bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Korean Dental Hygienists’ Experiences Related to the Elderly on Their Perception of Human Rights Violations of the Elderly: A Cross-Sectional Study
Authors: Jang Kyeung-Ae , Kim Yu-Rin
Published: March 2022

Background: Korean society has become an elderly society at an unprecedented rate, and the associated social and economic problems are very serious. Maintaining a healthy oral condition is important for older people’s well-being and quality of life, and is essential for healthy ageing. Therefore, the purpose of this study was to investigate the effect of dental hygienists’ experiences related to the elderly on their perception of human rights violations toward the elderly. Methods: This study was conducted through an IRB review at Silla University in Korea (No. 1041449-202012-HR-001). For about a month after 1 February 2021, the survey questionnaire was distributed to dental hygienists living in South Korea, and 153 people who completed and sent back the questionnaires were selected as the final subjects. The items on the questionnaire consisted of perception of human rights violations for the elderly and experiences related to the elderly. A polyserial correlation analysis was performed to confirm the relevance of each factor, and a multiple regression analysis was performed to identify the factors of elderly-related experiences that affect the perception of human rights violations against the elderly. Results: All three experiences related to the elderly (the experience of receiving education related to the elderly, the experience of volunteer work related to the elderly, and the experience of being interested in issues related to the elderly) were highly related to the perception of violations of financial human rights of the elderly (p < 0.01). In addition, the experience of education related to the elderly showed a high perception of psychological violations of the human rights of the elderly (R = 0.405, p < 0.01), and the experience of volunteer activities related to the elderly showed a high perception of neglectful violations of human rights of the elderly (R = 0.277, p < 0.01). Conclusions: In this study, it was confirmed that there is a relationship between dental hygienists’ experiences related to the elderly and their perception of human rights violations in the elderly. Therefore, dental hygienists should do their best to manage the elderly’s oral health by raising awareness of the human rights violations against the elderly through the elderly professional course based on their experience with the elderly.
The Association of Nutrition Quality with Frailty Syndrome among the Elderly
Authors: Rolf Katarzyna , Santoro Aurelia , Martucci Morena , Pietruszka Barbara
Published: March 2022

Low diet quality among the elderly may be correlated with some diseases, including Frailty Syndrome (FS). This decline in function restricts the activity of older people, resulting in higher assistance costs. The aim of this study was to increase knowledge of diet quality predictors. Dietary intake was assessed among 196 individuals aged 60+ years using the three-day record method and FS by Fried’s criteria. Based on the compliance with the intake recommendation (% of EAR/AI), we distinguished three clusters that were homogeneous in terms of the nutritional quality of the diet, using Kohonen’s neural networks. The prevalence of frailty in the entire group was 3.1%, pre-frailty 38.8%, and non-frailty 58.1%. Cluster 1 (91 people with the lowest diet quality) was composed of a statistically significant higher number of the elderly attending day care centers (20.7%), frail (6.9%), pre-frail (51.7%), very low vitamin D intake (23.8% of AI), using sun cream during the summer months (always 19.8% or often 39.6%), having diabetes (20.7%), having leg pain when walking (43.1%), and deteriorating health during the last year (53.5%). The study suggests the need to take initiatives leading to the improvement of the diet of the elderly, especially in day care senior centers, where there are more frail individuals, including nutritional education for the elderly and their caregivers.
Structural Equation Modelling for Predicting the Relative Contribution of Each Component in the Metabolic Syndrome Status Change
Authors: Teixeira José E. , Bragada José A. , Bragada João P. , Coelho Joana P. , Pinto Isabel G. , Reis Luís P. , Fernandes Paula O. , Morais Jorge E. , Magalhães Pedro M.
Published: March 2022

Understanding the factor weighting in the development of metabolic syndrome (MetS) may help to predict the progression for cardiovascular and metabolic diseases. Thus, the aim of this study was to develop a confirmatory model to describe and explain the direct and indirect effect of each component in MetS status change. A total of 3581 individuals diagnosed with MetS, aged 18–102 years, were selected between January 2019 and December 2020 from a community-representative sample of Portuguese adults in a north-eastern Portuguese region to test the model’s goodness of fit. A structural equation modelling (SEM) approach and a two-way ANOVA (age × body composition) were performed to compare the relative contribution of each MetS component using joint interim statement (JIS). Waist circumference (β = 0.189–0.373, p < 0.001), fasting glucose (β = 0.168–0.199, p < 0.001) and systolic blood pressure (β = 0.140–0.162, p < 0.001) had the highest direct effect on the change in MetS status in the overall population and concerning both sexes. Moreover, diastolic blood pressure (DBP), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-c) had a low or non-significant effect. Additionally, an indirect effect was reported for age and body composition involving the change in MetS status. The findings may suggest that other components with higher specificity and sensitivity should be considered to empirically validate the harmonised definition of MetS. Current research provides the first multivariate model for predicting the relative contribution of each component in the MetS status change, specifically in Portuguese adults.
Enotourism in Southern Spain: The Montilla-Moriles PDO
Authors: Cava Jimenez Jose Antonio , Millán Vázquez de la Torre Mª Genoveva , Dancausa Millán Mª Genoveva
Published: March 2022

