bluuebunny/crossref_metadata_2025 huggingface dataset:
CFD Prediction of Wind Loads on FPSO and Shuttle Tankers during Side-by-Side Offloading
Authors: Yoo Jung-Hee , Schrijvers Patrick , Koop Arjen , Park Jong-Chun
Published: May 2022

This study entailed the estimation of wind loads performed using computational fluid dynamics (CFD) simulations for four typical offshore vessels and for a Floating Production, Storage, and Offloading (FPSO) and shuttle tanker in a side-by-side configuration on offloading. For all vessels, under the wind heading condition, four meshes were used to carry out the verification and validation (V&V) study to check the numerical uncertainty. The CFD simulation results for the aerodynamic coefficients were compared with wind tunnel tests from the Offloading Operability 2 JIP. All CFD simulation results show generally good agreement with the experimental data, and the overall trend of the coefficients are well captured. In addition, the effect on the gap sizes between the FPSO and shuttle tanker in the range of 4–30 m was examined. On this basis, the shielding effect was analyzed according to the size of the gap between the two ships.
Nonlinear Model Reduction by Moment-Matching for a Point Absorber Wave Energy Conversion System
Authors: Papini Guglielmo , Dores Piuma Francisco Javier Dores , Faedo Nicolás , Ringwood John V. , Mattiazzo Giuliana
Published: May 2022

This paper presents a data-driven model reduction by moment-matching approach to construct control-oriented models for a point absorber device. The methodology chosen and developed generates models which are input-to-state linear, with any nonlinear behaviour confined to the output map. Such a map is the result of a data-driven approximation procedure, where the so-called moment of the point absorber system is estimated via a least-squares procedure. The resulting control-oriented model can inherently preserve steady-state properties of the target WEC system for a user-defined class of input signals of interest, with the computation only dependent upon a suitably defined set of input-output data.
Identification of Distributed Dynamic Characteristics of Journal Bearing with Large Aspect Ratio under Shaft Bending
Authors: Ouyang Wu , Liu Qilin , Cheng Qichao , Wan Gao , Jin Yong
Published: May 2022

The classical theory of centralized dynamic characteristics with eight coefficients is adopted for traditional journal bearings. However, under cantilevered load, distributed dynamic characteristics along the axial direction will be generated for the journal bearing with a large aspect ratio (L/D). A double-section loading method simulating shaft bending and excitation was developed, a dynamic characteristic test-rig of a large-aspect-ratio bearing was set-up, the novel four-time vertical excitation method and eight-time cross excitation method were put forward, and the equations of 16 dynamic characteristic coefficients of the bearing were deduced. The dynamic characteristic test was carried out. The results showed that the four-time vertical excitation method had a small response amplitude in the horizontal direction, and was vulnerable to interference by the vibration of the test-rig. The eight-time cross excitation method had a higher SNR with more accurate identification results. When the cantilevered load was not applied, the dynamic characteristic coefficients were evenly distributed along the axial direction, the stiffness coefficients fluctuated slightly as the rotation rate increased, while the main damping coefficients decreased significantly. Shaft bending resulted in a significant increase in local dynamic characteristic coefficients, in which the relative increase in the stiffness coefficients was greater than that of the damping coefficients. Increasing the rotational speed can weaken the effect of shaft bending, and key factors that cause the axially nonuniform distribution of dynamic characteristic coefficients of the bearing are shaft bending and large aspect ratio under low speed and cantilevered load.
Comparative Study of Marine Cave Communities in a Protected Area of the South-Eastern Aegean Sea, Greece
Authors: Digenis Markos , Arvanitidis Christos , Dailianis Thanos , Gerovasileiou Vasilis
Published: May 2022

Although more than 600 marine caves have been recorded so far along the Greek coasts of the Aegean Sea (Eastern Mediterranean), only a few have been systematically studied for their biodiversity. In this study, the benthic communities of six marine caves within a Protected Area of South-Eastern Aegean were studied for the first time, both qualitatively and quantitatively. The association of different geomorphological and topographical factors of the caves with the benthic community structure was investigated. A total of 120 photographic quadrats covering the entrance and semi-dark cave zones were analysed, with regard to coverage and taxon abundance, while motile taxa were qualitatively recorded by visual census. The ecological quality status of the caves was also assessed under an ecosystem-based approach. In total, 81 sessile and 45 motile taxa were recorded, including 12 protected and 10 non-indigenous species. Multivariate community analysis demonstrated that the geomorphological and topographical variables of the caves are significantly associated with the observed biotic patterns. The ecological quality of the caves was assessed as poor or moderate according to the CavEBQI index, highlighting the necessity for systematic monitoring. This study paves the way for similar studies in marine cave habitats aiming at the development of management and conservation actions.
Stachybotrys chartarum—A Hidden Treasure: Secondary Metabolites, Bioactivities, and Biotechnological Relevance
Authors: Ibrahim Sabrin R. M. , Choudhry Hani , Asseri Amer H. , Elfaky Mahmoud A. , Mohamed Shaimaa G. A. , Mohamed Gamal A.
Published: May 2022

