bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Plastic Improvement and Interference Behavior in Current-Assisted Riveting of CFRP Laminates
Authors: Qi Zhenchao , Zhang Ziqin , Xiao Yexin , Wang Xingxing
Published: February 2022

In order to improve the joint performance of a titanium alloy rivet connecting aircraft CFRP structure and promote the wide application of ordinary titanium alloy rivets in the aviation field, the ductility of a Ti45Nb rivet was improved using a current-assisted method in this paper. Through experiments, the mechanical behavior and temperature during the riveting process were monitored, and the variation rules of interference and damage were studied in detail. The results show that a current within 16.5 A/mm2 can effectively reduce the riveting pressure requirement, and the maximum engineering stress is reduced by nearly 22%. As the current density increases, the softening effect is obvious, but as the processing time increases, the softening effect has an upper threshold. The current-assisted method can significantly increase the interference fit level, and the uniformity of riveting can be improved by nearly 30%. The outlet burr height of a joint obtained by new technology meets the relevant standards. When the current density is too large or the action time is long, the damage pattern and mechanism at different depths of hole have obvious regional differences.
The Influence of Expanded Glass and Expanded Clay on Lightweight Aggregate Shotcrete Properties
Authors: Augonis Algirdas , Ivanauskas Ernestas , Bocullo Vytautas , Kantautas Aras , Vaičiukynienė Danutė
Published: February 2022

In the construction industry, the selection of sustainable materials leads to a movement towards more sustainable construction. In this study, lightweight aggregate shotcrete based on expanded glass (EG) and expanded clay (EC) is investigated. The goal of the study is to determine the influence of EG and EC inclusion on the properties of shotcrete. Ordinary Portland cement (OPC) powder with supplementary cementitious materials, such as silica fume and ground glass waste, are used as binders. The mechanical, physical and morphological properties, as well as the mineral and oxygen compositions, are obtained through compressive and flexural strength tests, thermal conductivity measurements, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM–EDX), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis. In this study, the mechanical, physical and thermal properties and waste utilization as cement supplementary materials are balanced. The shotcrete samples show that a density of 790 kg/m3 had a good thermal performance (thermal conductivity coefficient of 0.174 W/(m·K)) with the sufficient compressive strength of 6.26 MPa.
Structural, Electrical and Optical Properties of Pyrrolo[1,2-i][1,7] Phenanthroline-Based Organic Semiconductors
Authors: Doroftei Corneliu , Carlescu Aurelian , Leontie Liviu , Danac Ramona , Al-Matarneh Cristina Maria
Published: February 2022

This work reports a study on structural, electrical and optical properties of some recently synthesized pyrrolo[1,2-i][1,7] phenanthrolines derivatives in thin films. The thin films were deposited onto glass substrates by spin coating technique, using chloroform as solvent. The obtained films exhibited a polycrystalline structure with an n–type semiconductor behavior after heat treatment in the temperature range 293–543 K, specific to each sample. The thermal activation energy lies between 0.68 and 0.78 eV, while the direct optical band gap values were found in the range 4.17–4.24 eV. The electrical and optical properties of the investigated organic semiconductor films were discussed in relation to microstructural properties, determined by the molecular structure. The investigated organic compounds are promising for applications in organic optoelectronics and nanoelectronics.
Influence of Heat Treatment of Steel AISI316L Produced by the Selective Laser Melting Method on the Properties of Welded Joint
Authors: Mohyla Petr , Hajnys Jiri , Gembalová Lucie , Zapletalová Andrea , Krpec Pavel
Published: February 2022

This work is focused on the influence of heat treatment of a part produced by the SLM (selective laser melting) method of stainless steel, 316L. Two heat treatment regimens were tested and compared with the state without heat treatment. Subsequently, TIG (tungsten inert gas) welds were created on the base materials processed in this way. All welds were subjected to mechanical tests and microstructural analysis. The tensile test was performed both for the welded joint and for the base material in the transverse and longitudinal directions. The tensile strength values of the samples with the welded joint were compared with the values required for the base material, 316L forged steel (1.4404). Microstructural analysis revealed significant differences between samples with and without heat treatment. The results of these tests are supported by SEM analysis. EDAX (energy dispersive analysis of X-rays) semiquantitative analysis confirmed the presence of ultra-fine pores in the structure. The results of mechanical tests show that the solution annealing at 1040 °C for 0.5 h gives better results than the same heat treatment with a duration of 2 h.
Combustion Synthesis of High Density ZrN/ZrSi2 Composite: Influence of ZrO2 Addition on the Microstructure and Mechanical Properties
Authors: Zaki Zaki I. , Alotaibi Saad H. , Alhejji Bashayer A. , Mostafa Naser Y. , Amin Mohammed A. , Qhatani Mohsen M.
Published: February 2022

