bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability of Octadecyltrimethoxysilane-Based Coatings on Aluminum Alloy Surface
Authors: Zhizhchenko Alexey Y. , Shabalina Anastasiia V. , Aljulaih Ali A. , Gurbatov Stanislav O. , Kuchmizhak Aleksandr A. , Iwamori Satoru , Kulinich Sergei A.
Published: March 2022

Long-term stability in contact with water of organosilane layers formed by octadecyltrimethoxysilane (ODTMS) on polished aluminum alloy (AA2024) through dip-coating was studied by combining SEM, water contact angle measurements, and X-ray photoelectron spectroscopy. Similar organosilane layers were formed on AA2024 coated with permanganate conversion coating, 1,2-bis(triethoxysilyl)ethane (BTSE) and hydrated SiOx as under-layers, after which their long-term durability was also tested. During immersion in water for about one month, all the samples exhibited a decrease in hydrophobicity, implying the prepared organosilane layer was not stable over time, gradually hydrolyzing and letting water interact with the underlying layer. In parallel, SEM images of one-layer samples taken after immersion showed clear signs of local electrochemical corrosion, while XPS analysis confirmed a loss of silicon from the surface layer. The highest stability over time was demonstrated by a one-layer sample prepared in an ethanol/water bath for 5 min and by a similar ODTMS layer prepared on hydrated MnOx as an under-layer.
Effects of Intercooling Intensity on Temperature Field and Microstructure of Large-Scale 2219 Al Alloy Billet Prepared by Internal Electromagnetic Stirring Casting
Authors: Qiu Yang , Li Xintao , Liu Mingyang , Zhou Nan , Zheng Kaihong
Published: March 2022

Internal electromagnetic stirring is an advanced melt treatment method, which can be used in direct chill casting to prepare large-scale Al alloy billets. Intercooling intensity is a primary parameter of internal electromagnetic stirring; its effects on temperature fields and microstructures have been investigated via numerical simulations and industrial experiments, respectively. The simulated results show an increase in the intercooling affected area and a decrease in sump depth with an increase in the intercooling heat transfer coefficient. The heat transfer coefficient should not exceed 500 W/(m2 °C) because the solid fraction of the intercooling end bottom may exceed 50%. The experiment’s results demonstrate that the average grain sizes in the edge, 1/2 radius, and center are 151 ± 13 μm, 159 ± 14 μm, and 149 ± 16 μm, respectively, under a liquid nitrogen flow rate of 160 L/min, which is much finer than that of 80 L/min and more homogeneous than that of 240 L/min. Furthermore, an experimental liquid nitrogen flow rate of 80 L/min, 160 L/min, and 240 L/min approximately correspond to the simulated heat transfer coefficient of 200 W/(m2 °C), 300 W/(m2 °C), and 400 W/(m2 °C), respectively.
Study on Deterioration of Gray Brick with Different Moisture Contents under Freeze–Thaw Environment
Authors: Yue Jianwei , Ma Can , Zhao Limin , Kong Qingmei , Xu Xiangchun , Wang Zifa , Chen Ying
Published: March 2022

Generally, brick buildings are in the open-air environment year round, and damage to them is aggravated by the effect of repeated freezing and thawing cycles. In order to determine freeze–thaw damage and deterioration mechanism, the initial moisture content of gray brick specimens was set as 20%, 40%, 60%, 80%, 100%. The effects of moisture content and the number of freeze–thaw cycles on the quality, mechanical properties and microstructure of gray brick were investigated by uniaxial compression tests and scanning electron microscopy (SEM) tests. Numerical simulations were applied to model the freezing and thawing process. The results showed that: as the number of freeze–thaw cycles increased, the mass loss rate and peak strength reduction rate of gray brick both increased. The initial moisture content had a greater impact on damage to gray brick due to freeze–thaw; ω = 80% was defined as the limit moisture content of gray brick. Under the repeated action of freeze–thaw cycles, the areas affected by thermal stress were mainly concentrated in the center of the outer surface and the center of the side of gray bricks. The maximum thermal stress after 55 freeze–thaw cycles was 1.522 × 10−2 MPa. This research results provide a theoretical basis for the prevention and protection of frost damage of brick buildings in a freeze–thaw environment.
Investigation of the Dynamic Stiffness of Poroelastic and Asphalt Concrete Layers under In Situ and Laboratory Conditions
Authors: Czech Krzysztof Robert , Gardziejczyk Wladyslaw
Published: March 2022

Compounds with lower dynamic stiffness are a better solution from the tyre/road noise point of view. The article presents the constructed test stand for the evaluation of dynamic stiffness both in in situ and in laboratory conditions. As a result of the tests, it was found that poroelastic pavements have a much lower dynamic stiffness (from 138.3 to 143.0 dB re. 1 N/m) compared to the asphalt concrete pavement (150.3 dB re. 1 N/m). In the group of poroelastic pavements, lower dynamic stiffness is characteristic for pavements with a binder course of porous asphalt. The results of the research are a contribution to further work on the influence of the dynamic stiffness of the pavements on the tyre/road noise level. The conducted measurements and analysis of the results prove the usefulness of the proposed test stand for determining the dynamic stiffness of bituminous mixtures in laboratory and field conditions. This is confirmed by the coherence between the force and acceleration signals at the level of at least 0.96—which indicates a very good validation of the test results with a random error lower than ±5% with 90% confidence level.
Osteogenic Induction with Silicon Hydroxyapatite Using Modified Autologous Adipose Tissue-Derived Stromal Vascular Fraction: In Vitro and Qualitative Histomorphometric Analysis
Authors: Khan Muhammad Marghoob , Butt Shadab Ahmed , Chaudhry Aqif Anwar , Rashid Amir , Ijaz Kashif , Majeed Asifa , Gul Hashmat
Published: March 2022

