bluuebunny/crossref_metadata_2025 huggingface dataset:
Disability-Disaggregated Data Collection: Hospital-Based Application of the Washington Group Questions in an Eye Hospital in Paraguay
Authors: Mörchen Manfred , Zambrano Olmedo , Páez Alexander , Salgado Paola , Penniecook Jason , Brandt von Lindau Andrea , Lewis David
Published: August 2019

Disability-disaggregated data are increasingly considered important to monitor progress in Universal Eye Health Care. Hospital-based data are still elusive because of the cultural ambiguities of the term disability, especially in under-resourced Health Information Systems in low-and middle-income countries. The aim of this study was to estimate the hospital-based rate of disability in patients presenting at an eye department of a rural hospital in Paraguay and to discuss implications for the management of access barriers. Therefore, we introduced two standardized sets of the Washington Group (WG) Questions as a pilot project. In total, 999 patients answered the self-report WG short set (WG-SS) questionnaire with six functional domains, and 501 of these patients answered an extended set, which included additional domains for “anxiety” and “depression” (WG-ES3). Overall, 27.7% (95% Confidence Interval (CI) 24.9–30.3) were categorized as having a disability. A total of 9.6% (95% CI 7.9–11.6) were categorized as having a disability because of communication difficulties, which was second only to visual difficulties. The odds ratio for disability for patients aged 70 years and older was 8.5 (95% CI 5.0–14.4) and for male patients, it was 0.83 (95% CI 0.62–1.1). Of those patients who answered the WG-ES3, 3.4% were categorized as having a disability because of being worried, nervous or anxious and 1.4% because of feeling depressed. An analysis of the questions of the “depression” domain was impeded by a high rate of measurement errors. The results of the different domains can now be used to inform the identification and mitigation of potential access barriers to eye health services for different types of impairments.
Body Changes and Decreased Sexual Drive after Dialysis: A Qualitative Study on the Experiences of Women at an Ambulatory Dialysis Unit in Spain
Authors: Álvarez-Villarreal Miriam , Velarde-García Juan Francisco , Chocarro-Gonzalez Lourdes , Pérez-Corrales Jorge , Gueita-Rodriguez Javier , Palacios-Ceña Domingo
Published: August 2019

Chronic kidney disease (CKD) has considerable effects on the quality of life of patients, impairing everyday activities and leading to lifestyle changes, as well as affecting body image and intimate relationships. Our aim was to describe the experience of female patients with CKD at an ambulatory dialysis unit regarding body changes and sexuality. A qualitative phenomenological study exploring how 18 female patients, treated at the dialysis unit of a Spanish hospital, perceived their sexuality and intimate relationships. Data were collected using in-depth interviews, researcher field notes, and patients’ personal letters. A thematic analysis was performed. Four main themes arose from the data describing the experience of how CKD impacts body changes and sexuality: (a) Accepting body changes, (b) The catheter, the fistula, and body image, (c) Experiencing a different sexuality, and (d) The catheter, the fistula, and sexuality. Patients experienced changes in their body, perceiving it as being bloated or deformed, together with overall decline. The catheter and/or the fistula triggered changes in the way the women dress in an attempt to hide port sites. Women experience sexuality changes, affecting sexual desire and satisfaction. The presence of catheters was found to be the most cumbersome during sexual acts.
New Policy and Implementation of Municipal Solid Waste Classification in Shanghai, China
Authors: Zhou Ming-Hui , Shen Shui-Long , Xu Ye-Shuang , Zhou An-Nan
Published: August 2019

To promote sustainable development, the Chinese government launched a new municipal solid waste (MSW) classification strategy in 2017. Shanghai was selected as one of the first pilot cities for MSW classification. The Shanghai municipal government first established the new MSW classification policy in 2017. The Shanghai Municipal Solid Waste Management Regulation was published in 2019 and came into effect on 1 July 2019. This short communication reports on Shanghai’s new MSW classification policy and its implementation. The main content and measures adopted by Shanghai’s government to ensure the effective implementation of the new MSW classification policy are introduced. Besides, a SWOT (i.e., strengths, weaknesses, opportunities, and threats) analysis on the present policy and measures is conducted, and based on the results, some discussions and suggestions regarding the implementation of MSW classification in Shanghai and the whole of China are presented.
E-Cigarettes: A Disruptive Technology? An Analysis of Health Actors’ Positions on E-Cigarette Regulation in Scotland
Authors: Weishaar Heide Beatrix , Ikegwuonu Theresa , Smith Katherine E. , Buckton Christina H. , Hilton Shona
Published: August 2019

Concerns have been raised that the divisions emerging within public health in response to electronic cigarettes are weakening tobacco control. This paper employed thematic and network analysis to assess 90 policy consultation submissions and 18 interviews with political actors to examine the extent of, and basis for, divisions between health-focused actors with regard to the harms and benefits of e-cigarettes and appropriate approaches to regulation in Scotland. The results demonstrated considerable engagement in e-cigarette policy development by health-focused actors and a widely held perception of strong disagreement. They show that actors agreed on substantive policy issues, such as age-of-sale restrictions and, in part, the regulation of advertising. Points of contestation were related to the harms and benefits of e-cigarettes and the regulation of vaping in public places. The topicality, limitations of the evidence base and underlying values may help explain the heightened sense of division. While suggesting that some opportunities for joint advocacy might have been missed, this analysis shows that debates on e-cigarette regulation cast a light upon differences in thinking about appropriate approaches to health policy development within the public health community. Constructive debates on these divisive issues among health-focused actors will be a crucial step toward advancing public health.
Cardiovascular Risk in Non-Alcoholic Fatty Liver Disease: Mechanisms and Therapeutic Implications
Authors: Tana Claudio , Ballestri Stefano , Ricci Fabrizio , Di Vincenzo Angelo , Ticinesi Andrea , Gallina Sabina , Giamberardino Maria Adele , Cipollone Francesco , Sutton Richard , Vettor Roberto , Fedorowski Artur , Meschi Tiziana
Published: August 2019

