bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementation of Portable Digital Chest X-ray Machine for Tuberculosis Contact Tracing in Oyo and Osun States, Nigeria: A Formative Assessment
Authors: Dakum Patrick , Agbaje Aderonke , Daniel Olugbenga , Anyaike Chukwuma , Chijoke-Akaniro Obioma , Okpokoro Evaezi , Akingbesote Samuel , Anyomi Christian , Adekunle Adekola , Alege Abiola , Gbadamosi Moroof , Babalola Olutunde , Mensah Charles , Eneogu Rupert , Ihesie Austin , Nongo Debby , Adelekan Ademola
Published: August 2024

This paper presents a formative assessment for the implementation of mobile portable chest X-ray (PDX) machines for tuberculosis (TB) contact tracing in the Oyo and Osun states, Nigeria. This descriptive qualitative study was carried out in eight local government areas, and 24 focus group discussions and 30 key informant interviews were conducted using a four-stage sampling technique to select participants. Validated transcribed notes were entered and analyzed using Nvivo. The respondents’ ages ranged from 17 to 85 years, with a mean age of 42.08 ± 14.9 years, and 4.0% had a postgraduate degree. The majority of government officials stated that deploying the PDX machine for screening at the community level is the best means for implementation because it will offer a level of proximity convenience to the TB contacts and assuage concerns about the cost of transportation to the health facility. In addition, it was suggested that TB community screening should be carried out with screening for other health conditions such as high blood pressure and diabetes. This portable X-ray machine intervention, therefore, should be implemented at the community level for contact tracing to allow more TB contacts living with the index patient to be screened without proximity and transportation constraints.
Starvation and Inflammation Modulate Adipose Mesenchymal Stromal Cells’ Molecular Signature
Authors: Piccolo Simona , Grieco Giulio , Visconte Caterina , De Luca Paola , Taiana Michela , Zagra Luigi , Ragni Enrico , de Girolamo Laura
Published: August 2024

Mesenchymal stromal cells (MSCs) and their released factors (secretome) are intriguing options for regenerative medicine approaches based on the management of inflammation and tissue restoration, as in joint disorders like osteoarthritis (OA). Production strategy may modulate cells and secretome fingerprints, and for the latter, the effect of serum removal by starvation used in clinical-grade protocols has been underestimated. In this work, the effect of starvation on the molecular profile of interleukin 1 beta (IL1β)-primed adipose-derived MSCs (ASCs) was tested by assessing the expression level of 84 genes related to secreted factors and 84 genes involved in defining stemness potential. After validation at the protein level, the effect of starvation modulation in the secretomes was tested in a model of OA chondrocytes. IL1β priming in vitro led to an increase in inflammatory mediators’ release and reduced anti-inflammatory potential on chondrocytes, features reversed by subsequent starvation. Therefore, when applying serum removal-based clinical-grade protocols for ASCs’ secretome production, the effects of starvation must be carefully considered and investigated.
Perioperative Modulation of Left Ventricular Systolic Performance: A Retrospective Study on Ionized Calcium and Vitamin D in Cardiac Surgery Patients
Authors: Ștef Adrian , Bodolea Constantin , Bocșan Ioana Corina , Achim Alexandru , Tintiuc Nadina , Pop Raluca Maria , Solomonean Aurelia Georgeta , Manea Alexandru , Buzoianu Anca Dana
Published: August 2024

Background: The perioperative impact of calcium and vitamin D on left ventricular (LV) performance during major cardiac surgery remains unexplored. We aimed to assess the relation of calcium and vitamin D measured at different time points with the LV ejection fraction (EF), and to investigate whether changes in EF correlate with postoperative outcomes. Methods: We enrolled 83 patients, in whom ionized calcium was measured before, during, and after surgery (until discharge), vitamin D preoperatively, and EF pre- and postoperatively at 24 h. The postoperative outcomes were cardiopulmonary bypass (CPB) time, aortic cross-clamp time, mechanical ventilation time, vasoactive inotropic score (VIS) (intraoperative, day 0, day 1), and ICU stay time. Results: The mean age was 64.9 ± 8.5 years, with 21 of the patients (25%) having an EF < 50%. The median change from preoperative to postoperative EF was −2.0 (−10.0–0.0) % (p < 0.001). At the baseline, the EF < 50% group had significantly lower preoperative vitamin D levels than the EF ≥ 50% group (p = 0.048). The calcium trend did not differ across the groups. Preoperative EF was significantly associated with CPB time (r = 0.22, p = 0.044) and aortic cross-clamp time (r = 0.24, p = 0.031). Postoperative EF was significantly and inversely associated with intraoperative VIS (r = −0.28, p = 0.009), VIS day 0 (r = −0.25, p = 0.020), VIS day 1 (r = −0.23, p = 0.036), and ICU length of stay (r = −0.22, p = 0.047). Finally, the change in ejection fraction was significantly and inversely associated with CPB time (r = −0.23, p = 0.037), aortic cross-clamp time (r = −0.22, p = 0.044), intraoperative VIS (r = −0.42, p < 0.001), VIS day 0 (r = −0.25, p = 0.024), mechanical ventilation time (r = −0.22, p = 0.047), and ICU length of stay (r = −0.23, p = 0.039). Conclusions: The fluctuations in perioperative ionized calcium levels were not associated with the evolution of LVEF, although preoperative vitamin D levels may affect those with low EF. Correspondingly, a reduced EF significantly impacted all the studied postoperative outcomes. Further investigation into biomarkers affecting cardiac inotropic function is warranted to better understand their significance.
Targeted Screening for Cancer: Learnings and Applicability to Melanoma: A Scoping Review
Authors: Zheng Lejie , Smit Amelia K. , Cust Anne E. , Janda Monika
Published: August 2024

