bluuebunny/crossref_metadata_2025 huggingface dataset:
2,3,4,5,6-Pentabromobenzoic Acid
Authors: Taydakov Ilya V. , Vlasova Tatiana S. , Belousov Yury A. , Zanizdra Sergey R. , Gontcharenko Victoria E.
Published: September 2022

Pentabromobenzoate is a useful fragment in organic synthesis and in coordination chemistry. Among known synthetic approaches to pentabromobenzoic acid (PBA), we have assessed and identified exhaustive bromination of benzoic acid by using 1.3-dibromoisocyanuric acid in concentrated H2SO4 solution as the most efficient method for the preparation of PBA on a multigram scale. As the crude bromination product is typically contaminated with 3,4,5,6-tetrabromobenzoic acid (TBA) and pentabromobenzene, C6Br5H, a simple purification protocol for preparation of analytically pure PBA has been developed. The molecular structure and crystal packing of PBA established by single-crystal X-ray diffractometry suggests a pattern of H-bonding and halogen bonding in solid state.
Bis(2-hydroxyethyl) 2-phenylsuccinate
Authors: Olivieri Diego , Tarroni Riccardo , Carfagna Carla
Published: September 2022

Succinic acid esters are important compounds that find many applications in various industrial fields. One of the most promising and easy ways of producing these molecules is represented by the bis-alkoxycarbonylation reaction of olefins. In particular, a recently developed catalytic system, consisting of an aryl α-diimine/palladium(II) catalyst and p-benzoquinone as an oxidant, has allowed succinates to be obtained in high yields. A similar methodology was applied here for the unprecedented synthesis of the bis(2-hydroxyethyl) 2-phenylsuccinate in 78% isolated yield, starting from the cheap and commercially available compounds styrene and ethylene glycol. To our knowledge, no other examples of bis-alkoxycarbonylations of olefins involving diols have been reported thus far. The obtained product was fully characterized by NMR and ESI-MS analyses.
Nanostructured Metals with an Excellent Synergy of Strength and Ductility: A Review
Authors: Pu Pengpeng , Chen Tijun
Published: September 2022

Nanocrystalline metals developed based on fine grain strengthening always have an excellent strength, but are accompanied by a drop in ductility. In the past 20 years, substantial efforts have been dedicated to design new microstructures and develop the corresponding processing technologies in order to solve this problem. In this article, the novel nanostructures designed for simultaneously achieving high strength and high ductility developed in recent years, including bimodal grain size distribution nanostructure, nanotwinned structure, hierarchical nanotwinned structure, gradient nanostructure, and supra-nano-dual-phase nanostructure, are reviewed. Based on a comprehensive understanding of the simultaneously strengthening and toughening mechanisms, the microstructures and corresponding processing techniques are mainly discussed, and the related prospects that may be emphasized in the future are proposed.
Uncertainty Quantification for Full-Flight Data Based Engine Fault Detection with Neural Networks
Authors: Weiss Matthias , Staudacher Stephan , Mathes Jürgen , Becchio Duilio , Keller Christian
Published: September 2022

Current state-of-the-art engine condition monitoring is based on a minimum of one steady-state data point per flight. Due to the scarcity of available data points, there are difficulties distinguishing between random scatter and an underlying fault introducing a detection latency of several flights. Today’s increased availability of data acquisition hardware in modern aircraft provides continuously sampled in-flight measurements, so-called full-flight data. These full-flight data give access to sufficient data points to detect faults within a single flight, significantly improving the availability and safety of aircraft. Artificial neural networks are considered well suited for the timely analysis of an extensive amount of incoming data. This article proposes uncertainty quantification for artificial neural networks, leading to more reliable and robust fault detection. An existing approach for approximating the aleatoric uncertainty was extended by an Out-of-Distribution Detection in order to take the epistemic uncertainty into account. The method was statistically evaluated, and a grid search was performed to evaluate optimal parameter combinations maximizing the true positive detection rates. All test cases were derived based on in-flight measurements of a commercially operated regional jet. Especially when requiring low false positive detection rates, the true positive detections could be improved 2.8 times while improving response times by approximately 6.9 compared to methods only accounting for the aleatoric uncertainty.
An Efficient IIoT Gateway for Cloud–Edge Collaboration in Cloud Manufacturing
Authors: Zhang Yi , Tang Dunbing , Zhu Haihua , Zhou Shihui , Zhao Zhen
Published: September 2022

The cloud manufacturing system can provide consumers with on-demand manufacturing services, which significantly improve the utilization rate of distributed manufacturing resources and the response speed of personalized product needs. In the cloud manufacturing platform, the successful implementation of various industrial applications relies on the uploading and streaming of related field-level manufacturing data. For example, the realization of manufacturing service composition application should match the manufacturing tasks with distributed manufacturing resources according to their working state data and performance measurement data. Therefore, this paper proposes a data integration and analysis framework of a cloud manufacturing system based on cloud–edge collaboration and the Industrial Internet of Things (IIoT). A service-oriented information model is established to uniformly describe the related operational data and functional attributes of heterogeneous manufacturing resources. Secondly, a real-time transmission and integration method of high-volume operational field and sensor data based on message middleware is proposed to realize the remote monitoring of distributed manufacturing resources and efficient distribution of related data. Finally, a cloud–edge collaboration mechanism is put forward to train and update the parameters of various artificial intelligence models deployed at edge gateways. In the experiment, taking the computer numerical control (CNC) lathe as an example, the effectiveness of the proposed manufacturing resource access method is verified. Taking the fault diagnosis model of the CNC lathe as an example, the efficiency of the proposed cloud–edge collaboration mechanism for model updating is verified.
A Multiphysics Co-Simulation Framework of a Gas Engine and Three-Way Catalyst toward a Complete Vehicle Design Model
Authors: Di Maio Dario , Stramaccioni Elena , Misul Daniela Anna , Napolitano Pierpaolo , Beatrice Carlo
Published: September 2022