Fungi are renowned as a fountainhead of bio-metabolites that could be employed for producing novel therapeutic agents, as well as enzymes with wide biotechnological and industrial applications. Stachybotrys chartarum (black mold) (Stachybotriaceae) is a toxigenic fungus that is commonly found in damp environments. This fungus has the capacity to produce various classes of bio-metabolites with unrivaled structural features, including cyclosporins, cochlioquinones, atranones, trichothecenes, dolabellanes, phenylspirodrimanes, xanthones, and isoindoline and chromene derivatives. Moreover, it is a source of various enzymes that could have variable biotechnological and industrial relevance. The current review highlights the formerly published data on S. chartarum, including its metabolites and their bioactivities, as well as industrial and biotechnological relevance dated from 1973 to the beginning of 2022. In this work, 215 metabolites have been listed and 138 references have been cited.
MID-Crypt: A Cryptographic Algorithm for Advanced Medical Images Protection
Authors: Ahmad Ashraf , AbuHour Yousef , Younisse Remah , Alslman Yasmeen , Alnagi Eman , Abu Al-Haija Qasem
Published: May 2022

Privacy-preserving of medical information (such as medical records and images) is an essential right for patients to ensure security against undesired access parties. This right is typically protected by law through firm regulations set by healthcare authorities. However, sensitive-private data usually requires the application of further security and privacy mechanisms such as encipherment (encryption) techniques. ’Medical images’ is one such example of highly demanding security and privacy standards. This is due to the quality and nature of the information carried among these images, which are usually sensitive-private information with few features and tonal variety. Hence, several state-of-the-art encryption mechanisms for medical images have been proposed and developed; however, only a few were efficient and promising. This paper presents a hybrid crypto-algorithm, MID-Crypt, to secure the medical image communicated between medical laboratories and doctors’ accounts. MID-Crypt is designed to efficiently hide medical image features and provide high-security standards. Specifically, MID-Crypt uses a mix of Elliptic-curve Diffie–Hellman (ECDH) for image masking and Advanced Encryption Standard (AES) with updatable keys for image encryption. Besides, a key management module is used to organize the public and private keys, the patient’s digital signature provides authenticity, and integrity is guaranteed by using the Merkle tree. Also, we evaluated our proposed algorithm in terms of several performance indicators including, peak signal-to-noise ratio (PSNR) analysis, correlation analysis, entropy analysis, histogram analysis, and timing analysis. Consequently, our empirical results revealed the superiority of MID-Crypt scoring the best performance values for PSNR, correlation, entropy, and encryption overhead. Finally, we compared the security measures for the MID-Crypt algorithm with other studies, the comparison revealed the distinguishable security against several common attacks such as side-channel attacks (SCA), differential attacks, man-in-the-middle attacks (MITM), and algebraic attacks.
Hydration and Mechanical Properties of Blended Cement with Copper Slag Pretreated by Thermochemical Modification
Authors: Wang Daolin , Zhang Qinli , Feng Yan , Chen Qiusong , Xiao Chongchun , Li Hongpeng , Xiang Yujing , Qi Chongchong
Published: May 2022

The application of granulated copper slag (GCS) to partially replace cement is limited due to its low pozzolanic activity. In this paper, reconstituted granulated copper slag (RGCS) was obtained by adding alumina oxide (Al2O3) to liquid copper slag. Blended cement pastes were formulated by a partial substitute for ordinary Portland cement (OPC) with the RGCS (30 wt%). The pozzolanic activity, mechanical development, and the microstructure were characterized. The results show that 5–10 wt% Al2O3 contributes to the increase in magnetite precipitation in RGCS. The addition of Al2O3 alleviates the inhibition of C3S by RGCS and accelerates the dissociation of RGCS active molecules, thus increasing the exothermic rate and cumulative heat release of the blended cement pastes, which are the highest in the CSA10 paste with the highest Al2O3 content (10 wt%) in RGCS. The unconfined compressive strength (UCS) values of blended cement mortar with 10 wt% Al2O3 added to RGCS reach 27.3, 47.4, and 51.3 MPa after curing for 7, 28 and 90 d, respectively, which are the highest than other blended cement mortars, and even exceed that of OPC mortar at 90 d of curing. The pozzolanic activity of RGCS is enhanced with the increase in Al2O3 addition, as evidenced by more portlandite being consumed in the CSA10 paste, forming more C-S-H (II) gel with a higher Ca/Si ratio, and a more compact microstructure with fewer pores than other pastes. This work provided a novel, feasible, and clean way to enhance the pozzolanic activity of GCS when it was used as a supplementary cementitious material.
Spatial Dispersion in Hypercrystal Distributed Feedback Lasing
Authors: Janaszek Bartosz , Szczepański Paweł
Published: May 2022

This work is a first approach to investigate the role of spatial dispersion in photonic hypercrystals (PHCs). The scope of the presented analysis is focused on exploiting nonlocality, which can be controlled by appropriate design of the structure, to obtain new light generation effects in a distributed feedback (DFB) laser based on PHC, which are not observable under weak spatial dispersion. Here, we use effective medium approximation and our original model of threshold laser generation based on anisotropic transfer matrix method. To unequivocally identify nonlocal generation phenomena, the scope of our analysis includes comparison between local and nonlocal threshold generation spectra, which may be obtained for different geometries of PHC structure. In particular, we have presented that, in the presence of strong spatial dispersion, it is possible to obtain spectrally shifted Bragg wavelengths of TE- and TM-polarization spectra, lowered generation threshold levels for both light polarizations, generation of light of selected light polarization (TE or TM), or simultaneous generation of TE- and TM-polarized waves at different frequencies with controllable spectral separation, instead of single mode operation anticipated with local approach.
Response Surface of Speed-Loading Path to Grain Refinement during Current-Heating Compression at SAE 5137H Steel
Authors: Quan Guo-Zheng , Yang Kun , Yu Yan-Ze , Sheng Xue , Wen Zhi-Hang , Lu Chao-Long
Published: May 2022

