bluuebunny/crossref_metadata_2025 huggingface dataset:
The Electronic Property Differences between dA::dG and dA::dGoxo. A Theoretical Approach
Authors: Karwowski Boleslaw T.
Published: August 2020

The dA::dGoxo pair appearing in nucleic ds-DNA can lead to a mutation in the genetic information. Depending on the dGoxo source, an AT→GC and GC→AC transversion might be observed. As a result, glycosylases are developed during the evolution, i.e., OGG1 and MutY. While the former effectively removes Goxo from the genome, the second one removes adenine from the dA::dGoxo and dA:dG pair. However, dA::dGoxo is recognized by MutY as ~6–10 times faster than dA:dG. In this article, the structural and electronic properties of simple nucleoside pairs dA:dG, dC:::dGoxo, dC:::dG, dA::dGoxo in the aqueous phase have been taken into theoretical consideration. The influence of solvent relaxation on the above is also discussed. It can be concluded that the dA::dGoxo nucleoside pair shows a lower ionization potential and higher electron affinity than the dA:dG pair in both a vertical and adiabatic mode. Therefore, it could be predicted, under electronic properties, that the electron ejected, for instance by a MutY 4[Fe-S]2+ cluster, is predisposed to trapping by the ds-DNA part containing the dA::dGoxo pair rather than by dA::dG.
Caesalpinia ferrea C. Mart. (Fabaceae) Phytochemistry, Ethnobotany, and Bioactivities: A Review
Authors: Macêdo Nair Silva , Silveira Zildene de Sousa , Bezerra Antonio Henrique , Costa José Galberto Martins da , Coutinho Henrique Douglas Melo , Romano Barbara , Capasso Raffaele , Cunha Francisco Assis Bezerra da , da Silva Márcia Vanusa
Published: August 2020

Caesalpinia ferrea C. Mart., popularly known as “Jucá” or “Pau-ferro”, belongs to the Fabaceae family, and is classified as a native and endemic species in Brazil. Numerous studies that portray its ethnobotany, chemical composition, and biological activities exist in the literature. The present study aimed to systematically review publications addressing the botanical aspects, uses in popular medicine, phytochemical composition, and bioactivities of C. ferrea. The searches focused on publications from 2015 to March 2020 using the Scopus, Periódicos Capes, PubMed, Google Scholar, and ScienceDirect databases. The leaves, fruits, seeds, and bark from C. ferrea are used in popular medicine to treat disorders affecting several systems, including the circulatory, immune, cardiovascular, digestive, respiratory, genitourinary, musculoskeletal, and conjunctive systems. The most commonly found chemical classes in phytochemical studies are flavonoids, polyphenols, terpenoids, tannins, saponins, steroids, and other phenolic compounds. The biological properties of the extracts and isolated compounds of C. ferrea most cited in the literature were antibacterial, antifungal, antioxidant, antiproliferative, anti-inflammatory, and healing potential. However, further studies are still needed to clarify a link between its traditional uses, the active compounds, and the reported pharmacological activities, as well as detailed research to determine the toxicological profile of C. ferrea.
Box–Behnken Response Surface Design of Polysaccharide Extraction from Rhododendron arboreum and the Evaluation of Its Antioxidant Potential
Authors: Ahmad Ajaz , Rehman Muneeb U. , Wali Adil Farooq , El-Serehy Hamed A. , Al-Misned Fahad A. , Maodaa Saleh N. , Aljawdah Hossam M. , Mir Tahir Maqbool , Ahmad Parvaiz
Published: August 2020

In the present investigation, the ultrasound-assisted extraction (UAE) conditions and optimization of Rhododendron arboreum polysaccharide (RAP) yield were studied by a Box–Behnken response surface design and the evaluation of its antioxidant potential. Three parameters that affect the productivity of UAE, such as extraction temperature (50–90 °C), extraction time (10–30 min), and solid–liquid ratio (1–2 g/mL), were examined to optimize the yield of the polysaccharide percentage. The chromatographic analysis revealed that the composition of monosaccharides was found to be glucose, galactose, mannose, arabinose, and fucose. The data were fitted to polynomial response models, applying multiple regression analysis with a high coefficient of determination value (R2 = 0.999). The data exhibited that the extraction parameters have significant effects on the extraction yield of polysaccharide percentage. Derringer’s desirability prediction tool was attained under the optimal extraction conditions (extraction temperature 66.75 °C, extraction time 19.72 min, and liquid–solid ratio 1.66 mL/g) with a desirability value of 1 yielded the highest polysaccharide percentage (11.56%), which was confirmed through validation experiments. An average of 11.09 ± 1.65% of polysaccharide yield was obtained in optimized extraction conditions with a 95.43% validity. The in vitro antioxidant effect of polysaccharides of R. arboreum was studied. The results showed that the RAP extract exhibited a strong potential against free radical damage.
Biocompatibility of Biomaterials for Nanoencapsulation: Current Approaches
Authors: Witika Bwalya A. , Makoni Pedzisai A. , Matafwali Scott K. , Chabalenge Billy , Mwila Chiluba , Kalungia Aubrey C. , Nkanga Christian I. , Bapolisi Alain M. , Walker Roderick B.
Published: August 2020