New evidence suggests that non-alcoholic fatty liver disease (NAFLD) has a strong multifaceted relationship with diabetes and metabolic syndrome, and is associated with increased risk of cardiovascular events, regardless of traditional risk factors, such as hypertension, diabetes, dyslipidemia, and obesity. Given the pandemic-level rise of NAFLD—in parallel with the increasing prevalence of obesity and other components of the metabolic syndrome—and its association with poor cardiovascular outcomes, the question of how to manage NAFLD properly, in order to reduce the burden of associated incident cardiovascular events, is both timely and highly relevant. This review aims to summarize the current knowledge of the association between NAFLD and cardiovascular disease, and also to discuss possible clinical strategies for cardiovascular risk assessment, as well as the spectrum of available therapeutic strategies for the prevention and treatment of NAFLD and its downstream events.
Cortical Seizures in FoxG1+/− Mice are Accompanied by Akt/S6 Overactivation, Excitation/Inhibition Imbalance and Impaired Synaptic Transmission
Authors: Testa Giovanna , Olimpico Francesco , Pancrazi Laura , Borello Ugo , Cattaneo Antonino , Caleo Matteo , Costa Mario , Mainardi Marco
Published: August 2019

The correct morphofunctional shaping of the cerebral cortex requires a continuous interaction between intrinsic (genes/molecules expressed within the tissue) and extrinsic (e.g., neural activity) factors at all developmental stages. Forkhead Box G1 (FOXG1) is an evolutionarily conserved transcription factor, essential for the cerebral cortex patterning and layering. FOXG1-related disorders, including the congenital form of Rett syndrome, can be caused by deletions, intragenic mutations or duplications. These genetic alterations are associated with a complex phenotypic spectrum, spanning from intellectual disability, microcephaly, to autistic features, and epilepsy. We investigated the functional correlates of dysregulated gene expression by performing electrophysiological assays on FoxG1+/− mice. Local Field Potential (LFP) recordings on freely moving animals detected cortical hyperexcitability. On the other hand, patch-clamp recordings showed a downregulation of spontaneous glutamatergic transmission. These findings were accompanied by overactivation of Akt/S6 signaling. Furthermore, the expression of vesicular glutamate transporter 2 (vGluT2) was increased, whereas the level of the potassium/chloride cotransporter KCC2 was reduced, thus indicating a higher excitation/inhibition ratio. Our findings provide evidence that altered expression of a key gene for cortical development can result in specific alterations in neural circuit function at the macro- and micro-scale, along with dysregulated intracellular signaling and expression of proteins controlling circuit excitability.
A Cell’s Fate: An Overview of the Molecular Biology and Genetics of Apoptosis
Authors: Cavalcante Giovanna C. , Schaan Ana Paula , Cabral Gleyce Fonseca , Santana-da-Silva Mayara Natália , Pinto Pablo , Vidal Amanda F. , Ribeiro-dos-Santos Ândrea
Published: August 2019

Apoptosis is one of the main types of regulated cell death, a complex process that can be triggered by external or internal stimuli, which activate the extrinsic or the intrinsic pathway, respectively. Among various factors involved in apoptosis, several genes and their interactive networks are crucial regulators of the outcomes of each apoptotic phase. Furthermore, mitochondria are key players in determining the way by which cells will react to internal stress stimuli, thus being the main contributor of the intrinsic pathway, in addition to providing energy for the whole process. Other factors that have been reported as important players of this intricate molecular network are miRNAs, which regulate the genes involved in the apoptotic process. Imbalance in any of these mechanisms can lead to the development of several illnesses, hence, an overall understanding of these processes is essential for the comprehension of such situations. Although apoptosis has been widely studied, the current literature lacks an updated and more general overview on this subject. Therefore, here, we review and discuss the mechanisms of apoptosis, highlighting the roles of genes, miRNAs, and mitochondria involved in this type of cell death.
Edoxaban Exerts Antioxidant Effects Through FXa Inhibition and Direct Radical-Scavenging Activity
Authors: Narita Yuki , Hamamura Kana , Kashiyama Mami , Utsumi Sara , Kakizoe Yutaka , Kondo Yuki , Ishitsuka Yoichi , Jono Hirofumi , Irie Tetsumi , Mukoyama Masashi , Saito Hideyuki , Kadowaki Daisuke , Hirata Sumio , Kitamura Kenichiro
Published: August 2019

