bluuebunny/crossref_metadata_2025 huggingface dataset:
Management Control Systems in Shopping Centres: Analysis of the Managing Director
Authors: Aquilino-Navarro Andrea , Ramón-Jerónimo Juan Manuel , Flórez-López Raquel
Published: February 2022

Background: How do Shopping Centre Managers use the Management Control System (MCS) to adapt to the available resources according to the characteristics of the centre and external factors that may affect such management? We identified the differences in the MCS between three types of shopping centres: urban-conventional centres, peripheral-conventional centres, and peripheral-outlet centres. Methods: This qualitative research, based on a multiple case study, aims to obtain a descriptive and explanatory view of the situation of the MCS in the analysed centres. For the study, an interview with a store manager in a shopping centre and semi-structured interviews with the managers of the selected centres were conducted. Results: The relevant factors that affect management were detected: ownership structure, budget management, centre maintenance, marketing-mix management, and the image of the centre to be projected, based on the public that the manager intends to attract. Conclusions: MCSs within each shopping centre vary little, depending on the external factors described, and the differences in management are not based on the characteristics of the centre but on the vision of the manager. A detailed description of the role of the manager is offered, and the door is opened for further research on the subject.
6-Chloro-3H-benzo[d][1,2,3]dithiazol-2-ium Chloride
Authors: Nicholls Alexander J. , Baxendale Ian R.
Published: February 2022

This short note describes the synthesis of an amorphous benzo[1,2,3]dithiazole chloride salt (commonly known as a ‘Herz salt’) by use of the Herz reaction. Hetero- and homolytic transformations of this species to a variety of useful adducts in medicinal and materials chemistry are well established, although there are limited examples of isolation in the literature, and characterisation data is even harder find. While several studies have confirmed the structure of the benzodithiazole ring beyond doubt, (having generated suitably crystalline salts with large counterions for XRD-analysis), there remains value in understanding and optimising the synthesis of the simple, amorphous polymorphs. For the first time, MS data is provided for this compound and a new mechanism of its formation is proposed based upon new experimental observations and data.
Cathodoluminescent Analysis of Sapphire Surface Etching Processes in a Medium-Energy Electron Beam
Authors: Muslimov Arsen , Kanevsky Vladimir
Published: February 2022

Sapphire crystals are widely used in optics and optoelectronics. In this regard, it is important to study the stability of crystals under external influence and the possibility of modifying their surfaces by external influence. This work presents the results of studying the processes of the action of an electron beam with an average energy of 70 keV or less under vacuum conditions on the surfaces of sapphire substrates of various orientations. The effect of etching a sapphire surface by an electron beam in vacuum at room temperature was discovered. The highest etching rate was observed for A-plane sapphire (the average pit etching rate was 10−6 µm3/s). It was shown that the rate of etching of a sapphire surface increased many times over when gold is deposited. An in situ method for studying the process of etching a sapphire surface using cathodoluminescence analysis was considered. Possible mechanisms of sapphire etching by a beam of bombarding electrons were considered. The results obtained could be important in solving the problem of the stability of sapphire windows used in various conditions, including outer space. In addition, the proposed method of metal-stimulated etching of a sapphire surface can be widely used in patterned sapphire substrate (PSS) technology and further forming low-dislocation light-emitting structures on them.
The Influence of the Depth of Grinding on the Condition of the Surface Layer of 20MnCr5 Steel Ground with the Minimum Quantity Lubrication (MQL) Method
Authors: Stachurski Wojciech , Sawicki Jacek , Januszewicz Bartłomiej , Rosik Radosław
Published: February 2022

This paper describes the research on abrasive machining conditions and their influence on microhardness and residual stresses distribution in the technological surface layer of 20MnCr5 steel. The roughness of ground samples was also measured. Samples underwent a vacuum carburizing process (LPC) followed by high-pressure gas quenching (HPGQ) in a 4D quenching chamber. Processes were realized with a single-piece flow method. Then, the flat surfaces of samples were ground with a Vortex type IPA60EH20VTX alumina grinding wheel using a flat-surface grinder. The samples were ground to three depths of grinding (ae = 0.01; 0.02; 0.03 mm) with grinding fluid supply using either flood method (WET) or minimum quantity lubrication (MQL) method. The condition of the technological surface layer was described using microhardness and residual stresses, as well as some selected parameters of surface roughness. The results obtained revealed that changes in microhardness as compared to microhardness of the material before grinding were lower in samples ground with grinding fluid supplied with MQL method. At the same time, the values of residual stresses were also better for samples ground using MQL method. Furthermore, the use of grinding fluid fed with MQL method produced lower values of surface roughness compared to the parameters obtained with WET method. It was concluded that for the tested scope of machining conditions, the MQL method can be a favourable alternative to the flood method of supplying grinding fluid into the grinding zone.
Electroplastic Effects on the Mechanical Responses and Deformation Mechanisms of AZ31 Mg Foils
Authors: Xu Shuai , Xiao Xinwei , Zhang Haiming , Cui Zhenshan
Published: February 2022

