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Recent Submissions

  • Structures, band gaps, and formation energies of highly stable phases of inorganic ABX3 halides: A = Li, Na, K, Rb, Cs, Tl; B = Be, Mg, Ca, Ge, Sr, Sn, Pb; and X = F, Cl, Br, I

    Alqahtani, Saad M.; Alsayoud, Abduljabar Q.; Alharbi, Fahhad H. (RSC advances, Royal Society of Chemistry (RSC), 2023-03-20) [Article]
    Recently, halide perovskites have attracted a substantial attention. Although the focus was mostly on hybrid ones with organic polyatomic cations and with inadequate stability, there is a sizable inorganic halide space that is not well explored and may be more stable than hybrid perovskites. In this work, a robust automated framework is used to calculate the essential properties of the highly stable phases of 168 inorganic halide perovskites. The considered space of ABX3 compounds consists of A = Li, Na, K, Rb, Cs, Tl, B = Be, Mg, Ca, Ge, Sr, Sn, Pb, and X = F, Cl, Br, I. The targeted properties are the structure, the formation energy to assess stability, and the energy gap for potential applicability. The calculations are carried out using the density functional theory (DFT) integrated with the precision library of Standard Solid-State Pseudopotentials (SSSP) for structure relaxation and PseudoDojo for energy gap calculation. Furthermore, we adopted a very sufficient and robust random sampling to identify the highly stable phases. The results illustrated that only 118 of the possible 168 compounds are formidable and have reliable results. The remaining 50 compounds are either not formidable or suffer from computational inconsistencies.
  • Laser-Induced Creation of Antiferromagnetic 180-Degree Domains in NiO/Pt Bilayers

    Meer, Hendrik; Wust, Stephan; Schmitt, Christin; Herrgen, Paul; Fuhrmann, Felix; Hirtle, Steffen; Bednarz, Beatrice; Rajan, Adithya; Ramos, Rafael; Niño, Miguel Angel; Foerster, Michael; Kronast, Florian; Kleibert, Armin; Rethfeld, Baerbel; Saitoh, Eiji; Stadtmüller, Benjamin; Aeschlimann, Martin; Kläui, Mathias (Advanced Functional Materials, Wiley, 2023-03-18) [Article]
    The antiferromagnetic order in heterostructures of NiO/Pt thin films can be modified by optical pulses. After the irradiation with laser light, the optically induced creation of antiferromagnetic domains can be observed by imaging the created domain structure utilizing the X-ray magnetic linear dichroism effect. The effect of different laser polarizations on the domain formation can be studied and used to identify a polarization-independent creation of 180° domain walls and domains with 180° different Néel vector orientation. By varying the irradiation parameters, the switching mechanism can be determined to be thermally induced. This study demonstrates experimentally the possibility to optically create antiferromagnetic domains, an important step towards future functionalization of all optical switching mechanisms in antiferromagnets.
  • Entropy Density and Speed of Sound from Improved Energy-Momentum Tensor in Lattice QCD

    Loan, Mushtaq; Demir, Nasser (arXiv, 2023-03-16) [Preprint]
    We present a lattice calculation of the entropy density of gluedynamics in the region near the critical temperature, Tc, in the deconfined phase. By exploring the temperature dependence of entropy density in this temperature regime, we aim to analyse the significant discrepancies between the previous computations. The calculation of entropy density is carried out by numerical simulation of O(a4) mean-field improved energy-momentum tensor (EMT) of SU(3) lattice gauge theory. We expand on reaching O(a4) improvement using tadpole-improved Symanzik action. The entropy density is calculated directly from the expectation value of the space-time component of the improved EMT in the presence of shifted boundary conditions at several lattice spacings (a≈0.043−0.012 fm). The absence of ultraviolet divergences and the minimal discretisation effects allow for the precision determination of the entropy density. It is demonstrated that the entropy density can be extrapolated to the continuum limit with precision and control. Furthermore, the continuum results are well represented by Pade approximation and in good agreement with the results of previous high-precision data obtained using the gradient flow method. We find that at temperatures of about 3Tc, deviations of entropy density from the Stefan-Boltzmann limit for a free theory are about 10%. The speed of sound in SU(3) gluedynamics is found to be c2s≤0.333 in the temperature region 1.06Tc≤T≤3.05Tc explored in this study.
  • Al/Si dopants effect on the electronic and optical behaviors of graphene mono-layers useful for infrared detector devices

