bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting the Tumour Response to Radiation by Modelling the Five Rs of Radiotherapy Using PET Images
Authors: Hami Rihab , Apeke Sena , Redou Pascal , Gaubert Laurent , Dubois Ludwig J. , Lambin Philippe , Visvikis Dimitris , Boussion Nicolas
Published: June 2023

Despite the intensive use of radiotherapy in clinical practice, its effectiveness depends on several factors. Several studies showed that the tumour response to radiation differs from one patient to another. The non-uniform response of the tumour is mainly caused by multiple interactions between the tumour microenvironment and healthy cells. To understand these interactions, five major biologic concepts called the “5 Rs” have emerged. These concepts include reoxygenation, DNA damage repair, cell cycle redistribution, cellular radiosensitivity and cellular repopulation. In this study, we used a multi-scale model, which included the five Rs of radiotherapy, to predict the effects of radiation on tumour growth. In this model, the oxygen level was varied in both time and space. When radiotherapy was given, the sensitivity of cells depending on their location in the cell cycle was taken in account. This model also considered the repair of cells by giving a different probability of survival after radiation for tumour and normal cells. Here, we developed four fractionation protocol schemes. We used simulated and positron emission tomography (PET) imaging with the hypoxia tracer 18F-flortanidazole (18F-HX4) images as input data of our model. In addition, tumour control probability curves were simulated. The result showed the evolution of tumours and normal cells. The increase in the cell number after radiation was seen in both normal and malignant cells, which proves that repopulation was included in this model. The proposed model predicts the tumour response to radiation and forms the basis for a more patient-specific clinical tool where related biological data will be included.
Submarine Geomorphology and Sedimentary Features around the Egadi Islands (Western Mediterranean Sea)
Authors: Agate Mauro , Lombardo Christina , Lo Iacono Claudio , Sulli Attilio , Polizzi Sabrina , Chemello Renato , Orrù Paolo Emanuele
Published: June 2023

In this paper, the physiography, geomorphological features, and sedimentary bedforms of the offshore Egadi Islands (Italy) have been illustrated and mapped through an integrated analysis of high-resolution bathymetric, seismo-acoustic, and sedimentological data. The study area is characterized by a wide, up to 25 km, continental shelf which is separated by a NNW-trending linear incision, the Marettimo Channel, along which several erosional and depositional features have been detected and mapped. Sedimentary prograding wedges were detected at water depths between 100–125 m along the shelf margin, which accumulated during the sea-level fall and lowstand stages of the last glacio-eustatic cycle (post- MIS 5.5). This study detected several slope breaks defining scarps across the continental shelf, which were interpreted as coastal cliffs that originated during the post-LGM eustatic sea-level rise. Several fields of different types of sedimentary bedforms, including 2-D and 3-D hydraulic dunes and sorted bedforms, were found across the continental shelf, providing evidence of a high hydrodynamic regime affecting the seafloor. Further on, this study recognized erosive and depositional features related to bottom currents (contourites) in the Marettimo Channel. These findings provide a better understanding of the morpho-sedimentary evolution of the Egadi Islands offshore in the latest Quaternary. Moreover, they offer essential scientific support for effectively managing the most valuable priority habitats for conservation, such as the Posidonia oceanica meadow and coralline algae bioconstructions (Coralligenous habitat).
Subsea Pipelines
Authors: Chen Bai-Qiao , Guedes Soares C.
Published: June 2023

A subsea pipeline (also known as an offshore pipeline or submarine pipeline) is a pipeline that is laid on the seabed or inside a specially constructed trench [...]
Damage Stability of Ships
Authors: Ruponen Pekka , Papanikolaou Apostolos
Published: June 2023

Ensuring adequate damage stability of ships is essential in ship design and directly contributes to their safe operation [...]
Heart Failure Therapies following Acute Coronary Syndromes with Reduced Ejection Fraction: Data from the ACSIS Survey
Authors: Zafrir Barak , Ovdat Tal , Abu Akel Mahmood , Bahouth Fadel , Orvin Katia , Beigel Roy , Amir Offer , Elbaz-Greener Gabby
Published: June 2023