In thermal deformation of materials, grain refinement induced by dynamic recrystallization (DRX) is often pursued to obtain excellent mechanical properties. Here, the thermal deformation behaviors of SAE 5137H steel were investigated and characterized at temperature and strain rate range of 1123–1483 K and 0.01–10 s−1. Meanwhile, a design approach in speed-loading paths for grain refinement during current-heating compression was proposed, and these paths are linked to a typical three-dimensional (3D) response surface. Depending on the acquired stress–strain curves, the flow behaviors of this steel were analyzed and the typical 3D processing map was constructed to clarify the stable processing parameter domains during the continuous deformation process. Then, by the typical 3D processing map and microstructure observation, the 3D deformation mechanism map was constructed to connect the processing parameters and microstructural mechanisms. Subsequently, the 3D activation energy map was constructed to evaluate these deformation mechanisms, and the enhanced deformation mechanism map was constructed. Eventually, based on the enhanced deformation mechanism map, the speed-loading paths for SAE 5137H steel during current-heating compression were designed and they are mapped in a 3D response surface.
Prediction of the Compressive Strength for Cement-Based Materials with Metakaolin Based on the Hybrid Machine Learning Method
Authors: Huang Jiandong , Zhou Mengmeng , Yuan Hongwei , Sabri Mohanad Muayad Sabri , Li Xiang
Published: May 2022

Cement-based materials are widely used in construction engineering because of their excellent properties. With the continuous improvement of the functional requirements of building infrastructure, the performance requirements of cement-based materials are becoming higher and higher. As an important property of cement-based materials, compressive strength is of great significance to its research. In this study, a Random Forests (RF) and Firefly Algorithm (FA) hybrid machine learning model was proposed to predict the compressive strength of metakaolin cement-based materials. The database containing five input parameters (cement grade, water to binder ratio, cement-sand ratio, metakaolin to binder ratio, and superplasticizer) based on 361 samples was employed for the prediction. In this model, FA was used to optimize the hyperparameters, and RF was used to predict the compressive strength of metakaolin cement-based materials. The reliability of the hybrid model was verified by comparing the predicted and actual values of the dataset. The importance of five variables was also evaluated, and the results showed the cement grade has the greatest influence on the compressive strength of metakaolin cement-based materials, followed by the water-binder ratio.
Improved Ion/Ioff Current Ratio and Dynamic Resistance of a p-GaN High-Electron-Mobility Transistor Using an Al0.5GaN Etch-Stop Layer
Authors: Wang Hsiang-Chun , Liu Chia-Hao , Huang Chong-Rong , Shih Min-Hung , Chiu Hsien-Chin , Kao Hsuan-Ling , Liu Xinke
Published: May 2022

In this study, we investigated enhance mode (E-mode) p-GaN/AlGaN/GaN high-electron-mobility transistors (HEMTs) with an Al0.5GaN etch-stop layer. Compared with an AlN etch-stop layer, the Al0.5GaN etch-stop layer not only reduced lattice defects but engendered improved DC performance in the device; this can be attributed to the lattice match between the layer and substrate. The results revealed that the Al0.5GaN etch-stop layer could reduce dislocation by 37.5% and improve device characteristics. Compared with the device with the AlN etch-stop layer, the p-GaN HEMT with the Al0.5GaN etch-stop layer achieved a higher drain current on/off ratio (2.47 × 107), a lower gate leakage current (1.55 × 10−5 A/mm), and a lower on-state resistance (21.65 Ω·mm); moreover, its dynamic RON value was reduced to 1.69 (from 2.26).
Correction: Borinelli et al. VOC Emission Analysis of Bitumen Using Proton-Transfer Reaction Time-Of-Flight Mass Spectrometry. Materials 2020, 13, 3659
Authors: Borinelli Jaffer Bressan , Blom Johan , Portillo-Estrada Miguel , Kara De Maeijer Patricia , Van den bergh Wim , Vuye Cedric
Published: May 2022

The authors wish to make the following corrections to this paper [...]
Stress Relaxation Behavior of Additively Manufactured Polylactic Acid (PLA)
Authors: Bertocco Alcide , Bruno Matteo , Armentani Enrico , Esposito Luca , Perrella Michele
Published: May 2022

In this work, the stress relaxation behavior of 3D printed PLA was experimentally investigated and analytically modeled. First, a quasi-static tensile characterization of additively manufactured samples was conducted by considering the effect of printing parameters like the material infill orientation and the outer wall presence. The effect of two thermal conditioning treatments on the material tensile properties was also investigated. Successively, stress relaxation tests were conducted, on both treated and unconditioned specimens, undergoing three different strains levels. Analytical predictive models of the viscous behavior of additive manufactured material were compared, highlighting and discussing the effects of considered printing parameters.
Research Progress of Alumina-Forming Austenitic Stainless Steels: A Review
Authors: Liu Ling , Fan Cuilin , Sun Hongying , Chen Fuxiao , Guo Junqing , Huang Tao
Published: May 2022

