bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting the Swallow-Related Quality of Life of the Elderly Living in a Local Community Using Support Vector Machine
Authors: Byeon Haewon
Published: November 2019

Background and Objectives: This study developed a support vector machine (SVM) algorithm-based prediction model with considering influence factors associated with the swallowing quality-of-life as the predictor variables and provided baseline information for enhancing the swallowing quality of elderly people’s lives in the future. Methods and Material: This study sampled 142 elderly people equal to or older than 65 years old who were using a senior welfare center. The swallowing problem associated quality of life was defined by the swallowing quality-of-life (SWAL-QOL). In order to verify the predictive power of the model, this study compared the predictive power of the Gaussian function with that of a linear algorithm, polynomial algorithm, and a sigmoid algorithm. Results: A total of 33.9% of the subjects decreased in swallowing quality-of-life. The swallowing quality-of-life prediction model for the elderly, based on the SVM, showed both preventive factors and risk factors. Risk factors were denture use, experience of using aspiration in the past one month, being economically inactive, having a mean monthly household income <2 million KRW, being an elementary school graduate or below, female, 75 years old or older, living alone, requiring time for finishing one meal on average ≤15 min or ≥40 min, having depression, stress, and cognitive impairment. Conclusions: It is necessary to monitor the high-risk group constantly in order to maintain the swallowing quality-of-life in the elderly based on the prevention and risk factors associated with the swallowing quality-of-life derived from this prediction model.
Evaluation of the Effectiveness of Mobile App-Based Stress-Management Program: A Randomized Controlled Trial
Authors: Hwang Won Ju , Jo Hyun Hee
Published: November 2019

Improving mental healthcare using mobile apps might be an effective way to increase interest in mental health and respond to the demand for better psychological health. However, few studies have investigated the effectiveness of app-based stress-management programs. This study aimed to assess the efficacy of an app-based stress-management program. A non-equivalent comparison group pretest-posttest design was used. Participants were randomized into the experimental (n = 26) and control (n = 30) groups. The experimental group used an application developed for workers for four weeks. The results indicated that stress, emotional labor, self-efficacy, and well-being were significantly different in the experimental group, but the control group’s average scores did not change significantly. On average, the Perceived Stress Scale scores decreased by 1.5 points (p = 0.035) and the Korean Occupational Stress Scale scores decreased by 0.87 points (p = 0.4). However, depression and anxiety were not significantly different. Emotional labor decreased by 0.16 points (p = 0.027), and well-being and self-efficacy mean scores increased by 0.492 (p = 0.005) and 0.162 (p = 0.025), respectively. These findings support the developed application’s value for promoting mental health and healthy lifestyles. Further research and supplementation are needed for the application’s sustainability.
A Cluster Randomised Controlled Trial of an Intervention to Increase Physical Activity of Preschool-Aged Children Attending Early Childhood Education and Care: Study Protocol for the ‘Everybody Energise’ Trial
Authors: Delaney Tessa , Jackson Jacklyn K. , Jones Jannah , Hall Alix , Dives Ashleigh , Wedesweiler Taya , Campbell Libby , Nathan Nicole , Romiti Maria , Trost Stewart G. , Lum Melanie , Colliver Yeshe , Hernandez Lara , Yoong Sze Lin
Published: November 2019

The use of ‘Energisers,’ short bouts of moderate-to-vigorous physical activity (MVPA), have been shown to significantly increase children’s physical activity within the school setting but not within Early Childhood Education and Care (ECEC) centres. The aim of this study is to assess the efficacy of an intervention involving the provision of educator-led daily Energisers to increase the time children spend in MVPA while attending ECEC. Fourteen ECEC centres in the Hunter region of New South Wales, Australia, will be randomised to either an intervention or control group. The intervention group will be supported by the research team to implement three brief (5-min) educator-led Energisers each day for children aged three to six years between the hours of 9:00 a.m. to 3.00 p.m. Control ECEC centres will continue to provide ‘normal practice’ to children. The primary trial outcome is child minutes of MVPA whilst in ECEC, assessed objectively via accelerometery over three days. Outcome assessment will occur at baseline and 6 months post-baseline. Linear mixed models under an intention-to-treat framework will be used to compare differences between groups in MVPA at follow-up. This will be the first cluster randomised controlled trial to test the efficacy of Energisers in isolation on increasing the time children spend in MVPA.
Spatio-Temporal Variation Characteristics of PM2.5 in the Beijing–Tianjin–Hebei Region, China, from 2013 to 2018
Authors: Wang Lili , Xiong Qiulin , Wu Gaofeng , Gautam Atul , Jiang Jianfang , Liu Shuang , Zhao Wenji , Guan Hongliang
Published: November 2019

Air pollution, including particulate matter (PM2.5) pollution, is extremely harmful to the environment as well as human health. The Beijing–Tianjin–Hebei (BTH) Region has experienced heavy PM2.5 pollution within China. In this study, a six-year time series (January 2013–December 2018) of PM2.5 mass concentration data from 102 air quality monitoring stations were studied to understand the spatio-temporal variation characteristics of the BTH region. The average annual PM2.5 mass concentration in the BTH region decreased from 98.9 μg/m3 in 2013 to 64.9 μg/m3 in 2017. Therefore, China has achieved its Air Pollution Prevention and Control Plan goal of reducing the concentration of fine particulate matter in the BTH region by 25% by 2017. The PM2.5 pollution in BTH plain areas showed a more significant change than mountains areas, with the highest PM2.5 mass concentration in winter and the lowest in summer. The results of spatial autocorrelation and cluster analyses showed that the PM2.5 mass concentration in the BTH region from 2013–2018 showed a significant spatial agglomeration, and that spatial distribution characteristics were high in the south and low in the north. Changes in PM2.5 mass concentration in the BTH region were affected by both socio-economic factors and meteorological factors. Our results can provide a point of reference for making PM2.5 pollution control decisions.
Newly Qualified Nurses’ Perception of Their Competency Achievement on Leaving University: A Qualitative Study
Authors: López-Entrambasaguas Olga María , Martínez-Yebenes Rocío , Calero-García María José , Granero-Molina José , Martínez-Linares José Manuel
Published: November 2019