Background: Guideline-directed medical therapies for heart failure (HF) may benefit patients with reduced left ventricular ejection fraction (LVEF) following acute coronary syndromes (ACS). Few real-world data are available regarding the early implementation of HF therapies in patients with ACS and reduced LVEF. Methods: Data collected from the 2021 nationwide, prospective ACS Israeli Survey (ACSIS). Drug classes included: (a) angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARB) or angiotensin receptor-neprilysin inhibitors (ARNI); (b) beta-blockers; (c) mineralocorticoid receptor antagonist (MRA) and (d) sodium-glucose cotransporter-2 inhibitors (SGLT2I). The utilization of HF therapies at discharge or 90 days following ACS was analyzed in relation to LVEF [reduced ≤40% (n = 406) or mildly-reduced 41–49% (n = 255)] and short-term adverse outcomes. Results: History of HF, anterior wall myocardial infarction and Killip class II-IV (32% vs. 14% p < 0.001) were more prevalent in those with reduced compared to mildly-reduced LVEF. ACEI/ARB/ARNI and beta-blockers were used by the majority of patients in both LVEF groups, though ARNI was prescribed to only 3.9% (LVEF ≤ 40%). MRA was used by 42.9% and 12.2% of patients with LVEF ≤40% and 41–49%, respectively, and SGLT2I in about a quarter of both LVEF groups. Overall, ≥3 HF drug classes were documented in 44% of the patients. A trend towards higher rates of 90-day HF rehospitalizations, recurrent ACS or all-cause death was noted in those with reduced (7.6%) vs. mildly-reduced (3.7%) LVEF, p = 0.084. No association was observed between the number of HF drug classes or the use of ARNI and/or SGLT2I with adverse clinical outcomes. Conclusions: In current clinical practice, the majority of patients with reduced and mildly-reduced LVEF are treated by ACEI/ARB and beta-blockers early following ACS, whereas MRA is underutilized and the adoption of SGLT2I and ARNI is low. A greater number of therapeutic classes was not associated with reduced short-term rehospitalizations or mortality.
Clinical Asthma Remission Obtained with Biologics in Real Life: Patients’ Prevalence and Characteristics
Authors: Sposato Bruno , Bianchi Francesco , Ricci Alberto , Scalese Marco
Published: June 2023

Background: The prevalence of clinical asthma remission with biologics in severe asthma has not been well understood yet. We do not even know whether there might be characteristics that identify subjects prone to remission of the disease. Materials and Methods: Retrospectively, four groups of severe asthmatics already treated with Omalizumab, Mepolizumab, Benralizumab and Dupilumab (302, 55, 95 and 34 patients, respectively) for at least 12 months were considered. The number of individuals with clinical asthma remission was sought in each group. This was considered when patients, after a treatment of at least 1 year with one of the aforesaid biologics, showed the disappearance of asthma symptoms (ACT ≥ 20), zero exacerbations, suspension of oral corticosteroids and a FEV1% ≥ 80%. Baseline characteristics of patients with and without remission were also taken into account. Results: The prevalence of asthma remission after a mean of 37.8 ± 19.2, 13.5 ± 1.7, 15.4 ± 5.5 and 12 ± 0 months of Omalizumab, Mepolizumab, Benralizumab and Dupilumab treatments was 21.8%, 23.6%, 35.8% and 23.5%, respectively. For each biologic, different baseline characteristics, seem to be associated with failure to achieve clinical asthma remission. Older age, higher BMI, a later age of asthma onset, rhinitis/sinusitis/nasal polyposis, comorbidities and a greater asthma severity may be the characteristics of a suboptimal response to biologic treatments. Conclusion: All biologics have the potential to induce disease remission in severe asthmatics. For each biologic, there may be several markers that can identify the patients who will not achieve asthma remission. It would be important to detect them (by carrying out targeted studies) as they would allow us to select the best biologic that may induce clinical asthma remission on a larger number of patients.
Data and Values: Axiological Interpretations of Building Sprawl Landscape Risk in the Rural Territory of Noto (Italy)
Authors: Minioto Chiara , Martinico Francesco , Trovato Maria Rosa , Giuffrida Salvatore
Published: June 2023

This research concerns the issue of landscape risk due to the progressive spread of construction in rural areas through the creation of a “site-specific” analysis and evaluation model and its application to the context of the municipal area of Noto (Italy). The phenomenon of construction in rural areas was facilitated by the regulatory evolution of the Sicilian Region, which supported the construction of artifacts in agricultural areas to boost cultivation and production, but which, for the most part, was intended for seasonal residential use. In particular, the municipal territory of Noto is characterized by remarkable landscape values, including very low building density, large portions of the territory remaining almost uncontaminated, and the widespread presence of cultural and ethno-anthropological assets. Consequently, the demand for localization in rural areas, now also driven by the tendency to decongest dense urban areas in order to contain the effects of the pandemic, is a phenomenon that must be countered, on the one hand, and addressed and regulated on the other. The objective of this study is to provide the local administration with a planning tool to determine permissible interventions in various areas of the landscape context. This has guided the process of representing the phenomenon in quantitative and spatial terms, and of evaluating the territory targeted. A large set of data, coordinated in a hierarchical set of indices by means of a multidimensional valuation approach, allows us to provide an orderly and robust representation of the resilience of the landscape at risk from building pressure while considering multiple perspectives.
Which Spatial Elements Influence Waterfront Space Vitality the Most?—A Comparative Tracking Study of the Maozhou River Renewal Project in Shenzhen, China
Authors: Fan Yating , Kuang Da , Tu Wei , Ye Yu
Published: June 2023

Urban waterfront renewal, especially public space improvement, is important for regaining waterfront space vitality. However, existing studies constrained by sparse and hard-to-access data are hard to explore how changes in spatial elements during waterfront renewal would affect space vitality. Waterfront space vitality comprises social vitality represented by public behaviors and economic vitality represented by urban functional facilities. Taking the Maozhou River renewal project in China as an example, we collect spatial elements and vitality on corresponding periods in 2018 and 2020 (before and after the renewal construction) and use multiple linear regression models to assess the relationships. We find that the functional diversity (e.g., commercial and cultural facilities) and design quality (e.g., path density and the shoreline’s proximity to the water) are the two most influential spatial elements affecting space vitality during waterfront renewal. Overall, the use of two-time datasets has generated strong evidence for measuring waterfront revitalization.
Possible Mechanisms Linking Obesity, Steroidogenesis, and Skeletal Muscle Dysfunction
Authors: Sheptulina Anna F. , Antyukh Karina Yu , Kiselev Anton R. , Mitkovskaya Natalia P. , Drapkina Oxana M.
Published: June 2023

