bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of halogen precursors on the growth of InSb nanostructures
Authors: Sten Alexander K , Roccapriore Kevin M , Squires Brian , Littler Chris , Syllaios A J , Philipose Usha
Published: February 2024

The present work highlights the role of halogen compounds in modifying the shape of the InSb nanostructures, while maintaining a high crystalline quality of the nanostructures. One-dimensional (1D) nanowires (NWs) and two-dimensional (2D) nanoplatelets (NPLs) were synthesized by ambient pressure chemical vapor deposition. Our experimental results suggest that at a critical growth temperature of 512 ∘C, InSb NWs grow by the traditional vapor–liquid–solid growth mechanism when gold (Au) nanoparticles are used to initiate growth on an InSb film. The resulting NWs were found to have a cylindrical or tapered shape, were of high crystalline quality, and had stoichiometric composition. In the presence of halogen precursors, a change in morphology was observed and the resulting nanostructures were 2D NPLs and faceted NWs. Using existing models of crystal growth and concepts of volume, surface and edge energies, the experimental results are explained on the basis of chlorine atoms adsorbed on the wide or narrow facets of a nanocrystal, initiating nucleation and facilitating NPL or faceted NW formation. The incorporation of the chlorine atoms add a new degree of freedom to CVD synthesis of nanostructures and the results are promising for the controlled growth of novel 1D and 2D nanostructures for nano-electronic devices.
Theoretical study of the Ca+ − He ionic system with spin–orbit coupling
Authors: Yandjah L , Smida O , Alioua K , Abdul-rahman Allouche , Lamoudi N , Bouazza M T
Published: February 2024

We have performed ab-initio calculations to investigate the van der Waals interaction between a Ca+ ion and a helium atom. We have focused on determining the low-lying electronic states of the Ca+−He ionic system using advanced theoretical methods, including RCCSD(T) and SA-CASSCF/MRCI , with the incorporation of Davidson and BSSE corrections. Furthermore, we have considered the impact of spin–orbit coupling SO on these states using the state-interacting method. Spectroscopic parameters of the potential energy curves PECs were calculated and compared with existing data from previous studies. Additionally, we have evaluated vibrational levels, their spacing, radiative lifetimes, transition dipole moments TDMs and permanent electric dipole moments PDMs. The position of satellites in the absorption spectra of white dwarfs was determined. Our results were compared with available theoretical and experimental data to assess their accuracy and agreement. This study provides valuable insights into the van der Waals interaction and electronic properties of the Ca+−He ionic molecule.
Highly flexible poly-O-aminothiophenol/intercalated iodide composite with highly morphological properties for green hydrogen generation from Red Sea water
Authors: Rabia Mohamed , Aldosari Eman , Geneidy Adbelrhaman Hamdeldein Ahmed
Published: February 2024

A highly flexible poly-O-amino thiophenol/intercalated iodide (POATP-I) nanocomposite has been successfully synthesized, in a one-step process, as a promising photocathode for H2 production through the Red Sea water. The fabrication of the photocathode involves the oxidation of O-amino thiophenol with iodine, leading to the formation of a remarkably flexible thin film of POATP-I. This thin film exhibits a well-developed network of polymer films. Notably, the nanocomposite demonstrates outstanding light absorbance properties in UV and Vis segments, boasting a calculated bandgap of 2.56 eV. To assess the efficiency of the photocathode, the current density (Jph) generated during the process is employed as a quantitative metric. The Jph values recorded in dark and light range from −0.2 to −1.7 mAcm−2, respectively. This substantial change in Jph highlights the impressive responsiveness of the POATP-I thin film to incident light, facilitating the high-energy electrons formation that contributes to the environmentally friendly hydrogen gas. Furthermore, the thin film exhibits notable responsiveness across various monochromatic photons, from 340 to 730 nm. Optimal performance is observed at 340 nm, where Jph reaches −0.45 mA.cm−2. Additionally, the estimated hydrogen production rate is calculated at 0.15 mmol h−1 for every 10 cm2 of the material’s surface. These remarkable characteristics position the material for potential industrial applications in hydrogen gas production, providing a sustainable and environmentally friendly solution for hydrogen production.
The clustering of dark sirens' invisible host galaxies
Authors: Dalang Charles , Baker Tessa
Published: February 2024

Dark sirens are a powerful way to infer cosmological and astrophysical parameters from the combination of gravitational wave sirens and galaxy catalogues. Importantly, the method relies on the completeness of the galaxy catalogues being well modelled. A magnitude-limited catalogue will always be incomplete to some extent, requiring a completion scheme to avoid biasing the parameter inference. Standard methods include homogeneous and multiplicative completion, which have the advantage of simplicity but underestimate or overestimate the amplitude of structure at low completeness, respectively. In this work, we propose a new method to complete galaxy catalogues which uses clustering information to incorporate knowledge of the large scale structure into the dark sirens method. We find that if the structure of the true number of galaxies is sufficiently well preserved in the catalogue, our estimator can perform drastically better than both homogeneous and multiplicative completion. We lay the foundations for a maximally informative dark sirens analysis and discuss its limitations.
A parametric model for self-interacting dark matter halos
Authors: Yang Daneng , Nadler Ethan O. , Yu Hai-Bo , Zhong Yi-Ming
Published: February 2024

