bluuebunny/crossref_metadata_2025 huggingface dataset:
An Adjoint Optimization Prediction Method for Partially Cavitating Hydrofoils
Authors: Anevlavi Dimitra , Belibassakis Kostas
Published: September 2021

Much work has been done over the past years to obtain a better understanding, predict and alleviate the effects of cavitation on the performance of lifting surfaces for hydrokinetic turbines and marine propellers. Lifting-surface sheet cavitation, when addressed as a free-streamline problem, can be predicted up to a desirable degree of accuracy using numerical methods under the assumptions of ideal flow. Typically, a potential solver is used in conjunction with geometric criteria to determine the cavity shape, while an iterative scheme ensures that all boundary conditions are satisfied. In this work, we propose a new prediction model for the case of partially cavitating hydrofoils in a steady flow that treats the free-streamline problem as an inverse problem. The objective function is based on the assumption that on the cavity boundary, the pressure remains constant and is evaluated at each optimization cycle using a source-vorticity BEM solver. The attached cavity is parametrized using B-splines, and the control points are included in the design variables along with the cavitation number. The sensitivities required for the gradient-based optimization are derived using the continuous adjoint method. The proposed numerical scheme is compared against other methods for the NACA 16-series hydrofoils and is found to predict well both the cavity shape and cavitation number for a given cavity length.
Current Trends in Advanced Alginate-Based Wound Dressings for Chronic Wounds
Authors: Barbu Andreea , Neamtu Bogdan , Zăhan Marius , Iancu Gabriela Mariana , Bacila Ciprian , Mireșan Vioara
Published: September 2021

Chronic wounds represent a major public health issue, with an extremely high cost worldwide. In healthy individuals, the wound healing process takes place in different stages: inflammation, cell proliferation (fibroblasts and keratinocytes of the dermis), and finally remodeling of the extracellular matrix (equilibrium between metalloproteinases and their inhibitors). In chronic wounds, the chronic inflammation favors exudate persistence and bacterial film has a special importance in the dynamics of chronic inflammation in wounds that do not heal. Recent advances in biopolymer-based materials for wound healing highlight the performance of specific alginate forms. An ideal wound dressing should be adherent to the wound surface and not to the wound bed, it should also be non-antigenic, biocompatible, semi-permeable, biodegradable, elastic but resistant, and cost-effective. It has to give protection against bacterial, infectious, mechanical, and thermal agents, to modulate the level of wound moisture, and to entrap and deliver drugs or other molecules This paper explores the roles of alginates in advanced wound-dressing forms with a particular emphasis on hydrogels, nanofibers networks, 3D-scaffolds or sponges entrapping fibroblasts, keratinocytes, or drugs to be released on the wound-bed. The latest research reports are presented and supported with in vitro and in vivo studies from the current literature.
A Preclinical Pipeline for Translational Precision Medicine—Experiences from a Transdisciplinary Brain Tumor Stem Cell Project
Authors: Vargas-Toscano Andres , Janiak Christoph , Sabel Michael , Kahlert Ulf Dietrich
Published: September 2021

Efficient transdisciplinary cooperation promotes the rapid discovery and clinical application of new technologies, especially in the competitive sector of oncology. In this review, written from a clinical-scientist point of view, we used glioblastoma—the most common and most aggressive primary brain tumor as a model disease with a largely unmet clinical need, despite decades of intensive research—to promote transdisciplinary medicine. Glioblastoma stem-like cells (GSCs), a special tumoral cell population analogue to healthy stem cells, are considered largely responsible for the progression of the disease and the mediation of therapy resistance. The presented work followed the concept of translational science, which generates the theoretical backbones of translational research projects, and aimed to close the preclinical gap between basic research and clinical application. Thus, this generated an integrated translational precision medicine pipeline model based on recent theoretical and experimental publications, which supports the accelerated discovery and development of new paths in the treatment of GSCs. The work may be of interest to the general field of precision medicine beyond the field of neuro-oncology such as in Cancer Neuroscience.
The Ascent of Bitcoin: Bibliometric Analysis of Bitcoin Research
Authors: Aysan Ahmet Faruk , Demirtaş Hüseyin Bedir , Saraç Mustafa
Published: September 2021

Bitcoin, as the first decentralized cryptocurrency, pioneers the cryptocurrency markets, both in terms of market capitalization and scientific interest. In this paper, we performed a comprehensive bibliometric study of the Bitcoin-related literature. Using the Scopus database, we created a sample that comprises 4495 documents written in the 2011–2020 period. Furthermore, we provided insights about dimensions such as the change in the number of publications over the course of years, the main research areas, types of published documents, most important platforms and sources of Bitcoin publications, highly cited studies, productive authors, author’s countries, and finally main funders of Bitcoin-related research. Lastly, our bibliometric study manifests the current state and future path of Bitcoin literature from distinct perspectives.
Uniform Dichotomy Concepts for Discrete-Time Skew Evolution Cocycles in Banach Spaces
Authors: Găină Ariana , Megan Mihail , Popa Carmen Florinela
Published: September 2021

In the present paper, we consider the problem of dichotomic behaviors of dynamical systems described by discrete-time skew evolution cocycles in Banach spaces. We study two concepts of uniform dichotomy: uniform exponential dichotomy and uniform polynomial dichotomy. Some characterizations of these notions and connections between these concepts are given.
Development of Breathable Pebax®/PEG Films for Optimization of the Shelf-Life of Fresh Agri-Food Products
Authors: Préfol Thibaut , Gain Olivier , Sudre Guillaume , Gouanvé Fabrice , Espuche Eliane
Published: September 2021