Increasing evidence suggests that skeletal muscles may play a role in the pathogenesis of obesity and associated conditions due to their impact on insulin resistance and systemic inflammation. Skeletal muscles, as well as adipose tissue, are largely recognized as endocrine organs, producing biologically active substances, such as myokines and adipokines. They may have either beneficial or harmful effects on the organism and its functions, acting through the endocrine, paracrine, and autocrine pathways. Moreover, the collocation of adipose tissue and skeletal muscles, i.e., the amount of intramuscular, intermuscular, and visceral adipose depots, may be of major importance for metabolic health. Traditionally, the generalized and progressive loss of skeletal muscle mass and strength or physical function, named sarcopenia, has been thought to be associated with age. That is why most recently published papers are focused on the investigation of the effect of obesity on skeletal muscle function in older adults. However, accumulated data indicate that sarcopenia may arise in individuals with obesity at any age, so it seems important to clarify the possible mechanisms linking obesity and skeletal muscle dysfunction regardless of age. Since steroids, namely, glucocorticoids (GCs) and sex steroids, have a major impact on the amount and function of both adipose tissue and skeletal muscles, and are involved in the pathogenesis of obesity, in this review, we will also discuss the role of steroids in the interaction of these two metabolically active tissues in the course of obesity.
Artemisia arborescens and Artemisia inculta from Crete; Secondary Metabolites, Trace Metals and In Vitro Antioxidant Activities
Authors: Lantzouraki Dimitra Z. , Amerikanou Charalampia , Karavoltsos Sotirios , Kafourou Vasiliki , Sakellari Aikaterini , Tagkouli Dimitra , Zoumpoulakis Panagiotis , Makris Dimitris P. , Kalogeropoulos Nick , Kaliora Andriana C.
Published: June 2023

Background: Currently, the use of medicinal plants has increased. Artemisia species have been used in several applications, including medicinal use and uses in cosmetics, foods and beverages. Artemisia arborescens L. and Artemisia inculta are part of the Mediterranean diet in the form of aqueous infusions. Herein, we aimed to compare the secondary metabolites of the decoctions and two different extracts (methanolic and aqueous-glycerolic) of these two species, as well as their antioxidant capacity and trace metal levels. Methods: Total phenolic, total flavonoid, total terpenes, total hydroxycinnamate, total flavonol, total anthocyanin contents and antioxidant/antiradical activity were determined, and GC/MS analysis was applied to identify and quantify phenolics and terpenoids. Trace metals were quantified with ICP-MS. Results: Aqueous-glycerolic extracts demonstrated higher levels of total secondary metabolites, greater antioxidant potential and higher terpenoid levels than decoctions and methanolic extracts. Subsequently, the aqueous-glycerolic extract of a particularly high phenolic content was further analyzed applying targeted LC-MS/MS as the most appropriate analytic tool for the determination of the phenolic profile. Overall, twenty-two metabolites were identified. The potential contribution of infusions consumption to metal intake was additionally evaluated, and did not exceed the recommended daily intake. Conclusions: Our results support the use of these two species in several food, cosmetic or pharmaceutical applications.
Specularly-Reflected Wave Guidance of Terahertz Plasmonic Metamaterial Based on the Metal-Wire-Woven Hole Arrays: Functional Design and Application of Transmission Spectral Dips
Authors: You Borwen , Iwasa Ryuji , Chen Po-Lun , Hung Tun-Yao , Huang Chih-Feng , Yu Chin-Ping , Lee Hsin-Ying
Published: June 2023

Terahertz (THz) plasmonic metamaterial, based on a metal-wire-woven hole array (MWW-HA), is investigated for the distinct power depletion in the transmittance spectrum of 0.1–2 THz, including the reflected waves from metal holes and woven metal wires. Woven metal wires have four orders of power depletion, which perform sharp dips in a transmittance spectrum. However, only the first-order dip at the metal–hole–reflection band dominates specular reflection with a phase retardation of approximately π. The optical path length and metal surface conductivity are modified to study MWW-HA specular reflection. This experimental modification shows that the first order of MWW-HA power depletion is sustainable and sensitively correlated with a bending angle of the woven metal wire. Specularly reflected THz waves are successfully presented in hollow-core pipe wave guidance specified from MWW-HA pipe wall reflectivity.
Fracture Toughness and Fatigue Crack Growth Analyses on a Biomedical Ti-27Nb Alloy under Constant Amplitude Loading Using Extended Finite Element Modelling
Authors: Abdellah Mohammed Y. , Alharthi Hamzah
Published: June 2023

