bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring the Current Provided by a Hall Sensor Integrated in a Drive Wheel Module of a Mobile Robot
Authors: Constantin George , Maroșan Iosif-Adrian , Crenganiș Mihai , Botez Corina , Gîrjob Claudia-Emilia , Biriș Cristina-Maria , Chicea Anca-Lucia , Bârsan Alexandru
Published: March 2023

This article describes a method for the real-time monitoring of the current consumed by a Dynamixel MX 64 AT servomotor used in the actuation system of modular mobile robotic platforms having differential locomotion and conventional wheels. The data acquisition method is based on an Arduino Mega 2560 development board interfaced with Matlab Simulink and the ASC712-5A hall sensor for current detection. A Simulink model is presented that performs the detection of a sensor reference voltage, which needs to be calibrated for a correct reading of the current. Due to the low resolution of the analog-to-digital converter with which the Arduino Mega is equipped, current monitoring is difficult to achieve, having large fluctuations and a lower resolution than the current absorbed by the servomotor. The solution to this problem is achieved by implementing, in the hardware construction, an ADS115 conversion module with 16-bit resolution, which leads to an increase in the measurement range of the ASC712-5A sensor. The current acquisition model with the Hall sensor is experimentally validated using measurements on the physical model of the drive wheel. This article further deals with the CAD and digital block modeling of mobile platforms with four and two wheels. The dynamic model of the robot is created in the Simulink–Simscape–Multibody environment and is used to determine the servomotor torques when the robot is moving along the predefined path. The torque variations are entered as variables in the Simulink digital block model of the robot. The Simulink model is simulated when moving along a square path, which determines the variation in the current absorbed by the motors. Experimental validation of the model is carried out using measurements on the functional models that operate in real conditions. A power consumption method is further proposed.
Multi-Story Building Model for Efficient IoT Network Design
Authors: Bushelenkov Sergey , Paramonov Alexander , Muthanna Ammar , El-Latif Ahmed A. Abd , Koucheryavy Andrey , Alfarraj Osama , Pławiak Paweł , Ateya Abdelhamied A.
Published: March 2023

This article presents a new network model for IoT that is based on a multi-story building structure. The model locates network nodes in a regular, cubic lattice-like structure, resulting in an equation for the signal-to-noise ratio (SNR). The study also determines the relationship between traffic density, network density, and SNR. In addition, the article explores the potential of percolation theory in characterizing network functionality. The findings offer a new approach to network design and planning, allowing for selecting a network topology that meets criteria and requirements while ensuring connectivity and improving efficiency. The developed analytical apparatus provides valuable insights into the properties of the network and its applicability to specific conditions.
Robust Semi-Quantum Summation over a Collective-Dephasing Noise Channel
Authors: Yang Chun-Wei , Tsai Chia-Wei , Chen Chi-An , Lin Jason
Published: March 2023

Quantum summation is one of the various applications in secure multi-party computation. However, most of the existing quantum summation protocols assume that the participants possess all the quantum devices. Considering future applications, the capability of the participants must be adjusted before it can be put into practical use. Although Boyer et al. proposed that the semi-quantum environment could be used to solve this problem; another practical problem is the interference by noise. In 2022, Ye et al. proposed a two-party semi-quantum summation (SQS) protocol resistant to the interference of collective noise, in which two classical participants can accomplish the summation of their private binary sequences with the assistance of a quantum semi-honest third party. They proved that their SQS protocol is resistant to various eavesdropping attacks. This paper unveils two risks of information leakage in Ye et al.’s SQS protocol. If the aforementioned security issues are not resolved, Ye et al.’s SQS protocol may not be able to perform private quantum computations securely. Fortunately, the SQS protocol against the collective-dephasing noise proposed in this study is free from the issue of information leakage as well as resistant to various quantum attacks. In addition, the quantum efficiency of the SQS protocol proposed in this study is four times higher than that of Ye et al.’s SQS protocol, which can effectively improve the quantum utilization rate.
PACR: Pixel Attention in Classification and Regression for Visual Object Tracking
Authors: Li Da , Chai Haoxiang , Wei Qin , Zhang Yao , Xiao Yunhan
Published: March 2023

Anchor-free-based trackers have achieved remarkable performance in single visual object tracking in recent years. Most anchor-free trackers consider the rectangular fields close to the target center as the positive sample used in the training phase, while they always use the maximum of the corresponding map to determine the location of the target in the tracking phase. Thus, this will make the tracker inconsistent between the training and tracking phase. To solve this problem, we propose a pixel-attention module (PAM), which ensures the consistency of the training and tracking phase through a self-attention module. Moreover, we put forward a new refined branch named Acc branch to inherit the benefit of the PAM. The score of Acc branch can tune the classification and the regression of the tracking target more precisely. We conduct extensive experiments on challenging benchmarks such as VOT2020, UAV123, DTB70, OTB100, and a large-scale benchmark LaSOT. Compared with other anchor-free trackers, our tracker gains excellent performance in small-scale datasets. In UAV benchmarks such as UAV123 and DTB70, the precision of our tracker increases 4.3% and 1.8%, respectively, compared with the SOTA in anchor-free trackers.
Quantum Advantages of Teleportation and Dense Coding Protocols in an Open System
Authors: Haddadi Saeed , Hadipour Maryam , Haseli Soroush , Rahman Atta Ur , Czerwinski Artur
Published: March 2023