Background: After implementing the Tuning Educational Structures in Europe Project, numerous efforts have been made to define, establish, and evaluate nursing competences. The European Federation of Nurses Association played a key role in enacting the nursing competences included in Directive 2013/55/EU. Nevertheless, assessing competences remains elusive, and there is little research into nurses’ perceptions of the competency training provided by their universities. The purpose of the study was to explore the perceptions and experiences of newly qualified nurses about the competences they acquired during their university education. Methods: A qualitative research study was developed in a Spanish university. Twelve semi-structured interviews with newly qualified nurses were conducted, and two focus groups made up of twelve students were carried out in order to triangulate the results. Participants were recruited through email contact. Interviews focused on clinical training, theoretical content, and the reality of healthcare. Data was analyzed thematically. Results: Two main themes emerged: (1) improving theoretical content and (2) rethinking practical lessons and clinical training. A lack of knowledge about mental health, pharmacology, or critical care has been found; in addition, it was highlighted, among others, the need to improve communication skills in difficult and conflictive situations. Conclusions: Considering the participants’ perception of deficiency in some aspects of most of the competences established by the European Federation of Nurses Association, further research has been suggested to include other stakeholders’ views.
Computer-Aided Strategies for Determining the Amino Acid Composition of Medium for Chinese Hamster Ovary Cell-Based Biomanufacturing Platforms
Authors: Traustason Bergthor , Cheeks Matthew , Dikicioglu Duygu
Published: November 2019

Chinese hamster ovary (CHO) cells are used for the production of the majority of biopharmaceutical drugs, and thus have remained the standard industry host for the past three decades. The amino acid composition of the medium plays a key role in commercial scale biologics manufacturing, as amino acids constitute the building blocks of both endogenous and heterologous proteins, are involved in metabolic and non-metabolic pathways, and can act as main sources of nitrogen and carbon under certain conditions. As biomanufactured proteins become increasingly complex, the adoption of model-based approaches become ever more popular in complementing the challenging task of medium development. The extensively studied amino acid metabolism is exceptionally suitable for such model-driven analyses, and although still limited in practice, the development of these strategies is gaining attention, particularly in this domain. This paper provides a review of recent efforts. We first provide an overview of the widely adopted practice, and move on to describe the model-driven approaches employed for the improvement and optimization of the external amino acid supply in light of cellular amino acid demand. We conclude by proposing the likely prevalent direction the field is heading towards, providing a critical evaluation of the current state and the future challenges and considerations.
Immunomodulatory Effects of MSCs in Bone Healing
Authors: Medhat Dalia , Rodríguez Clara I. , Infante Arantza
Published: November 2019

Mesenchymal stem cells (MSCs) are capable of differentiating into multilineage cells, thus making them a significant prospect as a cell source for regenerative therapy; however, the differentiation capacity of MSCs into osteoblasts seems to not be the main mechanism responsible for the benefits associated with human mesenchymal stem cells hMSCs when used in cell therapy approaches. The process of bone fracture restoration starts with an instant inflammatory reaction, as the innate immune system responds with cytokines that enhance and activate many cell types, including MSCs, at the site of the injury. In this review, we address the influence of MSCs on the immune system in fracture repair and osteogenesis. This paradigm offers a means of distinguishing target bone diseases to be treated with MSC therapy to enhance bone repair by targeting the crosstalk between MSCs and the immune system.
Allelic Variants for Candidate Nitrogen Fixation Genes Revealed by Sequencing in Red Clover (Trifolium pratense L.)
Authors: Trněný Oldřich , Vlk David , Macková Eliška , Matoušková Michaela , Řepková Jana , Nedělník Jan , Hofbauer Jan , Vejražka Karel , Jakešová Hana , Jansa Jan , Piálek Lubomír , Knotová Daniela
Published: November 2019

Plant–rhizobia symbiosis can activate key genes involved in regulating nodulation associated with biological nitrogen fixation (BNF). Although the general molecular basis of the BNF process is frequently studied, little is known about its intraspecific variability and the characteristics of its allelic variants. This study’s main goals were to describe phenotypic and genotypic variation in the context of nitrogen fixation in red clover (Trifolium pretense L.) and identify variants in BNF candidate genes associated with BNF efficiency. Acetylene reduction assay validation was the criterion for selecting individual plants with particular BNF rates. Sequences in 86 key candidate genes were obtained by hybridization-based sequence capture target enrichment of plants with alternative phenotypes for nitrogen fixation. Two genes associated with BNF were identified: ethylene response factor required for nodule differentiation (EFD) and molybdate transporter 1 (MOT1). In addition, whole-genome population genotyping by double-digest restriction-site-associated sequencing (ddRADseq) was performed, and BNF was evaluated by the natural 15N abundance method. Polymorphisms associated with BNF and reflecting phenotype variability were identified. The genetic structure of plant accessions was not linked to BNF rate of measured plants. Knowledge of the genetic variation within BNF candidate genes and the characteristics of genetic variants will be beneficial in molecular diagnostics and breeding of red clover.
Metabolic Profile, Bioavailability and Toxicokinetics of Zearalenone-14-Glucoside in Rats after Oral and Intravenous Administration by Liquid Chromatography High-Resolution Mass Spectrometry and Tandem Mass Spectrometry
Authors: Sun Feifei , Tan Haiguang , Li Yanshen , De Boevre Marthe , De Saeger Sarah , Zhou Jinhui , Li Yi , Rao Zhenghua , Yang Shupeng , Zhang Huiyan
Published: November 2019

