bluuebunny/crossref_metadata_2025 huggingface dataset:
An Adaptive Multipath Linear Interpolation Method for Sample Optimization
Authors: Du Yukun , Jin Xiao , Wang Hongxia , Lu Min
Published: February 2023

When using machine learning methods to make predictions, the problem of small sample sizes or highly noisy observation samples is common. Current mainstream sample expansion methods cannot handle the data noise problem well. We propose a multipath sample expansion method (AMLI) based on the idea of linear interpolation, which mainly solves the problem of insufficient prediction sample size or large error between the observed sample and the actual distribution. The rationale of the AMLI method is to divide the original feature space into several subspaces with equal samples, randomly extract a sample from each subspace as a class, and then perform linear interpolation on the samples in the same class (i.e., K-path linear interpolation). After the AMLI processing, valid samples are greatly expanded, the sample structure is adjusted, and the average noise of the samples is reduced so that the prediction effect of the machine learning model is improved. The hyperparameters of this method have an intuitive explanation and usually require little calibration. We compared the proposed method with a variety of machine learning prediction methods and demonstrated that the AMLI method can significantly improve the prediction result. We also propose an AMLI plus method based on the linear interpolation between classes by combining the idea of AMLI with the clustering method and present theoretical proofs of the effectiveness of the AMLI and AMLI plus methods.
The Improved Element-Free Galerkin Method for 3D Steady Convection-Diffusion-Reaction Problems with Variable Coefficients
Authors: Cheng Heng , Xing Zebin , Liu Yan
Published: February 2023

In order to obtain the numerical results of 3D convection-diffusion-reaction problems with variable coefficients efficiently, we select the improved element-free Galerkin (IEFG) method instead of the traditional element-free Galerkin (EFG) method by using the improved moving least-squares (MLS) approximation to obtain the shape function. For the governing equation of 3D convection-diffusion-reaction problems, we can derive the corresponding equivalent functional; then, the essential boundary conditions are imposed by applying the penalty method; thus, the equivalent integral weak form is obtained. By introducing the IMLS approximation, we can derive the final solved linear equations of the convection-diffusion-reaction problem. In numerical examples, the scale parameter and the penalty factor of the IEFG method for such problems are discussed, the convergence is proved numerically, and the calculation efficiency of the IEFG method are verified by four numerical examples.
Automated Settings of Overcurrent Relays Considering Transformer Phase Shift and Distributed Generators Using Gorilla Troops Optimizer
Authors: Draz Abdelmonem , Elkholy Mahmoud M. , El-Fergany Attia A.
Published: February 2023

The relative protective devices are cascaded in a proper sequence with a proper min/max coordination time margin (CTM) to minimize the outage area of the network in case of fault condition. This manuscript addresses a new methodology based on the gorilla troops optimizer (GTO) to produce the best automated settings for overcurrent relays. In the GTO, the exploration and exploitation phases are realized using five methodologies. Three of them are used in the exploration phase and the other two in the exploitation phase. In the exploration phase, all gorillas are considered as candidate solutions and the best one is considered as the silverback gorilla. Then again, the exploitation phase comprises two steps: (i) the first one is the follow of silverback gorilla, and (ii) the second one is the competition for adult females. The latter mentioned offers an added advantage to the GTO framework to move forward steadily to global minima and to avoid trapping into local minima. Two test cases under numerous scenarios are demonstrated comprising an isolated real distribution network with distributed generations for the Agiba Petroleum company which is in the Western Desert of Egypt. The relay coordination problem is adapted as an optimization problem subject to a set of predefined constraints which is solved using the GTO including fixed and varied inverse IEC curves, in which the practical constraints including transformer phase shift and other scenarios for min/max fault conditions are dealt with. In due course, this current effort aims at proving the best strategy for achieving the smoothest coordination of overcurrent relays (OCRs), with the least obtained value of CTMs for the studied cases being established via the automated relay settings. At last, it can be pointed out that the GTO successfully dealt with this problem and was able to produce competitive answers compared to other competitors.
Training Multilayer Neural Network Based on Optimal Control Theory for Limited Computational Resources
Authors: Alkawaz Ali Najem , Kanesan Jeevan , Khairuddin Anis Salwa Mohd , Badruddin Irfan Anjum , Kamangar Sarfaraz , Hussien Mohamed , Baig Maughal Ahmed Ali , Ahammad N. Ameer
Published: February 2023

Backpropagation (BP)-based gradient descent is the general approach to train a neural network with a multilayer perceptron. However, BP is inherently slow in learning, and it sometimes traps at local minima, mainly due to a constant learning rate. This pre-fixed learning rate regularly leads the BP network towards an unsuccessful stochastic steepest descent. Therefore, to overcome the limitation of BP, this work addresses an improved method of training the neural network based on optimal control (OC) theory. State equations in optimal control represent the BP neural network’s weights and biases. Meanwhile, the learning rate is treated as the input control that adapts during the neural training process. The effectiveness of the proposed algorithm is evaluated on several logic gates models such as XOR, AND, and OR, as well as the full adder model. Simulation results demonstrate that the proposed algorithm outperforms the conventional method in terms of improved accuracy in output with a shorter time in training. The training via OC also reduces the local minima trap. The proposed algorithm is almost 40% faster than the steepest descent method, with a marginally improved accuracy of approximately 60%. Consequently, the proposed algorithm is suitable to be applied on devices with limited computation resources, since the proposed algorithm is less complex, thus lowering the circuit’s power consumption.
Recent Advances in Bioelectrochemical Systems for Nitrogen and Phosphorus Recovery Using Membranes
Authors: Cerrillo Míriam , Riau Victor , Bonmatí August
Published: February 2023

