bluuebunny/crossref_metadata_2025 huggingface dataset:
Categories and Frequency: Cognition Verbs in Spanish Subject Expression
Authors: Travis Catherine E. , Torres Cacoullos Rena
Published: July 2021

Are semantic classes of verbs genuine or do they merely mask idiosyncrasies of frequent verbs? Here, we examine the interplay between semantic classes and frequent verb-form combinations, providing new evidence from variation patterns in spontaneous speech that linguistic categories are centered on high frequency members to which other members are similar. We offer an account of the well-known favoring effect of cognition verbs on Spanish subject pronoun expression by considering the role of high-frequency verbs (e.g., creer ‘think’ and saber ‘know’) and particular expressions ((yo) creo ‘I think’, (yo) no sé ‘I don’t know’). Analysis of variation in nearly 3000 tokens of unexpressed and pronominal subjects in conversational data replicates well-established predictors, but highlights that the cognition verb effect is really one of 1sg cognition verbs. In addition, particular expressions stand out for their high frequency relative to their component parts (for (yo) creo, proportion of lexical type, and proportion of pronoun). Further analysis of 1sg verbs with frequent expressions as fixed effects reveals shared patterns with other cognition verbs, including an association with non-coreferential contexts. Thus, classes can be identified by variation constraints and contextual distributions that are shared among class members and are measurably different from those of the more general variable structure. Cognition verbs in variable Spanish subject expression form a class anchored in lexically particular constructions.
Definiteness Systems and Dialect Classification
Authors: Turner Mike
Published: July 2021

In this article I explore how typological approaches can be used to construct novel classification schemes for Arabic dialects, taking the example of definiteness as a case study. Definiteness in Arabic has traditionally been envisioned as an essentially binary system, wherein definite substantives are marked with a reflex of the article al- and indefinite ones are not. Recent work has complicated this model, framing definiteness instead as a continuum along which speakers can locate referents using a broader range of morphological and syntactic strategies, including not only the article al-, but also reflexes of the demonstrative series and a diverse set of ‘indefinite-specific’ articles found throughout the spoken dialects. I argue that it is possible to describe these strategies with even more precision by modeling them within cross-linguistic frameworks for semantic typology, among them a model known as the ‘Reference Hierarchy,’ which I adopt here. This modeling process allows for classification of dialects not by the presence of shared forms, but rather by parallel typological configurations, even if the forms within them are disparate.
Marrying Young: Limiting the Impact of a Crisis on the High Prevalence of Child Marriages in Niger
Authors: Deane Tameshnie
Published: July 2021

Child marriage is a harmful and discriminatory global practice, robbing millions of girls of their childhood. Global attention and momentum to end early marriage has increased over the years; however, the impact of the COVID-19 pandemic has affected this progress. It has been predicted that over the next decade up to 10–13 million more girls will be at risk of child marriage because of the pandemic. Since Niger has consistently had the highest rate of child marriage in the world, this study will explore the impact of the COVID-19 pandemic on child marriages within the west and African region but specifically within Niger. This article will look at past response efforts to other pandemics, specifically Ebola, and show how the girl-child remains disproportionately disadvantaged, especially during pandemics. The article will conclude with recommendations on the importance of incorporating a gender analysis into preparedness and response efforts to eliminate child marriages.
SBS Modified Bitumen with Organic Layered Double Hydroxides: Compatibility and Aging Effects on Rheological Properties
Authors: Zhang Canlin , Dong Hongjun , Yan Zhengli , Yu Meng , Wang Ting , Xu Shi , Jiang Zhenliang , Hu Changbin
Published: July 2021

SBS-modified bitumen (SMB) is susceptible to aging, which seriously influences its service performance and life. In order to strengthen the anti-aging ability of SMB, triethoxyvinylsilane was designed to organically modify layered double hydroxides (LDHs) and was applied to modify SMB. The dispersibility and storage stability of LDHs in SMB were markedly enhanced after triethoxyvinylsilane organic modification, and the compatibility and storage stability of SBS in bitumen were simultaneously enhanced. Compared with SMB, the introduction of LDHs and organic LDHs (OLDHs) could ameliorate the high-temperature properties of SMB, and the thermostability of SBS in bitumen at a high temperature was also distinctly improved, especially OLDHs. After aging, due to the oxidation of molecular bitumen and the degradation of molecular SBS, SMB became hardened and brittle, and the rheological properties were significantly deteriorated, which had serious impacts on the performance of SMB. LDHs can mitigate the detriment of aging to bitumen and SBS, and the deterioration of the rheological properties of SMB is obviously alleviated. As a result of the better dispersibility and storage stability, OLDHs exerted superior reinforcement of the anti-aging ability of SMB.
Investigation of Photoexcitation Energy Impact on Electron Mobility in Single Crystalline CdTe
Authors: Djurberg Viktor , Majdi Saman , Suntornwipat Nattakarn , Isberg Jan
Published: July 2021