The profile of tourists during the COVID-19 pandemic is changing toward those seeking health, safety and quality products. One of the modalities that best adapts to these needs is gastronomic tourism and, within this segment, wine tourism (enotourism), which can be enjoyed in many areas across the world. The great diversity of grapes, climates, terrains and winemaking processes gives rise to an enormous variety of wines that ensures that no two wines are alike. The current situation of the tourism market necessitates enhancing the uniqueness of areas that offer differentiated products, helping to position such locations as benchmarks for gastronomic tourism. Gastronomic routes provide a way to unify and benefit rural areas through the recently increased demand of tourists seeking to experience regional foods. In this study, the Montilla-Moriles Wine Route is analyzed with the objective of forecasting the demand (using autoregressive integrate moving average, ARIMA models), establishing a tourist profile and calculating the probability that a wine tourist is satisfied with the visit based on their personal characteristics (logit model). The results obtained indicate a slight increase (3.6%) in wine tourists with a high degree of satisfaction, primarily derived from the gastronomic or catering services of the area, from the number of wineries visited, from the treatment received and from the age of the tourist. Consequently, a high percentage of these tourists recommend the route. By increasing the demand for enotourism in this area and applying the results obtained, marketing initiatives could be established, particularly for wine festivals to improve this tourist segment and generate wealth in that area.
The Fight against Cancer by Microgravity: The Multicellular Spheroid as a Metastasis Model
Authors: Grimm Daniela , Schulz Herbert , Krüger Marcus , Cortés-Sánchez José Luis , Egli Marcel , Kraus Armin , Sahana Jayashree , Corydon Thomas J. , Hemmersbach Ruth , Wise Petra M. , Infanger Manfred , Wehland Markus
Published: March 2022

Cancer is a disease exhibiting uncontrollable cell growth and spreading to other parts of the organism. It is a heavy, worldwide burden for mankind with high morbidity and mortality. Therefore, groundbreaking research and innovations are necessary. Research in space under microgravity (µg) conditions is a novel approach with the potential to fight cancer and develop future cancer therapies. Space travel is accompanied by adverse effects on our health, and there is a need to counteract these health problems. On the cellular level, studies have shown that real (r-) and simulated (s-) µg impact survival, apoptosis, proliferation, migration, and adhesion as well as the cytoskeleton, the extracellular matrix, focal adhesion, and growth factors in cancer cells. Moreover, the µg-environment induces in vitro 3D tumor models (multicellular spheroids and organoids) with a high potential for preclinical drug targeting, cancer drug development, and studying the processes of cancer progression and metastasis on a molecular level. This review focuses on the effects of r- and s-µg on different types of cells deriving from thyroid, breast, lung, skin, and prostate cancer, as well as tumors of the gastrointestinal tract. In addition, we summarize the current knowledge of the impact of µg on cancerous stem cells. The information demonstrates that µg has become an important new technology for increasing current knowledge of cancer biology.
Long Non-Coding RNAs Might Regulate Phenotypic Switch of Vascular Smooth Muscle Cells Acting as ceRNA: Implications for In-Stent Restenosis
Authors: Arencibia Alberto , Lanas Fernando , Salazar Luis A.
Published: March 2022

Coronary in-stent restenosis is a late complication of angioplasty. It is a multifactorial process that involves vascular smooth muscle cells (VSMCs), endothelial cells, and inflammatory and genetic factors. In this study, the transcriptomic landscape of VSMCs’ phenotypic switch process was assessed under stimuli resembling stent injury. Co-cultured contractile VSMCs and endothelial cells were exposed to a bare metal stent and platelet-derived growth factor (PDGF-BB) 20 ng/mL. Migratory capacity (wound healing assay), proliferative capacity, and cell cycle analysis of the VSMCs were performed. RNAseq analysis of contractile vs. proliferative VSMCs was performed. Gene differential expression (DE), identification of new long non-coding RNA candidates (lncRNAs), gene ontology (GO), and pathway enrichment (KEGG) were analyzed. A competing endogenous RNA network was constructed, and significant lncRNA–miRNA–mRNA axes were selected. VSMCs exposed to “stent injury” conditions showed morphologic changes, with proliferative and migratory capacities progressing from G0-G1 cell cycle phase to S and G2-M. RNAseq analysis showed DE of 1099, 509 and 64 differentially expressed mRNAs, lncRNAs, and miRNAs, respectively. GO analysis of DE genes showed significant enrichment in collagen and extracellular matrix organization, regulation of smooth muscle cell proliferation, and collagen biosynthetic process. The main upregulated nodes in the lncRNA-mediated ceRNA network were PVT1 and HIF1-AS2, with downregulation of ACTA2-AS1 and MIR663AHG. The PVT1 ceRNA axis appears to be an attractive target for in-stent restenosis diagnosis and treatment.
BMP-2 Long-Term Stimulation of Human Pre-Osteoblasts Induces Osteogenic Differentiation and Promotes Transdifferentiation and Bone Remodeling Processes
Authors: Ingwersen Lena-Christin , Frank Marcus , Naujokat Hendrik , Loger Klaas , Bader Rainer , Jonitz-Heincke Anika
Published: March 2022

