bluuebunny/crossref_metadata_2025 huggingface dataset:
Hippocampal Over-Expression of Cyclooxygenase-2 (COX-2) Is Associated with Susceptibility to Stress-Induced Anhedonia in Mice
Authors: Strekalova Tatyana , Pavlov Dmitrii , Trofimov Alexander , Anthony Daniel C. , Svistunov Andrei , Proshin Andrey , Umriukhin Aleksei , Lyundup Alexei , Lesch Klaus-Peter , Cespuglio Raymond
Published: February 2022

The phenomenon of individual variability in susceptibility/resilience to stress and depression, in which the hippocampus plays a pivotal role, is attracting increasing attention. We investigated the potential role of hippocampal cyclooxygenase-2 (COX-2), which regulates plasticity, neuroimmune function, and stress responses that are all linked to this risk dichotomy. We used a four-week-long chronic mild stress (CMS) paradigm, in which mice could be stratified according to their susceptibility/resilience to anhedonia, a key feature of depression, to investigate hippocampal expression of COX-2, a marker of microglial activation Iba-1, and the proliferation marker Ki67. Rat exposure, social defeat, restraints, and tail suspension were used as stressors. We compared the effects of treatment with either the selective COX-2 inhibitor celecoxib (30 mg/kg/day) or citalopram (15 mg/kg/day). For the celecoxib and vehicle-treated mice, the Porsolt test was used. Anhedonic (susceptible) but not non-anhedonic (resilient) animals exhibited elevated COX-2 mRNA levels, increased numbers of COX-2 and Iba-1-positive cells in the dentate gyrus and the CA1 area, and decreased numbers of Ki67-positive cells in the subgranular zone of the hippocampus. Drug treatment decreased the percentage of anhedonic mice, normalized swimming activity, reduced behavioral despair, and improved conditioned fear memory. Hippocampal over-expression of COX-2 is associated with susceptibility to stress-induced anhedonia, and its pharmacological inhibition with celecoxib has antidepressant effects that are similar in size to those of citalopram.
Heat Stress Reduces Root Meristem Size via Induction of Plasmodesmal Callose Accumulation Inhibiting Phloem Unloading in Arabidopsis
Authors: Liu Jie , Liu Yao , Wang Shuang , Cui Yongqi , Yan Dawei
Published: February 2022

The intercellular transport of sugars, nutrients, and small molecules is essential for plant growth, development, and adaptation to environmental changes. Various stresses are known to affect the cell-to-cell molecular trafficking modulated by plasmodesmal permeability. However, the mechanisms of plasmodesmata modification and molecules involved in the phloem unloading process under stress are still not well understood. Here, we show that heat stress reduces the root meristem size and inhibits phloem unloading by inducing callose accumulation at plasmodesmata that connect the sieve element and phloem pole pericycle. Furthermore, we identify the loss-of-function of CALLOSE SYNTHASE 8 (CalS8), which is expressed specifically in the phloem pole pericycle, decreasing the plasmodesmal callose deposition at the interface between the sieve element and phloem pole pericycle and alleviating the suppression at root meristem size by heat stress. Our studies indicate the involvement of callose in the interaction between root meristem growth and heat stress and show that CalS8 negatively regulates the thermotolerance of Arabidopsis roots.
Factors Determining Plasticity of Responses to Drugs
Authors: Parnham Michael J. , Kricker Jennifer A.
Published: February 2022

The plasticity of responses to drugs is an ever-present confounding factor for all aspects of pharmacology, influencing drug discovery and development, clinical use and the expectations of the patient. As an introduction to this Special Issue of the journal IJMS on pharmacological plasticity, we address the various levels at which plasticity appears and how such variability can be controlled, describing the ways in which drug responses can be affected with examples. The various levels include the molecular structures of drugs and their receptors, expression of genes for drug receptors and enzymes involved in metabolism, plasticity of cells targeted by drugs, tissues and clinical variables affected by whole body processes, changes in geography and the environment, and the influence of time and duration of changes. The article provides a rarely considered bird’s eye view of the problem and is intended to emphasize the need for increased awareness of pharmacological plasticity and to encourage further debate.
Heterogenicity within the LPS Structure in Relation to the Chosen Genomic and Physiological Features of the Plant Pathogen Pectobacterium parmentieri
Authors: Ossowska Karolina , Motyka-Pomagruk Agata , Kaczyńska Natalia , Kowalczyk Agnieszka , Sledz Wojciech , Lojkowska Ewa , Kaczyński Zbigniew
Published: February 2022

