bluuebunny/crossref_metadata_2025 huggingface dataset:
Aluminium Bridges under Fire Conditions: Structural Behaviour
Authors: Portnov Fedor Aleksandrovich , Korolchenko Dmitry Aleksandrovich
Published: June 2023

Due to a number of advantages, aluminium is used in the attachment units of mullion and transom systems for decorative panels and translucent fillings, as well as for bridge structures. Despite its advantages, aluminium has a low melting point and does not have fire resistance performances required by regulatory documents under fire conditions. Therefore, this article is aimed at studying the behaviour of aluminium structures under high temperatures. To achieve this objective, we have analysed the aluminium structures most commonly used in construction—the attachment units of mullion and transom systems, with different protections against fire, columns and orthotropic decks used in bridge construction. In order to assess the behaviour of selected structures under fire conditions, we have developed methods for studying temperature distributions in structures in detail. Using the developed methods, tests have been carried out. Based on the received experimental data, we analysed the behaviour of aluminium structures in fire conditions and developed measures to increase the fire resistance of aluminium structures. Such measures include using hollow profiles to ensure air exchange with the cold sections of the structure, applying dedicated cooling agents to cool the structure and removing heat to the atmosphere and thermal barriers so as to protect aluminium structures. We found that fire resistance measures enhance the fire resistance of aluminium attachment units of mullion and transom systems by 1.5 times. The use of hollow air-permeable profiles and cooling agents in orthotropic decks increases fire resistance by 3 times by removing heat from the structures. The fire resistance rating of hollow profile aluminium columns is 1.5 times higher than that of structures without air-permeable profiles. The obtained results can be used as the most effective basis for the design of aluminium structures. The principles of increasing fire resistance given in this article are applicable to other types of structures, and can also be used with other methods of fire protection. Increasing the fire resistance of aluminium structures enables the expansion of the scope of their applications.
A New Direction of Professional Activity of Consulting Engineers in the Construction Industry
Authors: Lapidus Azariy , Topchiy Dmitriy , Kuzmina Tatyana , Shevchenko Irina
Published: June 2023

Today, the professional activities of consulting engineers need new functions based on a research-based approach to the design, construction and operation of sophisticated construction projects. The authors introduce new terms and use the concept of technology platforms to present a research-driven platform for consulting engineers. This platform is a complex system that has three constituent subsystems, including “Processes”, the “Database of work items” and “Participants”. Formalized interaction between the platform constituents is based on a tree of goals. The implementation of actions, focused on each goal, allowed (1) clustering the requirements applicable to the new type of consulting engineers; (2) developing an algorithm that underlies the database of work items to be performed by new consulting engineers; (3) developing the principle of automated selection of work items; (4) making a graphical representation of activities, performed by consulting engineers in the form of a BPMN diagram. The platform is a concept for a novel approach to the activities of consulting engineers, who will contribute their experience and use the research-driven approach to ensure the reliability and safety of sophisticated construction projects.
Integrating User-Centered Design and Biophilic Design to Improve Biophilia and Intelligentization in Office Environments
Authors: Gao Wa , Jin Dong , Wang Qian , Zhu Pengfei
Published: June 2023

Intelligent technology has had a profound impact on working patterns and the needs of office workers. The corresponding office environments have also changed to some extent. As more and more intelligent functions are integrated, a question as to whether the intelligent office environment really meets needs of office workers needs to be considered. In this study, a methodology that is applicable to improve biophilic and intelligent designs simultaneously in office environments was developed according to the needs of office workers. The observations of office environments, interviews, and questionnaires of an office group were performed. The physical and psychological health needs of office workers, as well as the correlations between six office environmental factors and six intelligent functions were discussed using the data of 211 office workers. Then, 12 patterns of biophilic design were addressed from existing biophilic theory, and the results of a user study, as well as the corresponding design framework of intelligent office products, which are the carriers of intelligent functions, were described. The feasibility and the positive influence in the office have been illustrated through a design case and its evaluation in real office environments. This study mainly explores the design of office environments from the perspective of humans with the hope to provide helpful guidance for intelligent offices and related workspace design in the future.
Structural Performance of Cold-Formed Steel (CFS) Structures
Authors: Poologanathan Keerthan , Perampalam Gatheeshgar , Gunalan Shanmuganathan , Corradi Marco
Published: June 2023

Cold-formed steel (CFS) has emerged as a prominent choice for structural components and sections in the construction industry [...]
Developing a Reference Framework for Claim Management Office: A Multi-Method Approach of an International Construction Firm
Authors: Mirzaee Ali Mohammad , Edwards David , Thwala Wellington Didibhuku
Published: June 2023

A claim management office (CMO) is a new intra-organisation fit based on an organisational project management (OPM) approach and deals specifically with improving claim performance. However, CMOs are either misunderstood or often overlooked in construction companies, mainly due to ignorance of the OPM context but further exacerbated by a lack of real case study research on how to adopt CMOs in these organisations. To address this knowledge gap, this present study integrates organisational ambidexterity with X-inefficiency theory (due to organisation intra-firm irrational decisions when managing such claims) to generate a reference framework for the CMO by probing its implementation within an international construction firm. A multi-method approach, including a single case study (a firm which adopted a CMO) and internal and external expert panels, was used for sampling, data collection, analysis and validation of the framework. The reference framework provides new perspectives on how construction-related companies and practitioners can adopt a CMO structure, which enables them to improve claims performance by planning in three interrelated activities, viz. function-, process- and performance-based. Theoretically, findings also contribute to the X-inefficiency and organisational ambidexterity theories, specifically, how different influences among the reference framework’s elements lead to better organisational claim performance as a plausible roadmap for future work.
Efficacy of a HER2-Targeted Thorium-227 Conjugate in a HER2-Positive Breast Cancer Bone Metastasis Model
Authors: Karlsson Jenny , Hagemann Urs B. , Cruciani Véronique , Schatz Christoph A. , Grant Derek , Ellingsen Christine , Kristian Alexander , Katoozi Shirin , Mihaylova Dessislava , Uran Steinar R. , Suominen Mari , Bjerke Roger M. , Ryan Olav B. , Cuthbertson Alan
Published: June 2023

