bluuebunny/crossref_metadata_2025 huggingface dataset:
Over-Prescription and Overuse of Antimicrobials in the Eastern Mediterranean Region: The Urgent Need for Antimicrobial Stewardship Programs with Access, Watch, and Reserve Adoption
Authors: Talaat Maha , Tolba Sara , Abdou Enjy , Sarhan Mohamed , Gomaa Mohamed , Hutin Yvan J-F.
Published: December 2022

Excessive antimicrobial use contributes to the development of antimicrobial resistance. In the Eastern Mediterranean region (EMR), there is dearth of information on the prevalence of antimicrobial use in patients hospitalized in acute healthcare settings, clinical indications, types of antimicrobials prescribed, and quality indicators for prescriptions. Between September and December 2019, seven countries in the EMR conducted a standardized point prevalence survey. All patients present in the hospital wards at 8 a.m. on the day of the survey constituted the sample population. We collected data, including patient characteristics, antimicrobials received, therapeutic indication according to predefined lists, and markers of prescribing quality. The survey included data from 139 hospitals in seven countries. Among the 19,611 inpatients surveyed, 11,168 patients received at least one antimicrobial {crude prevalence: 56.9% (95%CI: 56.2–57.6%). The top three classes of antimicrobials prescribed were third-generation cephalosporins (26.7%), beta-lactam penicillins (18.1%), and imidazole derivatives (n = 1655, 9.8%). Carbapenems were most frequently prescribed for the treatment of healthcare-associated infections. Compliance with quality indicators of antimicrobial use was limited where treatment guidelines were available for 41% of antimicrobial prescriptions and targeted antimicrobial treatment represented 21% of therapeutic indications. Overall hospital antimicrobial use was high in countries of the EMR, pointing to the need to design and implement context-specific antimicrobial stewardship programs to optimize antimicrobial use and reduce antimicrobial resistance.
Whole Genome Sequencing (WGS) Analysis of Virulence and AMR Genes in Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli from Animal and Environmental Samples in Four Italian Swine Farms
Authors: Bonvegna Miryam , Tomassone Laura , Christensen Henrik , Olsen John Elmerdahl
Published: December 2022

Whole genome sequencing (WGS) is a powerful tool to analyze bacterial genomes rapidly, and can be useful to study and detect AMR genes. We carried out WGS on a group of Escherichia coli (n = 30), sampled from healthy animals and farm environment in four pigsties in northern Italy. Two × 250bp paired end sequencing strategy on Illumina MiSeq™ was used. We performed in silico characterization of E. coli isolates through the web tools provided by the Center for Genomic Epidemiology (cge.cbs.dtu.dk/services/) to study AMR and virulence genes. Bacterial strains were further analyzed to detect phenotypic antimicrobial susceptibility against several antimicrobials. Data obtained from WGS were compared to phenotypic results. All 30 strains were MDR, and they were positive for the genes blaCTX-M and blaTEM as verified by PCR. We observed a good concordance between phenotypic and genomic results. Different AMR determinants were identified (e.g., qnrS, sul, tet). Potential pathogenicity of these strains was also assessed, and virulence genes were detected (e.g., etsC, gad, hlyF, iroN, iss), mostly related to extraintestinal E. coli pathotypes (UPEC/APEC). However, enterotoxin genes, such as astA, ltcA and stb were also identified, indicating a possible hybrid pathogenic nature. Various replicons associated to plasmids, previously recovered in pathogenic bacteria, were identified (e.g., IncN and IncR plasmid), supporting the hypothesis that our strains were pathogenic. Eventually, through WGS it was possible to confirm the phenotypic antibiotic resistance results and to appreciate the virulence side of our ESBL-producing E. coli. These findings highlight the need to monitor commensal E. coli sampled from healthy pigs considering a One Health perspective.
Synergistic Potentiation of Antimicrobial and Antibiofilm Activities of Penicillin and Bacitracin by Octyl Gallate, a Food-Grade Antioxidant, in Staphylococcus epidermidis
Authors: Santativongchai Pitchaya , Tulayakul Phitsanu , Ji Yinduo , Jeon Byeonghwa
Published: December 2022

Staphylococcus epidermidis is a major nosocomial pathogen that frequently forms biofilms on indwelling medical devices. This study aimed to investigate the synergistic antimicrobial and antibiofilm activities of octyl gallate (OG) in combination with penicillin and bacitracin against S. epidermidis. Antimicrobial synergy was assessed by conducting checkerboard titration assays, and antibiofilm activity was determined with biofilm assays and fluorescence microscopy analysis. The presence of 8 µg/mL of OG increased both the bacteriostatic and bactericidal activities of penicillin and bacitracin against S. epidermidis. It lowered the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of penicillin by eight-fold and those of bacitracin by four-fold. Moreover, when used with penicillin or bacitracin, OG significantly decreased the level of biofilm production by preventing microcolony formation. Furthermore, OG significantly permeabilized the bacterial cell wall, which may explain its antimicrobial synergy with penicillin and bacitracin. Together, these results demonstrate that OG, a food-grade antioxidant, can be potentially used as a drug potentiator to enhance the antimicrobial and antibiofilm activities of penicillin and bacitracin against S. epidermidis.
Development of Citrus-Based Functional Jelly and an Investigation of Its Anti-Obesity and Antioxidant Properties
Authors: Peng Mingfang , Gao Zhipeng , Liao Yanfang , Guo Jiajing , Shan Yang
Published: December 2022

