bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Reuse of SLS Polyamide 12 Powder
Authors: Gomes Pedro C. , Piñeiro Oscar G. , Alves Alexandra C. , Carneiro Olga S.
Published: August 2022

In the Selective Laser Sintering (SLS) technique, the great majority of the powder involved is not included in the final printed parts, being just used as a support material. However, the quality of this powder is negatively affected during the process since it is subjected to high temperatures (close to its melting temperature) during a long time, i.e., the printing cycle time, especially in the neighborhood of the printed part contour. This type of powder is relatively expensive and large amounts of used powder result after each printing cycle. The present paper focuses on the reuse of Polyamide 12 (PA 12) powder. For this sake, the same PA 12 powder was used in consecutive printing cycles. After each cycle, the remaining non-used powder was milled and filtered before subsequent use. Properties of the powder and corresponding prints were characterized in each cycle, using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), computed tomography (CT), and tensile tests. It was concluded that subjecting the same powder to multiple SLS printing cycles affects the properties of the printed parts essentially regarding their morphology (voids content), mechanical properties reproducibility, and aesthetical aspect. However, post-processing treatment of the powder enabled to maintain the mechanical performance of the prints during the first six printing cycles without the need to add virgin powder.
Corrosion Testing of CrNx-Coated 310 H Stainless Steel under Simulated Supercritical Water Conditions
Authors: Tudose Aurelia Elena , Golgovici Florentina , Anghel Alexandru , Fulger Manuela , Demetrescu Ioana
Published: August 2022

The paper’s aim is the assessment of corrosion behaviour of a CrNx-coated 310 H stainless steel under simulated supercritical water conditions (550 °C and 25 MPa) for up to 2160 h. The CrNx coating was obtained by the thermionic vacuum arc (TVA) method. The oxides grown on this coating were characterized using metallographic and gravimetric analysis, SEM with EDS, and grazing incidence X-ray diffraction (GIXRD). A diffusion mechanism drives oxidation kinetics because it follows a parabolic law. By XRD analysis, the presence of Cr2O3 and Fe3O4 on the surface of the autoclaved CrNx-coated 310 H samples were highlighted. Corrosion susceptibility assessment was performed by electrochemical impedance spectroscopy (EIS) and linear potentiodynamic polarization. EIS impedance spectra show the presence of two capacitive semicircles in the Nyquist diagram, highlighting both the presence of the CrNx coating and the oxide film formed during autoclaving on the 310 H stainless steel. Very low corrosion rates, with values up to 11 nm × year−1, obtained in the case of autoclaved for 2160 h, CrNx-coated samples indicated that the oxides formed on these samples are protective and provide better corrosion resistance. The determination of micro hardness Vickers completed the above investigation.
Peak Net Pressure Coefficients of Elliptical Center-Open Dome Roofs
Authors: Lee Jong Ho , Cheon Dong Jin , Kim Yong Chul , Yoon Sung Won
Published: August 2022

Recently, the demand for spatial structures such as retractable dome roofs is increasing. The safety of dome roofs must be ensured even when they are open. Hence, studies analyzing the peak pressure coefficients of spherical dome roofs are actively being conducted. However, no peak pressure coefficients for the cladding design of elliptical retractable dome roofs have been proposed. Although several studies on elliptical open dome roofs that open from the edge to the center have been conducted, studies on those that open from the center to the edge are still insufficient. This study investigated the peak pressure coefficients of elliptical center-open dome roofs. For wind tunnel tests, a model was fabricated with an opening ratio of 30%. Under experimental conditions, five different wall height-to-span ratios (from 0.1 to 0.5) were used, with the roof rise-to-span ratio set at 0.1. Accordingly, the experimental values of the peak pressure coefficients of elliptical center-open dome roofs were compared with those of the closed dome roofs proposed in the Korean and Japanese wind load codes. Subsequently, their efficiency was verified. The findings were also compared with previous research outcomes. Based on the results, peak net pressure coefficients are proposed for cladding designs suitable for elliptical center-open dome roofs.
The Mechanism of Wear Reduction in the Ni-CaF2 Composite Material: Raman and Confocal Microscopy Insights
Authors: Kotkowiak Mateusz , Piasecki Adam , Kotkowiak Michał , Buchwald Tomasz
Published: August 2022

A powder metallurgy process was used to produce high temperature self-lubricating composites based on Ni, with varying content of calcium fluoride (10 wt.% and 20 wt.%). The wear properties of the samples were investigated by a pin-on-disc test at elevated temperature, up to 600 °C. Aside from standard techniques for the sample characterization, confocal microscopy and micro-Raman spectroscopy were used for the first time for this type of sample. These methods were used to examine the changes in topography and to detect the distribution of the tribofilm on sample surfaces. The addition of solid lubricant particles decreased the coefficient of friction and improved the tribological properties, because of the tribofilm which formed on sample surfaces.
An Improved Quasi-Z-Source Boost DC-DC Converter Using Single-Stage Switched-Inductor Boosting Technique
Authors: Premkumar Manoharan , Ramakrishnan Chandran , Kumar Chandrasekaran , Sowmya Ravichandran , Sumithira Thulasimani Ramalingam , Jangir Pradeep
Published: August 2022

