bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Supports on the Catalytic Activity and Coke Resistance of Ni Catalyst in Dry Reforming of Methane
Authors: Song Da Hye , Jung Un Ho , Kim Young Eun , Im Hyo Been , Lee Tae Ho , Lee Ki Bong , Koo Kee Young
Published: February 2022

The dependence of the catalytic activity and coke resistance of Ni-based catalysts on the support type was investigated in the dry reforming of methane (DRM). Catalysts were prepared using incipient wetness impregnation and analyzed using ICP-OES, BET-BJH, XRD, H2-chemisorption, H2-TPR, and CO2-TPD. DRM was performed at 600–750 °C at 144,000 mL/gcat∙h of GHSV (CH4/CO2/N2 = 1/1/1). Ni/Al2O3 and Ni/MgO catalysts formed NiAl2O4 and NiO-MgO solid solutions, respectively, owing to strong binding between the metal and support. In contrast, MgO-Al2O3 and MgAl2O4 supports suppressed NiAl2O4 and NiO-MgO solid solution formation, due to Mg addition, with high metal dispersions of 4.6 and 6.6%, respectively. In the DRM reaction, the Ni/MgO-Al2O3 and Ni/MgAl2O4 catalysts showed high CH4 conversions of 78.1 and 76.8%, respectively, compared with Ni/Al2O3 and Ni/MgO at 750 °C. A stability test was performed at 600 °C for 20 h. A coke study of the spent catalysts was performed using SEM and TGA. Alkaline-earth metal-containing catalysts Ni/MgO-Al2O3 and Ni/MgAl2O4 with strong CO2 adsorption properties showed 20 wt% reduction in carbon deposition compared to commercial catalysts. Therefore, the support and basic properties of the catalyst significantly influenced the catalyst performance and coke resistance in the DRM.
Asymptomatic Hyperuricemia Promotes Recovery from Ischemic Organ Injury by Modulating the Phenotype of Macrophages
Authors: Gnemmi Viviane , Li Qiubo , Ma Qiuyue , De Chiara Letizia , Carangelo Giulia , Li Chenyu , Molina-Van den Bosch Mireia , Romagnani Paola , Anders Hans-Joachim , Steiger Stefanie
Published: February 2022

Acute organ injury, such as acute kidney injury (AKI) and disease (AKD), are major causes of morbidity and mortality worldwide. Hyperuricemia (HU) is common in patients with impaired kidney function but the impact of asymptomatic HU on the different phases of AKI/AKD is incompletely understood. We hypothesized that asymptomatic HU would attenuate AKD because soluble, in contrast to crystalline, uric acid (sUA) can attenuate sterile inflammation. In vitro, 10 mg/dL sUA decreased reactive oxygen species and interleukin-6 production in macrophages, while enhancing fatty acid oxidation as compared with a physiological concentration of 5 mg/dL sUA or medium. In transgenic mice, asymptomatic HU of 7–10 mg/dL did not affect post-ischemic AKI/AKD but accelerated the recovery of kidney excretory function on day 14. Improved functional outcome was associated with better tubular integrity, less peritubular inflammation, and interstitial fibrosis. Mechanistic studies suggested that HU shifted macrophage polarization towards an anti-inflammatory M2-like phenotype characterized by expression of anti-oxidative and metabolic genes as compared with post-ischemic AKI-chronic kidney disease transition in mice without HU. Our data imply that asymptomatic HU acts as anti-oxidant on macrophages and tubular epithelial cells, which endorses the recovery of kidney function and structure upon AKI.
Osteochondral Lesions of the Ankle Treated with Bone Marrow Concentrate with Hyaluronan and Fibrin: A Single-Centre Study
Authors: Abas Sameera , Kuiper Jan Herman , Roberts Sally , McCarthy Helen , Williams Mike , Bing Andrew , Tins Bernhard , Makwana Nilesh
Published: February 2022

Osteochondral defects of the ankle (OCD) are being increasingly identified as a clinically significant consequence of injury to the ankle, with the potential to lead to osteoarthritis if left untreated. The aim of this retrospective cohort study was to evaluate a single-stage treatment of OCD, based on bone marrow aspirate (BMA) centrifuged to produce bone marrow concentrate (BMC). In a dual syringe, the concentrate was mixed with thrombin in one syringe, whereas hyaluronan and fibrinogen were mixed in a second syringe. The two mixtures were then injected and combined into the prepared defect. Clinical outcome and quality of life scores (MOXFQ and EQ-5D) were collected at baseline and yearly thereafter. Multilevel models were used to analyse the pattern of scores over time. Ninety-four patients were treated between 2015 and 2020. The means of each of the three components of the MOXFQ significantly improved between baseline and 1 year (p < 0.001 for each component), with no further change from year 1 to year 3. The EQ-5D index also improved significantly from baseline to 1 year, with no evidence for further change. Our results strongly indicate that this BMC treatment is safe for, and well tolerated by, patients with OCD of the ankle as both primary treatment and those who have failed primary treatment. This technique provides a safe, efficacious alternative to currently employed cartilage repair techniques, with favourable outcomes and a low complication rate at 36 months.
Upregulation of USP22 and ABCC1 during Sorafenib Treatment of Hepatocellular Carcinoma Contribute to Development of Resistance
Authors: Chang Yung-Sheng , Su Chien-Wei , Chen San-Chi , Chen Yen-Ying , Liang Yuh-Jin , Wu Jaw-Ching
Published: February 2022