In this work, thin transparent breathable films were prepared for food packaging applications. The films were obtained by the solvent casting method from both the binary blends Pebax® MH1657 copolymer/ hydroxyl-terminated polyethylene glycol (PEGOH) and Pebax® MH1657/polyethylene glycol dimethyl ether (PEGDME) as well as the ternary blend Pebax® MH1657/PEGOH/PEGDME with a 50/50 and 37.5/62.5 PEGOH/PEGDME weight ratio for additive amounts comprised between 0 and 50 wt.%. The microstructure of these materials was investigated by differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) analyses. Regardless of the PEG’s nature, for a PEG amount inferior to 30 wt.%, the Pebax® and PEG phases were totally miscible. For higher amounts, a phase separation was obtained. In the presence of PEG, a decrease in crystallinity was obtained. The effects of the nature and amount of PEG on the thermo-mechanical, hydration, and gas (CO2, O2) transport properties were investigated. A study of the film’s stability in terms of composition over time was also performed. From this work, a wide range of films could be proposed with a stable composition over time and adjustable mechanical and gas transport properties for the prolongation of the shelf-life of highly breathable fresh products.
Effects of Plasma-Chemical Composition on AISI 316L Surface Modification by Active Screen Nitrocarburizing Using Gaseous and Solid Carbon Precursors
Authors: Jafarpour Saeed M. , Pipa Andrei V. , Puth Alexander , Dalke Anke , Röpcke Jürgen , van Helden Jean-Pierre H. , Biermann Horst
Published: September 2021

Low-temperature plasma nitrocarburizing treatments are applied to improve the surface properties of austenitic stainless steels by forming an expanded austenite layer without impairing the excellent corrosion resistance of the steel. Here, low-temperature active screen plasma nitrocarburizing (ASPNC) was investigated in an industrial-scale cold-wall reactor to compare the effects of two active screen materials: (i) a steel active screen with the addition of methane as a gaseous carbon-containing precursor and (ii) an active screen made of carbon-fibre-reinforced carbon (CFC) as a solid carbon precursor. By using both active screen materials, ASPNC treatments at variable plasma conditions were conducted using AISI 316L. Moreover, insight into the plasma-chemical composition of the H2-N2 plasma for both active screen materials was gained by laser absorption spectroscopy (LAS) combined with optical emission spectroscopy (OES). It was found that, in the case of a CFC active screen in a biased condition, the thickness of the nitrogen-expanded austenite layer increased, while the thickness of the carbon-expanded austenite layer decreased compared to the non-biased condition, in which the nitrogen- and carbon-expanded austenite layers had comparable thicknesses. Furthermore, the crucial role of biasing the workload to produce a thick and homogeneous expanded austenite layer by using a steel active screen was validated.
Visualization Experimental Study on Silicon-Based Ultra-Thin Loop Heat Pipe Using Deionized Water as Working Fluid
Authors: Song Wenzhe , Xu Yanfeng , Xue Lihong , Li Huajie , Guo Chunsheng
Published: September 2021

As a type of micro flat loop heat pipe, s-UTLHP (silicon-based ultra-thin loop heat pipe) is of great significance in the field of micro-scale heat dissipation. To prove the feasibility of s-UTLHP with high heat flux in a narrow space, it is necessary to study its heat transfer mechanism visually. In this paper, a structural design of s-UTLHP was proposed, and then, to realize the working fluid charging and visual experiment, an experimental system including a holding module, heating module, cooling module, data acquisition module, and vacuum chamber was proposed. Deionized water was selected as a working fluid in the experiment. The overall and micro phenomena of s-UTLHP during startup, as well as the evaporation and condensation phenomena of s-UTLHP during stable operation, were observed and analyzed. Finally, the failure phenomenon of s-UTLHP was analyzed, and several solutions were proposed. The observed phenomena and experimental conclusions can provide references for further related experimental research.
A Review of the Health Protective Effects of Phenolic Acids against a Range of Severe Pathologic Conditions (Including Coronavirus-Based Infections)
Authors: Kiokias Sotirios , Oreopoulou Vassiliki
Published: September 2021

Phenolic acids comprise a class of phytochemical compounds that can be extracted from various plant sources and are well known for their antioxidant and anti-inflammatory properties. A few of the most common naturally occurring phenolic acids (i.e., caffeic, carnosic, ferulic, gallic, p-coumaric, rosmarinic, vanillic) have been identified as ingredients of edible botanicals (thyme, oregano, rosemary, sage, mint, etc.). Over the last decade, clinical research has focused on a number of in vitro (in human cells) and in vivo (animal) studies aimed at exploring the health protective effects of phenolic acids against the most severe human diseases. In this review paper, the authors first report on the main structural features of phenolic acids, their most important natural sources and their extraction techniques. Subsequently, the main target of this analysis is to provide an overview of the most recent clinical studies on phenolic acids that investigate their health effects against a range of severe pathologic conditions (e.g., cancer, cardiovascular diseases, hepatotoxicity, neurotoxicity, and viral infections—including coronaviruses-based ones).
Protective Effect of Potentilla glabra in UVB-Induced Photoaging Process
Authors: You Long , Kim Mi-Yeon , Cho Jae Youl
Published: September 2021