In this study, a high-density ZrN/ZrSi2 composite reinforced with ZrO2 as an inert phase was synthesized under vacuum starting with a Zr-Si4N3-ZrO2 blend using combustion-synthesis methodology accompanied by compaction. The effects of ZrO2 additions (10–30 wt%) and compression loads (117–327 MPa) on the microstructure, porosity and hardness of the samples were studied. The process was monitored using XRD, SEM, EDS, porosity, density and hardness measurements. Thermodynamic calculations of the effect of ZrO2 addition on the combustion reaction were performed including the calculation of the adiabatic temperatures and the estimation of the fractions of the liquid phase. The addition of up to 20 wt% ZrO2 improved the hardness and reduced the porosity of the samples. Using 20 wt% ZrO2, the sample porosity was reduced to 1.66 vol%, and the sample hardness was improved to 1165 ± 40.5 HV at 234 MPa.
Correlation Tests of Ultrasonic Wave and Mechanical Parameters of Spot-Welded Joints
Authors: Ulbrich Dariusz , Kańczurzewska Marta
Published: February 2022

Resistance spot welding as the basic method of joining car body elements has been used in the automotive industry for many years. For these connections, it is required to obtain the appropriate diameter of the weld nugget, which results in a high strength and durability of the connection during vehicle operation. The article presents the methodology of testing spot-welded joints using both destructive methods: shearing test of the spot weld and the ultrasonic method. The main goals of the performed tests are (1) to determine the correlation between the mechanical strength of a joint, measured in kN, and the selected parameters of the ultrasonic longitudinal wave with a frequency of 20 MHz propagating in the area of the spot weld and (2) to build and verify the predictive models of the weld nugget quality. The correlation of these parameters allows assessing the strength of the connection with the use of a non-destructive test method. On the basis of the performed analyses, it was determined that there is a strongly positive correlation between the number of reverse echoes and the force necessary to destroy the spot weld (0.41) and the diameter of the weld nugget (0.50). A strong negative correlation was also obtained between the number of echoes and the strength (−0.69) and diameter of the weld nugget (−0.72).
Depth Control of an Oil Bladder Type Deep-Sea AUV Based on Fuzzy Adaptive Linear Active Disturbance Rejection Control
Authors: Zhang Fengrui , Hou Jiaoyi , Ning Dayong , Gong Yongjun
Published: February 2022

The deep-sea autonomous underwater vehicle (AUV) is equipment of vital importance for ocean exploration, monitoring, and surveying. With a variable buoyancy system (VBS), AUV can achieve rising, diving, and hovering in the water column. This paper proposes a deep-sea AUV with an oil bladder type hydraulic VBS, which controls the oil flow rate with a proportional valve. However, the implementation of accurate depth control for AUV faces various challenges due to the varying water density with depth, the non-linear feature of the hydraulic system, and the disturbance from sea flows and currents. To tackle these problems, a third-order linear active disturbance rejection controller (LADRC) and its fuzzy adaptive version were designed and implemented in MATLAB/Simulink based on the state-space function of the proposed AUV system. Compared with the conventional PID controller, the simulation results indicate that the proposed LADRC controller shows strong robustness to disturbance, with other advantages including smaller steady-state error, overshoot, settling time, and response time. Moreover, the proposed fuzzy LADRC controller could further decrease the overshoot caused by the increasing target distance. The results prove that the designed depth controllers can meet the control requirements of the proposed deep-sea AUV.
Evaluation and Mathematical Analysis of a Four-Dimensional Lotka–Volterra-like Equation Designed to Describe the Batch Nisin Production System
Authors: Giménez-Palomares Fernando , Fernández de Córdoba Pedro , Mejuto Juan C. , Bendaña-Jácome Ricardo J. , Pérez-Guerra Nelson
Published: February 2022

Nisin, an antibacterial compound produced by Lactococcus lactis strains, has been approved by the US Food and Drug Administration to be used as a safe food additive to control the growth of undesirable pathogenic bacteria. Nisin is commonly described as a pH-dependent primary metabolite since its production depends on growth and culture pH evolution. However, the relationships between bacteriocin synthesis (BT), biomass production (X), culture pH, and the consumption of the limiting nutrient (total nitrogen: TN) have not been described until now. Therefore, this study aims to develop a competitive four-dimensional Lotka–Volterra-like Equation (predator-prey system) to describe these complex relationships in three series of batch fermentations with L. lactis CECT 539 in diluted whey (DW)-based media. The developed four-dimensional predator-prey system accurately described each individual culture, providing a good description of the relationships between pH, TN, X, and BT, higher values for R2 and F-ratios, lower values (<10%) for the mean relative percentage deviation modulus, with bias and accuracy factor values approximately equal to one. The mathematical analysis of the developed equation showed the existence of one asymptotically stable equilibrium point, and the phase’s diagram obtained did not show the closed elliptic trajectories observed in biological predator-prey systems.
A Dynamical Model for Financial Market: Among Common Market Strategies Who and How Moves the Price to Fluctuate, Inflate, and Burst?
Authors: Fabretti Annalisa
Published: February 2022

A piecewise linear dynamical model is proposed for a stock price. The model considers the price is driven by three rather standard demand components: chartist, fundamental and market makers. The chartist demand component is related to the study of differences between moving averages. This generates a high order system characterized by a piecewise linear map not trivial to study. The model has been studied analytically in its fixed points and dynamics and then numerically. Results are in line with the related literature: the fundamental demand component helps the stability of the system and keeps prices bounded; market makers satisfy their role of restoring stability, while the chartist demand component produces irregularity and chaos. However, in some cases, the chartist demand component assumes the role to compensate the fundamental demand component, felt in an autogenerated loop, and pushes the dynamics to equilibrium. This fact suggests that the instability must not be searched into the nature of the different investment styles rather in the relative proportion of the contribution of market actors.
Analytic Resolving Families for Equations with Distributed Riemann–Liouville Derivatives
Authors: Fedorov Vladimir E. , Du Wei-Shih , Kostić Marko , Abdrakhmanova Aliya A.
Published: February 2022

