bluuebunny/crossref_metadata_2025 huggingface dataset:
Current Therapeutic Approach to Atrial Fibrillation in Patients with Congenital Hemophilia
Authors: Badescu Minerva Codruta , Badulescu Oana Viola , Butnariu Lacramioara Ionela , Floria Mariana , Ciocoiu Manuela , Costache Irina-Iuliana , Popescu Diana , Bratoiu Ioana , Buliga-Finis Oana Nicoleta , Rezus Ciprian
Published: March 2022

Cardiovascular disease in hemophiliacs has an increasing prevalence due to the aging of this population. Hemophiliacs are perceived as having a high bleeding risk due to the coagulation factor VIII/IX deficiency, but it is currently acknowledged that they also have an important ischemic risk. The treatment of atrial fibrillation (AF) is particularly challenging since it usually requires anticoagulant treatment. The CHA2DS2-VASc score is used to estimate the risk of stroke and peripheral embolism, and along with the severity of hemophilia, guide the therapeutic strategy. Our work provides the most complete, structured, and updated analysis of the current therapeutic approach of AF in hemophiliacs, emphasizing that there is a growing interest in therapeutic strategies that allow for short-term anticoagulant therapy. Catheter ablation and left atrial appendage occlusion have proven to be efficient and safe procedures in hemophiliacs, if appropriate replacement therapy can be provided.
A Singular Stochastic Control Approach for Optimal Pairs Trading with Proportional Transaction Costs
Authors: Xing Haipeng
Published: March 2022

Optimal trading strategies for pairs trading have been studied by models that try to find either optimal shares of stocks by assuming no transaction costs or optimal timing of trading fixed numbers of shares of stocks with transaction costs. To find optimal strategies that determine optimally both trade times and number of shares in a pairs trading process, we use a singular stochastic control approach to study an optimal pairs trading problem with proportional transaction costs. Assuming a cointegrated relationship for a pair of stock log-prices, we consider a portfolio optimization problem that involves dynamic trading strategies with proportional transaction costs. We show that the value function of the control problem is the unique viscosity solution of a nonlinear quasi-variational inequality, which is equivalent to a free boundary problem for the singular stochastic control value function. We then develop a discrete time dynamic programming algorithm to compute the transaction regions, and show the convergence of the discretization scheme. We illustrate our approach with numerical examples and discuss the impact of different parameters on transaction regions. We study the out-of-sample performance in an empirical study that consists of six pairs of U.S. stocks selected from different industry sectors, and demonstrate the efficiency of the optimal strategy.
Shareholder Activism and Its Impact on Profitability, Return, and Valuation of the Firms in India
Authors: Shingade Sudam , Rastogi Shailesh , Bhimavarapu Venkata Mrudula , Chirputkar Abhijit
Published: March 2022

The paper’s prime objective is to understand the impact of Shareholder activism on firm performance. This study is conducted in a unique setup where traditional activist investors such as pension funds and hedge funds are not present. However, the activism cases are increasing yearly in an emerging economy like India. We have created a comprehensive shareholder activism index (sha index) using multiple activisms and corporate governance factors. To measure firm performance, we have used valuation (Tobin’s Q and Market capitalization), profitability (operating profit margin and net profit margin), and return ratios (Return on capital and return on equity). Panel data analysis (PDA) is employed for the current study as it overcomes the shortcomings of the time series analysis and cross-sectional studies. The sample comprises 37 listed firms’ data for FY2017 to FY2020. Chosen firms have experienced activism instances at least once during the 2017–2020 period. As per our analysis, shareholder activism has a significant negative impact on valuation measured in market capitalization and profitability estimated by operating profit margin. Activism primarily impacts the other four parameters negatively, but it is insignificant. India is in the nascent stage of activism, partly explaining the insignificance of the effects of shareholder activism on firm performance. Also, activist investors are targeting companies. These attacks are not fructifying desired outcomes as promoters own over 50% stake in the listed companies. The latest data for FY2021 has not been considered for the study as covid-19 impacted the businesses during the financial year. Also, we cannot capture activism instances that are not reported in regulatory filings. Unlike past research in this area, we have used a comprehensive activism index as a proxy of activism and have employed PDA instead of event studies to assess the impact on firm performance. Also, this is the first such empirical study conducted in an emerging economy setup where neither large hedge nor pension funds are present.
Landscape and Settlement over 4 Millennia on the South Side of Lake Issyk Kul, Kyrgyzstan: Preliminary Results of Survey Research in 2019–2021
Authors: Chang Claudia , Ivanov Sergei S. , Tourtellotte Perry A.
Published: March 2022

This paper discusses the preliminary results of archaeological surveys conducted in the Juuku Region of north-central Kyrgyzstan on the south side of Lake Issyk-Kul. Our goal was to document ancient and contemporary agropastoral systems over a four-millennia period. During the surveys, about 350 loci were identified as settlements, burial mounds, graves, single artifact finds, and artifact scatters (ceramic). The areas of Juuku Valley surveyed included two discrete polygons: Polygon 1, Lower Juuku at 1750 to 1950 m asl in elevation and Polygon 2, Chak Juuku or Upper Eastern Branch Juuku Valley at 2060 to 2100 m asl in elevation. Three radiometric dates and preliminary archaeobotanical studies were conducted at three exposed profile cuts. The methods included here are: (1) pedestrian surveys; (2) use of digital maps (Google Earth, Nakarte); (3) placing archaeological loci within known chronological time periods; (4) AMS dating of charcoal samples collected from profile deposits; and (5) preliminary identification of plant remains found from archaeobotanical samples. The results of our research represent the first step toward inventorying and interpreting archaeological data in the Juuku Valley derived from field studies.
Multifunctional Territorialized Agri-Food Systems, Geographical Quality Marks and Agricultural Landscapes: The Case of Vineyards
Authors: Martínez-Arnáiz Marta , Baraja-Rodríguez Eugenio , Herrero-Luque Daniel
Published: March 2022