The interplay between oxidative stress, inflammation, and tissue fibrosis leads to the progression of chronic kidney disease (CKD). Edoxaban, an activated blood coagulation factor Xa (FXa) inhibitor, ameliorates kidney disease by suppressing inflammation and tissue fibrosis in animal models. Interestingly, rivaroxaban, another FXa inhibitor, suppresses oxidative stress induced by FXa. Thus, FXa inhibitors could be multitargeted drugs for the three aforementioned risk factors for the progression of CKD. However, the exact mechanism responsible for eliciting the antioxidant effect of FXa inhibitors remains unclear. In this study, the antioxidant effect of edoxaban was evaluated. First, the intracellular antioxidant properties of edoxaban were evaluated using human proximal tubular cells (HK-2 cells). Next, direct radical scavenging activity was measured using the electron spin resonance and fluorescence analysis methods. Results show that edoxaban exhibited antioxidant effects on oxidative stress induced by FXa, indoxyl sulfate, and angiotensin II in HK-2 cells, as well as the FXa inhibitory activity, was involved in part of the antioxidant mechanism. Moreover, edoxaban exerted its antioxidative effect through its structure-specific direct radical scavenging activity. Edoxaban exerts antioxidant effects by inhibiting FXa and through direct radical-scavenging activity, and thus, may serve as multitargeted drugs for the three primary risk factors associated with progression of CKD.
Molecular-Level Interactions between Engineered Materials and Cells
Authors: Jang Yoon-ha , Jin Xuelin , Shankar Prabakaran , Lee Jung Heon , Jo Kyubong , Lim Kwang-il
Published: August 2019

Various recent experimental observations indicate that growing cells on engineered materials can alter their physiology, function, and fate. This finding suggests that better molecular-level understanding of the interactions between cells and materials may guide the design and construction of sophisticated artificial substrates, potentially enabling control of cells for use in various biomedical applications. In this review, we introduce recent research results that shed light on molecular events and mechanisms involved in the interactions between cells and materials. We discuss the development of materials with distinct physical, chemical, and biological features, cellular sensing of the engineered materials, transfer of the sensing information to the cell nucleus, subsequent changes in physical and chemical states of genomic DNA, and finally the resulting cellular behavior changes. Ongoing efforts to advance materials engineering and the cell–material interface will eventually expand the cell-based applications in therapies and tissue regenerations.
Cytosolic Copper Binding by a Bacterial Storage Protein and Interplay with Copper Efflux
Authors: Lee Jaeick , Dennison Christopher
Published: August 2019

Escherichia coli has a well-characterized copper (Cu) transporting ATPase (CopA) that removes this potentially toxic metal ion from the cytosol. Growth of the strain lacking CopA (ΔcopA) is inhibited above 0.5 mM Cu, whilst a similar effect does not occur in wild type (WT) E. coli until over 2.5 mM Cu. Limited expression of CopA can restore growth to WT levels in ΔcopA E. coli in the presence of Cu. To study the influence of a bacterial cytosolic Cu storage protein (Csp3) on how E. coli handles Cu, the protein from Bacillus subtilis (BsCsp3) has been overexpressed in the WT and ΔcopA strains. BsCsp3 can protect both strains from Cu toxicity, promoting growth at up to ~1.5 and ~3.5 mM Cu, respectively. Higher levels of Csp3 expression are needed to provide resistance to Cu toxicity in ΔcopA E. coli. At 1.5 mM Cu, BsCsp3 purified from ΔcopA E. coli binds up to approximately four equivalents of Cu(I) per monomer. A similar number of Cu(I) equivalents can be bound by BsCsp3 purified from WT E. coli also grown at 1.5 mM Cu, a concentration that does not cause toxicity in this strain. Much lower amounts of BsCsp3 are produced in WT E. coli grown in the presence of 3.4 mM Cu, but the protein still counteracts toxicity and is almost half loaded with Cu(I). Csp3s can protect E. coli from Cu toxicity by sequestering cuprous ions in the cytosol. This appears to include an ability to acquire and withhold Cu(I) from the main efflux system in a heterologous host.
Diagnostic and Prognostic Role of Blood and Cerebrospinal Fluid and Blood Neurofilaments in Amyotrophic Lateral Sclerosis: A Review of the Literature
Authors: Gagliardi Delia , Meneri Megi , Saccomanno Domenica , Bresolin Nereo , Comi Giacomo Pietro , Corti Stefania
Published: August 2019

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder affecting upper and lower motor neurons (MNs) that still lacks an efficacious therapy. The failure of recent therapeutic trials in ALS, other than depending on the poor knowledge of pathogenic mechanisms responsible for MNs loss, is largely due to diagnostic delay and the lack of reliable biomarkers for diagnosis, prognosis and response to pharmacologic intervention. Neurofilaments (Nfs) are neuron-specific cytoskeletal proteins, whose levels increased in biological fluids proportionally to the degree of axonal damage, both in normal and in pathologic conditions, representing potential biomarkers in various neurological disorders, such as motor neuron disorder (MND). Growing evidence has shown that phosphorylated neurofilaments heavy chain (p-NfH) and neurofilaments light chain (NfL) are increased in blood and cerebrospinal fluid (CSF) of ALS patients compared to healthy and neurological controls and are found to correlate with disease progression. In this review, we reported the most relevant studies investigating the diagnostic and prognostic role of Nfs in ALS. Given their reliability and reproducibility, we consider Nfs as promising and useful biomarkers in diagnosis of MND, early patient identification for inclusion in clinical trials, prediction of disease progression, and response to pharmacological intervention, and we suggest the validation of their measurement in clinical activity.
Gut Microbiome: A Promising Biomarker for Immunotherapy in Colorectal Cancer
Authors: Temraz Sally , Nassar Farah , Nasr Rihab , Charafeddine Maya , Mukherji Deborah , Shamseddine Ali
Published: August 2019