A modified single-stage Quasi-Z-Source (QZS) boost DC-DC converter using a single MOSFET switch with a single-stage switched-inductor (SI) network is proposed in this paper. The DC-DC converter proposed in this study provides an extra voltage gain compared to the traditional QZS DC-DC converter. An additional capacitor and diode circuit are added to the existing QZS converter to decrease the voltage stress on the MOSFET switch. Therefore, compared to the traditional QZS boost converter, the proposed Modified QZS (MQZS) converter provides large voltage gain under a low duty ratio, less voltage stress, and continuous input current. Moreover, the reliability and the conversion efficiency can be increased. The derivation of the proposed MQZS converter and its operation, selection of parameters, and comparison with another similar converter are discussed in this paper. Lastly, the simulation and experimental results are illustrated to prove the notional deliberations of the proposed MQZS converter.
The Development of PSO-ANN and BOA-ANN Models for Predicting Matric Suction in Expansive Clay Soil
Authors: Davar Saeed , Nobahar Masoud , Khan Mohammad Sadik , Amini Farshad
Published: August 2022

Disasters have different shapes, and one of them is sudden landslides, which can put the safety of highway users at risk and result in crucial economic damage. Along with the risk of human losses, each day a highway malfunctions causes high expenses to citizens, and repairing a failed highway is a time- and cost-consuming process. Therefore, correct highway functioning can be categorized as a high-priority reliability factor for cities. By detecting the failure factors of highway embankment slopes, monitoring them in real-time, and predicting them, managers can make preventive, preservative, and corrective operations that would lead to continuing the function of intracity and intercity highways. Expansive clay soil causes many infrastructure problems throughout the United States, and much of Mississippi’s highway embankments and fill slopes are constructed of this clay soil, also known as High-Volume Change Clay Soil (HVCCS). Landslides on highway embankments are caused by recurrent volume changes due to seasonal moisture variations (wet-dry cycles), and the moisture content of the HVCCS impacts soil shear strength in a vadose zone. Soil Matric Suction (SMS) is another indication of soil shear strength, an essential element to consider. Machine learning develops high-accuracy models for predicting the SMS. The current work aims to develop hybrid intelligent models for predicting the SMS of HVCCS (known as Yazoo clay) based on field instrumentation data. To achieve this goal, six Highway Slopes (HWS) in Jackson Metroplex, Mississippi, were extensively instrumented to track changes over time, and the field data was analyzed and generated to be used in the proposed models. The Artificial Neural Network (ANN) with a Bayesian Regularization Backpropagation (BR-BP) training algorithm was used, and two intelligent systems, Particle Swarm Optimization (PSO) and Butterfly Optimization Algorithm (BOA) were developed to optimize the ANN-BR algorithm for predicting the HWS’ SMS by utilizing 13,690 data points for each variable. Several performance indices, such as coefficient of determination (R2), Mean Square Error (MSE), Variance Account For (VAF), and Regression Error Characteristic (REC), were also computed to analyze the models’ accuracy in prediction outcomes. Based on the analysis results, the PSO-ANN outperformed the BOA-ANN, and both had far better performance than ANN-BR. Moreover, the rainfall had the highest impact on SMS among all other variables and it should be carefully monitored for landslide prediction HWS. The proposed hybrid models can be used for SMS prediction for similar slopes.
Infrared Target-Background Separation Based on Weighted Nuclear Norm Minimization and Robust Principal Component Analysis
Authors: Rawat Sur Singh , Singh Sukhendra , Alotaibi Youseef , Alghamdi Saleh , Kumar Gyanendra
Published: August 2022

The target detection ability of an infrared small target detection (ISTD) system is advantageous in many applications. The highly varied nature of the background image and small target characteristics make the detection process extremely difficult. To address this issue, this study proposes an infrared patch model system using non-convex (IPNCWNNM) weighted nuclear norm minimization (WNNM) and robust principal component analysis (RPCA). As observed in the most advanced methods of infrared patch images (IPI), the edges, sometimes in a crowded background, can be detected as targets due to the extreme shrinking of singular values (SV). Therefore, a non-convex WNNM and RPCA have been utilized in this paper, where varying weights are assigned to the SV rather than the same weights for all SV in the existing nuclear norm minimization (NNM) of IPI-based methods. The alternate direction method of multiplier (ADMM) is also employed in the mathematical evaluation of the proposed work. The observed evaluations demonstrated that in terms of background suppression and target detection proficiency, the suggested technique performed better than the cited baseline methods.
Dynamical Analysis of a Stochastic Cholera Epidemic Model
Authors: Zhou Xueyong
Published: August 2022

Environmental disturbances have a strong impact on cholera transmission. Stochastic differential equations are an effective tool for characterizing environmental perturbations. In this paper, a stochastic infectious disease model for cholera is established and investigated. The dynamics of the stochastic cholera model are discussed. Firstly, the existence and uniqueness of the positive solution are proven. Then, the asymptotical stability of the disease-free equilibrium of the system is investigated. Furthermore, the asymptotical stability of the endemic equilibrium of the deterministic system corresponding to the stochastic system is obtained. Then, the theoretical results are verified by some numerical simulations. Finally, the optimal problem is considered as the theoretical basis for the control of cholera. Both theoretical and numerical results indicate that the random perturbations may make the model more realistic, which provides theoretical assessment for the control of cholera transmission.
Optimal Control of PC-PLC Virus-Mutation and Multi-Delay Propagation Model in Distribution Network CPS
Authors: Su Yingying , Qiu Zijing , Liu Guiyun , Liang Zhongwei
Published: August 2022

