bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Shape Memory Alloy Actuators to Vibration and Motion Control of Structural Systems: A Review
Authors: Sohn Jung Woo , Ruth Josephine Selvarani , Yuk Do-Gyeong , Choi Seung-Bok
Published: January 2023

This paper comprehensively reviews effective control applications using shape memory alloy (SMA) actuators. Among many applications, this paper focuses on the vibration and stiffness control of flexible structures and shape control in the aerospace engineering field. In the vibration control of flexible structures, three different methods are introduced and discussed, including their merits and demerits. In addition, several control strategies, such as neuro-fuzzy controller, are investigated in terms of the implementation associated with the microchip. In the control process, the inherent hysteretic behavior of SMA is also reviewed as a feedforward loop or actuating force compensator. At the second part, applications on the morphing wing in the field of aerospace engineering are reviewed, and salient characteristics are discussed. In this review, the morphing wing, which is closely related to aircraft stability, is mainly investigated considering control logics and geometrical parameters. For easily understanding morphing control using SMA, a table which summarizes the main contribution of each research is presented. It is expected, since this review article provides numerous approaches for vibration and morphing control conducted over the last decade, it will be very helpful to the same research community to create novel ideas to achieve more advanced and effective results in vibration and morphing control using SMA actuators.
Response of Bridge Foundation with Drainage Structure in the Liquefied Inclined Site under Sinusoidal Waves
Authors: Chen Zhixiong , Wang Buxin , Gao Xuecheng , Yan Haocheng
Published: January 2023

Many earthquake damage investigations have shown that lateral spreading is one of the main causes of damage to bridge foundations. However, the seismic research on bridge foundations with drainage systems is relatively lacking. Therefore, based on the shaking table test, the seismic response of a drained sheet pile-reinforced bridge foundation on a liquefied inclined site was studied under the action of sinusoidal waves. Compared with the conventional group, the peak excess pore water pressure ratio and the lateral displacement of the sheet-pile wall of the test group were smaller, but the acceleration amplification factor was larger, indicating that the anti-liquefaction performance of the site was effectively improved. Meanwhile, the acceleration amplification factor of the test group was larger, and the lateral displacement of the bridge superstructure was smaller. These results indicated that the drainage structure significantly improved the stability and safety of the bridge system.
Spirulina Supplements as a Source of Mineral Nutrients in the Daily Diet
Authors: Janda-Milczarek Katarzyna , Szymczykowska Kinga , Jakubczyk Karolina , Kupnicka Patrycja , Skonieczna-Żydecka Karolina , Pilarczyk Bogumiła , Tomza-Marciniak Agnieszka , Ligenza Alicja , Stachowska Ewa , Dalewski Bartosz
Published: January 2023

Spirulina is a microalga cultivated in many countries. It is a source of valuable protein, polyunsaturated fatty acids, vitamins, antioxidants and elements. We have not found studies that address the effect of supplement form or cultivation method on the mineral content of spirulina supplements. The aim of this study was to determine whether supplement form (tablet and powder) and cultivation method (organic and conventional) of spirulina have a bearing on the mineral nutrients content. Such an approach accounts for the innovation of our research. The material used in the study was spirulina in tablets and powder form, marketed as a dietary supplement. Samples were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). In turn, selenium (Se) content was determined by spectrofluorimetry. Overall, in terms of mean values, the most abundant mineral in spirulina supplements was phosphorus (P) (15,149 mg/kg) and the least abundant was Se (0.31 mg/kg). Our findings show that both supplement form and cultivation method affect the mineral content of spirulina. Supplements in powder form had a significantly higher content of important elements, such as iron (Fe) (673 mg/kg), magnesium (Mg) (4151 mg/kg) and potassium (K) (16,686 mg/kg), while at the same time containing significantly less sodium (Na) (9868 mg/kg). In terms of the cultivation method, organic spirulina supplements turned out to be a richer dietary source of Fe (703 mg/kg) and K (14,893 mg/kg). In turn, conventionally grown supplements had higher contents of calcium (Ca) (11,269 mg/kg), phosphorus (P) (16,314 mg/kg) and strontium (Sr) (47 mg/kg). Spirulina can therefore be a valuable addition to the daily diet, helping people to achieve the required intake of micronutrients.
Application of High-Pressure Gas Expansion Rock-Cracking Technology in Hard Rock Tunnel near Historic Sites
Authors: Liu Dunwen , Wang Chong , Tang Yu , Chen Haofei
Published: January 2023

In order to study the applicability of high-pressure gas expansion rock-cracking technology in hard rock tunnel near historic sites, theoretical analysis, field tests as well as vibration monitoring are conducted to obtain suitable rock mass cracking parameters for tunnel excavation. The results show that the ideal effect of rock mass cracking can be achieved with the cutting mode of “central vertical empty hole + double wedge cutting hole” and the auxiliary hole network parameter of “0.8 m × 0.7 m”. The measured vibration velocity is less than 0.1 cm/s at the monitoring point 60 m away from the tunnel face in the field test, which meets the vibration control requirements of the historic sites in the process of tunnel excavation. The research results show that as long as there is a high quality of hole plugging and no punching, the high-pressure gas expansion rock-cracking technology has the advantages of little vibration, low noise and less flying rocks, which provides a technical reference for the excavation of hard rock tunnels near ancient buildings and historic sites.
Evaluation and Validation of Photovoltaic Potential Based on Time and Pathway of Solar-Powered Electric Vehicle
Authors: Park Chanwook , Park Haneul , Jeon Hwanhee , Choi Kyoik , Suh Jangwon
Published: January 2023