Quantum teleportation and dense coding are well-known quantum protocols that have been widely explored in the field of quantum computing. In this paper, the efficiency of quantum teleportation and dense coding protocols is examined in two-level atoms with two-photon transitions via the Stark shift effect, where each atom is separately coupled to a dissipative reservoir at zero temperature. Our results show that non-Markovianity and Stark shift can play constructive roles in restoring the quantum advantages of these protocols after they are diminished. These findings could offer a potential solution to preserving the computational and communicative advantages of quantum technologies.
Convergence Analysis for Generalized Yosida Inclusion Problem with Applications
Authors: Akram Mohammad , Dilshad Mohammad , Khan Aysha , Chandok Sumit , Ahmad Izhar
Published: March 2023

A new generalized Yosida inclusion problem, involving A-relaxed co-accretive mapping, is introduced. The resolvent and associated generalized Yosida approximation operator is construed and a few of its characteristics are discussed. The existence result is quantified in q-uniformly smooth Banach spaces. A four-step iterative scheme is proposed and its convergence analysis is discussed. Our theoretical assertions are illustrated by a numerical example. In addition, we confirm that the developed method is almost stable for contractions. Further, an equivalent generalized resolvent equation problem is established. Finally, by utilizing the Yosida inclusion problem, we investigate a resolvent equation problem and by employing our proposed method, a Volterra–Fredholm integral equation is examined.
Determining Dimensionality with Dichotomous Variables: A Monte Carlo Simulation Study and Applications to Missing Data in Longitudinal Research
Authors: Dai Ting , Davey Adam
Published: March 2023

Dichotomous data correspond with various types of commonly encountered data, e.g., positive/negative, case/control, missing/observed, in many fields, including medicine, health, and social sciences. Despite their ubiquity, criteria for determining dimensionality from dichotomous variables are not yet established. We conducted a large-scale simulation (Study 1) to evaluate four criteria—Kaiser, empirical Kaiser, parallel analysis, and profile likelihood—to determine the dimensionality of dichotomous data across combinations of correlation matrices (Pearson r or tetrachoric ρ) and analysis methods (principal component analysis or exploratory factor analysis), and combinations of study characteristics: sample sizes (100, 250, and 1000), variable splits (10%/90%, 25%/75%, and 50%/50%), dimensions (1, 3, 5, and 10), and items per dimension (3, 5, and 10) with 1000 replications per condition. Parallel analysis performed best, recovering dimensionality in 87.9% of replications when using principal component analysis with Pearson correlations. Guidance for selecting criteria is provided. In Study 2, we applied this dimensionality reduction approach to two different longitudinal data sets where missing data posed difficulty for multivariate data analysis. The applications of this approach to longitudinal data suggest that the exploration of resulting missing data meta-patterns is useful in practice.
On the Generalized Adjacency Spread of a Graph
Authors: Baghipur Maryam , Ghorbani Modjtaba , Pirzada Shariefuddin , Amraei Najaf
Published: March 2023

For a simple finite graph G, the generalized adjacency matrix is defined as Aα(G)=αD(G)+(1−α)A(G),α∈[0,1], where A(G) and D(G) are respectively the adjacency matrix and diagonal matrix of the vertex degrees. The Aα-spread of a graph G is defined as the difference between the largest eigenvalue and the smallest eigenvalue of the Aα(G). In this paper, we answer the question posed in (Lin, Z.; Miao, L.; Guo, S. Bounds on the Aα-spread of a graph. Electron. J. Linear Algebra 2020, 36, 214–227). Furthermore, we show that the path graph, Pn, has the smallest S(Aα) among all trees of order n. We establish a relationship between S(Aα) and S(A). We obtain several bounds for S(Aα).
Active Debris Removal Mission Planning Method Based on Machine Learning
Authors: Xu Yingjie , Liu Xiaolu , He Renjie , Zhu Yuehe , Zuo Yahui , He Lei
Published: March 2023

To prevent the proliferation of space debris and stabilize the space environment, active debris removal (ADR) has increasingly gained public concern. Considering the complexity of space operations and the viability of ADR missions, it would be necessary to schedule the ADR process in order to remove as much debris as possible. This paper presents an active debris removal mission planning problem, devoted to generate an optimal debris removal plan to guide the mission process. According to the problem characteristics, a two-layer time-dependent traveling salesman problem(TSP) mathematical model is established, involving the debris removal sequence planning and the transfer trajectory planning. Subsequently, two main novel methods based on machine learning are proposed for the ADR mission planning problem, including a deep neural networks(DNN)-based estimation method for approximating the optimal velocity increments of perturbed multiple-impulse rendezvous and an reinforcement learning(RL)-based method for optimizing the sequence of debris removal and rendezvous time. Experimental results of different simulation scenarios have verified the effectiveness and superiority of the proposed method, indicating the good performance for solving the active debris removal mission planning problem.
New Bioactive β-Resorcylic Acid Derivatives from the Alga-Derived Fungus Penicillium antarcticum KMM 4685
Authors: Leshchenko Elena V. , Antonov Alexandr S. , Borkunov Gleb V. , Hauschild Jessica , Zhuravleva Olesya I. , Khudyakova Yuliya V. , Menshov Alexander S. , Popov Roman S. , Kim Natalya Yu , Graefen Markus , Bokemeyer Carsten , von Amsberg Gunhild , Yurchenko Anton N. , Dyshlovoy Sergey A.
Published: March 2023

