bluuebunny/crossref_metadata_2025 huggingface dataset:
Consensus Guidelines on Human Epidermal Growth Factor Receptor 2 (HER2)-Low Testing in Breast Cancer in Malaysia
Authors: Rajadurai Pathmanathan , Ravindran Sarala , Lee Bang Rom , Md Pauzi Suria Hayati , Chiew Seow Fan , Teoh Kean Hooi , S. Raja Gopal Navarasi , Md Yusof Mastura , Yip Cheng Har
Published: June 2024

Breast cancer is one of the most common cancers in Malaysia. Recently, a new nomenclature was introduced for breast cancers with human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) 1+, or 2+ with negative in situ hybridization (ISH), i.e., HER2-low breast cancer. In current clinical practice, these breast cancers are reported as HER2-negative. Clinical trials have shown that HER2-low breast cancer benefits from targeted therapy with anti-HER2 antibody-drug conjugates. Unfortunately, various challenges and obstacles are faced by local pathologists in HER2 testing, which may jeopardize the standard of care for patients with HER2-low breast cancer. This consensus guideline aims to elucidate standard practices pertaining to HER2 testing and HER2-low interpretation in Malaysia. Topics discussed among a panel of local experts include tissue sampling and handling, assay and antibody selection, result interpretation and reporting, and quality assurance. Practice recommendations made in this consensus guideline reflect current international guidelines and, where appropriate, adapted to the Malaysian landscape.
Efficacy of Cisplatin–CXCR4 Antagonist Combination Therapy in Oral Cancer
Authors: Yoshida Saori , Kawai Hotaka , Soe Yamin , Eain Htoo Shwe , Sanou Sho , Takabatake Kiyofumi , Takeshita Yohei , Hisatomi Miki , Nagatsuka Hitoshi , Asaumi Junichi , Yanagi Yoshinobu
Published: June 2024

Cisplatin is a platinum-based compound that is widely used for treating inoperable oral squamous cell carcinoma (OSCC) in Japan; however, resistance to cisplatin presents a challenge and innovative approaches are required. We aimed to investigate the therapeutic potential of targeting the chemokine receptor CXCR4, which is involved in angiogenesis and tumor progression, using the CXCR4 inhibitor AMD3100, in combination with cisplatin. AMD3100 induced necrosis and bleeding in OSCC xenografts by inhibiting angiogenesis. We investigated the combined ability of AMD3100 plus cisplatin to enhance the antitumor effect in cisplatin-resistant OSCC. An MTS assay identified HSC-2 cells as cisplatin-resistant cells in vitro. Mice treated with the cisplatin-AMD combination exhibited the most significant reduction in tumor volume, accompanied by extensive hemorrhage and necrosis. Histological examination indicated thin and short tumor vessels in the AMD and cisplatin–AMD groups. These results indicated that cisplatin and AMD3100 had synergistic antitumor effects, highlighting their potential for vascular therapy of refractory OSCC. Antitumor vascular therapy using cisplatin combined with a CXCR4 inhibitor provides a novel strategy for addressing cisplatin-resistant OSCC.
Transformer-Less Seven-Level Inverter with Triple Boosting Capability and Common Ground
Authors: Vosoughi Kurdkandi Naser , Varesi Kazem , Fallah Ardashir Jaber , Gao Wei , Cao Zhi , Mi Chunting (Chris)
Published: June 2024

This paper proposes a single-phase, transformer-less, seven-level inverter that utilizes eight switches, three capacitors, and two diodes to produce seven voltage levels with triple boosting ability. The availability of the common-ground point eliminates the leakage current in PV applications. The proposed Transformer-Less Triple-Boosting Seven-Level Inverter (TLTB7LI) has the ability to feed different types of loads from non-unity to unity power factors. The voltage balancing of capacitors takes place naturally without the need for auxiliary circuits and complicated control strategies. This paper investigates the appropriateness of the proposed TLTB7LI for grid-connected application. The Peak Current Controller (PCC) is employed to generate the switching pulses and regulate the active/reactive power transfer between the converter and the output, which guarantees the high quality of injected current to the output. Moreover, the operational principles, its control technique, as well as the design procedure of the key components of the proposed inverter have been presented. The superiority of the proposed inverter over existing counterparts has been verified through comparative analysis. The simulation and experimental analysis validated the proper operation of the proposed TLTB7LI.
Effect of Accumulated Dust Conductivity on Leakage Current of Photovoltaic Modules
Authors: Gao Yu , Guo Fei , Tian Haibo , Xue Mengyuan , Jin Yaoyang , Wang Baomiao
Published: June 2024

Photovoltaic (PV) modules are often situated in hot and windy environments, such as deserts, where dust accumulation poses a significant problem. The build-up of dust can result in an increase in PV module leakage current, making the modules more vulnerable to potential-induced degradation (PID), ultimately leading to a reduction in the efficiency of PV power generation. In this study, we investigate the impact of dust accumulation on the surface of PV modules on leakage current. A dust model is developed based on the Arrhenius relation, taking into account the impact of temperature and density on dust conductivity. The equation for leakage current due to dust accumulation is derived based on the clean module leakage current equation. We undertake a simulation of natural conditions in a laboratory setting to analyze the impact of dust on the leakage current of photovoltaic modules. The results show the following: At high temperatures, the leakage current will significantly increase due to the elevated conductivity of the dust. The conductivity increased by 27.1%, 48.9%, 64.3%, and 118% for the four groups of dusty PV modules, respectively. Leakage current prediction has a better accuracy when dust is equated to series conductance. Dust can reduce the activation energy of PV modules by up to 3.48%.
Characterization of the TCO Layer on a Glass Surface for PV IInd and IIIrd Generation Applications
Authors: Kwaśnicki Paweł , Gronba-Chyła Anna , Generowicz Agnieszka , Ciuła Józef , Makara Agnieszka , Kowalski Zygmunt
Published: June 2024

