bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost of Coexisting with a Relict Large Carnivore Population: Impact of Apennine Brown Bears, 2005–2015
Authors: Galluzzi Andrea , Donfrancesco Valerio , Mastrantonio Gianluca , Sulli Cinzia , Ciucci Paolo
Published: May 2021

Human-carnivore conflicts are a major conservation issue. As bears are expanding their range in Europe’s human-modified landscapes, it is increasingly important to understand, prevent, and address human-bear conflicts and evaluate mitigation strategies in areas of historical coexistence. Based on verified claims, we assessed costs, patterns, and drivers of bear damages in the relict Apennine brown bear population in the Abruzzo Lazio and Molise National Park (PNALM), central Italy. During 2005–2015, 203 ± 71 (SD) damage events were verified annually, equivalent to 75,987 ± 30,038 €/year paid for compensation. Most damages occurred in summer and fall, with livestock depredation, especially sheep and cattle calves, prevailing over other types of damages, with apiaries ranking second in costs of compensation. Transhumant livestock owners were less impacted than residential ones, and farms that adopted prevention measures loaned from the PNALM were less susceptible to bear damages. Livestock farms chronically damaged by bears represented 8 ± 3% of those annually impacted, corresponding to 24 ± 6% of compensation costs. Further improvements in the conflict mitigation policy adopted by the PNALM include integrated prevention, conditional compensation, and participatory processes. We discuss the implications of our study for Human-bear coexistence in broader contexts.
Karyotype Evolution and Genomic Organization of Repetitive DNAs in the Saffron Finch, Sicalis flaveola (Passeriformes, Aves)
Authors: Kretschmer Rafael , Rodrigues Benilson Silva , Barcellos Suziane Alves , Costa Alice Lemos , Cioffi Marcelo de Bello , Garnero Analía del Valle , Gunski Ricardo José , de Oliveira Edivaldo Herculano Corrêa , Griffin Darren K.
Published: May 2021

The Saffron finch (Sicalis flaveola), a semi-domestic species, is tolerant of human proximity and nesting in roof spaces. Considering the importance of cytogenomic approaches in revealing different aspects of genomic organization and evolution, we provide detailed cytogenetic data for S. flaveola, including the standard Giemsa karyotype, C- and G-banding, repetitive DNA mapping, and bacterial artificial chromosome (BAC) FISH. We also compared our results with the sister groups, Passeriformes and Psittaciformes, bringing new insights into the chromosome and genome evolution of birds. The results revealed contrasting rates of intrachromosomal changes, highlighting the role of SSR (simple short repetition probes) accumulation in the karyotype reorganization. The SSRs showed scattered hybridization, but brighter signals were observed in the microchromosomes and the short arms of Z chromosome in S. flaveola. BACs probes showed conservation of ancestral syntenies of macrochromosomes (except GGA1), as well as the tested microchromosomes. The comparison of our results with previous studies indicates that the great biological diversity observed in Passeriformes was not likely accompanied by interchromosomal changes. In addition, although repetitive sequences often act as hotspots of genome rearrangements, Passeriformes species showed a higher number of signals when compared with the sister group Psittaciformes, indicating that these sequences were not involved in the extensive karyotype reorganization seen in the latter.
Morphological and Histological Features of the Vomeronasal Organ in African Pygmy Hedgehog (Atelerix albiventris)
Authors: Kondoh Daisuke , Tanaka Yusuke , Kawai Yusuke K. , Mineshige Takayuki , Watanabe Kenichi , Kobayashi Yoshiyasu
Published: May 2021

The vomeronasal organ (VNO) detects specific chemicals such as pheromones and kairomones. Hedgehogs (Eulipotyphla: Erinaceidae) have a well-developed accessory olfactory bulb that receives projections from the VNO, but little is known about the hedgehog VNO. Here, we studied the histological features of the VNO in five individual African pygmy hedgehogs by hematoxylin-eosin, periodic acid-Schiff, and Alcian blue stains. The hedgehog VNO comprises a hyaline cartilage capsule, soft tissue and epithelial lumen, and it branches from the site just before the incisive duct opening into the nasal cavity. The soft tissues contain several small mucous (or mucoserous) glands and a large serous gland, and many venous sinuses all around the lumen. The VNO lumen is round to oval throughout the hedgehog VNO, and the sensory epithelium lines almost the entire rostral part and medial wall of the middle part. These findings indicate that the VNO is functional and plays an important role in the hedgehog. Notably, the VNO apparently has a characteristic flushing mechanism with serous secretions like those of gustatory glands, which the hedgehog might frequently use to recognize the external environment.
Antibacterial Activity of TiO2 Nanoparticles Prepared by One-Step Laser Ablation in Liquid
Authors: Khashan Khawla S. , Sulaiman Ghassan M. , Abdulameer Farah A. , Albukhaty Salim , Ibrahem Mohammed A. , Al-Muhimeed Tahani , AlObaid Abeer A.
Published: May 2021

