSTRACT
Modelling dust formation in single stars evolving through the carbon-star stage of the asymptotic giant branch (AGB) reproduces well the mid-infrared colours and magnitudes of most of the C-rich sources in the Large Magellanic Cloud (LMC), apart from a small subset of extremely red objects (EROs). An analysis of the spectral energy distributions of EROs suggests the presence of large quantities of dust, which demand gas densities in the outflow significantly higher than expected from theoretical modelling. We propose that binary interaction mechanisms that involve common envelope (CE) evolution could be a possible explanation for these peculiar stars; the CE phase is favoured by the rapid growth of the stellar radius occurring after C/O overcomes unity. Our modelling of the dust provides results consistent with the observations for mass-loss rates $\dot{M} \sim 5\times 10^{-4}\,{\rm M}_{\odot }$ yr−1, a lower limit to the rapid loss of the envelope experienced in the CE phase. We propose that EROs could possibly hide binaries with orbital periods of about days and are likely to be responsible for a large fraction of the dust production rate in galaxies.
Vibrational and stochastic resonances in driven nonlinear systems
Authors: Vincent U. E. , McClintock P. V. E. , Khovanov I. A. , Rajasekar S. 
Published: January 2021

Nonlinear systems are abundant in nature. Their dynamics have been investigated very extensively, motivated partly by their multidisciplinary applicability, ranging from all branches of physical and mathematical sciences through engineering to the life sciences and medicine. When driven by external forces, nonlinear systems can exhibit a plethora of interesting and important properties—one of the most prominent being that of resonance. In the presence of a second, higher frequency, driving force, whether stochastic or deterministic/periodic, a resonance phenomenon arises that can generally be termed stochastic resonance or vibrational resonance. Operating a system in or out of resonance promises applications in several advanced technologies, such as the creation of novel materials at the nano, micro and macroscales including, but not limited to, materials having photonic band gaps, quantum control of atoms and molecules as well as miniature condensed matter systems. Motivated in part by these potential applications, this 2-part Theme Issue provides a concrete up-to-date overview of vibrational and stochastic resonances in driven nonlinear systems. It assembles state-of-the-art, original contributions on such induced resonances—addressing their analysis, occurrence and applications from either the theoretical, numerical or experimental perspectives, or through combinations of these.
This article is part of the theme issue ‘Vibrational and stochastic resonance in driven nonlinear systems (part 1)’.
On representing noise by deterministic excitations for interpreting the stochastic resonance phenomenon
Authors: Sorokin V. , Demidov I. 
Published: January 2021

Adding noise to a system can ‘improve’ its dynamic behaviour, for example, it can increase its response or signal-to-noise ratio. The corresponding phenomenon, called stochastic resonance, has found numerous applications in physics, neuroscience, biology, medicine and mechanics. Replacing stochastic excitations with high-frequency ones was shown to be a viable approach to analysing several linear and nonlinear dynamic systems. For these systems, the influence of the stochastic and high-frequency excitations appears to be qualitatively similar. The present paper concerns the discussion of the applicability of this ‘deterministic’ approach to stochastic systems. First, the conventional nonlinear bi-stable system is briefly revisited. Then dynamical systems with multiplicative noise are considered and the validity of replacing stochastic excitations with deterministic ones for such systems is discussed. Finally, we study oscillatory systems with nonlinear damping and analyse the effects of stochastic and deterministic excitations on such systems.
This article is part of the theme issue ‘Vibrational and stochastic resonance in driven nonlinear systems (part 1)’.
Spatiotemporal dynamics of maximal and minimal EEG spectral power
Authors: Menceloglu Melisa , Grabowecky Marcia , Suzuki Satoru 
Published: January 2021