In contrast to the industrial agricultural systems aimed at producing unlabeled origin foods without unique characteristics, Multifunctional and Territorialized Agri-food Systems (MTAS) claim their identity in productions whose singularity comes from specific environmental conditions and distinctive knowhow—factors often linked to tradition. Their systemic complexity goes beyond the agri-food production function (high quality, sustainable, and differentiated by origin) because the territories gain cohesion and viability from the positive effects resulting therefrom: environmental quality—in the context of sustainable agriculture based on practices that respect the environment and the local productive vocation of the territories—, landscape value, greater economic diversification by stimulating integrated production chains, tourism potential, etc. In this context, the MTAS finds in the geographical indication one of the most expressive quality reference formulas for the identification of agri-food products. This paper delves into the regulatory nature of the main territorial indications (PDO, PGI) and explores their configuration and regulatory evolution, particularly focusing on the wine geographical indications—the first and most common ones. The Spanish indications are taken as the object of analysis, whose operational maturity reveals their solidity, but also their inadequacies, with the demand for adjustments for greater flexibility in the regulatory framework that identifies them as collective marks. Along the same lines, emphasis is placed on the recent advance of individualistic PDO figures, which call into question the very collective basis of the territorial trademark. These conceptual adaptations of geographical indications provide future lines of research necessary to interpret the coherence of these figures with the sustainable development of the territories, whose name they adopt to gain distinction and market competition.
Bacterial Infections, Antimicrobial Resistance and Antibiotic Therapy
Authors: Kolář Milan
Published: March 2022

Bacterial infections have been, and are very likely to continue to be, among the most serious problems in medicine [...]
Interobserver Reliability of Magnetic Resonance Imaging of Sacroiliac Joints in Axial Spondyloarthritis
Authors: Mușetescu Anca Emanuela , Bobircă Anca , Gherghina Florin Liviu , Florescu Alesandra , Bobircă Florin , Ciurea Paulina Lucia , Criveanu Cristina , Muscă Alice , Florescu Lucian Mihai , Gheonea Ioana Andreea
Published: March 2022

Introduction: Axial spondyloarthritis (axSpA) is characterized by damage to the axial skeleton and entheses, and is often associated with extra-articular manifestations, in the presence of the human leukocyte antigen (HLA) B27. The aim of our study is to assess the performance of rheumatologists in interpreting the inflammatory and structural damage to sacroiliac joints, in comparison to radiologists. Material and Methods: The present study included a total of 34 patients diagnosed with axSpA, according to the Assessment of SpondyloArthritis International Society (ASAS) criteria for axSpA, examined from January 2021 to November 2021 in the Departments of Rheumatology and Radiology and Medical Imaging of the University of Medicine and Pharmacy of Craiova. All patients underwent physical examination, laboratory tests, and magnetic resonance imaging (MRI) of the sacroiliac joints. The images were interpreted by a senior radiologist (SR), a junior radiologist (JR), a senior rheumatologist (SRh), and a junior rheumatologist (JRh), who were blinded to the clinical and paraclinical data. Results: The overall κ was 0.7 for the JR (substantial agreement), 0.707 for the SRh (substantial agreement), and 0.601 for the JRh (moderate agreement), in comparison with the SR. Regarding the overall inflammatory changes, the SRh and JR were proven to have substantial agreement (κ = 0.708 and 0.742, respectively) with the SR, while the JRh was proven to have moderate agreement (κ = 0.607). The structural damage observed by the JR showed substantial agreement (κ = 0.676) with the SR, while the SRh and JRh had substantial and moderate agreement (κ = 0.705 and 0.596, respectively) with the SR. Conclusions: Our study showed substantial agreement between the senior radiologist, senior rheumatologist, and junior radiologist, and moderate agreement with the junior rheumatologist.
Book Review: Jensen (2021). Our Silver City 2094, e-Book. Nottingham: Nottingham Contemporary. ISBN: 978-1399908481
Authors: Mundler Helen E.
Published: March 2022

Liz Jensen has become a significant voice in British literary fiction in recent years, so reading Our Silver City 2094 comes with the pleasure of rediscovery [...]
Performance of MQL and Nano-MQL Lubrication in Machining ER7 Steel for Train Wheel Applications
Authors: Çamlı Kerem Yavuz , Demirsöz Recep , Boy Mehmet , Korkmaz Mehmet Erdi , Yaşar Nafiz , Giasin Khaled , Pimenov Danil Yurievich
Published: March 2022