Some new necessary and sufficient conditions for the existence of analytic resolving families of operators to the linear equation with a distributed Riemann–Liouville derivative in a Banach space are established. We study the unique solvability of a natural initial value problem with distributed fractional derivatives in the initial conditions to corresponding inhomogeneous equations. These abstract results are applied to a class of initial boundary value problems for equations with distributed derivatives in time and polynomials with respect to a self-adjoint elliptic differential operator in spatial variables.
Efficient Prediction of Court Judgments Using an LSTM+CNN Neural Network Model with an Optimal Feature Set
Authors: Alghazzawi Daniyal , Bamasag Omaimah , Albeshri Aiiad , Sana Iqra , Ullah Hayat , Asghar Muhammad Zubair
Published: February 2022

As the amount of historical data available in the legal arena has grown over time, industry specialists are driven to gather, compile, and analyze this data in order to forecast court case rulings. However, predicting and justifying court rulings while using judicial facts is no easy task. Currently, previous research on forecasting court outcomes using small experimental datasets yielded a number of unanticipated predictions utilizing machine learning (ML) models and conventional methodologies for categorical feature encoding. The current work proposes forecasting court judgments using a hybrid neural network model, namely a long short-term memory (LSTM) network with a CNN, in order to effectively forecast court rulings using historic judicial datasets. By prioritizing and choosing features that scored the highest in the provided legal data set, only the most pertinent features were picked. After that, the LSTM+CNN model was utilized to forecast lawsuit verdicts. In contrast to previous related experiments, this composite model’s testing results were promising, showing 92.05 percent accuracy, 93 percent precision, 94 percent recall, and a 93 percent F1-score.
Equity Warrants Pricing Formula for Uncertain Financial Market
Authors: Shokrollahi Foad
Published: February 2022

In this paper, inside the system of uncertainty theory, the valuation of equity warrants is explored. Different from the strategies of probability theory, the valuation problem of equity warrants is unraveled by utilizing the strategy of uncertain calculus. Based on the suspicion that the firm price follows an uncertain differential equation, a valuation formula of equity warrants is proposed for an uncertain stock model.
A Novel Alginate Lyase: Identification, Characterization, and Potential Application in Alginate Trisaccharide Preparation
Authors: Xue Zhao , Sun Xiao-Meng , Chen Cui , Zhang Xi-Ying , Chen Xiu-Lan , Zhang Yu-Zhong , Fan Shou-Jin , Xu Fei
Published: February 2022

Alginate oligosaccharides (AOS) have many biological activities and significant applications in prebiotics, nutritional supplements, and plant growth development. Alginate lyases have unique advantages in the preparation of AOS. However, only a limited number of alginate lyases have been so far reported to have potentials in the preparation of AOS with specific degrees of polymerization. Here, an alginate-degrading strain Pseudoalteromonasarctica M9 was isolated from Sargassum, and five alginate lyases were predicted in its genome. These putative alginate lyases were expressed and their degradation products towards sodium alginate were analyzed. Among them, AlyM2 mainly generated trisaccharides, which accounted for 79.9% in the products. AlyM2 is a PL6 lyase with low sequence identity (≤28.3%) to the characterized alginate lyases and may adopt a distinct catalytic mechanism from the other PL6 alginate lyases based on sequence alignment. AlyM2 is a bifunctional endotype lyase, exhibiting the highest activity at 30 °C, pH 8.0, and 0.5 M NaCl. AlyM2 predominantly produces trisaccharides from homopolymeric M block (PM), homopolymeric G block (PG), or sodium alginate, with a trisaccharide production of 588.4 mg/g from sodium alginate, indicating its promising potential in preparing trisaccharides from these polysaccharides.
Amycolachromones A–F, Isolated from a Streptomycin-Resistant Strain of the Deep-Sea Marine Actinomycete Amycolatopsis sp. WP1
Authors: Chen Jianwei , Chen Jun , Wang Siqi , Bao Xiaoze , Li Songwei , Wei Bin , Zhang Huawei , Wang Hong
Published: February 2022

In this study, a detailed chemical investigation of a streptomycin-resistant strain of the deep-sea marine, actinomycete Amycolatopsis sp. WP1, yielded six novel amycolachromones A–F (1–6), together with five known analogues (7–11). Amycolachromones A–B (1–2) possessed unique dimer skeletons. The structures and relative configurations of compounds 1–11 were elucidated by extensive spectroscopic data analyses combined with X-ray crystal diffraction analysis. Plausible biogenetic pathways of amycolachromones A–F were also proposed.
The Learning Curve of Urodynamics for the Evaluation of Lower Urinary Tract Symptoms
Authors: Frigerio Matteo , Barba Marta , Cola Alice , Volontè Silvia , Marino Giuseppe , Regusci Luca , Sorice Paola , Ruggeri Giovanni , Castronovo Fabiana , Serati Maurizio , Torella Marco , Braga Andrea
Published: February 2022

