bluuebunny/crossref_metadata_2025 huggingface dataset:
Melatonin, Its Metabolites and Their Interference with Reactive Nitrogen Compounds
Authors: Hardeland Rüdiger
Published: July 2021

Melatonin and several of its metabolites are interfering with reactive nitrogen. With the notion of prevailing melatonin formation in tissues that exceeds by far the quantities in blood, metabolites come into focus that are poorly found in the circulation. Apart from their antioxidant actions, both melatonin and N1-acetyl-5-methoxykynuramine (AMK) downregulate inducible and inhibit neuronal NO synthases, and additionally scavenge NO. However, the NO adduct of melatonin redonates NO, whereas AMK forms with NO a stable product. Many other melatonin metabolites formed in oxidative processes also contain nitrosylatable sites. Moreover, AMK readily scavenges products of the CO2-adduct of peroxynitrite such as carbonate radicals and NO2. Protein AMKylation seems to be involved in protective actions.
Novel Silsesquioxane-Derived Boronate Esters—Synthesis and Thermal Properties
Authors: Frydrych Miłosz , Pakuła Daria , Sztorch Bogna , Brząkalski Dariusz , Przekop Robert E. , Marciniec Bogdan
Published: July 2021

The functionalization of mono- and octahydrospherosilicate with vinylboranes and allylboranes via hydrosilylation reaction in the presence of a Karstedt’s platinum (0) catalyst is presented. This is the catalytic route to obtain a new class of silsesquioxanes containing boron atoms in their structure in high yields (>90%) and with satisfactory selectivity. The obtained compounds were fully characterized by spectroscopic (1H, 13C, 29Si NMR) and spectrometric methods (MALDI-TOF-MS), as well as thermal analysis (TGA). The obtained compounds were subjected to thermal tests, characterizing the processes of melting, thermal evaporation, sublimation and thermal decomposition.
Phytochemical Constituents, Antioxidant Activity, and Toxicity Assessment of the Aerial Part Extracts from the Infraspecific Taxa of Matthiola fruticulosa (Brassicaceae) Endemic to Sicily
Authors: Taviano Maria Fernanda , Cavò Emilia , Spadaro Vivienne , Raimondo Francesco Maria , Musolino Vincenzo , Cacciola Francesco , El Majdoub Yassine Oulad , Mondello Luigi , Condurso Concetta , Cincotta Fabrizio , Verzera Antonella , Miceli Natalizia
Published: July 2021

In a project designed to investigate the specific and infraspecific taxa of Matthiola endemic to Sicily (Italy) as new potential sources of bioactive compounds in this work, the infraspecific taxa of Matthiola fruticulosa were studied, namely, subsp. fruticulosa and subsp. coronopifolia. HPLC–PDA/ESI–MS and SPME–GC/MS analyses of hydroalcoholic extracts obtained from the aerial parts of the two subspecies led to the detection of 51 phenolics and 61 volatile components, highlighting a quite different qualitative–quantitative profile. The antioxidant properties of the extracts were explored through in vitro methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power and Fe2+ chelating activity assays. The results of the antioxidant tests showed that the extracts possess a different antioxidant ability: particularly, the extract of M. fruticulosa subsp. fruticulosa exhibited higher radical scavenging activity than that of subsp. coronopifolia (IC50 = 1.25 ± 0.02 mg/mL and 2.86 ± 0.05 mg/mL), which in turn displayed better chelating properties (IC50 = 1.49 ± 0.01 mg/mL and 0.63 ± 0.01 mg/mL). Lastly, Artemia salina lethality bioassay was performed for toxicity assessment. The results of the bioassay showed lack of toxicity against brine shrimp larvae for both extracts. The data presented indicate the infraspecific taxa of M. fruticulosa as new and safe sources of antioxidant compounds.
Electrochemical Determination of the “Furanic Index” in Honey
Authors: Salis Severyn , Spano Nadia , Ciulu Marco , Floris Ignazio , Pilo Maria I. , Sanna Gavino
Published: July 2021