Zearalenone-14-glucoside (ZEN-14G), a key modified mycotoxin, has attracted a great deal of attention due to the possible conversion to its free form of zearalenone (ZEN) exerting toxicity. In this study, the toxicokinetics of ZEN-14G were investigated in rats after oral and intravenous administration. The plasma concentrations of ZEN-14G and its major five metabolites were quantified using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The data were analyzed via non-compartmental analysis using software WinNonlin 6.3. The results indicated that ZEN-14G was rapidly hydrolyzed into ZEN in vivo. In addition, the major parameters of ZEN-14G following intravenous administration were: area under the plasma concentration–time curve (AUC), 1.80 h·ng/mL; the apparent volume of distribution (VZ), 7.25 L/kg; and total body clearance (CL), 5.02 mL/h/kg, respectively. After oral administration, the typical parameters were: AUC, 0.16 h·ng/mL; VZ, 6.24 mL/kg; and CL, 4.50 mL/h/kg, respectively. The absolute oral bioavailability of ZEN-14G in rats was about 9%, since low levels of ZEN-14G were detected in plasma, which might be attributed to its extensive metabolism. Therefore, liquid chromatography high-resolution mass spectrometry (LC-HRMS) was adopted to clarify the metabolic profile of ZEN-14G in rats’ plasma. As a result, eight metabolites were identified in which ZEN-14-glucuronic acid (ZEN-14GlcA) had a large yield from the first time-point and continued accumulating after oral administration, indicating that ZEN-14-glucuronic acid could serve a potential biomarker of ZEN-14G. The obtained outcomes would prompt the accurate safety evaluation of ZEN-14G.
Transforming Growth Factor Beta 3-Loaded Decellularized Equine Tendon Matrix for Orthopedic Tissue Engineering
Authors: Roth Susanne Pauline , Brehm Walter , Groß Claudia , Scheibe Patrick , Schubert Susanna , Burk Janina
Published: November 2019

Transforming growth factor beta 3 (TGFβ3) promotes tenogenic differentiation and may enhance tendon regeneration in vivo. This study aimed to apply TGFβ3 absorbed in decellularized equine superficial digital flexor tendon scaffolds, and to investigate the bioactivity of scaffold-associated TGFβ3 in an in vitro model. TGFβ3 could effectively be loaded onto tendon scaffolds so that at least 88% of the applied TGFβ3 were not detected in the rinsing fluid of the TGFβ3-loaded scaffolds. Equine adipose tissue-derived multipotent mesenchymal stromal cells (MSC) were then seeded on scaffolds loaded with 300 ng TGFβ3 to assess its bioactivity. Both scaffold-associated TGFβ3 and TGFβ3 dissolved in the cell culture medium, the latter serving as control group, promoted elongation of cell shapes and scaffold contraction (p < 0.05). Furthermore, scaffold-associated and dissolved TGFβ3 affected MSC musculoskeletal gene expression in a similar manner, with an upregulation of tenascin c and downregulation of other matrix molecules, most markedly decorin (p < 0.05). These results demonstrate that the bioactivity of scaffold-associated TGFβ3 is preserved, thus TGFβ3 application via absorption in decellularized tendon scaffolds is a feasible approach.
Current Understanding of Residual Force Enhancement: Cross-Bridge Component and Non-Cross-Bridge Component
Authors: Fukutani Atsuki , Herzog Walter
Published: November 2019

Muscle contraction is initiated by the interaction between actin and myosin filaments. The sliding of actin filaments relative to myosin filaments is produced by cross-bridge cycling, which is governed by the theoretical framework of the cross-bridge theory. The cross-bridge theory explains well a number of mechanical responses, such as isometric and concentric contractions. However, some experimental observations cannot be explained with the cross-bridge theory; for example, the increased isometric force after eccentric contractions. The steady-state, isometric force after an eccentric contraction is greater than that attained in a purely isometric contraction at the same muscle length and same activation level. This well-acknowledged and universally observed property is referred to as residual force enhancement (rFE). Since rFE cannot be explained by the cross-bridge theory, alternative mechanisms for explaining this force response have been proposed. In this review, we introduce the basic concepts of sarcomere length non-uniformity and titin elasticity, which are the primary candidates that have been used for explaining rFE, and discuss unresolved problems regarding these mechanisms, and how to proceed with future experiments in this exciting area of research.
Chip-Based Digital PCR Approach Provides A Sensitive and Cost-Effective Single-Day Screening Tool for Common Fetal Aneuploidies—A Proof of Concept Study
Authors: Nykel Anna , Kaszkowiak Marcin , Fendler Wojciech , Gach Agnieszka
Published: November 2019