Pectobacterium parmentieri is a pectinolytic plant pathogenic bacterium causing high economic losses of cultivated plants. The highly devastating potential of this phytopathogen results from the efficient production of plant cell wall-degrading enzymes, i.e., pectinases, cellulases and proteases, in addition to the impact of accessory virulence factors such as motility, siderophores, biofilm and lipopolysaccharide (LPS). LPS belongs to pathogen-associated molecular patterns (PAMPs) and plays an important role in plant colonization and interaction with the defense systems of the host. Therefore, we decided to investigate the heterogeneity of O-polysaccharides (OPS) of LPS of different strains of P. parmentieri, in search of an association between the selected genomic and phenotypic features of the strains that share an identical structure of the OPS molecule. In the current study, OPS were isolated from the LPS of two P. parmentieri strains obtained either in Finland in the 1980s (SCC3193) or in Poland in 2013 (IFB5432). The purified polysaccharides were analyzed by utilizing 1D and 2D NMR spectroscopy (1H, DQF-COSY, TOCSY, ROESY, HSQC, HSQC-TOCSY and HMBC) in addition to chemical methods. Sugar and methylation analyses of native polysaccharides, absolute configuration assignment of constituent monosaccharides and NMR spectroscopy data revealed that these two P. parmentieri strains isolated in different countries possess the same structure of OPS with a very rare residue of 5,7-diamino-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic acid (pseudaminic acid) substituted in the position C-8: →3)-β-d-Galf-(1→3)-α-d-Galp-(1→8)-β-Pse4Ac5Ac7Ac-(2→6)-α-d-Glcp-(1→6)-β-d-Glcp-(1→. The previous study indicated that three other P. parmentieri strains, namely IFB5427, IFB5408 and IFB5443, exhibit a different OPS molecule than SCC3193 and IFB5432. The conducted biodiversity-oriented assays revealed that the P. parmentieri IFB5427 and IFB5408 strains possessing the same OPS structure yielded the highest genome-wide similarity, according to average nucleotide identity analyses, in addition to the greatest ability to macerate chicory tissue among the studied P. parmentieri strains. The current research demonstrated a novel OPS structure, characteristic of at least two P. parmentieri strains (SCC3193 and IFB5432), and discussed the observed heterogenicity in the OPS of P. parmentieri in a broad genomic and phenotype-related context.
Data Processing in Cloud Computing Model on the Example of Salesforce Cloud
Authors: Marańda Witold , Poniszewska-Marańda Aneta , Szymczyńska Małgorzata
Published: February 2022

Data processing is integrated with every aspect of operation enterprises—from accounting to marketing and communication internal and control of production processes. The best place to store the information is a properly prepared data center. There are a lot of providers of cloud computing and methods of data storage and processing. Every business must do the right thing, which is to think over how the data at your disposal are to be managed. The main purpose of this paper is research and the comparison of available methods of data processing and storage outside the enterprise in the cloud computing model. The cloud in SaaS (software as a service) model—Salesforce.com and a free platform development offered by Salesforce.com—force.com were used to perform the research. The paper presents the analysis results of available methods of processing and storing data outside the enterprise in the cloud computing model on the example of Salesforce cloud. Salesforce.com offers several benefits, but each service provider offers different services, systems, products, and forms of data protection. The choice of customer depends on individual needs and business plans for the future. A comparison of available methods of data processing and storage outside the enterprise in the cloud computing model was presented. On the basis of collected results, it was determined for what purposes the data processing methods available on the platform are suitable and how they can meet the needs of enterprises.
Comparison of Ultra-Wide Field Photography to Ultra-Wide Field Angiography for the Staging of Sickle Cell Retinopathy
Authors: Torres-Villaros Héloise , Fajnkuchen Franck , Amari Fatima , Janicot Lucie , Giocanti-Aurégan Audrey
Published: February 2022

Sickle cell retinopathy (SCR) is classified by Goldberg based on peripheral vascular changes. Ultra-wide field (UWF) imaging has enhanced visualization of the peripheral retina. However, there is no consensus on the optimal imaging technique for the screening of SCR. We performed a monocentric observational cross-sectional study to compare UWF fundus photography (UWF-FP) with UWF angiography (UWF-FA). All patients who underwent UWF-imaging (Optos, PLC, Scotland, UK) for screening of sickle cell retinopathy between January 2016 and December 2019 were retrospectively included. Eyes with previous laser treatment or concomitant retinal disease were excluded. UWF-FP images were graded based on the Goldberg classification by four graders with various degrees of experience. UWF-FA pictures were reviewed by an independent retina specialist. Differences in Goldberg staging across UWF-FP and UWF-FA were assessed. A total of 84 eyes of 44 patients were included. Based on UWF-FA, most eyes were stage 2 (77.4%) and 19 were stage 3 (22.6%). The pre-retinal neovascularization detection sensitivity on UWF-FP was 52.6 to 78.9%, depending on the graders. UWF-FA led to a later Goldberg stage of retinopathy, in most cases from stage 1 to stage 2. Neovascularization (stage 3) was not detected by our graders on UWF-FP in 21.1 to 57.9% of eyes. UWP-FP tends to underestimate Goldberg stages of retinopathy compared with UWF-FA and is less accurate when detecting neovascularization in sickle cell retinopathy, which has a direct impact on therapeutic management and prognosis.
The Importance of the Transcription Factor Foxp3 in the Development of Primary Immunodeficiencies
Authors: Mertowska Paulina , Mertowski Sebastian , Podgajna Martyna , Grywalska Ewelina
Published: February 2022