Large bone defects requiring invasive surgical procedures have long been a problem for orthopedic surgeons. Despite the use of autologous bone grafting, satisfactory results are often not achieved due to associated limitations. Biomaterials are viable alternatives and have lately been used in association with Stromal Vascular Fraction (SVF), stem cells, and signaling factors for bone tissue engineering (BTE). The objective of the current study was to assess the biocompatibility of Silicon Hydroxyapatite (Si-HA) and to improve osteogenic potential by using autologous adipose-derived SVF with Si-HA in a rabbit bone defect model. Si-HA granules synthesized using a wet precipitation method were used. They were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). A hemolysis assay was used to assess the hemolytic effects of Si-HA, while cell viability was assessed through Alamar Blue assay using MC3T3 mouse osteoblasts. The osteogenic potential of Si-HA both alone and with enzymatically/non-enzymatically-derived SVF (modified) was performed by implantation in a rabbit tibia model followed by histomorphometric analysis and SEM of dissected bone after six weeks. The results showed that Si-HA granules were microporous and phase pure and that the addition of Silicon did not influence Si-HA phase composition. Si-HA granules were found to be non-hemolytic on the hemolysis assay and non-toxic to MC3T3 mouse osteoblasts on the Alamar Blue assay. Six weeks following implantation Si-HA showed high biocompatibility, with increased bone formation in all groups compared to control. Histologically more mature bone was formed in the Si-HA implanted along with non-enzymatically-derived modified SVF. Bone formation was observed on and around Si-HA, reflecting osseointegration. In conclusion, Si-HA is osteoconductive and promotes osteogenesis, and its use with SVF enhances osteogenesis.
Fucoidan (Undaria pinnatifida)/Polydopamine Composite-Modified Surface Promotes Osteogenic Potential of Periodontal Ligament Stem Cells
Authors: Kwack Kyu Hwan , Ji Ju Young , Park Borami , Heo Jung Sun
Published: March 2022

Fucoidan, a marine-sulfated polysaccharide derived from brown algae, has been recently spotlighted as a natural biomaterial for use in bone formation and regeneration. Current research explores the osteoinductive and osteoconductive properties of fucoidan-based composites for bone tissue engineering applications. The utility of fucoidan in a bone tissue regeneration environment necessitates a better understanding of how fucoidan regulates osteogenic processes at the molecular level. Therefore, this study designed a fucoidan and polydopamine (PDA) composite-based film for use in a culture platform for periodontal ligament stem cells (PDLSCs) and explored the prominent molecular pathways induced during osteogenic differentiation of PDLSCs through transcriptome profiling. Characterization of the fucoidan/PDA-coated culture polystyrene surface was assessed by scanning electron microscopy and X-ray photoelectron spectroscopy. The osteogenic differentiation of the PDLSCs cultured on the fucoidan/PDA composite was examined through alkaline phosphatase activity, intracellular calcium levels, matrix mineralization assay, and analysis of the mRNA and protein expression of osteogenic markers. RNA sequencing was performed to identify significantly enriched and associated molecular networks. The culture of PDLSCs on the fucoidan/PDA composite demonstrated higher osteogenic potency than that on the control surface. Differentially expressed genes (DEGs) (n = 348) were identified during fucoidan/PDA-induced osteogenic differentiation by RNA sequencing. The signaling pathways enriched in the DEGs include regulation of the actin cytoskeleton and Ras-related protein 1 and phosphatidylinositol signaling. These pathways represent cell adhesion and cytoskeleton organization functions that are significantly involved in the osteogenic process. These results suggest that a fucoidan/PDA composite promotes the osteogenic potential of PDLSCs by activation of critical molecular pathways.
The Impact of Industry Funding on Randomized Controlled Trials of Biologic Therapies
Authors: Gazendam Aaron M. , Slawaska-Eng David , Nucci Nicholas , Bhatt Om , Ghert Michelle
Published: March 2022

Background: There has been substantial interest from the pharmaceutical industry to study and develop new biologic agents. Previous studies outside of the biologics field have demonstrated that industry funding has the potential to impact the design and findings of clinical trials. The objective of this study was to evaluate the impact of industry funding on randomized controlled trials (RCTs) that investigated the efficacy of biologic therapies. Methods: A review of all RCTs involving biologic therapies in top impact factor medical journals from January 2018 to December 2020 was performed. The relationship between industry funding and the presence of statistically significant primary outcomes and the use of active comparators were analyzed. Results: Among the 157 RCTs included, 120 (76%) were industry funded and 37 (24%) declared no industry funding. Industry-funded studies were significantly more likely to report a statistically significant positive primary outcome compared to studies without industry funding (85% vs. 67%, χ2 = 5.867, p = 0.015) and were significantly more likely to utilize placebo or no comparator than non-industry-funded trials (78% vs. 49%, χ2 = 4.430, p = 0.035). Conclusions: Industry-funded trials investigating biologic therapies are more likely to yield statistically significant positive outcomes and use placebo comparators when compared to non-industry-funded biologic therapy trials in high-impact medical journals.
Baseline Peritoneal Membrane Transport Characteristics Are Associated with Peritonitis Risk in Incident Peritoneal Dialysis Patients
Authors: Chou Yi-Hsin , Chen Yung-Tai , Chen Jinn-Yang , Tarng Der-Cherng , Lin Chih-Ching , Li Szu-Yuan
Published: March 2022