In the rail industry, there are four types of steel grades used for monoblock wheels, namely ER6, ER7, ER8 and ER9. ER7 steel is manufactured in accordance with the EN13262 standard and is utilized in European railway lines. These train wheels are formed by pressing and rolling after which they are machined using turning process to achieve their final dimensions. However, machining ER7 steels can be challenging due to their high mechanical properties, which can facilitate rapid tool wear and thermal cracking. Therefore, while the use of coolants is critical to improving their machinability, using conventional flood coolants adds extra operational costs, energy and waste. An alternative is to use minimum quantity lubrication (MQL) cooling technology, which applies small amounts of coolant mixed with air to the cutting zone, leaving a near-dry machined surface. In the current study, preliminary tests were undertaken under dry conditions and using coated carbide inserts to determine the optimal cutting parameters for machining ER7 steel. The impact of the cutting speed and feed rate on surface roughness (Ra), energy consumption and cutting temperature were investigated and used as a benchmark to determine the optimal cutting parameters. Next, additional machining tests were conducted using MQL and nano-MQL cooling technologies to determine their impact on the aforementioned machining outputs. According to preliminary tests, and within the tested range of the cutting parameters, using a cutting speed of 300 m/min and a feed rate of 0.15 mm/rev resulted in minimal surface roughness. As a result, using these optimal cutting parameters with MQL and Nano-MQL (NMQL) cooling technologies, the surface roughness was further reduced by 24% and 34%, respectively, in comparison to dry conditions. Additionally, tool wear was reduced by 34.1% and 37.6%, respectively. The overall results from this study demonstrated the feasibility of using MQL coolants as a sustainable machining alternative for steel parts for rail wheel applications. In addition, the current study highlight the enhanced performance of MQL cooling technology with the addition of nano additives.
Mechanical Properties, Crack Width, and Propagation of Waste Ceramic Concrete Subjected to Elevated Temperatures: A Comprehensive Study
Authors: Najm Hadee Mohammed , Nanayakkara Ominda , Ahmad Mahmood , Sabri Sabri Mohanad Muayad
Published: March 2022

Waste ceramic concrete (WOC) made from waste ceramic floor tiles has several economic and environmental benefits. Fire is one of the most common disasters in buildings, and WOC is a brittle construction material; therefore, the mechanical properties of WOC structures under high temperatures should be considered. According to previous studies, hybrid fiber can further reduce damage to concrete under high temperatures. Meanwhile, crack width and propagation are among the key characteristics of concrete materials that need to be considered, but few studies have focused on their behavior when subjected to elevated temperatures. The new concrete materials proposed by the authors are WOC and WOC-Hybrid. WOC was prepared with Natural Coarse Aggregates (NCA), Natural Fine Aggregate (NFA), Ordinary Portland Cement (OPC 43 grade), and ceramic waste tiles with 20% replacements for coarse aggregates, 10% replacements for fine aggregates, and 10% replacement for cement. In contrast, WOC-Hybrid was prepared with the addition of hybrid fiber (1% crimped steel fiber and 1% polyvinyl alcohol fiber) in WOC. The specimens were exposed to temperatures of 100–300 °C, and then the specimens were tested for tensile and compressive strength. The present study aims to find a new method to improve concrete resistance to elevated temperatures at the lowest costs by experimental and computational analysis via machine learning models. The application of machine learning models such as artificial neural networks (ANN) and multiple linear regression (MLR) was employed in this study to predict the compressive and tensile strength of concrete. The linear coefficient correlation (R2) and mean square error (MSE) were evaluated to investigate the performance of the models. Based on the experimental analysis, the results show that the effect of hybrid fiber on the crack width and propagation is greater than that on the crack width and propagation of WOC and PC after exposure to high temperatures. However, the enhanced effect of hybrid fiber on the mechanical properties, rack width, and propagation decreases after subjecting it to a high-temperature treatment, owing to the melting and ignition of hybrid fibers at high temperatures. Regarding the computational analysis, it was found that the developed MLR model shows higher efficiency than ANN in predicting the compressive and tensile strength of PC, WOC, and WOC-Hybrid concrete.
Effect of Laser Remelting Strategy on the Forming Ability of Cemented Carbide Fabricated by Laser Powder Bed Fusion (L-PBF)
Authors: Liu Decheng , Yue Wen , Kang Jiajie , Wang Chengbiao
Published: March 2022

Due to the high degree of design freedom and rapid prototyping, laser powder bed fusion (L-PBF) presents a great advantage in the super-hard cemented carbide compared with conventional methods. However, optimizing processing parameters to improve the relative density and surface roughness is still a challenge for cemented carbide fabricated by L-PBF. For this, the effect of the remelting strategy on the forming quality of the L-PBF processed cemented carbide was studied in this article, aiming to explore a suitable process window. The surface quality, relative density, microstructure, and microhardness of the cemented carbide parts fabricated under a single melting and remelting strategy were compared. The results showed that the remelting strategy could efficiently improve the specimens’ surface quality and relative density. Besides, the cracks were not obviously aggravated, and the WC grains could distribute more homogeneously on the binder matrix under the remelting strategy. Therefore, the microhardness showed an improvement compared to the single melting strategy.
Modeling Impulsive Ball Mill Forces Effects on the Dynamic Behavior of a Single-Stage Gearbox
Authors: Ngandu Kalala Gauthier , Chiementin Xavier , Rasolofondraibe Lanto , Boujelben Abir , Kilundu Bovic
Published: March 2022