Nanoencapsulation is an approach to circumvent shortcomings such as reduced bioavailability, undesirable side effects, frequent dosing and unpleasant organoleptic properties of conventional drug delivery systems. The process of nanoencapsulation involves the use of biomaterials such as surfactants and/or polymers, often in combination with charge inducers and/or ligands for targeting. The biomaterials selected for nanoencapsulation processes must be as biocompatible as possible. The type(s) of biomaterials used for different nanoencapsulation approaches are highlighted and their use and applicability with regard to haemo- and, histocompatibility, cytotoxicity, genotoxicity and carcinogenesis are discussed.
Antiarthritic Effects of a Root Extract from Harpagophytum procumbens DC: Novel Insights into the Molecular Mechanisms and Possible Bioactive Phytochemicals
Authors: Mariano Alessia , Di Sotto Antonella , Leopizzi Martina , Garzoli Stefania , Di Maio Valeria , Gullì Marco , Dalla Vedova Pietro , Ammendola Sergio , Scotto d’Abusco Anna
Published: August 2020

Harpagophytum procumbens (Burch.) DC. ex Meisn. is a traditional remedy for osteoarticular diseases, including osteoarthritis (OA), although the bioactive constituents and mechanisms involved are yet to be clarified. In the present study, an aqueous H. procumbens root extract (HPE; containing 1.2% harpagoside) was characterized for its effects on synoviocytes from OA patients and phytochemical composition in polyphenols, and volatile compounds were detected. HPE powder was dissolved in different solvents, including deionized water (HPEH2O), DMSO (HPEDMSO), 100% v/v ethanol (HPEEtOH100), and 50% v/v ethanol (HPEEtOH50). The highest polyphenol levels were found in HPEDMSO and HPEEtOH50, whereas different volatile compounds, mainly β-caryophyllene and eugenol, were detected in all the extracts except for HPEH2O. HPEH2O and HPEDMSO were able to enhance CB2 receptor expression and to downregulate PI-PLC β2 in synovial membranes; moreover, all the extracts inhibited FAAH activity. The present results highlight for the first time a multitarget modulation of the endocannabinoid system by HPE, likely ascribable to its hydrosoluble compounds, along with the presence of volatile compounds in H. procumbens root. Although hydrosoluble compounds seem to be mainly responsible for endocannabinoid modulation by HPE, a possible contribution of volatile compounds can be suggested, strengthening the hypothesis that the entire phytocomplex can contribute to the H. procumbens healing properties.
Dietary Protein Intake and Single-Nephron Glomerular Filtration Rate
Authors: Oba Rina , Kanzaki Go , Sasaki Takaya , Okabayashi Yusuke , Haruhara Kotaro , Koike Kentaro , Kobayashi Akimitsu , Yamamoto Izumi , Tsuboi Nobuo , Yokoo Takashi
Published: August 2020

High protein intake can increase glomerular filtration rate (GFR) in response to excretory overload, which may exacerbate the progression of kidney disease. However, the direct association between glomerular hemodynamic response at the single-nephron level and dietary protein intake has not been fully elucidated in humans. In the present study, we evaluated nutritional indices associated with single-nephron GFR (SNGFR) calculated based on corrected creatinine clearance (SNGFRCr). We retrospectively identified 43 living kidney donors who underwent enhanced computed tomography and kidney biopsy at the time of donation at Jikei University Hospital in Tokyo from 2007 to 2018. Total nephron number was estimated with imaging-derived cortical volume and morphometry-derived glomerular density. SNGFRCr was calculated by dividing the corrected creatinine clearance by the number of non-sclerosed glomeruli (NglomNSG). The mean (± standard deviation) NglomNSG/kidney and SNGFRCr were 685,000 ± 242,000 and 61.0 ± 23.9 nL/min, respectively. SNGFRCr was directly associated with estimated protein intake/ideal body weight (p = 0.005) but not with body mass index, mean arterial pressure, albumin, or sodium intake. These findings indicate that greater protein intake may increase SNGFR and lead to glomerular hyperfiltration.
Association between Infant and Young Child Feeding (IYCF) Indicators and the Nutritional Status of Children (6–23 Months) in Northern Ghana
Authors: Anin Stephen Kofi , Saaka Mahama , Fischer Florian , Kraemer Alexander
Published: August 2020

Although recommended infant and young child feeding (IYCF) practices have been found to be protective against undernutrition in some settings, there is no finality yet due to inconsistencies in the literature. A cross-sectional survey of 581 mother-child pairs was conducted in northern Ghana in June 2018. The association between IYCF indicators and child undernutrition (stunting and wasting) were assessed. The descriptive analysis showed that 66.4% of the children (6–23 months) were introduced to complementary feeding in a timely manner, 69.4% met the minimum meal frequency, and 38.9% met the minimum acceptable diet daily. The prevalence of stunting, wasting, underweight and overweight was 33.2%, 14.1%, 27% and 2.6%, respectively. From the multivariable binary logistic regression, child gender, child age group and source of power for lighting the household were significantly associated with wasting. Intake of iron-rich foods, child age group, and maternal height were significantly associated with stunting after adjusting for confounders. The prevalence of the compliance with IYCF indicators was relatively high. None of the individual IYCF indicators showed significant association with undernutrition, except intake of iron-rich foods for stunting. Nutrition-specific interventions targeted at improving IYCF practices, dietary diversification and intake of nutrient-rich meals, should be adopted and scaled up to address undernutrition in northern Ghana.
Role of Epstein-Barr Virus and Human Papillomavirus Coinfection in Cervical Cancer: Epidemiology, Mechanisms and Perspectives
Authors: Blanco Rancés , Carrillo-Beltrán Diego , Osorio Julio C. , Calaf Gloria M , Aguayo Francisco
Published: August 2020