Laser ablation in liquid was utilized to prepare a TiO2 NP suspension in in deionized distilled water using Q-switch Nd: YAG laser at various laser energies and ablation times. The samples were characterized using UV–visible absorption spectra obtained with a UV–visible spectrophotometer (UV-Vis,) Fourier transform infrared (FTIR), X-ray diffraction (XRD), and transmission electron microscope (TEM). While, UV-Vis spectra showed the characteristic band-to-band absorption peak of TiO2 NPs in the UV range. FTIR analysis showed the existence of O-Ti-O bond. XRD patterns indicated the presence of (101) and (112) plane crystalline phases of TiO2. TEM images showed a spherical-like structure of TiO2 NPs with various size distributions depending on the ablation period. It was also found that there is a relationship between laser ablation time and TiO2 NP size distribution, where longer ablation times led to the smaller size distribution. The antibacterial activity of TiO2 NPs was evaluated with different species of bacteria such as Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, and Staphylococcus aureus, using the liquid approach. The optimum activity of TiO2 NPs is found to be against E. coli at 1000 μg mL−1. Furthermore, adding, TiO2 NPs (1000 μg mL−1) in the presence of amoxicillin has a synergic effect on E. coli and S. aureus growth, as measured by the well diffusion method. However, both E. coli (11.6 ± 0.57mm) and S. aureus (13.3 ± 0.57mm) were inhibited by this process.
Reduction of Annual Operational Costs in Power Systems through the Optimal Siting and Sizing of STATCOMs
Authors: Montoya Oscar Danilo , Fuentes Jose Eduardo , Moya Francisco David , Barrios José Ángel , Chamorro Harold R.
Published: May 2021

The problem of the optimal siting and placement of static compensates (STATCOMs) in power systems is addressed in this paper from an exact mathematical optimization point of view. A mixed-integer nonlinear programming model to present the problem was developed with the aim of minimizing the annual operating costs of the power system, which is the sum of the costs of the energy losses and of the installation of the STATCOMs. The optimization model has constraints regarding the active and reactive power balance equations and those associated with the devices’ capabilities, among others. To characterize the electrical behavior of the power system, different load profiles such as residential, industrial, and commercial are considered for a period of 24 h of operation. The solution of the proposed model is reached with the general algebraic modeling system optimization package. The numerical results indicate the positive effect of the dynamic reactive power injections in the power systems on annual operating cost reduction. A Pareto front was built to present the multi-objective behavior of the studied problem when compared to investment and operative costs. The complete numerical validations are made in the IEEE 24-, IEEE 33-, and IEEE 69-bus systems, respectively.
Sargassum Influx on the Mexican Coast: A Source for Synthesizing Silver Nanoparticles with Catalytic and Antibacterial Properties
Authors: López-Miranda Jose Luis , Esparza Rodrigo , González-Reyna Marlen Alexis , España-Sánchez Beatriz Liliana , Hernandez-Martinez Angel Ramon , Silva Rodolfo , Estévez Miriam
Published: May 2021

This work reports, for the first time, the synthesis of silver nanoparticles using extracts of the species of Sargassum natans and Sargassum fluitans (AgNPs-S). Their antibacterial and catalytic properties are compared with silver nanoparticles obtained by chemical synthesis (AgNPs-C). The characterization of AgNPs-S and AgNPs-C was carried out using ultraviolet–visible spectroscopy (UV–Vis), dynamic light scattering (DLS), zeta potential, a scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis. The synthesis of silver nanoparticles using Sargassum extract was optimized through varying experimental parameters, such as the type of solvent used to prepare the extract, the volume of the extract, and the pH of the system. The most efficient sample (AgNPs-S) was prepared with a water–ethanol-based extract, using a 3:1 volumetric ratio of extract: a precursor salt with the addition of 1 mL of NaOH pH = 14. The AgNPs-C were spherical in shape, with an average particle size of 11.55 nm, while the AgNPs-S were polyhedral shaped, with an average particle size of 26.39 nm. The synthesized AgNPs-S were found to have significantly higher catalytic activity for the degradation of methylene blue and more effective antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa than AgNPs-C.
Alexander Technique vs. Targeted Exercise for Neck Pain—A Preliminary Comparison
Authors: Becker Jordan J. , McIsaac Tara L. , Copeland Shawn L. , Cohen Rajal G.
Published: May 2021

Background: Alexander technique private lessons have been shown to reduce chronic neck pain and are thought to work by different mechanisms than exercise. Group classes may also be effective and would be cost-effective. Design: A two-group pre-test/post-test design. Participants were assigned to either a general Alexander technique class or an exercise class designed to target neck pain. Both groups met over 5 weeks for two 60 min sessions/week. Participants: A total of 16 participants with chronic neck pain (aged 50+/−16 years) completed this study. Interventions: The Alexander class used awareness-building methods to teach participants to reduce habitual tension during everyday activities. The exercise class was based on physical therapy standard of care to strengthen neck and back muscles thought to be important for posture. Measures: We assessed neck pain/disability, pain self-efficacy, activation of the sternocleidomastoid muscles during the cranio-cervical flexion test, and posture while participants played a video game. Results: Both groups reported decreased neck pain/disability after the interventions. Sternocleidomastoid activation decreased only in the Alexander group. Conclusion: In this small preliminary study, Alexander classes were at least as effective as exercise classes in reducing neck pain and seemed to work via a different mechanism. Larger, multi-site studies are justified.
Wound Healing and Antioxidant Evaluations of Alginate from Sargassum ilicifolium and Mangosteen Rind Combination Extracts on Diabetic Mice Model
Authors: Wulandari Pugar Arga Cristina , Ilmi Zulfa Nailul , Husen Saikhu Akhmad , Winarni Dwi , Alamsjah Mochammad Amin , Awang Khalijah , Vastano Marco , Pellis Alessandro , MacQuarrie Duncan , Pudjiastuti Pratiwi
Published: May 2021