Gearboxes are frequently used in the mining industry, especially for power transmission between the electric drive and the ball mill; besides the extreme complexity of a ball mill gear transmission system, the fault diagnosis by vibration analysis can be easily distorted by the presence of impulsive noises due to the ball pulses on the mill shell. Although several works in the literature are related to the influence of an impulsive noise on the accuracy of the diagnosis, no dynamic model exists yet in the literature that can explain the influence of these forces on the dynamic behavior of gearboxes. This paper presents a new approach to determine the influence of the grinding forces in crack defects diagnosis. This approach is based on a hybrid numerical model of a 24-degree-of-freedom gearbox, simulating one gear train and two drive shafts. The impact forces of the mill drum are modelled by a discrete element method (DEM). The ball-filling rate (Fr), the mill speed (Nr), and the ball size (Db) are considered to study this phenomenon. The simulations results show by a time series representation, fast Fourier transform, and short-time Fourier transform (STFT), that the acceleration is significantly affected by the presence of the grinding forces, developing an impulsive noise due to the impact of the balls governed by the studied parameters.
A Tensor Splitting AOR Iterative Method for Solving a Tensor Absolute Value Equation
Authors: Chen Yuhan , Li Chenliang
Published: March 2022

In this paper, a tensor splitting AOR iterative method for solving the H+-tensor absolute value equation is presented. Some sufficient conditions for the existence of the solution to the tensor absolute value equation are given. Under suitable conditions, the new method is proved to be convergent. Finally, some numerical examples demonstrate that our new method is effective.
A New Algorithm for Multivariate Genome Wide Association Studies Based on Differential Evolution and Extreme Learning Machines
Authors: Álvarez Gutiérrez David , Sánchez Lasheras Fernando , Martín Sánchez Vicente , Suárez Gómez Sergio Luis , Moreno Víctor , Moratalla-Navarro Ferrán , Molina de la Torre Antonio José
Published: March 2022

Genome-wide association studies (GWAS) are observational studies of a large set of genetic variants, whose aim is to find those that are linked to a certain trait or illness. Due to the multivariate nature of these kinds of studies, machine learning methodologies have been already applied in them, showing good performance. This work presents a new methodology for GWAS that makes use of extreme learning machines and differential evolution. The proposed methodology was tested with the help of the genetic information (370,750 single-nucleotide polymorphisms) of 2049 individuals, 1076 of whom suffer from colorectal cancer. The possible relationship of 10 different pathways with this illness was tested. The results achieved showed that the proposed methodology is suitable for detecting relevant pathways for the trait under analysis with a lower computational cost than other machine learning methodologies previously proposed.
Generalized Exp-Function Method to Find Closed Form Solutions of Nonlinear Dispersive Modified Benjamin–Bona–Mahony Equation Defined by Seismic Sea Waves
Authors: Shakeel Muhammad , Attaullah  , El-Zahar Essam Roshdy , Shah Nehad Ali , Chung Jae Dong
Published: March 2022

Using the new generalized exp-function method, we were able to derive significant novel closed form solutions to the nonlinear dispersive modified Benjamin–Bona–Mahony (DMBBM) equation. The general framework of the new generalized exp-function method has been given. Many novel closed form solutions have been obtained in the form of hyperbolic, trigonometric, and rational function solutions. Using the computer application Wolfram Mathematica 10, we plotted 2D, 3D, and contour surfaces of closed form solutions found in this work. In the form of a table, the acquired results are compared to the known solutions in the existing literature.
Identifying the Association of Time-Averaged Serum Albumin Levels with Clinical Factors among Patients on Hemodialysis Using Whale Optimization Algorithm
Authors: Yang Cheng-Hong , Chen Yin-Syuan , Moi Sin-Hua , Chen Jin-Bor , Chuang Li-Yeh
Published: March 2022

Time-averaged serum albumin (TSA) is commonly associated with clinical outcomes in hemodialysis (HD) patients and considered as a surrogate indicator of nutritional status. The whale optimization algorithm-based feature selection (WOFS) model could address the complex association between the clinical factors, and could further combine with regression models for application. The present study aimed to demonstrate an optimal multifactor TSA-associated model, in order to interpret the complex association between TSA and clinical factors among HD patients. A total of 829 HD patients who met the inclusion criteria were selected for analysis. Monthly serum albumin data tracked from January 2009 to December 2013 were converted into TSA categories based on a critical value of 3.5 g/dL. Multivariate logistic regression was used to analyze the association between TSA categories and multiple clinical factors using three types of feature selection models, namely the fully adjusted, stepwise, and WOFS models. Five features, albumin, age, creatinine, potassium, and HD adequacy index (Kt/V level), were selected from fifteen clinical factors by the WOFS model, which is the minimum number of selected features required in multivariate regression models for optimal multifactor model construction. The WOFS model yielded the lowest Akaike information criterion (AIC) value, which indicated that the WOFS model could achieve superior performance in the multifactor analysis of TSA for HD patients. In conclusion, the application of the optimal multifactor TSA-associated model could facilitate nutritional status monitoring in HD patients.
Boosting Ant Colony Optimization with Reptile Search Algorithm for Churn Prediction
Authors: Al-Shourbaji Ibrahim , Helian Na , Sun Yi , Alshathri Samah , Abd Elaziz Mohamed
Published: March 2022

