bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of Financial Real Estate Risks and Spatial Interactions: Evidence from 35 Cities in China
Authors: Liu Fengyun , Ren Honghao , Liu Chuanzhe , Tan Dejun
Published: December 2022

The real estate prices in urban China have been soaring sharply since the commercialization reform of the housing market in 1998, but have suffered from downward pressure recently. In addition to the peculiarities of the state-owned land system, newly built houses dominate market across the vast territories of China, and this study of China will further the understanding of the financial real estate risks. Based on theoretical analyses, a spatial Durbin model is adopted to evaluate the financial real estate risks based on various sectors’ participation in the real estate market, because it can overcome the biased results brought about by the omission of possible spatial dependence. The results show the following: (1) the four sectors’ participation in the real estate market promotes the rise of real estate prices in the both local and other cities with spatial contagion effects, while the most important factors are different across regions; (2) the real estate price fluctuations, the local government’s land revenue, the bank credit provided to the real estate industry, the demand in the local city, and the real estate developers’ investments in other cities increase the local financial real estate risks, and there are strong spatial diffusion effects among the cities. This study sheds light on the roles of the various sectors’ participation in promoting the financial real estate risk as well as their spatial interactions from both theoretical and empirical aspects. Particularly, the different roles of local governments and real estate developers in China should be highlighted. The rules on the sector and spatial levels suggest that government policy should take the different features of various sectors and regions and spatial connections into account.
The Effect of Harsh Environmental Conditions on Concrete Plastic Shrinkage Cracks: Case Study Saudi Arabia
Authors: Alshammari Talal O. , Guadagnini Maurizio , Pilakoutas Kypros
Published: December 2022

Due to climate change and population expansion, concrete structures are progressively being subjected to more extreme environments. As the environment affects plastic shrinkage directly, there is a need to understand the effect of environmental changes on plastic shrinkage cracking. This paper examines the plastic shrinkage crack development parametrically at low, mid, and high drying environmental conditions, corresponding to different environments in three Saudi cities. The effects of water-cement ratios and quantities of recycled tire steel fibers (RTSF) in concrete are also investigated. The different environmental conditions for the plastic shrinkage tests were simulated in a specially designed chamber as per ASTM C1579, 2006. A digital image processing (DIP) technique was used to monitor crack initiation and development. Through the use of the crack reduction ratio (CRR), it was found that 30 kg/m3 of RTSF can control plastic shrinkage cracks at low and mid conditions. For the more extreme (high) conditions, the use of 40 kg/m3 of RTSF fiber was sufficient to completely eliminate surface plastic shrinkage cracks. This work can help develop more sustainable concrete structures in a wider set of environmental conditions and help mitigate the impact of climate change on concrete infrastructure.
Finite Element Simulation of Ultrasonic Scattering by Rough Flaws with Multi-Scale Distortions
Authors: Wang Zheng , Zeng Zhanhong , Song Yongfeng , Li Xiongbing
Published: December 2022

The roughness of a flaw’s surface significantly affects the scattering behavior of ultrasonic waves. It is vital to understand the impact of roughness on flaw echoes, especially when performing ultrasonic nondestructive inspection on safety-critical components. However, the current approach for creating rough flaw models fails to reconstruct complicated cracks with secondary cracks. Here, a multi-scale distortion method is developed to generate a rough flaw by using an optical microscope image of a real flaw. The finite element (FE) is then implemented to simulate the near-surface rough flaws in nickel-based bars, which are detected by an offsetting immersion transducer with mode-converted transverse waves. Numerical results show that the randomness and complexity of flaw echoes from rough flaws are exceptionally high. The gap between the maximum and minimum normalized amplitude values of flaw echoes from a rough crack with secondary cracks can reach 7.125 dB. Meanwhile, the maximum time of flight (TOF) is almost twice as large as the minimum TOF. Therefore, the present method can generate effective rough flaw models in terms of macroscopic rough geometry and microscopic rough surface. Moreover, the impact of the rough flaw surface on the flaw echoes goes beyond amplitude changes and may make flaw location challenging.
Features of the Carrier Concentration Determination during Irradiation of Wide-Gap Semiconductors: The Case Study of Silicon Carbide
Authors: Lebedev Alexander A. , Kozlovski Vitali V. , Davydovskaya Klavdia S. , Kuzmin Roman A. , Levinshtein Mikhail E. , Strel’chuk Anatolii M.
Published: December 2022

In this paper, the features of radiation compensation of wide-gap semiconductors are discussed, considering the case study of silicon carbide. Two classical methods of concentration determination are compared and analyzed: capacitance-voltage (C–V) and current-voltage (I–V) characteristics. The dependence of the base resistance in high-voltage 4H-SiC Schottky diodes on the dose of irradiation by electrons and protons is experimentally traced in the range of eight orders of magnitude. It is demonstrated that the dependence of the carrier concentration on the irradiation dose can be determined unambiguously and reliably in a very wide range of compensation levels, based on the results of measuring the I–V characteristics. It is shown that the determination of the carrier removal rate using the I–V characteristics is more correct than using the C–V characteristics, especially in the case of high radiation doses.
Bidirectional Terahertz Vortex Beam Regulator
Authors: Li Jiusheng , Guo Fenglei , Zhang Shuping , Liu Chao
Published: December 2022

