bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydroxychloroquine as an Adjunct Therapy for Diabetes in Pregnancy
Authors: Basri Nurul Iftida , Murthi Padma , Abd Rahman Rahana
Published: September 2024

This review discusses the pathophysiology of diabetes in pregnancy in relation to the placental function. We review the potential use of hydroxychloroquine in improving pregnancy outcomes affected by diabetes. The review focuses on the mechanism of action of hydroxychloroquine and its potential effects on diabetes. There are several pathways in which hydroxychloroquine mediates its effects: through the inflammasome complex, inflammatory cytokines, oxidative stress, modulatory effects, and antihyperglycemic effects. As a safe drug to be used in pregnancy, it is worth exploring the possible use hydroxychloroquine as an adjunct treatment to the current therapy of diabetes in pregnancy.
Mesocorticolimbic and Cardiometabolic Diseases—Two Faces of the Same Coin?
Authors: Papp Csaba , Mikaczo Angela , Szabo Janos , More Csaba E. , Viczjan Gabor , Gesztelyi Rudolf , Zsuga Judit
Published: September 2024

The risk behaviors underlying the most prevalent chronic noncommunicable diseases (NCDs) encompass alcohol misuse, unhealthy diets, smoking and sedentary lifestyle behaviors. These are all linked to the altered function of the mesocorticolimbic (MCL) system. As the mesocorticolimbic circuit is central to the reward pathway and is involved in risk behaviors and mental disorders, we set out to test the hypothesis that these pathologies may be approached therapeutically as a group. To address these questions, the identification of novel targets by exploiting knowledge-based, network-based and disease similarity algorithms in two major Thomson Reuters databases (MetaBase™, a database of manually annotated protein interactions and biological pathways, and IntegritySM, a unique knowledge solution integrating biological, chemical and pharmacological data) was performed. Each approach scored proteins from a particular approach-specific standpoint, followed by integration of the scores by machine learning techniques yielding an integrated score for final target prioritization. Machine learning identified characteristic patterns of the already known targets (control targets) with high accuracy (area under curve of the receiver operator curve was ~93%). The analysis resulted in a prioritized list of 250 targets for MCL disorders, many of which are well established targets for the mesocorticolimbic circuit e.g., dopamine receptors, monoamino oxidases and serotonin receptors, whereas emerging targets included DPP4, PPARG, NOS1, ACE, ARB1, CREB1, POMC and diverse voltage-gated Ca2+ channels. Our findings support the hypothesis that disorders involving the mesocorticolimbic circuit may share key molecular pathology aspects and may be causally linked to NCDs, yielding novel targets for drug repurposing and personalized medicine.
Balancing Risk and Profit: Predicting the Performance of Potential New Customers in the Insurance Industry
Authors: Soriano-Gonzalez Raquel , Tsertsvadze Veronika , Osorio Celia , Fuster Noelia , Juan Angel A. , Perez-Bernabeu Elena
Published: September 2024

In the financial sector, insurance companies generate large volumes of data, including policy transactions, customer interactions, and risk assessments. These historical data on established customers provide opportunities to enhance decision-making processes and offer more customized services. However, data on potential new customers are often limited, due to a lack of historical records and to legal constraints on personal data collection. Despite these limitations, accurately predicting whether a potential new customer will generate benefits (high-performance) or incur losses (low-performance) is crucial for many service companies. This study used a real-world dataset of existing car insurance customers and introduced advanced machine learning models, to predict the performance of potential new customers for whom available data are limited. We developed and evaluated approaches based on traditional binary classification models and on more advanced boosting classification models. Our computational experiments show that accurately predicting the performance of potential new customers can significantly reduce operation costs and improve the customization of services for insurance companies.
Meta-Analysis and MaxEnt Model Prediction of the Distribution of Phenacoccus solenopsis Tinsley in China under the Context of Climate Change
Authors: Liu Zhiqian , Peng Yaqin , Xu Danping , Zhuo Zhihang
Published: September 2024

Phenacoccus solenopsis Tinsley is a pest that poses a significant threat to agricultural crops, especially cotton, and is now widely distributed across many regions worldwide. In this study, we performed a meta-analysis on the collected experimental data and found that within the suitable temperature range, the survival rate of P. solenopsis increases with rising temperatures, indicating that climate plays a decisive role in its distribution. Using the MaxEnt model this study predicted that under three future climate scenarios (SSP1–2.6, SSP3–7.0, and SSP5–8.5), the distribution of P. solenopsis will expand and move towards higher latitudes. Climate change is the primary factor influencing changes in pest distribution. We conducted a meta-analysis of P. solenopsis, including seven independent studies covering 221 observation results, and examined the impact of temperature ranging from 18 °C to 39 °C on the developmental cycle of P. solenopsis. As the temperature rises, the development cycle of P. solenopsis gradually decreases. Additionally, by combining the MaxEnt model, we predicted the current and potential future distribution range of P. solenopsis. The results show that under future climate warming, the distribution area of P. solenopsis in China will expand. This research provides a theoretical basis for early monitoring and control of this pest’s occurrence and spread. Therefore, the predictive results of this study will provide important information for managers in monitoring P. solenopsis and help them formulate relevant control strategies.
Pressure Capacity Assessment of L-PBF-Produced Microchannel Heat Exchangers
Authors: An Jiabao , Guo Luyao , Zou Junjia , Zhang Keliang , Zhong Yiheng , Liu Taimingwang , Huang Long , Chen Yi
Published: September 2024