Sorafenib is a small molecule that blocks tumor proliferation by targeting the activity of multi-kinases for the treatment of advanced hepatocellular carcinoma (HCC). Increasing sorafenib resistance following long-term treatment is frequently encountered. Mechanisms underlying sorafenib resistance remain not completely clear. To further understand the mechanism of sorafenib resistance in HCC, we established sorafenib-resistant cell lines by slowly increasing sorafenib concentration in cell culture medium. Upregulation of USP22 and ABCC1 were found in Sorafenib-resistant cells. Sorafenib-resistant cells treated with USP22 siRNA showed significant reduction in endogenous mRNA and protein levels of ABCC1. During sorafenib treatment, upregulation of USP22 increases ABCC1 expression and subsequently contributes to sorafenib resistance in HCC cells. Immunohistochemical analysis revealed a positive correlation between USP22 and ABCC1 expression in tissue samples from sorafenib-resistant patients (Pearson’s correlation = 0.59, p = 0.03). Our findings indicate that upregulation of USP22 and ABCC1 expression during treatment contribute to sorafenib resistance in HCC cells and that USP22 has strong potential as a therapeutic target for overcoming sorafenib resistance in HCC patients.
The Nephrotoxin Puromycin Aminonucleoside Induces Injury in Kidney Organoids Differentiated from Induced Pluripotent Stem Cells
Authors: Nguyen Lisa , Wruck Wasco , Erichsen Lars , Graffmann Nina , Adjaye James
Published: February 2022

Kidney diseases, including acute kidney injury (AKI) and chronic kidney disease (CKD), which can progress to end stage renal disease (ESRD), are a worldwide health burden. Organ transplantation or kidney dialysis are the only effective available therapeutic tools. Therefore, in vitro models of kidney diseases and the development of prospective therapeutic options are urgently needed. Within the kidney, the glomeruli are involved in blood filtration and waste excretion and are easily affected by changing cellular conditions. Puromycin aminonucleoside (PAN) is a nephrotoxin, which can be employed to induce acute glomerular damage and to model glomerular disease. For this reason, we generated kidney organoids from three iPSC lines and treated these with PAN in order to induce kidney injury. Morphological observations revealed the disruption of glomerular and tubular structures within the kidney organoids upon PAN treatment, which were confirmed by transcriptome analyses. Subsequent analyses revealed an upregulation of immune response as well as inflammatory and cell-death-related processes. We conclude that the treatment of iPSC-derived kidney organoids with PAN induces kidney injury mediated by an intertwined network of inflammation, cytoskeletal re-arrangement, DNA damage, apoptosis and cell death. Furthermore, urine-stem-cell-derived kidney organoids can be used to model kidney-associated diseases and drug discovery.
Overexpression of MET4 Leads to the Upregulation of Stress-Related Genes and Enhanced Sulfite Tolerance in Saccharomyces uvarum
Authors: Wei Zhuo , Zhang Zhiming , Zhao Wenjuan , Yin Tuo , Liu Xiaozhen , Zhang Hanyao
Published: February 2022

Saccharomyces uvarum is one of the few fermentative species that can be used in winemaking, but its weak sulfite tolerance is the main reason for its further use. Previous studies have shown that the expression of the methionine synthase gene (MET4) is upregulated in FZF1 (a gene encoding a putative zinc finger protein, which is a positive regulator of the transcription of the cytosolic sulfotransferase gene SSU1) overexpression transformant strains, but its exact function is unknown. To gain insight into the function of the MET4 gene, in this study, a MET4 overexpression vector was constructed and transformed into S. uvarum strain A9. The MET4 transformants showed a 20 mM increase in sulfite tolerance compared to the starting strain. Ninety-two differential genes were found in the transcriptome of A9-MET4 compared to the A9 strain, of which 90 were upregulated, and two were downregulated. The results of RT-qPCR analyses confirmed that the expression of the HOMoserine requiring gene (HOM3) in the sulfate assimilation pathway and some fermentation-stress-related genes were upregulated in the transformants. The overexpression of the MET4 gene resulted in a significant increase in sulfite tolerance, the upregulation of fermentation-stress-related gene expression, and significant changes in the transcriptome profile of the S. uvarum strain.
Non-Coding RNA Analyses of Seasonal Cambium Activity in Populus tomentosa
Authors: Xu Huimin , Chen Bo , Zhao Yuanyuan , Guo Yayu , Liu Guijun , Li Ruili , Zeisler-Diehl Viktoria V. , Chen Yanmei , He Xinqiang , Schreiber Lukas , Lin Jinxing
Published: February 2022

Non-coding RNA, known as long non-coding RNA (lncRNA), circular RNA (circRNA) and microRNA (miRNA), are taking part in the multiple developmental processes in plants. However, the roles of which played during the cambium activity periodicity of woody plants remain poorly understood. Here, lncRNA/circRNA-miRNA-mRNA regulatory networks of the cambium activity periodicity in Populus tomentosa was constructed, combined with morphologic observation and transcriptome profiling. Light microscopy and Periodic Acid Schiff (PAS) staining revealed that cell walls were much thicker and number of cell layers was increased during the active-dormant stage, accompanied by abundant change of polysaccharides. The novel lncRNAs and circRNAs were investigated, and we found that 2037 lncRNAs and 299 circRNAs were differentially expression during the vascular cambium period, respectively. Moreover, 1046 genes were identified as a target gene of 2037 novel lncRNAs, and 89 of which were the miRNA precursors or targets. By aligning miRNA precursors to the 7655 lncRNAs, 21 lncRNAs were identified as precursors tof 19 known miRNAs. Furthermore, the target mRNA of lncRNA/circRNA-miRNA network mainly participated in phytohormone, cell wall alteration and chlorophyll metabolism were analyzed by GO enrichment and KEGG pathway. Especially, circRNA33 and circRNA190 taking part in the phytohormone signal pathway were down-regulated during the active-dormant transition. Xyloglucan endotransglucosylase/hydrolase protein 24-like and UDP-glycosyltransferase 85A1 involved in the cell wall modification were the targets of lncRNA MSTRG.11198.1 and MSTRG.1050.1. Notably, circRNA103 and MSTRG.10851.1 regulate the cambium periodicity may interact with the miR482. These results give a new light into activity–dormancy regulation, associated with transcriptional dynamics and non-coding RNA networks of potential targets identification.
Application of Rapid Fluorescence Lifetime Imaging Microscopy (RapidFLIM) to Examine Dynamics of Nanoparticle Uptake in Live Cells
Authors: Ahmed-Cox Aria , Macmillan Alexander M. , Pandzic Elvis , Whan Renee M. , Kavallaris Maria
Published: February 2022

