bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypofractionated Post-Prostatectomy Radiotherapy in 16 Fractions: A Single-Institution Outcome
Authors: Dubinsky Pavol , Vojtek Vladimir , Belanova Katarina , Janickova Natalia , Balazova Noemi , Tomkova Zuzana
Published: July 2023

Background: The optimal hypofractionated schedule of post-prostatectomy radiotherapy remains to be established. We evaluated treatment outcomes and toxicity of moderately hypofractionated post-prostatectomy radiotherapy in 16 daily fractions delivered with intensity-modulated radiotherapy. The treatment schedule selection was motivated by limited technology resources and was radiobiologically dose-escalated. Methods: One hundred consecutive M0 patients with post-prostatectomy radiotherapy were evaluated. Radiotherapy indication was adjuvant (ART) in 19%, early-salvage (eSRT) in 46% and salvage (SRT) in 35%. The dose prescription for prostate bed planning target volume was 52.8 Gy in 16 fractions of 3.3 Gy. The Common Terminology Criteria v. 4 for Adverse Events scale was used for toxicity grading. Results: The median follow-up was 61 months. Five-year biochemical recurrence-free survival (bRFS) was 78.6%, distant metastases-free survival (DMFS) was 95.7% and overall survival was 98.8%. Treatment indication (ART or eSRT vs. SRT) was the only significant factor for bRFS (HR 0.15, 95% CI 0.05–0.47, p = 0.001) and DMFS (HR 0.16, 95% CI 0.03–0.90; p = 0.038). Acute gastrointestinal (GI) toxicity grade 2 was recorded in 24%, grade 3 in 2%, acute genitourinary (GU) toxicity grade 2 in 10% of patients, and no grade 3. A cumulative rate of late GI toxicity grade ≥ 2 was observed in 9% and late GU toxicity grade ≥ 2 in 16% of patients. Conclusions: The observed results confirmed efficacy and showed a higher than anticipated rate of early GI, late GI, and GU toxicity of post-prostatectomy radiobiologically dose-escalated hypofractionated radiotherapy in 16 daily fractions.
Hemostatic Effects of Raloxifene in Ovariectomized Rats
Authors: Alva-Chavarría Denys , Soto-Núñez Maribel , Flores-Soto Edgar , Jaimez Ruth
Published: July 2023

This study aimed to explore the effects of raloxifene (Rx) and estradiol (E2) on prothrombin time (PT), partial thromboplastin time (APTT), coagulation factors (VII, X, XI), and fibrinogen concentrations in rats. Female rats were ovariectomized 11 days prior to starting the treatment. Afterward, they received Rx or E2 (1, 10, 100, and 1000 µg/kg) or propylene glycol (0.3 mL; vehicle, V) subcutaneously for 3 consecutive days. Plasma was collected to measure the hemostatic parameters. Rx significantly increased PT (8%, at 1000 µg/kg; p < 0.05) and APTT at all doses evaluated (32, 70, 67, 30%; p < 0.05, respectively). Rx (1, 10, 100, and 1000 µg/kg) decreased the activity of factor VII by −20, −40, −37, and −17% (p < 0.05), respectively, and E2 increased it by 9, 34, 52, and 29%. Rx reduced factor X activity at 10 and 100 µg/kg doses (−30, and −30% p < 0.05), and E2 showed an increment of 24% with 1000 µg/kg dose only. Additionally, Rx (1, 10, 100 µg/kg) diminished FXI activity (−71, −62, −66; p < 0.05), E2 (1 and 10 µg/kg) in −60 and −38, respectively (p < 0.05), and Rx (1000 µg/kg) produced an increment of 29% (p < 0.05) in fibrinogen concentration, but not E2. Our findings suggest that raloxifene has a protective effect on hemostasis in rats.
Transcriptomics of Congenital Hepatic Fibrosis in Autosomal Recessive Polycystic Kidney Disease Using PCK Rats
Authors: Khare Satyajeet , Jiang Lu , Paine-Cabrera Diego , Apte Udayan , Pritchard Michele T.
Published: July 2023

Congenital hepatic fibrosis/Autosomal recessive polycystic kidney disease (CHF/ARPKD) is an inherited neonatal disease induced by mutations in the PKHD1 gene and characterized by cysts and robust pericystic fibrosis in the liver and kidneys. The PCK rat is an excellent animal model that carries a Pkhd1 mutation and exhibits similar pathophysiology. We performed RNA-Seq analysis on liver samples from PCK rats over a time course of postnatal day (PND) 15, 20, 30, and 90 using age-matched Sprague Dawley (SD) rats as controls to characterize molecular mechanisms of CHF/ARPKD pathogenesis. A comprehensive gene expression analysis identified 1298 differentially expressed genes (DEGs) between PCK and SD rats. The genes overexpressed in the PCK rats at PND30 and 90 were involved cell migration (e.g., Lamc2, Tgfb2, and Plet1), cell adhesion (e.g., Spp1, Adgrg1, and Cd44), and wound healing (e.g., Plat, Celsr1, Tpm1). Connective tissue growth factor (Ctgf) and platelet-derived growth factor (Pdgfb), two genes associated with fibrosis, were upregulated in PCK rats at all time points. Genes associated with MHC class I molecules (e.g., RT1-A2) or involved in ribosome assembly (e.g., Pes1) were significantly downregulated in PCK rats. Upstream regulator analysis showed activation of proteins involved tissue growth (MTPN) inflammation (STAT family members), chromatin remodeling (BRG1), reduction in fibrosis (SMAD7), and inhibition of proteins involved in hepatic differentiation (HNF4α). Immunofluorescence staining revealed that cyst wall epithelium cells also express hepatic progenitor cell markers. The increase in mRNAs of four top upregulated genes, including Reg3b, Aoc1, Tm4sf20, and Cdx2, was confirmed at the protein level using immunohistochemistry. In conclusion, these studies indicate that a combination of increased inflammation, cell migration, wound healing, decreased antifibrotic gene expression, and inhibition of hepatic function are the major underlying pathogenic mechanisms in CHF/ARPKD.
A New Thermal Elasto-Hydrodynamic Lubrication Solver Implementation in OpenFOAM
Authors: Layton James , Rothwell Benjamin C. , Ambrose Stephen , Eastwick Carol , Medina Humberto , Rebelo Neville
Published: July 2023

