bluuebunny/crossref_metadata_2025 huggingface dataset:
Klimakrise: Welche gastroenterologischen Folgeerkrankungen dieses medizinischen Notfalls sollten wir kennen?
Authors: Walldorf Jens , Mezger Nikolaus Christian Simon , Weber Lena , Knothe Anja , Klose Michelle , Moritz Stefan , Kantelhardt Eva Johanna , Feller Stephan , Schlitt Axel , Greinert Robin , Michl Patrick
Published: April 2023

Einleitung Die Klimakrise hat gravierende Folgen für viele Lebensbereiche. Ganz besonders gilt dies für die Gesundheit des Menschen – auch in Europa. Während kardiovaskuläre, pneumologische und dermatologische Erkrankungen mit Bezug auf die Klimakrise häufig diskutiert werden, sind gastroenterologische Erkrankungen als Folge der Krise ebenfalls von erheblicher Bedeutung.

Methoden Anhand einer Literaturrecherche (Pubmed, Cochrane Library) wurden für die Gastroenterologie in (Mittel-)Europa relevante Arbeiten identifiziert. Diese Arbeiten wurden von einem interdisziplinären Team um weitere Arbeiten ergänzt und zusammengefasst.

Ergebnisse Die Klimakrise hat in Europa durch vermehrte Hitzewellen, Hochwasser und Luftverschmutzung Einfluss auf die Häufigkeit und Schwere von Erkrankungen des Gastrointestinaltraktes. Dabei sind Patienten mit Darmerkrankungen besonders vulnerabel für akute Wetterereignisse. Hinsichtlich der Langzeitfolgen des Klimawandels haben gastrointestinale Karzinome und Lebererkrankungen eine herausragende Bedeutung. Neben Gastroenteritiden sind weitere durch die stetige Erwärmung, Hitzewellen und Überschwemmungen begünstigte Infektionskrankheiten wie vektorübertragene Erkrankungen und Parasiten von Bedeutung.

Diskussion Für vulnerable Patientengruppen sind konsequent Anpassungsstrategien zu entwickeln und umzusetzen. Risikopersonen müssen hinsichtlich individuell umsetzbarer Maßnahmen wie Hitzevermeidung, entsprechendem Trinkverhalten und Hygiene beraten werden. Zur Prävention von Lebererkrankungen und Karzinomen sind in erster Linie Empfehlungen zur physischen Aktivität und gesunden nachhaltigen Ernährung sinnvoll. Maßnahmen zur Prävention und Resilienzförderung können von der Ärzteschaft auf verschiedenen Ebenen unterstützt werden. Neben Bemühungen zu Nachhaltigkeit im unmittelbaren eigenen Arbeitsumfeld ist ein übergeordnetes Engagement für Klimaschutz von Bedeutung.
Metabolic Fingerprinting of Different Sideritis Taxa Infusions and Their Neurogenic Activity
Authors: Tomou Ekaterina-Michaela , Bieler Lara , Spöttl Tobias , Couillard-Despres Sebastien , Skaltsa Helen , Urmann Corinna
Published: April 2023

Over the last years, Sideritis extracts were shown to improve memory. However, their potential to promote the generation of new neurons, starting with the neuronal differentiation of
neural stem cells, remains unexplored. Therefore, the present study aimed to evaluate the neurogenic effects of different Sideritis infusions in neural stem and precursor cells and
their impact on cell viability. Moreover, the metabolic fingerprints were recorded using LC-DAD, LC-HRESIMS, and GC-MS. The neurogenic potential of infusions of the eight Sideritis
taxa tested was as potent as the classical neuronal inducer combination of retinoic acid and valproic acid. Further cytotoxicity assays revealed that the IC50 values of the
extracts were between 163 and 322 µg/mL. Hierarchical cluster analyses of the metabolic fingerprints unveiled that the two Sideritis taxa with the lowest IC50 values were
the most divergent in the analytical techniques used. As the analysis focused on polyphenols, it is reasonable to assume that these compounds are responsible for the effect on the cell
viability of SH-SY5Y neuroblastoma cells. This study is the first report on the neurogenic potential of Sideritis taxa and might support the use of Sideritis herbal
preparations in the context of neurodegenerative diseases.
Effect of Locally Administered Estradiol on Wound Healing in a Nasal Septal Perforation Animal Model
Authors: Yılmaz Yetkin Zeki , Çakan Dogan
Published: April 2023

We aimed to investigate the effect of estradiol on wound healing in an experimental nasal septal perforation (NSP) model created in rats. Twenty-two Sprague Dawley healthy male rats were separated into two groups. NSP, approximately 2 mm in diameter, was created in each animal. The 0.1 mL 0.12% estradiol (12 g/L) (study group) and 0.1 mL 0.9% saline (9 g/L) (control group) were applied topically once a day for 14 days. The rats were sacrificed on the 14th day and the cartilage nasal septum of each animal was excised for histopathological examination. The nasal mucosal epithelial regeneration and degeneration, acute inflammatory cell count, fibroblast number, vascularization, granulation tissue formation, giant cell number, eosinophil number, degeneration and regeneration of the nasal cartilage, and collagen density were examined. The macroscopic closure rate of the perforations and histopathological parameters were evaluated statistically. In this study, the epithelial regeneration, the fibroblast count, the granulation tissue formation, and the amount of collagen were significantly higher in the study group than in the saline group (p < 0.05). The acute inflammatory activity was lower in the estradiol group than in the saline group (p < 0.05). There was no statistically significant difference in the closure rate of perforation between the two groups (p = 0.163). No significant difference was found in other comparisons (p > 0.05). The locally administered estradiol may improve wound healing of the nasal septum in an experimental NSP animal model.