5-(hydroxymethyl)furan-2-carbaldehyde, better known as hydroxymethylfurfural (HMF), is a well-known freshness parameter of honey: although mostly absent in fresh samples, its concentration tends to increase naturally with aging. However, high quantities of HMF are also found in fresh but adulterated samples or honey subjected to thermal or photochemical stresses. In addition, HMF deserves further consideration due to its potential toxic effects on human health. The processes at the origin of HMF formation in honey and in other foods, containing saccharides and proteins—mainly non-enzymatic browning reactions—can also produce other furanic compounds. Among others, 2-furaldehyde (2F) and 2-furoic acid (2FA) are the most abundant in honey, but also their isomers (i.e., 3-furaldehyde, 3F, and 3-furoic acid, 3FA) have been found in it, although in small quantities. A preliminary characterization of HMF, 2F, 2FA, 3F, and 3FA by cyclic voltammetry (CV) led to hypothesizing the possibility of a comprehensive quantitative determination of all these compounds using a simple and accurate square wave voltammetry (SWV) method. Therefore, a new parameter able to provide indications on quality of honey, named “Furanic Index” (FI), was proposed in this contribution, which is based on the simultaneous reduction of all analytes on an Hg electrode to ca. −1.50 V vs. Saturated Calomel Electrode (SCE). The proposed method, validated, and tested on 10 samples of honeys of different botanical origin and age, is fast and accurate, and, in the case of strawberry tree honey (Arbutus unedo), it highlighted the contribution to the FI of the homogentisic acid (HA), i.e., the chemical marker of the floral origin of this honey, which was quantitatively reduced in the working conditions. Excellent agreement between the SWV and Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) data was observed in all samples considered.
Discovery of New Hits as Antitrypanosomal Agents by In Silico and In Vitro Assays Using Neolignan-Inspired Natural Products from Nectandra leucantha
Authors: Araujo Sheila C. , Sousa Fernanda S. , Costa-Silva Thais A. , Tempone Andre G. , Lago João Henrique G. , Honorio Kathia M.
Published: July 2021

In the present study, the phytochemical study of the n-hexane extract from flowers of Nectandra leucantha (Lauraceae) afforded six known neolignans (1–6) as well as one new metabolite (7), which were characterized by analysis of NMR, IR, UV, and ESI-HRMS data. The new compound 7 exhibited potent activity against the clinically relevant intracellular forms of T. cruzi (amastigotes), with an IC50 value of 4.3 μM and no observed mammalian cytotoxicity in fibroblasts (CC50 > 200 μM). Based on the results obtained and our previous antitrypanosomal data of 50 natural and semi-synthetic related neolignans, 2D and 3D molecular modeling techniques were employed to help the design of new neolignan-based compounds with higher activity. The results obtained from the models were important to understand the main structural features related to the biological response of the neolignans and to aid in the design of new neolignan-based compounds with better biological activity. Therefore, the results acquired from phytochemical, biological, and in silico studies showed that the integration of experimental and computational techniques consists of a powerful tool for the discovery of new prototypes for development of new drugs to treat CD.
Cyanovinylation of Aldehydes: Organocatalytic Multicomponent Synthesis of Conjugated Cyanomethyl Vinyl Ethers
Authors: Delgado-Hernández Samuel , García-Tellado Fernando , Tejedor David
Published: July 2021

A novel organocatalytic multicomponent cyanovinylation of aldehydes was designed for the synthesis of conjugated cyanomethyl vinyl ethers. The reaction was implemented for the synthesis of a 3-substituted 3-(cyanomethoxy)acrylates, using aldehydes as substrates, acetone cyanohydrin as the cyanide anion source, and methyl propiolate as the source of the vinyl component. The multicomponent reaction is catalyzed by N-methyl morpholine (2.5 mol%) to deliver the 3-(cyanomethoxy)acrylates in excellent yields and with preponderance of the E-isomer. The multicomponent reaction manifold is highly tolerant to the structure and composition of the aldehyde (aliphatic, aromatic, heteroaromatics), and it is instrumentally simple (one batch, open atmospheres), economic (2.5 mol% catalyst, stoichiometric reagents), environmentally friendly (no toxic waste), and sustainable (easy scalability).
Bioactive Abietane-Type Diterpenoid Glycosides from Leaves of Clerodendrum infortunatum (Lamiaceae)
Authors: Uddin Md. Josim , Russo Daniela , Haque Md. Anwarul , Çiçek Serhat Sezai , Sönnichsen Frank D. , Milella Luigi , Zidorn Christian
Published: July 2021

In this study, two previously undescribed diterpenoids, (5R,10S,16R)-11,16,19-trihydroxy-12-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)-diabeo-3,8,11,13-abietatetraene-7-one (1) and (5R,10S,16R)-11,16-dihydroxy-12-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)-diabeo-4-carboxy-3,8,11,13-abietatetraene-7-one (2), and one known compound, the C13-nor-isoprenoid glycoside byzantionoside B (3), were isolated from the leaves of Clerodendrum infortunatum L. (Lamiaceae). Structures were established based on spectroscopic and spectrometric data and by comparison with literature data. The three terpenoids, along with five phenylpropanoids: 6′-O-caffeoyl-12-glucopyranosyloxyjasmonic acid (4), jionoside C (5), jionoside D (6), brachynoside (7), and incanoside C (8), previously isolated from the same source, were tested for their in vitro antidiabetic (α-amylase and α-glucosidase), anticancer (Hs578T and MDA-MB-231), and anticholinesterase activities. In an in vitro test against carbohydrate digestion enzymes, compound 6 showed the most potent effect against mammalian α-amylase (IC50 3.4 ± 0.2 μM) compared to the reference standard acarbose (IC50 5.9 ± 0.1 μM). As yeast α-glucosidase inhibitors, compounds 1, 2, 5, and 6 displayed moderate inhibitory activities, ranging from 24.6 to 96.0 μM, compared to acarbose (IC50 665 ± 42 μM). All of the tested compounds demonstrated negligible anticholinesterase effects. In an anticancer test, compounds 3 and 5 exhibited moderate antiproliferative properties with IC50 of 94.7 ± 1.3 and 85.3 ± 2.4 μM, respectively, against Hs578T cell, while the rest of the compounds did not show significant activity (IC50 > 100 μM).
Improved Surface-Enhanced-Raman Scattering Sensitivity Using Si Nanowires/Silver Nanostructures by a Single Step Metal-Assisted Chemical Etching
Authors: Kochylas Ioannis , Gardelis Spiros , Likodimos Vlassis , Giannakopoulos Konstantinos , Falaras Polycarpos , Nassiopoulou Androula
Published: July 2021