    Hussein, Z.; Khan, W.; Laref, A.; AlQahtani, H. R.; Booq, Z. I.Y.; Alsalamah, R.; Ahmed, A.; Nya, Fridolin Tchangnwa; Chowdhury, Shahariar; El Amine Monir, Mohammed; Kumar, Atul; Huang, H. M.; Xiong, Y. C.; Yang, J. T. (Journal of Electron Spectroscopy and Related Phenomena, Elsevier BV, 2023-03-14) [Article]
    Two-dimensional (2D) graphene with different forms is a prosperous class of materials beneficial in nano-electronics, and infrared-detector devices. Herein, we analyze the electronic and optical behaviours of electron acceptor (Al)- and isovalent (Si) inserted into graphene sheets, which are computed by utilizing ab-initio simulations. We find that the individual doping impurities of Al or Si atoms onto monolayer graphene result in p-type and semiconducting behaviours, respectively, attributed to the contribution of the valence electrons number of these atoms to the host 2D honeycomb lattice of graphene. Even though the Al atom contributing one less electron to the host lattice, both individual impurities of the Al- or Si-doped materials are found to cause a splitting in the valence states and conduction states at the K-point, leading to the opening of the Dirac cone. In monolayer graphene, doping two Al atoms into the nearest neighbour sites creates a trivial metallic system, while doping two Si atoms into the nearest neighbour sites causes the Dirac cone to re-emerge. Owing to the stark difference in the electronic structure results of mono- and double-atom substitution of Al/Si in graphene single-layers, we find different optical behaviours in these doped systems. Additionally, X-ray absorption spectroscopy simulations are employed to inspect the core-level spectra of pure and substitutional doped graphene single layers. Accordingly, the optical spectral features of graphene single-layers substituted with foreign impurities, such as Al/Si have revealed the tailoring of optical absorption from the infrared to the visible windows. Due to the outstanding characteristics of this 2D dimensional gapless graphene, our simulated results could provide a guidance for future experimental investigations into the fabrication of doped graphene sheets suitable for infrared detectors, photonics, and modern optoelectronic devices integrated into advanced technologies.
  • XPS determined mechanism of selenite (HSeO3−) sorption in absence/presence of sulfate (SO42−) on Mg-Al-CO3 Layered double hydroxides (LDHs): Solid phase speciation focus

    Chubar, Natalia (Journal of Environmental Chemical Engineering, Elsevier BV, 2023-03-14) [Article]
    Success in adsorptive removal depends on solid phase speciation, which predetermines the extraction mechanism. This work investigates the mechanism of selenite (HSeO3−) sorption on Mg-Al Layered double hydroxides (LDHs), prepared by the original alkoxide-free sol-gel method, which already demonstrated outstanding removal of aqueous selenium species. Using X-ray Photoelectron Spectroscopy (XPS) as most relevant technique allowed to reveal the phase speciation in solid state as a function of two variables, competing sulfate and pH (8.5; 7.0; 4.5), and to detect the phases responsible for selenite uptake. Despite the leading initializing role of Mg-containing phases, selenite ended up to be chemically bound to one aluminium-based phase. The involvement of the second sorption mechanism via anion exchange of the interlayer carbonate with aqueous selenite depended on absence/presence of competing sulfate and pH. Comparison with the analogues results on selenate (SeO42−) sorption on the same material (published) resulted in discovery of the differences in XPS feature changes upon either physisorption or chemisorption. This is the first report, which discloses that physisorption of aqueous anion to a particular solid phase shifts the respective envelopment binding energies, whist chemisorptive binding causes considerable alterations (decreases/shifts) of XPS features of the specific binding solid species, such as Al(OH)3, however, it preserves nearly the same XPS characteristics of the envelopment peaks. Based on these discoveries, here we suggest a methodological idea on using the results of XPS analysis for interpretation of molecular mechanism of ion sorption on inorganic ion exchangers and to reliably distinguish the chemisorption from physisorption.
  • Conventional and nano-enhanced Phase Change Material melting simulation by using Lattice Boltzmann method: A comprehensive review

