bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Characteristics of Fiber-Reinforced Flexible Pipe Subjected to Axial Tensile Load
Authors: Sun Zhenwen , Huang Weiping , Lu Hailong , Bu Yufeng , Yin Yuanchao , Wang Shichao , Fan Yimeng
Published: March 2023

Fiber-reinforced flexible pipes are subjected to large axial tension loads in deep-water applications, which may result in the excessive deformation of the pipes. Owing to the anisotropy of the composite materials, accurately describing the tensile behavior of these pipes is difficult. Theoretical, numerical, and experimental methods are employed in this study to investigate the mechanical characteristics of a glass fiber-reinforced unbonded flexible pipe under axial tensile loads. Based on the load–strain relationship of each pipe layer, analytical equations considering the effect of anisotropy and radial deformation are first proposed to calculate the axial tensile stiffness of the pipe. A detailed numerical model is established to simulate the tensile behavior of the pipe. A prototype test is performed on a 4500 mm long sample using a tensile testing machine. The leading roles of outer tensile reinforcement layers in axial tensile capacity are illustrated by the strain energy of the pipe layers obtained by the numerical model. Subsequently, a comparison analysis of the mean fiber direction strains of the selected sections are performed between numerical and experimental results, which validates the numerical model. Additionally, the stress distributions of different pipe layers are discussed based on the results of the numerical analysis. Finally, the comparison of axial tensile stiffness results validates the accuracy of the analytical model considering radial deformation. This study proposes effective theoretical and numerical models to predict the tensile behavior of a fiber-reinforced flexible pipe, which provides useful references for the design and structural analysis of these pipes.
Term Premia in Norwegian Interest Rate Swaps
Authors: de Lange Petter Eilif , Risstad Morten , Semmen Kristian , Westgaard Sjur
Published: March 2023

Fundamentally, the term premium in long-term nominal yields is compensation to investors for bearing interest rate risk. There is substantial evidence of sizable and time-varying term premia. As opposed to yields, term premia are not directly observable. In this paper, we estimate term premia in Norwegian interest rate swaps from a set of dynamic term structure models, covering the period from 2001/04 until 2022/06. In line with international studies, we find evidence of declining term premia over the sample period. Furthermore, our estimates indicate that term premia have been close to zero, as well as negative in periods, during the last decade of global extraordinary monetary policy measures. We find that the recent rise in Norwegian interest rate swaps is partly caused by increases in term premia. From a practitioner’s perspective, our term premia estimates can be utilized as part of applied management of both investment and debt portfolios.
Sound Change in Albanian Monolinguals and Albanian–English Sequential Bilingual Returnees in Tirana, Albania
Authors: de Leeuw Esther , Kapia Enkeleida , Lewis Scott
Published: March 2023

This research investigated contrastive perception of L1 phonological categories in Albanian–English bilinguals who returned to Albania after living abroad for over on average a decade. In Standard Albanian, there are phonemic contrasts between /c/ and /tʃ/, /ɫ/ and /l/, and /ɹ/ and /r/. These phonemic contrasts do not occur in English. Using a “real speech” binary minimal pair identification task, we compared the accuracy and response times of bilingual returnees against functional Albanian monolinguals who had never lived abroad. Results showed that (1) reaction times for /c/ versus /tʃ/ were longest for both groups, indicating that this contrast was “harder” than the other contrasts. Surprisingly, (2) bilinguals outperformed monolinguals in accurately identifying /c/ versus /tʃ/; and (3) no significant group differences were found for the other two phonemic contrasts. In combination with other research showing that Albanian is undergoing a merger of /c/ and /tʃ/, our findings suggest that this merger is more advanced in monolinguals than bilinguals—probably because the bilinguals were abroad when the merger started. Examination of variation within the bilinguals indicated that (4) the younger the speaker was when they left Albania, and the more recently they had returned, the lower their accuracy was in identifying the laterals. These phonological findings enhance our understanding of perceptual L1 attrition whilst underlining the need to examine language change in the country of origin in L1 attrition research.
Archaeometallurgical Analysis of the Provincial Silver Coinage of Judah: More on the Chaîne Opératoire of the Minting Process
Authors: Cohen Maayan , Ashkenazi Dana , Gitler Haim , Tal Oren
Published: March 2023

Silver coins were the first coins to be manufactured by mass production in the southern Levant. An assemblage of tiny provincial silver coins of the local (Judahite standard) and (Attic) obol-based denominations from the Persian and Hellenistic period Yehud and dated to the second half of the fourth century BCE were analyzed to determine their material composition. Of the 50 silver coins, 32 are defined as Type 5 (Athena/Owl) of the Persian period Yehud series (ca. 350–333 BCE); 9 are Type 16 (Persian king wearing a jagged crown/Falcon in flight) (ca. 350–333); 3 are Type 24 series (Portrait/Falcon) of the Macedonian period (ca. 333–306 BCE); and 6 are Type 31 (Portrait/Falcon) (ca. 306–302/1 BCE). The coins underwent visual testing, multi-focal light microscope observation, XRF analysis, and SEM-EDS analysis. The metallurgical findings revealed that all the coins from the Type 5, 16, 24, and 31 series are made of high-purity silver with a small percentage of copper. Based on these results, it is suggested that each series was manufactured using a controlled composition of silver–copper alloy. The findings present novel information about the material culture of the southern Levant during the Late Persian period and Macedonian period, as expressed through the production and use of these silver coins.
Thermodynamical Analysis of the Formation of α-Si Ring Structures on Silicon Surface
Authors: Jarutis Vygandas , Paipulas Domas , Jukna Vytautas
Published: March 2023

