bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Cell Cycle Progression by Growth Factor-Induced Cell Signaling
Authors: Wang Zhixiang
Published: November 2021

The cell cycle is the series of events that take place in a cell, which drives it to divide and produce two new daughter cells. The typical cell cycle in eukaryotes is composed of the following phases: G1, S, G2, and M phase. Cell cycle progression is mediated by cyclin-dependent kinases (Cdks) and their regulatory cyclin subunits. However, the driving force of cell cycle progression is growth factor-initiated signaling pathways that control the activity of various Cdk–cyclin complexes. While the mechanism underlying the role of growth factor signaling in G1 phase of cell cycle progression has been largely revealed due to early extensive research, little is known regarding the function and mechanism of growth factor signaling in regulating other phases of the cell cycle, including S, G2, and M phase. In this review, we briefly discuss the process of cell cycle progression through various phases, and we focus on the role of signaling pathways activated by growth factors and their receptor (mostly receptor tyrosine kinases) in regulating cell cycle progression through various phases.
Lipotoxicity and β-Cell Failure in Type 2 Diabetes: Oxidative Stress Linked to NADPH Oxidase and ER Stress
Authors: Vilas-Boas Eloisa Aparecida , Almeida Davidson Correa , Roma Leticia Prates , Ortis Fernanda , Carpinelli Angelo Rafael
Published: November 2021

A high caloric intake, rich in saturated fats, greatly contributes to the development of obesity, which is the leading risk factor for type 2 diabetes (T2D). A persistent caloric surplus increases plasma levels of fatty acids (FAs), especially saturated ones, which were shown to negatively impact pancreatic β-cell function and survival in a process called lipotoxicity. Lipotoxicity in β-cells activates different stress pathways, culminating in β-cells dysfunction and death. Among all stresses, endoplasmic reticulum (ER) stress and oxidative stress have been shown to be strongly correlated. One main source of oxidative stress in pancreatic β-cells appears to be the reactive oxygen species producer NADPH oxidase (NOX) enzyme, which has a role in the glucose-stimulated insulin secretion and in the β-cell demise during both T1 and T2D. In this review, we focus on the acute and chronic effects of FAs and the lipotoxicity-induced β-cell failure during T2D development, with special emphasis on the oxidative stress induced by NOX, the ER stress, and the crosstalk between NOX and ER stress.
Microvalve Bioprinting of MSC-Chondrocyte Co-Cultures
Authors: Dudman Joseph , Ferreira Ana Marina , Gentile Piergiorgio , Wang Xiao , Dalgarno Kenneth
Published: November 2021

Recent improvements within the fields of high-throughput screening and 3D tissue culture have provided the possibility of developing in vitro micro-tissue models that can be used to study diseases and screen potential new therapies. This paper reports a proof-of-concept study on the use of microvalve-based bioprinting to create laminar MSC-chondrocyte co-cultures to investigate whether the use of MSCs in ACI procedures would stimulate enhanced ECM production by chondrocytes. Microvalve-based bioprinting uses small-scale solenoid valves (microvalves) to deposit cells suspended in media in a consistent and repeatable manner. In this case, MSCs and chondrocytes have been sequentially printed into an insert-based transwell system in order to create a laminar co-culture, with variations in the ratios of the cell types used to investigate the potential for MSCs to stimulate ECM production. Histological and indirect immunofluorescence staining revealed the formation of dense tissue structures within the chondrocyte and MSC-chondrocyte cell co-cultures, alongside the establishment of a proliferative region at the base of the tissue. No stimulatory or inhibitory effect in terms of ECM production was observed through the introduction of MSCs, although the potential for an immunomodulatory benefit remains. This study, therefore, provides a novel method to enable the scalable production of therapeutically relevant micro-tissue models that can be used for in vitro research to optimise ACI procedures.
Molecular Signaling to Preserve Mitochondrial Integrity against Ischemic Stress in the Heart: Rescue or Remove Mitochondria in Danger
Authors: Yu Justin D. , Miyamoto Shigeki
Published: November 2021

Cardiovascular diseases are one of the leading causes of death and global health problems worldwide, and ischemic heart disease is the most common cause of heart failure (HF). The heart is a high-energy demanding organ, and myocardial energy reserves are limited. Mitochondria are the powerhouses of the cell, but under stress conditions, they become damaged, release necrotic and apoptotic factors, and contribute to cell death. Loss of cardiomyocytes plays a significant role in ischemic heart disease. In response to stress, protective signaling pathways are activated to limit mitochondrial deterioration and protect the heart. To prevent mitochondrial death pathways, damaged mitochondria are removed by mitochondrial autophagy (mitophagy). Mitochondrial quality control mediated by mitophagy is functionally linked to mitochondrial dynamics. This review provides a current understanding of the signaling mechanisms by which the integrity of mitochondria is preserved in the heart against ischemic stress.
Pluripotent Stem Cells for Spinal Cord Injury Repair
Authors: Martin-Lopez Maria , Fernandez-Muñoz Beatriz , Canovas Sebastian
Published: November 2021