The intelligent manufacturing of power systems has led to many challenges. The cyber-physical system (CPS) was introduced to solve the problem of insufficient integration of equipment and systems. It brings advantages, but also risks. In the distribution network CPS, malicious attacks on the PC-PLC communication network can cause significant incidents and affect system safety. The paper discusses two challenges, of possible mutated virus attacks and multi-delay in the PC-PLC coupled network. We present for the first time a virus-mutation and multi-delay propagation model. Then, to effectively control the virus propagation in the network and minimize the cost, the paper proposes five control measures, introduces their possible control combinations, and solves the optimal control problem with the Pontryagin maximum theorem. Finally, simulations verify the optimal control strategies for all combinations. By comparing the effects of maximum control, minimum control, average control, and optimal control, the optimal control strategy has been proven to be effective.
HOME: 3D Human–Object Mesh Topology-Enhanced Interaction Recognition in Images
Authors: Peng Weilong , Li Cong , Tang Keke , Liu Xianyong , Fang Meie
Published: August 2022

Human–object interaction (HOI) recognition is a very challenging task due to the ambiguity brought by occlusions, viewpoints, and poses. Because of the limited interaction information in the image domain, extracting 3D features of a point cloud has been an important means to improve the recognition performance of HOI. However, the features neglect topological features of adjacent points at low level, and the deep topology relation between a human and an object at high level. In this paper, we present a 3D human–object mesh topology enhanced method (HOME) for HOI recognition in images. In the method, human–object mesh (HOM) is built by integrating the reconstructed human and object mesh from images firstly. Therefore, under the assumption that the interaction comes from the macroscopic pattern constructed by spatial position and microscopic topology of human–object, HOM is inputted into MeshCNN to extract the effective edge features by edge-based convolution from bottom to up, as the topological features that encode the invariance of the interaction relationship. At last, topological cues are fused with visual cues to enhance the recognition performance greatly. In the experiment, HOI recognition results have achieved an improvement of about 4.3% mean average precision (mAP) in the Rare cases of the HICO-DET dataset, which verifies the effectiveness of the proposed method.
The Shape Parameter in the Shifted Surface Spline—An Easily Accessible Approach
Authors: Luh Lin-Tian
Published: August 2022

In this paper, we present an easily accessible approach to finding a suitable shape parameter in the shifted surface spline for function interpolation. We aim at helping more readers, including mathematicians and non-mathematicians, to use our method to solve practical problems. Hence, some highly complicated mathematical theorems and definitions are avoided. The major requirement, as in our previous approach, that the data points should be evenly spaced in the domain is also relaxed. This means that the data points are purely scattered without restrictions. The drawback is that the shape parameter thus obtained is not exactly the same as the theoretically predicted optimal value, which can always be achieved by using our previous rigorous approach. However, experiments show that the gap is quite small and the final interpolation errors thus obtained are satisfactory.
Sustainable Management in Active Networks
Authors: Ougolnitsky Gennady , Gorbaneva Olga
Published: August 2022

This paper synthesizes two areas of research: control models in networks and sustainable development of active systems. The concept of an active network (an active system with a network structure) is proposed and formalized. Two common classes, hierarchical and non-hierarchical active networks, are identified and studied; some illustrative examples are given. The sustainable management problem of active networks is stated, and approaches to its solution are described. A model example of opinion control in an active network with sustainable development requirements is numerically simulated. For this purpose, the author’s method of qualitatively representative scenarios is used.
Extended Comparative Study between Newton’s and Steffensen-like Methods with Applications
Authors: Argyros Ioannis K. , Argyros Christopher , Ceballos Johan , González Daniel
Published: August 2022

Comparisons between Newton’s and Steffensen-like methods are given for solving systems of equations as well as Banach space valued equations. Our idea of the restricted convergence domain is used to compare the sufficient convergence criteria of these methods under the same conditions as in previous papers. It turns out that the following advantages are shown: enlarged convergence domain; tighter error estimates and a more precise information on the location of the solution. Advantages are obtained under the same or at least as tight Lipschitz constants, which are specializations of earlier ones. Hence, the applicability of these methods is extended. Numerical experiments complete this study.
Technology Spillovers among Innovation Agents from the Perspective of Network Connectedness
Authors: Zhang Cui , Feng Xiongjin , Wang Yanzhen
Published: August 2022