Superficial modifications on silicon wafers produced by single-shot focused femtosecond laser irradiation having a 1030 nm wavelength and 300 fs pulse duration were experimentally and theoretically analyzed. The laser fluence window when the amorphous silicon phase develops, resulting in a ring-like modification shape, was experimentally estimated to be between 0.26 J/cm2 and 0.40 J/cm2 and was independent of the silicon dopant type and laser focusing conditions; however, the window was narrower when compared to results reported for shorter pulse durations. In addition, we present a simplified numerical model that can explain and predict the formation of these patterns based on the caloric coefficients of silicon and the energy distribution of the deposited material.
Mangiferin-Enriched Mn–Hydroxyapatite Coupled with β-TCP Scaffolds Simultaneously Exhibit Osteogenicity and Anti-Bacterial Efficacy
Authors: Swain Subhasmita , Koduru Janardhan Reddy , Rautray Tapash Ranjan
Published: March 2023

Biphasic calcium phosphate (BCP) containing β-tricalcium phosphate and manganese (Mn)-substituted hydroxyapatite (HAP) was synthesized. Biomedical scaffolds were prepared using this synthesized powder on a sacrificial polyurethane sponge template after the incorporation of mangiferin (MAN). Mn was substituted at a concentration of 5% and 10% in HAP to examine the efficacy of Mn at various concentrations. The phase analysis of the as-formed BCP scaffold was carried out by X-ray diffraction analysis, while the qualitative observation of morphology and the osteoblast cell differentiation were carried out by scanning electron microscopy and confocal laser scanning microscopy techniques. Gene expressions of osteocalcin, collagen 1, and RUNX2 were carried out using qRT-PCR analyses. Significantly higher (p < 0.05) levels of ALP activity were observed with extended osteoblast induction on the mangiferin-incorporated BCP scaffolds. After characterization of the specimens, it was found that the scaffolds with 10% Mn-incorporated BCP with mangiferin showed better osteogenicity and simultaneously the same scaffolds exhibited higher anti-bacterial properties as observed from the bacterial viability test. This study was carried out to evaluate the efficacy of Mn and MAN in BCP for osteogenicity and antibacterial action.
The Effect of Smart PEO-Coatings Impregnated with Corrosion Inhibitors on the Protective Properties of AlMg3 Aluminum Alloy
Authors: Gnedenkov Andrey S. , Kononenko Yana I. , Sinebryukhov Sergey L. , Filonina Valeriia S. , Vyaliy Igor E. , Nomerovskii Alexey D. , Ustinov Alexander Yu. , Gnedenkov Sergey V.
Published: March 2023

The protective coating with a self-organized microtubular structure was formed using plasma electrolytic oxidation (PEO) on AlMg3 aluminum alloy in the tartrate-fluoride electrolyte. This protective layer was further modified using corrosion inhibitors of the azole group (1,2,4-triazole, benzotriazole) and polymer material (polyvinilidene fluoride, PVDF). X-ray diffraction analysis and scanning electron microscopy with energy dispersive spectroscopy were used to study the morphology and composition of the obtained oxide coatings. The presence of the inhibitor in the PEO-layer was confirmed using micro-Raman spectroscopy and X-ray photoelectron spectroscopy. The level of corrosion protection of formed coatings as well as the effect of loaded inhibitors on the anticorrosion efficiency was evaluated using electrochemical impedance spectroscopy (EIS) and localized scanning techniques (SVET/SIET). The coating impregnation with corrosion inhibitors of the azole group significantly improves the corrosion characteristics of the material. Impregnation of the base PEO-layer with 1,2,4-triazole during 24 h results in a 36 times increase in the impedance modulus measured at the lowest frequency (|Z|f=0.1Hz). Additional sealing of impregnated coating with polymer improves the corrosion stability of the treated material. On the base of the obtained data, the optimal way of protective inhibitor- and polymer-containing formation using surface treatment was suggested. The best barrier properties were established for hybrid coatings obtained by the immersion of a PEO-coated sample in 1,2,4-triazole solution for 24 h and following spraying the PVDF solution. The value of |Z|f=0.1Hz for this protective layer increased by more than two orders of magnitude in comparison with the base PEO-layer. The three-stage mechanism of corrosion inhibition of the sample with smart inhibitor-containing coating was established.
Experimental and Analytical Investigation of Flexural Behavior of Carbon Nanotube Reinforced Textile Based Composites
Authors: Madenci Emrah , Özkılıç Yasin , Aksoylu Ceyhun , Asyraf Muhammad , Syamsir Agusril , Supian Abu , Elizaveta Bobrynina
Published: March 2023

In this study, the main goal of this study was to understand the effect of carbon nanotube (CNT) additives on the elastic behaviors of textile-based composites. The materials have three phases: carbon fiber fabric, epoxy matrix, and carbon nanotubes. Different weight fractions of CNTs were used (0% as a reference, 0.3%). Mechanical tests were performed, such as tension and three-point bending beam tests. In addition, the composite material damages were examined in detail. The experimental results show that the samples with CNT carried 9% and 23% more axial tensile force and bending capacity on average than those with NEAT. Besides, it was understood that adding 0.3% by weight of MWCNT increases the tensile modulus by approximately 9%. Finally, the mechanical tensile and bending tests are supported by analytical solutions successfully applied in the literature.
Structural, Optical, Electric and Magnetic Characteristics of (In1−xGdx)2O3 Films for Optoelectronics
Authors: Ahmed Moustafa , Al-Hadeethi Yas M. , Abdel-Daiem Ali M. , Shaaban Essam R.
Published: March 2023