In this study, we developed highly sensitive substrates for Surface-Enhanced-Raman-Scattering (SERS) spectroscopy, consisting of silicon nanowires (SiNWs) decorated by silver nanostructures using single-step Metal Assisted Chemical Etching (MACE). One-step MACE was performed on p-type Si substrates by immersion in AgNO3/HF aqueous solutions resulting in the formation of SiNWs decorated by either silver aggregates or dendrites. Specifically, dendrites were formed during SiNWs’ growth in the etchant solution, whereas aggregates were grown after the removal of the dendrites from the SiNWs in HNO3 aqueous solution and subsequent re-immersion of the specimens in a AgNO3/HF aqueous solution by adjusting the growth time to achieve the desired density of silver nanostructures. The dendrites had much larger height than the aggregates. R6G was used as analyte to test the SERS activity of the substrates prepared by the two fabrication processes. The silver aggregates showed a considerably lower limit of detection (LOD) for SERS down to a R6G concentration of 10−13 M, and much better uniformity in terms of detection in comparison with the silver dendritic structures. Enhancement factors in the range 105–1010 were calculated, demonstrating very high SERS sensitivities for analytic applications.
Ultralow Threshold Lasing from Carbon Dot–Ormosil Gel Hybrid-Based Planar Microcavity
Authors: Ni Yiqun , Han Zhixia , Ren Junkai , Wang Zhen , Zhang Wenfei , Xie Zheng , Shao Yonghong , Zhou Shuyun
Published: July 2021

The absence of an ideal solid matrix with resistance to harsh conditions for carbon dots (CDs) and high transmittance in the visible/near infrared region is the bottleneck in CD applications. In this study, we show that a stable rigid structure can be formed between CDs and organically modified silicates (ormosil) gel when CDs are incorporated into ormosil gel hybrids as a solid matrix. A high photoluminescence quantum yield (PLQY) of 63% is achieved at a 583 nm emission. Peak optical gain of the hybrids was found to be 67 cm−1 at peak wavelength. Ultralow threshold (~70 W/cm2) lasing can also be demonstrated from a planar microcavity by using CD–ormosil gel hybrids as a gain medium.
Study on the Effect of Nanoparticle Used in Nano-Fluid Flooding on Droplet–Interface Electro-Coalescence
Authors: Yang Donghai , Sun Huayao , Chang Qing , Sun Yongxiang , He Limin
Published: July 2021

Nano-fluid flooding is a new method capable of improving oil recovery; however, nanoparticles (NPs) significantly affect electric dehydration, which has rarely been investigated. The effect of silica (SiO2) NPs on the droplet–interface coalescence was investigated using a high-speed digital camera under an electric field. The droplet experienced a fall, coalescence, and secondary droplet formation. The results revealed that the oil–water interfacial tension and water conductivity changed because of the SiO2 NPs. The decrease of interfacial tension facilitated droplet deformation during the falling process. However, with the increase of particle concentration, the formed particle film inhibited the droplet deformation degree. Droplet and interface are connected by a liquid bridge during coalescence, and the NP concentration also resulted in the shape of this liquid bridge changing. The increase of NP concentration inhibited the horizontal contraction of the liquid bridge while promoting vertical collapse. As a result, it did not facilitate secondary droplet formation. Moreover, the droplet falling velocity decreased, while the rising velocity of the secondary droplet increased. Additionally, the inverse calculation of the force balance equation showed that the charge of the secondary droplet also increased. This is attributed to nanoparticle accumulation, which resulted in charge accumulation on the top of the droplet.
Oncological Children and Well-Being: Occupational Performance and HRQOL Change after Fine Motor Skills Stimulation Activities
Authors: Taverna Livia , Bellavere Martina , Tremolada Marta , Santinelli Lietta , Rudelli Nicola , Mainardi Michele , Onder Graziano , Putti Maria Caterina , Biffi Alessandra , Tosetto Barbara
Published: July 2021

