bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinematic Chain of a Morphing Winglet: Specifications, Conceptual and Advanced Design
Authors: Ameduri Salvatore , Dimino Ignazio , Pellone Lorenzo , Concilio Antonio , Mercurio Umberto , Gallorini Federico , Pispola Giulio , D’Andrea Moreno
Published: May 2023

The present work focuses on the actuation system of a morphing winglet conceived to adaptively alter the load distribution on the wing, to reduce its stress level and enhance the climb performance. The winglet is equipped with two flaps, independently controlled by dedicated kinematic chains, in turn moved by linear electro-magnetic actuators. An interior finger-like architecture, relevant part of the actuation system, makes particularly smooth the deflections. Starting from a survey on similar applications and on the basis of the requirements at aircraft level, the specifications of the actuation system were defined. A preliminary outline of the system was thus addressed, identifying the main components, their role and their working mode. Then, the advanced design was finalized. To this scope and considering the large displacements that characterize this kind of application, a non-linear finite element approach was implemented. Both the deflection capability with and without loads and the stress level of the system were investigated. A critical overview was finally organized, comparing the achieved results with the expectations.
Contribution to Improve Magnetic Performance and Torque Ripple Reduction of the Low-Speed DSPM Machine
Authors: Kendjouh Tarek , Guerroudj Cherif , Charpentier Jean-Frédéric , Bracikowski Nicolas , Hadjout Larbi , Bekhouche Lemnouer
Published: May 2023

This article deals with the performance improvement of a toothed pole variable reluctance machine excited by permanent magnets housed in the stator yoke. The objective was to reduce the electromagnetic torque ripples caused by the structure geometry and by the supply technique. The machine was designed to meet the specifications of a small wind energy conversion system. The proposed solution improved the electromagnetic design of the new structure in order to minimize the variation of the reluctance. This improvement was obtained by action on the geometry of the structure (the location of the permanent magnets), by action on the stator and rotor tooth pitch, and by the application of an indirect control strategy called torque sharing function. The PSO optimization algorithm was applied in the first part for the optimization of the machine’s global parameters to maximize torque density and then, in the second part, for the research of the optimum tooth pitch parameters to minimize torque ripple. Static and dynamic performances were obtained using 2D-FEM and MATLAB/Simulink software. The results reveal that by action on the stator/rotor tooth pitch, the ripple torque was reduced by about 53%, and by approximately 76% with the used command technique.
Combinatorial Olfactory Signaling in Short-Distance Determines Host Plant Recognition in Locust
Authors: Pan Xueqin , Liu Jun , Xu Xiao , Zhang Liwei , Zhang Long
Published: May 2023

Selecting palatable plants matters for insect herbivores’ survival, especially for food-restricted oligophagous and monophagous species. However, the definite selection strategy to distinguish host plants from nonhost plants, as well as the underlying sensory basis, remains controversial. Here, we investigated the olfactory recognition of host plants in oligophagous migratory locusts. By establishing one novel behavioral paradigm that allowed the free-moving locusts to make olfactory choices in short-distance, we demonstrated that palps were required to differentiate host plants apart from nonhost counterparts sensitively. Specifically, the characteristic odors between the host plant and nonhost plant defined the behavioral differentiation of food sources, and this process required intact palps. Further, single nonhost odor suppressed the behavioral potency to host plant extraction, while single host odor attenuated the behavioral repulsion to nonhost plant. We also identified the palps odorant receptors (ORs) repertoire that modulated the short-range recognition of key volatiles from host plants and nonhost and demonstrated that combinatorial olfactory signaling controls food choice. Our results support a “pull–push” model in which olfactory signaling on locust palps acts as a key tuning modulator in host plant recognition, expanding the knowledge of insect chemosensation.
Fertilization Highly Increased the Water Use Efficiency of Spring Maize in Dryland of Northern China: A Meta-Analysis
Authors: Shi Jiao , Zhou Huaiping , Xu Minggang , Zhang Qiang , Li Jianhua , Wang Jinfeng
Published: May 2023

Water and fertilizer play an important role in crop growth in dryland areas. It is a necessity to improve the water use efficiency (WUE) of the crop once the water resource is limited. In northern China, where there is a wide shortage of water resources, it is therefore necessary to investigate how fertilization affects the WUE of spring maize and to quantify the effects. A total of 33 published peer-reviewed papers were collected, and a meta-analysis and random forest model analysis were performed with 364 WUE comparisons, aiming to explore the effects of fertilization on the WUE of spring maize and to clarify the optimal conditions for WUE under fertilizer management. The results showed that fertilization significantly increased the WUE of spring maize by 56.72% (P < 0.01) when compared with non-fertilization. The WUE effect under the organic–inorganic fertilizer combination (MNPK) was approximately twice as high as that under inorganic fertilizer (NPK) or organic fertilizer (M). The greatest increase in WUE occurred at 0–100 kg ha−1 of nitrogen application (NA). Under environmental conditions including 7 ≤ mean annual temperature in the test year (T) ≤ 10 °C, 400 ≤ mean annual precipitation in the test year (P) ≤ 600 mm, and mean altitude (A) > 1500 m, and soil conditions including 10 ≤ soil organic matter content (SOM) ≤ 14 g kg−1 and available phosphorus (AP) < 5 mg kg−1, the fertilization optimally enhanced the WUE of spring maize when the agronomic measures of ridge–furrow planting (RFP) and mulching film (MF) were used. The random forest model analysis indicated that the influence factors (i.e., fertilizer regimes, environmental factors, soil factors, and agronomic measures) caused 65.62% of the variation in spring maize WUE effects, while in all influence factors, fertilizer types related to fertilizer regimes caused the most variation. The initial available potassium (AK) and available nitrogen (AN) of the soil were negatively correlated to the WUE effect, indicating that fertilization imposed a better effect on the WUE of spring maize when the soil was infertile. Fertilization significantly increased the WUE of spring maize, and organic and inorganic fertilizer application provided an effective measure for the sustainable development of spring maize in northern China. After clarifying the required conditions for fertilization increasing WUE, high-efficiency water use may be achieved.
Effect of Dietary Chlorella vulgaris or Tetradesmus obliquus on Laying Performance and Intestinal Immune Cell Parameters
Authors: Kim Yoo-Bhin , Park Jina , Heo Yun-Ji , Lee Hyun-Gwan , Kwon Byung-Yeon , Joo Sang Seok , Joo Sung Yong , Kim Myunghoo , Kim Z-Hun , Lee Kyung-Woo
Published: May 2023