The human body normally uses alternative materials such as implants to replace injured or damaged bone. Fatigue fracture is a common and serious type of damage in implant materials. Therefore, a deep understanding and estimation or prediction of such loading modes, which are influenced by many factors, is of great importance and attractiveness. In this study, the fracture toughness of Ti-27Nb, a well-known implant titanium alloy biomaterial, was simulated using an advanced finite element subroutine. Furthermore, a robust direct cyclic finite element fatigue model based on a fatigue failure criterion derived from Paris’ law is used in conjunction with an advanced finite element model to estimate the initiation of fatigue crack growth in such materials under ambient conditions. The R-curve was fully predicted, yielding a minimum percent error of less than 2% for fracture toughness and less than 5% for fracture separation energy. This provides a valuable technique and data for fracture and fatigue performance of such bio-implant materials. Fatigue crack growth was predicted with a minimum percent difference of less than nine for compact tensile test standard specimens. The shape and mode of material behaviour have a significant effect on the Paris law constant. The fracture modes showed that the crack path is in two directions. The finite element direct cycle fatigue method was recommended to determine the fatigue crack growth of biomaterials.
Recent Advances in Molybdenum Disulfide and Its Nanocomposites for Energy Applications: Challenges and Development
Authors: Ismail Kamal Batcha Mohamed , Arun Kumar Manoharan , Mahalingam Shanmugam , Kim Junghwan , Atchudan Raji
Published: June 2023

Energy storage and conversion are critical components of modern energy systems, enabling the integration of renewable energy sources and the optimization of energy use. These technologies play a key role in reducing greenhouse gas emissions and promoting sustainable development. Supercapacitors play a vital role in the development of energy storage systems due to their high power density, long life cycles, high stability, low manufacturing cost, fast charging-discharging capability and eco-friendly. Molybdenum disulfide (MoS2) has emerged as a promising material for supercapacitor electrodes due to its high surface area, excellent electrical conductivity, and good stability. Its unique layered structure also allows for efficient ion transport and storage, making it a potential candidate for high-performance energy storage devices. Additionally, research efforts have focused on improving synthesis methods and developing novel device architectures to enhance the performance of MoS2-based devices. This review article on MoS2 and MoS2-based nanocomposites provides a comprehensive overview of the recent advancements in the synthesis, properties, and applications of MoS2 and its nanocomposites in the field of supercapacitors. This article also highlights the challenges and future directions in this rapidly growing field.
A Micromechanical Analysis to the Viscoplastic Behavior of Sintered Silver Joints under Shear Loading
Authors: Ma Kun , Liu Xun , Sun Yameng , Song Yifan , Feng Zheng , Zhou Yang , Liu Sheng
Published: June 2023

Ag paste has been recognized as a promising substitute for Sn/Pb solder in SiC or GaN power electronic devices, owing to its ability to withstand high temperatures and facilitate low-temperature packing. The reliability of these high-power circuits is greatly influenced by the mechanical properties of sintered Ag paste. However, there exist substantial voids inside the sintered silver layer after sintering, and the conventional macroscopic constitutive models have certain limitation to describe the shear stress–strain relationship of sintered silver materials. To analyze the void evolution and microstructure of sintered silver, Ag composite pastes composed of micron flake silver and nano-silver particles were prepared. The mechanical behaviors were studied at different temperatures (0–125 °C) and strain rates (1 × 10−4–1 × 10−2) for Ag composite pastes. The crystal plastic finite element method (CPFEM) was developed to describe the microstructure evolution and shear behaviors of sintered silver at varied strain rates and ambient temperatures. The model parameters were obtained by fitting experimental shear test data to a representative volume element (RVE) model built on representative volume elements, also known as Voronoi tessellations. The numerical predictions were compared with the experimental data, which showed that the introduced crystal plasticity constitutive model can describe the shear constitutive behavior of a sintered silver specimen with reasonable accuracy.
Microstructural and Performance Analysis of TP304H/T22 Dissimilar Steel Welded Joints
Authors: Sun Jian , Wang Tong , Liu Fuguang , Zhang Zhoubo , Chen Yunhui , Lin He , Liu Hui , Zhao Xiaohui , Cheng Xiaole
Published: June 2023

In the power plant boiler industry, dissimilar steel welding is widely used in the connection of thermal power generation units. As an important component of the unit, research on the organizational properties of dissimilar steel welded joints has significant guidance for the life design of the joint. For the long-term service state of TP304H/T22 dissimilar steel welded joints, the microstructure’s morphological evolution, the microhardness, and the tensile properties of tube samples were analyzed using tests and numerical simulations. The results show that the microstructure of each part of the welded joint was free of damaged features, such as a creep cavity and intergranular cracks. The microhardness of the weld was higher than that of the base metal. In the tensile test, the welded joints broke at the weld metal at room temperature and at the side of the TP304H base metal at a temperature of 550 °C. The tensile fracture morphology demonstrated a change from a ductile fracture to a hybrid fracture when the temperature rose. The fusion zone and base metal on the TP304H side were the stress concentration areas of the welded joint, which easily sprouted cracks. This study holds significant reference value in assessing the safety and reliability of dissimilar steel welded joints in superheater units.
Synthesis and Evaluation of Engineering Properties of Polymer-Coated Glass Beads
Authors: Yoon Boyoung , Choo Hyunwook , Lee Changho
Published: June 2023