Research has been driven towards finding therapy predictive biomarkers for colorectal cancer (CRC) with a special interest in studying the gut microbiome. Gut microbiome acts not only as a barrier to prevent bacterial invasion and infection, but it also affects the efficacy of hematopoietic-cell transplantation, chemotherapy, and immunotherapy. Recently, immunotherapy, which potentiates the host immune system, has revolutionized cancer therapy in general and CRC treatment specifically by increasing the quality of life and the survival of a subset of patients with this disease. In immunotherapy, the gut microbiome plays an important role in cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) blockade, programmed cell death protein 1 (PD-L1) mediation, and T cell stimulation. As such, this review will cover the role of gut microbiome in CRC, summarize approved immunotherapy treatments for CRC, and focus on the potential use of gut microbiome as a biomarker for immunotherapy.
Rett Syndrome and Other Neurodevelopmental Disorders Share Common Changes in Gut Microbial Community: A Descriptive Review
Authors: Borghi Elisa , Vignoli Aglaia
Published: August 2019

In this narrative review, we summarize recent pieces of evidence of the role of microbiota alterations in Rett syndrome (RTT). Neurological problems are prominent features of the syndrome, but the pathogenic mechanisms modulating its severity are still poorly understood. Gut microbiota was recently demonstrated to be altered both in animal models and humans with different neurodevelopmental disorders and/or epilepsy. By investigating gut microbiota in RTT cohorts, a less rich microbial community was identified which was associated with alterations of fecal microbial short-chain fatty acids. These changes were positively correlated with severe clinical outcomes. Indeed, microbial metabolites can play a crucial role both locally and systemically, having dynamic effects on host metabolism and gene expression in many organs. Similar alterations were found in patients with autism and down syndrome as well, suggesting a potential common pathway of gut microbiota involvement in neurodevelopmental disorders.
Zebrafish and Medaka: Two Teleost Models of T-Cell and Thymic Development
Authors: Bajoghli Baubak , Dick Advaita M. , Claasen Annisa , Doll Larissa , Aghaallaei Narges
Published: August 2019

Over the past two decades, studies have demonstrated that several features of T-cell and thymic development are conserved from teleosts to mammals. In particular, works using zebrafish (Danio rerio) and medaka (Oryzias latipes) have shed light on the cellular and molecular mechanisms underlying these biological processes. In particular, the ease of noninvasive in vivo imaging of these species enables direct visualization of all events associated with these processes, which are, in mice, technically very demanding. In this review, we focus on defining the similarities and differences between zebrafish and medaka in T-cell development and thymus organogenesis; and highlight their advantages as two complementary model systems for T-cell immunobiology and modeling of human diseases.
Prenatal and Postnatal Hair Steroid Levels Predict Post-Partum Depression 12 Weeks after Delivery
Authors: Jahangard Leila , Mikoteit Thorsten , Bahiraei Saman , Zamanibonab Mehrangiz , Haghighi Mohammad , Sadeghi Bahmani Dena , Brand Serge
Published: August 2019

Background: Within three to six months after delivery, 13%–19% of women suffer from post-partum depression (PPD), understood as a dysfunctional adaptation to the postpartum condition and motherhood. In the present cross-sectional study, we compared the hair steroid levels of women 12 weeks before and after delivery and with or without PPD. Method: The present study was a cross-sectional study conducted twelve weeks after delivery. At that time, 48 women (mean age: 25.9 years) with PPD and 50 healthy controls (mean age: 25.2 years) completed questionnaires on depressive symptoms. Further, at the same time point, 6 cm lengths of hair strands were taken, providing samples of hair steroids 12 weeks before and 12 weeks after delivery in order to analyze hair steroids (cortisol, cortisone, progesterone, testosterone, and dehydroepiandrosterone (DHEA)). Results: Compared to those of women without PPD, hair steroid levels (cortisol, cortisone, progesterone) were significantly lower in women with PPD both before and after delivery. Lower prenatal cortisone and progesterone levels predicted higher depression scores 12 weeks after delivery. Lower prenatal levels of cortisol and progesterone and higher levels of DHEA, and postnatal lower levels of cortisol, cortisone, and progesterone, along with higher levels of DHEA predicted PPD-status with an accuracy of 98%. Conclusions: PPD is associated with blunted hair cortisol, cortisone, and progesterone secretions both pre- and postpartum. Such blunted steroid levels appear to reflect a stress responsivity that is less adaptive to acute and transient stressors. It follows that prenatally assessed low hair cortisol and progesterone levels, along with high DHEA levels, are reliable biomarkers of post-partum depression 12 weeks after delivery.
A Study of the Effects of Doxorubicin-Containing Liposomes on Osteogenesis of 3D Stem Cell Spheroids Derived from Gingiva
Authors: Lee Hyunjin , Son Jihwan , Min Sae Kyung , Na Chae-Bin , Yi Gawon , Koo Heebeom , Park Jun-Beom
Published: August 2019