Level of Evidence Not applicable.
Synthesis of Clausena Alkaloids Using Unique Ring Expansion of Dihydroisoquinolines and Their Cholinesterase Inhibitory Activity
Authors: Worayuthakarn Rattana , Thasana Nopporn , Ngernnak Chuleeporn , Ruchirawat Somsak , Chainok Kittipong , Wannarit Nanthawat
Published: April 2023

A facile and direct synthetic entry to the carbon skeleton of Clausena alkaloids, the benzo[d]azocin-4-one, is reported featuring the ring expansion of 1-phenyldihydroisoquinoline derivatives initially triggered by oxazolone under environmentally benign conditions in a one-pot procedure. Functionalization of the eight-membered lactam framework provided a set of Clausena alkaloid derivatives. Some derivatives show a promising inhibition toward acetylcholinesterase and a better selectivity index than the previously used Alzheimer’s disease (AD) drug, tacrine, and the currently used AD drug, galantamine.
Evaluation of Clinical, Demographic, and Biochemical Profiles of Trinidadian Patients Undergoing Coronary Angiography
Authors: Nayak Shivananda B , Monplaisir Tamika Kachada , Bhaktha Geetha , Ali Ronan , Mohan Surapaneni Krishna , Priya Vishnu
Published: April 2023

Background

Trinidad and Tobago ranks number 45 in the world for total deaths due to coronary heart disease. Predictive tests for coronary angiographic results set the basis for earlier monitoring of the disease before additional complications become obvious.

Aims and Methods

This study aimed to evaluate the anthropometric and biochemical parameters of 124 patients with suspected coronary artery disease (CAD) in Trinidad and how these parameters correlate to the findings at angiography.

Results

The biochemical parameters showed statistically significant correlations with CAD severity by Spearman's rank-order correlation. Two clinical parameters showed significant associations with CAD severity—ethnicity (χ2 (4) = 12.925, p = 0.012) and presence of type 2 diabetes at baseline (χ2 (4) = 21.483, p < 0.001).

Conclusion

Biochemical parameters such as fasting blood sugar, N-terminal pro B-type natriuretic peptide, creatinine, and hemoglobin A1c were well correlated and well associated with the severity of CAD after diagnosis by the process of coronary angiography. Hence, these factors can be taken into consideration to predict the severity of CAD.
47.1.2.1.5 Synthesis of Alkenes by Cross-Coupling and Heck Reactions
Authors: Ho C.-Y. , Raja D.
Published: April 2023

Since their discovery, Heck and cross-coupling reactions have become essential for catalytic alkene synthesis. Selected homogeneous methods for non-aromatic and unactivated alkene synthesis by catalytic alkenylation are reviewed herein (ca. 2008–2020). By using new combinations of ligands, additives, co-catalysts, and transition metals, significant advances and new mechanistic insights have been revealed recently. New strategies for accessing a broader substrate scope, milder reaction conditions, higher functional-group compatibility, and highly stereoselective synthesis are highlighted.
Creation and evolution of a “hotline” in superfluid helium
Authors: Vovk R. V. , Nemchenko K. E.
Published: April 2023

The paper provides a theoretical consideration of the “hotline” phenomenon, a region with an increased phonon energy density, which occurs when two beams cross in helium. An analysis of the results of observations and a theoretical consideration of the formation of a “hotline” are carried out. The results of calculations are also compared with experimental data on the dependence of the “hotline” parameters on the power of the initial beams, and the angle between the directions of their movement.
Effect of “pseudorotation” on cyclopentane isochoric thermal conductivity
Authors: Revyakin V. P. , Revyakina M. G. , Revyakin G. V.
Published: April 2023

The isochoric heat conductivity in plastic phases I and II solid cyclopentane(C5H10) is investigated. Various temperature dependents of heat conductivity indicate various characteristics of a rotary motion of molecules in these phases. In phase II, the motion of the molecules has mainly character of libration, and in phase I, is close to the hindered rotation. In a phase I of cyclopentane an increase in the slope of isochoric heat conductivity with the growth of the density of samples is revealed. Such behavior of heat conductivity is not characteristic of molecular crystals and can point to a contribution of “pseudorotation” to heat transfer. In phase II, cyclopentane the behavior of heat conductivity is close to a case of strong scattering of phonons.
Electric characteristics of calcium-phosphate ceramics with impurities
Authors: Vovk R. V. , Sokol K. I.
Published: April 2023

The electrical characteristics of calcium phosphate materials have been studied at various frequencies in the temperature interval from room temperature to 1200 °C. It has been shown that the electrical characteristics (relative permittivity, capacitance, and electric resistance) change with the annealing temperature. Temperature changes in these characteristics are associated with the presence of impurities in the studied samples, as well as the nonstoichiometry of the phase composition of the initial samples. The phase composition and structure of the studied samples were studied by X-ray diffraction, Mass-spectrometry, and IR-spectroscopy. It has been shown that the studied calcium-phosphate samples have dielectric properties. The temperature intervals for the stability of the electrical characteristics of these materials have been established.
Special features of low-temperature microwave ferromagnetic resonance in nanometer ferrite layer patterned by macroporous silicon substrate
Authors: Vakula A. S. , Polevoy S. Yu. , Sova K. Yu. , Nedukh S. V. , Girich A. A. , Tarapov S. I.
Published: April 2023