Cancer children experience long periods of hospitalization, which are associated with limited performance in several developmental domains and participation restrictions in age appropriate occupations. Fine motor abilities represent building blocks in performing daily life skills and have been found to be closely connected with later academic success. Moreover, medical and psychological sequelae for cancer inpatients may result in diminished daily activities functioning, poor perceived health related quality of life (HRQOL), and increase the likelihood of long-term impairments. This study examines the variations in the occupational performance of children hospitalized for acute lymphoblastic leukemia (ALL) after their participation to a stimulation program designed to enhance fine motor skills. Parents reported significant gains in children’s motor functioning, a slight improvement in overall occupational performance related to an increase in the area of productivity and self-care, and a better quality of life perception following the stimulation activities. Feasibility of the stimulation program in a health care setting are discussed evaluating its benefits for cancer children and their families.
In Vitro Skin Permeation of Idebenone from Lipid Nanoparticles Containing Chemical Penetration Enhancers
Authors: Montenegro Lucia , Santagati Ludovica Maria , Sarpietro Maria Grazia , Castelli Francesco , Panico Annamaria , Siciliano Edy Angela , Lai Francesco , Valenti Donatella , Sinico Chiara
Published: July 2021

Lipid nanoparticles (LNPs) have been proposed as carriers for drug skin delivery and targeting. As LNPs effectiveness could be increased by the addition of chemical penetration enhancers (PE), in this work, the feasibility of incorporating PE into LNPs to improve idebenone (IDE) targeting to the skin was investigated. LNPs loading IDE 0.7% w/w were prepared using hydrophilic (propylene glycol, PG, 10% w/w or N-methylpyrrolidone, NMP, 10% w/w) and/or lipophilic PE (oleic acid, OA, 1% w/w; isopropyl myristate, IPM, 3.5% w/w; a mixture of 0.5% w/w OA and 2.5% w/w IPM). All LNPs showed small sizes (<60 nm), low polydispersity index and good stability. According to the obtained results, IDE release from LNPs was not the rate-limiting step in IDE skin penetration. No IDE permeation was observed through excised pigskin from all LNPs, while the greatest increase of IDE penetration into the different skin layers was obtained using the mixture OA/IPM. The antioxidant activity of IDE-loaded LNPs, determined by the oxygen radical absorbance capacity assay, was greater than that of free IDE. These results suggest that the use of suitable PE as LNPs components could be regarded as a promising strategy to improve drug targeting to the skin.
Gancaonin N from Glycyrrhiza uralensis Attenuates the Inflammatory Response by Downregulating the NF-κB/MAPK Pathway on an Acute Pneumonia In Vitro Model
Authors: Ko Hyun Min , Lee Seung-Hyeon , Jee Wona , Jung Ji Hoon , Kim Kwan-Il , Jung Hee-Jae , Jang Hyeung-Jin
Published: July 2021

Acute pneumonia is an inflammatory disease caused by several pathogens, with symptoms such as fever and chest pain, to which children are particularly vulnerable. Gancaonin N is a prenylated isoflavone of Glycyrrhiza uralensis that has been used in the treatment of various diseases in oriental medicine. There are little data on the anti-inflammatory efficacy of Gancaonin N, and its effects and mechanisms on acute pneumonia are unknown. Therefore, this study was conducted as a preliminary analysis of the anti-inflammatory effect of Gancaonin N in lipopolysaccharide (LPS)-induced RAW264.7 cells, and to identify its preventive effect on the lung inflammatory response and the molecular mechanisms underlying it. In this study, Gancaonin N inhibited the production of NO and PGE2 in LPS-induced RAW264.7 cells and significantly reduced the expression of iNOS and COX-2 proteins at non-cytotoxic concentrations. In addition, in LPS-induced A549 cells, Gancaonin N significantly reduced the expression of COX-2 and pro-inflammatory cytokines, such as TNF-α, IL-1β, and IL-6. Moreover, Gancaonin N reduced MAPK signaling pathway phosphorylation and NF-κB nuclear translocation. Therefore, Gancaonin N relieved the inflammatory response by inactivating the MAPK and NF-κB signaling pathways; thus, it is a potential natural anti-inflammatory agent that can be used in the treatment of acute pneumonia.
Machine Learning Assisted Inverse Design for Ultrafine, Dynamic and Arbitrary Gain Spectrum Shaping of Raman Amplification
Authors: Huang Yuting , Du Jiangbing , Chen Yufeng , Xu Ke , He Zuyuan
Published: July 2021

