bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Differentially Expressed Genes in Different Glioblastoma Regions and Their Association with Cancer Stem Cell Development and Temozolomide Response
Authors: Hsu Justin Bo-Kai , Lee Tzong-Yi , Cheng Sho-Jen , Lee Gilbert Aaron , Chen Yung-Chieh , Le Nguyen Quoc Khanh , Huang Shiu-Wen , Kuo Duen-Pang , Li Yi-Tien , Chang Tzu-Hao , Chen Cheng-Yu
Published: October 2021

The molecular heterogeneity of gene expression profiles of glioblastoma multiforme (GBM) are the most important prognostic factors for tumor recurrence and drug resistance. Thus, the aim of this study was to identify potential target genes related to temozolomide (TMZ) resistance and GBM recurrence. The genomic data of patients with GBM from The Cancer Genome Atlas (TCGA; 154 primary and 13 recurrent tumors) and a local cohort (29 primary and 4 recurrent tumors), samples from different tumor regions from a local cohort (29 tumor and 25 peritumoral regions), and Gene Expression Omnibus data (GSE84465, single-cell RNA sequencing; 3589 cells) were included in this study. Critical gene signatures were identified based an analysis of differentially expressed genes (DEGs). DEGs were further used to evaluate gene enrichment levels among primary and recurrent GBMs and different tumor regions through gene set enrichment analysis. Protein–protein interactions (PPIs) were incorporated into gene regulatory networks to identify the affected metabolic pathways. The enrichment levels of 135 genes were identified in the peritumoral regions as being risk signatures for tumor recurrence. Fourteen genes (DVL1, PRKACB, ARRB1, APC, MAPK9, CAMK2A, PRKCB, CACNA1A, ERBB4, RASGRF1, NF1, RPS6KA2, MAPK8IP2, and PPM1A) derived from the PPI network of 135 genes were upregulated and involved in the regulation of cancer stem cell (CSC) development and relevant signaling pathways (Notch, Hedgehog, Wnt, and MAPK). The single-cell data analysis results indicated that 14 key genes were mainly expressed in oligodendrocyte progenitor cells, which could produce a CSC niche in the peritumoral region. The enrichment levels of 336 genes were identified as biomarkers for evaluating TMZ resistance in the solid tumor region. Eleven genes (ARID5A, CDC42EP3, CDKN1A, FLT3, JUNB, MAP2K3, MYBPC2, RGS14, RNASEK, TBC1D30, and TXNDC11) derived from the PPI network of 336 genes were upregulated and may be associated with a high risk of TMZ resistance; these genes were identified in both the TCGA and local cohorts. Furthermore, the expression patterns of ARID5A, CDKN1A, and MAP2K3 were identical to the gene signatures of TMZ-resistant cell lines. The identified enrichment levels of the two gene sets expressed in tumor and peritumoral regions are potentially helpful for evaluating TMZ resistance in GBM. Moreover, these key genes could be used as biomarkers, potentially providing new molecular strategies for GBM treatment.
An Assessment of the Efficiency of Canadian Power Generation Companies with Bootstrap DEA
Authors: Dia Mohamed , Shahi Shashi K. , Zéphyr Luckny
Published: October 2021

Power generation companies play an important role in the Canadian economy, as most of the economic activities in the manufacturing and service sectors are powered by electricity. The significance of the Canadian power generation industry shows that efficiency analysis is essential for efficiently managing power generation and distribution in Canada. However, there have been few attempts to study the relative efficiencies of the Canadian power generation companies. This study fills in this gap by assessing the overall technical, managerial, and scale efficiencies of a sample of Canadian power generation companies via the non-parametric bootstrap DEA methodology, with firm-level annual inputs and outputs data over an 18-year horizon. The results of our investigation indicate low levels of overall technical and managerial efficiencies but relatively high levels of scale efficiencies of the Canadian power generation companies over the entire study period. We also found that the 2007–2009 financial crisis impacted the relative performance of the Canadian power generation companies. Our results also allowed us to identify the benchmark power generation companies for each type of efficiency that the inefficient companies should target toward improving their efficiency.
Determinants of EMNEs’ Entry Mode Decision with Environmental Volatility Issues: A Review and Research Agenda
Authors: Li Yameng , Gao Ruosu , Wang Jingyi
Published: October 2021

Emerging market multinational enterprises (EMNEs) play a vital role in global economic development and usually adopt aggressive internationalization strategies. However, the volatile global environment has caused EMNEs to face various risks in their overseas expansion. To maximize the competitive advantages and achieve successful expansion, EMNEs should choose the most suitable foreign entry mode. Therefore, EMNEs need to understand what environmental factors affect their decision-making and how they influence the choice of entry modes, especially in a volatile environment. This review examines 44 selected journal articles from 1996 to June 2021 on the environmental volatility determinants of EMNEs’ entry mode choice. The entry mode choice we examined is mainly wholly-owned subsidiary versus international joint venture. We categorized the environmental volatility determinants investigated in the literature we reviewed into country-level factors (such as cross-national distance) and industry-level factors (such as industry condition). The main contributions are: (1) the review reveals three research gaps in extant studies, which are lack of research on external environmental factors, lack of research on multinationals from less concerning emerging economies, and lack of research on small-to-medium (SMEs) enterprises. (2) Practically, the study highlights the importance of understanding external environmental factors for EMNEs to make the most suitable entry mode decisions.
Experts’ Perspective on the Development of Experiential Marketing Strategy: Implementation Steps, Benefits, and Challenges
Authors: Urdea Ana-Maria , Constantin Cristinel Petrișor
Published: October 2021