In view of the increasingly stringent emission regulations, the automotive sector needs considerable support from the development of robust and reliable engine and aftertreatment models. Accurate reproduction of engine-out and tailpipe pollutants plays a crucial role in complying with these legislations. Given the difficulty in characterizing some critical phenomena, frequently caused by strong dynamics and related to experimental uncertainties, communication between several calibrated and reliable models is mandatory. This is certainly valid for powertrains that will be powered with alternative gas fuels such as natural gas, bio-methane and hydrogen in the future. This paper describes a methodology to co-simulate a 1D CNG HD 6-cyl engine model and a 1D quasi-steady Three-Way Catalyst model in a global framework for high-fidelity virtual prototyping of the vehicle system. Through the implementation of a dedicated control logic in MATLAB/Simulink, the modeling architecture allows for the reproduction of the engine performance parameters together with the evaluation of the TWC pollutants’ conversion efficiency. An extensive database of experimental tests was used to assess the model response. The latter was validated in multiple steady-state operating conditions of the engine workplan. Using a semi-predictive combustion model, the validation was carried out over a wide range of different air-to-fuel ratios and during fast rich/lean transitions to evaluate the formation and conversion phenomena of the main chemical species, both engine-out and tailpipe. Subsequently, the complete model was validated in dynamic conditions throughout a WHTC, accurately reproducing the cut-off phases and their sudden accelerations. The numerical–experimental agreement on pollutant reproduction is generally good and globally below 3%. Larger deviations occur in extremely rich conditions and in CH4 emission evaluation due to the lack of information related to the combustion process and chemical mechanisms involving the Pd surface.
Comparison of Imputation Methods for Missing Rate of Perceived Exertion Data in Rugby
Authors: Epp-Stobbe Amarah , Tsai Ming-Chang , Klimstra Marc
Published: September 2022

Rate of perceived exertion (RPE) is used to calculate athlete load. Incomplete load data, due to missing athlete-reported RPE, can increase injury risk. The current standard for missing RPE imputation is daily team mean substitution. However, RPE reflects an individual’s effort; group mean substitution may be suboptimal. This investigation assessed an ideal method for imputing RPE. A total of 987 datasets were collected from women’s rugby sevens competitions. Daily team mean substitution, k-nearest neighbours, random forest, support vector machine, neural network, linear, stepwise, lasso, ridge, and elastic net regression models were assessed at different missingness levels. Statistical equivalence of true and imputed scores by model were evaluated. An ANOVA of accuracy by model and missingness was completed. While all models were equivalent to the true RPE, differences by model existed. Daily team mean substitution was the poorest performing model, and random forest, the best. Accuracy was low in all models, affirming RPE as multifaceted and requiring quantification of potentially overlapping factors. While group mean substitution is discouraged, practitioners are recommended to scrutinize any imputation method relating to athlete load.
A Thermal-Hydraulic-Gas-Mechanical Coupling Model on Permeability Enhancement in Heterogeneous Shale Volume Fracturing
Authors: Shang Xiaoji , Zhang Zhizhen , Yang Weihao , Wang J.G. , Zhai Cheng
Published: September 2022

Heat treatment on shale reservoirs can promote the development of secondary fractures in a matrix on the basis of hydraulic fracturing, forming multi-scale gas–water seepage channels and strengthening the gas desorption. Experimental evidence shows that heat treatment can enhance gas recovery in the same mining life. Heat treatment on a shale gas reservoir is a multi-physical and multi-phase coupling process. However, how the thermal stimulation interacts with nonlinear two-phase flow in heterogeneous shale volume fracturing has not been clear. In this paper, a fully coupled THGM model for heating-enhanced shale-gas recovery in heterogeneous shale reservoirs is proposed. First, the governing equations are formulated for the shale-reservoir deformation involving both gas adsorption and thermal expansion, the permeability evolution model for the cracking process of fractured shale, the gas–water two-phase continuity equation considering the effects of gas solubility and the heat transfer equation for heat conduction and convection. The interactions among stress, temperature and seepage in a heterogeneous shale reservoir were studied. Secondly, a test on shale permeability after 50 °C temperature treatment was conducted. The evolution of temperature, capillary pressure, water and gas saturation and the permeability of shale during the heat treatment of the reservoir were numerically analyzed. Finally, the gas production from a shale gas reservoir was numerically simulated with this THGM model. The numerical results indicated that the thermal-induced fracturing, gas desorption and separation from water make predominant contributions to the evolution of permeability. The heat treatment can enhance cumulative gas production by 58.7% after 27.4 years of heat injection through promoting gas desorption and matrix diffusion.
A New Series Representation and the Laplace Transform for the Lognormal Distribution
Authors: Ortigueira Manuel D.
Published: September 2022