After (In1−xGdx)2O3 powder with a wide x range of 0 to 10 at.% was chemically produced, (In1−xGdx)2O3 thin films were evaporated under ultra-vacuum using an electron beam apparatus. We investigated the influence of the Gd doping concentration on the magnetic, optical, electrical, and structural properties of the resultant In2O3 deposits. The produced Gd-doped In2O3 films have a cubic In2O3 structure without a secondary phase, as shown by the X-ray diffraction results. Additionally, the chemical analysis revealed that the films are nearly stoichiometric. A three-layer model reproduced the spectroscopic ellipsometer readings to determine the optical parameters and energy gap. The Egopt changed toward the lower wavelength with growing the Gd doping in (In1−xGdx)2O3 films. The Egopt in the (In1−xGdx)2O3 films was observed to increase from 3.22 to 3.45 eV when the Gd concentration climbed. Both carrier concentration and hall mobility were found during the Hall effect studies. It was possible to construct the heterojunction of Ni (Al)/n-(In1−xGdx)2O3/p-Si/Al. At voltages between −2 and 2 volts, investigations into the dark (cutting-edge-voltage) characteristics of the produced heterojunctions were made. The oxygen vacancies and cationic defects in the lattice caused by the uncompensated cationic charges resulted in significant magnetism and ferromagnetic behavior in the undoped In2O3 films. The (In1−xGdx)2O3 films, however, displayed faint ferromagnetism. The ferromagnetism seen in the (In1−xGdx)2O3 films was caused by oxygen vacancies formed during the vacuum film production process. Metal cations created ferromagnetic exchange interactions by snatching free electrons in oxygen.
Hydrothermal Mixed Convection in a Split-Lid-Driven Triangular Cavity Suspended by NEPCM
Authors: Younis Obai , Ahmed Sameh E. , Abderrahmane Aissa , Alenazi Abdulaziz , Hassan Ahmed M.
Published: March 2023

A numerical investigation of the magnetohydrodynamics of a mixed convection of nano-enhanced phase change material (NEPCM) within a triangular chamber containing an elliptical heat source is presented in this article. The forced convection has resulted from the movement of the upper cavity, while the free convection is due to the temperature difference between the heat source and cold inclined sidewalls. Four cases are considered based on the directions of the moving of the upper wall parts, namely, Case 1, where the left part is moving in the positive direction of the X-axis and the right part moves in the opposite direction (1(+−)), Case 2, where the two parts move in the positive direction of the X-axis (2(++)), Case 3, where the two parts move in the negative direction of the X-axis (3(− −)), and Case 4, where the left part moves in the negative direction of the X-axis and the right part moves in the negative direction (4(−+)). The Galerkin finite element method (GFEM) is employed for addressing the governing equations of the system under study. The impacts of the Reynolds number (1≤Re≤100), the inclination angle of the elliptic heat source (0≤γ≤90), the nanoparticles volume fraction ϕ (0%≤ϕ≤8%) and the movement directions of the parts of the upper wall (four cases) are presented and discussed. The results suggested that increasing Re enhanced the heat transfer rate, while increasing Ha reduced it. The vertical positions of the elliptical heat source resulted in the maximum heat transmission rate. At the highest Re, changing the location of the heat source from horizontal (γ=0) to vertical (γ=90) enhanced the average Nusselt number by 60%, while choosing Case 1 for upper wall movement increased the average Nusselt number by 300% compared to Cases 2 and 3.
Physical Attention-Gated Spatial-Temporal Predictive Network for Weather Forecasting
Authors: Zhao Xueliang , Sun Qilong , Lin Xiaoguang
Published: March 2023

Spatial-temporal sequence prediction is one of the hottest topics in the field of deep learning due to its wide range of potential applications in video-like data processing, specifically weather forecasting. Since most spatial-temporal observations evolve under physical laws, we adopt an attentional gating scheme to leverage the dynamic patterns captured by tailored convolution structures and propose a novel neural network, PastNet, to achieve accurate predictions. By highlighting useful parts of the whole feature map, the gating units help increase the efficiency of the architecture. Extensive experiments conducted on synthetic and real-world datasets reveal that PastNet bears the ability to accomplish this task with better performance than baseline methods.
Heterogeneous Blockchain-Based Secure Framework for UAV Data
Authors: Aljumah Abdullah , Ahanger Tariq Ahamed , Ullah Imdad
Published: March 2023

Unmanned aerial vehicles, drones, and internet of things (IoT) based devices have acquired significant traction due to their enhanced usefulness. The primary use is aerial surveying of restricted or inaccessible locations. Based on the aforementioned aspects, the current study provides a method based on blockchain technology for ensuring the safety and confidentiality of data collected by virtual circuit-based devices. To test the efficacy of the suggested technique, an IoT-based application is integrated with a simulated vehicle monitoring system. Pentatope-based elliptic curve encryption and secure hash algorithm (SHA) are employed to provide anonymity in data storage. The cloud platform stores technical information, authentication, integrity, and vehicular responses. Additionally, the Ethbalance MetaMask wallet is used for BCN-based transactions. Conspicuously, the suggested technique aids in the prevention of several attacks, including plaintext attacks and ciphertext attacks, on sensitive information. When compared to the state-of-the-art techniques, the outcomes demonstrate the effectiveness and safety of the suggested method in terms of operational cost (2.95 units), scalability (14.98 units), reliability (96.07%), and stability (0.82).
REST/NRSF Silencing Modifies Neuronal Gene Expression in siRNA-Treated HeLa Cells: A Preliminary Exploration in the Search for Neuronal Biomarkers of Cervical Cancer
Authors: Cortés-Sarabia Karen , Alarcón-Romero Luz Del Carmen , Mendoza-Catalán Miguel Ángel , Carpio-Pedroza Juan Carlos , Castañeda-Saucedo Eduardo , Ortuño-Pineda Carlos
Published: March 2023