A key challenge in nanomedicine stems from the continued need for a systematic understanding of the delivery of nanoparticles in live cells. Complexities in delivery are often influenced by the biophysical characteristics of nanoparticles, where even subtle changes to nanoparticle designs can alter cellular uptake, transport and activity. Close examination of these processes, especially with imaging, offers important insights that can aid in future nanoparticle design or translation. Rapid fluorescence lifetime imaging microscopy (RapidFLIM) is a potentially valuable technology for examining intracellular mechanisms of nanoparticle delivery by directly correlating visual data with changes in the biological environment. To date, applications for this technology in nanoparticle research have not been explored. A PicoQuant RapidFLIM system was used together with commercial silica nanoparticles to follow particle uptake in glioblastoma cells. Importantly, RapidFLIM imaging showed significantly improved image acquisition speeds over traditional FLIM, which enabled the tracking of nanoparticle uptake into subcellular compartments. We determined mean lifetime changes and used this to delineate significant changes in nanoparticle lifetimes (>0.39 ns), which showed clustering of these tracks proximal to both extracellular and nuclear membrane boundaries. These findings demonstrate the ability of RapidFLIM to track, localize and quantify changes in single nanoparticle fluorescence lifetimes and highlight RapidFLIM as a valuable tool for multiparameter visualization and analysis of nanoparticle molecular dynamics in live cells.
Label-Free Digital Holographic Microscopy for In Vitro Cytotoxic Effect Quantification of Organic Nanoparticles
Authors: Eder Kai Moritz , Marzi Anne , Barroso Álvaro , Ketelhut Steffi , Kemper Björn , Schnekenburger Jürgen
Published: February 2022

Cytotoxicity quantification of nanoparticles is commonly performed by biochemical assays to evaluate their biocompatibility and safety. We explored quantitative phase imaging (QPI) with digital holographic microscopy (DHM) as a time-resolved in vitro assay to quantify effects caused by three different types of organic nanoparticles in development for medical use. Label-free proliferation quantification of native cell populations facilitates cytotoxicity testing in biomedical nanotechnology. Therefore, DHM quantitative phase images from measurements on nanomaterial and control agent incubated cells were acquired over 24 h, from which the temporal course of the cellular dry mass was calculated within the observed field of view. The impact of LipImage™ 815 lipidots® nanoparticles, as well as empty and cabazitaxel-loaded poly(alkyl cyanoacrylate) nanoparticles on the dry mass development of four different cell lines (RAW 264.7, NIH-3T3, NRK-52E, and RLE-6TN), was observed vs. digitonin as cytotoxicity control and cells in culture medium. The acquired QPI data were compared to a colorimetric cell viability assay (WST-8) to explore the use of the DHM assay with standard biochemical analysis methods downstream. Our results show that QPI with DHM is highly suitable to identify harmful or low-toxic nanomaterials. The presented DHM assay can be implemented with commercial microscopes. The capability for imaging of native cells and the compatibility with common 96-well plates allows high-throughput systems and future embedding into existing experimental routines for in vitro cytotoxicity assessment.
Progesterone Actions and Resistance in Gynecological Disorders
Authors: MacLean James A. , Hayashi Kanako
Published: February 2022

Estrogen and progesterone and their signaling mechanisms are tightly regulated to maintain a normal menstrual cycle and to support a successful pregnancy. The imbalance of estrogen and progesterone disrupts their complex regulatory mechanisms, leading to estrogen dominance and progesterone resistance. Gynecological diseases are heavily associated with dysregulated steroid hormones and can induce chronic pelvic pain, dysmenorrhea, dyspareunia, heavy bleeding, and infertility, which substantially impact the quality of women’s lives. Because the menstrual cycle repeatably occurs during reproductive ages with dynamic changes and remodeling of reproductive-related tissues, these alterations can accumulate and induce chronic and recurrent conditions. This review focuses on faulty progesterone signaling mechanisms and cellular responses to progesterone in endometriosis, adenomyosis, leiomyoma (uterine fibroids), polycystic ovary syndrome (PCOS), and endometrial hyperplasia. We also summarize the association with gene mutations and steroid hormone regulation in disease progression as well as current hormonal therapies and the clinical consequences of progesterone resistance.
Recent Advances in Ovarian Cancer: Therapeutic Strategies, Potential Biomarkers, and Technological Improvements
Authors: Akter Salima , Rahman Md. Ataur , Hasan Mohammad Nazmul , Akhter Hajara , Noor Priya , Islam Rokibul , Shin Yoonhwa , Rahman MD. Hasanur , Gazi Md. Shamim , Huda Md Nazmul , Nam Nguyen Minh , Chung Jinwook , Han Sunhee , Kim Bonglee , Kang Insug , Ha Joohun , Choe Wonchae , Choi Tae Gyu , Kim Sung Soo
Published: February 2022