The development of Alumina-Forming Austenitic (AFA) stainless steel is reviewed in this paper. As a new type of heat-resistant steel, AFA steel forms an alumina protective scale instead of chromia in a corrosive environment. This work summarizes the types of developed AFA steels and introduces the methods of composition design. Various precipitates appear in the microstructure that directly determine the performance at high temperatures. It was found that alloy elements and the heat treatment process have an important influence on precipitates. In addition, the corrosion resistance of AFA steel in different corrosive environments is systematically analyzed, and the beneficial or harmful effects of different elements on the formation of alumina protective scale are discussed. In this paper, the short-term mechanical properties, creep properties and influencing factors of AFA steel are also analyzed. This work aims to summarize the research status on this subject, analyze the current research results, and explore future research directions.
Correction: Huang et al. An Improved Lotka–Volterra Model Using Quantum Game Theory. Mathematics 2021, 9, 2217
Authors: Huang Dingxuan , Delang Claudio O. , Wu Yongjiao , Li Shuliang
Published: May 2022

Addition of Authors [...]
Equation for Egg Volume Calculation Based on Smart’s Model
Authors: Weng Yu-Kai , Li Cheng-Han , Lai Chia-Chun , Cheng Ching-Wei
Published: May 2022

In the egg industry, it is necessary to estimate the egg volume accurately when estimating egg quality or freshness in a non-destructive method. Egg volume and weight could obtain egg density and could be used to determine egg freshness. Therefore, the egg geometric must be obtained first to establish a volume equation with a geometric shape. This research proposes an innovative idea to derive the mathematical model and volume equation of egg shape, calculate its volume, and verify the accuracy of the mathematical equation proposed using the volume displacement method. Using the proposed equation, the minimum error between the calculated egg volume) and actual egg volume is 0.01%. The maximum volume error does not exceed 2%. The egg shape equation can accurately draw the outer contour curve of the egg by the half-length of the maximum long axis and maximum breadth of the short axis, and the distance from the center point of the egg to the maximum breadth (xm).
Fatigue Life Assessment of Intercity Track Viaduct Based on Vehicle–Bridge Coupled System
Authors: Cui Chenxing , Feng Fan , Meng Xiandong , Liu Xiang
Published: May 2022

During the long-term operation of an urban railway viaduct, it is subjected to multiple cyclic loads caused by the movement of a vehicle. As a result, the fatigue life of the bridge should be fully considered during the design process. Furthermore, the bridge structure will be subject to environmental corrosion for an extended period of time, resulting in concrete carbonization and reinforcement corrosion, which aggravates the bridge structure’s fatigue damage. To compensate for the disadvantage of the traditional static analysis method’s inability to consider vehicle speed, a vehicle–bridge system coupled model is established, material corrosion is considered, railway bridge damage under vehicle load is analyzed, and the service life of common 30 m and 25 m span bridges is calculated. The results show that ignoring corrosion will understate the bridge damage, and vehicle speed has a significant impact on bridge fatigue life. Finally, the recommended operating speeds for 30 m span and 25 m span bridges are provided.
Aerodynamic Heating Ground Simulation of Hypersonic Vehicles Based on Model-Free Control Using Super Twisting Nonlinear Fractional Order Sliding Mode
Authors: Lv Xiaodong , Zhang Guangming , Zhu Mingxiang , Shi Zhihan , Bai Zhiqing , Alexandrov Igor V.
Published: May 2022

In this article, a model-free control (MFC) using super twisting nonlinear fractional order sliding mode for aerodynamic heating ground simulation of hypersonic vehicles (AHGSHV) is proposed. Firstly, the mathematical model of AHGSHV is built up. To reduce order and simplify the dynamic model of AHGSHV, an ultra-local model of MFC is taken into consideration. Then, time delay estimation can be used to estimate systematic uncertainties and external unknown disturbances. On the basis of the original fractional order sliding mode surface, the nonlinear function fal is introduced to design the nonlinear fractional order sliding mode surface, which can guarantee stability, increase convergence rate, and reduce static error and saturation error. In addition, the super twisting reaching law is used to improve the control performance of the reaching phase, resulting from the existence of sign function in the integral term, and it can effectively reduce the high-frequency chattering. Moreover, the Lyapunov function is used to prove the stability of the whole system. Finally, several numerical simulations show that the designed controller has more advantages than others.
New Reductions of the Unsteady Axisymmetric Boundary Layer Equation to ODEs and Simpler PDEs
Authors: Aksenov Alexander V. , Kozyrev Anatoly A.
Published: May 2022

Reductions make it possible to reduce the solution of a PDE to solving an ODE. The best known are the traveling wave, self-similar and symmetry reductions. Classical and non-classical symmetries are also used to construct reductions, as is the Clarkson–Kruskal direct method. Recently, authors have proposed a method for constructing reductions of PDEs with two independent variables based on the idea of invariance. The proposed method in this work is a modification of the Clarkson–Kruskal direct method and expands the possibilities for its application. The main result of this article consists of a method for constructing reductions that generalizes the previously proposed approach to the case of three independent variables. The proposed method is used to construct reductions of the unsteady axisymmetric boundary layer equation to ODEs and simpler PDEs. All reductions of this equation were obtained.
Theoretical Study on Non-Improvement of the Multi-Frequency Direct Sampling Method in Inverse Scattering Problems
Authors: Park Won-Kwang
Published: May 2022

