bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacological Inhibition of Spleen Tyrosine Kinase Suppressed Neuroinflammation and Cognitive Dysfunction in LPS-Induced Neurodegeneration Model
Authors: Kim Min Woo , Choe Kyonghwan , Park Jun Sung , Lee Hyeon Jin , Kang Min Hwa , Ahmad Riaz , Kim Myeong Ok
Published: May 2022

Tyrosine-protein kinase (Syk) plays a potential role in neuroinflammation and adaptive immune responses in several neurodegenerative conditions. Seeing the significant role of Syk in the pathophysiology of neurodegeneration, several pharmacological inhibitors have been developed. One of the known inhibitors of Syk is BAY61-3606, which has shown efficacies in Alzheimer’s disease (AD) through regulating amyloid production. However, little is known about its efficacies in neuroinflammation and neurodegeneration. Our finding showed that Syk expression was up-regulated by lipopolysaccharide (LPS)-dependent manner, and BAY61-3606 significantly suppressed the activated microglia (ionized calcium-binding adaptor molecule 1 [Iba-1]) and the inflammatory cytokines (tumor necrosis factor-alpha [TNF-α], interleukin 1-beta [IL-1β], IL-6) and other inflammatory mediators (nuclear factor kappa B [NF-κB], cyclooxygenase-2 [Cox-2], and inducible nitric axide synthase [iNOS]) in the lipopolysaccharide (LPS)-treated in vivo and in vitro models. Moreover, BAY61-3606 significantly reduced microglia-mediated neuronal cell death by regulating the expression of Cytochrome C and Bim (B-cell lymphoma 2 [BCL-2] interacting mediator of cell death) in the LPS-treated mice brain and HT22 cells. Furthermore, the expression of synaptic markers, synaptosomal-associated protein, 25 kDa (SNAP25), synaptophysin (Syp), and postsynaptic density protein-95 (PSD95) in LPS-challenged mice showed that BAY61-3606 significantly recovered the synaptic markers. Finally, we have analyzed the effects of BAY61-3606 against memory and cognitive dysfunctions in the LPS injected mice. The Y-maze test and Passive avoidance test suggested that BAY61-3606 significantly protected against LPS-induced cognitive and memory dysfunctions. The current findings not only highlight the mechanisms of Syk in the pathophysiology of neuro-inflammation, but also support the therapeutic efficacy of BAY61-3606 in the management of neurodegeneration.
Hormetic Heat Shock Enhances Autophagy through HSF1 in Retinal Pigment Epithelium Cells
Authors: Amirkavei Mooud , Plastino Flavia , Kvanta Anders , Kaarniranta Kai , André Helder , Koskelainen Ari
Published: May 2022

To maintain homeostasis, cells have evolved stress-response pathways to cope with exogenous and endogenous stress factors. Diverse stresses at high doses may be detrimental, albeit low doses of stress, known as hormesis, can be beneficial. Upon exposure to stress, such as temperature rise, the conventional heat shock response (HSR) regulated by the heat shock transcription factor 1 (HSF1) facilitates refolding of misfolded proteins with the help of heat shock proteins (HSPs). However, the role and molecular mechanisms underlying the beneficial effects of HSR with other clearance processes, such as autophagy, remain poorly understood. In this study, human ARPE-19 cells, an in vitro model of retinal pigment epithelium, were treated with hormetic heat shock (HHS) and the autophagy expression profile was examined using quantitative PCR (qPCR), immunoblotting, immunoprecipitation, and immunofluorescence. We demonstrate that HHS enhances the expression of fundamental autophagy-associated genes in ARPE-19 cells through the activation of HSF1. HHS transiently increases the level of SQSTM1 and LC3B-II and activates autophagy. These findings reveal a role for autophagic HSF1-regulated functions and demonstrate the contribution of autophagy to hormesis in the HSR by improving proteostasis.
The Outside-In Journey of Tissue Transglutaminase in Cancer
Authors: Sima Livia Elena , Matei Daniela , Condello Salvatore
Published: May 2022

Tissue transglutaminase (TG2) is a member of the transglutaminase family that catalyzes Ca2+-dependent protein crosslinks and hydrolyzes guanosine 5′-triphosphate (GTP). The conformation and functions of TG2 are regulated by Ca2+ and GTP levels; the TG2 enzymatically active open conformation is modulated by high Ca2+ concentrations, while high intracellular GTP promotes the closed conformation, with inhibition of the TG-ase activity. TG2’s unique characteristics and its ubiquitous distribution in the intracellular compartment, coupled with its secretion in the extracellular matrix, contribute to modulate the functions of the protein. Its aberrant expression has been observed in several cancer types where it was linked to metastatic progression, resistance to chemotherapy, stemness, and worse clinical outcomes. The N-terminal domain of TG2 binds to the 42 kDa gelatin-binding domain of fibronectin with high affinity, facilitating the formation of a complex with β-integrins, essential for cellular adhesion to the matrix. This mechanism allows TG2 to interact with key matrix proteins and to regulate epithelial to mesenchymal transition and stemness. Here, we highlight the current knowledge on TG2 involvement in cancer, focusing on its roles translating extracellular cues into activation of oncogenic programs. Improved understanding of these mechanisms could lead to new therapeutic strategies targeting this multi-functional protein.
Small Extracellular Vesicles: Key Forces Mediating the Development and Metastasis of Colorectal Cancer
Authors: Zhang Wenjie , Hu Xiaoxue , Jiang Zhengting
Published: May 2022