In the dynamic field of photovoltaic technology, the pursuit of efficiency and sustainability has led to continuous novelty, shaping the landscape of solar energy solutions. One of the key elements affecting the efficiency of photovoltaic cells of IInd and IIIrd generation is the presence of transparent conductive oxide (TCO) layers, which are key elements impacting the efficiency and durability of solar panels, especially for DSSC, CdTe, CIGS (copper indium gallium diselenide) or organic, perovskite and quantum dots. TCO with low electrical resistance, high mobility, and high transmittance in the VIS–NIR region is particularly important in DSSC, CIGS, and CdTe solar cells, working as a window and electron transporting layer. This layer must form an ohmic contact with the adjacent layers, typically the buffer layer (such as CdS or ZnS), to ensure efficient charge collection Furthermore it ensures protection against oxidation and moisture, which is especially important when transporting the active cell structure to further process steps such as lamination, which ensures the final seal. Transparent conductive oxide layers, which typically consist of materials such as indium tin oxide (ITO) or alternatives such as fluorine-doped tin oxide (FTO), serve dual purposes in photovoltaic applications. Primarily located as the topmost layer of solar cells, TCOs play a key role in transmitting sunlight while facilitating the efficient collection and transport of generated electrical charges. This complex balance between transparency and conductivity highlights the strategic importance of TCO layers in maximizing the performance and durability of photovoltaic systems. As the global demand for clean energy increases and the photovoltaic industry rapidly develops, understanding the differential contribution of TCO layers becomes particularly important in the context of using PV modules as building-integrated elements (BIPV). The use of transparent or semi-transparent modules allows the use of building glazing, including windows and skylights. In addition, considering the dominant position of the Asian market in the production of cells and modules based on silicon, the European market is intensifying work aimed at finding a competitive PV technology. In this context, thin-film, organic modules may prove competitive. For this purpose, in this work, we focused on the electrical parameters of two different thicknesses of a transparent FTO layer. First, the influence of the FTO layer thickness on the transmittance over a wide range was verified. Next, the chemical composition was determined, and key electrical parameters, including carrier mobility, resistivity, and the Hall coefficient, were determined.
Parameter Estimation Method for Virtual Power Plant Frequency Response Model Based on SLP
Authors: Shi Zheng , Zhu Haixiao , Zhao Haibo , Wang Peng , Liang Yan , Wang Kaikai , Chen Jie , Zheng Xiaoming , Liu Hongli
Published: June 2024

In adapting to the double-high development trend of high-voltage direct current (HVDC) receiving-end power systems and solving optimization problems in emergency frequency control (EFC) supporting virtual power plants (VPPs) in large-scale power systems, a parameter estimation method for a VPP frequency response model based on a successive linear programming (SLP) method is proposed. First, a “centralized/decentralized” hierarchical control architecture for VPP participation in EFC is designed. Second, the frequency response characteristics of multiple flexible resources are scientifically analyzed, and the system frequency response (SFR) model and equivalent model of VPP are constructed. Subsequently, parameter estimation of the VPP frequency response model is carried out based on the SLP method, aiming to balance the accuracy and computational efficiency of the model. Finally, the effectiveness of the proposed methodology is verified by using PSD-BPA to simulate and test the three-zone HVDC recipient area grid.
Joint Deployment of Sensors and Chargers in Wireless Rechargeable Sensor Networks
Authors: Lian Jie , Yao Haiqing
Published: June 2024

As a promising technology to achieve the permanent operation of battery-powered wireless sensor devices, wireless rechargeable sensor networks (WRSNs) by radio-frequency radiation have attracted considerable attention in recent years. Determining how to save the deployment cost of WRSNs has been a hot topic. Previous scholars have mainly studied the cost of deploying chargers, thus ignoring the impact of sensor deployment on the network. Therefore, we consider the new problem of joint deployment of sensors and chargers on a two-dimensional plane, i.e., deploying the minimum number of sensors and chargers used to monitor points of interest (PoIs). Considering the interaction of deployed sensors and chargers, we divide the problem into two stages, P1 and P2. P1 addresses the sensor deployment, while P2 addresses the deployment of chargers. Both P1 and P2 have proved to be NP-hard. Meanwhile, we notice that the aggregation effect of sensors can effectively reduce the number of chargers deployed; therefore, we propose a greedy heuristic approximate solution for deploying sensors by using the aggregation effect (GHDSAE). Then, a greedy heuristic (GH) solution and a particle swarm optimization (PSO) solution are proposed for P2. The time complexity of these solutions is analyzed. Finally, extensive simulation results show that the PSO solution can always reduce the number of chargers deployed based on the GHDSAE solution sensor deployment approach. Therefore, it is more cost-effective to jointly deploy sensors and chargers by using the GHDSAE solution and the PSO solution.
The Development of an Improved Medium for the In Vitro Germination of Corylus avellana L. Pollen
Authors: Brandoli Claudio , Cristofori Valerio , Silvestri Cristian , Todeschini Claudio , Sgarbi Elisabetta
Published: June 2024