Transcription factors are an extremely important group of proteins that are responsible for the process of selective activation or deactivation of other cellular proteins, usually at the last stage of signal transmission in the cell. An important family of transcription factors that regulate the body’s response is the FOX family which plays an important role in regulating the expression of genes involved in cell growth, proliferation, and differentiation. The members of this family include the intracellular protein Foxp3, which regulates the process of differentiation of the T lymphocyte subpopulation, and more precisely, is responsible for the development of regulatory T lymphocytes. This protein influences several cellular processes both directly and indirectly. In the process of cytokine production regulation, the Foxp3 protein interacts with numerous proteins and transcription factors such as NFAT, nuclear factor kappa B, and Runx1/AML1 and is involved in the process of histone acetylation in condensed chromatin. Malfunctioning of transcription factor Foxp3 caused by the mutagenesis process affects the development of disorders of the immune response and autoimmune diseases. This applies to the impairment or inability of the immune system to fight infections due to a disruption of the mechanisms supporting immune homeostasis which in turn leads to the development of a special group of disorders called primary immunodeficiencies (PID). The aim of this review is to provide information on the role of the Foxp3 protein in the human body and its involvement in the development of two types of primary immunodeficiency diseases: IPEX (Immunodysregulation Polyendocrinopathy Enteropathy X-linked syndrome) and CVID (Common Variable Immunodeficiency).
Characteristics of the Maxillofacial Morphology in Patients with Idiopathic Mandibular Condylar Resorption
Authors: Tanimoto Kotaro , Awada Tetsuya , Onishi Azusa , Kubo Naoki , Asakawa Yuki , Kunimatsu Ryo , Hirose Naoto
Published: February 2022

Idiopathic mandibular condylar resorption (ICR) is a pathological condition characterized by idiopathic resorption of the mandibular condyle, resulting in a decrease in the size and height of the mandibular condyle. The purpose of this study was to characterize the maxillofacial morphology of ICR patients. Subjects were selected from patients that attended our orthodontic clinic between 1991 and 2019. Twenty-five patients were diagnosed with ICR by magnetic resonance imaging; however, growing patients were excluded. In total, 18 patients were finally selected. The control group comprised 18 healthy volunteers. Lateral and frontal cephalograms were also used. The ICR group had significantly more severe skeletal class II malocclusions than the control group, mainly due to retrusion of the mandible. In the ICR group, there was a tendency for a skeletal open bite due to a significantly larger clockwise rotation of the mandible than in the control group. There was no significant difference between the two groups in the inclination of the upper and lower central incisors or protrusion of the upper and lower central incisors and first molars. ICR patients have been suggested to exhibit skeletal open bite and maxillary protrusion with changes in maxillofacial morphology due to abnormal resorption of the mandibular condyle.
Paraaortic Lymphadenectomy in Gynecologic Oncology—Significance of Vessels Variations
Authors: Kostov Stoyan , Selçuk Ilker , Yordanov Angel , Kornovski Yavor , Yalçın Hakan , Slavchev Stanislav , Ivanova Yonka , Dineva Svetla , Dzhenkov Deyan , Watrowski Rafał
Published: February 2022

Lymphadenectomy has been an essential part of the surgical treatment in surgical oncology, as the lymphatic channels and nodes are the main dissemination pathway for most of the gynecological cancers. Pelvic and paraaortic lymphadenectomy are frequent surgical procedures in gynecologic oncology. Paraaortic lymph node dissection facilitates staging, prognosis, surgical and postoperative management of patients. It is one of the most challenging retroperitoneal surgeries. A comprehensive knowledge of the paraaortic region is mandatory. Intraoperative bleeding is the most common complication during lymphadenectomy due to direct vascular injury, poor tissue handling, exuberant retraction and possible anatomical variations of the vessels in the paraaortic region. Approximately, one-third of women will have at least one anatomic variation in the paraaortic region. It must be stressed that anomalous vessels may be encountered in every woman who will undergo surgery. Consequently, detailed knowledge of anatomical vessels variations is required in order to prevent iatrogenic vessel injury. The importance of these variations is well described in urology, vascular and general surgery. Conversely, in oncogynecological surgery, there are few articles, which described some of the vessels variations in the paraaortic region. The present article aims to propose a surgical classification and to describe the majority of vessels variation, which could be encountered during paraaortic lymphadenectomy in gynecologic oncology. Moreover, surgical considerations in order to prevent anomalous vessels injury are well described.
Clinical Comparison of a Novel Balloon-Expandable Versus a Self-Expanding Transcatheter Heart Valve for the Treatment of Patients with Severe Aortic Valve Stenosis: The EVAL Registry
Authors: Barki Monica , Ielasi Alfonso , Buono Andrea , Maliandi Gabriele , Pellicano Mariano , Bande Marta , Casilli Francesco , Messina Francesca , Uccello Giuseppe , Briguglia Daniele , Medda Massimo , Tespili Maurizio , Donatelli Francesco
Published: February 2022