High-risk human papillomavirus (HR-HPV) is etiologically associated with the development and progression of cervical cancer, although other factors are involved. Epstein-Barr virus (EBV) detection in premalignant and malignant tissues from uterine cervix has been widely reported; however, its contribution to cervical cancer development is still unclear. Here, a comprehensive analysis regarding EBV presence and its potential role in cervical cancer, the frequency of EBV/HR-HPV coinfection in uterine cervix and EBV infection in tissue-infiltrating lymphocytes were revised. Overall, reports suggest a potential link of EBV to the development of cervical carcinomas in two possible pathways: (1) Infecting epithelial cells, thus synergizing with HR-HPV (direct pathway), and/or (2) infecting tissue-infiltrating lymphocytes that could generate local immunosuppression (indirect pathway). In situ hybridization (ISH) and/or immunohistochemical methods are mandatory for discriminating the cell type infected by EBV. However, further studies are needed for a better understanding of the EBV/HR-HPV coinfection role in cervical carcinogenesis.
Clinical Course and Gross Pathological Findings in Wild Boar Infected with a Highly Virulent Strain of African Swine Fever Virus Genotype II
Authors: Rodríguez-Bertos Antonio , Cadenas-Fernández Estefanía , Rebollada-Merino Agustín , Porras-González Néstor , Mayoral-Alegre Francisco J. , Barreno Lucía , Kosowska Aleksandra , Tomé-Sánchez Irene , Barasona José A. , Sánchez-Vizcaíno José M.
Published: August 2020

African swine fever (ASF) is a notifiable disease that in recent years has spread remarkably in Europe and Asia. Eurasian wild boar (Sus scrofa) plays a key role in the maintenance and spread of the pathogen. Here we examined gross pathology of infection in wild boar with a highly virulent, hemadsorbing genotype II ASF virus (ASFV) strain. To this end, six wild boars were intramuscularly inoculated with the 10 HAD50 Arm07 ASFV strain, and 11 wild boars were allowed to come into direct contact with the inoculated animals. No animals survived the infection. Clinical course, gross pathological findings and viral genome quantification by PCR in tissues did not differ between intramuscularly inoculated or contact-infected animals. Postmortem analysis showed enlargement of liver and spleen; serosanguinous effusion in body cavities; and multiple hemorrhages in lungs, endocardium, brain, kidneys, urinary bladder, pancreas, and alimentary system. These results provide detailed insights into the gross pathology of wild boar infected with a highly virulent genotype II ASFV strain. From a didactic point of view, this detailed clinical course and macroscopic description may be essential for early postmortem detection of outbreaks in wild boar in the field and contribute to disease surveillance and prevention efforts.
Water-Soluble Pristine C60 Fullerene Inhibits Liver Alterations Associated with Hepatocellular Carcinoma in Rat
Authors: Kuznietsova Halyna , Dziubenko Natalia , Herheliuk Tetiana , Prylutskyy Yuriy , Tauscher Eric , Ritter Uwe , Scharff Peter
Published: August 2020

Excessive production of reactive oxygen species is the main cause of hepatocellular carcinoma (HCC) initiation and progression. Water-soluble pristine C60 fullerene is a powerful and non-toxic antioxidant, therefore, its effect under rat HCC model and its possible mechanisms were aimed to be discovered. Studies on HepG2 cells (human HCC) demonstrated C60 fullerene ability to inhibit cell growth (IC50 = 108.2 μmol), to induce apoptosis, to downregulate glucose-6-phosphate dehydrogenase, to upregulate vimentin and p53 expression and to alter HepG2 redox state. If applied to animals experienced HCC in dose of 0.25 mg/kg per day starting at liver cirrhosis stage, C60 fullerene improved post-treatment survival similar to reference 5-fluorouracil (31 and 30 compared to 17 weeks) and inhibited metastasis unlike the latter. Furthermore, C60 fullerene substantially attenuated liver injury and fibrosis, decreased liver enzymes, and normalized bilirubin and redox markers (elevated by 1.7–7.7 times under HCC). Thus, C60 fullerene ability to inhibit HepG2 cell growth and HCC development and metastasis and to improve animal survival was concluded. C60 fullerene cytostatic action might be realized through apoptosis induction and glucose-6-phosphate dehydrogenase downregulation in addition to its antioxidant activity.
Epigenetic Variation Induced by Gamma Rays, DNA Methyltransferase Inhibitors, and Their Combination in Rice
Authors: Lee Sung-Il , Park Jae Wan , Kwon Soon-Jae , Jo Yeong Deuk , Hong Min Jeong , Kim Jin-Baek , Choi Hong-Il
Published: August 2020

DNA methylation plays important roles in the regulation of gene expression and maintenance of genome stability in many organisms, including plants. In this study, we treated rice with gamma rays (GRs) and DNA methyltransferase inhibitors (DNMTis) to induce variations in DNA methylation and evaluated epigenetic diversity using methylation-sensitive amplified polymorphism (MSAP) and transposon methylation display (TMD) marker systems. Comparative and integrated analyses of the data revealed that both GRs and DNMTis alone have epimutagenic effects and that combined treatment enhanced these effects. Calculation of methylation rates based on band scoring suggested that both GRs and DNMTis induce epigenetic diversity by demethylation in a dose-dependent manner, and combined treatment can induce variations more synergistically. The difference in the changes in full and hemi-methylation rates between MSAP and TMD is presumed to be caused by the different genomic contexts of the loci amplified in the two marker systems. Principal coordinate, phylogenic, and population structure analyses commonly yielded two clusters of individuals divided by DNMTi treatment. The clustering pattern was more apparent in TMD, indicating that DNMTis have a stronger effect on hypermethylated repetitive regions. These findings provide a foundation for understanding epigenetic variations induced by GRs and DNMTis and for epigenetic mutation breeding.
A Green Approach to Modify Surface Properties of Polyurethane Foam for Enhanced Oil Absorption
Authors: Ng Zhi Chien , Roslan Rosyiela Azwa , Lau Woei Jye , Gürsoy Mehmet , Karaman Mustafa , Jullok Nora , Ismail Ahmad Fauzi
Published: August 2020