Modern construction projects are often challenging, which has increased the demand for innovative materials that ensure improved safety, durability, and functionality. To explore the potential of enhancing soil material functionality, this study synthesized polyurethane on the surface of glass beads and evaluated their mechanical properties. The synthesis of polymer proceeded according to a predetermined procedure, where the polymerization was confirmed through analysis of chemical structure by Fourier transform infrared spectroscopy (FT-IR) and microstructure observation by a scanning electron microscope (SEM) after complete synthesis. The constrained modulus (M) and the maximum shear modulus (Gmax) of mixtures with synthesized materials were examined by using an oedometer cell equipped with bender elements under a zero lateral strain condition. Both M and Gmax decreased with an increase in the contents of polymerized particles due to a decrease in the number of interparticle contacts and contact stiffness induced by the surface modification. The adhesion property of the polymer induced a stress-dependent change in M but was observed to have little effect on Gmax. Compared to the behavior of the rubber-sand mixtures, polymerized particles show the advantage of a smaller reduction of M.
Influence of Process Parameter and Alloy Composition on Misoriented Eutectics in Single-Crystal Nickel-Based Superalloys
Authors: Wittenzellner Tobias , Sumarli Shieren , Dai Zijin , Cocen Ocson , Schaar Helge , Wang Fu , Ma Dexin , Bührig-Polaczek Andreas
Published: June 2023

The nucleation and the growth of misoriented micro-structure components in single crystals depend on various process parameters and alloy compositions. Therefore, in this study, the influence of different cooling rates on carbon-free, as well as carbon-containing, nickel-based superalloys was investigated. Castings were carried out using the Bridgman and Bridgman–Stockbarger techniques under industrial and laboratory conditions, respectively, to analyze the impact of temperature gradients and withdrawing rates on six alloy compositions. Here, it was confirmed that eutectics could assume a random crystallographic orientation due to homogeneous nucleation in the residual melt. In carbon-containing alloys, eutectics also nucleated at low surface-to-volume ratio carbides due to the accumulation of eutectic-forming elements around the carbide. This mechanism occurred in alloys with high carbon contents and at low cooling rates. Furthermore, micro-stray grains were formed by the closure of residual melt in Chinese-script-shaped carbides. If the carbide structure was open in the growth direction, they could expand into the interdendritic region. Eutectics additionally nucleated on these micro-stray grains and consequently had a different crystallographic orientation compared with the single crystal. In conclusion, this study revealed the process parameters that induced the formation of misoriented micro-structures, which prevented the formation of these solidification defects by optimizing the cooling rate and the alloy composition.
Investigation of the Uncoordinated Bolt Deformation of a Disc–Drum Combined Structure in a Turbine under Various Operating Conditions
Authors: Wang Haijun , Xue Pu
Published: June 2023

At high speeds and under large axial forces, the disc–drum combined structure exhibits inconsistent deformation between parts. The difference in the structural characteristics of different parts, the speed, the preload, and its distribution mode, along with other factors, make the deformation of parts more complex, resulting in the deformation of parts during work; this deformation inconsistency has a direct impact on the engine performance. This paper presents a systemic investigation of the uncoordinated bolt deformation of an aeroengine. The finite element model of the disc–drum combined structure is established using Ansys workbench, where the deformation is uncoordinated. On this basis, the influence of different preload forces and various rotation speeds on the deformation discordance of the combined structure are discussed. Then, the relationship between the bolt deformation and component deformation incompatibility is obtained through a comprehensive analysis of the bolt deformation. A set of detailed analyses was carried out to investigate the uncoordinated deformation caused by the uneven distribution of the preload force.
Investigating the Stiffness Characteristics of a Tendon-Driven Continuum Manipulator Using Sensitivity Analysis: A Case Study in Transoral Laser Microsurgery
Authors: Sawant Kapil , Gkikakis Antonios E. , Mattos Leonardo S.
Published: June 2023

Continuum manipulators, with their characteristics of flexibility and dexterity, have gained significant interest in various applications across industries such as inspection, manufacturing, space exploration, and medical surgery. However, because of their inherent compliance, handling payloads may prove challenging due to shape distortion and deflection. This demonstrates the need to optimize the manipulator’s stiffness. The primary objective of this work was to show the merits of sensitivity analysis in the design of flexible surgical manipulators. Such analysis can guide important design decisions and enable the more efficient use of available resources, contributing to designing more effective prototypes. A new sensitivity analysis framework based on a multi-model and a multi-method approach was proposed to achieve this. This framework was then demonstrated by studying a tendon-driven rolling contact joint hyper-redundant manipulator for transoral laser microsurgery. In this analysis, the effects of independent design parameters on the stiffness of the manipulator were examined. Then, scaled-up 3D-printed prototypes were used to validate the accuracy of the stiffness model experimentally, which enabled us to assess the outcome of the sensitivity analysis framework. The results demonstrated that only two out of five design parameters for the considered manipulator significantly impacted the device’s performance. This information could enable the designer to efficiently allocate resources toward correctly setting these two most important parameters to achieve the desired system. Overall, the proposed analysis framework is a general tool that can be applied to any design architecture, helping to develop optimal manipulators for various applications.
A New Slurry for Photocatalysis-Assisted Chemical Mechanical Polishing of Monocrystal Diamond
Authors: Shao Junyong , Zhao Yanjun , Zhu Jianhui , Yuan Zewei , Du Haiyang , Wen Quan
Published: June 2023