This study evaluates and validates the power output potential of using the travel time and driving route of a photovoltaic (PV)-powered electric vehicle (EV). A scenario was constructed wherein a car with modules attached to four sides (roof, rear window, left door, and right door) drove on seventeen road sections with various inclinations and azimuths. The shadow effect of the surrounding terrain and buildings was considered to assess the PV potential. Consequently, it was possible to analyze the differences in the potential of the four modules in the same or two sections with different topographies. It was determined that the car could produce 0.0158 kWh for a single drive (approximately 10 min) and 221 kWh for one year (considering six hours a day). The potential of the roof module was the highest, followed by those of the rear and two doors. The potentials of the modules attached to the rear window and side doors were calculated to be approximately 42% and 27%, respectively, of the roof module potential. Furthermore, the possibility of enhancing the potential of future PV-powered EVs was discussed. The results obtained in this study can be used to develop power-output algorithms and navigation solutions for PV-powered EVs.
Multi-Range Sequential Learning Based Dark Image Enhancement with Color Upgradation
Authors: Das Mou Trisha , Alam Saadia Binte , Rahman Md. Hasibur , Srivastava Gautam , Hasan Mahady , Uddin Mohammad Faisal
Published: January 2023

Images under low-light conditions suffer from noise, blurring, and low contrast, thus limiting the precise detection of objects. For this purpose, a novel method is introduced based on convolutional neural network (CNN) dual attention unit (DAU) and selective kernel feature synthesis (SKFS) that merges with the Retinex theory-based model for the enhancement of dark images under low-light conditions. The model mentioned in this paper is a multi-scale residual block made up of several essential components equivalent to an onward convolutional neural network with a VGG16 architecture and various Gaussian convolution kernels. In addition, backpropagation optimizes most of the parameters in this model, whereas the values in conventional models depend on an artificial environment. The model was constructed using simultaneous multi-resolution convolution and dual attention processes. We performed our experiment in the Tesla T4 GPU of Google Colab using the Customized Raw Image Dataset, College Image Dataset (CID), Extreme low-light denoising dataset (ELD), and ExDark dataset. In this approach, an extended set of features is set up to learn from several scales to incorporate contextual data. An extensive performance evaluation on the four above-mentioned standard image datasets showed that MSR-MIRNeT produced standard image enhancement and denoising results with a precision of 97.33%; additionally, the PSNR/SSIM result is 29.73/0.963 which is better than previously established models (MSR, MIRNet, etc.). Furthermore, the output of the proposed model (MSR-MIRNet) shows that this model can be implemented in medical image processing, such as detecting fine scars on pelvic bone segmentation imaging, enhancing contrast for tuberculosis analysis, and being beneficial for robotic visualization in dark environments.
A Study on ML-Based Sleep Score Model Using Lifelog Data
Authors: Kim Jiyong , Park Minseo
Published: January 2023

The rate of people suffering from sleep disorders has been continuously increasing in recent years, such that interest in healthy sleep is also naturally increasing. Although there are many health-care industries and services related to sleep, specific and objective evaluation of sleep habits is still lacking. Most of the sleep scores presented in wearable-based sleep health services are calculated based only on the sleep stage ratio, which is not sufficient for studies considering the sleep dimension. In addition, most score generation techniques use weighted expert evaluation models, which are often selected based on experience instead of objective weights. Therefore, this study proposes an objective daily sleep habit score calculation method that considers various sleep factors based on user sleep data and gait data collected from wearable devices. A credit rating model built as a logistic regression model is adapted to generate sleep habit scores for good and bad sleep. Ensemble machine learning is designed to generate sleep habit scores for the intermediate sleep remainder. The sleep habit score and evaluation model of this study are expected to be in demand not only in health-care and health-service applications but also in the financial and insurance sectors.
A Modified k-ε Turbulence Model for Heavy Gas Dispersion in Built-Up Environment
Authors: Schalau Sebastian , Habib Abdelkarim , Michel Simon
Published: January 2023

For hazard assessment purposes, the dispersion of gases in complex urban areas is often a scenario to be considered. However, predicting the dispersion of heavy gases is still a challenge. In Germany, the VDI Guideline 3783, Part 1 and 2 is widely used for gas dispersion modelling. Whilst Part 1 uses a gauss model for calculating the dispersion of light or neutrally buoyant gases, Part 2 uses wind tunnel experiments to evaluate the heavier-than-air gas dispersion in generic built up areas. In practice, with this guideline, it is often not possible to adequately represent the existing obstacle configuration. To overcome this limitation, computational fluid dynamics (CFD) methods could be used. Whilst CFD models can represent obstacles in the dispersion area correctly, actual publications show that there is still further research needed to simulate the atmospheric flow and the heavy gas dispersion. This paper presents a modified k-ε-turbulence model that was developed in OpenFOAM v5.0 (England, London, The OpenFOAM Foundation Ltd Incorporated) to enhance the simulation of the atmospheric wind field and the heavy gas dispersion in built-up areas. Wind tunnel measurements for the dispersion of neutrally buoyant and heavy gases in built-up environments were used to evaluate the model. As a result, requirements for the simulation of the gas dispersion under atmospheric conditions have been identified and the model showed an overall good performance in predicting the experimental values.
A Game—Theoretic Model for a Stochastic Linear Quadratic Tracking Problem
Authors: Drăgan Vasile , Ivanov Ivan Ganchev , Popa Ioan-Lucian
Published: January 2023