The telecommunications industry is greatly concerned about customer churn due to dissatisfaction with service. This industry has started investing in the development of machine learning (ML) models for churn prediction to extract, examine and visualize their customers’ historical information from a vast amount of big data which will assist to further understand customer needs and take appropriate actions to control customer churn. However, the high-dimensionality of the data has a large influence on the performance of the ML model, so feature selection (FS) has been applied since it is a primary preprocessing step. It improves the ML model’s performance by selecting salient features while reducing the computational time, which can assist this sector in building effective prediction models. This paper proposes a new FS approach ACO-RSA, that combines two metaheuristic algorithms (MAs), namely, ant colony optimization (ACO) and reptile search algorithm (RSA). In the developed ACO-RSA approach, an ACO and RSA are integrated to choose an important subset of features for churn prediction. The ACO-RSA approach is evaluated on seven open-source customer churn prediction datasets, ten CEC 2019 test functions, and its performance is compared to particle swarm optimization (PSO), multi verse optimizer (MVO) and grey wolf optimizer (GWO), standard ACO and standard RSA. According to the results along with statistical analysis, ACO-RSA is an effective and superior approach compared to other competitor algorithms on most datasets.
Dactylospongia elegans—A Promising Drug Source: Metabolites, Bioactivities, Biosynthesis, Synthesis, and Structural-Activity Relationship
Authors: Ibrahim Sabrin R. M. , Fadil Sana A. , Fadil Haifa A. , Hareeri Rawan H. , Alolayan Sultan O. , Abdallah Hossam M. , Mohamed Gamal A.
Published: March 2022

Marine environment has been identified as a huge reservoir of novel biometabolites that are beneficial for medical treatments, as well as improving human health and well-being. Sponges have been highlighted as one of the most interesting phyla as new metabolites producers. Dactylospongia elegans Thiele (Thorectidae) is a wealth pool of various classes of sesquiterpenes, including hydroquinones, quinones, and tetronic acid derivatives. These metabolites possessed a wide array of potent bioactivities such as antitumor, cytotoxicity, antibacterial, and anti-inflammatory. In the current work, the reported metabolites from D. elegans have been reviewed, including their bioactivities, biosynthesis, and synthesis, as well as the structural-activity relationship studies. Reviewing the reported studies revealed that these metabolites could contribute to new drug discovery, however, further mechanistic and in vivo studies of these metabolites are needed.
Rare Cause of Severe Mitral Regurgitation after TAVI: Case Report and Literature Review
Authors: Moldovan Horațiu , Popescu Bogdan-Ştefan , Nechifor Elena , Badea Aida , Ciomaga Irina , Nica Claudia , Zaharia Ondin , Gheorghiță Daniela , Broască Marian , Diaconu Camelia , Parasca Cătălina , Chioncel Ovidiu , Iliescu Vlad Anton
Published: March 2022

Pre-procedure mitral regurgitation (MR) is a frequent coexistent finding in patients undergoing transcatheter aortic valve replacement (TAVR), and most of them (up to 55%) experience a significant improvement in MR after the procedure. Although seldom described, mitral valve perforation after TAVR is a potentially serious complication that physicians should be aware of, as moderate or severe MR in TAVR recipients is associated with a high early mortality rate. We herein describe the case of a 65-year-old man presenting with worsening heart failure symptoms 5 months after TAVR due to an intraprocedural anterior mitral leaflet perforation and discuss the diagnostic process and therapeutic course of the case. Furthermore, we draw attention to the essential role of echocardiography in the management of TAVR procedures, taking into account its ability in detecting early complications, and emphasize the value of CT as a main determinant to predict long-term MR improvement after TAVR and to assess the potential candidates for double valve repair with percutaneous techniques.
Association between the Horizontal Gaze Ability and Physical Characteristics of Patients with Dropped Head Syndrome
Authors: Igawa Tatsuya , Ishii Ken , Urata Ryunosuke , Suzuki Akifumi , Ui Hideto , Ideura Kentaro , Isogai Norihiro , Sasao Yutaka , Funao Haruki
Published: March 2022

Background and Objectives: Patients with dropped head syndrome exhibit weakness of the cervical paraspinal muscles. However, the relationship between horizontal gaze disorder and physical function remains unclear. This study aimed to examine and clarify this relationship. Materials and Methods: Ninety-six patients with dropped head syndrome were included. We measured the McGregor’s Slope and investigated physical characteristics, including cervical muscle strength, back muscle strength, and walking ability. Factor analysis was used to classify the characteristics of physical function, and a linear multiple regression analysis was used to evaluate independent variables explaining the variance in the McGregor’s Slope. The physical functions of DHS patients were classified into three categories by factor analysis: limb and trunk muscle strength, walking ability, and neck muscle strength. Results: The average value of the McGregor’s Slope was 22.2 ± 24.0 degrees. As a result of multiple regression analysis, walking speed (β = −0.46) and apex (β = −0.30) were extracted as significant factors influencing the McGregor’s Slope. Conclusions: Horizontal gaze disorders are not associated with cervical muscle strength but with the walking ability and the alignment type of dropped head syndrome.
Inhibitory Effect of Ulmus davidiana and Cornus officinalis Extracts on Osteoporotic Bone Loss In Vitro and In Vivo
Authors: Kim Jeonghyun , Lee Chang-Gun , Yun Seung-Hee , Hwang Seokjin , Jeon Hyoju , Park Eunkuk , Jeong Seon-Yong
Published: March 2022