The exceptional electronic properties of cadmium telluride (CdTe) allow the material to be used in a wide range of high energy radiation detection applications. Understanding the mechanisms of local carrier scattering is of fundamental importance to understand the charge transport in the material. Here, we investigate the effect of photoexcitation on electron transport properties in chlorine doped single crystalline cadmium telluride (SC-CdTe:Cl). For this purpose time of flight measurements were performed on SC-CdTe:Cl in order to study the electron drift mobility in the low injection regime. Measurements were made at the temperature intervals of 80 to 300 K, for an applied electric field between 270 and 1600 V/cm and for wavelengths of 532, 355 and 213 nm. We have found that the electron drift mobility was affected by the excitation energy for temperatures below 200 K. In addition, the measurements revealed that it is possible to determine impurity and shallow trap concentration by this method. The method proves to be extremely sensitive in measuring very low impurity levels and in identifying dominant scattering mechanisms.
Experimental and Numerical Investigation of the Effect of Projectile Nose Shape on the Deformation and Energy Dissipation Mechanisms of the Ultra-High Molecular Weight Polyethylene (UHMWPE) Composite
Authors: Shen Yonghua , Wang Yangwei , Yan Zhaopu , Cheng Xingwang , Fan Qunbo , Wang Fuchi , Miao Cheng
Published: July 2021

The effect of projectile nose shape on the ballistic performance of the ultra-high molecular weight polyethylene (UHMWPE) composite was studied through experiments and simulations. Eight projectiles such as conical, flat, hemispherical, and ogival nose projectiles were used in this study. The deformation process, failure mechanisms, and the specific energy absorption (SEA) ability were systematically investigated for analyzing the ballistic responses on the projectile and the UHMWPE composite. The results showed that the projectile nose shape could invoke different penetration mechanisms on the composite. The sharper nose projectile tended to shear through the laminate, causing localized damage zone on the composite. For the blunt nose projectile penetration, the primary deformation features were the combination of shear plugging, tensile deformation, and large area delamination. The maximum value of specific energy absorption (SEA) was 290 J/(kg/m2) for the flat nose projectile penetration, about 3.8 times higher than that for the 30° conical nose projectile. Furthermore, a ballistic resistance analytical model was built based on the cavity expansion theory to predict the energy absorption ability of the UHMWPE composite. The model exhibited a good match between the ballistic resistance curves in simulations with the SEA ability of the UHMWPE composite in experiments.
A Review on Microcellular Injection Moulding
Authors: Ding Yifei , Hassan Mohammed H. , Bakker Otto , Hinduja Srichand , Bártolo Paulo
Published: July 2021

Microcellular injection moulding (MuCell®) is a polymer processing technology that uses a supercritical fluid inert gas, CO2 or N2, to produce light-weight products. Due to environmental pressures and the requirement of light-weight parts with good mechanical properties, this technology recently gained significant attention. However, poor surface appearance and limited mechanical properties still prevent the wide applications of this technique. This paper reviews the microcellular injection moulding process, main characteristics of the process, bubble nucleation and growth, and major recent developments in the field. Strategies to improve both the surface quality and mechanical properties are discussed in detail as well as the relationships between processing parameters, morphology, and surface and mechanical properties. Modelling approaches to simulate microcellular injection moulding and the mathematical models behind Moldex 3D and Moldflow, the two most commonly used software tools by industry and academia, are reviewed, and the main limitations are highlighted. Finally, future research perspectives to further develop this technology are also discussed.
Key Factors Determining the Self-Healing Ability of Cement-Based Composites with Mineral Additives
Authors: Tomczak Kamil , Jakubowski Jacek , Kotwica Łukasz
Published: July 2021

This paper reveals the relationships between key factors that determine the ability of cementitious composites to self-heal autogenously and specific measures for quantifying the effects of this process. The following material factors: water-to-binder ratio (w/b), uniaxial compressive strength and age of the composite at the time of defect formation were considered, as well as the method and degree of damage to the tested material. The subjects of this study were mortars and concretes in which Portland cement was partially replaced, to varying degrees, with mechanically activated fluidized bed combustion fly ash (MAFBC fly ash) and siliceous fly ash. The samples were subjected to three-point bending or cyclic compression tests after 14 or 28 days of aging, in order to induce defects and then cured in water for 122 days. Microscopic (MO) and high-resolution scanning (HRS) observations along with computer image processing techniques were used to visualize and quantify the changes occurring in the macro-crack region near the outer surface of the material during the self-sealing process. Techniques based on the measurement of the ultrasonic pulse velocity (UPV) allowed the quantification of the changes occurring inside the damaged materials. Mechanical testing of the composites allowed quantification of the effects of the activity of the binder-supplementary cementitious materials (SCMs) systems. The analysis of the results indicates a significant influence of the initial crack width on the ability to completely close the cracks; however, there are repeated deviations from this rule and local variability of the self-sealing process. It has been shown that the compressive strength of a material is an important indicator of binder activity concerning crack width reduction due to self-sealing. Regardless of the crack induction method, the internal material changes caused by self-sealing are dependent on the degree of material damage.
Effect of Minor Er Additions on the Microstructures and Mechanical Properties of Cast Al-Cu-Mg-Ag Alloys
Authors: Xie Haoyu , Zhao Juangang , Cao Jing , Luo Lei , Guo Shuai , Ou Linnan , Liu Zhiyi , Bai Song
Published: July 2021