Background: Transcatheter aortic valve replacement (TAVR) is an effective treatment option for patients with severe, symptomatic AS, regardless of the transcatheter heart valve (THV) implanted. Prior studies demonstrated a higher device success with lower paravalvular leak (PVL) using the balloon-expandable (BE) Sapien/XT THV vs. a self-expanding (SE) THV. However, few data are available on the performance of a novel BE THV. Purpose: to compare early clinical performance and safety of the newly available BE Myval THV (Myval, Meril Life Sciences Pvt. Ltd., India) vs. the commonly used SE (Evolut R, Medtronic) THV. Methods: A single-center, retrospective cohort analysis was performed with 166 consecutive patients undergoing TAVR from March 2019 to March 2021 for severe symptomatic AS treated with either the novel BE Myval or the SE Evolut R (ER) bioprosthesis. The primary endpoint was device success at day 30 according to the Valve Academic Research Consortium-3 (VARC-3). Secondary endpoints included 30-day all-cause mortality, cardiovascular mortality, more than mild PVL, permanent pacemaker implantation (PPI) rates and a composite of all-cause mortality and disabling stroke at 6 months. Results: Among the 166 included patients, 108 patients received the SE ER THV and 58 patients were treated with the BE Myval THV. At baseline, the two groups showed comparable demographic characteristics. The primary composite endpoint of early device success occurred in 55 patients (94.8%) in the BE Myval group and in 90 patients (83.3%) in the SE ER group (OR 3.667, 95% CI 1.094–12.14; p = 0.048). At day 30, the BE Myval THV group exhibited a significantly lower incidence of more than mild PVL (BE Myval 3.45% vs. SE ER 14.8%, OR 0.2, 95% CI 0.05–0.8; p = 0.0338), along with a lower rate of PPI (BE Myval 11% vs. SE ER 24.2%, OR 0.38, 95% CI 0.15–0.99; p = 0.0535). At the 6-month follow-up, the incidence of all-cause mortality and disabling stroke did not significantly differ between the two groups, while the incidence of PPI (BE Myval 11% vs. SE ER 27.5%, OR 0.32, CI 95% 0.1273–0.8; p = 0.02) and ≥moderate PVL (BE Myval 6.9% vs. SE ER 19.8%, OR 0.31, 95% CI 0.1–0.94; p = 0.0396) was significantly lower in the BE Myval group. Conclusions: In patients with severe symptomatic AS undergoing TAVR, the novel Myval BE THV provided a comparable performance to the well-known ER SE THV, and it was associated with a lower rate of PPI and ≥moderate PVL within 30 days and 6 months after the procedure. Randomized, head-to-head comparison trials are needed to confirm our results.
A Note on Parameter Setting in Contact Situations
Authors: Etxepare Ricardo , Gallego Ángel J.
Published: February 2022

This paper revisits the study of linguistic variation within the Government and Binding approach to parameters, pointing out some limitations of parameter schemata in language contact scenarios. Discussion is focused on the possibility that clustering effects (the schemata themselves) are more complex than conventional approaches suggest. We outline an alternative approach, directly connected to Uriagereka’s typology or parameters, which is itself based on Chomsky’s Theory of Formal Languages. Empirically, we focus on language contact situations, as they provide cases where variation by contact operates under what we call an Excess of Stimulus, whereby access to the relevant data is overwhelming, but somehow ignored by learners.
Can Restorative Justice Provide a Better Outcome for Participants and Society than the Courts?
Authors: Leonard Liam J.
Published: February 2022

This article will examine understandings that underpin restorative justice outcomes for participants in order to propose that restorative justice conferences may provide better outcomes for participants than the formal courts of the criminal justice system. The analysis will attempt to shed light on the benefits of the restorative justice conferencing process. These benefits will be shown to include positive individual and community outcomes, which ‘restore’ participants in a manner which may be closer to concepts of ‘justice’ than the formal court process.
Body Composition as a Modulator of Bone Health Changes in Patients with Inflammatory Bowel Disease
Authors: Soare Iulia , Sirbu Anca , Popa Miruna , Martin Sorina , Tieranu Cristian George , Mateescu Bogdan , Diculescu Mircea , Barbu Carmen , Fica Simona
Published: February 2022

Background: Bone impairment of multifactorial etiology is a common feature in inflammatory bowel disease (IBD). Body composition parameters, which might be selectively modified in these patients, are important determinants of bone strength. Our aim was to investigate the relationship between components of body composition and bone parameters in IBD patients. Methods: This is a cross-sectional, retrospective study including 80 IBD patients (43 women, 37 men). Lumbar spine (LS), femoral neck (FN) and whole body DXA scans were performed to analyze regional bone mineral density (BMD), as well as body composition, including appendicular skeletal muscle mass index (ASMI), total and visceral fat mass (VAT). Trabecular bone score (TBS) was assessed using iNsight Software. Results: Twenty (25%) IBD patients had inadequate LS-BMD z scores (<=−2DS). Lean mass (LM) was a significant determinant of LS-BMD, after adjusting for age, gender, BMI and fat mass (p < 0.01), while fat mass% remained associated with FN-BMD (p < 0.01). TBS correlated positively with BMI (r = 0.24, p < 0.05), LS-BMD (r = 0.56, p < 0.001), ASMI (r = 0.34, p < 0.001) and negatively with VAT/total fat% (r = −0.27, p < 0.05). Multivariate analysis showed that ASMI, LS-BMD (positively) and VAT/total fat% (negatively) were independently associated with TBS. Conclusions: In IBD patients, skeletal muscle mass and fat percentage and distribution are important factors associated with bone health.
Potential Applications of Artificial Intelligence in Clinical Trials for Alzheimer’s Disease
Authors: Seo Younghoon , Jang Hyemin , Lee Hyejoo
Published: February 2022

Clinical trials for Alzheimer’s disease (AD) face multiple challenges, such as the high screen failure rate and the even allocation of heterogeneous participants. Artificial intelligence (AI), which has become a potent tool of modern science with the expansion in the volume, variety, and velocity of biological data, offers promising potential to address these issues in AD clinical trials. In this review, we introduce the current status of AD clinical trials and the topic of machine learning. Then, a comprehensive review is focused on the potential applications of AI in the steps of AD clinical trials, including the prediction of protein and MRI AD biomarkers in the prescreening process during eligibility assessment and the likelihood stratification of AD subjects into rapid and slow progressors in randomization. Finally, this review provides challenges, developments, and the future outlook on the integration of AI into AD clinical trials.
Influence of Bi2O3 on Mechanical Properties and Radiation-Shielding Performance of Lithium Zinc Bismuth Silicate Glass System Using Phys-X Software
Authors: Almuqrin Aljawhara H. , Sayyed M. I. , Prabhu Nimitha S. , Kamath Sudha D.
Published: February 2022