Background and Objectives: Traditional herbal medicines are becoming more popular as a complementary medication as they have the advantages of being mostly harmless and safe, causing fewer side-effects than conventional medications. Here, we demonstrate the inhibitory effects of the combination of Ulmus davidiana (UD) and Cornus officinalis (CO) extracts on osteoporotic bone loss. Materials and Methods: This study presented osteogenic effects in primary cultured osteoblasts, pre-osteoblastic MC3T3-E1 cell lines, and osteoclastogenic effects in osteoclasts derived from bone marrow monocytes, and finally, protective effects on bone loss in an ovariectomy (OVX)-induced osteoporotic animal model. Results: A significant increase in alkaline phosphatase (ALP) activity was observed following treatment with UD and CO mixtures (8:2, 7:3, and 5:5 ratios) and individual UD and CO extracts, with the highest ALP activity being detected for the treatment with UD and CO extracts at a 5:5 ratio. An optimal ratio of UD and CO (UC) extract promoted osteoblast differentiation in both pre-osteoblastic cells and primary osteoblasts by increasing osteoblastic markers such as Alpl, Runx2, and Bglap. However, treatment with the UC extract inhibited osteoclast differentiation with a decreased expression of osteoclastogenesis-related genes, including Ctsk, Acp5, Mmp9, and Nfatc1. In addition, UC treatment prevented osteoporotic bone loss in OVX mice and improved impaired skeletal structure parameters. Conclusions: This study suggests that combined UD and CO extracts may be a beneficial traditional medicine for the prevention of postmenopausal osteoporosis.
Morphologic Evaluation of Dentoalveolar Structures after Corticotomy-Assisted Orthodontic Treatment in Romanian Adult Patients
Authors: Panainte Irinel , Nenovici Dorin-Horațiu , Mariș Marius , Șerbănoiu Dan-Cosmin , Vartolomei Claudiu , Păcurar Mariana
Published: March 2022

Background and Objectives: Corticotomy-facilitated orthodontics is an approach that can be useful in treating complex orthodontic cases and that could enhance the rate of tooth movement. The aim of this study was to evaluate the changes that occurred in the buccal cortical bone and at the root level after an orthodontic treatment when corticotomy was used, in Romanian patients. Materials and Methods: After dividing the subjects into two groups (maxillary and mandibular corticotomy), based on CBCT, measurements were made of the thickness of the cortical buccal bone at the cervical, median and apical level, and of the root length at T0 (before corticotomy) and T1 (6 months after surgery). Several tests were used for statistical analysis of the data. Results: In the maxillary arch, the bone thickness measured after corticotomy in males was 0.64 mm at the cervical level, 0.53 mm at the medial level and 0.30 mm in the apical area. In females, the values were 0.46 mm (cervical), 0.37 mm (medial) and 0.36 mm (apical). In the lower arch, the values obtained for these three regions were 0.37 mm, 0.30 mm and 0.37 mm for males and 0.58 mm, 0.32 mm and 0.43 mm for female subjects. All values were statistically significant. The root length for the lower teeth at T0 was 11.98 ± 2.24 mm at T0 and 11.97 ± 2.24 mm at T1. For the upper teeth, the root length at T0 was 13.83 ± 2.28 mm and 13.81 ± 2.28 mm. Conclusions: Comparing the measurements, it was observed that the biggest changes in the cortical bone were at the cervical level. In the maxillary arch, the most significant modifications were registered at the canines and the level of the first premolars, and in the lower arch at the incisors level. The measured root resorption of the teeth was considered to be statistically insignificant.
Sequential Membrane Filtration to Recover Polyphenols and Organic Acids from Red Wine Lees: The Antioxidant Properties of the Spray-Dried Concentrate
Authors: Filippou Polychronis , Mitrouli Soultana T. , Vareltzis Patroklos
Published: March 2022

The vinification process produces a considerable amount of waste. Wine lees are the second most generated byproduct, representing around 14% of total vinification wastes. They are a valuable source of natural antioxidants, mainly polyphenols, as well as organic acids, such as tartaric acid. This paper deals with the application of an integrated, environment friendly membrane separation process to recover polyphenols and organic acids. A two-step membrane process is described, consisting of an ultra- and a nano-filtration process. The physicochemical and antioxidant properties of all the process streams were determined. High Pressure Liquid Chromatography (HPLC) was employed for identifying certain individual organic acids and polyphenols, while the antioxidant potential was determined by the 2,2′-diphenyl-1-picrylhydrazyl radical) (DPPH) radical scavenging ability and ferric reducing ability. A liquid concentrate stream containing 1351 ppm of polyphenols was produced and then spray dried. The resulting powder retained most of the polyphenols and antioxidant properties and was successfully applied to a real food system to retard lipid oxidation, followed by Thiobarbituric Acid Reactive Substances (TBARS) and the determination of oxymyoglobin content. The results show that membrane separation technology is an attractive alternative process for recovering value-added ingredients from wine lees.
Surface Engineering of Metals and Alloys
Authors: Rokosz Krzysztof
Published: March 2022