Spinal cord injury (SCI) is a devastating condition of the central nervous system that strongly reduces the patient’s quality of life and has large financial costs for the healthcare system. Cell therapy has shown considerable therapeutic potential for SCI treatment in different animal models. Although many different cell types have been investigated with the goal of promoting repair and recovery from injury, stem cells appear to be the most promising. Here, we review the experimental approaches that have been carried out with pluripotent stem cells, a cell type that, due to its inherent plasticity, self-renewal, and differentiation potential, represents an attractive source for the development of new cell therapies for SCI. We will focus on several key observations that illustrate the potential of cell therapy for SCI, and we will attempt to draw some conclusions from the studies performed to date.
Coordination of Zika Virus Infection and Viroplasm Organization by Microtubules and Microtubule-Organizing Centers
Authors: Buchwalter Rebecca A. , Ogden Sarah C. , York Sara B. , Sun Li , Zheng Chunfeng , Hammack Christy , Cheng Yichen , Chen Jieyan V. , Cone Allaura S. , Meckes David G. , Tang Hengli , Megraw Timothy L.
Published: November 2021

Zika virus (ZIKV) became a global health concern in 2016 due to its links to congenital microcephaly and other birth defects. Flaviviruses, including ZIKV, reorganize the endoplasmic reticulum (ER) to form a viroplasm, a compartment where virus particles are assembled. Microtubules (MTs) and microtubule-organizing centers (MTOCs) coordinate structural and trafficking functions in the cell, and MTs also support replication of flaviviruses. Here we investigated the roles of MTs and the cell’s MTOCs on ZIKV viroplasm organization and virus production. We show that a toroidal-shaped viroplasm forms upon ZIKV infection, and MTs are organized at the viroplasm core and surrounding the viroplasm. We show that MTs are necessary for viroplasm organization and impact infectious virus production. In addition, the centrosome and the Golgi MTOC are closely associated with the viroplasm, and the centrosome coordinates the organization of the ZIKV viroplasm toroidal structure. Surprisingly, viroplasm formation and virus production are not significantly impaired when infected cells have no centrosomes and impaired Golgi MTOC, and we show that MTs are anchored to the viroplasm surface in these cells. We propose that the viroplasm is a site of MT organization, and the MTs organized at the viroplasm are sufficient for efficient virus production.
Blood Immunoproteasome Activity Is Regulated by Sex, Age and in Chronic Inflammatory Diseases: A First Population-Based Study
Authors: Kammerl Ilona Elisabeth , Flexeder Claudia , Karrasch Stefan , Thorand Barbara , Heier Margit , Peters Annette , Schulz Holger , Meiners Silke
Published: November 2021

Dysfunction of the immunoproteasome has been implicated in cardiovascular and pulmonary diseases. Its potential as a biomarker for predicting disease stages, however, has not been investigated so far and population-based analyses on the impact of sex and age are missing. We here analyzed the activity of all six catalytic sites of the proteasome in isolated peripheral blood mononuclear cells obtained from 873 study participants of the KORA FF4 study using activity-based probes. The activity of the immuno- and standard proteasome correlated clearly with elevated leukocyte counts of study participants. Unexpectedly, we observed a strong sex dimorphism for proteasome activity with significantly lower immunoproteasome activity in women. In aging, almost all catalytic activities of the proteasome were activated in aged women while maintained upon aging in men. We also noted distinct sex-related activation patterns of standard and immunoproteasome active sites in chronic inflammatory diseases such as diabetes, cardiovascular diseases, asthma, or chronic obstructive pulmonary disease as determined by multiple linear regression modeling. Our data thus provides a conceptual framework for future analysis of immunoproteasome function as a bio-marker for chronic inflammatory disease development and progression.
Protein Aggregation in the ER: Calm behind the Storm
Authors: Li Haisen , Sun Shengyi
Published: November 2021

As one of the largest organelles in eukaryotic cells, the endoplasmic reticulum (ER) plays a vital role in the synthesis, folding, and assembly of secretory and membrane proteins. To maintain its homeostasis, the ER is equipped with an elaborate network of protein folding chaperones and multiple quality control pathways whose cooperative actions safeguard the fidelity of protein biogenesis. However, due to genetic abnormalities, the error-prone nature of protein folding and assembly, and/or defects or limited capacities of the protein quality control systems, nascent proteins may become misfolded and fail to exit the ER. If not cleared efficiently, the progressive accumulation of misfolded proteins within the ER may result in the formation of toxic protein aggregates, leading to the so-called “ER storage diseases”. In this review, we first summarize our current understanding of the protein folding and quality control networks in the ER, including chaperones, unfolded protein response (UPR), ER-associated protein degradation (ERAD), and ER-selective autophagy (ER-phagy). We then survey recent research progress on a few ER storage diseases, with a focus on the role of ER quality control in the disease etiology, followed by a discussion on outstanding questions and emerging concepts in the field.
Deciphering Molecular Mechanisms and Intervening in Physiological and Pathophysiological Processes of Ca2+ Signaling Mechanisms Using Optogenetic Tools
Authors: Maltan Lena , Najjar Hadil , Tiffner Adéla , Derler Isabella
Published: November 2021