Human epidermal growth factor receptor 2 (HER2) is overexpressed in 15–30% of breast cancers but has low expression in normal tissue, making it attractive for targeted alpha therapy (TAT). HER2-positive breast cancer typically metastasizes to bone, resulting in incurable disease and significant morbidity and mortality. Therefore, new strategies for HER2-targeting therapy are needed. Here, we present the preclinical in vitro and in vivo characterization of the HER2-targeted thorium-227 conjugate (HER2-TTC) TAT in various HER2-positive cancer models. In vitro, HER2-TTC showed potent cytotoxicity in various HER2-expressing cancer cell lines and increased DNA double strand break formation and the induction of cell cycle arrest in BT-474 cells. In vivo, HER2-TTC demonstrated dose-dependent antitumor efficacy in subcutaneous xenograft models. Notably, HER2-TTC also inhibited intratibial tumor growth and tumor-induced abnormal bone formation in an intratibial BT-474 mouse model that mimics breast cancer metastasized to bone. Furthermore, a match in HER2 expression levels between primary breast tumor and matched bone metastases samples from breast cancer patients was observed. These results demonstrate proof-of-concept for TAT in the treatment of patients with HER2-positive breast cancer, including cases where the tumor has metastasized to bone.
Recent Mechanistic Understanding of Fischer-Tropsch Synthesis on Fe-Carbide
Authors: Chai Jiachun , Jiang Jidong , Gong Yan , Wu Peng , Wang Annan , Zhang Xuebing , Wang Tao , Meng Xiangkun , Lin Quan , Lv Yijun , Men Zhuowu , Wang Peng
Published: June 2023

With an increase in energy consumption globally, Fischer-Tropsch (FT) synthesis is a good alternative for producing fuels and chemicals from coal, natural gas or biomass. Among them, coal to liquids has been put into production in countries that have large coal reserves. In this process, Fe-based catalysts are commonly used due to their earth abundance, comparatively wide operation range and ready availability to handle low H2/CO ratio from coal. Despite their extensive applications, the kinetic and mechanistic understandings of Fe carburization and FT reaction on Fe-carbides are relatively limited due to the complexity of the phase composition of the applied catalysts. This review summarizes the current state of knowledge of FT synthesis on Fe-carbide with an emphasis on the underlying mechanism. Specifically, the employment of a model catalyst, such as Raney Fe, could provide a convenient way to furnish kinetic information regarding Fe carburization and subsequent FT reaction. A major challenge for further understanding catalytic reactions occurring at the Fe-carbide surface is correlating FT activity and selectivity to a specific active site. To address this issue, the advancements of both DFT calculations and surface science techniques are highly demanded.
Copper-Catalyzed N-Arylation of Pyranoquinolinones with Boronic Acids at Room Temperature without Ligand
Authors: Gao Wei , Gao Fang , Yang Haikuan , Wang Zongde , Huang Yaru
Published: June 2023

Pyranoquinolinones synthesized from citral were used for Cu-catalyzed N-arylation with a wide range of arylboric acids. The reaction proceeded well with a broad substrate scope, providing a direct way to access highly functional pyranoquinolinone core structure derivatives in yields of up to 80%. Compared to citral, the compounds we obtained have a much better inhibitory effect on HeLa cervical cancer cells, and compound 3p has an IC50 value of 4.6 μM, lower than cisplatin’s 5.9 μM.
Tight Regulation of Mechanotransducer Proteins Distinguishes the Response of Adult Multipotent Mesenchymal Cells on PBCE-Derivative Polymer Films with Different Hydrophilicity and Stiffness
Authors: Argentati Chiara , Morena Francesco , Guidotti Giulia , Soccio Michelina , Lotti Nadia , Martino Sabata
Published: June 2023

Mechanotransduction is a molecular process by which cells translate physical stimuli exerted by the external environment into biochemical pathways to orchestrate the cellular shape and function. Even with the advancements in the field, the molecular events leading to the signal cascade are still unclear. The current biotechnology of tissue engineering offers the opportunity to study in vitro the effect of the physical stimuli exerted by biomaterial on stem cells and the mechanotransduction pathway involved in the process. Here, we cultured multipotent human mesenchymal/stromal cells (hMSCs) isolated from bone marrow (hBM-MSCs) and adipose tissue (hASCs) on films of poly(butylene 1,4-cyclohexane dicarboxylate) (PBCE) and a PBCE-based copolymer containing 50 mol% of butylene diglycolate co-units (BDG50), to intentionally tune the surface hydrophilicity and the stiffness (PBCE = 560 Mpa; BDG50 = 94 MPa). We demonstrated the activated distinctive mechanotransduction pathways, resulting in the acquisition of an elongated shape in hBM-MSCs on the BDG50 film and in maintaining the canonical morphology on the PBCE film. Notably, hASCs acquired a new, elongated morphology on both the PBCE and BDG50 films. We found that these events were mainly due to the differences in the expression of Cofilin1, Vimentin, Filamin A, and Talin, which established highly sensitive machinery by which, rather than hASCs, hBM-MSCs distinguished PBCE from BDG50 films.
Origin, Diversity, and Multiple Roles of Enzymes with Metallo-β-Lactamase Fold from Different Organisms
Authors: Diene Seydina M. , Pontarotti Pierre , Azza Saïd , Armstrong Nicholas , Pinault Lucile , Chabrière Eric , Colson Philippe , Rolain Jean-Marc , Raoult Didier
Published: June 2023