By constructing a technology spillover connectedness index and connectedness matrix, this paper studies the technology spillover connectedness among innovation agents in China from the perspective of network topology. An empirical study based on invention patent data finds that there is noticeable technology spillover connectedness among the six innovation agents: central enterprises, other domestic enterprises, universities and scientific research institutes, troops, individuals and other organizations, and foreign-funded enterprises. Other domestic enterprises are the hub of technology spillover connectedness among these agents, while foreign-funded enterprises play a limited role. The study of further subdividing foreign-funded enterprises according to their sources finds that the United States, South Korea, and Japan are the centers of technology spillover connectedness in China. The dynamic evolution of technology spillover connectedness shows that the total technology spillover connectedness among innovation agents presents an obvious downward trend, which is closely related to the complex and changeable international economic situation and the uncertainty of China’s economic policy in recent years. This paper concludes with insights into how China uses the spillover connectedness among innovation agents to spur agents’ innovation performance and promote the nation’s economic growth and competitiveness.
Salvage Post-Operative Stereotatic Ablative Radiotherapy for Re-Current Squamous Cell Carcinoma of Head and Neck
Authors: Pellizzon Antonio , Silva Maria , Fogaroli Ricardo , Neto Elson , Chen Michael , Godim Guilherme , Castro Douglas , Ramos Henderson , Abrahao Carolina
Published: August 2022

Background and Objectives: Patients with recurrent squamous cell carcinoma of the head and neck (rHNC) face an aggressive disease. Surgical resection is the gold standard treatment. Immediate adjuvant post-operative stereotactic ablative radiotherapy (PO-SABR) for rHNC is debatable. Materials and Methods: We retrospectively identified patients who were treated with PO-SABR at the AC Camargo Cancer Center, Brazil. Results: Eleven patients were treated between 2018 and 2021. The median time between salvage surgery and PO-SABR was 31 days (range, 25–42) and the median PO-SABR total dose was 40 Gy (range, 30–48 Gy). The 2-and 4-year actuarial DFS were 62.3% and 41.6%, while the 2-and 4-year OS probabilities were 80.0% and 53.3%, respectively. Eight (72.7%) patients were alive and six (54.5%) were without disease at the last follow-up. Two (18.1%) patients had local failure in the PO-SABR field. Three (27.3%) patients had distant metastasis, diagnosed in a median time of 9 months (range, 4–13) after completion of PO-SABR. On univariate analysis, predictive factors related to worse OS were: interval between previous radiotherapy and PO-SABR ≤ 24 months (p = 0.033) and location of the salvage target in the oral cavity (p = 0.013). The total dose of PO-SABR given in more than three fractions was marginally statistically significant, favoring the OS (p = 0.051). Conclusions: Our results encourage the use of a more aggressive approach in selected patients with rHNC by combining salvage surgery with immediate PO-SABRT, but this association needs to be further explored.
Online Instruction to Measure Axial Alignment with the Bonesetter App
Authors: Bernstein Mitchell , Bunge Tatiana , Rosinski Kadence , Kfuri Mauricio , Crist Brett , Knapp Andrew , Vaidya Rahul
Published: August 2022

Background and objectives: Alignment of the lower extremity is important when treating congenital deformities, fractures, and joint replacement. During the COVID-19 pandemic, AO North America offered an online course on deformity measurement and planning. The Bonesetter app is a deformity planning tool that is freely available online. The purpose of this study was to see how effective an online course was in teaching axial alignment measurement and to assess that skill using an online digital planning tool, the Bonesetter app. Materials and Methods: An online module on axial alignment was provided during the AONA osteotomy course as well as a tutorial on how to use an online digital planning tool (Bonesetter app). The tools within the Bonesetter app allow users to draw digital lines directly on the CT images and measure the exact angle between two planes. Participants in this study were directed to perform these measurements in four different cases that tested different variations of deformity. Results: The measurements were completed correctly in case 1 = 56%, case 2 = 61%, case 3 = 84%, and case 4 = 76%. The standard deviation of angular digital measurements between individuals was ±4.26 degrees. Measuring the angle directly vs. drawing angles to a horizontal line had smaller standard deviations per case (p < 0.005) and less incidents outside 1 standard deviation for each measurement. Errors in adding and subtracting were the most common errors, particularly in relation to femoral anteversion or retroversion. Conclusions: The online course successfully instructed a group of orthopedic surgeons to measure alignment and malalignment of lower limb axial deformities. The Bonesetter app helped participants to learn this skill and identify errors in measurement. The inability to differentiate between anteversion and retroversion of the femur is a common source of error when it occurs and should be a focus of instruction.
Clinicopathological Characteristics and Overall 5-Year Survival of Colorectal Cancer: A Retrospective Study
Authors: Almuhanna Rahaf , Al-Thoubaity Fatma , Almalki Khadijah , Algarni Nada , Hamad Renad , Makhtoum Toleen
Published: August 2022

Colorectal cancer (CRC) is the third leading cause of cancer-related death. We aimed to investigate the clinicopathological characteristics and 5-year survival in CRC. This retrospective study reviewed King Abdulaziz University Hospital records from 2009 to 2019. Tumor staging was performed using Dukes’ pathological classification. Additionally, we measured the frequency of qualitative data and performed the chi-square and Mann–Whitney U-tests. Kaplan–Meier analysis was performed to calculate overall survival. Of the 574 included patients (age (mean ± standard deviation), 55.51 ± 14.28 years), 43.2% were Saudis, and most were male (58.7%). The rectum was the most common location of CRC (30.8%); 33.1% of patients presented with abdominal pain. The dominant histological variant was mucinous adenocarcinoma (95.5%). Age at diagnosis was significantly associated with Dukes’ staging; 36.3% of individuals aged <50 years had Dukes’ D stage. The 5-year survival rate was 47.9%. Better survival was noted for those of Saudi nationality, those with Dukes’ A stage, and those who were overweight (51.6%, 56.3%, and 46.8%, respectively). Significantly better survival was seen in Saudi patients due to accessible healthcare and in overweight patients due to better treatment tolerance. The outcome of CRC was not related to sex or metformin use in patients with diabetes mellitus.
Optimal Design of Functionally Graded Parts
Authors: Nayak Priyambada , Armani Amir
Published: August 2022