Designing effective thermal management systems within transmission systems requires simulations to consider the contributions from phenomena such as hydrodynamic lubrication regions. Computational fluid dynamics (CFD) remains computationally expensive for practical cases of hydrodynamic lubrication while the thermo elasto-hydrodynamic lubrication (TEHL) theory has demonstrated good accuracy at a lower computational cost. To account for the effects of hydrodynamic lubrication in high-power transmission systems requires integrating TEHL into a CFD framework such that these methodologies can be interfaced. This study takes an initial step by developing a TEHL solver within OpenFOAM such that the program is prepared to be interfaced with a CFD module in future versions. The OpenFOAM solver includes the Elrod–Adams cavitation model, thermal effects, and elastic deformation of the surfaces, and considers mixing between the recirculating flow and oil feed by applying energy and mass continuity. A sensitivity study of the film mesh is presented to show the solution variation with refinement along the circumferential, axial and radial directions. A validation case is presented of an experimental single axial groove journal bearing which shows good agreement in the pressure and temperature results. The peak pressure in the film is predicted within 12% and the peak temperature in the bush is predicted within 5% when comparing the centerline profiles.
A Study on the Corrosion Resistance of a Coating Prepared by Electrical Explosion of 321 Metal Wire
Authors: Liu Ye , Song Qiuzhi , Deng Hongbin , Liu Yali , Chen Pengwan , Huang Kun
Published: July 2023

Corrosion is known as a breakdown effect that causes the deterioration of substances in enriched petroleum/gas conditions. This reaction occurs in all materials, which is highlighted in alloys. In the present study, the morphological properties, as well as the corrosion resistance behavior of the AISI1045 steel substrate coated with 321 austenitic stainless steel metal particulate fillers, were investigated. The electro-explosive spraying technique was employed to achieve a homogenous coating on the substrate surface. According to the results, the grain size of the 321 austenitic stainless steel coating layer was shrunk and reduced to 1–3 μm after the coating procedure. The coated layer also showed a homogenous and uniform thickness with an average value of 137 μm. Also, the average adhesion strength of 49.21 MPa was obtained between the sprayed coating and the substrate. The analytical analysis found the presence of Fe-Cr and Fe-Ni phases in the coating layer. The hardness of the original metal wire is 186 HV, and the microhardness of the coating after spraying is 232 HV. After subjecting the specimen to the corrosion examination, a 0.1961 mm/a corrosion rate was obtained for up to 120 h. Moreover, the corrosion products of CaCO3, Fe3O4, and MgFe2O4 were determined by XRD analysis. Furthermore, the observed results were further confirmed by the data obtained from EPMA and EDS evaluations. Hence, this study implies the beneficial role of electro-explosive sprayed alloy 321 austenitic stainless steel in creating a protective layer against corrosion on 45 steel substrate in an enriched oil/water environment.
Dynamics and Wear Prediction of Mechanisms Considering Multiple Clearances and Coatings
Authors: Jing Qian , Liu Hongzhao
Published: July 2023

The increase in joint clearance and system vibration caused by joint wear are important factors that may lead to the failure of the mechanism and a decrease in the motion accuracy of the actuator. In this paper, to investigate the impact of different numbers of spherical joint clearances on the dynamics performance of the mechanism and explore effective measures to reduce the vibration of the mechanism caused by multiple joint clearances, on the basis of the previous research on the mechanism dynamics when there is clearance in a single spherical joint, an improved contact force model is used to study the effects of coating, no coating, and different clearance quantities on the dynamics of a mechanism containing multiple spherical joint clearances. Moreover, the joint reaction forces and contact-impact forces under different working conditions are calculated. In order to reduce the difficulty of calculating the joint wear, an approximate calculation method for contact area is proposed, and an improved Archard wear model is employed to calculate and analyze the changes in wear amount under the influence of both spherical joint clearance and coating.
6,7-Dihydroxy-5,8-dimethoxy-2H-chromen-2-one
Authors: Adaeva Olga I. , Demchuk Dmitry V. , Semenov Victor V.
Published: July 2023