Background and Objectives: REST (RE1-silencing transcription factor) diminution is associated with transcriptional relaxation, neuropeptide overexpression, and phenotype redefinition in neuroendocrine cancers, but this effect has barely been studied in cervical cancer (CC). We previously reported reduced expressions of REST in samples with premalignant lesions and CC; however, the transcriptional consequences for neural genes associated with reduced REST expression in CC are unknown. Therefore, the objective of this work was to evaluate the expression of neuronal genes in cancerous cells with reduced expression levels of REST. Materials and Methods: Here, we monitored levels of REST by immunostaining along the premalignant lesions and in invasive cervical squamous cell carcinoma (SCC) and endocervical adenocarcinoma (ADC) in tissue samples from female patients from southern Mexico and the derivative cell lines SiHa and HeLa, respectively. Next, we selected REST target genes in silico and explored the effect of REST silencing by RT-PCR in siRNA-treated HeLa cells. Results: The results show a REST diminution in premalignant lesions, SCC, ADC, and cancerous cell lines. Further REST silencing in HeLa cells altered the expression of genes containing the RE1 (Restrictive Element 1) sequence, including CgA (chromogranin A), CHRNβ2 (cholinergic receptor nicotinic β 2 subunit), BDNF (brain-derived neurotrophic factor), CRF (corticotropin-releasing factor), and RASSF1A (Ras association domain family 1). Conclusions: This work provides preliminary evidence of the role of REST loss in the transcriptional regulation of its target genes in HeLa cells, which could have positive implications for the search for new biomarkers of cervical cancer.
High-Resolution Computed Tomography as an Initial Diagnostic and Localization Tool in Patients with Cerebrospinal Fluid Rhinorrhea: A Meta-Analysis
Authors: Kim Do Hyun , Kim Sung Won , Han Jae Sang , Kim Geun-Jeon , Basurrah Mohammed Abdullah , Hwang Se Hwan
Published: March 2023

Background and Objectives: This study was performed to investigate the utility of high-resolution computed tomography (HRCT) for the initial localization of cerebrospinal fluid rhinorrhea. Methods: HRCT data regarding the point of cerebrospinal fluid leakage (as confirmed in the operating room), collected up to December 2022, were extracted from five databases. The risk of bias of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Results: The search revealed eight relevant studies with a total of 254 patients. The diagnostic odds ratio of the imaging studies was 10.0729 (95% confidence interval [CI]: 2.4486; 41.4376; I2 = 54.1%). The area under the summary receiver operating characteristic curve was 0.8. Sensitivity, specificity, the negative predictive value, and the positive predictive value were 0.7550 (95% CI: 0.6163; 0.8553; I2 = 69.8%), 0.8502 (95% CI: 0.5986; 0.9557, I2 = 49.3%), 0.4106 (95% CI: 0.2418; 0.6035; I2 = 59.0%), and 0.9575 (95% CI: 0.8955; 0.9834; I2 = 27.7%), respectively. Conclusions: HRCT can be used to accurately localize cerebrospinal fluid rhinorrhea because it shows bony defects in high detail. However, it has limited utility for the evaluation of active leakage, and localization is difficult in the presence of coexisting lesions.
Case Series of Patients with Coronavirus Disease 2019 Pneumonia Treated with Hydroxychloroquine
Authors: Tanaka Tomohiro , Okamoto Masaki , Matsuo Norikazu , Naitou-Nishida Yoshiko , Nouno Takashi , Kojima Takashi , Nishii Yuuya , Uchiyashiki Yoshihiro , Takeoka Hiroaki , Nagasaki Yoji
Published: March 2023

The efficacy of hydroxychloroquine (HCQ) therapy, a previous candidate drug for coronavirus disease 2019 (COVID-19), was denied in the global guideline. The risk of severe cardiac events associated with HCQ was inconsistent in previous reports. In the present case series, we show the tolerability of HCQ therapy in patients treated in our hospital, and discuss the advantages and disadvantages of HCQ therapy for patients with COVID-19. A representative case was a 66-year-old woman who had become infected with severe acute respiratory syndrome coronavirus 2 and was diagnosed as having COVID-19 pneumonia via polymerase chain reaction. She was refractory to treatment with levofloxacin, lopinavir, and ritonavir, while her condition improved after beginning HCQ therapy without severe side effects. We show the tolerability of HCQ therapy for 27 patients treated in our hospital. In total, 21 adverse events occurred in 20 (74%) patients, namely, diarrhea in 11 (41%) patients, and elevated levels of both aspartate aminotransferase and alanine transaminase in 10 (37%) patients. All seven grade ≥ 4 adverse events were associated with the deterioration in COVID-19 status. No patients discontinued HCQ treatment because of HCQ-related adverse events. Two patients (7%) died of COVID-19 pneumonia. In conclusion, HCQ therapy that had been performed for COVID-19 was well-tolerated in our case series.
Impact of Physical and Chemical Modification of the Surface of Porous Al2O3 Ceramic Membranes on the Quality of Transferred HSMG® and CVD Graphene
Authors: Bednarek Aleksandra , Dybowski Konrad , Romaniak Grzegorz , Grabarczyk Jacek , Kaczorowski Witold , Sobczyk-Guzenda Anna
Published: March 2023

