bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbiomic Analysis of Bacteria Associated with Rock Tripe Lichens in Continental and Maritime Antarctic Regions
Authors: He Zichen , Naganuma Takeshi , Nakai Ryosuke , Imura Satoshi , Tsujimoto Megumu , Convey Peter
Published: August 2022

Increased research attention is being given to bacterial diversity associated with lichens. Rock tripe lichens (Umbilicariaceae) were collected from two distinct Antarctic biological regions, the continental region near the Japanese Antarctic station (Syowa Station) and the maritime Antarctic South Orkney Islands (Signy Island), in order to compare their bacterial floras and potential metabolism. Bulk DNA extracted from the lichen samples was used to amplify the 18S rRNA gene and the V3-V4 region of the 16S rRNA gene, whose amplicons were Sanger- and MiSeq-sequenced, respectively. The fungal and algal partners represented members of the ascomycete genus Umbilicaria and the green algal genus Trebouxia, based on 18S rRNA gene sequences. The V3-V4 sequences were grouped into operational taxonomic units (OTUs), which were assigned to eight bacterial phyla, Acidobacteriota, Actinomyceota, Armatimonadota, Bacteroidota, Cyanobacteria, Deinococcota, Pseudomonadota and the candidate phylum Saccharibacteria (also known as TM7), commonly present in all samples. The OTU floras of the two biological regions were clearly distinct, with regional biomarker genera, such as Mucilaginibacter and Gluconacetobacter, respectively. The OTU-based metabolism analysis predicted higher membrane transport activities in the maritime Antarctic OTUs, probably influenced by the sampling area’s warmer maritime climatic setting.
Enhanced N-Type Bismuth-Telluride-Based Thermoelectric Fibers via Thermal Drawing and Bridgman Annealing
Authors: Sun Min , Zhang Pengyu , Li Qingmin , Tang Guowu , Zhang Ting , Chen Dongdan , Qian Qi
Published: August 2022

N-type bismuth telluride (Bi2Te3) based thermoelectric (TE) fibers were fabricated by thermal drawing and Bridgman annealing, and the influence of Bridgman annealing on the TE properties of n-type Bi2Te3-based TE fibers was studied. The Bridgman annealing enhanced the electrical conductivity and Seebeck coefficient because of increasing crystalline orientation and decreasing detrimental elemental enrichment. The TE performance of n-type Bi2Te3-based TE fibers was improved significantly by enhancing the power factor. Hence the power factor increased from 0.14 to 0.93 mW/mK2, and the figure-of-merit value is from 0.11 to 0.43 at ~300 K, respectively.
Implant—Abutment Misfit after Cyclic Loading: An In Vitro Experimental Study
Authors: de Vasconcelos John Eversong Lucena , de Matos Jefferson David Melo , Queiroz Daher Antonio , Lopes Guilherme da Rocha Scalzer , de Lacerda Bruna Caroline Gonçalves Vasconcelos , Bottino Marco Antonio , Turssi Cecilia Pedroso , Basting Roberta Tarkany , do Amaral Flávia Lucisano Botelho , França Fabiana Mantovani Gomes
Published: August 2022

This study aimed to evaluate the influence of thermomechanical cycling (TMC) and type of abutment on the misfit and compressive strength of the implant–abutment interface. Forty 3.75-mm external hexagon implants with 25° angled abutments were divided into four groups (N = 10). Group A: overcast plus TMC; Group B: overcast without TMC; Group C: completely cast plus TMC; Group D: completely cast without TMC. Abutments were fixed to the implants with 32-Ncm torque, and groups A and C specimens were cyclically loaded at 80 N with 2 Hz for 1 million cycles. The misfit on the implant–abutment interface was evaluated by optical microscope (100×) and the compressive strength test was performed in a universal test machine. For statistical analysis, a two-way ANOVA and post hoc Tukey test were used. There was no difference in misfit presented by all the abutments in the absence of TMC (p > 0.05). When TMC was performed, the completely cast abutments showed greater misfit than overcast ones (p = 0.001). Regarding compressive strength, irrespective of TMC performed, the overcast abutments showed higher compressive strength values than completely cast abutments (p = 0.003). Moreover, disregarding the type of abutment used, the absence of TMC provided higher compressive strength values (p < 0.001). It was concluded that thermomechanical cyclic loading aggravated the misfit, especially in completely cast abutments, regardless of material or fabrication technique, and reduced the compressive strength of the two types of abutments tested.
Effect of Non-Thermal Plasma Treatment of Contaminated Zirconia Surface on Porphyromonas gingivalis Adhesion and Osteoblast Viability
Authors: Lee Seon-Ki , Ji Min-Kyung , Jo Yu-Jin , Park Chan , Cho Hoonsung , Lim Hyun-Pil
Published: August 2022