Bone morphogenic protein (BMP-) 2 plays an important role in the regeneration of bone defects by promoting osteogenic differentiation. However, several animal studies have reported adverse side effects of BMP-2, including osteoclast activation, induction of peroxisome proliferator- activated receptor gamma (PPARG)expression, and inflammation. High BMP-2 concentrations are thought to be responsible for these side effects. For this reason, primary pre-osteoblasts were exposed to lower BMP-2 concentrations (1 and 2 µg/mL). Long-term exposure (up to 28 days) was performed to investigate whether this stimulation protocol may promote osteogenic differentiation without causing the side effects mentioned above. The results showed that BMP-2 treatment for 14 or 28 days resulted in increased osteogenesis, through an increase in runt-related transcription factor 2, osterix, alkaline phosphatase, and integrin-binding sialoprotein expression. However, an increase in tumor necrosis factor alpha and receptor activator of nuclear factor kappa-Β ligand protein levels was observed after BMP-2 exposure, indicating also an increased potential for osteoclast activation by osteoblasts. Additionally, morphological changes like intracellular, filled vacuoles could be detected. Enhanced PPARG and perilipin 1 mRNA transcripts and lipid droplets indicated an induced adipogenic differentiation. Overall, the data demonstrate that long-term BMP-2 exposure promotes not only osteogenic differentiation but also adipogenesis and regulates mediators involved in osteoclast activation in vitro.
Neuroinflammation and COVID-19 Ischemic Stroke Recovery—Evolving Evidence for the Mediating Roles of the ACE2/Angiotensin-(1–7)/Mas Receptor Axis and NLRP3 Inflammasome
Authors: Che Mohd Nassir Che Mohd Nasril , Zolkefley Mohd K. I. , Ramli Muhammad Danial , Norman Haziq Hazman , Abdul Hamid Hafizah , Mustapha Muzaimi
Published: March 2022

Cerebrovascular events, notably acute ischemic strokes (AIS), have been reported in the setting of novel coronavirus disease (COVID-19) infection. Commonly regarded as cryptogenic, to date, the etiology is thought to be multifactorial and remains obscure; it is linked either to a direct viral invasion or to an indirect virus-induced prothrombotic state, with or without the presence of conventional cerebrovascular risk factors. In addition, patients are at a greater risk of developing long-term negative sequelae, i.e., long-COVID-related neurological problems, when compared to non-COVID-19 stroke patients. Central to the underlying neurobiology of stroke recovery in the context of COVID-19 infection is reduced angiotensin-converting enzyme 2 (ACE2) expression, which is known to lead to thrombo-inflammation and ACE2/angiotensin-(1–7)/mitochondrial assembly receptor (MasR) (ACE2/Ang-(1-7)/MasR) axis inhibition. Moreover, after AIS, the activated nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome may heighten the production of numerous proinflammatory cytokines, mediating neuro-glial cell dysfunction, ultimately leading to nerve-cell death. Therefore, potential neuroprotective therapies targeting the molecular mechanisms of the aforementioned mediators may help to inform rehabilitation strategies to improve brain reorganization (i.e., neuro-gliogenesis and synaptogenesis) and secondary prevention among AIS patients with or without COVID-19. Therefore, this narrative review aims to evaluate the mediating role of the ACE2/Ang- (1-7)/MasR axis and NLRP3 inflammasome in COVID-19-mediated AIS, as well as the prospects of these neuroinflammation mediators for brain repair and in secondary prevention strategies against AIS in stroke rehabilitation.
Applications of Genomic Tools in Plant Breeding: Crop Biofortification
Authors: Medina-Lozano Inés , Díaz Aurora
Published: March 2022

Crop breeding has mainly been focused on increasing productivity, either directly or by decreasing the losses caused by biotic and abiotic stresses (that is, incorporating resistance to diseases and enhancing tolerance to adverse conditions, respectively). Quite the opposite, little attention has been paid to improve the nutritional value of crops. It has not been until recently that crop biofortification has become an objective within breeding programs, through either conventional methods or genetic engineering. There are many steps along this long path, from the initial evaluation of germplasm for the content of nutrients and health-promoting compounds to the development of biofortified varieties, with the available and future genomic tools assisting scientists and breeders in reaching their objectives as well as speeding up the process. This review offers a compendium of the genomic technologies used to explore and create biodiversity, to associate the traits of interest to the genome, and to transfer the genomic regions responsible for the desirable characteristics into potential new varieties. Finally, a glimpse of future perspectives and challenges in this emerging area is offered by taking the present scenario and the slow progress of the regulatory framework as the starting point.
PRP4 Induces Epithelial–Mesenchymal Transition and Drug Resistance in Colon Cancer Cells via Activation of p53
Authors: Islam Salman Ul , Ahmed Muhammad Bilal , Sonn Jong-Kyung , Jin Eun-Jung , Lee Young-Sup
Published: March 2022

Pre-mRNA processing factor 4B (PRP4) promotes pre-mRNA splicing and signal transduction. Recent studies have shown that PRP4 modulates the assembly of actin cytoskeleton in cancer cells and induces epithelial–mesenchymal transition (EMT) and drug resistance. PRP4 displays kinase domain-like cyclin-dependent kinases and mitogen-activated protein kinases, making it capable of phosphorylating p53 and other target proteins. In the current study, we report that PRP4 induces drug resistance and EMT via direct binding to the p53 protein, inducing its phosphorylation. Moreover, PRP4 overexpression activates the transcription of miR-210 in a hypoxia-inducible factor 1α (HIF-1α)-dependent manner, which activates p53. The involvement of miR-210 in the activation of p53 was confirmed by utilizing si-miR210. si-miR210 blocked the PRP4-activated cell survival pathways and reversed the PRP4-induced EMT phenotype. Moreover, we used deferoxamine as a hypoxia-mimetic agent, and si-HIF to silence HIF-1α. This procedure demonstrated that PRP4-induced EMT and drug resistance emerged in response to consecutive activation of HIF-1α, miR-210, and p53 by PRP4 overexpression. Collectively, our findings suggest that the PRP4 contributes to EMT and drug resistance induction via direct interactions with p53 and actions that promote upregulation of HIF-1α and miR-210. We conclude that PRP4 is an essential factor promoting cancer development and progression. Specific PRP4 inhibition could benefit patients with colon cancer.
Therapeutic Effect of Melittin–dKLA Targeting Tumor-Associated Macrophages in Melanoma
Authors: Han Ik-Hwan , Jeong Chanmi , Yang Juwon , Park Seung-Hyeok , Hwang Deok-Sang , Bae Hyunsu
Published: March 2022