Most of the reported vortex beam generators with orbital angular momentum (OAM) in the terahertz region only operate in either the reflection mode or the transmission mode, which greatly limits the integration and application in terahertz technology systems. Herein, we propose a full-space vortex beam regulator at two different frequencies. By changing the VO2 phase transition state, the transmission and reflection mode OAM beams can be flexibly controlled by a single metasurface. For the transmission mode, the proposed structure realizes an OAM beam at the topological charges of l = 1 and 2 at 0.6 THz and 1.4 THz. For the reflection mode, our structure generates an OAM beam at the topological charges of l = 1 and 2 at 0.9 THz and 1.5 THz. Based on the superposition theorem and convolution operation principle, the regulation of an OAM vortex beam with a specific deflection angle and a symmetrical deflection OAM vortex beam are realized. The designed metasurface integrates multiple transmitted and reflected vortex beam functions in full space and has potential application in different terahertz systems.
Insight of Salt Spray Corrosion on Mechanical Properties of TA1-Al5052 Self-Piercing Riveted Joint
Authors: Lai Jiamei , Huang Zhichao , Tang Nanlin , Hu Zhaoxiao , Jiang Yuqiang
Published: December 2022

Self-piercing riveted (SPR) joints in automobiles inevitably suffer from corrosion damage and performance reduction. In this work, the influence of salt spray corrosion on the mechanical properties of TA1-Al5052 alloy SPR joints was studied. The TA1-5052 SPR joints were prepared and salt spray tests were carried out for different durations. The static and fatigue strengths of the joints after salt spray corrosion were tested to analyze the effect of salt spray duration on the performance of the joints. The results show that the joints’ static strength and fatigue strength decrease with prolonged salt spray time. The salt spray duration affects the joint’s tensile failure mode. The tensile failure without corrosion and with a short salt spray time is the fracture failure of the lower aluminum sheet, and the tensile failure of the joints after a long time of salt spray corrosion is the failure of the rivets. The fatigue failure form of the SPR joint is the formation of fatigue cracks in the lower aluminum sheet, and salt spray time has little effect on the fatigue failure form. Salt spray corrosion can promote the initiation and propagation of fatigue cracks. The fatigue crack initiation area is located at the boundary between the lower aluminum sheet and the rivet leg. The initiation of cracks originates from the wear zones among the sheet metal, rivets, and salt spray particles.
Advancement of Polyaniline/Carbon Nanotubes Based Thermoelectric Composites
Authors: Zhang Chun , Li Hui , Liu Yalong , Li Pengcheng , Liu Siqi , He Chaobin
Published: December 2022

Organic thermoelectric (TE) materials have been widely investigated due to their good stability, easy synthesis, and high electrical conductivity. Among them, polyaniline/carbon nanotubes (PANI/CNTs) composites have attracted significant attention for pursuing enhanced TE properties to meet the demands of commercial applications. In this review, we summarize recent advances in versatile PANI/CNTs composites in terms of the dispersion methods of CNTs (such as the addition of surfactants, mechanical grinding, and CNT functional group modification methods), fabrication engineering (physical blending and in-situ polymerization), post-treatments (solvent treatments to regulate the doping level and microstructure of PANI), and multi-components composites (incorporation of other components to enhance energy filtering effect and Seebeck coefficient), respectively. Various approaches are comprehensively discussed to illustrate the microstructure modulation and conduction mechanism within PANI/CNTs composites. Furthermore, we briefly give an outlook on the challenges of the PANI/CNTs composites for achieving high performance and hope to pave a way for future development of high-performance PANI/CNTs composites for sustainable energy utilization.
Highly-Efficient and Visible Light Photocatalytical Degradation of Organic Pollutants Using TiO2-Loaded on Low-Cost Biomass Husk
Authors: Li Yuan , Lin Xirong , Li Zhanpeng , Liu Jinyun
Published: December 2022

A composite composing of TiO2 nanoparticles load on biomass rice husk (RH) is developed by directly growing TiO2 nanoparticles on RH. The in-situ growth of the nanocrystals on RH is achieved by a low-cost and one-step homogeneous precipitation. Rapid hydrolysis proceeds at 90 °C by using ammonium fluotitanate and urea to facilitate the selective growth of TiO2. The method provides an easy access to the TiO2-RH composite with a strong interaction between TiO2 nanoparticles and the underlying RH. The structure and composition of TiO2-RH are characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and UV-vis absorption spectroscopy. TiO2 nanoparticles-RH exhibits a good photocatalytic degradation of methyl orange. The results show that 92% of methyl orange (20 mg L−1) can be degraded within three hours in visible light. The catalytic activity of the composite is not reduced after 6 cycles, and it still reaches 81% after 6 cycles. The enhanced performance is ascribed to the suitable particle size the good dispersibility. It is expected that the high photocatalytical performance and the cost-effective composite presented here will inspire the development of other high-performance photocatalysts.
Rhenium Electrodeposition and Its Electrochemical Behavior in Molten KF-KBF4-B2O3-KReO4
Authors: Chernyshev Aleksandr A. , Arkhipov Stepan P. , Apisarov Alexey P. , Shmygalev Aleksander S. , Isakov Andrey V. , Zaikov Yury P.
Published: December 2022