The objective of the present investigation is to determine the effects of neutral, anionic, and cationic liposomes loaded with doxorubicin with thin-lipid-film-hydration method on the cellular viability and osteogenesis of stem cell spheroids. Spheroid formation and morphology of the three-dimensional spheroid were noted with an inverted microscope. Quantitative cellular viability was assessed using a commercially available kit. Osteogenic potential was evaluated by applying alkaline phosphatase activity and anthraquinone dye of Alizarin Red S. Western blot analysis was performed using collagen I expression. Spheroids were formed in each silicon elastomer-based concave microwell on Day 1. Noticeable changes of the spheroid were seen with a higher concentration of doxorubicin, especially in the cationic liposome group at Days 5 and 7. We found that the application of doxorubicin for 5 days significantly reduced the cellular viability. A higher concentration of doxorubicin produced a significant decrease in alkaline phosphatase activity. Alizarin Red S staining showed that extracellular calcium deposits were evenly noted in each group. An increase of calcium deposits was noted on Day 14 when compared to Day 7. The morphology of the groups with higher concentrations of doxorubicin showed to be more dispersed. We noticed that doxorubicin-loaded cationic liposomes resulted in the highest uptake of the examined cell spheroids and that doxorubicin-loaded liposomes affected the osteogenic differentiation. The implication of this study is that the type of liposome should be selected based on the purpose of the application.
Evaluation of Static and Dynamic Residual Mechanical Properties of Heat-Damaged Concrete for Nuclear Reactor Auxiliary Buildings in Korea Using Elastic Wave Velocity Measurements
Authors: Kee Seong-Hoon , Kang Jun Won , Choi Byong-Jeong , Kwon Juho , Candelaria Ma. Doreen
Published: August 2019

The main objectives of this study are (1) to investigate the effects of heating and cooling on the static and dynamic residual properties of 35 MPa (5000 psi) concrete used in the design and construction of nuclear reactor auxiliary buildings in Korea; and (2) to establish the correlation between static and dynamic properties of heat-damaged concrete. For these purposes, concrete specimens (100 mm × 200 mm cylinder) were fabricated in a batch plant at a nuclear power plant (NPP) construction site in Korea. To induce thermal damages, the concrete specimens were heated to target temperatures from 100 °C to 1000 °C with intervals of 100 °C, at a heating rate of 5 °C/min and allowed to reach room temperature by natural cooling. The dynamic properties (dynamic elastic modulus and dynamic Poisson’s ratio) of concrete were evaluated using elastic wave measurements (P-wave velocity measurements according to ASTM C597/C597M-16 and fundamental longitudinal and transverse resonance tests according to ASTM C215-14) before and after the thermal damages. The static properties (compressive strength, static elastic modulus and static Poisson’s ratio) of heat-damaged concrete were measured by the uniaxial compressive testing in accordance with ASTM C39-14 and ASTM C469-14. It was demonstrated that the elastic wave velocities of heat-damaged concrete were proportional to the square root of the reduced dynamic elastic moduli. Furthermore, the relationship between static and dynamic elastic moduli of heat-damaged concrete was established in this study. The results of this study could improve the understanding of the static and dynamic residual mechanical properties of Korea NPP concrete under heating and cooling.
Microstructure and Mechanical Properties of Underwater Laser Welding of Titanium Alloy
Authors: Guo Ning , Cheng Qi , Zhang Xin , Fu Yunlong , Huang Lu
Published: August 2019

Underwater laser beam welding (ULBW) with filler wire was applied to Ti-6Al-4V alloy. Process parameters including the back shielding gas flow rate (BSGFR) (the amount of protective gas flowing over the back of the workpiece per unit time), focal position, and laser power were investigated to obtain a high-quality butt joint. The results showed that the increase of BSGFR could obtain the slighter oxidation level and refiner crystal grain in the welded metals. Whereas the back shielding gas at a flow rate of 35 L/min resulting in pores in the welded metals. With the increasing of the heat input, the welded metals went through three stages, i.e., not full penetration, crystal grain refinement, and coarseness. Crystal grain refinement could improve the mechanical properties, however, not full penetration and pores led to the decline in mechanical properties. Under optimal process parameters, the microstructure in the fusion zones of the underwater and in-air weld metals was acicular martensite. The near the fusion zone of the underwater and in-air weld metals consisted of the α + α′ phase, but almost without the α′ phase in the near base metal zone. The tensile strength and impact toughness of the underwater welded joints were 852.81 MPa and 39.07 J/cm2, respectively, which approached to those of the in-air welded joints (861.32 MPa and 38.99 J/cm2).
Nanosilica Extracted from Hexafluorosilicic Acid of Waste Fertilizer as Reinforcement Material for Natural Rubber: Preparation and Mechanical Characteristics
Authors: Nguyen Van-Huy , Vu Cuong Manh , Choi Hyoung Jin , Kien Bui Xuan
Published: August 2019

Nanosilica particles are extracted from waste water containing a hexafluorosilicic acid discharged from Vietnamese fertilizer plants as an effective way not only to reduce waste water pollution but also to enhance the value of their waste water. Amorphous nanosilica particles are produced with diameters ranging from 40 to 60 nm and then adopted as a reinforcing additive for natural rubber (NR) composites. Morphological, mechanical, rheological, and thermal behaviors of the nanosilica-added NR composites are examined. Especially, mechanical behaviors of nanosilica-filled NR composites reach the optimum with 3 phr of nanosilica, at which its tensile strength, hardness, and decomposition temperature are improved by 20.6%, 7.1%, and 2.5%, respectively, compared with the pristine vulcanized NR. The improved mechanical properties can be explained by the tensile fractured surface morphology, which shows that the silica-filled NR is rougher than the pristine natural rubber sample.
Wideband RCS Reduction Using Coding Diffusion Metasurface
Authors: Ali Luqman , Li Qinlong , Ali Khan Tayyab , Yi Jianjia , Chen Xiaoming
Published: August 2019