Several additive manufacturing processes are capable of fabricating three-dimensional parts with complex distribution of material composition to achieve desired local properties and functions. This unique advantage could be exploited by developing and implementing methodologies capable of optimizing the distribution of material composition for one-, two-, and three-dimensional parts. This paper is the first effort to review the research works on developing these methods. The underlying components (i.e., building blocks) in all of these methods include the homogenization approach, material representation technique, finite element analysis approach, and the choice of optimization algorithm. The overall performance of each method mainly depends on these components and how they work together. For instance, if a simple one-dimensional analytical equation is used to represent the material composition distribution, the finite element analysis and optimization would be straightforward, but it does not have the versatility of a method which uses an advanced representation technique. In this paper, evolution of these methods is followed; noteworthy homogenization approaches, representation techniques, finite element analysis approaches, and optimization algorithms used/developed in these studies are described; and most powerful design methods are identified, explained, and compared against each other. Also, manufacturing techniques, capable of producing functionally graded materials with complex material distribution, are reviewed; and future research directions are discussed.
Two-Step Converging Spherical Wave Diffracted at a Circular Aperture of Digital In-Line Holography
Authors: Tian Peng , He Liang , Guo Xiaoyi , Ma Zeyu , Song Ruiqi , Liao Xiaoqiao , Gan Fangji
Published: August 2022

The aspheric light emitted from a pinhole restrains the reconstruction quality of a digital in-line hologram. Herein, the Fresnel-diffracted spot from the first step converging spherical wave diffracted at a rough circular aperture is collimated and expanded to generate an even plane wave, which is converged again by an objective lens and matching a minimum aperture while the central spot is varying from light to dark. We observed that the collected background hologram is filled with a round spot with high contrast as an ideal spherical wave. The resolution board and biology experimental results demonstrated a distinctively reconstructed image without any image processing in a single exposure. The adjustable field of view and magnification, single exposure, and noncontact make it suitable for an online microscope.
An Annular Fresnel Zone Plate without Central Spots Fabricated by Femtosecond Laser Direct Writing
Authors: Sun Xiaoyan , Zhou Fang , Duan Lian
Published: August 2022

In recent years, micro-annular beams have been widely used, which has expanded the possibilities for laser processing. However, the current method of generating an annular beam still has shortcomings, such as spot energy at the center of the produced beam. In this study, a Fresnel zone plate with an annular structure was machined using a femtosecond laser. After focusing, an annular laser beam without a spot in the center was obtained, and the radius and focal length of the annular beam could be easily adjusted. In addition, two annular Fresnel zone plates were concentrically connected to obtain a concentric double-ring beam in the same focal plane. The simulation and experimental results were consistent, providing effective potential for applications related to nontraditionally shaped laser beams.
Controlling an Unprecedented Outbreak with Vancomycin-Resistant Enterococcus faecium in Germany, October 2015 to November 2019
Authors: Bender Jennifer K. , Hermes Julia , Zabel Lutz T. , Haller Sebastian , Mürter Nadja , Blank Hans-Peter , Werner Guido , Hüttner Ingo , Eckmanns Tim
Published: August 2022

Hospital outbreaks with vancomycin-resistant enterococci (VRE) pose a serious health threat and a challenge to infection prevention and control (IPC). We herein report on a VRE outbreak of unprecedented extent in Southern Germany (October 2015–November 2019). We used descriptive epidemiology and whole-genome sequencing (WGS) for a detailed outbreak investigation. Of the 2905 cases, 2776 (95.3%) were colonized, whereas from 127 (3.7%), VRE could be isolated from otherwise sterile body fluids or sites unlikely for enterococci colonization. Cases had a median age of 78 years (IQR 68–84) and 1339/2905 (46%) were female. The majority of isolates sequenced belonged to the clonal lineage ST80/CT1013 (212/397, 53%). Nosocomial transmission was observed as well as the constant import of VRE into the hospital. Extensive IPC measures were implemented and terminated the outbreak in late 2019, eventually. Our study shows that the combination of epidemiological and genomic analyses is indispensable for comprehensive outbreak investigations. The adaptation of IPC measures to these findings, their timely implementation, and strict execution also allow containment of large VRE outbreaks in hospital settings.
A 2-Year Retrospective Case Series on Isolates of the Emerging Pathogen Actinotignum schaalii from a Canadian Tertiary Care Hospital
Authors: Kakodkar Pramath , Hamula Camille
Published: August 2022

