bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvent Influence on Zeta Potential of Stationary Phase—Mobile Phase Interface
Authors: Dembek Mikołaj , Bocian Szymon , Buszewski Bogusław
Published: February 2022

Zeta potential is a surface characteristic formed on the solid surface and liquid interface. It is an interesting way to describe the surface properties of materials; thus, a series of four homemade polar embedded stationary phases that contain phosphate groups incorporated into hydrophobic ligands were investigated according to surface zeta potential. Measurements were carried out using Zetasizer Nano ZS for the stationary phases suspensions prepared in various solvent and solvent binary mixtures. The negative zeta potential values were obtained for most cases due to negatively charged residual silanols and phosphate groups. However, in some solvents: tetrahydrofuran, isopropanol, and toluene zeta potential are positive. Additionally, it was observed that the zeta potential seems to be independent of the type of silica gel used for the stationary phase synthesis.
A Potential Valorization Strategy of Wine Industry by-Products and Their Application in Cosmetics—Case Study: Grape Pomace and Grapeseed
Authors: Ferreira Sara M. , Santos Lúcia
Published: February 2022

Grape pomace and grapeseed are agro-industrial by-products, whose inadequate treatment generates socioeconomic and environmental concerns. Nevertheless, it is possible to valorize them by extracting their bioactive compounds, such as antioxidants (phenolic compounds), vitamin E and fatty acids. The bioactive compounds were extracted using solid-liquid extraction. The yields for phenolic compounds were 18.4 ± 0.4% for grape pomace, and 17.4 ± 0.4%, for grapeseed. For the oil, the yields were 13.3 ± 0.2% and 14.5 ± 0.3% for grape pomace and grapeseed. Antioxidant capacity was assessed by the assay with 2,2-diphenyl-1-picrylhydrazyl (DPPH), and showed that phenolic extract has higher antioxidant capacity than the oils. Grape pomace and grapeseed extracts exhibit, correspondingly, values of 90.8 ± 0.8 and 87.5 ± 0.5 of DPPH inhibition and IC50 of 48.9 ± 0.5 and 55.9 ± 0.7 μgextract·mLDPPH−1. The antimicrobial capacity was assessed by the disk diffusion test, and revealed that, phenolic extracts inhibit the growth of Staphylococcus aureus and Staphylococcus epidermidis. The obtained extracts were incorporated in 10 face cream formulations, with slight modifications in quantities of formulation stabilizers. Their stability was studied for 35 days, and this revealed the possibility of incorporating extracts and oils obtained from by-products as antioxidants in cosmetics, and replacing synthetic ones. As a future recommendation, microencapsulation of the extracts should be performed, in order to increase their stability.
The Response Surface Optimization of Supercritical CO2 Modified with Ethanol Extraction of p-Anisic Acid from Acacia mearnsii Flowers and Mathematical Modeling of the Mass Transfer
Authors: da Silva Graciane Fabiela , de Souza Júnior Edgar Teixeira , Almeida Rafael Nolibos , Fianco Ana Luisa Butelli , do Espirito Santo Alexandre Timm , Lucas Aline Machado , Vargas Rubem Mário Figueiró , Cassel Eduardo
Published: February 2022

A widely disseminated native species from Australia, Acacia mearnsii, which is mainly cultivated in Brazil and South Africa, represents a rich source of natural tannins used in the tanning process. Many flowers of the Acacia species are used as sources of compounds of interest for the cosmetic industry, such as phenolic compounds. In this study, supercritical fluid extraction was used to obtain non-volatile compounds from A. mearnsii flowers for the first time. The extract showed antimicrobial activity and the presence of p-anisic acid, a substance with industrial and pharmaceutical applications. The fractionation of the extract was performed using a chromatographic column and the fraction containing p-anisic acid presented better minimum inhibitory concentration (MIC) results than the crude extract. Thus, the extraction process was optimized to maximize the p-anisic acid extraction. The response surface methodology and the Box–Behnken design was used to evaluate the pressure, temperature, the cosolvent, and the influence of the particle size on the extraction process. After the optimization process, the p-anisic acid yield was 2.51% w/w and the extraction curve was plotted as a function of time. The simulation of the extraction process was performed using the three models available in the literature.
Cytotoxicity of Mahanimbine from Curry Leaves in Human Breast Cancer Cells (MCF-7) via Mitochondrial Apoptosis and Anti-Angiogenesis
Authors: Hobani Yahya Hasan
Published: February 2022