Consumer needs change over time as a result of the fast-paced advancement in technology and the induction of the Internet, expansion that leads to a difficulty for brands to adapt their marketing promotion strategy and trying to remain innovative and effective at meeting their consumers’ expectations. This research investigates what effect experiential marketing campaigns have on both customers’ perception and business outcomes, aiming to develop a deeper understanding of experiential marketing, its challenges, and benefits, to understand customers’ reactions to experiential touchpoints, to explore what type of technology increases experiential perceived value, and to envisage the evolution of experiential marketing strategy. To capture all the important facets of the research objectives, an exploratory survey based on the voices of 31 marketing experts from all around the world was applied. By identifying the key drivers of experiential marketing campaigns in a hybrid setting, the present study highlighted the important role that experiential marketing has as a communication strategy, offering additional insights to marketing specialists on the experiential marketing implementation steps. A theoretical framework of the steps needed to put into practice an experiential marketing strategy was proposed.
Efficient Variance Reduction for American Call Options Using Symmetry Arguments
Authors: Boire François-Michel , Reesor R. Mark , Stentoft Lars
Published: October 2021

Recently it was shown that the estimated American call prices obtained with regression and simulation based methods can be significantly improved on by using put-call symmetry. This paper extends these results and demonstrates that it is also possible to significantly reduce the variance of the estimated call price by applying variance reduction techniques to corresponding symmetric put options. First, by comparing performance for pairs of call and (symmetric) put options for which the solution coincides, our results show that efficiency gains from variance reduction methods are different for calls and symmetric puts. Second, control variates should always be used and is the most efficient method. Furthermore, since control variates is more effective for puts than calls, and since symmetric pricing already offers some variance reduction, we demonstrate that drastic reductions in the standard deviation of the estimated call price is obtained by combining all three variance reduction techniques in a symmetric pricing approach. This reduces the standard deviation by a factor of over 20 for long maturity call options on highly volatile assets. Finally, we show that our findings are not particular to using in-sample pricing but also hold when using an out-of-sample pricing approach.
The Influence of Strip-City Street Network Structure on Spatial Vitality: Case Studies in Lanzhou, China
Authors: Li Xin , Qian Yongsheng , Zeng Junwei , Wei Xuting , Guang Xiaoping
Published: October 2021

In the context of China’s recent urbanization, the agglomeration and diffusion of the strip-city spatial network are gradually being reconstructed. The ways in which the street network structure affects the underlying logic of economic and social development is worthy of in-depth consideration. This study takes Lanzhou (a typical strip city in China) as a case study, using dynamic, geographic, big data and spatial syntactic-theory models to explore the influence of street network accessibility and structure on the spatial and temporal distribution of strip-city spatial vitality. We use Hotspot Analysis (Getis-Ord Gi*) to analyze the dispersal characteristics of street space vitality. In addition, the spatial and temporal heterogeneity characteristics and mechanism of the influence of street accessibility on spatial vitality are evaluated using the spatial Durbin model (SDM). The results show that: the temporal and spatial performance of urban vitality on weekdays and weekends conforms to people’s daily activities, offering similar spatial agglomeration and dispersion effects; accessibility and pedestrian-friendly streets have better urban spatial vitality clustering; street network integration significantly affects the reshaping of urban vitality, but there is apparent temporal heterogeneity in the degree of impact.
The Circadian Rhythms of STAT3 in the Rat Pineal Gland and Its Involvement in Arylalkylamine-N-Acetyltransferase Regulation
Authors: Moravcová Simona , Filipovská Eva , Spišská Veronika , Svobodová Irena , Novotný Jiří , Bendová Zdeňka
Published: October 2021

In rodents, the melatonin production by the pineal gland is controlled through adrenergic signaling from the suprachiasmatic nuclei and regulation of the principal enzyme in its synthesis, arylalkylamine-N-acetyltransferase (AANAT). In the present study, we identified increased isoprenaline-induced aa-nat expression and nocturnal AANAT activity in the pineal glands in response to the silencing of the signal transducer and activator of transcription 3 (STAT3) with siRNA or STAT3 inhibitors WP1066 and AZD1480. This AANAT activity enhancement in vivo did not interfere with light-induced AANAT suppression. Systemic or in vitro lipopolysaccharide (LPS) administration markedly increased Stat3 expression and STAT3 phosphorylation, but it did not significantly affect AANAT expression or activity. Simultaneous LPS administration and Stat3 silencing enhanced the aa-nat transcription and AANAT activity to a similar extent as Stat3 inhibition without LPS co-administration. Furthermore, we describe the circadian rhythmicity in Stat3 expression and the phosphorylated form of STAT3 protein in the rat pineal gland. Our data suggest that the higher nocturnal endogenous level of STAT3 in the pineal gland decelerates or hampers the process of NA-induced AANAT activation or affects the AANAT enzyme stability.
The Inhibitory Effect of Noscapine on the In Vitro Cathepsin G-Induced Collagen Expression in Equine Endometrium
Authors: Amaral Ana , Fernandes Carina , Szóstek-Mioduchowska Anna , Lukasik Karolina , Rebordão Maria Rosa , Pinto-Bravo Pedro , Skarzynski Dariusz Jan , Ferreira-Dias Graça
Published: October 2021