Experimental magnetic resonance spectra for nanometer ferrite brand 1SCh4 layer deposited on macroporous silicon substrate, obtained at T = 300 and 4.2 K in the frequency ranges of 5–15 and 60–75 GHz, respectively, were analyzed. In addition to the ferromagnetic resonance mode, additional peaks were found in the magnetoresonance spectra. An analysis using the known theoretical concepts of the modern spin dynamic theory, together with the results of micromagnetic simulation, showed the formation of spin-wave oscillation modes that arise due to the structurization of the ferrite layer by a substrate of macroporous silicon.
Residual entropy of a two-dimensional Ising model with crossing and four-spin interactions
Authors: Li De-Zhang , Zhao Yu-Jun , Yao Yao , Yang Xiao-Bao
Published: April 2023

We study the residual entropy of a two-dimensional Ising model with crossing and four-spin interactions, both in the case of a zero magnetic field and in an imaginary magnetic field iπ/2kBT. The spin configurations of this Ising model can be mapped into the hydrogen configurations of square ice with the defined standard direction of the hydrogen bonds. Making use of the equivalence of this Ising system with the exactly solved eight-vertex model and taking the low temperature limit, we obtain the residual entropy. Two soluble cases in the zero field and one soluble case in the imaginary field are examined. In the case that the free-fermion condition holds in zero field, we find that the ground states in the low temperature limit include the configurations disobeying the ice rules. In another case in zero field where the four-spin interactions are −∞ and another case in imaginary field where the four-spin interactions are 0, the residual entropy exactly agrees with the result of square ice determined by Lieb in 1967. In the solutions to the latter two cases, we have shown alternative approaches to the residual entropy problem of square ice.
Multi-band oscillations emerge from a simple spiking network
Authors: Wu Tianyi , Cai Yuhang , Zhang Ruilin , Wang Zhongyi , Tao Louis , Xiao Zhuo-Cheng
Published: April 2023

In the brain, coherent neuronal activities often appear simultaneously in multiple frequency bands, e.g., as combinations of alpha (8–12 Hz), beta (12.5–30 Hz), and gamma (30–120 Hz) oscillations, among others. These rhythms are believed to underlie information processing and cognitive functions and have been subjected to intense experimental and theoretical scrutiny. Computational modeling has provided a framework for the emergence of network-level oscillatory behavior from the interaction of spiking neurons. However, due to the strong nonlinear interactions between highly recurrent spiking populations, the interplay between cortical rhythms in multiple frequency bands has rarely been theoretically investigated. Many studies invoke multiple physiological timescales (e.g., various ion channels or multiple types of inhibitory neurons) or oscillatory inputs to produce rhythms in multi-bands. Here, we demonstrate the emergence of multi-band oscillations in a simple network consisting of one excitatory and one inhibitory neuronal population driven by constant input. First, we construct a data-driven, Poincaré section theory for robust numerical observations of single-frequency oscillations bifurcating into multiple bands. Then, we develop model reductions of the stochastic, nonlinear, high-dimensional neuronal network to capture the appearance of multi-band dynamics and the underlying bifurcations theoretically. Furthermore, when viewed within the reduced state space, our analysis reveals conserved geometrical features of the bifurcations on low-dimensional dynamical manifolds. These results suggest a simple geometric mechanism behind the emergence of multi-band oscillations without appealing to oscillatory inputs or multiple synaptic or neuronal timescales. Thus, our work points to unexplored regimes of stochastic competition between excitation and inhibition behind the generation of dynamic, patterned neuronal activities.
Lattice constants and magnetism of L10-ordered FePt under high pressure
Authors: Sawada S. , Okai K. , Fukui H. , Takahashi R. , Ishimatsu N. , Maruyama H. , Kawamura N. , Kawaguchi S. , Hirao N. , Seki T. , Takanashi K. , Ohmura S. , Wadati H.
Published: April 2023

We studied the relationship between the lattice constant and magnetism of L10-ordered FePt under high pressure by means of first-principles calculations and synchrotron x-ray measurements. Based on our calculations, we found that the c/a ratio shows a local maximum at ∼20 GPa and that the Pt magnetic moment first remains almost unchanged and is sharply suppressed at ∼60 GPa. As for the c/a, we experimentally verified the local maximum at ∼20 GPa by powder x-ray diffraction. We also measured the x-ray magnetic circular dichroism at the Pt L edge up to ∼20 GPa. Any significant change in the Pt magnetic moment was not observed in agreement with the calculations. These results, thus, indicate that magnetic states, where the magnetization of Fe decreased and that of Pt did not change, can be created in L10-ordered FePt by lattice deformation under high pressure.
Highly flexible anisotropic magnetoresistance sensor for wearable electronics
Authors: Chen Yanning , Zhao Dongyan , Shao Jin , Fu Zhen , Wang Chenying , Wang Shuaipeng , Du Jian , Zhong Mingchen , Duan Junbao , Li Yang , Hu Zhongqiang
Published: April 2023

The emerging market of wearable devices for tracking and positioning requires the development of highly flexible magnetic sensors. Due to the stable magnetoresistance ratio and simple fabrication process, sensors based on the anisotropic magnetoresistance (AMR) effect have been proposed as promising candidates. However, the stability of AMR sensors under different bending situations has rarely been investigated. In this work, we proposed a flexible AMR magnetic sensor deposited on an ultra-thin Kapton substrate, which exhibits excellent anti-fatigue behavior at different bending curvatures ranging from 1/3 to 1/10 mm−1. Experimental results show that the sensitivity of our proposed flexible AMR sensor remains as high as 0.25 Oe−1 after being bent 500 times, showing promising potential for application in wearable electronic devices.
Enhancing the accuracy of density functional tight binding models through ChIMES many-body interaction potentials
Authors: Goldman Nir , Fried Laurence E. , Lindsey Rebecca K. , Pham C. Huy , Dettori R.
Published: April 2023