A feeding trial was conducted to investigate the effect of dietary supplementation of Chlorella vulgaris (CV) or Tetradesmus obliquus (TO) on laying performance, egg quality, and gut health indicators of laying hens. A total of 144 Hy-Line Brown laying hens aged 21 weeks were randomly assigned to one of three dietary treatments with eight replicates of six hens. Dietary treatments were as follows: CON, basal diet; CV, basal diet + 5 g C. vulgaris/kg of diet; TO, basal diet + 5 g T. obliquus/kg of diet. The results showed that diets supplemented with CV or TO had insignificant effects on laying performance, egg quality (i.e., Haugh unit and eggshell strength and thickness), jejunal histology, cecal short-chain fatty acids, and antioxidant/immune markers in ileal mucosa samples of laying hens. Compared with the control group, the egg yolk color score was higher (p < 0.05) in laying hens fed on diets containing CV and TO, although the former was a more intense yellow than the latter. Small intestinal lamina propria cells were isolated using flow cytometry to examine the percentages of immune cell subpopulations. Dietary microalgae did not affect B cells or monocytes/macrophages but altered the percentage of CD4+ T cells and CD8− TCR γδ T cells. Collectively, diets supplemented with C. vulgaris or T. obliquus can improve egg yolk color and would modulate host immune development and competence in laying hens.
Harnessing the Dual Antimicrobial Mechanism of Action with Fe(8-Hydroxyquinoline)3 to Develop a Topical Ointment for Mupirocin-Resistant MRSA Infections
Authors: Abeydeera Nalin , Benin Bogdan M. , Mudarmah Khalil , Pant Bishnu D. , Chen Guanyu , Shin Woo Shik , Kim Min-Ho , Huang Songping D.
Published: May 2023

8-Hydroxyquinoline (8-hq) exhibits potent antimicrobial activity against Staphylococcus aureus (SA) bacteria with MIC = 16.0–32.0 µM owing to its ability to chelate metal ions such as Mn2+, Zn2+, and Cu2+ to disrupt metal homeostasis in bacterial cells. We demonstrate that Fe(8-hq)3, the 1:3 complex formed between Fe(III) and 8-hq, can readily transport Fe(III) across the bacterial cell membrane and deliver iron into the bacterial cell, thus, harnessing a dual antimicrobial mechanism of action that combines the bactericidal activity of iron with the metal chelating effect of 8-hq to kill bacteria. As a result, the antimicrobial potency of Fe(8-hq)3 is significantly enhanced in comparison with 8-hq. Resistance development by SA toward Fe(8-hq)3 is considerably delayed as compared with ciprofloxacin and 8-hq. Fe(8-hq)3 can also overcome the 8-hq and mupirocin resistance developed in the SA mutant and MRSA mutant bacteria, respectively. Fe(8-hq)3 can stimulate M1-like macrophage polarization of RAW 264.7 cells to kill the SA internalized in such macrophages. Fe(8-hq)3 exhibits a synergistic effect with both ciprofloxacin and imipenem, showing potential for combination therapies with topical and systemic antibiotics for more serious MRSA infections. The in vivo antimicrobial efficacy of a 2% Fe(8-hq)3 topical ointment is confirmed by the use of a murine model with skin wound infection by bioluminescent SA with a reduction of the bacterial burden by 99 ± 0.5%, indicating that this non-antibiotic iron complex has therapeutic potential for skin and soft tissue infections (SSTIs).
Progressive Sub-MIC Exposure of Klebsiella pneumoniae 43816 to Cephalothin Induces the Evolution of Beta-Lactam Resistance without Acquisition of Beta-Lactamase Genes
Authors: Anderson Jasmine R. , Lam Nghi B. , Jackson Jazmyne L. , Dorenkott Sean M. , Ticer Taylor , Maldosevic Emir , Velez Amanda , Camden Megan R. , Ellis Terri N.
Published: May 2023