We analyzed the mechanical properties and radiation-shielding performance of a lithium zinc bismuth silicate glass system. The composition of these glasses is 20ZnO-30Li2O-(50-x)SiO2-xBi2O3 (x varies between 10 and 40 mol%). The mechanical properties of the investigated glass system, such as Young’s modulus (E), bulk modulus (K), shear modulus (S), and longitudinal modulus (L), were determined using the Makishima–Mackenzie model. The elastic moduli gradually decreased with the addition of Bi2O3. E decreased from 46 to 31 GPa, K decreased from 27 to 14 GPa, S decreased from 19 to 14 GPa, and L decreased from 52 to 32 GPa as Bi2O3 was substituted for SiO2. The mass attenuation coefficient (MAC) was investigated at energies between 0.284 and 1.33 MeV to understand the radiation-shielding performance of the glasses. The MAC value increased when SiO2 was replaced by Bi2O3. We found that the effect of Bi2O3 on MAC values was noticeably stronger at energies of 0.284 and 0.347 MeV, while the effect of Bi2O3 on MAC values became weaker as energy increased. The linear attenuation coefficient (LAC) results demonstrated that if the samples were exposed to low-energy photons, the glass could prevent the penetration of photons, and thus, the glass samples were effective in radiation protection. The LAC values for the lowest- and highest-density samples changed from 0.998 to 1.976 cm−1 (at 0.284 MeV) and from 0.286 to 0.424 cm−1 (at 0.826 MeV). According to the radiation-shielding results, the thick, high-density glass sample has special and distinctive shielding properties.
Enhancement of Multi-Scale Self-Organization Processes during Inconel DA 718 Machining through the Optimization of TiAlCrSiN/TiAlCrN Bi-Nano-Multilayer Coating Characteristics
Authors: Fox-Rabinovitch Guerman , Dosbaeva Goulnara , Kovalev Anatoly , Gershman Iosif , Yamamoto Kenji , Locks Edinei , Paiva Jose , Konovalov Egor , Veldhuis Stephen
Published: February 2022

Optimization of the composition of a new generation of bi-nano-multilayered TiAlCrSiN/TiAlCrN-based coatings is outlined in this study for the machining of direct aged (DA) Inconel 718 alloy. Three types of TiAlCrSiN/TiAlCrN-based bi-nano-multi-layer coatings with varying chemical compositions were investigated: (1) a previous state-of-the-art Ti0.2Al0.55Cr0.2Si0.03Y0.02N/Ti0.25Al0.65Cr0.1N (coating A); (2) Ti0.2Al0.52Cr0.2Si0.08N/Ti0.25Al0.65Cr0.1N with increased amount of Si (up to 8 at.%; coating B); (3) a new Ti0.18Al0.55Cr0.17Si0.05Y0.05N/Ti0.25Al0.65Cr0.1N coating (coating C) with an increased amount of both Si and Y (up to 5 at.% each). The structure of each coating was evaluated by XRD analysis. Micro-mechanical characteristics were investigated using a MicroMaterials NanoTest system and an Anton Paar-RST3 tester. The wear performance of nano-multilayered TiAlCrSiN/TiAlCrN-based coatings was evaluated during the finish turning of direct aged (DA) Inconel 718 alloy. The wear patterns were assessed using optical microscopy imaging. The tribological performance was evaluated through (a) a detailed chip characteristic study and (b) XPS studies of the worn surface of the coated cutting tool. The difference in tribological performance was found to correspond with the type and amount of tribo-films formed on the friction surface under operation. Simultaneous formation of various thermal barrier tribo-films, such as sapphire, mullite, and garnet, was observed. The overall amount of beneficial tribo-films was found to be greater in the new Ti0.18Al0.55Cr0.17Si 0.05Y0.05N/Ti0.25Al0.65Cr0.1N nano-bi-multilayer coating (coating C) than in the previous state-of-the-art coatings (A and B). This resulted in over two-fold improvement of this coating’s tool life compared with those of the commercial benchmark AlTiN coating and coating B, as well as a 40% improvement of the tool life of the previous state-of-the-art coating A. Multi-scale self-organization processes were observed: nano-scale tribo-film formation on the cutting tool surface combined with micro-scale generation of strain-induced martensite zones as a result of intensive metal flow during chip formation. Both of these processes are strongly enhanced in the newly developed coating C.
Containment Liner Plate Void Defect Detection Technique Using Phased Array Ultrasonic Testing and Acoustic Resonance Method
Authors: Yeom Yun-Taek , Choi Yeong-Won , Kim Hak-Joon , Kim Hun-Hee , Park Jae-Suk , Ryu Sung-Woo , Song Sung-Jin
Published: February 2022

The CLP (containment liner plate) of a nuclear power plant protects the internal system from the external environment and sudden changes in internal pressure or temperature, and it is a structure that blocks and protects radioactive materials leaking inside and outside in the event of a nuclear accident and is composed of a liner plate, reinforcing bars, tendons, and concrete. Recently, corrosion on the rear side of the liner plate and concrete voids has emerged as a severe defect in nuclear power plants across South Korea. Therefore, in this study, we proposed a new inspection method that a line-type inspection method applied phased array ultrasonic testing and the area inspection method applied acoustic resonance method using developed moveable tapper. The acoustic signals were signal-processed and reproduced to a mapping image following the inspection area, and with the image, it was possible to determine the type of defect. Furthermore, an automated inspection system for within the CLP was proposed.
Intermetallics Formation during Solidification of Al-Si-Cu-Mg Cast Alloys
Authors: Mohamed Adel M. A. , Samuel Ehab , Zedan Yasser , Samuel Agnes M. , Doty Herbert W. , Samuel Fawzy H.
Published: February 2022

