bluuebunny/crossref_metadata_2025 huggingface dataset:
Quasi-Periodic Oscillations of Roll System in Corrugated Rolling Mill in Resonance
Authors: He Dongping , Xu Huidong , Wang Tao , Wang Zhihua
Published: December 2021

This paper investigates quasi-periodic oscillations of roll system in corrugated rolling mill in resonance. The two-degree of freedom vertical nonlinear mathematical model of roller system is established by considering the nonlinear damping and nonlinear stiffness within corrugated interface of corrugated rolling mill. In order to investigate the quasi-periodic oscillations at the resonance points, the Poincaré map is established by solving the power series solution of dynamic equations. Based on the Poincaré map, the existence and stability of quasi-periodic oscillations from the Neimark-Sacker bifurcation in the case of resonance are analyzed. The numerical simulation further verifies the correctness of the theoretical analysis.
Minimal Systems of Binomial Generators for the Ideals of Certain Monomial Curves
Authors: Branco Manuel B. , Colaço Isabel , Ojeda Ignacio
Published: December 2021

Let a,b and n>1 be three positive integers such that a and ∑j=0n−1bj are relatively prime. In this paper, we prove that the toric ideal I associated to the submonoid of N generated by {∑j=0n−1bj}∪{∑j=0n−1bj+a∑j=0i−2bj∣i=2,…,n} is determinantal. Moreover, we prove that for n>3, the ideal I has a unique minimal system of generators if and only if a<b−1.
Factors Associated with ICU Admission in Patients with COVID-19: The GOL2DS Score
Authors: Candelli Marcello , Pignataro Giulia , Ferrigno Miriana , Cicchinelli Sara , Torelli Enrico , Gullì Antonio , Sacco Fernandez Marta , Piccioni Andrea , Ojetti Veronica , Covino Marcello , Gasbarrini Antonio , Antonelli Massimo , Franceschi Francesco
Published: December 2021

Background and Objectives: The COVID-19 pandemic has been shaking lives around the world for nearly two years. The discovery of highly effective vaccines has not been able to stop the transmission of the virus. SARS-CoV-2 shows completely different clinical manifestations. A large percentage (about 40%) of admitted patients require treatment in an intensive care unit (ICU). This study investigates the factors associated with admission of COVID-19 patients to the ICU and whether it is possible to obtain a score that can help the emergency physician to select the hospital ward. Materials and Methods: We retrospectively recorded 313 consecutive patients who were presented to the emergency department (ED) of our hospital and had a diagnosis of COVID-19 confirmed by polymerase chain reaction (PCR) on an oropharyngeal swab. We used multiple logistic regression to evaluate demographic, clinical, and laboratory data statistically associated with ICU admission. These variables were used to create a prognostic score for ICU admission. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver-operating characteristic curve (ROC) of the score for predicting ICU admission during hospitalization were calculated. Results: Of the variables evaluated, only blood type A (p = 0.003), PaO2/FiO2 (p = 0.002), LDH (p = 0.004), lactate (p = 0.03), dyspnea (p = 0.03) and SpO2 (p = 0.0228) were significantly associated with ICU admission after adjusting for sex, age and comorbidity using multiple logistic regression analysis. We used these variables to create a prognostic score called GOL2DS (group A, PaO2/FiO2, LDH, lactate and dyspnea, and SpO2), which had high accuracy in predicting ICU admission (AUROC 0.830 [95% CI, 0.791–0.892). Conclusions: In our single-center experience, the GOL2DS score could be useful in identifying patients at high risk for ICU admission.
Reverse Osmosis Treatment of Wastewater for Reuse as Process Water—A Case Study
Authors: Simonič Marjana
Published: December 2021

The aim of this work was to purify mixed wastewater from three different production processes in such a manner that they could be reused as process water. The maximum allowed concentrations (MAC) from the Environmental Standards for emissions of substances released into surface water were set as target concentrations. Wastewaters contained solid particles, sodium, aluminium, chloride, and nitrogen in high amounts. Quantitatively, most wastewaters were generated in the production line of alumina washing. The second type of wastewater was generated from the production line of boehmite. The third type of wastewater was from regeneration of ion exchangers, which are applied for feed boiler water treatment. The initial treatment step of wastewater mixture was neutralisation, using 35% HCl. The precoat filtration followed, and the level of suspended solids was reduced from 320 mg/L to only 9 mg/L. The concentrations of ions, such as aluminium, sodium and chlorides remained above the MAC. Therefore, laboratory reverse osmosis was applied to remove the listed pollutants from the water. We succeeded in removal of all the pollutants. The concentration of aluminium decreased below 3 mg/L, the sodium to 145 mg/L and chlorides to 193 mg/L. The concentration of nitrate nitrogen decreased below 20 mg/L.
Capillary-like Formations of Endothelial Cells in Defined Patterns Generated by Laser Bioprinting
Authors: Koch Lothar , Deiwick Andrea , Chichkov Boris
Published: December 2021

Bioprinting is seen as a promising technique for tissue engineering, with hopes of one day being able to produce whole organs. However, thick tissue requires a functional vascular network, which naturally contains vessels of various sizes, down to capillaries of ~10 µm in diameter, often spaced less than 200 µm apart. If such thick tissues are to be printed, the vasculature would likely need to be printed at the same time, including the capillaries. While there are many approaches in tissue engineering to produce larger vessels in a defined manner, the small capillaries usually arise only in random patterns by sprouting from the larger vessels or from randomly distributed endothelial cells. Here, we investigated whether the small capillaries could also be printed in predefined patterns. For this purpose, we used a laser-based bioprinting technique that allows for the combination of high resolution and high cell density. Our aim was to achieve the formation of closed tubular structures with lumina by laser-printed endothelial cells along the printed patterns on a surface and in bioprinted tissue. This study shows that such capillaries are directly printable; however, persistence of the printed tubular structures was achieved only in tissue with external stimulation by other cell types.
Analysis of the Influence of Ferromagnetic Material on the Output Characteristics of Halbach Array Energy-Harvesting Structure
Authors: Zhang Xiangyong , Liu Haipeng , He Yunli , Peng Tingrui , Su Bin , Guan Huiyuan
Published: December 2021