Laser powder bed fusion (L-PBF) manufacturing technology is an emerging field of research that focuses on evaluating constraints in printed products. This study highlights the importance of considering various factors, such as mechanical properties and support structures, during the design phase, particularly in the context of microchannel heat exchangers where all limiting factors are critical. This paper presents a methodology for analyzing channel pressure limitations and examines the impact of pipe porosity on the loss of mechanical properties. A combination of simulation experiments and pressure capacity tests is used to elucidate the pressure distribution characteristics of microchannel flat tubes and their true pressure capacity. This study also explores potential methods for improving the performance of L-PBF-printed microchannel flat tubes. The results and the development of the experimental setup are summarized.
Diagnosis of Human Endemic Mycoses Caused by Thermally Dimorphic Fungi: From Classical to Molecular Methods
Authors: García-Martín Joaquina María , Muro Antonio , Fernández-Soto Pedro
Published: September 2024

Human endemic mycoses are potentially fatal diseases caused by a diverse group of fungi that can alter their morphology in response to an increase in temperature. These thermally dimorphic fungi affect both healthy and immunocompromised hosts, causing a substantial health and economic burden. Despite this, the diagnosis of endemic mycoses is still a formidable challenge for several reasons, including similar symptomatology, limited utility of classical diagnostic methods, inaccessibility to reliable molecular approaches in most endemic areas, and a lack of clinical suspicion out of these regions. This review summarizes essential knowledge on thermally dimorphic fungi and the life-threatening diseases they cause. The principle, advantages and limitations of the methods traditionally used for their diagnosis are also described, along with the application status and future directions for the development of alternative diagnostic strategies, which could help to reduce the disease burden in endemic areas.
An Empirical Analysis of Tax Evasion among Companies Engaged in Stablecoin Transactions
Authors: Moura de Carvalho Rubens , Inácio Helena Coelho , Marques Rui Pedro
Published: September 2024

This research investigates the relationship between stablecoin usage and tax evasion. We present a model that includes variables related to transactions such as intensity, frequency, environment on-chain (P2P) vs. off-chain (IntraVasp), and company characteristics such as age, sector, and size. Our model was empirically tested using a logistic regression based on data from the Brazilian Federal Revenue Service (Receita Federal do Brasil (RFB)) in 2021. This novel approach aims to understand the tax behaviours associated with stablecoin use in corporate financial practices. Our results indicate that the intensity, frequency, environment of transactions (specifically IntraVasp and P2P transactions), age, sector, and size are factors significantly associated with tax evasion behaviour. However, we found no evidence to suggest that firms engaging in only P2P transactions have a higher propensity for tax evasion than those engaging only in IntraVasp transactions. Our findings reveal that younger and medium-sized companies with intensive use of stablecoin, with high stablecoin transaction frequency, engaging in IntraVasp and P2P transactions, and belonging to the service sector are more likely to evade tax. Therefore, our research provides a detailed understanding of how digital financial practices with crypto assets (blockchain-based technology) intersect with corporate tax strategies, which can offer valuable insights for regulators, industry practitioners, and policymakers.
Welcome to LabMed: A New Open Access Journal in Laboratory Medicine
Authors: Liu Weiyong
Published: September 2024

It is my great honor and pleasure to announce the launch of LabMed (ISSN: 2813-9038) [...]
Site Selection Optimisation Using Fuzzy-GIS Integration for Wastewater Treatment Plant
Authors: Abdelmagid Tasneem I. M. , Abdel-Magid Isam , Onsa Elsadig Eltayeb H. , Abdalla Ghassan M. T. , Abdel-Magid Hisham I. M. , Lakhouit Abderrahim , Al-Rashed Wael S. , Yaseen Ahmed Hassan A. , Hayder Gasim
Published: September 2024

Municipal management involves making decisions on various technical issues, and one such crucial aspect is the multicriteria decision-making process. When choosing suitable locations for wastewater treatment plants, it becomes necessary to consider a range of factors such as technical feasibility, economic viability, environmental impact, ecological aspects, and management requirements. However, evaluating these criteria and dealing with uncertainties can be complex. To address this challenge in the Tabuk region, a combination of two powerful analytical methods, the fuzzy analytical hierarchy process (FAHP) and geographical information system (GIS), were employed. The FAHP methodology allows for considering uncertainties and subjective judgements, while GIS provides spatial analysis capabilities. By combining FAHP and GIS, a thorough evaluation of potential wastewater treatment plant locations was conducted by determining the relative weights for each geospatial parameter. These weights were then used to generate a suitability map, visually representing the most favourable areas for site selection. The FAHP analysis resulted in higher importance given to the treatment plant’s distance to urban areas, followed by the distance to roads among the seven investigated parameters. The integrated FAHP-GIS model results show that the western parts of the region are most suitable for constructing wastewater treatment plants. These findings are valuable in facilitating multicriteria decision-making for identifying the optimum site in the area. In summary, integrating FAHP and GIS in the assessment process enables decision-makers to consider various technical, economic, environmental, ecological, and management aspects, thereby providing a comprehensive framework for site selection that can be replicated in other regions with different conditions. This approach enhances the decision-making process in municipal management and promotes more informed and effective planning in the Tabuk region.
Numerical Analysis of Cavitation Erosion in 316L Steel with CrN PVD Coating
Authors: Maurin Artur
Published: September 2024