    Bu sinnah, Zainab Ali (Energy Reports, Elsevier BV, 2023-03-03) [Article]
    Phase Change Materials (PCMs) are latent heat energy storage mediums that have received considerable attentions regarding their high heat capacity and applicability for other purposes such as thermal management. Numerical simulation has been applied for these materials to investigate their heat transfer characteristics such as the rate of phase change and energy storage capacity. Lattice Boltzmann method is a promising approach for modeling and simulation of PCMs in both charging and discharging processes. In this article, studies on the melting (charging) of PCMs, with and without existence of nanomaterials, are reviewed and their results are represented and summarized. Corresponding to the findings of the reviewed studies it can be concluded that this approach is able to properly simulate the melting process of various PCMs. Simulation of charging process by means of this method showed that the melting rate is improvable by employing different ideas namely adding nanomaterials, using fins and heat pipes. Applying these ideas have significant impact on melting rate under specific conditions, i.e. more than 52% improvement in the melting rate for adding Cu nanoparticles with 4% concentration. Finally, some recommendations are suggested for the forthcoming studies in this field.
  • 16S rDNA-based diversity analysis of bacterial communities associated with soft corals of the Red Sea, Al Rayyis, White Head, KSA

    Alsharif, Sultan M.; Waznah, Moayad S.; Ismaeil, Mohamed; El-Sayed, Wael S. (Journal of Taibah University for Science, Informa UK Limited, 2023-03-02) [Article]
    Coral reef endogenous to the Red Sea ecosystem is one of the largest globally known living reefs that are remarkably distinctive to constant high temperature and salinity. Coral microbiota is one of the most important prespectives contributing to coral survival in such conditions. Four soft corals endogenous to the eastern Red Sea side at Al Rayyis White Head, KSA were collected and identified as Litophyton sp., Sinularia sp., Xenia sp. and Sarcophyton sp. Soft corals-associated microbiota were investigated using Illumina sequencing of bacterial 16S rRNA genes. Results revealed higher bacterial diversity. Assignment of bacterial reads at the phylum level revealed the predominance of Proteobacteria in all coral-associated microbiotas followed by Bacteroidetes and Firmicutes. At the family level, Litophyton sp. was dominated by Hahellaceae, Staphylococcaceae, Prevotellaceae, Moraxellaceae and Bacteroidaceae, while Xenia sp. was dominated by Hahellaceae and Anaplasmataceae. The microbiota of Sinularia sp. were dominated by Pseudomonadaceae and Enterobacteriaceae. Sarcophyton sp. microbiota mainly include members of Enterobacteriaceae only.
  • Using Hydraulic Theory to Monitor Dense Overflows in a Parabolic Channel

    Saberi, A. T. O. U. S. A.; Pratt, Lawrence J.; Haine, Thomas W. N.; Helfrich, Karl R. (JOURNAL OF PHYSICAL OCEANOGRAPHY, American Meteorological Society, 2023-02-27) [Article]
    Deep ocean passages are advantageous sites for long-term monitoring of deep transport and other physical properties relevant to climate. Rotating hydraulic theory provides potential for simplifying monitoring strategy by reducing the number of quantities that need to be measured. However, the applicability of these theories has been limited by idealizations such as restriction to zero or uniform potential vorticity (pv) and to channels with rectangular cross sections. Here the relationship between the flow characteristics in a canonical sea strait and its upstream condition is studied using uniform pv rotating hydraulic theory and a reduced-gravity shallow-water numerical model that allows for variation in pv. The paper is focused mainly on the sensitivity of the hydraulic solution to the strait geometry. We study the dynamics of channels with continuously varying (parabolic) cross sections to account for the rounded nature of sea-strait topographies and potentially improve monitoring strategies for realistic channel geometries. The results show that far enough from the channel entrance, the hydraulically controlled flow in the strait is insensitive to the basin circulation regardless of parabolic curvature. The controlled transport relation is derived for the case of uniform pv theory. Comparing the model to theory, we find that the measurement of the wetted edges of the interface height at the critical section can be used to estimate the volume flux. Based on this finding, we suggest three monitoring strategies for transport estimation and compare the estimates with the observed values at the Faroe Bank Channel. The results showed that the estimated transports are within the range of observed values. Significance Statement The paper investigates the relationship between the flow characteristics in an idealized sea strait and its upstream condition using rotating hydraulic theory and numerical modeling. We study the dynamics of channels with continuously varying (parabolic) cross sections to account for the rounded nature of sea-strait topographies and potentially improve monitoring strategies for realistic channel geometries. We suggest three monitoring strategies for transport estimation and apply the methods to the Faroe Bank Channel. Our estimates of dense water transport are within the range of observed values. This is significant, because the suggested monitoring strategies only require 1–3 measurements to estimate the transport at a given passage and can be used to guide observing systems.
  • Mirroring Skyrmions in Synthetic Antiferromagnets via Modular Design