Five new β-resorcylic acid derivatives, 14-hydroxyasperentin B (1), β-resoantarctines A-C (3, 5, 6) and 8-dehydro-β-resoantarctine A (4), together with known 14-hydroxyasperentin (5′-hydroxyasperentin) (2), were isolated from the ethyl acetate extract of the fungus Penicillium antarcticum KMM 4685 associated with the brown alga Sargassum miyabei. The structures of the compounds were elucidated by spectroscopic analyses and modified Mosher’s method, and the biogenetic pathways for compounds 3–6 were proposed. For the very first time, the relative configuration of the C-14 center of a known compound 2 was assigned via analyses of magnitudes of the vicinal coupling constants. The new metabolites 3–6 were biogenically related to resorcylic acid lactones (RALs); however, they did not possess lactonized macrolide elements in their structures. Compounds 3, 4 and 5 exhibited moderate cytotoxic activity in LNCaP, DU145 and 22Rv1 human prostate cancer cells. Moreover, these metabolites could inhibit the activity of p-glycoprotein at their noncytotoxic concentrations and consequently synergize with docetaxel in p-glycoprotein-overexpressing drug-resistant cancer cells.
Efficient Degradation of Alginate and Preparation of Alginate Oligosaccharides by a Novel Biofunctional Alginate Lyase with High Activity and Excellent Thermophilic Features
Authors: Li Li , Cao Shengsheng , Zhu Benwei , Yao Zhong , Zhu Bo , Qin Yimin , Jiang Jinju
Published: March 2023

The enzymatic degradation of seaweed polysaccharides is gaining interest for its potential in the production of functional oligosaccharides and fermentable sugars. Herein, a novel alginate lyase, AlyRm3, was cloned from a marine strain, Rhodothermus marinus DSM 4252. The AlyRm3 showed optimal activity (37,315.08 U/mg) at 70 °C and pH 8.0, with the sodium alginate used as a substrate. Noticeably, AlyRm3 was stable at 65 °C and also exhibited 30% of maximal activity at 90 °C. These results indicated that AlyRm3 is a thermophilic alginate lyase that efficiently degrades alginate at high industrial temperatures (>60 °C). The FPLC and ESI−MS analyses suggested that AlyRm3 primarily released disaccharides and trisaccharides from the alginate, polyM, and polyG in an endolytic manner. In the saccharification process of sodium alginate (0.5%, w/v), the AlyRm3 yielded numerous reducing sugars (1.73 g/L) after 2 h of reaction. These results indicated that AlyRm3 has a high enzymatic capacity for saccharifying the alginate, and could be used to saccharify the alginate biomass before the main fermentation process for biofuels. These properties make AlyRm3 a valuable candidate for both fundamental research and industrial applications.
Does the Polydimethylsiloxane Urethral Injection (Macroplastique®) Improve Sexual Function in Women, in Fertile Age, Affected by Stress Urinary Incontinence?
Authors: Serati Maurizio , Braga Andrea , Scancarello Chiara , De Rosa Andrea , Frigerio Matteo , Baruch Yoav , Torella Marco , Salvatore Stefano , Ruffolo Alessandro
Published: March 2023

Background and Objectives: Stress urinary incontinence (SUI) negatively affects women’s quality of life, including sexual function. The aim of the current study was to evaluate the effect of polydimethylsiloxane (Macroplastique®) on sexual function in women of fertile age affected by SUI. Materials and Methods: Single-center prospective study. Sexually active women of fertile age with symptoms of pure SUI, which were urodynamically proven, were submitted to intraurethral Macroplastique® injection. At 6-months follow-up, their sexual function was evaluated with Female Sexual Function Index (FSFI), while the SUI cure rate was objectively assessed through a negative stress test and subjectively by a Patient Global Impression of Improvement (PGI-I) score < 3. The difference of coital incontinence prevalence was assessed between the baseline and the 6-month follow-up. Peri- and postoperative complications of Macroplastique® injection were recorded and classified according to the Clavien–Dindo system. Results: Twenty-one women fulfilled inclusion criteria and were submitted to Macroplastique® procedure. The concerning sexual function, desire, satisfaction, and overall FSFI score significantly improved. Since other domains were less impaired at the baseline, we could not assess significant improvement for all of them. We observed a complete regression of coital incontinence (0/21, 0%) in comparison with the baseline (5/21, 23.8%; p = 0.04). The objective SUI cure rate was 76% (16/21), while the subjective SUI cure rate was 80.9% (17/21). One woman developed de novo overactive bladder, and two women developed postoperative voiding dysfunction (self-solved in 24 h). Conclusions: The Macroplastique® urethral injection was demonstrated to be safe and effective in improving sexual function in sexually active women of fertile age affected by pure SUI, urodinamically proven at 6-months follow-up.
Treatment of Semiconductor Wastewater Containing Tetramethylammonium Hydroxide (TMAH) Using Nanofiltration, Reverse Osmosis, and Membrane Capacitive Deionization
Authors: Lee Juyoung , Lee Song , Choi Yongjun , Lee Sangho
Published: March 2023