Due to the particular arrangement of permanent magnets, a Halbach array has an significant effect of magnetism and magnetic self-shielding. It can stretch the magnetic lines on one side of the magnetic field to obtain an ideal sinusoidal unilateral magnetic field. It has a wide application range in the field of energy harvesting. In practical applications, magnetic induction intensity of each point in magnetic field is not only related to the induced current and conductor but also related to the permeability of the medium (also known as a magnetic medium) in the magnetic field. Permeability is the physical quantity that represents the magnetism of the magnetic medium, which indicates the resistance of magnetic flux or the ability of magnetic lines to be connected in the magnetic field after coil flows through current in space or in the core space. When the permeability is much greater than one, it is a ferromagnetic material. Adding a ferromagnetic material in a magnetic field can increase the magnetic induction intensity B. Iron sheet is a good magnetic material, and it is easy to magnetize to generate an additional magnetic field to strengthen the original magnetic field, and it is easy to obtain at low cost. In this paper, in order to explore the influence of ferromagnetic material on the magnetic field and energy harvesting efficiency of the Halbach array energy harvesting structure, iron sheets are installed on the periphery of the Halbach array rotor. Iron sheet has excellent magnetic permeability. Through simulation, angle between iron sheet and Halbach array, radian size of iron sheet itself and distance between iron sheet and Halbach array can all have different effects on the magnetic field of the Halbach array. It shows that adding iron sheets as a magnetic medium could indeed change the magnetic field distribution of the Halbach array and increase energy harvesting efficiency. In this paper, a Halbach array can be used to provide electrical power for passive wireless low-power devices.
Deformation Analysis of the Glass Preform in the Progress of Precision Glass Molding for Fabricating Chalcogenide Glass Diffractive Optics with the Finite Element Method
Authors: Liu Yue , Xing Yintian , Fu Hang , Li Chuang , Yang Chao , Cao Bo , Xue Changxi
Published: December 2021

Precision glass molding (PGM) technology is a cost-efficient process for the production of micro/nanostructured glass components with complex surface geometries. The stress distribution, surface profile, and reduced refractive index of the molded lens are based on the lens being fully formed. The process of the deformation of the glass preform is rarely discussed, especially in the case of multi-machining parameters in the experiment. The finite element method (FEM) was adopted to analyze the glass preform deformation. Due to the phenomenon of incomplete deformation of the glass preforms in the experiments, two groups of finite element simulations with different boundary conditions were carried out with MSC.Marc software, to reveal the relationship between the deformation progress and the parameters settings. Based on the simulation results, a glass preform deformation model was established. The error between the model result and the simulation result was less than 0.16. The establishment method of the glass preform deformation model and the established model can be used as a reference in efficiently optimizing PGM processing parameters when the designed lens has two different base radii of curvature.
Enhancing the Shock Response Performance of Micromachined Silicon Resonant Accelerometers by Electrostatic Active Damping Control
Authors: Huang Libin , Jiang Kai , Wang Peng , Zhang Meimei , Ding Xukai , Li Hongsheng
Published: December 2021

This paper presents a micromachined silicon resonant accelerometer based on electrostatic active damping control, which can improve the shock response performance of the accelerometer. In the accelerometer, an electrostatic active damping structure and damping control circuit are designed to improve the equivalent damping coefficient of the system. System-level Simulink modeling and simulation of the accelerometer with an electrostatic active damping closed-loop control link were carried out. The simulation results indicate that the system can quickly return to normal output without an obvious vibration process after the shock. The fabricated and packaged accelerometer was connected to an external test circuit for shock performance testing. The stabilization time of the accelerometer after a 100 g, 3–5 ms half-sine shock was reduced from 19.8 to 5.6 s through use of the damping control. Furthermore, the change in deviation before and after the shock without damping control was 0.8197 mg, whereas it was 0.1715 mg with damping control. The experimental results demonstrate that the electrostatic active damping control can effectively improve the dynamic performance of the micromachined silicon resonant accelerometer.
Ultra Narrow Dual-Band Perfect Absorber Based on a Dielectric−Dielectric−Metal Three-Layer Film Material
Authors: Liu Bin , Wu Pinghui , Zhu Hongyang , Lv Li
Published: December 2021

This paper proposes a perfect metamaterial absorber based on a dielectric−dielectric−metal structure, which realizes ultra-narrowband dual-band absorption in the near-infrared band. The maximum Q factor is 484. The physical mechanism that causes resonance is hybrid coupling between magnetic polaritons resonance and plasmon resonance. At the same time, the research results show that the intensity of magnetic polaritons resonance is much greater than the intensity of the plasmon resonance. By changing the structural parameters and the incident angle of the light source, it is proven that the absorber is tunable, and the working angle tolerance is 15°. In addition, the sensitivity and figure of merit when used as a refractive index sensor are also analyzed. This design provides a new idea for the design of high-Q optical devices, which can be applied to photon detection, spectral sensing, and other high-Q multispectral fields.
Preparation, Characterization, and Acetylcholinesterase Inhibitory Ability of the Inclusion Complex of β-Cyclodextrin–Cedar (Juniperus phoenicea) Essential Oil
Authors: Kavetsou Eleni , Pitterou Ioanna , Katopodi Annita , Petridou Georgia , Adjali Abdelaziz , Grigorakis Spyros , Detsi Anastasia
Published: December 2021