In this paper, we solve a stochastic linear quadratic tracking problem. The controlled dynamical system is modeled by a system of linear Itô differential equations subject to jump Markov perturbations. We consider the case when there are two decision-makers and each of them wants to minimize the deviation of a preferential output of the controlled dynamical system from a given reference signal. We assume that the two decision-makers do not cooperate. Under these conditions, we state the considered tracking problem as a problem of finding a Nash equilibrium strategy for a stochastic differential game. Explicit formulae of a Nash equilibrium strategy are provided. To this end, we use the solutions of two given terminal value problems (TVPs). The first TVP is associated with a hybrid system formed by two backward nonlinear differential equations coupled by two algebraic nonlinear equations. The second TVP is associated with a hybrid system formed by two backward linear differential equations coupled by two algebraic linear equations.
Metal-Organic Frameworks-Based Optical Nanosensors for Analytical and Bioanalytical Applications
Authors: Wen Cong , Li Rongsheng , Chang Xiaoxia , Li Na
Published: January 2023

Metal-organic frameworks (MOFs)-based optical nanoprobes for luminescence and surface-enhanced Raman spectroscopy (SERS) applications have been receiving tremendous attention. Every element in the MOF structure, including the metal nodes, the organic linkers, and the guest molecules, can be used as a source to build single/multi-emission signals for the intended analytical purposes. For SERS applications, the MOF can not only be used directly as a SERS substrate, but can also improve the stability and reproducibility of the metal-based substrates. Additionally, the porosity and large specific surface area give MOF a sieving effect and target molecule enrichment ability, both of which are helpful for improving detection selectivity and sensitivity. This mini-review summarizes the advances of MOF-based optical detection methods, including luminescence and SERS, and also provides perspectives on future efforts.
Is There an Early Morphological Decomposition during L2 Lexical Access? A Meta-Analysis on the Morphological Priming Effect
Authors: Fernandes Ana Isabel , Luna Karlos , Soares Ana Paula , Comesaña Montserrat
Published: January 2023

A considerable body of experimental data currently exists on the representation and processing of derived words. However, no theoretical account has led to a consensus so far, due in part to inconsistencies in empirical results which show either the presence or the absence of signs of early morphological decomposition during lexical access. In this paper, we present the results of a meta-analysis that sought to examine the robustness of the masked morphological priming effect (MMP) in native and non-native speakers. This effect is indexed by faster responses to targets preceded by morphologically related primes vs. unrelated primes (e.g., fighter-FIGHT < needle-FIGHT), and is perhaps the most widespread effect used to test whether speakers of a given language are sensitive to the morphological components of words at early stages of lexical access. To this end, we selected 10 masked priming lexical decision studies (16 experiments) conducted with native and non-native speakers. Variables such as prime duration and level of L2 proficiency were considered in the analyses to assess their impact on the MMP effect. Results showed significant MMP effects, which were restricted to native speakers. No modulations were found for the prime duration. Results are interpreted in light of prevalent models of complex word processing.
Bending Properties and Vibration Characteristics of Dowel-Laminated Timber Panels Made with Short Salvaged Timber Elements
Authors: Giordano Lorenzo , Derikvand Mohammad , Fink Gerhard
Published: January 2023

Salvaged timber elements often have length limitations, and therefore, their reuse in structural products normally would require additional processing and end-to-end joining. This increases the costs of reusing such materials, which makes them even less attractive to the timber sector. In the presented research, a new approach is proposed for reusing short, salvaged timber elements combined with new (full-scale) timber boards to fabricate dowel-laminated timber (DLT) panels without significant processing or end-to-end joining or gluing. In this approach, salvaged timber elements are pressed in the system in such a way that they can contribute to the bending performance of the DLT panels by resisting compression stress. In order to evaluate the effectiveness, several small-scale and large-scale DLT panels were fabricated. Salvaged plywood tenons were used as connectors. The bending stiffness of the small-scale DLT panels and the first eigenfrequency, damping ratio, bending properties, and failure modes of the large-scale DLT panels were evaluated. The results exhibited that by using the proposed approach, the short, salvaged timber elements can contribute substantially to the bending stiffness of the DLT panels without requiring end-to-end joining or gluing. On average, about a 40% increase in the bending stiffness could be achieved by pressing in the salvaged timber elements, which results in relatively similar stiffness properties compared to conventional DLT panels. One further characteristic is that the failure of the panels, and therefore the panel’s strength, is mainly governed by the quality of the full-scale timber boards instead of the salvaged ones. This can be beneficial for practical use as the qualitative assessment of the strength properties of salvaged timber becomes less critical.
Large-Scale Triaxial Testing of TDA Mixed with Fine and Coarse Aggregates
Authors: El Naggar Hany , Ashari Mohammad
Published: January 2023