The peritoneal equilibration test (PET) is a semi-quantitative measurement that characterizes the rate of transfer of solutes and the water transfer rate across the peritoneum in patients treated with peritoneal dialysis (PD). The results of the PET are used to maximize daily peritoneal ultrafiltration and solute clearances. Previous studies have shown that high transport status is associated with ultrafiltration failure, malnutrition, and reduced survival; however, the way in which peritoneum transport characteristics affect peritonitis risk is unknown. In the current cohort study, we recruited 898 incident-PD patients and used intention-to-treat analysis to test if baseline PET affected the subsequent 3-year peritonitis rate. Among all recruited PD patients, 308 (34.2%) developed peritonitis within three years. Multivariate Cox regression analysis showed that the high-transport group has the greatest peritonitis risk (HR 1.98, 95% CI: 1.08–3.62) even after an adjustment for demographics, comorbid diseases, and biochemical measurements. We concluded that a baseline high peritoneal membrane transport rate is an independent risk factor for peritonitis in incident PD patients.
Wrinkled CNTs@PLLA Composite Membranes for Enhanced Separation Performance
Authors: Xu Jinyan , Chen Bajin , Yin Lu , Zhang Liang , Li Yongjin , You Jichun
Published: March 2022

To break the trade-off effect between permeability and selectivity in separation, wrinkled carbon nanotubes@polylactic acid (CNTs@PLLA) composite membranes were successfully fabricated in this work. On pre-deformed PLLA membranes, CNTs were loaded by filtrating their suspension, followed by releasing the PLLA upon heating based on its shape memory effect. The asynchronous deformations of CNTs and PLLA layers produced wrinkled CNTs@PLLA composite membranes. Relative to the reference without wrinkles, the attained wrinkled composite membranes exhibit much higher flux (~12 times) without any loss of rejection ratio during the separation of water-in-hexadecane emulsion. The significant improvement of separation performance can be attributed to the following issues: Firstly, the existence of wrinkles results in higher surface roughness, providing an additional driving force for separation resulting from the enlarged contact-angle difference between water and oil; Secondly, the shrinkage of the supporting PLLA layer during recovery induces the preferred alignment of CNTs along the wrinkle direction, which is the reason for the orientated slit pores with enhanced overlap of neighboring pores in the film-thickness direction; Finally, a wrinkled surface significantly increases the available area for separation. The synergism of the effects discussed above contributes to much higher permeability and comparable selectivity relative to the reference.
TRPV4 Stimulation Level Regulates Ca2+-Dependent Control of Human Corneal Endothelial Cell Viability and Survival
Authors: Donau Jennifer , Luo Huan , Virta Iiris , Skupin Annett , Pushina Margarita , Loeffler Jana , Haertel Frauke V. , Das Anupam , Kurth Thomas , Gerlach Michael , Lindemann Dirk , Reinach Peter S. , Mergler Stefan , Valtink Monika
Published: March 2022

The functional contribution of transient receptor potential vanilloid 4 (TRPV4) expression in maintaining human corneal endothelial cells (HCEC) homeostasis is unclear. Accordingly, we determined the effects of TRPV4 gene and protein overexpression on responses modulating the viability and survival of HCEC. Q-PCR, Western blot, FACS analyses and fluorescence single-cell calcium imaging confirmed TRPV4 gene and protein overexpression in lentivirally transduced 12V4 cells derived from their parent HCEC-12 line. Although TRPV4 overexpression did not alter the baseline transendothelial electrical resistance (TEER), its cellular capacitance (Ccl) was larger than that in its parent. Scanning electron microscopy revealed that only the 12V4 cells developed densely packed villus-like protrusions. Stimulation of TRPV4 activity with GSK1016790A (GSK101, 10 µmol/L) induced larger Ca2+ transients in the 12V4 cells than those in the parental HCEC-12. One to ten nmol/L GSK101 decreased 12V4 viability, increased cell death rates and reduced the TEER, whereas 1 µmol/L GSK101 was required to induce similar effects in the HCEC-12. However, the TRPV4 channel blocker RN1734 (1 to 30 µmol/L) failed to alter HCEC-12 and 12V4 morphology, cell viability and metabolic activity. Taken together, TRPV4 overexpression altered both the HCEC morphology and markedly lowered the GSK101 dosages required to stimulate its channel activity.
Modification of Thin Film Composite Pressure Retarded Osmosis Membrane by Polyethylene Glycol with Different Molecular Weights
Authors: Idris Siti Nur Amirah , Jullok Nora , Lau Woei Jye , Ma’Radzi Akmal Hadi , Ong Hui Lin , Ramli Muhammad Mahyidin , Dong Cheng-Di
Published: March 2022

