bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of miniatured MRI coils for MRI‐guided tumor diagnosis and hyperthermia therapy
Authors: Karuppanan Sakthisudhan , V R Vinothini , Narasimman Saranraj , Chenguttuvan Ezhilazhagan 
Published: January 2024

AbstractIn this paper, the researchers offer a miniatured design of microstrip lines based on magnetic resonance imaging (MRI) coils that can be utilized to detect tumor tissues and to restore those tissues after radiotherapy. A 61.67% reduction in size was achieved in the MRI array dimensions when compared to the previously reported MRI coils. The reliability of the design specifications was verified. The proposed MRI coils could contribute two resonant modes. Primarily, these MRI coils were suitable for homogenous magnetic field and they enable radio frequency (RF) heating by generating a concentrated electric field |E|. The collective temperature and specific absorption ratio (SAR) have been estimated at Larmor frequency. In this study, it was possible to create a uniform magnetic flux density |B1| field operating at 500 MHz. These proposed coils were excited at 8.06 GHz. When simulating cancer in a biological system, healthy tissues were introduced into a Class A scenario and malignant tissues were introduced into a Class B scenario. According to these two scenarios, tumor tissues were magnetically (|B1|) homogeneous with a 44.1% standard deviation with rapidly raised temperature at 4.77°C. These MRI coils delivered an impact on diagnostic imaging and parallelly restored the cancerous tissues by hyperthermia.
Possible improvements in effective fill factor using X‐ray fluorescent interpixel reflectors
Authors: Hsieh Scott S. 
Published: January 2024

AbstractBackgroundThe spatial resolution of energy‐integrating diagnostic CT scanners is limited by interpixel reflectors on the detector, which optically isolate pixels but create dead space. Because the width of the reflector cannot easily be decreased, fill factor diminishes as resolution increases.PurposeWe propose loading (or mixing) a high‐Z element into the reflectors, causing the reflectors to be X‐ray fluorescent. Re‐emitted characteristic X‐rays could be detected in adjacent pixels, increasing the effective fill factor and compensating for fill factor loss with higher‐resolution detectors. The purpose of this work is to understand the physical principles of this approach and to analyze its effectiveness using Monte Carlo simulations.MethodsDetector pixels were modeled using the GEANT4 Monte Carlo package. The width of the reflector was kept constant at 0.1 mm throughout, and we considered pixel pitches between 0.5 and 1 mm. The pixelated scintillator material was gadolinium oxysulfide, 3 mm thick. The baseline reflector material was chosen to be acrylic, and varying concentrations of a high‐Z element were loaded into the material. We assumed that the optical characteristics of pixels were ideal (no absorption within pixels, perfect reflection at boundaries). The detector was irradiated uniformly with 10,000 X‐ray photons to estimate its spectral response. The figure of merit was the variance of the detector signal at zero frequency normalized to that of an ideal single‐bin photon‐counting detector with 100% fill factor. Sensitivity analyses were conducted to understand the effect of varying the high‐Z element concentration and the spectrum.ResultsInitial simulations suggested that a k‐edge near 50 keV would be ideal. Gd was therefore selected as the high‐Z material. The relative variances for a conventional energy integrating detector without Gd at 1 mm pixel pitch (81% fill factor) and 0.5 mm pixel pitch (64% fill factor) were 1.38 and 1.74, compared to 1.00 for an ideal photon counting detector, implying a 26% variance penalty for 0.5 mm pitch. When 1 g/cm3 Gd was loaded into the interpixel reflector, the relative variance improved to 1.27 and 1.43, respectively, implying that the variance penalty for including Gd together with 0.5 mm pitch is only 4%. Performance was nearly maximized at 1.0 g/cm3 of Gd, but a concentration of 0.5 g/cm3 of Gd showed most of the benefit. Improvements depend weakly on kV, with lower kV associated with higher improvements. An external anti‐scatter grid was not modeled in our simulations and would reduce the expected benefit, depending greatly on the pitch and dimensionality of the anti‐scatter grid.ConclusionsThe losses in fill factor associated with smaller pixel pitch can be reduced if Gd or a similar element could be loaded into the interpixel reflector. These improvements in noise efficiency are yet to be verified experimentally.
Rock fracture propagation in a damage zone by a constitutive model coupling volume and cohesive elements
Authors: He Haozhou , Arson Chloé 
Published: January 2024