Distributed Raman amplifier (DRA) has been widely studied in recent decades because of its low noise figure and flexible gain. In this paper, we present a novel scheme of DRA with broadband amplified spontaneous emission(ASE) source as pump instead of discrete pump lasers. The broadband pump is optimized by machine learning based inverse design and shaped by programmable waveshaper, so as to realize the ultrafine, dynamic and arbitrary gain spectrum shaping of Raman amplification. For the target of flat gain spectrum, the maximum gain flatness of 0.1086 dB is realized based on the simulation results. For the target of arbitrary gain spectrum, we demonstrate four gain profiles with maximum root mean square error (RMSE) of 0.074 dB. To further measure the performance of arbitrary gain spectrum optimization, the probability density functions (PDF) of RMSE and Errormax are presented. Meanwhile, the numeral relationship between the bands of broadband pump and signal is also explored. Furthermore, this work has great application potential to compensate the gain distortion or dynamic change caused by other devices in communication systems.
Thermal Noise in Cubic Optical Cavities
Authors: Xu Guanjun , Jiao Dongdong , Chen Long , Zhang Linbo , Dong Ruifang , Liu Tao , Wang Junbiao
Published: July 2021

Thermal noise in optical cavities sets a fundamental limit to the frequency instability of ultra-stable lasers. Numata et al. derived three equations based on strain energy and the fluctuation–dissipation theorem to estimate the thermal noise contributions of the spacer, substrates, and coating. These equations work well for cylindrical cavities. Extending from that, an expression for the thermal noise for a cubic spacer based on the fluctuation–dissipation theorem is derived, and the thermal noise in cubic optical cavities is investigated in detail by theoretical analysis and finite element simulation. The result shows that the thermal noise of the analytic estimate fits well with that of finite element analysis. Meanwhile, the influence of the compressive force Fp on the thermal noise in cubic optical cavities is analyzed for the first time. For a 50 mm long ultra-low expansion cubic cavity with fused silica substrates and GaAs/AlGaAs crystalline coating, the displacement noise contributed from every Fp of 100 N is about three times more than that of the substrate and coating.
Comparison of Refractive and Visual Outcomes after Transepithelial Photorefractive Keratectomy (TransPRK) in Low versus Moderate Myopia
Authors: de Ortueta Diego , von Rüden Dennis , Arba-Mosquera Samuel
Published: July 2021

Is it possible to obtain good results in myopia of 2 or fewer diopters (D) with transepithelial photorefractive keratectomy (TransPRK) changing the optical zone and epithelium thickness? We retrospectively analyzed two groups of 296 eyes with a minimum follow-up of 4 months. Group A had 2 or less D, treated with an optical zone (OZ) 0.2 mm bigger than recommended, and a central epithelium thickness of 60 microns, and group B had 2 D to 5 D, with the recommended optical zone, and a 55-micron epithelium ablation at the center. The outcomes were not different between the two myopic ranges; the postop uncorrected distance visual acuity was 20/20 ± 4 in both groups (p = 0.2), which was −0.3 ± 0.8 lines worse than the preoperative corrected distance visual acuity in both groups (p = 0.5). The safety of the treatments resulted in a change of 0.0 ± 0.7 lines in the low myopia group, versus a gain of +0.1 ± 0.8 lines in the moderate myopia group (p = 0.1). The deviation from the intended target was −0.04 ± 0.33 D in the low myopia group and +0.07 ± 0.32 D in the moderate myopia group (p < 0.0001); the postoperative spherical equivalent was 0.00 ± 0.33 D in the low myopia group and +0.10 ± 0.31 D in the moderate myopia group (p < 0.0001). The postop refractive astigmatism was 0.32 ± 0.16 D in both groups (p = 0.5). In conclusion, the refractive and visual outcomes after TransPRK are comparable in low myopia changing the optical zone and epithelium thickness versus moderate myopia with standard optical zone and epithelium thickness.
Preparation and Properties of the Urea-Formaldehyde Res-In/Reactive Halloysite Nanocomposites Adhesive with Low-Formaldehyde Emission and Good Water Resistance
Authors: Song Jingbiao , Chen Shiwei , Yi Xibin , Zhao Xinfu , Zhang Jing , Liu Xiaochan , Liu Benxue
Published: July 2021

Low-cost urea formaldehyde resin (UF)/reactive halloysite nanotubes (HNTs) nanocomposite adhesive was prepared successfully via in situ polymerization. The HNTs were modified to improve its compatibility with polymer. The XRD and FTIR results showed that physical and chemical interaction between the HNTs and polymer resin influenced the structure of UF owing to the functional groups on the HNTs. It is found from SEM images that the modified HNTs could be dispersed uniformly in the resin and the nanocomposite particles were spherical. The performance experiment confirmed that thermal stability of nanocomposite increased largely, formaldehyde emission of UF wood adhesive reduced 62%, and water resistance of UF wood adhesive improved by 84%. Meanwhile, the content of HNTs on the nanocomposites could be up to 60 wt %. The mechanism of the nanocomposites based on the reactive HNTs was proposed. The approach of the preparation could supply an idea to prepare other polymer/clay nanocomposites.
Synthesis, Characterization, and Evaluation of Nanoparticles Loading Adriamycin Based on 2-Hydroxypropyltrimethyl Ammonium Chloride Chitosan Grafting Folic Acid
Authors: Mi Yingqi , Zhang Jingjing , Zhang Lulin , Li Qing , Cheng Yuanzheng , Guo Zhanyong
Published: July 2021

