bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Schisandra chinensis Extract Supplementation on Quadriceps Muscle Strength and Fatigue in Adult Women: A Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Park Jinkee , Han Seoungho , Park Hyuntae
Published: April 2020

The fruit of Schisandra chinensis (SC) is a well-known traditional herb used for pharmacological purposes in Asian countries (e.g., Korea, China, and Japan). In animal studies, SC extract supplementation had beneficial effects on muscle strength and lactate level. However, the effect of SC extract supplementation on skeletal muscle strength and lactate at rest in humans remains unclear. The purpose of this study was to evaluate the effect of SC extract supplementation on quadriceps muscle strength (QMS) and lactate at rest in adult women. Forty five healthy post-menopausal middle-aged women (61.9 ± 8.4 years) were randomly divided into the SC (n = 24) or the placebo group (n = 21). The SC group consumed 1000 mg of SC extract per day, whereas the placebo group consumed 1000 mg of starch per day for 12 weeks. The difference in muscle mass, physical function, and biomarkers and the relative changes between baseline and 12 weeks were evaluated. We used two-factor repeated measures analysis of variance (ANOVA) to determine interaction (group × time) effects for variables. Statistical significance was accepted at p < 0.05. In ANOVA results, QMS (p = 0.001) and lactate level (p = 0.038) showed significant interactions. With paired t-tests, QMS was significantly increased (p < 0.001) and lactate level at rest was significantly decreased (p < 0.05) after 12 weeks in the SC group. However, no interactions were found between the other variables. Supplementation of SC extract may help to improve QMS as well as decrease lactate level at rest in adult women. We believe that SC extract is a health supplement that can support healthy life in this population.
Humor Styles as New Resources in a Primary Preventive Perspective: Reducing Resistance to Change for Negotiation
Authors: Di Fabio Annamaria , Duradoni Mirko
Published: April 2020

Reducing resistance to change is fundamental to dealing with the rapid and continuous changes of the 21st century labor market. Personality traits have been widely studied in relation to resistance to change. However, personality is not completely suitable for primary prevention intervention, since it does not change over time. Instead, humor styles appear to be a promising preventive resource to facilitate the negotiation process by enabling individuals to cope with the current work environment. Using a sample of 149 university students, this study analyzed the relationship between personality traits, such as extraversion and emotionality, humor styles, and resistance to change. The mediation analysis highlighted that both affiliative and self-enhancing humor styles could promote integrative negotiations within organizations in relation to change, due to their negative relationships with resistance to change. Thus, implementing dedicated interventions to increase the usage of affiliative and self-enhancing humor styles could help in lowering the failure risk in negotiation processes, supporting changes.
Relationship between School Backpacks and Musculoskeletal Pain in Children 8 to 10 Years of Age: An Observational, Cross-Sectional and Analytical Study
Authors: López Hernández Tania , Caparó Ferré Marina , Giné Martí Sílvia , Salvat Salvat Isabel
Published: April 2020

Back pain in children is a reality and various factors are involved in its etiology. The study’s aim was to analyze the relationship between the use and type of backpack and pain in children. An analytical observational cross-sectional study was conducted among 123 schoolchildren between 8–10 years. Data on the participants’ weight and height and their backpacks were collected, as well as the way of travel to school and their physical activity during the week. The results indicated that all backpacks were large because the backpack’s height is longer than torso length. Participants who studied in a traditional educational system (62.60%) carried backpacks that exceeded 10% of their body weight. Additionally, 31.7% of the students presented pain. There is no significant correlation between the weight or type of backpack and the pressure pain threshold collected from shoulders muscles. Participants who carried backpacks heavier than 10% of their body weight did not have more musculoskeletal pain or a lower pressure pain threshold than the others, although they did report greater fatigue. All these topics should be debated considering the student’s social environment and the backpack’s discomfort to the children, even though no relationship was found between musculoskeletal pain and backpack weight.
Fear of Falling among Older Patients Admitted to Hospital after Falls in Vietnam: Prevalence, Associated Factors and Correlation with Impaired Health-Related Quality of Life
Authors: Nguyen Long Hoang , Thu Vu Giang , Ha Giang Hai , Tat Nguyen Cuong , Vu Hai Minh , Nguyen Tien Quoc , Tran Tung Hoang , Pham Kiet Tuan Huy , Latkin Carl A. , Xuan Tran Bach , Ho Roger C.M. , Ho Cyrus S.H.
Published: April 2020

Fear of falling (FOF) diminishes older people’s independence in daily activities, as well as causes serious health and economic consequences. This study examined the prevalence of FOF in older patients hospitalized due to fall-injuries, its effect on health-related quality of life (HRQOL), and its associated factors. We conducted a cross-sectional study in seven hospitals in Thai Binh, Vietnam. FOF was assessed using a single close-ended question. HRQOL was evaluated by the EQ-5D-5L instrument. Multilevel logistic regression and Tobit regression models were utilized. The prevalence of FOF in 405 older patients admitted to hospitals after fall injuries was 88.2%, with a mean EQ-5D index and EQ-VAS of 0.34 (SD = 0.38) and 61.6 (SD = 15.2), respectively. Factors associated with FOF included living alone (OR = 0.13, 95%CI = 0.04; 0.50.,), history of eye diseases (OR = 4.12; 95%CI = 1.91; 8.89), and experiencing psychological distress (OR= 3.56, 95% CI = 1.05; 12.00). After adjusting for confounders, the EQ-5D index in the FOF group reduced by 0.15 points (Coef. = −0.15; 95%CI= −0.24; −0.05) compared to that of non-FOF group. Our study shows that FOF had an independent negative relationship with HRQOL of patients. Improving knowledge about fall prevention in patients and caregivers could reduce the burden of falls in older people.
The Prevalence of Injuries and Traumas in Elite Goalball Players
Authors: Zwierzchowska Anna , Rosołek Barbara , Celebańska Diana , Gawlik Krystyna , Wójcik Martyna
Published: April 2020

