bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Retinal Nerve Fiber Layer Thickness in ‎Axial High Myopic Patients after Uncomplicated Phacoemulsification
Authors: Fadda Ahmed Awad , Shalaby Said Mohammad , Seht Rabab Mohamed El , Khater Mohamed Mostafa 
Published: April 2022

Background: ‎On examining the RNFL thickness by OCT, the media opacity caused ‎by cataract will increase light scattering
and absorption, so the RNFL thickness measurement can be increased after uncomplicated cataract surgery also, inflammatory reaction by mechanical injury of phacoemulsification ‎surgery, traction reaction of optic nerve head induced by parts of vitreous liquefaction in ultrasonic emulsification process, with the addition of optic ‎neuropathy from ultrasonic energy. For all above, these factors could increase NFL thickness.‎
Aim: Evaluation of retinal nerve fiber layer thickness in axial high myopic ‎patients after uncomplicated phacoemulsification.‎
Patients and Methods: Our patients collected from outpatient clinic of Ophthalmology ‎department; Tanta University and outpatient clinic at Ophthalmology ‎department of Matarya Teaching Hospital during the period from December 2019 to June 2020 and extended to December 2020 due to Covid_19 ‎pandemic.‎
‎Results: This study including 20 eyes of high axial myopic cataracts patients (group Ⅰ) and 10 eyes of normal cataracts patients (group II) from which age range between (50-70) years old , males were (30%) and females were (70%) in group Ⅰand males (50%) were equal to female (50%) in group II.
Conclusion: There is a significant increase in thickness of peripapillary RNFL measured by OCT after 1 week of uncomplicated phacoemulsification cataract surgery. ‎This increase in thickness occurs as the media opacity caused by cataracts increases the light scattering and absorption thus affects the quality ‎of measurements which improves after cataract extraction.‎
Role of Diffusion Weighted Magentic Resonance Imaging in Evaluation of Hepatocellular Carcinoma Post Chemoembolization
Authors: Ali Moustafa Ahmed Hassan , Mohammed Saleh Hanan Ahmad Nagy , Teama Atef Hammad 
Published: April 2022

Background: Hepatocellular carcinoma (HCC) is the fifth most common type of cancer in the world and the third most prevalent frequent death reason in patients who suffers from malignant tumors. The apparent diffusion coefficient (ADC) is a method for measurement of the water movement within tissues. Tumors that are viable have a high cellularity, and the cells' membranes are intact which water molecules' mobility is restricted, leading to a small ADC. But from the other hand, necrosis increases the permeability of the cell of the membrane, permitting water molecules to circulate freely and resulting in an elevation in the ADC's relative value. This study aimed to describe the use of diffusion weighted MRI to evaluate hepatocellular carcinoma in the setting of trans-arterial chemoembolization (TACE).
Methods: This study was carried out on 30 patient (males: 22, eight females) aged 42 to 75 years with biopsy-proven HCC, candidate for trans arterial hepatic chemoembolization as a plan of treatment. They were referred from Oncology Department to MRI unit in radiology department over a period of 1 year starting in June 2018 to June 2019.
Results: According to diffusion weighted Imaging (DWIs) and ADC values, there were 4 TP (13.33%), 22 TN (73.33%), 2 FP (6.66%) and 2 FN (6.66%) studies. The P-value by Fisher’s Exact was <0.05 denoting agreement between the DWI and ADC findings and the standard of references. Regarding the false negative studies by diffusion MRI, On diffusion images, there was a loss of signal or a mild sustained hyperintensity with a bright ADC map, so it was considered as well ablated lesion. Follow up triphasic CT or dynamic MRI after 3-6 months shows lesion enhancement at arterial phase and wash out at both venous and delayed phases with restricted diffusion. The optimal cutoff value for sensitivity and specificity is 1.069; at this ADC value, the sensitivity is 66.66 percent and the specificity is 91.66 percent.
Conclusions: ADC obtained from diffusion-weighted magnetic resonance imaging has developed into a a useful biomarker for the response of tumours to therapy. Analysis of the ADC value is helpful in detecting the presence of residuals in non-successfully ablated lesions.
A feasibility study of a modified treatment strategy combined external beam radiation therapy and brachytherapy for cervical cancer
Authors: Fu Qi , Li Wei , Zuo Jing , Yang Xi , Xu Yingjie , Huang Manni , An Jusheng , Jia Shuangzheng , Wu Lingying 
Published: April 2022