Bioelectrochemical systems (BESs) have emerged as a technology that is able to recover resources from different kinds of substrates, especially wastewater. Nutrient recovery, mostly based on membrane reactor configuration, is a clear niche for BES application. The recovery of nitrogen or phosphorus allows for treatment of wastewater while simultaneously collecting a concentrated stream with nutrients that can be reintroduced into the system, becoming a circular economy solution. The aim of this study is to review recent advances in membrane-based BESs for nitrogen and phosphorus recovery and compare the recovery efficiencies and energy requirements of each system. Finally, there is a discussion of the main issues that arise from using membrane-based BESs. The results presented in this review show that it would be beneficial to intensify research on BESs to improve recovery efficiencies at the lowest construction cost in order to take the final step towards scaling up and commercialising this technology.
Modeling and Validation of a LiOH Production Process by Bipolar Membrane Electrodialysis from Concentrated LiCl
Authors: González Alonso , Grágeda Mario , Ushak Svetlana
Published: February 2023

Electromembrane processes for LiOH production from lithium brines obtained from solar evaporation ponds in production processes of the Salar de Atacama are considered. In order to analyze high concentrations’ effect on ion exchange membranes, the use of concentrated LiCl aqueous solutions in a bipolar membrane electrodialysis process to produce LiOH solutions higher than 3.0% by mass is initially investigated. For this purpose, a mathematical model based on the Nernst–Planck equation is developed and validated, and a parametric study is simulated considering as input variables electrolyte concentrations, applied current density, stack design, process design and membrane characteristics. As a novelty, this mathematical model allows estimating LiOH production in a wide concentration range of LiCl, HCl and LiOH solutions and its effect on the process, providing data on final LiOH solution purity, current efficiency, specific electricity consumption and membrane performance. Among the main results, a concentration of 4.0% to 4.5% by LiOH mass is achieved, with a solution purity higher than 95% by mass and specific electrical energy consumption close to 4.0 kWh/kg. The work performed provides key information on process sensitivity to operating conditions and process design characteristics. These results serve as a guide in the application of this technology to lithium hydroxide production.
Biochar Addition in Membrane Bioreactor Enables Membrane Fouling Alleviation and Nitrogen Removal Improvement for Low C/N Municipal Wastewater Treatment
Authors: Wang Kanming , Ye Qiaoqiao , Shen Yuxiang , Wang Yajing , Hong Qiankun , Zhang Chenlong , Liu Min , Wang Hongyu
Published: February 2023

Membrane bioreactors (MBRs) are frequently used to treat municipal wastewater, but membrane fouling is still the main weakness of this technology. Additionally, the low carbon-nitrogen (C/N) ratio influent has been shown to not only increase the membrane fouling, but also introduce challenges to meet the effluent discharge standard for nitrogen removal. Herein, the authors addressed the challenges by adding cost-effective biochar. The results suggested that the biochar addition can enable membrane fouling alleviation and nitrogen removal improvement. The reduced membrane fouling can be ascribed to the biochar adsorption capacity, which facilitates to form bigger flocs with carbon skeleton in biochar as a core. As a result, the biochar addition significantly altered the mixed liquor suspension with soluble microbial product (SMP) concentration reduction of approximately 14%, lower SMP protein/polysaccharide ratio from 0.28 ± 0.02 to 0.22 ± 0.03, smaller SMP molecular weight and bigger sludge particle size from 67.68 ± 6.9 μm to 113.47 ± 4.8 μm. The nitrogen removal is also dramatically improved after biochar addition, which can be due to the initial carbon source release from biochar, and formation of aerobic–anaerobic microstructures. Microbial diversity analysis results suggested more accumulation of denitrification microbes including norank_f__JG30-KF-CM45 and Plasticicumulans. Less relative abundance of Aeromonas after biochar addition suggested less extracellular polymer substance (EPS) secretion and lower membrane fouling rate.
SiC-Based Composite Material Reinforced with Molybdenum Wire
Authors: Kaledin Alexei , Shikunov Sergey , Komarov Kirill , Straumal Boris , Kurlov Vladimir
Published: February 2023

Silicon carbide (SiC) possesses a unique combination of properties such as high mechanical strength at elevated temperatures, wear resistance, low thermal expansion coefficient, high temperature oxidation resistance, corrosion stability, radiation hardness, high chemical inertness, and thermal conductivity. Unfortunately, SiC is very brittle and cannot, therefore, be used “as is”. SiC’s crack resistance, due to the prevention of crack propagation, can be increased by the reinforcing of SiC. In this paper, a novel method for manufacturing SiC-based composites reinforced with Mo wire is developed. The composites are produced by infiltrating porous carbon blanks with molten silicon. The molten silicon reacts with the molybdenum wire embedded in the carbon blanks. As a result, a complex interfacial silicide layer with a predominant MoSi2 phase is formed on the surface of the Mo wire. In addition, a thin layer of Mo5Si3 is formed between the residual metal in the core of the wire and the disilicide. A stable bond of the interfacial layer with both the residual metal and the SiC-based ceramic matrix is observed. Mechanical tests on the obtained samples for three-point bending at 20 and 1500 °C showed quasi-plastic damage. The reinforcing elements act as stoppers for propagating cracks in the event of a matrix failure. The developed method for producing composites with a ceramic matrix reinforced with metal wire makes it possible to reduce the cost of machining and manufacturing products with complex geometric shapes. It also opens the way for broader applications of SiC-based composites.
Flexible Ion Adsorption Electrodes Using Natural Zeolite and Rice Husk Charcoal for FEM-EK Treatment
Authors: Kumagai Ayaka , Kabir Mahmudul , Okuda Shogo , Komachi Hitori , Obara Naoko , Sato Yusuke , Saito Takahiro , Sato Michio , Tomioka Masahiro , Kumagai Seiji , Yoshimura Noboru
Published: February 2023