We propose a parametric model for studying self-interacting dark matter (SIDM) halos. The
model uses an analytical density profile, calibrated using a controlled N-body SIDM simulation
that covers the entire gravothermal evolution, including core-forming and -collapsing phases. By
normalizing the calibrated density profile, we obtain a universal description for SIDM halos at
any evolution phase. The model allows us to infer properties of SIDM halos based on their cold
dark matter (CDM) counterparts. As a basic application, we only require two characteristic
parameters of an isolated CDM halo at z = 0. We then extend the model to incorporate effects
induced by halo mass changes, such as major mergers or tidal stripping, making it applicable to
both isolated halos and subhalos. The parametric model is tested and validated using cosmological
zoom-in SIDM simulations available in the literature.
Coupled action potential and calcium dynamics underlie robust spontaneous firing in dopaminergic neurons
Authors: Khamis Hadeel , Cohen Ohad
Published: February 2024

Dopaminergic neurons are specialized cells in the substantia nigra, tasked with dopamine secretion. This secretion relies on intracellular calcium signaling coupled to neuronal electrical activity. These neurons are known to display spontaneous calcium oscillations in-vitro and in-vivo, even in synaptic isolation, controlling the basal dopamine levels. Here we outline a kinetic model for the ion exchange across the neuronal plasma membrane. Crucially, we relax the assumption of constant, cytoplasmic sodium and potassium concentration. We show that sodium-potassium dynamics are strongly coupled to calcium dynamics and are essential for the robustness of spontaneous firing frequency. The model predicts several regimes of electrical activity, including tonic and ‘burst’ oscillations, and predicts the switch between those in response to perturbations. ‘Bursting’ correlates with increased calcium amplitudes, while maintaining constant average, allowing for a vast change in the calcium signal responsible for dopamine secretion. All the above traits provide the flexibility to create rich action potential dynamics that are crucial for cellular function.
Quasi-classical dynamics of a charged particle under conditions of ionization losses in a weak magnetic field
Authors: Sazonov S V
Published: February 2024

The quasi-classical dynamics of a charged particle in a weak magnetic field in the presence of dissipative losses caused by ionization of the medium is studied. The approximate approach proposed here is a generalization of the Caldirola—Kanai method for quantizing the translational motion of particles in dissipative media. It is shown that a weak curvature of a classical trajectory by the magnetic field is accompanied by an isotropic increase of uncertainty of the particle coordinates to the some maximum value at the moment the localized probability density wave packet stops. The limitation of the increase of coordinate uncertainty is due to irreversible ionization losses.
Probing valence quark width of the proton in deeply virtual Compton scattering at high energies*
Authors: Xiang 向 Wenchang 文昌 , Cao 曹 Dewen 德文 , Zhou 周 Daicui 代翠
Published: February 2024

We use the refined hot spot model to study the valence quark shape of the proton with the deeply virtual Compton scattering at high energies in the color glass condensate framework. To investigate the individual valence quark shape, a novel treatment of the valence quark width is employed. We calculate the cross-sections for coherent and incoherent deeply virtual Compton scattering using, for the first time, different widths (

and

) for the profile density distributions of the up and down quarks instead of using the same width as in the literature. We find that the cross-sections calculated with

at each collision energy are consistent with each other, which is in agreement with theoretical expectations, whereas those computed with

show some discrepancies. This outcome implies that the up quark might emit more gluons than the down quark, leading to

at high energy. The impact of energy on the outcome is estimated. Our results show that as the collision energy increases, the aforementioned discrepancies are not only significantly broadened, but also shift to a relatively smaller momentum transfer range at the future Electron-Ion Collider (EIC) and Large Hadron Electron Collider (LHeC) energies, which indicates that the EIC and LHeC can provide an unprecedented chance to access the shape of the valence quark of the proton.
Study of the topological quantities of lattice QCD using a modified DCGAN frame
Authors: Gao 高 Lin 璘 , Ying 应 Heping 和平 , Zhang 张 Jianbo 剑波
Published: February 2024

A modified deep convolutional generative adversarial network (M-DCGAN) frame is proposed to study the N-dimensional (ND) topological quantities in lattice QCD based on Monte Carlo (MC) simulations. We construct a new scaling structure including fully connected layers to support the generation of high-quality high-dimensional images for the M-DCGAN. Our results suggest that the M-DCGAN scheme of machine learning will help to more efficiently calculate the 1D distribution of topological charge and the 4D topological charge density compared with MC simulation alone.
Dark energy and matter interacting scenario to relieve H
0 and S
8 tensions*
Authors: Gao 高 Li-Yang 立扬 , Xue 薛 She-Sheng 社生 , Zhang 张 Xin 鑫
Published: February 2024