This scoping review aims to systematically gather evidence from personalized cancer-screening studies across various cancers, summarize key components and outcomes, and provide implications for a future personalized melanoma-screening strategy. Peer-reviewed articles and clinical trial databases were searched for, with restrictions on language and publication date. Sixteen distinct studies were identified and included in this review. The studies’ results were synthesized according to key components, including risk assessment, risk thresholds, screening pathways, and primary outcomes of interest. Studies most frequently reported about breast cancers (n = 7), followed by colorectal (n = 5), prostate (n = 2), lung (n = 1), and ovarian cancers (n = 1). The identified screening programs were evaluated predominately in Europe (n = 6) and North America (n = 4). The studies employed multiple different risk assessment tools, screening schedules, and outcome measurements, with few consistent approaches identified across the studies. The benefit–harm assessment of each proposed personalized screening program indicated that the majority were feasible and effective. The establishment of a personalized screening program is complex, but results of the reviewed studies indicate that it is feasible, can improve participation rates, and screening outcomes. While the review primarily examines screening programs for cancers other than melanoma, the insights can be used to inform the development of a personalized melanoma screening strategy.
Comparative Study between Mechanical Rotational Atherectomy Combined with Drug-Coated Balloon versus Drug-Coated Balloon Alone for Treatment of In-Stent Restenosis during Peripheral Endovascular Interventions: A Multicentric Trial
Authors: Ali Mohamed , Noureldin Mohamed , Elokda Amr , Tawfik Ahmed
Published: August 2024

Purpose: To compare the efficacy and safety of percutaneous mechanical debulking (PMD) using mechanical rotational atherectomy combined with paclitaxel drug-coated balloon (DCB) versus using paclitaxel DCB alone in the treatment of in-stent restenosis. Material and Methods: This is a multicentric retrospective observational study conducted over a period of 2 years from 2020 to 2022. The study included 49 patients presented with chronic limb-threatening ischemia (CLTI) associated with in-stent restenosis, either acute (<14 days), subacute (<3 months) or chronic (>3 months). The enrolled patients underwent endovascular revascularization using either PMD combined with paclitaxel DCB or paclitaxel DCB only. They were followed up for 6 months after the intervention clinically and by duplex evaluation. Results: The lesion length was about 14.2 mm in the group treated by PMD+ DCB and 9.3 mm in the group treated by DCB alone. The technical success rate was the same between the two groups. However, the follow-up after 6 months showed that patencies for PMD + DCB and DCB alone were 15 (68.2%) patients and 15 (55.6%) patients, respectively (significant p value = 0.028). Procedural-related complications for PMD + DCB are distal embolization (9%) of cases and no vessel perforation. Regarding the candidates who were treated by DCB alone, there were minor groin hematomas (11.1%), distal arterial thrombosis (11.1%) and contrast-induced nephropathy (CIN) (11.1%) cases. Conclusion: The endovascular management of in-stent restenosis using percutaneous mechanical debulking (PMD) in conjunction with paclitaxel drug-coated balloon (DCB) showed that PMD combined with DCB is a safe and effective modality for achieving recanalization. It gives a satisfactory outcome in terms of technical success, freedom from clinically driven target lesion revascularization rate (CD-TLR) and mortality. Despite these promising results, further research with a large enrolled population may be required to determine the cost/benefit.
Anti-Cataract Effect of the Traditional Aqueous Extract of Yerba Mate (Ilex paraguariensis A. St.-Hil.): An In Ovo Perspective
Authors: Oncu Seyma , Becit-Kizilkaya Merve , Bilir Abdulkadir , Saritas Alperen , Arikan-Soylemez Evrim Suna , Koca Halit Bugra , Firat Fatma , Ugur-Kaplan Afife Busra , Yilmaz Mustafa Abdullah
Published: August 2024

Introduction: The therapeutic effect of different doses of the traditional aqueous extract of dried leaves of yerba mate (Ilex paraguariensis A. St.-Hil.) was investigated in an experimental cataract model in chicken embryos. Methods and Results: LC-MS/MS analysis allowed the identification and quantification of 53 metabolites. In the hydrocortisone-induced cataract model, lenses were examined morphologically after treatment and parameters related to oxidative stress (total antioxidant/oxidant status (TAS/TOS), glutathione (GSH), and malondialdehyde (MDA)) were evaluated. Antiproliferative cell nuclear antigen (PCNA) and caspase-3 H-scores were determined and crystallin alpha A (CRYAA) gene expression in the lenses was measured by RT-PCR. The degree of cataract decreased in all treatment groups. While there was no significant difference in TAS levels compared to the negative control, TOS, GSH, and MDA levels were dose-dependently regulated. Treatment groups other than the high-dose group regulated the decrease in PCNA and the increase in caspase-3. CRYAA gene expression increased significantly only at the lowest dose. Conclusion: YM, which is becoming increasingly popular as a traditional tea, showed a therapeutic effect on hydrocortisone-induced cataracts in chicken embryos at relatively low doses.
Adversarial Training Based Domain Adaptation of Skin Cancer Images
Authors: Gilani Syed Qasim , Umair Muhammad , Naqvi Maryam , Marques Oge , Kim Hee-Cheol
Published: August 2024