As the semiconductor industry has grown tremendously over the last decades, its environmental impact has become a growing concern, including the withdrawal of fresh water and the generation of harmful wastewater. Tetramethylammonium hydroxide (TMAH), one of the toxic compounds inevitably found in semiconductor wastewater, should be removed before the wastewater is discharged. However, there are few affordable technologies available to remove TMAH from semiconductor wastewater. Therefore, the objective of this study was to compare different treatment options, such as Membrane Capacitive Deionization (MCDI), Reverse Osmosis (RO), and Nanofiltration (NF), for the treatment of semiconductor wastewater containing TMAH. A series of bench-scale experimental setups were conducted to investigate the removal efficiencies of TMAH, TDS, and TOC. The results confirmed that the MCDI process showed its great ability as well as RO to remove them, while the NF could not make a sufficient removal under identical recovery conditions. MCDI showed higher removals of monovalent ions, including TMA+, than divalent ions. Moreover, the removal of TMA+ by MCDI was higher under the basic solution than under both neutral and acidic conditions. These results were the first to demonstrate that MCDI has significant potential for treating semiconductor wastewater that contains TMAH.
Polydimethylsiloxane/Magnesium Oxide Nanosheet Mixed Matrix Membrane for CO2 Separation Application
Authors: Zainuddin Muhd Izzudin Fikry , Ahmad Abdul Latif , Shah Buddin Meor Muhammad Hafiz
Published: March 2023

Carbon dioxide (CO2) concentration is now 50% higher than in the preindustrial period and efforts to reduce CO2 emission through carbon capture and utilization (CCU) are blooming. Membranes are one of the attractive alternatives for such application. In this study, a rubbery polymer polydimethylsiloxane (PDMS) membrane is incorporated with magnesium oxide (MgO) with a hierarchically two-dimensional (2D) nanosheet shape for CO2 separation. The average thickness of the synthesized MgO nanosheet in this study is 35.3 ± 1.5 nm. Based on the pure gas separation performance, the optimal loading obtained is at 1 wt.% where there is no observable significant agglomeration. CO2 permeability was reduced from 2382 Barrer to 1929 Barrer while CO2/N2 selectivity increased from only 11.4 to 12.7, and CO2/CH4 remained relatively constant when the MMM was operated at 2 bar and 25 °C. Sedimentation of the filler was observed when the loading was further increased to 5 wt.%, forming interfacial defects on the bottom side of the membrane and causing increased CO2 gas permeability from 1929 Barrer to 2104 Barrer as compared to filler loading at 1 wt.%, whereas the CO2/N2 ideal selectivity increased from 12.1 to 15.0. Additionally, this study shows that there was no significant impact of pressure on separation performance. There was a linear decline of CO2 permeability with increasing upstream pressure while there were no changes to the CO2/N2 and CO2/CH4 selectivity.
Modified Electrospun Membranes Using Different Nanomaterials for Membrane Distillation
Authors: Khatri Muzamil , Francis Lijo , Hilal Nidal
Published: March 2023

Obtaining fresh drinking water is a challenge directly related to the change in agricultural, industrial, and societal demands and pressure. Therefore, the sustainable treatment of saline water to get clean water is a major requirement for human survival. In this review, we have detailed the use of electrospun nanofiber-based membranes (ENMs) for water reclamation improvements with respect to physical and chemical modifications. Although membrane distillation (MD) has been considered a low-cost water reclamation process, especially with the availability of low-grade waste heat sources, significant improvements are still required in terms of preparing efficient membranes with enhanced water flux, anti-fouling, and anti-scaling characteristics. In particular, different types of nanomaterials have been explored as guest molecules for electrospinning with different polymers. Nanomaterials such as metallic organic frameworks (MOFs), zeolites, dioxides, carbon nanotubes (CNTs), etc., have opened unprecedented perspectives for the implementation of the MD process. The integration of nanofillers gives appropriate characteristics to the MD membranes by changing their chemical and physical properties, which significantly enhances energy efficiency without impacting the economic costs. Here, we provide a comprehensive overview of the state-of-the-art status, the opportunities, open challenges, and pitfalls of the emerging field of modified ENMs using different nanomaterials for desalination applications.
Seasonal Changes in Qualitative and Quantitative Characteristics of Humic Substances in Waters of Different Genesis: Membrane Technologies and Equilibrium Processes
Authors: Dinu Marina
Published: March 2023

Membrane filtration methods were applied in this study to research natural waters specification (and speciation). Lysimetric waters (soil waters) of background territories in different seasons are considered. Features of the change in molecular weights, elemental composition, and zeta potential of organic matter during fractionation from 8 μm to 100 kDa were found. The number of labile and non-labile speciation of some elements obtained by membrane filtration and ion-exchange separation methods were found and compared. The highest molecular weights of organic substances were found in summer samples of lysimetric waters (more than 100 kDa) with a predominance of the aromatic component in the IR spectra of the samples. Several maxima were also found in the molecular weight distribution, including the increase in autochthonous organic substances. The most stable negative zeta potential, as a stabilized colloid matter, are represented in summer (near −26 mV) and in autumn (near −22 mV) lysimetric water. A slight increase in metal ions bound into organic complexes is typical for summer and autumn samples.
Characteristics of Bubble Behavior and Inclusion Removal in Liquid Steel Based on Industrial Trials of Argon Injection into Ladle Shroud
Authors: He Yang , Liu Jianhua , Su Xiaofeng , Li Wei , Pan Yukang , Wang Daya
Published: March 2023