Melanoma is an immunogenic tumor and a serious type of skin cancer. Tumor-associated macrophages (TAMs) express an M2-like phenotype and are involved in all stages of melanomagenesis; it is hence a promising target for cancer immunotherapy. We herein investigated whether melittin–dKLA inhibits the growth of melanoma by inducing apoptosis of M2-like macrophages. For the in vitro study, a conditioned medium of macrophages was prepared from M0, M1, or M2-differentiated THP-1 cells with and without melittin–dKLA. The affinity of melittin for M2 macrophages was studied with FITC (fluorescein isothiocyanate)-conjugated melittin. For the in vivo study, murine melanoma cells were inoculated subcutaneously in the right flank of mice, melittin–dKLA was intraperitoneally injected at 200 nmol/kg every three days, and flow cytometry analysis of TAMs was performed. Since melittin binds preferentially to M2-like macrophages, melittin–dKLA induced more caspase 3 expression and cell death in M2 macrophages compared with M0 and M1 macrophages and melanoma cells. Melittin–dKLA significantly inhibited the proliferation and migration of M2 macrophages, resulting in a decrease in melanoma tumor growth in vivo. The CD206+ M2-like TAMs were reduced, while the CD86+ M1-like TAMs were not affected. Melittin–dKLA is therapeutically effective against melanoma by inducing the apoptosis of M2-like TAMs.
A Homozygous Deep Intronic Variant Causes Von Willebrand Factor Deficiency and Lack of Endothelial-Specific Secretory Organelles, Weibel–Palade Bodies
Authors: Yadegari Hamideh , Jamil Muhammad Ahmer , Marquardt Natascha , Oldenburg Johannes
Published: March 2022

A type 3 von Willebrand disease (VWD) index patient (IP) remains mutation-negative after completion of the conventional diagnostic analysis, including multiplex ligation-dependent probe amplification and sequencing of the promoter, exons, and flanking intronic regions of the VWF gene (VWF). In this study, we intended to elucidate causative mutation through next-generation sequencing (NGS) of the whole VWF (including complete intronic region), mRNA analysis, and study of the patient-derived endothelial colony-forming cells (ECFCs). The NGS revealed a variant in the intronic region of VWF (997 + 118 T > G in intron 8), for the first time. The bioinformatics assessments (e.g., SpliceAl) predicted this variant creates a new donor splice site (ss), which could outcompete the consensus 5′ donor ss at exon/intron 8. This would lead to an aberrant mRNA that contains a premature stop codon, targeting it to nonsense-mediated mRNA decay. The subsequent quantitative real-time PCR confirmed the virtual absence of VWF mRNA in IP ECFCs. Additionally, the IP ECFCs demonstrated a considerable reduction in VWF secretion (~6% of healthy donors), and they were devoid of endothelial-specific secretory organelles, Weibel–Palade bodies. Our findings underline the potential of NGS in conjunction with RNA analysis and patient-derived cell studies for genetic diagnosis of mutation-negative type 3 VWD patients.
Cuticle Protein LmACP19 Is Required for the Stability of Epidermal Cells in Wing Development and Morphogenesis of Locusta migratoria
Authors: Zhao Xiaoming , Shao Ti , Su Yazhi , Zhang Jing , Gou Xin , Liu Weimin , Zhang Jianzhen
Published: March 2022

Insect wing consists of a double layer of epidermal cells that produce and secrete the dorsal and ventral cuticular components. It is important for the stability of epidermal cells during wing development and morphogenesis, but its specific gene expression and physiological function during this process remain unclear. In our previous work, a wing cuticle protein gene LmACP19 was identified in Locusta migratoria based on transcriptomic data. Here, we report on its roles in wing development and morphogenesis. LmACP19 encodes a chitin-binding protein belonging to RR-2 subfamily of CPR family, which is highly homologous to CP19-like proteins in other insect species. RT-qPCR analysis revealed that LmACP19 is highly expressed in wing pads of fifth-instar nymphs, and its encoded protein is located in two layers of epidermal cells but not in the cuticle. Suppression of LmACP19 by RNA interference led to abnormal wing pad and wing morphogenesis with curved, unclosed, and wrinkled phenotypes during nymph-to-nymph and nymph-to-adult transition, respectively. Furthermore, deficiency of LmACP19 affected arrangement of epidermal cells, resulting in apoptosis. Our results indicate that LmACP19 is indispensable for wing development and normal morphological structure by maintaining the stability of epidermal cells during L. migratoria molting.
LPPR5 Expression in Glioma Affects Growth, Vascular Architecture, and Sunitinib Resistance
Authors: Stange Lena , Lucia Kristin Elizabeth , Ghori Adnan , Vajkoczy Peter , Czabanka Marcus , Broggini Thomas
Published: March 2022