Background: The last decade has seen the dynamic development of Paralympic sport, including the development of training facilities and training methods that allow for the achievement of results at the highest level in this group. This may be associated with an increased risk of injury and traumas. This study aimed to evaluate the prevalence and locations of injuries and the types of trauma suffered by goalball players. Methods: The study covered 43 players (24 women and 19 men) of the Goalball European Championship. A questionnaire survey was conducted. Results: The injuries were reported by 44%. Most often they concerned the upper limbs (92%). Positive correlations were found between age and prevalence of pelvis and knee joint injuries, whereas negative correlations occurred between competitive experience and the prevalence and location of injuries in the area of the upper limb. The highest percentage of trauma was found for epidermal abrasions, contusions, and dislocations. A negative correlation was observed between age and the prevalence of epidermal abrasions, whereas a positive correlation occurred between age and the prevalence of sprains and dislocations. The competitive experience was negatively correlated with the prevalence of abrasions and contusions and positively correlated with the prevalence of sprains and dislocations. A statistically significant correlation was found between body mass (BM) and the prevalence of injuries. In 23% of cases, training was interrupted for more than one month, whereas in 43%, the break was below one month. Conclusions: Playing position in goalball does not affect the prevalence of injuries and traumas, while body mass has a moderate effect on the prevalence of these events. The age of the subjects and their sports experience impact significantly on the prevalence and types of injuries.
Impact of Capital Regulation and Market Discipline on Capital Ratio Selection: A Cross Country Study
Authors: Hunjra Ahmed Imran , Zureigat Qasim , Mehmood Rashid
Published: April 2020

We aim to analyze the impact of capital regulation and market discipline on capital to risk-weighted assets ratio. We used the panel data of Asian developing-countries banks for the period from 2009 to 2018. We collected data from the financial statements of 73 banks of Pakistan, Jordan, Indonesia, the Philippines, Saudi Arabia, and Thailand. We used the generalized method of moment (GMM) to analyze the results. We find that capital regulation and market disciplines significantly influence the capital ratio in Asian developing countries.
Antibodies, Nanobodies, or Aptamers—Which Is Best for Deciphering the Proteomes of Non-Model Species?
Authors: Dhar Poshmaal , Samarasinghe Rasika M. , Shigdar Sarah
Published: April 2020

This planet is home to countless species, some more well-known than the others. While we have developed many techniques to be able to interrogate some of the “omics”, proteomics is becoming recognized as a very important part of the puzzle, given how important the protein is as a functional part of the cell. Within human health, the proteome is fairly well-established, with numerous reagents being available to decipher cellular pathways. Recent research advancements have assisted in characterizing the proteomes of some model (non-human) species, however, in many other species, we are only just touching the surface. This review considers three main reagent classes—antibodies, aptamers, and nanobodies—as a means of continuing to investigate the proteomes of non-model species without the complications of understanding the full protein signature of a species. Considerations of ease of production, potential applications, and the necessity for producing a new reagent depending on homology are presented.
Detecting the Effects of the Glucocorticoid Dexamethasone on Primary Human Skeletal Muscle Cells—Differences to the Murine Cell Line
Authors: Langendorf Eva K. , Rommens Pol M. , Drees Philipp , Mattyasovszky Stefan G. , Ritz Ulrike
Published: April 2020

Skeletal muscle atrophy is characterized by a decrease in muscle fiber size as a result of a decreased protein synthesis, which leads to degradation of contractile muscle fibers. It can occur after denervation and immobilization, and glucocorticoids (GCs) may also increase protein breakdown contributing to the loss of muscle mass and myofibrillar proteins. GCs are already used in vitro to induce atrophic conditions, but until now no studies with primary human skeletal muscle existed. Therefore, this study deals with the effects of the GC dexamethasone (dex) on primary human myoblasts and myotubes. After incubation with 1, 10, and 100 µM dex for 48 and 72 h, gene and protein expression analyses were performed by qPCR and Western blot. Foxo, MuRF-1, and MAFbx were significantly upregulated by dex, and there was increased gene expression of myogenic markers. However, prolonged incubation periods demonstrated no Myosin protein degradation, but an increase of MuRF-1 expression. In conclusion, applying dex did not only differently affect primary human myoblasts and myotubes, as differences were also observed when compared to murine cells. Based on our findings, studies using cell lines or animal cells should be interpreted with caution as signaling transduction and functional behavior might differ in diverse species.
Mitochondrial Damage and Necroptosis in Aging Cochlea
Authors: Lyu Ah-Ra , Kim Tae Hwan , Park Sung Jae , Shin Sun-Ae , Jeong Seong-Hun , Yu Yang , Huh Yang Hoon , Je A Reum , Park Min Jung , Park Yong-Ho
Published: April 2020