AbstractThis paper presents a method to simulate fracture propagation in a damage zone in 2D, whereby Cohesive Zone (CZ) elements are assigned the same Continuum Damage Mechanics (CDM) model as their adjacent finite elements. Material hardening is a result of damage‐induced stiffness reduction in the finite and cohesive elements, while softening is modeled by cohesive debonding only. The damage components calculated at the numerical integration points of each finite element are averaged and that average is assigned to the nodes of the adjacent CZ elements. CZ element debonding triggers when a critical damage threshold is reached, beyond which, a linear softening law is used in both mode I and mode II. The proposed model is calibrated against published triaxial compression tests conducted on shale. Single‐CZ element simulations confirm that, below the critical damage threshold, elastic deformation energy is stored and energy is dissipated by damage propagation and irreversible deformation. Passed the critical damage threshold, stored elastic energy is released in the form of cohesive debonding energy. Borehole breakout simulations indicate that the proposed CDM‐based CZ model can predict the formation of spiral‐shaped fractures around a free circular cavity under biaxial stress. Simulations of fracture propagation in textured materials suggest that cohesive debonding within and between grains is triggered by the coalescence of localized zones of continuum damage, and that the grain size distribution affects both the fracture pattern and the softening behavior of the specimen considered.
Preparation of a novel SiO2/PMMA nanocomposite with high transparency, thermal stability, and superior surface hardness via gamma‐radiation polymerization
Authors: Dong Chunlei , Mao Xuanzhi , Wang Minglei , Zhang Maojiang , Chen Jianbing , Hu Jiangtao , Wu Guozhong 
Published: January 2024

AbstractHeat‐resistant, highly surface‐hardened, and transparent composites of poly(methylmethacrylate) (PMMA) play a significant role in modern devices. However, conventional PMMA‐based composites with high nanoparticle loadings often compromise transparency for high surface hardness and heat resistance due to nanoparticle aggregation and poor interfacial compatibility. In this work, we successfully fabricated an exceptional composite (MSiO2/PMMA composites) with high transparency, superior heat resistance, and high surface hardness using γ‐ray irradiation‐induced polymerization of methyl methacrylate (MMA) containing uniformly dispersed SiO2 that was modified by 3‐methacryloxypropyl trimethoxysilane and trimethylchlorosilane. Specific silanes were utilized for polarity regulation to reduce the agglomeration of SiO2 nanoparticles and improve compatibility with MMA. Compared to pure PMMA, the 40‐MSiO2/PMMA composite sample exhibited significantly improved thermal stability in terms of the temperature at 10% weight loss (T10%), glass transition temperature (Tg), and decreased coefficient of thermal expansion (CTE). Furthermore, this composite achieves a very high surface hardness (pencil hardness of 6H versus H for pure PMMA) while maintaining transparency similar to PMMA. These MSiO2/PMMA composites open up new avenues to enhance the performance and durability of materials used in various industries such as electronics, optics, automotive, and aerospace.
Experimental and numerical investigation on the crashworthiness performance of double hat‐section Al‐CFRP beam subjected to quasi‐static bending test
Authors: Bidadi J. , Hampaiyan Miandowab H. , Saeidi Googarchin H. , Akhavan‐Safar A. , da Silva L. F. M. 
Published: January 2024

AbstractNowadays, hybrid structures, which combine low‐density composites with low‐cost thin‐walled metals, have shown great effect in enhancing the performance of automotive body structures, especially the energy absorber components. This study focuses on the experimental and numerical investigation of the bending energy absorption behavior of CFRP/aluminum hybrid double hat‐section beams used in the side part of the car body. In the experimental section, two types of double hat‐section beams were fabricated: aluminum and Al/CFRP. These beams were then subjected to quasi‐static three‐point bending tests. The results demonstrated that the hybrid beam exhibited superior energy absorption capabilities compared to the single beam. Subsequently, a finite element model was developed using LS‐Dyna software and was validated by comparing the experimental and numerical load–displacement results. In‐depth numerical analyses were conducted to investigate the influence of various design parameters, including CFRP‐reinforcement configuration, numbers of CFRP layers, CFRP ply‐angle, CFRP reinforced length, and aluminum/CFRP mass, on crashworthiness indicators. The numerical findings indicate that the hybrid beam with , ply‐angles exhibited better crash force efficiency (CFE) and specific energy absorption (SEA) compared to other ply‐angles, respectively. Furthermore, increasing the number of CFRP layers within the total beam's mass improved its energy absorption capacity. It was also revealed that the CFRP length on the upper and lower hats could be considered as 42.5% of the total aluminum beam length, as opposed to the full CFRP length, providing enhanced energy absorption capabilities.Highlights
Bending behavior of the Al and Al/CFRP double hat section beams.
Effects of variable thickness and identical mass on the double hat section beam.
Effects of variable ply angle and number of CFRP layers on the hybrid beams.
Discrete effect of CFRP reinforcement configurations and inner CFRP lengths.
Analyzing domain features of small proteins using a machine‐learning method
Authors: Ding ShiJian , Liao HuiPing , Huang FeiMing , Chen Lei , Guo Wei , Feng KaiYan , Huang Tao , Cai Yu‐Dong 
Published: January 2024