The aim of the present study was the encapsulation of cedar (Juniperus phoenicea) essential oil (CEO) of Greek origin in β-cyclodextrin (β-CD) through the formation of inclusion complexes (ICs) using the co-precipitation method with different β-CD-to-CEO weight ratios (90:10, 85:15, 80:20, 70:30 (w/w)). The encapsulation of CEO in β-CD through host–guest interactions was confirmed by Nuclear Magnetic Resonance (NMR) spectroscopy, FT-IR spectroscopy, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The obtained ICs exhibited nanoscale size (315.9 nm to 769.6 nm),Polydispersity Index from 0.326 to 0.604 and satisfactory stability in suspension (−37.0 mV to −17.0 mV). The process yield was satisfactory, ranging between 65% and 78%, while the inclusion efficiency ranged from 10% to 27%. The in vitro release study conducted for the IC with the optimal characteristics (β-CD:CEO 80:20 (w/w)) exhibited a sustained release profile, with an initial burst effect in the first 5 h. The release profile could be well expressed by the Higuchi equation: Q = 18.893 t1/2 + 9.5919, R2 = 0.8491. The cedar EO presented significant acetylcholinesterase inhibition (IC50 37 μg/mL), which was prolonged by its encapsulation into the β-CD cavity.
HIV-1 Tat and Heparan Sulfate Proteoglycans Orchestrate the Setup of in Cis and in Trans Cell-Surface Interactions Functional to Lymphocyte Trans-Endothelial Migration
Authors: Urbinati Chiara , Milanesi Maria , Lauro Nicola , Bertelli Cinzia , David Guido , D’Ursi Pasqualina , Rusnati Marco , Chiodelli Paola
Published: December 2021

HIV-1 transactivating factor Tat is released by infected cells. Extracellular Tat homodimerizes and engages several receptors, including integrins, vascular endothelial growth factor receptor 2 (VEGFR2) and heparan sulfate proteoglycan (HSPG) syndecan-1 expressed on various cells. By means of experimental cell models recapitulating the processes of lymphocyte trans-endothelial migration, here, we demonstrate that upon association with syndecan-1 expressed on lymphocytes, Tat triggers simultaneously the in cis activation of lymphocytes themselves and the in trans activation of endothelial cells (ECs). This “two-way” activation eventually induces lymphocyte adhesion and spreading onto the substrate and vascular endothelial (VE)-cadherin reorganization at the EC junctions, with consequent endothelial permeabilization, leading to an increased extravasation of Tat-presenting lymphocytes. By means of a panel of biochemical activation assays and specific synthetic inhibitors, we demonstrate that during the above-mentioned processes, syndecan-1, integrins, FAK, src and ERK1/2 engagement and activation are needed in the lymphocytes, while VEGFR2, integrin, src and ERK1/2 are needed in the endothelium. In conclusion, the Tat/syndecan-1 complex plays a central role in orchestrating the setup of the various in cis and in trans multimeric complexes at the EC/lymphocyte interface. Thus, by means of computational molecular modelling, docking and dynamics, we also provide a characterization at an atomic level of the binding modes of the Tat/heparin interaction, with heparin herein used as a structural analogue of the heparan sulfate chains of syndecan-1.
Quality Evaluation of Taxilli Herba from Different Hosts Based on Simultaneous Determination of Multiple Bioactive Constituents Combined with Multivariate Statistical Analysis
Authors: Wu Nan , Li Li , Cai Zhi-Chen , Yuan Jia-Huan , Wang Wen-Xin , Yin Sheng-Xin , Liu Sheng-Jin , Wei Li-Fang , Mei Yu-Qi , Chen Cui-Hua , Liu Xun-Hong , Zou Li-Si , Li Jie
Published: December 2021

Taxilli Herba (TAXH) is an important traditional Chinese medicine with a long history, dating from the Eastern Han Dynasty to the present times. However, the active constituents in it that parasitize different hosts vary, affecting its clinical efficacy. Given the complexity of the host origins, evaluating the quality of TAXH is critical to ensure the safety and effectiveness of clinical medication. In the present study, a quantitative method based on ultra-fast liquid chromatography tandem triple quadrupole mass spectrometry (UFLC-QTRAP-MS/MS) was established, which simultaneously determined the content of 33 active constituents, including 12 flavonoids, 4 organic acids, 12 amino acids, and 5 nucleosides in 45 samples. Orthogonal partial least squares discriminant analysis (OPLS-DA) was employed to classify and distinguish between TAXH and its adulterants, Tolypanthi Herba (TOLH). A hierarchical clustering analysis (HCA) was conducted combined with a heatmap to visually observe the distribution regularity of 33 constituents in each sample. Furthermore, gray relational analysis (GRA) was applied to evaluate the quality of samples to get the optimal host. The results demonstrated that TAXH excelled TOLH in quality as a whole. The quality of TAXH parasitizing Morus alba was also better, while those that were parasitic on Cinnamomum camphora and Glyptostrobus pensilis had relatively poor quality. This study may provide comprehensive information that is necessary for quality control and supply a scientific basis for further exploring the quality formation mechanism of TAXH.
Discovery of Novel Cyclic Ethers with Synergistic Antiplasmodial Activity in Combination with Valinomycin
Authors: Watson Daniel J. , Meyers Paul R. , Acquah Kojo Sekyi , Dziwornu Godwin A. , Barnett Christopher Bevan , Wiesner Lubbe
Published: December 2021