Diamond needs to have a perfectly smooth surface due to the growing requirements in the fields of electronic semiconductors, optical windows and high-fidelity loudspeakers. However, the polishing of diamonds is highly challenging due to their exceptional hardness and chemical stability. In this study, a new polishing slurry is prepared for the proposed photocatalysis-assisted chemical mechanical polishing (PCMP) approach to obtain an ultra-smooth surface for large-area diamond. The analyses and experimental findings revealed the significance of the photocatalyst, abrasive, electron capture agent and pH regulator as essential components of the PCMP slurry. TiO2 with a 5 nm pore size and P25 TiO2 possess improved photocatalysis efficiency. Moreover, diamond removal is smooth under the acidic environment of H3PO4 due to the high oxidation–reduction potential (ORP) of the slurry, and, during the methyl orange test, P25 TiO2 exhibits reasonable photocatalytic effects. Moreover, in 8 h, a smooth surface free of mechanical scratches can be obtained by reducing the surface roughness from Ra 33.6 nm to Ra 2.6 nm.
Optimizing the Gating System for Rapid Investment Casting of Shape Memory Alloys: Computational Numerical Analysis for Defect Minimization in a Simple-Cubic Cell Structure
Authors: Albuquerque Carlos E. S. , Silva Paulo C. S. , Grassi Estephanie N. D. , De Araujo Carlos J. , Delgado João M. P. Q. , Lima Antonio G. B.
Published: June 2023

With the aid of virtual prototyping and casting numerical simulation, this work presents the optimization of an injection system used in a non-traditional investment casting process that applies perpendicular centrifugal force to inject the molten metal into refractory plaster molds. In this study, advanced techniques of simulation and production of complex geometries in Computer-Aided Design CAD (Computer-Aided Design) are used in the design of the casting system of a miniaturized simple-cubic cell structure. The cast part has a complex shape profile and needs a high surface finish with strict dimensional tolerance. The alloy used to fill the mold is an aluminum bronze shape memory alloy (SMA). CAD was used to model the part and the proposed models for casting optimization. ProCAST software was used for the numerical simulation of the casting process. Experimental parameters were used as input data for the numerical simulation. The simulation results were analyzed focusing on the identification of defects in the Cu–Al–Mn SMA simple-cubic structures. Different feeding systems have been designed to eliminate the identified defects. Concerning the molten recirculation, the optimal nozzle model has a truncated cone profile, with a larger radius of 6.5 mm, a smaller radius of 2.0 mm and a height of 8.0 mm (called here model 3). Experimental observations from cast SMA parts agree with the simulated results of the optimized nozzle model 3. In addition to the elimination of alloy recirculation with the nozzle optimization in this work, the shrinkage porosity at the upper base of the part was eliminated with the addition of a compensation volume close to the region where porosity is more intense. By exploring the possibilities offered by commercial software, the work contributes to advance the knowledge and application of the non-traditional investment casting process, highlighting its advantages and potential applications.
A 4340 Steel with Superior Strength and Toughness Achieved by Heterostructure via Intercritical Quenching and Tempering
Authors: Sang Yi , Sun Guosheng , Liu Jizi
Published: June 2023

The conventional 4340 steel was used after quenching and tempering, strengthened by the classical pearlitic structure where cementite particles are dispersed through the ferrite matrix. In the present study, a heterostructure microstructure consisting of micro-sized residual ferrite zones and pearlitic zones was introduced by an optimized process of intercritical quenching and tempering, resulting in a steel with higher strength and better toughness. The pearlite steel has a tensile strength of 1233 MPa, yield strength of 1156 MPa, and toughness of 121.5 MJ/m3. Compared with the pearlite steel, the tensile strength and yield strength of the heterostructure steel have been improved by 67 MPa and 74 MPa, respectively, while the toughness has been increased by 52.5 MJ/m3. In this heterostructure, the micro-sized ferrite bulks serve as the soft zones surrounded by the hard zones of the pearlite structure to achieve a remarkable work-hardening capacity. Statistical analysis shows that the heterostructure has the best hetero-deformation-induced (HDI) hardening capability when the residual ferrite bulk contributes ~31% by volume fraction, and the quenching temperature is around 780 °C. This study opens new ways of thinking about the strengthening and toughening mechanism of heat treatment of medium carbon steels.
Experimental and Analytical Investigation of the Re-Melting Effect in the Manufacturing of 316L by Direct Energy Deposition (DED) Method
Authors: Kahya Harun , Gurun Hakan , Kucukturk Gokhan
Published: June 2023