    Deng, Panluo; Zhuo, Fengjun; Li, Hang; Cheng, Zhenxiang (Nanomaterials (Basel, Switzerland), 2023-02-25) [Article]
    Skyrmions are promising for the next generation of spintronic devices, which involves the production and transfer of skyrmions. The creation of skyrmions can be realized by a magnetic field, electric field, or electric current while the controllable transfer of skyrmions is hindered by the skyrmion Hall effect. Here, we propose utilizing the interlayer exchange coupling induced by the Ruderman–Kittel–Kasuya–Yoshida interactions to create skyrmions through hybrid ferromagnet/synthetic antiferromagnet structures. An initial skyrmion in ferromagnetic regions could create a mirroring skyrmion with an opposite topological charge in antiferromagnetic regions driven by the current. Furthermore, the created skyrmions could be transferred in synthetic antiferromagnets without deviations away from the main trajectories due to the suppression of the skyrmion Hall effect in comparison to the transfer of the skyrmion in ferromagnets. The interlayer exchange coupling can be tuned, and the mirrored skyrmions can be separated when they reach the desired locations. Using this approach, the antiferromagnetic coupled skyrmions can be repeatedly created in hybrid ferromagnet/synthetic antiferromagnet structures. Our work not only supplies a highly efficient approach to create isolated skyrmions and correct the errors in the process of skyrmion transport, but also paves the way to a vital information writing technique based on the motion of skyrmions for skyrmion-based data storage and logic devices.
  • Photoexcited Cobalt Catalysed Endo-Selective Alkyl Heck Reaction

    Wang, Chenyang; Azofra, Luis Miguel; Dam, Phong; Espinoza Suarez, Edelman Jose; Do, Hieu Trung; Rabeah, Jabor; Brückner, Angelika; El-Sepelgy, Osama (Chemical Communications, Royal Society of Chemistry (RSC), 2023-02-24) [Article]
    Herein we report an intramolecular endo-selective Heck reaction of iodomethylsilyl ethers of phenols and alkenols. The reaction leads to the formation of seven- and eight-membered siloxycycles in excellent yields which could be further converted into the corresponding allylic alcohols upon oxidation. Thus, the method could be used for the selective (Z)-hydroxymethylation of o-hydroxystyrenes and alkenols. Rapid scan EPR experiments and DFT calculations suggests a concerted β-hydrogen elimination event to take place in the triplet state.
  • Antiferromagnetic insulatronics: Spintronics in insulating 3d metal oxides with antiferromagnetic coupling

    Meer, H.; Gomonay, Olena; Wittmann, A.; Kläui, Mathias (Applied Physics Letters, AIP Publishing, 2023-02-23) [Article]
    Antiferromagnetic transition metal oxides are an established and widely studied materials system in the context of spin-based electronics, commonly used as passive elements in exchange bias-based memory devices. Currently, major interest has resurged due to the recent observation of long-distance spin transport, current-induced switching, and THz emission. As a result, insulating transition metal oxides are now considered to be attractive candidates for active elements in future spintronic devices. Here, we discuss some of the most promising materials systems and highlight recent advances in reading and writing antiferromagnetic ordering. This article aims to provide an overview of the current research and potential future directions in the field of antiferromagnetic insulatronics.
  • Deep learning-based local wavefront attributes and their application to 3D prestack data enhancement