Semi-empirical quantum models such as Density Functional Tight Binding (DFTB) are attractive methods for obtaining quantum simulation data at longer time and length scales than possible with standard approaches. However, application of these models can require lengthy effort due to the lack of a systematic approach for their development. In this work, we discuss the use of the Chebyshev Interaction Model for Efficient Simulation (ChIMES) to create rapidly parameterized DFTB models, which exhibit strong transferability due to the inclusion of many-body interactions that might otherwise be inaccurate. We apply our modeling approach to silicon polymorphs and review previous work on titanium hydride. We also review the creation of a general purpose DFTB/ChIMES model for organic molecules and compounds that approaches hybrid functional and coupled cluster accuracy with two orders of magnitude fewer parameters than similar neural network approaches. In all cases, DFTB/ChIMES yields similar accuracy to the underlying quantum method with orders of magnitude improvement in computational cost. Our developments provide a way to create computationally efficient and highly accurate simulations over varying extreme thermodynamic conditions, where physical and chemical properties can be difficult to interrogate directly, and there is historically a significant reliance on theoretical approaches for interpretation and validation of experimental results.
Simultaneous direct measurement of the electrocaloric and dielectric dynamics of ferroelectrics with microsecond temporal resolution
Authors: Fischer J. , Döntgen J. , Molin C. , Gebhardt S. E. , Hambal Y. , Shvartsman V. V. , Lupascu D. C. , Hägele D. , Rudolph J.
Published: April 2023

A contactless technique for direct time-resolved measurements of the full dynamics of the adiabatic temperature change in electrocaloric materials is introduced. The infrared radiation emitted by the electrocaloric sample is sensitively detected with μs time resolution and mK temperature resolution. We present time-resolved measurements of the electrocaloric effect up to kHz frequencies of the driving electric field and down to small field strengths. The simultaneous recording of transients for applied electric field and induced polarization gives a comprehensive view of the correlation of electrocaloric and ferroelectric properties. The technique can further be applied to the continuous measurement of fatigue for >106 electric field cycles.
A theory of chemical reactions in biomolecules in solution: Generalized Langevin mode analysis (GLMA)
Authors: Hirata Fumio
Published: April 2023

The generalized Langevin mode analysis (GLMA) is applied to chemical reactions in biomolecules in solution. The theory sees a chemical reaction in solution as a barrier-crossing process, similar to the Marcus theory. The barrier is defined as the crossing point of two free-energy surfaces that are attributed to the reactant and product of the reaction. It is assumed that both free-energy surfaces are quadratic or harmonic. The assumption is based on the Kim-Hirata theory of structural fluctuation of protein, which proves that the fluctuation around an equilibrium structure is quadratic with respect to the structure or atomic coordinates. The quadratic surface is a composite of many harmonic functions with different modes or frequencies. The height of the activation barrier will be dependent on the mode or frequency—the less the frequency, the lower the barrier. Hence, it is essential to decouple the fluctuational modes into a hierarchical order. GLMA is impeccable for this purpose. It is essential for a theoretical study of chemical reactions to choose a reaction coordinate along which the reaction proceeds. We suppose that the mode whose center of coordinate and/or the frequency changes most before and after the reaction is the one relevant to the chemical reaction and choose the coordinate as the reaction coordinate. The rate of reaction along the reaction coordinate is krate=ν⁡exp−ΔF(†)/kBT, which is similar to the Marcus expression for the electron transfer reaction. In the equation, ΔF(†) is the activation barrier defined by ΔF(†)≡F(r)Q†−F(r)(Qeq(r)), where F(r)(Qeq(r)) and F(r)Q† denote the free energies at equilibrium Qeq(r) and the crossing point Q†, respectively, both on the free energy surface of the reactant.
Bismuth trichloride as a molecular precursor for silicon doping
Authors: Lundgren Eric A. S. , Conybeare Rebecca , Stock Taylor J. Z. , Curson Neil J. , Warschkow Oliver , Schofield Steven R.
Published: April 2023

Dopant impurity species can be incorporated into the silicon (001) surface via the adsorption and dissociation of simple precursor molecules. Examples include phosphine (PH3), arsine (AsH3), and diborane (B2H6) for the incorporation of phosphorus, arsenic, and boron, respectively. Through exploitation of precursor surface chemistry, the spatial locations of these incorporated dopants can be controlled at the atomic scale via the patterning of a hydrogen lithographic resist layer using scanning tunneling microscopy (STM). There is strong interest in the spatial control of bismuth atoms incorporated into silicon for quantum technological applications; however, there is currently no known precursor for the incorporation of bismuth that is compatible with this STM-based lithographic method. Here, we explore the precursor chemistry (adsorption, diffusion, and dissociation) of bismuth trichloride (BiCl3) on Si(001). We show atomic-resolution STM images of BiCl3 exposed Si(001) surfaces at low coverage and combine this with density functional theory calculations to produce a model of the surface processes and the observed features. Our results show that, at room temperature, BiCl3 completely dissociates to produce bismuth ad-atoms, ad-dimers, and surface-bound chlorine, and we explain how BiCl3 is a strong candidate for a bismuth precursor compound compatible with lithographic patterning at the sub-nanometer scale.
Combining electrically detected magnetic resonance techniques to study atomic-scale defects generated by hot-carrier stressing in HfO2/SiO2/Si transistors
Authors: Moxim S. J. , Ashton J. P. , Anders M. A. , Ryan J. T.
Published: April 2023