Calcium ion channels are involved in numerous biological functions such as lymphocyte activation, muscle contraction, neurotransmission, excitation, hormone secretion, gene expression, cell migration, memory, and aging. Therefore, their dysfunction can lead to a wide range of cellular abnormalities and, subsequently, to diseases. To date various conventional techniques have provided valuable insights into the roles of Ca2+ signaling. However, their limited spatiotemporal resolution and lack of reversibility pose significant obstacles in the detailed understanding of the structure–function relationship of ion channels. These drawbacks could be partially overcome by the use of optogenetics, which allows for the remote and well-defined manipulation of Ca2+-signaling. Here, we review the various optogenetic tools that have been used to achieve precise control over different Ca2+-permeable ion channels and receptors and associated downstream signaling cascades. We highlight the achievements of optogenetics as well as the still-open questions regarding the resolution of ion channel working mechanisms. In addition, we summarize the successes of optogenetics in manipulating many Ca2+-dependent biological processes both in vitro and in vivo. In summary, optogenetics has significantly advanced our understanding of Ca2+ signaling proteins and the used tools provide an essential basis for potential future therapeutic application.
Cardiac Glycosides as Autophagy Modulators
Authors: Škubník Jan , Svobodová Pavlíčková Vladimíra , Psotová Jana , Rimpelová Silvie
Published: November 2021

Drug repositioning is one of the leading strategies in modern therapeutic research. Instead of searching for completely novel substances and demanding studies of their biological effects, much attention has been paid to the evaluation of commonly used drugs, which could be utilized for more distinct indications than they have been approved for. Since treatment approaches for cancer, one of the most extensively studied diseases, have still been very limited, great effort has been made to find or repurpose novel anticancer therapeutics. One of these are cardiac glycosides, substances commonly used to treat congestive heart failure or various arrhythmias. Recently, the antitumor properties of cardiac glycosides have been discovered and, therefore, these compounds are being considered for anticancer therapy. Their mechanism of antitumor action seems to be rather complex and not fully uncovered yet, however, autophagy has been confirmed to play a key role in this process. In this review article, we report on the up-to-date knowledge of the anticancer activity of cardiac glycosides with special attention paid to autophagy induction, the molecular mechanisms of this process, and the potential employment of this phenomenon in clinical practice.
microRNAs in Human Adipose Tissue Physiology and Dysfunction
Authors: Kurylowicz Alina
Published: November 2021

In recent years, there has been a large amount of evidence on the role of microRNA (miRNA) in regulating adipose tissue physiology. Indeed, miRNAs control critical steps in adipocyte differentiation, proliferation and browning, as well as lipolysis, lipogenesis and adipokine secretion. Overnutrition leads to a significant change in the adipocyte miRNOME, resulting in adipose tissue dysfunction. Moreover, via secreted mediators, dysfunctional adipocytes may impair the function of other organs and tissues. However, given their potential to control cell and whole-body energy expenditure, miRNAs also represent critical therapeutic targets for treating obesity and related metabolic complications. This review attempts to integrate present concepts on the role miRNAs play in adipose tissue physiology and obesity-related dysfunction and data from pre-clinical and clinical studies on the diagnostic or therapeutic potential of miRNA in obesity and its related complications.
Chronic Histological Outcomes of Indirect Traumatic Optic Neuropathy in Adolescent Mice: Persistent Degeneration and Temporally Regulated Glial Responses
Authors: Hetzer Shelby M. , Shalosky Emily M. , Torrens Jordyn N. , Evanson Nathan K.
Published: November 2021

Injury to the optic nerve, termed, traumatic optic neuropathy (TON) is a known comorbidity of traumatic brain injury (TBI) and is now known to cause chronic and progressive retinal thinning up to 35 years after injury. Although animal models of TBI have described the presence of optic nerve degeneration and research exploring acute mechanisms is underway, few studies in humans or animals have examined chronic TON pathophysiology outside the retina. We used a closed-head weight-drop model of TBI/TON in 6-week-old male C57BL/6 mice. Mice were euthanized 7-, 14-, 30-, 90-, and 150-days post-injury (DPI) to assess histological changes in the visual system of the brain spanning a total of 12 regions. We show chronic elevation of FluoroJade-C, indicative of neurodegeneration, throughout the time course. Intriguingly, FJ-C staining revealed a bimodal distribution of mice indicating the possibility of subpopulations that may be more or less susceptible to injury outcomes. Additionally, we show that microglia and astrocytes react to optic nerve damage in both temporally and regionally different ways. Despite these differences, astrogliosis and microglial changes were alleviated between 14–30 DPI in all regions examined, perhaps indicating a potentially critical period for intervention/recovery that may determine chronic outcomes.
Repeated Social Defeat Exaggerates Fibrin-Rich Clot Formation by Enhancing Neutrophil Extracellular Trap Formation via Platelet–Neutrophil Interactions
Authors: Sugimoto Takeshi , Yamada Hiroyuki , Wada Naotoshi , Motoyama Shinichiro , Saburi Makoto , Kubota Hiroshi , Miyawaki Daisuke , Wakana Noriyuki , Kami Daisuke , Ogata Takehiro , Ibi Masakazu , Matoba Satoaki
Published: November 2021