The non-selective property of conventional polyurethane (PU) foam tends to lower its oil absorption efficiency. To address this issue, we modified the surface properties of PU foam using a rapid solvent-free surface functionalization approach based on the chemical vapor deposition (CVD) method to establish an extremely thin yet uniform coating layer to improve foam performance. The PU foam was respectively functionalized using different monomers, i.e., perfluorodecyl acrylate (PFDA), 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA), and hexamethyldisiloxane (HMDSO), and the effect of deposition times (1, 5 and 10 min) on the properties of foam was investigated. The results showed that all the modified foams demonstrated a much higher water contact angle (i.e., greater hydrophobicity) and greater absorption capacities compared to the control PU foam. This is due to the presence of specific functional groups, e.g., fluorine (F) and silane (Si) in the modified PU foams. Of all, the PU/PHFBAi foam exhibited the highest absorption capacities, recording 66.68, 58.15, 53.70, and 58.38 g/g for chloroform, acetone, cyclohexane, and edible oil, respectively. These values were 39.19–119.31% higher than that of control foam. The promising performance of the PU/PHFBAi foam is due to the improved surface hydrophobicity attributed to the original perfluoroalkyl moieties of the HFBA monomer. The PU/PHFBAi foam also demonstrated a much more stable absorption performance compared to the control foam when both samples were reused for up to 10 cycles. This clearly indicates the positive impact of the proposed functionalization method in improving PU properties for oil absorption processes.
Drawbacks of Low Lattice Energy Ammonium Salts for Ion-Conducting Polymer Electrolyte Preparation: Structural, Morphological and Electrical Characteristics of CS:PEO:NH4BF4-Based Polymer Blend Electrolytes
Authors: Brza Mohamad A. , Aziz Shujahadeen B. , Nofal Muaffaq M. , Saeed Salah R. , Al-Zangana Shakhawan , Karim Wrya O. , Hussen Sarkawt A. , Abdulwahid Rebar T. , Kadir Mohd F. Z.
Published: August 2020

In the present work it was shown that low lattice energy ammonium salts are not favorable for polymer electrolyte preparation for electrochemical device applications. Polymer blend electrolytes based on chitosan:poly(ethylene oxide) (CS:PEO) incorporated with various amounts of low lattice energy NH4BF4ammonium salt have been prepared using the solution cast technique. Both structural and morphological studies were carried out to understand the phenomenon of ion association. Sharp peaks appeared in X-ray diffraction (XRD) spectra of the samples with high salt concentration. The degree of crystallinity increased from 8.52 to 65.84 as the salt concentration increased up to 40 wt.%. These are correlated to the leakage of the associated anions and cations of the salt to the surface of the polymer. The structural behaviors were further confirmed by morphological study. The morphological results revealed the large-sized protruded salts at high salt concentration. Based on lattice energy of salts, the phenomena of salt leakage were interpreted. Ammonium salts with lattice energy lower than 600 kJ/mol are not preferred for polymer electrolyte preparation due to the significant tendency of ion association among cations and anions. Electrical impedance spectroscopy was used to estimate the conductivity of the samples. It was found that the bulk resistance increased from 1.1 × 104 ohm to 0.7 × 105 ohm when the salt concentration raised from 20 wt.% to 40 wt.%, respectively; due to the association of cations and anions. The low value of direct current (DC) conductivity (7.93 × 10−7 S/cm) addressed the non-suitability of the electrolytes for electrochemical device applications. The calculated values of the capacitance over the interfaces of electrodes-electrolytes (C2) were found to drop from 1.32 × 10−6 F to 3.13 × 10−7 F with increasing salt concentration. The large values of dielectric constant at low frequencies are correlated to the electrode polarization phenomena while their decrements with rising frequency are attributed to the lag of ion polarization in respect of the fast orientation of the applied alternating current (AC) field. The imaginary part of the electric modulus shows obvious peaks known as conduction relaxation peaks.
A Stimulus-Responsive Polymer Composite Surface with Magnetic Field-Governed Wetting and Photocatalytic Properties
Authors: Mérai László , Deák Ágota , Sebők Dániel , Kukovecz Ákos , Dékány Imre , Janovák László
Published: August 2020

With the increasing demand for liquid manipulation and microfluidic techniques, surfaces with real-time tunable wetting properties are becoming the focus of materials science researches. In this study, we present a simple preparation method for a 0.5–4 µm carbonyl iron (carbonyl Fe) loaded polydimethylsiloxane (PDMS)-based magnetic composite coating with magnetic field-tailored wetting properties. Moreover, the embedded 6.3–16.7 wt.% Ag-TiO2 plasmonic photocatalyst (d~50 nm) content provides additional visible light photoreactivity to the external stimuli-responsive composite grass surfaces, while the efficiency of this photocatalytic behavior also turned out to be dependent on the external magnetic field. The inclusion of the photocatalyst introduced hierarchical surface roughness to the micro-grass, resulting in the broadening of the achievable contact and sliding angle ranges. The photocatalyst-infused coatings are also capable of catching and releasing water droplets, which alongside their multifunctional (photocatalytic activity and tunable wetting characteristics) nature makes surfaces of this kind the novel sophisticated tools of liquid manipulation.
The Study of EDLC Device with High Electrochemical Performance Fabricated from Proton Ion Conducting PVA-Based Polymer Composite Electrolytes Plasticized with Glycerol
Authors: Brza Mohamad A. , B. Aziz Shujahadeen , Anuar Hazleen , Dannoun Elham M. A. , Ali Fathilah , Abdulwahid Rebar T. , Al-Zangana Shakhawan , Kadir Mohd F.Z.
Published: August 2020