(1) Background: Actinotignum schaalii is an emerging, opportunistic pathogen often linked with UTIs but can extend beyond the urogenital system. Data on the clinical significance of A. schaalii are still emerging. (2) Methods: A retrospective review of A. schaalii isolates in a Canadian tertiary care hospital was conducted. The clinical data of patients that grew A. schaalii from January 2020 to 2022 were documented. Demographics, site, management, and microbiological parameters surrounding culture and sensitivities were recorded. (3) Results: A total of 43 cases of A. schaalii were identified. Actinotignum schaalii was primarily involved in UTIs (n = 17), abscesses (n = 9), bacteremia (n = 6), septic arthritis (n = 5), and ulcers (n = 5). A. schaalii had a slight predilection for polymicrobial infections (51.1%, n = 22 out of 43), with Aerococcus urinae (n = 5) being the most common coisolate. Susceptibility testing was only performed in two cases that showed sensitivity to beta-lactam antibiotics and resistance to metronidazole and ciprofloxacin. Amoxicillin–clavulanate (n = 5) is the most frequently prescribed antibiotic. (4) Conclusions: The non-urogenic clinical significance of A. schaalii remains undervalued. The management of A. schaalii infection is multimodal, consisting predominantly of antimicrobials and surgical procedures specific to the etiology. Clinicians should request sensitivities for A. schaalii so that appropriate antimicrobial coverage can be provided.
The Role of Thermokarst Lake Expansion in Altering the Microbial Community and Methane Cycling in Beiluhe Basin on Tibetan Plateau
Authors: Xu Qian , Du Zhiheng , Wang Lei , Xue Kai , Wei Zhiqiang , Zhang Gaosen , Liu Keshao , Lin Jiahui , Lin Penglin , Chen Tuo , Xiao Cunde
Published: August 2022

One of the most significant environmental changes across the Tibetan Plateau (TP) is the rapid lake expansion. The expansion of thermokarst lakes affects the global biogeochemical cycles and local climate regulation by rising levels, expanding area, and increasing water volumes. Meanwhile, microbial activity contributes greatly to the biogeochemical cycle of carbon in the thermokarst lakes, including organic matter decomposition, soil formation, and mineralization. However, the impact of lake expansion on distribution patterns of microbial communities and methane cycling, especially those of water and sediment under ice, remain unknown. This hinders our ability to assess the true impact of lake expansion on ecosystem services and our ability to accurately investigate greenhouse gas emissions and consumption in thermokarst lakes. Here, we explored the patterns of microorganisms and methane cycling by investigating sediment and water samples at an oriented direction of expansion occurred from four points under ice of a mature-developed thermokarst lake on TP. In addition, the methane concentration of each water layer was examined. Microbial diversity and network complexity were different in our shallow points (MS, SH) and deep points (CE, SH). There are differences of microbial community composition among four points, resulting in the decreased relative abundances of dominant phyla, such as Firmicutes in sediment, Proteobacteria in water, Thermoplasmatota in sediment and water, and increased relative abundance of Actinobacteriota with MS and SH points. Microbial community composition involved in methane cycling also shifted, such as increases in USCγ, Methylomonas, and Methylobacter, with higher relative abundance consistent with low dissolved methane concentration in MS and SH points. There was a strong correlation between changes in microbiota characteristics and changes in water and sediment environmental factors. Together, these results show that lake expansion has an important impact on microbial diversity and methane cycling.
Improving the Efficiency of Downhole Uranium Production Using Oxygen as an Oxidizer
Authors: Rakishev Bayan , Kenzhetaev Zhiger , Mataev Muhametkaly , Togizov Kuanysh
Published: August 2022

The features occurring during borehole uranium mining in deposits with low filtration characteristics, as well as the conditions and reasons for the reduction of geotechnological parameters of uranium mining by the well are considered in this study. Core material samples were taken from the productive horizon of the Chu-Sarysui province deposit and granulometric compositions were established. The contents of uranium, aluminum, calcium, magnesium, iron and carbonate minerals in the samples were determined by atomic emission spectroscopy. The X-ray phase analysis method established the features and quantitative and qualitative characteristics of ore-containing minerals. A special technique has been developed for conducting experiments in laboratory conditions using core samples, where the intensity of uranium leaching in tubes is determined. The results of laboratory studies are analyzed and discussed and graphs are constructed, to show the dependencies of change in: the filtration coefficients of Kf; the uranium content in solution; the extraction coefficient; and the specific consumption of sulfuric acid on the values of L:S (the ratio of liquid to solid) in the experiments. The effectiveness of using a mild acidity regime, with the addition of oxygen as an oxidizer, is determined and shown. The values of the uranium content in the productive solution, with the addition of oxygen as an oxidizer, reached 220 mg/L, which exceeds the design parameters. The results of uranium extraction from ore show a positive trend, reaching 68%, with L:S from 1.7 to 3.0, low acidity values and the addition of oxygen as an oxidizer. The specific consumption of sulfuric acid reaches the minimum values when using leaching solutions with reduced acidity of 26 kg/kg. The obtained results, on the flow rate of the solution in the tube, the extraction of uranium from ore and the specific consumption of sulfuric acid, indicate a decrease in sedimentation in a porous medium and increased filtration characteristics, with reduced acidity values in the leaching solution.
Comparison of the Chemical Composition of Selected Varieties of Elderberry with Wild Growing Elderberry
Authors: Nawirska-Olszańska Agnieszka , Oziembłowski Maciej , Brandova Pavla , Czaplicka Marta
Published: August 2022