We consider a new cosmological model (called

CDM), in which the vacuum energy interacts with matter and radiation, and test this model using the current cosmological observations. Using the CMB+BAO+SN (CBS) dataset to constrain the model, we find that

and

tensions are relieved to

and

, respectively. However, in this case, the

CDM model is not favored by the data, compared with ΛCDM. We find that when the

and

data are added to the data combination, the situation is significantly improved. In the CBS+

case, the model relieves the

tension to

, and the model is favored over ΛCDM. In the CBS+

+

case, we obtain a synthetically best situation, in which the

and

tensions are relieved to

and

, respectively. In this case, the model is most favored by the data. Therefore, this cosmological model can greatly relieve the

tension and simultaneously effectively alleviate the

tension.
The role of stimulus periodicity on spinal cord stimulation-induced artificial sensations in rodents
Authors: Slack Jacob C , Zeiser Sidnee L , Yadav Amol P
Published: February 2024

Objective. Sensory feedback is critical for effectively controlling brain-machine interfaces and neuroprosthetic devices. Spinal cord stimulation (SCS) is proposed as a technique to induce artificial sensory perceptions in rodents, monkeys, and humans. However, to realize the full potential of SCS as a sensory neuroprosthetic technology, a better understanding of the effect of SCS pulse train parameter changes on sensory detection and discrimination thresholds is necessary. Approach. Here we investigated whether stimulation periodicity impacts rats’ ability to detect and discriminate SCS-induced perceptions at different frequencies. Main results. By varying the coefficient of variation (CV) of interstimulus pulse interval, we showed that at lower frequencies, rats could detect highly aperiodic SCS pulse trains at lower amplitudes (i.e. decreased detection thresholds). Furthermore, rats learned to discriminate stimuli with subtle differences in periodicity, and the just-noticeable differences from a highly aperiodic stimulus were smaller than those from a periodic stimulus. Significance. These results demonstrate that the temporal structure of an SCS pulse train is an integral parameter for modulating sensory feedback in neuroprosthetic applications.
Strategy revision phase with payoff threshold in the public goods game
Authors: Alberto Javarone Marco , Pratap Singh Shaurya
Published: February 2024

Commonly, the strategy revision phase in evolutionary games relies on payoff comparison. Namely, agents compare their payoff with the opponent, assessing whether changing strategy can be potentially convenient. Even tiny payoff differences can be crucial in this decision process. In this work, we study the dynamics of cooperation in the public goods game, introducing a threshold ε in the strategy revision phase. In doing so, payoff differences narrower than ε entail the decision process reduces to a coin flip. Interestingly, with ordinary agents, results show that payoff thresholds curb the emergence of cooperation. Yet, the latter can be sustained by these thresholds if the population is composed of conformist agents, which replace the random-based revision with selecting the strategy of the majority. To conclude, agents sensible only to consistent payoff differences may represent ‘real-world’ individuals unable to properly appreciate advantages or disadvantages when facing a dilemma. These agents may be detrimental to the emergence of cooperation or, on the contrary, supportive when endowed with a conformist attitude.
Development of a knowledge base for an expert system supporting the decision of industrial mobile robot selection
Authors: Boleraczki M
Published: February 2024

With the growth of industrial mobile robots, more and more manufacturing companies are producing such robots. As a result, there is a growing market variety for companies wanting to adopt these robots. It is an economic advantage if a robot selected for a specific task can be operated optimally. To this end, the selection process must already be carried out with optimal operation in mind. In my research, I develop such an industrial mobile robot selection support system, which generates a knowledge base from a database and then supports the selection decision with an expert system. In this paper, I describe the structure, interrelationship and test results of this database and knowledge base.
Real-time detecting deformation on pantograph contact strip based on image processing technique
Authors: Militaru G , Panoiu M , Panoiu C
Published: February 2024

Railway vehicles’ traction power supply system has two main components, the catenary contact and the pantograph. During the operation, contact is influenced by electromechanical wear phenomena. Deformation on the pantograph contact strip affects its power transmission quality because contact loos with the catenary reduces the railway system’s overall reliability. Their maintenance and inspection are usually done for periods of time with negative consequences in terms of costs and safety. Thus, in this study, we developed a contact strip monitoring method based on image processing for inspection to measure the contact strip thickness. The measurement system is made through a single camera that acquires images from the contact area, measuring the contact strip’s thickness using image processing techniques.
Study of MOS and IGBT transistors at switching with variable duty cycle
Authors: Cunţan C D , Baciu I , Osaci M
Published: February 2024

In this paper, the functionality of MOS and IGBT transistors is examined under identical working conditions, both in terms of command frequency and load circuit. A variable duty cycle and variable frequency signal generator is used to control transistors. Various electronic components and Arduino-UNO modules, as well as the 16×2 LCD screen, were used to create the signal generator. The control signal is amplified by a current amplifier to adapt the output voltage to the value required to control the transistors. The operation of MOS and IGBT transistors at various operating frequencies with resistive or inductive loads is compared. Thus, the communication times of the transistor capsules were determined at various operating temperatures. The temperature was determined indirectly by connecting a thermistor to the transistor capsule.
Design and Strength Analysis of a New Construction of a Sweeper with an Independent Surface Copying System Dedicated to Small Loaders and Front Loaders
Authors: Gierz Ł , Łykowski W , Ślaski G , Nowakowski M
Published: February 2024