Aggressive and recurrent gynecological cancers are associated with worse prognosis and a lack of effective therapeutic response. Ovarian cancer (OC) patients are often diagnosed in advanced stages, when drug resistance, angiogenesis, relapse, and metastasis impact survival outcomes. Currently, surgical debulking, radiotherapy, and/or chemotherapy remain the mainstream treatment modalities; however, patients suffer unwanted side effects and drug resistance in the absence of targeted therapies. Hence, it is urgent to decipher the complex disease biology and identify potential biomarkers, which could greatly contribute to making an early diagnosis or predicting the response to specific therapies. This review aims to critically discuss the current therapeutic strategies for OC, novel drug-delivery systems, and potential biomarkers in the context of genetics and molecular research. It emphasizes how the understanding of disease biology is related to the advancement of technology, enabling the exploration of novel biomarkers that may be able to provide more accurate diagnosis and prognosis, which would effectively translate into targeted therapies, ultimately improving patients’ overall survival and quality of life.
Correction: Boiten et al. Pathologically Decreased CSF Levels of Synaptic Marker NPTX2 in DLB Are Correlated with Levels of Alpha-Synuclein and VGF. Cells 2021, 10, 38
Authors: Boiten Walter A. , van Steenoven Inger , Xiao Mei-Fang , Worley Paul F. , Noli Barbara , Cocco Cristina , Ferri Gian-Luca , Lemstra Afina W. , Teunissen Charlotte E.
Published: February 2022

The authors want to notify that they have made the following changes to the author list of the paper [...]
Workup and Clinical Assessment for Allergen Immunotherapy Candidates
Authors: Pitsios Constantinos , Petalas Konstantinos , Dimitriou Anastasia , Parperis Konstantinos , Gerasimidou Kyriaki , Chliva Caterina
Published: February 2022

Allergen Immunotherapy (AIT) is a well-established, efficient, and safe way to treat respiratory and insect-venom allergies. After determining the diagnosis of the clinically relevant culprit allergen, AIT can be prescribed. However, not all patients are eligible for AIT, since some diseases/conditions represent contraindications to AIT use, as described in several guidelines. Allergists are often preoccupied on whether an extensive workup should be ordered in apparently healthy AIT candidates in order to detect contra-indicated diseases and conditions. These preoccupations often arise from clinical, ethical and legal issues. The aim of this article is to suggest an approach to the workup and assessment of the presence of any underlying diseases/conditions in patients with no case history before the start of AIT. Notably, there is a lack of published studies on the appropriate evaluation of AIT candidates, with no globally accepted guidelines. It appears that Allergists are mostly deciding based on their AIT training, as well as their clinical experience. Guidance is based mainly on experts’ opinions; the suggested preliminary workup can be divided into mandatory and optional testing. The evaluation for possible underlying neoplastic, autoimmune, and cardiovascular diseases, primary and acquired immunodeficiencies and pregnancy, might be helpful but only in subjects for whom the history and clinical examination raise suspicion of these conditions. A workup without any reasonable correlation with potential contraindications is useless. In conclusion, the evaluation of each individual candidate for possible medical conditions should be determined on a case-by-case basis.
Proteomic Changes to the Updated Discovery of Engineered Insulin and Its Analogs: Pros and Cons
Authors: Hanif Naeema , Wu Hezhou , Xu Peizhou , Li Yun , Bibi Amir , Zulfiqar Asma , Iqbal Muhammad Zafar , Tahir Muhammad , Zhang Xiangyang , Ali Asif
Published: February 2022

The destruction of β-cells of the pancreas leads to either insulin shortage or the complete absence of insulin, which in turn causes diabetes Mellitus. For treating diabetes, many trials have been conducted since the 19th century until now. In ancient times, insulin from an animal’s extract was taken to treat human beings. However, this resulted in some serious allergic reactions. Therefore, scientists and researchers have tried their best to find alternative ways for managing diabetes with progressive advancements in biotechnology. However, a lot of research trials have been conducted, and they discovered more progressed strategies and approaches to treat type I and II diabetes with satisfaction. Still, investigators are finding more appropriate ways to treat diabetes accurately. They formulated insulin analogs that mimic the naturally produced human insulin through recombinant DNA technology and devised many methods for appropriate delivery of insulin. This review will address the following questions: What is insulin preparation? How were these devised and what are the impacts (both positive and negative) of such insulin analogs against TIDM (type-I diabetes mellitus) and TIIDM (type-II diabetes mellitus)? This review article will also demonstrate approaches for the delivery of insulin analogs into the human body and some future directions for further improvement of insulin treatment.
Nickel–Titanium Rotary Instruments: Mechanical and Metallurgical Characteristics
Authors: Zanza Alessio , Reda Rodolfo , Testarelli Luca
Published: February 2022

During the last two decades, the field of the nickel–titanium (NiTi) rotary instruments has been thoroughly changed by the latest, exciting innovations in both manufacturing technologies and the knowledge of their mechanical performance [...]
Depriving Mice of Sleep also Deprives of Food
Authors: Đukanović Nina , La Spada Francesco , Emmenegger Yann , Niederhäuser Guy , Preitner Frédéric , Franken Paul
Published: February 2022