The electrochemical behavior of rhenium ions in the molten KF-KBF4-B2O3 salt was systematically studied, and pure metallic rhenium was obtained at the cathode. The processes of rhenium ions reduction and diffusion in molten KF-KBF4-B2O3 were determined using cyclic voltammetry, stationary galvanostatic and polarization curves analyses. The values of diffusion coefficients were 3.15 × 10−5 cm2/s and 4.61 × 10−5 cm2/s for R1 and R2, respectively. Rhenium electrodeposition was carried out at a constant potential. The process of rhenium cathode reduction in KF-KBF4-B2O3 at 773 K was found to be a one-step reaction Re(VII) → Re, and rhenium electrodeposition presumably occurred from two types of complex rhenium ions (KReO4 and K3ReO5). Both processes are quasi-reversible and controlled by diffusion. The obtained cathode deposit was analyzed by SEM, EDX, ICP-OES and XRD methods. The obtained deposit had a thread structure and rhenium was the main component.
Research on the Lightweight Design of an Aircraft Support Based on Lattice-Filled Structures
Authors: Huang Zhou , Liu Yong , Huang Xin , Mu Dong
Published: December 2022

This work studied the lightweight design of an aircraft support based on lattice-filled structures. Different from the traditional design process of lattice-filled structures, this work combined several approaches, including topology optimization, homogenization analysis, and Non-Uniform Rational B-splines (NURBS) surface modeling, to reduce the structural weight more effectively. The theories and implementations involved in the design process are introduced in this work. The new lattice-filled design of the aircraft support component reduced the weight by 40% compared with the original value, and its additive manufacturability was verified. Finally, the structural responses of the lattice-filled design from both a detailed model and homogenization model were determined and compared, considering both the static responses and dynamic characteristics. The results revealed that the homogenization method efficiently and accurately obtained the structural displacements and natural frequencies of the complex lattice-filled design. This indicates that the homogenization method can effectively reduce the calculation burden of the design process of lattice-filled structures, which opens a new channel for the structural optimizations of lattice-filled structures.
Thermal and Mechanical Characterization of Yarn Samples from Flemish Tapestry of the Sixteenth Century
Authors: Caruso Maria Rita , Lisuzzo Lorenzo , Cavallaro Giuseppe , Mirto Giacomo , Milioto Stefana , Lazzara Giuseppe
Published: December 2022

We propose a physico-chemical approach for theharacterization of the conservation condition of yarns from a Flemish tapestry of the sixteenth century. The aging effect on the yarns’ performance was evaluated by comparison with commercial materials. Water uptake experiments highlighted the aptitude of yarns toward water sorption and their increased hydrophilicity upon aging. Thermogravimetric analysis can be considered a fast approach for the fiber identification and assessment on the material life-time. The dynamic mechanical analysis provided direct evidence on the yarns, conservation state and their performance under different mechanical stresses. The proposed characterization path can be relevant for stating the condition of the tapestry and for designing a conservation protocol for the preservation of the artwork.
Dissipation and Dietary Risk Assessment of Pydiflumetofen Residues in Soybean
Authors: Wei Liping , Hou Xingang , Hou Zhiguang , Yu Xiaolong , Wang Xiumei , Zhao Qinghui , Gao Hemin , Liu Hanju , Zheng Xiaodong , Lu Zhongbin
Published: December 2022

In this study, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, combined with high-performance liquid chromatography–tandem mass spectrometry, was chosen for detecting pydiflumetofen residues in soybean plants, soybeans and soil, and assessing the risk of short- and long-term dietary intake. Pydiflumetofen concentrations ranging from 0.001–0.5 mg/L exhibited good linearity (r > 0.997). At varying doses, the average pydiflumetofen recovery rates and relative standard deviations among soybean plants, soybeans, and soil ranged from 83.9 ± 1.1% to 99.5 ± 3.3% and from 0.77 to 7.77%, respectively. The sensitivity, accuracy, and precision of the chosen methodology met the requirements of pesticide residue analysis. The results of the degradation dynamics test showed that the half-life of pydiflumetofen (t1/2) in soybean plants and in soil were 3.6 to 5.7 and from 7.9 to 25.7 d, respectively. Assessment of the concentration of pydiflumetofen residues in soybeans revealed acute and chronic dietary exposure risks of 0.06 and 7.54%, respectively. As these values are very low, pydiflumetofen residues in soybeans present an acceptable risk to public health. The results of this study will help to guide the practical application of pydiflumetofen and minimize the environmental risks associated with its use.
Regioselective Synthesis and Molecular Docking Studies of 1,5-Disubstituted 1,2,3-Triazole Derivatives of Pyrimidine Nucleobases
Authors: Algieri Vincenzo , Costanzo Paola , Tallarida Matteo Antonio , Olivito Fabrizio , Jiritano Antonio , Fiorani Giulia , Peccati Francesca , Jiménez-Osés Gonzalo , Maiuolo Loredana , De Nino Antonio
Published: December 2022

1,2,3-triazoles are versatile building blocks with growing interest in medicinal chemistry. For this reason, organic chemistry focuses on the development of new synthetic pathways to obtain 1,2,3-triazole derivatives, especially with pyridine moieties. In this work, a novel series of 1,5-disubstituted-1,2,3-triazoles functionalized with pyrimidine nucleobases were prepared via 1,3-dipolar cycloaddition reaction in a regioselective manner for the first time. The N1-propargyl nucleobases, used as an alkyne intermediate, were obtained in high yields (87–92%) with a new two-step procedure that selectively led to the monoalkylated compounds. Then, FeCl3 was employed as an efficient Lewis acid catalyst for 1,3-dipolar cycloaddition between different aryl and benzyl azides and the N1-propargyl nucleobases previously synthesized. This new protocol allows the synthesis of a series of new 1,2,3-triazole derivatives with good to excellent yields (82–92%). The ADME (Absorption, Distribution, Metabolism, and Excretion) analysis showed good pharmacokinetic properties and no violations of Lipinsky’s rules, suggesting an appropriate drug likeness for these new compounds. Molecular docking simulations, conducted on different targets, revealed that two of these new hybrids could be potential ligands for viral and bacterial protein receptors such as human norovirus capsid protein, SARS-CoV-2 NSP13 helicase, and metallo-β-lactamase.
Integrated Adsorption–Photodegradation of Organic Pollutants by Carbon Xerogel/Titania Composites
Authors: Safri Anam , Fletcher Ashleigh Jane , Safri Ramsha , Rasheed Hifza
Published: December 2022