Background and Objectives: Urodynamics is considered the gold standard for lower urinary tract functional assessment. However, it requires very specific skills and training, which are currently difficult to master due to its reduced use. Moreover, no studies or data are available to define the workload and the learning curve of this diagnostic tool. As a consequence, we aimed to evaluate the learning curve of residents with no previous experience to correctly perform and interpret urodynamics, and properly address and manage patients with pelvic floor disorders based on urodynamics findings. Materials and Methods: This prospective study analyzed a series of proficiency parameters in residents performing urodynamics under consultant supervision, including the following: duration of procedure, perceived difficulty, need for consultant intervention, accuracy of interpretation, and therapeutic proposal. The number of procedures performed was then divided into groups of five to evaluate the progressive grade of autonomy (technical and full management autonomy) reached by each resident. Results: In total, 69 patients underwent urodynamics performed by three residents, with every resident performing at least 20 exams. Duration of procedure, perceived difficulty, need for consultant intervention, accuracy of interpretation, and the appropriateness of the hypothetical proposal of management/treatment based on their interpretation of clinical data and urodynamic findings was shown to be directly related to the number of exams performed. Technical autonomy in the execution of uroflowmetry was reached in the group performing 6–10 procedures, while technical autonomy in the execution of cystomanometry with pressure/flow study was obtained in the group of 16–20 procedures. The latter corresponded also to the gain of full autonomy which also included an optimal therapeutic proposal. Conclusion: We found that there is a tangible learning curve for urodynamics in terms of several proficiency parameters. A workload of 5 uroflowmetries and 15 cystomanometries with pressure/flow studies may be adequate to complete the learning curve.
A Systematic Analysis of the Available Human Clinical Studies of Dental Implant Failure in Patients with Inflammatory Bowel Disease
Authors: Voina-Tonea Andrada , Labunet Anca , Objelean Adriana , Onisor Florin , Bran Simion , Mester Alexandru , Piciu Andra , Sava Sorina
Published: February 2022

Background and objectives: The aim was to evaluate the current literature on the influence of inflammatory bowel disease (ulcerative colitis/Crohn’s disease) in dental implant osseointegration in human clinical studies. Materials and methods: This review was conducted under the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. PubMed, Scopus, and Web of Science databases were electronic screened to find relevant articles published until October 2021. The inclusion criteria consisted of human clinical studies that reported the use of dental implant in patients diagnosed with inflammatory bowel disease. Risk of bias was assessed according to The Strengthening the Reporting of Observational studies in Epidemiology criteria. Results: A total of 786 studies were identified from databases. Of these, six studies were included in the review and reported the use of implants in patients with Crohn’s disease. No articles were available for ulcerative colitis. Included articles indicated that Crohn’s disease may determine early and late implant failure. Besides Crohn’s disease, several patients presented associated risk factors and systemic disease that determined implant failure. Conclusions: The presence of clinical studies on the influence of IBD in implant therapy is low. When recommending an implant therapy to IBD patients, the multidisciplinary team should be aware of side effects and a close collaboration between members of this team is necessary. More data are needed to sustain the effect of IBD on implant therapy.
Edentulous Patient Satisfaction with Conventional Complete Dentures
Authors: Soboleva Una , Rogovska Irena
Published: February 2022

Background and Objectives: Edentulism is considered to be an impediment impacting both patients’ quality of life and their nutrition. Conventional complete dentures are still a preferred treatment. However, there is no consensus on the most important factors which could substantially reduce the risk of patient dissatisfaction. This study evaluated the following determinants concerning patient satisfaction with complete maxillary and mandibular dentures: sex, denture-related functional and aesthetic aspects, and the degree of bone resorption. Materials and Methods: This study included 70 patients aged 34–81 years of age. All complete dentures were made by following the same technology. Visual analogue scales were used to assess patients’ overall satisfaction with dentures, comfort, ability to speak and chew, denture aesthetics, stability, and ease of prosthesis cleaning. Satisfaction with upper and lower dentures was rated separately. The degree of bone resorption was classified by using the Kalk and de Baat (1989) method. Results: The mean (SD) age of the study participants was 67.3 (10.4) years; 65.7% (n = 46) were females and 34.3% (n = 24) were males. There were no significant sex-based differences in resorption of the maxilla or mandibula. There were significant differences between maxillary and mandibular dentures, with lower mean satisfaction scores concerning chewing and maxillary complete dentures, and in regard to stability and comfort for mandibular complete dentures. There was a non-significant overall lower satisfaction with increased age. In multivariate analysis for mandibular complete dentures, aesthetics and stability significantly predicted the patient’s comfort levels, and the patient’s comfort significantly predicted overall satisfaction. For maxillary complete dentures, patient comfort and aesthetics significantly predicted overall patient satisfaction. Conclusions: Age, sex, and degree of resorption were not associated with patient satisfaction with complete dentures. Overall, patient satisfaction with both maxillary and mandibular complete dentures was related to their comfort level and denture aesthetics, and patient comfort itself was associated with stability of the mandibular denture.
Investigating Prescription Medication Expenditures and Level of Perceived Health Status among Older Adults with Pain in the United States
Authors: Axon David R. , Barrios Leonard P.
Published: February 2022