Both sleep-wake behavior and circadian rhythms are tightly coupled to energy metabolism and food intake. Altered feeding times in mice are known to entrain clock gene rhythms in the brain and liver, and sleep-deprived humans tend to eat more and gain weight. Previous observations in mice showing that sleep deprivation (SD) changes clock gene expression might thus relate to altered food intake, and not to the loss of sleep per se. Whether SD affects food intake in the mouse and how this might affect clock gene expression is, however, unknown. We therefore quantified (i) the cortical expression of the clock genes Per1, Per2, Dbp, and Cry1 in mice that had access to food or not during a 6 h SD, and (ii) food intake during baseline, SD, and recovery sleep. We found that food deprivation did not modify the SD-incurred clock gene changes in the cortex. Moreover, we discovered that although food intake during SD did not differ from the baseline, mice lost weight and increased food intake during subsequent recovery. We conclude that SD is associated with food deprivation and that the resulting energy deficit might contribute to the effects of SD that are commonly interpreted as a response to sleep loss.
Preparation and Corrosion Resistance of Ni-W-CF Composite Coating on P110 Steel
Authors: Zhang Qiuli , Feng Yi , Chen Zhaoyang , Liao Wenzhi , Zhang Shuo , Zhou Jun , Wu Lei
Published: February 2022

Metal matrix composites have become a research hotspot due to their unique properties. In this paper, Ni-W-Carbon fiber (CF) composite coating was prepared by electrodeposition method, and the effects of CF content on the microstructure, composition, and corrosion resistance of the coating were studied by means of Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDS) and electrochemical testing by changing the concentration of CF in the plating solution. The results show that when 0.4 g/L nano-CF is added, the CF content in the composite coating is the largest and the distribution is uniform; the surface roughness Ra of the composite coating reaches a minimum of 14 nm. The electrochemical results show that the composite coating electrodeposited in the electrolyte containing 0.4 g/L nano-CF has the highest corrosion resistance. The Guglielmi model can be used to describe the co-deposition behavior. This study provides useful enlightenment for the further application of Ni-W-CF coating in harsh corrosive environments.
Mechanically Enhanced Self-Stratified Acrylic/Silicone Antifouling Coatings
Authors: Xue Jingjing , Wang Li , Fan Yong , Xu Jianing , Zhao Jie , Tian Limei , Du Wenbo
Published: February 2022

Great attention has been paid to silicone-based fouling-release coatings (FRCs) in the realm of maritime antifouling due to their highly efficient and eco-friendly properties, but many challenges remain for developing a silicone-based FRC that improves its adhesion performance without reducing the antifouling property. Herein, a non-toxic silicone-based FRC has been developed by integrating acrylic resin (AR) with a silicon resin (PDMS) to spontaneously form a self-stratified AR/PDMS coating. The AR/PDMS antifouling coating still has the same fouling-release performance but improved adhesion strength (from 0.4 to 2.0 MPa) in comparison with pristine PDMS. Moreover, the antifouling coating has proven to be extremely stable in different environments (such as pH, heating, and ultraviolet exposure). The study provides a facile and convenient self-stratified strategy to develop antifouling coatings, contributing to environmentally friendly coatings in marine applications.
Critical Velocity Prediction and Characterization of Bonding Types of High-Velocity, Air-Fuel-Sprayed Titanium Coating on Aluminum Alloys
Authors: Liang Guang , Zhou Chaoji , Liu Yuxiang
Published: February 2022

This study established finite-element models via LS-DYNA software to predict the critical velocity of Ti spray particles under different collision velocities and preheating temperatures. Particle deformation, collision temperature, and bonding types of the Ti coating/Al substrate system were simulated. At the predicted critical velocity (650 m/s) and the corresponding preheating temperature (300 °C), the TC4 titanium coating was fabricated on a 6061 aluminum substrate by high-velocity air fuel (HVAF) spray. The coating’s microstructure and phase transition were analyzed by a scanning electron microscope (SEM) equipped with energy-dispersion X-ray spectroscopy (EDS) and transmission electron microscopy (TEM), revealing that critical velocity decreases with increasing particle velocity and preheating temperature. At 650 m/s, the coating was well-bonded to the matrix in metallurgical bonding type, and mechanical interlock and metallurgical bonding coexisted among particles. Experimental results show that the coating is characterized by the metallurgical bonding type, a fusion layer, and recrystallization, which verifies the simulated collision temperatures.
Electronic Structure of Graphene on the Hexagonal Boron Nitride Surface: A Density Functional Theory Study
Authors: Casiano-Jiménez Gladys , Ortega-López César , Rodríguez-Martínez Jairo Arbey , Moreno-Armenta María Guadalupe , Espitia-Rico Miguel J.
Published: February 2022

Poor electron-related cutting current in graphene-based field-effect transistors (FETs) can be solved by placing a graphene layer over a hexagonal boron nitride (BN) substrate, as established by Giovannetti et al. and other researchers. In order to produce high-quality results, this investigation uses 2 × 2 cells (~2.27% mismatch), given that larger cells lead to more favourable considerations regarding interactions on cell edges. In this case, the substrate-induced band gap is close to 138 meV. In addition, we propose a new material based on graphene on BN in order to take advantage of the wonderful physical properties of both graphene and BN. In this new material, graphene is rotated with respect to BN, and it exhibits a better mismatch, only ~1.34%, than the 1 × 1-graphene/1 × 1-BN; furthermore, it has a very small bandgap, which is almost zero. Therefore, in the bands, there are electronic states in cone form that are like the Dirac cones, which maintain the same characteristics as isolated graphene. In the first case (2 × 2-graphene/2 × 2-BN), for example, the resulting band gap of 138 meV is greater than Giovannetti’s value by a factor of ~2.6. The 2 × 2-graphene/2 × 2-BN cell is better than the 1 × 1-graphene/BN one because a greater bandgap is an improvement in the cutting current of graphene-based FETs, since the barrier created by the bandgap is larger. The calculations in this investigation are performed within the density functional theory (DFT) theory framework, by using 2 × 2-graphene/2 × 2-BN and 13 × 13-graphene/23 × 23-(0001) BN cells. Pseudopotentials and the generalized gradient approximation (GGA), combined with the Perdew–Burke–Ernzerhof parametrization, were used. Relaxation is allowed for all atoms, except for the last layer of the BN substrate, which serves as a reference for all movements and simulates the bulk BN.
Evaluation of Zirconia and High Performance Polymer Abutment Surface Roughness and Stress Concentration for Implant-Supported Fixed Dental Prostheses
Authors: Lo Giudice Roberto , Sindoni Alessandro , Tribst João Paulo Mendes , Dal Piva Amanda Maria de Oliveira , Lo Giudice Giuseppe , Bellezza Ugo , Lo Giudice Giorgio , Famà Fausto
Published: February 2022