Age-related hearing loss (ARHL) is an irreversible, progressive neurodegenerative disorder and is presently untreatable. Previous studies using animal models have suggested mitochondrial damage and programmed cell death to be involved with ARHL. Thus, we further investigated the pathophysiologic role of mitochondria and necroptosis in aged C57BL/6J male mice. Aged mice (20 months old) exhibited a significant loss of hearing, number of hair cells, neuronal fibers, and synaptic ribbons compared to young mice. Ultrastructural analysis of aged cochleae revealed damaged mitochondria with absent or disorganized cristae. Aged mice also showed significant decrease in cochlear blood flow, and exhibited increase in gene expression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α), receptor-interacting serine/threonine-protein kinase 1 and 3 (RIPK1 and RIPK3) and the pseudokinase mixed-lineage kinase domain-like (MLKL). Immunofluorescence (IF) assays of cytochrome C oxidase I (COX1) confirmed mitochondrial dysfunction in aged cochleae, which correlated with the degree of mitochondrial morphological damage. IF assays also revealed localization and increased expression of RIPK3 in sensorineural tissues that underwent significant necroptosis (inner and outer hair cells and stria vascularis). Together, our data shows that the aging cochlea exhibits damaged mitochondria, enhanced synthesis of proinflammatory cytokines, and provides new evidence of necroptosis in the aging cochlea in in vivo.
Oral Bioavailability Enhancement and Anti-Fatigue Assessment of the Andrographolide Loaded Solid Dispersion
Authors: Yen Ching-Chi , Liang Yu-Kai , Cheng Chao-Pei , Hsu Mei-Chich , Wu Yu-Tse
Published: April 2020

Andrographolide (AG), a major diterpene lactone isolated from Andrographis paniculata (Burm. f.) Nees (Acanthaceae), possesses a wide spectrum of biological activities. However, its poor water solubility and low bioavailability limit its clinical application. Therefore, this study aimed to develop a solid dispersion (SD) formulation to increase the aqueous solubility and dissolution rate of AG. Different drug-polymer ratios were used to prepare various SDs. The optimized formulation was characterized for differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder X-ray diffraction. The analysis indicated that the optimized SD enhanced AG solubility and dissolution rates by changing AG crystallinity to an amorphous state. The dissolution behaviors of the optimum SD composed of an AG-polyvinylpyrrolidone K30-Kolliphor EL ratio of 1:7:1 (w/w/w) resulted in the highest accumulated dissolution (approximately 80%). Pharmacokinetic studies revealed that Cmax/dose and the AUC/dose increased by 3.7-fold and 3.0-fold, respectively, compared with AG suspension. Furthermore, pretreatment using the optimized AG-SD significantly increased the swimming time to exhaustion by 1.7-fold and decreased the plasma ammonia level by 71.5%, compared with the vehicle group. In conclusion, the optimized AG-SD formulation appeared to effectively improve its dissolution rate and oral bioavailability. Moreover, the optimized AG-SD provides a promising treatment against physical fatigue.
The Tumor Suppressor TFF1 Occurs in Different Forms and Interacts with Multiple Partners in the Human Gastric Mucus Barrier: Indications for Diverse Protective Functions
Authors: Heuer Jörn , Heuer Franziska , Stürmer René , Harder Sönke , Schlüter Hartmut , Braga Emidio Nayara , Muttenthaler Markus , Jechorek Dörthe , Meyer Frank , Hoffmann Werner
Published: April 2020

TFF1 is a protective peptide of the Trefoil Factor Family (TFF), which is co-secreted with the mucin MUC5AC, gastrokine 2 (GKN2), and IgG Fc binding protein (FCGBP) from gastric surface mucous cells. Tff1-deficient mice obligatorily develop antropyloric adenoma and about 30% progress to carcinomas, indicating that Tff1 is a tumor suppressor. As a hallmark, TFF1 contains seven cysteine residues with three disulfide bonds stabilizing the conserved TFF domain. Here, we systematically investigated the molecular forms of TFF1 in the human gastric mucosa. TFF1 mainly occurs in an unusual monomeric form, but also as a homodimer. Furthermore, minor amounts of TFF1 form heterodimers with GKN2, FCGBP, and an unknown partner protein, respectively. TFF1 also binds to the mucin MUC6 in vitro, as shown by overlay assays with synthetic 125I-labeled TFF1 homodimer. The dominant presence of a monomeric form with a free thiol group at Cys-58 is in agreement with previous studies in Xenopus laevis and mouse. Cys-58 is likely highly reactive due to flanking acid residues (PPEEEC58EF) and might act as a scavenger for extracellular reactive oxygen/nitrogen species protecting the gastric mucosa from damage by oxidative stress, e.g., H2O2 generated by dual oxidase (DUOX).
Extracellular Vesicles as Signaling Mediators and Disease Biomarkers across Biological Barriers
Authors: Simeone Pasquale , Bologna Giuseppina , Lanuti Paola , Pierdomenico Laura , Guagnano Maria Teresa , Pieragostino Damiana , Del Boccio Piero , Vergara Daniele , Marchisio Marco , Miscia Sebastiano , Mariani-Costantini Renato
Published: April 2020