Intervention with natural products is becoming a promising obesity control strategy as healthy eating becomes increasingly popular. The present study aimed to prepare a citrus-based functional jelly (CFJ) from citrus by-products and investigate its bioactive effects in mice. The results of the CFJ preparation showed that the optimal formula of CFJ was 29.12%, 20%, and 3.61% for chenpi, orange juice, and pectin, respectively. The optimized CFJ can be personalized and designed with jelly shapes using 3D food printing technology. The evaluation of the biological activity of the CFJ showed that it was low in calories, with a total phenolic content of 12.44 ± 0.26 mg GAE/g. Moreover, the CFJ has a good free radical scavenging ability for ABTS. The results of the mouse experiments showed that the CFJ significantly suppressed the body weight gain and fat deposits with a dose-dependent effect, compared with the control group (p < 0.05). In addition, the activities of the antioxidant-related enzymes (CAT and SOD) of the mice were also enhanced after a supplementation with the CFJ. In short, the CFJ is a functional snack enriched in phenolic substances with low-calorie, antioxidant and anti-obesity properties. This work promotes the utilization of citrus by-products and the healthy development of its processing industry.
Effects of Synthetic Short Cationic Antimicrobial Peptides on the Catalytic Activity of Myeloperoxidase, Reducing Its Oxidative Capacity
Authors: Vakhrusheva Tatyana V. , Sokolov Alexey V. , Moroz Grigoriy D. , Kostevich Valeria A. , Gorbunov Nikolay P. , Smirnov Igor P. , Grafskaia Ekaterina N. , Latsis Ivan A. , Panasenko Oleg M. , Lazarev Vassili N.
Published: December 2022

Cationic antimicrobial peptides (CAMPs) have gained attention as promising antimicrobial therapeutics causing lower or no bacterial resistance. Considerable achievements have been made in designing new CAMPs that are highly active as antimicrobials. However, there is a lack of research on their interaction with biologically important proteins. This study focused on CAMPs’ effects on myeloperoxidase (MPO), an enzyme which is microbicidal and concomitantly damaging to host biomolecules and cells due to its ability to produce reactive oxygen and halogen species (ROS/RHS). Four CAMPs designed by us were employed. MPO catalytic activity was assessed by an absorbance spectra analysis and by measuring enzymatic activity using Amplex Red- and Celestine Blue B-based assays. The peptide Hm-AMP2 accelerated MPO turnover. Pept_1545 and Hm-AMP8 inhibited both the MPO chlorinating and peroxidase activities, with components of different inhibition types. Hm-AMP8 was a stronger inhibitor. Its Ki towards H2O2 and Cl– was 0.3–0.4 μM vs. 11–20 μM for pept_1545. Peptide tyrosine and cysteine residues were involved in the mechanisms of the observed effects. The results propose a possible dual role of CAMPs as both antimicrobial agents and agents that downregulate MPO activation, and suggest CAMPs as prototypes for the development of antioxidant compounds to prevent MPO-mediated ROS/RHS overproduction.
Alpha-Lipoic Acid as an Antioxidant Strategy for Managing Neuropathic Pain
Authors: Viana Max Denisson Maurício , Lauria Pedro Santana Sales , Lima Alyne Almeida de , Opretzka Luiza Carolina França , Marcelino Henrique Rodrigues , Villarreal Cristiane Flora
Published: December 2022

Neuropathic pain (NP) is the most prevalent and debilitating form of chronic pain, caused by injuries or diseases of the somatosensory system. Since current first-line treatments only provide poor symptomatic relief, the search for new therapeutic strategies for managing NP is an active field of investigation. Multiple mechanisms contribute to the genesis and maintenance of NP, including damage caused by oxidative stress. The naturally occurring antioxidant alpha-lipoic acid (ALA) is a promising therapeutic agent for the management of NP. Several pre-clinical in vitro and in vivo studies as well as clinical trials demonstrate the analgesic potential of ALA in the management of NP. The beneficial biological activities of ALA are reflected in the various patents for the development of ALA-based innovative products. This review demonstrates the therapeutic potential of ALA in the management of NP by discussing its analgesic effects by multiple antioxidant mechanisms as well as the use of patented ALA-based products and how technological approaches have been applied to enhance ALA’s pharmacological properties.
Combined Effects of Cold Treatment and Phosphine in Drosophila suzukii (Diptera: Drosophilidae)
Authors: Seok Seung-Ju , Kim Hyun Kyung , Koo Hyun-Na , Kim Gil-Hah
Published: December 2022

This study analyzed the effect of combined phosphine (PH3) fumigation and low-temperature treatment on the control of Drosophila suzukii. In the low-temperature, single-treatment experiment, there was no significant difference in insecticidal activity between 1 °C and 5 °C except in D. suzukii adults. Adults showed 98.0% mortality after exposure to 1 °C for 7 d. Regarding fumigation treatment with PH3 alone, adults were the most susceptible, and pupae had the highest tolerance. Combined low-temperature treatment and fumigation showed a synergistic effect, except in the egg stage, and showed slight synergistic effects in larvae and pupae regardless of the combined treatment order. In pupae, the combination group exposed to 1 °C for 24 h after exposure to PH3 for 4 h had the lowest LCT99 value, at 10.49 mg·h/L. The sorption rate of PH3 on grapes decreased to 85.49% after 4 h of exposure, with a 15% loading ratio (w/v), and there was no significant difference in various criteria of phytotoxicity in exposed grapes compared to control, even after 14 d of combined treatment. Therefore, this study indicates that combined PH3 fumigation and low-temperature treatment could be useful in D. suzukii control.
Manipulating the Hardness of HATS-Mounted Ear Pinna Simulators to Reproduce Cartilage Sound Conduction
Authors: Shimokura Ryota , Nishimura Tadashi , Hosoi Hiroshi
Published: December 2022