Bacterial exposure to antibiotic concentrations below the minimum inhibitory concentration (MIC) may result in a selection window allowing for the rapid evolution of resistance. These sub-MIC concentrations are commonly found in soils and water supplies in the greater environment. This study aimed to evaluate the adaptive genetic changes in Klebsiella pneumoniae 43816 after prolonged but increasing sub-MIC levels of the common antibiotic cephalothin over a fourteen-day period. Over the course of the experiment, antibiotic concentrations increased from 0.5 μg/mL to 7.5 μg/mL. At the end of this extended exposure, the final adapted bacterial culture exhibited clinical resistance to both cephalothin and tetracycline, altered cellular and colony morphology, and a highly mucoid phenotype. Cephalothin resistance exceeded 125 μg/mL without the acquisition of beta-lactamase genes. Whole genome sequencing identified a series of genetic changes that could be mapped over the fourteen-day exposure period to the onset of antibiotic resistance. Specifically, mutations in the rpoB subunit of RNA Polymerase, the tetR/acrR regulator, and the wcaJ sugar transferase each fix at specific timepoints in the exposure regimen where the MIC susceptibility dramatically increased. These mutations indicate that alterations in the secretion of colanic acid and attachment of colonic acid to LPS may contribute to the resistant phenotype. These data demonstrate that very low sub-MIC concentrations of antibiotics can have dramatic impacts on the bacterial evolution of resistance. Additionally, this study demonstrates that beta-lactam resistance can be achieved through sequential accumulation of specific mutations without the acquisition of a beta-lactamase gene.
Supplement Treatment with NAC and Omega-3 Polyunsaturated Fatty Acids during Pregnancy Partially Prevents Schizophrenia-Related Outcomes in the Poly I:C Rat Model
Authors: Edemann-Callesen Henriette , Bernhardt Nadine , Hlusicka Elizabeth Barroeta , Hintz Franziska , Habelt Bettina , Winter Rebecca , Neubert Isabell , Pelz Meike , Filla Alexandra , Soto-Montenegro Maria Luisa , Winter Christine , Hadar Ravit
Published: May 2023

Background: Heightened levels of inflammation and oxidative stress are thought to be involved in the pathophysiology of schizophrenia. We aimed to assess whether intake of anti-inflammatory and anti-oxidant drugs during pregnancy prevents later schizophrenia-related outcomes in a neurodevelopmental rat model of this disorder. Methods: Pregnant Wistar rats were injected with polyriboinosinic–polyribocytidilic acid (Poly I:C) or saline and subsequently treated with either N-acetyl cysteine (NAC) or omega-3 polyunsaturated fatty acids (PUFAs) until delivery. Controls rats received no treatment. In the offspring, neuroinflammation and anti-oxidant enzyme activity were assessed on postnatal day (PND) 21, 33, 48, and 90. Behavioral testing was performed at PND 90, followed by post-mortem neurochemical assessment and ex vivo MRI. Results: The supplement treatment led to a quicker restoration of the wellbeing of dams. In the adolescent Poly I:C offspring, the supplement treatment prevented an increase in microglial activity and partially prevented a deregulation in the anti-oxidant defense system. In the adult Poly I:C offspring, supplement treatment partially prevented dopamine deficits, which was paralleled by some changes in behavior. Exposure to omega-3 PUFAs prevented the enlargement of lateral ventricles. Conclusion: Intake of over-the-counter supplements may assist in especially targeting the inflammatory response related to schizophrenia pathophysiology, aiding in diminishing later disease severity in the offspring.
Application of Adaptive Neuro-Fuzzy Inference Systems with Principal Component Analysis Model for the Forecasting of Carbonation Depth of Reinforced Concrete Structures
Authors: Liu Juan , Bai Xuewei
Published: May 2023

The carbonation of reinforced concrete is one of the intrinsic factors that cause a significant decrease in service performance in concrete structures. To decrease the effect of carbonation-induced corrosion during the lifetime of the concrete structure, a prediction of carbonation depth should be made. The carbonation of concrete is affected by many factors, such as the compressive strength of the concrete, service life, carbonation time, carbon dioxide concentration, working stress, temperature, and humidity. On the basis of these seven parameters, combined with the predictive power of the adaptive network-based fuzzy inference system (ANFIS) and principal component analysis (PCA), which can reduce data dimensions before modeling, we introduced a novel approach—the PCA–ANFIS model—that can predict the carbonation of reinforced concrete. Practical engineering examples were adopted to verify the superiority of the suggested PCA–ANFIS model, with 90% of the carbonation depth data used for training and 10% used for testing. The root mean square error (RMSE) values for the ANFIS, ANN, PCA–ANN, and PCA–ANFIS training were 12.23, 6.28, 5.42, and 1.38, respectively. The results showed that the PCA–ANFIS model is accurate and can be used as a fundamental tool for predicting the service life of concrete structures.
Sunspot Detection Using YOLOv5 in Spectroheliograph H-Alpha Images
Authors: Santos José , Peixinho Nuno , Barata Teresa , Pereira Carlos , Coimbra A. Paulo , Crisóstomo Manuel M. , Mendes Mateus
Published: May 2023