AbstractSmall proteins (SPs) are a unique group of proteins that play crucial roles in many important biological processes. Exploring the biological function of SPs is necessary. In this study, the InterPro tool and the maximum correlation method were utilized to analyze functional domains of SPs. The purpose was to identify important functional domains that can indicate the essential differences between small and large protein sequences. First, the small and large proteins were represented by their functional domains via a one‐hot scheme. Then, the MaxRel method was adopted to evaluate the relationships between each domain and the target variable, indicating small or large protein. The top 36 domain features were selected for further investigation. Among them, 14 were deemed to be highly related to SPs because they were annotated to SPs more frequently than large proteins. We found the involvement of functional domains, such as ubiquitin‐conjugating enzyme/RWD‐like, nuclear transport factor 2 domain, and alpha subunit of guanine nucleotide‐binding protein (G‐protein) in regulating the biological function of SPs. The involvement of these domains has been confirmed by other recent studies. Our findings indicate that protein functional domains may regulate small protein–related functions and predict their biological activity.
Impact of ring structure and conjugation on the dielectric properties of polyimides at a high frequency of 10–40 GHz
Authors: Wu Meng‐Hsuan , Chang Chieh‐Yuan , Liu Yu , Chen Wen‐Chang , Lin Yan‐Cheng 
Published: January 2024

AbstractPolyimides (PIs) are widely used materials due to their high thermal stability and potentially low dielectric constant (Dk) and dissipation factor (Df). However, Dk and Df values tend to increase at higher frequencies. Therefore, there is a significant need to reduce the Dk and Df values of PIs, which is the main purpose of this study. This research considers multiple factors, including the ring structures and conjugations on the conformation of the PI backbone. The effects of five‐membered and six‐membered PIs and the conjugated length of benzene and naphthalene structures in the repeating units on the thermomechanical and dielectric properties are systematically investigated. As a result, the PI with a six‐membered imide contributes to higher thermal stability, with a glass transition temperature higher than 350 °C, a thermal decomposition point of 529 °C, and a lower Dk of 2.7–2.8. Still, it exhibits a lower molecular weight than that of a five‐membered imide. On the other hand, PIs with esterified structures show an extremely low Df value, 0.002–0.005. This situation can be attributed to the vital correlation between the Df and the volumetric dipole moment. This study also presents the different properties arising from ring structures and conjugations. Meanwhile, the relationships between Dk and volumetric polarizability and between Df and volumetric dipole moment are confirmed. This work provides a guideline for the structure−dielectric relationship of PI at a high frequency of 10–40 GHz.
Scopolamine regulates the osteogenic differentiation of human periodontal ligament stem cells through lactylation modification of RUNX2 protein
Authors: Wu Ying , Gong Pan 
Published: January 2024

AbstractPeriodontal ligament stem cells (PDLSCs) are important mesenchymal stem cells contributing to regenerating lost periodontal tissues and repairing bone defects. Studies on the molecular mechanism affecting the osteogenic differentiation of PDLSCs are necessary. Scopolamine (SCO) is known as a regulator of neural cell damage. The focus of the current study is on unveiling the role of SCO‐mediated molecular mechanism in the osteogenic differentiation of PDLSCs. Through CCK‐8 assay and LDH detection, we confirmed that SCO enhanced the viability of PDLSCs. Moreover, we determined that SCO induced the PDLSCs osteogenic differentiation, according to data of ALP activity measurement and ARS staining. Mechanistically, we performed western blot and identified that SCO could promote the lactylation of runt‐related transcription factor 2 (RUNX2). We also found through rescue assays that knockdown of RUNX2 could reverse the effect of SCO treatment on the osteogenic differentiation of PDLSCs. Further mechanism investigation revealed that lactylation of RUNX2 at K176 site enhances the protein stability of RUNX2 through deubiquitination. Collectively, our present study unveils that SCO stabilizes RUNX2 to promote the osteogenic differentiation of PDLSCs through the lactylation modification of RUNX2.
Tandem mass spectrometry using continuous‐wave infrared multiphoton dissociation in an electrostatic linear ion trap
Authors: Carrick Ian J. , Fabijanczuk Kimberly C. , Rong Jiayue , McLuckey Scott A. 
Published: January 2024