Cathepsin G (CAT) is a protease released by neutrophils when forming neutrophil extracellular traps that was already associated with inducing type I collagen (COL1) in equine endometrium in vitro. Endometrosis is a fibrotic condition mainly characterized by COL1 deposition in the equine endometrium. The objective was to evaluate if noscapine (an alkaloid for cough treatment with anti-neoplastic and anti-fibrotic properties) would reduce COL1A2 transcription (evaluated by qPCR) and COL1 protein relative abundance (evaluated by western blot) induced by CAT in equine endometrial explants from follicular and mid-luteal phases treated for 24 or 48 h. The explants treated with CAT increased COL1 expression. Noscapine decreased COL1A2 transcription at both estrous cycle phases, but COL1 relative protein only at the follicular phase, both induced by CAT. Additionally, the noscapine anti-fibrotic action was found to be more effective in the follicular phase. The CAT treatment caused more fibrosis at the longest period of treatment, while noscapine acted better at the shortest time of treatment. Our results showed that noscapine could act as an anti-fibrotic drug in equine endometrosis by inhibiting CAT in vitro. Noscapine offers a new promising therapeutic tool for treating fibrosis as a single non-selective agent to be considered in the future.
Genetics and Cognitive Vulnerability to Sleep Deprivation in Healthy Subjects: Interaction of ADORA2A, TNF-α and COMT Polymorphisms
Authors: Erblang Mégane , Drogou Catherine , Gomez-Merino Danielle , Rabat Arnaud , Guillard Mathias , Beers Pascal , Quiquempoix Michael , Boland Anne , Deleuze Jean , Olaso Robert , Derbois Céline , Prost Maxime , Dorey Rodolphe , Léger Damien , Thomas Claire , Chennaoui Mounir , Sauvet Fabien
Published: October 2021

Several genetic polymorphisms differentiate between healthy individuals who are more cognitively vulnerable or resistant during total sleep deprivation (TSD). Common metrics of cognitive functioning for classifying vulnerable and resilient individuals include the Psychomotor Vigilance Test (PVT), Go/noGo executive inhibition task, and subjective daytime sleepiness. We evaluated the influence of 14 single-nucleotide polymorphisms (SNPs) on cognitive responses during total sleep deprivation (continuous wakefulness for 38 h) in 47 healthy subjects (age 37.0 ± 1.1 years). SNPs selected after a literature review included SNPs of the adenosine-A2A receptor gene (including the most studied rs5751876), pro-inflammatory cytokines (TNF-α, IL1-β, IL-6), catechol-O-methyl-transferase (COMT), and PER3. Subjects performed a psychomotor vigilance test (PVT) and a Go/noGo-inhibition task, and completed the Karolinska Sleepiness Scale (KSS) every 6 h during TSD. For PVT lapses (reaction time >500 ms), an interaction between SNP and SDT (p < 0.05) was observed for ADORA2A (rs5751862 and rs2236624) and TNF-α (rs1800629). During TSD, carriers of the A allele for ADORA2A (rs5751862) and TNF-α were significantly more impaired for cognitive responses than their respective ancestral G/G genotypes. Carriers of the ancestral G/G genotype of ADORA2A rs5751862 were found to be very similar to the most resilient subjects for PVT lapses and Go/noGo commission errors. Carriers of the ancestral G/G genotype of COMT were close to the most vulnerable subjects. ADORA2A (rs5751862) was significantly associated with COMT (rs4680) (p = 0.001). In conclusion, we show that genetic polymorphisms in ADORA2A (rs5751862), TNF-α (rs1800629), and COMT (rs4680) are involved in creating profiles of high vulnerability or high resilience to sleep deprivation. (NCT03859882).
Effect of Weather Aging on Viscoelasticity and Fatigue Performance of Asphalt Mastic
Authors: Xu Gang , Zhou Yixin , Zhu Yu , Wang Rui , Chen Xianhua
Published: October 2021

The long-term effect of climate factors, such as sunlight, oxygen, and water, leads to the performance degradation of the asphalt mastic, which is the binding part in the asphalt mixture. It is not conducive to satisfy the long-term performance requirements of long-life asphalt pavement. In this study, five kinds of base asphalt mastic and styrene-butadiene-styrene (SBS) modified asphalt mastic were prepared with the filler-asphalt ratio of 0.6, 0.8, 1.0, 1.2, and 1.4. The indoor simulated weather aging tests were carried out considering multi-factors including sunlight, oxygen, and water. The master curves of the complex shear modulus and phase angle of the asphalt mastic with different aging degrees were obtained by the frequency sweep test. The curves of fatigue damage characteristics and fatigue life were fitted based on the viscoelastic continuum damage (VECD) model. The influence of weather aging on the viscoelasticity and fatigue performance of asphalt mastic were analyzed. Results indicated that the effect of weather aging increases the elastic component and decreases the viscous component. The fatigue performance of SBS modified asphalt mastic was better than that of base asphalt mastic. As the aging degree deepens, the brittle failure characteristics of asphalt mastic with a higher filler–asphalt ratio were more obvious. The base asphalt mastic becomes more sensitive to the strain level due to weather aging, and its fatigue life increased under the low strain loading and decreased under the high strain loading. The fatigue performance of SBS modified asphalt mastic was less sensitive to the strain level. The fatigue life reduced after aging under low and high strain load. Taking the impact of weather aging on the fatigue performance into consideration, the optimal filler–asphalt ratios of the base asphalt mastic SBS modified asphalt mastic are 1.0 and 1.2, respectively.
Syntheses, Structures and Properties of Alkali and Alkaline Earth Metal Diamond-Like Compounds Li2MgMSe4 (M = Ge, Sn)
Authors: Gao Hongbo , Zhang Kewang , Abudurusuli Ailijiang , Bai Chen , Yang Zhihua , Lai Kangrong , Li Junjie , Pan Shilie
Published: October 2021