Plasma treatment on a zirconia surface prevents bacterial contamination and maintains osteoblast activity. To assess the degree of adhesion of Porphyromonas gingivalis on a zirconia surface after non-thermal plasma (NTP) treatment, specimens were treated with plasma for 60, 300, and 600 s, after which P. gingivalis was inoculated onto the surface and incubated for 48 h. To assess osteoblast activity after NTP treatment, osteoblasts (MC3T3-E1) were dispensed onto the specimens contaminated with P. gingivalis immediately after NTP for 60 and 120 s, followed by incubation for 48, 72, and 96 h. P. gingivalis was cultured after 60 s of NTP treatment of zirconia. The NTP and control groups showed no significant difference (p = 0.91), but adhesion was significantly increased following NTP treatment for 300 s or longer (300, 600 s groups) (p < 0.05). After NTP treatment of P. gingivalis-contaminated zirconia, osteoblast activity significantly increased at 72 and 96 h (I60 and I120 s group) in the groups treated with plasma (p < 0.017). Application of NTP to dental zirconia implants for 60 s not only inhibits the proliferation of P. gingivalis, which causes peri-implantitis but also increases osseointegration on zirconia surfaces contaminated with P. gingivalis.
Research Progress in Interfacial Characteristics and Strengthening Mechanisms of Rare Earth Metal Oxide-Reinforced Copper Matrix Composites
Authors: Fu Xuemin , Jiang Jiaxin , Jiang Xiaosong
Published: August 2022

The existence of a small amount of rare earth metal oxides (REMOs) can greatly affect the structure and function of copper matrix composites owing to improvement of surface and interface properties between REMOs and metal matrix, and there are still some challenges concerning interfaces and complex interfacial reactions. This review summarizes the interfacial characteristics and strengthening mechanisms of REMO-reinforced copper matrix composites, including fabrication methods for solving rare earth metal oxide-dispersion problems and characterization of the microstructure and properties of REMO-reinforced copper matrix composites. In particular, the strengthening effects of various rare earth metal oxide-reinforced copper matrix composites are systematically summarized. The interface characteristics of composites from a thermodynamics standpoint and the strengthening mechanism are emphatically investigated and discussed in order to help unveil design principles and to provide reference for future research of REMO-reinforced copper matrix composites.
Bionic Synthesis of Mussel-like Adhesive L-DMA and Its Effects on Asphalt Properties
Authors: Wu Jinyi , Liu Quantao , Wu Shaopeng
Published: August 2022

Cracks are inevitable during the service life of asphalt pavement and the water at the fracture surfaces tends to cause the grouting materials to fail. Studies have shown that the catechol groups in adhesion proteins secreted by mussels can produce strong adhesion performance in the water. In this paper, the mussel-like adhesive L-Dopa Methacrylic anhydride (L-DMA) was prepared based on the concept of bionic design and used to improve the properties of asphalt. By using Fourier-transform infrared spectroscopy (FTIR) and Thermogravimetric analysis (TGA), the thermal stability and structural composition of L-DMA were investigated. Then, the rheological and low-temperature properties of L-DMA-modified asphalt were investigated using the dynamic shear rheological (DSR) test and bending beam rheological (BBR) test. Moreover, the modification mechanism was explored by FTIR. It was found that L-DMA can be effectively synthesized and has good thermal stability. The incorporation of L-DMA increases the composite modulus, viscosity, creep recovery rate and rutting factor of asphalt binder, resulting in an enhancement of its high-temperature performance. At a high L-DMA content of 10%, the low-temperature performance of the modified asphalt was enhanced. The modification of L-DMA to asphalt is mainly a physical process. Hydrogen bonds and conjugated systems generated by the introduction of catechol groups enhance the adhesion properties of asphalt. In general, L-DMA improves the properties of asphalt and theoretically can improve the water resistance of asphalt, which will be explored in future research.
Analyzing the Mechanism of Zinc Oxide Nanowires Bending and Bundling Induced by Electron Beam under Scanning Electron Microscope Using Numerical and Simulation Analysis
Authors: ElZein Basma , Elrashidi Ali , Dogheche Elhadj , Jabbour Ghassan
Published: August 2022

The bending effect of self-catalyst zinc oxide nanowires on a photoconducting behavior has been investigated by in-situ scanning electron microscope method and interpreted by analytical modeling. Zinc oxide NWs tend to incline due to geometric instability and because of the piezoelectric properties, which was confirmed by scanning electron microscope images. A cantilever bending model adequately describes the bending and bundling events, which are linked to the electrostatic interaction between nanowires. The light absorption of zinc oxide nanowires in the visible and near infrared bands has been modelled using the finite difference time domain method. The influence of the density of nanowires (25%, 50%, 75%) and the integration of plasmonic nanoparticles distributed on the seed layer (with varied radii) on the light absorption of zinc oxide nanowires was studied using simulation analysis. We have shown that the geometry of zinc oxide nanowires in terms of length, separation distance, and surface charge density affects the process of zinc oxide nanowires bending and bundling and that absorption will be maximized by integrating Au plasmonic nanoparticles with a radius of 10 nm.
Superhydrophobic Anticorrosive Phosphonate–Siloxane Films Formed on Zinc with Different Surface Morphology
Authors: Redkina Galina V. , Sergienko Alexandra S. , Kuznetsov Yurii I. , Grafov Oleg Yu.
Published: August 2022

The composition, structure, and protective and hydrophobic properties of nanoscale films formed layer-by-layer in solutions of sodium dodecylphosphonate (SDDP) and vinyltrimethoxysilane or n-octyltriethoxysilane (OTES) on the zinc surface with different morphologies were studied by SEM, XPS, water contact angle measurements, and electrochemical and corrosion tests. The protective, hydrophobic properties of phosphonate–siloxane films on zinc and their stability in a corrosive media are determined both by the initial surface morphology and composition of the surface oxide layer, and by the nature of inhibitors. It was shown that preliminary laser texturing of the zinc surface is preferable than chemical etching to enhance the anticorrosive properties of the resulting thin films. The most stable films with excellent superhydrophobic and protective properties in atmospheres of high humidity and salt spray are formed on the zinc surface with fractal morphology during layer-by-layer passivation with SDDP and OTES.
A High Sensitivity Custom-Built Vibrating Sample Magnetometer
Authors: Phillips Jared Paul , Yazdani Saeed , Highland Wyatt , Cheng Ruihua
Published: August 2022