Depression is an independent risk factor for cardiovascular disease (CVD). We have previously shown that repeated social defeat (RSD) exaggerates atherosclerosis development by enhancing neutrophil extracellular trap (NET) formation. In this study, we investigated the impact of RSD on arterial thrombosis. Eight-week-old male wild-type mice (C57BL/6J) were exposed to RSD by housing with larger CD-1 mice in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. After confirming depression-like behaviors, mice underwent FeCl3-induced carotid arterial injury and were analyzed after 3 h. Although the volume of thrombi was comparable between the two groups, fibrin(ogen)-positive areas were significantly increased in defeated mice, in which Ly-6G-positive cells were appreciably co-localized with Cit-H3-positive staining. Treatment with DNase I completely diminished exaggerated fibrin-rich clot formation in defeated mice. Flow cytometric analysis showed that neutrophil CD11b expression before FeCl3 application was significantly higher in defeated mice than in control mice. In vitro NET formation induced by activated platelets was significantly augmented in defeated mice, which was substantially inhibited by anti-CD11b antibody treatment. Our findings demonstrate that RSD enhances fibrin-rich clot formation after arterial injury by enhancing NET formation, suggesting that NET can be a new therapeutic target in depression-related CVD.
Cost-Effective Foam-Based Colorimetric Sensor for Roadside Testing of Alcohol in Undiluted Saliva
Authors: Kaewnu Krittapas , Promsuwan Kiattisak , Phonchai Apichai , Thiangchanya Adul , Somapa Dongsayam , Somapa Namchoke , Tayayuth Kunanunt , Limbut Warakorn
Published: November 2021

A novel foam-based colorimetric alcohol sensor was developed for the detection of alcohol in saliva. Detection was based on the color change of a potassium dichromate-sulfuric acid solution absorbed by melamine foam. In the presence of alcohol, the orange colorimetric sensor changed color to brown, green and, ultimately, blue, depending on the concentration of alcohol in the sample. The response of the proposed sensor toward alcohol was linear from 0.10 to 2.5% v/v. The limit of detection was 0.03% v/v. Alcohol concentration could be determined using the naked eye in the range of 0.00 to 10% v/v. The developed alcohol sensor presented good operational accuracy (RSD = 0.30–1.90%, n = 8) and good stability for 21 days when stored at 25 °C and 75 days when stored at 4 °C. The results of alcohol detection with the developed sensor showed no significant difference from the results of spectrophotometric detection at a 95% confidence level (p > 0.05). The sensor was easy to use, small, inexpensive and portable, enabling drivers to accurately measure their own blood alcohol level and providing convenient speed in forensic applications.
Update on Febrile Neutropenia in Pediatric Oncological Patients Undergoing Chemotherapy
Authors: Cennamo Federica , Masetti Riccardo , Largo Prisca , Argentiero Alberto , Pession Andrea , Esposito Susanna
Published: November 2021

Febrile neutropenia (FN) is a common complication of chemotherapy in oncological children and one of the most important causes of morbidity and mortality in these patients. The early detection of a bacteremia and the rapid therapeutic intervention are crucial to improve the outcome. We analyzed the literature in order to clarify the epidemiology of FN in children undergoing chemotherapy, the specific factors associated with a negative outcome, the most common etiology, and the value of biological markers as a tool to make an early diagnosis or to monitor the evolution of the infection. Several studies have tried to identify specific factors that could help the clinician in the detection of an infection and in its microbiological identification. However, due to the heterogenicity of the available studies, sufficient evidence is lacking to establish the role of these risk factors in clinical practice and future research on this topic appear mandatory. Determinations of risk factors, etiology, and markers of febrile episodes in these patients are complicated by the characteristics of the underlying illness and the effects of treatments received. Although some studies have tried to develop an evidence-based guideline for the empiric management of FN in pediatrics, validated predictive scores and algorithms are still lacking and urgently needed.
Comparison of Heart Rate Feedback from Dry-Electrode ECG, 3-Lead ECG, and Pulse Oximetry during Newborn Resuscitation
Authors: Rettedal Siren , Eilevstjønn Joar , Kibsgaard Amalie , Kvaløy Jan Terje , Ersdal Hege
Published: November 2021

Background: Assessment of heart rate (HR) is essential during newborn resuscitation, and comparison of dry-electrode ECG technology to standard monitoring by 3-lead ECG and Pulse Oximetry (PO) is lacking. Methods: NeoBeat, ECG, and PO were applied to newborns resuscitated at birth. Resuscitations were video recorded, and HR was registered every second. Results: Device placement time from birth was median (quartiles) 6 (4, 18) seconds for NeoBeat versus 138 (97, 181) seconds for ECG and 152 (103, 216) seconds for PO. Time to first HR presentation from birth was 22 (13, 45) seconds for NeoBeat versus 171 (129, 239) seconds for ECG and 270 (185, 357) seconds for PO. Proportion of time with HR feedback from NeoBeat during resuscitation from birth was 85 (69, 93)%, from arrival at the resuscitation table 98 (85, 100)%, and during positive pressure ventilation 100 (95, 100)%. For ECG, these proportions were, 25 (0, 43)%, 28 (0, 56)%, and 33 (0, 66)% and for PO, 0 (0, 16)%, 0 (0, 16)%, and 0 (0, 18)%. All p < 0.0001. Conclusions: NeoBeat was faster to place, presented HR more rapidly, and provided feedback on HR for a larger proportion of time during ongoing resuscitation compared to 3-lead ECG and PO.
The Use of a Disposable Umbilical Clamp to Secure an Umbilical Venous Catheter in Neonatal Emergencies—An Experimental Feasibility Study
Authors: Schwaberger Bernhard , Schlatzer Christoph , Freidorfer Daniel , Bruckner Marlies , Wolfsberger Christina H. , Mileder Lukas P. , Pichler Gerhard , Urlesberger Berndt
Published: November 2021