Maintaining skin homeostasis is one of the most important factors for skin health. UVB-induced skin photoaging is a difficult problem that has negative impacts on skin homeostasis. So far, a number of compounds have been discovered that improve human skin barrier function and hydration, and are thought to be effective ways to protect skin homeostasis. Potentilla glabra var. mandshurica (Maxim.) Hand.-Mazz. Ethanol Extract (Pg-EE) is a compound that has noteworthy anti-inflammatory properties. However, its skin-protective effects are poorly understood. Therefore, we evaluated the capacity of Pg-EE to strengthen the skin barrier and improve skin hydration. Pg-EE can enhance the expression of filaggrin (FLG), transglutaminase (TGM)-1, hyaluronic acid synthase (HAS)-1, and HAS-2 in human keratinocytes. Moreover, Pg-EE down-regulated the expression of pro-inflammatory cytokines and up-regulated the production of FLG, HAS-1, and HAS-2 suppressed by UVB through inhibition of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK) pathways. Given the above, since Pg-EE can improve skin barrier, hydration and reduce the UVB-induced inflammation on skin, it could therefore be a valuable natural ingredient for cosmetics or pharmaceuticals to treat skin disorders.
CB1 Cannabinoid Receptor Signaling and Biased Signaling
Authors: Leo Luciana M. , Abood Mary E.
Published: September 2021

The CB1 cannabinoid receptor is a G-protein coupled receptor highly expressed throughout the central nervous system that is a promising target for the treatment of various disorders, including anxiety, pain, and neurodegeneration. Despite the wide therapeutic potential of CB1, the development of drug candidates is hindered by adverse effects, rapid tolerance development, and abuse potential. Ligands that produce biased signaling—the preferential activation of a signaling transducer in detriment of another—have been proposed as a strategy to dissociate therapeutic and adverse effects for a variety of G-protein coupled receptors. However, biased signaling at the CB1 receptor is poorly understood due to a lack of strongly biased agonists. Here, we review studies that have investigated the biased signaling profile of classical cannabinoid agonists and allosteric ligands, searching for a potential therapeutic advantage of CB1 biased signaling in different pathological states. Agonist and antagonist bound structures of CB1 and proposed mechanisms of action of biased allosteric modulators are used to discuss a putative molecular mechanism for CB1 receptor activation and biased signaling. Current studies suggest that allosteric binding sites on CB1 can be explored to yield biased ligands that favor or hinder conformational changes important for biased signaling.
Nanoparticle-Encapsulated Camptothecin: Epigenetic Modulation in DNA Repair Mechanisms in Colon Cancer Cells
Authors: Farhana Aisha , Koh Avin Ee-Hwan , Tong Jia Bei , Alsrhani Abdullah , Kumar Subbiah Suresh , Mok Pooi Ling
Published: September 2021

Molecular crosstalk between the cellular epigenome and genome converge as a synergistic driver of oncogenic transformations. Besides other pathways, epigenetic regulatory circuits exert their effect towards cancer progression through the induction of DNA repair deficiencies. We explored this mechanism using a camptothecin encapsulated in β-cyclodextrin–EDTA–Fe3O4 nanoparticles (CPT-CEF)-treated HT29 cells model. We previously demonstrated that CPT-CEF treatment of HT29 cells effectively induces apoptosis and cell cycle arrest, stalling cancer progression. A comparative transcriptome analysis of CPT-CEF-treated versus untreated HT29 cells indicated that genes controlling mismatch repair, base excision repair, and homologues recombination were downregulated in these cancer cells. Our study demonstrated that treatment with CPT-CEF alleviated this repression. We observed that CPT-CEF exerts its effect by possibly affecting the DNA repair mechanism through epigenetic modulation involving genes of HMGB1, APEX1, and POLE3. Hence, we propose that CPT-CEF could be a DNA repair modulator that harnesses the cell’s epigenomic plasticity to amend DNA repair deficiencies in cancer cells.
Low-Field NMR Study of Shortcake Biscuits with Cricket Powder, and Their Nutritional and Physical Characteristics
Authors: Smarzyński Krzysztof , Sarbak Paulina , Kowalczewski Przemysław Łukasz , Różańska Maria Barbara , Rybicka Iga , Polanowska Katarzyna , Fedko Monika , Kmiecik Dominik , Masewicz Łukasz , Nowicki Marcin , Lewandowicz Jacek , Jeżowski Paweł , Kačániová Miroslava , Ślachciński Mariusz , Piechota Tomasz , Baranowska Hanna Maria
Published: September 2021

The growing human population renders challenges for the future supply of food products with high nutritional value. Here, we enhanced the functional and nutritional value of biscuits, a popular sweet snack, by replacing the wheat flour with 2%, 6%, or 10% (w/w) cricket powder. Consumer acceptance ratings for reference and 2% augmented cookies were comparable, whereas the higher levels of enhancement received inferior consumer scores. This relatively small change in biscuit recipe provided significant and nutritionally desirable enhancements in the biscuits, observed in a series of analyses. An increase in the protein content was observed, including essential amino acids, as well as minerals and fat. This conversion also affected the physical properties of the biscuits, including hardness, and water molecular dynamics measured by 1H NMR. Cricket powder-augmented biscuits join the line of enhanced, functionally superior food products. This and similar food augmentation provide a viable scenario to meet the human food demands in the future.
Raffinose Capped Silver Nanoparticles: A New Localized Surface Plasmon Resonance Based Sensor for Selective Quantification of Cr(VI) in Waste Waters
Authors: Vasileva Penka , Djerahov Lubomir , Karadjova Irina
Published: September 2021