Colorectal cancer (CRC) is the third most common cancer worldwide, and its incidence and mortality rates have been increasing annually in recent years. A variety of different small extracellular vesicles (sEVs) are important mediators of intercellular communication and have an important role in tumor metastasis and progression. The development and metastasis of CRC are closely linked to tumor-cell-derived sEVs, non-tumor-cell-derived sEVs, and intestinal-microbiota-derived sEVs. Numerous studies have shown that the tumor microenvironment (TME) is a key component in the regulation of CRC proliferation, development, and metastasis. These sEVs can create a TME conducive to CRC growth and metastasis by forming an immunosuppressive microenvironment, remodeling the extracellular matrix, and promoting tumor cell metabolism. Therefore, in this paper, we review the role of different types of sEVs in colorectal cancer development and metastasis. Furthermore, based on the properties of sEVs, we further discuss the use of sEVs as early biomarkers for colorectal cancer diagnosis and the potential for their use in the treatment of CRC.
Cellular Senescence in Aging Lungs and Diseases
Authors: Aghali Arbi , Koloko Ngassie Maunick Lefin , Pabelick Christina M. , Prakash Y. S.
Published: May 2022

Cellular senescence represents a state of irreversible cell cycle arrest occurring naturally or in response to exogenous stressors. Following the initial arrest, progressive phenotypic changes define conditions of cellular senescence. Understanding molecular mechanisms that drive senescence can help to recognize the importance of such pathways in lung health and disease. There is increasing interest in the role of cellular senescence in conditions such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) in the context of understanding pathophysiology and identification of novel therapies. Herein, we discuss the current knowledge of molecular mechanisms and mitochondrial dysfunction regulating different aspects of cellular senescence-related to chronic lung diseases to develop rational strategies for modulating the senescent cell phenotype in the lung for therapeutic benefit.
Claudin-17 Deficiency in Mice Results in Kidney Injury Due to Electrolyte Imbalance and Oxidative Stress
Authors: Adil Mir S. , Parvathagiri Varun , Verma Arti , Liu Fang , Rudraraju Madhuri , Narayanan S. Priya , Somanath Payaningal R.
Published: May 2022

The multi-gene claudin (CLDN) family of tight junction proteins have isoform-specific roles in blood–tissue barrier regulation. CLDN17, a putative anion pore-forming CLDN based on its structural characterization, is assumed to regulate anion balance across the blood-tissue barriers. However, our knowledge about CLDN17 in physiology and pathology is limited. The current study investigated how Cldn17 deficiency in mice affects blood electrolytes and kidney structure. Cldn17−/− mice revealed no breeding abnormalities, but the newborn pups exhibited delayed growth. Adult Cldn17−/− mice displayed electrolyte imbalance, oxidative stress, and injury to the kidneys. Ingenuity pathway analysis followed by RNA-sequencing revealed hyperactivation of signaling pathways and downregulation of SOD1 expression in kidneys associated with inflammation and reactive oxygen species generation, demonstrating the importance of Cldn17 in the maintenance of electrolytes and reactive oxygen species across the blood-tissue barrier.
Genetic Characterization of Rat Hepatic Stellate Cell Line HSC-T6 for In Vitro Cell Line Authentication
Authors: Nanda Indrajit , Steinlein Claus , Haaf Thomas , Buhl Eva M. , Grimm Domink G. , Friedman Scott L. , Meurer Steffen K. , Schröder Sarah K. , Weiskirchen Ralf
Published: May 2022

Immortalized hepatic stellate cells (HSCs) established from mouse, rat, and humans are valuable in vitro models for the biomedical investigation of liver biology. These cell lines are homogenous, thereby providing consistent and reproducible results. They grow more robustly than primary HSCs and provide an unlimited supply of proteins or nucleic acids for biochemical studies. Moreover, they can overcome ethical concerns associated with the use of animal and human tissue and allow for fostering of the 3R principle of replacement, reduction, and refinement proposed in 1959 by William M. S. Russell and Rex L. Burch. Nevertheless, working with continuous cell lines also has some disadvantages. In particular, there are ample examples in which genetic drift and cell misidentification has led to invalid data. Therefore, many journals and granting agencies now recommend proper cell line authentication. We herein describe the genetic characterization of the rat HSC line HSC-T6, which was introduced as a new in vitro model for the study of retinoid metabolism. The consensus chromosome markers, outlined primarily through multicolor spectral karyotyping (SKY), demonstrate that apart from the large derivative chromosome 1 (RNO1), at least two additional chromosomes (RNO4 and RNO7) are found to be in three copies in all metaphases. Additionally, we have defined a short tandem repeat (STR) profile for HSC-T6, including 31 species-specific markers. The typical features of these cells have been further determined by electron microscopy, Western blotting, and Rhodamine-Phalloidin staining. Finally, we have analyzed the transcriptome of HSC-T6 cells by mRNA sequencing (mRNA-Seq) using next generation sequencing (NGS).
Chronic Chemogenetic Activation of the Superior Colliculus in Glaucomatous Mice: Local and Retrograde Molecular Signature
Authors: Claes Marie , Geeraerts Emiel , Plaisance Stéphane , Mentens Stephanie , Van den Haute Chris , De Groef Lies , Arckens Lut , Moons Lieve
Published: May 2022