This work details the construction and optimization of a fully automated, custom-built, remote controlled vibrating sample magnetometer for use in spintronics related research and teaching. Following calibration by a standard 6 mm diameter Ni disc sample with known magnetic moment, hysteresis measurements of Nd-Fe-B thin films acquired by this built vibrating sample magnetometer were compared to the data taken using a commercial superconducting quantum interference device and showed very similar results. In plane and out of plane magnetic hysteresis data acquired for 25 nm Fe thin films are also presented. The developed vibrating sample magnetometer is able to achieve a sensitivity approaching 1 × 10−5 emu. Further alterations to the design that may improve beyond this limit are also discussed.
Comparative Evaluation of Gingival Crevicular Fluid Interleukin-17, 18 and 21 in Different Stages of Periodontal Health and Disease
Authors: Nair Vineet , Grover Vishakha , Arora Suraj , Das Gotam , Ahmad Irfan , Ohri Anchal , Sainudeen Shan , Saluja Priyanka , Saha Arindam
Published: August 2022

Background and Objectives: The elicitation of a host’s immune–inflammatory responses to overcome oral bacterial biofilm challenges is mediated by numerous cytokines. We explored the role of three such cytokines, viz. interleukin (IL)-17, 18 and 21, by measuring their levels in the gingival crevicular fluid (GCF) of Indian individuals with healthy gingiva, chronic gingivitis, or chronic periodontitis. Materials and Method: Ninety systemically healthy individuals were enrolled in the study on the basis of predefined criteria and were categorized into three groups of 30 participants each. Groups A, B and C were composed of a control group with healthy gingiva, subjects with chronic gingivitis and subjects with chronic periodontitis, respectively. The periodontal disease status was assessed on the basis of a subject’s gingival index, probing pocket depth, clinical attachment loss and radiographic evidence of bone loss. After the complete history-taking and identification of gingival sulcus/pocket depth areas for GCF collection, a sample was collected from each subject in all groups for an estimation of the cytokine levels using ELISA. Statistical analysis was performed using SPSS v 21.0. Intergroup comparisons were conducted using a post hoc Tukey’s test. A value of p < 0.05 was considered to be statistically significant. Results: The mean IL-17, 18 and 21 concentrations in pg/mL was the greatest for Group C (99.67 ± 18.85, 144.61 ± 20.83 and 69.67 ± 12.46, respectively), followed by Group B (19.27 ± 2.78, 22.27 ± 2.43 and 22.74 ± 1.43, respectively) and finally by Group A (healthy control; 11.56 ± 0.99, 17.94 ± 1.24 and 12.83 ± 1.21 respectively). A statistically significant difference in the mean concentrations of two interleukins (IL-17 and IL-18) was observed between Groups A and C and also between Groups B and C. A statistically significant difference in the mean concentrations of IL-21 was observed between Groups B and C. Conclusions: Within the limitations of the present study, the findings revealed that the GCF levels of IL-17, IL-18 and IL-21 rose and correlated well with the severity of the disease. Thus, these cytokines present in GCF have the potential to be considered as biomarkers for periodontal tissue destruction. IL-21 in particular appears to be a promising biomarker for differentiating between gingivitis and periodontitis.
Soft Skills Are Hard Skills—A Historical Perspective
Authors: Iorio Silvia , Cilione Marco , Martini Mariano , Tofani Marco , Gazzaniga Valentina
Published: August 2022

The increasingly swift changes in the field of medicine require a reassessment of the skills necessary for the training of technically qualified doctors. Today’s physicians also need to be capable of managing the complex issue of personal relationships with patients. Recent pedagogical debates have focused on so-called “soft skills”, whose acquisition is presented in literature as a quite recent addition to medical studies. Moreover, the historical investigation of deontological texts dating from the mid-nineteenth century back to the Hippocratic Oath shows that medicine has always discussed the need to integrate technical expertise in medicine with specific personal and relationship-based skills. Debates have often circled around whether these “soft skills” could actually be taught or how they could be successfully transmitted to training physicians. The belief that defining medicine is more complex than defining other similar sciences and that the instruments to be used in the relationship with patients cannot be limited to those provided by technical aspects shows a new awareness. Today, this view is often stated as an innovative realization on the part of doctors with regard to the complexity of training and action in a delicate area in which they are entrusted with the management of the balance of the system that is the human body.
Prevention of Shivering Post Subarachnoid Block: Comparison between Different Doses of Intravenous Magnesium Sulphate
Authors: Low Ren Geng , Izaham Azarinah , Zain Jaafar Md , Nor Nadia Md , Low Hsueh Jing , Yusof Aliza Mohamad
Published: August 2022