In the present work, a novel polymer composite electrolytes (PCEs) based on poly(vinyl alcohol) (PVA): ammonium thiocyanate (NH4SCN): Cd(II)-complex plasticized with glycerol (Gly) are prepared by solution cast technique. The film structure was examined by XRD and FTIR routes. The utmost ambient temperature DC ionic conductivity (σDC) of 2.01 × 10−3 S cm−1 is achieved. The film morphology was studied by field emission scanning electron microscopy (FESEM). The trend of σDC is further confirmed with investigation of dielectric properties. Transference numbers of ions (tion) and electrons (tel) are specified to be 0.96 and 0.04, respectively. Linear sweep voltammetry (LSV) displayed that the PCE potential window is 2.1 V. The desired mixture of activated carbon (AC) and carbon black was used to fabricate the electrodes of the EDLC. Cyclic voltammetry (CV) was carried out by sandwiching the PCEs between two carbon-based electrodes, and it revealed an almost rectangular shape. The EDLC exhibited specific capacitance, energy density, and equivalent series resistance with average of 160.07F/g, 18.01Wh/kg, and 51.05Ω, respectively, within 450 cycles. The EDLC demonstrated the initial power density as 4.065 × 103 W/Kg.
The Effect of Matrix Stiffness on Human Hepatocyte Migration and Function—An In Vitro Research
Authors: Xia Tingting , Zhao Runze , Feng Fan , Yang Li
Published: August 2020

The extracellular matrix (ECM) regulates cellular function through the dynamic biomechanical and biochemical interplay between the resident cells and their microenvironment. Pathologically stiff ECM promotes phenotype changes in hepatocytes during liver fibrosis. To investigate the effect of ECM stiffness on hepatocyte migration and function, we designed an easy fabricated polyvinyl alcohol (PVA) hydrogel in which stiffness can be controlled by changing the concentration of glutaraldehyde. Three stiffnesses of hydrogels corresponding to the health of liver tissue, early stage, and end stage of fibrosis were selected. These were 4.8 kPa (soft), 21 kPa (moderate), and 45 kPa (stiff). For hepatocytes attachment, the hydrogel was coated with fibronectin. To evaluate the optimal concentration of fibronectin, hydrogel was coated with 0.1 mg/mL, 0.01 mg/mL, 0.005 mg/mL, or 0.003 mg/mL fibronectin, and the migratory behavior of single hepatocyte cultured on different concentrations of fibronectin was analyzed. To further explore the effect of substrate stiffness on hepatocyte migration, we used a stiffness controllable commercial 3D collagen gel, which has similar substrate stiffness to that of PVA hydrogel. Our result confirmed the PVA hydrogel biocompatibility with high hepatocytes survival. Fibronectin (0.01 mg/mL) promoted optimal migratory behavior for single hepatocytes. However, for confluent hepatocytes, a stiff substrate promoted hepatocellular migration compared with the soft and moderate groups via enhancing the formation of actin- and tubulin-rich structures. The gene expression analysis and protein expression analysis showed that the stiff substrate altered the phenotype of hepatocytes and induced apoptosis. Hepatocytes in stiff 3D hydrogel showed a higher proportion of cell death and expression of filopodia.
Preparation of a Novel Polystyrene-Poly(hydroxamic Acid) Copolymer and Its Adsorption Properties for Rare Earth Metal Ions
Authors: Cao Xiaoyan , Wang Qing , Wang Shuai , Man Ruilin
Published: August 2020

In this study, a novel polystyrene-poly(hydroxamic acid) copolymer was synthesized as an effective adsorbent for the treatment of rare earth elements. Through the use of elemental analysis as well as FTIR, SEM, XPS, and Brunauer-Emmett-Teller (BET) surface area measurement, the synthesized polymer was found to have a specific surface area of 111.4 m2·g−1. The adsorption performances of rare metal ions were investigated under different pH levels, contact times, initial concentrations of rare earth ions, and temperatures. The adsorption equilibrium for La3+, Ce3+, and Y3+ onto a polystyrene-poly(hydroxamic acid) copolymer is described by the Langmuir model, which confirms the applicability of monolayer coverage of rare earth ions onto a polystyrene-poly(hydroxamic acid) copolymer. The amount of adsorption capacities for La3+, Ce3+, and Y3+ reached 1.27, 1.53, and 1.83 mmol·g−1 within four hours, respectively. The adsorption process was controlled by liquid film diffusion, particle diffusion, and chemical reaction simultaneously. The thermodynamic parameters, including the change of Gibbs free energy (∆G), the change of enthalpy (∆H), and the change of entropy (∆S), were determined. The results indicate that the adsorption of resins for La3+, Ce3+ and Y3+ was spontaneous and endothermic. The polymer was also used as a recyclable adsorbent by the desorption experiment.
Enzymatic Polycondensation of 1,6-Hexanediol and Diethyl Adipate: A Statistical Approach Predicting the Key-Parameters in Solution and in Bulk
Authors: Nasr Kifah , Meimoun Julie , Favrelle-Huret Audrey , Winter Julien De , Raquez Jean-Marie , Zinck Philippe
Published: August 2020