This paper presents a radar cross-section (RCS) reduction technique by using the coding diffusion metasurface, which is optimised through a random optimization algorithm. The design consists of two unit cells, which are elements ‘1’ and ‘0’. The reflection phase between the two-unit cells has a 180° ± 37° phase difference. It has a working frequency band from 8.6 GHz to 22.5 GHz, with more than 9 dB RCS reduction. The monostatic RCS reduction has a wider bandwidth of coding diffusion metasurface as compared to the traditional chessboard metasurface. In addition, the bistatic performance of the designed metasurfaces is observed at 15.4 GHz, which shows obvious RCS reduction when compared to a metallic plate of the same size. The simulated and measured result shows the proficiency of the designed metasurface.
Electronic Structure of B20 (FeSi-Type) Transition-Metal Monosilicides
Authors: Pshenay-Severin Dmitry A. , Burkov Alexander T.
Published: August 2019

Monosilicides of transition metals crystallizing in a B20 (FeSi-type) structure (space group P2 1 3, #198) possess a wide range of specific properties. Among them are semiconductors, metals, and paramagnetic, diamagnetic, and ferromagnetic compounds. Some of them were studied as promising thermoelectric materials. Recently, B20 monosilicides have attracted attention as a new class of topological semimetals with topological charge greater than unity. In the present work, we analyze the electronic structures of B20-type monosilicides of the fourth, fifth, and sixth periods of the Periodic Table in order to reveal their common features and peculiarities. To make this analysis more consistent, we performed a density-functional study of the electronic structures of the monosilicides in a unified manner. We reviewed the results of previous calculations and the available experimental data, comparing them with our results. The band structures of ReSi and TcSi not found in the literature were calculated and analyzed as well. The topological properties of these materials and of some isostructural germanides and stannides were investigated. Analysis reveals the current understanding of electronic structures and properties of this compound group.
Ablation Behavior of the SiC-Coated Three-Dimensional Highly Thermal Conductive Mesophase-Pitch-Based Carbon-Fiber-Reinforced Carbon Matrix Composite under Plasma Flame
Authors: Ye Chong , Huang Dong , Li Baoliu , Yang Pingjun , Liu Jinshui , Wu Huang , Yang Jianxiao , Li Xuanke
Published: August 2019

This study is focused on a novel high-thermal-conductive C/C composite used in heat-redistribution thermal protection systems. The 3D mesophase pitch-based carbon fiber (CFMP) preform was prepared using CFMP in the X (Y) direction and polyacrylonitrile carbon fiber (CFPAN) in the Z direction. After the preform was densified by chemical vapor infiltration (CVI) and polymer infiltration and pyrolysis (PIP), the 3D high-thermal-conductive C/C (CMP/C) composite was obtained. The prepared CMP/C composite has higher thermal conduction in the X and Y directions. After an ablation test, the CFPAN becomes needle-shaped, while the CFMP shows a wedge shape. The fiber/matrix and matrix/matrix interfaces are preferentially oxidized and damaged during ablation. After being coated by SiC coating, the thermal conductivity plays a significant role in decreasing the hot-side temperature and protecting the SiC coating from erosion by flame. The SiC-coated CMP/C composite has better ablation resistance than the SiC-coated CPAN/C composite. The mass ablation rate of the sample is 0.19 mg·(cm−2·s−1), and the linear ablation rate is 0.52 μm·s−1.
Developing 9,10-anthracene Derivatives: Optical, Electrochemical, Thermal, and Electrical Characterization
Authors: Vorona Mikhail Y. , Yutronkie Nathan J. , Melville Owen A. , Daszczynski Andrew J. , Agyei Kwame T. , Ovens Jeffrey S. , Brusso Jaclyn L. , Lessard Benoît H.
Published: August 2019

Anthracene-based semiconductors are a class of molecules that have attracted interest due to their air stability, planarity, potential for strong intermolecular interactions, and favorable frontier molecular orbital energy levels. In this study seven novel 9,10-anthracene-based molecules were synthesized and their optical, electrochemical, and thermal properties were characterized, along with their single crystal arrangement. We found that functionalization of the 9,10-positions with different phenyl derivatives resulted in negligible variation in the optical properties with minor (±0.10 eV) changes in electrochemical behavior, while the choice of phenyl derivative greatly affected the thermal stability (Td > 258 °C). Preliminary organic thin film transistors (OTFTs) were fabricated and characterized using the 9,10-anthracene-based molecules as the semiconductor layer. These findings suggest that functionalization of the 9,10-position of anthracene leads to an effective handle for tuning of the thermal stability, while having little to no effect on the optical properties and the solid-state arrangement
Carbides and Nitrides of Zirconium and Hafnium
Authors: Ushakov Sergey V. , Navrotsky Alexandra , Hong Qi-Jun , van de Walle Axel
Published: August 2019

Among transition metal carbides and nitrides, zirconium, and hafnium compounds are the most stable and have the highest melting temperatures. Here we review published data on phases and phase equilibria in Hf-Zr-C-N-O system, from experiment and ab initio computations with focus on rocksalt Zr and Hf carbides and nitrides, their solid solutions and oxygen solubility limits. The systematic experimental studies on phase equilibria and thermodynamics were performed mainly 40–60 years ago, mostly for binary systems of Zr and Hf with C and N. Since then, synthesis of several oxynitrides was reported in the fluorite-derivative type of structures, of orthorhombic and cubic higher nitrides Zr3N4 and Hf3N4. An ever-increasing stream of data is provided by ab initio computations, and one of the testable predictions is that the rocksalt HfC0.75N0.22 phase would have the highest known melting temperature. Experimental data on melting temperatures of hafnium carbonitrides are absent, but minimum in heat capacity and maximum in hardness were reported for Hf(C,N) solid solutions. New methods, such as electrical pulse heating and laser melting, can fill the gaps in experimental data and validate ab initio predictions.
Exploration of the Structural and Photophysical Characteristics of Mono- and Binuclear Ir(III) Cyclometalated Complexes for Optoelectronic Applications
Authors: Adeloye Adewale Olufunsho
Published: August 2019