The present study was undertaken to examine the effect of iron, manganese, copper and magnesium on the microstructural characteristics of Al-11%Si-2%Cu-Mg-based alloy referred to as 396 under different working conditions. The results show that strontium (Sr) has high affinity to react with magnesium (Mg), resulting in reduced effectiveness as eutectic silicon modifier or age hardening agent. In addition, Sr alters the sequence of the precipitation of the α-AlFeMnSi phase from post-eutectic to pro-eutectic which would harden the soft α-Aluminum matrix. The mechanism is still under investigation. The interactions between iron (Fe) and Mg and Sr-Mg result in the formation of serval dissolvable intermetallics during the solutionizing treatment such as β-AlFeSi, π-AlFeMgSi and Q-AlMgSiCu phases. The study also emphasizes the role of modification and grain refining as well as intermetallics in porosity formation and hardness of samples aged in the temperature range 155–240 °C.
Frictional Losses of Polyamides Mounted on Tensioning Guides in Contact with Chains
Authors: Velicu Radu Gabriel , Lates Mihai Tiberiu , Gavrila Cornel Catalin
Published: February 2022

The development of polyamides has increased in recent years due to scientific research and the aim of the industry to find materials characterized by good frictional behavior at high temperatures, high loads and high speeds. The wide areas of application of polyamides in the mechanical contacts with relative motions offered new development opportunities for polyamides (PA), such as PA66, PA46 and PTFE mixed PA46. One of the applications of these polyamides in mechanical contacts with relative motions is the contact between the timing chains and the active part of the tensioning guides. For a comparison with a previous study of friction of PA66, PA46 and PTFE mixed PA46, performed on a pin-on-disk tribometer, this study is based on performing tests on the same materials, on the tensioning guide of a silent chain used as a timing chain in combustion engines, with lubricating conditions much closer to the application field. The diagrams comparatively present the variation of the percentage of frictional losses for PTFE mixed PA46, PA46 and PA66 polyamides mounted on tensioning guides in contact with chains. The results clearly show that the PTFE mixed PA46 polyamide has smaller frictional losses than the PA46 and the PA66 polyamides, but the influence of speed and tensioning is also important. A comparison with the previous study is also useful for making a decision on using a polyamide for the guide of a timing chain.
Interfacial Effect on Photo-Modulated Magnetic Properties of Core/Shell-Structured NiFe/NiFe2O4 Nanoparticles
Authors: Zhou Wenda , Chen Mingyue , Huang He , Wang Guyue , Luo Xingfang , Yuan Cailei , Zhang Jingyan , Wu Yanfei , Zheng Xinqi , Shen Jianxin , Wang Shouguo , Shen Baogen
Published: February 2022

Photo-modulated magnetism has become an emerging method for technological applications, such as magneto-optical devices. In this work, by introducing oxygen during rapid thermal annealing, NiFe/NiFe2O4 core/shell nanoparticles were successfully fabricated by pulsed laser deposition. Obvious photo-modulated ferromagnetism was observed in core/shell nanoparticles confined in Al2O3 film. Theoretical and experimental investigations indicate much more photogenerated electrons are captured at the interface of NiFe/NiFe2O4 compared with NiFe nanoparticles due to interfacial effect, resulting in the improved ferromagnetism under light irradiation. This work provides a promising strategy for optical engineering design of optical information storage, high-speed wireless communication, and magneto-optical semiconductor devices.
Oxide Metallurgy Technology in High Strength Steel: A Review
Authors: Liang Wei , Geng Ruming , Zhi Jianguo , Li Jing , Huang Fei
Published: February 2022

Oxide metallurgy technology plays an important role in inclusion control and is also applied to improve the weldability of high strength steel. Based on the requirements of the weldability in high strength steel, the influencing factors of weld heat affected zone (HAZ) as well as the development and application status of oxide metallurgy technology are summarized in this review. Moreover, the advantages and difficulties in the application of rare earth (RE) oxide metallurgy technology are analyzed, combined with the performance mechanism of RE and its formation characteristics of fine and high melting point RE inclusions with distribution dispersed in liquid steel. With the weldability diversities of different high strength steels, the research status of weldability of high strength steel with high carbon equivalent and the effects of RE on the microstructure and properties of HAZ are discussed, and some suggestions about further research in the future are proposed.
Kinetics and Dynamics of the Stiff and Flexible Tines with the Duckfoot and the Coulter after Impact with Stones Embedded in Compacted Soil. Part II
Authors: Lisowski Aleksander , Świętochowski Adam , Dąbrowska Magdalena , Klonowski Jacek , Nowakowski Tomasz , Chlebowski Jarosław , Ferré Samuel , Roberge Martin
Published: February 2022