Mahanimbine (MN) is a carbazole alkaloid present in the leaves of Murraya koenigii, which is an integral part of medicinal and culinary practices in Asia. In the present study, the anticancer, apoptotic and anti-invasive potential of MN has been delineated in vitro. Apoptosis cells determination was carried out utilizing the acridine orange/propidium iodide double fluorescence test. During treatment, caspase-3/7,-8, and-9 enzymes and mitochondrial membrane potentials (Δψm) were evaluated. Anti-invasive properties were tested utilizing a wound-healing scratch test. Protein and gene expression studies were used to measure Bax, Bcl2, MMP-2, and -9 levels. The results show that MN could induce apoptosis in MCF-7 cells at 14 µM concentration IC50. MN-induced mitochondria-mediated apoptosis, with loss in Δψm, regulation of Bcl2/Bax, and accumulation of ROS (p ≤ 0.05). Caspase-3/7 and -9 enzyme activity were detected in MCF-7 cells after 24 and 48 h of treatment with MN. The anti-invasive property of MN was shown by inhibition of wound healing at the dose-dependent level and significantly suppressed mRNA and protein expression on MMP-2 and -9 in MCF-7 cells treated with a sub-cytotoxic dose of MN. The overall results indicate MN is a potential therapeutic compound against breast cancer as an apoptosis inducer and anti-invasive agent.
The Glycemic Control Potential of Some Amaranthaceae Plants, with Particular Reference to In Vivo Antidiabetic Potential of Agathophora alopecuroides
Authors: Amin Elham , Abdel-Bakky Mohamed Sadek , Darwish Mostafa Assem , Mohammed Hamdoon A. , Chigurupati Sridevi , Qureshi Kamal Ahmad , Hassan Marwa H. A.
Published: February 2022

Natural products continue to provide inspiring moieties for the treatment of various diseases. In this regard, investigation of wild plants, which have not been previously explored, is a promising strategy for reaching medicinally useful drugs. The present study aims to investigate the antidiabetic potential of nine Amaranthaceae plants: Agathophora alopecuroides, Anabasis lachnantha, Atriplex leucoclada, Cornulaca aucheri, Halothamnus bottae, Halothamnus iraqensis, Salicornia persia, Salsola arabica, and Salsola villosa, growing in the Qassim area, the Kingdom of Saudi Arabia. The antidiabetic activity of the hydroalcoholic extracts was assessed using in vitro testing of α-glucosidase and α-amylase inhibitory effects. Among the nine tested extracts, A. alopecuroides extract (AAE) displayed potent inhibitory activity against α-glucosidase enzyme with IC50 117.9 µg/mL noting better activity than Acarbose (IC50 191.4 µg/mL). Furthermore, AAE displayed the highest α- amylase inhibitory activity among the nine tested extracts, with IC50 90.9 µg/mL. Based upon in vitro testing results, the antidiabetic activity of the two doses (100 and 200 mg/kg) of AAE was studied in normoglycemic and streptozotocin (STZ)-induced diabetic mice. The effects of the extract on body weight, food and water intakes, random blood glucose level (RBGL), fasting blood glucose level (FBGL), insulin, total cholesterol, and triglycerides levels were investigated. Results indicated that oral administration of the two doses of AAE showed a significant dose-dependent increase (p < 0.05) in the body weight and serum insulin level, as well as a significant decrease in food and water intake, RBGL, FBGL, total cholesterol, and triglyceride levels, in STZ-induced diabetic mice, compared with the diabetic control group. Meanwhile, no significant differences of both extract doses were observed in normoglycemic mice when compared with normal control animals. This study revealed a promising antidiabetic activity of the wild plant A. alopecuroides.
Analytical Techniques for Phytocannabinoid Profiling of Cannabis and Cannabis-Based Products—A Comprehensive Review
Authors: Stefkov Gjoshe , Cvetkovikj Karanfilova Ivana , Stoilkovska Gjorgievska Veronika , Trajkovska Ana , Geskovski Nikola , Karapandzova Marija , Kulevanova Svetlana
Published: February 2022

Cannabis is gaining increasing attention due to the high pharmacological potential and updated legislation authorizing multiple uses. The development of time- and cost-efficient analytical methods is of crucial importance for phytocannabinoid profiling. This review aims to capture the versatility of analytical methods for phytocannabinoid profiling of cannabis and cannabis-based products in the past four decades (1980–2021). The thorough overview of more than 220 scientific papers reporting different analytical techniques for phytocannabinoid profiling points out their respective advantages and drawbacks in terms of their complexity, duration, selectivity, sensitivity and robustness for their specific application, along with the most widely used sample preparation strategies. In particular, chromatographic and spectroscopic methods, are presented and discussed. Acquired knowledge of phytocannabinoid profile became extremely relevant and further enhanced chemotaxonomic classification, cultivation set-ups examination, association of medical and adverse health effects with potency and/or interplay of certain phytocannabinoids and other active constituents, quality control (QC), and stability studies, as well as development and harmonization of global quality standards. Further improvement in phytocannabinoid profiling should be focused on untargeted analysis using orthogonal analytical methods, which, joined with cheminformatics approaches for compound identification and MSLs, would lead to the identification of a multitude of new phytocannabinoids.
Antibacterial and Chemical Characterization of Silica-Quercetin-PEG Hybrid Materials Synthesized by Sol–Gel Route
Authors: Blanco Ignazio , Latteri Alberta , Cicala Gianluca , D’Angelo Antonio , Viola Veronica , Arconati Vincenzo , Catauro Michelina
Published: February 2022

This paper aims to synthesize, via the sol–gel method, a biomaterial usable in the medical field. Here, the silica-PEG-quercetin system was evaluated in relation to the different concentrations of PEG (0, 6, 12, 24, 50 wt%) and quercetin (0, 5, 10, 15 wt%), respectively. In addition, Fourier Transform-Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and Kirby–Bauer analyses were performed. FT-IR was used to evaluate the hybrid formation and the influence of both PEG and Quercetin in the hybrid synthesized materials, SEM was used to evaluate the morphological properties, while the Kirby–Bauer test was used to understand the ability of the materials to inhibit the growth of the assayed bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, and Staphylococcus aureus).
The Antiproliferative and Apoptotic Effects of a Novel Quinazoline Carrying Substituted-Sulfonamides: In Vitro and Molecular Docking Study
Authors: Alqahtani Ali S. , Ghorab Mostafa M. , Nasr Fahd A. , Ahmed Mohammad Z. , Al-Mishari Abdullah A. , Attia Sabry M.
Published: February 2022