Electrical-assisted (EA) forming technology is a promising technology to improve the formability of hard-deformable materials, such as Mg alloys. Herein, EA micro tensile tests and various microstructure characterizations were conducted to study the electroplastic effect (EPE) and size effect on the mechanical responses, deformation mechanisms, and fracture characteristics of AZ31 Mg foils. With the assistance of electric currents, the ductility of the foils was significantly improved, the size effects caused by grain size and sample thickness were weakened, and the sigmoidal shape of the flow stress curves during the early deformation stage became less obvious. The EBSD characterization results showed that the shape change of the flow stress curves was due to the EPE suppressing the activation of extension twinning at the early deformation stage, especially for the coarse grain samples. The suppression of extension twinning resulted in a quick increase in flow stress due to the dislocation-dominant work hardening, and the increased flow stress eventually promoted extensive deformation twins at large deformation. Thus, as the sample strained to 10% tensile deformation, the EA-tested samples showed a larger volume fraction of deformation twins than the non-EA samples. The reference orientation deviation analysis verified that the deformation twins in the EA samples were formed in the large deformation stage. Combined with the fractography, the EPE also improved the ductility by suppressing the expansion of cleavage surfaces.
High-Selective Extraction of Scandium (Sc) from Bauxite Residue (Red Mud) by Acid Leaching with MgSO4
Authors: Shoppert Andrei , Loginova Irina , Napol’skikh Julia , Valeev Dmitry
Published: February 2022

Bauxite residue, also known as red mud (RM), from alumina production is the most promising technogenic material for the production of scandium (Sc) and other rare earth elements (REEs). Conveniently, RM is processed by using a strong acid (pH < 2.5), which lead to co-dissolution of iron and other undesirable major components. In this work, for the first time, the possibility of selective extraction of scandium from red mud by using highly diluted acid (pH > 4) in the presence of MgSO4 was shown. The effect of temperature (40–80 °C), time (0–60 min), pH (2–5), and the MgSO4 concentration (12–36 g L−1) on Sc extraction efficiency was evaluated. It was shown that Sc extraction was higher than 63% even at a pH of 4, at 80 °C, after 1 h, while more than 80% could be extracted at a pH of 2. Iron extraction reduced from 7.7 to 0.03% by increasing the pH from 2 to 4. The kinetics study using the shrinking core model (SCM) has shown that diffusion through a product layer is a rate-limiting stage of the process at high temperatures (>60 °C) and low pH (<3), whereas, at lower temperatures and higher pH values, the leaching rate is limited by diffusion through the liquid film.
The Effect of Polyhydroxy Fullerene Derivative on Human Myeloid Leukemia K562 Cells
Authors: Guo Wei , Liu Xing , Ye Lianjie , Liu Jie , Larwubah Kollie , Meng Ge , Shen Weiqiang , Ying Xiangxian , Zhu Jun , Yang Shengjie , Guo Jianjun , Jia Yanrong , Yu Meilan
Published: February 2022

The use of nanomedicines for cancer treatment has been widespread. Fullerenes have significant effects in the treatment of solid tumors. Here, we are going to study the effects of hydroxylated fullerene C60(OH)n(n = 18–22) treatment on chronic myeloid leukemia cell proliferation and investigate its toxicity. The results showed that hydroxylated fullerene C60(OH)n (n = 18–22) at low concentrations (less than 120 μM) not only had apparent toxic side effects, but also promoted the growth of K562 cells, while a high concentration of C60(OH)n had different degrees of inhibition on K562 cells. When the concentration is higher than 160 μM, the K562 cells showed morphological changes, the mitochondrial membrane potential decreased, the cell cycle was blocked in the stage of G2-phase, and cell apoptosis occurred, which may cause apoptosis, autophagy, and a variety of other damage leading to cell death. Meanwhile, it also indicated that its inhibition of solid tumors might be related to the tumor microenvironment; we verified the safety of fullerene without apparent cellular toxicity at a specific concentration.
Properties of Microplasma Coating on AZ91 Magnesium Alloy Prepared from Electrolyte with and without the Borax Addition
Authors: Bisztyga-Szklarz Magdalena , Rząd Ewa , Boroń Łukasz , Klimczyk Piotr , Polczyk Tomasz , Łętocha Aneta , Rajska Maria , Hebda Marek , Długosz Piotr
Published: February 2022

Magnesium alloys, due to their unique properties, low density and high strength properties, are becoming more frequently used in industrial applications. However, a limitation of their use may be the need to ensure high abrasive wear resistance and corrosion resistance. Therefore, magnesium alloys are often protected by applying protective coatings. The paper presents the influence of the modification of the electrolyte composition, with or without the addition of borax, on the morphology (observed by SEM method) and phase composition (analyzed by EDS and XRD) of the formed layers on the AZ91 magnesium alloy, and their abrasive wear (determined with Ball-on-Disc method) and corrosion resistance (evaluated using the immersion method and by electrochemical tests), especially in chloride solutions. It has been clearly demonstrated that the modification of the electrolyte composition significantly impacts the final properties of the protective coatings on the AZ91 alloy formed by the plasma electrolytic oxidation (PEO) process. On the basis of the results, it was found that the new type of PEO coatings with the borax addition, compared to base PEO coatings, showed significantly higher abrasion resistance and an order of magnitude lower corrosion rate.
Polymer–Nickel Composite Filaments for 3D Printing of Open Porous Materials
Authors: Mackiewicz Ewelina , Wejrzanowski Tomasz , Adamczyk-Cieślak Bogusława , Oliver Graeme J.
Published: February 2022