Two new diamond-like (DL) chalcogenides, Li2MgGeSe4 and Li2MgSnSe4, have been successfully synthesized using a conventional high-temperature solid-state method. The two compounds crystallize in the non-centrosymmetric space group Pmn21 with a = 8.402 (14) Å, b = 7.181 (12) Å, c = 6.728 (11) Å, Z = 2 for Li2MgSnSe4, and a = 8.2961 (7) Å, b = 7.0069 (5) Å, c = 6.6116 (6) Å, Z = 2 for Li2MgGeSe4. The calculated results show that the second harmonic generation (SHG) coefficients of Li2MgSnSe4 (d33 = 12.19 pm/v) and Li2MgGeSe4 (d33 = −14.77 pm/v), mainly deriving from the [MSe4] (M = Ge, Sn) tetrahedral units, are close to the one in the benchmark AgGaS2 (d14 = 13.7 pm/V). The calculated band gaps for Li2MgSnSe4 and Li2MgGeSe4 are 2.42 and 2.44 eV, respectively. Moreover, the two compounds are the first series of alkali and alkaline-earth metal DL compounds in the I2-II-IV-VI4 family, enriching the structural diversity of DL compounds.
Enhanced Fluidity of ZL205A Alloy with the Combined Addition of Al–Ti–C and La
Authors: Zhang Guowei , Wang Zhaojie , Niu Jingwei , Xu Hong , Ren Xiaoyan
Published: October 2021

The effects of Al–Ti–C and La on the fluidity of a ZL205A alloy after separate and combined addition were studied by conducting a fluidity test. The fluidity of the ZL205A alloy first increased and then decreased with the increasing addition of Al–Ti–C and La; it peaked at 0.3% and 0.1% for Al–Ti–C and La, respectively. The combined addition of Al–Ti–C and La led to better fluidity, which increased by 74% compared with the base alloy. The affecting mechanism was clarified through microstructure characterization and a DSC test. The heterogeneous nucleation aided by Al–Ti–C and La, the number of particles in the melt, and the evolution of the solidification range all played a role. Based on the evolution of the fluidity and grain size, the optimal levels of Al–Ti–C and La leading to both high fluidity and small grain size were identified.
The Effect of Waste Plastics on the Ageing Phenomenon of Bituminous Binders and Asphalt Mixtures
Authors: Hall Finn , White Greg
Published: October 2021

The push for environmental sustainability in the civil engineering industry has resulted in an increased interest in the use of recycled construction materials, with one example being the use of waste plastic for the modification of bituminous binder in asphalt mixtures. Existing research has associated waste plastics with various binder and asphalt mixture performance enhancing properties. However, there is a lack of research on the age-related durability of waste plastic-modified roads. This research compared the effect of commercially available waste plastic binder modifiers on the ageing phenomenon of bituminous binders and asphalt mixtures, to the effect of conventional polymers SBS and EVA, through artificial bituminous binder and asphalt mixture ageing performed in a laboratory. The addition of polymers (both waste and virgin) resulted in an increase in binder stiffness after short-term ageing as the polymer content increased. The effect of the waste plastic on ageing was comparable to the effects associated with the conventional polymers, and it was concluded that the waste plastic binder modified products should be considered sustainable alternatives to standard polymers for bituminous binder and asphalt mixture modification.
Instability of the Homogeneous Distribution of Chemical Waves in the Belousov–Zhabotinsky Reaction
Authors: Suematsu Nobuhiko J. , Nakata Satoshi
Published: October 2021

Chemical traveling waves play an important role in biological functions, such as the propagation of action potential and signal transduction in the nervous system. Such chemical waves are also observed in inanimate systems and are used to clarify their fundamental properties. In this study, chemical waves were generated with equivalent spacing on an excitable medium of the Belousov–Zhabotinsky reaction. The homogeneous distribution of the waves was unstable and low- and high-density regions were observed. In order to understand the fundamental mechanism of the observations, numerical calculations were performed using a mathematical model, the modified Oregonator model, including photosensitive terms. However, the homogeneous distribution of the traveling waves was stable over time in the numerical results. These results indicate that further modification of the model is required to reproduce our experimental observations and to discover the fundamental mechanism for the destabilization of the homogeneous-distributed chemical traveling waves.
Optimization Method of Tool Parameters and Cutting Parameters Considering Dynamic Change of Performance Indicators
Authors: Yue Daxun , Zhang Anshan , Yue Caixu , Liu Xianli , Li Mingxing , Hu Desheng
Published: October 2021