This article presents a novel approach for synthesizing a new 5,8-dimethoxy derivative of esculetin via the selective cleavage of the methylene bridge in sabandin—naturally occurring and easily synthetically accessible methoxylated coumarin. A high selectivity is achieved by using acetoxylation of methylenedioxy group with lead tetraacetate. Natural coumarin sabandin as a starting compound was prepared in a few simple steps from 5-allyl-4,7-dimethoxybenzo[d][1,3]dioxole (apiol), which is readily available from parsley and dill seed extracts. The developed method enables an efficient and straightforward synthesis of a new derivative of esculetin with potential medicinal and therapeutic applications.
Reversible Thermochromic Microcapsules and Their Applications in Anticounterfeiting
Authors: Liu Haisheng , Deng Yuhao , Ye Yang , Liu Xingqiang
Published: July 2023

The common, commercial reversible thermochromic (RT) melamine–formaldehyde resin microcapsules containing formaldehyde are very harmful to human health. To address this issue, we successfully prepared a novel formaldehyde-free microcapsule via interfacial polymerization using RT compositions as the core and poly(urethane-urea) (PUU) as the shell. The core material consisted of a color former (crystal violet lactone), a developer (bisphenol AF), and a solvent (methyl stearate). To optimize the synthesis of the microcapsules, an L9 (34) orthogonal design and single-factor experiments were employed to analyze the effects of four factors (N3300-to-L75 shell material mass ratio, core-to-shell material mass ratio, emulsifier concentration, and shear rate during emulsification) on the encapsulation efficiency. The results showed that the optimal parameter values were as follows: a shear rate of 2500 rpm, N3300-to-L75 shell material mass ratio of 1:4, core-to-shell material mass ratio of 11:5, and emulsifier concentration of 3.5%. The influence of the shear rate on the particle size and distribution, surface morphology, dispersibility, and reversible thermochromic properties of the microcapsules was investigated. Furthermore, analyses on the phase-change characteristics, thermal stability, ultraviolet aging, and solvent and acid–base resistances of the microcapsules were conducted systematically. Finally, a reversible thermochromic mark containing the RTPUU microcapsules was designed and fabricated, which could be used against falsification. Moreover, these RTPUU microcapsules can be potentially used for anticounterfeiting applications.
Analysis of the Influence of Downhole Drill String Vibration on Wellbore Stability
Authors: Shan Yonggang , Xue Qilong , Wang Jin , Li Yafeng , Wang Chong
Published: July 2023

Most studies related to aspects of wellbore stability, such as wellbore breakage, block dropping, and wellbore expansion, revolve around the physicochemical interaction between drilling fluid and surrounding rock, but relevant studies show that drill string vibration during drilling also has a crucial and even decisive influence on wellbore stability. In order to thoroughly explore the influence mechanism of drill string vibration on wellbore stability, our research group established a finite element flexible simulation model of drill string dynamics and used a storage downhole vibration measurement device to collect downhole real drilling vibration data to verify the correctness of the simulation model. Then, based on the critical conditions of wellbore breakage, a wellbore stability evaluation method was established, and the wellbore stability under different drilling parameters and drilling tool combination conditions was evaluated and analyzed. The research results play an important role in revealing the influence mechanism of drill string vibration on wellbore stability and can provide theoretical guidance for engineering problems such as wellbore instability risk assessment.
Tendon-Driven Crawling Robot with Programmable Anisotropic Friction by Adjusting Out-of-Plane Curvature
Authors: Kim Hyeonsu , Cho Sumin , Kam Dongik , Lee Seong Jin , Park Seongjae , Choi Dongwhi , Kim Jongwoo
Published: July 2023

Origami crawling robots, inspired by the principles of origami folding, have emerged as a promising approach for developing lightweight and flexible robots capable of navigating tight spaces. These robots utilize anisotropic friction, where the frictional forces between surfaces vary depending on the direction of motion, enabling controlled movement by changing the robot’s body orientation. While various actuation methods have been explored, such as pneumatic and magnetic systems, they suffer from limitations such as bulkiness or restricted workspace. In this paper, we propose a tendon-driven crawling robot that achieves anisotropic friction by controlling its out-of-plane curvature. By manipulating the robot’s shape and out-of-plane curvature, we can modulate the friction forces and enable efficient crawling motion. To maximize anisotropic friction, we design an asymmetric contact film composed of elastomer and polyester. We analyze the relationship between out-of-plane curvature and frictional force through experiments on flat and sloped surfaces, considering different leg angles and slope angles of the contact film. The results demonstrate the gait loss ratio of 1.96% for the optimized design, highlighting the robot’s ability to crawl efficiently with quick response times and a low-profile system. This research contributes to the advancement of origami-based crawling robots and their potential applications in confined and unstructured environments.
Study on the Influence of the Pilot Stage Swirl Intensity on the Double-Swirl Combustor’s Ignition Process via Large Eddy Simulation
Authors: Zhu Pengfei , Ju Hongyu , Li Yue , Yan Yue , Suo Jianqin , Liu Zhenxia
Published: July 2023