Catalysis has been a key way of improving the efficiency-to-cost ratio of chemical and electrochemical processes. There have been recent developments in catalyst materials that enable the development of novel and more sophisticated devices that, for example, can be used in applications, such as membranes, batteries or fuel cells. Since catalytic reactions occur on the surface, most catalyst materials are based on open porous structures, which facilitates the transport of fluids (gas or liquid) and chemical (or electrochemical) specific surface activity, thus determining the overall efficiency of the device. Noble metals are typically used for low temperature catalysis, whereas lower cost materials, such as nickel, are used for catalysis at elevated temperatures. 3D printing has the potential to produce a more sophisticated fit for purpose catalyst material. This article presents the development, fabrication and performance comparison of three thermoplastic composites where PLA (polylactic acid), PVB (polyvinyl butyral) or ABS (acrylonitrile butadiene styrene) were used as the matrix, and nickel particles were used as filler with various volume fractions, from 5 to 25 vol%. The polymer–metal composites were extruded in the form of filaments and then used for 3D FDM (Fused Deposition Modeling) printing. The 3D printed composites were heat treated to remove the polymer and sinter the nickel particles. 3D printed composites were also prepared using nickel foam as a substrate to increase the final porosity and mechanical strength of the material. The result of the study demonstrates the ability of the optimized filament materials to be used in the fabrication of high open porosity (over 60%) structures that could be used in high-temperature catalysis and/or electrocatalysis.
Aging Behavior and Heat Treatment for Room-Temperature CO-Sensitive Pd-SnO2 Composite Nanoceramics
Authors: Gui Fubing , Huang Yong , Wu Menghan , Lu Xilai , Hu Yongming , Chen Wanping
Published: February 2022

A high long-term stability is crucial for room-temperature gas-sensitive metal oxide semiconductors (MOSs) to find practical applications. A series of Pd-SnO2 mixtures with 2, 5, and 10 wt% Pd separately were prepared from SnO2 and Pd powders. Through pressing and sintering, Pd-SnO2 composite nanoceramics have been successfully prepared from the mixtures, which show responses of 50, 100, and 60 to 0.04% CO-20% O2-N2 at room temperature for samples of 2, 5, and 10 wt% Pd, respectively. The room-temperature CO-sensing characteristics were degraded obviously after dozens of days’ aging for all samples. For samples of 5 wt% Pd, the response to CO was decreased by a factor of 4 after 20 days of aging. Fortunately, some rather mild heat treatments will quite effectively reactivate those aged samples. Heat treatment at 150 °C for 15 min in air tripled the response to CO for a 20 days-aged sample of 5 wt% Pd. It is proposed that the deposition of impurity gases in air on Pd in Pd-SnO2 composite nanoceramics has resulted in the observed aging, while their desorption from Pd through mild heat treatments leads to the reactivation. More studies on aging and reactivation of room-temperature gas sensitive MOSs should be conducted to achieve high long-term stability for room-temperature MOS gas sensors.
Dipicolinate Complexes of Oxovanadium(IV) and Dioxovanadium(V) with 2-Phenylpyridine and 4,4′-Dimethoxy-2,2′-bipyridyl as New Precatalysts for Olefin Oligomerization
Authors: Drzeżdżon Joanna , Pawlak Marta , Gawdzik Barbara , Wypych Aleksandra , Kramkowski Karol , Kowalczyk Paweł , Jacewicz Dagmara
Published: February 2022

Polyolefins are used in everyday life, including in the production of many types of plastic. In addition, polyolefins account for over 50% of the polymers produced in the world. After conducting the oligomerization reactions of 2-propen-1-ol, 2-chloro-2-propen-1-ol, and norborene, polyolefins are obtained. In this report, two complexes of oxovanadium(IV) and dioxovanadium(V) with dipicolinate, 2-phenylyridine, and 4,4′-dimethoxy-2,2′-bipyridyl as precatalysts for 2-propen-1-ol, 2-chloro-2-propen-1-ol, and norborene oligomerizations are prepared. We present for the first time the new dipicolinate complex compound of oxovanadium(IV) with 4,4′-dimetoxy-2,2′-bipyridyl. Both complexes were tested for catalytic activity in the oligomerization reactions of 2-propen-1-ol, 2-chloro-2-propen-1-ol, and norbornene. Both synthesized complexes showed high catalytic activity in these oligomerization reactions, except for the oligomerization of norbornene.
Contrast-Independent Partially Explicit Time Discretizations for Quasi Gas Dynamics
Authors: Chetverushkin Boris , Efendiev Yalchin , Leung Wing Tat
Published: February 2022

In the paper, we study a design and stability of contrast-independent partially explicit time discretizations for Quasi-Gas-Dynamics (QGD) Equations in multiscale high-contrast media. In our previous works, we have introduced contrast-independent partially explicit time discretizations. In this paper, we extend these ideas to multiscale QGD problems. Because of high contrast, explicit methods require a very small time stepping. By designing appropriate spatial splitting and temporal splitting, partially explicit methods remove this constraint. The proposed partially explicit time discretization consists of two steps. First, we split the space into contrast dependent (fast) and contrast independent (slow) components on a coarse grid that is much larger compared to spatial heterogeneities. Secondly, we design a temporal splitting algorithm in a such way that it is stable and the time step is independent of the contrast and only depends on the coarse mesh size. Using proposed method, a few degrees of freedom are treated implicitly and the approach is mostly explicit. We prove that the proposed splitting is unconditionally stable under some suitable conditions formulated for the second space (slow). We present numerical results and show that the proposed methods provide results similar to implicit methods with the time step that is independent of the contrast.
Chitosan/Alginate Nanoparticles for the Enhanced Oral Antithrombotic Activity of Clam Heparinoid from the Clam Coelomactra antiquata
Authors: Chen Guan-Lan , Cai Hong-Ying , Chen Jian-Ping , Li Rui , Zhong Sai-Yi , Jia Xue-Jing , Liu Xiao-Fei , Song Bing-Bing
Published: February 2022