In the prenatal period, the copy number aberrations of chromosomes 13, 18, 21, X and Y account for over 80% of the clinically significant chromosome abnormalities. Classical cytogenetic analysis is the gold standard in invasive prenatal diagnostics but the long test waiting time affects its clinical utility. Several molecular rapid tests have been developed and employed in clinical practice, however all have substantial drawbacks. The aim of the study was to design and evaluate an optimized tool for rapid molecular detection of fetal aneuploidies. We established a novel single-day method using a chip-based platform, the QuantStudio 3D Digital PCR system. In order to assess the clinical usefulness of our screening test, we analyzed 133 prenatal samples. The difference in distributions of euploid and aneuploid samples identified the ploidy of each of the target chromosomes with high precision. The distribution of the chromosome ratio for euploid and aneuploid samples showed a statistically significant result (p = 0.003 for trisomy 13, p = 0.001 for trisomies 18 and 21, Mann–Whitney U test). Our results suggest that this novel chip-based approach provides a tool for rapid, technically simple, cost-effective screening for common fetal aneuploidies.
Continentalic Acid Rather Than Kaurenoic Acid Is Responsible for the Anti-Arthritic Activity of Manchurian Spikenard In Vitro and In Vivo
Authors: Hong Riwon , Kim Kyoung Soo , Choi Gwang Muk , Yeom Mijung , Lee Bombi , Lee Sanghyun , Kang Ki Sung , Lee Hyang Sook , Park Hi-Joon , Hahm Dae-Hyun
Published: November 2019

The aim of this study was to identify the active compound responsible for the pharmacological activities of Manchurian spikenard (Aralia continentalis Kitag.). Interleukin (IL)-1β-stimulated human chondrocytes and monoiodoacetate (MIA)-induced osteoarthritic rats were treated with the 50% ethanolic extract of spikenard or its major components, such as continentalic acid (ent-pimara-8(14),15-diene-19-oic acid) and kaurenoic acid (ent-kaura-16-en-19-oic acid). The spikenard extract significantly inhibited IL-1β-stimulated production of IL-6, IL-8, metalloproteinase (MMP)-1, MMP-13, cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) and prostaglandin(PG)E2 in a dose-dependent manner but not MMP-3 production. The extract also inhibited the IL-1β-induced translocation of NF-κB/p65 into the nucleus and dose-dependent phosphorylation levels of extracellular signal-regulated kinase (ERK), Jun amino-terminal kinase (JNK) and p38 mitogen-activated protein (MAP) kinase. Continentalic acid exhibited significant anti-arthritic activity corresponding exactly to that of the extract containing an equivalent amount of continentalic acid. On the other hand, kaurenoic acid exhibited a compatible activity at about a 10-times higher molar concentration than that of continentalic acid. In vitro anti-arthritic activities of the spikenard extract and continentalic acid were also confirmed in MIA-induced osteoarthritic rats. The 50% ethanolic extract of Manchurian spikenard exhibited promising anti-arthritic activities in the in vitro and in vivo osteoarthritis models, and continentalic acid, not kaurenoic acid, was most probably responsible for those activities.
Density-Dependent Growth and Fitness in Dastarcus helophoroides (Coleoptera: Bothrideridae)
Authors: Gao Shang-kun , Geng Cui-cui , Ji Ying-chao , Li Zi-kun , Zhou Cheng-gang
Published: November 2019

The ectoparasitoid Dastarcus helophoroides Fairmaire (Coleoptera: Bothrideridae) is an important natural enemy insect, which is artificially mass-reared and released into woodland to control medium and large longhorn beetle species. This study examined the developmental duration (days) of larvae and adult fitness (including numbers of adults emerging per host and mean body size) by exposing a single substitute host, a pupa of Zophobas morio (Coleoptera: Tenebrionidae), to different densities of D. helophoroides larvae. We showed that there was no significant effect on the rate of successful parasitism and cocoon formation, but emergence success and measures of individual adult body size (length, width, and weight) declined with increasing larval density. Larval period and cocoon period increased with larval density, while total weight of adults emerging per host increased initially before reaching a plateau. Our results suggest that a pupa of Z. morio could be successfully parasitized by a single D. helophoroides larva, but multiple D. helophoroides larvae can share one host. Excessive larval density caused intraspecific competition among D. helophoroides larvae, manifesting in extended developmental duration of immature stage and reduced fitness of adults. Furthermore, the tradeoff between the numbers of adults and body size may stabilize the population dynamics with detectable mutual interference, particularly in competing for limited host resources. These findings suggest six larvae per host would achieve the highest adult fitness and would enhance mass-rearing techniques as part of IPM strategies for longhorn beetles.
Investigation of the Correlation between Graves’ Ophthalmopathy and CTLA4 Gene Polymorphism
Authors: Chen Ding-Ping , Chu Yen-Chang , Wen Ying-Hao , Lin Wei-Tzu , Hour Ai-Ling , Wang Wei-Ting
Published: November 2019