The ignition reliability of the combustion chamber is crucial for the overall performance of an engine. As the aero-engine combustion chambers continue to advance, the scope of the ignition problem has also expanded. This study employs large eddy simulation to investigate the flow characteristics and ignition process of a double-swirl combustor. The non-reacting flow field and ignition propagation process are acquired using particle image velocimetry (PIV) and high-speed cameras. Experimental findings are employed to validate the numerical simulations. The results demonstrate a close relationship between the ignition process of the double-swirl combustor and the flow field within the combustor. Following the spark discharge, a core is generated at the edge of the recirculation zone. Over time, the spark gradually propagates towards the center of the combustor along the direction of swirl due to the flow. Once the flame reaches the head, the fuel and gas mixture ignited by the core within the recirculation zone stabilizes within the boundary layer of the primary and pilot stages. The flame continues to propagate throughout the combustor until complete ignition is achieved. Additionally, the swirl intensity of the pilot mode is identified as a key factor influencing the ignition propagation process of the double-swirl combustor.
Oversampling Application of Identifying 3D Selective Laser Sintering Yield by Hybrid Mathematical Classification Models
Authors: Chen You-Shyang , Chang Jieh-Ren , Hung Ying-Hsun , Lai Jia-Hsien
Published: July 2023

Selective laser sintering (SLS) is one of the most popular 3D molding technologies; however, the manufacturing steps of SLS machines are cumbersome, and the most important step is focused on molding testing because it requires a lot of direct labor and material costs. This research establishes advanced hybrid mathematical classification models, including random forest (RF), support vector machine (SVM), and artificial neural network (ANN), for effectively identifying the SLS yield of the sintering results from three sintered objects (boxes, cylinders, and flats) to achieve the key purpose of reducing the number of model verification and machine parameter adjustments, thereby saving a lot of manufacturing time and costs. In the experimental process, performance evaluation indicators, such as classification accuracy (CA), area under the ROC curve (AUC), and F1-score, are used to measure the proposed models’ experience with practical industry data. In the experimental results, the ANN gets the highest 0.6168 of CA, and it is found that each machine reduces the average sintering time by four hours when compared with the original manufacturing process. Moreover, we employ an oversampling method to expand the sample data to overcome the existing problems of class imbalance in the dataset collected. An important finding is that the RF algorithm is more suitable for predicting the sintering failure of objects, and its average sintering times per machine are 1.7, which is lower than the 1.95 times of ANN and 2.25 times of SVM. Conclusively, this research yields some valuable empirical conclusions and core research findings. In terms of research contributions, the research results can be provided to relevant academic circles and industry requirements for referential use in follow-up studies or industrial applications.
Free-Space Quantum Teleportation with Orbital Angular Momentum Multiplexed Continuous Variable Entanglement
Authors: Ruan Xinchao , Zhang Hang , Peng Wenqi , Xian Hui , Zhu Yiwu , Zhao Wei , Xiong Sha
Published: July 2023

Quantum teleportation is one of the fundamental primitives of quantum cryptography. In order to achieve a wider range of high-capacity information transfer, we propose a free-space quantum teleportation (QT) protocol with orbital angular momentum (OAM) multiplexed continuous variable (CV) entangled states. The preparation of the entangled states is accomplished by the spontaneous four-wave mixing (SFWM) process occurring in a hot 85Rb vapor cell, and the mode selection for the Bell-state measurement is achieved by employing the balanced homodyne detection technique. The fidelity of teleporting EPR entangled states carrying different topological charges via a Kolmogorov-type atmospheric turbulence channel is derived, and the superiority of enhancing the system channel capacity via OAM multiplexing is demonstrated. Our work provides a feasible scheme to implement high-capacity quantum communication in atmospheric environments.
A Novel Hybrid Algorithm Based on Jellyfish Search and Particle Swarm Optimization
Authors: Nayyef Husham Muayad , Ibrahim Ahmad Asrul , Mohd Zainuri Muhammad Ammirrul Atiqi , Zulkifley Mohd Asyraf , Shareef Hussain
Published: July 2023

Metaheuristic optimization is considered one of the most efficient and powerful techniques of recent decades as it can deal effectively with complex optimization problems. The performance of the optimization technique relies on two main components: exploration and exploitation. Unfortunately, the performance is limited by a weakness in one of the components. This study aims to tackle the issue with the exploration of the existing jellyfish search optimizer (JSO) by introducing a hybrid jellyfish search and particle swarm optimization (HJSPSO). HJSPSO is mainly based on a JSO structure, but the following ocean current movement operator is replaced with PSO to benefit from its exploration capability. The search process alternates between PSO and JSO operators through a time control mechanism. Furthermore, nonlinear and time-varying inertia weight, cognitive, and social coefficients are added to the PSO and JSO operators to balance between exploration and exploitation. Sixty benchmark test functions, including 10 CEC-C06 2019 large-scale benchmark test functions with various dimensions, are used to showcase the optimization performance. Then, the traveling salesman problem (TSP) is used to validate the performance of HJSPSO for a nonconvex optimization problem. Results demonstrate that compared to existing JSO and PSO techniques, HJSPSO contributes in terms of exploration and exploitation improvements, where it outperforms other well-known metaheuristic optimization techniques that include a hybrid algorithm. In this case, HJSPSO secures the first rank in classical and large-scale benchmark test functions by achieving the highest hit rates of 64% and 30%, respectively. Moreover, HJSPSO demonstrates good applicability in solving an exemplar TSP after attaining the shortest distance with the lowest mean and best fitness at 37.87 and 36.12, respectively. Overall, HJSPSO shows superior performance in solving most benchmark test functions compared to other optimization techniques, including JSO and PSO. As a conclusion, HJSPSO is a robust technique that can be applied to solve most optimization problems with a promising solution.
A Weighted Generalization of Hardy–Hilbert-Type Inequality Involving Two Partial Sums
Authors: Yang Bicheng , Wu Shanhe
Published: July 2023