The European hazelnut (Corylus avellana L.) is a self-incompatible, wind-pollinated species of significant economic-productive interest, mainly cultivated between the Mediterranean basin and the Black Sea. Hazelnut breeding programs and high cropping in commercial orchards are necessarily linked to the availability of fertile pollen with wide germinability and high viability. The objective was to develop an improved method to determine the germinability of pollen, comparing the results with those found in the literature. Pollen germinability was firstly evaluated on a wild-type accession using boric acid (H3BO3), calcium nitrate (Ca(NO3)2), magnesium sulfate (MgSO4), potassium nitrate (KNO3), casein hydrolysate and different concentrations of sugars, including sucrose (10, 15 and 25%) and two monosaccharides, glucose (15%) and fructose (15%). The optimal composition included 15% sucrose in a semi-solid medium composed of 1% animal gelatin, containing collagen. This formulation was then tested on three cultivars of commercial interest, evaluating the effect of different concentrations of sucrose. The comparison between different in vitro germination methods showed that the hanging drop technique in a semi-solid medium provides a statistically higher germination index compared to the liquid and solid/agarized techniques. This study proposes an easy-to-use medium for the in vitro germination of Corylus avellana L. pollen.
BPN-YOLO: A Novel Method for Wood Defect Detection Based on YOLOv7
Authors: Wang Rijun , Chen Yesheng , Liang Fulong , Wang Bo , Mou Xiangwei , Zhang Guanghao
Published: June 2024

The detection of wood defect is a crucial step in wood processing and manufacturing, determining the quality and reliability of wood products. To achieve accurate wood defect detection, a novel method named BPN-YOLO is proposed. The ordinary convolution in the ELAN module of the YOLOv7 backbone network is replaced with Pconv partial convolution, resulting in the P-ELAN module. Wood defect detection performance is improved by this modification while unnecessary redundant computations and memory accesses are reduced. Additionally, the Biformer attention mechanism is introduced to achieve more flexible computation allocation and content awareness. The IOU loss function is replaced with the NWD loss function, addressing the sensitivity of the IOU loss function to small defect location fluctuations. The BPN-YOLO model has been rigorously evaluated using an optimized wood defect dataset, and ablation and comparison experiments have been performed. The experimental results show that the mean average precision (mAP) of BPN-YOLO is improved by 7.4% relative to the original algorithm, which can better meet the need to accurately detecting surface defects on wood.
A Brief Review of Fractional Calculus as a Tool for Applications in Physics: Adsorption Phenomena and Electrical Impedance in Complex Fluids
Authors: Barbero Giovanni , Evangelista Luiz. R. , Zola Rafael S. , Lenzi Ervin K. , Scarfone Antonio M.
Published: June 2024

Many fundamental physical problems are modeled using differential equations, describing time- and space-dependent variables from conservation laws. Practical problems, such as surface morphology, particle interactions, and memory effects, reveal the limitations of traditional tools. Fractional calculus is a valuable tool for these issues, with applications ranging from membrane diffusion to electrical response of complex fluids, particularly electrolytic cells like liquid crystal cells. This paper presents the main fractional tools to formulate a diffusive model regarding time-fractional derivatives and modify the continuity equations stating the conservation laws. We explore two possible ways to introduce time-fractional derivatives to extend the continuity equations to the field of arbitrary-order derivatives. This investigation is essential, because while the mathematical description of neutral particle diffusion has been extensively covered by various authors, a comprehensive treatment of the problem for electrically charged particles remains in its early stages. For this reason, after presenting the appropriate mathematical tools based on fractional calculus, we demonstrate that generalizing the diffusion equation leads to a generalized definition of the displacement current. This modification has strong implications in defining the electrical impedance of electrolytic cells but, more importantly, in the formulation of the Maxwell equations in material systems.
A Historical Perspective on Dental Composite Restorative Materials
Authors: Ferracane Jack L.
Published: June 2024

This review article will discuss the origin of resin-based dental composite materials and their adoption as potentially useful adjuncts to the primary material used by most dentists for direct restorations. The evolution of the materials, largely driven by the industry’s response to the needs of dentists, has produced materials that are esthetic, strong, and versatile enough to be used in most areas of the oral cavity to replace or restore missing tooth structures. Significant advancements, such as the transition from chemical to light-curing materials, refinements in reinforcing particles to produce optimum polishing and wear resistance, formulating pastes with altered viscosities to create highly flowable and highly stiff materials, and creating materials with enhanced depth of cure to facilitate placement, will be highlighted. Future advancements will likely reflect the movement away from simply being a biocompatible material to one that is designed to produce some type of beneficial effect upon interaction within the oral environment. These new materials have been called “bioactive” by virtue of their potential effects on bacterial biofilms and their ability to promote mineralization of adjacent tooth structures.
Influence of Confining Element Stiffness on the In-Plane Seismic Performance of Confined Masonry Walls
Authors: Ajmal Muhammad Mubashir , Qazi Asad Ullah , Ahmed Ali , Mughal Ubaid Ahmad , Kazmi Syed Minhaj Saleem , Munir Muhammad Junaid
Published: June 2024