One important facet of glaucoma pathophysiology is axonal damage, which ultimately disrupts the connection between the retina and its postsynaptic brain targets. The concurrent loss of retrograde support interferes with the functionality and survival of the retinal ganglion cells (RGCs). Previous research has shown that stimulation of neuronal activity in a primary retinal target area—i.e., the superior colliculus—promotes RGC survival in an acute mouse model of glaucoma. To build further on this observation, we applied repeated chemogenetics in the superior colliculus of a more chronic murine glaucoma model—i.e., the microbead occlusion model—and performed bulk RNA sequencing on collicular lysates and isolated RGCs. Our study revealed that chronic target stimulation upon glaucomatous injury phenocopies the a priori expected molecular response: growth factors were pinpointed as essential transcriptional regulators both in the locally stimulated tissue and in distant, unstimulated RGCs. Strikingly, and although the RGC transcriptome revealed a partial reversal of the glaucomatous signature and an enrichment of pro-survival signaling pathways, functional rescue of injured RGCs was not achieved. By postulating various explanations for the lack of RGC neuroprotection, we aim to warrant researchers and drug developers for the complexity of chronic neuromodulation and growth factor signaling.
Investigating Organic Vapor Sensing Properties of Composite Carbon Nanotube-Zinc Oxide Nanowire
Authors: Shooshtari Mostafa , Pahlavan Saeideh , Rahbarpour Saeideh , Ghafoorifard Hasan
Published: May 2022

The low operating temperature of nanowire gas sensors along with their high surface-to-volume ratio are two factors that make gas sensors more practical. In this paper, the growth of ZnO nanowires on a vertically aligned CNT forest is reported. The utilized method for ZnO growth was a rapid microwave-assisted hydrothermal route, which facilitates low-temperature and ultra-fast fabrication. Organic vapor sensing properties of fabricated samples were studied in response to different alcoholic vapors at a wide operating temperature range of 25 to 300 °C. Enhancement of the gas response was observed with increasing operating temperature. Moreover, the effect of the ZnO nanowire length on organic vapor sensing properties of CNT-ZnO samples was investigated. Results proved that CNT-ZnO samples with long ZnO wires exhibit higher sensitivity to examined analytes. Different length ZnO nanowires were attained via variation of the microwave exposure time and power. Fabrication parameters were selected based on numerous runs. The length of ZnO synthesized at each distinct run was calculated based on SEM micrographs of the samples.
National Cross-Sectional Study of Mental Health Screening Practices for Primary Caregivers of NICU Infants
Authors: Bloyd Cooper , Murthy Snehal , Song Clara , Franck Linda S. , Mangurian Christina
Published: May 2022

Universal screening for postpartum mood and anxiety disorders (PMADs) has been recommended for all new parents at outpatient postpartum and well-child visits. However, parents of newborns admitted to the NICU are rarely able to access these services during their infant’s prolonged hospitalization. The objective of this study was to determine the prevalence of mental health screening and treatment programs for parents or other primary caregivers in NICUs across the country. In this cross-sectional study, US NICU medical directors were invited to complete an online survey about current practices in mental health education, screening, and treatment for primary caregivers of preterm and ill infants in the NICU. Comparative analyses using Fisher’s exact test were performed to evaluate differences in practices among various NICU practice settings. Survey responses were obtained from 75 out of 700 potential sites (10.7%). Of participating NICUs, less than half routinely provided caregivers with psychoeducation about mental health self-care (n = 35, 47%) or routinely screened caregivers for PPD or other mental health disorders (n = 33, 44%). Nearly one-quarter of the NICUs did not provide any PMAD screening (n = 17, 23%). Despite consensus that postpartum psychosocial care is essential, routine mental health care of primary caregivers in the NICU remains inadequate.
Copeptin Release in Arterial Hypotension and Its Association with Severity of Disease in Critically Ill Children
Authors: Baumann Philipp , Gotta Verena , Atkinson Andrew , Deisenberg Markus , Hersberger Martin , Roggia Adam , Schmid Kevin , Cannizzaro Vincenzo
Published: May 2022

Low copeptin levels may indicate inadequate arginine-vasopressin release promoting arterial hypotension, whereas high copeptin concentrations may reflect disease severity. This single-center prospective non-randomized clinical trial analyzed the course of blood copeptin in critically ill normo- and hypotensive children and its association with disease severity. In 164 patients (median age 0.5 years (interquartile range 0.1, 2.9)), the mean copeptin concentration at baseline was 43.5 pmol/L. Though not significantly different after 61 h (primary outcome, mean individual change: −12%, p = 0.36, paired t-test), we detected 1.47-fold higher copeptin concentrations during arterial hypotension when compared to normotension (mixed-effect ANOVA, p = 0.01). In total, 8 out of 34 patients (23.5%) with low copeptin concentrations <10 pmol/L were hypotensive. Copeptin was highest in the adjusted mixed-effect regression analysis within the first day (+20% at 14 h) and decreased significantly at 108 h (−27%) compared to baseline (p = 0.002). Moreover, we found a significant association with vasopressor-inotrope treatment intensity, infancy (1–12 months) and cardiopulmonary bypass (all p ≤ 0.001). In conclusion, high copeptin values were associated with arterial hypotension and severity of disease in critically ill children. This study does not support the hypothesis that low copeptin values might be indicative of arginine-vasopressin deficiency.
The Challenges of Eradicating Pediatric Helicobacter pylori Infection in the Era of Probiotics
Authors: Meliț Lorena Elena , Mărginean Cristina Oana , Săsăran Maria Oana
Published: May 2022