Although hearing devices based on cartilage conduction have become more widely used in Japan, methods for evaluating the output volume of such devices have not yet been established. Although the output of air-conduction-based sound-generating devices (e.g., earphones and hearing aids) can be standardized via the head and torso simulator (HATS), this is not applicable to cartilage conduction devices because the simulated pinna is too soft (hardness: A5) compared with human aural cartilage. In this study, we developed polyurethane pinna that had the same shape but different degrees of hardness (A40, A20, and A10). We then compared the HATS results for the new pinna simulators with data from human ears. We found that the spectral shapes of the outputs increasingly approximated those of human ears as the simulated pinna hardness decreased. When a durometer was pressed against the ear tragus of a human ear, the hardness value ranged from A10 to A20. Accordingly, cartilage-conduction-based sound information could be obtained using a HATS that had a simulated pinna with a similar hardness value.
Method for Determining the Susceptibility of the Track
Authors: Kisilowski Jerzy , Kowalik Rafał
Published: December 2022

This paper discusses real-world experiments in which selected ground imperfections were dynamically analysed in terms of track susceptibility for a linear and non-linear system. The imperfections included wheel pressure on local ground irregularities within the railway turnout. In this study, susceptibility was assumed as an element between two points (two masses)—most often susceptibility is assumed as a Voigt model (parallel combination of stiffness and damping). The tests were carried out for two configurations of train passage through a railway turnout on straight and diverging track. The track stiffness parameters of the railway turnout were determined from deflection measurements measured by sensors positioned at different points of the turnout. The components of the railway turnout were loaded with different forces. The damping parameter was determined from bench measurements of the actual track component. The function describing this damping is dry friction and such a function was determined. The second part of the study was concerned with measurements of stiffness and moments of inertia in a railway switchyard. The analysis carried out indicated the significance of the adverse effects of selected factors on the operation of the railway track (e.g., increasing the length of non-contact of the track with the ground or additional deflections of the railway track rail arising). The paper points out that such imperfections, in addition to the calculated additional deflections, cause, among other things, disturbances in the progressive movement of the rolling stock.
Comparison of the Fluoride Ion Release from Composite and Compomer Materials under Varying pH Conditions—Preliminary In Vitro Study
Authors: Kosior Piotr , Dobrzynski Maciej , Zakrzewska Aneta , Diakowska Dorota , Nienartowicz Jan , Blicharski Tomasz , Nagel Sebastian , Sikora Mateusz , Wiglusz Katarzyna , Watras Adam , Wiglusz Rafal J.
Published: December 2022

Fluoride prevents the demineralization and supports remineralization of enamel. It is important to maintain a constant low level of fluoride in the oral cavity at all times. Dental restorative materials that are used for this purpose contain NaF in their composition, which is a source of fluoride ions that diffuse into body fluids and surrounding tissues. Two such materials, the flowable composite material Wave (W) (SDI, Hamilton Parkway Itasca, Australia) and compomer material Freedom (F) (SDI, Hamilton Parkway Itasca, Australia), were studied in regards to their release of fluoride ions into various solutions imitating the oral environment: artificial saliva solution with the addition of hydrated calcium chloride (CaCl2) × 2H2O in the pH range of 4.5 and 5.5; artificial saliva free of calcium chloride in the pH range of 4.5, 5.5, 6.0, 7.0, and 7.5; deionized water; and saline solution. The results were assessed over a period of 7 days, i.e., 168 h. The Freedom (F) compomer showed the highest cumulative release of fluoride ions into artificial saliva solution at pH 4.5 (31.195 ± 10.461 μg F/mm2) and the lowest into saline solution (3.694 ± 1.115 μg F/mm2). The Wave (W) composite material revealed the highest cumulative release of fluoride ions into deionized water (7.982 ± 2.011 μg F/mm2); its lowest cumulative emission was observed in artificial saliva solution at pH 7.0 (1.391 ± 0.489 μg F/mm2). The amounts of released fluoride from the Freedom (F) compomer were considerably higher compared to the Wave (W) composite material. The ability to release the largest amounts of fluoride ions in an acidic environment results from the erosion of the surface layer. Different calcium content in available experimental and commercial artificial saliva preparations may influence the obtained results. Both the flowable Wave composite and Freedom compomer released more fluoride in an acidic environment with a pH of 4.5–5.5, but with different dynamics—Wave material had its maximum on the third day while Freedom on the first day of the experiment.
Effect of Commercial Microbial Preparations Containing Paenibacillus azotofixans, Bacillus megaterium and Bacillus subtilis on the Yield and Photosynthesis of Winter Wheat and the Nitrogen and Phosphorus Content in the Soil
Authors: Stępień Arkadiusz , Wojtkowiak Katarzyna , Kolankowska Ewelina
Published: December 2022