With drug resistance threatening our first line antimalarial treatments, novel chemotherapeutics need to be developed. Ionophores have garnered interest as novel antimalarials due to their theorized ability to target unique systems found in the Plasmodium-infected erythrocyte. In this study, during the bioassay-guided fractionation of the crude extract of Streptomyces strain PR3, a group of cyclodepsipeptides, including valinomycin, and a novel class of cyclic ethers were identified and elucidated. Further study revealed that the ethers were cyclic polypropylene glycol (cPPG) oligomers that had leached into the bacterial culture from an extraction resin. Molecular dynamics analysis suggests that these ethers are able to bind cations such as K+, NH4+ and Na+. Combination studies using the fixed ratio isobologram method revealed that the cPPGs synergistically improved the antiplasmodial activity of valinomycin and reduced its cytotoxicity in vitro. The IC50 of valinomycin against P. falciparum NF54 improved by 4–5-fold when valinomycin was combined with the cPPGs. Precisely, it was improved from 3.75 ± 0.77 ng/mL to 0.90 ± 0.2 ng/mL and 0.75 ± 0.08 ng/mL when dosed in the fixed ratios of 3:2 and 2:3 of valinomycin to cPPGs, respectively. Each fixed ratio combination displayed cytotoxicity (IC50) against the Chinese Hamster Ovary cell line of 57–65 µg/mL, which was lower than that of valinomycin (12.4 µg/mL). These results indicate that combinations with these novel ethers may be useful in repurposing valinomycin into a suitable and effective antimalarial.
Hepatoprotective Effects of Bioflavonoid Luteolin Using Self-Nanoemulsifying Drug Delivery System
Authors: Shakeel Faiyaz , Alamer Moad M. , Alam Prawez , Alshetaili Abdullah , Haq Nazrul , Alanazi Fars K. , Alshehri Sultan , Ghoneim Mohammed M. , Alsarra Ibrahim A.
Published: December 2021

Luteolin (LUT) is a natural pharmaceutical compound that is weakly water soluble and has low bioavailability when taken orally. As a result, the goal of this research was to create self-nanoemulsifying drug delivery systems (SNEDDS) for LUT in an attempt to improve its in vitro dissolution and hepatoprotective effects, resulting in increased oral bioavailability. Using the aqueous phase titration approach and the creation of pseudo-ternary phase diagrams with Capryol-PGMC (oil phase), Tween-80 (surfactant), and Transcutol-HP (co-emulsifier), various SNEDDS of LUT were generated. SNEDDS were assessed for droplet size, polydispersity index (PDI), zeta potential (ZP), refractive index (RI), and percent of transmittance (percent T) after undergoing several thermodynamic stability and self-nanoemulsification experiments. When compared to LUT suspension, the developed SNEDDS revealed considerable LUT release from all SNEDDS. Droplet size was 40 nm, PDI was <0.3, ZP was −30.58 mV, RI was 1.40, percent T was >98 percent, and drug release profile was >96 percent in optimized SNEDDS of LUT. For in vivo hepatoprotective testing in rats, optimized SNEDDS was chosen. When compared to LUT suspension, hepatoprotective tests showed that optimized LUT SNEDDS had a substantial hepatoprotective impact. The findings of this investigation suggested that SNEDDS could improve bioflavonoid LUT dissolution rate and therapeutic efficacy.
Synthesis of sp2-Iminosugar Selenoglycolipids as Multitarget Drug Candidates with Antiproliferative, Leishmanicidal and Anti-Inflammatory Properties
Authors: Sánchez-Fernández Elena M. , García-Hernández Raquel , Gamarro Francisco , Arroba Ana I. , Aguilar-Diosdado Manuel , Padrón José M. , García Fernández José M. , Ortiz Mellet Carmen
Published: December 2021

sp2-Iminosugar glycolipids (sp2-IGLs) represent a consolidated family of glycoconjugate mimetics encompassing a monosaccharide-like glycone moiety with a pseudoamide-type nitrogen replacing the endocyclic oxygen atom of carbohydrates and an axially-oriented lipid chain anchored at the pseudoanomeric position. The combination of these structural features makes them promising candidates for the treatment of a variety of conditions, spanning from cancer and inflammatory disorders to parasite infections. The exacerbated anomeric effect associated to the putative sp2-hybridized N-atom imparts chemical and enzymatic stability to sp2-IGLs and warrants total α-anomeric stereoselectivity in the key glycoconjugation step. A variety of O-, N-, C- and S-pseudoglycosides, differing in glycone configurational patterns and lipid nature, have been previously prepared and evaluated. Here we expand the chemical space of sp2-IGLs by reporting the synthesis of α-d-gluco-configured analogs with a bicyclic (5N,6O-oxomethylidene)nojirimycin (ONJ) core incorporating selenium at the glycosidic position. Structure–activity relationship studies in three different scenarios, namely cancer, Leishmaniasis and inflammation, convey that the therapeutic potential of the sp2-IGLs is highly dependent, not only on the length of the lipid chain (linear aliphatic C12 vs. C8), but also on the nature of the glycosidic atom (nitrogen vs. sulfur vs. selenium). The ensemble of results highlights the α-dodecylseleno-ONJ-glycoside as a promising multitarget drug candidate.
Quantification of Caffeine and Chlorogenic Acid in Green and Roasted Coffee Samples Using HPLC-DAD and Evaluation of the Effect of Degree of Roasting on Their Levels
Authors: Awwad Shady , Issa Reem , Alnsour Lilian , Albals Dima , Al-Momani Idrees
Published: December 2021