A diabetic foot ulcer is an open wound that can become sore and frequently occurs in diabetic patients. Alginate has the ability to form a hydrophilic gel when in contact with a wound surface in diabetic patients. Xanthones are the main compounds of mangosteen rind and have antibacterial and anti-inflammatory properties. The purpose of this research was to evaluate the wound healing and antioxidants assay with a combination of alginate from S. ilicifolium and mangosteen rind combination extracts on a diabetic mice model. The characterization of alginate was carried out by size exclusion chromatography with multiple angle laser light scattering (SEC-MALLS) and thermogravimetric analysis (TGA). The M/G ratio of alginate was calculated by using proton nuclear magnetic resonance (1H NMR). The antioxidant activity of mangosteen rind and the combination extracts was determined using the DPPH method. The observed parameters were wound width, number of neutrophils, macrophages, fibrocytes, fibroblasts, and collagen densities. The 36 male mice were divided into 12 groups including non-diabetic control (NC), diabetes alginate (DA), alginate–mangosteen (DAM), and diabetes control (DC) groups in three different groups by a histopathology test on skin tissue. The treatment was carried out for 14 days and mice were evaluated on Days 3, 7, and 14. The SEC-MALLS results showed that the molecular weight and dispersity index (Ð) of alginate were 2.77 × 104 Dalton and 1.73, respectively. The M/G ratio of alginate was 0.77 and described as single-stage decomposition based on TGA. Alginate, mangosteen rind extract, and their combination were divided into weak, medium, and strong antioxidant, respectively. The treatment of the DA and DAM groups showed a decrease in wound width and an increase in the number of fibrocytes, fibroblasts, and macrophages. The number of neutrophils decreased while the percentage of collagen densities increased for all the considered groups.
Optimal Design of Earthquake-Resistant Buildings Based on Neural Network Inversion
Authors: Calledda Carlo , Montisci Augusto , Porcu Maria Cristina
Published: May 2021

An effective seismic design entails many issues related to the capacity-based assessment of the non-linear structural response under strong earthquakes. While very powerful structural calculation programs are available to assist the designer in the code-based seismic analysis, an optimal choice of the design parameters leading to the best performance at the lowest cost is not always assured. The present paper proposes a procedure to cost-effectively design earthquake-resistant buildings, which is based on the inversion of an artificial neural network and on an optimization algorithm for the minimum total cost under building code constraints. An exemplificative application of the method to a reinforced-concrete multi-story building, with seismic demands corresponding to a medium-seismicity Italian zone, is shown. Three design-governing parameters are assumed to build the input matrix, while eight capacity-design target requirements are assigned for the output dataset. A non-linear three-dimensional concentrated plasticity model of the structure is implemented, and time-history dynamic analyses are carried out with spectrum-consistent ground motions. The results show the promising ability of the proposed approach for the optimal design of earthquake-resistant structures.
Characterising the Mould Rectification Process for Designing Scoliosis Braces: Towards Automated Digital Design of 3D-Printed Braces
Authors: Sanz-Pena Inigo , Arachchi Shanika , Halwala-Vithanage Dhammika , Mallikarachchi Sanjaya , Kirumbara-Liyanage Jeewantha , McGregor Alison , Silva Pujitha , Newell Nicolas
Published: May 2021

The plaster-casting method to create a scoliosis brace consists of mould generation and rectification to obtain the desired orthosis geometry. Alternative methods entail the use of 3D scanning and CAD/CAM. However, both manual and digital design entirely rely on the orthotist expertise. Characterisation of the rectification process is needed to ensure that digital designs are as efficient as plaster-cast designs. Three-dimensional scans of five patients, pre-, and post-rectification plaster moulds were obtained using a Structure Mark II scanner. Anatomical landmark positions, transverse section centroids, and 3D surface deviation analyses were performed to characterise the rectification process. The rectification process was characterised using two parameters. First, trends in the external contours of the rectified moulds were found, resulting in lateral tilt angles of 81 ± 3.8° and 83.3 ± 2.6° on the convex and concave side, respectively. Second, a rectification ratio at the iliac crest (0.23 ± 0.04 and 0.11 ± 0.02 on the convex and concave side, respectively) was devised, based on the pelvis width to estimate the volume to be removed. This study demonstrates that steps of the manual rectification process can be characterised. Results from this study can be fed into software to perform automatic digital rectification.
Transient Numerical Modelling of the Pin-in-Paste Technology
Authors: Al-Ma'aiteh Tareq Ibrahim , Krammer Oliver , Illés Balázs
Published: May 2021