The erosion process of a 4 μm monolayer CrN coating deposited on 316L stainless steel due to cavitation was investigated using finite element analysis (FEA). To estimate load parameters from cavitation pit geometry resulting from high impact velocity and high strain rate, the explicit dynamic solver was employed. Water microjet impacts at velocities of 100, 200 and 500 m/s were simulated to recreate different cavitation erosion intensities observed in the experiment. The resulting damage characteristics were compared to previous studies on uncoated 316L steel. The relationship between impact velocity and postimpact geometry was examined. Simulations revealed that only impact at 500 m/s can exceed the maximum yield stress of the substrate without penetrating the coating. Subsequent impacts on the same zone deepen the impact pit and penetrate the coating, leading to direct substrate degradation. The influence of impact velocity on the coating degradation process is discussed.
Aerogels for Phase-Change Materials in Functional and Multifunctional Composites: A Review
Authors: Suchorowiec Katarzyna , Paprota Natalia , Pielichowska Kinga
Published: September 2024

Phase-change materials (PCMs) have gained more attention during the last few decades. As the main function of these materials is to store and release energy in the form of latent heat during phase transitions, they perfectly fulfill the direction of modern research focused on energy-related topics. Although they have basic energy-related properties, recent research shows a need to upgrade those materials in terms of improving their common drawbacks like shape stability, leakage, and poor conductivity. The research related to PCM-based composites leads to imparting some additional functional properties such as different types of conversion abilities or extra performance such as shape memory and thermal protection. Together with a new emerging material group—aerogels (AGs), extra-light and highly porous matrices—PCMs could become functional and multifunctional materials. AG-PCM composites could be implemented in a large variety of applications in different sectors like energy, buildings, medical, defense, space technologies, and more. This study aims to help summarize current trends, methods, and works on PCM–aerogel composites in terms of developing new functional materials, especially for energy conversion purposes but also for improved conductivity, mechanical properties, and flame retardancy.
The Designs and Testing of Biodegradable Energy-Absorbing Inserts for Enhanced Crashworthiness in Sports Helmets
Authors: Kaczyński Paweł , Skwarski Mateusz , Dmitruk Anna , Makuła Piotr , Ludwiczak Joanna
Published: September 2024

This article addresses manufacturing structures made via injection molding from biodegradable materials. The mentioned structures can be successfully used as energy-absorbing liners of all kinds of sports helmets, replacing the previously used expanded polystyrene. This paper is focused on injection technological tests and tensile tests (in quasi-static and dynamic conditions) of several composites based on a PLA matrix with the addition of other biodegradable softening agents, such as PBAT and TPS (the blends were prepared via melt blending using a screw extruder with mass compositions of 50:50, 30:70, and 15:85). Tensile tests showed a positive strain rate sensitivity of the mixtures and a dependence of the increase in the ratio of the dynamic to static yield stress on the increase in the share of the plastic component in the mixture. Technological tests showed that increasing the amount of the plasticizing additive by 35% (from 50% to 85%) results in a decrease in the minimal thickness of the thin-walled element that can be successfully injection molded by about 32% in the case of PLA/PBAT blends (from 0.22 mm to 0.15 mm) and by about 26% in the case of PLA/TPS blends (from 0.23 mm to 0.17 mm). Next, the thin-walled elements (dimensions of 55 × 55 × 20 mm) were manufactured and evaluated using a spring-loaded drop hammer. The 60 J impact energy was tested in accordance with the EN 1078 standard. The dynamic crushing test included checking the influence of the materials’ temperature (−20, 0, 20, and 40 °C) and the impact velocity. It was proven that the maximum deflection increases with increasing material temperature and an increase in the share of the plastic component in the mixture. The PLA15PBAT85 blend was selected as the most effective material in terms of its use as an energy-absorbing liner for sport helmets. Johnson–Cook and Cowper–Symonds material plasticizing models were constructed. Their use during dynamic FE simulation provided results that were in good agreement with those of the conducted experiment.
Changes in the Success and Characteristics of Tobacco Dependence Treatment before and during the COVID-19 Pandemic: Clinical Sample Comparisons
Authors: Stepankova Lenka , Zvolska Kamila , Pankova Alexandra , Rafl Jakub , Donin Gleb , Tichopad Ales , Kralikova Eva
Published: September 2024