The number of scrap tires discarded worldwide is increasing annually. Stockpiling these tires is not a viable option due to environmental concerns and space limitations. Landfilling is likewise unacceptable and is not permitted in many areas. Recycling these tires is the best alternative. Shredding scrap tires to create a product known as tire-derived aggregate (TDA) is one of the most environmentally friendly methods of recycling scrap tires. In the past few decades, TDA and TDA-soil mixtures have been used increasingly in civil engineering projects. Nevertheless, only limited research has so far been conducted on TDA and TDA mixed with soil. In addition, the majority of past research has focused on TDA particles that do not have steel wires and are small in size. In the present research, triaxial tests were performed on various mixtures of TDA with sand or gravel. Each sample was subjected to three different confining pressures. The results of the tests are presented and discussed, and empirical equations are proposed to match the laboratory results.
Consolidating Efficiency of Nanolime Product CaLoSiL on Porous Limestone
Authors: Slížková Zuzana , Frankeová Dita , Drdácký Miloš
Published: January 2023

The effects of the double and the multiple application (2 to 6) of Calosil® (IBZ-Salzchemie GmbH, Halsbruecke, Germany) E25, IP 25 and E50 products were studied on Maastricht limestone, which is characterized by high porosity and large pores. Both destructive and non-destructive laboratory tests we performed in order to assess the consolidating efficiency of the nanolimes—the bending and compressive strengths, ultrasound velocity measurement, porosity determination and SEM examination. Except for the compressive strength, the other characteristics were investigated in the depth profile of stone specimens to find the distribution of the treatment product within the substrate. The performed tests showed good penetration of CaLoSiL nanolime products into the studied limestone. The bending strengths of limestone samples after double treatment using nanolime E 25, IP25 and E 50 were found to be increased by 50%, 44% and 89%, respectively, whereas the compressive strength increased by 50%, 23% and 73%. The porosity of the stone was reduced by the treatment, but only slightly, to an acceptable extent. The higher sum of performed nanolime applications resulted in a higher strengthening effect but at the same time at the uneven distribution of the product in the stone specimen, which was followed by an increase in the strength and decrease of open porosity in the surface part. SEM examination showed a modification of the stone microstructure by the added binder.
Catalytic Hydrodeoxygenation of Vanillin, a Bio-Oil Model Compound over Renewable Ni/Biochar Catalyst
Authors: Mudi Ismaila , Hart Abarasi , Ingram Andrew , Wood Joseph
Published: January 2023

This study aims to examine the hydrodeoxygenation (HDO) of vanillin, an oxygenated phenolic compound present in bio-oil, into creosol. Biochar residue generated when wood is slowly pyrolyzed is utilized as a catalyst support. To improve biochar’s physicochemical properties, H2SO4 (sulfuric acid) and KOH (potassium hydroxide) are used as chemical activators. By means of a wet impregnation method with nickel salt, an Ni/biochar catalyst was prepared and utilized in the HDO of vanillin using a 100 mL Parr reactor, catalyst loading 0.4–0.8 g, temperature 100 °C to 150 °C, hydrogen (H2) pressures of 30 to 50 bar, and a stirring rate of 1000 rpm. The prepared catalysts were characterized with the nitrogen-sorption isotherm technique, carbon dioxide temperature-programmed desorption (CO2-TPD), scanning electron microscopy (SEM) coupled with energy dispersed X-ray analysis (EDX), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). Based on chemical treatment, Ni/biochar (KOH) pore sizes were found to be dominated by mesopores, with a surface area increase of 64.7% and a volume increase of 65.3%, while Ni/biochar (H2SO4) was mostly microporous and mesoporous, with an area increase of 372.3% and a volume increase of 256.8% in comparison to Ni/biochar (74.84 m2g−1 and 0.095 cm3g−1). Vanillin conversion of up to 97% with 91.17% selectivity to p-creosol was obtained over Ni/biochar catalyst; in addition to being highly selective and active for p-creosol, a plausible fuel, the catalyst was stable after four cycles. Chemical treatments of the biochar support resulted in improved physicochemical properties, leading to improved catalytic performance in terms of vanillin conversion and p-creosol yield in the order Ni/biochar (H2SO4) > Ni/biochar (KOH) > Ni/biochar.
Genome-Wide Methylation Changes Associated with Replicative Senescence and Differentiation in Endothelial and Bone Marrow Mesenchymal Stromal Cells
Authors: Giuliani Angelica , Bacalini Maria Giulia , Ramini Deborah , Mensà Emanuela , Giordani Chiara , Xumerle Luciano , Garagnani Paolo , Olivieri Fabiola , Procopio Antonio Domenico , Rippo Maria Rita , Sabbatinelli Jacopo
Published: January 2023