This work explores the atomic-scale nature of defects within hafnium dioxide/silicon dioxide/silicon (HfO2/SiO2/Si) transistors generated by hot-carrier stressing. The defects are studied via electrically detected magnetic resonance (EDMR) through both spin-dependent charge pumping and spin-dependent tunneling. When combined, these techniques probe defects both at the Si-side interface and within the oxide-based gate stack. The defects at the Si-side interface are found to strongly resemble Pb-like defects common in the Si/SiO2 system. The defect within the gate stack has not been positively identified in the literature thus far; this work argues that it is a Si-dangling bond coupled to one or more hafnium atoms. The use of EDMR techniques indicates that the defects detected here are relevant to electronic transport and, thus, device reliability. This work also highlights the impressive analytical power of combined EDMR techniques when studying complex, modern materials systems.
A fully compensated ferrimagnetic half metal Co1−xCrxS2 with Curie temperature above room temperature
Authors: He Yangkun , Coey J. M. D. , Gercsi Zsolt
Published: April 2023

Fully compensated ferrimagnetic half metals have attracted great attention in spintronics. Unlike many previous calculations based on hypothetical ordered alloys, here we look for existing solid solution series taking as an example Co1−xCrxS2. Calculations find that a low-spin state for Cr that matches early experiments and a fully compensated ferrimagnetic half metal with Curie temperature above room temperature is found at x ≈ 0.33. Our study demonstrates the method of combining two half metals with light and heavy 3d metals in a solid solution to achieve compensation, where atomic disorder does not destroy the desired properties.
Pleiotropic role of TRAF7 in skull-base meningiomas and congenital heart disease
Authors: Mishra-Gorur Ketu , Barak Tanyeri , Kaulen Leon D. , Henegariu Octavian , Jin Sheng Chih , Aguilera Stephanie Marie , Yalbir Ezgi , Goles Gizem , Nishimura Sayoko , Miyagishima Danielle , Djenoune Lydia , Altinok Selin , Rai Devendra K. , Viviano Stephen , Prendergast Andrew , Zerillo Cynthia , Ozcan Kent , Baran Burcin , Sencar Leman , Goc Nukte , Yarman Yanki , Ercan-Sencicek A. Gulhan , Bilguvar Kaya , Lifton Richard P. , Moliterno Jennifer , Louvi Angeliki , Yuan Shiaulou , Deniz Engin , Brueckner Martina , Gunel Murat
Published: April 2023

While somatic variants of 
TRAF7
(Tumor necrosis factor receptor-associated factor 7) underlie anterior skull-base meningiomas, here we report the inherited mutations of 
TRAF7
 that cause congenital heart defects. We show that TRAF7 mutants operate in a dominant manner, inhibiting protein function via heterodimerization with wild-type protein. Further, the shared genetics of the two disparate pathologies can be traced to the common origin of forebrain meninges and cardiac outflow tract from the
TRAF7-
expressing neural crest. Somatic and inherited mutations disrupt TRAF7–IFT57 interactions leading to cilia degradation. 
TRAF7
-mutant meningioma primary cultures lack cilia, and TRAF7 knockdown causes cardiac, craniofacial, and ciliary defects in 
Xenopus
and zebrafish, suggesting a mechanistic convergence for 
TRAF7
-driven meningiomas and developmental heart defects.
SIR telomere silencing depends on nuclear envelope lipids and modulates sensitivity to a lysolipid
Authors: Sosa Ponce Maria Laura , Remedios Mayrene Horta , Moradi-Fard Sarah , Cobb Jennifer A. , Zaremberg Vanina
Published: April 2023

The nuclear envelope (NE) is important in maintaining genome organization. The role of lipids in communication between the NE and telomere regulation was investigated, including how changes in lipid composition impact gene expression and overall nuclear architecture. Yeast was treated with the non-metabolizable lysophosphatidylcholine analog edelfosine, known to accumulate at the perinuclear ER. Edelfosine induced NE deformation and disrupted telomere clustering but not anchoring. Additionally, the association of Sir4 at telomeres decreased. RNA-seq analysis showed altered expression of Sir-dependent genes located at sub-telomeric (0–10 kb) regions, consistent with Sir4 dispersion. Transcriptomic analysis revealed that two lipid metabolic circuits were activated in response to edelfosine, one mediated by the membrane sensing transcription factors, Spt23/Mga2, and the other by a transcriptional repressor, Opi1. Activation of these transcriptional programs resulted in higher levels of unsaturated fatty acids and the formation of nuclear lipid droplets. Interestingly, cells lacking Sir proteins displayed resistance to unsaturated-fatty acids and edelfosine, and this phenotype was connected to Rap1.
Local continuity of angular momentum and noether charge for matter in general relativity
Authors: Croft Robin
Published: April 2023