Graves’ disease (GD) is an autoimmune inflammatory disease, and Graves’ ophthalmopathy (GO) occurs in 25–50% of patients with GD. Several susceptible genes were identified to be associated with GO in some genetic analysis studies, including the immune regulatory gene CTLA4. We aimed to find out the correlation of CTLA4 gene polymorphism and GO. A total of 42 participants were enrolled in this study, consisting of 22 patients with GO and 20 healthy controls. Chi-square or Fisher’s exact test were used to appraise the association between Graves’ ophthalmopathy and CTLA4 single nucleotide polymorphisms (SNPs). All regions of CTLA4 including promoter, exon and 3’UTR were investigated. There was no nucleotide substitution in exon 2 and exon 3 of CTLA4 region, and the allele frequencies of CTLA4 polymorphisms had no significant difference between patients with GO and controls. However, the genotype frequency of “TT” genotype in rs733618 significantly differed between patients with GO and healthy controls (OR = 0.421, 95%CI: 0.290–0.611, p = 0.043), and the “CC” and “CT” genotype in rs16840252 were nearly significantly differed in genotype frequency (p = 0.052). Haplotype analysis showed that CTLA4 Crs733618Crs16840252 might increase the risk of GO (OR = 2.375, 95%CI: 1.636–3.448, p = 0.043). In conclusion, CTLA4 Crs733618Crs16840252 was found to be a potential marker for GO, and these haplotypes would be ethnicity-specific. Clinical application of CTLA4 Crs733618Crs16840252 in predicting GO in GD patients may be beneficial.
Sarcopenia in Older Adults
Authors: Scott David
Published: November 2019

Sarcopenia was first described in 1988 as the age-related decline of skeletal muscle mass [...]
Pink1-Mediated Chondrocytic Mitophagy Contributes to Cartilage Degeneration in Osteoarthritis
Authors: Shin Hyo Jung , Park Hyewon , Shin Nara , Kwon Hyeok Hee , Yin Yuhua , Hwang Jeong-Ah , Song Hee-Jung , Kim Jinhyun , Kim Dong Woon , Beom Jaewon
Published: November 2019

Cartilage loss is a central event in the pathogenesis of osteoarthritis (OA), though other than mechanical loading, the biochemical mechanisms underlying OA pathology remain poorly elucidated. We investigated the role of Pink1-mediated mitophagy in mitochondrial fission, a crucial process in OA pathogenesis. We used a monosodium iodoacetate (MIA)-induced rodent model of OA, which inhibits the activity of articular chondrocytes, leading to disruption of glycolytic energy metabolism and eventual cell death. The OA rat cartilage exhibits significant induction of autophagy-related proteins LC3B and p62, similar to human osteoarthritic cartilage. Moreover, expression of Pink1 and Parkin proteins were also increased in OA. Here, we confirm that Pink1-mediated mitophagy leads to cell death in chondrocytes following MIA treatment, while deficiency in Pink1 expression was associated with decreased cartilage damage and pain behaviors in MIA-induced OA. Finally, we found that autophagy and mitophagy-related genes are highly expressed in human osteoarthritic cartilage. These results indicate that OA is a degenerative condition associated with mitophagy, and suggest that targeting the Pink1 pathway may provide a therapeutic avenue for OA treatment.
Conditional Controlled Light/Dark Cycle Influences Exercise-Induced Benefits in a Rat Model with Osteoarthritis: In Vitro and In Vivo Study
Authors: Hong Yunkyung , Lee Seunghoon , Choi Jeonghyun , Jin Yunho , Won Jinyoung , Jo Youngjin , Hong Yonggeun
Published: November 2019

Physical exercise has long been recommended as a treatment for osteoarthritis (OA), though its effects vary based on the exercise protocol. Here, we examined whether environmental lighting conditions influence the anti-inflammatory benefits of exercise in a rat model of OA. Moderate-intensity treadmill exercise (Ex) was performed for six weeks under a 12:12 h light/dark (L/D) cycle, and compared against rats housed in a 24 h continuous light (L/L) environment. L/L conditions were associated with serological changes shortly after OA induction, which exacerbated the inflammatory microenvironment in the joint. Differentiation capacity was also impaired in bone precursor cells isolated from normal rats maintained under L/L conditions, despite elevated inflammatory responses. Exercise training under L/L conditions led to increased corticosterone levels in the blood, which exacerbated the progression of cartilaginous and synovial lesions. Osteoporotic phenomena were also observed in exercise-trained rats maintained under L/L conditions, along with inflammation-induced catabolism in the gastrocnemius muscle. Aberrant light/dark cycle conditions were also found to be associated with suppression of splenic Cry1 expression in exercise-trained rats, leading to dysregulation of immune responses. Taken together, these data suggest that lighting condition may be an important environmental factor influencing the exercise-induced benefits on OA.
Secretome and Extracellular Vesicles as New Biological Therapies for Knee Osteoarthritis: A Systematic Review
Authors: D’Arrigo Daniele , Roffi Alice , Cucchiarini Magali , Moretti Matteo , Candrian Christian , Filardo Giuseppe
Published: November 2019

Secretome and extracellular vesicles (EVs) are considered a promising option to exploit mesenchymal stem cells’ (MSCs) properties to address knee osteoarthritis (OA). The aim of this systematic review was to analyze both the in vitro and in vivo literature, in order to understand the potential of secretome and EVs as a minimally invasive injective biological approach. A systematic review of the literature was performed on PubMed, Embase, and Web of Science databases up to 31 August 2019. Twenty studies were analyzed; nine in vitro, nine in vitro and in vivo, and two in vivo. The analysis showed an increasing interest in this emerging field, with overall positive findings. Promising in vitro results were documented in terms of enhanced cell proliferation, reduction of inflammation, and down-regulation of catabolic pathways while promoting anabolic processes. The positive in vitro findings were confirmed in vivo, with studies showing positive effects on cartilage, subchondral bone, and synovial tissues in both OA and osteochondral models. However, several aspects remain to be clarified, such as the different effects induced by EVs and secretome, which is the most suitable cell source and production protocol, and the identification of patients who may benefit more from this new biological approach for knee OA treatment.
Categorization and Analysis of Relevant Factors for Optimal Locations in Onshore and Offshore Wind Power Plants: A Taxonomic Review
Authors: Gil-García Isabel C. , García-Cascales M. Socorro , Fernández-Guillamón Ana , Molina-García Angel
Published: November 2019