Skin lesion datasets used in the research are highly imbalanced; Generative Adversarial Networks can generate synthetic skin lesion images to solve the class imbalance problem, but it can result in bias and domain shift. Domain shifts in skin lesion datasets can also occur if different instruments or imaging resolutions are used to capture skin lesion images. The deep learning models may not perform well in the presence of bias and domain shift in skin lesion datasets. This work presents a domain adaptation algorithm-based methodology for mitigating the effects of domain shift and bias in skin lesion datasets. Six experiments were performed using two different domain adaptation architectures. The domain adversarial neural network with two gradient reversal layers and VGG13 as a feature extractor achieved the highest accuracy and F1 score of 0.7567 and 0.75, respectively, representing an 18.47% improvement in accuracy over the baseline model.
Using a Model Created Using a 3D Printer to Mould a Grey Cast Iron Casting
Authors: Ráž Karel , Chval Zdeněk , Kořínek Jiří
Published: August 2024

This article deals with the possibility of using 3D-printed models as an input for the production of a mould for cast iron castings. This new progressive process is significantly faster (with sufficient accuracy) compared to the current way of making models for moulds. The need to create a wooden model is removed by this process. The quality of this wooden model was highly dependent on the experience and qualifications of the worker. This article describes the manufacturing process of the model and mould in detail. The key dimensions of the final parts are compared with the model and, thus, the accuracy of the chosen procedure is verified. A 3D-printing technology known as Multi Jet Fusion (MJF) was used to produce the model. The material used for the production of the model is polyamide PA12 with 40% glass fibre filling. This material has sufficient structural and strength properties to be used for the given application. Taking into account the dimensions of the part and the printing space of the printer, it was necessary to structurally modify and divide the part. The inlet cone of a turbine is used as an example This cone is produced from grey cast iron as standard.
Atomistic Insights into Impact-Induced Energy Release and Deformation of Core–Shell-Structured Ni/Al Nanoparticle in an Oxygen Environment
Authors: Zhu Kexin , Xie Yifan , Shao Jian-Li , Chen Pengwan
Published: August 2024

In actual atmospheric environments, Ni/Al composites subjected to high-velocity impact will undergo both intermetallic reaction and oxidative combustion simultaneously, and the coupling of mechanical and multiple chemical processes leads to extremely complex characteristics of energy release. This work employs ReaxFF molecular dynamics simulations to investigate the impact-induced deformation and energy release of a core–shell-structured Ni/Al nanoparticle in an oxygen environment. It was found that Al directly undergoes fragmentation, while Ni experiences plastic deformation, melting, and fragmentation in sequence as the impact velocity increased. This results in the final morphology of the nanoparticles being an ellipsoidal-clad nanoparticle, spherical Ni/Al melt, and debris cloud. Furthermore, these deformation characteristics are strongly related to the material property of the shell, manifested as Ni shell–Al core particle, being more prone to breakage. Interestingly, the dissociation phenomenon of Ni–Al–O clusters during deformation is observed, which is driven by Ni dissociation and Al oxidation. In addition, the energy release is strongly related to the deformation behavior. When the nanoparticle is not completely broken (Ni undergoes plastic deformation and melting), the energy release comes from the oxidative combustion of Al fragments and the intermetallic reaction driven by atomic mixing. When the nanoparticle is completely broken, the energy release mainly comes from the oxidative combustion of the debris cloud. At the same time, the promoting effect of oxygen concentration on the energy release efficiency is examined. These findings can provide atomic insights into the regulation of impact-induced energy release for reactive intermetallic materials.
CO2 Sorption on Ti-, Zr-, and [Ti,Zr]-Pillared Montmorillonites
Authors: Klimek Agnieszka , Gaweł Adam , Górniak Katarzyna , Tomczyk-Chmiel Anna , Serwicka Ewa M. , Bahranowski Krzysztof
Published: August 2024

Montmorillonite is a layered clay mineral whose modification by pillaring, i.e., insertion of oxide nanoclusters between the layers, yields porous materials of great potential in sorption and catalysis. In the present study, an unrefined industrial bentonite from Kopernica (Slovakia), containing ca. 70% of montmorillonite, was used for the preparation of Ti-, Zr-, and mixed [Ti,Zr]-pillared clay sorbents. The pillared samples were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and N2 adsorption at −196 °C and tested for the capacity of CO2 sorption at 0 °C and 1 bar pressure. The experiments revealed that pillared samples sorbed at least four times more CO2 than the parent bentonite. Of the materials tested, the sample pillared with mixed [Ti,Zr] oxide props showed the best performance, which was attributed to its superior microporosity. The results of CO2 adsorption demonstrated that the cost-effective use of crude industrial bentonite as the sorbent precursor is a viable synthesis option. In another experiment, all pillared montmorillonites were subjected to 24 h exposure at room temperature to a flow of dry CO2 and then tested using simultaneous thermal analysis (STA) and the mass spectrometry (MS) analysis of the evolving gases (STA/QMS). It was found that interaction with dry CO2 reduces the amount of bound carbon dioxide and affects the processes of dehydration, dehydroxylation, and the mode of CO2 binding in the pillared structure.
Optimization and Evaluation of Accelerated Corrosion Tests Based on Mechanism Equivalence Principles
Authors: Wei Mumeng , Yao Jinghua , Chen Yufan , Yang Bojun , Chen Dichun , Cai Yikun
Published: August 2024