Graphene transfer onto ceramics, like Si/SiO2, is well-developed and described in the literature. However, it is problematic for other ceramic materials (e.g., Al2O3 and ZrO2), especially porous ones. In this case, it is mainly due to poor adhesion to the substrate, resulting in strong degradation of the graphene. For these reasons, the research topic of this study was undertaken. This article presents research on the development of the methodology of graphene transfer onto ceramic Al2O3 surfaces. Polycrystalline graphene chemical vapour deposition (CVD) monolayer and quasimonocrystalline high-strength metallurgical graphene (HSMG®) synthesised on liquid copper were used. When developing the transfer methodology, the focus was on solving the problem of graphene adhesion to the surface of this type of ceramic, and thus reducing the degree of graphene deterioration at the stage of producing a ceramic–graphene composite, which stands in the way of its practical use. Plasma and chemical ceramic surface modification were applied to change its hydrophobicity, and thus to improve the adhesion between the graphene and ceramic. The modification included the use of dielectric barrier discharge (DBD) plasma, oxygen plasma (RF PACVD method - Radio Frequency Plasma Assisted Chemical Vapour Deposition), and hydrofluoric acid treatment. Changes in surface properties caused by the modifications were determined by measuring the contact angle and (in the case of chemical modification) measuring the degree of surface development. The effectiveness of the applied surface preparation methodology was evaluated based on the damage degree of CVD and HSMG® graphene layer transferred onto modified Al2O3 using optical microscopy and Raman spectroscopy. The best average ID/IG ratio for the transferred HSMG® graphene was obtained after oxygen plasma modification (0.63 ± 0.18) and for CVD, graphene DBD plasma was the most appropriate method (0.17 ± 0.09). The total area of graphene defects after transfer to Al2O3 was the smallest for HSMG® graphene after modification with O2 plasma (0.251 mm2/cm2), and for CVD graphene after surface modification with DBD plasma (0.083 mm2/cm2).
Improved Combustion Performance of Fluororubber-Coated Micro-Nano Composite Aluminum Powder
Authors: Wu Xinzhou , Ren Hui , Jiao Qingjie
Published: March 2023

In order to improve the reaction rate and reaction degree of aluminized explosives, the micro-nano composite aluminum powder was fabricated by a new method of in situ electro-explosion. The combustion performances of the composite aluminum powder were studied. The results showed that the micro-nano composite aluminum powder was like a “sea urchin structure” with many nano-sized powders around a single micro-sized aluminum particle. The heat of combustion was 25.67 MJ/kg at 3 MPa oxygen pressure, and the rising rate of pressure was particularly obvious. The ignition performance in an air environment was much better than the micro-sized aluminum powder. At the same time, the reaction process of the micro-nano composite aluminum powder was analyzed. The reaction can be divided into three stages, the decomposition of fluororubber between 500 and 600 °C, then melting, and the first step of the oxidation of aluminum powder occurred between 600 and 700 °C. In the third stage, the micro-nano composite aluminum powder reacted violently around 1000 °C and the released energy reached 3779 J/g. The micro-nano composite aluminum powder had excellent combustion performance and a good application prospect in high-power energy storage materials.
Changing Rhizosphere Microbial Community and Metabolites with Developmental Stages of Coleus barbatus
Authors: Jamwal Vijay Lakshmi , Rather Irshad Ahmad , Ahmed Sajad , Kumar Amit , Gandhi Sumit G.
Published: March 2023

Coleus barbatus is a medicinal herb belonging to Lamiaceae. It is the only living organism known to produce forskolin, which is a labdane diterpene and is reported to activate adenylate cyclase. Microbes associated with plants play an important role in maintaining plant health. Recently, the targeted application of beneficial plant-associated microbes and their combinations in abiotic and biotic stress tolerance has gained momentum. In this work, we carried out the rhizosphere metagenome sequencing of C. barbatus at different developmental stages to understand how rhizosphere microflora are affected by and affect the metabolite content in plants. We found that the Kaistobacter genus was abundantly present in the rhizosphere of C. barbatus and its accumulation pattern appears to correlate with the quantities of forskolin in the roots at different developmental stages. Members of the Phoma genus, known for several pathogenic species, were in lower numbers in the C. barbatus rhizosphere in comparison with C. blumei. To our knowledge, this is the first metagenomic study of the rhizospheric microbiome of C. barbatus, which may help to explore and exploit the culturable and non-culturable microbial diversity present in the rhizosphere.
Acanthamoeba castellanii Genotype T4: Inhibition of Proteases Activity and Cytopathic Effect by Bovine Apo-Lactoferrin
Authors: Ramírez-Rico Gerardo , Martinez-Castillo Moises , Cárdenas-Zúñiga Roberto , Coronado-Velázquez Daniel , Silva-Olivares Angélica , De la Garza Mireya , Shibayama Mineko , Serrano-Luna Jesús
Published: March 2023

Acanthamoeba castellanii genotype T4 is a clinically significant free-living amoeba that causes granulomatous amoebic encephalitis and amoebic keratitis in human beings. During the initial stages of infection, trophozoites interact with various host immune responses, such as lactoferrin (Lf), in the corneal epithelium, nasal mucosa, and blood. Lf plays an important role in the elimination of pathogenic microorganisms, and evasion of the innate immune response is crucial in the colonization process. In this study, we describe the resistance of A. castellanii to the microbicidal effect of bovine apo-lactoferrin (apo-bLf) at different concentrations (25, 50, 100, and 500 µM). Acanthamoeba castellanii trophozoites incubated with apo-bLf at 500 µM for 12 h maintained 98% viability. Interestingly, despite this lack of effect on viability, our results showed that the apo-bLf inhibited the cytopathic effect of A. castellanii in MDCK cells culture, and analysis of amoebic proteases by zymography showed significant inhibition of cysteine and serine proteases by interaction with the apo-bLf. From these results, we conclude that bovine apo-Lf influences the activity of A. castellanii secretion proteases, which in turn decreases amoebic cytopathic activity.
Current Trends in Bioaugmentation Tools for Bioremediation: A Critical Review of Advances and Knowledge Gaps
Authors: Muter Olga
Published: March 2023