A series of industrial trials of argon injection into ladle shroud (AIILS) with different argon-blowing rates were conducted in this study. Firstly, bubbles in actual liquid steel of the tundish were captured by the method of “cold steel plate dipping” and characterized by microscope examination. A detailed investigation on the three-dimension morphology of bubbles was carried out by using industrial computerized tomography (ICT). Then, the two-phase flow of liquid steel and argon gas in the tundish was numerically simulated to further investigate the motion behaviors of bubbles in liquid steel of the tundish. The simulated results showed that bubbles in the size range of this investigation had a large enough filtration rate to demonstrate a good performance on inclusion removal. Finally, the effect of AIILS on inclusion removal was analyzed by detecting the variations of inclusions as well as total oxygen content in steels taken from the ladle, tundish, and casting billet. The method of AIILS was more effective at improving the removal of inclusions in the range of 5 to 10 μm and obviously increased the removal rate of total oxygen content.
Influencing Factors of the Specific Total Loss of Non-Oriented Electrical Steels Processed by Laser Cutting
Authors: Xiang Qian , Cheng Lin , Wu Kaiming
Published: March 2023

Specific total loss is one of the most important evaluation indexes for the magnetic properties of non-oriented electrical steel sheets. The aim of this study is to investigate the influencing mechanisms of laser cutting parameters as well as the sample characteristics on the specific total loss of thin non-oriented electrical steel sheets processed by laser cutting using a machine learning method. Eight input parameters were finally considered; namely, silicon and manganese contents, thickness of the steel sheets, laser nozzle diameter, laser power, cutting speed, the pressure of process gas, and laser defocus, while one output parameter, the specific total loss, was evaluated. It was found that the specific total loss was positively correlated with the sample thickness, but negatively correlated with silicon and manganese contents, the process gas pressure and laser nozzle diameter. In addition, laser power and cutting speed exhibit complicated non-linear relationships with the specific total loss.
Effect of Sodium Silicate on the Hydration of Alkali-Activated Copper-Nickel Slag Materials
Authors: Yang Jie , Zhang Tingting , Guo Lijie , Zhi Shiwei , Han Junnan
Published: March 2023

This paper studied the influence of the modulus and dosage of sodium silicate on the hydration of alkali-activated copper-nickel slag (CNS) materials. CNS was used as the main raw material, and ground granulated blast furnace slag (GBFS) powder was selected as the mineral additive. The hydration and hardening mechanisms were discussed. The experimental results showed that [SiO4]4− and [AlO4]5− with a high degree of polymerization in the CNS glassy phase more easily underwent depolymerization-condensation and produced more C-S-H gels when the modulus was small and the sodium silicate dosage was high. When the content of sodium silicate was 7.0% and the modulus of sodium silicate solution was 1.0, the 28-day compressive strength of the material reached 125 MPa. This alkali-activated copper-nickel slag material can be used for mine filling, which has certain economic and ecological benefits.
Cross-Regulation of the Cellular Redox System, Oxygen, and Sphingolipid Signalling
Authors: Huwiler Andrea , Beck Karl-Friedrich , Pfeilschifter Josef
Published: March 2023

Redox-active mediators are now appreciated as powerful molecules to regulate cellular dynamics such as viability, proliferation, migration, cell contraction, and relaxation, as well as gene expression under physiological and pathophysiological conditions. These molecules include the various reactive oxygen species (ROS), and the gasotransmitters nitric oxide (NO∙), carbon monoxide (CO), and hydrogen sulfide (H2S). For each of these molecules, direct targets have been identified which transmit the signal from the cellular redox state to a cellular response. Besides these redox mediators, various sphingolipid species have turned out as highly bioactive with strong signalling potential. Recent data suggest that there is a cross-regulation existing between the redox mediators and sphingolipid molecules that have a fundamental impact on a cell’s fate and organ function. This review will summarize the effects of the different redox-active mediators on sphingolipid signalling and metabolism, and the impact of this cross-talk on pathophysiological processes. The relevance of therapeutic approaches will be highlighted.
Ultrafast Microfluidic PCR Thermocycler for Nucleic Acid Amplification
Authors: An Yi-Quan , Huang Shao-Lei , Xi Bang-Chao , Gong Xiang-Lian , Ji Jun-Hao , Hu You , Ding Yi-Jie , Zhang Dong-Xu , Ge Sheng-Xiang , Zhang Jun , Xia Ning-Shao
Published: March 2023

The polymerase chain reaction (PCR) is essential in nucleic acid amplification tests and is widely used in many applications such as infectious disease detection, tumor screening, and food safety testing; however, most PCR devices have inefficient heating and cooling ramp rates for the solution, which significantly limit their application in special scenarios such as hospital emergencies, airports, and customs. Here, we propose a temperature control strategy to significantly increase the ramp rates for the solution temperature by switching microfluidic chips between multiple temperature zones and excessively increasing the temperature difference between temperature zones and the solution; accordingly, we have designed an ultrafast thermocycler. The results showed that the ramp rates of the solution temperature are a linear function of temperature differences within a range, and a larger temperature difference would result in faster ramp rates. The maximum heating and cooling ramp rates of the 25 μL solution reached 24.12 °C/s and 25.28 °C/s, respectively, and the average ramp rate was 13.33 °C/s, 6–8 times higher than that of conventional commercial PCR devices. The thermocycler achieved 9 min (1 min pre-denaturation + 45 PCR cycles) ultrafast nucleic acid amplification, shortening the time by 92% compared to the conventional 120 min nucleic acid amplification, and has the potential to be used for rapid nucleic acid detection.
Design and Print Terahertz Metamaterials Based on Electrohydrodynamic Jet
Authors: Yang Tong , Li Xinyu , Yu Bo , Gong Cheng
Published: March 2023