Confined masonry (CM) construction is being increasingly adopted for its cost-effectiveness and simplicity, particularly in seismic zones. Despite its known benefits, limited research exists on how the stiffness of confining elements influences the in-plane behavior of CM. This study conducted a comprehensive parametric analysis using experimentally validated numerical models of single-wythe, squat CM wall panels under quasi-static reverse cyclic loading. Various cross-sections and reinforcement ratios were examined to assess the impact of the confining element stiffness on the deformation response, the cracking mechanism, and the hysteretic behavior. The key findings included the observation of symmetrical hysteresis in experimental CM panels under cyclic loading, with a peak lateral strength of 114.3 kN and 108.5 kN in push-and-pull load cycles against 1.7% and 1.3% drift indexes, respectively. A finite element (FE) model was developed based on a simplified micro-modeling approach, demonstrating a maximum discrepancy of 2.6% in the peak lateral load strength and 5.4% in the initial stiffness compared to the experimental results. The parametric study revealed significant improvements in the initial stiffness and seismic strength with increased depth and reinforcement in the confining elements. For instance, a 35% increase in the lateral strength was observed when the depth of the confining columns was augmented from 150 mm to 300 mm. Similarly, increasing the steel reinforcement percentage from 0.17% to 0.78% resulted in a 16.5% enhancement in the seismic strength. These findings highlight the critical role of the stiffness of confining elements in enhancing the seismic performance of CM walls. This study provides valuable design insights for optimizing CM construction in seismic-prone areas, particularly regarding the effects of confining element dimensions and reinforcement ratios on the structural resilience.
Ammonothermal Crystal Growth of Functional Nitrides for Semiconductor Devices: Status and Potential
Authors: Wostatek Thomas , Chirala V. Y. M. Rajesh , Stoddard Nathan , Civas Ege N. , Pimputkar Siddha , Schimmel Saskia
Published: June 2024

The state-of-the-art ammonothermal method for the growth of nitrides is reviewed here, with an emphasis on binary and ternary nitrides beyond GaN. A wide range of relevant aspects are covered, from fundamental autoclave technology, to reactivity and solubility of elements, to synthesized crystalline nitride materials and their properties. Initially, the potential of emerging and novel nitrides is discussed, motivating their synthesis in single crystal form. This is followed by a summary of our current understanding of the reactivity/solubility of species and the state-of-the-art single crystal synthesis for GaN, AlN, AlGaN, BN, InN, and, more generally, ternary and higher order nitrides. Investigation of the synthesized materials is presented, with a focus on point defects (impurities, native defects including hydrogenated vacancies) based on GaN and potential pathways for their mitigation or circumvention for achieving a wide range of controllable functional and structural material properties. Lastly, recent developments in autoclave technology are reviewed, based on GaN, with a focus on advances in development of in situ technologies, including in situ temperature measurements, optical absorption via UV/Vis spectroscopy, imaging of the solution and crystals via optical (visible, X-ray), along with use of X-ray computed tomography and diffraction. While time intensive to develop, these technologies are now capable of offering unprecedented insight into the autoclave and, hence, facilitating the rapid exploration of novel nitride synthesis using the ammonothermal method.
Study on Bottom Distributed Bragg Reflector Radius and Electric Aperture Radius on Performance Characteristics of GaN-Based Vertical-Cavity Surface-Emitting Laser
Authors: Dąbrówka Dominika , Sarzała Robert P.
Published: June 2024

This article presents the results of a numerical analysis of a nitride-based vertical-cavity surface-emitting laser (VCSEL). The analyzed laser features an upper mirror composed of a monolithic high-contrast grating (MHCG) and a dielectric bottom mirror made of SiO2 and Ta2O5 materials. The emitter was designed for light emission at a wavelength of 403 nm. We analyze the influence of the size of the dielectric bottom mirrors on the operation of the laser, including its power–current–voltage (LIV) characteristics. We also study the effect of changing the electrical aperture radius (active area dimensions). We demonstrate that the appropriate selection of these two parameters enables the temperature inside the laser to be reduced, lowering the laser threshold current and increasing its optical power output significantly.
Investigating the Impact of Superabsorbent Polymer Sizes on Absorption and Cement Paste Rheology
Authors: Adsul Nilam , Lee Jun-Woo , Kang Su-Tae
Published: June 2024