Background and Objectives: There is little information on changes in the process and outcomes of intensive tobacco dependence treatment during the COVID-19 pandemic. The following characteristics were evaluated: interest in treatment, the number of face-to-face or telephone follow-ups, the duration of pharmacotherapy use, and the success rate. The aim of our study was to compare the number of patients who entered tobacco dependence treatment programmes and evaluate the one-year success rate in patients three years before and three years after the COVID-19 pandemic. Materials and Methods: A single-site retrospective cohort study using data from patients treated at the Centre for Tobacco Dependence in Prague, Czech Republic, between 2017 and 2022 (n = 2039) was performed. The one-year abstinence rate was validated by measuring carbon monoxide in exhaled air (6 ppm cut-off). Patients were divided into two groups: the group for which treatment was initiated in 2017–2019 (i.e., before the COVID-19 pandemic, BC; n= 1221) and the group for which treatment was initiated in 2020–2022 (i.e., during the COVID-19 pandemic, DC; n = 818). Results: No significant differences in the success rate of tobacco dependence treatment were found between the two groups (BC group, 40.5% (494/1221) vs. DC group, 42.2% (345/818)) (χ2 (1, N = 2.039) = 0.6, p = 0.440). Furthermore, differences were not found in sex, education level, age at first cigarette, the duration of pharmacotherapy use, or the number of in-person visits. In contrast, there was an increase in the number of telephone contacts between the groups (18.7% (SD = 17.5%) vs. 32.9% (SD = 18.2%), p < 0.001). Conclusions: The number of patients who started treatment during the COVID-19 pandemic decreased by one-third compared to that during the 3-year period before the pandemic. The overall treatment success rate did not change significantly even with the increase in the number of telephone visits with the therapist.
The Influence of the Type of Breathing on the Masticatory Muscle Patterns in Children
Authors: Neves-Leal Daniela , Caleya Antonia M. , Martin-Vacas Andrea , Gallardo-López Nuria E. , Gallego Carlos
Published: September 2024

Background and Objectives: The aim was to compare the activity of the masseter muscles in children with different types of breathing. Materials and Methods: A cross-sectional study was conducted including patients aged 6–12 years with mixed dentition, who came for oral care at the Master’s Degree in Pediatric Dentistry program at the Complutense University of Madrid (UCM), according to inclusion and exclusion criteria. The sample was divided into three groups: nasal breathers without dental alterations (control group), oral breathers with dental malocclusion, and oral breathers with previous orthodontic treatment. An electromyography was performed, and statistic methods were conducted with a 95% confidence to contrast hypothesis. Results: A total of 122 children were analyzed and distributed into three groups. The electrical muscle activity of masseters was significantly different between the study groups (p < 0.001 for all comparisons). Pairwise comparisons revealed a significantly higher electrical muscle activity in the control group (nasal breathers) during chewing compared to both groups of oral breathers (p < 0.001 for both comparisons). Orthodontic treatment decreased electrical muscle activity during isometric contraction in oral breathers compared to nasal breathers (p < 0.001), but did not significantly affect electrical muscle activity during chewing. Higher decompensation values were obtained in oral breathers without previous orthodontic treatment compared the other study groups (p < 0.001 for both comparisons), although electrical muscle activity values were similar in both groups of oral breathers (p > 0.05 for both comparisons). Conclusions: Differences in electrical muscle activity between nasal and oral breathers can be confirmed. Oral breathers with and without orthodontic treatment showed lower electrical muscle activity of masseters during chewing than nasal breathers, while at isometric contraction, only oral breathers with previous orthodontic treatment showed lower electrical activity. Higher decompensation values were found in oral breathers without previous orthodontic treatment, in comparison to the control group and oral breathers with previous orthodontic treatment.
The Role of Repeated Surgical Resections for Recurrent Brain Metastases in Older Population
Authors: Goldberg Maria , Heinrich Valeri , Altawalbeh Ghaith , Negwer Chiara , Wagner Arthur , Gempt Jens , Meyer Bernhard , Aftahy Amir Kaywan
Published: September 2024

Background and Objectives: The impact of surgery for recurrent brain metastases in elderly patients has been the object of debate due to limited information in the literature. We analyzed clinical outcome and survival of elderly patients with recurrent brain metastases in order to assess potentially beneficial role of surgery. Materials and methods: In total, 219 patients with recurrent brain metastases between 2007 and 2022 were identified, of which 95 underwent re-resection; 83 patients aged 65 and older were analyzed. A survival analysis was performed, and clinical outcomes were evaluated. Results: The median survival time after surgery for recurrent brain metastases was 6 months (95CI 4–10) in older patients and 8 (95CI 7–9) in younger patients (p = 0.619). Out of all the older patients, 33 who underwent surgical resection showed prolonged survival compared with patients who did not receive surgical resection (median: 14, 95CI 8–19 vs. 4, 95CI 4–7, p = 0.011). All patients had preoperative Karnofsky performance scores of >70, which did not deteriorate after surgery (87.02 ± 5.76 vs. 85 ± 6.85; p = 0.055). In the univariate analysis, complete cytoreduction was a favorable prognostic factor. The tumor volume, the number of metastases, extracranial disease progression, adjuvant radiation, and systemic therapy did not affect survival in this cohort. Conclusions: Patients aged 65 and older benefit from neurosurgical resections of recurrent brain metastases. Survival did not differ from that in younger patients, which can be explained by a better preoperative functional status. Moreover, independent of the extent of resection, older patients who underwent surgery showed better survival than patients who did not receive surgical treatment. Complete cytoreduction was a favorable prognostic marker.
Current Diagnostic and Therapeutic Challenges in Superficial Venous Thrombosis
Authors: Balahura Ana-Maria , Florescu Adrian-Gabriel , Barboi Teodora-Maria , Weiss Emma , Miricescu Daniela , Jurcuț Ciprian , Jinga Mariana , Stanciu Silviu
Published: September 2024