    Gadylshin, Kirill; Silvestrov, Ilya; Bakulin, Andrey (GEOPHYSICS, Society of Exploration Geophysicists, 2023-02-23) [Article]
    The work presents a novel workflow to accelerate the estimation of local wavefront attributes (LWAs) from massive 3D prestack seismic data using deep learning (DL) focusing on data enhancement. A standard estimation method based on a semblance-based brute-force optimization provides good results but is time consuming. A modification of the U-net convolutional neural network, commonly used in image processing applications, is proposed to link the seismic data with the wavefront attributes. Color pixel image input for the neural network is generated through a straightforward seismic data regularization based on supergrouping followed by red, green, and blue encoding. The proposed workflow can be adapted to any 3D prestack seismic volume. Conventional semblance-based attributes estimation is required for the training step but only for approximately 1% of the total data. The prediction step is very efficient and reduces the overall run time significantly. The verification of the proposed approach is performed on challenging real land and marine data sets. As a result, DL-based estimation of LWAs accelerates computation up to 200 times compared to the standard method. The attributes from the proposed DL-based approach indicate an acceptable match compared with the brute-force semblance-based optimization results. Conventional and proposed estimation methods result in comparable prestack data enhancement results for more reliable seismic processing in challenging areas.
  • Gelation and Re-entrance in Mixtures of Soft Colloids and Linear Polymers of Equal Size

    Parisi, Daniele; Truzzolillo, Domenico; Slim, Ali H.; Dieudonné-George, Phillippe; Narayanan, Suresh; Conrad, Jacinta C.; Deepak, Vishnu D.; Gauthier, Mario; Vlassopoulos, D. (Macromolecules, American Chemical Society (ACS), 2023-02-22) [Article]
    Liquid mixtures composed of colloidal particles and much smaller non-adsorbing linear homopolymers can undergo a gelation transition due to polymer-mediated depletion forces. We now show that the addition of linear polymers to suspensions of soft colloids having the same hydrodynamic size yields a liquid-to-gel-to-re-entrant liquid transition. In particular, the dynamic state diagram of 1,4-polybutadiene star-linear polymer mixtures was determined with the help of linear viscoelastic and small-angle X-ray scattering experiments. While keeping the star polymers below their nominal overlap concentration, a gel was formed upon increasing the linear polymer content. Further addition of linear chains yielded a re-entrant liquid. This unexpected behavior was rationalized by the interplay of three possible phenomena: (i) depletion interactions, driven by the size disparity between the stars and the polymer length scale which is the mesh size of its entanglement network; (ii) colloidal deswelling due to the increased osmotic pressure exerted onto the stars; and (iii) a concomitant progressive suppression of the depletion efficiency on increasing the polymer concentration due to reduced mesh size, hence a smaller range of attraction. Our results unveil an exciting new way to tailor the flow of soft colloids and highlight a largely unexplored path to engineer soft colloidal mixtures.
  • Synthesis and Characterization of Electrospun Carbon Nanofibers from Polyacrylonitrile and Graphite Nanoplatelets

    Albetran, Hani Manssor (Materials (Basel, Switzerland), MDPI AG, 2023-02-20) [Article]
    Sol-gel electrospinning process was used to prepare electrospun carbon nanofibers (ECNFs) from polyacrylonitrile and graphite nanoplatelets. The nanofibers of as-electrospun carbon were calcinated in argon from room temperature to 500 °C for 1h. Scanning and transmission electron microscopy with energy-dispersive X-ray spectroscopy and X-ray diffractometry (XRD) were used to characterize the synthesized ECNFs. The smooth ECNFs with a diameter of 129 ± 43 nm comprised conical platelets of 30–200 µm length. The plane-layered nanofibers contained crystallites along the long fiber axis and were mainly parallel.
  • High-Throughput Exonuclease Assay Based on the Fluorescent Base Analogue 2-Aminopurine

    Botto, Margherita M.; Murthy, Sudarshan; Lamers, Meindert H. (ACS Omega, American Chemical Society (ACS), 2023-02-20) [Article]
    Exonucleases are essential enzymes that remove nucleotides from free DNA ends during DNA replication, DNA repair, and telomere maintenance. Due to their essential role, they are potential targets for novel anticancer and antimicrobial drugs but have so far been little exploited. Here, we present a simple and versatile real-time exonuclease assay based on 2-aminopurine, an intrinsically fluorescent nucleotide that is quenched by neighboring bases when embedded in DNA. We show that our assay is applicable to different eukaryotic and bacterial exonucleases acting on both 3′ and 5′ DNA ends over a wide range of protein activities and suitable for a high-throughput inhibitor screening campaign. Using our assay, we discover a novel inhibitor of the Mycobacterium tuberculosis PHP-exonuclease that is part of the replicative DNA polymerase DnaE1. Hence, our novel assay will be a useful tool for high-throughput screening for novel exonuclease inhibitors that may interfere with DNA replication or DNA maintenance.
  • The effect of collisions on the multi-fluid plasma Richtmyer–Meshkov instability