Terahertz metamaterials are some of the core components of the new generation of high-frequency optoelectronic devices, which have excellent properties that natural materials do not have. The unit structures are generally much smaller than the wavelength, so preparation is mainly based on semiconductor processes, such as coating, photolithography and etching. Although the processing resolution is high, it is also limited by complex processing, long cycles, and high cost. In this paper, a design method for dual-band terahertz metamaterials and a simple, rapid, low-cost metamaterial preparation scheme based on step-motor-driven electrohydrodynamic jet technology are proposed. By transforming an open-source 3D printer, the metamaterial structures can be directly printed without complex semiconductor processes. To verify effectiveness, the sample was directly printed using nano conductive silver paste as consumable material. Then, a fiber-based multi-mode terahertz time-domain spectroscopy system was built for testing. The experimental results were in good agreement with the theoretical simulation.
Fresh Produce as a Potential Vector and Reservoir for Human Bacterial Pathogens: Revealing the Ambiguity of Interaction and Transmission
Authors: Esmael Ahmed , Al-Hindi Rashad R. , Albiheyri Raed S. , Alharbi Mona G. , Filimban Amani A. R. , Alseghayer Mazen S. , Almaneea Abdulaziz M. , Alhadlaq Meshari Ahmed , Ayubu Jumaa , Teklemariam Addisu D.
Published: March 2023

The consumer demand for fresh produce (vegetables and fruits) has considerably increased since the 1980s for more nutritious foods and healthier life practices, particularly in developed countries. Currently, several foodborne outbreaks have been linked to fresh produce. The global rise in fresh produce associated with human infections may be due to the use of wastewater or any contaminated water for the cultivation of fruits and vegetables, the firm attachment of the foodborne pathogens on the plant surface, and the internalization of these agents deep inside the tissue of the plant, poor disinfection practices and human consumption of raw fresh produce. Several investigations have been established related to the human microbial pathogens (HMPs) interaction, their internalization, and survival on/within plant tissue. Previous studies have displayed that HMPs are comprised of several cellular constituents to attach and adapt to the plant’s intracellular niches. In addition, there are several plant-associated factors, such as surface morphology, nutrient content, and plant–HMP interactions, that determine the internalization and subsequent transmission to humans. Based on documented findings, the internalized HMPs are not susceptible to sanitation or decontaminants applied on the surface of the fresh produce. Therefore, the contamination of fresh produce by HMPs could pose significant food safety hazards. This review provides a comprehensive overview of the interaction between fresh produce and HMPs and reveals the ambiguity of interaction and transmission of the agents to humans.
Effect of a Fourth Dose of mRNA Vaccine and of Immunosuppression in Preventing SARS-CoV-2 Breakthrough Infections in Heart Transplant Patients
Authors: Masetti Marco , Scuppa Maria Francesca , Aloisio Alessio , Giovannini Laura , Borgese Laura , Manno Stefania , Tazza Beatrice , Pascale Renato , Bonazzetti Cecilia , Caroccia Natascia , Sabatino Mario , Spitaleri Giosafat , Viale Pierluigi , Giannella Maddalena , Potena Luciano
Published: March 2023

Patients with heart transplantation (HT) have an increased risk of COVID-19 disease and the efficacy of vaccines on antibody induction is lower, even after three or four doses. The aim of our study was to assess the efficacy of four doses on infections and their interplay with immunosuppression. We included in this retrospective study all adult HT patients (12/21–11/22) without prior infection receiving a third or fourth dose of mRNA vaccine. The endpoints were infections and the combined incidence of ICU hospitalizations/death after the last dose (6-month survival rate). Among 268 patients, 62 had an infection, and 27.3% received four doses. Following multivariate analysis, three vs. four doses, mycophenolate (MMF) therapy, and HT < 5 years were associated with an increased risk of infection. MMF ≥ 2000 mg/day independently predicted infection, together with the other variables, and was associated with ICU hospitalization/death. Patients on MMF had lower levels of anti-RBD antibodies, and a positive antibody response after the third dose was associated with a lower probability of infection. In HT patients, a fourth dose of vaccine against SARS-CoV-2 reduces the risk of infection at six months. Mycophenolate, particularly at high doses, reduces the clinical effectiveness of the fourth dose and the antibody response to the vaccine.
Ticks and Tick-Borne Pathogens in Recreational Greenspaces in North Central Florida, USA
Authors: Bhosale Chanakya R. , Wilson Kristen N. , Ledger Kimberly J. , White Zoe S. , Dorleans Rayann , De Jesus Carrie E. , Wisely Samantha M.
Published: March 2023