In order to investigate for a new effective and safe anticancer drug, we synthesized a novel series of quinazoline containing biologically active substituted-sulfonamide moiety at 3- position 4a–n. The structure of the newly prepared compounds was proved by microanalysis, IR, 1H-NMR, 13C-NMR and mass spectral data. All the synthesized compounds were evaluated for their in vitro cytotoxic activity in numerous cancer cell lines including A549, HepG-2, LoVo and MCF-7 and normal HUVEC cell line. The two most active compounds 4d and 4f were then tested for their apoptosis induction using DNA content and Annexin V-FITC/PI staining. Moreover, apoptosis initiation was also confirmed using RT-PCR and Western blot. To further understand the binding preferences of quinazoline sulfonamides, docking simulations were used. Among the fourteen new synthesized compounds, we found that compounds 4d and 4f exerted the strongest cytotoxicity against MCF-7 cells with an IC50 value of 2.5 and 5 μM, respectively. Flow cytometry data revealed the ability of compounds 4d and 4f to mediate apoptosis and arrest cell cycle growth at G1 phase. Furthermore, RT-PCR and Western blot results suggested that both 4d and 4f activates apoptotic cell death pathway in MCF-7 cells. Molecular docking assessments indicated that compounds 4d and 4f fit perfectly into Bcl2’s active site. Based on the biological properties, we conclude that both compounds 4d and 4f could be used as a new type of anticancer agent, which provides a scientific basis for further research into the treatment of cancer.
New Experimental Conditions for Diels–Alder and Friedel-Crafts Alquilation Reactions with Thiophene: A New Selenocyanate with Potent Activity against Cancer
Authors: Calvo-Martín Gorka , Plano Daniel , Sanmartín Carmen
Published: February 2022

The reactivity of thiophene in Diels-Alder reactions is investigated with different maleimide derivatives. In this paper, we have synthesized for the first time the Diels–Alder adducts of thiophene at room temperature and atmospheric pressure. Maleimido–thiophene adducts were promoted by AlCl3. The effects of solvent, time, temperature and the use of different Lewis acids were studied, showing dramatic effects for solvent and Lewis acid. Furthermore, the catalysis with AlCl3 is highly stereoselective, preferably providing the exo form of the adduct. Additionally, we also discovered the ability of AlCl3 to catalyze the arylation of maleimides to yield 3-aryl succinimides in a straightforward manner following a Friedel–Crafts-type addition. The inclusion of a selenocyanate group contributes to the cytotoxic activity of the adduct. This derivatization (from compound 7 to compound 15) results in an average GI50 value of 1.98 µM in the DTP (NCI-60) cell panel, resulting in being especially active in renal cancer cells.
Recognition of Dimethylarginine Analogues by Tandem Tudor Domain Protein Spindlin1
Authors: Porzberg Miriam R. B. , Moesgaard Laust , Johansson Catrine , Oppermann Udo , Kongsted Jacob , Mecinović Jasmin
Published: February 2022

Epigenetic readout of the combinatorial posttranslational modification comprised of trimethyllysine and asymmetric dimethylarginine (H3K4me3R8me2a) takes place via biomolecular recognition of tandem Tudor-domain-containing protein Spindlin1. Through comparative thermodynamic data and molecular dynamics simulations, we sought to explore the binding scope of asymmetric dimethylarginine mimics by Spindlin1. Herein, we provide evidence that the biomolecular recognition of H3K4me2R8me2a is not significantly affected when R8me2a is replaced by dimethylarginine analogues, implying that the binding of K4me3 provides the major binding contribution. High-energy water molecules inside both aromatic cages of the ligand binding sites contribute to the reader–histone association upon displacement by histone peptide, with the K4me3 hydration site being lower in free energy due to a flip of Trp151.
Protic Ionic Liquid Cation Alkyl Chain Length Effect on Lysozyme Structure
Authors: Han Qi , Broomhall Hayden C. , Vieira Veríssimo Nathalia , Ryan Timothy M. , Drummond Calum J. , Pereira Jorge F. B. , Greaves Tamar L.
Published: February 2022