Most enterprises and farms have paved parking lots, yards, warehouses, or sidewalks that need to be cleaned or cleaned. There are many sweepers available on the Polish and European markets, but there is still a lack of a solution that would be mounted on pallet forks and would have an independent copying system to support sweeping surfaces with different inclinations. The aim of the work was to develop a conceptual design for a new sweeper equipped with an independent surface copying system dedicated to small loaders and front loaders, as a well as strength analysis of the main frame. The conceptual design included an analysis of available solutions, development of a 3D CAD model of the new sweeper, and a detailed strength analysis of the sweeper’s main frame using the finite element method (FEM). The sweeper model was made in the Autodesk Inventor program, while the FEM strength analysis was made in the Siemens NX program. The designed frame model did not have nodes in which the stresses would be greater than 25% of the allowable stress in the material structure and 33% of the maximum allowable stress in the structure of the joints. The sweeper developed new design fulfills all the assumed functions and has a good chance of application.
Determination of the reliability of cement mills
Authors: Vasiu T , Berghian A Budiul
Published: February 2024

For any industrial entity put into operation, the problem is that it fulfils its specified function, under certain conditions of use and for a specified period of time, i.e. to have an appropriate reliability. In calculating the reliability of industrial entities in general and cement mills in particular, the main problem is to obtain the necessary information. They may be obtained from laboratory tests or tests under normal operating conditions, from maintenance teams, or from specialized control institutions. The general opinion is that only tests under normal operating conditions can provide real data on the behaviour of entities, subassemblies, and their component parts, which is why in general, reliability calculations are based on data obtained from so-called operation / failure reports. Therefore, considering this opinion, the reliability of cement mills was assessed following the operation of such a machine.
Possibilities of exploitation of useful metals from used Li-ion batteries
Authors: Rus I A , Băneasă C Birtok , Socalici A , Nicolae E V , Gaianu O
Published: February 2024

The paper presents the possibilities of recovering cobalt from used batteries. Given the evolution of the electric car market, the demand for cells of those raw materials for batteries such as cobalt, nickel, lithium will increase in the coming years. Efforts must be made by all actors involved to meet these needs in a sustainable manner. The recycling of used batteries involves the utilization of valuable elements present within them. Electric car batteries are part of the circular economy in which battery materials are recovered and reused to produce other batteries. Recycling is important because it reduces the pressure on the demand for raw materials.
Simulation of the casting and solidification process of the brake shoes intended for rolling stock
Authors: Bucur F , Socalici A , Josan A , Putan V , Birtok-Baneasă C
Published: February 2024

The paper presents the results obtained from the simulation of the casting and solidification process of the phosphorous cast iron brake blocks intended for rolling stock. The simulation of the casting and solidification process was carried out using the SolidWorks and Altair inspire cast programs. A S1 type brake shoe was chosen for this process. The solidification of phosphorous cast iron brake blocks is influenced by a number of constructive and technological factors. The simulation allows analysis of technological characteristics of casting and solidification of the alloy. The solidification process influences the micro and macrostructure of the parts, their compactness, mechanical strength, dimensional accuracy and surface quality.
Machine learning enabled detection of COVID-19 pneumonia using exhaled breath analysis: a proof-of-concept study
Authors: Cusack Ruth P , Larracy Robyn , Morrell Christian B , Ranjbar Maral , Le Roux Jennifer , Whetstone Christiane E , Boudreau Maxime , Poitras Patrick F , Srinathan Thiviya , Cheng Eric , Howie Karen , Obminski Catie , O’Shea Tim , Kruisselbrink Rebecca J , Ho Terence , Scheme Erik , Graham Stephen , Beydaghyan Gisia , Gavreau Gail M , Duong MyLinh
Published: February 2024

Detection of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) relies on real-time-reverse-transcriptase polymerase chain reaction (RT-PCR) on nasopharyngeal swabs. The false-negative rate of RT-PCR can be high when viral burden and infection is localized distally in the lower airways and lung parenchyma. An alternate safe, simple and accessible method for sampling the lower airways is needed to aid in the early and rapid diagnosis of COVID-19 pneumonia. In a prospective unblinded observational study, patients admitted with a positive RT-PCR and symptoms of SARS-CoV-2 infection were enrolled from three hospitals in Ontario, Canada. Healthy individuals or hospitalized patients with negative RT-PCR and without respiratory symptoms were enrolled into the control group. Breath samples were collected and analyzed by laser absorption spectroscopy (LAS) for volatile organic compounds (VOCs) and classified by machine learning (ML) approaches to identify unique LAS-spectra patterns (breathprints) for SARS-CoV-2. Of the 135 patients enrolled, 115 patients provided analyzable breath samples. Using LAS-breathprints to train ML classifier models resulted in an accuracy of 72.2%–81.7% in differentiating between SARS-CoV2 positive and negative groups. The performance was consistent across subgroups of different age, sex, body mass index, SARS-CoV-2 variants, time of disease onset and oxygen requirement. The overall performance was higher than compared to VOC-trained classifier model, which had an accuracy of 63%–74.7%. This study demonstrates that a ML-based breathprint model using LAS analysis of exhaled breath may be a valuable non-invasive method for studying the lower airways and detecting SARS-CoV-2 and other respiratory pathogens. The technology and the ML approach can be easily deployed in any setting with minimal training. This will greatly improve access and scalability to meet surge capacity; allow early and rapid detection to inform therapy; and offers great versatility in developing new classifier models quickly for future outbreaks.
Freshwater invertebrates from Livingston and Horseshoe Islands, Maritime Antarctica
Authors: Evtimova Vesela , Pandourski Ivan , Kenderov Lyubomir
Published: February 2024