AbstractPurposeTo evaluate the feasibility of a modified treatment strategy combined external beam radiation therapy (EBRT) and brachytherapy (BT) for cervical cancer through a dosimetry analysis.Material and methodsThis study retrospectively selected 12 cervical cancer patients treated with the conventional treatment strategy, which consisted of 45─50 Gy/25 fractions of EBRT using volumetric‐modulated arc therapy (VMAT) and image‐guided BT with a fraction dose of 5─7 Gy. The modified treatment strategy decreased the central EBRT dose while increasing the number of BT fractions. New target volumes were additionally contoured, and new VMAT EBRT plans were generated for the modified treatment strategy. The dosimetric parameters for evaluation included the doses to the most irradiated 2 cc (D2cc) of the organs at risk (OARs) and doses to at least 90% (D90) of the gross tumor volume (GTV) and high‐risk clinical target volume (HR‐CTV). The total doses to OARs and targets obtained by adding the equivalent doses in 2 Gy fraction (EQD2) from the EBRT and BT plans were used for quantitative comparison between the modified and conventional treatment strategies.ResultsComparison to the conventional treatment strategy, the modified treatment strategy resulted in a higher bladder D2cc, a slightly lower rectal D2cc and a similar HR‐CTV D90, all with no significant differences (p > 0.05). The GTV D90 of the modified treatment strategy was significantly higher than that of the conventional treatment strategy (p < 0.01).ConclusionThe modified treatment strategy can significantly increase the BT dose while remaining the total doses to the bladder and rectum basically unchanged, demonstrating its feasibility and promising prospect in clinical use.
Dirac Fermion Cloning, Moiré Flat Bands, and Magic Lattice Constants in Epitaxial Monolayer Graphene
Authors: Lu Qiangsheng , Le Congcong , Zhang Xiaoqian , Cook Jacob , He Xiaoqing , Zarenia Mohammad , Vaninger Mitchel , Miceli Paul F. , Singh David J. , Liu Chang , Qin Hailang , Chiang Tai‐Chang , Chiu Ching‐Kai , Vignale Giovanni , Bian Guang 
Published: April 2022

AbstractTuning interactions between Dirac states in graphene has attracted enormous interest because it can modify the electronic spectrum of the 2D material, enhance electron correlations, and give rise to novel condensed‐matter phases such as superconductors, Mott insulators, Wigner crystals, and quantum anomalous Hall insulators. Previous works predominantly focus on the flat band dispersion of coupled Dirac states from different twisted graphene layers. In this work, a new route to realizing flat band physics in monolayer graphene under a periodic modulation from substrates is proposed. Graphene/SiC heterostructure is taken as a prototypical example and it is demonstrated experimentally that the substrate modulation leads to Dirac fermion cloning and, consequently, the proximity of the two Dirac cones of monolayer graphene in momentum space. Theoretical modeling captures the cloning mechanism of the Dirac states and indicates that moiré flat bands can emerge at certain magic lattice constants of the substrate, specifically when the period of modulation becomes nearly commensurate with the supercell of graphene. The results show that epitaxial single monolayer graphene on suitable substrates is a promising platform for exploring exotic many‐body quantum phases arising from interactions between Dirac electrons.
Self‐Powered Active Sensing Based on Triboelectric Generators
Authors: Khandelwal Gaurav , Dahiya Ravinder 
Published: April 2022

AbstractThe demand for portable and wearable chemical or biosensors and their expeditious development in recent years has created a scientific challenge in terms of their continuous powering. As a result, mechanical energy harvesters such as piezoelectric and triboelectric generators (TEGs) have been explored recently either as sensors or harvesters to store charge in small, but long‐life, energy‐storage devices to power the sensors. The use of energy harvesters as sensors is particularly interesting, as with such multifunctional operations it is possible to reduce the number devices needed in a system, which also helps overcome the integration complexities. In this regard, TEGs are promising, particularly for energy autonomous chemical and biological sensors, as they can be developed with a wide variety of materials, and their mechanical energy to electricity conversion can be modulated by various analytes. This review focuses on this interesting dimension of TEGs and presents various self‐powered active chemical and biological sensors. A brief discussion about the development of TEG‐based physical, magnetic, and optical sensors is also included. The influence of environmental factors, various figures of merit, and the significance of TEG design are explained in context with the active sensing. Finally, the key applications, challenges, and future perspective of chemical and biological detection via TEGs are discussed with a view to drive further advances in the field of self‐powered sensors.
Preparation of Amorphous SnO2‐Encapsulated Multiphased Crystalline Cu Heterostructures for Highly Efficient CO2 Reduction
Authors: Yin Peng‐Fei , Fu Jiaju , Yun Qinbai , Chen Bo , Liu Guigao , Li Lujiang , Huang Zhiqi , Ge Yiyao , Zhang Hua 
Published: April 2022