Recent guidelines recommend the umbilical venous catheter (UVC) as the optimal vascular access method during neonatal resuscitation. In emergencies the UVC securement may be challenging and time-consuming. This experimental study was designed to test the feasibility of new concepts for the UVC securement. Umbilical cord remnants were catheterized with peripheral catheters and secured with disposable umbilical clamps. Three different securement techniques were investigated. Secure 1: the disposable umbilical clamp was closed at the level of the inserted catheter. Secure 2: the clamp was closed at the junction of the catheter and plastic wings. Secure 3: the setting of Secure 2 was combined with an umbilical tape. The main outcomes were the feasibility of fluid administration and the maximum force to release the securement. This study shows that inserting peripheral catheters into the umbilical vein and securing them with disposable umbilical clamps is feasible. Rates of lumen obstruction and the effectiveness of the securement were superior with Secure 2 and 3 compared to Secure 1. This new approach may be a rewarding option for umbilical venous catheterization and securement particularly in low-resource settings and for staff with limited experience in neonatal emergencies. However, although promising, these results need to be confirmed in clinical trials before being introduced into clinical practice.
A New Web Score to Predict Health Status in Paediatric Patients with Chronic Diseases: Design and Development of the PENSAMI Study
Authors: Mastorci Francesca , Ait-Ali Lamia , Festa Pierluigi , Martini Marco , Gagliardi Luigi , Calabri Giovanni , La Marca Giancarlo , Trivellini Gabriele , Casu Anselmo , Dalmiani Stefano , Marcheschi Paolo , Celi Simona , Pingitore Alessandro
Published: November 2021

Paediatric chronic diseases (CD) are characterised by their ongoing duration and the fact that they are often managed throughout the lifespan, with the need to adjust lifestyle and expectations with the limitations coming from the CD. The aim of the PENSAMI study is to not only cure the disease, but to also care for the person from a clinical and psychosocial perspective. Data will be collected from 150 paediatric patients affected by heart disease, diabetes, and asthma admitted during in-hospital stay or outpatient visits, and from 200 healthy control subjects. The protocol will consist of two phases. The first one will aim at elaborating the predictive model by detecting (clinical, anthropometric at birth, environmental, lifestyle, social context, emotional state, and mental abilities) in order to develop a model predictive of the events considered: (1) re-hospitalisation; (2) severity and progression of the disease; (3) adherence to therapy; (4) HRQoL; (5) obesity and metabolic syndrome; (6) illness-stress related; (7) school drop-out; (8) school performance. The second one will address validating the previous predictive model. This model will aim to: (1) understand, prevent, and halt the progression of childhood CD; (2) develop new and improved diagnostic tools; (3) pave the way for innovative treatments and additional therapies to traditional clinical practice; and (4) create truly personalised therapeutic and preventive strategies in various sectors, such as cardiology, diabetes, and respiratory diseases.
Parental Pesticide Exposure and Childhood Brain Cancer: A Systematic Review and Meta-Analysis Confirming the IARC/WHO Monographs on Some Organophosphate Insecticides and Herbicides
Authors: Feulefack Joseph , Khan Aiza , Forastiere Francesco , Sergi Consolato M.
Published: November 2021

Background: Brain tumors are the second most common neoplasm in the pediatric age. Pesticides may play an etiologic role, but literature results are conflicting. This review provides a systematic overview, meta-analysis, and IARC/WHO consideration of data on parental exposure to pesticides and childhood brain tumors. Methods: We searched PubMed, SCOPUS, and Google Scholar for literature (1 January 1966–31 December 2020) that assessed childhood brain tumors and parental exposure to pesticides. We undertook a meta-analysis addressing prenatal exposure, exposure after birth, occupational exposure, and residential exposure. A total of 130 case-control investigations involving 43,598 individuals (18,198 cases and 25,400 controls) were included. Results: Prenatal exposure is associated with childhood brain tumors (odds ratio, OR = 1.32; 95% CI: 1.17–1.49; I2 = 41.1%). The same occurs after birth exposure (OR = 1.22; 95% CI: 1.03–1.45, I2 = 72.3%) and residential exposure to pesticides (OR = 1.31; 95% CI: 1.11–1.54, I2 = 67.2%). Parental occupational exposure is only marginally associated with CBT (OR = 1.17, 95% CI: 0.99–1.38, I2 = 67.0%). Conclusions: There is an association between CBT and parental pesticides exposure before childbirth, after birth, and residential exposure. It is in line with the IARC Monograph evaluating the carcinogenicity of diazinon, glyphosate, malathion, parathion, and tetrachlorvinphos.
Ferroelectric and Ferroelastic Domain Related Formation and Influential Mechanisms of Vapor Deposited Piezoelectric Thin Films
Authors: Chen Chu , Song Jian , Zhang Qi , Gong Mingyu , Liu Yue , Fan Tongxiang
Published: November 2021

Compared to the bulk piezoelectric materials counterpart, piezoelectric thin films (PTFs) possess advantages of smaller size, lower power consumption, better sensitivity, and have broad application in advanced micro-electro-mechanical system (MEMS) devices. However, the performance of MEMS transducers and actuators are largely limited by PTFs piezoelectric properties. In this review, we focus on understanding structure-property relationship of vapor deposited PTFs, with emphasis on the effect of strain energy and electrostatic energy in thin films, especially, energy relaxation induced misfit dislocation and ferroelectric (FS) and ferroelastic (FC) domain formation mechanisms. We then discuss the microstructure of these domains and their influential mechanisms on piezoelectric properties, as well as the domain engineering strategies (i.e., internal and external stimuli). This review will motivate further experimental, theoretical, and simulation studies on FS and FC domain engineering in PTFs.
Mixtures of Scutellaria baicalensis and Glycyrrhiza L. Extracts as Antibacterial and Antiviral Agents in Active Coatings
Authors: Ordon Magdalena , Nawrotek Paweł , Stachurska Xymena , Schmidt Anna , Mizielińska Małgorzata
Published: November 2021