Helicobacter pylori (H. pylori), the most common infection of childhood, results in life-threatening complications during adulthood if left untreated. Most of these complications are related to H. pylori-induced chronic inflammation. The dysbiosis caused by H. pylori is not limited to the gastric microenvironment, but it affects the entire gastrointestinal tract. Eradication of H. pylori has recently become a real challenge for clinicians due to both the persistent increase in antibiotic resistance worldwide and the wide spectrum of side effects associated with the eradication regimens resulting; therefore, there is an urgent need for more effective and less noxious treatment options. Thus, probiotics might be a promising choice in both adults and children with H. pylori infection since their role in improving the eradication rate of this infection has been proved in multiple studies. The positive effects of probiotics might be explained by their abilities to produce antimicrobial compounds and antioxidants, alter local gastric pH, and subsequently decrease H. pylori colonization and adherence to gastric epithelial cells. Nevertheless, if used alone probiotics do not considerably increase the eradication rate.
Adolescents with Higher Cognitive and Affective Domains of Physical Literacy Possess Better Physical Fitness: The Importance of Developing the Concept of Physical Literacy in High Schools
Authors: Gilic Barbara , Malovic Pavle , Sunda Mirela , Maras Nevenka , Zenic Natasa
Published: May 2022

Physical literacy (PL) is thought to facilitate engagement in physical activity, which could lead to better physical fitness (PF). The aim of this study was to examine the reliability of the Croatian version of two frequently applied PL questionnaires that evaluate knowledge and understanding, perceived competence, environment, and value for literacy, numeracy, and PL and validity regarding correlation with objectively evaluated PF in adolescents. Five hundred forty-four high school students (403 females, 141 males) from Croatia were tested on PF (standing long jump, sit-ups for 30 s, sit-and-reach test, multilevel endurance test) and two PL questionnaires. The reliability of the Croatian version of the Canadian Assessment of Physical Literacy knowledge and understanding (CAPL-2-KU) and PLAYself was good (α = 0.71–0.81 for PLAYself subscales, κ = 0.39–0.69 for CAPL-2-KU). Genders differed in the self-description dimension of PLAYself, with higher results in boys (Z = 3.72, p < 0.001). CAPL-2-KU and PLAYself total score were associated with PF in boys and girls, with PLAYself having stronger associations with PF. This research supports the idea of PL as an essential determinant for the development of PF, highlighting the necessity of the development of cognitive and affective domains of PL in physical education throughout a specifically tailored pedagogical process.
Effect of a Strategic Physical Activity Program on Cognitive Flexibility among Children with Internet Addiction: A Pilot Study
Authors: Tseng Yu-Hsien , Chao Hsiao-Han , Hung Chiao-Ling
Published: May 2022

The purpose of this study was to explore whether a strategic physical activity program can improve cognitive flexibility among children with Internet addiction. Ten school-aged children were recruited by distributing flyers at an elementary school in Taiwan. The participants were screened using the Chinese Internet Addiction Scale. Their executive functions were assessed by a task-switching paradigm and their motor competence was evaluated by the Movement Assessment Battery for Children–Second Edition (MABC-2) before and after a 12-week strategic physical activity intervention (twice per week, 90 min per session). The posttest scores showed significant improvements in accuracy in the pure, mixed, and switch trials and in the manual dexterity and total score of the MABC-2 compared with the pretest scores. Despite the inherited limitations of a single group pretest-posttest design this study employed, the findings shed light on the possibility that a strategic physical activity intervention might be a feasible and effective behavioral approach to enhance cognitive function and motor competence in children with Internet addiction. Further studies including a control group, preferably with a randomized controlled trial design, will be needed to validate the findings.
Comparative Analysis of CIBSE Admittance and ASHRAE Radiant Time Series Cooling Load Models
Authors: Hepple Ryan , Yang Siliang , Khattak Sanober , Qian Zi , Prasad Deo
Published: May 2022

Due to the impacts of carbon emissions on climate change and the expected dramatic increase in global cooling demand by 2050, it is of a paramount importance that the required energy to cool buildings is accurately predicted. This ensures that equipment is appropriately sized, which ultimately reduces energy consumption and global carbon emissions. CIBSE and ASHRAE standards are both widely adopted for cooling load predictions, but they adopt different calculation methods, with CIBSE adopting admittance and ASHRAE adopting radiant time series (RTS), which produce significantly different results in cooling load. This study comparatively and qualitatively evaluates the CIBSE admittance and ASHRAE RTS cooling load models by analysing their structures and key input parameters for a mock-up building to identify inconsistencies between the two methods. There were flaws within both models that resulted in the CIBSE method underpredicting the cooling load, whereas the ASHRAE method typically overpredicting it. This resulted in a maximal average difference of over 60%. The substantial predicted cooling load difference was mainly caused by the ASHRAE RTS model, which was highly receptive to solar gains, and it consequently led to overprediction in cooling load when compared to the CIBSE admittance model.
Wave Climate along Calabrian Coasts
Authors: Foti Giandomenico , Barbaro Giuseppe , Besio Giovanni , Barillà Giuseppina Chiara , Mancuso Pierluigi , Puntorieri Pierfabrizio
Published: May 2022

The wave climate is highly variable temporally and spatially, depending mainly on the atmospheric conditions and on fetch extensions. Wave climate is one of the main causes of coastal erosion processes, together with anthropogenic pressure and with coastal and river sedimentary balance. Therefore, a detailed spatial and temporal knowledge of wave climate is very important in managing coastal areas and in planning coastal defense works. This paper describes an analysis of the wave climate carried out along the Calabrian coasts in over 50 areas, each of them covering an average of 15 km of coastline. For each area, over 40 years of wave data were analyzed to calculate over 20 parameters, representative of annual and seasonal average and maximum wave conditions. The large number of areas is related to the geomorphological and climatic complexity of Calabria. This analysis mainly highlighted that the two Ionian and Tyrrhenian coasts are very different from the wave climate point of view. Indeed, the Ionian coast is heavier in ordinary wave conditions, while the Tyrrhenian coast is heavier in extreme wave conditions.
Impact of Bacterial Cellulose Nanocrystals-Gelatin/Cinnamon Essential Oil Emulsion Coatings on the Quality Attributes of ‘Red Delicious’ Apples
Authors: Sadat Razavi Mahsa , Golmohammadi Abdollah , Nematollahzadeh Ali , Ghanbari Alireza , Davari Mahdi , Rovera Cesare , Carullo Daniele , Farris Stefano
Published: May 2022