AbstractControlling the architectures and crystal phases of metal@semiconductor heterostructures is very important for modulating their physicochemical properties and enhancing their application performances. Here, a facile one‐pot wet‐chemical method to synthesize three types of amorphous SnO2‐encapsulated crystalline Cu heterostructures, i.e., hemicapsule, yolk–shell, and core–shell nanostructures, in which unconventional crystal phases (e.g., 2H, 4H, and 6H) and defects (e.g., stacking faults and twin boundaries) are observed in the crystalline Cu cores, is reported. The hemicapsule Cu@SnO2 heterostructures, with voids that not only expose the Cu core with unconventional phases but also retain the interface between Cu and SnO2, show an excellent electrocatalytic CO2 reduction reaction (CO2RR) selectivity toward the production of CO and formate with high Faradaic efficiency (FE) above 90% in a wide potential window from −1.05 to −1.55 V (vs reversible hydrogen electrode (RHE)), and the highest FE of CO2RR (95.3%) is obtained at −1.45 V (vs RHE). This work opens up a new way for the synthesis of new heterostructured nanomaterials with promising catalytic application.
Magnetic Anisotropy Control with Curie Temperature above 400 K in a van der Waals Ferromagnet for Spintronic Device
Authors: Li Zeya , Tang Ming , Huang Junwei , Qin Feng , Ao Lingyi , Shen Zhiwei , Zhang Caorong , Chen Peng , Bi Xiangyu , Qiu Caiyu , Yu Zhipeng , Zhai Kun , Ideue Toshiya , Wang Lin , Liu Zhongyuan , Tian Yongjun , Iwasa Yoshihiro , Yuan Hongtao 
Published: April 2022

AbstractThe technological appeal of van der Waals ferromagnetic materials is the ability to control magnetism under external fields with desired thickness toward novel spintronic applications. For practically useful devices, ferromagnetism above room temperature or tunable magnetic anisotropy is highly demanded but remains challenging. To date, only a few layered materials exhibit unambiguous ferromagnetic ordering at room temperature via gating techniques or interface engineering. Here, it is demonstrated that the magnetic anisotropy control and dramatic modulation of Curie temperature (Tc) up to 400 K are realized in layered Fe5GeTe2 via the high‐pressure diamond‐anvil‐cell technique. Magnetic phases manifesting with in‐plane anisotropic, out‐of‐plane anisotropic and nearly isotropic magnetic states can be tuned in a controllable way, depicted by the phase diagram with a maximum Tc up to 360 K. Remarkably, the Tc can be gradually enhanced to above 400 K owing to the Fermi surface evolution during a pressure loading–deloading process. Such an observation sheds light on the understanding and control of emergent magnetic states in practical spintronic applications.
Divergent Synthesis of C5‐Heteroatom Substituted Oxazoles
Authors: Oberheide Ansgar , Gaigne Frédéric , Arndt Hans‐Dieter 
Published: April 2022

Abstract5‐Oxazoyl‐sulfamates have been profiled as versatile building blocks for modifications of oxazoles with various nucleophiles. The unified approach provides a diversification platform to directly access 5‐amino‐oxazoles, 5‐oxazolyl‐sulfides, and 5‐oxazoyl‐aryl ethers from a single precursor.magnified image
Combined Approach of Hypervalent Iodine Reagents and Transition Metals in Organic Reactions
Authors: Rani Neha , Soni Rinku , Sihag Monika , Kinger Mayank , Aneja Deepak K. 
Published: April 2022