Generally, it has been confirmed that applying multiple frequencies guarantees a successful imaging result for various non-iterative imaging algorithms in inverse scattering problems. However, the application of multiple frequencies does not yield good results for direct sampling methods (DSMs), which has been confirmed through simulation but not theoretically. This study proves this premise theoretically by showing that the indicator function with multi-frequency can be expressed by the Bessel and Struve functions and the propagation direction of the incident field. This is based on the fact that the indicator function with single frequency can be expressed by the exponential and Bessel function of order zero of the first kind. Various simulation outcomes are shown to support the theoretical result.
Water Dynamics in Cancer Cells: Lessons from Quasielastic Neutron Scattering
Authors: Martins Murillo L. , Bordallo Heloisa N. , Mamontov Eugene
Published: May 2022

The severity of the cancer statistics around the globe and the complexity involving the behavior of cancer cells inevitably calls for contributions from multidisciplinary areas of research. As such, materials science became a powerful asset to support biological research in comprehending the macro and microscopic behavior of cancer cells and untangling factors that may contribute to their progression or remission. The contributions of cellular water dynamics in this process have always been debated and, in recent years, experimental works performed with Quasielastic neutron scattering (QENS) brought new perspectives to these discussions. In this review, we address these works and highlight the value of QENS in comprehending the role played by water molecules in tumor cells and their response to external agents, particularly chemotherapy drugs. In addition, this paper provides an overview of QENS intended for scientists with different backgrounds and comments on the possibilities to be explored with the next-generation spectrometers under construction.
Biosurfactant-Producing Bacillus velezensis PW192 as an Anti-Fungal Biocontrol Agent against Colletotrichum gloeosporioides and Colletotrichum musae
Authors: Jumpathong Watthanachai , Intra Bungonsiri , Euanorasetr Jirayut , Wanapaisan Pagakrong
Published: May 2022

In this study, plant-root-associated Bacillus species were evaluated as antifungal biocontrol agents by analyzing the production of surface bioactive molecules known as lipopeptide biosurfactants. This study aimed to isolate and characterize antifungal biosurfactant-producing Bacillus bacterium. Bacillusvelezensis PW192 was isolated from the rhizosphere of Lagerstroemia macrocarpa var macrocarpa and identified based on phylogenetic analysis of the 16S rRNA gene. The biosurfactant was excreted to cultured supernatant and exhibited emulsification power up to 60% and a decrease in surface tension from 72 in distilled water to 21 mN/m. The surface tension properties were stable in a broad range of pH from 6 to 10, in high temperatures up to 100 °C, and in salinities with a NaCl concentration up to 12% (w/v). Starting from 0.5 mg of acid, precipitated crude biosurfactant exhibited antifungal activity toward Anthracnose, caused by the phytopathogens Colletotrichum gloeosporioides and C. musae. The chemical structures of the biosurfactant were structurally characterized as lipopeptides fengycin A and fengycin B. The stability of the biosurfactant, as well as the antifungal properties of B. velezensis PW192, can potentially make them useful as agricultural biocontrol agents, as well as in other biotechnological applications.
Porphyrin NanoMetal-Organic Frameworks as Cancer Theranostic Agents
Authors: Figueira Flávio , Tomé João P. C. , Paz Filipe A. Almeida
Published: May 2022

Metal-Organic Frameworks (MOFs) are hybrid multifunctional platforms that have found remarkable applications in cancer treatment and diagnostics. Independently, these materials can be employed in cancer treatment as intelligent drug carriers in chemotherapy, photothermal therapy, and photodynamic therapy; conversely, MOFs can further be used as diagnostic tools in fluorescence imaging, magnetic resonance imaging, computed tomography imaging, and photoacoustic imaging. One essential property of these materials is their great ability to fine-tune their composition toward a specific application by way of a judicious choice of the starting building materials (metal nodes and organic ligands). Moreover, many advancements were made concerning the preparation of these materials, including the ability to downsize the crystallites yielding nanoporous porphyrin MOFs (NMOFs) which are of great interest for clinical treatment and diagnostic theranostic tools. The usage of porphyrins as ligands allows a high degree of multifunctionality. Historically these molecules are well known for their reactive oxygen species formation and strong fluorescence characteristics, and both have proved helpful in cancer treatment and diagnostic tools. The anticipation that porphyrins in MOFs could prompt the resulting materials to multifunctional theranostic platforms is a reality nowadays with a series of remarkable and ground-breaking reports available in the literature. This is particularly remarkable in the last five years, when the scientific community witnessed rapid development in porphyrin MOFs theranostic agents through the development of imaging technologies and treatment strategies for cancer. This manuscript reviews the most relevant recent results and achievements in this particular area of interest in MOF chemistry and application.
Within the Ischemic Penumbra, Sub-Cellular Compartmentalization of Heat Shock Protein 70 Overlaps with Autophagy Proteins and Fails to Merge with Lysosomes
Authors: Mastroiacovo Federica , Biagioni Francesca , Lenzi Paola , Lazzeri Gloria , Ferrucci Michela , Puglisi-Allegra Stefano , Frati Alessandro , Nicoletti Ferdinando , Fornai Francesco
Published: May 2022