The microstructures and mechanical properties of novel cast Al-Cu-Mg-Ag alloys with and without minor additions of Er (0.09 and 0.2 wt %) are investigated by Vickers hardness tests, tensile tests, optical metallographic examination, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results reveal that the Er addition decreases the hardness value of peak-aged Al-Cu-Mg-Ag alloy but has little influence on the time required for achieving the peak aging condition. Meanwhile, the Ω phase is suppressed in Er-added alloys, leading to a lower tensile strength at room temperature, which causes the (Mg, Ag, Er, V, Ti)-rich phase in the matrix in Er-added alloys. This blocky phase consumes available Mg and Ag atoms for Ω nucleation, leading to the low number density of Ω plates. The strength properties of Er-added alloys at 300 °C are found to be enhanced, which benefits from the pinning effect of the Al8Cu4Er phase on grain boundaries. Meanwhile, the brittle fracture of Er-added alloys at room temperature is directly associated with the Al8Cu4Er phase and the blocky (Mg, Ag, Er, V, Ti)-rich phase, which acts as the source of microcracks during deformation. In addition, no obvious grain refinement effect can be observed in Er-added alloys.
Progress in Novel Electrodeposited Bond Coats for Thermal Barrier Coating Systems
Authors: Maniam Kranthi Kumar , Paul Shiladitya
Published: July 2021

The increased demand for high performance gas turbine engines has resulted in a continuous search for new base materials and coatings. With the significant developments in nickel-based superalloys, the quest for developments related to thermal barrier coating (TBC) systems is increasing rapidly and is considered a key area of research. Of key importance are the processing routes that can provide the required coating properties when applied on engine components with complex shapes, such as turbine vanes, blades, etc. Despite significant research and development in the coating systems, the scope of electrodeposition as a potential alternative to the conventional methods of producing bond coats has only been realised to a limited extent. Additionally, their effectiveness in prolonging the alloys’ lifetime is not well understood. This review summarises the work on electrodeposition as a coating development method for application in high temperature alloys for gas turbine engines and discusses the progress in the coatings that combine electrodeposition and other processes to achieve desired bond coats. The overall aim of this review is to emphasise the role of electrodeposition as a potential cost-effective alternative to produce bond coats. Besides, the developments in the electrodeposition of aluminium from ionic liquids for potential applications in gas turbines and the nuclear sector, as well as cost considerations and future challenges, are reviewed with the crucial raw materials’ current and future savings scenarios in mind.
Tetragonal–Cubic Phase Transition and Low-Field Dielectric Properties of CH3NH3PbI3 Crystals
Authors: Patru Roxana , Khassaf Hamidreza , Pasuk Iuliana , Botea Mihaela , Trupina Lucian , Ganea Constantin-Paul , Pintilie Lucian , Pintilie Ioana
Published: July 2021

The frequency and temperature dependence of dielectric properties of CH3NH3PbI3 (MAPI) crystals have been studied and analyzed in connection with temperature-dependent structural studies. The obtained results bring arguments for the existence of ferroelectricity and aim to complete the current knowledge on the thermally activated conduction mechanisms, in dark equilibrium and in the presence of a small external a.c. electric field. The study correlates the frequency-dispersive dielectric spectra with the conduction mechanisms and their relaxation processes, as well as with the different transport regimes indicated by the Nyquist plots. The different energy barriers revealed by the impedance spectroscopy highlight the dominant transport mechanisms in different frequency and temperature ranges, being associated with the bulk of the grains, their boundaries, and/or the electrodes’ interfaces.
Residual Probability Function for Dependent Lifetimes
Authors: Mesfioui Mhamed , Kayid Mohamed
Published: July 2021

In this paper, the residual probability function is applied to analyze the survival probability of two used components relative to each other in the case when their lifetimes are dependent. The expression of the function by copulas has been derived along with some examples of particular copulas. The behaviour of the residual probability function in terms of the underlying dependence is also discussed. The residual probability order is also considered in the dependent case. In the class of Archimedean survival copulas, we prove that the residual probability order implies the usual stochastic order in the reversed direction, and the hazard rate order concludes the residual probability order.
Predator–Prey Models: A Review of Some Recent Advances
Authors: Diz-Pita Érika , Otero-Espinar M. Victoria
Published: July 2021

In recent years, predator–prey systems have increased their applications and have given rise to systems which represent more accurately different biological issues that appear in the context of interacting species. Our aim in this paper is to give a state-of-the-art review of recent predator–prey models which include some interesting characteristics such as Allee effect, fear effect, cannibalism, and immigration. We compare the qualitative results obtained for each of them, particularly regarding the equilibria, local and global stability, and the existence of limit cycles.
On Robust Saddle-Point Criterion in Optimization Problems with Curvilinear Integral Functionals
Authors: Treanţă Savin , Das Koushik
Published: July 2021

In this paper, we introduce a new class of multi-dimensional robust optimization problems (named (P)) with mixed constraints implying second-order partial differential equations (PDEs) and inequations (PDIs). Moreover, we define an auxiliary (modified) class of robust control problems (named (P)(b¯,c¯)), which is much easier to study, and provide some characterization results of (P) and (P)(b¯,c¯) by using the notions of normal weak robust optimal solution and robust saddle-point associated with a Lagrange functional corresponding to (P)(b¯,c¯). For this aim, we consider path-independent curvilinear integral cost functionals and the notion of convexity associated with a curvilinear integral functional generated by a controlled closed (complete integrable) Lagrange 1-form.
Cytotoxic Minor Piericidin Derivatives from the Actinomycete Strain Streptomyces psammoticus SCSIO NS126
Authors: Li Kunlong , Su Ziqi , Gao Yongli , Lin Xiuping , Pang Xiaoyan , Yang Bin , Tao Huaming , Luo Xiaowei , Liu Yonghong , Zhou Xuefeng
Published: July 2021