The aim of this study was to develop active packaging materials covered in active coatings (offering antibacterial and antiviral properties) that contain selected plant extracts. In addition, the synergistic effect of the active substances in these extracts was also analysed. The results of the study demonstrated that Scutellaria baicalensis and Glycyrrhiza L. extracts (two of six analysed plant extracts) were the most active agents against selected Gram-positive and Gram-negative bacterial strains. Additionally, the synergistic effect of S. baicalensis and Glycyrrhiza L. extracts was noted, meaning that the effect of these two plant extract mixtures on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas syringae growth was higher than the activity of individual pure extracts. Mixtures of the extracts were introduced into the coating carrier. A polyethylene (PE) foil was then coated with active layers containing mixtures of S. baicalensis and Glycyrrhiza L. extracts as antimicrobial agents. The results of this research showed that all of the active coatings had a bacteriolytic effect on B. subtilis and a bacteriostatic effect on S. aureus cells. The coatings were found to be inactive against E. coli and P. syringae cells. This means that the coatings could be used as internal coatings to preserve food products against Gram-positive bacteria that may be responsible for food spoilage. The results of this study also demonstrated that the coatings were highly active against phage phi 6 phage particles, used as SARS-CoV-2 surrogate. This means that the coatings could be used as external coatings to limit the spread of SARS-CoV-2 and pathogenic Gram-positive bacteria via human hands.
Influence of Applied Frequency on Thermal Physical Properties of Coatings Prepared on Al and AlSi Alloys by Plasma Electrolytic Oxidation
Authors: Li Guodong , Ma Fei , Li Zhijie , Xu Yi , Gao Fangyuan , Guo Lingyan , Zhu Jianwei , Li Guang , Xia Yuan
Published: November 2021

In this study, plasma electrolytic oxidation (PEO) was performed on Al and AlSi substrates using a pulsed direct current (DC) power source. The coating process was carried out in a Na2SiO3 electrolyte with the systematic change of pulse frequency (50–1400 Hz). The surface characteristics of the coatings were examined using scanning electron microscopy (SEM). The phase structure was characterized using X-ray diffraction (XRD). A differential scanning calorimeter (DSC) and a laser flash apparatus (LFA) were employed to test heat capacity and heat conductivity, respectively. Results showed that as the discharge frequency increased, the thermal physical properties of Al-PEO and AlSi-PEO coatings changed in different ways. At a high frequency, Al-PEO coatings had low porosity and were closed-pore structured whereas AlSi-PEO coatings had high porosity and large-size open-pore structures could be observed on their surfaces due to concentrated discharges. Based on these findings, it was found that the thermal productivity of coatings is closely correlated with the open-/closed-pore structure instead of porosity. PEO coatings with low heat capacity or low heat conductivity could be obtained with a controlled frequency.
Study of Wear and Redistribution Dynamic Forces of Wheel Pairs Restored by a Wear-Resistant Coating 15Cr17Ni12V3F
Authors: Savinkin Vitaliy , Zhumekenova Zaure , Sandu Andrei , Vizureanu Petrica , Savinkin Sergey , Kolisnichenko Sergey , Ivanova Olga
Published: November 2021

The relevance of this study lies in the need to research the wear process of the elements of dynamic systems and to establish the dependence of the geometric and structural characteristics of wheels restored by plasma surfacing with a coating of 15Cr17Ni12V3F on dynamic, cyclically varying loads. The study was aimed to establish the dependencies between the deviation of the wear area, the formation of contact and fatigue stresses, and the change in the phase structure of the wheel defect. It is important to justify the permissible limits of wear of the transverse profile in the contact zone of a wheel and ridge. The object of the study was the dynamic interaction of the “wheel–ridge–rail contact surface” system. To achieve the goal, the following methodology was adopted: kinematic analysis, strength calculation, the use of mathematical analysis in dynamic system modelling, virtual modelling in the SOLIDWORKS software environment of the GearTrax application, experiment planning, and model correction through the results of metallographic studies. The results of the study are presented as reasonable prediction criteria that consider contact cycles during the formation of fatigue stresses at the stage of defect origin. The process of the dynamic interaction of the contact worn profile of a wheel with a railway rail is explored. Polynomial equations are proposed to substantiate the optimal design and technological parameters of designing a railway carriage wheel. The permissible limits of wear of the transverse profile in the contact zone of the wheel and the ridge are justified while taking the coefficient of the reduction of contact stresses in the metal into account. The dependences of the change in static load on the utilization factor of the railway carriage load capacity are established. The dependences of changes in fatigue stresses on the design deviation of the contact area of wheel wear are established. It is confirmed that the stress concentration under cyclic loads is formed in the ferritic layers of the material structure before the appearance of wear.
Enhancement of Charge Transport of a Dye-Sensitized Solar Cell Utilizing TiO2 Quantum Dot Photoelectrode Film
Authors: Zaine Siti Nur Azella , Mohamed Norani Muti , Khatani Mehboob , Shahid Muhammad Umair
Published: November 2021