Bioaugmentation is widely used in soil bioremediation, wastewater treatment, and air biofiltration. The addition of microbial biomass to contaminated areas can considerably improve their biodegradation performance. Nevertheless, analyses of large data sets on the topic available in literature do not provide a comprehensive view of the mechanisms responsible for inoculum-assisted stimulation. On the one hand, there is no universal mechanism of bioaugmentation for a broad spectrum of environmental conditions, contaminants, and technology operation concepts. On the other hand, further analyses of bioaugmentation outcomes under laboratory conditions and in the field will strengthen the theoretical basis for a better prediction of bioremediation processes under certain conditions. This review focuses on the following aspects: (i) choosing the source of microorganisms and the isolation procedure; (ii) preparation of the inoculum, e.g., cultivation of single strains or consortia, adaptation; (iii) application of immobilised cells; (iv) application schemes for soil, water bodies, bioreactors, and hydroponics; and (v) microbial succession and biodiversity. Reviews of recent scientific papers dating mostly from 2022–2023, as well as our own long-term studies, are provided here.
Discovery of “Meteoritic” Layered Disulphides ACrS2 (A = Na, Cu, Ag) in Terrestrial Rock
Authors: Galuskin Evgeny V. , Galuskina Irina O. , Vapnik Yevgeny , Zieliński Grzegorz
Published: March 2023

For the first time, chromium disulphides, known from meteorites, such as caswellsilverite, NaCrS2; grokhovskyite, CuCrS2; and a potentially new mineral, AgCrS2, as well as the products of their alteration, such as schöllhornite, Na0.3CrS2∙H2O, and a potentially new mineral with the formula {Fe0.3(Ba,Ca)0.2} CrS2·0.5H2O, have been found in terrestrial rock. Layered chromium disulphides were found in unusual phosphide-bearing breccia of the pyrometamorphic Hatrurim Complex in the Negev Desert, Israel. The chromium disulphides belong to the central fragment of porous gehlenite paralava cementing altered host rock clasts. The empirical formula of caswellsilverite is (Na0.77Sr0.03Ca0.01)Σ0.81(Cr3+0.79Cr4+0.18V3+0.01 Fe3+0.01)Σ0.99S2·0.1H2O, and the end-member content of NaCrS2 is 76%. It forms single crystals in altered pyrrhotite aggregates. Grokhovskyite has the empirical formula {Cu+0.84Fe3+0.10Ca0.06 Na0.01 Sr0.01Ba0.01}Σ1.03(Cr3+0.94 Fe3+0.05 V3+0.05)Σ1.00S2·0.35H2O, and the CuCrS2 end-member content is 75–80%. A potentially new Ag-bearing chromium disulphide is characterised by the composition (Ag0.89Cu0.07)Σ0.96(Cr0.98 Fe0.03V0.01Ni0.01)Σ1.04S2. Caswellsilverite, grokhovskyite and AgCrS2 form in gehlenite paralava at high temperatures (near 1000 °C) and low pressure under reducing conditions. The structure of the layered chromium disulphides, MCrS2, is characterised by the presence of hexagonal octahedral layers (CrS2)1−, between which M-sites of the monovalent cations Ag, Cu and Na set. A low-temperature alteration of the layered chromium disulphides, when schöllhornite and {Fe0.3(Ba,Ca)0.2}CrS2·0.5H2O form, is reflected in the composition and structural modification of the layer with monovalent cations, whereas the octahedral layer (CrS2)1− remains unchanged.
Impact of Mining and Ore Processing on Soil, Drainage and Vegetation in the Zambian Copperbelt Mining Districts: A Review
Authors: Kříbek Bohdan , Nyambe Imasiku , Sracek Ondra , Mihaljevič Martin , Knésl Ilja
Published: March 2023

The regional environmental–geochemical surveying of the long-term impacts of mining and ore processing on a large part of the Zambian Copperbelt mining district was carried out by the Czech Research Group with cooperation of the Geology Department, University of Zambia, and the Geological Survey of Zambia in the period 2002–2018. This included the characterization of various sources of contamination, the extent of contamination of soils and crops, and the degree of contamination of river water and sediments. Solid speciation studies of potentially harmful chemical elements (PHEs), plant and human bioaccessibility studies, and a range of mineralogical techniques were used to assess the pathways of PHE cycling in terrestrial and aqueous systems and their impacts on human health. Ores of the Zambian Copperbelt mining district are mined for Cu and Co, but a number of other trace elements (Pb, As, Cd, Hg, Pb, Zn) gradually accumulated in soils and stream sediments. It was concluded that the most important problems related to ore mining and processing are the contamination of soil and crops due to dust fall out from tailing facilities and emissions from smelters. Moreover, leakages of solutions from tailing dams, insufficient technological control of their stability and breakdowns on pipelines transporting slurry from treatment plants to tailing impoundments cause contamination of water courses and deposition of metal(loids) in stream sediments. However, the contamination of the Kafue River water is relatively limited due to its high neutralization capacity. In contrast, in some Kafue River tributaries, especially those close to big mining centers, the concentrations of dissolved Cu and Co are high (up to 14,752 μg/L and 1917 μg/L) and exceed Zambian effluent limits. We also recommend measures that could contribute to minimizing the impact of ore mining and processing on the environment and the health of the local population.
Lithofacies and Shale Oil Potential of Fine-Grained Sedimentary Rocks in Lacustrine Basin (Upper Cretaceous Qingshankou Formation, Songliao Basin, Northeast China)
Authors: Sun Ningliang , He Wenyuan , Zhong Jianhua , Gao Jianbo , Sheng Pengpeng
Published: March 2023