In this study, a new method for selective determination of Cr(VI) in water samples at pH 4 is presented using raffinose capped silver nanoparticles (Ag/Raff NPs) as an optical sensor. The method is based on the variation of LSPR absorption band intensity as a result of electrostatic interaction between the negatively charged Ag/Raff NPs and positive Cr(III) ions, in-situ produced by chemical reduction of Cr(VI) with ascorbic acid, combined with the fast kinetics of Cr(III) coordination to the –OH groups of the capping agent on the nanoparticle surface, further causing the nanoparticle aggregation. The calibration curve for Cr(VI) is linear in the range 2.5–7.5 μmol L−1, the limit of quantification achieved is 1.9 μmol L−1, and values of relative standard deviation vary from 3 to 5% for concentration level 1.9–7.5 μmol L−1. The interference studies performed in the presence of various metal ions show very good selectivity of Ag/Raff NPs toward Cr(VI) species. The added–found method is used to confirm the accuracy and precision of developed analytical approach.
Adsorption/Desorption Behaviors and SERS Chemical Enhancement of 6-Mercaptopurine on a Nanostructured Gold Surface: The Au20 Cluster Model
Authors: Hang Nguyen Thi Nhat , Si Nguyen Thanh , Nguyen Minh Tho , Nhat Pham Vu
Published: September 2021

Computational approaches are employed to elucidate the binding mechanism and the SERS phenomenon of 6-mercaptopurine (6MP) adsorbed on the tetrahedral Au20 cluster as a simple model for a nanostructured gold surface. Computations are carried out in both vacuum and aqueous environments using a continuum model. In the gaseous phase and neutral conditions, interaction of 6MP with the gold cluster is mostly dominated by a covalent Au−S bond and partially stabilized by the Au⋅⋅⋅H−N coupling. However, in acidic solution, the nonconventional Au⋅⋅⋅H−S hydrogen-bond becomes the most favorable binding mode. The 6MP affinity for gold clusters decreases in the order of vacuum > neutral solution > acidic medium. During the adsorption, the energy gap of Au20 substantially declines, leading to an increase in its electrical conductivity, which can be converted to an electrical noise. Moreover, such interaction is likely a reversible process and triggered by either the low pH in sick tissues or the presence of cysteine residues in protein matrices. While N−H bending and stretching vibrations play major roles in the SERS phenomenon of 6MP on gold surfaces in neutral solution, the strongest enhancement in acidic environment is mostly due to an Au⋅⋅⋅H−S coupling, rather than an aromatic ring-gold surface π overlap as previously proposed.
Targeting the Integrated Stress Response Kinase GCN2 to Modulate Retroviral Integration
Authors: Torres Chloé , Garling Asja , Taouji Saïd , Calmels Christina , Andreola Marie-Line , Métifiot Mathieu
Published: September 2021

Multiple viral targets are now available in the clinic to fight HIV infection. Even if this targeted therapy is highly effective at suppressing viral replication, caregivers are facing growing therapeutic failures in patients due to resistance, with or without treatment-adherence glitches. Accordingly, it is important to better understand how HIV and other retroviruses replicate in order to propose alternative antiviral strategies. Recent studies have shown that multiple cellular factors are implicated during the integration step and, more specifically, that integrase can be regulated through post-translational modifications. We have shown that integrase is phosphorylated by GCN2, a cellular protein kinase of the integrated stress response, leading to a restriction of HIV replication. In addition, we found that this mechanism is conserved among other retroviruses. Accordingly, we developed an in vitro interaction assay, based on the AlphaLISA technology, to monitor the integrase-GCN2 interaction. From an initial library of 133 FDA-approved molecules, we identified nine compounds that either inhibited or stimulated the interaction between GCN2 and HIV integrase. In vitro characterization of these nine hits validated this pilot screen and demonstrated that the GCN2-integrase interaction could be a viable solution for targeting integrase out of its active site.
Tualang Honey: A Decade of Neurological Research
Authors: Azman Khairunnuur Fairuz , Aziz Che Badariah Abd , Zakaria Rahimah , Ahmad Asma Hayati , Shafin Nazlahshaniza , Ismail Che Aishah Nazariah
Published: September 2021

Tualang honey has been shown to protect against neurodegeneration, leading to improved memory/learning as well as mood. In addition, studies have also demonstrated its anti-inflammatory and antioxidant properties. However, a substantial part of this research lacks systematization, and there seems to be a tendency to start anew with every study. This review presents a decade of research on Tualang honey with a particular interest in the underlying mechanisms related to its effects on the central nervous system. A total of 28 original articles published between 2011 and 2020 addressing the central nervous system (CNS) effects of Tualang honey were analysed. We identified five main categories, namely nootropic, antinociceptive, stress-relieving, antidepressant, and anxiolytic effects of Tualang honey, and proposed the underlying mechanisms. The findings from this review may potentially be beneficial towards developing new therapeutic roles for Tualang honey and help in determining how best to benefit from this brain supplement.
HS–SPME–GC–MS and Electronic Nose Reveal Differences in the Volatile Profiles of Hedychium Flowers
Authors: Zhou Yiwei , Abbas Farhat , Wang Zhidong , Yu Yunyi , Yue Yuechong , Li Xinyue , Yu Rangcai , Fan Yanping
Published: September 2021