The Fukushima Daiichi nuclear power plant accident happened after the devastating earthquake in the Pacific coastal area of Japan on 11 March 2011. After the accident, radioactive materials spread out over a wide area in Japan. Radioactive materials were retained on soil surfaces, causing environmental problems. Among the radioactive materials, cesium (137Cs) has a long half-life of 30.2 years, and it remains near the surface soil; therefore, it is necessary to remove soil contaminated by 137Cs. The contaminated soil layer of inhabited areas in Fukushima was already removed before April 2020. However, the remediation method of Cs with other radioactive materials needs further study, as the large quantity of contaminated soil is not easy to preserve. Electrokinetic (EK) treatment is one of the soil remediation technologies that utilizes EK phenomena at the interface between contaminated soils by transferring ions from the soil. We have developed a new type of EK method in which a cathode is placed on the surface of the soil and an anode is place inside the soil. By applying DC voltage in between the electrodes, the Cs ions can be removed from the contaminated soil. The removed Cs ions are gathered near to the cathode, and if the cathode can adsorb the Cs ions, then only the cathode needs to be preserved, solving the problem of storing a large amount of soil. We have been working to prepare a new type of cathode that can be effective in adsorbing Cs ions and at the same time easier to store and handle. We used natural zeolite and rice husk charcoal (kuntan) to prepare this electrode, which showed good potential for adsorbing Cs ions. The electrode showed flexibility, which is helpful for storing it in the same way as pasture rolls. However, the experiments were conducted in the laboratory with non-radioactive Cs; field experiments and observations are needed for practical applications of this method, as well as the new electrodes.
Effectiveness of Design Procedures in Counteracting Second Order Effects in Steel Moment Resisting Frames
Authors: Barbagallo Francesca , Bosco Melina , Floridia Andrea , Marino Edoardo M. , Rossi Pier Paolo
Published: February 2023

The seismic response of structures is always influenced by second order (P–Δ) effects. The importance of these effects becomes significant when the structure experiences large plastic deformations. Seismic codes indicate that P–Δ effects may be counteracted by means of an increase of the lateral strength required by a first order analysis, but the expressions of the Strength Amplification Factor (SAF) given in codes are often criticized by researchers. This paper proposes and validates a formulation of the SAF for Moment Resisting Frames (MRFs), which is a generalization of that derived in the past by some of the authors based on the response of SDOF systems. To this end, in a first stage of the research a set of steel MRFs is designed and analyzed neglecting P–Δ effects. The seismic response is determined by nonlinear static and incremental dynamic analyses and the mean annual frequency of exceedance of the Significant Damage (SD) and Near Collapse (NC) limit states is computed. In a second stage, each structure is re-designed and analyzed considering P–Δ effects. P–Δ effects are counteracted in design according to provisions of European, American and Canadian seismic codes or according to other formulations proposed in literature, such as that proposed by Bernal and that proposed by the authors. The accuracy of the design provisions accounting for P–Δ effects is determined by comparing the response of the structures designed in the first and in the second stages.
Projections from the Rostral Zona Incerta to the Thalamic Paraventricular Nucleus Mediate Nociceptive Neurotransmission in Mice
Authors: Wu Feng-Ling , Chen Si-Hai , Li Jia-Ni , Zhao Liu-Jie , Wu Xue-Mei , Hong Jie , Zhu Ke-Hua , Sun Han-Xue , Shi Su-Juan , Mao E , Zang Wei-Dong , Cao Jing , Kou Zhen-Zhen , Li Yun-Qing
Published: February 2023

Zona incerta (ZI) is an integrative subthalamic region in nociceptive neurotransmission. Previous studies demonstrated that the rostral ZI (ZIR) is an important gamma–aminobutyric acid-ergic (GABAergic) source to the thalamic paraventricular nucleus (PVT), but whether the ZIR–PVT pathway participates in nociceptive modulation is still unclear. Therefore, our investigation utilized anatomical tracing, fiber photometry, chemogenetic, optogenetic and local pharmacological approaches to investigate the roles of the ZIRGABA+–PVT pathway in nociceptive neurotransmission in mice. We found that projections from the GABAergic neurons in ZIR to PVT were involved in nociceptive neurotransmission. Furthermore, chemogenetic and optogenetic activation of the ZIRGABA+–PVT pathway alleviates pain, whereas inhibiting the activities of the ZIRGABA+-PVT circuit induces mechanical hypersensitivity and partial heat hyperalgesia. Importantly, in vivo pharmacology combined with optogenetics revealed that the GABA-A receptor (GABAAR) is crucial for GABAergic inhibition from ZIR to PVT. Our data suggest that the ZIRGABA+–PVT pathway acts through GABAAR-expressing glutamatergic neurons in PVT mediates nociceptive neurotransmission.
Hypertriglyceridemic Waist Phenotype and Its Association with Metabolic Syndrome Components, among Greek Children with Excess Body Weight
Authors: Dikaiakou Eirini , Athanasouli Fani , Fotiadou Anatoli , Kafetzi Maria , Fakiolas Stefanos , Michalacos Stefanos , Vlachopapadopoulou Elpis Athina
Published: February 2023