Chlorogenic acid and caffeine are among the important components in coffee beans, determining the taste and aroma. In addition, phenols and antioxidants content possess vital health values. The main aim of this study is to determine the levels of caffeine and chlorogenic acid in several coffee samples of different origins and degrees of roasting. The coffee samples were extracted using hot water. The levels of caffeine and chlorogenic acid were quantified using high-performance liquid chromatography (HPLC) equipped with a diode array detector, a reverse phase system, and an ODS column (C18). Total phenol and antioxidant contents were previously determined for the same samples. The results showed that the highest content of caffeine was found in the medium roasted coffee (203.63 mg/L), and the highest content of chlorogenic acid content was found in the green coffee (543.23 mg/L). The results demonstrated a negative correlation between the chlorogenic acid levels with the degree of roasting, while it showed a positive correlation between the caffeine levels with the degree of roasting till a certain point where the levels dropped in the dark roasted coffee. The origin of coffee samples did not show any effect on any of the measured variables. Antioxidant effects of coffee samples were largely determined by chlorogenic acid content.
Silica Hydride: A Separation Material Every Analyst Should Know About
Authors: Pesek Joseph J. , Matyska Maria T.
Published: December 2021

This review describes the development, special features and applications of silica hydride-based stationary phases for HPLC. The unique surface of this material is in contrast to ordinary, standard silica, which is the material most frequently used in modern HPLC stationary phases. The standard silica surface contains mainly silanol (Si-OH) groups, while the silica hydride surface is instead composed of silicon-hydrogen groups, which is much more stable, less reactive and delivers different chromatographic and chemical characteristics. Other aspects of this material are described for each of the different bonded moieties available commercially. Some applications for each of these column types are also presented as well as a generic model for method development on silica hydride-based stationary phases.
Comparison of Different Extraction Solvents for Characterization of Antioxidant Potential and Polyphenolic Composition in Boletus edulis and Cantharellus cibarius Mushrooms from Romania
Authors: Fogarasi Melinda , Socaciu Maria-Ioana , Sălăgean Claudiu-Dan , Ranga Floricuța , Fărcaș Anca Corina , Socaci Sonia Ancuța , Socaciu Carmen , Țibulcă Dorin , Fogarasi Szabolcs , Semeniuc Cristina Anamaria
Published: December 2021

Edible mushrooms are well-known for their nutritional benefits and low energy density. In addition, mushroom extracts contain various bioactive compounds that account for their antioxidant activity; the applied extraction conditions influence the extraction efficiency of such compounds. Therefore, this study investigates the effects of four extractants on the content of polyphenols and antioxidant properties of Boletus edulis and Cantharellus cibarius mushrooms, aiming to optimize the extraction process. Powders of B. edulis and C. cibarius mushrooms were subjected to extraction with acidic water (10% CH3COOH), ethanol/water/acetic acid (15:76.5:8.5, v/v/v), hexane, and diethyl ether to measure their total phenolic content (TPC), total flavonoid content (TFC), and Trolox equivalent antioxidant capacity (TEAC). Furthermore, the level of individual polyphenolic compounds in these extracts was quantified using an HPLC-DAD-ESI-MS method. Results showed that the type of solvent significantly influenced the TPC and TEAC of mushroom powder but insignificantly influenced the TFC. A very strong positive correlation was found between TPC and TEAC, but no correlation was found between TFC and TEAC or TPC and TFC. Acidic water extracted the highest amount of polyphenolic compounds from these mushroom powders. Therefore, the aqueous extract showed the highest TPC and strongest antioxidant activity. Thus, acidic water is recommended for polyphenol analysis in B. edulis and C. cibarius mushrooms.
Sediment Assessment of the Pchelina Reservoir, Bulgaria
Authors: Venelinov Tony , Mihaylova Veronika , Peycheva Rositsa , Todorov Miroslav , Yotova Galina , Todorov Boyan , Lyubomirova Valentina , Tsakovski Stefan
Published: December 2021

The temporal dynamics of anthropogenic impacts on the Pchelina Reservoir is assessed based on chemical element analysis of three sediment cores at a depth of about 100–130 cm below the surface water. The 137Cs activity is measured to identify the layers corresponding to the 1986 Chernobyl accident. The obtained dating of sediment cores gives an average sedimentation rate of 0.44 cm/year in the Pchelina Reservoir. The elements’ depth profiles (Ti, Mn, Fe, Zn, Cr, Ni, Cu, Mo, Sn, Sb, Pb, Co, Cd, Ce, Tl, Bi, Gd, La, Th and Unat) outline the Struma River as the main anthropogenic source for Pchelina Reservoir sediments. The principal component analysis reveals two groups of chemical elements connected with the anthropogenic impacts. The first group of chemical elements (Mn, Fe, Cr, Ni, Cu, Mo, Sn, Sb and Co) has increasing time trends in the Struma sediment core and no trend or decreasing ones at the Pchelina sampling core. The behavior of these elements is determined by the change of the profile of the industry in the Pernik town during the 1990s. The second group of elements (Zn, Pb, Cd, Bi and Unat) has increasing time trends in Struma and Pchelina sediment cores. The increased concentrations of these elements during the whole investigated period have led to moderate enrichments for Pb and Unat, and significant enrichments for Zn and Cd at the Pchelina sampling site. The moderately contaminated, according to the geoaccumulation indexes, Pchelina Reservoir surface sediment samples have low ecotoxicity.
Artemisinin and Derivatives-Based Hybrid Compounds: Promising Therapeutics for the Treatment of Cancer and Malaria
Authors: Peter Sijongesonke , Jama Siphesihle , Alven Sibusiso , Aderibigbe Blessing A.
Published: December 2021