Bone marrow mesenchymal stromal cells (BMSCs) are multipotent cells able to self-renew and differentiate, depending on the microenvironment, into adipocytes and osteoblasts. These cells have a limited number of replications and enter replicative senescence during in vitro expansion. The role of DNA methylation (DNAm) assumes importance in cell function and commitment; however, its exact contribution to BMSC differentiation and replicative senescence is still unclear. We performed a genome-wide DNAm analysis on BMSCs cultured in vitro at early passages and induced to differentiate into adipocytes and osteoblasts, and on replicative senescent BMSCs and HUVECs, to identify DNAm patterns of senescence and differentiation. We also compared BMSCs and HUVECs in replicative senescence and found that, in both cellular systems, genome-wide hypomethylation was accompanied by a higher-than-expected overlap of differentially methylated positions (DMPs) and concordance in terms of direction of the change. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis on lineage-independent senescence-associated DMPs revealed 16 common pathways, including Insulin resistance, Molecule adhesion, and Wnt/β-catenin signaling. In both adipogenesis and osteogenesis, we observed a general demethylation of CpG sites compared with undifferentiated BMSCs with a higher number of DMPs in osteogenesis. KEGG analysis resulted in 30 pathways enriched in osteoblasts and only 2 in adipocytes when compared to undifferentiated cells. When comparing differentiated BMSCs with senescent ones, osteogenesis exhibited a greater overlap with senescence in terms of number of DMPs and direction of methylation change compared to adipogenesis. In conclusion, this study may be useful for future research on general mechanisms that occur in replicative senescence and furthermore to identify trajectories of BMSC differentiation and common aspects of differentiated and senescent cells.
Vasoactive Soluble Endoglin: A Novel Biomarker Indicative of Reperfusion after Cerebral Large-Vessel Occlusion
Authors: Haarmann Axel , Vollmuth Christoph , Kollikowski Alexander M. , Heuschmann Peter U. , Pham Mirko , Stoll Guido , Neugebauer Hermann , Schuhmann Michael K.
Published: January 2023

Now that mechanical thrombectomy has substantially improved outcomes after large-vessel occlusion stroke in up to every second patient, futile reperfusion wherein successful recanalization is not followed by a favorable outcome is moving into focus. Unfortunately, blood-based biomarkers, which identify critical stages of hemodynamically compromised yet reperfused tissue, are lacking. We recently reported that hypoxia induces the expression of endoglin, a TGF-β co-receptor, in human brain endothelium in vitro. Subsequent reoxygenation resulted in shedding. Our cell model suggests that soluble endoglin compromises the brain endothelial barrier function. To evaluate soluble endoglin as a potential biomarker of reperfusion (-injury) we analyzed its concentration in 148 blood samples of patients with acute stroke due to large-vessel occlusion. In line with our in vitro data, systemic soluble endoglin concentrations were significantly higher in patients with successful recanalization, whereas hypoxia alone did not induce local endoglin shedding, as analyzed by intra-arterial samples from hypoxic vasculature. In patients with reperfusion, higher concentrations of soluble endoglin additionally indicated larger infarct volumes at admission. In summary, we give translational evidence that the sequence of hypoxia and subsequent reoxygenation triggers the release of vasoactive soluble endoglin in large-vessel occlusion stroke and can serve as a biomarker for severe ischemia with ensuing recanalization/reperfusion.
Fresh Medium or L-Cystine as an Effective Nrf2 Inducer for Cytoprotection in Cell Culture
Authors: Dai Wujing , Chen Qin M.
Published: January 2023

The Nrf2 gene encodes a transcription factor best known for regulating the expression of antioxidant and detoxification genes. A long list of small molecules has been reported to induce Nrf2 protein via Keap1 oxidation or alkylation. Many of these Nrf2 inducers exhibit off-target or toxic effects due to their nature as electrophiles. In searching for non-toxic Nrf2 inducers, we found that a culture medium change to fresh DMEM is capable of inducing Nrf2 protein in HeLa, HEK293, AC16 and MCF7 cells. Testing the components of DMEM led to the discovery of L-Cystine as an effective Nrf2 inducer. L-Cystine induces a dose-dependent increase of Nrf2 protein, from 0.1 to 1.6 mM. RNA-seq analyses and RT-PCR revealed an induction of multiple Nrf2 downstream genes, including NQO1, HMOX1, GCLC, GCLM, SRXN1, TXNRD1, AKR1C and OSGIN1 by 0.8 mM L-Cystine. The induction of Nrf2 protein was dependent on L-Cystine entering cells via the cystine/glutamate antiporter and the presence of Keap1. The half-life of Nrf2 protein increased from 19.4 min to 30.9 min with 0.8 mM L-Cystine treatment. L-Cystine was capable of eliciting cytoprotection by reducing ROS generation and protecting against oxidant- or doxorubicin-induced apoptosis. As an amino acid derivative, L-Cystine is considered a non-toxic Nrf2 inducer that exhibits the potential for protection against oxidative stress and tissue injury.
Gelatin–Curcumin Nanocomposites as a Coating for Implant Healing Abutment: In Vitro Stability Investigation
Authors: Maleki Dizaj Solmaz , Torab Ali , Kouhkani Shadi , Sharifi Simin , Negahdari Ramin , Bohlouli Sepideh , Fattahi Shirin , Salatin Sara
Published: January 2023