The hypertriglyceridemic waist (HTGW) phenotype is characterized by abdominal obesity and elevated serum triglycerides. We aimed to assess the prevalence of the HTGW phenotype among children with overweight or obesity and its association with indices of insulin resistance (IR) and dyslipidemia. A total of 145 children with mean age of 10.2 years (SD = 2.31 years), 97.2% of whom with obesity, were analyzed. The HTGW phenotype was defined as WC > 90th Centers for Disease Control and Prevention (CDC) percentile and triglyceride levels of ≥100 mg/dL and ≥130 mg/dL for children 0 to 9 or >10 years of age, respectively. In total, 77.9% of the children had a waist circumference above the 90th percentile and 22.8% had elevated triglycerides. The prevalence of the HTGW phenotype in this sample was 19.3%. Patients with the HTGW phenotype had significantly lower levels of High-Density Lipoprotein (p < 0.001) and were insulin-resistant, as evident by an increased mean Triglycerides Glucose Index 8.64 (SD = 0.24) vs. 7.92 (SD = 0.41) for those without the HTGW phenotype (p < 0.001), and increased prevalence (54.5%) of Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) in ≥2.5 in patients with HTGW (p = 0.045). Children with the HTGW phenotype were more likely to have increased HOMA-IR [OR 7.9 95% CI (1.94, 32.1)]. The HTGW phenotype is a low-cost and easily available index that might help to identify children with increased cardiometabolic risk.
Muscle Pathology in Dystrophic Rats and Zebrafish Is Unresponsive to Taurine Treatment, Compared to the mdx Mouse Model for Duchenne Muscular Dystrophy
Authors: Terrill Jessica R. , Huchet Corinne , Le Guiner Caroline , Lafoux Aude , Caudal Dorian , Tulangekar Ankita , Bryson-Richardson Robert J. , Sztal Tamar E. , Grounds Miranda D. , Arthur Peter G.
Published: February 2023

Inflammation and oxidative stress are strongly implicated in the pathology of Duchenne muscular dystrophy (DMD), and the sulphur-containing amino acid taurine ameliorates both and decreases dystropathology in the mdx mouse model for DMD. We therefore further tested taurine as a therapy using dystrophic DMDmdx rats and dmd zebrafish models for DMD that have a more severe dystropathology. However, taurine treatment had little effect on the indices of dystropathology in both these models. While we and others have previously observed a deficiency in taurine in mdx mice, in the current study we show that the rat and zebrafish models had increased taurine content compared with wild-type, and taurine treatment did not increase muscle taurine levels. We therefore hypothesised that endogenous levels of taurine are a key determinate in potential taurine treatment efficacy. Because of this, we felt it important to measure taurine levels in DMD patient plasma samples and showed that in non-ambulant patients (but not in younger patients) there was a deficiency of taurine. These data suggest that taurine homeostasis varies greatly between species and may be influenced by age and disease progression. The potential for taurine to be an effective therapy may depend on such variables.
In the Beginning Was the Bud: Phytochemicals from Olive (Olea europaea L.) Vegetative Buds and Their Biological Properties
Authors: Popović Marijana , Burčul Franko , Veršić Bratinčević Maja , Režić Mužinić Nikolina , Skroza Danijela , Frleta Matas Roberta , Nazlić Marija , Ninčević Runjić Tonka , Jukić Špika Maja , Bego Ana , Dunkić Valerija , Vitanović Elda
Published: February 2023

Even though Olea europaea L. is one of the most important and well-studied crops in the world, embryonic parts of the plants remain largely understudied. In this study, comprehensive phytochemical profiling of olive vegetative buds of two Croatian cultivars, Lastovka and Oblica, was performed with an analysis of essential oils and methanol extracts as well as biological activities (antioxidant, antimicrobial, and cytotoxic activities). A total of 113 different volatiles were identified in essential oils with hydrocarbons accounting for up to 60.30% and (Z)-3-heptadecene being the most abundant compound. Oleacein, oleuropein, and 3-hydroxytyrosol had the highest concentrations of all phenolics in the bud extracts. Other major compounds belong to the chemical classes of sugars, fatty acids, and triterpenoid acids. Antioxidant, antimicrobial, and cytotoxic activities were determined for both cultivars. Apart from antioxidant activity, essential oils had a weak overall biological effect. The extract from cultivar Lastovka showed much better antioxidant activity than both isolates with both methods (with an oxygen radical absorbance capacity value of 1835.42 μM TE/g and DPPH IC50 of 0.274 mg/mL), as well as antimicrobial activity with the best results against Listeria monocytogenes. The human breast adenocarcinoma MDA-MB-231 cell line showed the best response for cultivar Lastovka bud extract (IC50 = 150 μg/mL) among three human cancer cell lines tested. These results demonstrate great chemical and biological potential that is hidden in olive buds and the need to increase research in the area of embryonic parts of plants.
Arsenic Exposure Causes Global Changes in the Metalloproteome of Escherichia coli
Authors: Larson James , Tokmina-Lukaszewska Monika , Fausset Hunter , Spurzem Scott , Cox Savannah , Cooper Gwendolyn , Copié Valérie , Bothner Brian
Published: February 2023