Various processes trigger the formation, disappearance or expansion of lakes and ponds in Antarctica. Such dynamic ecosystems are a challenging environment for their inhabitants. We studied aquatic invertebrates in lakes and ponds on Livingston and Horseshoe Islands, Antarctica. Invertebrate fauna was either poor, in terms of diversity, or completely lacking. The taxa we found were of the polyphyletic group Protozoa; phylla Nematoda, Tardigrada, Annelida (subclass Oligochaeta) and Arthropoda (subclass Collembola, classes Insecta, Branchiopoda and Copepoda). Whenever a species dominated the communities, it was the copepod Boeckella poppei. When other taxa were recorded, their density was relatively low with few exceptions (Macrothrix oviformis, Branchinecta gaini). High density of B. poppei was recorded in circa 65% of all samples and the majority of the lakes/ponds with fauna. Most of the studied water bodies were oligotrophic, likely among the reasons for the poor faunal diversity, together with the harsh environmental conditions in Antarctica, e.g. low temperatures and long periods during which the lakes are frozen or completely dried out. The formation of new lakes and ponds poses the question on the pathways of distribution of aquatic organisms and why some ponds and lakes are densely populated, while others are deprived of aquatic invertebrates.
The Harmful Effects of Microplastic Pollution on Aquatic Organisms
Authors: Yilmaz N , Emecan I T , Elhag M , Boteva S , Yilmaz S M
Published: February 2024

In recent years, microplastics have been recognized as the most popular pollutants in marine and fresh waters. Plastic is one of the most used materials in all areas of our lives due to its cheap, light, and durable properties. Because they are used as main or auxiliary materials in almost all industries and branches of industry, the disappearance of plastics, which are in our lives, requires very long processes. Since petroleum-derived plastic wastes, which bacteria cannot consume directly, are decomposed by solar heat and radon, only the resulting compounds can be consumed by bacteria. For this reason, awareness-raising efforts to reduce plastic consumption in daily use all over the world have been accelerated. In parallel with this situation, research on microplastic pollution in both seas and inland waters is carried out intensively. Considering the current consumption habits of us humans, who are at the top of the food chain, the rates of microplastics we are exposed to are at a substantial level. The determination of the amount of microplastics contained in seafood consumed as the main protein source is of great importance in terms of public health and shows the necessity of further scientific research on this subject. The purpose of our study is to reveal the effects of microplastic pollution on aquatic organisms both in sea and inland waters by compiling studies on this subject and to draw attention to microplastic pollution in waters.
Ecological evaluation of the Small Negovan Lake after habitat restoration
Authors: Tosheva A , Traykov I
Published: February 2024

The study presents result on the changes in the ecological status of the sandpit lake during first six years after its restoration. The lake is located on the remnants of an extensive wetland with high biodiversity and conservation value, which was drained in mid 30s of the 20th century. Later canalization and embankment of the river resulted in the hydrological cut-off and complete drying up of the wetland. Fortunately, the territory was simultaneously exploited for aggregate production, thus retaining water and providing refuge to a number of the original flora and fauna of the wetland. After the exploitation of bottom material was ended, the sandpit lake regained a semi natural appearance, partly due to a series of projects. The most recent and complete restoration took part in the period 2013-2015 with the aim to restore and improve the ecological conditions in the lake. Subsequently (2016-2020), a monitoring program was launched, to assess the effect of the restoration activities on the macrophytes community (hydrophytes and helophytes), part of which are presented here. The results suggest pronounced deterioration of the status after the interventions, but the impacts are overcome in the next two to three years.
Enrichment of anaerobic and facultative anaerobic bacteria from a graphite mine sample on graphene oxide
Authors: Yordanova M , Simeonova D
Published: February 2024

Graphene oxide (GO) is progressively synthesized and applied in various industrial fields, such as healthcare, medicine, gas transport, electric power industry, etc. Thus, its distribution in the environment increases, which leads to changes in various microbial communities. Mechanisms of interaction between bacterial communities and novel carbon-based nanomaterials, such as GO, are still to be elucidated. We developed stable consortia in order to identify bacteria with the ability to thrive in the presence of GO. Here, we show the results of metagenomic analyses of the graphite mine sample, a consortium with GO as a sole source of carbon and a consortium with fumarate as an additional carbon source. The aim of this study was to establish anaerobic enrichment cultures from a graphite mine sample and GO, and to identify their diversity/community composition.
The role of Lactic Acid Bacteria Microbiota in Determining the pH Value of Newborn Faeces
Authors: Asenova Asya , Hristova Hristiyana , Nedeva Trayana , Hristova Petya , Zhivkova Ivelina , Rasheva Iliyana
Published: February 2024