AbstractThis review outlines the progress over recent years in the reactions involving combined approach of hypervalent iodine reagents and transition metals such as palladium, nickel, iridium, gold, rhodium, copper, iron, ruthenium, platinum, silver, zinc, rhenium and cobalt. This approach enables organic transformations complimentary to traditional manifolds. Hypervalent iodine reagents play a preeminent role in organic chemistry due to their versatile reactivity, heteroatom ligands and mild reaction conditions. These reagents in combination of transition metal compounds are used in many synthetically useful organic reactions such as oxidation, rearrangement, amination, halogenation, amidation, ring‐opening, cyclization and C−H and C−C functionalization reactions, etc. which are discussed here.magnified image
Mechanical Nanoscale Polarization Control in Ferroelectric PVDF‐TrFE Films
Authors: Roth Robert , Koch Martin M. , Rata A. Diana , Dörr Kathrin 
Published: April 2022

AbstractFerroelectric polymer films offer strong advantages like mechanical flexibility, biocompatibility, optical transparency, and low‐cost processing. However, their dielectric or piezoelectric performance is often inferior to that of oxide ferroelectric materials. Key to the dielectric or piezoelectric performance of semicrystalline polymers is the enhancement of electric dipolar order that is naturally lower than in crystalline ferroelectrics. Here, reorientation and alignment of the electric polarization in thin films by the mechanical effect of a scanning unbiased force microscopy tip is demonstrated as a versatile tool for nanoscale domain writing. Thin films (50–150 nm) of PVDF‐TrFE (78:22) on graphite are prepared with dense (110)‐oriented β‐phase lamellae randomly oriented in the film plane. The in‐plane polarization can be poled “mechanically” along any deliberately chosen direction in the film plane after vertical electric poling. Domain patterns with resolution down to ≈50 nm are written with four (out of six possible) local polarization orientations. Written domains show excellent long‐time stability. The surface roughening from the mechanical treatment is moderate (rms roughness of 2–3 nm). A ferroelastic origin of the mechanical polarization switching is discussed. Finally, suggestions are made how to utilize the domain patterns in thin film devices.
A new approach to the inverse scattering and spectral problems for the Sturm‐Liouville equation
Authors: Ramm A.G. 
Published: April 2022

AbstractNew proofs of the known uniqueness theorems for the one‐dimensional inverse spectral and scattering problems are given. Proof of the invertibility of all of the steps in the inversion procedures of Gelfand‐Levitan and Marchenko is given. The proposed method of investigation yields some new results, for example, a Marchenko‐type equation at x = 0 which holds on the whole axis, rather than on a half‐axis, as usual for the scattering theory on half‐axis. It also yields a new method, shorter and simpler than earlier published, for proving that the potential in the class L1,1, obtained by the Marchenko reconstruction procedure, generates the scattering data from which it was reconstructed.
Acoustic and elastic waves in random media – CPA
Authors: Kafesaki M. , Economou E.N. 
Published: April 2022

AbstractWe study the propagation of acoustic and elastic waves in random composites consisting of spherical inclusions in a homogeneous elastic host (fluid or solid), using various extensions of the Coherent Potential Approximation (CPA) method, well‐known from the electronic problem. We calculate the phase velocity, the scattering mean free path and the transport velocity. The results are compared with experimental data and accurate computational results.
Electronic states in topologically disordered systems
Authors: Grimm U. , Römer R.A. , Schliecker G. 
Published: April 2022

AbstractNetworks generated from Voronoi tessellations of space are prototypes for topologically disordered systems. In order to assess the effects of random coordination on the statistical properties of energy spectra, we analyze tight‐binding models for planar topologically disordered systems. To this end, the networks are generated by a simple topological model covering a wide range of naturally observed random structures. We find that the energy‐level‐spacing distributions exhibit level repulsion, similar to the spacings in the energetically disordered Anderson model of localization in the metallic regime.
Wave functions in the Anderson model and in the quantum percolation model: a comparison
Authors: Kantelhardt Jan W. , Bunde Armin 
Published: April 2022