    Tapinou, K.C.; Wheatley, Vincent; Bond, D.; Jahn, I. (Physics of Plasmas, AIP Publishing, 2023-02-17) [Article]
    The Richtmyer–Meshkov instability (RMI) results from the impulsive acceleration of a density interface where the RMI itself or the acceleration is perturbed. The RMI is ubiquitous in shock environments and may arise due to an interface of fluid species, isotopes, temperature, or more. The plasma RMI can be significantly influenced by electromagnetic effects and can be modeled more accurately by a multi-fluid plasma (MFP) model rather than conventional magnetohydrodynamics, though with increased computational expense. MFP modeling of the plasma RMI has revealed many phenomena but has only been completed within the ideal regime. Modeling the effects of elastic collisions is vital for understanding the behavior of the instability in a dense plasma. The Braginskii transport coefficients provide theoretically based relations modeling thermal equilibration, inter-species drag, viscous momentum- and energy-transfers, and thermal conductivity. Our numerical simulations of the MFP RMI with these relations show that the key changes from the ideal case are (1) reduction of relative motion between the ion and electron fluids (consequently affecting the self-generated electromagnetic fields), (2) introduction of anisotropy in momentum and energy via transport coefficients, and (3) damping of high frequency electromagnetic waves and plasma waves. Under the conditions studied, the net effect is a reduction in the MFP RMI amplitude width and the growth rate to levels approaching the neutral fluid instability, as well as a reduction in large scale perturbations along the ion fluid density interface, a positive for inertial confinement fusion efforts. There are, however, two important caveats: small-scale density interface perturbations remain, and the conditions simulated are a few relevant points in a large parameter space that requires further investigation.
  • Cloud-resolving modeling and evaluation of microphysical schemes for flash flood-producing convection over the Black Sea

    Anisimov, Anatolii; Efimov, Vladimir; Lvova, Margarita; Mostamandy, Suleiman; Stenchikov, Georgiy (Journal of Hydrometeorology, American Meteorological Society, 2023-02-16) [Article]
    In the present study, the convective event over the Black Sea area in September 2018 is analyzed using the Weather Research and Forecasting (WRF) model configured with a fully convective-resolving setup. We test the WRF sensitivity to the choice of sea surface temperature (SST) dataset and microphysics scheme. The simulation is verified using weather radar measurements and ground observations. Both the choice of the microphysical scheme and SST dataset have a significant impact on the dynamic properties of the maritime convective system and associated rainfall. The best results are achieved with the WDM6 microphysical scheme and a more detailed and slightly warmer (compared to the default OSTIA SST) G1SST dataset. The optimally configured WRF simulations add value to coarser driving operational analysis, with more accurate amount and pattern of rainfall and the earlier arrival of the convective system, which is in better agreement with radar and weather station measurements. The vertical structure of the reflectivity profiles in the WDM6 scheme that simulates 15–20% larger rainwater loading compared to other schemes agrees best with the observed data. Other schemes reproduce excessive reflectivity above the freezing level. Enhanced rainfall estimates and faster convective system propagation in the G1SST WDM6 simulations are linked to stronger cold pools caused by enhanced evaporation due to the higher rainwater content and droplet number concentrations. Stronger cold pools result in the 15–20% enhancement of latent and sensible heat fluxes, reflecting the strong sensitivity of ocean–atmosphere heat and moisture exchange to the choice of microphysics scheme and SST dataset.
  • An ab initio method on large sized molecular aggregate system: Predicting absorption spectra of crystalline organic semiconducting films