Superficial venous thrombosis (SVT) is a fairly common disorder, characterized by the formation of thrombi inside superficial veins, with or without an associated inflammatory reaction. Its evolution is frequently self-limited. However, serious complications may change this clinical course with extension to deep vein thrombosis (DVT) and pulmonary embolism (PE). SVT shares similar risk factors with DVT and is frequently associated with the presence of varicose veins. However, the occurrence of non-varicose veins could conceal risk factors such as malignancies, thrombophilia, or Buerger’s disease. While the clinical diagnosis is generally straightforward, additional diagnostic evaluations are often necessary. Duplex ultrasound (DUS) is an invaluable tool that provides the location of SVT, the proximity to the sapheno–femoral junction, and the clot length, all of which influence the decision for optimal management. The treatment of SVT should be symptomatic, pathogenic (limiting the extension of thrombosis), and prognostic (to prevent complications). There are several guidelines that provide recommendations, and despite the need for more consensus and for further studies, the treatment of SVT should be mainly medical, including anticoagulation in specific clinical situations and symptom relief, with invasive treatment in a minority of cases. Initiation, intensity, and length of anticoagulant treatment should be based on the eventual risk of progression to DVT or PE, which can be high, intermediate, or low, based on the location of SVT and the clot length. Our review summarizes the evaluation and proper management of SVT and highlights the importance of a shared decision within the heart team regarding this condition in order to prevent further complications.
Modeling and Vibration Analysis of Carbon Nanotubes as Nanomechanical Resonators for Force Sensing
Authors: Natsuki Jun , Lei Xiao-Wen , Wu Shihong , Natsuki Toshiaki
Published: September 2024

Carbon nanotubes (CNTs) have attracted considerable attention as nanomechanical resonators because of their exceptional mechanical properties and nanoscale dimensions. In this study, a novel CNT-based probe is proposed as an efficient nanoforce sensing nanomaterial that detects external pressure. The CNT probe was designed to be fixed by clamping tunable outer CNTs. By using the mobile-supported outer CNT, the position of the partially clamped outer CNT can be controllably shifted, effectively tuning its resonant frequency. This study comprehensively investigates the modeling and vibration analysis of gigahertz frequencies with loaded CNTs used in sensing applications. The vibration frequency of a partially clamped CNT probe under axial loading was modeled using continuum mechanics, considering various parameters such as the clamping location, length, and boundary conditions. In addition, the interaction between external forces and CNT resonators was investigated to evaluate their sensitivity for force sensing. Our results provide valuable insights into the design and optimization of CNT-based nanomechanical resonators for high-performance force sensing applications.
Recent Advances in Polymer Science and Fabrication Processes for Enhanced Microfluidic Applications: An Overview
Authors: Alexandre-Franco María F. , Kouider Rahmani , Kassir Al-Karany Raúl , Cuerda-Correa Eduardo M. , Al-Kassir Awf
Published: September 2024

This review explores significant advancements in polymer science and fabrication processes that have enhanced the performance and broadened the application scope of microfluidic devices. Microfluidics, essential in biotechnology, medicine, and chemical engineering, relies on precise fluid manipulation in micrometer-sized channels. Recent innovations in polymer materials, such as flexible, biocompatible, and structurally robust polymers, have been pivotal in developing advanced microfluidic systems. Techniques like replica molding, microcontact printing, solvent-assisted molding, injection molding, and 3D printing are examined, highlighting their advantages and recent developments. Additionally, the review discusses the diverse applications of polymer-based microfluidic devices in biomedical diagnostics, drug delivery, organ-on-chip models, environmental monitoring, and industrial processes. This paper also addresses future challenges, including enhancing chemical resistance, achieving multifunctionality, ensuring biocompatibility, and scaling up production. By overcoming these challenges, the potential for widespread adoption and impactful use of polymer-based microfluidic technologies can be realized.
Surface Chemistry and Flotation of Gold-Bearing Pyrite
Authors: Özçelik Seda , Ekmekçi Zafir
Published: September 2024

Gold grains are observed in a variety of forms, such as coarse-liberated native gold grains, and ultra-fine grains associated with sulfide or non-sulfide mineral particles, in the form of solid solution in sulfide minerals, mainly pyrite. In the flotation of gold ores, bulk sulfide mineral flotation is generally applied to maximize gold recovery. This approach gives high gold recoveries, but it also causes the recovery of barren sulfide minerals (i.e., sulfide mineral particles with no gold content), which increases concentrate tonnage and transportation costs and reduces the grade sometimes to below the saleable limit (approx. 10 g/t Au). This study addresses the differences between gold-bearing and barren pyrite particles taken from various ore deposits and utilizes these differences for the selective flotation of gold-bearing pyrite. The laboratory scale flotation tests conducted on three pyrite samples having different cyanide soluble gold contents show that a selective separation between gold-bearing pyrite and barren pyrite particles could be achieved under specific flotation conditions. Gold recovery is correlated directly with the cyanide-soluble gold in the ore samples. Electrochemical experiments were conducted to elucidate the differences in surface properties of the two types of pyrite. The barren pyrite particles were more cathodic and prone to cathodic reduction of OH− and depressant ions on the surface, and they could be depressed effectively without significantly affecting the gold-bearing particles.
Recycling of Au during Serpentinization of Ultramafic Rocks: A Case Study from Neoproterozoic Forearc Ophiolites, Egypt
Authors: Zoheir Basem , Holzheid Astrid , Diab Aliaa , Ragab Azza , Deshesh Fatma , Abdelnasser Amr
Published: September 2024