β-lactamase enzymes have generated significant interest due to their ability to confer resistance to the most commonly used family of antibiotics in human medicine. Among these enzymes, the class B β-lactamases are members of a superfamily of metallo-β-lactamase (MβL) fold proteins which are characterised by conserved motifs (i.e., HxHxDH) and are not only limited to bacteria. Indeed, as the result of several barriers, including low sequence similarity, default protein annotation, or untested enzymatic activity, MβL fold proteins have long been unexplored in other organisms. However, thanks to search approaches which are more sensitive compared to classical Blast analysis, such as the use of common ancestors to identify distant homologous sequences, we are now able to highlight their presence in different organisms including Bacteria, Archaea, Nanoarchaeota, Asgard, Humans, Giant viruses, and Candidate Phyla Radiation (CPR). These MβL fold proteins are multifunctional enzymes with diverse enzymatic or non-enzymatic activities of which, at least thirteen activities have been reported such as β-lactamase, ribonuclease, nuclease, glyoxalase, lactonase, phytase, ascorbic acid degradation, anti-cancer drug degradation, or membrane transport. In this review, we (i) discuss the existence of MβL fold enzymes in the different domains of life, (ii) present more suitable approaches to better investigating their homologous sequences in unsuspected sources, and (iii) report described MβL fold enzymes with demonstrated enzymatic or non-enzymatic activities.
Effects of the Light/Dark Phase and Constant Light on Spatial Working Memory and Spine Plasticity in the Mouse Hippocampus
Authors: Schröder Jane K. , Abdel-Hafiz Laila , Ali Amira A. H. , Cousin Teresa C. , Hallenberger Johanna , Rodrigues Almeida Filipe , Anstötz Max , Lenz Maximilian , Vlachos Andreas , von Gall Charlotte , Tundo-Lavalle Federica
Published: June 2023

Circadian rhythms in behavior and physiology such as rest/activity and hormones are driven by an internal clock and persist in the absence of rhythmic environmental cues. However, the period and phase of the internal clock are entrained by the environmental light/dark cycle. Consequently, aberrant lighting conditions, which are increasing in modern society, have a strong impact on rhythmic body and brain functions. Mice were exposed to three different lighting conditions, 12 h light/12 h dark cycle (LD), constant darkness (DD), and constant light (LL), to study the effects of the light/dark cycle and aberrant lighting on the hippocampus, a critical structure for temporal and spatial memory formation and navigation. Locomotor activity and plasma corticosterone levels were analyzed as readouts for circadian rhythms. Spatial working memory via Y-maze, spine morphology of Golgi–Cox-stained hippocampi, and plasticity of excitatory synapses, measured by number and size of synaptopodin and GluR1-immunreactive clusters, were analyzed. Our results indicate that the light/dark cycle drives diurnal differences in synaptic plasticity in hippocampus. Moreover, spatial working memory, spine density, and size and number of synaptopodin and GluR1 clusters were reduced in LL, while corticosterone levels were increased. This indicates that acute constant light affects hippocampal function and synaptic plasticity.
The Role of Gut Microbiome in the Pathogenesis of Multiple Sclerosis and Related Disorders
Authors: Dunalska Anna , Saramak Kamila , Szejko Natalia
Published: June 2023

Multiple sclerosis (MS) is a chronic, progressive neuroinflammatory disease with a complex pathophysiological background. A variety of diverse factors have been attributed to the propagation of inflammation and neurodegeneration in MS, mainly genetic, immunological, and environmental factors such as vitamin D deficiency, infections, or hormonal disbalance. Recently, the importance of the gut-brain axis for the development of many neurological conditions, including stroke, movement disorders, and neuroinflammatory disorders, has been postulated. The purpose of our paper was to summarize current evidence confirming the role of the gut microbiome in the pathophysiology of MS and related disorders, such as neuromyelitis optica spectrum disorder (NMO-SD). For this aim, we conducted a systematic review of the literature listed in the following databases: Medline, Pubmed, and Scopus, and were able to identify several studies demonstrating the involvement of the gut microbiome in the pathophysiology of MS and NMO-SD. It seems that the most relevant bacteria for the pathophysiology of MS are those belonging to Pseudomonas, Mycoplasma, Haemophilus, Blautia, Dorea, Faecalibacterium, Methanobrevibacter, Akkermansia, and Desulfovibrionaceae genera, while Clostridium perfringens and Streptoccocus have been demonstrated to play a role in the pathophysiology of NMO-SD. Following this line of evidence, there is also some preliminary data supporting the use of probiotics or other agents affecting the microbiome that could potentially have a beneficial effect on MS/NMO-SD symptoms and prognosis. The topic of the gut microbiome in the pathophysiology of MS is therefore relevant since it could be used as a biomarker of disease development and progression as well as a potential disease-modifying therapy.
Disposable Microfluidic Paper-Based Device for On-Site Quantification of Urinary Creatinine
Authors: Melo Maria M. P. , Machado Ana , Rangel António O. S. S. , Mesquita Raquel B. R.
Published: June 2023