This study aims to understand the water retention capabilities of Superabsorbent Polymers (SAPs) in different alkaline environments for internal curing and to assess their impact on the rheological properties of cement paste. Therefore, the focus of this paper is on the absorption capacities of two different sizes of polyacrylic-based Superabsorbent Polymers : SAP A, with an average size of 28 µm, and SAP B, with an average size of 80 µm, in various solutions, such as pH 7, pH 11, pH 13, and cement filtrate solution (pH 13.73). Additionally, the study investigates the rheological properties of SAP-modified cement pastes, considering three different water-to-cement (w/c) ratios (0.4, 0.5, and 0.6) and four different dosages of SAPs (0.2%, 0.3%, 0.4%, and 0.5% by weight of cement). The results showed that the absorption capacity of SAP A was higher in all solutions compared to SAP B. However, both SAPs exhibited lower absorption capacity and early desorption in the cement filtrate solution. In contrast to the absorption results in pH 13 and cement filtrate solutions, the rheological properties, including plastic viscosity and yield stress, of the cement paste with a w/c ratio of 0.4 and 0.5, as well as both dry and wet (presoaked) SAPs, were higher than those of the cement paste without SAP, indicating continuous absorption by SAP. The viscosity and yield stress increased over time with increasing SAP dosage. However, in the mixes with a w/c ratio of 0.6, the values of plastic viscosity and yield stress were initially lower for the mixes with dry SAPs compared to the reference mix. Additionally, cement pastes containing wet SAP showed higher viscosity and yield stress compared to the pastes containing dry SAP.
Study on the Shear Strength of Loess Solidified by Guar Gum and Basalt Fiber
Authors: Xi Yu , Sun Mingming , Li Huanhuan , Li Gang , Wang Pengzhou , Li Li
Published: June 2024

Loess is widely distributed in the northwest and other regions, and its unique structural forms such as large pores and strong water sensitivity lead to its collapsibility and collapse, which can easily induce slope instability. Guar gum and basalt fiber are natural green materials. For these reasons, this study investigated the solidification of loess by combining guar gum and basalt fiber and analyzed the impact of the guar gum content, fiber length, and fiber content on the soil shearing strength. Using scanning electron microscopy (SEM), the microstructure of loess was examined, revealing the synergistic solidification mechanism of guar gum and basalt fibers. On this basis, a shear strength model was established through regression analysis with fiber length, guar gum content, and fiber content. The results indicate that adding guar gum and basalt fiber increases soil cohesion, as do fiber length, guar gum content, and fiber content. When the fiber length was 12 mm, the fiber content was 1.00%, and the guar gum content was equal to 0.50%, 0.75%, or 1.00%, the peak strength of the solidified loess increased by 82.80%, 85.90%, and 90.40%, respectively. According to the shear strength model, the predicted and test data of the shear strength of solidified loess are evenly distributed on both sides of parallel lines, indicating a good fit. These findings are theoretically significant and provide practical guidance for loess solidification engineering.
Oxide Scale Microstructure and Scale Growth Kinetics of the Hot-Pressed SiBCN-Ti Ceramics Oxidized at 1500 °C
Authors: Peng Hao , Jiang Haobo , Li Daxin , Yang Zhihua , Duan Wenjiu , Jia Dechang , Zhou Yu
Published: June 2024

In this study, the SiBCN-Ti series ceramics with different Ti contents were fabricated, and the oxidation resistance and microstructural evolution of the ceramics at 1500 °C for different times were explored. The results show that with the increase in oxidation time, pores and bubbles are gradually formed in the oxide layer. When the oxidation time is less than or more than 4 h, the Ti(C, N) in the ceramics will maintain its initial structure or mostly transform to TiN. The introduction of Ti content can promote the formation of rutile silicate glass, thus healing the cracks and improving the oxidation resistance of the ceramics effectively.
Percutaneous Epidural Neuroplasty for Symptomatic Lumbar Juxtafacet Cysts
Authors: Heo Juneyoung , Park Hyung-Ki , Baek Ji-Hoon , Ahn Hye-Sun , Lee Su-Chan
Published: June 2024

Background and Objectives: The term “Juxtafacet cyst” refers to both synovial cysts and ganglion pseudocysts associated with the lumbar facet joint. As conservative treatment for the juxtafacet cyst has a minimal effect, complete excision through surgery is considered the first choice of treatment. In this study, we retrospectively reviewed the clinical outcomes of percutaneous epidural neuroplasty for symptomatic lumbar juxtafacet cysts. Materials and Methods: We conducted a retrospective review of 34 patients with symptomatic juxtafacet cysts who visited a single institute from January 2010 to September 2023. Patients who received conservative treatment for at least 6 weeks but experienced no or insufficient effects were eligible for this study. After neuroplasty, a medical history check and neurological examination were performed during follow-up at 2 weeks, 1 month, 2 months, 3 months, 6 months, and once a year thereafter. Results: The pain improved for all patients to a VAS score of 3 or less immediately after neuroplasty; however, four of those patients (11%) had pain that worsened eventually to the same level as before the procedure and required surgery. The results showed that, regardless of cyst size, in cases with severe stenosis of the spinal canal, the outcome of neuroplasty was poor and often eventually required surgery. The cyst size was not associated with the procedure results. In addition, if the cyst was present at the L4–L5 level, or if diabetes mellitus was present, the likelihood of future surgery was significant (p-value = 0.003). Conclusions: Percutaneous neuroplasty showed a better success rate than other non-surgical treatments. In addition, severe spinal stenosis (Schizas grade C or higher), L4–L5 level, or diabetes mellitus produced a high possibility of surgery due to recurrence.
Molecular Weight Distribution of Humic Acids Isolated from Calcic Cryosol in Central Yakutia, Russia
Authors: Polyakov Vyacheslav , Abakumov Evgeny , Lodygin Evgeny , Vasilevich Roman , Petrov Alexey
Published: June 2024

