bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

AbstractIn 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

Abstract
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

Abstract
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

Abstract
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

Abstract

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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract

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.