An investigation of the effect of the molecular weight of polyethylene glycol (PEG) on thin-film composite (TFC) flat sheet polysulfone membrane performance was conducted systematically, for application in forward osmosis (FO) and pressure retarded osmosis (PRO). The TFC flat sheet PSf-modified membranes were prepared via a non-solvent phase-separation technique by introducing PEGs of different molecular weights into the dope solution. The TFC flat sheet PSf-PEG membranes were characterized by SEM, FTIR and AFM. The PSf membrane modified with PEG 600 was found to have the optimum composition. Under FO mode, this modified membrane had a water permeability of 12.30 Lm−2h−1 and a power density of 2.22 Wm−2, under a pressure of 8 bar in PRO mode, using 1 M NaCl and deionized water as the draw and feed solutions, respectively. The high water permeability and good mechanical stability of the modified TFC flat sheet PSF-PEG membrane in this study suggests that this membrane has great potential in future osmotically powered generation systems.
Clinical Perspectives for 18F-FDG PET Imaging in Pediatric Oncology: Μetabolic Tumor Volume and Radiomics
Authors: Lyra Vassiliki , Chatziioannou Sofia , Kallergi Maria
Published: March 2022

Pediatric cancer, although rare, requires the most optimized treatment approach to obtain high survival rates and minimize serious long-term side effects in early adulthood. 18F-FDG PET/CT is most helpful and widely used in staging, recurrence detection, and response assessment in pediatric oncology. The well-known 18F-FDG PET metabolic indices of metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) have already revealed an independent significant prognostic value for survival in oncologic patients, although the corresponding cut-off values remain study-dependent and not validated for use in clinical practice. Advanced tumor “radiomic” analysis sheds new light into these indices. Numerous patterns of texture 18F-FDG uptake features can be extracted from segmented PET tumor images due to new powerful computational systems supporting complex “deep learning” algorithms. This high number of “quantitative” tumor imaging data, although not decrypted in their majority and once standardized for the different imaging systems and segmentation methods, could be used for the development of new “clinical” models for specific cancer types and, more interestingly, for specific age groups. In addition, data from novel techniques of tumor genome analysis could reveal new genes as biomarkers for prognosis and/or targeted therapies in childhood malignancies. Therefore, this ever-growing information of “radiogenomics”, in which the underlying tumor “genetic profile” could be expressed in the tumor-imaging signature of “radiomics”, possibly represents the next model for precision medicine in pediatric cancer management. This paper reviews 18F-FDG PET image segmentation methods as applied to pediatric sarcomas and lymphomas and summarizes reported findings on the values of metabolic and radiomic features in the assessment of these pediatric tumors.
Research Progress on the Flexibility of an Implantable Neural Microelectrode
Authors: Zhao Huiqing , Liu Ruping , Zhang Huiling , Cao Peng , Liu Zilong , Li Ye
Published: March 2022

Neural microelectrode is the important bridge of information exchange between the human body and machines. By recording and transmitting nerve signals with electrodes, people can control the external machines. At the same time, using electrodes to electrically stimulate nerve tissue, people with long-term brain diseases will be safely and reliably treated. Young’s modulus of the traditional rigid electrode probe is not matched well with that of biological tissue, and tissue immune rejection is easy to generate, resulting in the electrode not being able to achieve long-term safety and reliable working. In recent years, the choice of flexible materials and design of electrode structures can achieve modulus matching between electrode and biological tissue, and tissue damage is decreased. This review discusses nerve microelectrodes based on flexible electrode materials and substrate materials. Simultaneously, different structural designs of neural microelectrodes are reviewed. However, flexible electrode probes are difficult to implant into the brain. Only with the aid of certain auxiliary devices, can the implant be safe and reliable. The implantation method of the nerve microelectrode is also reviewed.
A Novel Feature Extraction Algorithm and System for Flexible Integrated Circuit Packaging Substrate
Authors: Huang Dan , Wang Juan , Zeng Yong , Yu Yongxing , Hu Yueming
Published: March 2022

Aiming at the line defect detection of a flexible integrated circuit substrate (FICS) without reference template, there are some problems such as line discontinuity or inaccurate line defect location in the detection results. In order to address these problems, a line feature detection algorithm for extracting an FICS image is proposed. Firstly, FICS image acquisition is carried out by using the appearance defect intelligent detection system independently developed in our lab. Secondly, in the algorithm design of the software system, the binary image of the line image to be segmented is obtained after the color FICS image is classified by K-means, median filtering, morphological filling and closed operation. Finally, for an FICS binary image, an image segmentation model with convexity-preserving indirect regular level set is proposed, which is applied to extract the line features of an FICS image. Experiment results show that, compared with the CV model, LBF model, LCV model, LGIF model, Order-LBF model and RSF model, the proposed model can extract line features with high accuracy, and the line boundary is smooth, which lays an important foundation for high-precision measurement of line width and line distance and high-precision location of defects.
A Novel Planar Grounded Capacitively Coupled Contactless Conductivity Detector for Microchip Electrophoresis
Authors: Wang Jianjiao , Liu Yaping , He Wenhe , Chen Yuanfen , You Hui
Published: March 2022