Extracellular vesicles act as shuttle vectors or signal transducers that can deliver specific biological information and have progressively emerged as key regulators of organized communities of cells within multicellular organisms in health and disease. Here, we survey the evolutionary origin, general characteristics, and biological significance of extracellular vesicles as mediators of intercellular signaling, discuss the various subtypes of extracellular vesicles thus far described and the principal methodological approaches to their study, and review the role of extracellular vesicles in tumorigenesis, immunity, non-synaptic neural communication, vascular-neural communication through the blood-brain barrier, renal pathophysiology, and embryo-fetal/maternal communication through the placenta.
Machine Learning in Python: Main Developments and Technology Trends in Data Science, Machine Learning, and Artificial Intelligence
Authors: Raschka Sebastian , Patterson Joshua , Nolet Corey
Published: April 2020

Smarter applications are making better use of the insights gleaned from data, having an impact on every industry and research discipline. At the core of this revolution lies the tools and the methods that are driving it, from processing the massive piles of data generated each day to learning from and taking useful action. Deep neural networks, along with advancements in classical machine learning and scalable general-purpose graphics processing unit (GPU) computing, have become critical components of artificial intelligence, enabling many of these astounding breakthroughs and lowering the barrier to adoption. Python continues to be the most preferred language for scientific computing, data science, and machine learning, boosting both performance and productivity by enabling the use of low-level libraries and clean high-level APIs. This survey offers insight into the field of machine learning with Python, taking a tour through important topics to identify some of the core hardware and software paradigms that have enabled it. We cover widely-used libraries and concepts, collected together for holistic comparison, with the goal of educating the reader and driving the field of Python machine learning forward.
Special Issue: Recent Advances and Future Trends in Pavement Engineering
Authors: Kara De Maeijer Patricia
Published: April 2020

This Special Issue “Recent Advances and Future Trends in Pavement Engineering” has been proposed and organized to present recent developments in the field of innovative pavement materials and engineering. For this reason, the articles and state-of-the-art reviews highlighted in this editorial relate to different aspects of pavement engineering, from recycled asphalt pavements to alkali-activated materials, from hot mix asphalt concrete to porous asphalt concrete, from interface bonding to modal analysis, from destructive testing to non-destructive pavement monitoring by using fiber optics sensors.
Insecticidal and Histopathological Effects of Ageratum conyzoides Weed Extracts against Dengue Vector, Aedes aegypti
Authors: Pintong Ai-rada , Ampawong Sumate , Komalamisra Narumon , Sriwichai Patchara , Popruk Supaluk , Ruangsittichai Jiraporn
Published: April 2020

Crude extracts and essential oils of A. conyzoides were tested with larva and adult stages of Ae. aegypti mosquitoes to determine their insecticidal properties. The crude extracts and essential oils came from three varieties of A. conyzoides (with white flowers, purple flowers, or white-purple flowers) and from two places on each plant (leaves and flowers), giving six types overall: leaf-white (LW); leaf-purple (LP); leaf white-purple (LW-P); flower-white (FW); flower-purple (FP); and flower white-purple (FW-P). Chemical constituents and components of the essential oils were identified using gas chromatography-mass spectrometry (GC-MS). Electron microscopic and histopathological studies were performed to determine the toxicological effects on mosquitoes in terms of morphological alterations. The six types of crude extracts exhibited no activity against individuals in the larval stages. However, six types of essential oils were effective against adult Ae. aegypti females. The mortality of adult Ae. aegypti females was higher from leaf extracts, particularly LP (median lethal dose, LD50 = 0.84%). The number of chemical constituents identified by GC-MS was high in flowers, especially W-P. Precocene I was the most abundant chemical component among the five types of essential oils, except in LP, in which precocene II was the most abundant. Histopathological alterations in adult Ae. aegypti females included compound eye degeneration, muscular damage with cellular infiltration, gut epithelial degeneration and necrosis, pyknotic nuclei in the malpighian epithelium and ovarian cell degeneration. FW and FP plant types exhibited the highest severity of histopathological alterations in mosquitoes compared with other plants, probably owing to the presence of monoterpene compounds in their tissues. The present study demonstrated LP plant extracts from A. conyzoides could be effective adulticides against adult Ae. aegypti. As natural products are biodegradable and exhibit low toxicity to mammalian and non-target organisms, they are suitable candidates for use in vector control programmes.
A Layout Strategy for Distributed Barrage Jamming against Underwater Acoustic Sensor Networks
Authors: Xiong Mengchen , Zhuo Jie , Dong Yangze , Jing Xin
Published: April 2020

Underwater acoustic sensor networks (UASNs) can effectively detect and track targets and therefore play an important role in underwater detection technology. To protect a target from being detected by UASNs, a distributed barrage jamming layout strategy is proposed, which considers the detection performance of UASNs as an indicator of the jamming performance. Since common indices of detection performance often involve specific signal processing methods, the Cramér–Rao bound (CRB) of multiple targets estimated by an UASN for distributed jammers is deduced in this paper, which is universal for all signal processing methods. The optimization model of the distributed jamming layout strategy is designed by maximizing the CRB to achieve the best jamming effect with limited jammers. A heuristic algorithm is used to solve this optimization model, and a numerical simulation shows that the optimal layout strategy for distributed jammers proposed in this paper achieves better performance than traditional jamming layout strategies. Considering the deviation of the position of the jammers from the ideal value due to the movement of water in a real marine environment, this paper also analyzes the jamming effects of strategies when there is error in the position of the jammers. The result proves the effectiveness and superiority of the proposed optimal layout strategy in an actual environment.
Biofilm Formed by Candida haemulonii Species Complex: Structural Analysis and Extracellular Matrix Composition
Authors: Ramos Lívia S. , Mello Thaís P. , Branquinha Marta H. , Santos André L. S.
Published: April 2020