Background: the objective of this retrospective, cross sectional study was to assess the relationship between different levels of perceived health status and prescription medication expenditures among United States adults aged ≥50 years with self-reported pain. Methods: using 2019 Medical Expenditure Panel Survey (MEPS) data, four levels of perceived health status were formed (excellent, very good, good, and fair/poor health). Differences between characteristics in the groups were compared using chi square tests. Adjusted linear regression models, using logged positive annual prescription medication expenditures, were constructed to assess differences in prescription medication expenditures between levels of perceived health. Results: a total of 4826 individuals were included in the study. Adjusted linear regression analysis indicated those who reported excellent health had 65.8% lower annual prescription medication expenditures than those with fair/poor health. Those with very good health had 49.7% lower annual prescription medication expenditures than those with fair/poor health, while those with good health had 27.2% lower annual prescription medication expenditures than those with fair/poor health. Conclusions: better perceived health status was generally associated with relatively lower prescription medication expenditures. Further research is needed to investigate if this pattern is also observed for other categories of healthcare expenditures and in other populations.
Mechanisms of Efficient Desalination by a Two-Dimensional Porous Nanosheet Prepared via Bottom-Up Assembly of Cucurbit[6]urils
Authors: Zhou Feng , Lee Jaewoo , Wang Rong , Su Haibin
Published: February 2022

Many researchers have examined the desalination performance of various kinds of two-dimensional (2D) porous nanosheets prepared by top-down approaches such as forming pores on the plain based on molecular dynamics (MD) simulations. In contrast, it is rare to find MD simulations addressing the desalination performance of a 2D porous nanosheet prepared by bottom-up approaches. We investigated the desalination performance of a 2D porous nanosheet prepared by the assembly of cucurbit[6]uril (CB[6]) via MD simulation. The model 2D CB[6] nanosheet features CB[6] with the carbonyl-fringed portals of 3.9 Å and the interstitial space filled with hydrophobic linkers and dangling side chains. Our MD simulation demonstrated that the 2D porous CB[6] nanosheet possesses a 70 to 140 times higher water permeance than commercial reverse osmosis membranes while effectively preventing salt passage. The extremely high water permeance and perfect salt rejection stem from not only CB[6]’s nature (hydrophilicity, negative charge, and the right dimension for size exclusion) but also the hydrophobic and tightly filled interstitial space. We also double-checked that the extremely high water permeance was attributable to only CB[6]’s nature, not water leakage, by contrasting it with a 2D nanosheet comprising CB[6]-spermine complexes. Lastly, this paper provides a discussion on a better cucurbituril homologue to prepare a next-generation desalination membrane possessing great potential to such an extent to surpass the 2D porous CB[6] nanosheet based on quantum mechanics calculations.
Effects of Expanded Hemodialysis with Medium Cut-Off Membranes on Maintenance Hemodialysis Patients: A Review
Authors: Zhang Zhuyun , Yang Tinghang , Li Yupei , Li Jiameng , Yang Qinbo , Wang Liya , Jiang Luojia , Su Baihai
Published: February 2022

Kidney failure is associated with high morbidity and mortality. Hemodialysis, the most prevalent modality of renal replacement therapy, uses the principle of semipermeable membranes to remove solutes and water in the plasma of patients with kidney failure. With the evolution of hemodialysis technology over the last half century, the clearance of small water-soluble molecules in such patients is adequate. However, middle molecules uremic toxins are still retained in the plasma and cause cardiovascular events, anemia, and malnutrition, which significantly contribute to poor quality of life and high mortality in maintenance hemodialysis patients. A new class of membrane, defined as a medium cut-off (MCO) membrane, has emerged in recent years. Expanded hemodialysis with MCO membranes is now recognized as the artificial kidney model closest to natural kidney physiology. This review summarizes the unique morphological characteristics and internal filtration–backfiltration mechanism of MCO membranes, and describes their effects on removing uremic toxins, alleviating inflammation and cardiovascular risk, and improving quality of life in maintenance hemodialysis patients.
Influence of Surface Pretreatments on the Anticorrosion of Polypyrrole Electro-Polymerized Coatings for Copper in Artificial Seawater
Authors: Zhu Hetao , Liu Xiaoyan , Hao Hua , Zheng Xingwen
Published: February 2022

Plasma discharging treatment (hydroxylation) was conducted on copper surfaces for the subsequent electro-polymerization procedure of polypyrrole (PPy) coating (d-PPy). The hydroxylated surface could solve the criticized adhesion strength and protection efficiency of electropolymerized coatings for metal substrate in corrosive media. Compared with the counterpart obtained via passivation pretreatment (p-PPy), a well-adhered d-PPy layer was acquired on the hydroxylated copper surface, which earned a satisfactory adhesion grade, compactness and conductivity. Appreciable protection of d-PPy was measured for copper in the artificial seawater (ASW) at 298 K via electrochemical and surface analyses. Results of electrochemical measurements indicated that d-PPy coating effectively retarded copper corrosion in ASW with a lowered corrosion current density and improved charge transfer resistance. Surface analysis revealed that the typical morphology of PPy was retained after 240 h immersion in ASW. A favorable physical barrier and anodic protection efficacy might account for the superior protection of d-PPy coating for the underlying copper. Molecular dynamics simulations for the deposition of PPy chains on pristine and hydroxylated copper planes provided a definite correlation between the theoretical calculations and experimental observations. Theoretical modelling also disclosed in-depth the anchoring nature and anticorrosive mechanism for PPy toward the hydroxylated copper in ASW.
A Comprehensive Evaluation of Metabolomics Data Preprocessing Methods for Deep Learning
Authors: Abram Krzysztof Jan , McCloskey Douglas
Published: February 2022