Chitosan/alginate nanoparticles (DG1-NPs and DG1/Cur-NPs) aiming to enhance the oral antithrombotic activity of clam heparinoid DG1 were prepared by ionotropic pre-gelation. The influence of parameters, such as the concentration of sodium alginate (SA), chitosan (CTS), CaCl2, clam heparinoid DG1, and curcumin (Cur), on the characteristics of the nanoparticles, were investigated. Results indicate that chitosan and alginate can be used as polymer matrices to encapsulate DG1, and nanoparticle characteristics depend on the preparation parameters. Nano-particles should be prepared using 0.6 mg/mL SA, 0.33 mg/mL CaCl2, 0.6 mg/mL CTS, 7.2 mg/mL DG1, and 0.24 mg/mL Cur under vigorous stirring to produce DG1-NPS and DG1/Cur-NPS with small size, high encapsulation efficiency, high loading capacity, and negative zeta potential from approximately −20 to 30 mV. Data from scanning electron microscopy, Fourier-transform infrared spectrometry, and differential scanning calorimetry analyses showed no chemical reaction between DG1, Cur, and the polymers; only physical mixing. Moreover, the drug was loaded in the amorphous phase within the nanoparticle matrix. In the acute pulmonary embolism murine model, DG1-NPs enhanced the oral antithrombotic activity of DG1, but DG1/Cur-NPs did not exhibit higher antithrombotic activity than DG1-NPs. Therefore, the chitosan/alginate nanoparticles enhanced the oral antithrombotic activity of DG1, but curcumin did not further enhance this effect.
Citreobenzofuran D–F and Phomenone A–B: Five Novel Sesquiterpenoids from the Mangrove-Derived Fungus Penicillium sp. HDN13-494
Authors: Wu Qian , Chang Yimin , Che Qian , Li Dehai , Zhang Guojian , Zhu Tianjiao
Published: February 2022

Five new sesquiterpenoids, citreobenzofuran D–F (1–3) and phomenone A–B (4–5), along with one known compound, xylarenone A (6), were isolated from the culture of the mangrove-derived fungus Penicillium sp. HDN13-494. Their structures were deduced from extensive spectroscopic data, high-resolution electrospray ionization mass spectrometry (HRESIMS), and electronic circular dichroism (ECD) calculations. Furthermore, the absolute structures of 1 were determined by single-crystal X-ray diffraction analysis. Citreobenzofuran E–F (2–3) are eremophilane-type sesquiterpenoids with rare benzofuran frameworks, while phomenone A (4) contains a rare thiomethyl group, which is the first report of this kind of sesquiterpene with sulfur elements in the skeleton. All the compounds were tested for their antimicrobial and antitumor activity, and phomenone B (5) showed moderate activity against Bacillus subtilis, with an MIC value of 6.25 μM.
Inhibitory Effects of Nitrogenous Metabolites from a Marine-Derived Streptomyces bacillaris on Isocitrate Lyase of Candida albicans
Authors: Chung Beomkoo , Hwang Ji-Yeon , Park Sung Chul , Kwon Oh-Seok , Cho Eunji , Lee Jayho , Lee Hyi-Seung , Oh Dong-Chan , Shin Jongheon , Oh Ki-Bong
Published: February 2022

Two nitrogenous metabolites, bacillimide (1) and bacillapyrrole (2), were isolated from the culture broth of the marine-derived actinomycete Streptomyces bacillaris. Based on the results of combined spectroscopic and chemical analyses, the structure of bacillimide (1) was determined to be a new cyclopenta[c]pyrrole-1,3-dione bearing a methylsulfide group, while the previously reported bacillapyrrole (2) was fully characterized for the first time as a pyrrole-carboxamide bearing an alkyl sulfoxide side chain. Bacillimide (1) and bacillapyrrole (2) exerted moderate (IC50 = 44.24 μM) and weak (IC50 = 190.45 μM) inhibitory effects on Candida albicans isocitrate lyase, respectively. Based on the growth phenotype using icl-deletion mutants and icl expression analyses, we determined that bacillimide (1) inhibits the transcriptional level of icl in C. albicans under C2-carbon-utilizing conditions.
Association of Proteus mirabilis and Providencia stuartii Infections with Diabetes
Authors: Rus Maria , Licker Monica , Musuroi Corina , Muntean Delia , Vulpie Silvana , Magiar Oana , Sorescu Teodora , Musuroi Silvia Ioana , Voinescu Adela , Baditoiu Luminita Mirela
Published: February 2022