The mangrove-sediment-derived actinomycete strain Streptomyces psammoticus SCSIO NS126 was found to have productive piericidin metabolites featuring anti-renal cell carcinoma activities. In this study, in order to explore more diverse piericidin derivatives, and therefore to discover superior anti-tumor lead compounds, the NS126 strain was further fermented at a 300-L scale under optimized fermentation conditions. As a result, eight new minor piericidin derivatives (piericidins L-R (1–7) and 11-demethyl-glucopiericidin A (8)) were obtained, along with glucopiericidin B (9). The new structures including absolute configurations were determined by spectroscopic methods coupled with experimental and calculated electronic circular dichroism. We also proposed plausible biosynthetic pathways for these unusual post-modified piericidins. Compounds 1 and 6 showed selective cytotoxic activities against OS-RC-2 cells, and 2–5 exhibited potent cytotoxicity against HL-60 cells, with IC50 values lower than 0.1 μM. The new piericidin glycoside 8 was cytotoxic against ACHN, HL-60 and K562, with IC50 values of 2.3, 1.3 and 5.5 μM, respectively. The ability to arrest the cell cycle and cell apoptosis effects induced by 1 and 6 in OS-RC-2 cells, 2 in HL-60 cells, and 8 in ACHN cells were then further investigated. This study enriched the structural diversity of piericidin derivatives and confirmed that piericidins deserve further investigations as promising anti-tumor agents.
Systematic Review Shows Tele-Rehabilitation Might Achieve Comparable Results to Office-Based Rehabilitation for Decreasing Pain in Patients with Knee Osteoarthritis
Authors: Latif-Zade Tamila , Tucci Brian , Verbovetskaya Danna , Bialkin Elizabeth , Ng Brian , Heddon Stephan , Berteau Jean-Philippe
Published: July 2021

Background and Objectives This systematic review aims to evaluate the efficacy of Tele-Rehabilitation for decreasing pain in patients with knee osteoarthritis (OA). Materials and Methods: Following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), three electronic databases (CINAHL, PubMed, PEDro), along with the addition of grey literature, were used to collect information. Randomized control trials (RCTs) comparing tele-rehabilitation (TR) to office-based-rehabilitation (OB) were critically appraised using the 2005 University of Oxford Standard. A total of 139 articles (PubMed = 132, CINAHL = 5, PEDro = 0, grey literature = 2) were acquired. Results: After the screening, three RCTs were included in our review. Their results show no statistically significant differences between TR and OB intervention. Furthermore, their results showed an overall reduction in pain in both groups from the baseline to the end of the study. However, each intervention’s clinical efficiency was dependent on the exercise protocol itself and not on the method of delivery. There is a potential ceiling effect to the amount of therapy a patient can receive in which additional therapy would no longer lead to improved recovery. Conclusions: Our review suggests evidence that TR’s efficacy is similar to that of OB for improvement of WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) score parameters in patients suffering from knee OA.
Bacterial Infection-Mimicking Three-Dimensional Phagocytosis and Chemotaxis in Electrospun Poly(ε-caprolactone) Nanofibrous Membrane
Authors: Lee Seung-Jun , Maza Perry Ayn Mayson A , Sun Gyu-Min , Slama Petr , Lee In-Jeong , Kwak Jong-Young
Published: July 2021

In this study, we developed a three-dimensional (3D) in vitro infection model to investigate the crosstalk between phagocytes and microbes in inflammation using a nanofibrous membrane (NM). Poly(ε-caprolactone) (PCL)-NMs (PCL-NMs) were generated via electrospinning of PCL in chloroform. Staphylococcus aureus and phagocytes were able to adhere to the nanofibers and phagocytes engulfed S. aureus in the PCL-NM. The migration of phagocytes to S. aureus was evaluated in a two-layer co-culture system using PCL-NM. Neutrophils, macrophages and dendritic cells (DCs) cultured in the upper PCL-NM layer migrated to the lower PCL-NM layer containing bacteria. DCs migrated to neutrophils that cultured with bacteria and then engulfed neutrophils in two-layer system. In addition, phagocytes in the upper PCL-NM layer migrated to bacteria-infected MLE-12 lung epithelial cells in the lower PCL-NM layer. S. aureus-infected MLE-12 cells stimulated the secretion of tumor necrosis factor-α and IL-1α in 3D culture conditions, but not in 2D culture conditions. Therefore, the PCL-NM-based 3D culture system with phagocytes and bacteria mimics the inflammatory response to microbes in vivo and is applicable to the biomimetic study of various microbe infections.
Effect of Mn Content on the Reaction between Fe-xMn (x = 5, 10, 15, and 20 Mass pct) Steel and CaO-SiO2-Al2O3-MgO Slag
Authors: Yu Huixiang , Li Muming , Zhang Jiaming , Yang Dexin
Published: July 2021