Recent studies on the removal of pollutants via adsorption include the use of carbon-based adsorbents, due to their high porosity and large surface area; however, such materials lack photoactive properties. This study evaluates the synergistic effect of integrated mesoporous carbon xerogel (derived from resorcinol formaldehyde) and titanium dioxide (TiO2) for combined adsorption and photodegradation application. The complex formed between carbon xerogel and TiO2 phase was investigated through FTIR, proving the presence of a Ti-O–C chemical linkage. The physicochemical properties of the synthesised adsorbent–photocatalyst were probed using FESEM, BET analysis and UV–Vis analysis. The kinetics, equilibrium adsorption, effect of pH, and effect of adsorbent dosage were investigated. The expansion of the absorbance range to the visible range was verified, and the corresponding band gap evaluated. These properties enabled a visible light response when the system was exposed to visible light post adsorption. Hence, an assistive adsorption–photodegradation phenomenon was successfully executed. The adsorption performance exhibited 85% dye degradation which improved to 99% following photodegradation. Further experiments showed the reduction of microorganisms under visible light, where no microbial colonies were observed after treatment, indicating the potential application of these composite materials.
The Renewed Interest on Brunogeierite, GeFe2O4, a Rare Mineral of Germanium: A Review
Authors: Ambrosetti Marco , Bini Marcella
Published: December 2022

GeFe2O4, also known as brunogeierite, is a rare mineral of germanium. It has a normal spinel structure and, as with many other spinels, amazing functional properties thanks to its peculiar structural features. In the past, its spectroscopic, optical, magnetic and electronic properties were determined; then, for many years, this compound was left behind. Only recently, a renewed interest in this oxide has arisen, particularly for its application in the electrochemical field. In this review paper, the crystal structure of GeFe2O4 will be described, as well as the synthesis methods required to obtain single crystals or polycrystalline powders. Its spectroscopic, magnetic, optical and electrical properties will be reported in detail. Then, successful applications known so far will be described: its use as anode in Lithium Ion and Sodium Ion Batteries and as electrocatalyst for urea oxidation reaction.
Synthesis of Functionalized Isoquinolone Derivatives via Rh(III)-Catalyzed [4+2]-Annulation of Benzamides with Internal Acetylene-Containing α-CF3-α-Amino Carboxylates
Authors: Vorobyeva Daria V. , Petropavlovskikh Dmitry A. , Godovikov Ivan A. , Dolgushin Fedor M. , Osipov Sergey N.
Published: December 2022

A convenient pathway to a new series of α-CF3-substituted α-amino acid derivatives bearing pharmacophore isoquinolone core in their backbone has been developed. The method is based on [4+2]-annulation of N-(pivaloyloxy) aryl amides with orthogonally protected internal acetylene-containing α-amino carboxylates under Rh(III)-catalysis. The target annulation products can be easily transformed into valuable isoquinoline derivatives via a successive aromatization/cross-coupling operation.
Electrochemical Sensors Based on Au Nanoparticles Decorated Pyrene-Reduced Graphene Oxide for Hydrazine, 4-Nitrophenol and Hg2+ Detection in Water
Authors: Mejri Alma , Mandriota Giacomo , Elfil Hamza , Curri Maria Lucia , Ingrosso Chiara , Mars Abdelmoneim
Published: December 2022

Monitoring hazardous chemical compounds such as hydrazine (N2H4), 4-nitrophenol (4-NP) and Hg2+ in natural water resources is a crucial issue due to their toxic effects on human health and catastrophic impact on the environment. Electrochemical nanostructured platforms integrating hybrid nanocomposites based on graphene derivatives and inorganic nanoparticles (NPs) are of great interest for such a purpose. In this work, disposable screen-printed carbon electrodes (SPCEs) have been modified with a hybrid nanocomposite formed by reduced graphene oxide (RGO), functionalized by 1-pyrene carboxylic acid (PCA), and decorated by colloidal Au NPs. These hybrid platforms have been tested for the electrocatalytic detection of N2H4 and 4-NP by differential pulse voltammetry and have been modified with an electropolymerized film of Hg2+ ions imprinted polycurcumin for the electroanalytical detection of Hg2+ by DPV. LODs, lower and in line with the lowest ones reported for state-of-the-art electrochemical sensors, integrating similar Au-graphene < nanocomposites, have been estimated. Additionally, good repeatability, reproducibility, and storage stability have been assessed, as well as a high selectivity in the presence of a 100-fold higher concentration of interfering species. The applicability of the proposed platforms for the detection of the compounds in real complex matrices, such as tap and river water samples, has been effectively demonstrated.
Stimuli-Responsive Polypeptide Nanoparticles for Enhanced DNA Delivery
Authors: Korovkina Olga , Polyakov Dmitry , Korzhikov-Vlakh Viktor , Korzhikova-Vlakh Evgenia
Published: December 2022