This study aimed to assess the effectiveness of bacterial cellulose nanocrystals (BCNCs)-gelatin (GelA)/cinnamon essential oil (CEO) emulsion coatings containing various CEO concentrations (1200, 1800, and 2400 μL/L) in retarding ripening and senescence of ‘Red Delicious’ apples during cold storage (60 days at 4 °C). Coatings decreased the weight loss (WL) (~3.6%), as compared to uncoated fruit (~4.8%). A direct relationship between CEO concentration and respiration rate/ethylene production was also disclosed. Flesh firmness was higher for coated samples, with better results detected especially when the highest amount of CEO was applied (36.48 N for the 2400 μL/L delivered dose vs. 32.60 N for the 1200 μL/L one). These findings were corroborated by additional tests on the surface color, total acidity, soluble solids content, pH, ascorbic acid, and activities of polyphenol oxidase (PPO) and peroxidase (POD). This study demonstrated the capability of BCNCs-GelA/CEO systems to dramatically enhance the storability and quality of apples during refrigerated storage, thus avoiding undesired losses and increasing the economic performance of fresh fruit industries.
Numerical Analysis of Multifunctional Biosensor with Dual-Channel Photonic Crystal Fibers Based on Localized Surface Plasmon Resonance
Authors: Lv Jingwei , Wang Famei , Hu Chunjie , Yang Lin , Fu Haihao , Zeng Yanshu , Chu Paul K. , Liu Chao
Published: May 2022

A multifunctional biosensor composed of a dual-channel photonic crystal fiber (PCF) based on localized surface plasmon resonance (LSPR) is presented to measure dynamic changes in the magnetic field, temperature, and analyte refractive index at mid-infrared wavelengths. The finite-element method (FEM) is used to model and determine the sensing properties of the sensor. The flat dual-channel surface is coated with a gold film, and two nanowires are put on the fan-shaped openings to create directional resonance coupling to detect the analyte refractive index and temperature. By utilizing that the refractive index (RI) of the filled magnetic fluid (MF) is sensitive to the external magnetic field and temperature, a sensor with multi-physical detection functions is obtained. For refractive indexes ranging from 1.47 to 1.52, the maximum sensitivity is as high as 31,000 nm/RIU, with a resolution of 3.22 × 10−6 RIU. The maximum sensitivities for the magnetic field and temperature are 1970 pm/Oe and −5500 pm/°C, respectively.
High-Temperature Oxidation Behavior of Plasma-Sprayed CoCrAlTaY-30Al2O3 Cermet Coating at 1050 °C
Authors: Zhou Zimin , Huang Wen , Xue Zhaolu
Published: May 2022

Cermet coatings with ceramic and metal characteristics will play an increasingly important role in extending the service life of critical components in harsh service environments. In this paper, CoCrAlTaY-30Al2O3 (wt.%) cermet coating was prepared by air plasma spraying technique. The effect of powder feeding rate on the microstructure and mechanical properties of the coating and its high-temperature oxidation behavior was investigated. The results showed that the CoCrAlTaY-30Al2O3 spraying powder mainly consisted of Al5Co2, α-Al2O3, Co, Cr7C3, and TaC in five phases. The microstructure of cermet coating was uniform and its porosity was relatively low. The coating was mainly composed of Al5Co2, Cr, and Al2O3 phases, and the change of powder feeding rate had no obvious effect on the phase composition of the coating. When the powder feeding rate was 32 g/min, the minimum porosity of the coating was (3.68 ± 0.86)%, and the maximum Vickers hardness and binding strength were (664.9 ± 55.9) HV0.3 and (78.6 ± 6.6) MPa, respectively. The oxidation rate constant kp1 of the coating at 1050 °C was 0.066 mg2∙cm−4∙h−1, and the fitted curve R2 value was 0.99547. In the oxidization initial stages, the alloy elements Co, Al, and Cr in the cermet coating were rapidly oxidized to form CoO, Al2O3, and Cr2O3. Then Al2O3 and Cr2O3 reacted with CoO to form Co(Al,Cr)2O4 spinel oxides. The θ-Al2O3 phase was formed after initial oxidation while the θ-Al2O3 phase was completely transformed into α-Al2O3 after 200 h. The oxide film mainly contained Co(Cr,Al)2O4, Cr2O3, and α-Al2O3 phases.
Bi-Function TiO2:Yb3+/Tm3+/Mn2+-Assisted Double-Layered Photoanodes for Improving Efficiency of Dye-Sensitized Solar Cells
Authors: Chen Di , Fu Xiang , Li Xiaolong , Qian Yannan
Published: May 2022