In the process of metal cutting, the cutting performance of cutting tools varies with different parameter combinations, so the results of the performance indicators studied are also different. So in order to achieve the best performance indicator it is necessary to get the best parameter matching combination. In addition, in the process of metal cutting, the value of the performance index is different at each stage of the processing process. In order to consider the cutting process more comprehensively, it is necessary to use a comprehensive evaluation method that can evaluate the dynamic process of performance indicators. This paper uses a dynamic evaluation method that considers the dynamic change of performance indicators in each stage of the cutting process to comprehensively evaluate the tool parameters and cutting parameters at each level. For the purpose of high processing efficiency and long tool life, tool wear rate and material removal rate are used as performance indicators. In the case of specified rake angle, cutting speed and cutting width, titanium alloy is studied by end milling cutter side milling. The tool parameters and cutting parameters in milling process are optimized by using a dynamic comprehensive evaluation method based on gain horizontal excitation. Finally, the parameter matching combination that can make the performance indicator reach the best is obtained. The results show that when the rake angle is 8°, the cutting speed is 37.68 m/min, and the cutting width is 0.2 mm, the tool wear rate and material removal rate are the best when the clearance angle is 9°, the helix angle is 30°, the feed per tooth is 0.15 mm/z, and the cutting depth is 2.5 mm.
Retention of Pollutants Elements from Mine Tailings of Lead in Geopolymers for Construction
Authors: Terrones-Saeta Juan María , Suárez-Macías Jorge , Castañón Ana María , Gómez-Fernández Fernando , Corpas-Iglesias Francisco Antonio
Published: October 2021

The construction sector is one of the most demanding sectors of raw materials in existence today. As a consequence, the extraction of these materials has a significant impact on the environment. At the same time, mining activities produce a series of wastes, in some cases with polluting elements, which must be treated to avoid pollution. Therefore, the use of mining waste for the conformation of new construction materials is an important environmental advantage, even more so when such waste is prevented from producing polluting leachates. Therefore, in this research, geopolymers are developed with mine tailings from the Linares lead mines, chemically activated with potassium hydroxide. For this purpose, different percentages of the alkaline activator were tested and the physical and mechanical properties of the conformed materials were evaluated. The analysis of the different conformed geopolymers determined the optimum percentage of potassium hydroxide for conforming the geopolymer with the best mechanical and physical properties. In addition, the concentration in the leachate of potentially contaminating chemical elements in the mining waste was estimated to be lower than those regulated by the regulations. Consequently, this research shows the development of a sustainable material for construction with mining waste and reduction of the environmental impact of traditional products.
Development and Investigation of an Inexpensive Low Frequency Vibration Platform for Enhancing the Performance of Electrical Discharge Machining Process
Authors: Mertiya Abhimanyu Singh , Upadhyay Aman , Nirwan Kaustubh , Harane Pravin Pandit , Abdul-Rani Ahmad Majdi , Pruncu Catalin Iulian , Unune Deepak Rajendra
Published: October 2021

Difficulty in debris removal and the transport of fresh dielectric into discharge gap hinders the process performance of electrical discharge machining (EDM) process. Therefore, in this work, an economical low frequency vibration platform was developed to improve the performance of EDM through vibration assistance. The developed vibratory platform functions on an eccentric weight principle and generates a low frequency vibration in the range of 0–100 Hz. The performance of EDM was evaluated in terms of the average surface roughness (Ra), material removal rate (MRR), and tool wear rate (TWR) whilst varying the input machining parameters viz. the pulse-on-time (Ton), peak current (Ip), vibration frequency (VF), and tool rotational speed (TRS). The peak current was found to be the most significant parameter and contributed by 78.16%, 65.86%, and 59.52% to the Ra, MRR, and TWR, respectively. The low frequency work piece vibration contributed to an enhanced surface finish owing to an improved flushing at the discharge gap and debris removal. However, VF range below 100 Hz was not found to be suitable for the satisfactory improvement of the MRR and reduction of the TWR in an electrical discharge drilling operation at selected machining conditions.
Adsorption Features of Various Inorganic Materials for the Drug Removal from Water and Synthetic Urine Medium: A Multi-Technique Time-Resolved In Situ Investigation
Authors: Boccaleri Enrico , Marzetti Cristina , Celoria Giorgio , Cassino Claudio , Paul Geo , Miletto Ivana , Gianotti Enrica
Published: October 2021

Pharmaceutical active compounds, including hundreds of different substances, are counted among the emerging contaminants in waterbodies, whose presence raises a growing concern for the ecosystem. Drugs are metabolized and excreted mainly through urine as an unchanged active ingredient or in the form of metabolites. These emerging contaminants are not effectively removed with the technologies currently in use, making them a relevant environmental problem. This study proposes the treatment of urine and water at the source that can allow an easier removal of dissolved drugs and metabolites. The treatment of synthetic urine, with dissolved ibuprofen as a model compound, by adsorption, using various classes of inorganic materials, such as clays, hierarchical zeolites and ordered mesoporous silica (MCM-41), is presented. A multi-technique approach involving X-ray powder diffraction, solid-state NMR, UV-Vis and Raman spectroscopies was employed to investigate the adsorption process in inorganic adsorbents. Moreover, the uptake, the ensuing competition, the efficiency and selectivity as well as the packing of the model compound in ordered mesoporous silica during the incipient wetness impregnation process were all thoroughly monitored by a novel approach, involving combined complementary time-resolved in situ 1H and 13C MAS NMR spectroscopy as well as X-ray powder diffraction.
Critical State Theory for the Magnetic Coupling between Soft Ferromagnetic Materials and Type-II Superconductors
Authors: Fareed Muhammad U. , Ruiz Harold S.
Published: October 2021