Background and Objectives: Shivering is a common complication of subarachnoid block (SAB). Magnesium sulphate has been proven to be effective in preventing shivering. The aim of this study was to compare the effectiveness and adverse effects in hemodynamic parameters between 50 mg/kg and 30 mg/kg of intravenous magnesium sulphate for prevention of shivering post-subarachnoid block. Materials and Methods: Eighty-six patients scheduled for surgery under SAB, aged between 18 to 65 years old with American Society of Anesthesiologists physical status I and II were randomised into two groups. Group A received a bolus of 50 mg/kg, while Group B received 30 mg/kg of intravenous magnesium sulphate, given over a 20 min duration following SAB. Shivering grade was recorded intraoperatively according to the Crossley and Mahajan shivering scale. Mean arterial pressure (MAP), heart rate, tympanic temperature, oxygen saturation and the use of vasopressors were recorded. Results: Forty-five percent of patients in Group A and 20% of patients in Group B did not exhibit shivering (p-value < 0.01). High-grade shivering was observed in 12.5% in Group A and 40% in Group B, respectively (p-value 0.02). The MAP trend was lower in Group B (p-value < 0.01), but the incidence of hypotension was not significant in both groups. The use of vasopressors was also similar between groups. Group B showed a lower oxygen saturation trend (p-value 0.04). The trends of heart rate and tympanic temperature were not significant in both groups. No patients had episodes of bradycardia or oxygen desaturation. Conclusions: In this study, intravenous magnesium sulphate 50 mg/kg is the lowest effective dose for prevention and treatment of high-grade shivering post-SAB without significant hemodynamic adverse events.
Influence of Powder Characteristics on the Microstructure and Mechanical Behaviour of GH4099 Superalloy Fabricated by Electron Beam Melting
Authors: Wang Shixing , Tao Shen , Peng Hui
Published: August 2022

A Chinese superalloy, GH4099 (~20 vol.% γ′ phase), which can operate for long periods of time at temperatures of 1173–1273 K, was fabricated by electron beam melting (EBM). Argon gas atomized (GA) and plasma rotation electrode process (PREP) powders with similar composition and size distribution were used as raw materials for comparison. The microstructure and mechanical properties of both the as-EBMed and post-treated alloy samples were investigated. The results show that the different powder characteristics result in different build temperatures for GA and PREP samples, which are 1253 K and 1373 K, respectively. By increasing the building temperature, the EBM processing window shifts towards a higher scanning speed direction. Microstructure analysis reveals that both as-EBM samples show a similar grain width (measured to be ~200 μm), while the size of γ′ precipitated in the PREP sample (~90 nm) is larger than that of the GA sample (~130 nm) due to the higher build temperature. Fine spherical γ′ phase precipitates uniformly after heat treatment (HT). Furthermore, intergranular cracking was observed for the as-fabricated PREP sample as a result of local enrichment of Si at grain boundaries. The cracks were completely eliminated by hot isostatic pressing (HIP) and did not re-open during subsequent heat treatment (HT) of solution treatment and aging. The tensile strength of the PREP sample after HIP and HT is ~920 MPa in the building direction and ~850 MPa in the horizontal direction, comparable with that of the wrought alloy.
Analysis on Ancient Bloomery Ironmaking Technology: The Earliest Ironmaking Evidence in the Central Plains of China Was Taken as the Research Object
Authors: Li Shuoyang , Li Yanxiang , Zhu Rong , Wang Hongyang
Published: August 2022

The slag found in Hengdong Jiangxian County, Shanxi Province has been recognized by archaeologists as the earliest evidence of bloomery ironmaking in China. The slag was characterized and analyzed by chemical titration, inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive spectrometer (SEM-EDS), and tescan integrated mineral analysis (TIMA). The smelting technology in ancient China was explored, combined with thermodynamic theory. The results of chemical titration shown that the total Fe was as high as 64.18%, which means that it was very difficult to produce iron on a large scale with the ancient bloomery ironmaking technology, consuming a lot of iron ore while producing very little iron. The distribution of FeO was relatively dispersed, while that of Fe2O3 particles was concentrated and large. The source of Fe2O3 in the slag can be roughly identified as the oxidized metallic iron, which could not be separated in the slag in the past. Tescan integrated mineral analysis (TIMA) images show that Fayalite and Wustite are the main phase forms in smelting slag. The existence of fayalite proves that the temperature of a slag system should reach the condition of liquid phase formation during the smelting process. Based on the characterization results, the metallurgical conditions of the slag at that time are inferred by FactSage7.1. The theoretical smelting temperature was between 1150 °C and 1200 °C. The fayalite and aluminosilicate in the slag had obvious displacement and inhomogeneity, which pointed to the forging temperature ranging from 1050 °C to 1100 °C.
Mechanism of Surface Defects in Ultra-Precision Machining of Sesquioxide Laser Crystal Tm: GdScO3
Authors: Fang Yuanyuan , He Hongbo , Dun Aihuan , Zhang Long
Published: August 2022

It is well-known that the surface quality of laser gain crystal elements is very high in order to ensure the stability of laser system and laser output quality. In the ultra-precision machining process of a new sesquioxide laser crystal Tm: GdScO3, it is required to achieve very high surface shape and very low surface defects. In this paper, the molecular dynamics simulation model of single particle grinding was established. It was found that the normal load and tangential friction imposed by abrasive particles on the surface of components cause the spalling of atoms on the substrate surface, which constitutes the removal of materials at the macro-level. At the same time, it causes the displacement of the sub surface atoms, which constitutes the microscopic defects in the structure. Through the structural characterization of macro defects, it was confirmed that the essence of micro defects is the amorphous and distortion of surface structure, and the depth can reach 100 nm. The results of lapping and polishing experiments show that the adjustment of pressure has a limited effect on the improvement of surface defects in the process of machining crystal elements with granular abrasive.
Prediction of the Mechanical Performance of Cemented Tailings Backfill Using Ultrasonic Pulse Velocity Measurement
Authors: Tian Xichun , Xu Wenbin
Published: August 2022