A bi-function TiO2:Yb3+/Tm3+/Mn2+-assisted double-layered photoanode was designed to improve the efficiency of dye-sensitized solar cells (DSSCs). The scanning electron microscopy (SEM) results show that the introduction of Mn2+ ions leads to smaller-sized TiO2:Yb3+/Tm3+/Mn2+ nanospheres, which is changed from nanosheet-shaped TiO2 and TiO2:Yb3+/Tm3+. Based on Scherrer’s formula from the X-ray diffraction (XRD) peak (101), the crystallite sizes decrease due to the introduction of Mn2+ ions. By utilizing screen-printing techniques, DSSCs fabricated by bi-function TiO2:Yb3+/Tm3+/Mn2+-assisted double-layered photoanodes exhibit the short-circuit current density (Jsc) of 15.68 mA/cm2, open-circuit voltage (Voc) of 0.67 V, fill factor (FF) of 0.71 and the power conversion efficiency (PCE) of 7.41%. The PCE of our designed DSSC is higher than that of DSSCs with a TiO2/TiO2 photoanode (6.84%), which is attributed to the bi-function effects of TiO2:Yb3+/Tm3+/Mn2+ including the conversion of NIR into visible light and improved light scattering. An increased charge transfer resistance of the photoanode/electrolyte interface indicates the suppressed charge recombination of electrons with the electrolyte redox couple (I−/I3−) in DSSCs with a TiO2/TiO2:Yb3+/Tm3+/Mn2+ double-layered photoanode, which also contributes to the enhanced performance of DSSCs. The double-layered photoanode fabricated by bi-function TiO2:Yb3+/Tm3+/Mn2+ nanospheres will provide a promising avenue for moving DSSCs forward to meet practical applications.
Detection of Superficial Defects in the Insulation Layers of Aviation Cables by Infrared Thermographic Technique
Authors: Wen Fang , Jin Jie
Published: May 2022

Superficial defects in the insulation layers of aviation cables can cause serious failures of and disasters for aircraft. Considering the critical importance of safety for aircraft, there is a need to develop a nondestructive technique to detect these kinds of defects in aviation cables. The objective of this paper is to investigate defect detection in aviation cable insulation by an infrared technique. The temperature distribution in the tested cable insulation surface under different thermal excitations and its time variation law are firstly analyzed by numerical simulation. Experimental testing is simultaneously conducted to study the influence of insulation wear defects on the temperature distribution of the cable surface. Complex background temperature distributions are eliminated in infrared images to improve the recognition of defects and extract the difference of the cable surface to draw a curve. The obtained results clearly indicate that the temperature variation interval in the curve can successfully reflect the sizes and locations of insulation defects.
Study of Al–SiO2 Aesthetic Composite Coating on Orthodontic Metal Archwire
Authors: Wu Haopeng , Yang Jie , Yan Yuwen , Zheng Bowen , Algahefi Ahmed Lotf , Ma Song , Liu Yi
Published: May 2022

Nickel–titanium orthodontic wires (NTWs) play an essential role in orthodontic treatment. However, their corrosion and aesthetic properties limit their applications. To improve the aesthetic effects of nickel–titanium orthodontic archwires, we prepared aluminium–silicon dioxide (Al–SiO2) as a biocompatible layer coated onto the NTWs. The Al–SiO2 coating was first fabricated using physical vapor deposition magnetron sputtering, and its physicochemical and biocompatibility properties were investigated. Al–SiO2 layers were well coated on the NTWs. The corrosion currents in the nickel–titanium (NiTi) control, Al–SiO2-coated NiTi experimental, stainless steel (SS) control and Al–SiO2-coated SS experimental groups were 23.72 μA cm−2, 1.21 μA cm−2, 0.22 μA cm−2 and 0.06 μA cm−2, respectively. Al–SiO2-coated NTWs with reduced corrosion current density indicated that the preparation of Al–SiO2 coating on the surface of NiTi and SS could reduce the tendency of electrochemical corrosion. The friction coefficients of orthodontic wires in the NiTi control, NiTi experimental, SS control, and SS experimental groups were 0.68, 0.46, 0.58 and 0.45, respectively. A low friction coefficient was observed in the Al–SiO2-coated NTWs, and the reduced friction coefficient improved the efficiency of orthodontics. Furthermore, the excellent biocompatibility of the NTWs and SS coated with Al–SiO2 indicates that Al–SiO2 as a novel aesthetic layer could improve the physicochemical properties of NTW and SS without causing cytotoxicity, which has considerable potential for modification of NTW and SS surfaces.
Synthesis and Electron-Beam Evaporation of Gadolinium-Doped Ceria Thin Films
Authors: Kalyk Fariza , Žalga Artūras , Vasiliauskas Andrius , Tamulevičius Tomas , Tamulevičius Sigitas , Abakevičienė Brigita
Published: May 2022

Gadolinium-doped ceria (GDC) nanopowders, prepared using the co-precipitation synthesis method, were applied as a starting material to form ceria-based thin films using the electron-beam technique. The scanning electron microscopy (SEM )analysis of the pressed ceramic pellets’ cross-sectional views showed a dense structure with no visible defects, pores, or cracks. The AC impedance spectroscopy showed an increase in the total ionic conductivity of the ceramic pellets with an increase in the concentration of Gd2O3 in GDC. The highest total ionic conductivity was obtained for Gd0.1Ce0.9O2-δ (σtotal is 11 × 10−3 S∙cm−1 at 600 °C), with activation energies of 0.85 and 0.67 eV in both the low- and high-temperature ranges, respectively. The results of the X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectrometer (ICP-OES) measurements revealed that the stoichiometry for the evaporated thin films differs, on average, by ~28% compared to the target material. The heat-treatment of the GDC thin films at 600 °C, 700 °C, 800 °C, and 900 °C for 1 h in the air had a minor effect on the surface roughness and the morphology. The results of Raman spectroscopy confirmed the improvement of the crystallinity for the corresponding thin films. The optimum heat-treating temperature for thin films does not exceed 800 °C.
Application of SiON Coatings in Sandstone Artifacts Conservation
Authors: Qin Huoliang , Wen Yaping , Liu Qiang
Published: May 2022