Conventional indoor corrosion test design methods primarily focus on the rapid evaluation of material corrosion resistance, often neglecting the impact of environmental stress levels on the equivalence of corrosion mechanisms. This study introduces a novel indoor corrosion test design method based on the principle of corrosion mechanism equivalence, aimed at improving the accuracy of indoor accelerated corrosion simulations. We define the characteristic of corrosion mechanism equivalence as the Corrosion Mechanism Equivalence Degree (CMed), which quantifies the similarity between corrosion mechanisms in indoor accelerated tests and field tests. Then, modified conventional link function models are defined, integrating the probability distribution of environmental factors to estimate corrosion model parameters more precisely. Finally, an optimization problem is constructed for accelerated corrosion tests based on CMed, incorporating constraints on environmental stress levels and acceleration factors. A case study demonstrates the proposed method’s ability to accurately simulate the actual service environment of materials, determining the appropriate stress levels for indoor accelerated corrosion tests while ensuring the desired acceleration factor and corrosion mechanism equivalence.
Assessment of Gel-Based Thermochromic Glazing for Energy Efficiency in Architectural Applications
Authors: Zeng Kai , Xue Chang , Wu Jinbo , Wen Weijia
Published: August 2024

With the increasing global focus on energy efficiency and environmental sustainability, intelligent building materials such as thermochromic glazing have emerged as a hot topic of research. The intent of this paper is to explore the utilization of gel-type thermochromic glazing within the realm of architectural energy conservation calculations. It conducts an exhaustive examination of the material’s attributes, its capacity for energy savings, and the obstacles encountered in real-world applications. Through simulation studies and case analyses, this paper assesses the energy efficiency of gel-type thermochromic glazing across various climates and suggests strategies for optimization. The study revealed that the incorporation of gel-based thermochromic glazing leads to a marked reduction in energy usage within buildings, an improvement in indoor comfort levels, and significant environmental advantages.
System-of-Systems Resilience Analysis and Design Using Bayesian and Dynamic Bayesian Networks
Authors: Jiao Tianci , Yuan Hao , Wang Jing , Ma Jun , Li Xiaoling , Luo Aimin
Published: August 2024

A System-of-Systems (SoS) is characterized both by independence and by inter-dependency. This inter-dependency, while allowing an SoS to achieve its objectives, also means that failures can cascade throughout the SoS. An SoS needs to be resilient to deal with the impact of complex internal and external environments. In this paper, we propose a resilience analysis method of an SoS based on a hierarchy structure. Firstly, we establish a hierarchy structure, which is ranked from high to low as capability level, activity level and system level. Then, Bayesian Networks (BNs) and Dynamic Bayesian Networks (DBNs) are used to analyze the resilience of the SoS. A resilience-based system importance metric is introduced, which is used in the budget allocation optimization problem during the development domain of an SoS. This paper proposes a mathematical programming model aimed at optimizing SoS resilience by optimally using budget to the subsystem. The application of the proposed approach is demonstrated using a case study: a Next Generation Air Transportation setting. The study results provide evidence that the proposed inter-dependency analysis based on Bayesian theory and the SoS resilience design approach can assist SoS system engineers in increasing expected SoS resilience during the development domain.
Modeling and Rotation Control Strategy for Space Planar Flexible Robotic Arm Based on Fuzzy Adjustment and Disturbance Observer
Authors: Liu Jiaqi , Li Xiaopeng , Yin Meng , Wei Lai , Wang Haozhe
Published: August 2024

In precise space operation tasks, the impact of disturbing torques on the space flexible robotic arm (SFRA) cannot be ignored. Besides, the slender structure of the SFRA is very likely to generate vibration of the robotic arm. These are all potential hidden dangers in space safety. To quantify the potential risk, an accurate dynamics model of the SFRA considering the disturbing torque is built by Lagrange principle and the assumed modal method (AMM). Moreover, the effects of the disturbing torque, modal order and nonlinear terms on the deformation accuracy of the SFRA are compared. It is observed that the simplified dynamics model with neglecting the nonlinear terms (NNTs) has a high model accuracy and be easily solved. Therefore, the NNTs simplified model is chosen for deriving the transfer function of the SFRA. The parameters of the PI controller are adjusted in real time based on fuzzy rules to reduce the tracking error in the SFRA. In addition, the disturbance observer is designed to observe and compensate of the disturbance torque in the SFRA. The control method of adjusting controller parameters with fuzzy rules based on the disturbance observer greatly improves the rotational control accuracy of the SFRA. Finally, the validity of aforementioned control strategy is confirmed by simulation analysis and experimental results.
A New Renieramycin T Right-Half Analog as a Small Molecule Degrader of STAT3
Authors: Phookphan Preeyaphan , Racha Satapat , Yokoya Masashi , Ei Zin Zin , Hotta Daiki , Zou Hongbin , Chanvorachote Pithi
Published: August 2024