Cancer and malaria are major health conditions around the world despite many strategies and therapeutics available for their treatment. The most used strategy for the treatment of these diseases is the administration of therapeutic drugs, which suffer from several shortcomings. Some of the pharmacological limitations associated with these drugs are multi-drug resistance, drug toxicity, poor biocompatibility and bioavailability, and poor water solubility. The currently ongoing preclinical studies have demonstrated that combination therapy is a potent approach that can overcome some of the aforementioned limitations. Artemisinin and its derivatives have been reported to exhibit potent efficacy as anticancer and antimalarial agents. This review reports hybrid compounds containing artemisinin scaffolds and their derivatives with promising therapeutic effects for the treatment of cancer and malaria.
Mapping the Chemistry of Hair Strands by Mass Spectrometry Imaging—A Review
Authors: Philipsen Mai H. , Haxen Emma R. , Manaprasertsak Auraya , Malmberg Per , Hammarlund Emma U.
Published: December 2021

Hair can record chemical information reflecting our living conditions, and, therefore, strands of hair have become a potent analytical target within the biological and forensic sciences. While early efforts focused on analyzing complete hair strands in bulk, high spatial resolution mass spectrometry imaging (MSI) has recently come to the forefront of chemical hair-strand analysis. MSI techniques offer a localized analysis, requiring fewer de-contamination procedures per default and making it possible to map the distribution of analytes on and within individual hair strands. Applying the techniques to hair samples has proven particularly useful in investigations quantifying the exposure to, and uptake of, toxins or drugs. Overall, MSI, combined with optimized sample preparation protocols, has improved precision and accuracy for identifying several elemental and molecular species in single strands of hair. Here, we review different sample preparation protocols and use cases with a view to make the methodology more accessible to researchers outside of the field of forensic science. We conclude that—although some challenges remain, including contamination issues and matrix effects—MSI offers unique opportunities for obtaining highly resolved spatial information of several compounds simultaneously across hair surfaces.
Recent Advances in the Oxone-Mediated Synthesis of Heterocyclic Compounds
Authors: Goulart Helen A. , Araujo Daniela R. , Penteado Filipe , Jacob Raquel G. , Perin Gelson , Lenardão Eder J.
Published: December 2021

Oxone is a commercially available oxidant, composed of a mixture of three inorganic species, being the potassium peroxymonosulfate (KHSO5) the reactive one. Over the past few decades, this cheap and environmentally friendly oxidant has become a powerful tool in organic synthesis, being extensively employed to mediate the construction of a plethora of important compounds. This review summarizes the recent advances in the Oxone-mediated synthesis of N-, O- and chalcogen-containing heterocyclic compounds, through a wide diversity of reactions, starting from several kinds of substrate, highlighting the main synthetic differences, advantages, the scope and limitations.
Genome Mining of Pseudomonas Species: Diversity and Evolution of Metabolic and Biosynthetic Potential
Authors: Alam Khorshed , Islam Md. Mahmudul , Li Caiyun , Sultana Sharmin , Zhong Lin , Shen Qiyao , Yu Guangle , Hao Jinfang , Zhang Youming , Li Ruijuan , Li Aiying
Published: December 2021

Microbial genome sequencing has uncovered a myriad of natural products (NPs) that have yet to be explored. Bacteria in the genus Pseudomonas serve as pathogens, plant growth promoters, and therapeutically, industrially, and environmentally important microorganisms. Though most species of Pseudomonas have a large number of NP biosynthetic gene clusters (BGCs) in their genomes, it is difficult to link many of these BGCs with products under current laboratory conditions. In order to gain new insights into the diversity, distribution, and evolution of these BGCs in Pseudomonas for the discovery of unexplored NPs, we applied several bioinformatic programming approaches to characterize BGCs from Pseudomonas reference genome sequences available in public databases along with phylogenetic and genomic comparison. Our research revealed that most BGCs in the genomes of Pseudomonas species have a high diversity for NPs at the species and subspecies levels and built the correlation of species with BGC taxonomic ranges. These data will pave the way for the algorithmic detection of species- and subspecies-specific pathways for NP development.
Protective Role of Quercetin in Carbon Tetrachloride Induced Toxicity in Rat Brain: Biochemical, Spectrophotometric Assays and Computational Approach
Authors: Zargar Seema , Wani Tanveer
Published: December 2021

Carbon tetrachloride (CCL4) induces oxidative stress by free radical toxicities, inflammation, and neurotoxicity. Quercetin (Q), on the other hand, has a role as anti-inflammatory, antioxidant, antibacterial, and free radical-scavenging. This study explored protection given by quercetin against CCL4 induced neurotoxicity in rats at given concentrations. Male Wistar rats were divided into four groups Group C: control group; Group CCL4: given a single oral dose of 1 mL/kg bw CCL4; Group Q: given a single i.p injection of 100 mg/kg bw quercetin; and Group Q + CCL4: given a single i.p injection of 100 mg/kg bw quercetin before two hours of a single oral dose of 1 mL/kg bw CCL4. The results from brain-to-body weight ratio, morphology, lipid peroxidation, brain urea, ascorbic acid, reduced glutathione, sodium, and enzyme alterations (aspartate aminotransferase (AST), alanine aminotransferase (ALT), catalase, and superoxide dismutase) suggested alterations by CCL4 and a significant reversal of these parameters by quercetin. In silico analysis of quercetin with various proteins was conducted to understand the molecular mechanism of its protection. The results identified by BzScore4 D showed moderate binding between quercetin and the following receptors: glucocorticoids, estrogen beta, and androgens and weak binding between quercetin and the following proteins: estrogen alpha, Peroxisome proliferator-activated receptors (PPARγ), Herg k+ channel, Liver x, mineralocorticoid, progesterone, Thyroid α, and Thyroid β. Three-dimensional/four-dimensional visualization of binding modes of quercetin with glucocorticoids, estrogen beta, and androgen receptors was performed. Based on the results, a possible mechanism is hypothesized for quercetin protection against CCL4 toxicity in the rat brain.
Retrieval of High Added Value Natural Bioactive Coumarins from Mandarin Juice-Making Industrial Byproduct
Authors: Myrtsi Eleni D. , Angelis Apostolis , Koulocheri Sofia D. , Mitakou Sofia , Haroutounian Serkos A.
Published: December 2021