Background and Objectives: Proteus and Providencia are related genera of opportunistic pathogens belonging to the Morganellaceae family, often a cause of infections in the immunocompromised hosts, such as diabetic patients. Their clinical significance has increased due to their intrinsic resistance to polymyxins, which is often associated with acquired resistance mechanisms. In this study we evaluated the infections caused by Proteus mirabilis and Providencia stuartii in two groups of patients, with diabetes (group 1) and without diabetes (group 2) admitted to the intensive care unit and surgical wards. The infections were investigated in terms of infection type, risk factors, clinical course, predictive factors for unfavourable outcomes and antibiotic resistance profile. Materials and Methods: An observational, retrospective, cross-sectional study was conducted, comprising all patients infected with these pathogens. Bacterial identification and antibiotic sensitivity testing were performed using the Vitek2C automated system. Results: Comparison of the two groups showed that the statistically significant common infectious risk factors were found less frequently among diabetic patients when compared with non-diabetic patients, and that antimicrobial resistance was significantly lower in the diabetic patient group. However, survival rates did not differ between the two groups, drawing attention to the implications of diabetes as comorbidity. Additionally, with regard to the antibiotic resistance profile, 38.89% of P. stuartii strains isolated from diabetic patients belonged to the difficult-to-treat (DTR) phenotype, contributing to the severity of these infections compared with those caused by P. mirabilis, of which 32% were wild type strains and 0% were DTR phenotype. The DTR/extended spectrum beta-lactamase producing P. stuartii isolates more than doubled the risk of mortality, while the presence of nasogastric nutrition tripled the risk. Conclusions: P. stuartii infections that occurred in diabetic patients proved to be more difficult to treat, the majority of them being healthcare-associated bacteremias.
Insights into National Laboratory Newborn Screening and Future Prospects
Authors: Mujamammi Ahmed H.
Published: February 2022

Newborn screening (NBS) is a group of tests that check all newborns for certain rare conditions, covering several genetic or metabolic disorders. The laboratory NBS is performed through blood testing. However, the conditions that newborn babies are screened for vary from one country to another. Since NBS began in the 1960s, technological advances have enabled its expansion to include an increasing number of disorders, and there is a national trend to further expand the NBS program. The use of mass spectrometry (MS) for the diagnosis of inborn errors of metabolism (IEM) obviously helps in the expansion of the screening panels. This technology allows the detection of different metabolic disorders at one run, replacing the use of traditional techniques. Analysis of the targeted pathogenic gene variant is a routine application in the molecular techniques for the NBS program as a confirmatory testing to the positive laboratory screening results. Recently, a lot of molecular investigations, such as next generation sequencing (NGS), have been introduced in the routine NBS program. Nowadays, NGS techniques are widely used in the diagnosis of IMD where its results are rapid, confirmed and reliable, but, due to its uncertainties and the nature of IEM, it necessitates a holistic approach for diagnosis. However, various characteristics found in NGS make it a potentially powerful tool for NBS. A range of disorders can be analyzed with a single assay directly, and samples can reduce costs and can largely be automated. For the implementation of a robust technology such as NGS in a mass NBS program, the main focus should not be just technologically biased; it should also be tested for its long- and short-term impact on the family and the child. The crucial question here is whether large-scale genomic sequencing can provide useful medical information beyond what current NBS is already providing and at what economical and emotional cost? Currently, the topic of newborn genome sequencing as a public health initiative remains argumentative. Thus, this article seeks the answer to the question: NGS for newborn screening- are we there yet?
Interactions between Sleep and Emotions in Humans and Animal Models
Authors: Lefter Radu , Cojocariu Roxana Oana , Ciobica Alin , Balmus Ioana-Miruna , Mavroudis Ioannis , Kis Anna
Published: February 2022

Recently, increased interest and efforts were observed in describing the possible interaction between sleep and emotions. Human and animal model studies addressed the implication of both sleep patterns and emotional processing in neurophysiology and neuropathology in suggesting a bidirectional interaction intimately modulated by complex mechanisms and factors. In this context, we aimed to discuss recent evidence and possible mechanisms implicated in this interaction, as provided by both human and animal models in studies. In addition, considering the affective component of brain physiological patterns, we aimed to find reasonable evidence in describing the two-way association between comorbid sleep impairments and psychiatric disorders. The main scientific literature databases (PubMed/Medline, Web of Science) were screened with keyword combinations for relevant content taking into consideration only English written papers and the inclusion and exclusion criteria, according to PRISMA guidelines. We found that a strong modulatory interaction between sleep processes and emotional states resides on the activity of several key brain structures, such as the amygdala, prefrontal cortex, hippocampus, and brainstem nuclei. In addition, evidence suggested that physiologically and behaviorally related mechanisms of sleep are intimately interacting with emotional perception and processing which could advise the key role of sleep in the unconscious character of emotional processes. However, further studies are needed to explain and correlate the functional analysis with causative and protective factors of sleep impairments and negative emotional modulation on neurophysiologic processing, mental health, and clinical contexts.
Clinical and Biological Risk Factors Associated with Increased Mother-to-Child Transmission of HIV in Two South-East HIV-AIDS Regional Centers in Romania
Authors: Cambrea Simona Claudia , Marcu Eugenia Andreea , Cucli Elena , Badiu Diana , Penciu Roxana , Petcu Cristian Lucian , Dumea Elena , Halichidis Stela , Pazara Loredana , Mihai Cristina Maria , Dumitrescu Florentina
Published: February 2022