Conservation laws have many applications in numerical relativity. However, it is not straightforward to define local conservation laws for general dynamic spacetimes due the lack of coordinate translation symmetries. In flat space, the rate of change of energy-momentum within a finite spacelike volume is equivalent to the flux integrated over the surface of this volume; for general spacetimes it is necessary to include a volume integral of a source term arising from spacetime curvature. In this work a study of continuity of matter in general relativity is extended to include angular momentum of matter and Noether currents associated with gauge symmetries. Expressions for the Noether charge and flux of complex scalar fields and complex Proca fields are found using this formalism. Expressions for the angular momentum density, flux and source are also derived which are then applied to a numerical relativity collision of boson stars in 3D with non-zero impact parameter as an illustration of the methods.
Precursors for synthetic aperture radar
Authors: Cartwright Natalie A , Muller Kaitlyn
Published: April 2023

In this paper we study waveform design for synthetic-aperture radar (SAR) imaging through dispersive media. Under the assumptions of scalar wave propagation through a causal dielectric medium and single-scattering from an isotropic point scatterer, we use asymptotic analysis to derive the asymptotic approximation to the scattered electric field. From this asymptotic approximation, we define a sensing precursor that we propose for the transmit waveform for SAR imaging through dispersive material. We compare our sensing precursor with previously defined optimal waveforms (Varslot et al 2011 SIAM J. Appl. Math.
71 1780–800) in terms of both propagation and scattering capabilities, as well as imaging performance. With the filtered back-projection imaging algorithm that we use, we find that for high levels of signal-to-noise ratio (SNR), the optimal waveforms contain higher frequencies and thus produce better images. For low levels of SNR, the transmitted optimal waveforms and the sensing precursors are similar, thus giving comparable images.
Influence mechanisms of epoxy degradation on surface traps and charge accumulation under DC electrical–thermal stress
Authors: Zhang Yi , Qi Bo , Yang Xiao , Yan Jiaxuan , Luo Yuan , Yang Zhuodong , Lu Licheng , Li Chengrong
Published: April 2023

As trapping sites for surface charges, the surface trap is an important factor affecting the insulation performance of the epoxy–SF6 interface, which is closely related to the microstructure and its evolution. However, existing studies often ignore the effect of the degradation of the epoxy surface on the surface traps and charge accumulation during the long-term service of the insulation system. In this study, the surface physicochemical evolution and its influence on surface traps of a typical epoxy–SF6 insulation structure were researched under a DC-temperature gradient condition, and an evolution mechanism of surface traps was proposed. The results show that the free radicals introduced during the material degradation process increase the density and depth of both positive and negative charge traps on the epoxy surface. The effect of free radicals formed by the cleavage of epoxy molecules on the electronic orbital and molecular electrostatic potential of epoxy molecules is the intrinsic reason for the evolution of surface trap evolution. This work may help to understand the long-term evolution mechanisms of the physicochemical characteristics of the epoxy–SF6 interface in DC field and may provide a theoretical basis for the long-term failure mechanism revealing and the insulation performance enhancement.
Electric and magnetic tuning of Gilbert damping constant in LSMO/PMN-PT(011) heterostructure
Authors: Das Avisek , Mrinalini  , Usami Takamasa , Prakash Pati Satya , Taniyama Tomoyasu , Gorige Venkataiah
Published: April 2023

Electric field control of magnetodynamics in magnetoelectric (ME) heterostructures has been the subject of recent interest due to its fundamental complexity and promising applications in room temperature (RT) devices. The present work focuses on the tuning of magnetodynamic parameters of epitaxially grown ferromagnetic (FM) La0.7Sr0.3MnO3 (LSMO) on a ferro(piezo)electric (FE) Pb(Mg0.33Nb0.67)O3-PbTiO3 (PMN-PT) single crystal substrate. The uniaxial magnetic anisotropy of LSMO on PMN-PT confirms the ME coupling at the FM/FE heterointerface. The magnitude of the Gilbert damping constant (α) of this uniaxial LSMO film measured along the hard magnetic axis is significantly small compared to the easy axis. Furthermore, a marked decrease in the α values of LSMO at positive and negative electrical remanence of PMN-PT is observed, which is interpreted in the framework of strain induced spin dependent electronic structure. The present results clearly encourage the prospects of electric field controlled magnetodynamics, thereby realising the RT spin-wave based device applications with ultra-low power consumption.
High quality AlN film assisted by graphene/sputtered AlN buffer layer for deep-ultraviolet-LED
Authors: Wu Haidi , Ning Jing , Zhang Jincheng , Zeng Yu , Jia Yanqing , Zhao Jianglin , Bai Ling , Wang Yanbo , Li Shiyu , Wang Dong , Hao Yue
Published: April 2023

The advantages of van der Waals epitaxial nitrides have become a research hot topic. It is worth noting that graphene plays an important role in the research of epitaxial AlN epitaxial layer. In this work, we demonstrate a method to obtain high-quality and low-dislocation AlN epitaxial layer by combining graphene and sputtered AlN as the nucleation layer on the C-sapphire substrate via metal organic chemical vapor deposition, and successfully fabricated a 277 nm AlGaN-based deep ultraviolet light emitting diode (DUV-LED) based on the obtained AlN epitaxial layer. The presence of graphene promotes the stress release of AlN. Compared with the AlN epitaxial layer directly grown on graphene/sapphire substrate, the exist of sputtered AlN/graphene nucleation layer facilitates most of the threading dislocations in AlN can annihilate each other in the range of about 100 nm. Thus, as grown AlN epitaxial layer shows the decreasing of the screw dislocation from 2.31 × 109 to 2.08 × 108 cm−2 significantly. We manufacture an DUV-LED with 277 nm emission wavelength by using high-quality AlN films, which shows that magnitude of the leakage current is only on the order of nanoamperes and the forward turn on voltage is 3.5 V at room temperature. This study provides a meaningful strategy to achieve high-quality AlN film and high-performance DUV-LED.
Stable propagation of the Poincaré polarization solitons in strongly nonlocal media
Authors: Guan Siyin , Huang Hui , Weng Zhiwei , Xu Yongzheng , Wu Lijun , Guo Qi , Hu Wei , Shou Qian
Published: April 2023