In the microchip electrophoresis with capacitively coupled contactless conductivity detection, the stray capacitance of the detector causes high background noise, which seriously affects the sensitivity and stability of the detection system. To reduce the effect, a novel design of planar grounded capacitively coupled contactless conductivity detector (PG-C4D) based on printed circuit board (PCB) is proposed. The entire circuit plane except the sensing electrodes is covered by the ground electrode, greatly reducing the stray capacitance. The efficacy of the design has been verified by the electrical field simulation and the electrophoresis detection experiments of inorganic ions. The baseline intensity of the PG-C4D was less than 1/6 of that of the traditional C4D. The PG-C4D with the new design also demonstrated a good repeatability of migration time, peak area, and peak height (n = 5, relative standard deviation, RSD ≤ 0.3%, 3%, and 4%, respectively), and good linear coefficients within the range of 0.05–0.75 mM (R2 ≥ 0.986). The detection sensitivity of K+, Na+, and Li+ reached 0.05, 0.1, and 0.1 mM respectively. Those results prove that the new design is an effective and economical approach which can improve sensitivity and repeatability of a PCB based PG-C4D, which indicate a great application potential in agricultural and environmental monitoring.
Artificial Intelligence Algorithms Enable Automated Characterization of the Positive and Negative Dielectrophoretic Ranges of Applied Frequency
Authors: Michaels Matthew , Yu Shih-Yuan , Zhou Tuo , Du Fangzhou , Al Faruque Mohammad Abdullah , Kulinsky Lawrence
Published: March 2022

The present work describes the phenomenological approach to automatically determine the frequency range for positive and negative dielectrophoresis (DEP)—an electrokinetic force that can be used for massively parallel micro- and nano-assembly. An experimental setup consists of the microfabricated chip with gold microelectrode array connected to a function generator capable of digitally controlling an AC signal of 1 V (peak-to-peak) and of various frequencies in the range between 10 kHz and 1 MHz. The suspension of latex microbeads (3-μm diameter) is either attracted or repelled from the microelectrodes under the influence of DEP force as a function of the applied frequency. The video of the bead movement is captured via a digital camera attached to the microscope. The OpenCV software package is used to digitally analyze the images and identify the beads. Positions of the identified beads are compared for successive frames via Artificial Intelligence (AI) algorithm that determines the cloud behavior of the microbeads and algorithmically determines if the beads experience attraction or repulsion from the electrodes. Based on the determined behavior of the beads, algorithm will either increase or decrease the applied frequency and implement the digital command of the function generator that is controlled by the computer. Thus, the operation of the study platform is fully automated. The AI-guided platform has determined that positive DEP (pDEP) is active below 500 kHz frequency, negative DEP (nDEP) is evidenced above 1 MHz frequency and the crossover frequency is between 500 kHz and 1 MHz. These results are in line with previously published experimentally determined frequency-dependent DEP behavior of the latex microbeads. The phenomenological approach assisted by live AI-guided feedback loop described in the present study will assist the active manipulation of the system towards the desired phenomenological outcome such as, for example, collection of the particles at the electrodes, even if, due to the complexity and plurality of the interactive forces, model-based predictions are not available.
Recent Progress in Silicon-Based Slow-Light Electro-Optic Modulators
Authors: Han Changhao , Jin Ming , Tao Yuansheng , Shen Bitao , Wang Xingjun
Published: March 2022

As an important optoelectronic integration platform, silicon photonics has achieved significant progress in recent years, demonstrating the advantages on low power consumption, low cost, and complementary metal–oxide–semiconductor (CMOS) compatibility. Among the different silicon photonics devices, the silicon electro-optic modulator is a key active component to implement the conversion of electric signal to optical signal. However, conventional silicon Mach–Zehnder modulators and silicon micro-ring modulators both have their own limitations, which will limit their use in future systems. For example, the conventional silicon Mach–Zehnder modulators are hindered by large footprint, while the silicon micro-ring modulators have narrow optical bandwidth and high temperature sensitivity. Therefore, developing a new structure for silicon modulators to improve the performance is a crucial research direction in silicon photonics. Meanwhile, slow-light effect is an important physical phenomenon that can reduce the group velocity of light. Applying slow-light effect on silicon modulators through photonics crystal and waveguide grating structures is an attractive research point, especially in the aspect of reducing the device footprint. In this paper, we review the recent progress of silicon-based slow-light electro-optic modulators towards future communication requirements. Beginning from the principle of slow-light effect, we summarize the research of silicon photonic crystal modulators and silicon waveguide grating modulators in detail. Simultaneously, the experimental results of representative silicon slow-light modulators are compared and analyzed. Finally, we discuss the existing challenges and development directions of silicon-based slow-light electro-optic modulators for the practical applications.
Uranyl Minerals from Abandoned Podgórze Mine (Sudetes Mountains, SW Poland) and Their REE Content
Authors: Syczewski Marcin , Siuda Rafał , Rohovec Jan , Matoušková Šárka , Parafiniuk Jan
Published: March 2022