Cemented tailings backfill (CTB), prepared by a mixture of tailings, binder, and water in a certain proportion, is widely applied to mines worldwide for ground support and tailings disposal. The prediction of the mechanical properties of CTB during the whole consolidation process is of great practical importance. The objective of this paper focuses on the investigation of the prediction of the mechanical performance of CTB based on the ultrasonic pulse velocity (UPV) method. The CTB samples prepared with different binder-to-water (b/w) ratios, as well as solid content were monitored by the UPV method during the curing age of 28 days. The evolution of dynamic shear modulus and dynamic elasticity modulus properties of CTB samples were studied by UPV monitoring. Meanwhile, uniaxial compressive strength (UCS) and microstructure tests were performed on CTB samples at curing times of 3, 7, and 28 days. The results showed that the UPV development follows a trend that increases fast at early curing ages and then becomes stable at the 10 d curing age. UPV and UCS increased with the increase in b/w, solid content, and curing age. From the results of microstructure tests, the increase in UPV is attributed to the low porosity and compact structure due to the increase in the b/w ratio and solid content. For the purpose of predicting the UCS of CTB utilizing UPV monitoring, the empirical equations for the relationship between UCS and UPV of CTB with variation b/w ratios and solid content were regression analyses. F-tests, as well as t-tests, were used to check the validity of the equations, which indicate that higher calculated values for CTB to predicted UCS by means of the UPV method. The main finding of this paper shows that the UPV monitoring method can be an effective way to predict the mechanical property of CTB in the field and is non-destructive and effective.
Potential Toxicity of Natural Fibrous Zeolites: In Vitro Study Using Jurkat and HT22 Cell Lines
Authors: Betti Michele , Nasoni Maria Gemma , Luchetti Francesca , Giordani Matteo , Mattioli Michele
Published: August 2022

An emerging problem for human health is the exposure to non-regulated mineral fibers with an asbestos-like crystal habit, particularly fibrous zeolites. This study aimed to determine if and how selected fibrous zeolites (erionite, mesolite, and thomsonite) induce toxicity effects on two different in vitro cellular models, the adherent murine hippocampal (HT22) and human immortalized T lymphocyte (Jurkat) cell lines. Before proceeding with the cellular tests, the three zeolite samples were investigated using scanning electron microscopy–energy-dispersive spectroscopy and X-ray powder diffraction techniques. The cells were treated with 0.1 µM and 1 µM of fibrous erionite, mesolite, and thomsonite for 12, 24, and 48 h. Results showed a cytotoxic effect of erionite in both cellular models and revealed different toxic behaviors of the mesolite and thomsonite fibers, suggesting other potential mechanisms of action. The outcome of this study would be a first step for further research on fine biochemical interactions of zeolite fibers with cells and future in vivo investigations.
Smart Map Augmented: Exploring and Learning Maritime Audio-Tactile Maps without Vision: The Issue of Finger or Marker Tracking
Authors: Simonnet Mathieu
Published: August 2022

Background: When exploring audio-tactile nautical charts without vision, users could trigger vocal announcements of a seamark’s name thanks to video tracking. In a first condition they could simply use a green sticker fastened at the tip of a finger and in a second condition they could handle a small handy green object, called the marker. Methods: In this study, we attempted to compare finger and marker tracking conditions to complete spatial tasks without vision. More precisely, we aimed to better understand which kind of interaction was the most efficient to perform either localization or estimation of distance and direction tasks. Twelve blindfolded participants realized these two spatial tasks on a 3D-printed audio-tactile nautical chart. Results: Results of the localization tasks revealed that in finger condition, participants were faster in finding geographic elements, i.e., seamarks. During estimation tasks, no differences were found between the precision of distances and direction estimations in both conditions. However, spatial reasoning took significantly less time in marker condition. Finally, we discussed the issue of the efficiency of these two interaction conditions depending on the spatial tasks. Conclusions: More experimentation and discussion should be undertaken to identify better modalities for helping visually impaired persons to explore audio-tactile maps and to prepare navigation.
Removal of Methylene Blue by Crosslinked Egg White Protein/Graphene Oxide Bionanocomposite Aerogels
Authors: Jin Yonghui , Du Qiuju , Li Yanhui , Zhang Yang , Chen Bing , Wang Mingzhen , Chen Kewei , Sun Yaohui , Zhao Shiyong , Jing Zhenyu
Published: August 2022

Egg white protein is a non-toxic and biodegradable biopolymer that forms a gel easily via simple thermal denaturation treatment. A novel aerogel on the basis of egg white protein crosslinked with graphene oxide was prepared via a facile freeze-drying method. The structure and physicochemical characteristics of the aerogels were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) analysis. The adsorption properties of the aerogels were investigated by studying the influencing factors such as the solution pH, dose, temperature and contact time. The adsorption capacity of methylene blue onto the aerogels was tested, whose maximum adsorption capacity, calculated by the Langmuir isotherm equation, reached 91.7 mg/g. Adsorption kinetics studies showed that the adsorption followed the pseudo-second-order kinetic model. Thermodynamic data implied that methylene blue adsorbed by the aerogels was an exothermic and spontaneous process.
Enhanced Photodetection Range from Visible to Shortwave Infrared Light by ReSe2/MoTe2 van der Waals Heterostructure
Authors: Lin Zhitao , Zhu Wenbiao , Zeng Yonghong , Shu Yiqing , Hu Haiguo , Chen Weicheng , Li Jianqing
Published: August 2022