Machine learning has greatly advanced over the past decade, owing to advances in algorithmic innovations, hardware acceleration, and benchmark datasets to train on domains such as computer vision, natural-language processing, and more recently the life sciences. In particular, the subfield of machine learning known as deep learning has found applications in genomics, proteomics, and metabolomics. However, a thorough assessment of how the data preprocessing methods required for the analysis of life science data affect the performance of deep learning is lacking. This work contributes to filling that gap by assessing the impact of commonly used as well as newly developed methods employed in data preprocessing workflows for metabolomics that span from raw data to processed data. The results from these analyses are summarized into a set of best practices that can be used by researchers as a starting point for downstream classification and reconstruction tasks using deep learning.
Meteorology: A New Journal for a New Age of Weather Research
Authors: Williams Paul D.
Published: February 2022

The quest to understand and forecast the weather has occupied human minds since time immemorial [...]
Northern Hemisphere Flow Regime Transitions, Blocking, and the Onset of Spring in the Central USA during Late Winter 2019 and 2021
Authors: Est Madeline A. , Mount Samuel , Steward Christopher A. , Lupo Anthony R.
Published: February 2022

Studies have shown that maxima in the time series of Northern Hemisphere (NH) integrated enstrophy (IE) can be associated with large-scale flow regime transitions and, often, the onset and decay of blocking events. During February and March 2019, and then February 2021, strong IE maxima were associated with changes in the NH flow regimes that brought very cold conditions to the central United States. The colder conditions in the central USA during late winter 2019 and 2021 were also associated with very strong Pacific or Atlantic Region blocking events. Using the NCEP re-analyses, three different teleconnection indexes, and surface weather data from nine different cities in the central USA, IE maxima, flow regime transitions, and surface weather regimes are identified. The mean temperature and precipitation characteristics for the cities named here during the different large-scale flow regime characteristics are compared. The results have demonstrated that relatively warm conditions occurred through the first part of February 2019 before a period of anomalously colder (as much as 12 °C below normal) and drier weather, with more snow, persisted into early March. This period was bookended by maxima in the NH IE time series, changes in the character of the main NH teleconnection indexes, and a strong simultaneous NH blocking episode. Following the cold period, the temperature regime returned to values that were closer to seasonal normal values, which were then discussed as a possible indicator of a transition from a winter to a spring regime.
Gut Microbiota, Macrophages and Diet: An Intriguing New Triangle in Intestinal Fibrosis
Authors: Amamou Asma , O’Mahony Cian , Leboutte Mathilde , Savoye Guillaume , Ghosh Subrata , Marion-Letellier Rachel
Published: February 2022

Intestinal fibrosis is a common complication in inflammatory bowel disease (IBD) without specific treatment. As macrophages are the key actors in inflammatory responses and the wound healing process, they have been extensively studied in chronic diseases these past decades. By their exceptional ability to integrate diverse stimuli in their surrounding environment, macrophages display a multitude of phenotypes to underpin a broad spectrum of functions, from the initiation to the resolution of inflammation following injury. The hypothesis that distinct macrophage subtypes could be involved in fibrogenesis and wound healing is emerging and could open up new therapeutic perspectives in the treatment of intestinal fibrosis. Gut microbiota and diet are two key factors capable of modifying intestinal macrophage profiles, shaping their specific function. Defects in macrophage polarisation, inadequate dietary habits, and alteration of microbiota composition may contribute to the development of intestinal fibrosis. In this review, we describe the intriguing triangle between intestinal macrophages, diet, and gut microbiota in homeostasis and how the perturbation of this discreet balance may lead to a pro-fibrotic environment and influence fibrogenesis in the gut.
Time Limit of Gold Mineralization in Muping–Rushan Belt, Eastern Jiaodong Peninsula, China: Evidence from Muscovite Ar–Ar Dating
Authors: Chen Binghan , Deng Jun , Ji Xingzhong
Published: February 2022

Controversy surrounds the genetic relationship between gold mineralization and magmatism, especially in deposits in granite. Jiaodong Peninsula is the leading gold province in China, and most deposits are in Mesozoic granites; moreover, debate on the genesis persists. In eastern Jiaodong, the Muping–Rushan gold belt produces mainly quartz–sulfide vein-type gold, and the Upper Jurassic Kunyushan granite and Late Lower Cretaceous Sanfoshan granite are the wall rock. Precise mineralization ages should be identified to determine whether gold is related to the intrusion. In this study, three gold deposits (Sanjia, Yinggezhuang, and Xipo) from two ore-controlling faults were considered. Muscovites from quartz–sulfide veins and beresite were selected for Argon–Argon dating. The results obtained were 116.51 ± 0.47 Ma, 120.02 ± 0.38 Ma, and 121.65 ± 0.48 Ma for the three deposits, respectively. The mineralization lasted about 5 Ma in the Muping–Rushan gold belt. The test results showed that the mineralization was 16 Ma later than the intrusion time of Kunyushan granite and was earlier than that of Sanfoshan granite. Only the cooling age overlapped with the mineralization age. Previous studies have demonstrated that the ore fluid is of medium–low salinity and medium–low temperature. No typical high–low temperature mineral assemblage exists in the Muping–Rushan gold belt. Hence, gold deposits in Muping–Rushan gold belt could not be categorized as intrusion-related gold type.
Effects of Residual Xanthate on Flotation Efficiency of a Cu-Zn Sulfide Ore
Authors: Ozturk Yasemin , Bicak Ozlem , Ekmekci Zafir
Published: February 2022