The Podgórze uranium deposit is located near Kowary in the Sudetes Mountains, SW Poland. The mine is located in the Karkonosze-Izera block, largely comprising Cambrian to Devonian metamorphic rocks intruded by the Variscan Karkonosze granite. Uranyl minerals from the Podgórze mine can be divided into three assemblages. The first one is associated with heavily ventilated mining galleries. The next assemblage is related to the outflow of water from fissures in the walls of the mine galleries. The last assemblage appears in the mine dump, where there is increased activity of other weathering products. The main purpose of this paper is to determine the mineralogical characteristics of uranyl minerals from the abandoned Podgórze uranium mine and reconstruct the physicochemical crystallization conditions based on the concentrations of rare earth elements (REEs) in these minerals. The results of thermodynamic modeling show that the aqueous species of uranyl ion in the mine water are represented by UO2HAsO4 (aq), UO2CO3(OH)3−, UO2CO3 (aq), and UO2OH+. The content of REEs and their distribution patterns were used to determine the crystallization conditions of uranyl minerals. Uranyl carbonates and arsenates have generally low concentrations of REEs compared to uranyl silicates, phosphates, and hydroxides, which have higher concentrations. The differences in REE concentration patterns may be related with the oxidizing nature of water circulating in the subsurface part of the deposit.
Mineral-Melt Equilibria and Geothermobarometry of Campi Flegrei Magmas: Inferences for Magma Storage Conditions
Authors: Pelullo Carlo , Iovine Raffaella Silvia , Arienzo Ilenia , Di Renzo Valeria , Pappalardo Lucia , Petrosino Paola , D’Antonio Massimo
Published: March 2022

The eruptions of Campi Flegrei (Southern Italy), one of the most studied and dangerous active volcanic areas of the world, are fed by mildly potassic alkaline magmas, from shoshonite to trachyte and phonotrachyte. Petrological investigations carried out in past decades on Campi Flegrei rocks provide crucial information for understanding differentiation processes in its magmatic system. However, the compositional features of rocks are a palimpsest of many processes acting over timescales of 100–104 years, including crystal entrapment from multiple reservoirs with different magmatic histories. In this work, olivine, clinopyroxene and feldspar crystals from volcanic rocks related to the entire period of Campi Flegrei’s volcanic activity are checked for equilibrium with combined and possibly more rigorous tests than those commonly used in previous works (e.g., Fe–Mg exchange between either olivine or clinopyroxene and melt), with the aim of obtaining more robust geothermobarometric estimations for the magmas these products represent. We applied several combinations of equilibrium tests and geothermometric and geobarometric methods to a suite of rocks and related minerals spanning the period from ~59 ka to 1538 A.D. and compared the obtained results with the inferred magma storage conditions estimated in previous works through different methods. This mineral-chemistry investigation suggests that two prevalent sets of T–P (temperature–pressure) conditions, here referred to as “magmatic environments”, characterized the magma storage over the entire period of Campi Flegrei activity investigated here. These magmatic environments are ascribable to either mafic or differentiated magmas, stationing in deep and shallow reservoirs, respectively, which interacted frequently, mostly during the last 12 ka of activity. In fact, open-system magmatic processes (mixing/mingling, crustal contamination, CO2 flushing) hypothesized to have occurred before several Campi Flegrei eruptions could have removed earlier-grown crystals from their equilibrium melts. Moreover, our new results indicate that, in the case of complex systems such as Campi Flegrei’s, in which different pre-eruptive processes can modify the equilibrium composition of the crystals, one single geothermobarometric method offers little chance to constrain the magma storage conditions. Conversely, combined methods yield more robust results in agreement with estimates obtained in previous independent studies based on both petrological and geophysical methods.
Geochemistry and Petrogenesis of Shoshonitic Dyke Swarm in the Northeast of Meshkinshahr, NW Iran
Authors: Fadaeian Mohammad , Jahangiri Ahmad , Ao Songjian , Kamali Amin Allah , Xiao Wenjiao
Published: March 2022

The study area is located in Ardabil province in the northeast of Meshkinshahr city. More than 200 small and large Eocene-age dykes form outcrops in this area. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) U–Pb zircon analyses yield a consistent age of 44.3 ± 1.8 Ma for the dyke swarms. These dykes include tephritic, andesitic and basaltic compositions, and show enrichment in LREEs (relative to HREEs) and are characterized by enrichment in LILEs and depletion in HFSEs. Petrological observations, along with major, rare earth and trace elements geochemistry, suggest that the dykes have a shoshonitic signature. All the rocks are highly enriched in incompatible trace elements and have variable Sr–Nd isotopes. Enrichment in incompatible elements and other geochemical features for the dyke swarm rocks suggest that a metasomatized subcontinental lithospheric mantle is the magma source. The negative Nb–Ta–Ti anomalies in the rocks are comparable with the features of subduction-related magmatism and contamination with ancient crustal components. The radiogenic 87Sr/86Sr isotopic values of the rocks imply the involvement of slab terrigenous sediments and/or a continental lithosphere. Isotopically, the volcanic rocks exhibit a binary trend, representing 1–5% mixing between the primary mantle and sediment melts. Our melting models suggest that there are residual garnet + spinel in the source, which are incompatible with the partial melting of amphibole- and/or phlogopite-bearing lherzolites. The geochronological, geochemical and isotopic data for the northeast Meshkinshahr dyke swarms suggest that these Late Eocene magmas were derived from a small degree of partial melting of a subduction-metasomatized lithospheric mantle source in a post-collisional setting.
Assessment of Natural Radionuclide Distribution Pattern and Radiological Risk from Rocks in Precambrian Oban Massif, Southeastern Nigeria
Authors: E. Ekpe Ekpenyong , Ben Ubong C. , Ekwok Stephen E. , Ebong Ebong D. , Akpan Anthony E. , Eldosouky Ahmed M. , Abdelrahman Kamal , Gómez-Ortiz David
Published: March 2022