Improving our understanding of the physical coupling between type-II superconductors (SC) and soft ferromagnetic materials (SFM) is the root for progressing to the application of SC-SFM metastructures in scenarios such as magnetic cloaking, magnetic shielding, and power transmission systems. However, in the latter, some intriguing and yet unexplained phenomena occurred, such as a noticeable rise in the SC energy losses, and a local but not isotropic deformation of its magnetic flux density. These phenomena, which are in apparent contradiction with the most fundamental theory of electromagnetism for superconductivity, that is, the critical state theory (CST), have remained unexplained for about 20 years, given the acceptance of the controversial and yet paradigmatic existence of the so-called overcritical current densities. Therefore, aiming to resolve these long-standing problems, we extended the CST by incorporating a semi-analytical model for cylindrical monocore SC-SFM heterostructures, setting the standards for its validation with a variational approach of multipole functionals for the magnetic coupling between Sc and SFM materials. It is accompanied by a comprehensive numerical study for SFM sheaths of arbitrary dimensions and magnetic relative permeabilities μr, ranging from μr=5 (NiZn ferrites) to μr = 350,000 (pure Iron), showing how the AC-losses of the SC-SFM metastructure radically changes as a function of the SC and the SFM radius for μr≥100. Our numerical technique and simulations also revealed a good qualitative agreement with the magneto optical imaging observations that were questioning the CST validness, proving therefore that the reported phenomena for self-field SC-SFM heterostructures can be understood without including the ansatz of overcritical currents.
Effects of Artificial Tooth Brushing and Hydrothermal Aging on the Mechanical Properties and Color Stability of Dental 3D Printed and CAD/CAM Materials
Authors: Nam Na-Eun , Shin Seung-Ho , Lim Jung-Hwa , Shim June-Sung , Kim Jong-Eun
Published: October 2021

This study analyzed the surface roughness and waviness, Vickers hardness (VHN), and color changes of six types of 3D printed resins and computer-aided design/computer-aided manufacturing (CAD/CAM) materials after artificial toothbrushing. The average surface roughness height (Ra) change of Formlabs denture teeth A2 resin (FMLB) was not significant between after artificial toothbrushing (0.17 ± 0.02 μm and 0.17 ± 0.05 μm, respectively; mean ± standard deviation). However, the Ra value increased significantly in all remaining groups. Regarding waviness, polymethylmethacrylate (PMMA) had the largest increases in average waviness height (Wa) and maximum surface waviness height (Wz) between, before (0.43 ± 0.23 μm and 0.08 ± 0.02 μm), and after (8.67 ± 4.03 μm, 1.30 ± 0.58 μm) toothbrushing. There were no significant changes in Wa for Formlabs denture teeth A2 resin (FMLB) and NextDent C&B (NXT). After artificial toothbrushing, the dispersed-filler composite (DFC) group had the largest color difference (ΔE, of 2.4 ± 0.9), and the remaining materials had smaller changes than the clinical acceptance threshold of ΔE = 2.25. The VHN of FMLB and NXT were 9.1 ± 0.4 and 15.5 ± 0.4, respectively, and were not affected by artificial toothbrushing. The flexural strengths of the 3D printed materials were 139.4 ± 40.5 MPa and 163.9 ± 14.0 MPa for FMLB and NXT, respectively, which were similar to those of the polycarbonate and PMMA groups (155.2 ± 23.6 MPa and 108.0 ± 8.1 MPa, respectively). This study found that the evaluated 3D printed materials had mechanical and optical properties comparable to those of CAD/CAM materials and were stable even after artificial toothbrushing and hydrothermal aging.
Lagrangian Differencing Dynamics for Time-Independent Non-Newtonian Materials
Authors: Bašić Martina , Blagojević Branko , Peng Chong , Bašić Josip
Published: October 2021

This paper introduces a novel meshless and Lagrangian approach for simulating non-Newtonian flows, named Lagrangian Differencing Dynamics (LDD). Second-order-consistent spatial operators are used to directly discretize and solve generalized Navier–Stokes equations in a strong formulation. The solution is obtained using a split-step scheme, i.e., by decoupling the solutions of the pressure and velocity. The pressure is obtained by solving a Poisson equation, and the velocity is solved in a semi-implicit formulation. The matrix-free solution to the equations, and Lagrangian advection of mesh-free nodes allowed for a fully parallelized implementation on the CPU and GPU, which ensured an affordable computing time and large time steps. A set of four benchmarks are presented to demonstrate the robustness and accuracy of the proposed formulation. The tested two- and three-dimensional simulations used Power Law, Casson and Bingham models. An Abram slump test and a dam break test were performed using the Bingham model, yielding visual and numerical results in accordance with the experimental data. A square lid-driven cavity was tested using the Casson model, while the Power Law model was used for a skewed lid-driven cavity test. The simulation results of the lid-driven cavity tests are in good agreement with velocity profiles and stream lines of published reports. A fully implicit scheme will be introduced in future work. As the method precisely reproduces the pressure field, non-Newtonian models that strongly depend on the pressure will be validated.
Special Issue “Corrosion in Concrete: Inhibitors and Coatings”
Authors: Coppola Luigi
Published: October 2021

The climatic changes that are taking place in recent years have increased awareness of the importance of environmental protection and the urgent need for industrial strategies aimed at a sustainable development [...]
Space Maintainers Used in Pediatric Dentistry: An Insight of Their Biosecurity Profile by Applying In Vitro Methods
Authors: Luca Magda Mihaela , Popa Malina , Watz Claudia G. , Pinzaru Iulia , Draghici George Andrei , Mihali Ciprian V. , Dehelean Cristina Adriana , Buzatu Roxana , Szuhanek Camelia
Published: October 2021