The pin-in-paste technology is an advancing soldering technology for assembling complex electronic products, which include both surface-mounted and through-hole components. A computational fluid dynamics model was established to investigate the stencil printing step of this technology, where the hole-filling by the solder pastes is the most critical factor for acquiring reliable solder joints. The geometry of the transient numeric model included the printing squeegee, the stencil, and the through-holes of a printed circuit board with different geometries and arrangements. A two-phase fluid model (solder paste + air) was applied, utilizing the Volume of Fluid method (VoF). The rheological properties of the solder paste were addressed by an exhaustive viscosity model. It was found that the set of through-holes affected the flow-field and yielded a decrease in the hole-filling if they were arranged in parallel with the travelling direction of the printing squeegee. Similar disturbance on the flow-field was found for oblong-shaped through-holes if they were arranged in parallel with the squeegee movement. The findings imply that the arrangement of a set of through-holes and the orientation of oblong-shaped through-holes should be optimized even in the early design phase of electronic products and during the set of assembly processes. The soldering failures in pin-in-paste technology can be reduced by these early design-phase considerations, and the first-pass yield of electronic soldering technologies can be enhanced.
Color of Pan Trap Influences Sampling of Bees in Livestock Pasture Ecosystem
Authors: Acharya Roshani S. , Leslie Timothy , Fitting Emily , Burke Joan , Loftin Kelly , Joshi Neelendra K.
Published: May 2021

The decline in insect pollinators has increased the importance of accurately monitoring pollinator diversity and abundance over time. Sampling techniques include the use of passive insect traps such as pan traps, yet there is still discussion over their utility and effectiveness in different ecosystems. The objective was to examine four different colors of pan traps (blue, green, yellow, and purple) for their utility in sampling bees in native forages rotationally grazed by sheep and to compare the relative abundance, richness, similarity, and community assemblage patterns among the four trap colors. Most bees were from the Halictidae family (89%). The most abundant species were Lasioglossum imitatum (42.2%), Augochlorella aurata (8.3%), L. subviridatum (6.8), Agapostemon texanus (6.4), and L. birkmani (4.1%). Blue color traps exhibited the highest rates of bee capture and species accumulation. Purple and yellow colored traps were moderately effective in capturing bees, while the green color pan traps were least effective. Similarly, observed and extrapolated species richness was highest in blue trap, followed by purple, yellow, and green. Notably, the blue trap captured the highest number of unique species, followed by purple, yellow and green traps. Considering the total number of insects collected (including bees and other insects), yellow and green traps captured a significantly higher number of insects than other colored traps. The light reflectance from blue, purple, green and yellow pan traps had peaks at ~450, 400, 550, and 600 nm, respectively. Since different insects respond to different light intensities, wavelengths, and reflectivity, these results could be used to guide future trapping protocols targeting certain insect groups in livestock pasture and similar ecosystems.
Thermal Properties and Structural Features of Multilayer Films Based on Chitosan and Anionic Polysaccharides
Authors: Gubanova Galina , Petrova Valentina , Kononova Svetlana , Popova Elena , Smirnova Valentina , Bugrov Alexander , Klechkovskaya Vera , Skorik Yury
Published: May 2021

This study investigates the thermal and structural properties of multilayer composites based on chitosan (CS) and polyanions with different functionalities, including sodium sulfoethyl cellulose (SEC), sodium alginate (ALG), and sodium hyaluronate (HA). Unlike polyelectrolyte complexes (PECs) obtained by polymer mixing, the formation of a PEC layer by a process of layer-by-layer deposition of oppositely charged polymers is accompanied by the transformation of the CS polymorphic state, and this affects the relaxation and thermal properties of the resulting multilayer composite. X-ray diffraction analysis showed that the formation of the PEC layer in the CS/SEC multilayer film is accompanied by crystallization of the CS chains and the formation of a predominantly anhydrous CS modification. Thermogravimetric analysis of the CS/SEC film registers a high-temperature peak associated with the thermal decomposition of crystalline CS in the PEC composition. According to the dynamic mechanical analysis, the CS/SEC composite was characterized by a single glass transition temperature, indicating a strong interaction between the layers when using SEC (a strong acid salt) as the counterion to CS. For multilayer composites with weak polyacid salts (ALG and HA), the crystallization of CS in the PEC layer is weaker, as reflected in the thermal degradation of these films. A high-temperature peak is recorded in the thermal decomposition of CS/HA and is absent in the case of CS/ALG. Dynamic mechanical analysis of the CS/ALG composite showed two glass transition temperatures close to those of the original polymers, indicating weak PEC formation. The CS/HA composite showed an intermediate response. Thus, the effect of the PEC layer on the properties of the poly-layer composites decreases in the order CS/SEC > CS/HA > CS/ALG.
Store Operated Calcium Entry in Cell Migration and Cancer Metastasis
Authors: Hammad Ayat S. , Machaca Khaled
Published: May 2021

Ca2+ signaling is ubiquitous in eukaryotic cells and modulates many cellular events including cell migration. Directional cell migration requires the polarization of both signaling and structural elements. This polarization is reflected in various Ca2+ signaling pathways that impinge on cell movement. In particular, store-operated Ca2+ entry (SOCE) plays important roles in regulating cell movement at both the front and rear of migrating cells. SOCE represents a predominant Ca2+ influx pathway in non-excitable cells, which are the primary migrating cells in multicellular organisms. In this review, we summarize the role of Ca2+ signaling in cell migration with a focus on SOCE and its diverse functions in migrating cells and cancer metastasis. SOCE has been implicated in regulating focal adhesion turnover in a polarized fashion and the mechanisms involved are beginning to be elucidated. However, SOCE is also involved is other aspects of cell migration with a less well-defined mechanistic understanding. Therefore, much remains to be learned regarding the role and regulation of SOCE in migrating cells.
Modulation of Cyclic AMP Levels in Fallopian Tube Cells by Natural and Environmental Estrogens
Authors: Rosselli Marinella , Cometti Barbara P. S. , Leeners Brigitte , Szutkowska Marta Ewa , Jackson Edwin K. , Dubey Raghvendra K.
Published: May 2021