Chitosan nanoparticles have been considered as potential candidates for drug loading/release in drug delivery systems. In this paper, nanoparticles (HACAFNP) loading adriamycin based on 2-hydroxypropyltrimethyl ammonium chloride chitosan grafting folic acid (HACF) were synthesized. The surface morphology of the novel nanoparticles was spherical or oval, and the nanoparticles exhibited a relatively small hydrodynamic diameter (85.6 ± 2.04 nm) and positive zeta potential (+21.06 ± 0.96 mV). The drug release of nanoparticles was assayed and represented a burst effect followed by a long-term steady release. Afterward, the antioxidant efficiencies of nanoparticles were assayed. In particular, the target nanoparticles exhibited significant enhancement in radical scavenging activities. Cytotoxicities against cancer cells (MCF-7, BGC-823, and HEPG-2) were estimated in vitro, and results showed nanoparticles inhibited the growth of cancer cells. It’s worth noting that the inhibition index of HACAFNP against BGC-823 cells was 71.19% with the sample concentration of 25 μg/mL, which was much higher than the inhibitory effect of ADM. It was demonstrated that the novel nanoparticles with dramatically enhanced biological activity, reduced cytotoxicity, and steady release could be used as the practical candidates for drug loading/release in a delivery system.
Maximum Likelihood Estimation Based Nonnegative Matrix Factorization for Hyperspectral Unmixing
Authors: Jiang Qin , Dong Yifei , Peng Jiangtao , Yan Mei , Sun Yi
Published: July 2021

Hyperspectral unmixing (HU) is a research hotspot of hyperspectral remote sensing technology. As a classical HU method, the nonnegative matrix factorization (NMF) unmixing method can decompose an observed hyperspectral data matrix into the product of two nonnegative matrices, i.e., endmember and abundance matrices. Because the objective function of NMF is the traditional least-squares function, NMF is sensitive to noise. In order to improve the robustness of NMF, this paper proposes a maximum likelihood estimation (MLE) based NMF model (MLENMF) for unmixing of hyperspectral images (HSIs), which substitutes the least-squares objective function in traditional NMF by a robust MLE-based loss function. Experimental results on a simulated and two widely used real hyperspectral data sets demonstrate the superiority of our MLENMF over existing NMF methods.
Shortwave Radiance to Irradiance Conversion for Earth Radiation Budget Satellite Observations: A Review
Authors: Gristey Jake J. , Su Wenying , Loeb Norman G. , Vonder Haar Thomas H. , Tornow Florian , Schmidt K. Sebastian , Hakuba Maria Z. , Pilewskie Peter , Russell Jacqueline E.
Published: July 2021

Observing the Earth radiation budget (ERB) from satellites is crucial for monitoring and understanding Earth’s climate. One of the major challenges for ERB observations, particularly for reflected shortwave radiation, is the conversion of the measured radiance to the more energetically relevant quantity of radiative flux, or irradiance. This conversion depends on the solar-viewing geometry and the scene composition associated with each instantaneous observation. We first outline the theoretical basis for algorithms to convert shortwave radiance to irradiance, most commonly known as empirical angular distribution models (ADMs). We then review the progression from early ERB satellite observations that applied relatively simple ADMs, to current ERB satellite observations that apply highly sophisticated ADMs. A notable development is the dramatic increase in the number of scene types, made possible by both the extended observational record and the enhanced scene information now available from collocated imager information. Compared with their predecessors, current shortwave ADMs result in a more consistent average albedo as a function of viewing zenith angle and lead to more accurate instantaneous and mean regional irradiance estimates. One implication of the increased complexity is that the algorithms may not be directly applicable to observations with insufficient accompanying imager information, or for existing or new satellite instruments where detailed scene information is not available. Recent advances that complement and build on the base of current approaches, including machine learning applications and semi-physical calculations, are highlighted.
A Strong Kuroshio Intrusion into the South China Sea and Its Accompanying Cold-Core Anticyclonic Eddy in Winter 2020–2021
Authors: Sun Zhenyu , Hu Jianyu , Chen Zhaozhang , Zhu Jia , Yang Longqi , Chen Xirong , Wu Xuewen
Published: July 2021