Medium- and high-Mn steels have excellent properties but are very difficult to be commercially produced because of the high content of some alloy elements. To enhance the understanding of the reaction between medium/high-Mn steel and refining slag which is significantly different from the conventional steels, steel and slag composition and the inclusions were investigated by equilibrium reaction between Fe-xMn (x = 5, 10, 15, and 20 mass pct) and CaO-SiO2-Al2O3-MgO top slag at 1873 K in the laboratory. Furthermore, the effect of Mn content on inclusion transformation and steel cleanliness was also explored. After slag–steel reaction, both contents of MnO in slag and Si in steel increased. Most MnO inclusions in master steel transformed to MnO-SiO2 and MnO-Al2O3-MgO. With the increase in Mn content, the amount share of MnO type inclusions decreased and that of MnO-Al2O3-MgO type increased. In addition, both the number density of observed inclusions and the calculated oxygen content in inclusions increased. Thermodynamic analysis indicates that the composition change of steel and slag and the transformation of inclusions are mainly the consequence of the reaction between Mn in molten steel and SiO2 and MgO in top slag. The dissolved Mn in medium/high-Mn steel presents a strong reactivity.
Residue Valorization in the Iron and Steel Industries: Sustainable Solutions for a Cleaner and More Competitive Future Europe
Authors: Rieger Johannes , Colla Valentina , Matino Ismael , Branca Teresa Annunziata , Stubbe Gerald , Panizza Andrea , Brondi Carlo , Falsafi Mohammadtaghi , Hage Johannes , Wang Xuan , Voraberger Bernhard , Fenzl Thomas , Masaguer Victoria , Faraci Eros Luciano , di Sante Loredana , Cirilli Filippo , Loose Florian , Thaler Christoph , Soto Aintzane , Frittella Piero , Foglio Gianpaolo , di Cecca Cosmo , Tellaroli Mattia , Corbella Marco , Guzzon Marta , Malfa Enrico , Morillon Agnieszka , Algermissen David , Peters Klaus , Snaet Delphine
Published: July 2021

The steel industry is an important engine for sustainable growth, added value, and high-quality employment within the European Union. It is committed to reducing its CO2 emissions due to production by up to 50% by 2030 compared to 1990′s level by developing and upscaling the technologies required to contribute to European initiatives, such as the Circular Economy Action Plan (CEAP) and the European Green Deal (EGD). The Clean Steel Partnership (CSP, a public–private partnership), which is led by the European Steel Association (EUROFER) and the European Steel Technology Platform (ESTEP), defined technological CO2 mitigation pathways comprising carbon direct avoidance (CDA), smart carbon usage SCU), and a circular economy (CE). CE approaches ensure competitiveness through increased resource efficiency and sustainability and consist of different issues, such as the valorization of steelmaking residues (dusts, slags, sludge) for internal recycling in the steelmaking process, enhanced steel recycling (scrap use), the use of secondary carbon carriers from non-steel sectors as a reducing agent and energy source in the steelmaking process chain, and CE business models (supply chain analyses). The current paper gives an overview of different technological CE approaches as obtained in a dedicated workshop called “Resi4Future—Residue valorization in iron and steel industry: sustainable solutions for a cleaner and more competitive future Europe” that was organized by ESTEP to focus on future challenges toward the final goal of industrial deployment.
Easily Sinterable Low-Alloy Steel Powders for P/M Diamond Tools
Authors: Konstanty Janusz , Tyrala Dorota
Published: July 2021

The work presents the design and fabrication procedures used to manufacture inexpensive iron-base powders employed as a matrix in diamond-impregnated tool components. Three newly developed low alloy steel powders, containing from 94.4 to 99.4 wt.% Fe, have been formulated with the assistance of ThermoCalc software and produced by means of a proprietary process patented by AGH-UST. It has been shown that the powders are readily pressureless sintered to a closed porosity condition (>95% theoretical density) at a temperature range between 840 and 950 °C. All as-consolidated materials achieve the desired tool matrix hardness of more than 200 HV. One of the experimental powders has been designed to partly melt within the sintering window. This is particularly important in fabrication of wire saw beads by the conventional press and sinter route because sintering of a diamond-impregnated ring and its further brazing to a tubular steel holder can be combined into one operation.
In-Situ Laser Directed Energy Deposition of Biomedical Ti-Nb and Ti-Zr-Nb Alloys from Elemental Powders
Authors: Arias-González Felipe , Rodríguez-Contreras Alejandra , Punset Miquel , Manero José María , Barro Óscar , Fernández-Arias Mónica , Lusquiños Fernando , Gil Francisco Javier , Pou Juan
Published: July 2021

In order to achieve the required properties of titanium implants, more resources and research are needed to turn into reality the dream of developing the perfect implant material. The objective of this study was to evaluate the viability of the Laser Directed Energy Deposition to produce biomedical Ti-Nb and Ti-Zr-Nb alloys from elemental powders (Ti, Nb and Zr). The Laser Directed Energy Deposition is an additive manufacturing process used to build a component by delivering energy and material simultaneously. The material is supplied in the form of particles or wire and a laser beam is employed to melt material that is selectively deposited on a specified surface, where it solidifies. Samples with different compositions are characterized to analyze their morphology, microstructure, constituent phases, mechanical properties, corrosion resistance and cytocompatibility. Laser-deposited Ti-Nb and Ti-Zr-Nb alloys show no relevant defects, such as pores or cracks. Titanium alloys with lower elastic modulus and a significantly higher hardness than Ti grade 2 were generated, therefore a better wear resistance could be expected from them. Moreover, their corrosion resistance is excellent due to the formation of a stable passive protective oxide film on the surface of the material; in addition, they also possess outstanding cytocompatibility.
Toward Development of a Higher Flow Rate Hemocompatible Biomimetic Microfluidic Blood Oxygenator
Authors: Santos Jose , Vedula Else M. , Lai Weixuan , Isenberg Brett C. , Lewis Diana J. , Lang Dan , Sutherland David , Roberts Teryn R. , Harea George T. , Wells Christian , Teece Bryan , Karandikar Paramesh , Urban Joseph , Risoleo Thomas , Gimbel Alla , Solt Derek , Leazer Sahar , Chung Kevin K. , Sukavaneshvar Sivaprasad , Batchinsky Andriy I. , Borenstein Jeffrey T.
Published: July 2021