Solar activity has been subject to increasingly more research in the last decades. Its influence on life on Earth is now better understood. Solar winds impact the earth’s magnetic field and atmosphere. They can disrupt satellite communication and navigation tools and even electrical power grids and several other infrastructure crucial for our technology-based society. Coronal mass ejections (CMEs), solar energetic particles, and flares are the main causes of problems that affect the systems mentioned. It is possible to predict some of those by monitoring the sun and analyzing the images obtained in different spectra, thus identifying solar phenomena related to its activity, such as filaments, pores, and sunspots. Several studies have already been carried out on the subject of automation of the mentioned analysis, most of which use neural networks and other machine learning approaches. In this work, we develop a method for sunspot detection based on the YOLOv5 network, applying it to a dataset of images from the Geophysical and Astronomical Observatory of the University of Coimbra (OGAUC), which has one of the oldest and more complete datasets of sun images in the world. Our method reaches mAP@.5 over 90% with YOLOv5s, which is higher than other methods previously applied for the same dataset. This shows that CNN models can be used in spectroheliographs for detecting and tracking sunspots.
StereoVO: Learning Stereo Visual Odometry Approach Based on Optical Flow and Depth Information
Authors: Duan Chao , Junginger Steffen , Thurow Kerstin , Liu Hui
Published: May 2023

We present a novel stereo visual odometry (VO) model that utilizes both optical flow and depth information. While some existing monocular VO methods demonstrate superior performance, they require extra frames or information to initialize the model in order to obtain absolute scale, and they do not take into account moving objects. To address these issues, we have combined optical flow and depth information to estimate ego-motion and proposed a framework for stereo VO using deep neural networks. The model simultaneously generates optical flow and depth information outputs from sequential stereo RGB image pairs, which are then fed into the pose estimation network to achieve final motion estimation. Our experiments have demonstrated that our combination of optical flow and depth information improves the accuracy of camera pose estimation. Our method outperforms existing learning-based and monocular geometry-based methods on the KITTI odometry dataset. Furthermore, we have achieved real-time performance, making our method both effective and efficient.
Synthesis and Printing Features of a Hierarchical Nanocomposite Based on Nickel–Cobalt LDH and Carbonate Hydroxide Hydrate as a Supercapacitor Electrode
Authors: Simonenko Tatiana L. , Simonenko Nikolay P. , Gorobtsov Philipp Yu. , Nikitin Andrey S. , Muradova Aytan G. , Tokunov Yuri M. , Kalinin Stanislav G. , Simonenko Elizaveta P. , Kuznetsov Nikolay T.
Published: May 2023

The hydrothermal synthesis of a hierarchically organized nanocomposite based on nickel–cobalt carbonate hydroxide hydrate of composition M(CO3)0.5(OH)·0.11H2O (where M is Ni2+ and Co2+) and nickel–cobalt layered double hydroxides (NiCo-LDH) was studied. Using synchronous thermal analysis (TGA/DSC), it was determined that the material retained thermal stability up to 200 °C. The crystal structure of the powder and the set of functional groups in its composition were determined by X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). The resulting hierarchically organized nanopowder was employed as a functional ink component for microplotter printing of an electrode film, which is an array of miniature planar structures with a diameter of about 140 μm, on the surface of a nickel-plated steel substrate. Using scanning electron microscopy (SEM), it was established that the main area of the electrode “pixels” represents a thin film of individual nanorods with periodic inclusions of larger hierarchically organized spherical formations. According to atomic force microscopy (AFM) data, the mean square roughness of the material surface was 28 nm. The electrochemical properties of the printed composite film were examined; in particular, the areal specific capacitance at different current densities was calculated, and the electrochemical kinetics of the material was studied by impedance spectroscopy. It was found that the electrode material under study exhibited relatively low Rs and Rct resistance, which indicates active ion transfer at the electrode/electrolyte interface.
Improving Quality of Life in Chronic Patients: A Pilot Study on the Effectiveness of a Health Recommender System and Its Usability
Authors: del Rio Alberto , Jimenez Jennifer , Medina-García Rodrigo , Lozano-Hernández Cristina , Alvarez Federico , Serrano Javier
Published: May 2023

The TeNDER project aims to improve the quality of life (QoL) of chronic patients through an integrated care ecosystem. This study evaluates the health recommender system (HRS) developed for the project, which offers personalized recommendations based on data collected from a set of monitoring devices. The list of notifications covered different areas of daily life such as physical activity, nutrition, and sleep. We conducted this case study to evaluate the effectiveness and usability of the HRS in providing accurate and relevant recommendations to users. Evaluation process consisted on survey administration for QoL assessment and the satisfaction and usability of the HRS. The four-week pilot study involved several patients and caregivers and demonstrated that the HRS was perceived as user-friendly, consistent, and helpful, with a positive impact on patients’ QoL. However, the study highlights the need for improvement in terms of personalization of recommendations.
A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil Bearings
Authors: Sarrazin Marian , Liebich Robert
Published: May 2023

Conical gas foil bearings (CGFBs) have the potential to halve the number of necessary bearings in a conventional rotor system supported by gas foil bearings. Transient simulations of gas foil journal bearings and gas foil thrust bearings have proven their necessity to accurately predict the safe operating range of such bearings. This work presents the first transient model able to simulate the three-dimensional dynamics of CGFBs. The static behaviour of a single CGFB with a uniform bearing clearance is compared to a CGFB modified by thin metal shims and the resulting advantages of shimmed CGFBs are discussed. An investigation of the linear stability behaviour shows that the axial load of the bearing determines the stability of the equilibrium position. Furthermore, three transient simulations demonstrate the capability of the presented model to describe the nonlinear dynamics of a shimmed CGFB such as the occurrence of stable limit cycles and self-excited sub- and super-synchronous vibrations with and without a rotor unbalance. Additionally, waterfall diagrams are used to investigate the frequency response for different rotational speeds. The novel findings of this work are the importance of a non-uniform bearing clearance for the functionality of a CGFB and the identification of the axial force as a critical factor in maintaining bearing stability. These findings are specific to CGFBs and have not been discussed or mentioned in previous works.
A Preliminary Study Investigating the Effects of Elevated Antioxidant Capacity of Daily Snacks on the Body’s Antioxidant Defences in Patients with CVD
Authors: Czlapka-Matyasik Magdalena , Gut Pawel
Published: May 2023