The present state of knowledge and biotechnological advances have allowed the potential of microorganisms to be used effectively in crop cultivation. A field study on the use of commercial bacterial preparations in the cultivation of winter wheat (Triticum aestivum L.) was carried out in the years 2017–2019 at the Educational and Experimental Station in Tomaszkowo (53°71′ N, 20°43′ E), Poland. This study analysed the effect of commercial microbial preparations containing Paenibacillus azotofixans, Bacillus megaterium and Bacillus subtilis, applied during the winter wheat growing season, on the grain yield, protein content, leaf greenness index (SPAD), the course of photosynthesis and the N-NO3, N-NH4 and P contents in the soil. The highest grain yield was noted following the application of mineral fertilisation and the three microbial preparations in combination (Paenibacillus azotofixans, Bacillus megaterium and Bacillus subtilis), as well as NPK with Paenibacillus azotofixans, in relation to mineral fertilisation alone (by 19.6% and 18.4%, respectively). The microbial preparations had a significant effect on the leaf greenness index (SPAD) at both test dates. No interaction was recorded between the years of study and the preparations applied on the SPAD values. The highest leaf photosynthetic index at both observation dates was noted for the application of NPK + P. azotofixans, as well as for NPK and all the preparations combined (P. azotofixans, B. megaterium, B. subtilis). The highest N-NO3, N-NH4 and P contents in the soil were obtained using NPK and all microbial preparations combined. Strong correlations were found between the SPAD index and the photosynthetic index value and the protein content in wheat grains and between the N-NO3, N-NH4 and P contents in the soil and the wheat grain yield.
Piper nigrum Fruit Extract as an Antibiotic Resistance Reversal Agent in MDR Bacteria
Authors: Din Maryam Salah Ud , Gohar Umar Farooq , Hameed Uzma , Mukhtar Hamid , Morar Adriana , Herman Viorel , Imre Kálmán
Published: December 2022

Antibiotic resistance development and spread in clinical pathogens is an immense threat that has already outpaced the discovery and development of novel and more effective antibiotic drugs. Recently the focus has been shifted to medicinal plants as novel therapeutic options for reversing antibiotic resistance by targeting different resistance mechanisms. Piper nigrum is a plant that has the potential to reverse antibiotic resistance and increase the efficacy of the current drugs. In the present study, seven different antibiotics, clindamycin, gentamicin, levofloxacin, amikacin, tigecycline, imipenem, and tetracycline, were used against antibiotic-resistant Staphylococcus aureus and Salmonella typhi. Antibiotic resistance reversal analysis was tested by the AST disc method. Increased zones of inhibition of S. aureus by four antibiotics, clindamycin (9 mm), gentamicin (7 mm), levofloxacin (9 mm), and amikacin (9 mm) were recorded after using P. nigrum extract. In addition, the use of P. nigrum extract also increased the zone of inhibition of S. typhi with amikacin (11 mm), gentamicin (10 mm), tigecycline (9 mm), levofloxacin (11 mm), and imipenem (10 mm). This study suggests that P. nigrum extracts can be used as natural antibiotic resistance reversal agents that increase the effectiveness of current antibiotics and can reverse antibiotic resistance.
Multi-Objective Antenna Design Based on BP Neural Network Surrogate Model Optimized by Improved Sparrow Search Algorithm
Authors: Wang Zhongxin , Qin Jian , Hu Zijiang , He Jian , Tang Dong
Published: December 2022

To solve the time-consuming, laborious, and inefficient problems of traditional methods using classical optimization algorithms combined with electromagnetic simulation software to design antennas, an efficient design method of the multi-objective antenna is proposed based on the multi-strategy improved sparrow search algorithm (MISSA) to optimize a BP neural network. Three strategies, namely Bernoulli chaotic mapping, inertial weights, and t-distribution, are introduced into the sparrow search algorithm to improve its convergent speed and accuracy. Using the Bernoulli chaotic map to process the population of sparrows to enhance its population richness, the weight is introduced into the updated position of the sparrow to improve its search ability. The adaptive t-distribution is used to interfere and mutate some individual sparrows to make the algorithm reach the optimal solution more quickly. The initial parameters of the BP neural network were optimized using the improved sparrow search algorithm to obtain the optimized MISSA-BP antenna surrogate model. This model is combined with multi-objective particle swarm optimization (MOPSO) to solve the design problem of the multi-objective antenna and verified by a triple-frequency antenna. The simulated results show that this method can predict the performance of the antennas more accurately and can also design the multi-objective antenna that meets the requirements. The practicality of the method is further verified by producing a real antenna.
Longitudinal Study on the Association between Ambient Polycyclic Aromatic Hydrocarbons and Nasal Symptoms in Adult Japanese
Authors: Zhao Jiaye , Hara Akinori , Hayakawa Kazuichi , Pham Kim-Oanh , Suzuki Keita , Tsujiguchi Hiromasa , Matsuzaki Hiroshi , Odajima Hiroshi , Takami Akinori , Nakamura Hiroyuki
Published: December 2022