Gold, along with other highly siderophile elements, is hosted by Fe-Ni sulfide phases within peridotites and mantle melts. In this context, the lithospheric mantle emerges as a principal reservoir, providing materials crucial for the inception, augmentation, conveyance, and genesis of auriferous CO2-rich mantle fluids. EPMA and laser ablation ICP-MS data, integrated with petrographic and SEM studies, were used to assess the transfer of base and precious metals into the Earth’s crust, discerning between inputs from subduction-related processes and post-formation metasomatism. The study focuses on sulfide minerals in serpentinized peridotites of the Abu Dahr ophiolite in the Eastern Desert of Egypt. Originating in a supra-subduction setting during the Neoproterozoic era, the Abu Dahr peridotites underwent serpentinization and contain discrete sulfide minerals, including pentlandite, nickeloan pyrrhotite, millerite, chalcopyrite, and violarite. The uneven distribution of calcite ± magnesite ± serpentine veins throughout the host ophiolitic rocks reflects the intricate interplay of serpentinization and carbonation, as fO2 and fCO2 conditions fluctuated. Geochemical data of the host rocks reveal a progressive geochemical evolution marked by concurrent silicification and carbonate alteration, driven by the interaction of ultramafic rocks with hydrothermal fluids, ultimately leading to the extensive silicification and formation of birbirite. The ICP-MS data show that pentlandite contains up to 6.11 ppm of Au, pyrrhotite up to 0.41 ppm, millerite 0.34 ppm, and violarite 0.12 ppm. The gold concentration in pentlandite is significantly higher than in pyrrhotite, millerite, and violarite, which exhibit lower but detectable levels of Au. Desulfurization reactions of sulfide minerals during progressive serpentinization triggered the release and redistribution of Au as well as base metals and highly siderophile elements. Published thermodynamic modeling at temperatures below 300 °C and pressures of 50 MPa closely replicates the mineral assemblage observed in the Abu Dahr ophiolites, including sulfide assemblages and variations in major elements such as Mg and Fe. This suggests that the serpentinization process, along with associated hydrothermal fluids, played a crucial role in the mobilization and redistribution of gold, particularly affecting its incorporation into secondary sulfides. The mobilization of Au and other highly siderophile elements during serpentinization occurred in an environment marked by strong oxidation, as indicated by the presence of acicular antigorite, magnetite, millerite, and goethite intergrowths.
Characteristics of Micropore-Throat Structures in Tight Oil Reservoirs: A Case Study of the Jiufotang Formation in the Houhe Region, NE China
Authors: Zhang Guolong , Ma Chenglong
Published: September 2024

In order to examine further the characteristics of micropore-throat structures of the tight oil reservoir in the Jiufotang Formation in the Houhe region, this study used whole rock X-ray diffraction, routine physical property analysis, and routine thin section observations to analyze the material composition and physical properties of the tight oil reservoir. CT scanning, high-pressure mercury infiltration, and other test methods were employed to analyze the characteristics of the pore-throat structures in the tight oil reservoir. In addition, the Pearson correlation coefficients quantified the relationships between nine parameters and pore-throat structures. The parameters with high correlations were optimized for analysis, and a comprehensive classification scheme for micropore-throat structures in the tight oil reservoir in the study area was established. The results show that the reservoir in the Jiufotang Formation in the Houhe region is composed of feldspathic and lithic arkosic sandstone, with feldspar and clast pore dissolution pores as the main type of reservoir pore space. The tight oil reservoir has small pore-throat radius, complex structures, poor connectivity, and high heterogeneity. It generally contains micron-sized pores with submicron to nanometer throat widths and small- and medium-sized pores to fine micropore-throat structures. Porosity, permeability, coefficient of variation, skewness coefficient, and average pore-throat radius, were selected for k-means cluster analysis. The micropore-throat structures of the tight oil reservoir were divided into three categories: classes I, II, and III. The study area is dominated by class II pore throats, accounting for 58%. Diagenesis mainly controls the pore-throat structure. These results provide an effective reference for the identification and evaluation of favorable sweet spots in tight oil reservoirs in similar blocks in China.
Study of the Chemical Recovery and Selectivity against U in the Radiochemical Separation of Th with Tri-n-butyl Phosphate by Varying the Proportion of Xylene and HCl Concentration
Authors: Expósito-Suárez Víctor Manuel , Suárez-Navarro José Antonio , Benavente José Francisco
Published: September 2024