Background: The High Performance Polymer is a based polymer biomaterial that was introduced as dental material to manufacture dentures superstructure and dental implants abutments. However, its surface characteristics and stress state still need to be properly described. The aim of this study was to compare the surface characteristics of a High Performance Polymer (Bio-HPP, Bredent, Senden, Germany) for computer-aided design and computer-aided manufacturing (CAD/CAM) milling and a Zirconia (Zirkonzahn, Steger, Ahrntal, Italy). Methods: The abutments surface roughness (Ra) was evaluated for each abutment material (N = 12) using a confocal laser microscope. Data were evaluated using One-Way ANOVA and Tukey tests (p < 0.05). In addition, a finite element analysis software was used to present stress measurement data as stress maps with 100 N loading. Results were generated according to Von-mises stress criteria and stress peaks were recorded from each structure. Results: Results showed a mean Ra of 0.221 ± 0.09 μm for Bio-HPP and 1.075 ± 0.24 μm for Zirconia. Both surface profiles presented a smooth characteristic regardless the measurement axis. The stress peaks from implant fixture and screw were not affected by the abutment material, however the high performance polymer showed the highest stress magnitude for the abutment region. Conclusions: Comparing the present results with the literature it is suggested that the CAD/CAM High Performance Polymer abutments present an adequate surface roughness with acceptable values of stress.
SEM-EDX Analysis of Metal Particles Deposition from Surgical Burs after Implant Guided Surgery Procedures
Authors: Falisi Giovanni , Foffo Giordano , Severino Marco , Di Paolo Carlo , Bianchi Serena , Bernardi Sara , Pietropaoli Davide , Rastelli Sofia , Gatto Roberto , Botticelli Gianluca
Published: February 2022

The preparation of the implant site in guided surgery procedure takes place without irrigation, which could lead to increased friction of the drills with the formation and release of debris or metal particles. The presence of metal particles in the peri-implant tissue could represent a trigger for macrophage activity, bone resorption processes, and consequent implant loss. According to the guided surgical protocol, the study aimed to evaluate the presence of metal particles deposited during implant site preparation. Twenty-five adult porcine ribs from the same adult individual were chosen due to their trabecular bone structure, similar to facial bones. The samples were all 8 cm (length) × 3 cm (depth) × 2 cm (width) and were further subdivided to obtain 50 elements of 4 cm × 3 cm × 2 cm. Plexiglass was used to create structures such as surgical guides so that their function could be mimicked, and the guided implant site preparation sequence could be performed with them. The drill kit used in this study is a guided surgery drill kit characterized by high wear resistance, high yield strength, and good corrosion resistance. This same kit was used 50 times in this way to prepare 50 different implant sites and evaluated at different edges and number of preparation (T0-neutral edge, T1-1 full preparation, T2-10, T3-20, T4-30, T5-40, and T6-50) by SEM-EDX to assess the presence of any metal deposition. The presence of metal residues in the implant site increased according to the cycles of use of the drills. We have observed that in the first three groups, there is no presence of metals. This is evident in groups T3 and T4. Finally, the presence of metal residues becomes significant in the study’s last two groups of samples. The study highlighted how the lack of irrigation in the work site leads the deposition of metal particles and in addition to a reduction in the efficiency of the drills, resulting in less precise cutting, altering the shape of the prepared site, and, lastly, reducing the primary stability of the implants.
Experimental Study and Performance Characterization of Semi-Flexible Pavements
Authors: Li Guosheng , Xiong Huan , Ren Qi , Zheng Xiaoguang , Wu Libao
Published: February 2022

Semi-flexible pavement (SFP) is made up of a porous skeleton of asphalt mixture and cement grout. This special structure granted SFP superior strength and durability and made it a promising solution for the paving of heavy trafficked area. This paper performed in-depth study on the mechanistic behavior of SFP. Firstly, the volumetric mix design of SFP was introduced, and followed with strength, moisture susceptibility, viscoelastic behavior, fatigue life as well as rutting resistance through a series of laboratory tests. Marshall stability tests and dynamic stability tests suggested that SFP gained fair strength and rutting resistance from the curing of cement grout. Meanwhile, SFP was found not sensitive to freeze–thaw cycles through indirect tensile tests. In dynamic modulus tests, SFP exhibited significant viscoelastic behaviors. In four-point beam fatigue tests, the average fatigue lives of SFP reached 85.4 k loading repetition under 400 µε level. In Hamburg wheel tracking tests, the ultimate rutting depth of SFP was smaller than 2.5 mm. The viscoelastic behavior and rutting propagation of SFP was characterized with master curve and power function by fitting the test results. SFP was also compared with traditional asphalt mixtures in MMLS3 accelerated tests and its performance turned out to be prevailing.
Physicochemical and Morphological Properties of Hybrid Films Containing Silver-Based Silica Materials Deposited on Glass Substrates
Authors: Purcar Violeta , Rădiţoiu Valentin , Raduly Florentina Monica , Rădițoiu Alina , Anastasescu Mihai , Popa Monica , Căprărescu Simona , Şomoghi Raluca , Constantin Mariana , Firincă Cristina , Ispas Georgiana Cornelia
Published: February 2022