Despite intensive research, glioblastoma remains almost invariably fatal. Various promising drugs targeting specific aspects of glioma biology, in addition to or as an alternative to antiproliferative chemotherapy, were not successful in larger clinical trials. Further insights into the biology of glioma and the mechanisms behind the evasive-adaptive response to targeted therapies is needed to help identify new therapeutic targets, prognostics, or predictive biomarkers. As a modulator of the canonically oncogenic Rho-GTPase pathway, Lipid phosphate phosphatase-related protein type 5 (LPPR5) is pivotal in influencing growth, angiogenesis, and therapeutic resistance. We used a GL261 murine orthotopic allograft glioma model to quantify the tumor growth and to obtain tissue for histological and molecular analysis. Epicortical intravital epi-illumination fluorescence video microscopy of the tumor cell spheroids was used to characterize the neovascular architecture and hemodynamics. GL261-glioma growth was delayed and decelerated after LPPR5 overexpression (LPPR5OE). We observed increased tumor cell apoptosis and decreased expression and secretion of vascular endothelial growth factor A in LPPR5OE glioma. Hence, an altered micro-angioarchitecture consisting of dysfunctional small blood vessels was discovered in the LPPR5OE tumors. Sunitinib therapy eliminated these vessels but had no effect on tumor growth or apoptosis. In general, LPPR5 overexpression generated a more benign, proapoptotic glioma phenotype with delayed growth and a dysfunctional vascular architecture.
Cerebral Pulsatility Index and In-Hospital Mortality in Chinese Patients with Traumatic Brain Injury: A Retrospective Cohort Study
Authors: Mei Tao , Zhou Quan , Chen Lie , Jia Zheyong , Xiao Wei , Xu Lixin
Published: March 2022

There are limited studies on the relationship between the vascular transcranial Doppler (TCD) pulsatility index (PI) and in-hospital mortality in patients with traumatic brain injury (TBI). To address this issue, we conducted this study to explore whether, in newly diagnosed Chinese TBI patients, the PI is an independent predictor of the in-hospital mortality rate after adjusting for other covariates. This study is a retrospective cohort study. From 24 March 2019 to 24 January 2020, we recruited 144 Chinese patients with newly diagnosed TBI from a Chinese hospital. The independent variable was the PI, and the dependent variable was in-hospital mortality in TBI patients. The relationship between the PI and in-hospital mortality in TBI patients was nonlinear and had an inflection point of 1.11. In the multivariate analysis, after adjusting for potential confounders, the effect sizes and confidence intervals per additional 0.1 units on the left and right sides of the inflection point were 4.09 (1.30–12.83) and 1.42 (0.93–2.17). The relationship between the PI and in-hospital mortality was nonlinear. The PI was positively related with in-hospital mortality when the PI was less than 1.11.
Enhancing Thermoelectric Properties of (Cu2Te)1−x-(BiCuTeO)x Composites by Optimizing Carrier Concentration
Authors: Zhang Wenyu , Zhou Zhifang , Yang Yueyang , Zheng Yunpeng , Xu Yushuai , Zou Mingchu , Nan Ce-Wen , Lin Yuan-Hua
Published: March 2022

Because of the high carrier concentration, copper telluride (Cu2Te) has a relatively low Seebeck coefficient and high thermal conductivity, which are not good for its thermoelectric performance. To simultaneously optimize carrier concentration, lower thermal conductivity and improve the stability, BiCuTeO, an oxygen containing compound with lower carrier concentration, is in situ formed in Cu2Te by a method of combining self-propagating high-temperature synthesis (SHS) with spark plasma sintering (SPS). With the incorporation of BiCuTeO, the carrier concentration decreased from 8.1 × 1020 to 3.8 × 1020 cm−3, bringing the increase of power factor from ~1.91 to ~2.97 μW cm−1 K−2 at normal temperature. At the same time, thermal conductivity reduced from 2.61 to 1.48 W m−1 K−1 at 623 K. Consequently, (Cu2Te)0.95-(BiCuTeO)0.05 composite sample reached a relatively high ZT value of 0.13 at 723 K, which is 41% higher than that of Cu2Te.
Temperature- and Frequency-Dependent Ferroelectric Characteristics of Metal-Ferroelectric-Metal Capacitors with Atomic-Layer-Deposited Undoped HfO2 Films
Authors: Jang Chan-Hee , Kim Hyun-Seop , Kim Hyungtak , Cha Ho-Young
Published: March 2022

In this study, we evaluated the temperature- and frequency-dependent ferroelectric characteristics of TiN/undoped HfO2/TiN metal-ferroelectric-metal (MFM) capacitors in which an undoped HfO2 film was deposited through atomic layer deposition (ALD). Successful ferroelectric characteristics were achieved after postdeposition annealing at 650 °C, which exhibited a remanent polarization of 8 μC/cm2 and a coercive electric field of 1.6 MV/cm at 25 °C (room temperature). The ferroelectric property was maintained at 200 °C and decreased as the temperature increased. The ferroelectric property was completely lost above 320 °C and fully recovered after cooling. The frequency dependency was evaluated by bias-dependent capacitance–voltage and s-parameter measurements, which indicated that the ferroelectric property was maintained up to several hundred MHz. This study reveals the ultimate limitations of the application of an undoped HfO2 MFM capacitor.
Reorientation of Suspended Ceramic Particles in Robocasted Green Filaments during Drying
Authors: Dietemann Bastien , Wahl Larissa , Travitzky Nahum , Kruggel-Emden Harald , Kraft Torsten , Bierwisch Claas
Published: March 2022