In this paper, we address Hardy–Hilbert-type inequality by virtue of constructing weight coefficients and introducing parameters. By using the Euler–Maclaurin summation formula, Abel’s partial summation formula, and differential mean value theorem, a new weighted Hardy–Hilbert-type inequality containing two partial sums can be proven, which is a further generalization of an existing result. Based on the obtained results, we provide the equivalent statements of the best possible constant factor related to several parameters. Also, we illustrate how the inequalities obtained in the main results can generate some new Hardy–Hilbert-type inequalities.
Global Convergence of Algorithms Based on Unions of Non-Expansive Maps
Authors: Zaslavski Alexander J.
Published: July 2023

In his recent research, M. K. Tam (2018) considered a framework for the analysis of iterative algorithms which can be described in terms of a structured set-valued operator. At each point in the ambient space, the value of the operator can be expressed as a finite union of values of single-valued para-contracting operators. He showed that the associated fixed point iteration is locally convergent around strong fixed points. In the present paper we generalize the result of Tam and show the global convergence of his algorithm for an arbitrary starting point. An analogous result is also proven for the Krasnosel’ski–Mann iterations.
Exploring Low-Risk Anomalies: A Dynamic CAPM Utilizing a Machine Learning Approach
Authors: Wang Jiawei , Chen Zhen
Published: July 2023

Low-risk pricing anomalies, characterized by lower returns in higher-risk stocks, are prevalent in equity markets and challenge traditional asset pricing theory. Previous studies primarily relied on linear regression methods, which analyze a limited number of factors and overlook the advantages of machine learning in handling high-dimensional data. This study aims to address these anomalies in the Chinese market by employing machine learning techniques to measure systematic risk. A large dataset consisting of 770 variables, encompassing macroeconomic, micro-firm, and cross-effect factors, was constructed to develop a machine learning-based dynamic capital asset pricing model. Additionally, we investigated the differences in factors influencing time-varying beta between state-owned enterprises (SOEs) and non-SOEs, providing economic explanations for the black-box issues. Our findings demonstrated the effectiveness of random forest and neural networks, with the four-layer neural network performing best and leading to a substantial rise in the excess return of the long–short portfolio, up to 0.36%. Notably, liquidity indicators emerged as the primary drivers influencing beta, followed by momentum. Moreover, our analysis revealed a shift in variable importance during the transition from SOEs to non-SOEs, as liquidity and momentum gradually replaced fundamentals and valuation as key determinants. This research contributes to both theoretical and practical domains by bridging the research gap in incorporating machine learning methods into asset pricing research.
A Discrete JAYA Algorithm Based on Reinforcement Learning and Simulated Annealing for the Traveling Salesman Problem
Authors: Xu Jun , Hu Wei , Gu Wenjuan , Yu Yongguang
Published: July 2023

The JAYA algorithm is a population-based meta-heuristic algorithm proposed in recent years which has been proved to be suitable for solving global optimization and engineering optimization problems because of its simplicity, easy implementation, and guiding characteristic of striving for the best and avoiding the worst. In this study, an improved discrete JAYA algorithm based on reinforcement learning and simulated annealing (QSA-DJAYA) is proposed to solve the well-known traveling salesman problem in combinatorial optimization. More specially, firstly, the basic Q-learning algorithm in reinforcement learning is embedded into the proposed algorithm such that it can choose the most promising transformation operator for the current state to update the solution. Secondly, in order to balance the exploration and exploitation capabilities of the QSA-DJAYA algorithm, the Metropolis acceptance criterion of the simulated annealing algorithm is introduced to determine whether to accept candidate solutions. Thirdly, 3-opt is applied to the best solution of the current iteration at a certain frequency to improve the efficiency of the algorithm. Finally, to evaluate the performance of the QSA-DJAYA algorithm, it has been tested on 21 benchmark datasets taken from TSPLIB and compared with other competitive algorithms in two groups of comparative experiments. The experimental and the statistical significance test results show that the QSA-DJAYA algorithm achieves significantly better results in most instances.
Two-Round Multi-Signatures from Okamoto Signatures
Authors: Lee Kwangsu , Kim Hyoseung
Published: July 2023

Multi-signatures (MS) are a special type of public-key signature (PKS) in which multiple signers participate cooperatively to generate a signature for a single message. Recently, applications that use an MS scheme to strengthen the security of blockchain wallets or to strengthen the security of blockchain consensus protocols are attracting a lot of attention. In this paper, we propose an efficient two-round MS scheme based on Okamoto signatures rather than Schnorr signatures. To this end, we first propose a new PKS scheme by modifying the Okamoto signature scheme and prove the unforgeability of our PKS scheme under the discrete logarithm assumption in the algebraic group model (AGM) and the non-programmable random oracle model (ROM). Next, we propose a two-round MS scheme based on the new PKS scheme and prove the unforgeability of our MS scheme under the discrete logarithm assumption in the AGM and the non-programmable ROM. Our MS scheme is the first one to prove security among two-round MS based on Okamoto signatures.
Determination of Safety Monitoring Indices for Roller-Compacted Concrete Dams Considering Seepage–Stress Coupling Effects
Authors: Zhang Wenbing , Li Hanhan , Shi Danda , Shen Zhenzhong , Zhao Shan , Guo Chunhui
Published: July 2023