Candida haemulonii species complex (C. haemulonii, C. duobushaemulonii, and C. haemulonii var. vulnera) has emerged as opportunistic, multidrug-resistant yeasts able to cause fungemia. Previously, we showed that C. haemulonii complex formed biofilm on polystyrene. Biofilm is a well-known virulence attribute of Candida spp. directly associated with drug resistance. In the present study, the architecture and the main extracellular matrix (ECM) components forming the biofilm over polystyrene were investigated in clinical isolates of the C. haemulonii complex. We also evaluated the ability of these fungi to form biofilm on catheters used in medical arena. The results revealed that all fungi formed biofilms on polystyrene after 48 h at 37 °C. Microscopic analyses demonstrated a dense network of yeasts forming the biofilm structure, with water channels and ECM. Regarding ECM, proteins and carbohydrates were the main components, followed by nucleic acids and sterols. Mature biofilms were also detected on late bladder (siliconized latex), nasoenteric (polyurethane), and nasogastric (polyvinyl chloride) catheters, with the biomasses being significantly greater than on polystyrene. Collectively, our results demonstrated the ability of the C. haemulonii species complex to form biofilm on different types of inert surfaces, which is an incontestable virulence attribute associated with devices-related candidemia in hospitalized individuals.
Effect of Land Use and Land Cover Change on Soil Erosion in Erer Sub-Basin, Northeast Wabi Shebelle Basin, Ethiopia
Authors: Weldu Woldemariam Gezahegn , Edo Harka Arus
Published: April 2020

Land use and land cover change (LULCC) is a critical factor for enhancing the soil erosion risk and land degradation process in the Wabi Shebelle Basin. Up-to-date spatial and statistical data on basin-wide erosion rates can provide an important basis for planning and conservation of soil and water ecosystems. The objectives of this study were to examine the magnitude of LULCC and consequent changes in the spatial extent of soil erosion risk, and identify priority areas for Soil and Water Conservation (SWC) in the Erer Sub-Basin, Wabi Shebelle Basin, Ethiopia. The soil loss rates were estimated using an empirical prediction model of the Revised Universal Soil Loss Equation (RUSLE) outlined in the ArcGIS environment. The estimated total annual actual soil loss at the sub-basin level was 1.01 million tons in 2000 and 1.52 million tons in 2018 with a mean erosion rate of 75.85 t ha−1 y−1 and 107.07 t ha−1 y−1, respectively. The most extensive soil loss rates were estimated in croplands and bare land cover, with a mean soil loss rate of 37.60 t ha−1 y−1 and 15.78 t ha−1 y−1, respectively. The soil erosion risk has increased by 18.28% of the total area, and decreased by 15.93%, showing that the overall soil erosion situation is worsening in the study area. We determined SWC priority areas using a Multi Criteria Decision Rule (MCDR) approach, indicating that the top three levels identified for intense SWC account for about 2.50%, 2.38%, and 2.14%, respectively. These priority levels are typically situated along the steep slopes in Babile, Fedis, Fik, Gursum, Gola Oda, Haramaya, Jarso, and Kombolcha districts that need emergency SWC measures.
Influence of Cutting Parameters on the Surface Quality of Two-Layer Sandwich Structures
Authors: Doluk Elżbieta , Rudawska Anna , Kuczmaszewski Józef , Pieśko Paweł
Published: April 2020

Hybrid sandwich structures are more and more widely used in many industries. This is mainly due to their good properties. One of the limitations regarding the use of sandwich structures is their difficult processing. Therefore, it seems reasonable to determine the influence of cutting parameters and machining configuration on the characteristic defect (phase) formed at the boundary of the materials forming a hybrid sandwich structure. This study investigates the effects of layer orientations during milling and machining parameters such as the cutting speed Vc, the feed fz and the cutting width ae. The study is conducted on a two-layer sandwich structure composed of two materials: 2024 aluminum alloy and epoxy-carbon composite with 60% of high-strength carbon fibers. A statistical analysis is performed using the Statistica program. The results show that the change in the cutting parameters has a greater impact on the formation of a defect on the surface of samples when the machining process starts on the side of the composite rather than the metal. The highest defect value is obtained for the milling from the composite layer when the process is performed with the following cutting parameters: Vc = 300 m/min, fz = 0.08 mm/tooth, ae = 5 mm.
Influence of Copper Addition on Sigma Phase Precipitation during Hot Deformation of Duplex Steel
Authors: Stradomski Grzegorz , Szarek Arkadiusz , Rydz Dariusz
Published: April 2020

The paper presents an experimental study on microstructure changes in duplex steel after hot deformation. Duplex steels and cast steels are characterized by a multiphase microstructure. They are relatively new materials with great contributions to the many fields of industries. Due to the fact of deforming two different phase austenite and ferrite those materials have a complex plasticity. This work is a continuation and complementation of previous works and is a significant supplement to information presented in them. The article concerns precipitation phenomena and changes in the microstructure of two grades of ferritic-austenitic steels: X2CrNiMoN25-7-4 and X2CrNiMoCuN25-6-3. Those steels have a very similar chemical composition, differing by only 2.5% copper content. An important aspect presented in the work is we observed that adding 2.5% copper prevented precipitation of the destructive sigma phase during the hot deformation.
Process-Induced Nanostructures on Anatase Single Crystals via Pulsed-Pressure MOCVD
Authors: Gorthy Rukmini , Krumdieck Susan , Bishop Catherine
Published: April 2020