Wind power is widely considered to be a qualified renewable, clean, ecological and inexhaustible resource that is becoming a leader in the current energy transition process. It is a mature technology solution that was quickly developed and has been massively integrated into power systems in recent years. Indeed, a remarkable number of renewable integration policies have been promoted by different governments and countries. With the aim of maximizing the power given by wind resources, the locations of both onshore and offshore wind power plants must be optimized following a sort of different criteria. Under this scenario, a number of factors and decision criteria in the evaluation and selection of locations can be identified. Moreover, the relevant wind power increasing in the power generation mix is addressed, along with a standardization of factors and decision criteria in the optimization and selection of such optimal locations. In this context, this paper describes a systematic review and meta-analysis combining most of the contributions and studies proposed during the last decade. Thus, our aim is focused on reviewing and categorizing all factors to be considered for optimal location estimation, pointing out the differences among the selected factors and the decision criteria for onshore and offshore wind power plants. In addition, our review also includes an analysis of the representative key indicators for the contributions, such as the annual frequency of publications, geographical classification, analysis by category, evaluation method and determining factors.
Metal Nanoparticles as Green Catalysts
Authors: Narayan Neel , Meiyazhagan Ashokkumar , Vajtai Robert
Published: November 2019

Nanoparticles play a significant role in various fields ranging from electronics to composite materials development. Among them, metal nanoparticles have attracted much attention in recent decades due to their high surface area, selectivity, tunable morphologies, and remarkable catalytic activity. In this review, we discuss various possibilities for the synthesis of different metal nanoparticles; specifically, we address some of the green synthesis approaches. In the second part of the paper, we review the catalytic performance of the most commonly used metal nanoparticles and we explore a few roadblocks to the commercialization of the developed metal nanoparticles as efficient catalysts.
Properties of a Steel Slag–Permeable Asphalt Mixture and the Reaction of the Steel Slag–Asphalt Interface
Authors: Liu Wenhuan , Li Hui , Zhu Huimei , Xu Pinjing
Published: November 2019

Steel slag is an industrial solid waste with the largest output in the world. It has the characteristics of wear resistance, good particle shape, large porosity, etc. At the same time, it has good adhesion characteristics with asphalt. If steel slag is used in asphalt pavement, it not only solves the problem of insufficient quality aggregates in asphalt concrete, but can also give full play to the high hardness and high wear resistance of steel slag to improve the performance of asphalt pavement. In this study, a steel slag aggregate was mixed with road petroleum asphalt to prepare a permeable steel slag–asphalt mixture, which was then compared with the permeable limestone–asphalt mixture. According to the Technical Regulations for Permeable Asphalt Pavement (CJJT 190-2012), the permeability, water stability, and Marshall stability of the prepared asphalt mixtures were tested and analyzed. In addition, the high-temperature stability and expansibility were analyzed according to the Experimental Regulations for Highway Engineering Asphalt and Asphalt Mixture (JTG E20-2011). The chemical composition of the steel slag was tested and analyzed by X-ray fluorescence spectrometer (XRF). The mineral composition of the steel slag was tested and analyzed by X-ray diffractometer (XRD). The asphalt was analyzed by Fourier transform infrared spectroscopy (FTIR). The results show that the steel slag asphalt permeable mixture had good permeability, water stability, and Marshall stability, as well as good high-temperature stability and a low expansion rate. The main mineral composition was ferroferric oxide, the RO phase (RO phase is a broad solid solution formed by melting FeO, MgO, and other divalent metal oxides such as MnO), dicalcium silicate, and tricalcium silicate. In the main chemical composition of steel slag, there was no chemical reaction between aluminum oxide, calcium oxide, silicon dioxide, and asphalt, while ferric oxide chemically reacted with asphalt and formed new organosilicon compounds. The main mineral composition of the steel slag (i.e., triiron tetroxide, dicalcium silicate, and tricalcium silicate) reacted chemically with the asphalt and produced new substances. There was no chemical reaction between the RO phase and asphalt.
Fatigue Life of 7475-T7351 Aluminum After Local Severe Plastic Deformation Caused by Machining
Authors: Ohnistova Petra , Piska Miroslav , Petrenec Martin , Dluhos Jiri , Hornikova Jana , Sandera Pavel
Published: November 2019

The fatigue properties of thermo-mechanically treated and machined aluminum alloy 7475-T7351 have been studied. The applied advanced machining strategy induced intensive plastic deformation on the machined surface under defined cutting conditions. Therefore, a detailed study of 3D surface topography was performed. Advanced characterization of the material structure and electron back scattered diffraction mapping of selected chemical phases were performed, as well as energy dispersive X-ray analysis of the surface. Advanced mechanical properties of the material were investigated in situ with a scanning electron microscope that was equipped with a unique tensile fixture. The fatigue results confirmed an evident dispersion of the data, but the mechanism of crack nucleation was established. Fracture surface analysis showed that the cracks nucleated at the brittle secondary particles dispersed in the material matrix. The surface topography of samples that had been machined in wide range of cutting/deformation conditions by milling has not proved to be a decisive factor in terms of the fatigue behavior. The incoherent interface and decohesion between the alumina matrix and the brittle secondary phases proved to significantly affect the ultimate strength of the material. Tool engagement also affected the fatigue resistance of the material.
Effect of Cu Substrate Roughness and Sn Layer Thickness on Whisker Development from Sn Thin-Films
Authors: Illés Balázs , Hurtony Tamás , Krammer Olivér , Medgyes Bálint , Dušek Karel , Bušek David
Published: November 2019