Floral fragrance is one of the most important characteristics of ornamental plants and plays a pivotal role in plant lifespan such as pollinator attraction, pest repelling, and protection against abiotic and biotic stresses. However, the precise determination of floral fragrance is limited. In the present study, the floral volatile compounds of six Hedychium accessions exhibiting from faint to highly fragrant were comparatively analyzed via gas chromatography–mass spectrometry (GC–MS) and Electronic nose (E-nose). A total of 42 volatile compounds were identified through GC–MS analysis, including monoterpenoids (18 compounds), sesquiterpenoids (12), benzenoids/phenylpropanoids (8), fatty acid derivatives (2), and others (2). In Hedychium coronarium ‘ZS’, H. forrestii ‘Gaoling’, H. ‘Jin’, H. ‘Caixia’, and H. ‘Zhaoxia’, monoterpenoids were abundant, while sesquiterpenoids were found in large quantities in H. coccineum ‘KMH’. Hierarchical clustering analysis (HCA) divided the 42 volatile compounds into four different groups (I, II, III, IV), and Spearman correlation analysis showed these compounds to have different degrees of correlation. The E-nose was able to group the different accessions in the principal component analysis (PCA) corresponding to scent intensity. Furthermore, the pattern-recognition findings confirmed that the E-nose data validated the GC–MS results. The partial least squares (PLS) analysis between floral volatile compounds and sensors suggested that specific sensors were highly sensitive to terpenoids. In short, the E-nose is proficient in discriminating Hedychium accessions of different volatile profiles in both quantitative and qualitative aspects, offering an accurate and rapid reference technique for future applications.
Organic Dyes versus Adsorption Processing
Authors: Alguacil Francisco J. , López Félix A.
Published: September 2021

Even in the first quarter of the XXI century, the presence of organic dyes in wastewaters was a normal occurrence in a series of countries. As these compounds are toxic, their removal from these waters is a necessity. Among the separation technologies, adsorption processing appeared as one of the most widely used to reach this goal. The present work reviewed the most recent approaches (first half of the 2021 year) regarding the use of a variety of adsorbents in the removal of a variety of organic dyes of different natures.
Cashew Nut Shell Liquid (CNSL) as a Source of Drugs for Alzheimer’s Disease
Authors: Uliassi Elisa , de Oliveira Andressa Souza , de Camargo Nascente Luciana , Romeiro Luiz Antonio Soares , Bolognesi Maria Laura
Published: September 2021

Alzheimer’s disease (AD) is a complex neurodegenerative disorder with a multifaceted pathogenesis. This fact has long halted the development of effective anti-AD drugs. Recently, a therapeutic strategy based on the exploitation of Brazilian biodiversity was set with the aim of discovering new disease-modifying and safe drugs for AD. In this review, we will illustrate our efforts in developing new molecules derived from Brazilian cashew nut shell liquid (CNSL), a natural oil and a byproduct of cashew nut food processing, with a high content of phenolic lipids. The rational modification of their structures has emerged as a successful medicinal chemistry approach to the development of novel anti-AD lead candidates. The biological profile of the newly developed CNSL derivatives towards validated AD targets will be discussed together with the role of these molecular targets in the context of AD pathogenesis.
Uptake of Cell-Penetrating Peptide RL2 by Human Lung Cancer Cells: Monitoring by Electron Paramagnetic Resonance and Confocal Laser Scanning Microscopy
Authors: Ovcherenko Sergey S. , Chinak Olga A. , Chechushkov Anton V. , Dobrynin Sergey A. , Kirilyuk Igor A. , Krumkacheva Olesya A. , Richter Vladimir A. , Bagryanskaya Elena G.
Published: September 2021

RL2 is a recombinant analogue of a human κ-casein fragment, capable of penetrating cells and inducing apoptosis of cancer cells with no toxicity to normal cells. The exact mechanism of RL2 penetration into cells remains unknown. In this study, we investigated the mechanism of RL2 penetration into human lung cancer A549 cells by a combination of electron paramagnetic resonance (EPR) spectroscopy and confocal laser scanning microscopy. EPR spectra of A549 cells incubated with RL2 (sRL2) spin-labeled by a highly stable 3-carboxy-2,2,5,5-tetraethylpyrrolidine-1-oxyl radical were found to contain three components, with their contributions changing with time. The combined EPR and confocal-microscopy data allowed us to assign these three forms of sRL2 to the spin-labeled protein sticking to the membrane of the cell and endosomes, to the spin-labeled protein in the cell interior, and to spin labeled short peptides formed in the cell because of protein digestion. EPR spectroscopy enabled us to follow the kinetics of transformations between different forms of the spin-labeled protein at a minimal spin concentration (3–16 μM) in the cell. The prospects of applications of spin-labeled cell-penetrating peptides to EPR imaging, DNP, and magnetic resonance imaging are discussed, as is possible research on an intrinsically disordered protein in the cell by pulsed dipolar EPR spectroscopy.
Bimodal Ultrasound and X-ray Bioimaging Properties of Particulate Calcium Fluoride Biomaterial
Authors: Chingo Aimacaña Cristhian Marcelo , Pila Kevin O. , Quinchiguango Perez Dilan A. , Debut Alexis , Attia Mohamed F. , Santos-Oliveira Ralph , Whitehead Daniel C. , Reinoso Carlos , Alexis Frank , Dahoumane Si Amar
Published: September 2021