Constitutive activation of STAT3 contributes to tumor development and metastasis, making it a promising target for cancer therapy. (1R,4R,5S)-10-hydroxy-9-methoxy-8,11-dimethyl-3-(naphthalen-2-ylmethyl)-1,2,3,4,5,6-hexahydro-1,5-epiminobenzo[d]azocine-4-carbonitrile, DH_31, a new derivative of the marine natural product Renieramycin T, showed potent activity against H292 and H460 cells, with IC50 values of 5.54 ± 1.04 µM and 2.9 ± 0.58 µM, respectively. Structure–activity relationship (SAR) analysis suggests that adding a naphthalene ring with methyl linkers to ring C and a hydroxyl group to ring E enhances the cytotoxic effect of DH_31. At 1–2.5 µM, DH_31 significantly inhibited EMT phenotypes such as migration, and sensitized cells to anoikis. Consistent with the upregulation of ZO1 and the downregulation of Snail, Slug, N-cadherin, and Vimentin at both mRNA and protein levels, in silico prediction identified STAT3 as a target, validated by protein analysis showing that DH_31 significantly decreases STAT3 levels through ubiquitin-proteasomal degradation. Immunofluorescence and Western blot analysis confirmed that DH_31 significantly decreased STAT3 and EMT markers. Additionally, molecular docking suggests a covalent interaction between the cyano group of DH_31 and Cys-468 in the DNA-binding domain of STAT3 (binding affinity = −7.630 kcal/mol), leading to destabilization thereafter. In conclusion, DH_31, a novel RT derivative, demonstrates potential as a STAT3-targeting drug that significantly contribute to understanding of the development of new targeted therapy.
Impact of Teriparatide and Denosumab on Clinical and Radiographic Outcomes in Osteoporotic Vertebral Compression Fractures
Authors: Kwon Byung-Taek , Ham Dae-Woong , Park Sang-Min , Kim Ho-Joong , Yeom Jin S.
Published: August 2024

Background and Objectives: Osteoporotic vertebral compression fractures (OVCFs) are prevalent among the elderly, often leading to significant pain, morbidity, and mortality. Effective management of underlying osteoporosis is essential to prevent subsequent fractures. This study aimed to compare the clinical and radiographic outcomes of teriparatide and denosumab treatments in patients with OVCFs to determine their relative effectiveness in improving patient outcomes. Materials and Methods: This retrospective study included 78 patients diagnosed with an acute thoracolumbar OVCF who received either teriparatide (35 patients) or denosumab (43 patients) within three months of a fracture. Clinical outcomes were assessed using the visual analog scale (VAS) for back pain, Oswestry disability index (ODI), and EQ-5D quality of life scores at baseline, 6 months, and 12 months. Bone mineral density (BMD) and radiographic outcomes were evaluated initially and at 12 months post-treatment. Results: Both treatment groups demonstrated significant improvements in VAS, ODI, and EQ-5D scores over 12 months. No significant differences were observed between the teriparatide and denosumab groups in terms of clinical outcomes or radiographic measurements at any time point. Fracture union and BMD improvements were similarly observed in both groups. The teriparatide group had a lower baseline BMD, but this did not affect the overall outcomes. Conclusions: Both teriparatide and denosumab are effective in improving clinical and radiographic outcomes in patients with OVCFs. Despite concerns about denosumab’s potential to hinder fracture healing, our study found no significant differences between the two treatments. These findings support the use of denosumab for early treatment of OVCFs to prevent subsequent fractures without compromising fracture healing. Further prospective studies are needed to confirm these results.
Comparative Study of Heat Transfer Simulation and Effects of Different Scrap Steel Preheating Methods
Authors: Xiao Pengcheng , Jin Yuxin , Zhu Liguang , Wang Chao , Zhu Rong
Published: August 2024

The materials charged into a converter comprise molten iron and scrap steel. Adjusting the ratio by increasing scrap steel and decreasing molten iron is a steelmaking raw material strategy designed specifically for China’s unique circumstances, with the goal of lowering carbon emissions. To maintain the converter tapping temperature, scrap must be preheated to provide additional heat. Current scrap preheating predominantly utilizes horizontal tunnel furnaces, resulting in high energy consumption and low efficiency. To address these issues, a three-stage shaft furnace for scrap preheating was designed, and Fluent software was used to compare and study the preheating efficiency of the new three-stage furnace against the traditional horizontal furnace under various operational conditions. Initially, a three-dimensional transient multi-field coupling model was developed for two scrap preheating scenarios, examining the effects of both furnaces on scrap surface and core temperatures across varying preheating durations and gas velocities. Simulation results indicate that, under identical gas heat consumption conditions, scrap achieves markedly higher final temperatures in the shaft furnace compared to the horizontal furnace, with scrap surface and core temperatures increasing notably with extended preheating times and higher gas velocities, albeit with a gradual decrease in heating rate as the scrap temperature rises. At a gas velocity of 9 m/s and a preheating time of 600 s, the shaft furnace achieves the highest waste heat utilization rate for scrap, with scrap averaging 325 °C higher than in the horizontal furnace, absorbing an additional 202 MJ of heat per ton. In the horizontal preheating furnace, scrap steel exhibits a heat absorption efficiency of 35%, whereas in the vertical furnace, this efficiency increases notably to 63%. In the vertical furnace, the waste heat recovery rate of scrap steel reaches 57%.
Full Density Powder Metallurgical Cold Work Tool Steel through Nitrogen Sintering and Capsule-Free Hot Isostatic Pressing
Authors: Nagaram Anok Babu , Maistro Giulio , Adolfsson Erik , Cao Yu , Hryha Eduard , Nyborg Lars
Published: August 2024