Analyzing the working conditions of a dam using safety monitoring indices (SMIs) is a relatively intuitive and effective method for dam safety evaluation. Therefore, a reasonable and accurate method for determining the SMIs of a dam is of vital importance for dam safety assessment. However, the current methods for determining the SMIs of dams, especially roller-compacted concrete (RCC) dams, have many shortcomings, such as ignoring the construction process of the dam, the coupling effect among multiple physical fields, etc. In this paper, a novel SMI determination method considering the seepage–stress coupling effects was proposed for RCC dams with the assistance of a constructed seepage and stress coupling model so as to address the deficiency of existing RCC dams in determining SMIs. The coupled mathematical model was developed in COMSOL Multiphysics to establish a finite element analysis model of an RCC gravity dam in Henan Province, China. Moreover, the seepage anisotropy of the RCC construction layers was also considered in the model. Finally, the seepage, stress, and deformation characteristics of the RCC dam were analyzed based on the model, and the seepage and deformation SMIs of the dam were determined and compared with traditional methods. The results show that seepage, stress, and displacement fields are distributed similarly for both coupled and uncoupled models. However, in contrast to the uncoupled model, the hydraulic head contour distribution is more dispersed in the coupled model. Additionally, the stress and displacement simulated by the coupled model increase at different rates, with a more pronounced stress concentration near the dam heel. Comparing the seepage and stress SMIs of RCC dam obtained from different methods, it was found that the indices of dam seepage discharge and crest displacement that are calculated by considering the seepage–stress coupling effect and anisotropic characteristics of RCC construction layers are 34.78% and 31.98% lower than results obtained by ignoring these two effects, respectively. Therefore, it is crucial to consider the seepage–stress coupling effect and the anisotropic characteristics of RCC when determining the SMIs for RCC dams.
Color Image Encryption Algorithm Based on Cross-Spiral Transformation and Zone Diffusion
Authors: Zhang Xiaoqiang , Liu Mi , Yang Xiaochang
Published: July 2023

Due to their rich information, color images are frequently utilized in many different industries, but the network’s security in handling their delivery of images must be taken into account. To improve the security and efficiency of color images, this paper proposed a color image encryption algorithm based on cross-spiral transformation and zone diffusion. The proposed algorithm is based on Chen’s system and the piecewise linear chaotic map, and uses the chaotic sequences generated by them for related operations. Firstly, the R, G and B planes are extracted, and the spiral starting point of each plane is randomly selected by the chaotic sequence to implement the cross-spiral transformation. Secondly, the bit-level image matrix is constructed by the scrambled image matrix, and the bit-level chaotic matrix is constructed by the chaotic sequence. Finally, the three-dimensional matrix is divided into four zones by a dividing line, and partition diffusion is carried out to obtain the encrypted image. Simulation results and algorithm analyses indicate that the proposed algorithm has superior performance and can resist a wide range of attacks.
On the Unique Solvability of Inverse Problems of Magnetometry and Gravimetry
Authors: Stepanova Inna , Lukyanenko Dmitry , Kolotov Igor , Shchepetilov Alexey , Yagola Anatoly
Published: July 2023

This article deals with the question of the unique solvability of systems of linear algebraic equations, to the solution of which many inverse problems of geophysics are reduced as a result of discretization when applying the methods of integral equations or integral representations. Examples are given of degenerate and nondegenerate systems of different dimensions that arise in the processing of magnetometric and gravimetric data from experimental observations. Conclusions are drawn about the methods for constructing the optimal grid of experimental observation points.
Self-Evolving Chebyshev Radial Basis Function Neural Complementary Sliding Mode Control
Authors: Zhang Lei , Li Xiangguo , Fei Juntao
Published: July 2023

A novel intelligent complementary sliding mode control (ICSMC) method is proposed for nonlinear systems with unknown uncertainties in this paper. A self-evolving Chebyshev radial basis function neural network (RBFNN) (SECRBFNN) with self-learning parameters and structure is proposed and combined with complementary sliding mode control (CSMC). CSMC not only has the advantages of the strong robustness of traditional SMC but also has certain advantages in reducing chattering and control accuracy. The SECRBFNN, which combines the advantages of the Chebyshev network (CN) and an RBFNN, is used to estimate unknown uncertainties in nonlinear systems. Meanwhile, a node self-evolution mechanism is proposed to avoid redundancy in the number of neurons. Eventually, the detailed simulation results demonstrate the feasibility and superiority of the proposed method.
An Improved Dunnett’s Procedure for Comparing Multiple Treatments with a Control in the Presence of Missing Observations
Authors: Jiang Wenqing , Zhou Jiangjie , Liang Baosheng
Published: July 2023

Dunnett’s procedure has been frequently used for multiple comparisons of group means of several treatments with a control, in drug development and other areas. However, in practice, researchers usually face missing observations when performing Dunnett’s procedure. This paper presents an improved Dunnett’s procedure that can construct unique ensemble confidence intervals for comparing group means of several treatments with a control, in the presence of missing observations, using a derived multivariate t distribution under the framework of Rubin’s rule. This procedure fills the current research gap that Rubin’s repeated-imputation inferences cannot adjust for multiplicity and, thereby, cannot give a unified confidence interval to control the family-wise error rate (FWER) when dealing with this problem. Simulation results show that the constructed pooled confidence intervals archive nominal joint coverage and the interval estimations preserve comparable precision to Rubin’s repeated-imputation inference as the missing rate increases. The proposed procedure with propensity-score imputation method is shown to produce more accurate interval estimations and control the FWER well.
The Molecular and Genetic Interactions between Obesity and Breast Cancer Risk
Authors: Ajabnoor Ghada M. A.
Published: July 2023