The antioxidant potential of foods plays a vital role in counteracting oxidative stress and its consequences in the body. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) are the primary line of defence against cellular damage caused by reactive oxygen species (ROS). Glutathione is considered to be the most vital antioxidant for the body because its changes during oxidative stress increase the risk of CVD. The dietary antioxidant capacity supporting the glutathione defence system is not known. Therefore, we analysed the glutathione defence-related markers changes in the serum of CVD patients under the dietary supplementation of increased antioxidant capacity snacks. Patients were split into groups according to inclusion criteria and dietary intervention (DI) design. The serum concentration of GPx and GST (glutathione-S-transferase) was measured before and after the 6-week DI. During the DI, CVD and control (CON) subjects increased the total diet antioxidant capacity by 48% and 21%, respectively. It resulted in a significantly decreased GST (from 3.71 to 2.54 U/g Hb, p < 0.05) and an increased GPx (from 33.90 to 38.3 U/L). The results in the CON group did not reveal significant changes in GST and GPx. This study demonstrated that an increased antioxidant capacity might be associated with improving glutathione-related defence. However, the conclusion is not substantial due to the small sample used in this study.
Sustainable Polymer Technologies for a Circular Economy
Authors: Torres-Giner Sergio
Published: May 2023

We inhabit a defining moment in history [...]
Large Deformation Settlement Series Solution and Numerical Simulation for Underpass Project Track
Authors: Chen Li , Yu Fengxiao , Peng Yipu
Published: May 2023

The settlement of track in a railroad underpass project was studied by theoretical analysis and numerical simulation, based on the model of winkle beam on elastic foundation. Taking the settlement of roadbed as a nonlinear boundary condition, the control differential equation of the track large deformation settlement was established and solved by the Fourier series method; the numerical solution was obtained by establishing a numerical model based on an actual project and compared and analyzed with the series solution and cosine function solution. The correlation coefficients of the track settlement curves obtained from the series solution and the numerical solution were higher than those of the cosine function solution while the numerical solution with the maximum track settlement difference was only 0.8% of the maximum settlement of the track numerical solution. The accuracy of the series solution method is higher in this paper, and the track settlement curve obtained from theoretical calculation reflects and predicts the track settlement well when the track settlement cannot be measured directly.
WFO: Cloud-Edge Cooperative Data Offloading Strategy Akin to Water Flow
Authors: Li Shaonan , Xie Yongqiang , Li Zhongbo , Qi Jin , Xie Junjie , Yan Zexin
Published: May 2023

The exponential growth of video data in networks has led to video flow occupying a significant proportion of network traffic, causing congestion and poor service quality. To address this issue, it is crucial to quickly offload data and ensure high-quality service for users, especially in the context of cloud-edge collaboration. We propose a strategy for collaborative data offloading between cloud and edge computing, analogous to water flow (WFO). When users simultaneously access the same data from the same data source, WFO can serve more users within the limited bandwidth of the cloud while maintaining the quality of service. WFO creates a water flow-like data link between nodes to enable data offloading, using multiple nodes in collaboration to offload data for a single node. Experimental results show that compared with typical methods, such as fair-queue and first-come-first-served, WFO can significantly reduce the data offloading delay, guarantee service quality, and effectively reduce network congestion. Moreover, the number of service nodes can be as numerous as possible.
The Plagiochilins from Plagiochila Liverworts: Binding to α-Tubulin and Drug Design Perspectives
Authors: Vergoten Gérard , Bailly Christian
Published: May 2023

Among bryophytes, the Plagiochila genus represents a large group of leafy liverworts with over 500 species. Plagiochilins A to X are sesquiterpenoids isolated from Plagiochila species. The lead compound plagiochilin A (Plg-A), endowed with anticancer and antiparasitic properties, has been characterized as a potent mitosis inhibitor, acting selectively at the late stage of cytokinesis termed abscission. The compound perturbs the dynamics of microtubules, blocking cell cycle progression and triggering the death of malignant cells. Based on the compound’s mechanism of action and by analogy with other natural products bearing a dihydro-pyrone moiety, we postulated that Plg-A could bind to the pironetin site of α-tubulin. A molecular docking analysis was performed to compare the bindings of all 24 plagiochilins to α-tubulin and to establish structure–binding relationships. The identification of Plg-E and Plg-G as the best binders in the series highlighted the importance of the C13-OH or C=O group for α-tubulin recognition. This observation led to the testing of the natural-product ester plagiochilin A-15-yl n-octanoate and the corresponding alcohol (Plg-OH), both identified as robust α-tubulin binders. The study provides a rationale to potentially explain the mechanism of action of Plg-A and to guide the design of new derivatives.
A Reliable Computational Scheme for Stochastic Reaction–Diffusion Nonlinear Chemical Model
Authors: Arif Muhammad Shoaib , Abodayeh Kamaleldin , Nawaz Yasir
Published: May 2023