This work considers the fabrication of ceramic parts with the help of an additive manufacturing process, robocasting, in which a paste with suspended particles is robotically extruded. Within the final part, the material properties depend on the orientation of the particles. A prediction of the particle orientation is challenging as the part usually undergoes multiple processing steps with varying contributions to the orientation. As the main contribution to the final particle orientation arises from the extrusion process, many corresponding prediction models have been suggested. Robocasting involves, however, further processing steps that are less studied as they have a smaller influence on the orientation. One of the processing steps is drying by natural convection, which follows directly after the extrusion process. A quantification of the reorientation that occurs during drying is mostly unknown and usually neglected in the models. Therefore, we studied the amount of reorientation of suspended particles in robocasted green filaments during drying in detail. For our study, we applied the discrete element method, as it meets various requirements: The exact particle geometry can be resolved precisely; particle–particle interactions can be described; the paste composition is reproduced exactly; the initial particle orientation can be set in accordance with the prediction from the analytical models for the extrusion part; macroscopic force laws exist to represent capillary forces due to the remaining fluid phase that remains during drying. From our study, we concluded that the magnitude of particle reorientation during drying is small compared to the orientation occurring during the extrusion process itself. Consequently, reorientation during drying might further be neglected within analytical orientation prediction models.
Effects of Aluminum Oxide Addition on Electrical and Mechanical Properties of 3 mol% Yttria-Stabilized Tetragonal Zirconia Electrolyte for IT-SOFCs
Authors: Chłędowska (Pleśniak) Justyna , Wyrwa Jan , Rękas Mieczysław , Brylewski Tomasz
Published: March 2022

Composite tetragonal zirconia (3Y-TZP) sinters with Al2O3 contents of 0, 1, 5, 10 and 15 mol% were obtained from a 3-YSZ powder prepared using the gelatin method, and the influence of alumina addition on the mechanical and electrical properties of the obtained sinters was investigated. Al2O3 was added via two different methods, namely during the preparation of the 3-YSZ powder and via impregnation using an alcohol solution of aluminum nitrate. The obtained green bodies were sintered for 2 h in air at 1773 K. The structure and morphology of the two series of sinters were investigated using XRD and SEM-EDS, their electrical properties were determined using impedance spectroscopy, and their hardness and critical stress intensity factor were measured using the Vickers indentation test. We established that both the amount of alumina and the method used to introduce it into the 3Y-TZP matrix significantly affect the physicochemical properties of the obtained polycrystalline material. The 3-YSZ/10 mol% Al2O3 sinter that had Al2O3 introduced during the preparation of the 3-YSZ powder was found to exhibit the most advantageous mechanical and electrical properties while still having sufficiently low porosity.
Numerical and Experimental Investigation of Quasi-Static Crushing Behaviors of Steel Tubular Structures
Authors: Park Young IL , Cho Jin-Seong , Kim Jeong-Hwan
Published: March 2022

In this study, a numerical and experimental investigation of the quasi-static crushing behavior of steel tubular structures was conducted. As the crushing failure behavior involves a high level of nonlinearity for the numerical simulations, these were compared with previous experimental works, including crushing tests of steel square tubes to calibrate the numerical results. Six parameters for the numerical simulations, namely (1) loading boundary condition, (2) geometrical imperfection, (3) friction coefficient, (4) element size, (5) element type, and (6) material nonlinearity model, were examined using a series of finite element analyses. Through the sensitivity study for each parameter, the deformation and crushing load of the steel tube were investigated, and the value that best matched the experimental results was selected. The results of the numerical analysis for the determined model were compared with the experimental results. Finally, the authors provided recommendations that should be considered when performing nonlinear finite element simulations of crushing failure events.
Recent Advancements in the Fabrication of Functional Nanoporous Materials and Their Biomedical Applications
Authors: Hadden Matthew , Martinez-Martin David , Yong Ken-Tye , Ramaswamy Yogambha , Singh Gurvinder
Published: March 2022

Functional nanoporous materials are categorized as an important class of nanostructured materials because of their tunable porosity and pore geometry (size, shape, and distribution) and their unique chemical and physical properties as compared with other nanostructures and bulk counterparts. Progress in developing a broad spectrum of nanoporous materials has accelerated their use for extensive applications in catalysis, sensing, separation, and environmental, energy, and biomedical areas. The purpose of this review is to provide recent advances in synthesis strategies for designing ordered or hierarchical nanoporous materials of tunable porosity and complex architectures. Furthermore, we briefly highlight working principles, potential pitfalls, experimental challenges, and limitations associated with nanoporous material fabrication strategies. Finally, we give a forward look at how digitally controlled additive manufacturing may overcome existing obstacles to guide the design and development of next-generation nanoporous materials with predefined properties for industrial manufacturing and applications.
Study on Radiation Shielding Properties of New Barium-Doped Zinc Tellurite Glass
Authors: Yin Shiyu , Wang Hao , Li Aifeng , Ma Zhongjian , He Yintong
Published: March 2022