Solvents that stabilize protein structures can improve and expand their biochemical applications, particularly with the growing interest in biocatalytic-based processes. Aiming to select novel solvents for protein stabilization, we explored the effect of alkylammonium nitrate protic ionic liquids (PILs)-water mixtures with increasing cation alkyl chain length on lysozyme conformational stability. Four PILs were studied, that is, ethylammonium nitrate (EAN), butylammonium nitrate (BAN), hexylammonium nitrate (HAN), and octylammonium nitrate (OAN). The surface tension, viscosity, and density of PIL-water mixtures at low to high concentrations were firstly determined, which showed that an increasing cation alkyl chain length caused a decrease in the surface tension and density as well as an increase in viscosity for all PIL solutions. Small-angle X-ray scattering (SAXS) was used to investigate the liquid nanostructure of the PIL solutions, as well as the overall size, conformational flexibility and changes to lysozyme structure. The concentrated PILs with longer alkyl chain lengths, i.e., over 10 mol% butyl-, 5 mol% hexyl- and 1 mol% octylammonium cations, possessed liquid nanostructures. This detrimentally interfered with solvent subtraction, and the more structured PIL solutions prevented quantitative SAXS analysis of lysozyme structure. The radius of gyration (Rg) of lysozyme in the less structured aqueous PIL solutions showed little change with up to 10 mol% of PIL. Kratky plots, SREFLEX models, and FTIR data showed that the protein conformation was maintained at a low PIL concentration of 1 mol% and lower when compared with the buffer solution. However, 50 mol% EAN and 5 mol% HAN significantly increased the Rg of lysozyme, indicating unfolding and aggregation of lysozyme. The hydrophobic interaction and liquid nanostructure resulting from the increased cation alkyl chain length in HAN likely becomes critical. The impact of HAN and OAN, particularly at high concentrations, on lysozyme structure was further revealed by FTIR. This work highlights the negative effect of a long alkyl chain length and high concentration of PILs on lysozyme structural stability.
Automation and Standardization—A Coupled Approach towards Reproducible Sample Preparation Protocols for Nanomaterial Analysis
Authors: Radnik Jörg , Hodoroaba Vasile-Dan , Jungnickel Harald , Tentschert Jutta , Luch Andreas , Sogne Vanessa , Meier Florian , Burr Loïc , Schmid David , Schlager Christoph , Yoon Tae Hyun , Peters Ruud , Briffa Sophie M. , Valsami-Jones Eugenia
Published: February 2022

Whereas the characterization of nanomaterials using different analytical techniques is often highly automated and standardized, the sample preparation that precedes it causes a bottleneck in nanomaterial analysis as it is performed manually. Usually, this pretreatment depends on the skills and experience of the analysts. Furthermore, adequate reporting of the sample preparation is often missing. In this overview, some solutions for techniques widely used in nano-analytics to overcome this problem are discussed. Two examples of sample preparation optimization by automation are presented, which demonstrate that this approach is leading to increased analytical confidence. Our first example is motivated by the need to exclude human bias and focuses on the development of automation in sample introduction. To this end, a robotic system has been developed, which can prepare stable and homogeneous nanomaterial suspensions amenable to a variety of well-established analytical methods, such as dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), field-flow fractionation (FFF) or single-particle inductively coupled mass spectrometry (sp-ICP-MS). Our second example addresses biological samples, such as cells exposed to nanomaterials, which are still challenging for reliable analysis. An air–liquid interface has been developed for the exposure of biological samples to nanomaterial-containing aerosols. The system exposes transmission electron microscopy (TEM) grids under reproducible conditions, whilst also allowing characterization of aerosol composition with mass spectrometry. Such an approach enables correlative measurements combining biological with physicochemical analysis. These case studies demonstrate that standardization and automation of sample preparation setups, combined with appropriate measurement processes and data reduction are crucial steps towards more reliable and reproducible data.
Molecular Identification of the Transient Species Mediating the Deactivation Dynamics of Solvated Guanosine and Deazaguanosine
Authors: Ortín-Fernández Javier , González-Vázquez Jesús , Martínez-Fernández Lara , Corral Inés
Published: February 2022

Small structural alterations of the purine/pyrimidine core have been related to important photophysical changes, such as the loss of photostability. Similarly to canonical nucleobases, solute-solvent interactions can lead to a change in the excited state lifetimes and/or to the interplay of different states in the photophysics of these modified nucleobases. To shed light on both effects, we here report a complete picture of the absorption spectra and excited state deactivation of deoxyguanosine and its closely related derivative, deoxydeazaguanosine, in water and methanol through the mapping of the excited state potential energy surfaces and molecular dynamics simulations at the TD-DFT level of theory. We show that the N by CH exchange in the imidazole ring of deoxyguanosine translates into a small red-shift of the bright states and slightly faster dynamics. In contrast, changing solvent from water to methanol implies the opposite, i.e., that the deactivation of both systems to the ground state is significantly hindered.
In Vitro Assessment of the Cytotoxic and Antiproliferative Profile of Natural Preparations Containing Bergamot, Orange and Clove Essential Oils
Authors: Alexa Vlad Tiberiu , Galuscan Atena , Soica Codruța M. , Cozma Antoanela , Coricovac Dorina , Borcan Florin , Popescu Iuliana , Mioc Alexandra , Szuhanek Camelia , Dehelean Cristina Adriana , Jumanca Daniela
Published: February 2022