The low pH is considered a protective mechanism of the body against infections by providing unfavourable conditions for their causers. Analysis of fecal pH of newborns have been performed around the world during the last century, and a disturbing tendency has been surveilled due to industrialization and lifestyle change of mothers and their babies. Considering the lack of information of that kind in Bulgaria, we aimed at analysing the pH values of solely breastfed and mix-fed infants, and its relation to the quantity of the found lactic acid bacteria, their taxa and respective metabolic characteristics. A total of fifteen faecal samples were collected from neonates aged 0 to 6 months. The pH values and presence of the Lactobacillaceae family, along with significant representatives of the genus Bifidobacterium were measured and evaluated by using multiplex semi-quantitative PCR. The gathered information about infants’ supplementation intake and feeding was considered. The solely breastfed neonates showed the lowest pH values, and the highest bifidobacterial content in comparison to the mixed-fed. The average pH value is around 5.1, which we interpret as relatively low, compared to the data in the literature. No relation was observed between the probiotic supplementation and the respective stool samples. These results suggest that breastfeeding plays the main role in manifesting gut health, inducing the growth of beneficial bacteria and immunity development. More participants and additional analyses are needed.
Potential role of DNA methylation and histone H3 acetylation in parasitism of Cuscuta
Authors: Marinova Bianka , Pachedjieva Kalina , Tosheva Anita , Teofanova Denitsa , Zagorchev Lyuben
Published: February 2024

Cuscuta campestris, or field dodder, is a non-photosynthetic, parasitic weed and a prominent agricultural pest. It is widely distributed in various climatic conditions and parasitizes over 100 different host plants in Bulgaria. The objective of the present study was to test the hypothesis that epigenetic regulation is key to the adaptation of Cuscuta spp. to different environments and host plants, as well as the response of host plants to parasitism. First, we tested 12 populations of C. campestris. Still, we found no correlation between the percentage of methylated DNA or acetylated histones and the most common host plant species, although significant differences were found. However, the effect of Cuscuta parasitism was much more pronounced on the enzymes, responsible for both DNA methylation and histone acetylation in the host plants. While changes were not so notable in the susceptible model host, Arabidopsis thaliana, the resistant host Solanum lycopersicum responded to parasitism with increased DNA methyltransferase and histone deacetylase activities and decreased DNA demethylation. All this suggests adaptation to parasitism, which is partially guided by epigenetic regulation. Further studies, including mapping of the methylated regions, are needed to better understand the epigenetic mechanisms of host adaptation to Cuscuta parasitism.
Identification and quantification of very small embryonic-like (VSEL) stem cells in fresh umbilical cord blood
Authors: Ruseva M , Stoykov I , Parvanov D , Ganeva R , Handzhyiska M , Marinska D , Raponska B , Stamenov G
Published: February 2024

The present study aimed to identify, quantify and compare the quantities of very small embryonic-like (VSEL) stem cells in the two main fractions of fresh umbilical cord blood (UCB). To do this, UCB obtained during caesarean section underwent gradient centrifugation. Nucleated cells isolated from the two main fractions – the mononuclear cell layer above the gradient, and the red blood cell pellet below the gradient – were immunofluorescently labelled to identify the VSELs (CD45−/CD133+/SSEA4+). These two cell fractions were then analysed via multiparameter sorting on a flow cytometer and the quantities of positively stained cells were compared.
Effects of gas pressure and catheter length on the breakup of discontinuous NiTi droplets in electrode induction melting gas atomization
Authors: Xie Bo , Li Wei , Liu Xinyu , Zhou Ge , Zhao Sanchao , Liu Yongsheng , Wu Wang , Lu Dong , Peng Weixing
Published: February 2024

NiTi powders used for selective laser melting have here been fabricated by the breakup of discontinuous droplets in electrode induction melting gas atomization (EIGA). The morphology, particle size distribution, and hollow ratio of the powder were characterized by scanning electron microscopy (SEM), laser particle size analyzer, and computed tomography (CT), respectively. The effects of gas pressure and catheter length on the particle size distribution and powder morphology were then studied. Furthermore, the effects of the classifier wheel speed on the particle size distribution and yield of the 15–53 μm powder in the classification process were also analyzed. The results showed that the average particle size (D50) of the NiTi powder first decreased and, thereafter, increased as the atomization gas pressure increased. This was also the situation with catheter length. Also, the yield of the 15–53 μm powder increased with an increase in the classifier wheel speed. The optimum parameters were a gas atomization pressure of 5 MPa, a tension length of 28 mm, and a classifier wheel speed of 660 r min−1. For this optimized condition, the D50 value and the yield of the NiTi powder were 57.54 μm and 46.4%. In addition, the flowability, hollow ratio, and oxygen content were 15.8 s/50 g, 0.31%, and 450 ppm, respectively.
Notably enhanced dielectric response with low loss in PVDF composites filled with RuO2–BaTiO3 hybrid particles
Authors: Silakaew Kanyapak , Thongbai Prasit
Published: February 2024