This study aimed to investigate the effect of BaF2 on the radiation-shielding ability of lead telluride glass. A physical radioactive source was used to estimate the mass attenuation coefficient (μm) of the 60TeO2-20PbO-(20-x)ZnO-xBaF2 glass system (where x = 1,2,3,5,6,7,9 mol%). We tested the μm values at seven energies (0.059, 0.081, 0.122, 0.356, 0.662, 1.173, 1.332 MeV). To determine the accuracy of the obtained results, we compared the experimental data with the data calculated using the XCOM software. The experimental values obtained for the selected lead telluride glasses at different concentrations of BaF2 are in good agreement with the results of XCOM at all energies. The addition of BaF2 increased the μm value of the sample. At the same time, the half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), and fast neutron removal cross-section (RCS) of the glass were studied. With the increase in the BaF2 content, the HVL value and MFP value of the glass decreased, and the Zeff value and RCS increased, indicating that the addition of BaF2 enhanced the radiation-shielding performance of the glass.
The Influence of the Elemental Composition, Crystal Structure, and Grain Structure of the Ferro-Piezoceramics of Various Degrees of the Ferro-Hardness on the Stability of the Polarized State
Authors: Andryushin Konstantin , Dudkina Svetlana , Sahoo Sushrisangita , Shilkina Lidiya , Alyoshin Vladimir , Triger Ekaterina , Andryushina Inna , Verbenko Iliya , Rudskiy Daniil , Rudskaya Angela , Reznichenko Larisa
Published: March 2022

Ferro-piezoceramic materials (FPCM) with different degrees of ferrohardness were fabricated by double solid-phase synthesis followed by the sintering technique using hot pressing method. The X-ray studies carried out in a wide temperature range showed that with increasing temperature, each of the studied FPCM undergoes a series of phase transformations, accompanied by a change in the symmetry of the unit cell. In this case, near the phase transition to the nonpolar cubic phase, in each of the FPCM, the formation of a fuzzy symmetry region is observed, which is characterized by weak distortions and temperature–time instability of the crystal structure. The study of the piezoelectric modulus d33 in the quasi-static regime as a function of temperature made it possible to reveal the different nature of its behavior in materials of various degrees of ferrohardness. It was shown that the conservation of the state in ferrosoft materials above the Curie temperature is associated with the relaxation nature of the change in their properties, the existence of a region of fuzzy symmetry (noncubic phase) in them above the Curie temperature, and increased inertia of the system. The expediency of taking into account the presented results in the development of electromechanical converters based on FPCM of various degrees of ferrohardness, operated under temperature effects, including cyclic ones, was shown.
Effect of Annealing Temperature on the Interfacial Microstructure and Bonding Strength of Cu/Al Clad Sheets with a Stainless Steel Interlayer
Authors: Gao Haitao , Gu Hao , Wang Sai , Xuan Yanni , Yu Hailiang
Published: March 2022

To explore the influence of annealing temperatures on the interfacial structure and peeling strength of Cu/Al clad sheets with a 304 stainless steel foil interlayer, an intermediate annealing treatment was performed at temperatures of 450 °C, 550 °C, and 600 °C, separately. The experimental results indicate that the interfacial atomic diffusion is significantly enhanced by increasing the intermediate annealing temperature. The average peeling strength of the clad sheets annealed at 550 °C can reach 34.3 N/mm and the crack propagation is along the steel/Cu interface, Cu-Al intermetallic compounds layer, and Al matrix. However, after high-temperature annealing treatment (600 °C), the liquid phase is formed at the bonding interface and the clear Cu/steel/Al interface is replaced by the chaotic composite interfaces. The clad sheet broke completely in the unduly thick intermetallic compounds layer, resulting in a sharp decrease in the interfacial bonding strength.
Modeling Spheres in Some Paranormed Sequence Spaces
Authors: Veličković Vesna I. , Malkowsky Eberhard , Dolićanin Edin
Published: March 2022

We introduce a new sequence space hA(p), which is not normable, in general, and show that it is a paranormed space. Here, A and p denote an infinite matrix and a sequence of positive numbers. In the special case, when A is a diagonal matrix with a sequence d of positive terms on its diagonal and p=(1,1,…), then hA(p) reduces to the generalized Hahn space hd. We applied our own software to visualize the shapes of parts of spheres in three-dimensional space endowed with the relative paranorm of hA(p), when A is an upper triangle. For this, we developed a parametric representation of these spheres and solved the visibility and contour (silhouette) problems. Finally, we demonstrate the effects of the change of the entries of the upper triangle A and the terms of the sequence p on the shape of the spheres.
Recurrence of Nephrolithiasis and Surgical Events Are Associated with Chronic Kidney Disease in Adult Patients
Authors: Medina-Escobedo Martha , Sánchez-Pozos Katy , Gutiérrez-Solis Ana Ligia , Avila-Nava Azalia , González-Rocha Lizeth , Lugo Roberto
Published: March 2022