Regarding the importance of preventing peri-implantitis in dental implants, the current study aimed to coat a healing abutment with gelatin–curcumin nanocomposites, and the stability of this coating on the healing abutment was evaluated. A cell viability measuring test was used to determine the cytotoxicity of nanocomposites against dental pulp stem cells. To show the pattern of curcumin release from nanocomposites, drug dissolution apparatus two was applied. Then, 16 healing abutments were examined in vitro. Titanium healing abutments were coated with the gelatin–curcumin nanocomposite. The dip coating method was applied for coating and the consistency of coated cases was evaluated at intervals of one, 30, and 60 days after coating inside the simulated body fluid (SBF) solution. A scanning electron microscope (SEM) was used for investigating the microstructure and morphology of coatings, and an energy dispersive X-ray (EDX) was applied for determining the combination of the coating. Moreover, the healings were weighed before and after coating via an accurate digital scale with an accuracy of 0.0001. Finally, the data were analyzed using SPSS software. The prepared nanocomposite was non-cytotoxic against tested cells. The nanocomposite showed a relatively rapid release pattern in the first 10 days for curcumin. The release of curcumin from the nanoparticles continued slowly until the 30th day. The weight changes were statistically significant (p-value < 0.001) during this time. Based on the post hoc test, the weight between two times immediately after coating and 30 days after coating, and also one day after coating and 30 days after coating, was statistically insignificant. The results revealed that the coating of the gelatin–curcumin nanocomposite on the healing was successful and this consistency was kept for at least one month. It is necessary to investigate more evaluations in different fields of physicochemical, mechanical, and antimicrobial aspects for coated healing abutments.
A Study on the Improvement of the Photothermal Characteristics of the Adsorbent for Sorption-Based Atmospheric Water Harvesting Driven by Solar
Authors: Wu Jiangbo , Sui Ziyi , Du Xiaoze , Zhang Yaocong , Ma Tao
Published: January 2023

Facing the global freshwater resource crisis, using solar energy to produce fresh water resources in an environmentally friendly way, sorption-based atmospheric water harvesting driven by solar technology has attracted increasingly more attention. In the current research, the adsorbent MOF-801 has the advantages of a high adsorption capacity and is suitable for fields with a wide range of humidity. However, the strong interaction between the adsorbent and water molecules is conducive to rapid moisture absorption, but at the same time, the adsorbent needs higher heat to achieve regeneration, which restricts the practical application of the adsorbent. Based on the principle that carbon materials can improve the photothermal conversion performance of adsorbent, this paper prepared three composite adsorbents with MOF-801 and three different carbon materials, characterized the structure and morphology of each adsorbent, and compared the effects of different carbon materials on the performance of MOF-801 adsorbent. Among them, the photothermal characteristics of MOF-801/CNT adsorbent proposed in this paper are most significantly improved. The experiment shows that compared with MOF-801/G, the adsorption capacity is increased by 30%, and the desorption speed is increased by 50%. It maximizes water withdrawals over a period of time in arid environments.
Tribological Behaviors of Ni-P Coatings on PEO-Treated AA1050 Alloy
Authors: Kim Juseok , Kwon Duyoung , Pham Hien Van , Moon Sungmo , Shin Heon-Cheol
Published: January 2023

Tribological behaviors of the plasma electrolytic oxidation (PEO)-treated Al1050 alloy surface without and with Ni-P deposits was examined by analyzing of the width of abrasion groove, weight loss, friction coefficient and composition at the wear track after a 100 m ball-on-disc test. The surface color, surface and cross-sectional morphologies and surface roughness (Ra) were also investigated to explain different wear behaviors of PEO films without and with Ni-P deposit. After the 100 m ball-on-disc test, a circular abrasion groove with relatively large width and shallow depth was formed when Ni-P particles cover the top surface of PEO films, but a relatively narrow and deep circular abrasion groove was formed on the Ni-P layer-covered PEO film surface. Iron was only detected at the wear track of 5 and 10 μm PEO films without Ni-P deposit, suggesting that the steel ball is worn out by the PEO films but not by the Ni-P deposit. An extremely large amount of weight loss was obtained from the Ni-P layer-covered PEO film surface, which could be related to the high density and low hardness of the Ni-P layer.
Thermal Tunable Tribological Behavior of Shape Memory Biphenyl Epoxy Resin
Authors: Yang Jing , Cao Pengrui , Gao Ketian , Ding Chang , Chen Shoubing , Zhang Xinrui , Wang Tingmei , Wang Qihua , Zhang Yaoming
Published: January 2023

Although polymer-based self-lubricating materials have rapidly developed recently, intelligent lubricating materials with self-adaptable lubrication with external conditions changing are highly demanded, especially for harsh conditions. Herein, a shape memory epoxy resin based on the biphenyl units (BPEP) with tunable tribological behavior was systematically studied. X-ray diffraction (XRD), field emission scanning electron microscope (SEM), laser confocal three-dimensional profiler, and optical microscope were applied to analyze the friction and wear mechanism. Due to the presence of the specific biphenyl structural units, which could be performed a switching phase between crystalline and amorphous, that allows the self-assembly of the polymer chain under π–π interaction. As a result, the improving mechanical properties enable the BPEP to perform outstanding self-lubricating in a wide temperature range, and the friction coefficient (COF) can be tuned in a wide range of 0.10~0.175 by adjusting the temperature. The shape memory effect of the polymer refers to modulus changing and heat conversion during the shape morphing, and a thermal tunable tribological was observed based on the physicochemical properties varying of polymer with temperature changing. The shape memory effect of BPEPs drives the wear self-compensation so that a low wear rate (6.94 × 10−5 mm3 N−1 m−1) at 110 °C was obtained. The superb lubricating properties of this BPEP could broaden the application scope of shape memory polymers in the field of intelligent lubricating materials, and it is expected to guide future studies on the thermal regulating of tribological behavior.
Effect of Mesogenic Phase and Structure of Liquid Crystals on Tribological Properties as Lubricant Additives
Authors: Wu Han , Jiang Ying , Hu Wenjing , Feng Sijing , Li Jiusheng
Published: January 2023