The kinetics and dynamics of the stiff and flexible tines with the duckfoot and the coulter after impact with stones embedded in compacted soil were examined. The beak of the duckfoot was positioned in the axis of the row of stones embedded in the soil at the depth of stones thickness. The coulter covered the stone or impact the edge of the stone halfway along its length. The tools worked at a speed of 0.83–2.22 m·s−1 and a working depth of 0.05–0.10 m. The results of specific parameters were compared to the response of the tools to loads in soil without stones. For both soil conditions, the kinetics of the flexible tine was 24 times more reactive, and the dynamic loads were two times lower than for the stiff tine. The responses of both tines were suppressed along with the working depth because of the more favorable place of impact of the duckfoot beak with the stone. Along with the working speed, for a stiff tine, the specific accelerations decreased significantly, by ten times, and the specific forces increased slightly, by 1.6 times. Among the two systems of setting the coulter, the impact of the cutting edge of the coulter with the stone in the middle of its length was more unfavorable than the work of the coulter covering the stone.
The Thermal Properties of a Prototype Insulation with a Gyroid Structure—Optimization of the Structure of a Cellular Composite Made Using SLS Printing Technology
Authors: Anwajler Beata
Published: February 2022

This paper focuses on the search for novel insulating structures, and the generation of them by means of a state-of-the-art manufacturing method—3D printing. Bionic structures, which are successfully used in many branches of technology, were chosen as the source of inspiration for the research. The paper presents a design of spatial structures with a gyroid infill (e.g., TPMS), the shape of which reflects the bionic structure of the inside of a bone. For SLS printed single- and multi-layered structures, the design value of the thermal conductivity coefficient was determined through measurements and calculations. A statistical analysis was carried out to determine the effect of the direction of heat flow, as well as the internal structure and layering of the prototype materials, on the values of the thermal conductivity coefficient and the thermal resistance coefficient. On the basis of the multicriteria analysis, the composite’s optimal composition according to the adopted optimization criteria was determined. The lowest possible thermal conductivity of the insulation was equal to 0.033 W/(m·K). The highest possible thermal resistance was equal to 0.606 m2·K/W. Thermal insulation made of the prototype insulating partitions with a gyroidal structure is characterized by good insulating parameters.
Electrical and Thermal Properties of Carbon Nanotube Polymer Composites with Various Aspect Ratios
Authors: Lee Dong-Kwan , Yoo Jongchan , Kim Hyunwoo , Kang Byung-Ho , Park Sung-Hoon
Published: February 2022

In response to the rising need for flexible and lightweight materials capable of efficient heat transport, many studies have been conducted to improve the thermal properties of polymers via nanofillers. Among the various nanofillers, carbon nanotubes (CNTs) are considered as the most promising, owing to their excellent thermal and electrical properties. Accordingly, CNT/polymer composites can be used as flexible and lightweight heat transfer materials, owing to their low density. In this study, we fabricated multi-walled CNT (MWCNT)/polymer composites with different aspect ratios to investigate their effects on electrical and thermal properties. Through a three-roll milling process, CNTs were uniformly dispersed in the polymer matrix to form a conductive network. Enhanced electrical and thermal properties were observed in MWCNT composite with a high aspect ratio as compared to those with a low aspect ratio. The thermal conductivity of composites obtained as a function of the filler content was also compared with the results of a theoretical prediction model.
Pneumatic Bionic Hand with Rigid-Flexible Coupling Structure
Authors: Chen Chang , Sun Jiteng , Wang Long , Chen Guojin , Xu Ming , Ni Jing , Ramli Rizauddin , Su Shaohui , Chu Changyong
Published: February 2022

This paper presents a rigid-flexible composite of bionic hand structure design scheme solution for solving the problem of low load on the soft gripping hand. The bionic hand was designed based on the Fast Pneumatic Network (FPN) approach, which can produce a soft finger bending drive mechanism. A soft finger bending driver was developed and assembled into a human-like soft gripping hand which includes a thumb for omnidirectional movement and four modular soft fingers. An experimental comparison of silicone rubber materials with different properties was conducted to determine suitable materials. The combination of 3D printing technology and mold pouring technology was adopted to complete the prototype preparation of the bionic hand. Based on the second-order Yeoh model, a soft bionic finger mathematical model was established, and ABAQUS simulation analysis software was used for correction to verify the feasibility of the soft finger bending. We adopted a pneumatic control scheme based on a motor micro-pump and developed a human–computer interface through LabView. A comparative experiment was carried out on the bending performance of the finger, and the experimental data were analyzed to verify the accuracy of the mathematical model and simulation. In this study, the control system was designed, and the human-like finger gesture and grasping experiments were carried out.
First Principle Study of MgSnLa Compounds in Mg-3Sn-1Mn-1La Alloy Processed by Rheo-Rolling
Authors: Wang Jian-Hong , Zhao Zhan-Yong
Published: February 2022

In order to obtain a high-performance heat-resistant Mg alloy during the rheo-rolling process, the electronic structure, elastic constants, binding energy and thermodynamic properties of the MgSnLa compounds were conducted by first-principle calculations. The results show that the MgSnLa compounds (La5Sn3, Mg17La2 and Mg2Sn) all show certain metallicity, and La5Sn3 has better mechanical properties (higher bulk modulus (46.47091 GPa) and shear modulus (26.40561 GPa)) than the other two phases. The binding energy reveals that La5Sn3 is the most stable phase in these composite phases (5.33 eV/atom); additionally, thermodynamic studies show that the structural stability of the MgSnLa compounds increases with the increase in temperature, and the temperature has the greatest effect on the stability of Mg17La2. These all provide an efficient guide for the widespread engineering applications of high-performance heat-resistant Mg alloy.
Influence of Selective Laser Melting Additive Manufacturing Parameters in Inconel 718 Superalloy
Authors: Kladovasilakis Nikolaos , Charalampous Paschalis , Tsongas Konstantinos , Kostavelis Ioannis , Tzovaras Dimitrios , Tzetzis Dimitrios
Published: February 2022