In this work, a new microfluidic paper-based analytical device (µPAD) was developed for on-hand creatinine quantification in urine samples. When compared to conventional methods, this innovative paper device is more accessible and portable, it provides low-cost analysis (cost of consumables of 40 cents), and it is applicable to non-invasive biological fluids. Furthermore, the paper-based approach is used within an environmentally friendly assembly with no need for wax printing and small amounts of reagents resulting in low waste production and easy disposal by incineration. Its assembly method includes cutting paper discs arranged into several reading units within a plastic pouch, enabling effective creatinine quantification with accuracy based on a vertical flow approach. The method is based on the colourimetric reaction between creatinine and alkaline picric acid, where the solution colour changes from yellow to orange/red. Under optimal conditions, the developed method allowed creatinine quantification in the dynamic range of 2.20–35.0 mg/dL, with a limit of detection (LOD) of 0.66 mg/dL and a limit of quantification (LOQ) of 2.20 mg/dL. The colour intensity developed was processed in ImageJ software, based on digital image scanning, performed in 20 min (up to 4 h) after the sample insertion. The device is stable for up to one week when stored in a vacuum at 4 °C. The method was validated by comparing the results with a batch-wise procedure, where there were no statistically significant differences between both methods.
The Association between 24 h Movement Guidelines and Internalising and Externalising Behaviour Problems among Chinese Preschool Children
Authors: Zhu Na , Guo Hongzhi , Ma Dongmei , Wang Qiang , Ma Jiameng , Kim Hyunshik
Published: June 2023

This study examined the relationship between adherence to 24 h movement guidelines (24 h MGs) and internalising and externalising behavioural problems in Chinese children aged 3–6 years, with a specific focus on the differences between weekdays and weekends. The guidelines include recommendations for physical activity (PA), screen time (ST), and sleep duration (SD). The results indicated a stronger association between adherence to these guidelines and behavioural problems on weekends compared to weekdays. Specifically, the odds of experiencing internalising problems were 1.33 higher (95% CI: 1.05–1.69) when not satisfying all three behaviours compared to not satisfying one or two. Moreover, on weekends, when ST was not fulfilled, there was a higher likelihood of externalising behaviour problems compared to when it was fulfilled (OR, 1.18, 95% CI, 1.01–1.38), and when all three behaviours were not met, the likelihood was even higher (OR, 1.50, 95% CI, 1.04–2.18). Children who met all three guidelines had fewer internalising and externalising behavioural problems, suggesting a potential beneficial effect on mental health. The study revealed that a higher adherence to these recommendations corresponded to a lower risk of mental health problems. Additionally, higher screen time was linked to an increase in externalising behavioural issues. These findings underscore the importance of adherence to 24 h MGs for optimal mental health in children. Future interventions should consider these behavioural factors and incorporate strategies to promote adherence to these guidelines, particularly on weekends.
Intraoperative Ultrasound in Minimally Invasive Laparoscopic and Robotic Pediatric Surgery: Our Experiences and Literature Review
Authors: Di Mitri Marco , Thomas Eduje , Di Carmine Annalisa , Manghi Ilaria , Cravano Sara Maria , Bisanti Cristian , Collautti Edoardo , Ruspi Francesca , Cordola Chiara , Vastano Marzia , D’Antonio Simone , Libri Michele , Gargano Tommaso , Lima Mario
Published: June 2023

Ultrasound (US) is a non-invasive imaging technique frequently used to examine internal organs and superficial tissues, and invaluable in pediatric patients. In a surgical setting, intraoperative ultrasound allows to highlight anatomical structures in detail during traditional open and minimally invasive surgery, thanks to the use of specific probes. In fact, laparoscopic and robotic ultrasonography requires the development of specialized transducers that fit through laparoscopic trocars. In adults, laparoscopic ultrasound is used during cholecystectomy before dissection of the triangle of Calot, to guide liver biopsies and ablation procedures and for the staging of patients with pancreas adenocarcinoma. However, the applications in the pediatric field are still limited. This paper aims to share our preliminary experience with ultra-sound in minimally invasive laparoscopic and robotic pediatric surgery, describing two cases in which intra-operative ultrasound was applied, and to present a review of the literature on the state of the art of the actual uses in pediatric surgery.
Molecular Role of Asn680Ser and Asp37Glu Missense Variants in Saudi Women with Female Infertility and Polycystic Ovarian Syndrome
Authors: Alshammary Amal F. , Alsobaie Sarah F. , Alageel Arwa A. , Aldakheel Fahad M. , Ansar Sabah , Alrashoudi Reem , Farzan Raed , Alturki Norah A. , Alhaizan Maysoon Abdulhadi , Al-Mutawa Johara , Ali Khan Imran
Published: June 2023