The transition of soils into fallow state has a significant impact on the accumulation and transformation of soil organic matter (SOM). However, the issue of SOM transformation as a result of soil transition to fallow state in cryolithozone conditions is insufficiently studied. The aim of this study is to investigate the molecular weight (MW) distribution of humic acids (HAs) isolated from soils of central Yakutia. Native, fallow and agricultural soils in the vicinity of Yakutsk city were studied. MW distributions of HA preparations were obtained on an AKTAbasic 10 UPS chromatographic system (Amersam Biosciences, Uppsala, Sweden) using a SuperdexTM 200 10/300 GL column (with cross-linked dextran gel, fractionation range for globular proteins 10–600 kDa). The data on the molecular-mass distribution of HAs of fallow and agricultural soils of Central Yakutia were obtained for the first time. According to the obtained data, it was found that the highest carbon content in the structure of HAs was observed in agricultural soils (52.56%), and is associated with soil cultivation and fertilizer application. Among the HAs of fallow soils, we note that those soils that are in the process of self-vegetation have a relatively high carbon content in the HAs (45.84%), but the highest content was observed in fallow soils used as hayfields (49.98%), indicating that the reinvolvement of agriculture in fallow soils leads to an increase in the carbon content of HAs. According to the data of the MW distribution of HAs, it was found that the highest content of a high MW fraction of HAs was recorded in native soil (18.8%); this is due to the early stages of humification and the low maturity of organic matter. The highest content of a low MW fraction of HAs was recorded in agricultural soil (73.3%); this is due to the formation of molecular complexes of a “secondary” nature, which are more stable in the environment than the primary transformation products of humification precursors. The molecular composition of the HAs of fallow soils in the process of self-overgrowing is characterized by values closer to the HAs of native soils, which indicates their transformation towards HAs of native soils. The obtained results indicate that the reinvolvement of fallow soils leads to the transformation of the molecular composition of HAs towards HAs of agricultural soils, and to an increase in the resistance of SOM to biodegradation.
Exploring Healthy Eating Perceptions, Barriers, and Facilitators among Urban Indigenous Peoples in Saskatchewan
Authors: Shafiee Mojtaba , Al-Bazz Samer , Lane Ginny , Szafron Michael , Vatanparast Hassan
Published: June 2024

Urban Indigenous populations encounter distinctive challenges in maintaining traditional dietary practices, compounded by the complexities of socio-economic and environmental factors and the modern urban lifestyle. This qualitative study explores the perceptions of healthy eating, along with the facilitators and barriers to such practices, among urban Indigenous peoples in Saskatoon, Regina, and Prince Albert. Through virtual interviews, we engage 14 participants from these cities. Utilizing NVivo for thematic coding, we apply inductive thematic analysis to reveal relevant themes. The study highlights a preference for nutrient-rich, natural, and minimally processed foods, with a significant emphasis on incorporating traditional Indigenous foods into diets. These preferences are deeply entwined with cultural identity and underscore the importance of traditional foods in maintaining cultural heritage and promoting well-being. Despite the intrinsic value of these traditional foods, participants face several barriers to healthy eating, including economic constraints, limited access to traditional foods, and the psychological impacts of historical trauma. Nevertheless, facilitators such as community and family support, engagement in traditional food practices, and a growing awareness of nutritional knowledge are identified as being crucial in supporting healthy dietary choices. This research underscores the complex interplay of cultural, economic, and environmental factors in shaping the dietary practices of urban Indigenous peoples.
The Socio-Environmental Determinants of Childhood Malnutrition: A Spatial and Hierarchical Analysis
Authors: Sandler Austin , Sun Laixiang
Published: June 2024

Despite a remarkable reduction in global poverty and famines, substantial childhood malnutrition continues to persist. In 2017, over 50 million and 150 million young children suffered from acute malnutrition (wasting) and chronic malnutrition (stunting), respectively. Yet, the measurable impact of determinants is obscure. We evaluate proposed socio-environmental related determinants of stunting and wasting across Kenya and Nigeria and quantify their effectiveness. We combine health and demographic data from Kenya and Nigeria Demographic Health Surveys (2003, 2008–2009, 2013, 2014) with spatially explicit precipitation, temperature, and vegetation data. Geospatial and disaggregated data help to understand better who is at risk and where to target mitigation efforts. We evaluate the responsiveness of malnutrition indicators using a four-level random intercept hierarchical generalized logit model. We find that spatial and hierarchical relationships explain 28% to 36% of malnutrition outcome variation. Temporal variation in precipitation, temperature, and vegetation corresponds with more than a 50% change in malnutrition rates. Wasting is most impacted by mother’s education, family wealth, clinical delivery, and vaccinations. Stunting is most impacted by family wealth, mother’s education, clinical delivery, vaccinations, and children asymptomatic of fever, cough, or diarrhea. Remotely monitored climatic variables are powerful determinants, however, their effects are inconsistent across different indicators and locations.
Mixing and Thermal Transport Behavior in a Pin or Non-Pin Extruder Equipped with a Field Synergy Elongation Screw
Authors: Sun Yancai , Wang Shilong , Huang Shizheng , Pan Wei , He Yan , Jian Ranran
Published: June 2024