Tick-borne infections are an increasing medical and veterinary concern in the southeastern United States, but there is limited understanding of how recreational greenspaces influence the hazard of pathogen transmission. This study aimed to estimate the potential human and companion animal encounter risk with different questing tick species, and the bacterial or protozoal agents they carry in recreational greenspaces. We collected ticks bimonthly along trails and designated recreational areas in 17 publicly accessible greenspaces, in and around Gainesville, Florida, USA. We collected Amblyomma americanum, Ixodes scapularis, Amblyomma maculatum, Dermacentor variabilis, Ixodes affinis, and Haemaphysalis leporispalustris. Across the six tick species collected, we detected 18 species of bacteria or protozoa within the Babesia, Borrelia, Cytauxzoon, Cryptoplasma (Allocryptoplasma), Ehrlichia, Hepatozoon, Rickettsia, and Theileria genera, including pathogens of medical or veterinary importance. While tick abundance and associated microorganism prevalence and richness were the greatest in natural habitats surrounded by forests, we found both ticks and pathogenic microorganisms in manicured groundcover. This relationship is important for public health and awareness, because it suggests that the probability of encountering an infected tick is measurable and substantial even on closely manicured turf or gravel, if the surrounding landcover is undeveloped. The presence of medically important ticks and pathogenic microorganisms in recreational greenspaces indicates that public education efforts regarding ticks and tick-borne diseases are warranted in this region of the United States.
Chemical Modification of Lherzolite Xenoliths Due to Interaction with Host Basanite Melt: Evidence from Tumusun Volcano, Baikal Rift Zone
Authors: Gornova Marina A. , Belyaev Vasiliy A. , Karimov Anas A. , Perepelov Alexander B. , Dril Sergei I.
Published: March 2023

To investigate the process and chemistry of mineral reaction zone formation, we conducted detailed petrographic observations and chemical analysis of rocks and minerals of spinel lherzolite xenoliths from basanites of Tumusun volcano (Baikal Rift Zone). The reaction zones gradually disappear from contact toward the center of the xenoliths. The influence of basanite melt on major and trace element composition of secondary minerals of reaction zones is notable only at a distance up to 100–200 μm from the contact. At a distance of 0.3–1.0 mm from the contact, the major and trace composition of secondary clinopyroxenes from the orthopyroxene reaction zone indicates their formation from a melt formed by dissolution of orthopyroxene and influenced by the element diffusion from basanite melt. Inside xenoliths, the secondary minerals have Mg# values equal to or higher than Mg# of primary minerals, and secondary clinopyroxenes inherit their depleted or enriched REE pattern from primary pyroxenes. The compositional variations in secondary clinopyroxenes testify melt heterogeneity. Clinopyroxene rims have slightly higher LILE and similar abundances of other trace elements compared to clinopyroxene cores. This is consistent with the model developed from experimental studies: due to the interaction with basanite, incongruent dissolution of orthopyroxene occurs to form a melt which circulates in lherzolite and leads to pyroxenes and spinel dissolution. Diffusion of elements from basanite results in lherzolite enrichment in K, Na, Rb, Ba, La, and Ce, which are incorporated in feldspars and clinopyroxene of reaction zones as well as in feldspar veinlets. Non-dissolved mineral cores are homogenous and similar in major and trace element composition to primary minerals without reaction rims.
Trace Element and Sulfur Isotopic Analysis of Pyrite from the Luyuangou Gold Deposit, Xiong’ershan Au-Ag Polymetallic District, Central China: Implications for The Origin and Evolution of Ore-Forming Fluids
Authors: Song Fanyue , Zhang Qianhui , Koua Kadio Aka Donald , Wu Hangde , Zhou Chuang , Wu Di , Sun Huashan
Published: March 2023

The Luyuangou gold deposit is located in the eastern section of the Xiong’ershan Au-Ag polymetallic district (XESPMD) and consists of a few gold-bearing veins found in the EW-striking faults located in the Archean Taihua and Mesoproterozoic Xiong’er Groups. The gold deposits contain numerous gold-bearing pyrites in thin quartz veins, representing an ideal tool for explaining the enigmatic genesis of gold deposits in the XESPMD. The distributions of trace elements and the sulfur isotopes of gold-bearing pyrite in the Luyuangou gold deposit were investigated to define the origin and evolution of ore-forming fluids. Five generations of pyrite have been identified: coarse-grained euhedral pyrite cores (Py1-1) and margins (Py1-2) in milky quartz veins, fine-grained pyrite (Py2) in quartz veins and host rocks, pyrite (Py3) in quartz + polymetallic sulfide veins, and pyrites (Py4) in quartz calcite veins. The distributions of trace elements indicated that Py2 and Py3 represented the main gold-bearing minerals and contained high concentrations of As, Au, Ag, Pb, Zn, and Cu, and the distributions were controlled by the micro/nanoinclusions. The δ34S values in the five pyrite generations ranged from −19.5 to 3.4‰. Py2 (−15.4 to −6.1‰) and Py3 (−19.5 to −12.4‰) had the lowest δ34S values, indicating that the sulfur originated from an oxidizing fluid. Py1 showed δ34S values (−0.3 to 1.9‰) corresponding to a magmatic origin. Py4 (1.1–3.4‰) displayed the highest δ34S values, indicating that the sulfur originated from the host rock under the action of meteoric water cycles. Analyses of the pyrite’s trace elements and sulfur isotopes, in combination with geological evidence, indicated that magmatic ore-forming fluids contributed to the formation of the Luyuangou gold deposit. The magmatic ore-forming fluids interacted with meteoric water during the main mineralization period. The changing physicochemical conditions of the mineralized fluids caused the precipitation of a large amount of gold and other mineralized elements.
Recent Developments in Sonochemical Synthesis of Nanoporous Materials
Authors: Głowniak Sylwia , Szczęśniak Barbara , Choma Jerzy , Jaroniec Mietek
Published: March 2023