Selective laser melting (SLM) is one of the most reliable and efficient procedures for Metal Additive Manufacturing (AM) due to the capability to produce components with high standards in terms of dimensional accuracy, surface finish, and mechanical behavior. In the past years, the SLM process has been utilized for direct manufacturing of fully functional mechanical parts in various industries, such as aeronautics and automotive. Hence, it is essential to investigate the SLM procedure for the most commonly used metals and alloys. The current paper focuses on the impact of crucial process-related parameters on the final quality of parts constructed with the Inconel 718 superalloy. Utilizing the SLM process and the Inconel 718 powder, several samples were fabricated using various values on critical AM parameters, and their mechanical behavior as well as their surface finish were examined. The investigated parameters were the laser power, the scan speed, the spot size, and their output Volumetric Energy Density (VED), which were applied on each specimen. The feedstock material was inspected using Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) analysis, and Particle-size distribution (PSD) measurements in order to classify the quality of the raw material. The surface roughness of each specimen was evaluated via multi-focus imaging, and the mechanical performance was quantified utilizing quasi-static uniaxial tensile and nanoindentation experiments. Finally, regression-based models were developed in order to interpret the behavior of the AM part’s quality depending on the process-related parameters.
Rheological Properties of Soft Waste Granulates Produced in the Fabrication Process of Ceramic Tiles and the Possibility of Their Reuse
Authors: Wójcik Łukasz , Gajek Marcin , Rapacz-Kmita Alicja , Mastalska-Popławska Joanna , Pacan Robert , Puchyrska Izabela , Sacha Piotr , Cegłowski Dawid
Published: February 2022

The paper presents the results of research on the influence of the granulometric composition on the rheological properties of granulates from soft waste produced in the manufacturing of ceramic tiles using the Lamgea and Continua methods in terms of the possibility of their reuse. The composition of the granulates was modified by removing individual grain fractions in three measurement series. Comparatively, the measurement samples for the production granulates were prepared in the same way. Microscopic observations and granulometric analysis showed significant differences in the grain shape and grain size distribution of granulates. The soft waste granulates also showed much worse flow ability than the production granulates. It was shown that the removal of the smallest fractions significantly improved the rheological properties of soft waste granulates. This tendency was also observed in the case of measurements of changes in the bulk density. A Brookfield powder analyzer was used for rheological tests, and a flow analysis was performed using the numerical Jenike classification.
Effect of Cold Rolling and Annealing on the Microstructure and Texture of Erbium Metal
Authors: Chen Shiying , Zhang Xiaowei , Li Zongan , Wang Shuang , Wang Yixuan , Li Jinying , Wu Daogao , Wang Zhiqiang , Chen Dehong , Lu Wenli , Mao Ning , Yang Wensheng , Xu Minglei
Published: February 2022

Erbium metal with purity ≥ 99% was cold rolled to 30%, 40%, 50%, and 60% deformations and the Er metal of 60% deformation was annealed at different temperatures for 1 h. The effect of cold rolling deformation and annealing on the microstructure and texture evolution of Er metal was investigated by XRD, EBSD, Microhardness tester, and OM. P is the orientation index, which is used to judge the preferred orientation. The research results showed that grains were broken and refined gradually with increasing deformation, the average grain size was 3.37 µm, and the orientation distribution was uniform for 60% deformation; deformation twins appeared in the grain when the deformation was less than 40%, which contributed to the generation of (0001) plane orientation. Comparing with the initial state, the (011−0) plane orientation gradually weakened and the (111−0) plane orientation had a trend of further strengthening with the increasing deformation; the (1−21−0) plane orientation remained unchanged, but there was a gradual weakening trend when the deformation was greater than 50%. For 60% deformation of Er metal, the deformed microstructure was replaced by fine equiaxed grains with the increasing annealing temperature, and the high-performance Er metal with fine and uniform equiaxed grains can be obtained under annealing at 740 °C for 1 h.
Face Mask Wastes as Cementitious Materials: A Possible Solution to a Big Concern
Authors: Castellote Marta , Jiménez-Relinque Eva , Grande María , Rubiano Francisco , Castillo Ángel
Published: February 2022

After more than two years wearing surgical masks due to the COVID-19 pandemic, used masks have become a significant risk for ecosystems, as they are producing wastes in huge amounts. They are a potential source of disturbance by themselves and as microplastic contamination in the water system. As 5500 tons of face masks are estimated to be used each year, there is an urgent need to manage them according to the circular economy principles and avoid their inadequate disposal. In this paper, surgical wear masks (WM), without any further pretreatment, have been introduced as addition to mortars up to 5% in the weight of cement. Mechanical and microstructural characterization have been carried out. The results indicate that adding MW to the cement supposes a decrease in the properties of the material, concerning both strength and durability behavior. However, even adding a 5% of WM in weight of cement, the aspect of the mortars is quite good, the flexural strength is not significantly affected, and the strength and durability parameters are maintained at levels that—even lower than the reference—are quite reasonable for use. Provided that the worldwide production of cement is around 4.1 Bt/year, the introduction of a 5% of WM in less than 1% of the cement produced, would make it possible to get rid of the mask waste being produced.