The brain area which surrounds the frankly ischemic region is named the area penumbra. In this area, most cells are spared although their oxidative metabolism is impaired. area penumbra is routinely detected by immunostaining of a molecule named Heat Shock Protein 70 (HSP70). Within the area penumbra, autophagy-related proteins also increase. Therefore, in the present study, the autophagy-related microtubule-associated protein I/II-Light Chain 3 (LC3) was investigated within the area penumbra along with HSP70. In C57 black mice, ischemia was induced by permanent occlusion of the distal part of the middle cerebral artery. Immunofluorescence and electron microscopy show that LC3 and HSP70 are overexpressed and co-localize within the area penumbra in the same cells and within similar subcellular compartments. In the area penumbra, marked loss of co-localization of HSP70 and LC3-positive autophagy vacuoles, with lysosomal-associated membrane protein 1 (LAMP1) or cathepsin-D-positive lysosome vacuoles occurs. This study indicates that, within the area penumbra, a failure of autophagolysosomes depends on defective compartmentalization of LC3, LAMP1 and cathepsin-D and a defect in merging between autophagosomes and lysosomes. Such a deleterious effect is likely to induce a depletion of autophagolysosomes and cell clearing systems, which needs to be rescued in the process of improving neuronal survival.
An Experimental Design Approach to Quantitative Expression for Quality Control of a Multicomponent Antidiabetic Formulation by the HILIC Method
Authors: Attimarad Mahesh , Venugopala Katharigatta Narayanaswamy , Chohan Muhammad S. , David Marysheela , Molina Efren II Plaza , Sreeharsha Nagaraja , Nair Anroop Balachandran , Tratrat Christophe , Altaysan Abdulrahman Ibrahim , Balgoname Abdulmalek Ahmed
Published: May 2022

A rapid and reproducible hydrophilic liquid chromatography (HILIC) process was established for concomitant determination of remogliflozin etabonate (RE), vildagliptin (VD), and metformin (MF) in a formulation. A face-centered central composite experimental design was employed to optimize and predict the chromatographic condition by statistically studying the surface response model and design space with desirability close to one. A HILIC column with a simple mobile phase of acetonitrile (65% v/v) and 20 mM phosphate buffer (35% v/v, pH 6, controlled with orthophosphoric acid) was used to separate RE, VD, and MF. RE, VD, and MF were separated in 3.6 min using an isocratic mode mobile phase flow at a flow rate of 1.4 mL at room temperature, and the analytes were examined by recording the absorption at 210 nm. The developed HILIC method was thoroughly validated for all parameters recommended by ICH, and linearity was observed in the ranges 20–150 µg/mL, 10–75 µg/mL, and 50–750 µg/mL for RE, VD, and MF, respectively, along with excellent regression coefficients (r2 > 0.999). The calculated percentage relative deviation and relative error ascertained the precision and accuracy of the method. The selectivity and accuracy were further confirmed by the high percentage recovery of added standard drugs to the formulation using the standard addition technique. The robustness of the HILIC processes was confirmed by developing a half-normal probability plot and Pareto chart, as the slight variation of a single factor had no significant influence on the assay outcomes. Utilization of the optimized HILIC procedure for concurrent quantification of RE, VD, and MF in solid dosage forms showed accurate and reproducible results. Hence, the fast HILIC method can be regularly employed for the quality assurance of pharmaceutical preparations comprising RE, VD, and MF.
Self-Reported Total Screen Time and Viewing Modes Are Associated with Body Dissatisfaction, Disordered Eating, and Cosmetic Surgery Intentions among Young Adults
Authors: Tang Lisa , Rifas-Shiman Sheryl L. , Field Alison E. , Austin S. Bryn , Haines Jess
Published: May 2022

While numerous studies have shown that media exposure is linked to body dissatisfaction and disordered eating behavior, limited research has examined these associations by screen-viewing mode. This study examined associations of total screen-time and screen-viewing modes with body dissatisfaction, disordered eating, and cosmetic surgery intention among young adults. Men (n = 3466) and women (n = 7300), aged 19 to 34 years, self-reported their screen-time on various TV viewing modes, and their body dissatisfaction, overeating, disordered weight control behaviors, and cosmetic surgery intentions. We fit linear, logistic, and multivariate models to examine cross-sectional associations between total screen-time and screen-viewing modes and body dissatisfaction, disordered eating, and cosmetic surgery intention. Handheld viewing was associated with body dissatisfaction for women only, and online viewing was associated with greater body dissatisfaction among both men (βˆ = 0.40; 95% CI, 0.15 to 0.65) and women (βˆ = 0.25; 95% CI, 0.10 to 0.40). Downloaded viewing was associated with higher odds of overeating behaviors among both men (OR = 1.24; 95% CI, 1.10 to 1.40) and women (OR = 1.21; 95% CI, 1.12 to 1.32), respectively. Although total screen time was associated with greater cosmetic surgery intention for both men (βˆ = 0.24; 95% CI, 0.09 to 0.39) and women (βˆ = 0.43; 95% CI, 0.28 to 0.58), sex differences were found for the viewing modes. Our results suggest that different viewing modes may be differently associated with men and women’s body image, disordered eating behavior, and cosmetic surgery intention. Future research should consider all modes of screen-viewing in our media environment.
Metabolic Effects of an Oral Glucose Tolerance Test Compared to the Mixed Meal Tolerance Tests: A Narrative Review
Authors: Lages Marlene , Barros Renata , Moreira Pedro , Guarino Maria P.
Published: May 2022