Among the various catalysts that can be used for polycondensation reactions, enzymes have been gaining interest for three decades, offering a green and eco-friendly platform towards the sustainable design of renewable polyesters. However, limitations imposed by their delicate nature, render them less addressed. As a case study, we compare herein bulk and solution polycondensation of 1,6-hexanediol and diethyl adipate catalyzed by an immobilized lipase from Candida antarctica. The influence of various parameters including time, temperature, enzyme loading, and vacuum was assessed in the frame of a two-step polymerization with the help of response surface methodology, a statistical technique that investigates relations between input and output variables. Results in solution (diphenyl ether) and bulk conditions showed that a two-hour reaction time was enough to allow adequate oligomer growth for the first step conducted under atmospheric pressure at 100 °C. The number-average molecular weight (Mn) achieved varied between 5000 and 12,000 g·mol−1 after a 24 h reaction and up to 18,500 g∙mol−1 after 48 h. The statistical analysis showed that vacuum was the most influential factor affecting the Mn in diphenyl ether. In sharp contrast, enzyme loading was found to be the most influential parameter in bulk conditions. Recyclability in bulk conditions showed a constant Mn of the polyester over three cycles, while a 17% decrease was noticed in solution. The following work finally introduced a statistical approach that can adequately predict the Mn of poly(hexylene adipate) based on the choice of parameter levels, providing a handy tool in the synthesis of polyesters where the control of molecular weight is of importance.
Liposomes: From Bangham to Supercritical Fluids
Authors: Trucillo Paolo , Campardelli Roberta , Reverchon Ernesto
Published: August 2020

Liposomes are spherical vesicles made up of an aqueous core surrounded by phospholipids. These delivery systems (DS) are largely employed as drug carriers in several industrial fields, such as pharmaceutical and nutraceutical fields. The aim of this short review is to provide a fast overview on the main fundamentals of liposomes, thought as a compact guide for researchers and students that want to approach this topic for the first time. The mini-review will focus on the definitions, production methods and characterization protocols of the liposomes produced, making a critical comparison of the main conventional and supercritical based manufacturing methods available. The literature was analyzed deeply from the first works by Dr. Bangham in 1965 to the most recent supercritical fluid applications. The advantages and disadvantages of conventional and high-pressure processes will be described in terms of solvent elimination, production at the nanometric (50–300 nm) and micrometric level (1–100 μm) and encapsulation efficiency (20–90%). The first proposed methods were characterized by a low encapsulation efficiency (20–40%), resulting in drug loss, a high solvent residue and high operating cost. The repeatability of conventional processes was also low, due to the prevalent batch mode. Supercritical-assisted methods were developed in semi-continuous layouts, resulting in an easy process scale-up, better control of liposome dimensions (polydispersity index, PDI) and also higher encapsulation efficiencies (up to 90%).
Supercritical Fluid Extraction of Compounds of Pharmaceutical Interest from Wendita calysina (Burrito)
Authors: Baldino Lucia , Reverchon Ernesto
Published: August 2020

Wendita calysina (commonly known as burrito) is an indigenous Paraguayan medical plat, whose essential oil (EO) is characterized by some pharmaceutical properties. In particular, the main component is D-carvone, with anticancer action and antimicrobial properties against various microorganisms. In this work, supercritical CO2 (SC-CO2) was used for the extraction of volatile compounds from this plant, selecting different operative conditions to optimize the extract yield and purity. Pressure was varied from 80 to 250 bar, and two CO2 flow rates (0.8 kg/h and 1.2 kg/h) were tested. The highest EO percentage in the extract was obtained operating at 100 bar and 40 °C, using ground Wendita calysina leaves of 250 µm. CO2 flow rate did not influence the extraction yield, indicating that an internal mass transfer resistance governs this process. The largely prevailing compound identified in the extract was D-carvone, with a mean percentage up to 90% w/w.
Screening and Application of Chitin Synthase Inhibitors
Authors: Shi Xiaozai , Qiu Shuo , Bao Yingling , Chen Hanchi , Lu Yuele , Chen Xiaolong
Published: August 2020

Chitin is an important part of the fungal cell wall, but is not found in plants and mammals, so chitin synthase (CHS) can be a green fungicide target. In this paper, 35 maleimide compounds were designed and synthesized as CHS inhibitors. All the screened compounds showed different degrees of CHS inhibitory activity and antifungal activity in vitro. In particular, the half–inhibitory concentration (IC50) value of compound 20 on CHS was 0.12 mM, and the inhibitory effect was better than that of the control polyoxin B (IC50 = 0.19 mM). At the same time, this compound also showed good antifungal activity and has further development value.
Theoretical Aspects of Scholarly Publishing about the Internet in Spanish Communication Journals
Authors: Rubira-García Rainer , Baldiris-Navarro Silvia Margarita , Venet-Gutiérrez Jacqueline , Magro-Vela Silvia
Published: August 2020