The development of non-viral delivery systems for effective gene therapy is one of the current challenges in modern biomedicinal chemistry. In this paper, the synthesis of pH- and redox-responsive amphiphilic polypeptides for intracellular DNA delivery is reported and discussed. Two series of polypeptides consisting of L-lysine, L-phenylalanine, L-histidine, and L-cysteine as well as the same amino acids with L-glutamic acid were synthesized by a combination of copolymerization of N-carboxyanhydrides of α-amino acids and post-polymerization modification of the resulting copolymers. The presence of histidine provided pH-sensitive properties under weakly acidic conditions specific to endosomal pH. In turn, the presence of cysteine allowed for the formation of redox-responsive disulfide bonds, which stabilized the self-assembled nanoparticles in the extracellular environment but could degrade inside the cell. The formation of intraparticle disulfide bonds resulted in their compactization from 200–250 to 55–100 nm. Empty and pDNA-loaded cross-linked nanoparticles showed enhanced stability in various media compared to non-crosslinked nanoparticles. At the same time, the addition of glutathione promoted particle degradation and nucleic acid release. The delivery systems were able to retain their size and surface charge at polypeptide/pDNA ratios of 10 or higher. GFP expression in HEK 293 was induced by the delivery of pEGFP-N3 with the developed polypeptide nanoparticles. The maximal transfection efficacy (70%) was observed when the polypeptide/pDNA ratio was 100.
Zinc–Cobalt Oxide Thin Films: High Curie Temperature Studied by Electron Magnetic Resonance
Authors: Cieniek Bogumił , Stefaniuk Ireneusz , Virt Ihor , Gamernyk Roman V. , Rogalska Iwona
Published: December 2022

The material with a high Curie temperature of cobalt-doped zinc oxide embedded with silver-nanoparticle thin films was studied by electron magnetic resonance. The nanoparticles were synthesized by the homogeneous nucleation technique. Thin films were produced with the pulsed laser deposition method. The main aim of this work was to investigate the effect of Ag nanoparticles on the magnetic properties of the films. Simultaneously, the coexisting Ag0 and Ag2+ centers in zinc oxide structures are shown. A discussion of the signal seen in the low field was conducted. To analyze the temperature dependence of the line parameters, the theory described by Becker was used. The implementation of silver nanoparticles causes a significant shift of the line, and the ferromagnetic properties occur in a wide temperature range with an estimated Curie temperature above 500 K.
Metabolite Profiling of Alocasia gigantea Leaf Extract and Its Potential Anticancer Effect through Autophagy in Hepatocellular Carcinoma
Authors: Okasha Hend , Aboushousha Tarek , Coimbra Manuel A. , Cardoso Susana M. , Ghareeb Mosad A.
Published: December 2022

Hepatocellular carcinoma (HCC) is a poor-prognosis type of cancer with high resistance to chemotherapy, making the search for safe drugs a mandatory issue. Plant-derived products have potential to reduce negative side effects of cancer treatments. In this work, ability of a defatted methanolic extract of Alocasia gigantea leaves to fight HCC was evaluated in an animal model. Overall, treatment of HCC-induced mice with the methanolic extract at 150 mg/kg body weight for four consecutive weeks caused induction of autophagy through silencing of the relative expression of autophagy suppressor (mTOR) and inducement of autophagy markers (AMPK, Beclin-1, and LC-3). Moreover, it improved preservation of the hepatic histological architecture of the animals, with minor hepatocytic changes but scattered foci of hepatocytic apoptosis. Chemical profiling of the methanolic extract via ultra-high-performance liquid chromatography coupled to a diode array detector and an electrospray mass spectrometer (UHPLC–DAD–ESI–MS/MS) allowed identification of di-C-glycosyl flavones, mostly represented by 6-C-hexosyl-8-C-pentosyl apigenin isomers, which may possibly be associated with inducement of the autophagy pathway in HCC. Overall, these outcomes gave an initial visualization of the operative effect of some compounds in A. gigantea leaves that are potential treatment for HCC.
Phytochemical Characterization of Chamomile (Matricaria recutita L.) Roots and Evaluation of Their Antioxidant and Antibacterial Potential
Authors: Mailänder Lilo K. , Lorenz Peter , Bitterling Hannes , Stintzing Florian C. , Daniels Rolf , Kammerer Dietmar R.
Published: December 2022

Matricaria recutita L., German chamomile, is one of the most widely used medicinal plants, whose efficacy has been proven in numerous studies. However, its roots have attracted only little interest so far, since mainly above-ground plant parts are used for medicinal purposes. To broaden the knowledge of chamomile roots, a profound phytochemical characterization was performed along with a bioactivity screening of corresponding root extracts. While volatile constituents such as chamomillol and polyynes were detected using GC-MS, HPLC-MSn analyses revealed the occurrence of four coumarin glycosides, more than ten phenolic acid esters and five glyceroglycolipids. Furthermore, the antioxidant activity of the extracts was evaluated. Polar extracts revealed IC50 values ranging from 13 to 57 µg/mL in the DPPH radical scavenging assay, which is in the same range as reported for chamomile flower extracts. In addition, superoxide radical scavenging potential and mild antibacterial effects against S. aureus und B. subtilis were demonstrated. Moreover, to assess interspecies variation in chamomile roots, extracts of M. recutita were compared to those of M. discoidea DC. Interestingly, the latter revealed stronger antioxidant activity. The presented results aim at the valorization of chamomile roots, previously discarded as by-product of chamomile flower production, as a sustainable source of bioactive phytochemicals.
Cholinesterases Inhibition, Anticancer and Antioxidant Activity of Novel Benzoxazole and Naphthoxazole Analogs
Authors: Skrzypek Alicja , Karpińska Monika , Juszczak Małgorzata , Grabarska Aneta , Wietrzyk Joanna , Krajewska-Kułak Elżbieta , Studziński Marek , Paszko Tadeusz , Matysiak Joanna
Published: December 2022