    Liu, Wenlan; Andrienko, Denis (The Journal of Chemical Physics, AIP Publishing, 2023-02-13) [Article]
    Theoretical description of electronic excited states of molecular aggregates at an {\em ab initio} level is computationally demanding. To reduce the computational cost, we propose a model Hamiltonian (MH) approach that approximates the electronically excited state wavefunction of the molecular aggregate. We benchmark our approach on a thiophene hexamer, as well as calculate the absorption spectra of several crystalline non-fullerene acceptors (NFAs), including Y6 and ITIC, which are known for their high power conversion efficiency in organic solar cells. The method qualitatively predicts the experimentally measured spectral shape, which can be further linked to the molecular arrangement in the unit cell.
  • Recent progress and challenges in the treatment of spinal cord injury

    Tian, Ting; Zhang, Sensen; Yang, Maojun (PROTEIN & CELL, Oxford University Press (OUP), 2023-02-10) [Article]
    Spinal cord injury (SCI) disrupts the structural and functional connectivity between the higher center and the spinal cord, resulting in severe motor, sensory, and autonomic dysfunction with a variety of complications. The pathophysiology of SCI is complicated and multifaceted, and thus individual treatments acting on a specific aspect or process are inadequate to elicit neuronal regeneration and functional recovery after SCI. Combinatory strategies targeting multiple aspects of SCI pathology have achieved greater beneficial effects than individual therapy alone. Although many problems and challenges remain, the encouraging outcomes that have been achieved in preclinical models offer a promising foothold for the development of novel clinical strategies to treat SCI. In this review, we characterize the mechanisms underlying axon regeneration of adult neurons and summarize recent advances in facilitating functional recovery following SCI at both the acute and chronic stages. In addition, we analyze the current status, remaining problems, and realistic challenges towards clinical translation. Finally, we consider the future of SCI treatment and provide insights into how to narrow the translational gap that currently exists between preclinical studies and clinical practice. Going forward, clinical trials should emphasize multidisciplinary conversation and cooperation to identify optimal combinatorial approaches to maximize therapeutic benefit in humans with SCI.
  • Aerosol characteristics and types in the marine environments surrounding the East Mediterranean - Middle East (EMME) region during the AQABA campaign

    Kaskaoutis, D. G.; Pikridas, M.; Barmpounis, K.; Kassell, G.; Logan, D.; Rigler, M.; Ivančič, M.; Mohammadpour, K.; Mihalopoulos, N.; Lelieveld, J.; Sciare, J. (Atmospheric Environment, Elsevier BV, 2023-02-06) [Article]
    This study analyzes the aerosol optical properties (scattering, absorption coefficients, single scattering albedo), supported by chemical composition measurements, in the marine boundary layer of the East Mediterranean – Middle East (EMME) region, aiming to explore the spatio-temporal variability, aerosol mixing state, sources and dominant types. The measurements were taken during the AQABA (Air Quality and climate change in the Arabian Basin) cruise campaign (1st July – September 1, 2017) from the south of France to Kuwait and back. Both scattering and absorption coefficients for PM1 and PM10 particles maximized in the southern Red Sea, due to continental outflow from East Africa, and in the Arabian/Persian Gulf due to enhanced anthropogenic/industrial emissions, leading to 3-fold sulfate concentrations compared to the other regions. The East Mediterranean exhibited moderate aerosol loading, with high scattering Ångström Exponent (SAE) values (1.98, 1.30 for PM1 and PM10, respectively), which increased in the Suez Canal and the Arabian Gulf due to impact from combustion sources. The aerosol over the Gulf of Aden and the West Arabian Sea was dominated by coarse particles (SAE<1), with higher Ca2+ concentrations (dust influence). The absorption Ångström Exponent (AAE) remained close to 1, indicative of black carbon (BC) from fossil fuel combustion, while it increased in regions dominated by dust (Gulf of Aden, Arabian Sea). Contrasting aerosol types were identified between the sub-regions using the SAE vs. AAE classification scheme. The “BC-dominated” type prevailed over the East Mediterranean and Suez Canal, while dust mixtures dominated in the Gulf of Aden and the Arabian Sea. Over the Arabian Gulf, mixing of anthropogenic pollution with marine aerosols formed a type with fine particles and low spectral dependence of absorption (AAE<1). Spectral SSA significantly varied along the ship cruise, while it was used for determination of dust influence in the marine environment.

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