We report the first experimental observation of spatial solitons with complex polarization states, called the Poincaré polarization solitons (PPSs) in lead glass with strongly nonlocal nonlinearity. The formations of PPSs with topological charge of l = 1, including the cylindrical elliptical-polarization soliton (CEPS) and the angularly-hybrid polarization soliton (AHPS), were observed. We showed that the annular profiles and the complex polarization distributions of the first-order PPSs can be remained. Based on the linear stability analysis, we proved that the first-order PPSs are fully stable and the second-order PPS can survive only when one of the two component vortices dominates.
Investigation of electronic and magnetic properties in vacancy incorporated monolayer magnesium bromide for spintronics application: an ab-initio study
Authors: Lahiri Saurav , Thangavel R
Published: April 2023

Alkaline earth-based half-metallic materials attracted spintronics researchers, owing to their outstanding long spin relaxation time and robustness against spin current leakage. Using first principles calculations, defect-induced monolayer magnesium bromide (Mg1−x
δ
xBr2; x = 0.11, 0.22, 0.33) systems have been studied for the first time. Among these systems, Mg0.89
δ
0.11Br2 showed half-metallic nature that finds application in ultra-fast spintronics. Exfoliation energy (0.12 J/m2) calculation revealed the possibility of exfoliation of the monolayer MgBr2 from its bulk. Phonon dispersion plot confirmed dynamical stability of the free-standing monolayer. The formation energy of Mg vacancy defect (VMg) under Br-rich condition (2 eV) showed, defect-induced favourability. Mg0.89
δ
0.11Br2 has been found to be in a ferromagnetic ground state with a remarkable large spin-up gap (4.84 eV), which limits spin leakage. In addition, significant magnetic anisotropy energy (MAE) per VMg (4.16 meV) has been observed along (100) easy axis direction with a strong ferromagnetic coupling. Electric field modulated electronic structure showed an optimal spin-up gap up to 0.3 V/Å, desirable for the device operation. Robustness of the half-metallicity was confirmed by strain-dependent density of states which is vital during its synthesis and deposition onto a substrate. Hence, from the electronic and magnetic studies, vacancy incorporated monolayer magnesium bromide showed potential applications in spintronics.
Real-time biosensor application of structurally chiral medium for detection and sensing of plasma in human blood
Authors: Ghorani Nadia , Madani Amir , Entezar Samad Roshan
Published: April 2023

In this work, we theoretically investigated a unique and sensitive optical biosensor for detecting and sensing blood plasma using a structurally chiral medium. The proposed biosensor is a defective one-dimensional structure made from a structurally chiral material with

4
¯

2
m

point group symmetry where the defect layer is considered as a channel for the blood plasma. The transmission and reflection of the structure are investigated utilizing the transfer matrix method for the circularly polarized waves. It is shown that a defect mode is created in the middle of the circular Bragg photonic band gap for the right-handed circularly polarized waves and experiences a red shift by increasing the blood plasma concentration. Also, it is observed that the sensitivity of the sensor can be increased by increasing the thickness of the defect layer. In addition, we reveal that the increase of the tilt angle of the structurally chiral medium results in the decrease of photonic band gap width and causes to blue-shift of the defect mode. As a result, the performance of the sensor decreases by increasing the tilt angle. The proposed structure has an easy and efficient manufacturing process, high stability and cost-effectiveness and can provide real-time blood plasma biosensors.
Isospin-conserving hadronic decay of the Ds1(2460) into Dsπ+π−
Authors: Tang Meng-Na , Lin Yong-Hui , Guo Feng-Kun , Hanhart Christoph , Meißner Ulf-G.
Published: April 2023

The internal structure of the charm-strange mesonsDs0*(2317)andDs1(2460) are the subject of intensive studies. Their widths are small because they decay dominantly through isospin-breaking hadronic channelsDs0*(2317)+→Ds+π0andDs1(2460)+→Ds*+π0. TheDs1(2460) can also decay into the hadronic final statesDs+ππ, conserving isospin. In that case there is, however, a strong suppression from phase space. We study the transitionDs1(2460)+→Ds+π+π−in the scenario that theDs1(2460) is aD*Khadronic molecule. Theππfinal state interaction is taken into account through dispersion relations. We find that the ratio of the partial widths of theΓ(Ds1(2460)+→Ds+π+π−)/Γ(Ds1(2460)+→Ds*+π0)obtained in the molecular picture is consistent with the existing experimental measurement. More interestingly, we demonstrate that theπ+π−invariant mass distribution shows a double bump structure, which can be used to disentangle the hadronic molecular picture from the compact state picture for theDs1(2460)+. Predictions on theBs10→Bs0π+π−are also made.
Fluctuation dominated phase ordering in coarse-grained depth models: domain wall structures, extreme values and coarsening
Authors: Das Arghya , Barma Mustansir
Published: April 2023