The recent emergence of microfluidic extracorporeal lung support technologies presents an opportunity to achieve high gas transfer efficiency and improved hemocompatibility relative to the current standard of care in extracorporeal membrane oxygenation (ECMO). However, a critical challenge in the field is the ability to scale these devices to clinically relevant blood flow rates, in part because the typically very low blood flow in a single layer of a microfluidic oxygenator device requires stacking of a logistically challenging number of layers. We have developed biomimetic microfluidic oxygenators for the past decade and report here on the development of a high-flow (30 mL/min) single-layer prototype, scalable to larger structures via stacking and assembly with blood distribution manifolds. Microfluidic oxygenators were designed with biomimetic in-layer blood distribution manifolds and arrays of parallel transfer channels, and were fabricated using high precision machined durable metal master molds and microreplication with silicone films, resulting in large area gas transfer devices. Oxygen transfer was evaluated by flowing 100% O2 at 100 mL/min and blood at 0–30 mL/min while monitoring increases in O2 partial pressures in the blood. This design resulted in an oxygen saturation increase from 65% to 95% at 20 mL/min and operation up to 30 mL/min in multiple devices, the highest value yet recorded in a single layer microfluidic device. In addition to evaluation of the device for blood oxygenation, a 6-h in vitro hemocompatibility test was conducted on devices (n = 5) at a 25 mL/min blood flow rate with heparinized swine donor blood against control circuits (n = 3). Initial hemocompatibility results indicate that this technology has the potential to benefit future applications in extracorporeal lung support technologies for acute lung injury.
Analysis of Optical Diffraction Profiles Created by Phase-Modulating MEMS Micromirror Arrays
Authors: Mohammad Tarek , He Siyuan , Mrad Ridha Ben
Published: July 2021

This paper presents modeling and analysis of light diffraction and light-intensity modulation performed by an optical phased array (OPA) system based on metal-coated silicon micromirrors. The models can be used in the design process of a microelectromechanical system (MEMS)-based OPA device to predict its optical performance in terms of its field of view, response, angular resolution, and long-range transmission. Numerical results are derived using an extended model for the 1st-order diffracted light intensity modulation due to phase shift. The estimations of the optical characteristics are utilized in the designs of an OPA system capable of active phase modulation and an OPA system capable of array pitch tuning. Both designs are realized using the Multi-User MEMS Processes (PolyMUMPs) in which polysilicon is used as structural material for the MEMS-actuated mirrors. The experiments are performed to evaluate the optical performance of the prototypes. The tests show that the individually actuated micromirrors, which act as phase shifters, can transmit the most optical power along the 1st-order diffracted beam by actively changing their out-of-plane positions. In addition, the 1st-order diffracted beam with high optical intensity can be steered for distance measurement.
COVID-19 Infection, Vaccines, and Immunity—The Antibody Response Requires Detailed Analysis
Authors: Dimmock Nigel J.
Published: July 2021

Current tests for antibodies specific for the SARS-CoV-2 S protein say nothing about their precise epitope specificities. These data are needed to properly assess the immune status of individuals following infection or vaccination, and the risk posed by virus variants.
Single-Particle Characterization of SARS-CoV-2 Isoelectric Point and Comparison to Variants of Interest
Authors: Areo Oluwatoyin , Joshi Pratik U. , Obrenovich Mark , Tayahi Moncef , Heldt Caryn L.
Published: July 2021

SARS-CoV-2, the cause of COVID-19, is a new, highly pathogenic coronavirus, which is the third coronavirus to emerge in the past 2 decades and the first to become a global pandemic. The virus has demonstrated itself to be extremely transmissible and deadly. Recent data suggest that a targeted approach is key to mitigating infectivity. Due to the proliferation of cataloged protein and nucleic acid sequences in databases, the function of the nucleic acid, and genetic encoded proteins, we make predictions by simply aligning sequences and exploring their homology. Thus, similar amino acid sequences in a protein usually confer similar biochemical function, even from distal or unrelated organisms. To understand viral transmission and adhesion, it is key to elucidate the structural, surface, and functional properties of each viral protein. This is typically first modeled in highly pathogenic species by exploring folding, hydrophobicity, and isoelectric point (IEP). Recent evidence from viral RNA sequence modeling and protein crystals have been inadequate, which prevent full understanding of the IEP and other viral properties of SARS-CoV-2. We have thus experimentally determined the IEP of SARS-CoV-2. Our findings suggest that for enveloped viruses, such as SARS-CoV-2, estimates of IEP by the amino acid sequence alone may be unreliable. We compared the experimental IEP of SARS-CoV-2 to variants of interest (VOIs) using their amino acid sequence, thus providing a qualitative comparison of the IEP of VOIs.
Bacterial α-Glucan and Branching Sucrases from GH70 Family: Discovery, Structure–Function Relationship Studies and Engineering
Authors: Molina Manon , Cioci Gianluca , Moulis Claire , Séverac Etienne , Remaud-Siméon Magali
Published: July 2021