In this paper, the lognormal distribution is studied, and a new series representation is proposed. This series uses the powers of the bilinear function. From it, a simplified form is obtained and used to compute the Laplace transform of the distribution.
Extra Edge Connectivity and Extremal Problems in Education Networks
Authors: Liu Hongfang , Liang Jinxia , Das Kinkar Chandra
Published: September 2022

Extra edge connectivity and diagnosability have been employed to investigate the fault tolerance properties of network structures. The p-extra edge connectivity λp(Γ) of a graph Γ was introduced by Fàbrega and Fiol in 1996. In this paper, we find the exact values of p-extra edge connectivity of some special graphs. Moreover, we give some upper and lower bounds for λp(Γ), and graphs with λp(Γ)=1,2,n2n2−1,n2n2 are characterized. Finally, we obtain the three extremal results for the p-extra edge connectivity.
A Simple Stability Analysis for a Mathematical Model of Migration Due to Noise and Resources
Authors: Ramirez-Carrasco Carlos , Córdova-Lepe Fernando , Velásquez Nelson
Published: September 2022

This research studies a metapopulation model where each patch is considered a form of fragmentation of the environment produced by the spatio-temporal variability of anthropogenic noise. A deterministic mathematical model is proposed that describes two processes of migration between patches. The first process consists of migration due to chronic critical noise produced by an anthropogenic and biological source (self-generated acoustic signals of higher intensity, due to the Lombard effect). The second process consists of migration due to a higher level of stain occupancy. A simple and classical analysis of the local stability of the model is performed. The results indicate that no subpopulation goes extinct; in fact, a necessary condition for long-term stabilization of the size of the subpopulations is that the noise attenuation rate is higher. Moreover, as long as the noise is of low intensity the differences in the carrying capacity of each patch do not produce substantial, long-term differences in the sizes of the subpopulations. However, as the noise intensity increases, the difference in carrying capacities produce noticeable, long-term differences between subpopulation sizes. Finally, the results are corroborated by numerical simulations.
Modified Three-Point Fractional Formulas with Richardson Extrapolation
Authors: Batiha Iqbal M. , Alshorm Shameseddin , Ouannas Adel , Momani Shaher , Ababneh Osama Y. , Albdareen Meaad
Published: September 2022

In this paper, we introduce new three-point fractional formulas which represent three generalizations for the well-known classical three-point formulas; central, forward and backward formulas. This has enabled us to study the function’s behavior according to different fractional-order values of α numerically. Accordingly, we then introduce a new methodology for Richardson extrapolation depending on the fractional central formula in order to obtain a high accuracy for the gained approximations. We compare the efficiency of the proposed methods by using tables and figures to show their reliability.
Effects of Variable Properties on the Convective Flow of Water near Its Density Extremum in an Inclined Enclosure with Entropy Generation
Authors: Sivanandam Sivasankaran , Mallawi Fouad O. M.
Published: September 2022

The aim of the current numerical simulation was to understand the effects of the temperature-dependent properties of viscosity and thermal conductivity on the buoyant convection of cold water around its density extremum in a tilting chamber. The equations for thermal conductivity and viscosity were derived based on the reference temperature parameter. The entropy generation and cup mixing temperature were also calculated. The governing mathematical model was solved by the finite-volume-based iterative technique. The obtained results were deliberated for several values of inclination angles and for the density reversal parameter for variable viscosity and thermal conductivity cases. It was detected that density inversion has a strong effect on stream and thermal patterns through the development of a bi-cellular arrangement due to density inversion.
A Heuristic Construction Neural Network Method for the Time-Dependent Agile Earth Observation Satellite Scheduling Problem
Authors: Chen Jiawei , Chen Ming , Wen Jun , He Lei , Liu Xiaolu
Published: September 2022

The agile earth observation satellite scheduling problem (AEOSSP), as a time-dependent and arduous combinatorial optimization problem, has been intensively studied in the past decades. Many studies have proposed non-iterative heuristic construction algorithms and iterative meta-heuristic algorithms to solve this problem. However, the heuristic construction algorithms spend a relatively shorter time at the expense of solution quality, while the iterative meta-heuristic algorithms accomplish a high-quality solution with a lot of time. To overcome the shortcomings of these approaches and efficiently utilize the historical scheduling information and task characteristics, this paper introduces a new neural network model based on the deep reinforcement learning and heuristic algorithm (DRL-HA) to the AEOSSP and proposes an innovative non-iterative heuristic algorithm. The DRL-HA is composed of a heuristic construction neural network (HCNN) model and a task arrangement algorithm (TAA), where the HCNN aims to generate the task planning sequence and the TAA generates the final feasible scheduling order of tasks. In this study, the DRL-HA is examined with other heuristic algorithms by a series of experiments. The results demonstrate that the DRL-HA outperforms competitors and HCNN possesses outstanding generalization ability for different scenario sizes and task distributions. Furthermore, HCNN, when used for generating initial solutions of meta-heuristic algorithms, can achieve improved profits and accelerate interactions. Therefore, the DRL-HA algorithm is verified to be an effective method for solving AEOSSP. In this way, the high-profit and high-timeliness of agile satellite scheduling can be guaranteed, and the solution of AEOSSP is further explored and improved.
Patient-Centered Therapy for Obstructive Sleep Apnea: A Review
Authors: Taweesedt Pahnwat , Najeeb Hala , Surani Salim
Published: September 2022