Multiple remote sensing datasets, combined with in-situ drifter observations, were used to analyze the Kuroshio intrusion through the Luzon Strait (LS). The results showed that a strong Kuroshio Current Loop (KCL) and accompanying anticyclonic eddy (ACE) existed in winter 2020–2021. As quantitatively demonstrated by the Double Index (DI), the Kuroshio Warm Eddy Index (KWI) had low values during a long sustained period compared to those in all other years in the available historical records. Remarkable kinematic properties (i.e., amplitude, diameter, propagated distance, lifespan and propagating speed) of the accompanying ACE were extracted by automatic eddy detection algorithms, showing that the ACE had a maximum diameter of 381 km and a peak amplitude of 50 cm, which significantly exceeded the previous statistics in winter. The orographic negative wind stress curl southwest of Taiwan Island and the westward Ekman transport through the LS during the winter half year of 2020–2021 both had large values beyond their historical maxima. Hence wind forcing is regarded as the primary forcing mechanism during this event. Alternating cyclonic eddies (CEs) and ACEs approaching on the east of the LS were identified, indicating that the interaction between the Kuroshio and the impinging CEs at proper locations made extra contributions to enhancing the KCL. The accompanying ACE had a distinctive feature of a cold-core structure at the surface layer, so as to be categorized as a cold core ACE (CC-ACE), and the temperature difference between the cold core and outer warm ring was maintained for three months. The generation and long duration of the CC-ACE may be due to the sustaining entrainment supported by the warm water from Kuroshio intrusion and the Northwest Luzon Coastal Current (NWLCC) successively.
River Extraction under Bankfull Discharge Conditions Based on Sentinel-2 Imagery and DEM Data
Authors: Li Dan , Wang Ge , Qin Chao , Wu Baosheng
Published: July 2021

River discharge and width, as essential hydraulic variables and hydrological data, play a vital role in influencing the water cycle, driving the resulting river topography and supporting ecological functioning. Insights into bankfull river discharge and bankfull width at fine spatial resolutions are essential. In this study, 10-m Sentinel-2 multispectral instrument (MSI) imagery and digital elevation model (DEM) data, as well as in situ discharge and sediment data, are fused to extract bankfull river widths on the upper Yellow River. Using in situ cross-section morphology data and flood frequency estimations to calculate the bankfull discharge of 22 hydrological stations, the one-to-one correspondence relationship between the bankfull discharge data and the image cover data was determined. The machine learning (ML) method is used to extract water bodies from the Sentinel-2 images in the Google Earth Engine (GEE). The mean overall accuracy was above 0.87, and the mean kappa value was above 0.75. The research results show that (1) for rivers with high suspended sediment concentrations, the water quality index (SRMIR-Red) constitutes a higher contribution; the infrared band performs better in areas with greater amounts of vegetation coverage; and for rivers in general, the water indices perform best. (2) The effective river width of the extracted connected rivers is 30 m, which is 3 times the image resolution. The R2, root mean square error (RMSE), and mean bias error (MBE) of the estimated river width values are 0.991, 7.455 m, and −0.232 m, respectively. (3) The average river widths of the single-thread sections show linear increases along the main stream, and the R2 value is 0.801. The river width has a power function relationship with bankfull discharge and the contributing area, i.e., the downstream hydraulic geometry, with R2 values of 0.782 and 0.630, respectively. More importantly, the extracted river widths provide basic data to analyze the spatial distribution of bankfull widths along river networks and other applications in hydrology, fluvial geomorphology, and stream ecology.
Effects of Cloud Microphysics on the Vertical Structures of Cloud Radiative Effects over the Tibetan Plateau and the Arctic
Authors: Yan Yafei , Liu Yimin , Liu Xiaolin , Wang Xiaocong
Published: July 2021

The Tibetan Plateau (TP) and the Arctic are both cold, fragile, and sensitive to global warming. However, they have very different cloud radiative effects (CRE) and influences on the climate system. In this study, the effects of cloud microphysics on the vertical structures of CRE over the two regions are analyzed and compared by using CloudSat/CALIPSO satellite data and the Rapid Radiative Transfer Model. Results show there is a greater amount of cloud water particles with larger sizes over the TP than over the Arctic, and the supercooled water is found to be more prone to exist over the former than the latter, making shortwave and longwave CRE, as well as the net CRE, much stronger over the TP. Further investigations indicate that the vertical structures of CRE at high altitudes are primarily dominated by cloud ice water, while those at low altitudes are dominated by cloud liquid and mixed-phase water. The liquid and mixed-phase water results in a strong shallow heating (cooling) layer above the cooling (heating) layer in the shortwave (longwave) CRE profiles, respectively.
Limiting Accuracy of Height Measurement for a Precision Radar Altimeter in a Low Altitude Flying Vehicle above the Sea Surface
Authors: Baskakov Aleksandr I. , Komarov Alexey A. , Ruban Anna V. , Ka Min-Ho
Published: July 2021

This study presents mathematical analysis and numerical modeling for the estimation of measurement errors of height estimation over the sea surface for a precision radar altimeter installed in a low altitude flying vehicle. Reflective properties of the electromagnetic signals from the sea surface are determined by the local backscattering patterns of the sea surface illuminated. The height estimation of the flying vehicle from the received echo signals at the output of its tracking system is the sum of three factors: the first factor is the height to the average sea level the second is the bias of the estimation of the height, which is time-varying and depends on the slope of large-scale roughness; the third is the terms related to the surface topography. For the calculation of the estimation errors of the height measurement of a low altitude precision radar altimeter, a reasonable approximation of the large roughness of the sea surface by a deterministic function is necessary. In this study, we performed the derivation of the estimation function and the analysis of the limiting accuracy of the height measurement using the calculation of the estimation errors in spectral domain method describing the large-scale sea surface roughness. The results obtained for the limiting accuracy of a flying vehicle at low altitude above the sea surface, allows to obtain reasonable system parameters minimizing height errors of the flight altitude.
Can Gravitational Waves Halt the Expansion of the Universe?
Authors: Frauendiener Jörg , Hakata Jonathan , Stevens Chris
Published: July 2021