Elderberries of wild-growing shrubs are most often used; however, various cultivated varieties of this shrub appear more and more often. The aim of this research was to compare the fruit composition of specific varieties with those grown wild in urban and ecologically clean conditions. Six varieties of elderberry grown on one experimental farm and two wild-growing samples from the city center and the landscape park were assessed. The content of vitamin C, antioxidant activity, sugar and organic acid content, triterpenes and carotenoids was marked in the tested fruits. The analyses show that there were significant differences in the content of the tested ingredients between the varieties tested, while the place of cultivation was of less importance. Apart from organic acids and triterpenes, fruits from wild-growing shrubs were more abundant in other compounds determined. The white variety of ‘Albida’ turned out to be the poorest in bioactive compounds.
A Convenient, Rapid, Conventional Heating Route to MIDA Boronates
Authors: McGown Andrew , Edmonds Anthony K. , Guest Daniel , Holmes Verity L. , Dadswell Chris , González-Méndez Ramón , Goodall Charles A. I. , Bagley Mark C. , Greenland Barnaby W. , Spencer John
Published: August 2022

A cheap, conventional, sealed heating reactor proved to be a useful alternative to a microwave reactor in the synthesis of a >20-member MIDA boronate library (MIDA = N-methyliminodiacetic acid). Reaction times were 10 min and work-ups were minimal, saving on energy and solvent usage.
Fabrication of Effective Nanohybrids Based on Organic Species, Polyvinyl Alcohol and Carbon Nanotubes in Addition to Nanolayers for Removing Heavy Metals from Water under Severe Conditions
Authors: Alali Hasna Abdullah , Saber Osama , Osama Aya , Ezzeldin Mohamed Farouk
Published: August 2022

Industrial water has a dual problem because of its strong acidic characteristics and the presence of heavy metals. Removing heavy metals from water in these severe conditions has special requirements. For this problem, an economic method was used for removing iron (Fe), copper (Cu), chromium (Cr), nickel (Ni) and manganese (Mn) with extremely acidic characteristics from water. This method depends on the preparation of nanohybrids through host–guest interactions based on nanolayered structures, organic species (stearic acid), polyvinyl alcohol (PVA) and carbon nanotubes (CNTs). The formation of nanohybrids was confirmed using different techniques through the expansion of the interlayered spacing of the nanolayered structure from 0.76 nm to 1.60 nm, 1.40 nm and 1.06 nm. This nano-spacing is suitable for trapping and confining the different kinds of heavy metal. The experimental results indicated that the prepared nanohybrid was more effective than GreensandPlus, which is used on the market for purifying water. The high activity of the nanohybrid is obvious in the removal of both copper and nickel because the GreensandPlus was completely inactive for these heavy metals under severe conditions. Finally, these experimental results introduce new promising materials for purifying industrial water that can work under severe conditions.
Apoptosis-Inducing Potential of Selected Bromophenolic Flame Retardants 2,4,6-Tribromophenol and Pentabromophenol in Human Peripheral Blood Mononuclear Cells
Authors: Barańska Anna , Sicińska Paulina , Michałowicz Jaromir
Published: August 2022

(1) Background: 2,4,6-Tribromophenol (2,4,6-TBP) and pentabromophenol (PBP) are utilized as brominated flame retardants (BFRs) in order to reduce the combustion of materials used in various utility products. The presence of 2,4,6-TBP and PBP has been reported in environmental samples as well as in inhaled air, dust, food, drinking water, and the human body. To date, there are limited data concerning the toxic action of 2,4,6-TBP and particularly PBP, and no study has been conducted to assess the apoptotic mechanism of action of these substances in human leukocytes. (2) Methods: PBMCs were isolated from leukocyte–platelet buffy coat and treated with tested substances in concentrations ranging from 0.01 to 50 µg/mL for 24 h. The apoptotic mechanism of action of the tested BFRs was assessed by the determination of phosphatidylserine exposure on the PBMCs surface, the evaluation of mitochondrial potential and cytosolic calcium ion levels, and the determination of caspase-8, -9, and -3 activation. Moreover, poly (ADP-ribose) polymerase-1 (PARP-1) cleavage, DNA fragmentation, and chromatin condensation were analyzed. (3) Results: 2,4,6-TBP and, more strongly, PBP induced apoptosis in PBMCs, changing all tested parameters. It was also found that the mitochondrial pathway was mainly involved in the apoptosis of PBMCs exposed to the studied compounds. (4) Conclusions: 2,4,6-TBP and PBP triggered apoptosis in human PBMCs, and some observed changes occurred at 2,4,6-TBP concentrations that were detected in humans occupationally exposed to this substance.
Chemistry, Biosynthesis and Pharmacology of Viniferin: Potential Resveratrol-Derived Molecules for New Drug Discovery, Development and Therapy
Authors: Fuloria Shivkanya , Sekar Mahendran , Khattulanuar Farrah Syazana , Gan Siew Hua , Rani Nur Najihah Izzati Mat , Ravi Subban , Subramaniyan Vetriselvan , Jeyabalan Srikanth , Begum M. Yasmin , Chidambaram Kumarappan , Sathasivam Kathiresan V. , Safi Sher Zaman , Wu Yuan Seng , Nordin Rusli , Maziz Mohammad Nazmul Hasan , Kumarasamy Vinoth , Lum Pei Teng , Fuloria Neeraj Kumar
Published: August 2022