The effect of copper substrate roughness and tin layer thickness were investigated on whisker development in the case of Sn thin-films. Sn was vacuum-evaporated onto both unpolished and mechanically polished Cu substrates with 1 µm and 2 μm average layer thicknesses. The samples were stored in room conditions for 60 days. The considerable stress—developed by the rapid intermetallic layer formation—resulted in intensive whisker formation, even in some days after the layer deposition. The developed whiskers and the layer structure underneath them were investigated with both scanning electron microscopy and ion microscopy. The Sn thin-film deposited onto unpolished Cu substrate produced less but longer whiskers than that deposited onto polished Cu substrate. This phenomenon might be explained by the dependence of IML formation on the surface roughness of substrates. The formation of IML wedges is more likely on rougher Cu substrates than on polished ones. Furthermore, it was found that with the decrease of layer thickness, the development of nodule type whiskers increases due to the easier diffusion of other atoms into the whisker bodies.
Contactless Ultrasonic Cavitation in Alloy Melts
Authors: Pericleous Koulis , Bojarevics Valdis , Djambazov Georgi , Dybalska Agnieszka , Griffiths William D. , Tonry Catherine
Published: November 2019

A high frequency tuned electromagnetic induction coil is used to induce ultrasonic pressure waves leading to cavitation in alloy melts. This presents an alternative ‘contactless’ approach to conventional immersed probe techniques. The method can potentially offer the same benefits of traditional ultrasonic treatment (UST) such as degassing, microstructure refinement and dispersion of particles, but avoids melt contamination due to probe erosion prevalent in immersed sonotrodes, and it can be used on higher temperature and reactive alloys. An added benefit is that the induction stirring produced by the coil, enables a larger melt treatment volume. Model simulations of the process are conducted using purpose-built software, coupling flow, heat transfer, sound and electromagnetic fields. Modelling results are compared against experiments carried out in a prototype installation. Results indicate strong melt stirring and evidence of cavitation accompanying acoustic resonance. Up to 63% of grain refinement was obtained in commercial purity (CP-Al) aluminium and a further 46% in CP-Al with added Al–5Ti–1B grain refiner.
Evolution of the Structural, Mechanical, and Phonon Properties of GeSe Polymorphs in a Pressure-Induced Second-Order Phase Transition
Authors: Yang Jianhui , Fan Qiang , Xiao Bing , Ding Yingchun
Published: November 2019

A pressure-induced structural transition from the layered-like phase (Pnma) to another bilayer structure (Cmcm) in GeSe was investigated with first principle calculations. The variations of the structural, electronic, elastic, and vibrational properties of GeSe with the application of pressure were obtained. The transformation from the Pnma to Cmcm phase occurred at 34 GPa. The Cmcm phase structure showed dynamical stability above 37 GPa. The lattice parameters and the equation of state varied continuously at the transition pressure. Obvious stiffening in the C33 and C23 elastic constants associated with the compressive and shear components was observed to occur within the phase transition process. Two characteristic Raman modes (Ag and B3g) of the Pnma phase showed significant softening by increasing the pressure.
Uncertainty Quantification for Mechanical Properties of Polyethylene Based on Fully Atomistic Model
Authors: Vu-Bac Nam , Zhuang X. , Rabczuk T.
Published: November 2019

This study is to assess the effect of temperature and strain rate on the mechanical properties of amorphous polyethylene (PE) based on fully atomistic model. A stochastic constitutive model using data obtained from molecular dynamics (MD) simulations for the material is constructed. Subsequently, a global sensitivity analysis approach is then employed to predict the essential parameters of the mechanical model. The sensitivity indices show that the key parameter affecting Young’s modulus and yield stress is the temperature followed by the strain rate.
Deformation and Compressive Strength of Steel Fiber Reinforced MgO Concrete
Authors: Jiang Feifei , Mao Zhongyang , Deng Min , Li Dawang
Published: November 2019

To reduce the cracking caused by shrinkage and avoid the brittle behavior of concrete, MgO expansion agent and steel fibers were used in this paper. Firstly, the effect of MgO and steel fibers on the compressive strength of concrete was compared. The results showed that the compressive strength of steel fibers reinforced concrete (SC) and steel fiber reinforced MgO concrete (SMC) was significantly improved. Compared with ordinary concrete (OC), SMC’s 28 days compressive strength increased by 19.8%. Secondly, the influence of MgO and steel fibers with different contents on the self-volumetric deformation of concrete was compared through the experiment. The results showed that as a result of the hydration expansion of MgO, MC and SMC both showed obvious expansion, and their 190 days expansion was 335 μ ε and 288 μ ε , respectively. Lastly, through a scanning electron microscope (SEM) test, it was found that the constraint effect of steel fibers changed the expansion mode of MgO from outward expansion to inward extrusion, thus improving the interfacial bond strength of concrete.
Nanocomposites SnO2/SiO2:SiO2 Impact on the Active Centers and Conductivity Mechanism
Authors: Gulevich Dayana , Rumyantseva Marina , Marikutsa Artem , Shatalova Tatyana , Konstantinova Elizaveta , Gerasimov Evgeny , Gaskov Alexander
Published: November 2019