Benzoxazole and naphthoxazole fused systems are found in many biologically active molecules. Novel benzoxazole and naphthoxazole analogs functionalized by the 2,4-dihydroxyphenyl moiety were designed, obtained and evaluated as a broad spectrum of biological potency compounds. Sulfinylbis[(2,4-dihydroxyphenyl)methanethione] or its analogs and 2-aminophenols or 1-amino-2-naphthol were used as starting reagents. 4-(Naphtho[1,2-d][1,3]oxazol-2-yl)benzene-1,3-diol was identified as the most promising compound of the nanomolar activity against AChE (IC50 = 58 nM) of the mixed-type inhibition and of the moderate activity against BChE (IC50 = 981 nM). The higher antiproliferative potency against a panel of human cancer cell lines for naphtho[1,2-d][1,3]oxazoles than for benzoxazoles was found. The activity of the analog with chlorine atom was in the range of 2.18–2.89 µM (IC50) against all studied cells and it is similar to that of cisplatin studied comparatively. Moreover, this compound was not toxic at this concentration to human normal breast cells and keratinocytes. For some compounds it also has proved antioxidant properties at the level of IC50 = 0.214 µM, for the most active compound. The lipophilicity of all compounds, expressed as log p values, is within the range recommended for potential drugs. The biological activity profile of the considered analogs and their lipophilic level justify the search for agents used in AD or in anticancer therapy in this group of compounds.
Salvianolic Acid B Strikes Back: New Evidence in the Modulation of Expression and Activity of Matrix Metalloproteinase 9 in MDA-MB-231 Human Breast Cancer Cells
Authors: Ianni Andrea , Ruggeri Pierdomenico , Bellio Pierangelo , Martino Francesco , Celenza Giuseppe , Martino Giuseppe , Franceschini Nicola
Published: December 2022

Salvianolic acid B (SalB) is a bioactive compound from Salviae miltiorrhizae, one of the most important traditional herbal medicines widely used in several countries for the treatment of cardiovascular diseases. The aim of this study was to evaluate the in vitro effect of SalB on the expression and the activity of matrix metalloproteinase 9 (MMP-9), a zinc-dependent proteolytic enzyme, in human MDA-MB-231 breast cancer cells. This cellular model is characterized by a marked invasive phenotype, supported by a high constitutive expression of MMPs, especially gelatinases. SalB was first of all evaluated by in silico approaches primarily aimed at predicting the main pharmacokinetic parameters. The most favorable interaction between the natural compound and MMP-9 was instead tested by molecular docking analysis that was subsequently verified by an enzymatic inhibition assay. MDA-MB-231 cells were treated with SalB 5 µM and 50 µM for 24 h and 48 h. The conditioned media obtained from treated cells were then analyzed by gelatin zymography and reverse zymography to, respectively, evaluate the MMP-9 activity and the presence of TIMP-1. The expression of the enzyme was then evaluated by Western blot on conditioned media and by analysis of transcripts through reverse transcriptase-polymerase chain reaction (RT-PCR). The in silico approach showed the ability of SalB to interact with the catalytic zinc ion of the enzyme, with a plausible competitive mode of action. The analysis of conditioned culture media showed a reduction in MMP-9 activity and the concomitant decrease in the enzyme concentration, partially confirmed by analysis of transcripts. SalB showed the ability to modulate the function of MMP-9 in MDA-MB-231 cells. To our knowledge, this is the first time in which the role of SalB on MMP-9 in a highly invasive cellular model is investigated. The obtained results impose further and more specific evaluations in order to obtain a better understanding of the biochemical mechanisms that regulate the interaction between this natural compound and the MMP-9.
PET Imaging of Fructose Metabolism in a Rodent Model of Neuroinflammation with 6-[18F]fluoro-6-deoxy-D-fructose
Authors: Boyle Amanda J. , Murrell Emily , Tong Junchao , Schifani Christin , Narvaez Andrea , Wuest Melinda , West Frederick , Wuest Frank , Vasdev Neil
Published: December 2022

Fluorine-18 labeled 6-fluoro-6-deoxy-D-fructose (6-[18F]FDF) targets the fructose-preferred facilitative hexose transporter GLUT5, which is expressed predominantly in brain microglia and activated in response to inflammatory stimuli. We hypothesize that 6-[18F]FDF will specifically image microglia following neuroinflammatory insult. 6-[18F]FDF and, for comparison, [18F]FDG were evaluated in unilateral intra-striatal lipopolysaccharide (LPS)-injected male and female rats (50 µg/animal) by longitudinal dynamic PET imaging in vivo. In LPS-injected rats, increased accumulation of 6-[18F]FDF was observed at 48 h post-LPS injection, with plateaued uptake (60–120 min) that was significantly higher in the ipsilateral vs. contralateral striatum (0.985 ± 0.047 and 0.819 ± 0.033 SUV, respectively; p = 0.002, n = 4M/3F). The ipsilateral–contralateral difference in striatal 6-[18F]FDF uptake expressed as binding potential (BPSRTM) peaked at 48 h (0.19 ± 0.11) and was significantly decreased at one and two weeks. In contrast, increased [18F]FDG uptake in the ipsilateral striatum was highest at one week post-LPS injection (BPSRTM = 0.25 ± 0.06, n = 4M). Iba-1 and GFAP immunohistochemistry confirmed LPS-induced activation of microglia and astrocytes, respectively, in ipsilateral striatum. This proof-of-concept study revealed an early response of 6-[18F]FDF to neuroinflammatory stimuli in rat brain. 6-[18F]FDF represents a potential PET radiotracer for imaging microglial GLUT5 density in brain with applications in neuroinflammatory and neurodegenerative diseases.
Comparative Modelling of Organic Anion Transporting Polypeptides: Structural Insights and Comparison of Binding Modes
Authors: Tonduru Arun Kumar , Adla Santosh Kumar , Huttunen Kristiina M. , Kronenberger Thales , Poso Antti
Published: December 2022