Thorium is a radionuclide used in various environmental studies such as dating, sediment movement, soil–plant transfer studies, and contamination of waste from the natural fuel cycle. The liquid–liquid extraction method using tri-n-butyl phosphate (TBP) allows for the separation of Th from the accompanying actinides. However, the separation of Th and U present in the same sample is not trivial. This separation is influenced by the starting acid (HCl or HNO3), the concentration of TBP in an organic solvent, and the concentration of the acid used for re-extracting Th, which is typically HCl. Therefore, it is necessary to study these factors to ensure that the method has sufficient chemical yield and selectivity in complex matrices. This study presents a systematic investigation of the aforementioned parameters, making the necessary variations to select an optimal method for the radiochemical separation of Th. The ideal conditions were obtained using 4 M HCl as the acid prior to extraction, a 1:4 solution of TBP in xylene, and 4 M HCl as the re-extracting agent. The accuracy and precision were studied in four intercomparison exercises conducted in quadruplicate, using the parameters Enumbers, RB(%), and RSD(%) for 232Th and 230Th. The sensitivity of the method was experimentally studied and the limit of detection (LoD) was determined according to ISO 11929:2005. Additionally, the linearity of the method showed that the experimental and theoretical activity concentrations of 232Th and 230Th had slopes of 1 with an intercept close to 0.
Characterization and Cytotoxic Assessment of Bis(2-hydroxy-3-carboxyphenyl)methane and Its Nickel(II) Complex
Authors: Ahmed Ayman H. , Althobaiti Ibrahim O. , Alenezy Ebtsam K. , Asiri Yazeed M. , Ghalab Sobhy , Hussein Omar A.
Published: September 2024

A condensation reaction of salicylic acid with formaldehyde in the presence of sulfuric acid led to the synthesization of the bis(2-hydroxy-3-carboxyphenyl)methane (BHCM) ligand, which was subsequently allowed to bind with nickel (II) ions. In light of the information obtained from the elemental analyses (C, H, and M), spectral (IR, MS, 1H-NMR, and UV–Vis) and thermal and magnetic measurements, the most likely structures of the ligand and complex have been identified. It has been suggested that the BHCM coordinates in a tetradentate manner with two Ni(II) ions to produce an octahedral binuclear complex. The SEM and TEM morphology of the compounds showed spherical shapes. An X-ray diffraction analysis indicated a considerable difference in the diffraction patterns between BHCM (crystalline) and Ni–BHCM (amorphous), and the Scherrer equation was used to calculate the crystallite size. Some optical characteristics were estimated from UV–Vis spectra. The ligand and its nickel(II) complex underlie the range of semiconductors. It was verified that for human lung (A-549) cancer, the BHCM compound displayed a significant barrier to the proliferation test in noncancerous cells (human lung fibroblasts, WI-38), which was also undertaken. To demonstrate the binding affinities of the chosen compounds (BHCM and Ni–BHCM) in the receptor protein’s active site [PDB ID: 5CAO], a molecular docking (MD) study was carried out.
Insights into the Mechanisms of Single-Photon and Two-Photon Excited Surface Enhanced Fluorescence by Submicrometer Silver Particles
Authors: Wang Yan , Zhang Feng , Du Zaifa , Fan Xinmin , Huang Xiaodong , Zhang Lujun , Li Sensen , Liu Zhaohong , Wang Chunyan
Published: September 2024

Surface enhanced fluorescence (SEF) based on noble metal nanoparticles is an effective means to achieve high sensitivity in fluorescence detection. Currently, the physical mechanism behind enhanced fluorescence is not fully understood. This paper measures the fluorescence signals of Dihydroporphyrin f methyl ether (CPD4) under both single-photon and two-photon excitation based on submicrometer silver particles with rough morphologies, achieving enhancement factors of 34 and 45 times, respectively. On this basis, by combining the radiative field characteristics produced by the silver particles, a stimulated radiation model of molecules is established to elucidate the changes in the molecular photophysical process when influenced by silver particles. Moreover, the fluorescence lifetime of the molecules was measured, showing that the presence of silver particles induces an increase in the molecular radiative decay rate, causing the fluorescence lifetime to decay from 3.8 ns to 3 ns. The results indicate that the fluorescence enhancement primarily originates from the submicrometer silver particles’ enhancement effect on the excitation light. Additionally, the fluorescence signal emitted by the molecules couples with the silver particles, causing the local surface plasmon resonances generated by the silver particles to also emit light signals of the same frequency. Under the combined effect, the fluorescence of the molecules is significantly enhanced. The findings provide a theoretical foundation for understanding the fluorescence enhancement mechanism of silver particles, adjusting the enhancement effect, and developing enhanced fluorescence detection devices based on submicrometer silver particles, holding significant practical importance.
Comprehensive Utilization of Formation Water Scale to Prepare Controllable Size CaCO3 Nanoparticles: A New Method to Improve Oil Recovery
Authors: Huang Bo , Hou Shengzhen , Hua Zhao , Zhang Jian , Yang Huan , Zhu Yuejun , Tang Yumiao , Wang Benru
Published: September 2024