The main aim of this contribution is to construct a numerical scheme for solving stochastic time-dependent partial differential equations (PDEs). This has the advantage of solving problems with positive solutions. The scheme provides conditions for obtaining positive solutions, which the existing Euler–Maruyama method cannot do. In addition, it is more accurate than the existing stochastic non-standard finite difference (NSFD) method. Theoretically, the suggested scheme is more accurate than the current NSFD method, and its stability and consistency analysis are also shown. The scheme is applied to the linear scalar stochastic time-dependent parabolic equation and the nonlinear auto-catalytic Brusselator model. The deficiency of the NSFD in terms of accuracy is also shown by providing different graphs. Many observable occurrences in the physical world can be traced back to certain chemical concentrations. Examining and understanding the inter-diffusion between chemical concentrations is important, especially when they coincide. The Brusselator model is the gold standard for describing the relationship between chemical concentrations and other variables in chemical systems. A computational code for the proposed model scheme may be made available to readers upon request for convenience.
Assessment of the Influence of 5-Fluorouracil on SMAD4 and TGFB1 Gene Expression, Apoptosis Induction and DNA Damage in Human Cell Lines
Authors: Wosiak Agnieszka , Szmajda-Krygier Dagmara , Pietrzak Jacek , Boncela Joanna , Balcerczak Ewa
Published: May 2023

Purpose: Suppressor of mothers against decapentaplegic homolog 4 (SMAD family member 4, SMAD4) is involved in the adenoma–carcinoma pathway, leading to the development of colon cancer. The encoded protein is a key downstream signaling mediator in the TGFβ pathway. This pathway has tumor-suppressor functions, including cell-cycle arrest and apoptosis. Its activation in late-stage cancer can promote tumorigenesis, including metastasis and chemoresistance. Most colorectal cancer patients receive chemotherapy based on 5-FU as an adjuvant treatment. However, the success of therapy is hampered by multidrug resistance by neoplastic cells. In colorectal cancer, resistance to 5-FU-based therapy is influenced by SMAD4 gene expression, as patients with decreased SMAD4 gene expression probably have a higher risk of developing 5-FU-induced resistance. The mechanism leading to the development of this phenomenon is not fully understood. Therefore, the present study assesses the possible influence of 5-FU on changes in the expression of the SMAD4 and TGFB1 genes. Patients and methods: The effect of 5-FU on the expression of SMAD4 and TGFB1 in colorectal cancer cells derived from the CACO-2, SW480 and SW620 cell lines was evaluated using real-time PCR. The cytotoxicity of 5-FU on colon cancer cells was assessed by the MTT method, and its effect on the induction of cell apoptosis and the initiation of DNA damage using a flow cytometer. Results: Significant changes in the level of SMAD4 and TGFB1 gene expression were noted in the CACO-2, SW480 and SW620 cells treated with 5-FU at various concentrations during 24 h and 48 h exposure. The use of 5-FU at a concentration of 5 µmol/L resulted in a decrease in the expression of the SMAD4 gene in all cell lines at both exposure times, while the concentration of 100 µmol/L increased the expression of the SMAD4 gene in CACO-2 cells. The level of expression of the TGFB1 gene was higher for all cells treated with 5-FU at the highest concentrations, while the exposure time was extended to 48 h. Conclusion: The observed in vitro changes in CACO-2 cells caused by 5-FU may be of clinical relevance when choosing the drug concentration for treating patients with colorectal cancer. It is possible that 5-FU has a stronger effect on colorectal cancer cells at the higher concentrations. Low concentrations of 5-FU may not have a therapeutic effect and may also influence drug resistance in cancer cells. Higher concentrations and prolonged exposure time may affect SMAD4 gene expression, which may increase the effectiveness of therapy.
In Vitro Bone Differentiation of 3D Microsphere from Dental Pulp-Mesenchymal Stem Cells
Authors: Gaitán-Salvatella Iñigo , González-Alva Patricia , Montesinos Juan José , Alvarez-Perez Marco Antonio
Published: May 2023

Bone defects lead to the structural loss of normal architecture, and those in the field of bone tissue engineering are searching for new alternatives to aid bone regeneration. Dental pulp-mesenchymal stem cells (DP-MSC) could provide a promising alternative to repair bone defects, principally due to their multipotency and capacity to fabricate three-dimensional (3D) spheroids. The present study aimed to characterize the 3D DP-MSC microsphere and the osteogenic differentiation capacity potential cultured by a magnetic levitation system. To achieve this, the 3D DP-MSC microsphere was grown for 7, 14, and 21 days in an osteoinductive medium and compared to 3D human fetal osteoblast (hFOB) microspheres by examining the morphology, proliferation, osteogenesis, and colonization onto PLA fiber spun membrane. Our results showed good cell viability for both 3D microspheres with an average diameter of 350 μm. The osteogenesis examination of the 3D DP-MSC microsphere revealed the lineage commitment, such as the hFOB microsphere, as evidenced by ALP activity, the calcium content, and the expression of osteoblastic markers. Finally, the evaluation of the surface colonization exhibited similar patterns of cell-spreading over the fibrillar membrane. Our study demonstrated the feasibility of forming a 3D DP-MSC microsphere structure and the cell-behavior response as a strategy for the applications of bone tissue guiding.
The Effect of Coupled Electroencephalography Signals in Electrooculography Signals on Sleep Staging Based on Deep Learning Methods
Authors: Zhu Hangyu , Fu Cong , Shu Feng , Yu Huan , Chen Chen , Chen Wei
Published: May 2023