The relationship between exposure to polycyclic aromatic hydrocarbons and nasal symptoms currently remains unclear. Therefore, we herein examine this relationship in 51 adults living in Ishikawa prefecture, Japan, and conducted a 2 month follow-up survey on these participants. All participants were asked to record daily nasal symptoms in an allergy diary during the study period between 1 April to 31 May 2020. We collected air pollutant samples during the study period and determined the concentrations of PAHs and total suspended particulates by high-performance liquid chromatography. Sulfur dioxide and nitrogen dioxide concentrations were obtained through the Atmospheric Environmental Regional Observation System. We used generalized estimating equations to analyze the association between pollutant and nasal symptoms. After adjustment for confounding factors, the B values of fluoranthene, pyrene, and Benzo[k]fluoranthene were 2.389 (p = 0.026), 3.744 (p = 0.022) and 9.604 (p = 0.041), respectively, with a one-day lag. In contrast, the B value of indeno[1,2,3-cd]pyrene was −6.664 (p = 0.013) with no lag. Collectively, these results suggest ambient PAHs such as Flt, Pyr, and BkF were associated with nasal symptoms in adults. Further studies are needed to elucidate the mechanisms contributing to the relationships between specific PAHs and nasal symptoms.
An Innovative Parabolic Trough Collector Design with a Twin-Cavity Receiver
Authors: Korres Dimitrios N. , Bellos Evangelos , Lykas Panagiotis , Tzivanidis Christos
Published: December 2022

An innovative parabolic trough concentrator coupled to a twin cavity receiver (PTC-TC) in evacuated tube conditions is investigated thermally and optically. The suggested design is compared with a PTC design with a flat receiver (PTC-F) in order to evaluate the efficiency of the proposed configuration. In the very first stages of the study, the optical efficiency was calculated for both collectors, and the optimum design was determined in the PTC-TC case. Then a mass flow rate independency procedure was conducted to ensure accurate results and to make a suitable comparison. The collectors were examined in a wide range of inlet temperatures ranging from 20 °C to 200 °C, and the thermal performance was calculated. Through the comparison process, it was revealed that the proposed collector appears to have higher thermal performance than the typical collector. In particular, there was a mean enhancement of approximately 8%, while the minimum enhancement was found to be greater than 5%. The simulation results regarding both configurations were verified through two models based on theoretical equations. In both geometries, the mean deviations in the verification procedure were lower than 5.6% in both the Darcy friction factor and the Nusselt number. The design and the simulations were conducted with the SolidWorks Flow Simulation tool.
Reliability of a Global Gait Symmetry Index Based on Linear Joint Displacements
Authors: Cabral Silvia , Fernandes Rita , Selbie William Scott , Moniz-Pereira Vera , Veloso António P.
Published: December 2022

Gait symmetry is commonly used as an informal measure to assess functional gait recovery. As other outcome measures used for the evaluation of clinical change over time, gait symmetry indices must be reliable. However, studies assessing the reliability of symmetry indices are scarce and focused on discrete and local indices (i.e., peak joint angle, step length), which fail to assess overall gait symmetry. On the other hand, the repeatability of global symmetry indices (using multiple continuous waveforms) based on joint angles may be hampered by the sensitivity of these variables to marker placement imprecision. The aim of this study is to evaluate the test–retest intra-rater reliability and measurement error of an alternative global symmetry index. Two 3D gait analyses were performed on separate days (a week interval) on twenty-three healthy adults. Reliability and measurement error were assessed by calculating the intraclass correlation coefficient and the 95% limits of agreement, standard error of measurement and smallest detectable change, respectively. The new symmetry index presented acceptable results in terms of reliability (ICC = 0.71, 95% CI 0.33–0.88) and measurement error (95% LOA between −30.2% and 29.1%, SEM = 10.7% and SDC = 29.7%), thus being a more promising tool to assess overall gait symmetry.
Spectrophotometric Analysis of 3D Printed and Conventional Denture Base Resin after Immersion in Different Colouring Agents—An In Vitro Study
Authors: Dimitrova Mariya , Capodiferro Saverio , Vlahova Angelina , Kazakova Rada , Kazakov Stoyan , Barile Giuseppe , Corsalini Massimo
Published: December 2022

Three-dimensional printed denture base resins are relatively new materials, and their properties need to be thoroughly investigated to assess whether they can be used clinically. The aim of the current study was to evaluate the colour stability of 3D printed and conventional denture base resins after immersion in different staining solutions. A total of 200 specimens were manufactured from two types of materials: 3D printed dental resin NextDent Denture 3D+ (NextDent, 3D Systems, the Netherlands) and heat-polymerized PMMA Vertex (3D Systems, the Netherlands), which were immersed in four types of colourants—artificial saliva, coffee, red wine and coke (n = 25). For measuring the colour changes (CIE-L*a*b* system), a SpectroShade Micro spectrophotometer (SpectroShade, Oxnard, CA, USA) was used. After seven days (T1), 14 days (T2) and 21 days (T3), the mean ∆E values were calculated and compared by the Bonferonni post hoc test. The data were processed using the statistical software SPSS 26. The level of significance for rejecting the null hypothesis was fixed at p < 0.05. The highest mean values for ∆E were found for both types of dental resin in red wine, and the lowest mean values for ∆E were found for 3D printed specimens in artificial saliva. The 3D printed denture base resin demonstrated better colour stability than the conventional acrylic materials. The staining effect correlated with the immersion time, with the red wine and coke having the strongest chromogenic impact and the period with the highest colour changes being 21 days.
Backdoor Attacks on Deep Neural Networks via Transfer Learning from Natural Images
Authors: Matsuo Yuki , Takemoto Kazuhiro
Published: December 2022