Background and Objectives: The occurrence of human immunodeficiency virus (HIV) infection in children in Romania has been reported since 1989. This retrospective study was aimed at assessing clinical and biological risk factors for mother-to-child transmission (MTCT) of HIV in two HIV-acquired immune deficiency syndrome (AIDS) Regional Centers (RCs), Constanta and Craiova in Romania. Materials and Methods: During the study period (2008–2019), 408 HIV-positive pregnant women, 244 from Constanta RC and 164 from Craiova RC who attended antenatal visits, were included. All HIV-positive pregnant women were under combined antiretroviral therapy (cART) during pregnancy and childbirth, being followedup with their infants up to 18 months after delivery. We investigated the clinical as well as biological risk factorsassociated with increased MTCT of HIV. Results: Comparing different variables of HIV-positive pregnant women from the two HIV-AIDS CRs, we find that there are significant differences between the mean value of hemoglobin, CD4 level, environmental area, marital and amniotic membranes status, and HIV patient stage in the last trimester of pregnancy (p < 0.05), but without any differences in mother’s mean age, education level, type of delivery, breastfeeding, the duration of cART administration, HIV viral load, and survival rate. Conclusions: In 408 HIV-positive pregnant women followed up at two HIV-AIDS RCs in Romania, the most important clinical and biological risk factors associated with increased MTCT of HIV are represented by anemia, CD4 level, and HIV patient stage.
Outcome after Posterior Vertebral Column Resection in Patients with Severe Osteoporotic Fractures—A Retrospective Analysis from Two Centers
Authors: Koepke Leon-Gordian , Weiser Lukas , Stangenberg Martin , Dreimann Marc , Heuer Annika , Strahl André , Viezens Lennart
Published: February 2022

Background and Objectives: In osteoporotic fractures of the spine with resulting kyphosis and threatening compression of neural structures, therapeutic decisions are difficult. The posterior vertebral column resection (pVCR) has been described by different authors as a surgical treatment in a single-stage posterior procedure. The aim of this study is to evaluate midterm outcomes of patients treated by pVCR due to severe osteoporotic fractures. Materials and Methods: Retrospective data analysis of all the patients treated for osteoporotic fractures by pVCR from 2012–2020 at two centers was performed. Demographic data, visual analog scale (VAS), Frankel scale (FS), Karnofsky performance status (KPS), radiological result and spinal fusion rates were evaluated. Results: A total of 17 patients were included. The mean age was 70 ± 10.2 y. The mean VAS decreased significantly from 7.7 ± 2.8 preoperatively to 3.0 ± 1.6 at last follow-up (p < 0.001) and the segmental kyphosis decreased from 29.4 ± 14.1° to 7.9 ± 8.0° (p < 0.001). The neurologic function on the FS did not worsen in any and improved in four of the patients. The median KPS remained stable over the whole observation period (70% vs. 70%). Spinal fusion was observed in nine out of nine patients who received CT follow-up >120 days after index surgery. Conclusions: This study showed that pVCR is a safe surgical technique with few surgical complications and no neurological deterioration considering the cohort. The patients’ segmental kyphosis and VAS improved significantly, while the KPS remained stable.
A Comparison in Patient Comfort Using Conventional Syringe and Needleless Jet Anesthesia Technique in Periodontal Surgery—A Split-Mouth Randomized Clinical Trial
Authors: Shankar Preethi , Chellathurai Burnice Nalina Kumari , Kumar S. Ashok , Mahendra Jaideep , Mugri Maryam H. , Sayed Mohammed , Almagbol Mohammad , Al Wadei Mohammed Hussain Dafer , Vijayalakshmi Rajaram , Ambalavanan Namasivayam , Raj A. Thirumal , Patil Shankargouda
Published: February 2022

Background and Objectives: Periodontal surgery requires local anesthetic coverage to alleviate patient discomfort. Needles and injections can engender feelings of fear and anxiety in individuals. This study aimed to assess the level of comfort and anxiety in patients during the administration of local anesthesia using needleless jet anesthesia (JA) when compared to a conventional syringe (CS) in periodontal surgery. Method and Materials: 60 sites were designated for injection in a split-mouth design in 30 subjects who required periodontal surgery. Local anesthesia was administered in two appointments scheduled one week apart using either a JA system or a CS. The Visual Analogue Scale (VAS), Verbal Rating Scale (VRS), and Beck’s anxiety inventory were used to report the pain and anxiety levels while injecting local anesthesia. Statistical analysis of the results was performed using the Shapiro–Wilks test and Paired t-test. Results: Patients reported greater comfort with JA. The VAS and VRS values were statistically significant—(p = 0.003) and (p = 0.001), respectively. Patients showed fear and were nervous about receiving a local anesthetic using a CS. A few subjects experienced lingering pain with the CS, whereas greater comfort and no lingering soreness were reported post-operatively at the site of JA administration. Conclusions: This study provides the first comprehensive assessment of using JA for periodontal surgical procedures. Lower pain scores were consistently observed with the use of jet injectors. Patients were at ease and reported lesser anxiety and greater comfort with jet injectors, making it ideally suited for providing local anesthesia in periodontal surgery.
St. Thomas Modified Cardioplegia Effects on Myoblasts’ Viability and Morphology
Authors: Nowicki Rafał , Bieżuńska-Kusiak Katarzyna , Kulbacka Julita , Choromanska Anna , Daczewska Małgorzata , Potoczek Stanisław , Rachwalik Maciej , Saczko Jolanta
Published: February 2022