Shale oil has become a global hotspot of unconventional exploration and development. In this study, the latest drill core and experiment analyses of the Qingshankou Formation in the northern Songliao Basin were used to evaluate its lithofacies classification, sedimentary environment, pore types, pore-throat structure characterization, and shale oil potential. Lithofacies classification was determined according to the total organic carbon (TOC) content, sedimentary structure, and rock mineral content. Laminae genesis and micro-sedimentary structures indicate the deposition of fine-grained sedimentary rocks (FGSRs) in a semi-deep to deep lacustrine environment; however, evidence also suggests partial reworking by storm events and bottom current flows. FGSRs mostly comprise type I kerogen, with small amounts of type II1. The average vitrinite reflectance of the FGSRs was 1.37%, indicating middle to high stages of thermal maturation within the oil generation window. The N2 adsorption experiment indicated that silty mudstone (SM), silty fine mixed sedimentary rock (SFMR), and argillaceous fine mixed sedimentary rock (AFMR) had ink-bottle-shaped and slit-shaped pores, and the lithofacies were dominated by mesopores, accounting for 77.4%, 71.9%, and 80.8% of the total pore volume, respectively. Mercury injection capillary pressure analysis indicated that SM and SFMR had an average pore-throat radius of 0.01–0.04 μm, whereas AFMR and CM were dominated by nanopores, mainly distributed in the range of 0.004–0.0063 μm. Based on the comprehensive studies of TOC content, pore development, and brittleness, we concluded that organic-rich laminated SM and SFMR should be the focus of shale oil exploration of the Qingshankou Formation in the northern Songliao Basin, followed by organic-rich or organic-moderate laminated and layered AFMR, as well as calcareous fine mixed sedimentary rocks.
Current Achievements in Flexible Piezoelectric Nanogenerators Based on Barium Titanate
Authors: Okhay Olena , Tkach Alexander
Published: March 2023

Harvesting ambient mechanical energy at the nanometric scale holds great promise for powering small electronics and achieving self-powered electronic devices. The current review is focused on kinetic energy harvesters, particularly on flexible piezoelectric nanogenerators (p-NGs) based on barium titanate (BaTiO3) nanomaterials. p-NGs based on nanotubes, nanowires, nanofibres, nanoplatelets, nanocubes or nanoparticles of BaTiO3 fabricated in vertical or lateral orientation, as well as mixed composite structures, are overviewed here. The achievable power output level is shown to depend on the fabrication method, processing parameters and potential application conditions. Therefore, the most widely studied aspects, such as influence of geometry/orientation, BaTiO3 content, poling process and other factors in the output performance of p-NGs, are discussed. The current standing of BaTiO3-based p-NGs as possible candidates for various applications is summarized, and the issues that need to be addressed for realization of practical piezoelectric energy harvesting devices are discussed.
NanoDefiner Framework and e-Tool Revisited According to the European Commission’s Nanomaterial Definition 2022/C 229/01
Authors: Brüngel Raphael , Rückert Johannes , Müller Philipp , Babick Frank , Friedrich Christoph M. , Ghanem Antoine , Hodoroaba Vasile-Dan , Mech Agnieszka , Weigel Stefan , Wohlleben Wendel , Rauscher Hubert
Published: March 2023

The new recommended definition of a nanomaterial, 2022/C 229/01, adopted by the European Commission in 2022, will have a considerable impact on European Union legislation addressing chemicals, and therefore tools to implement this new definition are urgently needed. The updated NanoDefiner framework and its e-tool implementation presented here are such instruments, which help stakeholders to find out in a straightforward way whether a material is a nanomaterial or not. They are two major outcomes of the NanoDefine project, which is explicitly referred to in the new definition. This work revisits the framework and e-tool, and elaborates necessary adjustments to make these outcomes applicable for the updated recommendation. A broad set of case studies on representative materials confirms the validity of these adjustments. To further foster the sustainability and applicability of the framework and e-tool, measures for the FAIRification of expert knowledge within the e-tool’s knowledge base are elaborated as well. The updated framework and e-tool are now ready to be used in line with the updated recommendation. The presented approach may serve as an example for reviewing existing guidance and tools developed for the previous definition 2011/696/EU, particularly those adopting NanoDefine project outcomes.
Research Progress of Green Solvent in CsPbBr3 Perovskite Solar Cells
Authors: Cheng Jiajie , Fan Zhenjun , Dong Jingjing
Published: March 2023