Backdoor attacks are a serious security threat to open-source and outsourced development of computational systems based on deep neural networks (DNNs). In particular, the transferability of backdoors is remarkable; that is, they can remain effective after transfer learning is performed. Given that transfer learning from natural images is widely used in real-world applications, the question of whether backdoors can be transferred from neural models pretrained on natural images involves considerable security implications. However, this topic has not been evaluated rigorously in prior studies. Hence, in this study, we configured backdoors in 10 representative DNN models pretrained on a natural image dataset, and then fine-tuned the backdoored models via transfer learning for four real-world applications, including pneumonia classification from chest X-ray images, emergency response monitoring from aerial images, facial recognition, and age classification from images of faces. Our experimental results show that the backdoors generally remained effective after transfer learning from natural images, except for small DNN models. Moreover, the backdoors were difficult to detect using a common method. Our findings indicate that backdoor attacks can exhibit remarkable transferability in more realistic transfer learning processes, and highlight the need for the development of more advanced security countermeasures in developing systems using DNN models for sensitive or mission-critical applications.
Three Steps towards Better Forecasting for Streamflow Deep Learning
Authors: Tan Woon Yang , Lai Sai Hin , Teo Fang Yenn , Armaghani Danial Jahed , Pavitra Kumar , El-Shafie Ahmed
Published: December 2022

Elevating the accuracy of streamflow forecasting has always been a challenge. This paper proposes a three-step artificial intelligence model improvement for streamflow forecasting. Step 1 uses long short-term memory (LSTM), an improvement on the conventional artificial neural network (ANN). Step 2 performs multi-step ahead forecasting while establishing the rates of change as a new approach. Step 3 further improves the accuracy through three different kinds of optimization algorithms. The Stormwater and Road Tunnel project in Kuala Lumpur is the study area. Historical rainfall data of 14 years at 11 telemetry stations are obtained to forecast the flow at the confluence located next to the control center. Step 1 reveals that LSTM is a better model than ANN with R 0.9055, MSE 17,8532, MAE 1.4365, NSE 0.8190 and RMSE 5.3695. Step 2 unveils the rates of change model that outperforms the rest with R = 0.9545, MSE = 8.9746, MAE = 0.5434, NSE = 0.9090 and RMSE = 2.9958. Finally, Stage 3 is a further improvement with R = 0.9757, MSE = 4.7187, MAE = 0.4672, NSE = 0.9514 and RMSE = 2.1723 for the bat-LSTM hybrid algorithm. This study shows that the δQ model has consistently yielded promising results while the metaheuristic algorithms are able to yield additional improvement to the model’s results.
Study on Thermal Storage Wall Heating System of Traditional Houses in Cold Climate Zone of China: A Case Study in Southern Shaanxi
Authors: Chen Shuo , Yang Simin , Mo Wensheng , Dewancker Bart J. , Mao Jing , Chen Jie
Published: December 2022

Solar energy has the advantages of being green, renewable, and energy-efficient. The use of solar energy in buildings can result in significant energy savings, and a great deal of practical and theoretical research has been conducted on solar buildings around the world. Southern Shaanxi belongs to a climate zone with hot summers and cold winters (HSCW). The mean room temperature is 4 °C, and it is lower than 2 °C at night, which greatly exceeds the thermal comfort range that the human body can bear. Aiming at a range of challenges including backward heating methods and low heating efficiency in southern Shaanxi, a fully passive thermal storage wall heating system (TSWHS) is proposed for traditional houses in the area. The specific method is to set up a thermal storage wall (TSW) outside the outer walls on the east, west, and south sides of the residential buildings. The wall is provided with an air exchange port, and there is no glass in the outer area of the doors and windows, which does not affect the normal application. The principle is that after the TSW receives solar radiation, the temperature of the internal HDPE (high-density polyethylene) and the air inside the cavity rises, which raises the interior temperature via the heat transfer and the air exchange port inside the TSW. The hot air inside the thermal wall achieves the purpose of heating. Lastly, through a comparison with the original heating system (OHS), it is confirmed that the TSWHS has certain practicability. According to an experimental simulation, the system can increase the indoor temperature by an average of 5.1 °C in winter and save about 1726.43 kWh of energy, accounting for 27.24% of the energy saving.
Numerical Simulation of the Dispersion of Exhaled Aerosols from a Manikin with a Realistic Upper Airway
Authors: Wei Jiayu , Xie Hao , Chen Xiaole , Quan Xibin , Zhang Zhicong , Xie Xiaojian , Shi Jianping , Zeng Guanghui
Published: December 2022

Basic analysis of the flow field and aerosol deposition under different conditions when a spreader contains an upper airway tract is important to accurately predict the transmission of virus-laden aerosols. An upper airway was included to simulate aerosol transport and deposition. A flow field was simulated by the Transition SST model for validation. The simulation results show that, in the absence of the upper airway structure, an over-predicted aerosol deposition rate will occur. Higher upper-stream air velocity enhanced the intensity but added complexity to the recirculating flow between two manikins and increased the deposition rate of aerosol in the disseminator. A low-temperature environment can reduce the deposition rate of aerosol particles on the body of the disseminator due to a strong thermal plume. Therefore, the structure of the upper airway should be considered when predicting respiratory aerosol in order to increase the accuracy of aerosol propagation prediction.
A Novel Komodo Mlipir Algorithm and Its Application in PM2.5 Detection
Authors: Li Linxuan , Zhao Ming
Published: December 2022