The ductile forming process of a polymer in a standard screw extruder and pin-barrel extruder, equipped with or without a field synergy elongation screw, was investigated by the finite element method. In order to assess the mixing and heat transfer capabilities of screws, characteristic parameters such as the mixing efficiency, segregation scale, and temperature distribution of different structures were analyzed and compared. The results indicated that the flow pattern of the polymer melt in the extruder was significantly influenced by the screw structure and was improved by the newly designed field synergy screw configuration, which brought a desirable elongational flow to enhance the radial convection. This was attributed to the unique radial wedge-shaped repeated convergence region of the field synergy elongation screw, increasing the synergistic effect between the velocity field, velocity gradient field, and temperature gradient field and thus improving the heat transfer and mixing efficiency. After adding barrel pins, the flow was forced to split, resulting in a more significant stretching effect on the melt. The field synergy effect in the pin mixed region was strengthened, which further increased the heat and mass transfer efficiency of the screw. However, increasing barrel pins could also lead to undesired temperature fluctuation and flow resistance, which have a negative impact on the melt uniformity. This study offers an important reference for optimizing screw structure to obtain strong mixing and heat transfer performances.
Enhancing Wound Recovery: A Self-Gelling Powder for Improved Hemostasis and Healing
Authors: Zhao Yuzhou , Gao Yanni , Shen Zihao , Ni Mingze , Xu Juan , Wang Ting
Published: June 2024

A novel self-gelatinizing powder was designed to accelerate wound healing through enhanced hemostasis and tissue recovery. Significantly, this research addresses the critical need for innovative wound management solutions by presenting a novel approach. Carboxymethylcellulose calcium (CMC-Ca) was synthesized using an ion exchange method, and lysine (Lys) was integrated through physical mixing to augment the material’s functional characteristics. The prepared powder underwent comprehensive evaluation for its self-gelling capacity, gelation time, adhesion, swelling rate, coagulation efficiency, hemostatic effectiveness, and wound healing promotion. Results indicate that the self-gelatinizing powder exhibited remarkable water absorption capabilities, absorbing liquid up to 30 times its weight and achieving rapid coagulation within 3 min. The inclusion of Lys notably enhanced the powder’s gel-forming properties. The gelation time was determined to be within 4 s using a rotational rheometer, with the powder rapidly forming a stable gel on the skin surface. Furthermore, in a mouse skin injury model, near-complete skin recovery was observed within 14 days, underscoring the powder’s impressive self-healing attributes and promising application prospects in wound management.
Influence of High Strain Dynamic Loading on HEMA–DMAEMA Hydrogel Storage Modulus and Time Dependence
Authors: Cook-Chennault Kimberly , Anaokar Sharmad , Medina Vázquez Alejandra M. , Chennault Mizan
Published: June 2024

Hydrogels have been extensively studied for biomedical applications such as drug delivery, tissue-engineered scaffolds, and biosensors. There is a gap in the literature pertaining to the mechanical properties of hydrogel materials subjected to high-strain dynamic-loading conditions even though empirical data of this type are needed to advance the design of innovative biomedical designs and inform numerical models. For this work, HEMA–DMAEMA hydrogels are fabricated using a photopolymerization approach. Hydrogels are subjected to high-compression oscillatory dynamic mechanical loading at strain rates equal to 50%, 60%, and 70%, and storage and loss moduli are observed over time, e.g., 72 h and 5, 10, and 15 days. As expected, the increased strains resulted in lower storage and loss moduli, which could be attributed to a breakdown in the hydrogel network attributed to several mechanisms, e.g., increased network disruption, chain scission or slippage, and partial plastic deformation. This study helps to advance our understanding of hydrogels subjected to high strain rates to understand their viscoelastic behavior, i.e., strain rate sensitivity, energy dissipation mechanisms, and deformation kinetics, which are needed for the accurate modeling and prediction of hydrogel behavior in real-world applications.
Stretch-Induced Spin-Cast Membranes Based on Semi-Crystalline Polymers for Efficient Microfiltration
Authors: Saleem Junaid , Moghal Zubair Khalid Baig , Hafeez Ahsan , Sajjad Samra , Shoaib Mohammad , Alahmad Johaina , McKay Gordon
Published: June 2024

Microfiltration membranes derived from semi-crystalline polymers face various challenges when synthesized through the extrusion–casting technique, including the use of large quantities of polymer, long casting times, and the generation of substantial waste. This study focuses on synthesizing these membranes using spin-casting, followed by stretch-induced pore formation. Recycled high-density polyethylene (HDPE) and virgin polyethylene powder, combined with a calcium carbonate filler, were used as the source materials for the membranes. The influence of the polymer–filler ratio with and without stretching on the morphology, tensile strength, and water flow rate was investigated. Optimal conditions were determined, emphasizing a balance between pore structure and mechanical integrity. The permeable membrane exhibited a water flow rate of 19 mL/min, a tensile strength of 32 MPa, and a water contact angle of 126°. These membranes effectively eliminated suspended particles from water, with their performance evaluated against that of commercially available membranes. This research, carried out utilizing the spin-casting technique, outlines a synthesis route for microfiltration membranes tailored to semi-crystalline polymers and their plastic forms.
Effects of Carbon/Kevlar Hybrid Ply and Intercalation Sequence on Mechanical Properties and Damage Resistance of Composite Laminates under Quasi-Static Indentation
Authors: Wang Mingling , Pan Zhongxiang , Cai Qimao , Zhao Lei , Wu Zhenyu
Published: June 2024