Obstructive sleep apnea (OSA) is one of the most common sleep problems defined by cessation or decreased airflow despite breathing efforts. It is known to be related to multiple adverse health consequences. Positive airway pressure (PAP) is considered an effective treatment that is widely used. Various modes of PAP and other emerging treatment options are now available. A multidisciplinary approach, understanding diverse phenotypes of OSA, and shared decision-making are necessary for successful OSA treatment. Patient-centered care is an essential modality to support patient care that can be utilized in patients with OSA to help improve outcomes, treatment adherence, and patient satisfaction.
Effects of a 24-Week Exercise Program on Functional Fitness, Oxidative Stress, and Salivary Cortisol Levels in Elderly Subjects
Authors: Morucci Gabriele , Ryskalin Larisa , Pratesi Simone , Branca Jacopo J. V. , Modesti Alessandra , Modesti Pietro Amedeo , Gulisano Massimo , Gesi Marco
Published: September 2022

Background and Objectives: Aging is a biological and irreversible process characterized by physiological alterations resulting in a progressive decline in biological functions, decreased resistance or adaptability to stress, and increased disease susceptibility. A decline in functional fitness, imbalance between pro- and antioxidant capacity, and/or hormonal dysregulation adversely impact physical capacity, emotional status, and overall quality of life, especially within the elderly population. On the other hand, regular physical activity is considered an effective strategy to prevent and reduce those changes associated with primary aging and concurrent chronic disease, while slowing age-related physical degeneration. However, there is still limited evidence-based information regarding both the intensity and interval of effective interventions on physical functioning in older adults. Thus, the aim of the study was to assess the effects of a 24-week regular multimodal exercise program on functional fitness, oxidative stress, salivary cortisol level, and self-perceived quality of life in a group of eighteen physically active elderly subjects (mean age 72.8 ± 7.5 years). Materials and Methods: A set of anthropometric and physical measurements (grip strength, chair sit to stand, sit and reach and back scratch) assessing the functional fitness performance were evaluated. Moreover, biochemical markers (derived-reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP) tests, and salivary cortisol levels) and the EuroQoL 5-Dimension 3-Level (EuroQoL 5-D 3-L) self-perceived questionnaire of quality of life were measured before and after the intervention program. All measurements were normally distributed as assessed by D’Agostino and Pearson’s omnibus normality test. Student’s t-tests were used to evaluate the differences in all the parameters measured at baseline (T0) and after the 24-week physical program (T1). Results: The results showed that an age-tailored structured intervention exercise program (1 h per session, twice per week, for 24 weeks) was effective in improving flexibility and other biomechanical parameters, such as muscle strength and the dynamic balance fitness component, which are key to performing daily tasks independently. Moreover, biochemical analyses demonstrate that the proposed intervention program has beneficial effects on the balance between plasma ROS production and their neutralization. Conclusions: The results confirm the benefits of regular physical activity in older adults resulting in improved physical strength and flexibility in the functional fitness parameters, and in regulating anti- and pro-oxidant activity and cortisol (stress hormone) levels.
Identifying Factors Predicting Kidney Graft Survival in Chile Using Elastic-Net-Regularized Cox’s Regression
Authors: Magga Leandro , Maturana Simón , Olivares Marcelo , Valdevenito Martín , Cabezas Josefa , Chapochnick Javier , González Fernando , Kompatzki Alvaro , Müller Hans , Pefaur Jacqueline , Ulloa Camilo , Valjalo Ricardo
Published: September 2022

Background and Objectives: We developed a predictive statistical model to identify donor–recipient characteristics related to kidney graft survival in the Chilean population. Given the large number of potential predictors relative to the sample size, we implemented an automated variable selection mechanism that could be revised in future studies as more national data is collected. Materials and Methods: A retrospective multicenter study was conducted to analyze data from 822 adult kidney transplant recipients from adult donors between 1998 and 2018. To the best of our knowledge, this is the largest kidney transplant database to date in Chile. A procedure based on a cross-validated regularized Cox regression using the Elastic Net penalty was applied to objectively identify predictors of death-censored graft failure. Hazard ratios were estimated by adjusting a multivariate Cox regression with the selected predictors. Results: Seven variables were associated with the risk of death-censored graft failure; four from the donor: age (HR = 1.02, 95% CI: 1.00–1.03), male sex (HR = 0.64, 95% CI: 0.46–0.90), history of hypertension (HR = 1.49, 95% CI: 0.98–2.28), and history of diabetes (HR = 2.04, 95% CI: 0.97–4.29); two from the recipient: years on dialysis log-transformation (HR = 1.29, 95% CI: 0.99–1.67) and history of previous solid organ transplantation (HR = 2.02, 95% CI: 1.18–3.47); and one from the transplant: number of HLA mismatches (HR = 1.13, 95% CI: 0.99–1.28). Only the latter is considered for patient prioritization in deceased kidney allocation in Chile. Conclusions: A risk model for kidney graft failure was developed and trained for the Chilean population, providing objective criteria which can be used to improve efficiency in deceased kidney allocation.
Impact and Tolerance of Immunosuppressive Treatments in Patients Living with HIV with Inflammatory or Autoimmune Diseases
Authors: Guitton Zélie , Viget Nathalie , Surgers Laure , Cheret Antoine , Fontier Clotilde , Deconinck Laurène , Bataille Pierre , Meybeck Agnès , Bazus Hélène , Robineau Olivier
Published: September 2022