The paper presents an improved Komodo Mlipir Algorithm (KMA) with variable inertia weight and chaos mapping (VWCKMA). In contrast to the original Komodo Mlipir Algorithm (KMA), the chaotic sequence initialization population generated by Tent mapping and Tent Chaos disturbance used in VWCKMA can effectively prevent the algorithm from falling into a local optimal solution and enhance population diversity. Individuals of different social classes can be controlled by the variable inertia weight, and the convergence speed and accuracy can be increased. For the purpose of evaluating the performance of the VWCKMA, function optimization and actual predictive optimization experiments are conducted. As a result of the simulation results, the convergence accuracy and convergence speed of the VWCKMA have been considerably enhanced for single-peak, multi-peak, and fixed-dimensional complex functions in different dimensions and even thousands of dimensions. To address the nonlinearity of PM2.5 prediction in practical problems, the weights and thresholds of the BP neural network were iteratively optimized using VWCKMA, and the BP neural network was then used to predict PM2.5 using the optimal parameters. Experimental results indicate that the accuracy of the VWCKMA-optimized BP neural network model is 85.085%, which is 19.85% higher than that of the BP neural network, indicating that the VWCKMA has a certain practical application.
The Effect of European Climate Change on Indoor Thermal Comfort and Overheating in a Public Building Designed with a Passive Approach
Authors: Fürtön Balázs , Szagri Dóra , Nagy Balázs
Published: December 2022

Dynamic building energy performance modeling is becoming increasingly important in the architectural, engineering, and construction (AEC) industry because of the sector’s significant environmental impact. For such analysis, a climate file representing a typical meteorological year (TMY) is needed, including hourly values for the most important weather-related parameters. However, TMY shows little resemblance to the future of the particular location where a building has been used for decades. Therefore, using predicted future climates during building design is unfortunately rarely practiced, potentially undermining the strategies that should be the fundamental basis of the design. To explore this question, our study compared the heating and cooling energy consumption, indoor thermal comfort, and summer overheating potential of a selected building for three distinctive European climates, in Hungary, Portugal, and Lithuania. All of them were changed according to the IPCC RCP4.5 scenario, and were examined for the present, the 2050, and the 2100 scenarios. We also tested adaptive clothing to evaluate the indoor comfort parameters. The results show a 10% increase in heating and cooling energy use for the same construction and location between 2020 and 2100. The continental climate of Budapest is the most threatened by summer overheating, with an increase of 69% for the ODH26 indicator. A more balanced warming for Lisbon was found (23%), and moderate changes for the city of Kaunas (a 153% increase from a very low baseline).
Assessment of Greenhouse Gas Emissions into the Atmosphere from the Northern Peatlands Using the Wetland-DNDC Simulation Model: A Case Study of the Great Vasyugan Mire, Western Siberia
Authors: Mikhalchuk Alexander , Borilo Ludmila , Burnashova Elena , Kharanzhevskaya Yulia , Akerman Ekaterina , Chistyakova Natalia , Kirpotin Sergey N. , Pokrovsky Oleg S. , Vorobyev Sergey
Published: December 2022

The peatlands of Western Siberia occupy an area of about 1 million km2 and act as important regulator of carbon exchange between the earth and the atmosphere. Extrapolation of the results of discrete field measurements of CO2 fluxes in bog ecosystems to such a territory is a difficult task, and one of the ways to overcome it is to use a simulation model such as DNDC. However, using this model with a specific territory requires ground verification to confirm its effectiveness. Here, we tested the DNDC model on the largest pristine bog ecosystem of the world, the Great Vasyugan Mire (GVM). The GVM of western Siberia is virtually undisturbed by anthropogenic activity and is the largest bog of Northern Eurasia (53,000 km2). Based on various ground-based observations, the performance of the Wetland-DNDC model was demonstrated (Thale coefficient 0.085 and R2 = 0.675 for CO2). Model input parameters specific to the GVM were constrained and model sensitivity to a wide range of input parameters was analyzed. The estimated annual terrestrial carbon fluxes in 2019 from the GVM test site are mainly controlled by plant respiration (61%) and forest floor degradation (38%). The net CO2 emission flux was 8600 kg C ha−1 year−1, which is in line with estimates from other independent studies.
Investigations on the Global Spread of the Hunga Tonga-Hunga Ha’apai Volcanic Eruption Using Space-Based Observations and Lagrangian Transport Simulations
Authors: Mishra Manoj Kumar , Hoffmann Lars , Thapliyal Pradeep Kumar
Published: December 2022