Arsenic is a toxic metalloid with differential biological effects, depending on speciation and concentration. Trivalent arsenic (arsenite, AsIII) is more toxic at lower concentrations than the pentavalent form (arsenate, AsV). In E. coli, the proteins encoded by the arsRBC operon are the major arsenic detoxification mechanism. Our previous transcriptional analyses indicate broad changes in metal uptake and regulation upon arsenic exposure. Currently, it is not known how arsenic exposure impacts the cellular distribution of other metals. This study examines the metalloproteome of E. coli strains with and without the arsRBC operon in response to sublethal doses of AsIII and AsV. Size exclusion chromatography coupled with inductively coupled plasma mass spectrometry (SEC-ICPMS) was used to investigate the distribution of five metals (56Fe, 24Mg, 66Zn, 75As, and 63Cu) in proteins and protein complexes under native conditions. Parallel analysis by SEC-UV-Vis spectroscopy monitored the presence of protein cofactors. Together, these data reveal global changes in the metalloproteome, proteome, protein cofactors, and soluble intracellular metal pools in response to arsenic stress in E. coli. This work brings to light one outcome of metal exposure and suggests that metal toxicity on the cellular level arises from direct and indirect effects.
Geochemical Characterization of Laminated Crystalline Crust Travertines Formed by Ca2+-Deficient Hot Springs at Sobcha (China)
Authors: Lu Zhipeng , Wen Huaguo , Luo Lianchao , Li Liang , Nie Ying
Published: February 2023

Travertines formed of crystalline crust have been widely reported, but there has not been focus on their geochemical characteristics. We therefore carefully conducted a series of geochemical investigations and U-Th dating on a travertine mound mainly composed of crystalline crust from Sobcha (southwest China) to determine their geochemical features and geological implications. The Sobcha travertines dominantly consist of granular crystals and fan crystals and show δ13C from 3.4‰ to 4.9‰ V-PDB, δ18O from −26.7‰ to −23.7‰ V-PDB, and 87Sr/86Sr from 0.712458 to 0.712951. When normalized to PASS, the Sobcha travertines exhibit MREE enrichment relative to HREE and LREE, HREE enrichment relative to LREE, and positive Eu anomalies. The δ13C signatures and mother CO2 evaluation of the Sobcha travertines show that the Sobcha travertines were thermogene travertines largely receiving mother CO2 from (upper) mantle (i.e., magmatic CO2) or a mixture of soil-derived CO2 and CO2 related to carbonate decarbonation. The 87Sr/86Sr of the Sobcha travertines is out of the 87Sr/86Sr ranges of local deposits exposed at Sobcha and surrounding areas but is well matched with the mean 87Sr/86Sr of Nadi Kangri volcanic rocks which cropped out to the northeast of the studied travertines (over 20 km away). This might indicate the important role of the Nadi Kangri volcanic rocks in suppling Sr to the studied travertines, but more studies are required. The LREE depletion compared to MREE and HREE in the Sobcha travertines was interpreted to be caused by the difference in geochemical mobility between LREEs and HREEs during water–rock interaction at depth, while the MREE enrichment compared to HREE was considered to be most likely inherited from reservoir/aquifer rocks. The positive Eu anomalies of the Sobcha travertines may result from very high reservoir temperatures and/or preferential dissolution of Eu-rich minerals/rocks (especially plagioclase). The Sobcha travertine mounds displays no or very slight vertical variations in δ13C, 87Sr/86Sr, and REE patterns, indicating the compositional stability of mother CO2 and paleo-fluids. However, a significant vertical increase in δ18O was observed and was explained as the result of gradual water temperature decrease related to climate cooling, self-closure of the vents, or mound vertical growth. The findings in this study might help us better understand the deposition of crystalline crust in Ca2+-deficient hot spring systems.
Spectroscopic Investigation of a Color Painting on an Ancient Wooden Architecture from the Taiping Heavenly Kingdom Prince Dai’s Mansion in Jiangsu, China
Authors: Han Kezhu , Yang Hong , Teri Gele , Hu Shanshuang , Li Jiaxin , Li Yanli , Ma Ersudai , Tian Yuxiao , Fu Peng , Luo Yujia , Li Yuhu
Published: February 2023

This research sheds light on the analysis of pigments and adhesives applied on a color painting on wooden architecture in Taiping Heavenly Kingdom Prince Dai’s mansion, located in Changzhou, Jiangsu Province in China. Four samples were collected from the painting above the building beam in the mansion, and the samples were analyzed and identified using a series of techniques, including polarized light microscopy (PLM), scanning electron microscope coupled with an energy-dispersive X-ray spectroscopy (SEM-EDS), micro-Raman spectroscopy (m-RS) and Fourier-transform infrared spectroscopy (FTIR). The results indicate that the red, black, blue, and green pigments were identified to be cinnabar, ivory black, indigo, and phthalocyanine green, respectively. The green pigment was inferred to be a lately repainted pigment based on its production age, suggesting that this ancient building had been refurbished or repaired. Given the good stability and visual effect of this green pigment, it is suggested to be used in future conservation processes. The pyrolysis-gas chromatography/mass Spectrometry (Py-Gc/Ms) results indicate that glue containing protein was used as a binder for the pigment samples, and that walnut oil might have been applied to the wooden architecture as a primer before painting. Our findings can well inform curators and conservators of the selection of appropriate restoration materials if necessary, and also provide data support for conservation of similar ancient buildings in southern China.
Coronavirus-Like Core–Shell-Structured Co@C for Hydrogen Evolution via Hydrolysis of Sodium Borohydride
Authors: Su Shuyi , Chen Kailei , Yang Xu , Dang Dai
Published: February 2023