For a long time, a large number of sandstone cultural relics have been exposed to the outdoors, and they are facing unprecedented threats. Curing perhydropolysilazane at varied pyrolysis times results in a series of SiON solids. Fourier transform infrared absorption spectroscopy (FTIR) results show that the Si−H bond disappears at 2163 cm−1, and that the Si−O peaks at 460 cm−1, becoming stronger during the pyrolysis of Perhydropolysilazane (PHPS) to SiON solids. X-ray photoelectron spectroscopy (XPS) results indicate a decrease in the proportion of N atoms from 22.71% to 3.38% and an increase in the proportion of O atoms from 59.74% to 69.1%, indicating a gradual production of SiO2 from perhydropolysilazane. To protect the sandstone, the SiON protective layer and the commonly used protective materials—acrylic resin and polydimethylsiloxane—are applied. When compared to sandstone treated with acrylic resin B72 and polydimethylsiloxane coatings, SiON-coated sandstone effectively reduces porosity and water absorption. Ageing tests have shown that the SiON-coated sandstone is effective in resisting crystalline damage from sodium sulfate. These thenardites can change shape during formation, allowing their widespread distribution in different locations in the sandstone. The surface thenardite of the SiON-treated samples was smaller than that of the polydimethylsiloxane and acrylic resin B72-treated samples, while the untreated samples were flaky with obvious dehydration characteristics.
Levofloxacin and Amikacin Adsorption on Nanodiamonds: Mechanism and Application Prospects
Authors: Shen Tianyi , Chernysheva Maria G. , Badun Gennadii A. , Popov Andrey G. , Egorov Alexander V. , Anuchina Neli M. , Chaschin Ivan S. , Bakuleva Natalia P.
Published: May 2022

This research is focused on the adsorption modification of detonation nanodiamond surfaces with antibiotics for their further use as smart materials for cardiovascular surgery purposes, namely as bioprostheses modifiers. Tritium-labeled amikacin and levofloxacin were used as tracers for the adsorption process control. We found that nanodiamonds form adsorption complexes with levofloxacin via physical adsorption, while in the case of amikacin, electrostatic attraction contributes to the formation of more stable complexes, even in the presence of electrolytes and desorbing agents (models of biological fluids). Antimicrobial characterization of nanodiamond–levofloxacin and nanodiamond–amikacin complexes indicates a reduction in the dose of antibiotics that is used as an antimicrobial agent. Therefore, the use of biomaterial based on DND complexes with antibiotics as the basis of bioprostheses will allow one either to avoid or significantly reduce the duration and intensity of antibiotics use in the postoperative period, which is critically important from the viewpoint of the development of antibiotic resistance in pathogens.
Evaluating the Complex Relationship between Environmental Factors and Pavement Friction Based on Long-Term Pavement Performance
Authors: Rezapour Mahdi , Hafez Marwan , Ksaibati Khaled
Published: May 2022

Long-term pavement performance (LTPP) was used to investigate factors contributing to pavement skid resistance. The random effect model, with a Poisson distribution, was employed to analyze the relationship between various variables and pavement friction as a response, while accounting for the repetitive nature of panel-data observations. The results highlight a significant improvement in the model fit compared with the standard Poisson model. In this study, all pairwise interaction terms, instead of the additive impacts of various predictors, were considered. The results of this study highlight that the impacts of various predictors on pavement friction are not additive, but multiplicative. For instance, it was found that the impacts of pavement age, average annual temperature, number of lanes and annual Equivalent Single Axle Load (ESAL) on the pavement friction vary based on pavement type or on whether the pavement type is concrete or asphalt. The findings provide important information regarding the maintenance of pavement by paying the foremost attention to the pavement types for adjusting friction. This is one of the earliest studies that takes complex relations across various predictors and pavement frictions into consideration. A discussion regarding the implications of the findings is provided in the context of this study.
Polytypes of sp2-Bonded Boron Nitride
Authors: Gil Bernard , Desrat Wilfried , Rousseau Adrien , Elias Christine , Valvin Pierre , Moret Matthieu , Li Jiahan , Janzen Eli , Edgar James Howard , Cassabois Guillaume
Published: May 2022

The sp2-bonded layered compound boron nitride (BN) exists in more than a handful of different polytypes (i.e., different layer stacking sequences) with similar formation energies, which makes obtaining a pure monotype of single crystals extremely tricky. The co-existence of polytypes in a similar crystal leads to the formation of many interfaces and structural defects having a deleterious influence on the internal quantum efficiency of the light emission and on charge carrier mobility. However, despite this, lasing operation was reported at 215 nm, which has shifted interest in sp2-bonded BN from basic science laboratories to optoelectronic and electrical device applications. Here, we describe some of the known physical properties of a variety of BN polytypes and their performances for deep ultraviolet emission in the specific case of second harmonic generation of light.
Four-Coordinate Monoboron Complexes with 8-Hydroxyquinolin-5-Sulfonate: Synthesis, Crystal Structures, Theoretical Studies, and Luminescence Properties
Authors: Ruelas-Álvarez Glenda Y. , Cárdenas-Valenzuela A. Jaquelin , Galaviz-Moreno Luis L. , Cruz-Enríquez Adriana , Campos-Gaxiola José J. , Höpfl Herbert , Baldenebro-López Jesús , Vargas-Olvera Eva C. , Miranda-Soto Valentín , García Grajeda Blanca A. , Glossman-Mitnik Daniel
Published: May 2022