A dye-sensitized solar cell (DSC) is the third generation of solar technology, utilizing TiO2 nanoparticles with sizes of 20–30 nm as the photoelectrode material. The integration of smaller nanoparticles has the advantage of providing a larger surface area, yet the presence of grain boundaries is inevitable, resulting in a higher probability of electron trapping. This study reports on the improvement of charge transport through the integration of quantum dot (QD) TiO2 with a size of less than 10 nm as the dye absorption photoelectrode layer. The QD TiO2 samples were synthesized through sol–gel and reflux methods in a controlled pH solution without surfactants. The synthesized samples were analyzed using microscopic, diffraction, absorption, as well as spectroscopic analyses. A current–voltage and impedance analysis was used to evaluate the performance of a DSC integrated with synthesized TiO2 as the photoelectrode material. The sample with smaller crystallite structures led to a large surface area and exhibited a higher dye absorption capability. Interestingly, a DSC integrated with QD TiO2 showed a higher steady-state electron density and a lower electron recombination rate. The shallow distribution of the trap state led to an improvement of the electron trapping/de-trapping process between the Fermi level and the conduction band of oxide photoelectrode material, hence improving the lifetime of generated electrons and the overall performance of the DSC.
Deuterium Retention and Release Behavior from Beryllium Co-Deposited Layers at Distinct Ar/D Ratio
Authors: Dinca Paul , Staicu Cornel , Porosnicu Corneliu , Pompilian Oana G. , Banici Ana-Maria , Butoi Bogdan , Lungu Cristian P. , Burducea Ion
Published: November 2021

Beryllium-deuterium co-deposited layers were obtained using DC magnetron sputtering technique by varying the Ar/D2 gas mixture composition (10/1; 5/1; 2/1 and 1:1) at a constant deposition rate of 0.06 nm/s, 343 K substrate temperature and 2 Pa gas pressure. The surface morphology of the layers was analyzed using Scanning Electron Microscopy and the layer crystalline structure was analyzed by X-ray diffraction. Rutherford backscattering spectrometry was employed to determine the chemical composition of the layers. D trapping states and inventory quantification were performed using thermal desorption spectroscopy. The morphology of the layers is not influenced by the Ar/D2 gas mixture composition but by the substrate type and roughness. The increase of the D2 content during the deposition leads to the deposition of Be-D amorphous layers and also reduces the layer thickness by decreasing the sputtering yield due to the poisoning of the Be target. The D retention in the layers is dominated by the D trapping in low activation binding states and the increase of D2 flow during deposition leads to a significant build-up of deuterium in these states. Increase of deuterium flow during deposition consequently leads to an increase of D retention in the beryllium layers up to 300%. The resulted Be-D layers release the majority of their D (above 99.99%) at temperatures lower than 700 K.
Influence of Hydrogen-Nitrogen Hybrid Passivation on the Gate Oxide Film of n-Type 4H-SiC MOS Capacitors
Authors: Jia Yifan , Sun Shengjun , Liu Xiangtai , Lu Qin , Qin Ke , Wang Shaoqing , Guan Yunhe , Chen Haifeng , Tang Xiaoyan , Zhang Yuming
Published: November 2021

Hydrogen-nitrogen hybrid passivation treatment for growing high-property gate oxide films by high-temperature wet oxidation, with short-time NO POA, is proposed and demonstrated. Secondary ion mass spectroscopy (SIMS) measurements show that the proposed method causes hydrogen and appropriate nitrogen atoms to accumulate in Gaussian-like distributions near the SiO2/SiC interface. Moreover, the hydrogen atoms are also incorporated into the grown SiO2 layer, with a concentration of approximately 1 × 1019 cm−3. The conductance characteristics indicate that the induced hydrogen and nitrogen passivation atoms near the interface can effectively reduce the density of interface traps and near-interface traps. The current-voltage (I-V), X-ray photoelectron spectroscopy (XPS), and time-dependent bias stress (TDBS) with ultraviolet light (UVL) irradiation results demonstrate that the grown SiO2 film with the incorporated hydrogen passivation atoms can effectively reduce the density of oxide electron traps, leading to the barrier height being improved and the leakage current being reduced.
Study the Passivation Characteristics of Microwave Annealing Applied to APALD Deposited Al2O3 Thin Film
Authors: Huang Yu-Chun , Chuang Ricky Wenkuei , Lin Keh-Moh , Wu Tsung-Chieh
Published: November 2021

In this study, a self-developed atmospheric pressure atomic layer deposition (APALD) system is used to deposit Al2O3 passivation film, along with the use of precursor combinations of Al(CH3)3/H2O to improve its passivation characteristics through a short-time microwave post-annealing process. Comparing the unannealed and microwave-annealed samples whose temperature is controlled at 200–500 °C, APALD non-vacuum deposited film can be realized with a higher film deposition rate, which is beneficial for increasing the production throughput while at the same time reducing the operating cost of vacuum equipment at hand. Since the microwave has a greater penetration depth during the process, the resultant thermal energy provided can be spread out evenly to the entire wafer, thereby achieving the effect of rapid annealing. The film thickness is subsequently analyzed by TEM, whereas the chemical composition is verified by EDS and XPS. The negative fixed charge and interface trap density are analyzed by the C-V measurement method. Finally, the three major indicators of τeff, SRV, and IVoc are analyzed by QSSPC to duly verify the excellent passivation performance.
Polyacrylate Decorating Poly(ethylene terephthalate) (PET) Film Surface for Boosting Oxygen Barrier Property
Authors: Zhong Wen , Yang Xiaobin , Sun Jikun , Gao Hongwei , Bai Yongping , Shao Lu
Published: November 2021