Type II vertical heterojunction is a good solution for long-wavelength light detection. Here, we report a rhenium selenide/molybdenum telluride (n-ReSe2/p-MoTe2) photodetector for high-performance photodetection in the broadband spectral range of 405–2000 nm. Due to the low Schottky barrier contact of the ReSe2/MoTe2 heterojunction, the rectification ratio (RR) of ~102 at ±5 V is realized. Besides, the photodetector can obtain maximum responsivity (R = 1.05 A/W) and specific detectivity (D* = 6.66 × 1011 Jones) under the illumination of 655 nm incident light. When the incident wavelength is 1550–2000 nm, a photocurrent is generated due to the interlayer transition of carriers. This compact system can provide an opportunity to realize broadband infrared photodetection.
Flower-like ZnO Nanostructures Local Surface Morphology and Chemistry
Authors: Kwoka Monika , Comini Elisabetta , Zappa Dario , Szuber Jacek
Published: August 2022

This work presents the results of comparative studies using complementary methods, such as scanning electron microscopy (SEM), X-ray photoemission spectroscopy (XPS), and thermal desorption spectroscopy (TDS) to investigate the local surface morphology and chemistry of flower-like ZnO nanostructures synthesized by the thermal oxidation technique on native Si/SiO2 substrates. SEM studies showed that our flower-like ZnO nanostructures contained mostly isolated and irregular morphological low-dimensional forms, seen as rolled-up floss flowers, together with local, elongated, complex stalks similar to Liatris flowers, which contained joined short flosses in the form of nanodendrites. Beyond this, XPS studies showed that these nanostructures exhibited a slight surface nonstoichiometry, mostly related to the existence of oxygen-deficient regions, combined with strong undesired C surface contamination. In addition, the TDS studies showed that these undesired surface contaminations (including mainly C species and hydroxyl groups) are only slightly removed from the surface of our flower-like ZnO nanostructures, causing an expected modification of their nonstoichiometry. All of these effects are of great importance when using our flower-like ZnO nanostructures in gas sensor devices for detecting oxidizing gases because surface contamination leads to an undesired barrier for toxic gas adsorption, and it can additionally be responsible for the uncontrolled sensor aging effect.
Electrospun Biodegradable Poly(L-lactic acid) Nanofiber Membranes as Highly Porous Oil Sorbent Nanomaterials
Authors: Yang Jizhen , Li Fan , Lu Guibin , Lu Yuanbin , Song Chuanbo , Zhou Rong , Wu Shaohua
Published: August 2022

Crude oil spills seriously harm the ocean environment and endanger the health of various animals and plants. In the present study, a totally biodegradable polymer, poly(L-lactic acid) (PLLA), was employed to fabricate highly porous oil absorbent nanofibrous materials by using a combination of electrospinning technique and subsequent acetone treatment. We systematically investigated how the electrospinning parameters affected formation of the porous structure of PLLA nanofibers and demonstrated that PLLA nanofibers with decreased and uniform diameter and improved porosity could be rapidly prepared by adjusting solution parameters and spinning parameters. We also demonstrated that the acetone treatment could obviously enhance the pore diameter and specific surface area of as-optimized electrospun PLLA nanofibers. The acetone treatment could also improve the hydrophobic property of as-treated PLLA nanofiber membranes. All these led to a significant increase in oil absorption performance. Through our research, it was found that the oil absorption of PLLA nanofiber membrane increased by more than double after being treated with acetone and the oil retention rate was also improved slightly.
Cornuside Is a Potential Agent against Alzheimer’s Disease via Orchestration of Reactive Astrocytes
Authors: Shi Jun-Zhuo , Zheng Xiao-Ming , Zhou Yun-Feng , Yun Lu-Yao , Luo Dong-Mei , Hao Jiao-Jiao , Liu Peng-Fei , Zhang Wei-Ku , Xu Jie-Kun , Yan Yi , Xie Xin-Mei , He Yang-Yang , Pang Xiao-Bin
Published: August 2022

Cornuside is an iridoid glycoside from Cornus officinalis, with the activities of anti-inflammatory, antioxidant, anti-mitochondrial dysfunction, and neuroprotection. In the present research, a triple-transgenic mice model of AD (3 × Tg-AD) was used to explore the beneficial actions and potential mechanism of cornuside on the memory deficits. We found that cornuside prominently alleviated neuronal injuries, reduced amyloid plaque pathology, inhibited Tau phosphorylation, and repaired synaptic damage. Additionally, cornuside lowered the release of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nitric oxide (NO), lowered the level of malondialdehyde (MDA), and increased the activity of superoxide dismutase (SOD) and the level of glutathione peroxidase (GSH-Px). Cornuside also significantly reduced the activation of astrocytes and modulated A1/A2 phenotypes by the AKT/Nrf2/NF-κB signaling pathway. We further confirmed that LY294002 and Nrf2 silencing could block the cornuside-mediated phenotypic switch of C6 cells induced by microglia conditioned medium (MCM) in response to lipopolysaccharide (LPS), which indicated that the effects of cornuside in astrocyte activation are dependent on AKT/Nrf2/NF-κB signaling. In conclusion, cornuside may regulate the phenotypic conversion of astrocytes, inhibit neuroinflammation and oxidative stress, improve synaptic plasticity, and alleviate cognitive impairment in mice through the AKT/Nrf2/NF-κB axis. Our present work provides an experimental foundation for further research and development of cornuside as a candidate drug for AD management.
Identification of a Dual Inhibitor of Secreted Phospholipase A2 (GIIA sPLA2) and SARS-CoV-2 Main Protease
Authors: Theodoropoulou Maria A. , Koutoulogenis Giorgos S. , Zhang Linlin , Akrani Ifigeneia , Mikros Emmanuel , Hilgenfeld Rolf , Kokotos George
Published: August 2022