The main goal of this study was to present a facile and inexpensive approach for the preparation of hybrid coatings by the deposition under ambient air conditions of silver-based silica materials on glass substrates, which can be used to improve solar cells’ performance. The silica materials containing silver nanoparticles (AgNPs) were synthesized by the hydrolytic condensation of tetraethylorthosilicate (TEOS), triethoxymethylsilane (MTES), and trimethoxyhexadecylsilane (HDTMES), under acidic conditions, at room temperature (25 ± 2 °C). The silver nitrate solution (AgNO3, 0.1 wt. %) was used as a source of Ag+ ions. The final samples were investigated through Fourier Transform Infrared Spectroscopy–Attenuated Total Reflectance (FTIR–ATR), Transmission Electron Microscopy equipped with energy dispersive X–ray (TEM–EDX), UV–Vis spectroscopy, Atomic Force Microscopy (AFM), and Raman Spectroscopy (RS). The TEM images confirmed the formation of AgNPs and were found to be around 3 nm. It was observed that AgNPs were embedded in the silica matrix. EDX also confirmed the presence of the resulting AgNPs within the silica material. AFM images demonstrated that the morphology of the hybrid films’ surfaces can be changed as a function of sol–gel composition. RS analysis indicated that silanol groups were significantly present on the silver-based silica film surface. The UV–Vis spectra revealed that the hybrid coatings presented a reflectance of ~8%, at 550 nm. This study will enhance the value of nanocoating technology in optoelectronics, particularly in the development of nanostructures that improve the performance in thin-film solar cells.
Wear Properties of Iron-Based Alloy Coatings Prepared by Plasma Transfer Arc Cladding
Authors: Chen Baiyang , Gao Peihu , Zhang Bo , Zhao Daming , Wang Wei , Jin Can , Yang Zhong , Guo Yongchun , Liang Minxian , Li Jianping , Lu Yongqing , Jia Lu , Zhao Dan
Published: February 2022

Plasma transfer arc cladding technology has been widely utilized in surface engineering, repairing and remanufacturing. In the present work, multiple cladded thick claddings were prepared on compacted graphite cast iron (CGI) substrates with iron-based powders through plasma transfer arc cladding technology using different plasma arc currents to improve the surface wear resistance. The coatings’ phase and microstructure were analysed through XRD, SEM and EDS. The coatings’ microhardness and wear resistance were characterized. There were pearlite, graphite, austenite and secondary carbides in the iron-based alloy coatings. Due to the heat influence during the multiple cladding process, a spheroidal graphite transition zone appeared between the substrate and the coating. The microhardness of the claddings varied from 363 to 402 HV as the plasma arc current was changed from 45 to 60 A. With the increase of plasma arc current, the cladding’s microhardness increased. The iron-based coating’s minimum friction coefficient and wear mass loss were about 0.48 and 4.2 mg, respectively, when the plasma arc current was 60 A, which are lower values than those of the compacted graphite iron substrate with the friction coefficient and wear mass loss of 0.55 and 8.2 mg. Compared with the substrate, the iron-based alloy claddings achieved the effect of reducing friction and wear resistance simultaneously, which resulted from the self-lubricating effect of graphite and high wear-resistance of carbides in the claddings. The iron-based coatings had a similar abrasive wear mechanism to the CGI, which should be helpful to repair or remanufacture CGI workpieces.
Mineralogy and Geochemistry of “Laoshan Jade” from Shandong Province, China: Implications for Petrogenesis
Authors: Yu Xiaomin , Liu Yingxin , Cao Chuqi
Published: February 2022

“Laoshan Jade” is located in the Yangkou area of the Sulu UHP metamorphic belt. This is the first time a systematic research study is performed on its conventional gemological characteristics, mineral compositions, geochemical characteristics, and petrogenesis using a polarized light microscope, an electron probe microanalyzer (EMPA), an X-ray fluorescence spectrometer (XRF), and a Raman spectrometer. The gemological characteristics of “Laoshan Jade” are consistent with serpentine jade. It can be named serpentinite, mainly composed of serpentine (antigorite), chlorite (clinochlore), and magnetite. Some samples contain magnesite and chromite. Only small amounts of unaltered forsterite, chrysolite, and diopside can be found in poor-quality serpentine jade. The protolith of “Laoshan Jade” is metamorphic peridotite. Antigorite is altered from olivine. Clinochlorite is altered from the diopside. Disseminated magnetite is the metamorphic product. Unaltered olivine and diopside belong to protolith. Chromite with zonal texture also belongs to protolith. The average temperature and pressure of its core are calculated to be 1348 °C and 3.1 GPa, which indicates that the protolith comes from the mantle asthenosphere. The formation temperature of its edge is lower than 500 °C, with metamorphic origin. XRF experiments show that “Laoshan Jade” samples are relatively rich in Mg and more depleted in fusible elements (Al, Ca) than the original mantle peridotite, indicating that serpentinite protolith has undergone a certain degree of partial melting. Combined with EPMA results, the findings of this study reveal that protolith belongs to the depleted mantle peridotite in the subduction zone, partially melted in the mantle wedge, and reacted with subduction zone fluid. Pyroxene is altered into chlorite, olivine is altered into serpentine, and magnet is generated. The edge of chromite in the protolith is altered by the iron-rich fluid into magnetite. Finally, serpentinite is formed.
Effect of Flux Rate Variation at Fixed V/III Ratio on Semi-Polar (112¯2) GaN: Crystal Quality and Surface Morphology Study
Authors: Ooi Chong Seng , Shuhaimi Ahmad , Tan Gary , Al-Zuhairi Omar , Abd Majid Wan Haliza
Published: February 2022