Reuse of process water in the flotation of sulfide ores has crucial importance for environmental sustainability and improved process economy. However, the chemistry of process water may be a critical subject for the flotation efficiency as the dissolved ion concentration increases with water reuse. In this study, the effects of water reuse on the flotation efficiency of a Cu-Zn sulfide ore were investigated. The flotation flowsheet consists of a pre-flotation section to remove the naturally floatable talc particles, and sequential copper and zinc flotation sections. Calcium, sulfate, thiosulfate, and xanthate were found as major contaminating ionic species in the process water discharged from flotation circuits. The flotation tests with recirculated water from the zinc rougher tailing revealed that the presence of residual xanthate caused unintentional activation of copper minerals in the pre-float section. Copper recovery increased in the pre-flotation section and resulted in the loss of copper to the pre-float concentrate, which is considered as a tailing stream in the current flowsheet. Various types of activated carbon samples were tested to remove the residual xanthate from the tailing water. The carbon samples could be regenerated by heat treatment and reused for water treatment. Performance of the activated carbon samples was directly related to the pore size and surface area. Carbon-treated tailing water could be re-used in flotation without affecting the flotation performance.
Characterization and Removal Potential of Fluorine in Lignite from a Mine in Shaanxi Province, China: A Case Study
Authors: Ni Chao , Zhou Shaoqi , Bu Xiangning , Bilal Muhammad , Ul Hassan Fawad , Chen Yuran , Xu Guangqian , Xie Guangyuan
Published: February 2022

Fluorine appears in coal and is released into the atmosphere upon combustion, resulting in harmful impacts on the environment and life, which needs to be removed from coal before utilization. Coal can be processed by flotation and gravity separation to reduce its fluorine content. In this study, a lignite sample from a mine in Shaanxi Province, China, was characterized using the float–sink test, sieving test, X-ray diffraction (XRD), and polarized light microscopy. Mineralogical analysis indicated that the fluorine in coal is mainly contained in Muscovite and polylithionite, and partly in pyrite. The washability and floatability analyses were employed to evaluate the extent of fluorine removal from >0.5 and <0.5 mm size fractions of lignite, respectively. Compared to the raw sample that contained 347.74 μg/g fluorine content, the proposed combination of gravity-flotation separation process decreased the fluorine content to 90.14 μg/g, which meets the requisites of coal standards.
Detection and Characterization of TiO2 Nanomaterials in Sludge from Wastewater Treatment Plants of Chihuahua State, Mexico
Authors: Reyes-Herrera Juan , Acosta-Slane Damaris , Castillo-Michel Hiram , Pradas del Real Ana E. , Vogel-Mikus Katarina , Benetti Federico , Roman Marco , Villanova Julie , Valles-Aragón M. Cecilia
Published: February 2022

TiO2 nanoparticles (TiO2-NPs) have a wide range of industrial applications (paintings, sunscreens, food and cosmetics) and is one of the most intensively used nanomaterials worldwide. Leaching from commercial products TiO2-NPs are predicted to significantly accumulate in wastewater sludges, which are then often used as soil amendment. In this work, sludge samples from four wastewater treatment plants of the Chihuahua State in Mexico were obtained during spring and summer (2017). A comprehensive characterization study was performed by X-ray based (laboratory and synchrotron) techniques and electron microscopy. Ti was detected in all sludge samples (1810–2760 mg/kg) mainly as TiO2 particles ranging from 40 nm up to hundreds of nm. Micro-XANES data was analyzed by principal component analysis and linear combination fitting enabling the identification of three predominant Ti species: anatase, rutile and ilmenite. Micro-XANES from the smaller Ti particles was predominantly anatase (68% + 32% rutile), suggesting these TiO2-NPs originate from paintings and cosmetics. TEM imaging confirmed the presence of nanoscale Ti with smooth surface morphologies resembling engineered TiO2-NPs. The size and crystalline phase of TiO2-NPs in the sludge from this region suggest increased reactivity and potential toxicity to agro-systems. Further studies should be dedicated to evaluating this.
Tempranillo Grape Extract in Transfersomes: A Nanoproduct with Antioxidant Activity
Authors: Asensio-Regalado Carlos , Alonso-Salces Rosa María , Gallo Blanca , Berrueta Luis A. , Era Benedetta , Pintus Francesca , Caddeo Carla
Published: February 2022