Background and Objectives: The cardioplegic arrest of the heart during cardiosurgical procedures is the crucial element of a cardioprotection strategy. Numerous clinical trials compare different cardioplegic solutions and cardioprotective protocols, but a relatively small number of papers apply to in vitro conditions using cultured cells. This work aimed to analyze whether it is possible to use the rat heart myocardium cells as an in vitro model to study the protective properties of St. Thomas cardioplegia (ST2C). Methods: The rat heart myocardium cells-H9C2 were incubated with cold cardioplegia for up to 24 h. After incubation, we determined: viability, confluency, and cell size, the thiol groups’ level by modifying Ellman’s method, Ki67, and Proliferating Cell Nuclear Antigen expression (PCNA). The impact on cells’ morphology was visualized by the ultrastructural (TEM) study and holotomograpic 3D imaging. Results: The viability and confluency analysis demonstrated that the safest exposure to ST2C, should not exceed 4h. An increased expression of Ki67 antigen and PCNA was observed. TEM and 3D imaging studies revealed vacuolization after the longest period of exposure (24). Conclusions: According to obtained results, we conclude that STC can play a protective role in cardiac surgery during heart arrest.
Resolution of Papilledema Following Ventriculoperitoneal Shunt or Endoscopic Third Ventriculostomy for Obstructive Hydrocephalus: A Pilot Study
Authors: Das Sukriti , Montemurro Nicola , Ashfaq Musannah , Ghosh Dipankar , Sarker Asit , Khan Akhlaque , Dey Sharbari , Chaurasia Bipin
Published: February 2022

Background and Objectives: Ventriculoperitoneal Shunt (VPS) and Endoscopic Third Ventriculostomy (ETV) are both gold standard procedures to reduce intracranial pressure (ICP) in patients with obstructive hydrocephalus, which often results in papilledema. This comparative study was carried out at the Department of Neurosurgery of Dhaka Medical College and Hospital to compare the efficacy of VPS and ETV in the resolution of papilledema in 18 patients with obstructive hydrocephalus. Materials and Methods: The success of CSF diversion was evaluated by a decrease in retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT) and modified Frisen grading of papilledema at the same time. The statistical analyses were carried out by using paired sample t test and the Spearman’s correlation coefficient test. The level of significance (p value) was set at <0.05. Results: After 7 days, both VPS and ETV were able to reduce RNFL thickness of both eyes with a p value = 0.016 (right eye) and 0.003 (left eye) in group A (VPS) and with a p value <0.001 (both eyes) in group B (ETV). Change of Frisen grading after CSF diversion was not satisfying for both the procedures with p value > 0.05. Further, the inter-group comparison between VPS and ETV showed no difference in decreasing RNFL thickness and modified Frisen grading (p value = 0.56). Conclusion: VPS and ETV procedures both appear very efficient in treating obstructive hydrocephalus, which in turn reduces papilledema in these patients. This paper is preliminary and requires further work.
Microfluidics Approach to the Mechanical Properties of Red Blood Cell Membrane and Their Effect on Blood Rheology
Authors: Trejo-Soto Claudia , Lázaro Guillermo R. , Pagonabarraga Ignacio , Hernández-Machado Aurora
Published: February 2022

In this article, we describe the general features of red blood cell membranes and their effect on blood flow and blood rheology. We first present a basic description of membranes and move forward to red blood cell membranes’ characteristics and modeling. We later review the specific properties of red blood cells, presenting recent numerical and experimental microfluidics studies that elucidate the effect of the elastic properties of the red blood cell membrane on blood flow and hemorheology. Finally, we describe specific hemorheological pathologies directly related to the mechanical properties of red blood cells and their effect on microcirculation, reviewing microfluidic applications for the diagnosis and treatment of these diseases.
Mixed Oxide Electrodes Based on Ruthenium and Copper: Electrochemical Properties as a Function of the Composition and Method of Manufacture
Authors: Petrucci Elisabetta , Porcelli Francesco , Orsini Monica , De Santis Serena , Sotgiu Giovanni
Published: February 2022

The development of mixed oxide electrodes is being intensively investigated to reduce the high cost associated with the use of noble metals and to obtain versatile and long-lasting devices. To evaluate their use for charge storage or anodic oxidation, in this paper, thin-film electrodes coated with ruthenium (RuOx) and copper oxide (CuOx) are fabricated by thermal decomposition of organic solutions containing the precursors by drop-casting on titanium (Ti) foils. The coating consisted of four layers of metal oxide. To investigate the effect of copper (Cu) on electrochemical performances, different approaches are adopted by varying the ratios of precursors’ concentration and including a RuOx interlayer. A comparison with samples obtained by only RuOx has been also performed. The electrodes are characterized using scanning electron microscopy (SEM), cyclic (CV) and linear sweep (LSV) voltammetry, electrochemical impedance spectroscopy (EIS), and corrosion tests. The addition of Cu enhances the capacitive response of the materials and promotes electron transfer reversibility. The coatings obtained by the highest Ru:Cu ratio (95:5) exhibit a more uniform surface distribution and increased corrosion resistance. The interlayer is beneficial to further reduce the corrosion susceptibility and to promote the oxygen evolution but detrimental in the charge storage power. The results suggest the possibility to enhance the electrochemical performance of expensive RuOx through a combination with a low amount of cheaper and more abundant CuOx.
An Electrochemical Study of Gold Dissolution in Thiosulfate Solution with Cobalt–Ammonia Catalysis
Authors: Li Ke , Li Qian , Xu Bin , Yang Yongbin , Jiang Tao
Published: February 2022