Cold pressed essential oil (CPEO) of mandarin (Citrus reticulata Blanco), a by-product of the juice-making industrial process known to contain large amounts of polymethoxyflavones, was exploited for its content in high added value natural coumarins. The study herein afforded a method referring to the evaporation of CPEO volatile fraction under mild conditions (reduced pressure and temperature below 35 °C) as azeotrope with isopropanol. This allowed the isolation of high added value coumarins from the non-volatile fragment using preparative High Performance Liquid Chromatography (HPLC). Pilot-scale application of this procedure afforded for each kg of CPEO processed the following natural bioactive coumarins in chemically pure forms: heraclenol (38–55 mg), 8-gerayloxypsoralen (35–51 mg), auraptene (22–33 mg), and bergamottin (14–19 mg). The structures of coumarins were verified by Nuclear Magnetic Resonance (NMR) spectroscopy and HPLC co-injection with authentic standards. Thus, the low market value mandarin CPEO with current value of 17 to 22 EUR/kg can be valorized through the production of four highly bioactive natural compounds worth 3479 to 5057 EUR/kg, indicating the great potentials of this methodology in the terms of the circular economy.
Total Synthesis of Decahydroquinoline Poison Frog Alkaloids ent-cis-195A and cis-211A
Authors: Okada Takuya , Wu Naizhen , Takashima Katsuki , Ishimura Jungoh , Morita Hiroyuki , Ito Takuya , Kodama Takeshi , Yamasaki Yuhei , Akanuma Shin-ichi , Kubo Yoshiyuki , Hosoya Ken-ichi , Tsuneki Hiroshi , Wada Tsutomu , Sasaoka Toshiyasu , Shimizu Takahiro , Sakai Hideki , Dwoskin Linda P. , Hussaini Syed R. , Saporito Ralph A. , Toyooka Naoki
Published: December 2021

The total synthesis of two decahydroquinoline poison frog alkaloids ent-cis-195A and cis-211A were achieved in 16 steps (38% overall yield) and 19 steps (31% overall yield), respectively, starting from known compound 1. Both alkaloids were synthesized from the common key intermediate 11 in a divergent fashion, and the absolute stereochemistry of natural cis-211A was determined to be 2R, 4aR, 5R, 6S, and 8aS. Interestingly, the absolute configuration of the parent decahydroquinoline nuclei of cis-211A was the mirror image of that of cis-195A, although both alkaloids were isolated from the same poison frog species, Oophaga (Dendrobates) pumilio, from Panama.
Caralluma tuberculata N.E.Br Manifests Extraction Medium Reliant Disparity in Phytochemical and Pharmacological Analysis
Authors: Baig Muhammad Waleed , Ahmed Madiha , Akhtar Nosheen , Okla Mohammad K. , Nasir Bakht , Haq Ihsan-Ul , Al-Ghamdi Jihan , Al-Qahtani Wahidah H. , AbdElgawad Hamada
Published: December 2021

Solubility of phytoconstituents depends on the polarity of the extraction medium used, which might result in the different pharmacological responses of extracts. In line with this, ethnomedicinally important food plant (i.e., Caralluma tuberculata extracts) have been made in fourteen distinct solvent systems that were then analyzed phytochemically via total phenolic amount estimation, total flavonoid amount estimation, and HPLC detection and quantification of the selected polyphenols. Test extracts were then subjected to a battery of in vitro assays i.e., antioxidants (DDPH scavenging, antioxidant capacity, and reducing power estimation), antimicrobial (antibacterial, antifungal, and antileishmanial), cytotoxic (brine shrimps, THP-1 human leukemia cell lines and normal lymphocytes), and protein kinase inhibition assays. Maximum phenolic and flavonoid contents were computed in distilled water–acetone and acetone extracts (i.e., 16 ± 1 μg/mg extract and 8 ± 0.4/mg extract, respectively). HPLC-DAD quantified rutin (0.58 µg/mg extract) and gallic acid (0.4 µg/mg extract) in methanol–ethyl acetate and methanol extracts, respectively. Water–acetone extract exhibited the highest DPPH scavenging of 36 ± 1%. Total reducing potential of 76.0 ± 1 μg/mg extract was shown by ethanol chloroform while maximum total antioxidant capacity was depicted by the acetone extract (92.21 ± 0.70 μg/mg extract). Maximal antifungal effect against Mucor sp., antileishmanial, brine shrimp cytotoxicity, THP-1 cell line cytotoxicity, and protein kinase inhibitory activities were shown by ethyl acetate-methanol (MIC: 50 µg/disc), n-hexane (IC50: 120.8 ± 3.7 µg/mL), ethyl acetate (LD50: 29.94 ± 1.6 µg/mL), distilled water–acetone (IC50: 118 ± 3.4 µg/mL) and methanol–chloroform (ZOI: 19 ± 1 mm) extracts, respectively. Our findings show the dependency of phytochemicals and bioactivities on the polarity of the extraction solvent and our preliminary screening suggests the C. tuberculata extract formulations to be tested and used in different ailments, however, detailed studies remain necessary for corroboration with our results.
Optimization of S-Nitrosocaptopril Monohydrate Storage Conditions Based on Response Surface Method
Authors: Huang Lingyi , Zhou Yu , Wang Yizhi , Lin Min
Published: December 2021