Medicinal plants and essential oils (EOs), in particular, were intensively studied in recent years as viable alternatives for antiproliferative chemical synthetic agents. In the same lines, the present study focuses on investigating the effects of natural preparations (emulsions) based on EOs obtained from Citrus bergamia Risso (bergamot-BEO), Citrus sinensis Osbeck (orange-OEO), and Syzygium aromaticum Merill et L. M. Perry (clove-CEO) on different healthy (human immortalized keratinocytes—HaCaT and primary human gingival fibroblasts—HGF) and human tumor cell lines (human melanoma—A375 and oral squamous carcinoma—SCC-4) in terms of the cells’ viability and cellular morphology. The obtained results indicate that the CEO emulsion (ECEO) induced a dose-dependent cytotoxic in both healthy (HaCaT and HGF) and tumor (A375 and SCC-4) cells. OEO emulsion (EOEO) increased cell viability percentage both for HaCaT and A375 cells and had an antiproliferative effect at the highest concentration in HGF and SCC-4 cells. BEO emulsion (EBEO) decreased the viability percentage of SCC-4 tumor cells. By associating OEO with CEO as a binary mixture in an emulsified formulation, the inhibition of tumor cell viability increases. The E(BEO/OEO) binary emulsion induced an antiproliferative effect on oral health and tumor cells, with a minimal effect on skin cells. The non-invasive tests performed to verify the safety of the test compound’s emulsions at skin level indicated that these compounds do not significantly modify the physiological skin parameters and can be considered safe for human skin.
The Antioxidant, Cytotoxic and Antimicrobial Potential of Phenolic Acids-Enriched Extract of Elicited Hairy Roots of Salvia bulleyana
Authors: Krzemińska Marta , Owczarek Aleksandra , Gonciarz Weronika , Chmiela Magdalena , Olszewska Monika A. , Grzegorczyk-Karolak Izabela
Published: February 2022

Hairy root cultures are valuable sources of a range of phytochemicals. Among them, Salvia bulleyana root culture is a promising source of polyphenols, especially rosmarinic acid (RA), a phenolic acid depside with pleiotropic activity and a wide application in medicine and cosmetology. The aim of the study was to enhance the culture productivity by finding suitable elicitation protocol and to determine its biological potential in terms of antioxidant, anticancer and antimicrobial properties. The total content of phenols and the levels of particular constituents in root extracts were analyzed using HPLC-PDA. Among four elicitors tested (yeast extract; methyl jasmonate, MJA; trans-anethol; and cadmium chloride), MJA was found to be the most effective. The greatest boost in phenolic production (up to 124.4 mg/g dry weight) was observed after three-day treatment with MJA at 100 µM, with an almost 100% improvement compared to the controls (non-treated root culture). The hydromethanolic extract from the elicited culture exhibited strong antioxidant activity with IC50 values of 11.1 µg/mL, 6.5 µg/mL and 69.5 µg/mL for DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)) and superoxide anion radical, respectively. Moreover, in concentrations of 0.5–5 mg/mL the extract inhibited the growth of LoVo, AGS and HeLa cell lines, but was safe for the L929 cells up to the concentration of 5 mg/mL. The extract also exhibited moderate antimicrobial activity. Thus, the results confirmed that elicitation can be a beneficial strategy for increase the phenolic acid biosynthesis in hairy roots of S. bulleyana, and that such a highly productive culture can show significant biological potential.
Protective Effects of Green Tea Supplementation against Lead-Induced Neurotoxicity in Mice
Authors: Al-Qahtani Areej , Ajarem Jamaan , Okla Mohammad K. , Rubnawaz Samina , Alamri Saud A. , Al-Qahtani Wahidah H. , Al-Himaidi Ahmad R. , Elgawad Hamada Abd , Akhtar Nosheen , Maodaa Saleh N. , Abdel-Maksoud Mostafa A.
Published: February 2022

The use of natural products as therapeutic agents is rapidly growing recently. In the current study, we investigated the protective effects of green tea supplementation on lead-induced toxicity in mice. Forty albino mice were divided into four groups as follows: A: control group; B: green tea receiving group; C: lead-intoxicated group; and D: lead-intoxicated group supplemented with green tea. At the end of the experiment, the animals were tested for neurobehavioral and biochemical alterations. Green tea was analyzed through Gas Chromatography–Mass Spectrometry (GC/MS) analysis. We found that supplementation with green tea ameliorated the lead-associated increase in body weight and blood glucose. Green tea supplementation also changed the blood picture that was affected due to lead toxicity and ameliorated lead-induced dyslipidemia. The group of mice that were supplemented with green tea has shown positive alterations in locomotory, anxiety, memory, and learning behaviors. The GC/MS analysis revealed many active ingredients among which the two most abundant were caffeine and 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester. We concluded that green tea supplementation has several positive effects on the lead-induced neurotoxicity in mice and that these effects may be attributed to its main two active ingredients.
Hydrogen Bonding and Polymorphism of Amino Alcohol Salts with Quinaldinate: Structural Study
Authors: Podjed Nina , Modec Barbara
Published: February 2022

Three amino alcohols, 3-amino-1-propanol (abbreviated as 3a1pOH), 2-amino-1-butanol (2a1bOH), and 2-amino-2-methyl-1-propanol (2a2m1pOH), were reacted with quinoline-2-carboxylic acid, known as quinaldinic acid. This combination yielded three salts, (3a1pOHH)quin (1, 3a1pOHH+ = protonated 3-amino-1-propanol, quin− = anion of quinaldinic acid), (2a1bOHH)quin (2, 2a1bOHH+ = protonated 2-amino-1-butanol), and (2a2m1pOHH)quin (3, 2a2m1pOHH+ = protonated 2-amino-2-methyl-1-propanol). The 2-amino-1-butanol and 2-amino-2-methyl-1-propanol systems produced two polymorphs each, labeled 2a/2b and 3a/3b, respectively. The compounds were characterized by X-ray structure analysis on single-crystal. The crystal structures of all consisted of protonated amino alcohols with NH3+ moiety and quinaldinate anions with carboxylate moiety. The used amino alcohols contained one OH and one NH2 functional group, both prone to participate in hydrogen bonding. Therefore, similar connectivity patterns were expected. This proved to be true to some extent as all structures contained the NH3+∙∙∙−OOC heterosynthon. Nevertheless, different hydrogen bonding and π∙∙∙π stacking interactions were observed, leading to distinct connectivity motifs. The largest difference in hydrogen bonding occurred between polymorphs 3a and 3b, as they had only one heterosynton in common.
Semi-Quantitative MALDI Measurements of Blood-Based Samples for Molecular Diagnostics
Authors: Koc Matthew A. , Asmellash Senait , Norman Patrick , Rightmyer Steven , Roder Joanna , Georgantas Robert W. , Roder Heinrich
Published: February 2022