The development of novel agents to combat COVID-19 is of high importance. SARS-CoV-2 main protease (Mpro) is a highly attractive target for the development of novel antivirals and a variety of inhibitors have already been developed. Accumulating evidence on the pathobiology of COVID-19 has shown that lipids and lipid metabolizing enzymes are critically involved in the severity of the infection. The purpose of the present study was to identify an inhibitor able to simultaneously inhibit both SARS-CoV-2 Mpro and phospholipase A2 (PLA2), an enzyme which plays a significant role in inflammatory diseases. Evaluating several PLA2 inhibitors, we demonstrate that the previously known potent inhibitor of Group IIA secretory PLA2, GK241, may also weakly inhibit SARS-CoV-2 Mpro. Molecular mechanics docking and molecular dynamics calculations shed light on the interactions between GK241 and SARS-CoV-2 Mpro. 2-Oxoamide GK241 may represent a lead molecular structure for the development of dual PLA2 and SARS-CoV-2 Mpro inhibitors.
Noise Reduction of OCT Images Based on the External Patch Prior Guided Internal Clustering and Morphological Analysis
Authors: Fan Yingwei , Li Yangxi , Gao Tianxin , Tang Xiaoying
Published: August 2022

Optical coherence tomography (OCT) is widely used in biomedical imaging. However, noise severely affects diagnosing and identifying diseased tissues on OCT images. Here, a noise reduction method based on the external patch prior guided internal clustering and morphological analysis (E2PGICMA) is developed to remove the noise of OCT images. The external patch prior guided internal clustering algorithm is used to reduce speckle noise. The morphological analysis algorithm is employed to the background for contrast enhancement. OCT images of in vivo normal skin tissues were analyzed to remove noise using the proposed method. The estimated standard deviations of the noise were chosen as different values for evaluating the quantitative metrics. The visual quality improvement includes more textures and fine detail preservation. The denoising effects of different methods were compared. Then, quantitative and qualitative evaluations of this proposed method were conducted. The results demonstrated that the SNR, PSNR, and XCOR were higher than those of the other noise-reduction methods, reaching 15.05 dB, 27.48 dB, and 0.9959, respectively. Furthermore, the presented method’s noise reduction ratio (NRR) reached 0.8999. This proposed method can efficiently remove the background and speckle noise. Improving the proposed noise reduction method would outperform existing state-of-the-art OCT despeckling methods.
Desensitization Design Method for Freeform TMA Optical Systems Based on Initial Structure Screening
Authors: Qin Zichang , Qi Yunsheng , Ren Chengming , Wang Xiaodong , Meng Qingyu
Published: August 2022

Achieving aberration correction can improve the imaging quality of an optical system, and reducing the error sensitivity of system can improve the realizability of the system. In order to obtain an off-axis three-mirror optical system with high image quality and low error sensitivity, a design method is proposed which obtains the initial structure of the three-mirror anastigmatic (TMA) optical system with low error sensitivity through a nondominated sorting genetic algorithm II (NSGA-II). Combining the comprehensive evaluation function of image quality and error sensitivity, this method iteratively selects multiple freeform surface types to determine the combination with the lowest error sensitivity and obtains the freeform TMA optical system with optimal overall performance. A freeform TMA optical system is designed by the method proposed in this paper, and the error sensitivity of the optical system is analyzed. The results show that the image quality of the freeform optical system is effectively improved and the error sensitivity is effectively reduced with the same error applied, which verifies the correctness and practicality of the method.
The Quasi-History of Early Quantum Theory
Authors: Passon Oliver
Published: August 2022

While physics has a rather ahistoric teaching tradition, it is common to include at least anecdotal reference to historical events and actors. These brief remarks on the history are typically distorted. I take issue with the textbook narrative of the historical development of early quantum theory and rectify some of the more severe misrepresentations. This seems to be all the more important, since the history of physics is commonly (and rightly) regarded as a means to foster scientific literacy and a more appropriate understanding of the nature of science (NoS).
Evaluation of the Binding Relationship of the RdRp Enzyme to Novel Thiazole/Acid Hydrazone Hybrids Obtainable through Green Synthetic Procedure
Authors: Al-Humaidi Jehan Y. , Badrey Mohamed G. , Aly Ashraf A. , Nayl AbdElAziz A. , Zayed Mohie E. M. , Jefri Ohoud A. , Gomha Sobhi M.
Published: August 2022