The oral glucose tolerance test (OGTT) is recommended for assessing abnormalities in glucose homeostasis. Recognised as the gold standard test for diagnosing diabetes, the OGTT provides useful information about glucose tolerance. However, it does not replicate the process of absorption and digestion of complex foods, such as that which occurs with a mixed meal tolerance test (MMTT), an alternative that is still not well explored in the diagnosis of metabolic alterations. The MMTT could be an asset in detecting glucose homeostasis disorders, including diabetes since it has more similarities to the common dietary pattern, allowing early detection of subtle changes in metabolic homeostasis in response to combined nutrients. This alternative has the advantage of being more tolerable and pleasant to patients since it induces a more gradual increase in blood glucose, thus reducing the risk of rebound hypoglycemia and other related complications. The present article reviewed the clinical data available regarding the possibility of screening or diagnosing altered glucose homeostasis, including type 2 diabetes mellitus, with the MMTT.
Factors Related to Underweight Prevalence among 33,776 Children Below 60 Months Old Living in Northern Geopolitical Zones, Nigeria (2008–2018)
Authors: Goson Piwuna C. , Ishaya Tanko , Ezeh Osita K. , Oforkansi Gladys H. , Lim David , Agho Kingsley E.
Published: May 2022

The prevalence of underweight among children below 60 months old in Nigeria remains a significant public health challenge, especially in northern geopolitical zones (NGZ), ranging from 15% to 35%. This study investigates time-based trends in underweight prevalence and its related characteristics among NGZ children below 60 months old. Extracted NGZ representative dataset of 33,776 live births from the Nigeria Demographic and Health Survey between 2008 and 2018 was used to assess the characteristics related to underweight prevalence in children aged 0–23, 24–59, and 0–59 months using multilevel logistics regression. Findings showed that 11,313 NGZ children below 60 months old were underweight, and 24–59-month-old children recorded the highest prevalence (34.8%; 95% confidence interval: 33.5–36.2). Four factors were consistently significantly related to underweight prevalence in children across the three age groups: poor or average-income households, maternal height, children who had diarrhoea episodes, and children living in the northeast or northwest. Intervention initiatives that include poverty alleviation through cash transfer, timely health checks of offspring of short mothers, and adequate clean water and sanitation infrastructure to reduce the incidence of diarrhoea can substantially reduce underweight prevalence among children in NGZ in Nigeria.
Backscattering Estimation of a Tilted Spherical Cap for Different Kinds of Optical Scattering
Authors: Leng Rongkuan , Wang Zhi , Fang Chao , Liu Lei , Chen Zhiwei , Cui Xinxu
Published: May 2022

In many optical engineering applications, a spherical cap shaped optical element is widely used such as concave or convex mirrors in reflective optics. Such an element can also tilt around the vertex which corresponds to an off-axis optical design. The optical backscattering of such an optical element sometimes could be important. For example, in the space-based gravitational wave detection, the backscattering of such an element could be superimposed with the local oscillator and limits the sensitivity of the spacecraft. The scattered contributions depend on the scattering property of the mirror surfaces and the geometrical arrangement including the radius of curvature, the tilt and the interval between the scattering source and detector plane. Based on random estimation method, this paper starts from the radiometry, combines these variables and calculates the theoretical amount of back scattered light for both diffuse and superpolished surfaces. The results are compared with analytical and ray tracing solution. The conclusions can be used to further improve the optical design of the telescope or extended to other cases where the backscattered light should be controlled.
The Highly Leukotoxic JP2 Genotype of Aggregatibacter actinomycetemcomitans Is Present in the Population of the West African Island, Sal in Cape Verde: A Pilot Study
Authors: De Soet Johannes J. , Claesson Rolf , Haubek Dorte , Johansson Anders , Buijs Mark J. , Volgenant Catherine M. C.
Published: May 2022

Aggregatibacter actinomycetemcomitans is strongly associated with severe periodontitis, possibly due to its production of a potent leukotoxin. A genetic variant, the JP2 genotype, was found to produce more leukotoxin than the wild type because of a mutation in the leukotoxin gene, and this genotype is frequently found in African populations. The aim of this study was to investigate whether this JP2 genotype can be found in a randomly selected group of inhabitants of Sal, Cape Verde. Twenty-nine adults between 20 and 59 years of age (58.6% female) participated, and information on their oral health and living standards was collected. An oral examination was performed for each participant, including DMF-T and CPI scores. Plaque and saliva samples were collected and transported to Europe, where DNA was isolated, and the concentration of A. actinomycetemcomitans and its JP2 genotype was determined using dedicated PCR analyses. All 29 plaque and 31% of the saliva samples harboured A. actinomycetemcomitans, and two participants were positive for the JP2 genotype. The presence of this JP2 genotype was not associated with either CPI or DMF-T. This pilot study is the first to describe the presence of the A. actinomycetemcomitans JP2 genotype in a Cape Verdean population living in the Cape Verde Islands, and the findings warrant further research.
Fluorine-18 Labeled Urea-Based Ligands Targeting Prostate-Specific Membrane Antigen (PSMA) with Increased Tumor and Decreased Renal Uptake
Authors: Basuli Falguni , Phelps Tim E. , Zhang Xiang , Woodroofe Carolyn C. , Roy Jyoti , Choyke Peter L. , Swenson Rolf E. , Jagoda Elaine M.
Published: May 2022