Accurate and precise measurement of the relative protein content of blood-based samples using mass spectrometry is challenging due to the large number of circulating proteins and the dynamic range of their abundances. Traditional spectral processing methods often struggle with accurately detecting overlapping peaks that are observed in these samples. In this work, we develop a novel spectral processing algorithm that effectively detects over 1650 peaks with over 3.5 orders of magnitude in intensity in the 3 to 30 kD m/z range. The algorithm utilizes a convolution of the peak shape to enhance peak detection, and accurate peak fitting to provide highly reproducible relative abundance estimates for both isolated peaks and overlapping peaks. We demonstrate a substantial increase in the reproducibility of the measurements of relative protein abundance when comparing this processing method to a traditional processing method for sample sets run on multiple matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) instruments. By utilizing protein set enrichment analysis, we find a sizable increase in the number of features associated with biological processes compared to previously reported results. The new processing method could be very beneficial when developing high-performance molecular diagnostic tests in disease indications.
Influence of Low Molecular Weight Salts on the Viscosity of Aqueous-Buffer Bovine Serum Albumin Solutions
Authors: Zdovc Blaž , Jaklin Matej , Hribar-Lee Barbara , Lukšič Miha
Published: February 2022

Pharmaceutical design of protein formulations aims at maximum efficiency (protein concentration) and minimum viscosity. Therefore, it is important to know the nature of protein-protein interactions and their influence on viscosity. In this work, we investigated the dependence of the viscosity of BSA in an aqueous 20 mM acetate buffer at pH = 4.3 on protein concentration and on temperature (5–45 °C). The viscosity of the solution increased with protein concentration and was 230% higher than the viscosity of the protein-free formulation at 160 mg/mL. The viscosity decreased by almost 60% in the temperature range from 5 to 45 °C. The agreement of the modified Arrhenius theory with experiment was quantitative, whereas a hard-sphere model provided only a qualitative description of the experimental results. We also investigated the viscosity of a 100 mg/mL BSA solution as a function of the concentration of added low molecular weight salts (LiCl, NaCl, KCl, RbCl, CsCl, NaBr, NaI) in the range of salt concentrations up to 1.75 mol/L. In addition, the particle size and zeta potential of BSA-salt mixtures were determined for solutions containing 0.5 mol/L salt. The trends with respect to the different anions followed a direct Hofmeister series (Cl− > Br− > I−), whereas for cations in the case of viscosity the indirect Hofmeister series was observed (Li+ > Na+ > K+ > Rb+ > Cs+), but the values of particle sizes and zeta potential did not show cation-specific effects. Since the protein is positively charged at pH = 4.3, anions are more attracted to the protein surface and shield its charge, while the interaction with cations is less pronounced. We hypothesize that salt surface charge shielding reduces protein colloidal stability and promotes protein aggregate formation.
Predictive Validity of Image-Based Motivation-to-Eat Visual Analogue Scales in Normal Weight Children and Adolescents Aged 9–14 Years
Authors: Hammond Leila , Morello Olivia , Kucab Michaela , Totosy de Zepetnek Julia O. , Lee Jennifer J. , Doheny Tarah , Bellissimo Nick
Published: February 2022

Paper-based motivation-to-eat visual analogue scales (VASs) developed for adults are widely used in the pediatric age range. The VAS is comprised of four domains: hunger, fullness, desire to eat, and prospective food consumption. The purpose of the present study was to determine agreement between the traditional paper-based VAS and a novel digital VAS (with and without images), as well as the novel digital VAS’s predictive validity for subsequent food intake (FI) in 9–14-year-old children and adolescents. Following an overnight fast and 3 h after consuming a standardized breakfast at home, children and adolescents (n = 17) completed three different VAS instruments (VASpaper, VASimages, VASno-images) in a randomized order at five time-points: 0 min (baseline), 5 min (immediately after consuming a 147 kcal yogurt treatment), 20 min, 35 min (immediately before an ad libitum lunch), and 65 min (immediately post ad libitum lunch). All three instruments were comparable, as shown by low bias and limits of agreement on Bland–Altman plots, moderate to excellent intraclass correlation coefficients for all domains at all time-points (ICC = 0.72–0.98), and no differences between the incremental area under the curve for any of the domains. All three instruments also showed good predictive validity for subsequent FI, with the strongest relationship observed immediately before the ad libitum lunch (p = 0.56–0.63). There was no significant association between subjective thirst and water intake, except with VASno-images at baseline (r = 0.49, p = 0.046). In conclusion, the present study suggests that a novel image-based digital VAS evaluating motivation-to-eat is interchangeable with the traditional paper-based VAS, and provides good predictive validity for next-meal FI in 9–14-year-old normal weight children and adolescents.
Relationship of Obesity with Lifestyle and Comorbidities in Public School Teachers—A Cross-Sectional Study
Authors: Tebar William R. , Gil Fernanda C. S. , Delfino Leandro D. , Souza Jefferson M. , Mota Jorge , Christofaro Diego G. D.
Published: February 2022