Space maintainers have presented an increased interest due to their chemical composition which influences the electrochemical and electrolytic processes of the oral cavity, leading to important biological activity. The present study was purported to evaluate the biological in vitro activity of three types of space maintainers (S1, S2, and S3, differing from each other in terms of metal composition) used in pediatric dentistry, in terms of their antimicrobial effect and biosecurity profile using two types of keratinocytes (PGK: primary gingival keratinocytes, and HaCaT: human immortalized keratinocytes) by assessing the morphology, viability, cytotoxicity, and gene expression of the cells. Statistical differences were calculated by the one-way ANOVA test, followed by Tukey’s post-test. Antimicrobial screening highlighted a dilution-dependent influence that, in the case of all strains tested, did not show inhibition or stimulation of bacterial growth. The in vitro evaluations revealed that the test samples did not induce important cytotoxic potential on both keratinocyte cell lines (HaCaT and PGK), with the cells manifesting no morphological alteration, a good viability rate (above 90%: PGK–S1, * p < 0.05), and a low cytotoxic activity (less than 11%: PGK, S1 *** p < 0.001 and S3 * p < 0.05; HaCaT, S1 ** p < 0.01). The data obtained in this study highlight the fact that the samples analyzed are biocompatible and do not develop the growth of the studied bacteria or encode the gene expression of primary and immortalized keratinocytes.
Dialkyl Succinates and Adipates as Alternative Plasticizers—Even More Efficient Synthesis
Authors: Barteczko Natalia , Więcławik Justyna , Tracz Anna , Pankalla Ewa , Erfurt Karol , Latos Piotr , Boncel Sławomir , Matuszek Karolina , Chrobok Anna
Published: October 2021

As a result of strict regulations of phthalate plasticizers, alternative non-phthalate forms are desired and increasingly used. This work presents a synthetic method for alternative plasticizers (dialkyl succinates and adipates) via esterification of succinic and adipic acid with alcohols: butan-1-ol and 2-ethylhexan-1-ol. Ionic liquids were synthesized by the reaction of triethylamine with over-equimolar (1:2.7) amounts of sulfuric(VI) acid, which were used as an acidic catalyst and solvent. The two-phase liquid–liquid system was formed during the reaction due to immiscibility of the esters with the ionic liquid. This phenomenon is a driving force of this process, shifting the equilibrium toward the product formation. As a result, dialkyl succinates and adipates were obtained in high yields (99%) and selectivities (>99%), under mild reaction conditions at 70–80 °C and using a 4:1 molar ratio of alcohol to acid and 15 mol% of catalyst. The catalyst was recycled 10 times without any loss of activity. This alternative method is highly competitive: it involves a simple procedure for product isolation as well as a high yield and purity of the resulting esters. These advantages make this method sustainable and promising for industrial applications.
The Influence of Physical Properties and Increasing Woven Fabric Layers on the Noise Absorption Capacity
Authors: Samuel Bethalihem Teferi , Barburski Marcin , Witczak Ewa , Jasińska Izabela
Published: October 2021

Noise pollution from the environment may wreak havoc on a person’s wellbeing. Numerous sound-absorbing materials are employed to address these issues, one of which is textile-woven fabrics. In this study, 12 woven textiles with four different weave structures (plain, rib, sateen, and twill) and those formed from three distinct polyester yarns were evaluated for their sound absorption properties using an impedance tube. The study was conducted within the range of 80–5000 (Hz) frequency. Part of the investigation was measuring different layers of woven fabrics under three different measuring conditions. Firstly, only woven fabrics were evaluated. Following that, woven and nonwoven textiles were measured. The third variant, in addition to the woven fabrics, included an air gap. In addition, this study includes tests and analyses of the effect of roughness and porosity of the fabric structure on the effectiveness of noise reduction by woven fabrics. The absorption capacity of plain fabric is higher at lower frequencies than other woven fabrics. Other weave structures noise reduction efficiency is higher as the frequency range increases. The absorption efficiency of plain fabric decreases with fabric layering. Utilizing woven fabric combined with nonwoven fabric reduces noise more effectively than the air gap variant. Low surface roughness and a highly porous surface of the fabric indicate a high noise reduction coefficient (NRC).
Numerical Investigation of Composite Behavior and Strength of Rectangular Concrete-Filled Cold-Formed Steel Tubular Stub Columns
Authors: Wang Liping , An Yanan , Ding Faxing , Kuang Yachuan , Ma Qing , Tan Sui , Zhang Weizhen , Zhao Pengzhou , Ren Enhui
Published: October 2021

The objective of this study was to investigate the composite behavior of rectangular concrete-filled cold-formed steel (CFS) tubular stub columns under axial compression. A fine finite 3D solid element model of rectangular concrete-filled cold-formed steel tubular stub column was established by ABAQUS, which utilized a constitutive model of cold-formed steel considering the cold-forming effect and a triaxial plastic-damage constitutive model of the infilled concrete. Good agreement was achieved and the average discrepancy between the experimental and FE results was less than 5%. Based on the verified models, a further parametric analysis was carried out to reveal the influence of various factors on the strength and behavior of the concrete-filled rectangular cold-formed steel tubular stub columns. The factors included constitutive models adopted for cold-formed steel, length over width ratio of the rectangular section, wall-thickness and width, and concrete strength and yield strength of the cold-formed steel. A total of 144 FE models were analyzed. The stress nephogram was reasonably simplified in accordance with the limit state and a theoretical formula considering confinement coefficient was proposed to estimate the ultimate bearing capacity of concrete-filled rectangular cold-formed steel tubular stub columns using the superposition method. The calculated results showed satisfactory agreement with both the experimental and FE results, which proved the validity and accuracy of the formula proposed in this paper. In the proposed formula, the confinement coefficient of square concrete-filled cold-formed steel tubular stub columns is larger than that of hot-rolled steel counterparts but smaller than that of the stainless steel counterparts.
A Method for Characterising the Influence of Casting Parameters on the Metallurgical Bonding of Copper and Steel Bimetals
Authors: Kammerloher Simon , Hoyer Julika , Lechner Philipp , Mittler Tim , Volk Wolfram
Published: October 2021