Ultrasounds are commonly used in medical imaging, solution homogenization, navigation, and ranging, but they are also a great energy source for chemical reactions. Sonochemistry uses ultrasounds and thus realizes one of the basic concepts of green chemistry, i.e., energy savings. Moreover, reduced reaction time, mostly using water as a solvent, and better product yields are among the many factors that make ultrasound-induced reactions greener than those performed under conventional conditions. Sonochemistry has been successfully implemented for the preparation of various materials; this review covers sonochemically synthesized nanoporous materials. For instance, sonochemical-assisted methods afforded ordered mesoporous silicas, spherical mesoporous silicas, periodic mesoporous organosilicas, various metal oxides, biomass-derived activated carbons, carbon nanotubes, diverse metal-organic frameworks, and covalent organic frameworks. Among these materials, highly porous samples have also been prepared, such as garlic peel-derived activated carbon with an apparent specific surface area of 3887 m2/g and MOF-177 with an SSA of 4898 m2/g. Additionally, many of them have been examined for practical usage in gas adsorption, water treatment, catalysis, and energy storage-related applications, yielding satisfactory results.
Unveiling the Inhibitory Potentials of Peptidomimetic Azanitriles and Pyridyl Esters towards SARS-CoV-2 Main Protease: A Molecular Modelling Investigation
Authors: Mushebenge Aganze G. , Ugbaja Samuel C. , Mtambo Sphamandla E. , Ntombela Thandokuhle , Metu Joy I. , Babayemi Oludotun , Chima Joy I. , Appiah-Kubi Patrick , Odugbemi Adeshina I. , Ntuli Mthobisi L. , Khan Rene , Kumalo Hezekiel M.
Published: March 2023

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for COVID-19, which was declared a global pandemic in March 2020 by the World Health Organization (WHO). Since SARS-CoV-2 main protease plays an essential role in the virus’s life cycle, the design of small drug molecules with lower molecular weight has been a promising development targeting its inhibition. Herein, we evaluated the novel peptidomimetic azatripeptide and azatetrapeptide nitriles against SARS-CoV-2 main protease. We employed molecular dynamics (MD) simulations to elucidate the selected compounds’ binding free energy profiles against SARS-CoV-2 and further unveil the residues responsible for the drug-binding properties. Compound 8 exhibited the highest binding free energy of −49.37 ± 0.15 kcal/mol, followed by compound 7 (−39.83 ± 0.19 kcal/mol), while compound 17 showed the lowest binding free energy (−23.54 ± 0.19 kcal/mol). In addition, the absorption, distribution, metabolism, and excretion (ADME) assessment was performed and revealed that only compound 17 met the drug-likeness parameters and exhibited high pharmacokinetics to inhibit CYP1A2, CYP2C19, and CYP2C9 with better absorption potential and blood-brain barrier permeability (BBB) index. The additional intermolecular evaluations suggested compound 8 as a promising drug candidate for inhibiting SARS-CoV-2 Mpro. The substitution of isopropane in compound 7 with an aromatic benzene ring in compound 8 significantly enhanced the drug’s ability to bind better at the active site of the SARS-CoV-2 Mpro.
Antioxidant Activity and Photosynthesis Efficiency in Melissa officinalis Subjected to Heavy Metals Stress
Authors: Adamczyk-Szabela Dorota , Chrześcijańska Ewa , Zielenkiewicz Piotr , Wolf Wojciech M.
Published: March 2023

The aim of this study was to assess influence of cadmium and zinc treatments on antioxidant activity combined with the photosynthesis efficiency in a popular herb lemon balm (Melissa officinalis L.). Plants were grown under greenhouse conditions by the pot method. The Mn, Cu, Cd, and Zn contents in soil and plants were measured by HR-CS FAAS. The activity of net photosynthesis, stomatal conductance, transpiration rate, intercellular CO2, and index of chlorophyll in leaves were determined for all investigated species. Reduction of the net photosynthesis was observed for cultivations subjected to either Zn or Cd treatments. Phenolic contents were determined by the chemical Folin-Ciocalteu method, while enhanced voltammetric analysis was applied to assess the antioxidant properties of plant extracts. Both of these approaches yielded similar results. Herbal extracts had exceptional antioxidant capacities and were good scavengers of free radicals and reactive oxygen species. Structural similarity of cadmium and zinc facilitated their mutual structural exchange and prompted substantial expansion of phenolics under the mixed Zn and Cd treatments.
The Effect of Sodium Bentonite in the Thermo-Catalytic Reduction of Viscosity of Heavy Oils
Authors: Zhou Zhichao , Zhang Wangyuan , Yu Tao , Li Yongfei , Struhárová Alena , Matejdes Marián , Slaný Michal , Chen Gang
Published: March 2023

To study the synergistic catalysis of an ex situ catalyst and in situ clay in the aquathermolysis of heavy oil, in this paper, a series of bentonite-supported catechol-metal complexes were prepared, and the catalytic viscosity reduction performance in the aquathermolysis of heavy oil was investigated. Under the optimized conditions, the viscosity can be reduced by 73%, and the pour point can be lowered by 15.0 °C at most, showing the synergistic catalysis of the ex situ catalyst and in situ clay in this aquathermolytic reaction. Thermogravimetry, physical adsorption-desorption, and scanning electron microscopy were conducted to characterize the thermal stability and microstructure of the ex situ catalyst. The components of the heavy oil before and after the reaction were fully characterized. Six model compounds were used to simulate the aquathermolysis reaction process. In order to study the mechanism of viscosity reduction after the catalytic aquathermolysis reaction, the compounds were analyzed by GC-MS. It is believed that these results will be beneficial in the future for related research in this field.