RationaleThe electrostatic linear ion trap (ELIT) can be operated as a multi‐reflection time‐of‐flight (MR‐TOF) or Fourier transform (FT) mass analyzer. It has been shown to be capable of performing high‐resolution mass analysis and high‐resolution ion isolations. Although it has been used in charge‐detection mass spectrometry (CDMS), it has not been widely used as a conventional mass spectrometer for ensemble measurements of ions, or for tandem mass spectrometer. The advantages of tandem mass spectrometer with high‐resolution ion isolations in the ELIT have thus not been fully exploited.MethodsA homebuilt ELIT was modified with BaF2 viewports to facilitate transmission of a laser beam at the turnaround point of the second ion mirror in the ELIT. Fragmentation that occurs at the turnaround point of these ion mirrors should result in minimal energy partitioning due to the low kinetic energy of ions at these points. The laser was allowed to irradiate ions for a period of many oscillations in the ELIT.ResultsDue to the low energy absorption of gas‐phase ions during each oscillation in the ELIT, fragmentation was found to occur over a range of oscillations in the ELIT generating a homogeneous ion beam. A mirror‐switching pulse is shown to create time‐varying perturbations in this beam that oscillate at the fragment ion characteristic frequencies and generate a time‐domain signal. This was found to recover FT signal for protonated pYGGFL and pSGGFL precursor ions.ConclusionsFragmentation at the turnaround point of an ELIT by continuous‐wave infrared multiphoton dissociation (cw‐IRMPD) is demonstrated. In cases where laser power absorption is low and fragmentation occurs over many laps, a mirror‐switching pulse may be used to recover varying time‐domain signal. The combination of laser activation at the turnaround points and mirror‐switching isolation allows for tandem MS in the ELIT.
Nitrogen‐Doped Bifunctional Carbon Dots: Photoluminescence Investigation, and Fluorescent Recognition Applications
Authors: Zhang Ran , Fu Fubin , Cao Jing , Chen Zhengyang 
Published: January 2024

AbstractIn this work, three kinds of bifunctional carbon dots fluorescent sensor a‐CDs, b‐CDs and c‐CDs were prepared using 2,2‐di(prop‐2‐yn‐1‐yl)malonic acid as substrate, which are rich in carboxylic acid and conjugated structure. The morphology, chemical composition and optical properties of the prepared carbon quantum dots were characterized by transmission electron microscopy (TEM), X‐ray Photoelectron spectroscopy (XPS), FTIR, X‐ray diffraction (XRD), UV‐vis spectroscopy and fluorescence (FL). They display excellent water solubility, thermal stability and salt resistance, and overcomes the loss of optical activity in the dry state, which have been applied to the detection of aqueous metal ions and anions. Among them, the fluorescence quenching of Hg2+ and Cu2+ by a‐CDs and b‐CDs is obvious, which can be used as a highly sensitive dual ion sensor. At the same time, it has a good recognition and detection effect on 0–12 ppm ClO− or MnO4−, and the detection limits are as low as 0.1209 ppm and 0.0574 ppm, respectively. In addition, chiral c‐CDs can specifically recognize Hg2+, and the synergistic effect of c‐CDs and Hg2+ can improve the recognition of chiral enantiomers.
Designing Highly Fluorescent BenzoCoumarin‐Sesamol Conjugates for Optoelectronic Applications
Authors: Madar Mahesh , Pujar Malatesh S. , A. H. Shridhar , Basanagouda Mahanthesh M. , Sidarai Ashok H. 
Published: January 2024