Breast cancer (BC) is considered the leading cause of death among females worldwide. Various risk factors contribute to BC development, such as age, genetics, reproductive factors, obesity, alcohol intake, and lifestyle. Obesity is considered to be a pandemic health problem globally, affecting millions of people worldwide. Obesity has been associated with a high risk of BC development. Determining the impact of obesity on BC development risk in women by demonstrating the molecular and genetic association in pre- and post-menopause females and risk to BC initiation is crucial in order to improve the diagnosis and prognosis of BC disease. In epidemiological studies, BC in premenopausal women was shown to be protective in a certain pattern. These altered effects between the two phases could be due to various physiological changes, such as estrogen/progesterone fluctuating levels. In addition, the relationship between BC risk and obesity is indicated by different molecular alterations as metabolic pathways and genetic mutation or epigenetic DNA changes supporting a strong connection between obesity and BC risk. However, these molecular and genetic alteration remain incompletely understood. The aim of this review is to highlight and elucidate the different molecular mechanisms and genetic changes occurring in obese women and their association with BC risk and development.
Stability of Direct Oral Anticoagulants Concentrations in Blood Samples for Accessibility Expansion of Chromogenic Assays
Authors: Gavrilova Anna , Meisters Jānis , Latkovskis Gustavs , Urtāne Inga
Published: July 2023

Background and Objectives: Direct oral anticoagulants (DOACs) are used for minimising the risk of thromboembolic events. In clinical practice, there is no need to measure DOAC concentration in the routine. Nevertheless, there are cases where such measurements are necessary, as the European Society of Cardiology’s guideline recommends. However, determining DOAC levels is not available for everyone due to chromogenic assay availability limitations from sample storage problems, as tests are performed only in a few healthcare settings. This study aimed to assess whether more applicable storage conditions could be used for transportation to provide chromogenic assays for outpatient healthcare and other hospitals’ practices. Materials and Methods: Chromogenic assays measuring anti-FXa (for rivaroxaban and edoxaban) and anti-FIIa (for dabigatran) were used. Concentrations were determined immediately after blood collection as baseline value: (1) after the storage of citrated whole blood in refrigerator (+2–8 °C); (2) of citrated plasma in refrigerator (+2–8 °C); and (3) of citrated frozen plasma (−20 °C) on the third and seventh days of storage. Acceptable change limits were considered stable if the deviation did not exceed ±20% of the baseline value. Results: The median (Cl 95%) baseline value of rivaroxaban was 168 (147–236) ng/mL; of dabigatran 139 (99–178) ng/mL; and of edoxaban—174 (135–259) ng/mL. The median deviation from a baseline value stored as citrate whole blood samples (+2–8 °C) was 5.4% and 3.4%; as citrated plasma (+2–8 °C) was 0.4% and −0.6%; and as citrated frozen plasma (−20 °C) was −0.2% and 0.2% on the third and seventh days of storage, respectively. Conclusions: Our data suggest that whole blood samples stored in a refrigerator, as well as citrated plasma samples stored in both the refrigerator and freezer, preserve DOAC concentration stable at +2–8 °C or −20 °C for up to 7 days, and are suitable for transportation, except for low-concentration samples.
Headache in the Emergency Department: A Multicenter Observational Study from Singapore
Authors: Kuan Win Sen , Kumar Ranjeev , Yau Ying Wei , Ng Wei Ming , Chia Dennis Wen Jie , Ng Ee Yang , Lather Kanwar Sudhir , Chua Mui Teng
Published: July 2023

Background and Objectives: There is scarce data about the epidemiology, clinical features, investigations, diagnosis, treatment, and outcome in patients attending Singapore emergency departments (EDs) with nontraumatic headache. We sought to describe these characteristics of adult patients presenting to the ED with a primary complaint of headache. Materials and Methods: We performed a cross-sectional study on adult patients with nontraumatic headache over 4 consecutive weeks from 18 March 2019 to 14 April 2019 across four EDs in Singapore. Exclusion criteria were history of head trauma within 48 h of presentation, missing records, interhospital transfers, representation with the same headache as a recent previous visit and headache as an associated symptom. Results: During the study period, 579 patients (representing 1.8% of the total ED census) comprising 55.3% males and with a median age of 36 years presented to the four Singapore EDs with a primary complaint of nontraumatic headache. Paracetamol (41.5%), non-steroidal anti-inflammatory drugs (34.4%) and tramadol (31.5%) were the three commonest analgesics used either singly or in combination. Prochlorperazine (22.9%) and metoclopramide (17.4%) were frequent anti-emetic adjuncts. One-third of patients had computed tomography of the brain performed, which found abnormalities among 20.9% of them. ED diagnoses of primary headache conditions were made in 73.6% of patients. Conclusions: Primary headaches constituted most ED headache diagnoses. ED imaging of selected patients yielded a relatively high pick-up rate for significant intracranial abnormalities. Opioid use for symptomatic relief of headaches in the ED was found to be high, underscoring the need for improvement in headache analgesia relief practices in the ED.
Comparison of Central Aortic Pressure between Women with Preeclampsia and Normotensive Postpartum Women from an Urban Region of Western Mexico
Authors: Hernández-Mora Francisco J. , Cerda-Guerrero Claudia K. , García-Benavides Leonel , Cervantes-Pérez Enrique , Ramírez-Ochoa Sol , Vázquez-Beltrán Janet Cristina , Cervantes-Guevara Gabino , Ledezma-Hurtado Ernesto , Nápoles-Echauri Adriana , González-Ojeda Alejandro , Fuentes-Orozco Clotilde , Hernández-Rivas María Isabel , Chávez-Tostado Mariana , Cervantes-Cardona Guillermo A.
Published: July 2023