Autocrine/paracrine factors generated in response to 17β-estradiol (E2) within the fallopian tube (FT) facilitate fertilization and early embryo development for implantation. Since cyclic AMP (cAMP) plays a key role in reproduction, regulation of its synthesis by E2 may be of biological/pathophysiological relevance. Herein, we investigated whether cAMP production in FT cells (FTCs) is regulated by E2 and environmental estrogens (EE’s; xenoestrogens and phytoestrogens). Under basal conditions, low levels of extracellular cAMP were detectable in bovine FTCs (epithelial cells and fibroblasts; 1:1 ratio). Treatment of FTCs with forskolin (AC; adenylyl cyclase activator), isoproterenol (β-adrenoceptor agonist) and IBMX (phosphodiesterase (PDE) inhibitor) dramatically (>10 fold) increased cAMP; whereas LRE1 (sAC; soluble AC inhibitor) and 2’,5’-dideoxyadenosine (DDA; transmembrane AC (tmAC)) inhibitor decreased cAMP. Comparable changes in basal and stimulated intracellular cAMP were also observed. Ro-20-1724 (PDE-IV inhibitor), but not milrinone (PDE-III inhibitor) nor mmIBMX (PDE-I inhibitor), augmented forskolin-stimulated cAMP levels, suggesting that PDE-IV dominates in FTCs. E2 increased cAMP levels and CREB phosphorylation in FTCs, and these effects were mimicked by EE’s (genistein, 4-hydroxy-2’,4’,6’-trichlorobiphenyl, 4-hydroxy-2’,4’,6’-dichlorobiphenyl). Moreover, the effects of E2 and EE were blocked by the tmAC inhibitor DDA, but not by the ERα/β antagonist ICI182780. Moreover, BAPTA-AM (intracellular-Ca2+ chelator) abrogated the effects of E2, but not genistein, on cAMP suggesting differential involvement of Ca2+. Treatment with non-permeable E2-BSA induced cAMP levels and CREB-phosphorylation; moreover, the stimulatory effects of E2 and EEs on cAMP were blocked by G15, a G protein-coupled estrogen receptor (GPER) antagonist. E2 and IBMX induced cAMP formation was inhibited by LRE1 and DDA suggesting involvement of both tmAC and sAC. Our results provide the first evidence that in FTCs, E2 and EE’s stimulate cAMP synthesis via GPER. Exposure of the FT to EE’s and PDE inhibitors may result in abnormal non-cyclic induction of cAMP levels which may induce deleterious effects on reproduction.
Human Umbilical Cord-Derived Mesenchymal Stem Cells Promote Corneal Epithelial Repair In Vitro
Authors: Kacham Santhosh , Bhure Tejal Sunil , Eswaramoorthy Sindhuja D. , Naik Gaurav , Rath Subha Narayan , Parcha Sreenivasa Rao , Basu Sayan , Sangwan Virender Singh , Shukla Sachin
Published: May 2021

Corneal injuries are among the leading causes of blindness and vision impairment. Trauma, infectious keratitis, thermal and chemical (acids and alkali burn) injuries may lead to irreversible corneal scarring, neovascularization, conjunctivalization, and limbal stem cell deficiency. Bilateral blindness constitutes 12% of total global blindness and corneal transplantation remains a stand-alone treatment modality for the majority of end-stage corneal diseases. However, global shortage of donor corneas, the potential risk of graft rejection, and severe side effects arising from long-term use of immunosuppressive medications, demands alternative therapeutic approaches. Umbilical cord-derived mesenchymal stem cells can be isolated in large numbers using a relatively less invasive procedure. However, their role in injury induced corneal repair is largely unexplored. Here, we isolated, cultured and characterized mesenchymal stem cells from human umbilical cord, and studied the expression of mesenchymal (CD73, CD90, CD105, and CD34), ocular surface and epithelial (PAX6, WNT7A, and CK-8/18) lineage markers through immunofluorescence. The cultured human limbal and corneal epithelial cells were used as controls. Scratch assay was used to study the corneal epithelial repair potential of umbilical cord-derived mesenchymal stem cells, in vitro. The in vitro cultured umbilical cord-derived mesenchymal stem cells were plastic adherent, showed trilineage differentiation and expressed: mesenchymal markers CD90, CD105, CD73; epithelial marker CK-8/18, and ocular lineage developmental markers PAX6 and WNT-7A. Our findings suggest that umbilical cord-derived mesenchymal stem cells promote repair of the injured corneal epithelium by stimulating the proliferation of corneal epithelial cells, in vitro. They may serve as a potential non-ocular source of stem cells for treating injury induced bilateral corneal diseases.
Chromosome Instability, Aging and Brain Diseases
Authors: Iourov Ivan Y. , Yurov Yuri B. , Vorsanova Svetlana G. , Kutsev Sergei I.
Published: May 2021