Traditional casting technology offers two mayor drawbacks towards research activities. On the one hand, time and resources needed for every casting are rather high. The mould has to be able to withstand the high temperatures introduced by the melt and provide cooling for the cast part. Preparation and installation of measuring equipment therefore takes time. Additionally, due to the high mass of the mould when compared to the cast part, parameter variations are rather limited in their resulting effect on the temperature-time profile being one of the most prominent factors regarding cast quality. Especially when pouring by hand, variations in casting times and rates superimpose effects created intentionally. Therefore, a different process was advanced and evaluated, allowing to minimise some of the drawbacks mentioned before. The key idea is to drastically reduce casting size to the dimensions of one specimen and to apply a highly automated production route. As such, a mirror furnace was modified as to allow the processing of melt. Due to the specimens size, an adaption of mechanical testing equipment was performed and evaluated. As an example, copper-iron bimetal specimens were examined by light microscopy, micro hardness testing, nanoindentation as well as tensile and torsion testing. As the results were consistent, the newly introduced method can be applied successfully in casting research. This allows for highly reproducible results, reducing the uncertainty of temperature measurements of a specimen due to the distance between them. The possibility of separating influencing variables like maximum temperature and cooling rate allows an analysis of the casting process, which would require different moulds to do so in traditional casting methods. The next steps will be directed at a broader variety of metals processed and at a direct comparison between the new process route and traditional casting technology.
Recovery of Waste Polyurethane from E-Waste—Part I: Investigation of the Oil Sorption Potential
Authors: Santucci Vincenzo , Fiore Silvia
Published: October 2021

The shredding of end-of-life refrigerators produces every year in Italy 15,000 tons of waste polyurethane foam (PUF), usually destined for energy recovery. This work presents the results of the investigation of the oil sorption potential of waste PUF according to ASTM F726–17 standard. Three oils (diesel fuel and two commercial motor oils) having different densities (respectively, 0.83, 0.87, and 0.88 kg/dm3) and viscosities (respectively, 3, 95, and 140 mm2/s at 40 °C) were considered. The waste PUF was sampled in an Italian e-waste treatment plant, and its characterization showed 16.5 wt% particles below 0.71 mm and 13 wt% impurities (paper, plastic, aluminum foil), mostly having dimensions (d) above 5 mm. Sieving at 0.071 mm was applied to the waste PUF to obtain a “coarse” (d > 0.71 mm) and a “fine” fraction (d < 0.71 mm). Second sieving at 5 mm allowed an “intermediate” fraction to be obtained, with dimensions between 0.71 and 5 mm. The oil sorption tests involved the three fractions of waste PUF, and their performances were compared with two commercial oil sorbents (sepiolite and OKO-PUR). The results of the tests showed that the “fine” PUF was able to retain 7.1–10.3 g oil/g, the “intermediate” PUF, 4.2–7.4 g oil/g, and the “coarse” PUF, 4.5–7.0 g oil/g, while sepiolite and OKO-PUR performed worse (respectively, 1.3–1.6 and 3.3–5.3 g oil/g). In conclusion, compared with the actual management of waste PUF (100 wt% sent to energy recovery), the amount destined directly to energy recovery could be limited to 13 wt% (i.e., the impurities). The remaining 87 wt% could be diverted to reuse for oil sorption, and afterward directed to energy recovery, considered as a secondary option.
Advances Brought by Hydrophilic Ionic Liquids in Fields Involving Pharmaceuticals
Authors: Dinis Teresa B. V. , e Silva Francisca A. , Sousa Fani , Freire Mara G.
Published: October 2021

The negligible volatility and high tunable nature of ionic liquids (ILs) have been the main drivers of their investigation in a wide diversity of fields, among which is their application in areas involving pharmaceuticals. Although most literature dealing with ILs is still majorly devoted to hydrophobic ILs, evidence on the potential of hydrophilic ILs have been increasingly provided in the past decade, viz., ILs with improved therapeutic efficiency and bioavailability, ILs with the ability to increase drugs’ aqueous solubility, ILs with enhanced extraction performance for pharmaceuticals when employed in biphasic systems and other techniques, and ILs displaying low eco/cyto/toxicity and beneficial biological activities. Given their relevance, it is here overviewed the applications of hydrophilic ILs in fields involving pharmaceuticals, particularly focusing on achievements and advances witnessed during the last decade. The application of hydrophilic ILs within fields involving pharmaceuticals is here critically discussed according to four categories: (i) to improve pharmaceuticals solubility, envisioning improved bioavailability; (ii) as IL-based drug delivery systems; (iii) as pretreatment techniques to improve analytical methods performance dealing with pharmaceuticals, and (iv) in the recovery and purification of pharmaceuticals using IL-based systems. Key factors in the selection of appropriate ILs are identified. Insights and perspectives to bring renewed and effective solutions involving ILs able to compete with current commercial technologies are finally provided.