To better understand the functionality of organic anion transporting polypeptides (OATPs) and to design new ligands, reliable structural data of each OATP is needed. In this work, we used a combination of homology model with molecular dynamics simulations to generate a comprehensive structural dataset, that encompasses a diverse set of OATPs but also their relevant conformations. Our OATP models share a conserved transmembrane helix folding harbouring a druggable binding pocket in the shape of an inner pore. Our simulations suggest that the conserved salt bridges at the extracellular region between residues on TM1 and TM7 might influence the entrance of substrates. Interactions between residues on TM1 and TM4 within OATP1 family shown their importance in transport of substrates. Additionally, in transmembrane (TM) 1/2, a known conserved element, interact with two identified motifs in the TM7 and TM11. Our simulations suggest that TM1/2-TM7 interaction influence the inner pocket accessibility, while TM1/2-TM11 salt bridges control the substrate binding stability.
Transcriptional Responses for Biosynthesis of Triterpenoids in Exogenous Inducers Treated Inonotus Hispidus Using RNA-Seq
Authors: Huo Yonghong , Liu Dongchao , Yang Qin , Sun Changyan , Wang Zhanbin , Li Dehai
Published: December 2022

Inonotus hispidus is a traditional medicinal that grows in Northeast China and produces various economically important compounds, including polysaccharide compounds and terpenoids; triterpenoid saponins is the main bioactive component. Our research group has found that the accumulation of triterpenoid was affected by exogenous inducers. Experimental results showed that treatment with methyl jasmonate (MeJA) and oleic acid significantly increased the triterpenoid content of I. hispidus. However, how exogenous inducers enhance production of secondary metabolites in I. hispidus is not well understood. In this study, metabolite changes were further investigated with UPLC-TOF/MS following exogenous inducer treatment. As a result, a total of eight types of triterpenoids in I. hispidus were identified. The RNA-seq analysis was used to evaluate the effects of exogenous inducers on the expression of triterpenoid-synthesis-related genes in I. hispidus in liquid fermentation. This study is the first exploration to profile the transcriptome of I. hispidus after adding exogenous inducers; the generated data and gene will facilitate further molecular studies on the physiology and metabolism in this fungi. By comparative transcriptomic analysis, a series of candidate genes involved in the biosynthetic pathway of triterpenoids are identified, providing new insights into their biosynthesis at the transcriptome level.
Synergistically Enhancing the Therapeutic Effect on Cancer, via Asymmetric Bioinspired Materials
Authors: Ghahramani Yasamin , Mokhberi Marzieh , Mousavi Seyyed Mojtaba , Hashemi Seyyed Alireza , Fallahi Nezhad Fatemeh , Chiang Wei-Hung , Gholami Ahmad , Lai Chin Wei
Published: December 2022

The undesirable side effects of conventional chemotherapy are one of the major problems associated with cancer treatment. Recently, with the development of novel nanomaterials, tumor-targeted therapies have been invented in order to achieve more specific cancer treatment with reduced unfavorable side effects of chemotherapic agents on human cells. However, the clinical application of nanomedicines has some shortages, such as the reduced ability to cross biological barriers and undesirable side effects in normal cells. In this order, bioinspired materials are developed to minimize the related side effects due to their excellent biocompatibility and higher accumulation therapies. As bioinspired and biomimetic materials are mainly composed of a nanometric functional agent and a biologic component, they can possess both the physicochemical properties of nanomaterials and the advantages of biologic agents, such as prolonged circulation time, enhanced biocompatibility, immune modulation, and specific targeting for cancerous cells. Among the nanomaterials, asymmetric nanomaterials have gained attention as they provide a larger surface area with more active functional sites compared to symmetric nanomaterials. Additionally, the asymmetric nanomaterials are able to function as two or more distinct components due to their asymmetric structure. The mentioned properties result in unique physiochemical properties of asymmetric nanomaterials, which makes them desirable materials for anti-cancer drug delivery systems or cancer bio-imaging systems. In this review, we discuss the use of bioinspired and biomimetic materials in the treatment of cancer, with a special focus on asymmetric nanoparticle anti-cancer agents.
Highly Sensitive Adsorption and Detection of Iodide in Aqueous Solution by a Post-Synthesized Zirconium-Organic Framework
Authors: Zhang Jun , Yang Shanli , Shao Lang , Ren Yiming , Jiang Jiaolai , Wang Huaisheng , Tang Hao , Deng Hui , Xia Tifeng
Published: December 2022