Background: Patients living with HIV (PLWHIV) can develop autoimmune diseases (AD) needing immunosuppressive treatments (IST). This study aims to describe the impact of IST in PLWHIV. Methods: This was a multicentric retrospective observational study in six HIV referral centers on PLWHIV under IST for AD. Demographic factors, viral co-infections, immunovirological status before and under IST, infectious events, and their descriptions were collected and described focusing on infectious events, immunovirological variations, and IST effectiveness. Results: 9480 PLWHIV were screened for inclusion. Among them, 138 (1.5%) had a history of auto-immune disease, among which 32 (23%) received IST. There was mainly spondyloarthropathy (28%) and the most commonly used IST was methotrexate. The median follow-up under IST was 3.8 years (2.7; 5.9). There were 15 infectious events (0.5 events/individuals) concerning nine patients. At the last medical follow-up, 81% of these were in remission of their AD. Under IST, there was an increase in CD4 during follow-up (629 vs. 827 CD4/mm3, p = 0.04). No HIV virological failure was noted. Conclusions: This study supports a growing evidence base that IST can be used safely and effectively in PLWHIV with careful monitoring.
Infection by the Parasite Myxobolus bejeranoi (Cnidaria: Myxozoa) Suppresses the Immune System of Hybrid Tilapia
Authors: Maor-Landaw Keren , Smirnov Margarita , Brekhman Vera , Ofek-Lalzar Maya , Yahav Tal , Lotan Tamar
Published: September 2022

Myxozoa (Cnidaria) is a large group of microscopic obligate endoparasites that can cause emerging diseases, affecting wild fish populations and fisheries. Recently, the myxozoan Myxobolus bejeranoi was found to infect the gills of hybrid tilapia (Nile tilapia (Oreochromis niloticus) × Jordan/blue tilapia (O. aureus)), causing high morbidity and mortality. Here, we used comparative transcriptomics to elucidate the molecular processes occurring in the fish host following infection by M. bejeranoi. Fish were exposed to pond water containing actinospores for 24 h and the effects of minor, intermediate, and severe infections on the sporulation site, the gills, and on the hematopoietic organs, head kidney and spleen, were compared. Enrichment analysis for GO and KEGG pathways indicated immune system activation in gills at severe infection, whereas in the head kidney a broad immune suppression included deactivation of cytokines and GATA3 transcription factor responsible for T helper cell differentiation. In the spleen, the cytotoxic effector proteins perforin and granzyme B were downregulated and insulin, which may function as an immunomodulatory hormone inducing systemic immune suppression, was upregulated. These findings suggest that M. bejeranoi is a highly efficient parasite that disables the defense mechanisms of its fish host hybrid tilapia.
Survival of Campylobacter jejuni 11168H in Acanthamoebae castellanii Provides Mechanistic Insight into Host Pathogen Interactions
Authors: Nasher Fauzy , Lehri Burhan , Horney Megan F. , Stabler Richard A. , Wren Brendan W.
Published: September 2022

Campylobacter jejuni is the leading cause of bacterial foodborne gastroenteritis worldwide but is rarely transferred between human hosts. Although a recognized microaerophile, the majority of C. jejuni are incapable of growing in an aerobic environment. The persistence and transmission of this pathogen outside its warm-blooded avian and mammalian hosts is poorly understood. Acanthamoebae species are predatory protists and form an important ecological niche with several bacterial species. Here, we investigate the interaction of C. jejuni 11168H and Acanthamoebae castellanii at the single-cell level. We observe that a subpopulation of C. jejuni cells can resist killing by A. castellanii, and non-digested bacteria are exocytosed into the environment where they can persist. In addition, we observe that A. castellanii can harbor C. jejuni 11168H even upon encystment. Transcriptome analyses of C. jejuni interactions revealed similar survival mechanisms when infecting both A. castellanii and warm-blooded hosts. In particular, nitrosative stress defense mechanisms and flagellum function are important as confirmed by mutational analyses of C. jejuni 11168H. This study describes a new host–pathogen interaction for C. jejuni and confirms that amoebae are transient hosts for the persistence, adaptability, and potential transmission of C. jejuni.
Whole-Transcriptome Sequencing Reveals Characteristics of Cancer Microbiome in Korean Patients with GI Tract Cancer: Fusobacterium nucleatum as a Therapeutic Target
Authors: Ahn Hyeok , Min Kyungchan , Lee Eulgi , Kim Hyun , Kim Sujeong , Kim Yunjae , Kim Gihyeon , Cho Beomki , Jeong Chanyeong , Kim Yeongmin , Park Hansoo
Published: September 2022