High expression of prostate-specific membrane antigen (PSMA) in prostate cancers prompted the development of the PSMA-targeted PET-imaging agent [18F]DCFPyL, which was recently approved by the FDA. Fluorine-18-labeled Lys–Urea–Glu-based oxime derivatives of [18F]DCFPyL were prepared for the comparison of their in vitro and in vivo properties to potentially improve kidney clearance and tumor targeting. The oxime radiotracers were produced by condensation of an aminooxy functionalized PSMA-inhibitor Lys–Urea–Glu scaffold with fluorine-18-labeled aldehydes. The radiochemical yields were between 15–42% (decay uncorrected) in 50–60 min. In vitro saturation and competition binding assays with human prostate cancer cells transfected with PSMA, PC3(+), indicated similar high nM binding affinities to PSMA for all radiotracers. In vivo biodistribution studies with positive control PC3(+) tumor xenografts showed that the kidneys had the highest uptake followed by tumors at 60 min. The PC3(+) tumor uptake was blocked with non-radioactive DCFPyL, and PC3(−) tumor xenograft (negative control) tumor uptake was negligible indicating that PSMA targeting was preserved. The most lipophilic tracer, [18F]2a, displayed comparable tumor-targeting to [18F]DCFPyL and a desirable alteration in pharmacokinetics and metabolism, resulting in significantly lower kidney uptake with a shift towards hepatobiliary clearance and increased liver uptake.
Theoretical Study on the Ultrafast Selective Excitation of Surface-Enhanced Coherent Anti-Stokes Raman Scattering Based on Fano Resonance of Disk-Ring Nanostructures by Shaped Femtosecond Laser Pulses
Authors: Xia Yingjie , Cao Kaiqiang , Zhao Hua , Zhang Shian , Feng Donghai , Sun Zhenrong , Li Jinping , Jia Tianqing
Published: May 2022

The enhancement and selective excitation of coherent anti-Stokes Raman scattering (CARS) and the suppression of background noise are very important problems for real-time detection at the single-molecule level. Optimizing the plasmonic substrate to ensure that all the hot spots of the pump, probe, Stokes, and anti-Stokes light are at the same position is the key to increasing the CARS signal to reach the level of single-molecule detection. The selective excitation of the target CARS peak and the suppression of the other peaks are the key to improving the signal-to-noise ratio. In this paper, we present a theoretical study to control the selective excitation and enhancement of any one of the three CARS peaks using the Fano resonance of a disk-ring structure. By optimizing the modulation of the pump, Stokes, and probe pulse, one CARS peak is maximized, while the other two are suppressed to zero. Fano resonance is applied to simultaneously enhance the four surface plasmon modes of the pump, probe, Stokes, and anti-Stokes light and to ensure that all the hot spots are located at the same position by adjusting the size of the disk-ring structure. The hot spots of the four pulses are concentrated in the disk-ring gap with a deviation distance of less than 2 nm, and the intensity of the CARS is enhanced by 1.43 × 1012 times, which is much higher than the requirement of single-molecule detection. The time, frequency, and phase distribution of the input and the response of the four pulses are studied in detail. It was found that the selective excitation and the spectra of CARS are both well preserved.
Polyoxypregnane Ester Derivatives and Lignans from Euphorbia gossypina var. coccinea Pax.
Authors: Hammadi Reham , Kúsz Norbert , Dávid Csilla Zsuzsanna , Mwangi Peter Waweru , Berkecz Róbert , Szemerédi Nikoletta , Spengler Gabriella , Hohmann Judit , Vasas Andrea
Published: May 2022

From the aerial parts of Euphorbiagossypina var. coccinea Pax., eight new pregnane glycosides (euphogossypins A–H, 1–8) of the cynanforidine and deacetylmetaplexigenin aglycons, two new lignans (gossypilignans A and B, 9 and 10), and four known compounds, namely, the pregnane 12-O-benzoyldeaxcylmetaplexigenin (11), the lignan 9α-hydroxypinoresinol (12), and the flavonoids naringenin (13) and quercitrin (14) were isolated. The structure elucidation of the new compounds was carried out by a spectroscopic analysis, including HRMS, 1D (1H, 13C JMOD), and 2D NMR (HSQC, 1H–1H COSY, HMBC, and NOESY) experiments. The obtained pregnane glycosides were substituted with acetyl and benzoyl ester moieties, and sugar chains containing thevetose, cymarose, digitoxose, and glucose monosaccharides. All of the compounds are described for the first time from E. gossypina var. coccinea. The isolated pregnanes and lignans were tested for their antiproliferative activity on HeLa cells using the MTT assay; the compounds exerted no significant effect against the tumor cells.
Research and Application of Fast-Strengthening Environment-Friendly Sulfoaluminate Cement Slurry on Taguchi Method
Authors: Wu Yue , Liu Huini , Tang Chao , Zhu Yinge , Zhang Xiaoli
Published: May 2022

Most of the existing research on cement slurry materials are not environmentally friendly and environmental pollution is significant. Most researchers only test its performance, but do not conduct engineering feasibility verification. In this study, the materials extracted from various wastes were used to replace part of the sulfoaluminate cement, and orthogonal experiments were designed to analyze the reaction mechanism between different materials. Finally, the optimal mixing ratio was obtained. Then, through the regression equation analysis method, digital photograph restoration technology, the finite element method and various practical engineering conditions, the feasibility of the slurry under different applicable engineering conditions was compared and analyzed. The comparison between the experimental and numerical simulation results shows that the cement slurry obtained in this study has good reliability and feasibility. It can carry out rapid grouting reinforcement. The results of this study not only provide a feasible and environmentally friendly cement slurry for a wide range of construction projects, but also provide an effective method for the treatment of various wastes.