8-Hydroxyquinolin-5-sulfonic acid (8HQSA) was combined with 3-pyridineboronic acid (3PBA) or 4-pyridineboronic acid (4PBA) to give two zwitterionic monoboron complexes in crystalline form. The compounds were characterized by elemental analysis, single-crystal X-ray diffraction studies, and IR, 1H NMR, UV-Visible, and luminescence spectroscopy. The analyses revealed compounds with boron atoms adopting tetrahedral geometry. In the solid state, the molecular components are linked by charge-assisted (B)(O−H⋯−O(S) and N+−H⋯O(S) hydrogen bonds aside from C−H⋯O contacts and π⋯π interactions, as shown by Hirshfeld surface analyses and 2D fingerprint plots. The luminescence properties were characterized in terms of the emission behavior in solution and the solid state, showing emission in the bluish-green region in solution and large positive solvatofluorochromism, caused by intramolecular charge transfer. According to TD-DFT calculations at the M06-2X/6-31G(d) level of theory simulating an ethanol solvent environment, the emission properties are originated from π-π * and n-π * HOMO-LUMO transitions.
Demonstration of Acceptor-Like Traps at Positive Polarization Interfaces in Ga-Polar P-type (AlGaN/AlN)/GaN Superlattices
Authors: Krishna Athith , Raj Aditya , Hatui Nirupam , Keller Stacia , Mishra Umesh
Published: May 2022

The shortcomings with acceptors in p-type III-nitride semiconductors have resulted in not many efforts being presented on III-nitride based p-channel electronic devices (here, field effect transistors (FETs)). The polarization effects in III-nitride superlattices (SLs) lead to the periodic oscillation of the energy bands, exhibiting enhanced ionization of the deep acceptors (Mg in this study), and hence their use in III-nitride semiconductor-based light-emitting diodes (LEDs) and p-channel FETs is beneficial. This study experimentally demonstrates the presence of acceptor-like traps at the positive polarization interfaces acting as the primary source of holes in Ga-polar p-type uniformly doped (AlGaN/AlN)/GaN SLs with limited Mg doping. The observed concentration of holes exceeding that of the dopants incorporated into the samples during growth can be attributed to the ionization of acceptor-like traps, located at 0.8 eV above the valence band of GaN, at positive polarization interfaces. All samples were grown using the metal organic vapor phase epitaxy (MOVPE) technique, and the materials’ characterization was carried out using X-ray diffraction and Hall effect measurements. The hole concentrations experimentally measured are juxtaposed with the calculated value of hole concentrations from FETIS®, and the measured trends in mobility are explained using the amplitude of separation of the two-dimensional hole gas in the systems from the positive polarization interfaces.
Structure Tuning of Hafnium Metal–Organic Frameworks through a Mixed Solvent Approach
Authors: Ma Yanhong , Zhang Xin
Published: May 2022

The recent development of water-stable metal–organic frameworks (MOFs) has significantly broadened the application scope of this emerging type of porous material. Structure tuning of hafnium MOFs is less studied compared with zirconium MOFs. In this work, we report the synthesis of a mesoporous hafnium MOF, csq-MOF-1, through finely tuning the solvent mixture ratio. The successful synthesis of csq-MOF-1 also relies on the linker flexibility as linker bending and a symmetry decrease were observed in this framework as compared to its structural isomer NPF-300 (Hf). The mesoporous feature and permanent porosity were determined by the N2 adsorption at 77 K. Such a hierarchical pore feature is expected to enable a variety of applications through encapsulation of large functional molecules. The synthetic strategy of utilizing a mixed solvent and flexible linker is expected to inspire the development of new hafnium MOFs with diverse topological structures.
Ferroelectric Memory Based on Topological Domain Structures: A Phase Field Simulation
Authors: Huang Jing , Tan Pengfei , Wang Fang , Li Bo
Published: May 2022

The low storage density of ferroelectric thin film memory currently limits the further application of ferroelectric memory. Topologies based on controllable ferroelectric domain structures offer opportunities to develop microelectronic devices such as high-density memories. This study uses ferroelectric topology domains in a ferroelectric field-effect transistor (FeFET) structure for memory. The electrical behavior of FeFET and its flip properties under strain and electric fields are investigated using a phase-field model combined with the device equations of field-effect transistors. When the dimensionless electric field changes from −0.10 to 0.10, the memory window drops from 2.49 V to 0.6 V and the on-state current drops from 2.511 mA to 1.951 mA; the off-state current grows from 1.532 mA to 1.877 mA. External tensile stress increases the memory window and off-state current, while compressive stress decreases it. This study shows that a ferroelectric topology can be used as memory and could significantly increase the storage density of ferroelectric memory.
Demonstration of Molecular Tunneling Junctions Based on Vertically Stacked Graphene Heterostructures
Authors: Hong Seock-Hyeon , Seo Dong-Hyoup , Song Hyunwook
Published: May 2022

We demonstrate the fabrication and complete characterization of vertical molecular tunneling junctions based on graphene heterostructures, which incorporate a control series of arylalkane molecules acting as charge transport barriers. Raman spectroscopy and atomic force microscopy were employed to identify the formation of the molecular monolayer via an electrophilic diazonium reaction on a pre-patterned bottom graphene electrode. The top graphene electrode was transferred to the deposited molecular layer to form a stable electrical connection without filamentary damage. Then, we showed proof of intrinsic charge carrier transport through the arylalkane molecule in the vertical tunneling junctions by carrying out multiprobe approaches combining complementary transport characterization methods, which included length- and temperature-dependent charge transport measurements and transition voltage spectroscopy. Interpretation of all the electrical characterizations was conducted on the basis of intact statistical analysis using a total of 294 fabricated devices. Our results and analysis can provide an objective criterion to validate molecular electronic devices fabricated with graphene electrodes and establish statistically representative junction properties. Since many of the experimental test beds used to examine molecular junctions have generated large variation in the measured data, such a statistical approach is advantageous to identify the meaningful parameters with the data population and describe how the results can be used to characterize the graphene-based molecular junctions.