Remarkable progress has occurred over the past two decades in identifying microbiomes affecting the human body in numerous ways. The microbiome is linked to gastrointestinal (GI) tract cancer. The purpose of this study was to determine if there is a common microbiome among GI tract cancers and how the microbiome affects the disease. To ensure ethnic consistency, Korean patients with GI tract cancer were selected. Fusobacterium nucleatum is an enriched bacteria in all cancer tissues. F. nucleatum is a Gram-negative obligate anaerobe that promotes colorectal cancer. Through Gene Set Enrichment Analysis (GSEA) and Differentially Expressed Genes (DEG) analyses, the upregulation of the G2M checkpoint pathway was identified in the F. nucleatum-high group. Cell viability and G2M checkpoint pathway genes were examined in MC 38 cells treated with F. nucleatum. F. nucleatum upregulated the expression of G2M checkpoint pathway genes and the cell proliferation of MC 38 cells. F. nucleatum facilitated cancer’s use of G2M checkpoint pathways and F. nucleatum could be a therapeutic target in Korean GI tract cancer.
Effect of Polydextrose on the Growth of Pediococcus pentosaceus as Well as Lactic Acid and Bacteriocin-like Inhibitory Substances (BLIS) Production
Authors: Wanderley Porto Maria Carolina , de Souza de Azevedo Pamela Oliveira , Lourenço Felipe Rebello , Converti Attilio , Vitolo Michele , Oliveira Ricardo Pinheiro de Souza
Published: September 2022

Pediococcus pentosaceus was cultivated in MRS medium supplemented or not with polydextrose under different conditions in order to evaluate its effect on cell growth, lactic acid and bacteriocin-like inhibitory substance (BLIS) production. Independent variables were pH (4.0, 5.0, 6.0), rotational speed (50, 100, 150 rpm), polydextrose concentration (0.5, 1.0, 1.5%) and temperature (25, 30, 35 °C), while cell concentration and productivity after 24 h, maximum specific growth rate, specific rate of substrate (glucose) consumption, volumetric and specific lactic acid productivities, yields of biomass and lactic acid on consumed substrate were the dependent. The maximum cell concentration (10.24 ± 0.16 gX L−1) and productivity (0.42 ± 0.01 gX L−1 h−1) were achieved at pH 6.0, 35 °C, 150 rpm using 1.5% polydextrose, while the maximum specific growth rate (0.99 ± 0.01 h−1) and yield of biomass (2.96 ± 0.34 gX gS−1) were achieved at the same pH and polydextrose concentration, but at 25 °C and 50 rpm. The specific substrate consumption rate (0.09 ± 0.02 gS gX−1 h−1) and the volumetric lactic acid productivity (0.44 ± 0.02 gP L−1 h−1) were maximized at pH 6.0, 35 °C, 50 rpm and 0.5% polydextrose. BLIS produced in this last run displayed the highest antibacterial activity against Escherichia coli, while the same activity was displayed against Enterococcus faecium using 1.5% polydextrose. These results appear to be quite promising in view of possible production of this BLIS as an antibacterial agent in the food industry.
Intronization Signatures in Coding Exons Reveal the Evolutionary Fluidity of Eukaryotic Gene Architecture
Authors: Ryll Judith , Rothering Rebecca , Catania Francesco
Published: September 2022

The conventionally clear distinction between exons and introns in eukaryotic genes is actually blurred. To illustrate this point, consider sequences that are retained in mature mRNAs about 50% of the time: how should they be classified? Moreover, although it is clear that RNA splicing influences gene expression levels and is an integral part of interdependent cellular networks, introns continue to be regarded as accidental insertions; exogenous sequences whose evolutionary origin is independent of mRNA-associated processes and somewhat still elusive. Here, we present evidence that aids to resolve this disconnect between conventional views about introns and current knowledge about the role of RNA splicing in the eukaryotic cell. We first show that coding sequences flanked by cryptic splice sites are negatively selected on a genome-wide scale in Paramecium. Then, we exploit selection intensity to infer splicing-related evolutionary dynamics. Our analyses suggest that intron gain begins as a splicing error, involves a transient phase of alternative splicing, and is preferentially completed at the 5’ end of genes, which through intron gain can become highly expressed. We conclude that relaxed selective constraints may promote biological complexity in Paramecium and that the relationship between exons and introns is fluid on an evolutionary scale.
Performance of a Machine Learning-Based Methicillin Resistance of Staphylococcus aureus Identification System Using MALDI-TOF MS and Comparison of the Accuracy according to SCCmec Types
Authors: Jeon Kibum , Kim Jung-Min , Rho Kyoohyoung , Jung Seung Hee , Park Hyung Soon , Kim Jae-Seok
Published: September 2022

The prompt presumptive identification of methicillin-resistant Staphylococcus aureus (MRSA) using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) can aid in early clinical management and infection control during routine bacterial identification procedures. This study applied a machine learning approach to MALDI-TOF peaks for the presumptive identification of MRSA and compared the accuracy according to staphylococcal cassette chromosome mec (SCCmec) types. We analyzed 194 S. aureus clinical isolates to evaluate the machine learning-based identification system (AMRQuest software, v.2.1, ASTA: Suwon, Korea), which was constructed with 359 S. aureus clinical isolates for the learning dataset. This system showed a sensitivity of 91.8%, specificity of 83.3%, and accuracy of 87.6% in distinguishing MRSA. For SCCmec II and IVA types, common MRSA types in a hospital context, the accuracy was 95.4% and 96.1%, respectively, while for the SCCmec IV type, it was 21.4%. The accuracy was 90.9% for methicillin-susceptible S. aureus. This presumptive MRSA identification system may be helpful for the management of patients before the performance of routine antimicrobial resistance testing. Further optimization of the machine learning model with more datasets could help achieve rapid identification of MRSA with less effort in routine clinical procedures using MALDI-TOF MS as an identification method.
Correction: McLennan et al. Assessing the Use of Molecular Barcoding and qPCR for Investigating the Ecology of Prorocentrum minimum (Dinophyceae), a Harmful Algal Species. Microorganisms 2021, 9, 510
Authors: McLennan Kate , Ruvindy Rendy , Ostrowski Martin , Murray Shauna
Published: September 2022