The influence of the coupled electroencephalography (EEG) signal in electrooculography (EOG) on EOG-based automatic sleep staging has been ignored. Since the EOG and prefrontal EEG are collected at close range, it is not clear whether EEG couples in EOG or not, and whether or not the EOG signal can achieve good sleep staging results due to its intrinsic characteristics. In this paper, the effect of a coupled EEG signal in an EOG signal on automatic sleep staging is explored. The blind source separation algorithm was used to extract a clean prefrontal EEG signal. Then the raw EOG signal and clean prefrontal EEG signal were processed to obtain EOG signals coupled with different EEG signal contents. Afterwards, the coupled EOG signals were fed into a hierarchical neural network, including a convolutional neural network and recurrent neural network for automatic sleep staging. Finally, an exploration was performed using two public datasets and one clinical dataset. The results showed that using a coupled EOG signal could achieve an accuracy of 80.4%, 81.1%, and 78.9% for the three datasets, slightly better than the accuracy of sleep staging using the EOG signal without coupled EEG. Thus, an appropriate content of coupled EEG signal in an EOG signal improved the sleep staging results. This paper provides an experimental basis for sleep staging with EOG signals.
Generation of a Yeast Cell Model Potentially Useful to Identify the Mammalian Mitochondrial N-Acetylglutamate Transporter
Authors: Gorgoglione Ruggiero , Seccia Roberta , Ahmed Amer , Vozza Angelo , Capobianco Loredana , Lodi Alessia , Marra Federica , Paradies Eleonora , Palmieri Luigi , Coppola Vincenzo , Dolce Vincenza , Fiermonte Giuseppe
Published: May 2023

The human mitochondrial carrier family (MCF) consists of 53 members. Approximately one-fifth of them are still orphans of a function. Most mitochondrial transporters have been functionally characterized by reconstituting the bacterially expressed protein into liposomes and transport assays with radiolabeled compounds. The efficacy of this experimental approach is constrained to the commercial availability of the radiolabeled substrate to be used in the transport assays. A striking example is that of N-acetylglutamate (NAG), an essential regulator of the carbamoyl synthetase I activity and the entire urea cycle. Mammals cannot modulate mitochondrial NAG synthesis but can regulate the levels of NAG in the matrix by exporting it to the cytosol, where it is degraded. The mitochondrial NAG transporter is still unknown. Here, we report the generation of a yeast cell model suitable for identifying the putative mammalian mitochondrial NAG transporter. In yeast, the arginine biosynthesis starts in the mitochondria from NAG which is converted to ornithine that, once transported into cytosol, is metabolized to arginine. The deletion of ARG8 makes yeast cells unable to grow in the absence of arginine since they cannot synthetize ornithine but can still produce NAG. To make yeast cells dependent on a mitochondrial NAG exporter, we moved most of the yeast mitochondrial biosynthetic pathway to the cytosol by expressing four E. coli enzymes, argB-E, able to convert cytosolic NAG to ornithine. Although argB-E rescued the arginine auxotrophy of arg8∆ strain very poorly, the expression of the bacterial NAG synthase (argA), which would mimic the function of a putative NAG transporter increasing the cytosolic levels of NAG, fully rescued the growth defect of arg8∆ strain in the absence of arginine, demonstrating the potential suitability of the model generated.
The Utility of Faecal Calprotectin, Lactoferrin and Other Faecal Biomarkers in Discriminating Endoscopic Activity in Crohn’s Disease: A Systematic Review and Meta-Analysis
Authors: Bohra Anuj , Mohamed Ghada , Vasudevan Abhinav , Lewis Diana , Van Langenberg Daniel R. , Segal Jonathan P.
Published: May 2023

Introduction: Currently, faecal calprotectin (FC) is the predominate faecal biomarker utilised in clinical practice to monitor Crohn’s disease (CD) activity. However, there are several potential faecal biomarkers described in the literature. We performed a meta-analysis to determine the accuracy of faecal biomarkers in discriminating endoscopic activity and mucosal healing in CD. Methods: We searched the medical literature using MEDLINE, EMBASE, and PubMed from 1978 to 8 August 2022. Descriptive statistics, including sensitivity, specificity of the primary studies, their positive and negative likelihood ratios, and their diagnostic odds ratio (DOR), were calculated. The methodological quality of the included studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS) criteria. Results: The search found 2382 studies, of which 33 were included for analysis after screening. FC was found to have a pooled sensitivity and specificity, DOR, and negative predictive value (NPV) in discriminating active endoscopic disease (versus inactive) of 81%, 74%, 13.93, and 0.27, respectively. Faecal lactoferrin (FL) had a pooled sensitivity and specificity, DOR, and NPV in discriminating active endoscopic disease of 75%, 80%, 13.41, and 0.34, respectively. FC demonstrated a pooled sensitivity and specificity, DOR, and NPV of 88%, 72%, 18.17, and 0.19 in predicting mucosal healing. Conclusion: FC remains an accurate faecal biomarker. Further evaluation of the utility of novel faecal biomarkers is needed.
SARS-CoV-2 Infection in Venezuelan Pediatric Patients—A Single Center Prospective Observational Study
Authors: Crespo Francis Isamarg , Mayora Soriuska José , De Sanctis Juan Bautista , Martínez Wendy Yaqueline , Zabaleta-Lanz Mercedes Elizabeth , Toro Félix Isidro , Deibis Leopoldo Humberto , García Alexis Hipólito
Published: May 2023