Theoretical aspects of scholarly publishing about the Internet in communication sciences in Spain have received little attention. The present text analyses scientific framework, categories, concepts and keywords used in research, collected from the most relevant specialized Spanish journals in the field, as well as research objectives that are pursued in connection to communication levels of study and types of data. A content analysis of a representative sample of 227 scientific articles was done in the five leading Spanish journals in communication in the period 1995–2015, in which the academic interesting on Internet as an object of study was consolidated. The results show a predominance of descriptive theoretical frameworks and a hegemony of journalism as an academic reference. Nevertheless, there is an increase complexity out of the mass media field. The research on the Internet in the communication field is presented as a reflexive opportunity to understand interdisciplinarity and the way this acquires epistemological consistence in the scientific discourse.
Multi-Source Remote Sensing Data Product Analysis: Investigating Anthropogenic and Naturogenic Impacts on Mangroves in Southeast Asia
Authors: Sakti Anjar Dimara , Fauzi Adam Irwansyah , Wilwatikta Felia Niwan , Rajagukguk Yoki Sepwanto , Sudhana Sonny Adhitya , Yayusman Lissa Fajri , Syahid Luri Nurlaila , Sritarapipat Tanakorn , Principe Jeark A. , Trang Nguyen Thi Quynh , Sulistyawati Endah , Utami Inggita , Arief Candra Wirawan , Wikantika Ketut
Published: August 2020

This study investigated the drivers of degradation in Southeast Asian mangroves through multi-source remote sensing data products. The degradation drivers that affect approximately half of this area are unidentified; therefore, naturogenic and anthropogenic impacts on these mangroves were studied. Various global land cover (GLC) products were harmonized and examined to identify major anthropogenic changes affecting mangrove habitats. To investigate the naturogenic factors, the impact of the water balance was evaluated using the Normalized Difference Vegetation Index (NDVI), and evapotranspiration and precipitation data. Vegetation indices’ response in deforested mangrove regions depends significantly on the type of drivers. A trend analysis and break point detection of percentage of tree cover (PTC), percentage of non-tree vegetation (PNTV), and percentage of non-vegetation (PNV) datasets can aid in measuring, estimating, and tracing the drivers of change. The assimilation of GLC products suggests that agriculture and fisheries are the predominant drivers of mangrove degradation. The relationship between water balance and degradation shows that naturogenic drivers have a wider impact than anthropogenic drivers, and degradation in particular regions is likely to be a result of the accumulation of various drivers. In large-scale studies, remote sensing data products could be integrated as a remarkably powerful instrument in assisting evidence-based policy making.
Automatic Extraction of Grasses and Individual Trees in Urban Areas Based on Airborne Hyperspectral and LiDAR Data
Authors: Man Qixia , Dong Pinliang , Yang Xinming , Wu Quanyuan , Han Rongqing
Published: August 2020

Urban vegetation extraction is very important for urban biodiversity assessment and protection. However, due to the diversity of vegetation types and vertical structure, it is still challenging to extract vertical information of urban vegetation accurately with single remotely sensed data. Airborne light detection and ranging (LiDAR) can provide elevation information with high-precision, whereas hyperspectral data can provide abundant spectral information on ground objects. The complementary advantages of LiDAR and hyperspectral data could extract urban vegetation much more accurately. Therefore, a three-dimensional (3D) vegetation extraction workflow is proposed to extract urban grasses and trees at individual tree level in urban areas using airborne LiDAR and hyperspectral data. The specific steps are as follows: (1) airborne hyperspectral and LiDAR data were processed to extract spectral and elevation parameters, (2) random forest classification method and object-based classification method were used to extract the two-dimensional distribution map of urban vegetation, (3) individual tree segmentation was conducted on a canopy height model (CHM) and point cloud data separately to obtain three-dimensional characteristics of urban trees, and (4) the spatial distribution of urban vegetation and the individual tree delineation were assessed by validation samples and manual delineation results. The results showed that (1) both the random forest classification method and object-based classification method could extract urban vegetation accurately, with accuracies above 99%; (2) the watershed segmentation method based on the CHM could extract individual trees correctly, except for the small trees and the large tree groups; and (3) the individual tree segmentation based on point cloud data could delineate individual trees in three-dimensional space, which is much better than CHM segmentation as it can preserve the understory trees. All the results suggest that two- and three-dimensional urban vegetation extraction could play a significant role in spatial layout optimization and scientific management of urban vegetation.
Automatic Crop Classification in Northeastern China by Improved Nonlinear Dimensionality Reduction for Satellite Image Time Series
Authors: Zhai Yongguang , Wang Nan , Zhang Lifu , Hao Lei , Hao Caihong
Published: August 2020

Accurate and timely information on the spatial distribution of crops is of great significance to precision agriculture and food security. Many cropland mapping methods using satellite image time series are based on expert knowledge to extract phenological features to identify crops. It is still a challenge to automatically obtain meaningful features from time-series data for crop classification. In this study, we developed an automated method based on satellite image time series to map the spatial distribution of three major crops including maize, rice, and soybean in northeastern China. The core method used is the nonlinear dimensionality reduction technique. However, the existing nonlinear dimensionality reduction technique cannot handle missing data, and it is not designed for subsequent classification tasks. Therefore, the nonlinear dimensionality reduction algorithm Landmark–Isometric feature mapping (L–ISOMAP) is improved. The advantage of the improved L–ISOMAP is that it does not need to reconstruct time series for missing data, and it can automatically obtain meaningful featured metrics for classification. The improved L–ISOMAP was applied to Landsat 8 full-band time-series data during the crop-growing season in the three northeastern provinces of China; then, the dimensionality reduction bands were inputted into a random forest classifier to complete a crop distribution map. The results show that the area of crops mapped is consistent with official statistics. The 2015 crop distribution map was evaluated through the collected reference dataset, and the overall classification accuracy and Kappa index were 83.68% and 0.7519, respectively. The geographical characteristics of major crops in three provinces in northeast China were analyzed. This study demonstrated that the improved L–ISOMAP method can be used to automatically extract features for crop classification. For future work, there is great potential for applying automatic mapping algorithms to other data or classification tasks.
A Multi-GNSS Differential Phase Kinematic Post-Processing Method
Authors: Xi Ruijie , Chen Qusen , Meng Xiaolin , Jiang Weiping , An Xiangdong , He Qiyi
Published: August 2020