The authors wish to make the following corrections to this paper [...]
Polyphenolic Composition, Antioxidant, Antiproliferative and Antidiabetic Activities of Coronopus didymus Leaf Extracts
Authors: Muzammil Saima , Wang Yunsheng , Siddique Muhammad Hussnain , Zubair Errum , Hayat Sumreen , Zubair Muhammad , Roy Arpita , Mumtaz Rabia , Azeem Muhammad , Emran Talha Bin , Shahid Muhammad Qasim
Published: September 2022

Coronopus didymus (Brassicaceae) commonly known as lesser swine cress has been reported to be used for its pharmacological activities. This study aimed to evaluate the medicinal potential of C. didymus extracts against cancer, diabetes, infectious bacteria and oxidative stress and the identification of bioactive compounds present in these extracts. The effects of using different solvents for the extraction of C. didymus on the contents of major polyphenols and biological activities were investigated. Plant sample was shade dried, ground to a fine powder, and then soaked in pure acetone, ethanol and methanol. The highest contents of major polyphenols were found in methanol-based extract, i.e., chlorogenic acid, HB acid, kaempferol, ferulic acid, quercetin and benzoic acid with 305.02, 12.42, 11.5, 23.33, 975.7 and 428 mg/g of dry weight, respectively, followed by ethanol- and acetone-based extracts. The methanol-based extract also resulted in the highest antioxidant activities (56.76%), whereas the highest antiproliferative (76.36) and alpha glucosidase inhabitation (96.65) were demonstrated in ethanol-based extracts. No antibacterial property of C. didymus was observed against all the tested strains of bacteria. Further studies should be focused on the identification of specific bioactive compounds responsible for pharmacological activities.
Structural Characterization of Cis– and Trans–Pt(NH3)2Cl2 Conjugations with Chitosan Nanoparticles
Authors: Chanphai Penparapa , Bérubé Gervais , Tajmir-Riahi Heidar-Ali
Published: September 2022

The conjugation of chitosan 15 and 100 KD with anticancer drugs cis– and trans–Pt (NH3)2Cl2 (abbreviated cis–Pt and trans–Pt) were studied at pH 5–6. Using multiple spectroscopic methods and thermodynamic analysis to characterize the nature of drug–chitosan interactions and the potential application of chitosan nanoparticles in drug delivery. Analysis showed that both hydrophobic and hydrophilic contacts are involved in drug–polymer interactions, while chitosan size and charge play a major role in the stability of drug–polymer complexes. The overall binding constants are Kch–15–cis–Pt = 1.44 (±0.6) × 105 M−1, Kch–100–cis–Pt = 1.89 (±0.9) × 105 M−1 and Kch–15–trans–Pt = 9.84 (±0.5) × 104 M−1, and Kch–100–trans–Pt = 1.15 (±0.6) × 105 M−1. More stable complexes were formed with cis–Pt than with trans–Pt–chitosan adducts, while stronger binding was observed for chitosan 100 in comparison to chitosan 15 KD. This study indicates that polymer chitosan 100 is a stronger drug carrier than chitosan 15 KD in vitro.
Isolation, Molecular Identification and Amino Acid Profiling of Single-Cell-Protein-Producing Phototrophic Bacteria Isolated from Oil-Contaminated Soil Samples
Authors: Nalvothula Raju , Challa Surekha , Peddireddy Vidyullatha , Merugu Ramchander , Rudra M. P. Pratap , Alataway Abed , Dewidar Ahmed Z. , Elansary Hosam O.
Published: September 2022

In the current study, soil samples were gathered from different places where petrol and diesel filling stations were located for isolation of photosynthetic bacteria under anaerobic conditions using the paraffin wax-overlay pour plate method with Biebl and Pfennig’s medium. The three isolated strains were named Rhodopseudomonas palustris SMR 001 (Mallapur), Rhodopseudomonas palustris NR MPPR (Nacahram) and Rhodopseudomonas faecalis N Raju MPPR (Karolbagh). The morphologies of the bacteria were examined with a scanning electron microscope (SEM). The phylogenetic relationship between R. palustris strains was examined by means of 16S rRNA gene sequence analysis using NCBI-BLAST search and a phylogenetic tree. The sequenced data for R. palustris were deposited with the National Centre for Biotechnology Research (NCBI). The total amino acids produced by the isolated bacteria were determined by HPLC. A total of 14 amino acids and their derivatives were produced by the R. palustris SMR 001 strain. Among these, carnosine was found in the highest concentration (8553.2 ng/mL), followed by isoleucine (1818.044 ng/mL) and anserine (109.5 ng/mL), while R. palustris NR MPPR was found to produce 12 amino acids. Thirteen amino acids and their derivatives were found to be produced from R. faecalis N Raju MPPR, for which the concentration of carnosine (21601.056 ng/mL) was found to be the highest, followed by isoleucine (2032.6 ng/mL) and anserine (227.4 ng/mL). These microbes can be explored for the scaling up of the process, along with biohydrogen and single cell protein production.
13C-NMR Chemical Shifts in 1,3-Benzazoles as a Tautomeric Ratio Criterion
Authors: García-Báez Efrén V. , Padilla-Martínez Itzia I. , Cruz Alejandro , Rosales-Hernández Martha C.
Published: September 2022