Ultrasound (US) and X-ray imaging are diagnostic methods that are commonly used to image internal body structures. Several organic and inorganic imaging contrast agents are commercially available. However, their synthesis and purification remain challenging, in addition to posing safety issues. Here, we report on the promise of widespread, safe, and easy-to-produce particulate calcium fluoride (part-CaF2) as a bimodal US and X-ray contrast agent. Pure and highly crystalline part-CaF2 is obtained using a cheap commercial product. Scanning electron microscopy (SEM) depicts the morphology of these particles, while energy-dispersive X-ray spectroscopy (EDS) confirms their chemical composition. Diffuse reflectance ultraviolet-visible spectroscopy highlights their insulating behavior. The X-ray diffraction (XRD) pattern reveals that part-CaF2 crystallizes in the face-centered cubic cell lattice. Further analyses regarding peak broadening are performed using the Scherrer and Williamson–Hall (W-H) methods, which pinpoint the small crystallite size and the presence of lattice strain. X-ray photoelectron spectroscopy (XPS) solely exhibits specific peaks related to CaF2, confirming the absence of any contamination. Additionally, in vitro cytotoxicity and in vivo maximum tolerated dose (MTD) tests prove the biocompatibility of part-CaF2. Finally, the results of the US and X-ray imaging tests strongly signal that part-CaF2 could be exploited in bimodal bioimaging applications. These findings may shed a new light on calcium fluoride and the opportunities it offers in biomedical engineering.
Azocalix[4]arene-Rhodamine Supramolecular Hypoxia-Sensitive Systems: A Search for the Best Calixarene Hosts and Rhodamine Guests
Authors: Mironova Diana , Burilov Vladimir , Galieva Farida , Khalifa Mohamed Ali Mohamed , Kleshnina Sofia , Gazalieva Alsu , Nugmanov Ramil , Solovieva Svetlana , Antipin Igor
Published: September 2021

A potential hypoxia-sensitive system host-guest complex of three calixarenes (including two with four anionic carboxyl and sulphonate azo fragments on the upper rim and a newly synthesized bis-azo adduct of calixarene in the cone configuration with azo fragments on the lower rim with the most widespread cationic and zwitterionic rhodamine dyes (123, 6G and B)) was studied using UV-VIS spectrometry and fluorescence as well as 1D and 2D NMR techniques. It was found that all three calixarenes form a complex with rhodamine dyes with a 1:1 composition. The association constants of calixarene-dye complexes with sulfonate calixarenes, especially in the case of tetra-anionic calixarene, turned out to be higher compared with carboxyl calixarene due to the more intense electrostatic interactions. For the first time using an HRESI MS technique, it was shown that the treatment of rhodamine 6G and 123 with sodium dithionite (SDT) produces a non-fluorescent leuco form of the dye, and only rhodamine B can be used with SDT without the occurrence of a side reduction. Moreover, it was identified that in addition to the reduction in the azo groups, SDT causes partial cleavage of the aryl ether bonds. The found features of SDT should be taken into account when SDT is used as an azoreductase mimic.
Simultaneous Hydrodistillation-Steam Distillation of Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium from Morocco, Major Terpenes: Impact on Biological Activities
Authors: El Kharraf Sara , Faleiro Maria Leonor , Abdellah Farah , El-Guendouz Soukaïna , El Hadrami El Mestafa , Miguel Maria Graça
Published: September 2021

Interest in the use of essential oils (EOs) in the biomedical and food industries have seen growing over the last decades due to their richness in bioactive compounds. The challenges in developing an EO extraction process that assure an efficient levels of monoterpenes with impact on biological activities have driven the present study, in which the EO extraction process of rosemary, lavender and citrus was performed by simultaneous hydrodistillation–steam distillation, and the influence of EO composition on biological activities, namely antioxidant, anti-inflammatory, antidiabetic, anti-acetylcholinesterase, anti-tyrosinase, antibacterial, and antibiofilm activity, were evaluated. The EO yields of combinations were generally higher than the individual plants (R. officinalis (Ro), L. angustifolia (La), and C. aurantium (Ca)) extracted by the conventional hydrodistillation. The EOs obtained by this process generally had a better capacity for scavenging the free radicals, inhibiting α-glucosidase, and acetylcholinesterase activities than the individual EOs. The combination of EOs did not improve the ability for scavenging peroxide hydrogen or the capacity for inhibiting lipoxygenase activity. The antioxidant activity or the enzyme inhibition activity could not only be attributed to their major compounds because they presented lower activities than the EOs. The chemical composition of the combination Ro:La:Ca, at the ratio 1/6:1/6:2/3, was enriched in 1,8-cineole, linalool, and linalyl acetate and resulted in lower MIC values for all tested strains in comparison with the ratio 1/6:2/3:1/6 that was deprived on those components. The biofilm formation of Gram positive and Gram negative bacteria was impaired by the combination Ro:La:Ca at a sub-inhibitory concentration.
Bayesian Data Assimilation of Temperature Dependence of Solid–Liquid Interfacial Properties of Nickel
Authors: Nagatsuma Yuhi , Ohno Munekazu , Takaki Tomohiro , Shibuta Yasushi
Published: September 2021