Intrinsic characteristics possessed and exhibited by Ir(III) cyclometalated complexes need to be further examined, understood, and explored for greater value enhancement and potentiation. This work focuses primarily on the comparative studies of the ligand structures, types, and their substituent influence on the photophysical and optoelectronic properties of typical cyclometalated mono- and binuclear iridium(III) complexes in solution or solid states.
Experimental and Numerical Investigations of High-Speed Projectile Impacts on 7075-T651 Aluminum Plates
Authors: Jung Jae-Wook , Lee Sang Eon , Hong Jung-Wuk
Published: August 2019

Simulation of the material failure under high strain rate conditions is one of the most difficult problems in the finite element analyses, and many researchers have tried to understand and reproduce dynamic material fracture. In this study, we investigate a failure criterion that minimizes the mesh dependency at high strain rates and incorporates the criterion into the Johnson-Cook constitutive relationship by developing a user-defined material model. Impact tests were performed using a gas-gun system in order to investigate the response of the 7075-T651 aluminum plate in high-speed collision. On the other hand, numerical simulations are carried out by considering various element sizes and the relationship between element size and failure strain is inversely obtained using numerical results. By accommodating the relationship into the damage model and implementing in the user-defined material model, mesh dependency is significantly reduced, and sufficient accuracy is achieved with alleviated computational cost than the existing damage model. This study suggests an element size-dependent damage criterion that is applicable for impact simulation and it is expected that the criterion is useful to obtain accurate impact responses with a small computational cost.
Ground State Solution of Pohožaev Type for Quasilinear Schrödinger Equation Involving Critical Exponent in Orlicz Space
Authors: Chen Jianqing , Zhang Qian
Published: August 2019

We study the following quasilinear Schrödinger equation involving critical exponent − Δ u + V ( x ) u − Δ ( u 2 ) u = A ( x ) | u | p − 1 u + λ B ( x ) u 3 N + 2 N − 2 , u ( x ) > 0 for x ∈ R N and u ( x ) → 0 as | x | → ∞ . By using a monotonicity trick and global compactness lemma, we prove the existence of positive ground state solutions of Pohožaev type. The nonlinear term | u | p − 1 u for the well-studied case p ∈ [ 3 , 3 N + 2 N − 2 ) , and the less-studied case p ∈ [ 2 , 3 ) , and for the latter case few existence results are available in the literature. Our results generalize partial previous works.
Modeling Heavy Metal Sorption and Interaction in a Multispecies Biofilm
Authors: D’Acunto Berardino , Frunzo Luigi , Luongo Vincenzo , Mattei Maria Rosaria
Published: August 2019

A mathematical model able to simulate the physical, chemical and biological interactions prevailing in multispecies biofilms in the presence of a toxic heavy metal is presented. The free boundary value problem related to biofilm growth and evolution is governed by a nonlinear ordinary differential equation. The problem requires the integration of a system of nonlinear hyperbolic partial differential equations describing the biofilm components evolution, and a systems of semilinear parabolic partial differential equations accounting for substrates diffusion and reaction within the biofilm. In addition, a semilinear parabolic partial differential equation is introduced to describe heavy metal diffusion and sorption. The biosoption process modeling is completed by the definition and integration of other two systems of nonlinear hyperbolic partial differential equations describing the free and occupied binding sites evolution, respectively. Numerical simulations of the heterotrophic-autotrophic interaction occurring in biofilm reactors devoted to wastewater treatment are presented. The high biosorption ability of bacteria living in a mature biofilm is highlighted, as well as the toxicity effect of heavy metals on autotrophic bacteria, whose growth directly affects the nitrification performance of bioreactors.
Makgeolli Structures and Its Application in BCK/BCI-Algebras
Authors: Ahn Sun Shin , Song Seok-Zun , Jun Young Bae , Kim Hee Sik
Published: August 2019

A fuzzy set is an extension of an existing set using fuzzy logic. Soft set theory is a generalization of fuzzy set theory. Fuzzy and soft set theory are good mathematical tools for dealing with uncertainty in a parametric manner. The aim of this article is to introduce the concept of makgeolli structures using fuzzy and soft set theory and to apply it to BCK/BCI-algebras. The notion of makgeolli algebra and makgeolli ideal in BCK/BCI-algebras is defined, and several properties are investigated. It deals with the relationship between makgeolli algebra and makgeolli ideal, and several examples are given. Characterization of makgeolli algebra and makgeolli ideal are discussed, and a new makgeolli algebra from old one is established. A condition for makgeolli algebra to be makgeolli ideal in BCK-soft universe is considered, and we give example to show that makgeolli ideal is not makgeolli algebra in BCI-soft universe. Conditions for makgeolli ideal to be makgeolli algebra in BCI-soft universe are provided.
The Significance of Endometrial Scratching for Clinical Pregnancy Rate in Long Agonist and Antagonist Protocols
Authors: Gricius Rimantas , Balciuniene Greta , Jakubauskiene Lina , Ramasauskaite Diana
Published: August 2019