The recent global pandemic of COVID-19 highlights the urgent need for practical applications of anti-microbial coatings on touch-surfaces. Nanostructured TiO2 is a promising candidate for the passive reduction of transmission when applied to handles, push-plates and switches in hospitals. Here we report control of the nanostructure dimension of the mille-feuille crystal plates in anatase columnar crystals as a function of the coating thickness. This nanoplate thickness is key to achieving the large aspect ratio of surface area to migration path length. TiO2 solid coatings were prepared by pulsed-pressure metalorganic chemical vapor deposition (pp-MOCVD) under the same deposition temperature and mass flux, with thickness ranging from 1.3–16 μm, by varying the number of precursor pulses. SEM and STEM were used to measure the mille-feuille plate width which is believed to be a key functional nano-dimension for photocatalytic activity. Competitive growth produces a larger columnar crystal diameter with thickness. The question is if the nano-dimension also increases with columnar crystal size. We report that the nano-dimension increases with the film thickness, ranging from 17–42 nm. The results of this study can be used to design a coating which has co-optimized thickness for durability and nano-dimension for enhanced photocatalytic properties.
Preparation of Microcapsules Coating and the Study of Their Bionic Anti-Fouling Performance
Authors: Li Yu , Wang Guoqing , Guo Zehui , Wang Peiqing , Wang Aimin
Published: April 2020

With the increasing demands to better the marine environment, environmentally friendly anti-fouling coatings have attracted attention from society. Adding hydrolyzable microcapsules without toxin to paints is a very useful and safe method to get bionic anti-fouling coatings with a micro-nano surface structure. Based on this trend, a form of environment-friendly microcapsules were prepared through mini-emulsion polymerization. The target microcapsules had a poly(urea-formaldehyde) (PUF) shell and a mixed core of silicone oil and capsaicin. Additionally, the microcapsules were introduced into zinc acrylate resin to obtain bionic anti-fouling coatings with micro-nano morphology. The effects of polyvinyl alcohol (PVA) molecular weight, stirring rate, and temperature on the morphology of the microcapsules were studied by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that spherical nanoparticles with smooth surfaces were obtained, and the mean diameter was approximately 1.38 μm when the molecular weight of PVA was 77 K, the stirring rate was 600 rpm and the temperature was 55 °C. Fourier-transform infrared spectra (FTIR) results showed that the silicone oil and capsaicin were successfully encapsulated, the core materials of the microcapsules reached 72.37% and the yield of microcapsules was 68.91% by the Soxhlet method. Furthermore, the hydrophobicity, corrosion resistance and anti-fouling performance of the coatings were evaluated by the water contact angle, electrochemical and real-sea tests. The results indicated that the anti-fouling coatings had excellent hydrophobicity and anti-fouling performance due to the micro-nano convex structure and the release of core materials. Encouragingly, the anti-fouling coatings show excellent and long-term anti-fouling performance, which is expected to be widely applied in marine anti-fouling coatings.
The Use of ESEM-EDX as an Innovative Tool to Analyze the Mineral Structure of Peri-Implant Human Bone
Authors: Prati Carlo , Zamparini Fausto , Botticelli Daniele , Ferri Mauro , Yonezawa Daichi , Piattelli Adriano , Gandolfi Maria Giovanna
Published: April 2020

This study aimed to investigate the mineralization and chemical composition of the bone–implant interface and peri-implant tissues on human histological samples using an environmental scanning electron microscope as well as energy-dispersive x-ray spectroscopy (ESEM-EDX) as an innovative method. Eight unloaded implants with marginal bone tissue were retrieved after four months from eight patients and were histologically processed and analyzed. Histological samples were observed under optical microscopy (OM) to identify the microarchitecture of the sample and bone morphology. Then, all samples were observed under ESEM-EDX from the coronal to the most apical portion of the implant at 500x magnification. A region of interest with bone tissue of size 750 × 500 microns was selected to correspond to the first coronal and the last apical thread (ROI). EDX microanalysis was used to assess the elemental composition of the bone tissue along the thread interface and the ROI. Atomic percentages of Ca, P, N, and Ti, and the Ca/N, P/N and Ca/P ratios were measured in the ROI. Four major bone mineralization areas were identified based on the different chemical composition and ratios of the ROI. Area 1: A well-defined area with low Ca/N, P/N, and Ca/P was identified as low-density bone. Area 2: A defined area with higher Ca/N, P/N, and Ca/P, identified as new bone tissue, or bone remodeling areas. Area 3: A well-defined area with high Ca/N, /P/N, and Ca/P ratios, identified as bone tissue or bone chips. Area 4: An area with high Ca/N, P/N, and Ca/P ratios, which was identified as mature old cortical bone. Bone Area 2 was the most represented area along the bone–implant interface, while Bone Area 4 was identified only at sites approximately 1.5 mm from the interface. All areas were identified around implant biopsies, creating a mosaic-shaped distribution with well-defined borders. ESEM-EDX in combination with OM allowed to perform a microchemical analysis and offered new important information on the organic and inorganic content of the bone tissue around implants.
Effects of Boric Acid Ester Modified Magnesium Borate Whisker on the Mechanical Properties and Crystallization Kinetics of Polypropylene Composites
Authors: Luo Jin-Hua , Han Shi-Hu , Wang Juan , Liu Hui , Zhu Xiao-Dong , Chen Shan-Hua
Published: April 2020