Female infertility (FI) is a global health issue. Polycystic ovary syndrome (PCOS) is a common cause of FI. The renalase gene (RNLS) is associated with FI and other human diseases. Based on the documented missense variants, rs6166 and rs2296545 single-nucleotide polymorphisms (SNPs) were not identified in Saudi women with FI and PCOS. This study aimed to investigate the molecular role of the two SNPs in Saudi women with FI and PCOS. In this cross-sectional study, 96 healthy controls, 96 women with FI, and 96 women with PCOS were recruited. DNA was isolated, and polymerase chain reactions and Sanger sequencing analysis were performed using rs6166 and rs2296545 SNPs. The data obtained from the three groups were used to perform statistical analyses based on genotype, allele frequencies, regression models, and ANOVA analysis. Both rs6166 and rs2296545 had no role in FI or PCOS in Saudi women. A predicted reason for non-association in Saudi women could be the role of elderly women in the controls compared with women with FI and PCOS. Moreover, age, weight, and body mass index were higher in the control group than the FI and PCOS groups. In conclusion, rs6166 and rs2296545 SNPs were not associated with FI or PCOS in Saudi women.
The Effect of Incorporating 100% of Undiluted and Diluted Reclaimed Epoxy Asphalt Materials into Pervious Cement Mixes
Authors: Alamri Mohammed , Lu Qing , Elmagarhe Asad , Elnihum Ahmed
Published: June 2023

In order to improve the sustainability of road pavements, transportation agencies should consider designing pavements with recycled materials such as reclaimed epoxy asphalt pavement. Epoxy asphalt has recently attracted significant attention from the pavement community as a superior-performing binder that can help achieve long-lasting pavements. The recyclability of a proven long-life pavement material, such as epoxy asphalt, has now become one concern in promoting the use of epoxy asphalt binder in road pavements. Due to its thermosetting nature, the usual process of reclaiming asphalt pavement cannot be performed on epoxy asphalt pavement. Recent studies have investigated utilizing reclaimed epoxy asphalt materials in asphalt mixtures as black rock. In light of this, examining the use of reclaimed epoxy materials in cement-concrete mixes is important. The use of reclaimed epoxy asphalt materials in pavement construction is expected to gain more popularity and become a new sustainable construction option in various sustainable pavement applications in the near future. The main objective of this study is to investigate the effects of incorporating 100% reclaimed epoxy asphalt (hereinafter referred to as “epoxy RAP”) and reclaimed diluted epoxy asphalt materials (hereinafter referred to as “diluted epoxy RAP”) into cement-concrete mixes on the performance of the mixtures. The study also examined the effects of replacing cement with 5% silica fume on the performance of reclaimed mixtures. Five different mixtures were fabricated and tested in terms of density, void content, permeability, and compressive strength. Results of the density test revealed that replacing 100% natural aggregates with epoxy RAP and diluted epoxy RAP materials reduced density by an average of 10%. However, void content was found to increase with the incorporation of epoxy RAP, even when replacing Portland cement with silica fume. Regarding permeability, mixtures containing 100% epoxy RAP and diluted epoxy RAP materials have significantly higher permeability values compared with the natural mix value. However, adding 5% silica fume significantly reduced the permeability. Compressive test results indicated that substituting 100% of aggregates with epoxy RAP or diluted epoxy RAP materials would reduce compressive strength by 55% on average. Furthermore, adding silica fume to reclaimed mixes was found to have no apparent effect on compressive strength.
A Study on Using Magnetic Abrasive Finishing with a 6-Axis Robot to Polish the Internal Surface Finishing of Curved Tubes
Authors: Zhou Zhenfeng , Sun Xu , Yang Yanzhen , Fu Yongjian
Published: June 2023

This study proposed a new magnetic abrasive finishing (MAF) method, in which a 6-axis robot with a magnetic machining tool was used to polish the inner surfaces of curved tubes. We have also developed a magnetic machining tool jig, which can be fixed at the front of the 6-axis robot, rotating freely and suitable for polishing the inner surfaces of curved tubes. In this study, we focused on investigating the machining parameters in the initial machining stage and precision finishing stage. Based on the characteristics of machining parameters, a multi-stage MAF process was conducted to obtain an inner surface with high quality and high efficiency. The experimental results showed that both the roughness Ra and Rz of inner surface in the initial machining stage significantly decreased with the increase in the mixed magnetic abrasives, to as low as less than 20 nm Ra in the precision finishing stage when the machining parameters were appropriately adjusted. In addition, the roughness Ra of inner surface could be further reduced to less than 10 nm Ra in the multi-stage MAF process. Finally, the magnetic flux density cloud map and the magnetic field line distribution map were analyzed in Ansys Maxwell.
Numerical Simulation of a Simplified Reaction Model for the Growth of Graphene via Chemical Vapor Deposition in Vertical Rotating Disk Reactor
Authors: Yang Bo , Yang Ni , Zhao Dan , Chen Fengyang , Yuan Xingping , Hou Yanqing , Xie Gang
Published: June 2023

The process of graphene growth by CVD involves a series of complex gas-phase surface chemical reactions, which generally go through three processes, including gas phase decomposition, surface chemical reaction, and gas phase diffusion. The complexity of the CVD process for growing graphene is that it involves not only chemical reactions but also mass, momentum, and energy transfer. To solve these problems, the method of numerical simulation combined with the reactor structure optimization model provides a good tool for industrial production and theoretical research to explore the influencing factors of the CVD growth of graphene. The objective of this study was to establish a simplified reaction model for the growth of graphene by chemical vapor deposition(CVD) in a vertical rotating disk reactor (VRD). From a macroscopic modeling perspective, computational fluid dynamics (CFD) was used to investigate the conditions for the growth of graphene by chemical vapor deposition in a high-speed rotating vertical disk reactor on a copper substrate surface at atmospheric pressure (101,325 Pa). The effects of gas temperature, air inlet velocity, base rotation speed, and material ratio on the surface deposition rate of graphene in a VRD reactor were studied, and the technological conditions for the preparation of graphene via the CVD method in a VRD reactor based on a special structure were explored. Compared with existing models, the numerical results showed the following: the ideal growth conditions of graphene prepared using a CVD method in a VRD reactor involve a growth temperature of 1310 K, an intake speed of 470 mL/min, a base speed of 300 rpm, and an H2 flow rate of 75 sccm; thus, more uniform graphene with a better surface density and higher quality can be obtained. The effect of the carbon surface deposition rate on the growth behavior of graphene was studied using molecular dynamics (MD) from a microscopic perspective. The simulation showed that the graphene surface deposition rate could control the nucleation density of graphene. The combination of macro- and microsimulation methods was used to provide a theoretical reference for the production of graphene.
Response Spectrum Analysis of Multi-Story Shear Buildings Using Machine Learning Techniques
Authors: Georgioudakis Manolis , Plevris Vagelis
Published: June 2023