Benzimidazole is an important heterocyclic fragment, present in many biologically active compounds with a great variety of therapeutic purposes. Most of the benzimidazole activities are explained through the existence of 1,3-tautomeric equilibrium. As the binding affinity of each tautomer to a protein target depends on an established bioactive conformation, the effect of tautomers on the ligand protein binding mechanism is determinant. In this work, we searched and analyzed a series of reported 13C-NMR spectra of benzazoles and benzazolidine-2-thiones with the purpose of estimating their tautomeric equilibrium. Herein, several approaches to determine this problem are presented, which makes it a good initial introduction to the non-expert reader. This chemical shift difference and C4/C7 signals of benzimidazolidine-2-thione and 1-methyl-2-thiomethylbenzimidazole as references were used in this work to quantitatively calculate, in solution, the pyrrole–pyridine tautomeric ratio in equilibrium. The analysis will help researchers to correctly assign the chemical shifts of benzimidazoles and to calculate their intracyclic or exocyclic tautomeric ratio as well as mesomeric proportion in benzimidazoles.
Synthesis of Novel Pyrazole Derivatives Containing Phenylpyridine Moieties with Herbicidal Activity
Authors: Cai Zengfei , Zhang Wenliang , Yan Zhongjie , Du Xiaohua
Published: September 2022

To discover new compounds with favorable herbicidal activity, a range of phenylpyridine moiety-containing pyrazole derivatives were designed, synthesized, and identified via NMR and HRMS. Their herbicidal activities against six species of weeds were evaluated in a greenhouse via both pre- and post-emergence treatments at 150 g a.i./hm2. The bioassay revealed that a few compounds exhibited moderate herbicidal activities against Digitaria sanguinalis, Abutilon theophrasti, and Setaria viridis in post-emergence treatment. For instance, compounds 6a and 6c demonstrated 50% inhibition activity against Setaria viridis, which was slightly superior to pyroxasulfone. Thus, compounds 6a and 6c may serve as the new possible leading compounds for the discovery of post-emergence herbicides.
Broadband Multidimensional Spectroscopy Identifies the Amide II Vibrations in Silkworm Films
Authors: Chatterley Adam S. , Laity Peter , Holland Chris , Weidner Tobias , Woutersen Sander , Giubertoni Giulia
Published: September 2022

We used two-dimensional infrared spectroscopy to disentangle the broad infrared band in the amide II vibrational regions of Bombyx mori native silk films, identifying the single amide II modes and correlating them to specific secondary structure. Amide I and amide II modes have a strong vibrational coupling, which manifests as cross-peaks in 2D infrared spectra with frequencies determined by both the amide I and amide II frequencies of the same secondary structure. By cross referencing with well-known amide I assignments, we determined that the amide II (N-H) absorbs at around 1552 and at 1530 cm–1 for helical and β-sheet structures, respectively. We also observed a peak at 1517 cm−1 that could not be easily assigned to an amide II mode, and instead we tentatively assigned it to a Tyrosine sidechain. These results stand in contrast with previous findings from linear infrared spectroscopy, highlighting the ability of multidimensional spectroscopy for untangling convoluted spectra, and suggesting the need for caution when assigning silk amide II spectra.
Authentication of Citrus spp. Cold-Pressed Essential Oils by Their Oxygenated Heterocyclic Components
Authors: Dosoky Noura S. , Satyal Prabodh , Setzer William N.
Published: September 2022

Citrus essential oils are routinely adulterated because of the lack of regulations or reliable authentication methods. Unfortunately, the relatively simple chemical makeup and the tremendous price variations among Citrus varieties encouraged the interspecies adulteration of citrus oils. In this study, a sensitive UPLC-MS/MS method for the quantitation of 14 coumarins and furanocoumarins is developed and validated. This method was applied to screen the essential oils of 12 different Citrus species. This study, to our knowledge, represents the most comprehensive investigation of coumarin and furanocoumarin profiles across commercial-scale Citrus oils to date. Results show that the lowest amount was detected in calamansi oil. Expressed oil of Italian bergamot showed the highest furanocoumarin content and the highest level of any individual furanocoumarin (bergamottin). Notable differences were observed in the coumarin and furanocoumarin levels among oils of different crop varieties and origins within the same species. Potential correlations were observed between bergapten and xanthotoxin which matches with known biosynthetic pathways. We found patterns in furanocoumarin profiles that line up with known variations among the Citrus ancestral taxa. However, contrary to the literature, we also detected xanthotoxin in sweet orange and members of the mandarin taxon. Using multivariate analysis, we were able to divide the Citrus oils into 5 main groups and correlate them to the coumarin compositions.