Constructing a reliable and robust cobalt-based catalyst for hydrogen evolution via hydrolysis of sodium borohydride is appealing but challenging due to the deactivation caused by the metal leaching and re-oxidization of metallic cobalt. A unique core–shell-structured coronavirus-like Co@C microsphere was prepared via pyrolysis of Co-MOF. This special Co@C had a microporous carbon coating to retain the reduced state of cobalt and resist the metal leaching. Furthermore, several nano-bumps grown discretely on the surface afforded enriched active centers. Applied in the pyrolysis of NaBH4, the Co@C-650, carbonized at 650 °C, exhibited the best activity and reliable recyclability. This comparable performance is ascribed to the increased metallic active sites and robust stability.
Coordination Compounds of Cu, Zn, and Ni with Dicarboxylic Acids and N Donor Ligands, and Their Biological Activity: A Review
Authors: Loubalová Ivana , Kopel Pavel
Published: February 2023

Complexes of carboxylic acids are very often studied due to their interesting structural, spectral, and magnetic properties. This review is focused on complexes of four dicarboxylic acids, namely, 2,2′-thiodioacetic, 3,3′-thiodipropionic, 3,3′-dithiodipropionic, and fumaric acid. Many of the complexes were characterized by single crystal X-ray analyses. Without the analyses, it is very difficult to predict the coordination mode of carboxylate groups or nitrogen ligands on central atoms. Thus, structural properties are also discussed, as well as potential applications.
Sherlock—A Free and Open-Source System for the Computer-Assisted Structure Elucidation of Organic Compounds from NMR Data
Authors: Wenk Michael , Nuzillard Jean-Marc , Steinbeck Christoph
Published: February 2023

The structure elucidation of small organic molecules (<1500 Dalton) through 1D and 2D nuclear magnetic resonance (NMR) data analysis is a potentially challenging, combinatorial problem. This publication presents Sherlock, a free and open-source Computer-Assisted Structure Elucidation (CASE) software where the user controls the chain of elementary operations through a versatile graphical user interface, including spectral peak picking, addition of automatically or user-defined structure constraints, structure generation, ranking and display of the solutions. A set of forty-five compounds was selected in order to illustrate the new possibilities offered to organic chemists by Sherlock for improving the reliability and traceability of structure elucidation results.
Feature Selection for the Interpretation of Antioxidant Mechanisms in Plant Phenolics
Authors: Fujimoto Taiki , Gotoh Hiroaki
Published: February 2023

Antioxidants, represented by plant phenolics, protect living tissues by scavenging reactive oxygen species through diverse reaction mechanisms. Research on antioxidants is often individualized, for example, focusing on the evaluation of their activity against a single reactive oxygen species or examining the antioxidant properties of compounds with similar structures. In this study, multivariate analysis was used to comprehensively examine antioxidant properties. Eighteen features were selected to explain the results of the antioxidant capacity tests. These selected features were then evaluated by supervised learning, using the results of the antioxidant capacity assays. Dimension-reduction techniques were also used to represent the compound space with antioxidants as a two-dimensional distribution. A small amount of data obtained from several assays provided us with comprehensive information on the relationships between the structures and activities of antioxidants.
Porphyrin Functionalized Carbon Quantum Dots for Enhanced Electrochemiluminescence and Sensitive Detection of Cu2+
Authors: Zhang Xinying , Hou Xialing , Lu Decheng , Chen Yingying , Feng Lingyan
Published: February 2023

Porphyrin (TMPyP) functionalized carbon quantum dots (CQDs-TMPyP), a novel and efficient carbon nanocomposite material, were developed as a novel luminescent material, which could be very useful for the sensitive detection of copper ions in the Cu2+ quenching luminescence of functionalized carbon quantum dots. Therefore, we constructed a sensitive “signal off” ECL biosensor for the detection of Cu2+. This sensor can sensitively respond to copper ions in the range of 10 nM to 10 μM, and the detection limit is 2.78 nM. At the same time, it has good selectivity and stability and a benign response in complex systems. With excellent properties, this proposed ECL biosensor provides an efficient and ultrasensitive method for Cu2+ detection.
Glutamine Deprivation Synergizes the Anticancer Effects of Cold Atmospheric Plasma on Esophageal Cancer Cells
Authors: Zhao Wei , Jing Xumiao , Wang Tao , Zhang Fengqiu
Published: February 2023