AbstractWe compare numerically the localization behavior of electronic eigenfunctions in the Anderson model and on self‐similar percolation clusters at criticality. We find that the distributions of the local wave function amplitudes |ψ| at fixed distances from the localization center are very similar for both models. The amplitude distributions are well approximated by log‐normal fits, which seem to become exact at large distances. From the distributions, we can calculate analytically the behavior of the averages at sufficiently large distances. We observe two different localization regimes. In the first regime, at intermediate distances from the localization center, we find stretched exponential localization (‘sublocalization’), ln 〈|ψ|〉 ∼ —r, with effective localization exponents dψ < 1. In the second regime, for very large r, the averages strongly depend on the number of configurations N, and superlocalization (dψ > 1) is observed, converging to simple exponential behavior asymptotically as expected. The crossover from the intermediate to the asymptotic regime depends logarithmically on the number of configurations.
Eigenvector correlations in non‐Hermitian random matrix ensembles
Authors: Mehlig B. , Chalker J.T. 
Published: April 2022

AbstractWe analyse correlations of eigenvectors in Ginibre's and Girko's ensembles of Gaussian, non‐Hermitian random N × N matrices J. We study the ensemble average of 〈Lα|Lβ〉 〈Rβ|Rα〉, where 〈Lα| and |Rβ〉 are the left and right eigenvectors of J. The case of Ginibre's ensemble, in which the real and imaginary parts of each element of J are independent random variables, is sufficiently symmetric to allow for an exact solution. In the more general case of Girko's ensemble, we rely on approximations which become exact in the limit of N → ∞.
A numerical study of wave‐function and matrix‐element statistics in the Anderson model of localization
Authors: Uski V. , Mehlig B. , Römer R.A. 
Published: April 2022

AbstractWe have calculated wave functions and matrix elements of the dipole operator in the two‐ and three‐dimensional Anderson model of localization and have studied their statistical properties in the limit of weak disorder. In particular, we have considered two cases. First, we have studied the fluctuations as an external Aharonov‐Bohm flux is varied. Second, we have considered the influence of incipient localization. In both cases, the statistical properties of the eigenfunctions are non‐trivial, in that the joint probability distribution function of eigenvalues and eigenvectors does no longer factorize. We report on detailed comparisons with analytical results, obtained within the non‐linear sigma model and/or the semiclassical approach.
Interplay disorder–interaction in one‐dimensional quantum models
Authors: Pichard Jean‐Louis , Weinmann Dietmar , De Toro Arias Samuel , Jalabert Rodolfo A. , Schmitteckert Peter , Waintal Xavier , Wobst André 
Published: April 2022

AbstractWe show that the crossover from the weak interaction limit towards the strong interaction limit may be accompanied by a delocalization effect in one dimensional disordered quantum models. The spin degrees of freedom are frozen and the spatial wave functions remain symmetric or antisymmetric when the strength U of a short range interaction is varied. The study concerns the excited states for two interacting particles and the ground state for a finite density of carriers.First, for two particles in a chain of length L, we establish a duality transformation mapping the behavior at weak U onto the behavior at strong U. For intermediate U, the mixing of the one body states and the interaction induced delocalization effect are maximum. Furthermore, if L ≈︂ L1 (the one particle localization length), the system becomes weakly chaotic with critical spectral statistics. This weak chaos is related to the multifractality of the interaction matrix. For two particles starting close to each other, localization is reached in two steps. Before the time t1 necessary to propagate over L1 , U de‐favors the propagation. On the contrary, U favors a very slow delocalization after t1 , characterized by a log(t) spreading of the center of mass. Similarly, the curvatures of the energy levels with respect to an enclosed magnetic flux decrease as a function of U for L < L1 and increase for L > L1 . The changes of the curvatures can be described by a conductance‐like single scaling parameter.Second, using the density renormalization group algorithm, we have studied the ground state energy of a finite density of spinless fermions and its change under twisted boundary conditions. For a large disorder, a charge reorganization is induced by the interaction: When the system becomes instable between the inhomogeneous configuration driven by the random potential (Anderson insulator) and the homogeneous one driven by repulsive interactions (Mott insulator), the ground state sensitivity can be enhanced by orders of magnitude. In contrast, no enhancement occurs at weaker disorder, when there are many particles on a scale L1.
Lax pair formulation for a small‐polaron chain with integrable boundaries
Authors: Guan Xi‐Wen , Grimm Uwe , Römer Rudolf A. 
Published: April 2022

AbstractUsing a fermionic version of the Lax pair formulation, we construct an integrable small‐polaron model with general open boundary conditions. The Lax pair and the boundary supermatrices K± for the model are obtained. This provides a direct proof of the integrability of the model.