This study delineates the process of fabricating and the results of investigating the dielectric properties of hybrid particles created through the integration of Poly(vinylidene fluoride) (PVDF) filled with RuO2 coated on BaTiO3 nanoparticles (nBT), designated as RuO2–nBT. These hybrid particles were successfully synthesized employing a simple and cost–effective solid–state reaction method. The inclusion of RuO2–nBT in the PVDF matrix engendered a notable enhancement in its dielectric properties. Notably, a RuO2–nBT fraction of 0.5 manifested a dielectric constant (ε′) of 107.4 and a dielectric loss tangent (tanδ) value of 0.062 at 30 °C and 1 kHz. These findings signify the effective role of interfacial polarization occurring between the PVDF matrix and the RuO2–nBT hybrid particles, leading to a marked improvement in dielectric attributes. Moreover, the observed low tanδ value indicates the elimination of conductive pathways, an inhibitory effect attributed to the incorporation of RuO2–nBT hybrid particles. This study underscores the promising potential of RuO2–nBT hybrid particles in fine–tuning and augmenting the dielectric properties of polymer composites, particularly in scenarios necessitating low tanδ and high ε′ values.
Analysis of the weighted conical Radon transform
Authors: Duy Nguyen Ngoc
Published: February 2024

In this article, we consider the weighted conical Radon transform—the transform is motivated by Compton camera imaging as well as optical tomography. Our contribution involves introducing new inversion formulas for the weighted conical Radon transform, including explicit formulas and properties associated with convolution frames. Furthermore, we propose reconstruction formulas that solve for variety weighted parameters in the two-dimensional space.
Research on the impact of environmental regulations on green technological innovation in China from the perspective of digital transformation: a threshold model approach
Authors: Xiao Yanfei , Zhang Baoli , Wang Huilin
Published: February 2024

The digital transformation in developing countries is crucial in determining whether environmental regulations can better facilitate green technological innovation. This paper constructs a theoretical model to deduce the relationships among digital transformation, environmental regulations, and green technological innovation. Empirical research is conducted using a two-way fixed-effects model and a threshold regression approach, based on provincial panel data from China spanning the years 2013 to 2020. The results indicate that environmental regulation inhibits green technological innovation. However, digital transformation, by reducing cost pathways, can promote the efficiency of green technological innovation under environmental regulation. This moderating effect exhibits a nonlinear threshold characteristic. Regarding dimensions of digital transformation, the level of digital investment shows no threshold, while both the level of digital application and the scale of digital integration exhibit threshold effects. Presently, in China, digital transformation effectively incentivizes green technological innovation under environmental regulation. Therefore, increasing digital investment, advancing digital applications, and fostering digital integration are inevitable choices to drive green technological innovation under the pressure of environmental regulation.
Prenatal exposure to Di(2-ethylhexyl) phthalate and high-fat diet synergistically disrupts gonadal function in male mice
Authors: Barakat Radwa , Lin Po-Ching Patrick , Bunnell Mary , Oh Ji-Eun , Rattan Saniya , Arnieri Cyrus , Flaws Jodi A , Ko CheMyong J
Published: February 2024

Prenatal exposure to Di (2-ethylhexyl) phthalate (DEHP) impairs the reproductive system and causes fertility defects in male offspring. Additionally, high-fat (HF) diet is a risk factor for reproductive disorders in males. In this study, we tested the hypothesis that prenatal exposure to a physiologically relevant dose of DEHP in conjunction with HF diet synergistically impacts reproductive function and fertility in male offspring. Female mice were fed a control or HF diet 7 days prior to mating and until their litters were weaned on postnatal day 21. Pregnant dams were exposed to DEHP or vehicle from gestational day 10.5 until birth. The male offspring’s gross phenotype, sperm quality, serum hormonal levels, testicular histopathology, and testicular gene expression pattern were analyzed. Male mice born to dams exposed to DEHP + HF had smaller testes, epididymides, and shorter anogenital distance compared with those exposed to HF or DEHP alone. DEHP + HF mice had lower sperm concentration and motility compared with DEHP mice. Moreover, DEHP + HF mice had more apoptotic germ cells, fewer Leydig cells, and lower serum testosterone levels than DEHP mice. Furthermore, testicular mRNA expression of Dnmt1 and Dnmt3a was two to eight-fold higher than in DEHP mice by qPCR, suggesting that maternal HF diet and prenatal DEHP exposure additively impact gonadal function by altering the degree of DNA methylation in the testis. These results suggest that the combined exposure to DEHP and high-fat synergistically impairs reproductive function in male offspring, greater than exposure to DEHP or HF diet alone.
Fully automated CT imaging biomarkers for opportunistic prediction of future hip fractures
Authors: Liu Daniel , Garrett John W , Perez Alberto A , Zea Ryan , Binkley Neil C , Summers Ronald M , Pickhardt Perry J
Published: February 2024

Objective

Assess automated CT imaging biomarkers in patients who went on to hip fracture, compared with controls.