The dynamic analysis of structures is a computationally intensive procedure that must be considered, in order to make accurate seismic performance assessments in civil and structural engineering applications. To avoid these computationally demanding tasks, simplified methods are often used by engineers in practice, to estimate the behavior of complex structures under dynamic loading. This paper presents an assessment of several machine learning (ML) algorithms, with different characteristics, that aim to predict the dynamic analysis response of multi-story buildings. Large datasets of dynamic response analyses results were generated through standard sampling methods and conventional response spectrum modal analysis procedures. In an effort to obtain the best algorithm performance, an extensive hyper-parameter search was elaborated, followed by the corresponding feature importance. The ML model which exhibited the best performance was deployed in a web application, with the aim of providing predictions of the dynamic responses of multi-story buildings, according to their characteristics.
Crystallization of Intermetallic Phases Fe2Si, Fe5Si3 for High Alloyed Cast Irons
Authors: Stawarz Marcin
Published: June 2023

This paper presents the results of laboratory tests related to high-alloy silicon cast iron (HSCI). These materials are corrosion-resistant and commonly used in cathodic protection systems as protective electrodes. Due to their high fragility, alloys with increased Si content are not suitable for producing elements exposed to dynamic loads. This paper analyzes the crystallization process of silicon alloys (with Si content between 23% and 25%) using thermal and derivation analysis methods. The tests also included an extended analysis of chemical composition. The metallographic tests included scanning electron microscopy with an EDS system, and the phase composition was determined using X-ray diffraction. As a result of the tests, the warp components were identified, the primary share of which are intermetallic phases of the Fe5Si3 type. Moreover, single silicon crystals were found. The test results allowed for clarification of the temperature range of the transition of the Fe2Si phase into the Fe5Si3 phase and the determination of characteristic points of the crystallization process (TSolidus i TLiquidus). Furthermore, bifilm-type inclusions were identified in the alloys. We also managed to present the silicon crystals and Fe5Si3 phases in a spatial layout via observation of the surfaces of contraction cavities using scanning electron microscopy.
Synthesis and X-ray Crystal Structure Analysis of Substituted 1,2,4-Triazolo [4’,3’:2,3]pyridazino[4,5-b]indole and Its Precursor
Authors: Boraei Ahmed T. A. , Eltamany Elsayed H. , Haukka Matti , Soliman Saied M. , Barakat Assem , Sopaih Manar
Published: June 2023

The hit compound 1,2,4-triazolo[4’,3’:2,3]pyridazino[4,5-b]indole 3 was synthesized from the reflux of 4-amino-5-indolyl-1,2,4-triazole-3-thione 1 with 4′-bromoacetophenone 2 in methanol catalyzed by concentrated HCl and the desired final molecule was obtained by recrystallization from methanol. The suggested structures of compounds 1 and 3 based on the spectral characterizations were confirmed by X-ray single crystal diffraction analysis. Compound 3 crystallized in the triclinic crystal system and P-1 space group with a = 5.9308(2) Å, b = 10.9695(3) Å, c = 14.7966(4) Å, α = 100.5010(10)°, β = 98.6180(10)°, and γ = 103.8180(10)°. On the other hand, the crystal system of 1 is monoclinic, where a = 6.23510(10) Å, b = 26.0156(4) Å, c = 12.4864(2) Å, β = 93.243(2)° and the space group is P21. The triazole and indole rings are found twisted from each other in both compounds. The twist angle is higher in 3 (12.65°) than 1 (4.94–7.22°). In the case of the former, the H…H (39.6%), H…C (22.0%), N…H (12.8%) and Br…H (13.2%) contacts are the most dominant while the C…C, C…H, Br…H, N…H and S…S contacts have the characteristics of strong interactions. In the latter, the C…H, N…H, S…H, S…S, and C…C contacts are the most important. In this case, the percentages of the H…H, C…H, N…H and S…H contacts are in the range of 34.9–37.4, 20.5–24.0, 12.2–13.6, 14.0–15.8, respectively. In both systems, the shape index and curvedness of surfaces confirmed the presence of π–π stacking interactions.
Novel 3-Substituted 8-Methoxycoumarin Derivatives as Anti-Breast Cancer Drugs
Authors: Al-Warhi Tarfah , Abu Ali Ola A. , Alqahtani Leena S. , Abo-Elabass Eman , El Behery Mohammed , El-Baky Atef E. Abd , Samir A. Zaki Mohamed , Fayad Eman , Radwan Eman M.
Published: June 2023