Glucansucrases and branching sucrases are classified in the family 70 of glycoside hydrolases. They are produced by lactic acid bacteria occupying very diverse ecological niches (soil, buccal cavity, sourdough, intestine, dairy products, etc.). Usually secreted by their producer organisms, they are involved in the synthesis of α-glucans from sucrose substrate. They contribute to cell protection while promoting adhesion and colonization of different biotopes. Dextran, an α-1,6 linked linear α-glucan, was the first microbial polysaccharide commercialized for medical applications. Advances in the discovery and characterization of these enzymes have remarkably enriched the available diversity with new catalysts. Research into their molecular mechanisms has highlighted important features governing their peculiarities thus opening up many opportunities for engineering these catalysts to provide new routes for the transformation of sucrose into value-added molecules. This article reviews these different aspects with the ambition to show how they constitute the basis for promising future developments.
Cyclofaulknamycin with the Rare Amino Acid D-capreomycidine Isolated from a Well-Characterized Streptomyces albus Strain
Authors: Horbal Liliya , Stierhof Marc , Palusczak Anja , Eckert Nikolas , Zapp Josef , Luzhetskyy Andriy
Published: July 2021

Targeted genome mining is an efficient method of biosynthetic gene cluster prioritization within constantly growing genome databases. Using two capreomycidine biosynthesis genes, alpha-ketoglutarate-dependent arginine beta-hydroxylase and pyridoxal-phosphate-dependent aminotransferase, we identified two types of clusters: one type containing both genes involved in the biosynthesis of the abovementioned moiety, and other clusters including only arginine hydroxylase. Detailed analysis of one of the clusters, the flk cluster from Streptomyces albus, led to the identification of a cyclic peptide that contains a rare D-capreomycidine moiety for the first time. The absence of the pyridoxal-phosphate-dependent aminotransferase gene in the flk cluster is compensated by the XNR_1347 gene in the S. albus genome, whose product is responsible for biosynthesis of the abovementioned nonproteinogenic amino acid. Herein, we report the structure of cyclofaulknamycin and the characteristics of its biosynthetic gene cluster, biosynthesis and bioactivity profile.
Real-Time PCR for Molecular Detection of Zoonotic and Non-Zoonotic Giardia spp. in Wild Rodents
Authors: Klotz Christian , Radam Elke , Rausch Sebastian , Gosten-Heinrich Petra , Aebischer Toni
Published: July 2021

Giardiasis in humans is a gastrointestinal disease transmitted by the potentially zoonotic Giardia duodenalis genotypes (assemblages) A and B. Small wild rodents such as mice and voles are discussed as potential reservoirs for G. duodenalis but are predominantly populated by the two rodent species Giardia microti and Giardia muris. Currently, the detection of zoonotic and non-zoonotic Giardia species and genotypes in these animals relies on cumbersome PCR and sequencing approaches of genetic marker genes. This hampers the risk assessment of potential zoonotic Giardia transmissions by these animals. Here, we provide a workflow based on newly developed real-time PCR schemes targeting the small ribosomal RNA multi-copy gene locus to distinguish G. muris, G. microti and G. duodenalis infections. For the identification of potentially zoonotic G. duodenalis assemblage types A and B, an established protocol targeting the single-copy gene 4E1-HP was used. The assays were specific for the distinct Giardia species or genotypes and revealed an analytical sensitivity of approximately one or below genome equivalent for the multi-copy gene and of about 10 genome equivalents for the single-copy gene. Retesting a biobank of small rodent samples confirmed the specificity. It further identified the underlying Giardia species in four out of 11 samples that could not be typed before by PCR and sequencing. The newly developed workflow has the potential to facilitate the detection of potentially zoonotic and non-zoonotic Giardia species in wild rodents.
Genetic Diversity of Leuconostoc mesenteroides Isolates from Traditional Montenegrin Brine Cheese
Authors: Ruppitsch Werner , Nisic Andjela , Hyden Patrick , Cabal Adriana , Sucher Jasmin , Stöger Anna , Allerberger Franz , Martinović Aleksandra
Published: July 2021

In many dairy products, Leuconostoc spp. is a natural part of non-starter lactic acid bacteria (NSLAB) accounting for flavor development. However, data on the genomic diversity of Leuconostoc spp. isolates obtained from cheese are still scarce. The focus of this study was the genomic characterization of Leuconostoc spp. obtained from different traditional Montenegrin brine cheeses with the aim to explore their diversity and provide genetic information as a basis for the selection of strains for future cheese production. In 2019, sixteen Leuconostoc spp. isolates were obtained from white brine cheeses from nine different producers located in three municipalities in the northern region of Montenegro. All isolates were identified as Ln. mesenteroides. Classical multilocus sequence tying (MLST) and core genome (cg) MLST revealed a high diversity of the Montenegrin Ln. mesenteroides cheese isolates. All isolates carried genes of the bacteriocin biosynthetic gene clusters, eight out of 16 strains carried the citCDEFG operon, 14 carried butA, and all 16 isolates carried alsS and ilv, genes involved in forming important aromas and flavor compounds. Safety evaluation indicated that isolates carried no pathogenic factors and no virulence factors. In conclusion, Ln. mesenteroides isolates from Montenegrin traditional cheeses displayed a high genetic diversity and were unrelated to strains deposited in GenBank.
Recovering Escherichia coli Plasmids in the Absence of Long-Read Sequencing Data
Authors: Paganini Julian A. , Plantinga Nienke L. , Arredondo-Alonso Sergio , Willems Rob J. L. , Schürch Anita C.
Published: July 2021