Several studies suggest that children infected with SARS-CoV-2 have fewer clinical manifestations than adults; when they develop symptoms, they rarely progress to severe disease. Different immunological theories have been proposed to explain this phenomenon. In September 2020, 16% of the active COVID-19 cases in Venezuela were children under 19 years. We conducted a cross-sectional study of pediatric patients’ immune response and clinical conditions with SARS-CoV-2 infection. The patients were admitted to the COVID-19 area of the emergency department of Dr José Manuel de los Ríos Children’s Hospital (2021–2022). The lymphocyte subpopulations were analyzed by flow cytometry, and IFNγ, IL-6, and IL-10 serum concentrations were quantified using commercial ELISA assays. The analysis was conducted on 72 patients aged one month to 18 years. The majority, 52.8%, had mild disease, and 30.6% of the patients were diagnosed with MIS-C. The main symptoms reported were fever, cough, and diarrhea. A correlation was found between IL-10 and IL-6 concentrations and age group, lymphocyte subpopulations and nutritional status and steroid use, and IL-6 concentrations and clinical severity. The results suggest a different immune response depending on age and nutritional status that should be considered for treating pediatric COVID-19 patients.
The Roles of the Amyloid Beta Monomers in Physiological and Pathological Conditions
Authors: Schreiner Thomas Gabriel , Schreiner Oliver Daniel , Adam Maricel , Popescu Bogdan Ovidiu
Published: May 2023

Amyloid beta peptide is an important biomarker in Alzheimer’s disease, with the amyloidogenic hypothesis as one of the central hypotheses trying to explain this type of dementia. Despite numerous studies, the etiology of Alzheimer’s disease remains incompletely known, as the pathological accumulation of amyloid beta aggregates cannot fully explain the complex clinical picture of the disease. Or, for the development of effective therapies, it is mandatory to understand the roles of amyloid beta at the brain level, from its initial monomeric stage prior to aggregation in the form of senile plaques. In this sense, this review aims to bring new, clinically relevant data on a subject intensely debated in the literature in the last years. In the first part, the amyloidogenic cascade is reviewed and the possible subtypes of amyloid beta are differentiated. In the second part, the roles played by the amyloid beta monomers in physiological and pathological (neurodegenerative) conditions are illustrated based on the most relevant and recent studies published on this topic. Finally, considering the importance of amyloid beta monomers in the pathophysiology of Alzheimer’s disease, new research directions with diagnostic and therapeutic impacts are suggested.
A Comparison of Functional Connectivity in the Human Brainstem and Spinal Cord Associated with Noxious and Innocuous Thermal Stimulation Identified by Means of Functional MRI
Authors: Koning Elena , Powers Jocelyn M. , Ioachim Gabriela , Stroman Patrick W.
Published: May 2023

The somatosensory system is multidimensional and processes important information for survival, including the experience of pain. The brainstem and spinal cord serve pivotal roles in both transmitting and modulating pain signals from the periphery; although, they are studied less frequently with neuroimaging when compared to the brain. In addition, imaging studies of pain often lack a sensory control condition, failing to differentiate the neural processes associated with pain versus innocuous sensations. The purpose of this study was to investigate neural connectivity between key regions involved in descending modulation of pain in response to a hot, noxious stimulus as compared to a warm, innocuous stimulus. This was achieved with functional magnetic resonance imaging (fMRI) of the brainstem and spinal cord in 20 healthy men and women. Functional connectivity was observed to vary between specific regions across painful and innocuous conditions. However, the same variations were not observed in the period of anticipation prior to the onset of stimulation. Specific connections varied with individual pain scores only during the noxious stimulation condition, indicating a significant role of individual differences in the experience of pain which are distinct from that of innocuous sensation. The results also illustrate significant differences in descending modulation before and during stimulation in both conditions. These findings contribute to a deeper understanding of the mechanisms underlying pain processing at the level of the brainstem and spinal cord, and how pain is modulated.
Innovations in Trauma-Informed Care: Building the Nation’s First System of Trauma-Informed Recreation Centers
Authors: Holmes Megan R. , King Jennifer A. , Miller Emily K. , King-White Dakota L. , Korsch-Williams Amy E. , Johnson Erica M. , Oliver Tomeika S. , Conard Ivan T.
Published: May 2023

Exposure to adversity and traumatic events affects well-being across important domains of functioning, including mental, physical, social, emotional, spiritual, and neurobiological. Situated as a focal point throughout neighborhoods, recreation centers are a prime opportunity to cultivate spaces of safety and healing. However, current models of trauma-informed care largely do not map neatly onto the recreation organizational structure and functioning. This paper describes the efforts over the past five years to transform the City of Cleveland, Ohio’s 22 recreation centers into trauma-informed Neighborhood Resource and Recreation Centers (NRRCs)––places where children, youth, and adults can readily acquire the support and services they need in an environment in which trauma-informed care principles are fully embedded in the fabric of the organization’s culture. Phase 1 included transitioning the recreation centers to NRRCs, hiring of trained social workers and counselors to work within the recreation centers, and training all recreation staff about trauma. Phase 2 included development of NRRC trauma-informed standards, development of the Trauma-Informed Progress Tool to track change over time, development of Trauma-Informed Leadership Competencies for Center Managers, and ongoing training for the social workers and counselors. We discuss ideas for future work and lessons learned from each phase.