Obesity is one of the major public health burdens, and is a global pandemic that has been associated with lifestyle habits and comorbidities in the general population. Teachers comprise a wide category of workers with unestablished factors associated with obesity. This cross-sectional epidemiological study analyzed the association of obesity, defined by body mass index ≥ 30 kg/m², with work-related factors (years in the profession, hours worked weekly), lifestyle (sports practice, active commuting, TV viewing, smoking, alcohol consumption), and comorbidities (hypertension, diabetes, dyslipidemia) in a sample of 246 public school teachers. An elevated prevalence of obesity was observed in the sample (30.1%), which was associated with ≥2 h/day of TV viewing (OR: 2.10, p = 0.025) and hypertension (OR: 2.62, p = 0.010), whereas it was inversely associated with frequent active commuting by walking or cycling (OR: 0.22, p = 0.007), even after multiple adjustments. No association was observed between obesity and work-related factors. Actions focused on promoting active commuting while limiting TV time could be important strategies for facing the elevated prevalence of obesity in public school teachers. However, the analysis of longitudinal data and investigation of obesogenic determinants are still needed.
The Effects of Electron Beam Irradiation on the Morphological and Physicochemical Properties of Magnesium-Doped Hydroxyapatite/Chitosan Composite Coatings
Authors: Bita Bogdan , Stancu Elena , Stroe Daniela , Dumitrache Mirabela , Ciobanu Steluta Carmen , Iconaru Simona Liliana , Predoi Daniela , Groza Andreea
Published: February 2022

This work reports on the influence of 5 MeV electron beam radiations on the morphological features and chemical structure of magnesium-doped hydroxyapatite/chitosan composite coatings generated by the magnetron sputtering technique. The exposure to ionizing radiation in a linear electron accelerator dedicated to medical use has been performed in a controllable manner by delivering up to 50 Gy radiation dose in fractions of 2 Gy radiation dose per 40 s. After the irradiation with electron beams, the surface of layers became nano-size structured. The partial detachment of irradiated layers from the substrates has been revealed only after visualizing their cross sections by scanning electron microscopy. The energy dispersive X-ray spectral analysis of layer cross-sections indicated that the distribution of chemical elements in the samples depends on the radiation dose. The X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction analysis have shown that the physicochemical processes induced by the ionizing radiation in the magnesium doped hydroxyapatite/chitosan composite coatings do not alter the apatite structure, and Mg remains bonded with the phosphate groups.
Characterization of a Mass-Produced SiPM at Liquid Nitrogen Temperature for CsI Neutrino Coherent Detectors
Authors: Liu Fang , Fan Xiaoxue , Sun Xilei , Liu Bin , Li Junjie , Deng Yong , Jiang Huan , Jiang Tianze , Yan Peiguang
Published: February 2022

Silicon Photomultiplier (SiPM) is a sensor that can detect low-light signals lower than the single-photon level. In order to study the properties of neutrinos at a low detection threshold and low radioactivity experimental background, a low-temperature CsI neutrino coherent scattering detector is designed to be read by the SiPM sensor. Less thermal noise of SiPM and more light yield of CsI crystals can be obtained at the working temperature of liquid nitrogen. The breakdown voltage (Vbd) and dark count rate (DCR) of SiPM at liquid nitrogen temperature are two key parameters for coherent scattering detection. In this paper, a low-temperature test is conducted on the mass-produced ON Semiconductor J-Series SiPM. We design a cryogenic system for cooling SiPM at liquid nitrogen temperature and the changes of operating voltage and dark noise from room to liquid nitrogen temperature are measured in detail. The results show that SiPM works at the liquid nitrogen temperature, and the dark count rate drops by six orders of magnitude from room temperature (120 kHz/mm2) to liquid nitrogen temperature (0.1 Hz/mm2).
Electroencephalogram-Based Approaches for Driver Drowsiness Detection and Management: A Review
Authors: Li Gang , Chung Wan-Young
Published: February 2022

Drowsiness is not only a core challenge to safe driving in traditional driving conditions but also a serious obstacle for the wide acceptance of added services of self-driving cars (because drowsiness is, in fact, one of the most representative early-stage symptoms of self-driving carsickness). In view of the importance of detecting drivers’ drowsiness, this paper reviews the algorithms of electroencephalogram (EEG)-based drivers’ drowsiness detection (DDD). To facilitate the review, the EEG-based DDD approaches are organized into a tree structure taxonomy, having two main categories, namely “detection only (open-loop)” and “management (closed-loop)”, both aimed at designing better DDD systems that ensure early detection, reliability and practical utility. To achieve this goal, we addressed seven questions, the answers of which helped in developing an EEG-based DDD system that is superior to the existing ones. A basic assumption in this review article is that although driver drowsiness and carsickness-induced drowsiness are caused by different factors, the brain network that regulates drowsiness is the same.
Chemoresistive Sensor Readout Circuit Design for Detecting Gases with Slow Response Time Characteristics
Authors: Lee Dong-Yeon , Yu Joon-Boo , Byun Hyung-Gi , Kim Hyeon-June
Published: February 2022