In this study, the effects of the laser power (2000 W, 2250 W, 2500 W), scanning speed (0.6, 0.8, 1 m/min), and powder feed rate (10, 12.5, 15 g/min) on material structures and their mechanical properties were investigated in the production of 316L stainless steels through Direct Energy Deposition (DED). In addition, changes in the microstructure caused by the re-melting process were also investigated. Optimized process parameters were modeled using the CFD software (FLOW 3D V3.0). In order to see the effects on the density and mechanical properties, the sample production was repeated as a build and by applying the re-melting process between the layers. When the energy density and powder feed rate are considered together, it has been determined that the deposition rate increases in direct proportion to the energy density and tends to decrease inversely with the powder feed rate. When the experimental and analysis results of the single clad height are compared, it is seen that the values obtained are very approximate. It has been observed that the most important parameters affecting the formation of porosity are the energy density and powder feed density. Re-melting slightly affects the microstructure of the material and causes grain growth. Changes in the impact strength of the re-melted samples were observed depending on the energy density.
Enhancement of Leaching Copper from Printed Circuit Boards of Discarded Mobile Phones Using Ultrasound–Ozone Integrated Approach
Authors: Thi Hong Hoa Nguyen , Hoan Nguyen To , Nguyen Trong Nghia , Linh Nguyen Thi Ngoc , Quy Bui Minh , Pham Thi Thu Ha , Nguyen Van Que , Nguyen Van Phuoc , Nguyen Vinh Dinh
Published: June 2023

The recovery of metals from discarded mobile phones has been of interest due to its environmental and economic benefits. This work presents a simple and effective approach for leaching copper (Cu) from the printed circuit boards of discarded mobile phones by combining ultrasound and ozone approaches. The X-ray diffraction (XRD) technique and Fourier-transform infrared spectroscopy (FT-IR) were used to characterize the solid phases, and inductively coupled plasma optical emission spectrometry (ICP-OES) was utilized to determine the concentration of metals in the liquid phases. The effects of several influential parameters, including ultrasound, ozone dose, HCl concentration, liquid/solid ratio, temperature, and reaction time on the leaching efficiency were investigated. The results showed that the optimal conditions for Cu leaching included an ozone dose of 700 mg/h, HCl concentration of 3.0 M, liquid/solid ratio of 8, and temperature of 333 K. Under optimal conditions, about 99% of Cu was leached after 180 min. The shrinking core model was used to analyze the kinetics of the Cu leaching process, and the results showed that the surface chemical reaction governs this process. The activation energy of the leaching reaction, calculated using Two-Point form of the Arrhenius equation, was 10.852 kJ mol−1.
The Selective LAT1 Inhibitor JPH203 Enhances Mitochondrial Metabolism and Content in Insulin-Sensitive and Insulin-Resistant C2C12 Myotubes
Authors: Rivera Caroline N. , Smith Carly E. , Draper Lillian V. , Ochoa Gabriela E. , Watne Rachel M. , Wommack Andrew J. , Vaughan Roger A.
Published: June 2023

Population data have shown an association between higher circulating branched-chain amino acids (BCAA) and the severity of insulin resistance in people with diabetes. While several studies have assessed BCAA metabolism as a potential target for regulation, less attention has been paid to the role of L-type amino acid transporter 1 (LAT1), the primary transporter of BCAA in skeletal muscle. The aim of this study was to assess the impact of JPH203 (JPH), a LAT1 inhibitor, on myotube metabolism in both insulin-sensitive and insulin-resistant myotubes. C2C12 myotubes were treated with or without 1 μM or 2 μM JPH for 24 h with or without insulin resistance. Western blot and qRT-PCR were used to assess protein content and gene expression, respectively. Mitochondrial and glycolytic metabolism were measured via Seahorse Assay, and fluorescent staining was used to measure mitochondrial content. BCAA media content was quantified using liquid chromatography–mass spectrometry. JPH at 1 μM (but not 2 μM) increased mitochondrial metabolism and content without inducing changes in mRNA expression of transcripts associated with mitochondrial biogenesis or mitochondrial dynamics. Along with increased mitochondrial function, 1μM treatment also reduced extracellular leucine and valine. JPH at 2 μM reduced pAkt signaling and increased extracellular accumulation of isoleucine without inducing changes in BCAA metabolic genes. Collectively, JPH may increase mitochondrial function independent of the mitochondrial biogenic transcription pathway; however, high doses may reduce insulin signaling.
Association of Selenium Intake and Selenium Concentrations with Risk of Type 2 Diabetes in Adults: A Narrative Review
Authors: Alharithy Maha , Alafif Nora
Published: June 2023

Several recent studies have suggested selenium (Se) as a potential risk factor for diabetes mellitus (DM); however, the relationship between high Se levels and type 2 diabetes mellitus (T2DM) risk remains unclear. This review article aimed to provide a comprehensive discussion to clarify the association between high dietary Se intake and blood Se concentrations and the risk of T2DM among adults. We conducted searches in the PubMed, Science Direct, and Google Scholar databases for the years 2016 to 2022 and evaluated 12 articles from systematic reviews, meta-analyses, cohort studies, and cross-sectional studies. This review found a controversial association between high blood Se concentrations and T2DM risk while demonstrating a positive correlation with DM risk. In contrast, there are conflicting results regarding the association between high dietary Se intake and T2DM risk. Thus, longitudinal studies and randomized controlled trials are needed to better elucidate the link.
A Miniature Multi-Functional Photoacoustic Probe
Authors: Lin Riqiang , Zhang Jiaming , Gao Wen , Wang Xiatian , Lv Shengmiao , Lam Kwok-Ho , Gong Xiaojing
Published: June 2023