Alkali agents could be used to enhance the extraction of zinc from solution, but excess alkali can lead to emulsification of the solution. In this study, the redox couples of Co(III)/Co(II) could be formed based on the thermodynamic analysis, and catalyze the dissolution of gold in a cobalt–ammonia–thiosulfate system. The catalytic mechanism of cobalt–ammonia for gold dissolution in the thiosulfate solution was further proposed by the analysis of polarization curves to be that NH3 catalyzes the dissolution of gold in the anodic area, and Co(NH3)63+ catalyzes the reduction of dissolved oxygen in the cathodic area. In the dissolution of gold, the concentration of NH3, Co3+ and S2O32− increased, and the dissolution of gold increased. The apparent activation energy for gold dissolution is 41.15 kJ/mol in a temperature range of 25–40 °C, and this demonstrates that gold dissolution is chemically controlled. The SEM-EDS and XPS analyses indicate that the precipitate coating on gold surfaces is mainly S2− in CoS and S8. The decomposition of thiosulfate was also carried out in different thiosulfate solutions. Results have shown that the increase of NH3 concentration can reduce thiosulfate decomposition, while the increase of Co3+ and S2O32− concentration can accelerate thiosulfate decomposition. The apparent activation energy for thiosulfate decomposition with the temperature range of 26.6–41 °C is determined to be 22.12 kJ/mol, which shows that thiosulfate decomposition is mixed chemical-diffusion-controlled.
Solidification Calculations of Precious Alloys and Al-Base Alloys for Additive Manufacturing
Authors: Scaglione Federico , Arnaboldi Sergio , Viscardi Cristian , Baricco Marcello , Palumbo Mauro
Published: February 2022

In this paper, we report two cases studies where solidification processes were successfully investigated with CALPHAD-based methodologies. The first one refers to the use of thermodynamic databases to describe the solidification processes of a precious Au-base alloy containing Ir as a grain refiner. The second one concerns the development and use of a quaternary database for Al-Mg-Si-Er alloys for additive manufacturing, where Er is added as a nucleating agent. While in the former case, the solidification process was investigated by running the Thermo-Calc software with a specific TCNOBL1 commercial database, in the latter, the necessary database was first constructed, using available thermodynamic assessments in the literature and experimental data, and then applied to investigate the solidification behavior of selected alloys.
Frictional Behavior and Mechanical Performance of Al Reinforced with SiC via Novel Flake Powder Metallurgy
Authors: Alharthi Nabeel H. , Almotairy Saud M. , Almutairi Abdulrahman M.
Published: February 2022

This paper targets developing new low-cost sustainable materials. To achieve this objective, aluminum was utilized as base material for metal matrix nanocomposites (MMNC). Three routes of advanced manufacturing techniques were designed and implemented. Flake powder metallurgy as a reliable method to synthesis nanocomposites powder was employed. By reinforcing aluminium with SiC and using a similar amount of both constitutes, three metal matrix nanocomposites (MMNCs) with different properties were produced. The ball milled powder were characterized using filed emission scanning electron microscope (FE-SEM) to analyze the morphology of the powder. Different investigations and analysis were conducted on the produced samples. These include X-ray diffraction (XRD) analysis, density and porosity, mechanical properties, and frictional performance. The obtained results include relative density, Young’s modulus, compressive yield strength, elongation, toughness, hardness, coefficient of friction, and specific wear rate. Achieving superior mechanical and tribological performance is evident from these results. This is accredited to the homogeneity of the reinforcement dispersion within the aluminum matrix.
Electrochemical Investigation of Lateritic Ore Leaching Solutions for Ni and Co Ions Extraction
Authors: Mitterecker Jonas , Košević Milica , Stopic Srecko , Friedrich Bernd , Panić Vladimir , Stevanović Jasmina , Mihailović Marija
Published: February 2022

Determination of the extractive behavior of ionic species from lateritic ore leachates is complex, since the leachates are pregnant with tens of different ions in, as a rule, multiple oxide states. To examine the possible pathways of intrinsic electrochemical extraction of the crucial elements Ni and Co, it was necessary to make model solutions of these elements and to subject them to electrochemical examination techniques in order to obtain a benchmark. Beside Ni and Co, the model system for Fe had to be evaluated. Iron, as a dominant ore component by far, is the main interfering factor in the extraction processes of Ni and Co in rather low amounts from leaching solution. The leachate examination results were compared to separate model solutions, as well as to their combinations in concentrations and to pH values comparable to those of the leachate. The separation of the leachate components was initially performed by continuous increase in pH upon leaching with NaOH solution, and afterwards the pH-adjusted solutions were subjected to electrochemical investigation. With the purpose of connecting and quantifying the visual changes in leachate upon increase in pH, conductometric measurements were performed. Reactions of oxidation/precipitations were indicated, which led to the essential Fe removal by precipitation. Resulting solutions were found suitable for Ni and Co electrochemical extraction.
Crystal Chemistry and Electronic Properties of the Al-Rich Compounds, Al2Cu, ω-Al7Cu2Fe and θ-Al13Fe4 with Cu Solution
Authors: Fang Changming , Souissi Maaouia , Que Zhongping , Fan Zhongyun
Published: February 2022

In this work, we investigate Cu solution in θ-Al13Fe4 and related Al-rich ω-Al7Cu2Fe and Al2Cu phases in the Al-Cu-Fe system using the first-principles density functional theory (DFT) with on-site Coulomb interaction correction. The results show preference of Cu at Al7, forming a ternary θ-Al76Cu2Fe24 at ambient conditions, and both Al7 and Al9 sites (in Grin’s note), forming θ-(Al76−xCu2+x)Fe24 at a high temperature. The relative stability of the Al-rich compounds and their crystal and electronic properties are investigated. We show the importance of the Hubbard U correction to the standard DFT functionals for Cu-containing metallic materials. This study helps characterize the intermetallic compounds in Cu-containing Al alloys, and helps further control Fe-containing intermetallic compounds in the solidification of Al-based alloys.