We report on the crystal improvement of semi-polar (112¯2) gallium nitride epitaxy layer on m-plane (101¯0) sapphire substrate by changing the flux rate at a fixed V/III ratio. The high-resolution X-ray diffraction (HR-XRD) analysis showed that lower flux rate enhanced the crystal quality of GaN epitaxy with the lowest FWHM values of 394 and 1173 arc seconds at [11¯23] and [11¯00] planes, respectively. In addition, Raman spectroscopy showed that flux rate did not affect the stress state of the GaN crystal. However, atomic force microscopy (AFM) micrograph depicted an anomalous trend where the lowest flux rate produces roughest surface with RMS roughness of 40.41 nm. Further analysis of AFM results on the undulation period length along [11¯23] and [11¯00] directions is carried out. It shows that as the growth rate decreases, the average undulation period along [11¯23] and [11¯00] directions increases from 2.59 µm and 1.90 µm to 3.52 µm and 3.52 µm, respectively. The mechanism for the surface roughening at the lower flux rate is then explained by using the adatom surface diffusion relation L ~ Dτ.
Preparation of NbAs Single Crystal by the Seed Growth Process
Authors: Sun Yinchang , Zhao Bojin , Huo Zongju , Liu Hongjun , Xu Yongkuan , Hu Zhanggui , Qiu Hailong
Published: February 2022

A Weyl semimetal is a novel crystal with low-energy electronic excitations that behave as Weyl fermions. It has received worldwide interest and was believed to have introduced the next era of condensed matter physics after graphene and three-dimensional topological insulators. However, it is not easy to obtain a single large-sized crystal because there are many nucleations in the preparation process. A bottom-seed CVT growth method is proposed in this paper, and we acquired the large-sized, high-quality NbAs single crystals up to 4 × 3 × 3 mm3 finally. X-ray diffraction and STEM confirmed that they are tetragonal NbAs, which the key is to using the seed crystal in a vertical growth furnace. Notably, the photoelectric properties of the crystal are obtained under the existing conditions, which paves the way for follow-up work.
Human-Wildlife Conflict at a Suburban–Wildlands Interface: Effects of Short- and Long-Distance Translocations on Red Diamond Rattlesnake (Crotalus ruber) Activity and Survival
Authors: Corbit Aaron G. , Hayes William K.
Published: February 2022

The mitigation of human-rattlesnake conflicts often involves euthanizing or translocating the offending rattlesnake. Although translocation is generally considered more humane, especially by the general public, it may negatively impact the translocated individual and may not be effective if that individual returns to areas where the probability of human conflict is high. We used radiotelemetry to experimentally study the effects of short- (SDT) and long-distance translocation (LDT; beyond the typical home range or activity range) on adult Red Diamond Rattlesnakes (Crotalus ruber) near a residential development in Southern California. Though the results were mixed, some analyses suggested that higher numbers of SDTs were associated with larger activity areas and increased movement. For snakes undergoing LDT, the activity areas and mean daily movement distances were 1.8–4.6 times larger than those of non-LDT snakes in the year of translocation, but were similar in the following year. Cox regression models revealed that, for both LDT and non-LDT snakes, every 1 m increase in the distance moved resulted in a 1.2% decreased risk of moving back into a human-modified area and a 1.6% decreased risk of returning to the original site of conflict. We failed to detect an effect of either LDT or SDT on body mass change or survival. Our findings suggest that LDT of nuisance snakes may be a viable option for at least some rattlesnake populations or species, especially those in which individuals do not require communal overwintering sites.
Associating Automated Breast Ultrasound (ABUS) and Digital Breast Tomosynthesis (DBT) with Full-Field Digital Mammography (FFDM) in Clinical Practice in Cases of Women with Dense Breast Tissue
Authors: Boca (Bene) Ioana , Ciurea Anca Ileana , Vesa Ștefan Cristian , Ciortea Cristiana Augusta , Dudea Sorin Marian , Manole Simona
Published: February 2022

The purpose of the present study was to evaluate the value of full-field digital mammography (FFDM) and automated breast ultrasound (ABUS) in the diagnosis of breast cancer compared to FFDM associated with digital breast tomosynthesis (DBT). Methods: This retrospective study included 50 female patients with a denser framework of connective tissue fibers, characteristic of young women who underwent FFDM, DBT, handheld ultrasound (HHUS), and ABUS between January 2017 and October 2018. The sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and accuracy of FFDM+ABUS were 81.82% (95% CI [48.22–97.72]), 89.74% (95% CI [75.78–97.13]), 69.23% (95% CI [46.05–85.57]), 94.59% (95% CI [83.26–98.40]), and 88% (95% CI [75.69–95.47]), while for FFDM+DBT, the values were as follows: 91.67% (95% CI [61.52–99.79]), 71.79% (95% CI [55.13–85.00]), 50% (95% CI [37.08–62.92]), 96.55% (95% CI [80.93–99.46]), 76.47% (95% CI [62.51–87.21]). We found an almost perfect agreement between the two readers regarding FFDM associated with ABUS, and substantial agreement regarding FFDM+DBT, with a kappa coefficient of 0.896 and 0.8, respectively; p < 0.001. Conclusions: ABUS and DBT are suitable as additional diagnostic imaging techniques to FFDM in women at an intermediate risk of developing breast cancer through the presence of dense breast tissue. In this study, DBT reduced the number of false negative results, while the use of ABUS resulted in an increase in specificity.