To develop a high-performance additive that can meet different operating conditions, three liquid crystals (LCs) were developed as additives for a base oil. The structures and thermal stabilities of the obtained LCs were characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, mass spectroscopy (MS), and thermogravimetric analysis (TGA). The effects of mesogenic-phase temperature ranges on tribological properties were analyzed using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). UMT-TriboLab friction and wear tester was used to study the friction-reducing properties of LCs. The width of wear marks was observed by a Contour GT-K 3D profiler to illustrate the anti-wear performance of LCs. The friction surface was characterized by scanning electron microscopy (SEM) and Raman spectroscopy. It was demonstrated that, in comparison with the base oil, the addition of LCs caused a remarkable reduction in the coefficient of friction (21.57%) and wear width (31.82%). In addition, LCs show better tribological abilities in the mesogenic-phase temperature ranges. According to the results, we demonstrated that LCs can be used as lubricant additives, especially for several operating conditions under specific temperatures.
Study of Tribotechnical Properties of Multilayer Nanostructured Coatings and Contact Processes during Milling of Titanium Alloys
Authors: Migranov Mars Sharifullovich , Shehtman Semen Romanovich , Sukhova Nadezhda Aleksandrovna , Mitrofanov Artem Petrovich , Gusev Andrey Sergeevich , Migranov Arthur Marsovich , Repin Denis Sergeyevich
Published: January 2023

The paper presents the results of theoretical and experimental research on tribotechnical characteristics: tool wear on the back surface, tool durability period, critical length of the cutting path before blunting, adhesion component of the friction coefficient, contact processes, temperature, and force dependences for the application of innovative nanostructured multilayer composite coatings on a tool for milling of titanium alloys. The proposed thermodynamic model of cutting tool wear allows us to determine the ways by which cutting tool wear intensity decreases and the conditions of increase in cutting tool wear resistance with wear-resistant coatings. A substantial increase in wear resistance of end mills when processing titanium alloys with the use of innovative multilayer nanostructured coatings is established, in particular an improvement of an average of 1.5–2 times. These positive results are related to a significant decrease in temperature–force loading in the cutting zone, a decrease in the friction coefficient (adhesion component), and the phenomenon of adaptation (self-organization) of friction surfaces during cutting by tools with wear-resistant coatings, contributing to the formation of films of various compounds with shielding, protective, and lubricating properties.
Microwave-Assisted Synthesis of rGO-ZnO/CuO Nanocomposites for Photocatalytic Degradation of Organic Pollutants
Authors: Bekru Aklilu Guale , Tufa Lemma Teshome , Zelekew Osman Ahmed , Gwak Juyong , Lee Jaebeom , Sabir Fedlu Kedir
Published: January 2023

Nanomaterial-based catalytic conversion of hazardous organic pollutants into benign substances is one of the green methods employed for wastewater treatment. This study demonstrates the fabrication of (rGO-ZnO)/CuO nanocomposites (NCs) via a microwave (MW)-assisted method for (photo)catalytic application. The crystal structure, optical, morphological, and electrochemical characteristics were examined using X-ray diffraction (XRD), spectroscopic, microscopic, and electrochemical techniques. The analysis indicated that rod-like (rGO-ZnO)/CuO NCs having a nanoscale diameter with enhanced light absorption and well-matched band positions between rGO-ZnO and CuO were formed. Furthermore, the catalytic reduction of 4-nitrophenol (4-NP) and photocatalytic degradation of methylene blue (MB) tests showed remarkable results with rate constants of 0.468 min−1 for 4-NP reduction within 8 min and 0.02213 min−1 for MB degradation within 105 min. Thus, the artful decoration of ZnO nanorods (NRs) with CuO into the (rGO-ZnO)/CuO NCs interface is an effective strategy for fabricating highly efficient photocatalysts.
Real-Time In-Situ Investigation of the Neutron Irradiation Resistance Ability of Nd3+-Doped Gd3Sc2Al3O12 Laser Crystal
Authors: Gao Yuxi , Liu Wenpeng , Ding Shoujun , Chen Yuanzhi , Zhang Qingli
Published: January 2023

In optical crystals, photodarkening will occur after they were irradiated with high-energy particles, and such induced optical loss generally results in significant performance degradation whether they are used as passive or active optical elements. In the present study, the effects of neutron irradiation on the optical response of the Nd3+-doped Gd3Sc2Al3O12 (Nd:GSAG) single crystal has been revealed in real-time and in-situ. Transient and permanent transmittance reduction in the crystal induced by neutron radiation has been observed and the reduction mechanisms have been analyzed. The XRD characterization method demonstrated that the crystal structure remained constant both before and after neutron irradiation. Importantly, the X-ray photoelectron peak of the O 1s core level shifts to high binding energy, indicating that oxygen vacancies were produced in the crystal after irradiation with neutrons. Thus, the permanent reduction in the transmittance of the crystal after irradiation with neutrons can be attributed to the generation of oxygen vacancies in the crystal. To the best of our knowledge, it is the first time the damage types in rare earth oxide laser crystals caused by neutron irradiation were revealed.
Shear Wave Elastography in Bruxism—Not Yet Ready for Clinical Routine
Authors: Toker Cem , Marquetand Justus , Symmank Judit , Wahl Ebru , Huettig Fabian , Grimm Alexander , Kleiser Benedict , Jacobs Collin , Hennig Christoph-Ludwig
Published: January 2023