The incidence of infections caused by multidrug-resistant E. coli strains has risen in the past years. Antibiotic resistance in E. coli is often mediated by acquisition and maintenance of plasmids. The study of E. coli plasmid epidemiology and genomics often requires long-read sequencing information, but recently a number of tools that allow plasmid prediction from short-read data have been developed. Here, we reviewed 25 available plasmid prediction tools and categorized them into binary plasmid/chromosome classification tools and plasmid reconstruction tools. We benchmarked six tools (MOB-suite, plasmidSPAdes, gplas, FishingForPlasmids, HyAsP and SCAPP) that aim to reliably reconstruct distinct plasmids, with a special focus on plasmids carrying antibiotic resistance genes (ARGs) such as extended-spectrum beta-lactamase genes. We found that two thirds (n = 425, 66.3%) of all plasmids were correctly reconstructed by at least one of the six tools, with a range of 92 (14.58%) to 317 (50.23%) correctly predicted plasmids. However, the majority of plasmids that carried antibiotic resistance genes (n = 85, 57.8%) could not be completely recovered as distinct plasmids by any of the tools. MOB-suite was the only tool that was able to correctly reconstruct the majority of plasmids (n = 317, 50.23%), and performed best at reconstructing large plasmids (n = 166, 46.37%) and ARG-plasmids (n = 41, 27.9%), but predictions frequently contained chromosome contamination (40%). In contrast, plasmidSPAdes reconstructed the highest fraction of plasmids smaller than 18 kbp (n = 168, 61.54%). Large ARG-plasmids, however, were frequently merged with sequences derived from distinct replicons. Available bioinformatic tools can provide valuable insight into E. coli plasmids, but also have important limitations. This work will serve as a guideline for selecting the most appropriate plasmid reconstruction tool for studies focusing on E. coli plasmids in the absence of long-read sequencing data.
Editorial for the Special Issue “The Rietveld Method in Geomaterials Characterisation”
Authors: Kerestedjian Thomas N.
Published: July 2021

The raw materials obtained from the Earth’s crust (Geomaterials) are of fundamental importance for a wide range of industries [...]
Preparation and Characterization of Acid-Activated Bentonite with Binary Acid Solution and Its Use in Decreasing Electrical Conductivity of Tap Water
Authors: Nagahashi Eri , Ogata Fumihiko , Saenjum Chalermpong , Nakamura Takehiro , Kawasaki Naohito
Published: July 2021

The characteristics of acid-activated raw bentonite (RB) activated with binary acid solutions sulfuric acid + nitric acid, nitric acid + phosphoric acid, and phosphoric acid + sulfuric acid, at a concentration of 5 mol/L (denoted as 5-SN, 5-NP, and 5-PS), were evaluated. Moreover, its application for improving the electrical conductivity in tap water was demonstrated. Acid activation induced the partial destruction of RB; subsequently, there was a significant release of sodium ions from the RB. In addition, the specific surface area and pore volume of 5-SN, 5-NP, and 5-PS were higher than those of RB. Next, the electrical conductivity when using RB increased with adsorption treatment because sodium ions were released from the RB. However, the electrical conductivity significantly decreased with adsorption treatment when using acid-activated RB. Specifically, magnesium ions, calcium ions, and potassium ions were removed into 5-SN, 5-NP, and 5-PS, and sodium ions were not released from the RB simultaneously. The removal percentage of the electrical conductivity using 5-SN, 5-NP, and 5-PS was approximately 31% to 36%. The results indicated that employing acid-activated RB with a binary acid solution is a useful method for decreasing the electrical conductivity in tap water.
Editorial for Special Issue “Mineralogy of Noble Metals and ‘Invisible’ Speciations of These Elements in Natural Systems, Volume II”
Authors: Palyanova Galina
Published: July 2021

The articles published in the 2019 Special Issue “Mineralogy of Noble Metals and ‘Invisible’ Speciations of These Elements in Natural Systems” [...]
Rapid Detection and Quantification of Patulin and Citrinin Contamination in Fruits
Authors: Sadhasivam Sudharsan , Barda Omer , Zakin Varda , Reifen Ram , Sionov Edward
Published: July 2021

Patulin (PAT) and citrinin (CTN) are the most common mycotoxins produced by Penicillium and Aspergillus species and are often associated with fruits and fruit by-products. Hence, simple and reliable methods for monitoring these toxins in foodstuffs are required for regular quality assessment. In this study, we aimed to establish a cost-effective method for detection and quantification of PAT and CTN in pome fruits, such as apples and pears, using high-performance liquid chromatography (HPLC) coupled with spectroscopic detectors without the need for any clean-up steps. The method showed good performance in the analysis of these mycotoxins in apple and pear fruit samples with recovery ranges of 55–97% for PAT and 84–101% for CTN, respectively. The limits of detection (LOD) of PAT and CTN in fruits were 0.006 µg/g and 0.001 µg/g, while their limits of quantification (LOQ) were 0.018 µg/g and 0.003 µg/g, respectively. The present findings indicate that the newly developed HPLC method provides rapid and accurate detection of PAT and CTN in fruits.