Effective methods of detection and removal of iodide ions (I−) from radioactive wastewater are urgently needed and developing them remains a great challenge. In this work, an Ag+ decorated stable nano-MOF UiO-66-(COOH)2 was developed for the I− to simultaneously capture and sense in aqueous solution. Due to the uncoordinated carboxylate groups on the UiO-66-(COOH)2 framework, Ag+ was successfully incorporated into the MOF and enhanced the intrinsic fluorescence of MOF. After adding iodide ions, Ag+ would be produced, following the formation of AgI. As a result, Ag+@UiO-66-(COOH)2 can be utilized for the removal of I− in aqueous solution, even in the presence of other common ionic ions (NO2−, NO3−, F−, SO42−). The removal capacity as high as 235.5 mg/g was calculated by Langmuir model; moreover, the fluorescence of Ag+@UiO-66-(COOH)2 gradually decreases with the deposition of AgI, which can be quantitatively depicted by a linear equation. The limit of detection toward I− is calculated to be 0.58 ppm.
Antibacterial Activity of Syzygium aromaticum (Clove) Bud Oil and Its Interaction with Imipenem in Controlling Wound Infections in Rats Caused by Methicillin-Resistant Staphylococcus aureus
Authors: Alanazi Abdulaziz Khaleef , Alqasmi Mohammed Hussein , Alrouji Mohammed , Kuriri Fahd A. , Almuhanna Yasir , Joseph Babu , Asad Mohammed
Published: December 2022

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of infection worldwide. Clove oil’s ability to inhibit the growth of MRSA was studied through in vitro and in vivo studies. The phytochemical components of clove oil were determined through gas chromatography-mass spectrometry (GC-MS) analysis. The antibacterial effects of clove oil and its interaction with imipenem were determined by studying MIC, MBC, and FIC indices in vitro. The in vivo wound-healing effect of the clove oil and infection control were determined using excision wound model rats. The GC-MS analysis of clove oil revealed the presence of 16 volatile compounds. Clove oil showed a good antibacterial effect in vitro but no interaction was observed with imipenem. Clove bud oil alone or in combination with imipenem healed wounds faster and reduced the microbial load in wounds. The findings of this study confirmed the antibacterial activity of clove oil in vitro and in vivo and demonstrated its interaction with imipenem.
SnSe Nanosheets Mimic Lactate Dehydrogenase to Reverse Tumor Acid Microenvironment Metabolism for Enhancement of Tumor Therapy
Authors: Wang Heng , Wang Beilei , Jiang Jie , Wu Yi , Song Anning , Wang Xiaoyu , Yao Chenlu , Dai Huaxing , Xu Jialu , Zhang Yue , Ma Qingle , Xu Fang , Li Ruibin , Wang Chao
Published: December 2022

The acidic tumor microenvironment (TME) is unfriendly to the activity and function of immune cells in the TME. Here, we report inorganic nanozymes (i.e., SnSe NSs) that mimic the catalytic activity of lactate dehydrogenase to degrade lactate to pyruvate, contributing to the metabolic treatment of tumors. As found in this study, SnSe NSs successfully decreased lactate levels in cells and tumors, as well as reduced tumor acidity. This is associated with activation of the immune response of T cells, thus alleviating the immunosuppressive environment of the TME. More importantly, the nanozyme successfully inhibited tumor growth in mutilate mouse tumor models. Thus, SnSe NSs show a promising result in lactate depletion and tumor suppression, which exemplifies its potential strategy in targeting lactate for metabolic therapy.
In Vitro Evaluation of the Interaction of Seven Biologically Active Components in Anemarrhenae rhizoma with P-gp
Authors: Dai Jianying , He Yuzhen , Fang Jiahao , Wang Hui , Chao Liang , Zhao Liang , Hong Zhanying , Chai Yifeng
Published: December 2022

The efficacy and pharmacokinetics of the biologically active components in Anemarrhenae rhizoma (AR) would be affected by the interaction of P-glycoprotein(P-gp) and effective components in AR. However, little is known about the interaction between them. The goal of this research was to examine the transmembrane absorption of timosaponin AIII(TAIII), timosaponin BII(TBII), sarsasapogenin (SSG), mangiferin(MGF), neomangiferin(NMGF), isomangiferin(IMGF), and baohuosideI(BHI) in AR and their interaction with P-gp. Seven effective components in AR(TAIII, TBII, SSG, MGF, NMGF, IMGF, and BHI) were investigated, and MDCK-MDR1 cells were used as the transport cell model. CCK-8 assays, bidirectional transport assays, and Rhodamine-123 (Rh-123) transport assays were determined in the MDCK-MDR1 cells. LC/MS was applied to the quantitative analysis of TAIII, TBII, MGF, NMGF, IMGF, SSG, and BHI in transport samples. The efflux ratio of MGF, TAIII, TBII, and BHI was greater than 2 and significantly descended with the co-administration of Verapamil, indicating MGF, TAIII, TBII, and BHI as the substrates of P-gp. The efflux ratio of the seven effective components in the extracts (10 mg/mL) of AR decreased from 3.00~1.08 to 1.92~0.48. Compared to the efflux ratio of Rh-123 in the control group (2.46), the efflux ratios of Rh-123 were 1.22, 1.27, 1.25, 1.09, 1.31, and 1.47 by the addition of TAIII, TBII, MGF, IMGF, NMGF, and BHI, respectively, while the efflux ratio of Rh-123 with the co-administration of SSG had no statistical difference compared to the control group. These results indicated that MGF, TAIII, TBII, and BHI could be the substrates of P-gp. TAIII, TBII, MGF, IMGF, NMGF, and BHI show the effect of inhibiting P-gp function, respectively. These findings provide important basic pharmacological data to assist the therapeutic development of AR constituents and extracts.