Formation water scale blocks pipelines and results in oil/gas production decreasing and energy consumption increasing. Many methods have been developed to inhibit scale formation. However, these previous methods are limited by their complications and low efficiency. A new method is proposed in this paper that uses the scale in formation water as a nanomaterial to improve oil recovery via controlling particle size. A series of ligands were synthesized and characterized. Micrometer-CaCO3 was formed and accumulated to form scale of a large size under uncontrolled conditions. The tetradentate ligands (L4) exhibited an excellent capturing yield of Ca2+ (87%). The particle size was very small, but they accumulated to form large particles (approximately 1300 nm) in the presence of Na2CO3. The size of the CaCO3 could be further controlled by poly(aspartic acid) to form sizes of about 700 nm. The flooding test showed that this material effectively improved oil recovery from 55.2% without nano CaCO3 to 61.5% with nano CaCO3. This paves a new pathway for the utilization of Ca2+ in formation water.
The Influence of Silver-Containing Bionanomaterials Based on Humic Ligands on Biofilm Formation in Opportunistic Pathogens
Authors: Zykova Maria V. , Karpova Maria R. , Zhang Yu , Chubik Marianna V. , Shunkova Daria M. , Azarkina Lyudmila A. , Mihalyov Dmitrii A. , Konstantinov Andrey I. , Plotnikov Evgenii V. , Pestryakov Alexey N. , Perminova Irina V. , Belousov Mikhail V.
Published: September 2024

The uncontrolled use of antibiotics has led to a global problem of antimicrobial resistance. One of the main mechanisms of bacterial resistance is the formation of biofilms. In order to prevent the growth of antimicrobial resistance, it is crucial to develop new antibacterial agents that are capable of inhibiting the formation of biofilms. This makes this area of research highly relevant today. Promising candidates for these antibacterial agents are new bionanomaterials made from natural humic substances and silver nanoparticles. These substances have the potential to not only directly kill microorganisms but also penetrate biofilms and inhibit their formation. The goal of this study is to synthesize active pharmaceutical substances in the form of bionanomaterials, using ultradispersed silver nanoparticles in a matrix of coal humic substances, perform their characterization (NMR spectroscopy, TEM, and ICP-AES methods), and research their influence on biofilm formation in the most dangerous opportunistic pathogens (E. coli, Methicillin-resistant St. Aureus, K. pneumoniae, P. aeruginosa, St. aureus, A. baumannii, and K. Pneumonia). The results showed that all of the studied bionanomaterials had antibacterial activity against all of the opportunistic pathogens. Furthermore, they were found to have a suppressive effect on both pre-existing biofilms of these bacteria and their formation.
Hunger, Satiety, and Their Vulnerabilities
Authors: Stevenson Richard J. , Boutelle Kerri
Published: September 2024

The psychological states of hunger and satiety play an important role in regulating human food intake. Several lines of evidence suggest that these states rely upon declarative learning and memory processes, which are based primarily in the medial temporal lobes (MTL). The MTL, and particularly the hippocampus, is unusual in that it is especially vulnerable to insult. Consequently, we examine here the impact on hunger and satiety of conditions that: (1) are central to ingestive behaviour and where there is evidence of MTL pathology (i.e., habitual consumption of a Western-style diet, obesity, and anorexia nervosa); and (2) where there is overwhelming evidence of MTL pathology, but where ingestive behaviour is not thought central (i.e., temporal lobe epilepsy and post-traumatic stress disorder). While for some of these conditions the evidence base is currently limited, the general conclusion is that MTL impairment is linked, sometimes strongly, to dysfunctional hunger and satiety. This focus on the MTL, and declarative learning and memory processes, has implications for the development of alternative treatment approaches for the regulation of appetite.
No Difference between the Efficacy of High-Nitrate and Low-Nitrate Vegetable Supplementation on Blood Pressure after 16 Weeks in Individuals with Early-Stage Hypertension: An Exploratory, Double-Blinded, Randomized, Controlled Trial
Authors: Li Dandan , Jovanovski Elena , Zurbau Andreea , Sievenpiper John , Milicic Davor , El-Sohemy Ahmed , Vuksan Vladimir
Published: September 2024

Dietary inorganic nitrate lowers blood pressure (BP) in healthy individuals through improved nitric oxide (NO) bioavailability. However, there is limited evidence examining the long-term effects of dietary nitrate for managing hypertension. We aimed to determine whether the sustained intake of dietary nitrate improved BP and cardiovascular disease (CVD) risk factors in individuals with early-stage hypertension. The Dietary Nitrate (NO3) on BP and CVD Risk Factors (DINO3) Trial was a multi-center, double-blinded, parallel, randomized, controlled trial in participants with elevated BP. Participants were supplemented with high-nitrate (HN) (~400 mg nitrate) or low-nitrate (LN) vegetable powder (~50 mg nitrate) on top of their usual diets for 16 weeks. The primary outcome was office systolic BP at 16 weeks. The secondary outcomes were 24 h ambulatory BP, central BP, heart-rate-corrected augmentation index (AIx75), carotid–femoral pulse wave velocity (cf-PWV), lipids, and high-sensitivity C-reactive protein (hs-CRP). Sixty-six participants were randomized at baseline (39M:27F, age: 51.5 ± 10.8 years, BMI:27.9 ± 3.2 kg/m2). In an intention-to-treat analysis, no differences were observed between HN and LN groups in terms of office systolic BP at 16 weeks (3.91 ± 3.52 mmHg, p = 0.27) or secondary outcomes. In this exploratory study, sustained HN vegetable supplementation did not exhibit more favorable vascular effects than LN vegetable supplementation in individuals with elevated BP.