Nowadays, the surface treatments of metals and alloys allow us to obtain from them the films or coatings with different physical and chemical properties from the substrate [...]
Tribological Wear Effects of Laser Texture Design on AISI 630 Stainless Steel under Lubricated Conditions
Authors: Salguero Jorge , Sol Irene Del , Dominguez Guzman , Batista Moises , Vazquez-Martinez Juan Manuel
Published: March 2022

Surface texturing is used in many applications to control the friction and wear behaviour of mechanical components. The benefits of texture design on the tribological behaviour of conformal surfaces are well known. However, there is a big dependency between the geometrical features of the texture and the texture’s performance. In this paper, the effect of laser texturing parameters on textured geometrical features is studied, as well as its role in the tribological behaviour of AISI 630 steel under lubrication and high-contact pressure conditions. The results show a linear impact of the energy density on the surface quality, whereas the scanning speed influences the homogeneity of the sample. Nevertheless, the surface integrity is also affected by the laser parameters, reducing the micro-hardness on the textured area by up to 33%. Friction coefficient average values and stability presented high variations depending on the sample parameters. Finally, the wear mechanisms were analysed, detecting abrasion for the disc and adhesion for the pin.
Selection of Additive Elements Focusing on Impact Resistance in Practical TiAl Cast Alloys
Authors: Tetsui Toshimitsu
Published: March 2022

Despite the widespread use of TiAl alloys in many fields, their poor impact resistance has recently emerged again as a major issue. Therefore, in this study, the practical effects of additive elements were examined by considering impact resistance as the most important property of practical TiAl cast alloys. The impact resistance was evaluated via the Charpy impact test, which has been rarely applied to TiAl alloys, revealing that only V, Cr, Mn, and B slightly improved the impact resistance, compared to that of the Ti–Al binary alloy, both in the as-cast and heat-treated states. In contrast, Nb, Mo, W, Fe, Ni, Si, C, and N decreased the impact resistance. If a slight decrease in impact resistance is permitted, then only Si and C can improve the creep strength, and Nb and W can improve the anti-oxidation resistance. These results confirm the excellence of practical TiAl cast alloys developed a considerable time ago, containing these elements in addition to Cr, Mn, and B.
Effect of Microstructures on the Tribological Performance of Medium Carbon Steel
Authors: Jiang Tao , Wei Shizhong , Xu Liujie , Zhang Cheng , Wang Xiaodong , Xiong Mei , Mao Feng , You Long , Chen Chong
Published: March 2022

Improving wear resistance and reducing the coefficient of friction of the cylinder liner are critical to improving the service life and energy savings of internal combustion engines. In this paper, the effect of the characteristics of cementite precipitation on the tribological performance was studied using a medium carbon steel (AISI 1045 steel), which can be used to make cylinder liners. Three kinds of microstructures with different characteristics of cementite were obtained by heat treatments. Abrasive wear tests and dry sliding friction tests were conducted on the samples of each microstructure. The study indicated that the abrasive wear resistance of medium carbon steel mainly depends on its hardness rather than on the characteristics of cementite precipitation. However, increasing the hardness alone did not guarantee improvement of the dry sliding friction performance of medium carbon steel. The specimen with a spherical pearlite microstructure, which was granular cementite distributed in the ferrite matrix showed the best friction performance. Moreover, the abrasive wear mechanism and dry sliding friction mechanism were discussed. In the end, the correlation between the characteristics of cementite and tribological behavior was established. These findings can help develop multiphase materials with outstanding tribological performance.
Serum Metabolites Associated with Blood Pressure in Chronic Kidney Disease Patients
Authors: Yan Fengyao , Chen Dan-Qian , Tang Jijun , Zhao Ying-Yong , Guo Yan
Published: March 2022

Blood pressure is one of the most basic health screenings and it has a complex relationship with chronic kidney disease (CKD). Controlling blood pressure for CKD patients is crucial for curbing kidney function decline and reducing the risk of cardiovascular disease. Two independent CKD cohorts, including matched controls (discovery n = 824; validation n = 552), were recruited. High-throughput metabolomics was conducted with the patients’ serum samples using mass spectrometry. After controlling for CKD severity and other clinical hypertension risk factors, we identified ten metabolites that have significant associations with blood pressure. The quantitative importance of these metabolites was verified in a fully connected neural network model. Of the ten metabolites, seven have not previously been associated with blood pressure. The metabolites that had the strongest positive association with blood pressure were aspartylglycosamine (p = 4.58 × 10−5), fructose-1,6-diphosphate (p = 1.19 × 10−4) and N-Acetylserine (p = 3.27 × 10−4). Three metabolites that were negatively associated with blood pressure (phosphocreatine, p = 6.39 × 10−3; dodecanedioic acid, p = 0.01; phosphate, p = 0.04) have been reported previously to have beneficial effects on hypertension. These results suggest that intake of metabolites as supplements may help to control blood pressure in CKD patients.
A Low-Cost Microfluidic Method for Microplastics Identification: Towards Continuous Recognition
Authors: Mesquita Pedro , Gong Liyuan , Lin Yang
Published: March 2022