Temperature dependence of solid–liquid interfacial properties during crystal growth in nickel was investigated by ensemble Kalman filter (EnKF)-based data assimilation, in which the phase-field simulation was combined with atomic configurations of molecular dynamics (MD) simulation. Negative temperature dependence was found in the solid–liquid interfacial energy, the kinetic coefficient, and their anisotropy parameters from simultaneous estimation of four parameters. On the other hand, it is difficult to obtain a concrete value for the anisotropy parameter of solid–liquid interfacial energy since this factor is less influential for the MD simulation of crystal growth at high undercooling temperatures. The present study is significant in shedding light on the high potential of Bayesian data assimilation as a novel methodology of parameter estimation of practical materials an out of equilibrium condition.
The Effect of Annealing Ambience on the Material and Photodetector Characteristics of Sputtered ZnGa2O4 Films
Authors: Singh Anoop Kumar , Huang Shiau-Yuan , Chen Po-Wei , Chiang Jung-Lung , Wuu Dong-Sing
Published: September 2021

Spinel ZnGa2O4 films were grown on c-plane sapphire substrates at the substrate temperature of 400 °C by radio-frequency magnetron sputtering. Post thermal annealing was employed at the annealing temperature of 700 °C in order to enhance their crystal quality. The effect of thermal annealing on the microstructural and optoelectronic properties of ZnGa2O4 films was systematically investigated in various ambiences, such as air, nitrogen, and oxygen. The X-ray diffraction patterns of annealed ZnGa2O4 films showed the crystalline structure to have (111) crystallographic planes. Transmission electron micrographs verified that ZnGa2O4 film annealed under air ambience possesses a quasi-single-crystalline structure. This ZnGa2O4 film annealed under air ambience exhibited a smooth surface, an excellent average transmittance above 82% in the visible region, and a wide bandgap of 5.05 eV. The oxygen vacancies under different annealing ambiences were revealed a substantial impact on the material and photodetector characteristics by X-ray photoelectron spectrum investigations. ZnGa2O4 film exhibits optimal performance as a metal-semiconductor-metal photodetector when annealed under air ambience. Under these conditions, ZnGa2O4 film exhibits a higher photo/dark current ratio of ~104 order, as well as a high responsivity of 2.53 A/W at the bias of 5 V under an incident optical light of 240 nm. These results demonstrate that quasi-single-crystalline ZnGa2O4 films have significant potential in deep-ultraviolet applications.
Facile Sulfurization under Ambient Condition with Na2S to Fabricate Nanostructured Copper Sulfide
Authors: Hwang Eunseo , Park Yoonsu , Kim Jongbae , Paik Taejong , Ha Don-Hyung
Published: September 2021

The sulfurization reaction was investigated as a promising fabrication method for preparing metal sulfide nanomaterials. Traditional sulfurization processes generally require high vacuum systems, high reaction temperatures, and toxic chemicals, utilizing complicated procedures with poor composition and morphology controllability. Herein, a facile method is reported for synthesizing nanostructured copper sulfide using a sulfurization reaction with Na2S at room temperature under non-vacuum conditions. Moreover, we demonstrate that the morphology, composition, and optical properties of nanostructured copper sulfides could be controlled by the Na2S solution concentration and the reaction time. Nanostructured copper sulfides were synthesized in nanospheres, nanoplates, and nanoplate-based complex morphologies with various oxidation states. Furthermore, by comparing the optical properties of nanostructured copper sulfides with different oxidation states, we determined that reflectivity in the near infrared (NIR) region decreases with increasing oxidation states. These results reveal that the Na2S solution concentration and reaction time are key factors for designing nanostructured copper sulfides, providing new insights for synthesis methods of metal sulfide nanomaterials.
ZnO Nanoparticles Induce Dyslipidemia and Atherosclerotic Lesions Leading to Changes in Vascular Contractility and Cannabinoid Receptors Expression as Well as Increased Blood Pressure
Authors: Ceballos-Gutiérrez Adriana , Rodríguez-Hernández Alejandrina , Álvarez-Valadez María del Rosario , Limón-Miranda Saraí , Andrade Felipa , Figueroa-Gutiérrez Alejandro , Díaz-Reval Irene , Apolinar-Iribe Alejandro , Castro-Sánchez Luis , Alamilla Javier , Sánchez-Pastor Enrique , Virgen-Ortiz Adolfo
Published: September 2021