Vanadis 4E (V4E) is a powder metallurgical cold work tool steel predominantly used in application with demand for wear resistance, high hardness, and toughness. It is of interest to have a processing route that enables full density starting from clean gas-atomized powder allowing component shaping capabilities. This study presents a process involving freeze granulation of powder to facilitate compaction by means of cold isostatic pressing, followed by sintering to allow for capsule-free hot isostatic pressing (HIP) and subsequent heat treatments of fully densified specimens. The sintering stage has been studied in particular, and it is shown how sintering in pure nitrogen at 1150 °C results in predominantly closed porosity, while sintering at 1200 °C gives near full density. Microstructural investigation shows that vanadium-rich carbonitride (MX) is formed as a result of the nitrogen uptake during sintering, with coarser appearance for the higher temperature. Nearly complete densification, approximately 7.80 ± 0.01 g/cm3, was achieved after sintering at 1200 °C, and after sintering at 1150 °C, followed by capsule-free HIP, hardening, and tempering. Irrespective of processing once the MX is formed, the nitrogen is locked into this phase and the austenite is stabilised, which means any tempering tends to result in a mixture of austenite and tempered martensite, the former being predominate during the sequential tempering, whereas martensite formation during cooling from austenitization temperatures becomes limited.
An Efficient and Stable MXene-Immobilized, Cobalt-Based Catalyst for Hydrogen Evolution Reaction
Authors: Guo Wei , Wang Buxiang , Shu Qing
Published: August 2024

Hydrogen (H2) is considered to be the best carbon-free energy carrier that can replace fossil fuels because of its high energy density and the advantages of not producing greenhouse gases and air pollutants. As a green and sustainable method for hydrogen production, the electrochemical hydrogen evolution reaction (HER) has received widespread attention. Currently, it is a great challenge to prepare economically stable electrocatalysts for the HER using non-precious metals. In this study, a Co/Co3O4/Ti3C2Tx catalyst was synthesized by supporting Co/Co3O4 with Ti3C2Tx. The results show that Co/Co3O4/Ti3C2Tx has excellent HER activity and durability in 1 mol L−1 KOH, and the overpotential and Tafel slope at 10 mA·cm−2 were 87 mV and 61.90 mV dec−1, respectively. The excellent HER activity and stability of Co/Co3O4/Ti3C2Tx can be explained as follows: Ti3C2Tx provides a stable skeleton and a large number of attachment sites for Co/Co3O4, thus exposing more active sites; the unique two-dimensional structure of Ti3C2Tx provides an efficient conductive network for rapid electron transfer between the electrolyte and the catalyst during electrocatalysis; Co3O4 makes the Co/Co3O4/Ti3C2Tx catalyst more hydrophilic, which can accelerate the release rate of bubbles; Co/Co3O4 can accelerate the adsorption and deionization of H2O to synthesize H2. This study provides a new approach for the design and preparation of low-cost and high-performance HER catalysts.
Recent Developments in Mechanical Ultraprecision Machining for Nano/Micro Device Manufacturing
Authors: Olaniyan Tirimisiyu , Faisal Nadimul , Njuguna James
Published: August 2024

The production of many components used in MEMS or NEMS devices, especially those with com-plex shapes, requires machining as the best option among manufacturing techniques. Ultraprecision machining is normally employed to achieve the required shapes, dimensional accuracy, or improved surface quality in most of these devices and other areas of application. Compared to conventional machining, ultraprecision machining involves complex phenomenal processes that require extensive investigations for a better understanding of the material removal mechanism. Materials such as semiconductors, composites, steels, ceramics, and polymers are commonly used, particularly in devices designed for harsh environments or applications where alloyed metals may not be suitable. However, unlike alloyed metals, materials like semiconductors (e.g., silicon), ceramics (e.g., silicon carbide), and polymers, which are typically brittle and/or hard, present significant challenges. These challenges include achieving precise surface integrity without post-processing, managing the ductile-brittle transition, and addressing low material removal rates, among others. This review paper examines current research trends in mechanical ultraprecision machining and sustainable ultraprecision machining, along with the adoption of molecular dynamics simulation at the micro and nano scales. The identified challenges are discussed, and potential solutions for addressing these challenges are proposed.
Numerical and Experimental Approach to Evaluate Microplastic Transport in Saturated Porous Media
Authors: Okutan Hande , Sağır Çağdaş , Kurtuluş Bedri , Özmen Hasan Burak , Pekkan Emrah , Razack Moumtaz , Le Coustumer Philippe
Published: August 2024

Under varying flow rate conditions, the transport and retention of polydisperse microplastics (MPls), with an average particle size of 16 ± 6 µm, were investigated in saturated porous media. First-order reversible and irreversible kinetic sorption models were used to describe the sorption kinetics. Sensitivity analyses provided insight into the effects of each sorption parameter. Both numerical modeling and experimental measurements were utilized to evaluate the retention rates of sand filters. The influence of flow rate on sorption was reflected in variations in the distribution coefficient (Kd), the mass transfer coefficient (β), and the irreversible sorption rate (K1). Lower flow rates were associated with higher Kd and β values, indicating increased sorption and reduced mass transfer rates. An increase in Kd resulted in a more gradual sorption process, with a decrease in peak concentration, whereas changes in β had a comparatively smaller impact on sorption rate and peak concentration. Lower K1 values were linked to higher peak concentrations and decreased retention efficiency. Numerical modeling revealed retention rates of 28 ± 1% at a flow rate of 31 mL min−1 and 17 ± 1% at 65 mL min−1. The introduction of MPls into saturated sand environments modifies the transport dynamics within the medium. Consequently, these alterations affect the hydrological characteristics of porous media, impacting groundwater quality and agricultural output. The mean absolute error (MAE) of 6% between the modeled and observed retention rates indicated a high level of accuracy. This study underscores the importance of examining retention efficiency and the accuracy of numerical models in understanding MPl transport in porous media.
Microplastic Contamination in Field-Side Composting in Geneva, Switzerland (CH)
Authors: Berset Fanny C. D. , Stoll Serge
Published: August 2024