Background and objective: Nephrolithiasis (NL) is a public health problem in the population of Southeast Mexico because of its high prevalence and recurrence. The evolution of this pathology can result in renal damage and may even cause chronic kidney disease (CKD), leading to a reduced glomerular filtration rate (GFR), decreased kidney function, and kidney loss in advanced stages. However, few studies support this evidence in the population. The present study aimed to determine risk factors associated with CKD in adult patients in an endemic population of Mexico. Materials and methods: A case-control study was carried out with patients diagnosed with NL. Additionally, the clinical information of patients (age, weight, height, blood pressure, comorbidities, and time of progress of NL), characteristics of the stones (number, location, and Hounsfield units), and biochemical parameters were collected. Results: The recurrence of NL was associated with CKD (OR 1.91; 95% CI 1.37–2.27; p = 0.003). In addition, male sex (p = 0.016), surgical history (p = 0.011), bilateral kidney stones (p < 0.001), and urinary tract infections (p = 0.004) were other factors associated with CKD. Interestingly, thirty-two patients younger than 50 years old with >2 surgical events presented a significant decrease in GFR (p < 0.001). Conclusions: The recurrence of NL and the number of surgical events were risk factors associated with CKD in patients with NL treated in our population.
Factors Affecting Residual Stone Rate, Operative Duration, and Complications in Patients Undergoing Minimally Invasive Percutaneous Nephrolithotomy
Authors: Doykov Mladen , Kostov Gancho , Doykova Katya
Published: March 2022

Background and objectives: Although minimally invasive percutaneous nephrolithotomy (MPCNL) has demonstrated its efficacy, complete stone clearance was not always achieved, necessitating a second procedure. The purpose of this study was to evaluate factors associated with residual stone rate, operative duration, complications, and hospital stay, in order to develop algorithms for pre-operative prognosis and planning. Materials and Methods: This retrospective study involved 163 Bulgarian patients who underwent MPCNL with Holmium: YAG lithotripsy for the treatment of kidney stones. Patients were considered stone-free if no visible fragments (<3 mm) were found on nephroscopy at the end of the procedure, as well as on postoperative X-ray and abdominal ultrasound on the first postoperative day. Results: Immediate postoperative stone-free outcome was attained for 83.43% of the patients (136/163). Residuals were associated with staghorn stones (OR = 72.48, 95% CI: 5.76 to 91.81); stones in two locations (OR = 21.91, 95% CI: 4.15 to 137.56); larger stone size (OR = 1.12, 95% CI: 1.006 to 1.25); and higher density (OR = 1.03, 95% CI:1.005 to 1.06). The overall categorization accuracy for these factors was 93.80%, AUC = 0.971 (95% CI: 0.932 to 0.991), 89.71% sensitivity, and 96.30% specificity. Predictors of prolonged operative duration were staghorn stones and volume, R-square (adj.) = 39.00%, p < 0.001. Longer hospitalization was predicted for patients with hydronephrosis and staghorn stones, R-square (adj.) = 6.82%, p = 0.003. Post-operative complications were rare, predominantly of Clavien-Dindo Grade 1, and were more frequent in patients with hydronephrosis. We did not find a link between their occurrence and the outcome of MPCNL. Conclusions: Staghorn stones and stones in more than one location showed the strongest association with residual stone rate. Staghorn stones and larger volume were linked with a longer operative duration. Hydronephrosis increased the risk of complications and longer hospitalization.
High Sensitivity Strain Sensors Using Four-Core Fibers through a Corner-Core Excitation
Authors: Suo Lina , Peng Ya-Pei , Yao Cheng-Kai , Ren Shijie , Lu Xinhe , Chen Nan-Kuang
Published: March 2022

A weakly-coupled multicore fiber can generate supermodes when the multi-cores are closer to enter the evanescent power coupling region. The high sensitivity strain sensors using tapered four-core fibers (FCFs) were demonstrated. The fan-in and fan-out couplers were used to carry out light coupling between singlemode fibers and the individual core of the FCFs. A broadband lightsource from superlumminescent diodes (SLDs) was launched into one of the four cores arranged in a rectangular configuration. When the FCF was substantially tapered, the asymmetric supermodes were produced to generate interferences through this corner-core excitation scheme. During tapering, the supermodes were excited based on a tri-core structure initially and then transited to a rectangular quadruple-core structure gradually to reach the sensitivity of 185.18 pm/μԑ under a tapered diameter of 3 μm. The asymmetric evanescent wave distribution due to the corner-core excitation scheme is helpful to increase the optical path difference (OPD) between supermodes for improving the strain sensitivity.
Lignin from Agro-Industrial Waste to an Efficient Magnetic Adsorbent for Hazardous Crystal Violet Removal
Authors: Ali Rehab , Elsagan Zahwa , AbdElhafez Sara
Published: March 2022

The presence of cationic dyes, even in a tiny amount, is harmful to aquatic life and pollutes the environment. Therefore, it is essential to remove these hazardous dyes to protect the life of marine creatures from these pollutants. In this research, crystal violet (CV) dye elimination was performed using a lignin copper ferrite (LCF) adsorbent. The adsorbent was synthesized and characterized using FTIR, Raman, SEM, EDX with mapping, and VSM, which proved the successful formation of magnetic LCF. Adsorption experiments were performed using different effective parameters. The highest adsorption potential (97%) was executed at mild operating conditions, with a 5 min contact time at room temperature and pH 8. The adsorption kinetic study utilized four kinetic models: first-order, second-order, intraparticle diffusion, and Elovich. The results revealed that the adsorption process complies with the pseudo-first-order with a maximum adsorption capacity of 34.129 mg/g, proving that the adsorption process mechanism is a physical adsorption process. Three isotherm models, Langmuir, Freundlich, and Temkin, were examined. The adsorption mechanism of CV onto LCF was also followed by the Langmuir and Freundlich models. The thermodynamic parameters were examined and revealed that the adsorption onto LCF was an exothermic process. It was proposed that the adsorption process is a spontaneous exothermic process. LCF appears to forcefully remove toxic CV dye from textile wastewater.