Ultrasound shear wave elastography (SWE) is an emerging modality for the estimation of stiffness, but it has not been studied in relation to common disorders with altered stiffness, such as bruxism, which affects almost one-third of adults. Because this condition could lead to an increased stiffness of masticatory muscles, we investigated SWE in bruxism according to a proof-of-principle and feasibility study with 10 patients with known bruxism and an age- and gender-matched control group. SWE of the left and right masseter muscles was estimated under three conditions: relaxed jaw, 50% of the subjective maximal bite force, and maximal jaw opening. Rejecting the null hypothesis, SWE was significantly increased during relaxed jaw (bruxism 1.92 m/s ± 0.44; controls 1.66 m/s ± 0.24), whereas for maximal mouth opening, the result was vice versa increased with 2.89 m/s ± 0.93 for bruxism patients compared with 3.53 m/s ± 0.95 in the healthy control, which could be due to limited jaw movement in chronic bruxism patients (bruxism 4.46 m/s ± 1.17; controls 5.23 m/s ± 0.43). We show that SWE in bruxism is feasible and could be of potential use for diagnostics and monitoring, though we also highlight important limitations and necessary methodological considerations for future studies.
Clinical and Laboratory Diagnosis of Legionella Pneumonia
Authors: Bai Lu , Yang Wei , Li Yuanyuan
Published: January 2023

Legionella pneumonia is a relatively rare but extremely progressive pulmonary infection with high mortality. Traditional cultural isolation remains the gold standard for the diagnosis of Legionella pneumonia. However, its harsh culture conditions, long turnaround time, and suboptimal sensitivity do not meet the clinical need for rapid and accurate diagnosis, especially for critically ill patients. So far, pathogenic detection techniques including serological assays, urinary antigen tests, and mass spectrometry, as well as nucleic acid amplification technique, have been developed, and each has its own advantages and limitations. This review summarizes the clinical characteristics and imaging findings of Legionella pneumonia, then discusses the advances, advantages, and limitations of the various pathogenetic detection techniques used for Legionella pneumonia diagnosis. The aim is to provide rapid and accurate guiding options for early identification and diagnosis of Legionella pneumonia in clinical practice, further easing healthcare burden.
Thyroid Collision Tumors: The Presence of the Medullary Thyroid Carcinoma Component Negatively Influences the Prognosis
Authors: Negura Ion , Ianole Victor , Danciu Mihai , Preda Cristina , Iosep Diana Gabriela , Dănilă Radu , Grigorovici Alexandru , Ciobanu Apostol Delia Gabriela
Published: January 2023

Thyroid collision tumors (TCTs) are rare pathological findings, representing <1% of thyroid cancers. This study aimed to compare the main pathological features of TCTs containing medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) components with MTC-only tumors and PTC-only tumors. Methods: The retrospective study included 69 cases diagnosed with TCTs (with simultaneous MTC and PTC components), MTC and PTC. All tumors were comparatively assessed for the classical histopathological prognostic features, including a new grading system for MTC. Results: The main component of TCTs had more frequent microscopic extrathyroidal extension (mETE) (p = 0.000), lymphovascular invasion (LVI) (p = 0.000), perineural invasion (PNI) (p = 0.044), and lymph node metastasis (p = 0.042). Additionally, the TCTs’ MTC component presented with more frequent LVI (p = 0.010). Comparing TCTs’ MTC and PTC components with MTC-only tumors and PTC-only tumors revealed that only the TCTs’ MTC components had statistically significant more frequent mETE (p = 0.010) than MTC-only tumors. When applied to the MTC component of TCTs, the pathological parameters of the new grading system of MTC showed no correlations with other microscopic or clinical aspects. Conclusion: Using classical pathological prognostic features, the comparative analysis revealed that the main TCTs’ component was more aggressive than the minor one. Contrary to PTCs, in TCTs, the medullary component was more aggressive than the papillary one, but also more aggressive than MTC-only tumors.
Stochastic Particle Creation: From the Dynamical Casimir Effect to Cosmology
Authors: Mantiñan Matías , Mazzitelli Francisco D. , Trombetta Leonardo G.
Published: January 2023

We study a stochastic version of the dynamical Casimir effect, computing the particle creation inside a cavity produced by a random motion of one of its walls. We first present a calculation perturbative in the amplitude of the motion. We compare the stochastic particle creation with the deterministic counterpart. Then, we go beyond the perturbative evaluation using a stochastic version of the multiple scale analysis, that takes into account stochastic parametric resonance. We stress the relevance of the coupling between the different modes induced by the stochastic motion. In the single-mode approximation, the equations are formally analogous to those that describe the stochastic particle creation in a cosmological context, that we rederive using multiple scale analysis.