Plastic pollution has become a growing concern for environmental and human health in recent years. Currently, research suggests that soil compartments might be highly contaminated, with compost being one of the major sources for plastic contamination, especially at reduced sizes. In Geneva, microplastic contamination has already been evaluated in industrial compost but not yet in field-side compost. Therefore, this work focuses on the evaluation of concentrations and the characterization of microplastic particles (MPs) in field-side compost in Geneva. Four different field-side composts were sampled in Geneva and sieved with sizes ranging from >5 mm to 0.5 mm. The MPs were visually sorted when possible, and the smaller ones were treated by digestion and density separation processes. All of the MPs were analyzed with infrared spectroscopy. The results (sizes > 5 mm to 1.25 mm) reveal concentrations between 195 ± 64 and 1315 ± 375 plastic particles/kg of compost and the presence of conventional plastics in every compost. MPs were present in almost every size fraction for the four composts, and the origin of waste seemed to influence their concentrations. Indeed, composts free from organic household waste had lower concentrations than the ones accepting that kind of waste. Littering and waste still wrapped in plastic were also noticed for the composts with higher concentrations of MPs. The characterization results highlight the variety of plastic types among the composts, mostly represented by PE (polyethylene), PVA (polyvinyl alcohol), PP (polypropylene), and DAIP (polydiallyl iso-phthalate) in general but also specific contamination by PEMA (poly ethyl methacrylate) for only one of the composts. Further work is needed to evaluate the distribution of MPs according to their size or the types of waste used in composting, especially the potential degrading conditions of plastics, to mitigate their presence in composts.
A Protocol for Electron Probe Microanalysis (EPMA) of Monazite for Chemical Th-U-Pb Age Dating
Authors: Schulz Bernhard , Krause Joachim , Dörr Wolfgang
Published: August 2024

A protocol for the monazite (LREE,Y,Th,U,Si,Ca)PO4 in situ Th-U-Pb dating by electron probe microanalyser (EPMA) involves a suitable reference monazite. Ages of several potential reference monazites were determined by TIMS-U-Pb isotope analysis. The EPMA protocol is based on calibration with REE-orthophosphates and a homogeneous Th-rich reference monazite at beam conditions of 20 kV, 50 nA, and 5 µm for best possible matrix matches and avoidance of dead time bias. EPMA measurement of samples and repeated analysis of the reference monazite are performed at beam conditions of 20 kV, 100 nA, and 5 µm. Analysis of Pb and U on a PETL crystal requires YLg-on-PbMa and ThMz-on-UMb interference corrections. Offline re-calibration of the Th calibration on the Th-rich reference monazite, to match its nominal age, is an essential part of the protocol. EPMA-Th-U-Pb data are checked in ThO2*-PbO coordinates for matching isochrones along regressions forced through zero. Error calculations of monazite age populations are performed by weighted average routines. Depending on the number of analyses and spread in ThO2*-PbO coordinates, minimum errors <10 Ma are possible and realistic for Paleozoic monazite ages. A test of the protocol was performed on two garnet metapelite samples from the Paleozoic metamorphic Zone of Erbendorf-Vohenstrauß (NE-Bavaria, western Bohemian Massif).
Paleopressure during Hydrocarbon Charging and Its Evolution in the Funing Formation of the Gaoyou Sag, Subei Basin, Eastern China
Authors: Li Chunquan , Qian Shiyou , Zheng Yuancai
Published: August 2024

Abnormally high pressures are currently limited and locally developed in the Funing Formation of the Gaoyou Sag, Subei Basin, eastern China, but the paleopressure and its evolutionary history remain unclear. Based on the determination of hydrocarbon charging periods by performing systematic fluid inclusion analysis on sixteen core samples from the Funing Formation, thermodynamic modeling with fluid inclusion data was adopted to reconstruct the paleopressure and redisplay its evolutionary history throughout geological time. Results showed that the Funing Formation experienced two episodes of hydrocarbon charging periods. Episode 1 occurred with the charging of lower maturity oils in the period from 52.8 Ma to 49.5 Ma, which was recorded by yellow-fluorescing oil inclusions. Episode 2 happened with the charging of higher maturity oils in the period from 47.0 Ma to 37.0 Ma, which was characterized by blue-fluorescing oil inclusions. Each episode was an abnormally high-pressured hydrocarbon charging process. The pressure coefficient of Episode 1 reached as high as 1.44, while that of Episode 2 reached as high as 1.40. The current formation pressure is the evolutionary result of paleopressure after a process of rapid increasing and decreasing and slow increasing and is not as high as what it reached during the hydrocarbon charging periods. This work is valuable for the exploration of conventional clastic oil reservoirs and unconventional shale oils in the Funing Formation.
Impact of Changing Inlet Modes in Ski Face Masks on Adolescent Skiing: A Finite Element Analysis Based on Head Models
Authors: Huang Minxin , Zhang Ruiqiu , Zhang Xiaocheng
Published: August 2024