Polymeric barrier materials are critical in contemporary industries for food, medicine, and chemical packaging. However, these materials, such as PET films, are impeded by the optimization of barrier properties by virtue of molecular design. Herein, a new methyl methacrylate-methyl acrylate-diallyl maleate-maleic acid (MMA-MAc-DAM-MA) was synthesized to tailor the surface properties of PET films for maximizing oxygen barrier properties. During the MMA-MAc-DAM-MA coating and curing process, the chemical structure evolutions of MMA-MAc-DAM-MA coatings were characterized, indicating that the cross-linking conversion and proportion of –COOH groups are critical for the oxygen barrier properties of coatings. The inherent –COOH groups are transformed into designed structures, including intramolecular anhydride, inter-chain anhydride and retained carboxylic acid. Therein, the inter-chain anhydride restraining the activity of coated polymer chain mainly contributes to enhanced barrier properties. The thermal properties of novel coatings were analyzed, revealing that the curing behavior is strongly dependent on the curing temperatures. The impacts of viscosity of the coating solution, coating velocity, and coating thickness on the oxygen permeability (Po2) of the coatings were investigated using a gas permeability tester to explore the optimum operating parameters during practical applications, which can reduce the Po2 of PET film by 47.8%. This work provides new insights on advanced coating materials for excellent barrier performance.
RETRACTED: Synthesis, Characterization and Photodegradation Studies of Copper Oxide–Graphene Nanocomposites
Authors: Raya Indah , Ahmad Awais , Alkaim Ayad , Bokov Dmitry , Alwaily Enas , Luque Rafael , Alsaiari Mabkhoot , Jalalah Mohammed
Published: November 2021

In this work, a simple hydrothermal method was employed to prepare a pristine sample of copper oxide (CuO) and three samples of copper oxide–graphene nanocomposites (CuO-xG) with x = 2.5, 5, and 10 mg of graphene. The synthesized samples were characterized using X-ray powder diffractometry (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV-Vis) spectroscopy. The XRD patterns of CuO-xG nanocomposites exhibited the diffraction peaks related to the crystal planes of monoclinic CuO and hexagonal graphite. The surface morphology of the prepared samples was investigated using FESEM images. EDX analysis was used to investigate the chemical composition of the synthesized samples. FTIR spectroscopy identified the vibrational modes of the covalent bonds present in the samples. The allowed direct optical bandgap energy was calculated for all prepared samples using UV-Vis absorption spectra. The small bandgap of CuO-xG nanocomposites indicates their potential use as an effective photocatalyst in the presence of visible light. Photocatalytic activity of the samples was explored for the degradation of methylene blue (MB) dye contaminant under visible light irradiation. The results showed that the CuO-5G sample has the highest photodegradation efficiency (~56%).
Mechanism of Polyurethane Binder Curing Reaction and Evaluation of Polyurethane Mixture Properties
Authors: Sun Min , Bi Yufeng , Zhuang Wei , Chen Sai , Zhao Pinhui , Pang Dezheng , Zhang Wensheng
Published: November 2021

This study focuses on analyzing the curing reaction mechanism of polyurethane (PU) binders and comprehensively evaluating the PU mixture’s properties. The former was investigated by conducting a Fourier transform infrared spectroscopy (FTIR) test on PU binders with different curing times. The volume change characteristics, construction operation time, and strength formation law were clarified through the splitting tensile test of PU mixtures under different environmental conditions. The optimal PU mixture stacking time and curing time under different environmental conditions were determined. The properties of the PU mixture and asphalt mixture were evaluated and compared through a rutting test, low-temperature bending test, freeze–thaw splitting test, and four-point bending fatigue test. The results show that the physical and chemical curing of the PU binder occurred within the first 24 h of curing, and the reaction speed gradually accelerated to form a polyurea structure 24 h later. It is recommended to stack the PU mixture for 4 h before compaction and to cure it for 2 days before opening under the conditions of 50% humidity and 15–40 °C surrounding temperature. The PU mixture shows better temperature stability and fatigue resistance than the asphalt mixture, and the splitting tensile strength of the PU mixture before and after the freeze–thaw splitting test is also higher. It is clear that the PU mixture is a green road building material with good performance.
Providing a Specified Level of Electromagnetic Shielding with Nickel Thin Films Formed by DC Magnetron Sputtering
Authors: Testov Oleg A. , Komlev Andrey E. , Gareev Kamil G. , Khmelnitskiy Ivan K. , Luchinin Victor V. , Sevost’yanov Eugeniy N. , Testov Igor O.
Published: November 2021

Nickel films of 4–250 nm thickness were produced by DC magnetron sputtering onto glass and silicon substrates. The electrical properties of the films were investigated by the four-probe method and the surface morphology of the films was studied by atomic force microscopy. To measure the shielding effectiveness, a portable closed stand based on horn antennas was used. A theoretical assessment of the shielding effectiveness of nickel films of various thickness under electromagnetic radiation of a range of frequencies was carried out using two different approximations. The results demonstrate the shielding effectiveness of up to 35 dB of the nickel thin films in the frequency range of 2–18 GHz.