AbstractIn this report we have studied, the substitutional effect on photophysical properties of newly synthesized isomeric benzocoumarin‐Sesamol conjugates using absorption, steady‐state fluorescence emission, and time‐resolved emission measurements. The structural characterization of the synthesized dyes was carried out using FT‐IR, 1H‐NMR, 13C‐NMR, and MS. The ground state dipole moment of both the molecules in the gaseous phase is estimated from ab initio computations by using Gaussian 09W software and also from solvatochromic method and the results are compared. Stoke's shift exhibits a redshift with an increase in solvent polarity for synthesized indicating a π–π* transition. The HOMO‐LUMO energy gaps computed from density functional theory and absorption threshold wavelengths are found to be in good agreement with each other. The Global chemical reactivity descriptor parameter and electrostatic potential (MESP) plots suggest that molecules have strong electrophilic and nucleophilic sites. The preliminary photophysical observations and results suggest that the fluorescent dyes can be considered as potential material for the construction of solar cells, fluorescent probes, and chemosensors.
Synthesis, Characterization, Investigation of Anticancer Activity and Molecular Docking Studies of N2O2 Type Schiff Base Ligand and Metal Complexes
Authors: Türkmenoğlu Mustafa , Yıldırım Sümeyra Tuna , Altay Ahmet , Türkmenoğlu Burçin 
Published: January 2024

AbstractSchiff base ligands and their metal complexes play a great important role in pharmaceutical sciences because of their wide and significant activities. They are versatile pharmacophores for the design and discovery of many drugs. In this study, a Schiff base ligand and its complexes were synthesized. Some spectroscopic techniques such as FT‐IR, 1H‐NMR, 13C‐NMR, XRD, SEM, and UV‐Vis were used for structural characterization. Antiproliferative activities of the synthesized ligand and complexes were investigated on the human breast (MCF‐7) and colon (HT‐29) cancer cell lines by XTT [2,3‐Bis(2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐tetrazolium] method. The obtained data showed that the ligand and complexes exhibited dose‐dependent and cell‐selective in vitro antiproliferative activity on the tested cell line. In addition, it was determined that complexes showed statistically higher cytotoxic activity compared to the ligand. The binding parameter values and the important amino acids in the binding site were determined between the possible lead compounds synthesized by molecular docking from in silico approaches and the target. A molecular docking study of the cobalt complex was performed against Bcl‐2 (PDB ID:4IEH) and DNA recognition (PDB ID:423D) targets. In conclusion, these data show that the synthesized Schiff base ligand and metal complexes have the potential to be evaluated as a chemotherapeutic agent.
PTSA‐Mediated Bis 1,6‐Conjugate Addition of N‐Alkylcarbazoles and N‐Alkyliminodibenzyls to para‐Quinone Methides: Synthesis of Heterocyclic Bis Triarylmethanes
Authors: Sanjana Ramesh , Gurumurthy Palanivelu , Parthasarathy Kanniyappan 
Published: January 2024

AbstractAn efficient and simple PTSA‐mediated bis 1,6‐conjugate addition of N‐alkylcarbazoles, N‐alkyliminodibenzyls and hydroquinone to para‐quinone methides is discussed. This protocol is useful to prepare various bis‐triarylmethanes in good to excellent yields under mild reaction conditions with good functional group tolerance. It is important to mention that, these heterocyclic triarylmethanes are often used in the biological community.
High‐Throughput Miniaturized Synthesis of PROTAC‐Like Molecules
Authors: Tian Ye , Seifermann Maximilian , Bauer Liana , Luchena Charlotte , Wiedmann Janne J. , Schmidt Stefan , Geisel Alexander , Afonin Sergii , Höpfner Julius , Brehm Marius , Liu Xinyong , Hopf Carsten , Popova Anna A. , Levkin Pavel A. 
Published: January 2024

AbstractThe development of miniaturized high‐throughput in situ screening platforms capable of handling the entire process of drug synthesis to final screening is essential for advancing drug discovery in the future. In this study, an approach based on combinatorial solid‐phase synthesis, enabling the efficient synthesis of libraries of proteolysis targeting chimeras (PROTACs) in an array format is presented. This on‐chip platform allows direct biological screening without the need for transfer steps. UV‐induced release of target molecules into individual droplets facilitates further on‐chip experimentation. Utilizing a mitogen‐activated protein kinase kinases (MEK1/2) degrader as a template, a series of 132 novel PROTAC‐like molecules is synthesized using solid‐phase Ugi reaction. These compounds are further characterized using various methods, including matrix‐assisted laser desorption ionization mass spectrometry (MALDI‐MS) imaging, while consuming only a few milligrams of starting materials in total. Furthermore, the feasibility of culturing cancer cells on the modified spots and quantifying the effect of MEK suppression is demonstrated. The miniaturized synthesis platform lays a foundation for high‐throughput in situ biological screening of potent PROTACs for potential anticancer activity and offers the potential for accelerating the drug discovery process by integrating miniaturized synthesis and biological steps on the same array.