From unstable crystals to relatively stable monohydrate crystals, many researchers have been working on S-nitrosocaptopril for more than two decades. S-nitrosocaptopril monohydrate (Cap-NO·H2O) is a novel crystal form of S-nitrosocaptopril (Cap-NO), and is not only a nitric oxide (NO) donor, but also an angiotensin-converting enzyme inhibitor (ACEI). Yet, a method for long-term storage has never been reported. In order to determine the optimal storage conditions, Plackett–Burman (PB) design was performed to confirm the critical factors. Response surface methodology (RSM) was employed to determine the optimal Cap-NO·H2O storage condition, based on the rough interval determined by the path of steepest ascent experiment. The optimized storage condition was denoted as nitrogen purity of 97%, temperature of −10 °C and 1.20 g deoxidizer. In this case, a final preservation rate of 97.91 ± 0.59% could be obtained. In specific storage conditions, Cap-NO·H2O was found to be stable for at least 6 months in individual PE package, procreating a potentially applicable avenue.
A Comparison of Cysteine-Conjugated Nitroxide Spin Labels for Pulse Dipolar EPR Spectroscopy
Authors: Ackermann Katrin , Chapman Alexandra , Bode Bela E.
Published: December 2021

The structure-function and materials paradigms drive research on the understanding of structures and structural heterogeneity of molecules and solids from materials science to structural biology. Functional insights into complex architectures are often gained from a suite of complementary physicochemical methods. In the context of biomacromolecular structures, the use of pulse dipolar electron paramagnetic resonance spectroscopy (PDS) has become increasingly popular. The main interest in PDS is providing long-range nanometre distance distributions that allow for identifying macromolecular topologies, validating structural models and conformational transitions as well as docking of quaternary complexes. Most commonly, cysteines are introduced into protein structures by site-directed mutagenesis and modified site-specifically to a spin-labelled side-chain such as a stable nitroxide radical. In this contribution, we investigate labelling by four different commercial labelling agents that react through different sulfur-specific reactions. Further, the distance distributions obtained are between spin-bearing moieties and need to be related to the protein structure via modelling approaches. Here, we compare two different approaches to modelling these distributions for all four side-chains. The results indicate that there are significant differences in the optimum labelling procedure. All four spin-labels show differences in the ease of labelling and purification. Further challenges arise from the different tether lengths and rotamers of spin-labelled side-chains; both influence the modelling and translation into structures. Our comparison indicates that the spin-label with the shortest tether in the spin-labelled side-group, (bis-(2,2,5,5-Tetramethyl-3-imidazoline-1-oxyl-4-yl) disulfide, may be underappreciated and could increase the resolution of structural studies by PDS if labelling conditions are optimised accordingly.
Technologies for Multimodal Interaction in Extended Reality—A Scoping Review
Authors: Rakkolainen Ismo , Farooq Ahmed , Kangas Jari , Hakulinen Jaakko , Rantala Jussi , Turunen Markku , Raisamo Roope
Published: December 2021

When designing extended reality (XR) applications, it is important to consider multimodal interaction techniques, which employ several human senses simultaneously. Multimodal interaction can transform how people communicate remotely, practice for tasks, entertain themselves, process information visualizations, and make decisions based on the provided information. This scoping review summarized recent advances in multimodal interaction technologies for head-mounted display-based (HMD) XR systems. Our purpose was to provide a succinct, yet clear, insightful, and structured overview of emerging, underused multimodal technologies beyond standard video and audio for XR interaction, and to find research gaps. The review aimed to help XR practitioners to apply multimodal interaction techniques and interaction researchers to direct future efforts towards relevant issues on multimodal XR. We conclude with our perspective on promising research avenues for multimodal interaction technologies.
A Phase II Multicenter Trial on High-Dose Vitamin D Supplementation for the Correction of Vitamin D Insufficiency in Patients with Breast Cancer Receiving Adjuvant Chemotherapy
Authors: Chartron Elodie , Firmin Nelly , Touraine Célia , Chapelle Angélique , Legouffe Eric , Rifai Lobna , Pouderoux Stéphane , Roca Lise , D’Hondt Véronique , Jacot William
Published: December 2021

Breast cancer (BC) treatments induce vitamin D (VD) insufficiency and bone metabolism changes, resulting in osteoporosis and skeletal morbidity risk. We report the results of a bicentric phase II trial (ClinicalTrials.gov Identifier: NCT04091178) on the safety and efficacy of high-dose oral VD supplementation for VD deficiency correction in 44 patients with early BC treated with adjuvant chemotherapies. Patients received one dose of 100,000 IU 25-OH VD every 3 weeks from day 1 of cycle 1 to day 1 of cycle 5. The primary endpoint was the percentage of patients achieving serum 25-OH VD concentration normalization on day 1 of cycle 6 (D1C6). Secondary endpoints were safety, VD and calcium parameters at baseline and during chemotherapy, and identification of predictive biomarkers of VD normalization on D1C6. On D1C6, 21 patients (47.7%, 95% CI: 33.0–62.8) achieved VD normalization. No VD-related clinical toxicity was reported. However, 13 patients (29.5%) presented asymptomatic grade 1 hypercalciuria, leading to interruption of the high-dose oral VD supplementation in 10, followed by a rapid reduction in serum VD concentration. No baseline clinical factor was predictive of VD normalization on D1C6. This high-dose VD supplementation appears safe and efficient in patients with early BC receiving adjuvant chemotherapy.