Polypropylene (PP) is notch sensitive and brittle under severe conditions of deformation, limiting wider range of its usage as a structural load-bearing polymer. Hence, in this work the magnesium borate whisker (MBw), with similar mechanical properties to carbon fiber but much less expensive than polycrystalline silicon carbide, was modified by boric acid ester (BAE) and then used to fabricate PP composites. The mechanical properties, morphology, and non-isothermal crystallization property of virgin PP, PP/MBw, and PP/BAE-MBw composites were studied through mechanical testing, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC), respectively. The non-isothermal crystallization data was analyzed via Mo, Kissinger, and Dobreva methods. The results reveal that the incorporation of BAE-MBw into PP matrix results in higher tensile strength and impact strength than those of virgin PP and PP/MBw composite. The activation energies based on Kissinger were 190.20 kJ/mol for virgin PP, 206.59 kJ/mol for PP/MBw, and 218.98 kJ/mol for PP/BAE-MBw. The nucleation activities of whiskers determined by the Dobreva model were 0.86 for PP/MBw and 0.75 for PP/BAE-MBw. As a result, the whiskers, especially the modified whiskers, act as active substrates to facilitate heterogeneous nucleation, which leads to an increase in crystallization rate.
Wood Density and Moisture Content Estimation by Drilling Chips Extraction Technique
Authors: Martínez Roberto D. , Balmori José-Antonio , F. Llana Daniel , Bobadilla Ignacio
Published: April 2020

The novelty of this study is the development of an accurate wood moisture content (MC) estimation method based on a relatively brand-new, non-destructive testing technique (drilling chips extraction). The method is especially important in the assessment of existing timber structures, where non-destructive testing (NDT) results are affected by wood MC and should be adjusted to a reference MC, usually 12%. In the assessment of timber structures, it is not possible to determine MC by oven drying method and this should be estimated. Electrical resistance and capacitance are the conventional methods used for MC estimation. This research work aims to present an accurate MC estimation method based on the drilling chips extraction technique. For that, 99 specimens (90 × 65 × 38 mm3) from three softwood and hardwood species covering a wide range of densities (from 355 to 978 kg m−3) were tested after conditioning at five different MCs (5%, 10%, 15%, 20%, 25%). The Wood Extractor device based on the drilling chips extraction technique was used. The mass of the chips collected (drilling residue) from each drill was recorded. The results show that the MC of the chips extracted was statistically significantly different than the MC of the specimen and cannot be directly used as MC determination. However, the chips MC can be used as an estimator of specimen MC with high determination coefficients (R2 from 71% to 86%). As the main result, models to estimate density directly adjusted to a reference 12% MC from the wet and dry mass of chips extracted were developed with an R2 of 98%. In sum, the drilling chips extractor is a dependable and straightforward method to estimate MC and density from only one measurement. Density adjusted to a reference 12% MC can be directly estimated from a single model.
Seismic Assessment of RC Bridge Columns Retrofitted with Near-Surface Mounted Shape Memory Alloy Technique
Authors: Abbass Ammar , Attarnejad Reza , Ghassemieh Mehdi
Published: April 2020

From past earthquakes, it has been found that the large residual displacement of bridges after seismic events could be one of the major causes of instability and serviceability disruption of the bridge. The shape memory alloy bars have the ability to reduce permanent deformations of concrete structures. This paper represents a new approach for retrofitting and seismic rehabilitation of previously designed bridge columns. In this concept, the RC bridge column was divided into three zones. The first zone in the critical region of the column where the plastic hinge is possible to occur was retrofitted with near-surface mounted shape memory alloy technique and wrapped with FRP sheets. The second zone, being above the plastic hinge, was confined with Fiber-Reinforced Polymer (FRP) jacket only, and the rest of the column left without any retrofitting. For this purpose, five types of shape memory alloy bars were used. One rectangular and one circular RC bridge column was selected and retrofitted with this proposed technique. The retrofitted columns were numerically investigated under nonlinear static and lateral cyclic loading using 2D fiber element modeling in OpenSees software. The results were normalized and compared with the as-built column. The results indicated that the relative self-centering capacity of RC bridge piers retrofitted with this new approach was highly greater than that of the as-built column. In addition, enhancements in strength and ductility were observed.
Effect of Cooling Rate at the Eutectoid Transformation Temperature on the Corrosion Resistance of Zn-4Al Alloy
Authors: Lachowicz Marzena M. , Jasionowski Robert
Published: April 2020

The main purpose of this work was to experimentally determine the effect of the cooling rate during the eutectoid transformation on the corrosion resistance of a hypoeutectic Zn-4Al cast alloy in 5% NaCl solution. This was considered in relation to the alloy microstructure. For this purpose, metallographic and electrochemical studies were performed. It was found that the faster cooling promoted the formation of finer (α + η) eutectoid structures, which translated into a higher hardness and lower corrosion current density. In the initial stage of corrosion processes the eutectoid structure in the eutectic areas were attacked. At the further stages of corrosion development, the phase η was dissolved, and the α phase appears to be protected by the formation of corrosion products.
On Non-Tensor Product Bivariate Fractal Interpolation Surfaces on Rectangular Grids
Authors: Drakopoulos Vasileios , Manousopoulos Polychronis
Published: April 2020