Esophageal cancer is a highly aggressive malignancy with a low response to standard anti-cancer therapies. There is an unmet need to develop new therapeutic strategies to improve the clinical outcomes of current treatments. Cold atmospheric plasma (CAP) is a promising approach for cancer treatment, and has displayed anticancer efficacy in multiple preclinical models. Recent studies have shown that the efficacy of CAP is positively correlated with intracellular reactive oxygen species (ROS) levels. This suggests that aggressively increasing intracellular ROS levels has the potential to further improve CAP-mediated anticancer efficacy. Glutamine plays an important role in cellular ROS scavenging after being converted to glutathione (GSH, a well-described antioxidant) under physiological conditions, so reducing intracellular glutamine levels seems to be a promising strategy. To test this hypothesis, we treated esophageal cancer cells with CAP while controlling the supply of glutamine. The results showed that glutamine did affect the anticancer effect of CAP, and the combination of CAP stimulation and glutamine deprivation significantly inhibited the proliferation of esophageal cancer cells compared to the control group (p < 0.05). Furthermore, flow cytometric analysis documented a significant increase in more than 10% in apoptosis and necrosis of esophageal cancer cells after this synergistic treatment compared to the control group (p < 0.05). Thus, these results provide the first direct evidence that the biological function of CAP can be modulated by glutamine levels and that combined CAP stimulation and glutamine deprivation represent a promising strategy for the future treatment of esophageal cancer.
Three-Dimensional-QSAR and Relative Binding Affinity Estimation of Focal Adhesion Kinase Inhibitors
Authors: Ghosh Suparna , Cho Seung Joo
Published: February 2023

Precise binding affinity predictions are essential for structure-based drug discovery (SBDD). Focal adhesion kinase (FAK) is a member of the tyrosine kinase protein family and is overexpressed in a variety of human malignancies. Inhibition of FAK using small molecules is a promising therapeutic option for several types of cancer. Here, we conducted computational modeling of FAK-targeting inhibitors using three-dimensional structure–activity relationship (3D-QSAR), molecular dynamics (MD), and hybrid topology-based free energy perturbation (FEP) methods. The structure–activity relationship (SAR) studies between the physicochemical descriptors and inhibitory activities of the chemical compounds were performed with reasonable statistical accuracy using CoMFA and CoMSIA. These are two well-known 3D-QSAR methods based on the principle of supervised machine learning (ML). Essential information regarding residue-specific binding interactions was determined using MD and MM-PB/GBSA methods. Finally, physics-based relative binding free energy (ΔΔGRBFEA→B) terms of analogous ligands were estimated using alchemical FEP simulation. An acceptable agreement was observed between the experimental and computed relative binding free energies. Overall, the results suggested that using ML and physics-based hybrid approaches could be useful in synergy for the rational optimization of accessible lead compounds with similar scaffolds targeting the FAK receptor.
Decoration of Polyfluorene-Wrapped Carbon Nanotubes with Photocleavable Side-Chains
Authors: Ritaine Dialia , Adronov Alex
Published: February 2023

Functionalizing polyfluorene-wrapped carbon nanotubes without damaging their properties is effective via Copper-Catalyzed Azide–Alkyne Cycloaddition (CuAAC). However, the length and nature of polymer side-chains can impact the conductivity of polyfluorene-SWNT films by preventing close contact between the nanotubes. Here, we investigate the functionalization of a polyfluorene-SWNT complex using photocleavable side-chains that can be removed post-processing. The cleavage of the side-chains containing an ortho-nitrobenzyl ether derivative is efficient when exposed to a UV lamp at 365 nm. The photoisomerization of the o-nitrobenzyl ether linker into the corresponding o-nitrosobenzaldehyde was first monitored via UV-Vis absorption spectroscopy and 1H-NMR spectroscopy on the polymer, which showed efficient cleavage after 2 h. We next investigated the cleavage on the polyfluorene-SWNT complex via UV-Vis-NIR absorption spectroscopy. The precipitation of the nanotube dispersion and the broad absorption peaks after overnight irradiation also indicated effective cleavage. In addition, Raman spectroscopy post-irradiation showed that the nanotubes were not damaged upon irradiation. This paper reports a proof of concept that may find applications for SWNT-based materials in which side-chain removal could lead to higher device performance.
Chitosan-Based Hemostatic Hydrogels: The Concept, Mechanism, Application, and Prospects
Authors: Fan Peng , Zeng Yanbo , Zaldivar-Silva Dionisio , Agüero Lissette , Wang Shige
Published: February 2023

The design of new hemostatic materials to mitigate uncontrolled bleeding in emergencies is challenging. Chitosan-based hemostatic hydrogels have frequently been used for hemostasis due to their unique biocompatibility, tunable mechanical properties, injectability, and ease of handling. Moreover, chitosan (CS) absorbs red blood cells and activates platelets to promote hemostasis. Benefiting from these desired properties, the hemostatic application of CS hydrogels is attracting ever-increasing research attention. This paper reviews the recent research progress of CS-based hemostatic hydrogels and their advantageous characteristics compared to traditional hemostatic materials. The effects of the hemostatic mechanism, effects of deacetylation degree, relative molecular mass, and chemical modification on the hemostatic performance of CS hydrogels are summarized. Meanwhile, some typical applications of CS hydrogels are introduced to provide references for the preparation of efficient hemostatic hydrogels. Finally, the future perspectives of CS-based hemostatic hydrogels are presented.
Recent Advances of Modified Ni (Co, Fe)-Based LDH 2D Materials for Water Splitting
Authors: Li Chenguang , Bao Yupeng , Liu Enzhou , Zhao Binran , Sun Tao
Published: February 2023