The investigation of damage development is essential for the design and optimization of hybrid structures. This paper provides a reference for the structural design of brittle–ductile hybrid LVI-resistant laminates through analyzing the damage development mechanism of carbon/Kevlar fabric-reinforced composite laminates. The effects of Kevlar fabric hybrid ply and intercalation on the damage development of carbon/Kevlar composite laminates under low-velocity impact (LVI) were investigated using quasi-static indentation (QSI). It was found that an increase in the Kevlar hybrid ratio significantly reduced the peak load and stiffness of these laminates (the maximum decreases in strength and stiffness were 46.03% and 41.43%, respectively), while laminates with identical hybrid ratios but different plying configurations maintained a comparable stiffness under QSI, with differences of less than 5%. Interestingly, Kevlar fibers exhibited irregular fractures as the yarn was splitting, while carbon fibers presented neat breaks, which indicated material-specific failure modes. Notably, the introduction of Kevlar hybridization beyond pure Kevlar configurations (KKKK) resulted in a decrease in the percentage of fiber damage (CCCC, CCCK, CCKK, and KCCK accounted for 80%, 79.8%, 70%, and 60% of fiber damage, respectively), attributed to an increase in resin cracks and lower levels of Kevlar yarn breakage. The internal damage diameter of specimens was accurately predicted from the diameter of visible damage on the QSI surface. Compared with CCCC and CCKK setups, which are affected by resin cracks formed via the carbon surface on the loading side propagating along the yarn direction (including the yarn settling direction), KCCK demonstrated less delamination between the first and second ply.
Enhancing Machine Learning Performance in Estimating CDOM Absorption Coefficient via Data Resampling
Authors: Kim Jinuk , Kim Jin Hwi , Jang Wonjin , Pyo JongCheol , Lee Hyuk , Byeon Seohyun , Lee Hankyu , Park Yongeun , Kim Seongjoon
Published: June 2024

Chromophoric dissolved organic matter (CDOM) is a mixture of various types of organic matter and a useful parameter for monitoring complex inland surface waters. Remote sensing has been widely utilized to detect CDOM in various studies; however, in many cases, the dataset is relatively imbalanced in a single region. To address these concerns, data were acquired from hyperspectral images, field reflection spectra, and field monitoring data, and the imbalance problem was solved using a synthetic minority oversampling technique (SMOTE). Using the on-site reflectance ratio of the hyperspectral images, the input variables Rrs (452/497), Rrs (497/580), Rrs (497/618), and Rrs (684/618), which had the highest correlation with the CDOM absorption coefficient aCDOM (355), were extracted. Random forest and light gradient boosting machine algorithms were applied to create a CDOM prediction algorithm via machine learning, and to apply SMOTE, low-concentration and high-concentration datasets of CDOM were distinguished by 5 m−1. The training and testing datasets were distinguished at a 75%:25% ratio at low and high concentrations, and SMOTE was applied to generate synthetic data based on the training dataset, which is a sub-dataset of the original dataset. Datasets using SMOTE resulted in an overall improvement in the algorithmic accuracy of the training and test step. The random forest model was selected as the optimal model for CDOM prediction. In the best-case scenario of the random forest model, the SMOTE algorithm showed superior performance, with testing R2, absolute error (MAE), and root mean square error (RMSE) values of 0.838, 0.566, and 0.777 m−1, respectively, compared to the original algorithm’s test values of 0.722, 0.493, and 0.802 m−1. This study is anticipated to resolve imbalance problems using SMOTE when predicting remote sensing-based CDOM. It is expected to produce and implement a machine learning model with improved reliable performance.
A Multi-Cycle Echo Energy Concentration Method for High-Mobility Targets Enveloped by Time-Varying Plasma Sheath
Authors: Bai Bowen , Wang Qingmeng , Pu Bailiang , Zhang Ke , Xue Long
Published: June 2024

When a target moves at hypersonic speed, the aerodynamic thermal effect will cause air molecules to form a plasma sheath that envelopes the outer surface of the target, which consists of a large number of charged particles. The plasma sheath imposes a complicated modulation effect on the radar echo signal in terms of amplitude, phase, and frequency. When the plasma sheath is time-varying, the inter-pulse coherence of the multi-cycle echo signals is severely disrupted, resulting in the failure of coherent accumulation. To address the problem of abnormal inter-pulse energy accumulation in targets covered with time-varying plasma sheaths, we analyzed the dynamic modulation effects of time-varying plasma sheaths on echo signals and constructed a radar echo model enveloped with time-varying plasma sheaths. Based on this, we propose a method for inter-pulse energy concentration of multi-cycle echo signals based on range-frequency inversion, second-order Wigner–Ville distribution (WVD), and slow-time symmetric auto-correlation. The proposed method is capable of realizing energy concentration for targets enveloped with time-varying plasma sheaths and can accurately estimate the motion parameters of the target. The effectiveness of our proposed method has been verified via simulation analysis of multi-cycle echo signals from targets enveloped with time-varying plasma sheaths, and the reliability of the method has been further validated through statistical experimental analysis.