We propose a multiple global navigation satellite system (multi-GNSS) differential phase kinematic post-processing method, expand the current Track ability, and finely tune processing parameters to achieve the best results for research purposes. The double-difference (DD) phase formulas of GLONASS are especially formulated, and the method of arc ambiguity resolution (AR) in post-processing is developed. To verify the feasibility of this AR method, a group of static baselines with ranges from 8 m to 100 km and two kinematic tests were used. The results imply that 100% of ambiguities in short baselines and over 90% in long baselines can be fixed with the proposed ambiguity resolution method. Better than a 10-mm positioning precision was achieved for all the horizonal components of those selected baselines and the vertical components of the short baselines, and the vertical precision for long baselines is around 20 to 40 mm. In the posterior residual analysis, the means of the residual root-mean-squares (RMSs) of different systems are better than 10 mm for short baselines and at the range of 10–20 mm for baselines longer than 80 km. Mostly, the residuals satisfy the standard normal distribution. It proves that the new method could be applied in bridge displacement and vibration monitoring and for UAV photogrammetry.
Laboratory and UAV-Based Identification and Classification of Tomato Yellow Leaf Curl, Bacterial Spot, and Target Spot Diseases in Tomato Utilizing Hyperspectral Imaging and Machine Learning
Authors: Abdulridha Jaafar , Ampatzidis Yiannis , Qureshi Jawwad , Roberts Pamela
Published: August 2020

Tomato crops are susceptible to multiple diseases, several of which may be present during the same season. Therefore, rapid disease identification could enhance crop management consequently increasing the yield. In this study, nondestructive methods were developed to detect diseases that affect tomato crops, such as bacterial spot (BS), target spot (TS), and tomato yellow leaf curl (TYLC) for two varieties of tomato (susceptible and tolerant to TYLC only) by using hyperspectral sensing in two conditions: a) laboratory (benchtop scanning), and b) in field using an unmanned aerial vehicle (UAV-based). The stepwise discriminant analysis (STDA) and the radial basis function were applied to classify the infected plants and distinguish them from noninfected or healthy (H) plants. Multiple vegetation indices (VIs) and the M statistic method were utilized to distinguish and classify the diseased plants. In general, the classification results between healthy and diseased plants were highly accurate for all diseases; for instance, when comparing H vs. BS, TS, and TYLC in the asymptomatic stage and laboratory conditions, the classification rates were 94%, 95%, and 100%, respectively. Similarly, in the symptomatic stage, the classification rates between healthy and infected plants were 98% for BS, and 99–100% for TS and TYLC diseases. The classification results in the field conditions also showed high values of 98%, 96%, and 100%, for BS, TS, and TYLC, respectively. The VIs that could best identify these diseases were the renormalized difference vegetation index (RDVI), and the modified triangular vegetation index 1 (MTVI 1) in both laboratory and field. The results were promising and suggest the possibility to identify these diseases using remote sensing.
Remote Sensing-Informed Zonation for Understanding Snow, Plant and Soil Moisture Dynamics within a Mountain Ecosystem
Authors: Devadoss Jashvina , Falco Nicola , Dafflon Baptiste , Wu Yuxin , Franklin Maya , Hermes Anna , Hinckley Eve-Lyn S. , Wainwright Haruko
Published: August 2020

In the headwater catchments of the Rocky Mountains, plant productivity and its dynamics are largely dependent upon water availability, which is influenced by changing snowmelt dynamics associated with climate change. Understanding and quantifying the interactions between snow, plants and soil moisture is challenging, since these interactions are highly heterogeneous in mountainous terrain, particularly as they are influenced by microtopography within a hillslope. Recent advances in satellite remote sensing have created an opportunity for monitoring snow and plant dynamics at high spatiotemporal resolutions that can capture microtopographic effects. In this study, we investigate the relationships among topography, snowmelt, soil moisture and plant dynamics in the East River watershed, Crested Butte, Colorado, based on a time series of 3-meter resolution PlanetScope normalized difference vegetation index (NDVI) images. To make use of a large volume of high-resolution time-lapse images (17 images total), we use unsupervised machine learning methods to reduce the dimensionality of the time lapse images by identifying spatial zones that have characteristic NDVI time series. We hypothesize that each zone represents a set of similar snowmelt and plant dynamics that differ from other identified zones and that these zones are associated with key topographic features, plant species and soil moisture. We compare different distance measures (Ward and complete linkage) to understand the effects of their influence on the zonation map. Results show that the identified zones are associated with particular microtopographic features; highly productive zones are associated with low slopes and high topographic wetness index, in contrast with zones of low productivity, which are associated with high slopes and low topographic wetness index. The zones also correspond to particular plant species distributions; higher forb coverage is associated with zones characterized by higher peak productivity combined with rapid senescence in low moisture conditions, while higher sagebrush coverage is associated with low productivity and similar senescence patterns between high and low moisture conditions. In addition, soil moisture probe and sensor data confirm that each zone has a unique soil moisture distribution. This cluster-based analysis can tractably analyze high-resolution time-lapse images to examine plant-soil-snow interactions, guide sampling and sensor placements and identify areas likely vulnerable to ecological change in the future.