Chromosome instability (CIN) has been repeatedly associated with aging and progeroid phenotypes. Moreover, brain-specific CIN seems to be an important element of pathogenic cascades leading to neurodegeneration in late adulthood. Alternatively, CIN and aneuploidy (chromosomal loss/gain) syndromes exhibit accelerated aging phenotypes. Molecularly, cellular senescence, which seems to be mediated by CIN and aneuploidy, is likely to contribute to brain aging in health and disease. However, there is no consensus about the occurrence of CIN in the aging brain. As a result, the role of CIN/somatic aneuploidy in normal and pathological brain aging is a matter of debate. Still, taking into account the effects of CIN on cellular homeostasis, the possibility of involvement in brain aging is highly likely. More importantly, the CIN contribution to neuronal cell death may be responsible for neurodegeneration and the aging-related deterioration of the brain. The loss of CIN-affected neurons probably underlies the contradiction between reports addressing ontogenetic changes of karyotypes within the aged brain. In future studies, the combination of single-cell visualization and whole-genome techniques with systems biology methods would certainly define the intrinsic role of CIN in the aging of the normal and diseased brain.
Controlling Film Thickness Distribution by Magnetron Sputtering with Rotation and Revolution
Authors: Huang Handan , Jiang Li , Yao Yiyun , Zhang Zhong , Wang Zhanshan , Qi Runze
Published: May 2021

The laterally graded multilayer collimator is a vital part of a high-precision diffractometer. It is applied as condensing reflectors to convert divergent X-rays from laboratory X-ray sources into a parallel beam. The thickness of the multilayer film varies with the angle of incidence to guarantee every position on the mirror satisfies the Bragg reflection. In principle, the accuracy of the parameters of the sputtering conditions is essential for achieving a reliable result. In this paper, we proposed a precise method for the fabrication of the laterally graded multilayer based on a planetary motion magnetron sputtering system for film thickness control. This method uses the fast and slow particle model to obtain the particle transport process, and then combines it with the planetary motion magnetron sputtering system to establish the film thickness distribution model. Moreover, the parameters of the sputtering conditions in the model are derived from experimental inversion to improve accuracy. The revolution and rotation of the substrate holder during the final deposition process are achieved by the speed curve calculated according to the model. Measurement results from the X-ray reflection test (XRR) show that the thickness error of the laterally graded multilayer film, coated on a parabolic cylinder Si substrate, is less than 1%, demonstrating the effectiveness of the optimized method for obtaining accurate film thickness distribution.
Bonding and Thermal-Mechanical Property of Gradient NiCoCrAlY/YSZ Thermal Barrier Coatings with Millimeter Level Thickness
Authors: Wang Yu , Liu Qi , Zheng Quansheng , Li Tianqing , Chong Nanjing , Bai Yu
Published: May 2021

The thermal insulation properties of thermal barrier coatings (TBCs) can be significantly improved with increasing the coating thickness. However, due to the weak bonding of high-thickness TBCs, the low reliability and short lifetime greatly limits their application under some severe operating conditions. In this study, a novel and high-efficiency synchronous dual powder feeding method is used to deposit a series of gradient NiCoCrAlY/YSZ coatings with millimeter level thickness. The tensile bonding strengths and residual stress state of coatings are evaluated in order to explore the effect of thickness on the bonding strength of coatings. The results suggested that, due to some micro-convex structure at the “GC/TC” interface and inside “GC” layer, the bonding strength of 1000-μm-thickness gradient NiCoCrAlY/YSZ TBCs with the 4:6 and 2:8 hybrid ratios is over 44 MPa compared to the common TBCs. The fracture position gradually shifts from NiCoCrAlY bond coat to NiCoCrAlY/YSZ transition zone and finally to the YSZ top coat owing to the different position of residual stress concentrations. After thermal cycling tests, the 1000-μm-thickness gradient coating exhibits a higher thermal cycling life. Some coarse cracks initiate and propagate at the bottom region of TBCs, which is mainly due to thermal expansion mismatch stress that finally results in the failure of the gradient coating between the “BC” layer and the substrate.
Fabrication and Characterization of Fiber-Reinforced Composite Sandwich Structures Obtained by Fused Filament Fabrication Process
Authors: Buican George Razvan , Zaharia Sebastian-Marian , Pop Mihai Alin , Chicos Lucia-Antoneta , Lancea Camil , Stamate Valentin-Marian , Pascariu Ionut Stelian
Published: May 2021