The viral RNA-dependent RNA polymerase (RdRp) complex is used by SARS-CoV-2 for genome replication and transcription, making RdRp an interesting target for developing the antiviral treatment. Hence the current work is concerned with the green synthesis, characterization and docking study with the RdRp enzyme of the series of novel and diverse hydrazones and pyrazoles. 4-Methyl-2-(2-(1-phenylethylidene)hydrazineyl)thiazole-5-carbohydrazide was prepared and then condensed with different carbonyl compounds (aldehydes and ketones either carbocyclic aromatic or heterocyclic) afforded the corresponding hydrazide-hydrazones. The combination of the acid hydrazide with bifunctional reagents such as acetylacetone, β-ketoesters (ethyl acetoacetate and ethyl benzoylacetate) resulted in the formation of pyrazole derivatives. The synthesized compounds were all obtained through grinding method using drops of AcOH. Various analytical and spectral analyses were used to determine the structures of the prepared compounds. Molecular Operating Environment (MOE®) version 2014.09 was used to estimate interactions between the prepared thiazole/hydrazone hybrids and RdRp obtained from the protein data bank (PDB: 7bv2) using enzyme-ligand docking for all synthesized derivatives and Remdesivir as a reference. Docking results with the RdRp enzyme revealed that the majority of the investigated drugs bind well to the enzyme via various types of interactions in comparison with the reference drug.
Biaxial Elongation Behavior in Partially Molted State of Two-Layer Sheets Containing Postconsumer Material
Authors: Wittmann Lisa-Maria , Kaschta Joachim , Drummer Dietmar
Published: August 2022

Due to the lack of raw material and forced by political demand, an increasing percentage of postconsumer materials (PCR) shall be used in all processing methods in polymer technology. Thermoforming, as one of the oldest polymer-processing methods, has special requirements regarding the melt stability at high temperatures. Low melt stability affects the thermoforming in a negative manner, as the low stiffness leads the sheet to sag during the heating phase. In this study, two-layer sheets are used in order to improve melt stability of PCR material. The focus is placed on the influence of rheological properties on the biaxial stretching behavior of mono- and two-layer sheets in partially molted state. In order to create a stabilizing layer, two different thermoformable virgin materials with a melt flow rate (MFR) of 3 g/10 min and 6 g/10 min were chosen. The second layer consists of instable PCR materials with a MFR of 16 g/10min and 50 g/10 min. Rheological investigations, molecular characterization and biaxial stretching tests are used to show the benefit of two-layer sheets for processing PCR material under elongational stress. The results show that the use of two-layer sheets can improve the biaxial stretching properties, so that two-layer sheets can offer a significant potential in the processing of PCR materials in thermoforming.
Free Volume and Permeability of Mixed Matrix Membranes Made from a Terbutil-M-terphenyl Polyamide and a Porous Polymer Network
Authors: Soto Cenit , Carmona Javier , Freeman Benny D. , Palacio Laura , González-Ortega Alfonso , Prádanos Pedro , Lozano Ángel E. , Hernandez Antonio
Published: August 2022

A set of thermally rearranged mixed matrix membranes (TR-MMMs) was manufactured and tested for gas separation. These membranes were obtained through the thermal treatment of a precursor MMM with a microporous polymer network and an o-hydroxypolyamide,(HPA) created through a reaction of 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (APAF) and 5′-terbutil-m-terfenilo-3,3″-dicarboxylic acid dichloride (tBTmCl). This HPA was blended with different percentages of a porous polymer network (PPN) filler, which produced gas separation MMMs with enhanced gas permeability but with decreased selectivity. The thermal treatment of these MMMs gave membranes with excellent gas separation properties that did not show the selectivity decreasing trend. It was observed that the use of the PPN load brought about a small decrease in the initial mass losses, which were lower for increasing PPN loads. Regarding the glass transition temperature, it was observed that the use of the filler translated to a slightly lower Tg value. When these MMMs and TR-MMMs were compared with the analogous materials created from the isomeric 5′-terbutil-m-terfenilo-4,4″-dicarboxylic acid dichloride (tBTpCl), the permeability was lower for that of tBTmCl, compared with the one from tBTpCl, although selectivity was quite similar. This fact could be attributed to a lower rigidity as roughly confirmed by the segmental length of the polymer chain as studied by WAXS. A model for FFV calculation was proposed and its predictions compared with those evaluated from density measurements assuming a matrix-filler interaction or ideal independence. It turns out that permeability as a function of FFV for TR-MMMs follows an interaction trend, while those not thermally treated follow the non-interaction trend until relatively high PPN loads were reached.
La Vera Cruz: Wills, Confraternities, Catholic Reconquest and Reform in Sixteenth-Century Gibraltar
Authors: Asquez Ryan
Published: August 2022

In his Historia de Gibraltar, the Gibraltar-born jurado Alonso Hernández del Portillo described how “the confraternity of the Santa Vera Cruz has a fine and pleasant church on the Main Street”. Set in the heart of town, it was an impressive building, which caused the missionary Pedro Cubero Sebastián to describe it as “most excellent” in the late seventeenth-century. Within the church existed the confraternity’s pride and joy: el Cristo de la Vera Cruz, a miraculous image of the crucified Christ and a key feature of local devotion. Using unpublished testamentary evidence, this article explores the early years of this local manifestation of Christological devotion, as well as the devotional context out of which it grew. The timeline established by these wills not only allows us to place this church and confraternity, and therefore Gibraltar, within the context of the Catholic Reformation, but to locate these religious developments as part of a prolonged process of Christianisation which began with the city’s reconquest in 1462.