Polyphenols are gaining increasing interest due to their beneficial properties to human health. Grape pomace, the by-product of wine production, is a source of these bioactive compounds. An extract from Tempranillo grape pomace was obtained and characterized qualitatively and quantitatively. The major components found were anthocyanins, flavan-3-ols, and flavonols. To improve the bioavailability of these compounds, the extract was formulated in phospholipid vesicles, namely transfersomes. Spherical unilamellar vesicles around 100 nm each were obtained. The antioxidant activity of both the extract and the transfersomes was evaluated by using colorimetric assays (i.e., DPPH, FRAP, and Folin–Ciocalteu). The cells’ viability and the antioxidant activity were assessed in keratinocytes. The results showed that the extract and the transfersomes had no cytotoxic effects and exerted remarkable antioxidant activity, which was more evident in a vesicle formulation. These findings highlighted the potential of the Tempranillo grape pomace extract and the efficacy of the incorporation into phospholipid vesicles.
Synthesis and Characterization of Zinc and Vanadium Co-Substituted CoFe2O4 Nanoparticles Synthesized by Using the Sol-Gel Auto-Combustion Method
Authors: Imanipour Parvin , Hasani Saeed , Seifoddini Amir , Nabiałek Marcin
Published: February 2022

In recent years, cobalt ferrite has attracted considerable attention due to its unique physical properties. The present study aimed to produce cobalt ferrite magnetic nanoparticles doped with zinc and vanadium using the sol-gel auto-combustion method. For this purpose, Co1−xZnxFe2−yVyO4 (where x = 0.0, 0.1, 0.2, 0.5 and y = 0.00, 0.05, 0.15, 0.25) precursors were calcined at 800 °C for 3 h. The prepared samples were characterized with the X-ray diffraction (XRD) method in combination with Rietveld structure refinement, field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometery (VSM). The XRD patterns confirmed the formation of crystalline spinel structure for all samples. However, the diffraction peaks of hematite and iron vanadium oxide phases were observed in the patterns of some doped samples. The average crystallite size for all the synthesized samples was found to be in the range of ~45–24 nm, implying that it decreased by simultaneously doping cobalt ferrite with Zn and V. The FT-IR spectrum confirmed the formation of the spinal structure of ferrite through the observed vibrational bands assigned to the tetrahedral (υ2) and octahedral (υ1) interstitial complexes in the spinel structure. The FE-SEM images showed that morphology, average grain size, and agglomeration of the synthesized powders were affected by doping, which was due to the interactions of the magnetic surface of nanoparticles. The VSM curves demonstrated that saturation magnetization and coercivity values changed in the range of 30–83 emu/g and from 27–913 Oe, respectively. These changes occurred due to the alteration in cation distribution in the spinel structure. This can be attributed to the change in superexchange interactions between magnetic ions by co-substitution of Zn and V ions in Cobalt ferrite and the changes in magnetocrystalline anisotropy.
New Insights into Potential Beneficial Effects of Bioactive Compounds of Bee Products in Boosting Immunity to Fight COVID-19 Pandemic: Focus on Zinc and Polyphenols
Authors: Bakour Meryem , Laaroussi Hassan , Ousaaid Driss , El Ghouizi Asmae , Es-safi Imane , Mechchate Hamza , Lyoussi Badiaa
Published: February 2022

The coronavirus disease 2019 (COVID-19) is an epidemic caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Populations at risk as well as those who can develop serious complications are people with chronic diseases such as diabetes, hypertension, and the elderly. Severe symptoms of SARS-CoV-2 infection are associated with immune failure and dysfunction. The approach of strengthening immunity may be the right choice in order to save lives. This review aimed to provide an overview of current information revealing the importance of bee products in strengthening the immune system against COVID-19. We highlighted the immunomodulatory and the antiviral effects of zinc and polyphenols, which may actively contribute to improving symptoms and preventing complications caused by COVID-19 and can counteract viral infections. Thus, this review will pave the way for conducting advanced experimental research to evaluate zinc and polyphenols-rich bee products to prevent and reduce the severity of COVID-19 symptoms.
Implementing a Community-Based Initiative to Improve Nutritional Intake among Home-Delivered Meal Recipients
Authors: Juckett Lisa A. , Hariharan Govind , Dodonova Dimitri Camargo , Klaus Jared , Rowe Melinda , Burak Elana , Mason Benetta , Bunck Leah
Published: February 2022

Home-delivered meal (HDM) recipients are a highly vulnerable group of older adults at risk for malnutrition and subsequent health decline. To help HDM recipients increase their nutritional intake, HDM agencies may provide expanded meal options that allow older adults to have greater autonomy over their meal selection; however, the extent to which recipients are able to select nutritious meals that are responsive to their health complexities is unknown. This study examined the nutritional content of meals selected by HDM recipients enrolled in an expanded menu plan through a large HDM agency. Data were drawn from a retrospective chart review of 130 HDM recipients who had the option of selecting their own HDM meals and frequency of meal delivery. Findings indicate that older adults who selected their own meals chose meals that were significantly lower in protein, potassium, fat, and calories. The lack of these nutrients suggests that older adults enrolled in expanded menu plans should be referred to registered dietitian nutritionists who can provide skilled guidance in meal selection. To address this need, we also describe and provide preliminary data representing a referral program designed to connect HDM recipients to dietetic services with the goal of optimizing older adult nutrition and health-related outcomes.