The application of fused filament fabrication processes is rapidly expanding in many domains such as aerospace, automotive, medical, and energy, mainly due to the flexibility of manufacturing structures with complex geometries in a short time. To improve the mechanical properties of lightweight sandwich structures, the polymer matrix can be strengthened with different materials, such as carbon fibers and glass fibers. In this study, fiber-reinforced composite sandwich structures were fabricated by FFF process and their mechanical properties were characterized. In order to conduct the mechanical tests for three-point bending, tensile strength, and impact behavior, two types of skins were produced from chopped carbon-fiber-reinforced skin using a core reinforced with chopped glass fiber at three infill densities of 100%, 60%, and 20%. Using microscopic analysis, the behavior of the breaking surfaces and the most common defects on fiber-reinforced composite sandwich structures were analyzed. The results of the mechanical tests indicated a significant influence of the filling density in the case of the three-point bending and impact tests. In contrast, the filling density does not decisively influence the structural performance of tensile tests of the fiber-reinforced composite sandwich structures. Composite sandwich structures, manufactured by fused filament fabrication process, were analyzed in terms of strength-to-mass ratio. Finite element analysis of the composite sandwich structures was performed to analyze the bending and tensile behavior.
The Effect of Extraction Conditions on the Barrier and Mechanical Properties of Kefiran Films
Authors: Pop Carmen Rodica , Coldea Teodora Emilia , Salanţă Liana Claudia , Nistor Alina Lăcrămioara , Borşa Andrei , Fărcaș Anca Corina , Florian Vasile Constantin , Rotar Ancuţa Mihaela
Published: May 2021

Kefiran is an exopolysaccharide classified as a heteropolysaccharide comprising glucose and galactose in equimolar quantities, and it is classified as a water-soluble glucogalactan. This work aimed to investigate the effect of different extraction conditions of kefiran on the structural and physical properties of the edible films obtained. Fourier-transform infrared spectroscopy and scanning electron microscopy were performed, together with a determinations of moisture content, solubility, water vapor permeability and degree of swelling. The kefiran films presented values of the water vapor permeability between 0.93 and 4.38 × 10−11 g/m.s.Pa. These results can be attributed to the development of a more compact structure, where glycerol had no power to increase the free volume and the water vapor diffusion through their structure. The possible conformational changes in the kefiran film structure, due to the interspersing of the plasticizers and water molecules that they absorb, could be the reason for producing flexible kefiran films in the case of using glycerol as a plasticizer at 7.5% w/w. Moreover, it was observed that the extraction conditions are a significant factor in the properties of these films and their food technology applications.
Analysis of Different Mould Section Sizes to Optimize the Submerged Entry Nozzle to Measure the Meniscus Fluctuation in a Continuous Casting Mould
Authors: Kumar Manish , Mishra Praveen , Roy Apurba Kumar
Published: May 2021

An experimental investigation has been carried out to analyse different mould section sizes to measure the meniscus fluctuation by varying different liquid flow rates and different submerged entry nozzle port angles, i.e., 0° port angles, 15° downward and 15° upward port angles. The terms of maximum surface wave fluctuation and standard deviation have been analysed for the above mentioned parameters. It was observed that a submerged entry nozzle with 0° port was found to be superior when it was compared with a 15° downward and 15° upward port nozzle. By conducting an experiment, it was observed that as the water flow rate increased, the maximum wave amplitude was found to be increasing, which results in more turbulence. Different mould section sizes were analysed to provide background information to the steelmaker to analyse the behaviour of fluid flow pattern. The operating parameters of the result obtained from the present setup were compared with the published literature, and a scale down of slab moulds can be justifiedregarding the rough flow pattern in the mould but can lack accuracy. The reason behind this statement is that the integral length scales of the turbulent flow between scaled down and full scale models can be different. Therefore, details of the flow pattern can become great differences between both types of models.
Comparison of MRI Visualization Following Minimally Invasive and Open TLIF: A Retrospective Single-Center Study
Authors: Byvaltsev Vadim A. , Kalinin Andrei A. , Giers Morgan B. , Shepelev Valerii V. , Pestryakov Yurii Ya. , Biryuchkov Mikhail Yu.
Published: May 2021

Analysis of magnetic resonance image (MRI) quality after open (Op)-transforaminal interbody fusion (TLIF) and minimally invasive (MI)-TLIF with the implantation of structurally different systems has not previously been performed. The objective of this study was to conduct a comparative analysis of the postoperative MRI following MI and Op one-segment TLIF. Material and Methods: The nonrandomized retrospective single-center study included 80 patients (46 men and 24 women) aged 48 + 14.2 years. In group I (n = 20) Op-TLIF with open transpedicular screw fixation (TSF) was performed, in II group (n = 60), the MI-TLIF technique was used: IIa (n = 20)—rigid interspinous stabilizer; IIb (n = 20)—unilateral TSF and contralateral facet fixation; IIc (n = 20)—bilateral TSF. Results: Comparison of the quality of postoperative imaging in IIa and IIb subgroups showed fewer MRI artifacts and a significantly greater MR deterioration after Op and MI TSF. Comparison of the multifidus muscle area showed less atrophy after MI-TLIF and significantly greater atrophy after Op-TLIF. Conclusion: MI-TLIF and Op-TLIF with TSF have comparable postoperative MR artifacts at the operative level, with a greater degree of muscle atrophy using the Op-TLIF. Rigid interspinous implant and unilateral TSF with contralateral facet fixation have less artifacts and changes in the multifidus muscle area.
Is the Devil in h?
Authors: Khrennikov Andrei
Published: May 2021