On 15 January 2022, the Hunga Tonga-Hunga Ha’apai (HTHH) (175.38° W, 20.54° S) volcano erupted explosively. It is considered the most explosive volcanic eruption during the past 140 years. The HTHH volcanic eruption caused intense ripples, Lamb waves, and gravity waves in the atmosphere which encircled the globe several times, as reported by different studies. In this study, using OMI, SAGE-III/ISS, and CALIPSO satellite observations, we investigated the spread of the volcanic SO2 cloud due to the HTHH eruption and subsequent formation of sulfuric acid clouds in the stratosphere. It took about 19–21 days for the stratospheric SO2 injections of the HTHH to encircle the globe longitudinally due to a dominant westward jet with wind speeds of ~2500 km/day, and it slowly dispersed over the whole globe within several months due to poleward spread. The formation of sulfuric acid clouds intensified after about a month, causing the more frequent occurrence of high aerosol optical depth elevated layers in the stratosphere at an altitude of about 20–26 km. This study deals with the dynamics of volcanic plume spread in the stratosphere, knowledge of which is essential in estimating the accurate radiative effects caused by perturbations in the earth–atmosphere system due to a volcanic eruption. In addition, this knowledge provides important input for studies related to the geo-engineering of the earth’s atmosphere by injecting particulates and gases into the stratosphere.
Effect of the Addition of Waste Generated during the Plasma Cutting of Aluminum Products on the Friction and Emission Properties of a Commercial Friction Material Formulation
Authors: Jayashree Priyadarshini , Candeo Stefano , Leonardi Mara , Fidelio Carlo , Straffelini Giovanni
Published: December 2022

With recycling and reuse in mind, this study explores the possibility of the utilization of waste generated during the plasma cutting operations to produce aluminum products in a commercial friction material formulation for car braking applications. The as-received waste, analyzed in the form of a powder, was subjected to various characterization techniques to obtain its composition and phase constituents. The friction, wear, and emission analyses were organized in two ways: the first part focused on the selection of the most suitable waste content in the friction material formulation—10, 15, and 20 wt.%—tested in the form of pins, using a pin-on-disc tribometer. The second part evaluated the most suitable content in the formulation in the form of coupons on a subscale dynamometer to comprehend its friction and emission characteristics in a more complex scenario. Through the pin-on-disc analysis, it was seen that the 10 wt.% of waste in the formulation provided permissible friction and wear behavior, and similar emission magnitude and secondary plateau characteristics were seen, as compared to the reference composition. Similar results were recorded on the subscale dynamometer at mild braking conditions. At ‘severe’ testing conditions, a different trend was observed. Through this analysis, the possibility of the addition of this kind of waste in friction material composition has been evaluated deeply, paving a path for further analysis and possible implementation.
Experimental Investigation of Shear Strength of Carbonate Saline Soil under Freeze-Thaw Cycles
Authors: Qiu Kaichi , Ding Lin , Yu Wenbing , Chen Kezheng , Huang Shuai , Gao Kai
Published: December 2022

Climate change is accelerating its adverse impact on ecosystems and infrastructure systems in cold regions. For extensive carbonate saline soil areas, their response to the freeze-thaw cycle remains uncertain. By considering the continuous intensification of freeze-thaw cycle frequency, the mechanical characteristics of carbonate saline soils are analyzed for different salt content (0.6% to 2.1%) based on the mechanical test in this paper. The purpose is to reveal the change law of shear strength and its parameters of carbonate saline soils under the scenario of continuous freezing and thawing cycles. The micro-characteristics of the carbonate saline soil before and after freeze-thaw cycling were analyzed by scanning electron microscopy, indicating changes in the structural soil properties caused by the combination of freeze-thawing and salinity. The scanning electron microscope images reveal the cumulative effect of frost heaving and salt expansion, i.e., increasing the number of pores between particles, reducing the effective contact between particles, and weakening the interaction force, resulting in cracks development. A series of mechanical tests demonstrate the stress-strain behavior of carbonate saline soils for different numbers of freeze-thaw cycles under different confining pressures. A transformation from strain-softening to strain-hardening is observed with an increase in the salt content from 0.6% to 2.1%. Furthermore, the shear strength of the carbonate saline soil decreases as the salt content and number of freeze-thaw cycles increase. The shear strength degradation mechanism is attributed to the cohesion and the internal friction angle. These shear strength parameters are critical in geotechnical analyses, such as evaluating of load capacity of foundations and slope stability in similar saline soils.
Impact Analysis of Variable Resolution of MPAS on Intrinsic Predictability Using Bred Vectors
Authors: Kang Ji-Sun , Shin Seoleun , Myung Hunjoo
Published: December 2022

Variable resolution configuration is a defining feature of the NCAR MPAS (Model for Prediction Across Scales) model, which allows us to smoothly vary the horizontal resolution for taking a closer look at an area of interest. In this study, we aimed to analyze the impact of variable resolution on intrinsic predictability using bred vectors. Thus, the breeding cycles of the MPAS model with and without variable resolution configuration were implemented and tested with two different rescaling intervals of 6 h and 1 day. Rescaling within our breeding cycles were centered by the nature run, thus we could deal with the intrinsic predictability limited only by the initial error growth. We confirmed reasonable estimates of fast-growing errors by bred vectors at two different scales of convective and synoptic systems. We then found that the variable resolution configuration gave consistent improvement of intrinsic predictability not only over the high-resolution area but also outside. A quantitative analysis showed that an improvement with the variable resolution could be found in general for most vertical levels for both rescaling interval experiments. Additionally, we present the computational cost and experience of performing the variable resolution model which would help users in their decisions on this setting.
Second-Order Multiparameter Problems Containing Complex Potentials
Authors: Erdal Ibrahim , Uğurlu Ekin
Published: December 2022

In this work, we provide some lower bounds for the number of squarly integrable solutions of some second-order multiparameter differential equations. To obtain the results, we use both Sims and Sleeman’s ideas and the results are some generalization of the known results. To be more precise, we firstly construct the Weyl–Sims theory for the singular second-order differential equation with several spectral parameters. Then, we obtain some results for the several singular second-order differential equations with several spectral parameters.