A gamma spectrometric analysis of rock samples collected from the Precambrian Oban Massif, southeastern Nigeria, was performed to determine some primordial radioelements’ activity concentrations: U-238, Th-232, and K-40, and their associated radiological hazards. The mean activity of the primordial radionuclides was determined to be 1073.06 ± 0.65, 160.74 ± 1.32, and 250.76 ± 0.91 Bq·kg−1 for 40K, 238U, and 232Th, respectively, showing that they are inhomogeneously distributed, with activity changing with the rock type and location. The activity concentrations are highest in biotite garnet schist, quartz diorite, and biotite gneiss rock domains. The mean values of the radiological hazards are 0.08 Bq·kg−1 (alpha index), 2.15 Bq·kg−1(gamma index), 2.06 Bq·kg−1(internal) and 1.63 Bq·kg−1 (external4.30 Bq·kg−1(representative level index6), 602.23 Bq·kg−1, (radium equivalent), 780 nGy·h−1 (total absorbed dose rate), 270.91 nGy·h−1 (indoor), 509.78 nGy·h−1 (outdoor), 624.99, 1329.07 and 1954.06 mSv·yr−1 (outdoor, indoor and total annual effective dose equivalent, respectively), 6448.40 (cumulative excess lifetime cancer risk) and 248.94–3761.47 Bq·kg−1 (annual gonadal dose equivalent). These results are higher than their various permissible limits (except at Ako Community) and suggest that rocks in the area may be unsuitable for constructing dwelling places. It is strongly advised that basic safety standards and precautionary measures recommended by the European Commission should be strictly adhered to while dealing with these rocks.
Association Study on the Pore Structure and Mechanical Characteristics of Coarse-Grained Soil under Freeze–Thaw Cycles
Authors: Liu Yao , Deng Hongwei , Xu Jingbo , Tian Guanglin , Deng Junren
Published: March 2022

In this study, the relationship between the pore structure and macroscopic mechanical characteristics of coarse-grained soils from mine dumps is explored under various freeze–thaw cycles. A series of experiments were conducted on the mine dump materials using a standard cube sample of 7 cm × 7 cm × 7 cm, a moisture content of 7.5%, and a density of 2.34 g/cm3. The pore structure test and uniaxial compressive strength test were carried out on the coarse-grained soil samples under different freeze–thaw cycles by using a nuclear magnetic resonance (NMR) instrument and a universal servo material testing machine. The study explores the change law of the strength and pore structure of coarse-grained soil, and establishes the correlation model between the pore structure and mechanical characteristics. The results showed that: (1) With the increase in the number of freeze–thaw cycles, the porosity of the coarse-grained soil gradually increased, and the bonding ability between the internal soil particles weakened, resulting in a decrease in strength. (2) With the increase in freeze–thaw cycles, the proportion of pore volume of the main peak and secondary peak 2 of T-2 spectrum curve increases gradually, and the internal pore structure of coarse-grained soil gradually develops towards medium and large pores. (3) There is an exponential function between the variation of pore volume proportion of each peak of coarse-grained soil and the relative strength value, and there is a good fitting coefficient between the two, indicating that the change of pore structure can well reflect the evolution law of strength.
Cellular Effects of Cyclodextrins: Studies on HeLa Cells
Authors: Rusznyák Ágnes , Palicskó Mercédesz , Malanga Milo , Fenyvesi Éva , Szente Lajos , Váradi Judit , Bácskay Ildikó , Vecsernyés Miklós , Réti-Nagy Katalin Szászné , Vasvári Gábor , Haimhoffer Ádám , Fenyvesi Ferenc
Published: March 2022

Cyclodextrins are high molecular weight, hydrophilic, cyclic, non-reducing oligosaccharides, applied as excipients for the improvement of the solubility and permeability of insoluble active pharmaceutical ingredients. On the other hand, beta-cyclodextrins are used as cholesterol sequestering agents in life sciences. Recently, we demonstrated the cellular internalization and intracellular effects of cyclodextrins on Caco-2 cells. In this study, we aimed to further investigate the endocytosis of (2-hydroxylpropyl)-beta-(HPBCD) and random methylated-beta-cyclodextrin (RAMEB) to test their cytotoxicity, NF-kappa B pathway induction, autophagy, and lysosome formation on HeLa cells. These derivatives were able to enter the cells; however, major differences were revealed in the inhibition of their endocytosis compared to Caco-2 cells. NF-kappa B p65 translocation was not detected in the cell nuclei after HPBCD or RAMEB pre-treatment and cyclodextrin treatment did not enhance the formation of autophagosomes. These cyclodextrin derivates were partially localized in lysosomes after internalization.
Quantification of Total Phenols and Antioxidants in Coffee Samples of Different Origins and Evaluation of the Effect of Degree of Roasting on Their Levels
Authors: Alnsour Lilian , Issa Reem , Awwad Shady , Albals Dima , Al-Momani Idrees
Published: March 2022