In optoelectronic applications, all-Brominated inorganic perovskite CsPbBr3 solar cells have received a great deal of attention because of their remarkable stability and simplicity of production. Most of the solvents used in CsPbBr3 perovskite solar cells are toxic, which primarily hinders the commercialization of the products. In this review, we introduce the crystal structure and fundamental properties of CsPbBr3 materials and the device structure of perovskite cells, summarize the research progress of green solvents for CsPbBr3 PSCs in recent years from mono-green solvent systems to all-green solvent systems, and discuss the approaches to improving the PCE of CsPbBr3 PSCs, intending to facilitate the sustainable development of CsPbBr3 perovskite solar cells. Finally, we survey the future of green solvents in the area of CsPbBr3 perovskite solar cells.
Asymmetrical Plasmon Distribution in Hybrid AuAg Hollow/Solid Coded Nanotubes
Authors: Genç Aziz , Patarroyo Javier , Sancho-Parramon Jordi , Arenal Raul , Bastús Neus G. , Puntes Victor , Arbiol Jordi
Published: March 2023

Morphological control at the nanoscale paves the way to fabricate nanostructures with desired plasmonic properties. In this study, we discuss the nanoengineering of plasmon resonances in 1D hollow nanostructures of two different AuAg nanotubes, including completely hollow nanotubes and hybrid nanotubes with solid Ag and hollow AuAg segments. Spatially resolved plasmon mapping by electron energy loss spectroscopy (EELS) revealed the presence of high order resonator-like modes and localized surface plasmon resonance (LSPR) modes in both nanotubes. The experimental findings accurately correlated with the boundary element method (BEM) simulations. Both experiments and simulations revealed that the plasmon resonances are intensely present inside the nanotubes due to plasmon hybridization. Based on the experimental and simulated results, we show that the novel hybrid AuAg nanotubes possess two significant coexisting features: (i) LSPRs are distinctively generated from the hollow and solid parts of the hybrid AuAg nanotube, which creates a way to control a broad range of plasmon resonances with one single nanostructure, and (ii) the periodicity of the high-order modes are disrupted due to the plasmon hybridization by the interaction of solid and hollow parts, resulting in an asymmetrical plasmon distribution in 1D nanostructures. The asymmetry could be modulated/engineered to control the coded plasmonic nanotubes.
The Various Packing Structures of Tb@C82 (I, II) Isomers in Their Cocrystals with Ni(OEP)
Authors: Dong Wei , Zhou Qin , Shen Wangqiang , Yang Le , Jin Peng , Lu Xing , Lian Yongfu
Published: March 2023

Soot-containing terbium (Tb)-embedded fullerenes were prepared by evaporation of Tb4O7-doped graphite rods in an electric arc discharge chamber. After 1,2,4-trichlorobenzene extraction of the soot and rotary evaporation of the extract, a solid product was obtained and then dissolved into toluene by ultrasonication. Through a three-stage high-pressure liquid chromatographic (HPLC) process, Tb@C82 (I, II) isomers were isolated from the toluene solution of fullerenes and metallofullerenes. With the success of the growth of cocrystals of Tb@C82 (I, II) with Ni(OEP), the molecular structures of Tb@C82 (I) and Tb@C82 (II) were confirmed to be Tb@C2v(9)-C82 and Tb@Cs(6)-C82, respectively, based on crystallographic data from X-ray single-crystal diffraction. Moreover, it was found that Tb@C82 (I, II) isomers demonstrated different packing behaviors in their cocrystals with Ni(OEP). Tb@C2v(9)-C82 forms a 1:1 cocrystal with Ni(OEP), in which Tb@C2v(9)-C82 is aligned diagonally between the Ni(OEP) bilayers to form zigzag chains. In sharp contrast, Tb@Cs(6)-C82 forms a 2:2 cocrystal with Ni(OEP), in which Tb@Cs(6)-C82 forms a centrosymmetric dimer that is aligned linearly with Ni(OEP) pairs to form one-dimensional structures in the a–c lattice plane. In addition, the distance of a Ni atom in Ni(OEP) to the Cs(6)-C82 cage is much shorter than that to the C2v(9)-C82 one, indicative of a stronger π-π interaction between Ni(OEP) and the C82 carbon cage in the cocrystal of Tb@CS(6)-C82 and Ni(OEP). Density functional theory calculations reveal that the regionally selective dimerization of Tb@CS(6)-C82 is the result of a dominant unpaired spin existing on a particular C atom of the CS(6)-C82 cage.
Application of Thermally Fluorinated Multi-Wall Carbon Nanotubes as an Additive to an Li4Ti5O12 Lithium Ion Battery
Authors: Ha Seongmin , Jeong Seo Gyeong , Lim Chaehun , Min Chung Gi , Lee Young-Seak
Published: March 2023

In this study, multi-walled carbon nanotubes (MWCNTs) were modified by thermal fluorination to improve dispersibility between MWCNTs and Li4Ti5O12 (LTO) and were used as additives to compensate for the disadvantages of LTO anode materials with low electronic conductivity. The degree of fluorination of the MWCNTs was controlled by modifying the reaction time at constant fluorination temperature; the clear structure and surface functional group changes in the MWCNTs due to the degree of fluorination were determined. In addition, the homogeneous dispersion in the LTO was improved due to the strong electronegativity of fluorine. The F-MWCNT conductive additive was shown to exhibit an excellent electrochemical performance as an anode for lithium ion batteries (LIBs). In particular, the optimized LTO with added fluorinated MWCNTs not only exhibited a high specific capacity of 104.8 mAh g−1 at 15.0 C but also maintained a capacity of ~116.8 mAh g−1 at a high rate of 10.0 C, showing a capacity almost 1.4 times higher than that of LTO with the addition of pristine MWCNTs and an improvement in the electrical conductivity. These results can be ascribed to the fact that the semi-ionic C–F bond of the fluorinated MWCNTs reacts with the Li metal during the charge/discharge process to form LiF, and the fluorinated MWCNTs are converted into MWCNTs to increase the conductivity due to the bridge effect of the conductive additive, carbon black, with LTO.