Background and Objectives: Central aortic pressure (CAP) can be measured through noninvasive methods, and CAP wave analysis can provide information about arterial stiffness. The objective of this study was to compare CAP in women with preeclampsia and normotensive postpartum women from an urban region in western Mexico. Materials and Methods: We recruited 78 women in immediate puerperium, including 39 with preeclampsia and 39 with normotension, who received delivery care in our hospital between September 2017 and January 2018. Pulse wave analysis was used to assess central hemodynamics as well as arterial stiffness with an oscillometric device. For this purpose, the measurement of the wave of the left radial artery was obtained with a wrist applanation tonometer and the ascending aortic pressure wave was generated using the accompanying software (V 1.1, Omron, Japan). Additionally, the systolic CAP, diastolic pressure, pulse pressure, heart rate, and rise rate adjusted for a heart rate of 75 bpm were determined. The radial pulse wave was calibrated using the diastolic and mean arterial pressures obtained from the left brachial artery. For all the statistical analyses, we considered p < 0.05 to be significant. Results: The results were as follows: a systolic CAP of 125.40 (SD 15.46) vs. 112.10 (SD 10.12) with p < 0.0001 for women with and without preeclampsia, respectively. Systolic CAP was significantly elevated in women with preeclampsia and could indicate an elevated risk of cardiovascular disease. Conclusion: CAP is an important parameter that can be measured in this group of patients and is significantly elevated in women with postpartum preeclampsia, even when the brachial blood pressure is normal.
Leiomyoma with Uncommon Localization—Incisive Papilla and Palatal Fibromucosa: A Case Report
Authors: Rakitovan Marina , Nicoara Adrian , Closca Raluca , Balica Nicolae , Stefanescu Eugen , Baderca Flavia
Published: July 2023

The current paper presents a case of a 33-year-old female with an uncommon localization of a leiomyoma in the oral cavity—the anterior palatal fibromucosa and the incisive papilla. The patient referred to the Oro-Maxillo-Facial Surgery Clinic of Emergency City Hospital Timisoara, Romania, complaining of a slight discomfort in the act of mastication and the occurrence and persistence of a diastema between the upper central incisors, due to the presence of a nodule located in the anterior palatal mucosa, between the upper central incisors, without any changes of the subjacent bone structure in the anterior hard palate visible on a cone beam computed tomography image (CBCT). The lesion was removed using a surgical excisional biopsy and a histopathological examination was performed using morphological Hematoxylin–Eosin (HE) staining and additional immunohistochemical (IHC) reactions, in order to confirm the diagnosis. On microscopic examination, bundles of spindle cells were found with eosinophilic cytoplasm and vesicular nuclei, with finely granular chromatin. The immunohistochemical reactions were positive for smooth muscle actin (SMA) and desmin and negative for vimentin. The treatment of choice for leiomyoma of the oral cavity is surgical excision with clear margins, followed by periodical clinical monitoring.
Prevalence, Recognition, and Risk Factors of Constipation among Medically Hospitalized Patients: A Cohort Prospective Study
Authors: Al Nou’mani Jawahar , Al Alawi Abdullah M. , Al-Maqbali Juhaina Salim , Al Abri Nahid , Al Sabbri Maryam
Published: July 2023

Background and Objective: Constipation is a prevalent gastrointestinal condition that has a substantial impact on individuals and healthcare systems. This condition adversely affects health-related quality of life and leads to escalated healthcare expenses due to an increase in office visits, referrals to specialists, and hospital admission. This study aimed to evaluate the prevalence, recognition, risk factors, and course of constipation among hospitalized patients in medical wards. Materials and Methods: A prospective study was conducted, including all adult patients admitted to the General Medicine Unit between 1 February 2022 and 31 August 2022. Constipation was identified using the Constipation Assessment Scale (CAS), and relevant factors were extracted from the patients’ medical records. Results: Among the patients who met the inclusion criteria (n = 556), the prevalence of constipation was determined to be 55.6% (95% CI 52.8–58.4). Patients with constipation were found to be older (p < 0.01) and had higher frailty scores (p < 0.01). Logistic regression analysis revealed that heart failure (Odds ratio (OR) 2.1; 95% CI 1.2–3.7; p = 0.01), frailty score (OR 1.4; 95% CI 1.2–1.5; p < 0.01), and dihydropyridines calcium channel blockers (OR 1.8; 95% CI 1.2–2.8; p < 0.01) were independent risk factors for constipation. Furthermore, the medical team did not identify constipation in 217 patients (64.01%). Conclusions: Constipation is highly prevalent among medically hospitalized patients. To ensure timely recognition and treatment, it is essential to incorporate a daily constipation assessment scale into each patient’s medical records.