This note is a part of my effort to rid quantum mechanics (QM) nonlocality. Quantum nonlocality is a two faced Janus: one face is a genuine quantum mechanical nonlocality (defined by the Lüders’ projection postulate). Another face is the nonlocality of the hidden variables model that was invented by Bell. This paper is devoted the deconstruction of the latter. The main casualty of Bell’s model is that it straightforwardly contradicts Heisenberg’s uncertainty and Bohr’s complementarity principles generally. Thus, we do not criticize the derivation or interpretation of the Bell inequality (as was done by numerous authors). Our critique is directed against the model as such. The original Einstein-Podolsky-Rosen (EPR) argument assumed the Heisenberg’s principle without questioning its validity. Hence, the arguments of EPR and Bell differ crucially, and it is necessary to establish the physical ground of the aforementioned principles. This is the quantum postulate: the existence of an indivisible quantum of action given by the Planck constant. Bell’s approach with hidden variables implicitly implies rejection of the quantum postulate, since the latter is the basis of the reference principles.
Model Decoupled Synchronization Control Design with Fractional Order Filter for H-Type Air Floating Motion Platform
Authors: Sun Yixiu , Zeng Lizhan , Luo Ying , Li Xiaoqing
Published: May 2021

H-type motion platform with linear motors is widely used in two-degrees-of-freedom motion systems, and one-direction dual motors need to be precisely controlled with strict synchronization for high precision performance. In this paper, a synchronous control method based on model decoupling is proposed. The dynamic model of an H-type air floating motion platform is established and one direction control using two motors with position dependency coupling is decoupled and converted into independent position and rotation controls, separately. For the low damping second-order oscillation system of the rotation control loop, a new fractional order biquad filtering method is proposed to generate an antiresonance peak to improve the phase and control gain of the open loop system, which can ensure system stability and quick attenuation for external disturbances. In the multiple-degree-of-freedom decoupled control loops, a systematic feedback controller design methodology is proposed to satisfy the given frequency domain design specifications; a feed-forward control strategy is also applied to compensate the disturbance torque caused by the platform motion. The simulation and experimental results demonstrate that the proposed synchronization control method is effective, and achieves better disturbance rejection performance than the existing optimal cancellation filtering method and biquad filtering method.
Mitigation of the Effects of Network Outage on Video QoE Using a Sender Buffer
Authors: Minhas Tahir Nawaz , Fiedler Markus
Published: May 2021

With the growth of multimedia applications and the mobile Internet, quality sense and quality expectation of the end-user are rising rapidly. A small notable distortion in the multimedia applications may degrade the degree of delight of the user, who is very considerate of the video Quality of Experience (QoE). During live streaming, a network outage may result in video freezes and video jumps. To dampen the impact of a network outage on the video QoE, we propose the use of a well-sized sender buffer. We present the concept, derive key analytical relations, and perform a set of subjective tests. Based on those, we report a significant enhancement of user ratings due to the proposed sender buffer in the presence of network outages.
Common-Mode Voltage Harmonic Reduction in Variable Speed Drives Applying a Variable-Angle Carrier Phase-Displacement PWM Method
Authors: Marquez Alcaide Abraham , Monopoli Vito Giuseppe , Wang Xuchen , Leon Jose I. , Buticchi Giampaolo , Vazquez Sergio , Liserre Marco , Franquelo Leopoldo G.
Published: May 2021

Electric variable speed drives (VSD) have been replacing mechanic and hydraulic systems in many sectors of industry and transportation because of their better performance and reduced cost. However, the electric systems still face the issue of being considered less reliable than the mechanical ones. For this reason, researchers have been actively investigating effective ways to increase the reliability of such systems. This paper is focused on the analysis of the common-mode voltage (CMV) generated by the operation of the VSDs which directly affects to the lifetime and reliability of the complete system. The method is based on the mathematical description of the harmonic spectrum of the CMV depending on the PWM method implementation. A generalized PWM method where the carriers present a variable phase-displacement is developed. As a result of the presented analysis, the CMV reduction is achieved by applying the PWM method with optimal carrier phase-displacement angles without any external component and/or passive filtering technique. The optimal values of the carrier phase-displacement angles are obtained considering the minimization of the CMV total harmonic distortion. The resulting method is easily implementable on mostly off-the-shelf mid-range micro-controller control platforms. The strategy has been evaluated in a scaled-down experimental setup proving its good performance.
Exploring the Potentialities of Deep Reinforcement Learning for Incentive-Based Demand Response in a Cluster of Small Commercial Buildings
Authors: Deltetto Davide , Coraci Davide , Pinto Giuseppe , Piscitelli Marco Savino , Capozzoli Alfonso
Published: May 2021

Demand Response (DR) programs represent an effective way to optimally manage building energy demand while increasing Renewable Energy Sources (RES) integration and grid reliability, helping the decarbonization of the electricity sector. To fully exploit such opportunities, buildings are required to become sources of energy flexibility, adapting their energy demand to meet specific grid requirements. However, in most cases, the energy flexibility of a single building is typically too small to be exploited in the flexibility market, highlighting the necessity to perform analysis at a multiple-building scale. This study explores the economic benefits associated with the implementation of a Reinforcement Learning (RL) control strategy for the participation in an incentive-based demand response program of a cluster of commercial buildings. To this purpose, optimized Rule-Based Control (RBC) strategies are compared with a RL controller. Moreover, a hybrid control strategy exploiting both RBC and RL is proposed. Results show that the RL algorithm outperforms the RBC in reducing the total energy cost, but it is less effective in fulfilling DR requirements. The hybrid controller achieves a reduction in energy consumption and energy costs by respectively 7% and 4% compared to a manually optimized RBC, while fulfilling DR constraints during incentive-based events.