This paper is focused on the effect of the stabilizing component SiO2 on the type and concentration of active sites in SnO2/SiO2 nanocomposites compared with nanocrystalline SnO2. Previously, we found that SnO2/SiO2 nanocomposites show better sensor characteristics in CO detection (lower detection limit, higher sensor response, and shorter response time) compared to pure SnO2 in humid air conditions. Nanocomposites SnO2/SiO2 synthesized using the hydrothermal method were characterized by low temperature nitrogen adsorption, XRD, energy dispersive X-ray spectroscopy (EDX), thermo-programmed reduction with hydrogen (TPR-H2), IR-, and electron-paramagnetic resonance (EPR)-spectroscopy methods. The electrophysical properties of SnO2 and SnO2/SiO2 nanocomposites were studied depending on the oxygen partial pressure in the temperature range of 200–400 °C. The introduction of SiO2 results in an increase in the concentration of paramagnetic centers Sn3+ and the amount of surface hydroxyl groups and chemisorbed oxygen and leads to a decrease in the negative charge on chemisorbed oxygen species. The temperature dependences of the conductivity of SnO2 and SnO2/SiO2 nanocomposites are linearized in Mott coordinates, which may indicate the contribution of the hopping mechanism with a variable hopping distance over local states.
β-Si3N4 Microcrystals Prepared by Carbothermal Reduction-Nitridation of Quartz
Authors: Zhang Meng , Chen Zhi , Huang Juntong , Huang Saifang , Hu Zhihui , Feng Zhijun , Xiong Qingming , Li Xibao
Published: November 2019

Single phase β-Si3N4 with microcrystals was synthesized via carbothermal reduction-nitridation (CRN) of quartz and carbon coke powder as starting materials. The effects of reaction parameters, i.e., heating temperature, holding time, C/SiO2 ratio, Fe2O3 additive and β-Si3N4 seeds on the phase transformation and morphology of products were investigated and discussed. Rather than receiving a mixture of both α- and β- phases of Si3N4 in the products, we synthesized powders of β-Si3N4 single polymorph in this work. The mechanism for the CRN synthesis of β-Si3N4 from quartz and the formation mechanism of Fe3Si droplets were discussed. We also firstly reported the formation of Fe3Si Archimedean solids from a CRN process where Fe2O3 was introduced as additive. Comparing to the gear-like short columnar morphology observed in samples without β-Si3N4 seeding, the addition of β-Si3N4 seeds led to an elongated morphology of final products and much finer widths. In addition, the β-Si3N4 microcrystals exhibited a violet‒blue spectral emission range, which could be highly valuable for their future potential optoelectronic applications.
Effect of Nanosilica on Mechanical Properties and Microstructure of PVA Fiber-Reinforced Geopolymer Composite (PVA-FRGC)
Authors: Assaedi Hasan , Alomayri Thamer , Siddika Ayesha , Shaikh Faiz , Alamri Hatem , Subaer Subaer , Low It-Meng
Published: November 2019

This paper presents the effects of various nanosilica (NS) contents on the mechanical properties of polyvinyl alcohol (PVA) fiber-reinforced geopolymer composites (PVA-FRGC). Microstructure analysis with X-ray diffraction (XRD) and scanning electron microscopy (SEM) was used to characterize the geopolymer composites. The results showed that the mechanical properties in terms of compressive strength, impact strength, and flexural behavior were improved due to the addition of NS to the PVA-FRGC. The optimum NS content was 1.0 to 2.0 wt%, which exhibited highest improvement in the above mechanical properties. Microstructure analysis showed that the addition of NS up to an optimum level densified the microstructure of the matrix as well as the PVA fiber–geopolymer matrix interface.
Mechanical Properties, Biodegradation, and Biocompatibility of Ultrafine Grained Magnesium Alloy WE43
Authors: Dobatkin Sergey , Martynenko Natalia , Anisimova Natalia , Kiselevskiy Mikhail , Prosvirnin Dmitriy , Terentiev Vladimir , Yurchenko Nikita , Salishchev Gennady , Estrin Yuri
Published: November 2019

In this work, the effect of an ultrafine-grained (UFG) structure obtained by multiaxial deformation (MAD) on the mechanical properties, fatigue strength, biodegradation, and biocompatibility in vivo of the magnesium alloy WE43 was studied. The grain refinement down to 0.93 ± 0.29 µm and the formation of Mg41Nd5 phase particles with an average size of 0.34 ± 0.21 µm were shown to raise the ultimate tensile strength to 300 MPa. Besides, MAD improved the ductility of the alloy, boosting the total elongation from 9% to 17.2%. An additional positive effect of MAD was an increase in the fatigue strength of the alloy from 90 to 165 MPa. The formation of the UFG structure also reduced the biodegradation rate of the alloy under both in vitro and in vivo conditions. The relative mass loss after six weeks of experiment was 83% and 19% in vitro and 46% and 7% in vivo for the initial and the deformed alloy, respectively. Accumulation of hydrogen and the formation of necrotic masses were observed after implantation of alloy specimens in both conditions. Despite these detrimental phenomena, the desired replacement of the implant and the surrounding cavity with new connective tissue was observed in the areas of implantation.