Photoacoustic technology is a promising tool to provide morphological and functional information in biomedical research. To enhance the imaging efficiency, the reported photoacoustic probes have been designed coaxially involving complicated optical/acoustic prisms to bypass the opaque piezoelectric layer of ultrasound transducers, but this has led to bulky probes and has hindered the applications in limited space. Though the emergence of transparent piezoelectric materials helps to save effort on the coaxial design, the reported transparent ultrasound transducers were still bulky. In this work, a miniature photoacoustic probe with an outer diameter of 4 mm was developed, in which an acoustic stack was made with a combination of transparent piezoelectric material and a gradient-index lens as a backing layer. The transparent ultrasound transducer exhibited a high center frequency of ~47 MHz and a −6 dB bandwidth of 29.4%, which could be easily assembled with a pigtailed ferrule of a single-mode fiber. The multi-functional capability of the probe was successfully validated through experiments of fluid flow sensing and photoacoustic imaging.
The Role of the Plant–Soil Relationship in Agricultural Production—With Particular Regard to PGPB Application and Phytoremediation
Authors: Kisvarga Szilvia , Hamar-Farkas Dóra , Ördögh Máté , Horotán Katalin , Neményi András , Kovács Dezső , Orlóci László
Published: June 2023

Plant growth-promoting bacteria (PGPB) and other living organisms can help with the challenges of modern agriculture. PGPB offer ever-expanding possibilities for science and commerce, and the scientific results have been very advanced in recent years. In our current work, we collected the scientific results of recent years and the opinions of experts on the subject. Opinions and results on soil–plant relations, as well as the importance of PGPB and the latest related experiences, are important topics of our review work, which highlights the scientific results of the last 3–4 years. Overall, it can be concluded from all these observations that the bacteria that promote plant development are becoming more and more important in agriculture almost all over the world, thus, promoting more sustainable and environmentally conscious agricultural production and avoiding the use of artificial fertilizers and chemicals. Since many mechanisms of action, namely biochemical and operational processes, are still under investigation, a new emerging scientific direction is expected in the coming years with regard to PGPB, microbial, and other plant growth-stimulating substances, in which omics and microbial modulation also play a leading role.
Entomopathogenic Fungi: An Eco-Friendly Synthesis of Sustainable Nanoparticles and Their Nanopesticide Properties
Authors: Bihal Ritu , Al-Khayri Jameel M. , Banu A. Najitha , Kudesia Natasha , Ahmed Farah K. , Sarkar Rudradeb , Arora Akshit , Abd-Elsalam Kamel A.
Published: June 2023

The agricultural industry could undergo significant changes due to the revolutionary potential of nanotechnology. Nanotechnology has a broad range of possible applications and advantages, including insect pest management using treatments based on nanoparticle insecticides. Conventional techniques, such as integrated pest management, are inadequate, and using chemical pesticides has negative consequences. As a result, nanotechnology would provide ecologically beneficial and effective alternatives for insect pest control. Considering the remarkable traits they exhibit, silver nanoparticles (AgNPs) are recognized as potential prospects in agriculture. Due to their efficiency and great biocompatibility, the utilization of biologically synthesized nanosilver in insect pest control has significantly increased nowadays. Silver nanoparticles have been produced using a wide range of microbes and plants, which is considered an environmentally friendly method. However, among all, entomopathogenic fungi (EPF) have the most potential to be used in the biosynthesis of silver nanoparticles with a variety of properties. Therefore, in this review, different ways to get rid of agricultural pests have been discussed, with a focus on the importance and growing popularity of biosynthesized nanosilver, especially silver nanoparticles made from fungi that kill insects. Finally, the review highlights the need for further studies so that the efficiency of bio-nanosilver could be tested for field application and the exact mode of action of silver nanoparticles against pests can be elucidated, which will eventually be a boon to the agricultural industry for putting a check on pest populations.
Prediction of Ore Production in a Limestone Underground Mine by Combining Machine Learning and Discrete Event Simulation Techniques
Authors: Park Sebeom , Jung Dahee , Choi Yosoon
Published: June 2023

This study proposes a novel approach for enhancing the productivity of mining haulage systems by developing a hybrid model that combines machine learning (ML) and discrete event simulation (DES) techniques to predict ore production. This study utilized time data collected from a limestone underground mine using tablet computers and Bluetooth beacons for 15 weeks. The collected data were used to train an ML model to predict truck cycle time, and the support vector regression with particle swarm optimization (PSO–SVM) model demonstrated the best performance. The PSO–SVM model accurately predicted cycle time with a mean absolute error (MAE) of 2.79 min, mean squared error (MSE) of 14.29 min2, root mean square error (RMSE) of 3.79 min, and coefficient of determination (R2) of 0.68. The output of the ML model was linked to the DES model to predict ore production for each truck, section, and time period. Verification of the DES model demonstrated its ability to accurately simulate the haulage system in the study area by comparing production logs with the simulation results. This study’s novel approach offers a new method for predicting ore production and determining the optimal equipment combination for each workplace, thus enhancing productivity in mining haulage systems.