Water splitting technology is an efficient approach to produce hydrogen (H2) as an energy carrier, which can address the problems of environmental deterioration and energy shortage well, as well as establishment of a clean and sustainable hydrogen economy powered by renewable energy sources due to the green reaction of H2 with O2. The efficiency of H2 production by water splitting technology is intimately related with the reactions on the electrode. Nowadays, the efficient electrocatalysts in water splitting reactions are the precious metal-based materials, i.e., Pt/C, RuO2, and IrO2. Ni (Co, Fe)-based layered double hydroxides (LDH) two-dimensional (2D) materials are the typical non-precious metal-based materials in water splitting with their advantages including low cost, excellent electrocatalytic performance, and simple preparation methods. They exhibit great potential for the substitution of precious metal-based materials. This review summarizes the recent progress of Ni (Co, Fe)-based LDH 2D materials for water splitting, and mainly focuses on discussing and analyzing the different strategies for modifying LDH materials towards high electrocatalytic performance. We also discuss recent achievements, including their electronic structure, electrocatalytic performance, catalytic center, preparation process, and catalytic mechanism. Furthermore, the characterization progress in revealing the electronic structure and catalytic mechanism of LDH is highlighted in this review. Finally, we put forward some future perspectives relating to design and explore advanced LDH catalysts in water splitting.
Fundamentals of Rhenium-188 Radiopharmaceutical Chemistry
Authors: Kleynhans Janke , Duatti Adriano , Bolzati Cristina
Published: February 2023

The β− emitter, rhenium-188 (188Re), has long been recognized as an attractive candidate for targeted cancer radionuclide therapy (TRNT). This transition metal shares chemical similarities with its congener element technetium, whose nuclear isomer technetium-99m (99mTc) is the current workhorse of diagnostic nuclear medicine. The differences between these two elements have a significant impact on the radiolabelling methods and should always receive critical attention. This review aims to highlight what needs to be considered to design a successful radiopharmaceutical incorporating 118Re. Some of the most effective strategies for preparing therapeutic radiopharmaceuticals with 188Re are illustrated and rationalized using the concept of the inorganic functional group (core) and a simple ligand field theoretical model combined with a qualitative definition of frontiers orbitals. Of special interest are the Re(V) oxo and Re(V) nitrido functional groups. Suitable ligands for binding to these cores are discussed, successful clinical applications are summarized, and a prediction of viable future applications is presented. Rhenium-188 decays through the emission of a high energy beta particle (2.12 MeV max energy) and a half-life of 16.9 h. An ideal biological target would therefore be a high-capacity target site (transporters, potential gradients, tumour microenvironment) with less emphasis on saturable targets such as overexpressed receptors on smaller metastases.
The Development and Optimization of Lipid-Based Self-Nanoemulsifying Drug Delivery Systems for the Intravenous Delivery of Propofol
Authors: Kazi Mohsin , Alqahtani Athba , Alharbi Majed , Ahmad Ajaz , Hussain Muhammad Delwar , Alothaid Hani , Aldughaim Mohammed S.
Published: February 2023

Purpose: Propofol is a relatively short-acting potent anesthetic lipophilic drug used during short surgical procedures. Despite the success of propofol intravenous emulsions, drawbacks to such formulations include inherent emulsion instability, the lack of a safe vehicle to prevent sepsis, and concern regarding hyperlipidemia-related side effects. The aim of the current investigation was to develop a novel, lipid-based self-nanoemulsifying drug delivery system (SNEDDS) for propofol with improved stability and anesthetic activity for human use. Methods: A series of SNEDDS formulations were developed using naturally obtained medium-chain/long-chain mono-, di-, and triglycerides, glyceryl monocaprylate, and water-soluble cosolvents with hydrogenated castor oil constructing ternary phase diagrams for propofol. The developed SNEDDS formulations were characterized using visual observation, particle size analysis, zeta potential, transmission electron microscopy, equilibrium solubility, in vitro dynamic dispersion and stability, and in vivo sleeping disorder studies in rats. The in vivo bioavailability of the SNEDDSs in rats was also studied to compare the representative formulations with the marketed product Diprivan®. Results: Medium-chain triglycerides (M810) with mono-diglycerides (CMCM) as an oil blend and hydrogenated castor oil (KHS15) as a surfactant were selected as key ingredients in ternary phase diagram studies. The nanoemulsifying regions were identified from the studies and a number of SNEDDSs were formulated. Results from the characterization studies demonstrated the formation of efficient nanosized particles (28–45 nm globule size, 0.10–0.20 PDI) in the optimized SNEDDS with a drug loading of 50 mg/g, which is almost 500-fold higher than free propofol. TEM analysis showed the formation of spherical and homogeneous nanoparticles of less than 50 nm. The dissolution rate of the representative SNEDDS was faster than raw propofol and able to maintain 99% propofol in aqueous solution for around 24 h. The optimized liquid SNEDDS formulation was found to be thermodynamically stable. The intravenous administration of the SNEDDS in male Wistar rats induced a sleeping time of 73–88 min. The mean plasma concentrations after the IV administration of propofol nano-formulations PF2-SNEDDS and PF8-SNEDDS were 1348.07 ± 27.31 and 1138.66 ± 44.97 µg/mL, as compared to 891.44 ± 26.05 µg/mL (p = 0.05) observed after the IV administration of raw propofol. Conclusion: Propofol-loaded SNEDDS formulations could be a potential pharmaceutical product with improved stability, bioavailability, and anesthetic activity.