ZnO nanoparticles (ZnONPs) have been shown to have therapeutic potential in some diseases such as diabetes and cancer. However, concentration-dependent adverse effects have also been reported. Studies which evaluate the effects of ZnONPs on the cardiovascular system are scarce. This study aimed to evaluate the cardiovascular effects of a low dose of ZnONPs administered chronically in healthy rats. Changes in dyslipidemia biomarkers, blood pressure, aortic wall structure, vascular contractility, and expression of cannabinoid receptors in the aorta wall were evaluated. Healthy rats were divided into two groups: control or treated (one, two, and three months). The treated rats received an oral dose of 10 mg/kg/day. The results showed that treatment with ZnONPs induced dyslipidemia from the first month, increasing atherosclerosis risk, which was confirmed by presence of atherosclerotic alterations revealed by aorta histological analysis. In in vitro assays, ZnONPs modified the aorta contractile activity in response to the activation of cannabinoid receptors (CB1 and CB2). The expression of CB1 and CB2 was modified as well. Moreover, ZnONPs elicited an increase in blood pressure. In conclusion, long-time oral administration of ZnONPs induce dyslipidemia and atherosclerosis eliciting alterations in aorta contractility, CB1 and CB2 receptors expression, and an increase in blood pressure in healthy rats.
Bacterial Nanocellulose as a Scaffold for In Vitro Cell Migration Assay
Authors: Ugrin Milena , Dinic Jelena , Jeremic Sanja , Dragicevic Sandra , Banovic Djeri Bojana , Nikolic Aleksandra
Published: September 2021

Bacterial nanocellulose (BNC) stands out among polymers as a promising biomaterial due to its mechanical strength, hydrophilicity, biocompatibility, biodegradability, low toxicity and renewability. The use of scaffolds based on BNC for 3D cell culture has been previously demonstrated. The study exploited excellent properties of the BNC to develop an efficient and low-cost in vitro cell migration assay. The BNC scaffold was introduced into a cell culture 24 h after the SW480 cells were seeded, and cells were allowed to enter the scaffold within the next 24–48 h. The cells were stained with different fluorophores either before or after the introduction of the scaffold in the culture. Untreated cells were observed to enter the BNC scaffold in significant numbers, form clusters and retain a high viability after 48 h. To validate the assay’s usability for drug development, the treatments of SW480 cells were performed using aspirin, an agent known to reduce the migratory potential of this cell line in culture. This study demonstrates the application of BNC as a scaffold for cell migration testing as a low-cost alternative to commercial assays based on the Boyden chamber principle. The assay could be further developed for routine use in cancer research and anticancer drug development.
Plasma Metabolome Profiling by High-Performance Chemical Isotope-Labelling LC-MS after Acute and Medium-Term Intervention with Golden Berry Fruit (Physalis peruviana L.), Confirming Its Impact on Insulin-Associated Signaling Pathways
Authors: Vaillant Fabrice , Corrales-Agudelo Vanesa , Moreno-Castellanos Natalia , Ángel-Martín Alberto , Henao-Rojas Juan Camilo , Muñoz-Durango Katalina , Poucheret Patrick
Published: September 2021

Purpose: Golden berry (Physalis peruviana L.) is an exotic fruit exported from Colombia to different countries around the world. A review of the literature tends to demonstrate a hypoglycaemic effect with an improvement in insulin sensitivity after oral ingestion of fruit extracts in animal models. However, little is known about their potential effects in humans, and very little is known about the mechanisms involved. This study aimed at identifying discriminant metabolites after acute and chronic intake of golden berry. Method: An untargeted metabolomics strategy using high-performance chemical isotope-labelling LC-MS was applied. The blood samples of eighteen healthy adults were analysed at baseline, at 6 h after the intake of 250 g of golden berry (acute intervention), and after 19 days of daily consumption of 150 g (medium-term intervention). Results: Forty-nine and 36 discriminant metabolites were identified with high confidence, respectively, after the acute and medium-term interventions. Taking into account up- and downregulated metabolites, three biological networks mainly involving insulin, epidermal growth factor receptor (EGFR), and the phosphatidylinositol 3-kinase pathway (PI3K/Akt/mTOR) were identified. Conclusions: The biological intracellular networks identified are highly interconnected with the insulin signalling pathway, showing that berry intake may be associated with insulin signalling, which could reduce some risk factors related to metabolic syndrome. Primary registry of WHO.
Evolution of Shock-Induced Pressure in Laser Bioprinting
Authors: Mareev Evgenii , Minaev Nikita , Zhigarkov Vyacheslav , Yusupov Vladimir
Published: September 2021

Laser bioprinting with gel microdroplets that contain living cells is a promising method for use in microbiology, biotechnology, and medicine. Laser engineering of microbial systems (LEMS) technology by laser-induced forward transfer (LIFT) is highly effective in isolating difficult-to-cultivate and uncultured microorganisms, which are essential for modern bioscience. In LEMS the transfer of a microdroplet of a gel substrate containing living cell occurs due to the rapid heating under the tight focusing of a nanosecond infrared laser pulse onto thin metal film with the substrate layer. During laser transfer, living organisms are affected by temperature and pressure jumps, high dynamic loads, and several others. The study of these factors’ role is important both for improving laser printing technology itself and from a purely theoretical point of view in relation to understanding the mechanisms of LEMS action. This article presents the results of an experimental study of bubbles, gel jets, and shock waves arising in liquid media during nanosecond laser heating of a Ti film obtained using time-resolving shadow microscopy. Estimates of the pressure jumps experienced by microorganisms in the process of laser transfer are performed: in the operating range of laser energies for bioprinting LEMS technology, pressure jumps near the absorbing film of the donor plate is about 30 MPa. The efficiency of laser pulse energy conversion to mechanical post-effects is about 10%. The estimates obtained are of great importance for microbiology, biotechnology, and medicine, particularly for improving the technologies related to laser bioprinting and the laser engineering of microbial systems.