Background and Objectives: Assisted reproductive techniques today have helped many infertile couples achieve their desired pregnancy. However, unsuccessful implantation is usually the key failure in in vitro fertilization cycles. Many factors are now being studied to improve the implantation rate, one being endometrial artificial injury (endometrial scratching). The purpose of this study was to assess whether local endometrial artificial injury improved pregnancy rate, in long agonist and antagonist protocols. Materials and Methods: A retrospective analysis was carried out at the JSC Baltic American Clinic from January 1, 2016 to December 31, 2018. Women who were undergoing in vitro fertilization treatment were enrolled in the study. Medical data including demographic factors, menstrual history, and anamnesis of infertility were collected from medical records. Subjects were divided into intervention and control groups. The outcome of this study was clinical pregnancy rate (CPR). Results: A total of 137 women presenting with primary or secondary infertility were enrolled in the study. Clinical pregnancy was observed in 44/71 (61.9%) patients in the intervention group and 33/66 (50%) in the group without endometrial scratching (p value = 0.16). CPR in the intervention group was significantly higher in the patient group that had undergone ovarian stimulation with a long agonist protocol rather than the antagonist protocol (73.8% vs. 41.4%; p value = 0.006). In the multivariable logistic regression model, previously failed in vitro fertilization (IVF) (odds ratio (OR) = 0.07, 95% confidence interval (CI) 0.01–0.47), stimulation with the long agonist protocol (OR = 19.89, 95% CI 3.57–18.63), antagonist protocol (OR = 0.05, 95% CI 0.01–0.34), number of embryos (OR = 1.37, 95% CI 1.05–1.38), and number of blastocysts (OR = 2.96, 95% CI 1.43–8.36) remained important independent prognostic factors for clinical pregnancy. Conclusions: Our study findings indicate that randomized controlled studies are required to define patients for this procedure and to prove the effect and safety of local endometrial injury, before it is introduced to routine clinical practice.
Systemic Mastocytosis and Essential Thrombocythemia: Case Report and Literature Overview
Authors: Cancian Mauro , Cosi Elisabetta , Pizzi Marco , Giannini Sandro , Bertozzi Irene , Fabris Fabrizio , Randi Maria Luigia
Published: August 2019

Mastocytosis is a rare disease in which heightened amounts of mast cells accumulate in the skin, bone marrow, and other visceral organs. Upon activation, mast cells release a wide variety of preformed or newly synthesized mediators which can induce allergic symptoms and inflammatory reactions. Mastocytosis is diagnosed by biopsy and can be divided into cutaneous and systemic mastocytosis (SM). The first one affects the skin and is relatively benign, whilst SM, which involves bone marrow and other organs, may be aggressive and associate with both myelodisplastic and myeloproliferative diseases. Here we present a case of SM associated with essential thrombocythemia and complicated by severe osteoporosis, successfully treated with hydroxyurea, low-dose aspirin and zolendronic acid.
Effects of Machining Parameters on the Quality in Machining of Aluminium Alloys Thin Plates
Authors: Del Sol Irene , Rivero Asuncion , Gamez Antonio J.
Published: August 2019

Nowadays, the industry looks for sustainable processes to ensure a more environmentally friendly production. For that reason, more and more aeronautical companies are replacing chemical milling in the manufacture of skin panels and thin plates components. This is a challenging operation that requires meeting tight dimensional tolerances and differs from a rigid body machining due to the low stiffness of the part. In order to fill the gap of literature research on this field, this work proposes an experimental study of the effect of the depth of cut, the feed rate and the cutting speed on the quality characteristics of the machined parts and on the cutting forces produced during the process. Whereas surface roughness values meet the specifications for all the machining conditions, an appropriate cutting parameters selection is likely to lead to a reduction of the final thickness deviation by up to 40% and the average cutting forces by up to a 20%, which consequently eases the clamping system and reduces machine consumption. Finally, an experimental model to control the process quality based on monitoring the machine power consumption is proposed.
Modelling of the Temperature Difference Sensors to Control the Temperature Distribution in Processor Heat Sink
Authors: Markowski Piotr Marek , Gierczak Mirosław , Dziedzic Andrzej
Published: August 2019

This paper has three main purposes. The first is to investigate whether it is appropriate to use a planar thick-film thermoelectric sensor to monitor the temperature difference in a processor heat sink. The second is to compare the efficiency of two heat sink models. The third is to compare two kinds of sensors, differing in length. The model of the CPU heat sink sensor system was designed for numerical simulations. The relations between the CPU, heat sink, and the thermoelectric sensor were modelled because they are important for increasing the efficiency of fast processors without interfering with their internal structure. The heat sink was mounted on the top of the thermal model of a CPU (9.6 W). The plate fin and pin fin heat sinks were investigated. Two planar thermoelectric sensors were mounted parallel to the heat sink fins. These sensors monitored changes in the temperature difference between the CPU and the upper surface of the heat sink. The system was equipped with a cooling fan. Switching on the fan changed the thermal conditions (free or forced convection). The simulation results showed the temperature gradient appearing along the sensor for different heat sinks and under different thermal conditions. Comparison of the results obtained in the simulations of the CPU heat sink sensor systems proves that changes in the cooling conditions can cause a strong, step change in the response of the thermoelectric sensor. The results suggest that usage of the pin fin heat sink model is a better solution for free convection conditions. In the case of strong forced convection the heat sink type ceases to be significant.