Models of particles driven by a one-dimensional fluctuating surface are known to exhibit fluctuation dominated phase ordering (FDPO), in which both the order and fluctuations appear on macroscopic scales. Highly dynamic and macroscopically broad interfacial regions, each composed of many domain walls, appear between macroscopically ordered regions and consequently the scaled correlation function violates the Porod law. We focus on two essential quantities which together quantify the unique characteristics of FDPO, namely the total number of domain walls and the length of the largest ordered domain. We present results in the context of coarse-grained depth (CD) models, both in steady state and while coarsening. Analytic arguments supported by numerical simulations show that even though domain wall number fluctuations are very strong, the associated variance remains constant in time during coarsening. Further, the length of the largest cluster grows as a power law with significant multiplicative logarithms which involve both the time and system size. In addition, we identify corrections to the leading power law scaling in several quantities in the coarsening regime. We also study a generalisation of the CD model in which the domain wall density is controlled by a fugacity and show that it maps on to the truncated inverse distance squared Ising model. The generalised model shows a mixed order phase transition, with the regular CD model (which exhibits FDPO) corresponding to the critical point.
Multicomponent gauge-Higgs models with discrete Abelian gauge groups
Authors: Bracci Testasecca Giacomo , Pelissetto Andrea
Published: April 2023

We consider a variant of the charge-Q compact Abelian-Higgs model, in which an N

f
-dimensional complex vector is coupled with an Abelian

Z

q

gauge field. For

N
f

=
2

and Q = 1 we observe several transition lines that belong to the O(4), O(3), and O(2) vector universality classes, depending on the symmetry breaking pattern at the transition. The universality class is independent of q as long as

q
⩾
3

. The universality class of the transition is uniquely determined by the behavior of the scalar fields; gauge fields do not play any role. We also investigate the system for

N
f

=
15

and Q = 2. In the presence of U(1) gauge fields, the system undergoes transitions associated with charged fixed points of the Abelian-Higgs field theory. These continuous transitions turn into first-order ones when the U(1) gauge fields are replaced by the discrete

Z

q

fields: in the present compact model charged transitions appear to be very sensitive to the nature of the gauge fields.
Performance analysis of Polar Codes in a Visible Light Communication System
Authors: Vaz Aldrin Claytus , Hegde Navya Thirumaleshwar , Shetty Akhil Appu
Published: April 2023

One of the vital entity of any communication systems is Channel coding, which leads to the design of high performance codes for future wireless systems having low complexity encoder and decoder design. These systems will have a requirement of operating in highly reliable conditions, maximum throughput, and low and high code rates and to work with short and long information messages. Polar codes are one of the promising error correcting channel codes that can be used in these situations to obtain maximum throughput and coding gain in a communication systems because of their capacity approaching performance and finds interests in Satellite communication and 4G/5G services. These codes uses the concept of channel polarization to be constructed. The work proposed in this paper focusses on the Bit Error Rate evaluation and analysis of the Polar codes using traditional approach and Deep learning approach. The feedforward deep learning networks using different activation functions were used for the Deep learning approach. The Successive Cancellation algorithm and its variant using List decoding were used as traditional decoding methodology. The results obtained using Deep learning approach were satisfactory and was matching as per the traditional decoding.
Performance Comparison of Various Neural Networks for Speech Recognition
Authors: Sridhar C. , Kanhe Aniruddha
Published: April 2023

Speech recognition is a method where an audio signal is translated into text, words, or commands and also tells how the speech is recognized. Recently, many deep learning models have been adopted for automatic speech recognition and proved more effective than traditional machine learning methods like Artificial Neural Networks(ANN). This work examines the efficient learning architectures of features by different deep neural networks. In this paper, five neural network models, namely, CNN, LSTM, Bi-LSTM, GRU, and CONV-LSTM, for the comparative study. We trained the networks using Audio MNIST dataset for three different iterations and evaluated them based on performance metrics. Experimentally, CNN and Conv-LSTM network model consistently offers the best performance based on MFCC Features.
An approach for improving Optical Character Recognition using Contrast enhancement technique
Authors: Shine Nithin K , Bhutani Gariman , Keerthana Tamatapu Sai , Rohith G
Published: April 2023

Digital cameras and mobile image capture of documents are two examples of new developments in the fields of optical character recognition and text recognition. Scans of text or text photographic images and even natural photography results can be distorted to the point where OCR digitization is inaccurate. It offers a unique non-parametric unattended approach to correct unwanted document image distortions to achieve optimal OCR accuracy. It applies a highly effective stack of document image enhancement algorithms to restore perfect images distorted by unknown sources of distortion. First, it provides a means of modifying local brightness and contrast in order to better handle different illumination levels and atypical light transmission patterns in the image. Then apply a nifty grayscale conversion method to your photo to give it a new look. Third, it uses unsharp masking techniques to further enhance important details in grayscale images. Finally, we use the best global binarization technique to prepare the final document image for OCR recognition. The proposed technique has the potential to significantly improve the text recognition rate and accuracy of optical character recognition.
A review on techniques for improving mimo antenna performance in smart 5g devices
Authors: Kanisha R K Rabin , Rimmya C , Madhan M Ganesh
Published: April 2023

This paper presents the state-of-the-art literature on Multiple Input Multiple Output (MIMO) antennas for 5G systems. The degree of freedom offered by MIMO as a result of increasing transmitter and receiver elements has raised serious concern towards the impact due to mutual coupling between the adjacent elements in the MIMO antenna. Hence, this paper summarizes the various measures for suppressing mutual coupling between MIMO antenna elements. It also reports the methods for enhancing the bandwidth at the sub 6 GHz band by the deployment of different radiating structures and their influence over the crucial MIMO parameters. A study on the ways and means of handling the propagation losses at mm-wave frequencies by proper choice of PCB for fabrication is also discussed.