Due to the material properties of current ski face masks for adolescents, moisture in exhaled air can become trapped within the material fibers and freeze, leading to potential issues such as breathing difficulties and increased risk of facial frostbite after prolonged skiing. This paper proposes a research approach combining computational fluid dynamics (CFD) and ergonomics to address these issues and enhance the comfort of adolescent skiers. We developed head and face mask models based on the head dimensions of 15–17-year-old males. For enclosed cavities, ensuring the smooth expulsion of exhaled air to prevent re-inhalation is the primary challenge. Through fluid simulation of airflow characteristics within the cavity, we evaluated three different inlet configurations. The results indicate that the location of the air inlets significantly affects the airflow characteristics within the cavity. The side inlet design (type II) showed an average face temperature of 35.35 °C, a 38.5% reduction in average CO2 concentration within the cavity, and a smaller vortex area compared to the other two inlet configurations. Although the difference in airflow velocity within the cavity among the three configurations was minimal, the average exit velocity differed by up to 0.11 m/s. Thus, we conclude that the side inlet configuration offers minimal obstruction to airflow circulation and better thermal insulation when used in the design of fully enclosed helmets. This enhances the safety and comfort of adolescent wearers during physical activities in cold environments. Through this study, we aim to further promote the development of skiing education, enhance the overall quality of adolescents’ skiing, and thus provide them with more opportunities for the future.
A Novel Synthesis Method of Dumbbell-like (Gd1−xTbx)2O(CO3)2·H2O Phosphor for Latent Fingerprint
Authors: Huang Lei , Qian Jian , Sun Shijian , Li Zheng , Li Dechuan
Published: August 2024

A novel method for synthesizing dumbbell-shaped (Gd1−xTbx)2O(CO3)2·H2O (GOC:xTb3+) phosphors using sodium carbonate was investigated. An amount of 1 mmol of stable fluorescent powder can be widely prepared using 3–11 mmol of Na2CO3 at a pH value of 8.5–10.5 in the reaction solution. The optimal reaction conditions for the phosphors were determined to be 7 mmol for the amount of sodium carbonate and a pH of 9.5 in the solution. Mapping analysis of the elements confirmed uniform distribution of Gd3+ and Tb3+ elements in GOC:xTb3+. The analysis of fluorescence intensity shows that an optimal excitation wavelength of 273 nm is observed when the concentration of Tb3+ is between 0.005 and 0.3. The highest emission intensity was observed for GOC:0.05Tb3+ with a 57.5% maximum quantum efficiency. The chromaticity coordinates show that the color of GOC:Tb3+ is stable and suitable for fluorescence recognition. Latent fingerprint visualization reveals distinctive features like whorls, hooks, and bifurcations. Therefore, the sodium carbonate method offers an effective alternative to traditional urea chemical reaction conditions for preparing GOC:Tb3+.
An Investigation of Novel Series of 2-Thioxo-1,3-dithiol-carboxamides as Potential Antispasmodic Agents: Design, Synthesis via Coupling Reactions, Density Functional Theory Calculations, and Molecular Docking
Authors: Sghyar Riham , Lahyaoui Mouad , Aflak Noura , Moussaoui Oussama , Chda Alae , Bencheikh Rachid , El Hadrami El Mestafa , Sebbar Nada Kheira , Alanazi Ashwag S. , Hefnawy Mohamed
Published: August 2024

This study reports the synthesis of 2-thioxo-1,3-dithiol-carboxamides (TDTCAs) under mild conditions at room temperature using HBTU as a coupling agent, which significantly improved amide bond formation. The synthesized compounds were characterized using several analytical techniques, including 1H and 13C NMR spectroscopy, and HRMS, confirming their intended structures and structural integrity. A DFT computational study at the B3LYP/6-31G(d,p) level was conducted on the four synthesized compounds to compare their electronic properties and molecular structures. The results showed that these compounds demonstrated antispasmodic effects on jejunum contractions. Molecular docking revealed that compounds c and d displayed the highest docking scores on potassium and voltage-gated calcium channels and adrenergic receptors. In summary, compounds c and d exhibit antispasmodic effects, potentially blocking alpha-adrenergic receptors and calcium channels, thus providing a scientific basis for their potential use in treating gastrointestinal disorders.
Low Dielectric Medium for Hyperbolic Phonon Polariton Waveguide in van der Waals Heterostructures
Authors: Noh Byung-Il , Reza Salvio , Hardy Cassie , Li Jiahan , Taba Adib , Mahjouri-Samani Masoud , Edgar James H. , Dai Siyuan
Published: August 2024

Polar van der Waals (vdW) crystals, composed of atomic layers held together by vdW forces, can host phonon polaritons—quasiparticles arising from the interaction between photons in free-space light and lattice vibrations in polar materials. These crystals offer advantages such as easy fabrication, low Ohmic loss, and optical confinement. Recently, hexagonal boron nitride (hBN), known for having hyperbolicity in the mid-infrared range, has been used to explore multiple modes with high optical confinement. This opens possibilities for practical polaritonic nanodevices with subdiffractional resolution. However, polariton waves still face exposure to the surrounding environment, leading to significant energy losses. In this work, we propose a simple approach to inducing a hyperbolic phonon polariton (HPhP) waveguide in hBN by incorporating a low dielectric medium, ZrS2. The low dielectric medium serves a dual purpose—it acts as a pathway for polariton propagation, while inducing high optical confinement. We establish the criteria for the HPhP waveguide in vdW heterostructures with various thicknesses of ZrS2 through scattering-type scanning near-field optical microscopy (s-SNOM) and by conducting numerical electromagnetic simulations. Our work presents a feasible and straightforward method for developing practical nanophotonic devices with low optical loss and high confinement, with potential applications such as energy transfer, nano-optical integrated circuits, light trapping, etc.