Viniferin is a resveratrol derivative. Resveratrol is the most prominent stilbenoid synthesized by plants as a defense mechanism in response to microbial attack, toxins, infections or UV radiation. Different forms of viniferin exist, including alpha-viniferin (α-viniferin), beta-viniferin (β-viniferin), delta-viniferin (δ-viniferin), epsilon-viniferin (ε-viniferin), gamma-viniferin (γ-viniferin), R-viniferin (vitisin A), and R2-viniferin (vitisin B). All of these forms exhibit a range of important biological activities and, therefore, have several possible applications in clinical research and future drug development. In this review, we present a comprehensive literature search on the chemistry and biosynthesis of and the diverse studies conducted on viniferin, especially with regards to its anti-inflammatory, antipsoriasis, antidiabetic, antiplasmodic, anticancer, anti-angiogenic, antioxidant, anti-melanogenic, neurodegenerative effects, antiviral, antimicrobial, antifungal, antidiarrhea, anti-obesity and anthelminthic activities. In addition to highlighting its important chemical and biological activities, coherent and environmentally acceptable methods for establishing vinferin on a large scale are highlighted to allow the development of further research that can help to exploit its properties and develop new phyto-pharmaceuticals. Overall, viniferin and its derivatives have the potential to be the most effective nutritional supplement and supplementary medication, especially as a therapeutic approach. More researchers will be aware of viniferin as a pharmaceutical drug as a consequence of this review, and they will be encouraged to investigate viniferin and its derivatives as pharmaceutical drugs to prevent future health catastrophes caused by a variety of serious illnesses.
Photoactive Herbal Compounds: A Green Approach to Photodynamic Therapy
Authors: Sulaiman Cheruthazhakkat , George Blassan P. , Balachandran Indira , Abrahamse Heidi
Published: August 2022

Photodynamic therapy (PDT) is a minimally invasive, alternative, and promising treatment for various diseases, including cancer, actinic keratosis, Bowen’s disease, macular degeneration, and atherosclerotic plaques. PDT involves three different components, photosensitizers (PS), molecular oxygen, and light. The photoactivation of administered PSs using a specific wavelength of light in the presence of molecular oxygen leads to the generation of reactive oxygen species that leads to tumour cell death. Photosensitizing potentials of many commercially available compounds have been reported earlier. However, the possibilities of PDT using herbal medicines, which contain many photosensitizing phytochemicals, are not much explored. Medicinal plants with complex phytochemical compound mixtures have the benefit over single compounds or molecules in the treatment of many diseases with the benefit of low or reduced toxic side effects. This review emphasizes the role of various herbal medicines either alone or in combination to enhance the therapeutic outcome of photodynamic therapy.
Isoquinoline Antimicrobial Agent: Activity against Intracellular Bacteria and Effect on Global Bacterial Proteome
Authors: Karanja Caroline W. , Naganna Nimishetti , Abutaleb Nader S. , Dayal Neetu , Onyedibe Kenneth I. , Aryal Uma , Seleem Mohamed N. , Sintim Herman O.
Published: August 2022

A new class of alkynyl isoquinoline antibacterial compounds, synthesized via Sonogashira coupling, with strong bactericidal activity against a plethora of Gram-positive bacteria including methicillin- and vancomycin-resistant Staphylococcus aureus (S. aureus) strains is presented. HSN584 and HSN739, representative compounds in this class, reduce methicillin-resistant S. aureus (MRSA) load in macrophages, whilst vancomycin, a drug of choice for MRSA infections, was unable to clear intracellular MRSA. Additionally, both HSN584 and HSN739 exhibited a low propensity to develop resistance. We utilized comparative global proteomics and macromolecule biosynthesis assays to gain insight into the alkynyl isoquinoline mechanism of action. Our preliminary data show that HSN584 perturb S. aureus cell wall and nucleic acid biosynthesis. The alkynyl isoquinoline moiety is a new scaffold for the development of potent antibacterial agents against fatal multidrug-resistant Gram-positive bacteria.
High-Temperature Spin Crossover in Iron(II) Complexes with 2,6-Bis(1H-imidazol-2-yl)pyridine
Authors: Lavrenova Ludmila G. , Shakirova Olga G. , Korotaev Evgeniy V. , Trubina Svetlana V. , Tikhonov Alexsei Ya. , Os’kina Irina A. , Petrov Sergey A. , Zhizhin Konstantin Yu. , Kuznetsov Nikolay T.
Published: August 2022

Novel iron(II) coordination compounds containing a ligand 2,6-bis(1H-imidazol-2-yl)pyridine (L), having such a composition as [FeL2]SO4·0.5H2O, [FeL2]Br2·H2O, [FeL2](ReO4)2, [FeL2]B10H10∙H2O, [FeL2]B12H12∙1.5H2O had been synthesized and studied using UV-Vis (diffuse reflectance), infrared, extended X-ray absorption fine structure (EXAFS), and Mössbauer spectroscopy methods, as well as X-ray diffraction and static magnetic susceptibility methods. The analysis of the μeff(T) dependence in the temperature range of 80–600 K have shown that all the obtained complexes exhibit a high-temperature spin crossover 1A1 ↔ 5T2.