Scientists have been interested in hybrid coumarin derivatives due to their wide clinical anticancer use. Herein, ethyl 8-methoxycoumarin-3-carboxylate (Compound 1) served as the starting material for the synthesis of a series of novel hybrid coumarin derivatives (Compounds 3–6). Their structure was determined using 13C NMR, 1H NMR, elemental analysis, and mass spectrometry. The in vitro cytotoxic activities of coumarin derivatives (Compounds 3, 5, and 6) and brominated coumarin derivatives (Compounds 4, 8, and 9) against MCF-7 and MDA-MB-231 were evaluated. Several substances have been identified as promising candidates for future study, especially Compound 6 due to its potent activity against β-tubulin (TUB) polymerization, sulfatase, and aromatase enzymes. It also has a role in inducing cell-cycle arrest at the S phase in the MCF-7 cell line, as well as apoptosis.
Phase Compositions and Microwave Dielectric Properties of Na1+xSrB5O9+0.5x Ceramics
Authors: Lu Xuepeng , Wu Peng , Yang Huimin , Yang Min , Zheng Yong
Published: June 2023

Microwave dielectric ceramics composed of Na1+xSrB5O9+0.5x (0 ≤ x ≤ 0.125) were synthesized via a traditional solid-state reaction approach. The effects of non-stoichiometric Na on the crystal structures, phase compositions, chemical bond characteristics, and microwave dielectric properties of the Na1+xSrB5O9+0.5x ceramics were systematically studied. All Na1+xSrB5O9+0.5x ceramics sintered at optimum temperatures consisted of a NaSrB5O9 solid-solution phase and a SrB2O4 phase. Appropriate excess Na could suppress the generation of the SrB2O4 phase, and the lowest content of the SrB2O4 phase was achieved at x = 0.075. The εr values of the Na1+xSrB5O9+0.5x ceramics were primarily affected by the relative density and molecular polarization. The Q × f values showed a positive correlation with the lattice energy. The τf value was correlated to the SrB2O4 phase content, bond valence, and bond energy. Typically, the Na1.075SrB5O9.0375 ceramic sintered at 825 °C possessed good microwave dielectric properties of εr = 5.61, Q × f = 31, 937 GHz, and τf = −3.09 ppm/°C, which are suitable for high-frequency, low-temperature co-fired ceramics (LTCCs) substrate applications.
Structural Evolution in a Series of Isomorphous Rare Earth Compounds as Response of Lanthanide Contraction
Authors: Reuter Hans , Böltken Marcel , Horstmann Maik , Haase Markus
Published: June 2023

The structural parameters of the rare-earth diacetate halide trihydrates, RE(OAc)2Hal·3H2O with RE = Ce − (Pm) − Lu and Hal = Cl, Br, have been determined by low temperature, high-resolution SCXRD in order to examine the effect of lanthanide contraction on the coordination geometry in this series of isomorphous compounds consisting of cationic, acetate-bridged, non-linear, one-dimensional coordination polymers of composition [RE(H2O)3(OAc)2]+ and laterally hydrogen bonded halide ions, Hal−. Although the shrinkage of the unit cell volume follows lanthanide contraction very well over the complete range of investigated RE elements, many other parameters (i.e., lattice constants, angles and distances in the RE··· RE alignment, RE-O bond lengths, etc.) exhibit a more complex response on lanthanide contraction often expressed by sigmoid curves that can be ascribed to a continuous transition from CN9 (RE = Ce) to CN8 (RE = Lu) as one acetate group loses the chelate function, an effect accompanied by significant structural changes of the carboxylate group. Therefore, data are best analyzed by use of two subsets represented by the two different structure types of Ce and Lu, the structural features of which change with decreasing/increasing the size of RE3+, up to the borderline between both subsets.
Molecular Dynamics Simulation of Single-Crystal 4H-SiC Nano Scratching with Different Scratching Directions of the Tool
Authors: Liang Lie , Li Shujuan , Chai Peng , Lan Kehao , Yu Ruijiang
Published: June 2023

4H-SiC (silicon carbide) is widely used in semiconductor devices due to its superior characteristics. However, processing techniques such as cutting, grinding, and polishing generally have problems such as low processing efficiency, high cost, difficulties guaranteeing processing quality, and serious material waste. The in-depth research on the mechanical behavior, material removal, and damage mechanism of SiC single crystals at the micro/nano scale is the foundation for solving these problems. This paper establishes a molecular dynamics simulation model for 4H-SiC single-crystal nano scratches, using three different directions of a Berkovich indenter to scratch the surface of the workpiece, studying the surface morphology, scratching force, and material removal during the scratching process. The results indicate that scratching directions of the tool varies, and the surface morphology also varies. After the scratching depth exceeds 1.6 nm, complete dislocations with a Burges vector of 1/3<12¯10> appear on the crystal subsurface, leading to the plastic removal of the material. During the process of material removal, a smaller tool rake angle removes a larger amount of material chips. By analyzing the damage layer of the workpiece, the difference in the damage layer is smaller when the scratching direction is different, but the damage layer generated by the smaller rake angle of the scratching tool is thinner. It shows that the scratching force and workpiece temperature are relatively small when the rake angle of the scratching tool is small. Therefore, when scratching 4H-SiC single crystals, choosing a tool with a smaller rake angle is more beneficial for the process.
Hemoglobin and Endotoxin Levels Predict Sarcopenia Occurrence in Patients with Alcoholic Cirrhosis
Authors: Shibamoto Akihiko , Namisaki Tadashi , Suzuki Junya , Kubo Takahiro , Iwai Satoshi , Tomooka Fumimasa , Takeda Soichi , Fujimoto Yuki , Inoue Takashi , Tanaka Misako , Koizumi Aritoshi , Yorioka Nobuyuki , Matsuda Takuya , Asada Shohei , Tsuji Yuki , Fujinaga Yukihisa , Nishimura Norihisa , Sato Shinya , Takaya Hiroaki , Kitagawa Koh , Kaji Kosuke , Kawaratani Hideto , Akahane Takemi , Mitoro Akira , Yoshiji Hitoshi
Published: June 2023