Plastic pollution has emerged as a growing concern worldwide. In particular, the most abundant plastic debris, microplastics, has necessitated the development of rapid and effective identification methods to track down the stages and evidence of the pollution. In this paper, we combine low-cost plastic staining technologies using Nile Red with the continuous feature offered by microfluidics to propose a low-cost 3D printed device for the identification of microplastics. It is observed that the microfluidic devices indicate comparable staining and identification performance compared to conventional Nile Red staining processes while offering the advantages of continuous recognition for long-term environmental monitoring. The results also show that concentration, temperature, and residency time possess strong effects on the identification performance. Finally, various microplastics have been applied to further demonstrate the effectiveness of the proposed devices. It is found that, among different types of microplastics, non-spherical microplastics show the maximal fluorescence level. Meanwhile, natural fibers indicate better staining quality when compared to synthetic ones.
The Eco-Physiological Role of Microcystis aeruginosa in a Changing World
Authors: Giannuzzi Leda , Hernando Marcelo
Published: March 2022

Among the bloom-forming cyanobacteria, Microcystis aeruginosa is one of the most harmful species [...]
A Multi-Skilled Mathematical Model of Bacterial Attachment in Initiation of Biofilms
Authors: Chathoth Kanchana , Fostier Louis , Martin Bénédicte , Baysse Christine , Mahé Fabrice
Published: March 2022

The initial step of biofilm formation is bacteria attachment to biotic or abiotic surfaces and other bacteria through intra or interspecies interactions. Adhesion can be influenced by physicochemical conditions of the environment, such as iron. There is no available mathematical model of bacterial attachment giving realistic initiation rather than random adhesion. We describe a simple stochastic attachment model, from the simplest case in two dimensions with one bacterial species attaching on a homogeneous flat surface to more complex situations, with either several bacterial species, inhomogeneous or non-flat surfaces, or in three dimensions. The model depends on attachment probabilities (on the surface, laterally, or vertically on bacteria). Effects of each of these parameters were analyzed. This mathematical model is then applied to experimental oral microcolonies of Porphyromonas gingivalis, Streptococcus gordonii, and Treponema denticola, either as mono-, two, or three species, under different iron concentrations. The model allows to characterize the adhesion of three bacterial species and explore the effect of iron on attachment. This model appears as a powerful tool for initial attachment analysis of bacterial species. It will enable further modeling of biofilm formation in later steps with biofilm initialization more relevant to real-life subgingival biofilms.
Dinoflagellate Phosphopantetheinyl Transferase (PPTase) and Thiolation Domain Interactions Characterized Using a Modified Indigoidine Synthesizing Reporter
Authors: Williams Ernest , Bachvaroff Tsvetan , Place Allen
Published: March 2022

Photosynthetic dinoflagellates synthesize many toxic but also potential therapeutic compounds therapeutics via polyketide/non-ribosomal peptide synthesis, a common means of producing natural products in bacteria and fungi. Although canonical genes are identifiable in dinoflagellate transcriptomes, the biosynthetic pathways are obfuscated by high copy numbers and fractured synteny. This study focuses on the carrier domains that scaffold natural product synthesis (thiolation domains) and the phosphopantetheinyl transferases (PPTases) that thiolate these carriers. We replaced the thiolation domain of the indigoidine producing BpsA gene from Streptomyces lavendulae with those of three multidomain dinoflagellate transcripts and coexpressed these constructs with each of three dinoflagellate PPTases looking for specific pairings that would identify distinct pathways. Surprisingly, all three PPTases were able to activate all the thiolation domains from one transcript, although with differing levels of indigoidine produced, demonstrating an unusual lack of specificity. Unfortunately, constructs with the remaining thiolation domains produced almost no indigoidine and the thiolation domain for lipid synthesis could not be expressed in E. coli. These results combined with inconsistent protein expression for different PPTase/thiolation domain pairings present technical hurdles for future work. Despite these challenges, expression of catalytically active dinoflagellate proteins in E. coli is a novel and useful tool going forward.
Identification and Subtyping of Salmonella Isolates Using Matrix-Assisted Laser Desorption–Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF)
Authors: Persad Anil K. , Fahmy Hanan A. , Anderson Nicholas , Cui Jing , Topalcengiz Zeynal , Jeamsripong Saharuetai , Spanninger Patrick M. , Buchanan Robert L. , Kniel Kalmia E. , Jay-Russell Michele T. , Danyluk Michelle D. , Rajashekara Gireesh , LeJeune Jeffrey T.
Published: March 2022

Subtyping of bacterial isolates of the same genus and species is an important tool in epidemiological investigations. A number of phenotypic and genotypic subtyping methods are available; however, most of these methods are labor-intensive and time-consuming and require considerable operator skill and a wealth of reagents. Matrix-Assisted Laser Desorption–Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF), an alternative to conventional subtyping methods, offers a rapid, reproducible method for bacterial identification with a high sensitivity and specificity and at minimal cost. The purpose of this study was to determine the feasibility of using MALDI-TOF to differentiate between six Salmonella serovars recovered from experimental microcosms inoculated with known strains of Salmonella. Following the establishment of a MALDI-TOF reference library for this project, the identity of 843 Salmonella isolates recovered from these microcosms was assessed using both MALDI-TOF and conventional methods (serotyping/PCR). All 843 isolates were identified as being Salmonella species. Overall, 803/843 (95%) of these isolates were identified similarly using the two different methods. Positive percent agreement at the serovar level ranged from 79 to 100%, and negative percent agreement for all serovars was greater than 98%. Cohen’s kappa ranged from 0.85 to 0.98 for the different serovars. This study demonstrates that MALDI-TOF is a viable alternative for the rapid identification and differentiation of Salmonella serovars.