Methods

In this retrospective case-control study, 6926 total patients underwent initial abdominal CT over a 20-year interval at one institution. A total of 1308 patients (mean age at initial CT, 70.5 ± 12.0 years; 64.4% female) went on to hip fracture (mean time to fracture, 5.2 years); 5618 were controls (mean age 70.3 ± 12.0 years; 61.2% female; mean follow-up interval 7.6 years). Validated fully automated quantitative CT algorithms for trabecular bone attenuation (at L1), skeletal muscle attenuation (at L3), and subcutaneous adipose tissue area (SAT) (at L3) were applied to all scans. Hazard ratios (HRs) comparing highest to lowest risk quartiles and receiver operating characteristic (ROC) curve analysis including area under the curve (AUC) were derived.

Results

Hip fracture HRs (95% CI) were 3.18 (2.69-3.76) for low trabecular bone HU, 1.50 (1.28-1.75) for low muscle HU, and 2.18 (1.86-2.56) for low SAT. 10-year ROC AUC values for predicting hip fracture were 0.702, 0.603, and 0.603 for these CT-based biomarkers, respectively. Multivariate combinations of these biomarkers further improved predictive value; the 10-year ROC AUC combining bone/muscle/SAT was 0.733, while combining muscle/SAT was 0.686.

Conclusion

Opportunistic use of automated CT bone, muscle, and fat measures can identify patients at higher risk for future hip fracture, regardless of the indication for CT imaging.

Advances in knowledge

CT data can be leveraged opportunistically for further patient evaluation, with early intervention as needed. These novel AI tools analyse CT data to determine a patient’s future hip fracture risk.
Survival and safety after neoadjuvant chemotherapy or upfront surgery for locally advanced colon cancer: meta-analysis
Authors: Aliseda Daniel , Arredondo Jorge , Sánchez-Justicia Carlos , Alvarellos Alicia , Rodríguez Javier , Matos Ignacio , Rotellar Fernando , Baixauli Jorge , Pastor Carlos
Published: February 2024

Background

Neoadjuvant chemotherapy is increasingly used to treat locally advanced (T3–4 Nx–2 M0) colon cancer due to its potential advantages over the standard approach of upfront surgery. The primary objective of this systematic review and meta-analysis was to analyse data from comparative studies to assess the impact of neoadjuvant chemotherapy on oncological outcomes.

Methods

A systematic review was conducted by searching the MEDLINE and Scopus databases. The search encompassed RCTs, propensity score-matched studies, and controlled prospective studies published up to 1 April 2023. As a primary objective, overall survival and disease-free survival were compared. As a secondary objective, perioperative morbidity, mortality, and complete resection were compared using the DerSimonian and Laird models.

Results

A total of seven studies comprising a total of 2120 patients were included. Neoadjuvant chemotherapy was associated with a reduction in the hazard of recurrence (HR 0.73, 95% c.i. 0.59 to 0.90; P = 0.003) and death (HR 0.67, 95% c.i. 0.54 to 0.83; P < 0.001) compared with upfront surgery. Additionally, neoadjuvant chemotherapy was significantly associated with higher 5-year overall survival (79.9% versus 72.6%; P < 0.001) and disease-free survival (73.1% versus 64.5%; P = 0.028) rates. No significant differences were observed in perioperative mortality (OR 0.97, 95% c.i. 0.28 to 3.33), overall complications (OR 0.95, 95% c.i. 0.77 to 1.16), or anastomotic leakage/intra-abdominal abscess (OR 0.88, 95% c.i. 0.60 to 1.29). However, neoadjuvant chemotherapy was associated with a lower risk of incomplete resection (OR 0.70, 95% c.i. 0.49 to 0.99).

Conclusion

Neoadjuvant chemotherapy is associated with a reduced hazard of recurrence and death, as well as improved overall survival and disease-free survival rates, compared with upfront surgery in patients with locally advanced colon cancer.
Making the invisible visible: imaging techniques for assessing muscle mass and muscle quality in chronic kidney disease
Authors: Sabatino Alice , Sola Kristoffer Huitfeldt , Brismar Torkel B , Lindholm Bengt , Stenvinkel Peter , Avesani Carla Maria
Published: February 2024

Muscle wasting and low muscle mass are prominent features of protein energy wasting (PEW), sarcopenia and sarcopenic obesity in patients with chronic kidney disease (CKD). In addition, muscle wasting is associated with low muscle strength, impaired muscle function and adverse clinical outcomes such as low quality of life, hospitalizations and increased mortality. While assessment of muscle mass is well justified, the assessment of skeletal muscle should go beyond quantity. Imaging techniques provide the means for non-invasive, comprehensive, in-depth assessment of the quality of the muscle such as the infiltration of ectopic fat. These techniques include computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound. Dual energy X-ray absorptiometry is also an imaging technique, but one that only provides quantitative and not qualitative data on muscle. The main advantage of imaging techniques compared with other methods such as bioelectrical impedance analysis and anthropometry is that they offer higher precision and accuracy. On the other hand, the higher cost for acquiring and maintaining the imaging equipment, especially CT and MRI, makes these less-used options and available mostly for research purposes. In the field of CKD and end-stage kidney disease (ESKD), imaging techniques are gaining attention for evaluating muscle quantity and more recently muscle fat infiltration. This review describes the potential of these techniques in CKD and ESKD settings for muscle assessment beyond that of muscle quantity.