Alcohol is a major risk factor of liver cirrhosis (LC). This study aimed to elucidate a surrogate marker of sarcopenia in patients with LC of different etiology. Out of 775 patients with LC, 451 were assessed for handgrip strength and skeletal muscle mass (by computed tomography). They were then divided into two groups: alcoholic cirrhosis (AC; n = 149) and nonalcoholic cirrhosis (NAC; n = 302). Endotoxin activity (EA) levels were measured with an EA assay. Group AC showed significantly higher platelet counts (p = 0.027) and lower blood urea nitrogen levels and fibrosis-4 index than group NAC (p = 0.0020 and p = 0.038, respectively). The risk factors of sarcopenia were age ≥ 65 years, female sex, CP-C LC, Hb levels < 12 g/dL, and EA level > 0.4 in all patients with LC; hemoglobin (Hb) levels < 12 g/dL and EA level > 0.4 in group AC; and age ≥ 65 years, CP-C LC, and Hb levels < 12 g/dL in group NAC. The prediction accuracy of Hb for sarcopenia in group AC, group NAC, and all patients was 83.6%, 75.9%, and 78.1% (sensitivity: 92.0%, 69.0%, and 80.2%; specificity: 66.4%, 71.0%, and 64.0%), respectively. Although not significant, the predictive performance was better when using the combination of Hb and EA measurements than when using Hb alone in group AC but was comparable in all patients. Hb levels can predict sarcopenia in patients with LC, but in those with AC, the combination of Hb and EA improves the prediction performance.
Pretreatment CT Texture Parameters as Predictive Biomarkers of Progression-Free Survival in Follicular Lymphoma Treated with Immunochemotherapy and Rituximab Maintenance
Authors: Durot Carole , Durot Eric , Mulé Sébastien , Morland David , Godard François , Quinquenel Anne , Delmer Alain , Soyer Philippe , Hoeffel Christine
Published: June 2023

The purpose of this study was to determine whether texture analysis features present on pretreatment unenhanced computed tomography (CT) images, derived from 18F-fluorodeoxyglucose positron emission/computed tomography (18-FDG PET/CT), can predict progression-free survival (PFS), progression-free survival at 24 months (PFS 24), time to next treatment (TTNT), and overall survival in patients with high-tumor-burden follicular lymphoma treated with immunochemotherapy and rituximab maintenance. Seventy-two patients with follicular lymphoma were retrospectively included. Texture analysis was performed on unenhanced CT images extracted from 18-FDG PET/CT examinations that were obtained within one month before treatment. Skewness at a fine texture scale (SSF = 2) was an independent predictor of PFS (hazard ratio = 3.72 (95% CI: 1.15, 12.11), p = 0.028), PFS 24 (hazard ratio = 13.38; 95% CI: 1.29, 138.13; p = 0.029), and TTNT (hazard ratio = 5.11; 95% CI: 1.18, 22.13; p = 0.029). Skewness values above −0.015 at SSF = 2 were significantly associated with lower PFS, PFS 24, and TTNT. Kurtosis without filtration was an independent predictor of PFS (SSF = 0; HR = 1.22 (95% CI: 1.04, 1.44), p = 0.013), and TTNT (SSF = 0; hazard ratio = 1.23; 95% CI: 1.04, 1.46; p = 0.013). This study shows that pretreatment unenhanced CT texture analysis-derived tumor skewness and kurtosis may be used as predictive biomarkers of PFS and TTNT in patients with high-tumor-burden follicular lymphoma treated with immunochemotherapy and rituximab maintenance.
Propolis Controlled Delivery Systems for Oral Therapeutics in Dental Medicine: A Systematic Review
Authors: Barboza Andressa da Silva , Ribeiro de Andrade Juliana Silva , Ferreira Monika Lamas , Peña Carla Lucía David , da Costa Juliê Silveira , Fajardo André Ricardo , Lund Rafael Guerra
Published: June 2023

This systematic review synthesizes the existing evidence in the literature regarding the association of propolis with controlled delivery systems (DDSs) and its potential therapeutic action in dental medicine. Two independent reviewers performed a literature search up to 1 June 2023 in five databases: PubMed/Medline, Web of Science, Cochrane Library, Scopus, and Embase, to identify the eligible studies. Clinical, in situ, and in vitro studies that investigated the incorporation of propolis as the main agent in DDSs for dental medicine were included in this study. Review articles, clinical cases, theses, dissertations, conference abstracts, and studies that had no application in dentistry were excluded. A total of 2019 records were initially identified. After carefully examining 21 full-text articles, 12 in vitro studies, 4 clinical, 1 animal model, and 3 in vivo and in vitro studies were included (n = 21). Relevant data were extracted from the included studies and analyzed qualitatively. The use of propolis has been reported in cariology, endodontics, periodontics, stomatology, and dental implants. Propolis has shown non-cytotoxic, osteoinductive, antimicrobial, and anti-inflammatory properties. Moreover, propolis can be released from DDS for prolonged periods, presenting biocompatibility, safety, and potential advantage for applications in dental medicine.