Phenolic and antioxidant compounds have received considerable attention due to their beneficial effects on human health. The aim of this study is to determine the content of total phenols and antioxidants in fifty-two coffee samples of different origins, purchased from the Jordanian local market, and investigate the effect of the degree of roasting on the levels of these compounds. The coffee samples were extracted using the hot water extraction method, while Folin–Ciocalteu (FC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay methods were used to analyze these compounds. The results showed that the highest content of total phenol (16.55 mg/g equivalent to GAE) was found in the medium roasted coffee, and the highest content of antioxidants (1.07 mg/g equivalent to TEAC) content was found in the green coffee. Only light and medium roasted coffee showed a significant correlation (p < 0.05, R2 > 0.95) between the average of total phenolic and antioxidant content. A negative correlation between the antioxidant content and the degree of roasting (p < 0.05, R2 > 0.95) were shown, while it did not correlate with phenolic contents. Previously, a positive correlation between antioxidant and chlorogenic acids content was observed, with no correlation between the origin of coffee samples nor heavy metal content, which was previously determined for the same coffee samples. These findings suggest that the antioxidant content for coffee extracts is largely determined by its chlorogenic acid content, rather than the coffee origin or total phenolic and heavy metals content.
Macro-Reticular Ion Exchange Resins for Recovery of Direct Dyes from Spent Dyeing and Soaping Liquors
Authors: Naim Mona M. , Al-harby Nouf F. , El Batouti Mervette , Elewa Mahmoud M.
Published: March 2022

Dyes are a major class of organic pollutants that are well-known for their harmful impact on aquatic life and humans. Several new strategies for removing colours from industrial and residential effluents have recently emerged, with adsorption being the best option. The current study looked at the recovery of direct dyes from aqueous streams for reuse using macro-reticular ion exchange resins (IERs). The investigation includes dyeing single jersey cotton grey textiles with direct dyes from the Isma dye Company in Kafr El Dawar, Egypt. After centrifuging and separating the supernatant liquid, solutions from thirteen different dyes, produced at an average concentration between the wasted and soaping liquor concentrations, were calculated spectrophotometrically from the first dyeing trials. Kinetic data were well fitted with pseudo-second-order rate kinetics. The amounts of dye retained by the anion exchangers increased with a rise in temperature in the case of Strong Base Resin (SBR) and vice versa for Weak Base Resin (WBR). Batch adsorption experiments with SBR and WBR were conducted for each dye, and both Freundlich and Langmuir isotherms were constructed. It was found that adsorption obeyed both isotherms, that monolayer adsorption took place, and that the dye molecular weight, structure, and solubility, as well as the type of anionic resin used, had varying effects on the extent of absorption. The monolayer sorption capacities Q0 determined from the Langmuir isotherm model for the strongly and weakly basic anion exchangers were found to be 537.6 and 692 mg/g for Direct Yellow RL, respectively. As a result, Yellow RL exhibited the greatest adsorption on both SBR and WBR. Orange GRLL, Blue 3B, and Congo Red, on the other hand, were the poorest colours absorbed by the IERs, whereas Blue RL demonstrated good adsorption by SBR and accelerated adsorption by WBR. Most of the dyes may be recovered and reused in this manner.
A Comprehensive Review on Therapeutic Perspectives of Phytosterols in Insulin Resistance: A Mechanistic Approach
Authors: Prasad Monisha , Jayaraman Selvaraj , Eladl Mohamed Ahmed , El-Sherbiny Mohamed , Abdelrahman Mosaab Abdella Ebrahim , Veeraraghavan Vishnu Priya , Vengadassalapathy Srinivasan , Umapathy Vidhya Rekha , Jaffer Hussain Shazia Fathima , Krishnamoorthy Kalaiselvi , Sekar Durairaj , Palanisamy Chella Perumal , Mohan Surapaneni Krishna , Rajagopal Ponnulakshmi
Published: March 2022

Natural products in the form of functional foods have become increasingly popular due to their protective effects against life-threatening diseases, low risk of adverse effects, affordability, and accessibility. Plant components such as phytosterol, in particular, have drawn a lot of press recently due to a link between their consumption and a modest incidence of global problems, such as Type 2 Diabetes mellitus (T2DM), cancer, and cardiovascular disease. In the management of diet-related metabolic diseases, such as T2DM and cardiovascular disorders, these plant-based functional foods and nutritional supplements have unquestionably led the market in terms of cost-effectiveness, therapeutic efficacy, and safety. Diabetes mellitus is a metabolic disorder categoriszed by high blood sugar and insulin resistance, which influence major metabolic organs, such as the liver, adipose tissue, and skeletal muscle. These chronic hyperglycemia fallouts result in decreased glucose consumption by body cells, increased fat mobilisation from fat storage cells, and protein depletion in human tissues, keeping the tissues in a state of crisis. In addition, functional foods such as phytosterols improve the body’s healing process from these crises by promoting a proper physiological metabolism and cellular activities. They are plant-derived steroid molecules having structure and function similar to cholesterol, which is found in vegetables, grains, nuts, olive oil, wood pulp, legumes, cereals, and leaves, and are abundant in nature, along with phytosterol derivatives. The most copious phytosterols seen in the human diet are sitosterol, stigmasterol, and campesterol, which can be found in free form, as fatty acid/cinnamic acid esters or as glycosides processed by pancreatic enzymes. Accumulating evidence reveals that phytosterols and diets enriched with them can control glucose and lipid metabolism, as well as insulin resistance. Despite this, few studies on the advantages of sterol control in diabetes care have been published. As a basis, the primary objective of this review is to convey extensive updated information on the possibility of managing diabetes and associated complications with sterol-rich foods in molecular aspects.