Some years ago, several authors tried to construct fractal surfaces which pass through a given set of data points. They used bivariable functions on rectangular grids, but the resulting surfaces failed to be continuous. A method based on their work for generating fractal interpolation surfaces is presented. Necessary conditions for the attractor of an iterated function system to be the graph of a continuous bivariable function which interpolates a given set of data are also presented here. Moreover, a comparative study for four of the most important constructions and attempts on rectangular grids is considered which points out some of their limitations and restrictions.
Asymptotic Diffusion Analysis of Multi-Server Retrial Queue with Hyper-Exponential Service
Authors: Moiseev Alexander , Nazarov Anatoly , Paul Svetlana
Published: April 2020

A multi-server retrial queue with a hyper-exponential service time is considered in this paper. The study is performed by the method of asymptotic diffusion analysis under the condition of long delay in orbit. On the basis of the constructed diffusion process, we obtain approximations of stationary probability distributions of the number of customers in orbit and the number of busy servers. Using simulations and numerical analysis, we estimate the accuracy and applicability area of the obtained approximations.
Prevalence of Adverse Reactions to Glutenand People Going on a Gluten-Free Diet:A Survey Study Conducted in Brazil
Authors: Arámburo-Gálvez Jesús Gilberto , Beltrán-Cárdenas Carlos Eduardo , Geralda André Tatiane , Carvalho Gomes Itallo , Macêdo-Callou María Auxiliadora , Braga-Rocha Élida Mara , Mye-Takamatu-Watanabe Elaine Aparecida , Rahmeier-Fietz Vivian , Figueroa-Salcido Oscar Gerardo , Vergara-Jiménez Marcela de Jesus , Flores-Mendoza Lilian Karem , Ontiveros Noé , Cabrera-Chávez Francisco
Published: April 2020

Background: The prevalence of gluten-related disorders (GRD) and adherence to a gluten-free diet (GFD) remains unknown in Brazilian population and there is no published information on the scientific literature about the proportion of Brazilians that were diagnosed with a gluten-related disorder. Thus, the aim of this work was to estimate the prevalence of GRDs and adherence to a GFD by self-report in adult Brazilian population. Materials and Methods: A questionnaire-based cross-sectional study was conducted in two Brazilian cities. Results: The response rate was 93.2% (1630/1749). The self-reported prevalence rates were (95% CI): adverse reactions to gluten 10.06% (8.64–11.62); gluten sensitivity 2.33% (1.65–3.18); physician-diagnosed celiac disease 0.3% (0.09–0.71); non-celiac gluten sensitivity 1.71% (1.14–2.47); wheat allergy 0.79% (0.42–1.36); adherence to gluten-free diet 7.48% (6.25–8.87); gluten avoiders 15.21% (13.5–17.05). Among those who were following a GFD (n = 122), 65.6% (n = 80) of them reported that they did not develop symptoms after wheat/gluten ingestion and 50% (n = 61) were following the diet without medical/dietitian advice. The main motivation for following a GFD in the self-reported and non-self-reported gluten sensitivity groups were the symptoms triggered after wheat/gluten ingestion (86.8%) and weight control (57.1%), respectively. Conclusions: Implementation of programs to increase awareness about GRDs among healthcare professionals and giving scientifically sound information to the general population about the risks and benefits for following a GFD are desirable actions in Brazil. The results also add to the growing body of evidence for highlighting the under-diagnosis of GRD and the trend for following a GFD in Latin America.
Privacy-Preserving Non-Wearable Occupancy Monitoring System Exploiting Wi-Fi Imaging for Next-Generation Body Centric Communication
Authors: Aziz Shah Syed , Ahmad Jawad , Tahir Ahsen , Ahmed Fawad , Russell Gordon , Shah Syed Yaseen , Buchanan William J. , Abbasi Qammer H.
Published: April 2020

Nano-scaled structures, wireless sensing, wearable devices, and wireless communications systems are anticipated to support the development of new next-generation technologies in the near future. Exponential rise in future Radio-Frequency (RF) sensing systems have demonstrated its applications in areas such as wearable consumer electronics, remote healthcare monitoring, wireless implants, and smart buildings. In this paper, we propose a novel, non-wearable, device-free, privacy-preserving Wi-Fi imaging-based occupancy detection system for future smart buildings. The proposed system is developed using off-the-shelf non-wearable devices such as Wi-Fi router, network interface card, and an omnidirectional antenna for future body centric communication. The core idea is to detect presence of person along its activities of daily living without deploying a device on person’s body. The Wi-Fi signals received using non-wearable devices are converted into time–frequency scalograms. The occupancy is detected by classifying the scalogram images using an auto-encoder neural network. In addition to occupancy detection, the deep neural network also identifies the activity performed by the occupant. Moreover, a novel encryption algorithm using Chirikov and Intertwining map-based is also proposed to encrypt the scalogram images. This feature enables secure storage of scalogram images in a database for future analysis. The classification accuracy of the proposed scheme is 91.1%.