Based on an analysis of the signal characteristics of gas sensors, this work presents a chemoresistive sensor readout circuit design for detecting gases with slow response time characteristics. The proposed readout circuit directly generates a reference voltage corresponding to the initial value of the gas sensor and extracts only the amount of gas concentration change in the sensor. Because the proposed readout circuit can adaptively regenerate the suitable reference voltage under various changing ambient conditions, it can alleviate the variation in output values at the same gas concentration caused by non-uniformities among gas sensors. Furthermore, this readout circuit effectively eliminates the initial value shifts due to the poor reproducibility of the gas sensor itself without requiring complex digital signal calibrations. This work focuses on a commercially viable readout circuit structure that can effectively obtain slow response gas information without requiring a large capacitor. The proposed readout circuit operation was verified by simulations using spectre in cadence simulation software. It was then implemented on a printed circuit board with discrete components to confirm the effectiveness with existing gas sensor systems and its commercial viability.
On SFBC Schemes for Enabling Virtual Array Concept in Monostatic ISAC Scenarios
Authors: Leyva Leonardo , Costa Samuel , Castanheira Daniel , Silva Adão , Gameiro Atílio
Published: February 2022

The integrated sensing and communication (ISAC) paradigm is being proposed for 6G as a new feature of the physical layer (PHY), for tackling dual-functional applications, i.e., demanding radio-sensing and communication functions, such as the Internet of Things (IoT) and autonomous driving systems. This work considers the integration of sensing and communications functionalities in a unique platform. To achieve this goal, the use of orthogonal space frequency block codes (SFBC) is proposed. SFBC code orthogonality enables both the separation of communications data streams at a user terminal and the estimation of target parameters. The SFBC enhances the communications link diversity without requiring channel state information knowledge at the transmitter and enable the virtual antenna array concept for enhancing the direction-finding resolution. The use of different SFBCs provides a tradeoff between achieved diversity and sensing resolution. For example, an Alamouti code, applicable for the case with two transmitting antennas, duplicates sensing resolution and achieves a diversity order of two while the use of a Tarokh code, applicable for a scenario with four transmitting antennas, provides a fourfold better resolution and diversity order of four. However, the code rate achieved with the Tarokh code is half of the one achieved with the Alamouti code. Furthermore, the unambiguous range is reduced since the bandwidth is divided to multiplex the different antenna signals. For its simplicity, good performance and reduced integration requirements, the method is promising for future ISAC systems.
Semi-Empirical Model of Remote-Sensing Reflectance for Chosen Areas of the Southern Baltic
Authors: Lednicka Barbara , Kubacka Maria
Published: February 2022

Coastal waters are the richest parts of ocean ecosystems characterised by dynamic changes in water biology, physical and chemical features. Establishing local relationships between water constituents and optical properties in these areas will help to develop successful ocean colour algorithms allowing a thorough understanding of complex coastal waters and improving water quality monitoring. In this paper, the authors present the use of optical and biogeochemical measurements in complex aquatic environments and aim to create a semi-empirical model of remote-sensing reflectance (Rrs(λi)) for four wavelengths (λi = 420 nm, 488 nm, 555 nm, and 620 nm) based on multiparameter algorithms of absorption (a(λi)) and backscattering (bb(λi)) coefficients. The bio-optical properties of water were determined based on empirical data gathered from aboard the r/v Oceania from April 2007 to March 2010 in chosen areas of the southern Baltic (Polish coast). The analyses reveal that Rrs(λi) in the studied area can be described with satisfactory accuracy using a five-parameter model. Positive results with a statistical error magnitude of Rrs(λi) of less than 50% were achieved for all four applied wavelengths. Bio-optical algorithms proposed by the authors enable evaluating biogeochemical characteristics of coastal areas in a broader context of ecosystem assessment and contribute significantly to the development of Earth and environmental sciences.
Learning a Metric for Multimodal Medical Image Registration without Supervision Based on Cycle Constraints
Authors: Siebert Hanna , Hansen Lasse , Heinrich Mattias P.
Published: February 2022

Deep learning based medical image registration remains very difficult and often fails to improve over its classical counterparts where comprehensive supervision is not available, in particular for large transformations—including rigid alignment. The use of unsupervised, metric-based registration networks has become popular, but so far no universally applicable similarity metric is available for multimodal medical registration, requiring a trade-off between local contrast-invariant edge features or more global statistical metrics. In this work, we aim to improve over the use of handcrafted metric-based losses. We propose to use synthetic three-way (triangular) cycles that for each pair of images comprise two multimodal transformations to be estimated and one known synthetic monomodal transform. Additionally, we present a robust method for estimating large rigid transformations that is differentiable in end-to-end learning. By minimising the cycle discrepancy and adapting the synthetic transformation to be close to the real geometric difference of the image pairs during training, we successfully tackle intra-patient abdominal CT-MRI registration and reach performance on par with state-of-the-art metric-supervision and classic methods. Cyclic constraints enable the learning of cross-modality features that excel at accurate anatomical alignment of abdominal CT and MRI scans.