AbstractOscillatory neural activities are prevalent in the brain with their phase realignment contributing to the coordination of neural communication. Phase realignments may have especially strong (or weak) impact when neural activities are strongly synchronized (or desynchronized) within the interacting populations. We report that the spatiotemporal dynamics of strong regional synchronization measured as maximal EEG spectral power—referred to as activation—and strong regional desynchronization measured as minimal EEG spectral power—referred to as suppression—are characterized by the spatial segregation of small-scale and large-scale networks. Specifically, small-scale spectral-power activations and suppressions involving only 2-7% (1-4 of 60) of EEG scalp sites were prolonged (relative to stochastic dynamics) and consistently co-localized in a frequency specific manner. For example, the small-scale networks for θ, α, β1, and β2 bands (4-30 Hz) consistently included frontal sites when the eyes were closed, whereas the small-scale network for γ band (31-55 Hz) consistently clustered in medial-central-posterior sites whether the eyes were open or closed. Large-scale activations and suppressions involving over 17-30% (10-18 of 60) of EEG sites were also prolonged and generally clustered in regions complementary to where small-scale activations and suppressions clustered. In contrast, intermediate-scale activations and suppressions (involving 7-17% of EEG sites) tended to follow stochastic dynamics and were less consistently localized. These results suggest that strong synchronizations and desynchronizations tend to occur in small-scale and large-scale networks that are spatially segregated and frequency specific. These synchronization networks may broadly segregate the relatively independent and highly cooperative oscillatory processes while phase realignments fine-tune the network configurations based on behavioral demands.
HIV-1 uncoating occurs via a series of rapid biomechanical changes in the core related to individual stages of reverse transcription
Authors: Rankovic Sanela , Deshpande Akshay , Harel Shimon , Aiken Christopher , Rousso Itay 
Published: January 2021

AbstractThe HIV core consists of the viral genome and associated proteins encased by a cone-shaped protein shell termed the capsid. Successful infection requires reverse transcription of the viral genome and disassembly of the capsid shell within a cell in a process known as uncoating. The integrity of the viral capsid is critical for reverse transcription, yet the viral capsid must be breached to release the nascent viral DNA prior to integration. We employed atomic force microscopy to study the stiffness changes in HIV-1 cores during reverse transcription in vitro in reactions containing the capsid-stabilizing host metabolite IP6. Cores exhibited a series of stiffness spikes, with up to three spikes typically occurring between 10-30, 40-80, and 120-160 minutes after initiation of reverse transcription. Addition of the reverse transcriptase (RT) inhibitor efavirenz eliminated the appearance of these spikes and the subsequent disassembly of the capsid, thus establishing that both result from reverse transcription. Using timed addition of efavirenz, and analysis of an RNAseH-defective RT mutant, we established that the first stiffness spike requires minus-strand strong stop DNA synthesis, with subsequent spikes requiring later stages of reverse transcription. Additional rapid AFM imaging experiments revealed repeated morphological changes in cores that were temporally correlated with the observed stiffness spikes. Our study reveals discrete mechanical changes in the viral core that are likely related to specific stages of reverse transcription. Our results suggest that reverse-transcription-induced changes in the capsid progressively remodel the viral core to prime it for temporally accurate uncoating in target cells.
Regulation of bacterial Type III Secretion System export gate opening
Authors: Bryant Owain J. , Fraser Gillian M. 
Published: January 2021

AbstractType III Secretion Systems (T3SS) transport proteins from the bacterial cytosol for assembly into cell surface nanomachines or for direct delivery into target eukaryotic cells. At the core of the flagellar T3SS, the FlhAB-FliPQR export gate regulates protein entry into the export channel whilst maintaining the integrity of the cell membrane. Here, we identify critical residues in the export gate FliR plug that stabilise the closed conformation, preserving the membrane permeability barrier, and we show that the gate opens and closes in response to export substrate availability. Our data indicate that FlhAB-FliPQR gate opening, which is triggered by substrate export signals, is energised by FlhA in a proton motive force-dependent manner. We present evidence that the export substrate and the FliJ stalk of the flagellar ATPase provide mechanistically distinct, non-redundant gate-activating signals that are critical for efficient export.