We numerically investigate the propagation of plane gravitational waves in the form of an initial boundary value problem with de Sitter initial data. The full non-linear Einstein equations with positive cosmological constant λ are written in the Friedrich–Nagy gauge which yields a wellposed system. The propagation of a single wave and the collision of two with colinear polarization are studied and contrasted with their Minkowskian analogues. Unlike with λ=0, critical behaviours are found with λ>0 and are based on the relationship between the wave profile and λ. We find that choosing boundary data close to one of these bifurcations results in a “false” steady state which violates the constraints. Simulations containing (approximate) impulsive wave profiles are run and general features are discussed. Analytic results of Tsamis and Woodard, which describe how gravitational waves could affect an expansion rate at an initial instance of time, are explored and generalized to the entire space–time. Finally we put forward boundary conditions that, at least locally, slow down the expansion considerably for a time.
Promising Directions of Innovative Technologies for Home Care of Citizens
Authors: Khamadeeva Rita , Leonidovna Natalia
Published: July 2021

The article considers home social care as the most popular type of social service for citizens. It is noted that it is necessary to improve the quality and targeting of home care, its adaptation to modern realities, the introduction of information methods and technologies for providing social services to needy categories of the population.
Socio-economic consequences of the change of the Political Regime in Kyrgyzstan
Authors: Aitiev Shurkhat , Salmorbekova Rita
Published: July 2021

This article analyses the socio-economic and political reasons for the ineffectiveness of post-soviet regimes of Kyrgyzstan. Based on the analysis of current events, the author notes the role of third forces in the systematic instability in society. It also presents a lot of unresolved problems, in particular, ethno-nationalism, division of society into Southern and Northern clans (on a regional basis), growing problems of security of the country's citizens. At the same time, the summarising aspect indicates the driving forces of socio-political conflicts in Kyrgyzstan in 2005–2010, which led to the change of political regimes.
Programmes for the Formation of Elementary Social Interaction Skills in Young Children with Special Needs
Authors: Sass Anastasia , Savitskaya Mariya
Published: July 2021

Nowadays, in the Republic of Belarus conditions that allow every child with special needs to integrate into society are created. The solution of this problem is directly related to the implementation of the socialising function of the family and educational institutions. We have analysed the existing programmes for providing early comprehensive assistance to children with special needs and summarised the material on the problem of forming elementary skills of social interaction in young children based on the analysis of national and foreign programmes.
Information and psychological confrontation in the context of the formation of regional security of the post-Soviet space: content and main stages
Authors: Petrischev Evgeny
Published: July 2021

The relevance of this article is determined by the need to identify and concretize the challenges and threats to the regional security of the post-Soviet space and the national security of modern Russia. One of the insuffi ciently studied aspects of the modern theory of international relations is the problem of fi nding an adequate answer to the external information and psychological impact on the national interests of the Russian Federation in its “near abroad”.
A hermenêutica filosófica de Gadamer: a virada hermenêutica em direção à ontologia
Authors:   , Torres Neto Jungley de Oliveira
Published: July 2021

O presente trabalho pretende, a partir da obra Verdade e Método de Hans- Georg Gadamer, investigar a virada hermenêutica, que consiste na passagem do âmbito epistemológico para o ontológico, isto é, da epistemologia da interpretação à ontologia da compreensão no fio condutor da linguagem, onde toda problemática surge e se percute. Apontar, outrossim, que em Gadamer, a hermenêutica não se resume apenas no resultado de um procedimento técnico, mas se desvincula do método científico enquanto caminho único para se chegar à verdade, a qual se abre para o fenômeno da compreensão (Verstehen) através da experiência humana do mundo.
Patrice Chéreau e o Anel em Bayreuth
Authors:   , Miranda Lucas Souza
Published: July 2021

Este trabalho se propôs a analisar aspectos simbólicos relacionados ao ciclo de óperas “O Anel do Nibelungo” do compositor Richard Wagner, a fim de explorar contribuições da obra para o discernimento do homem contemporâneo através de um olhar interdisciplinar. Para isso, foi utilizada a montagem de Patrice Chéreau, diretor cênico francês, responsável pela montagem da ópera em Bayreuth em 1976/1980. A partir disto, intentou-se abordar uma das mais influentes peças musicais da história sob a ótica Junguiana, traçando conexões com áreas do conhecimento como a psicanálise, filosofia, história e cinema. Como resultado, foi possível perceber, por meio dos símbolos contidos em sua direção, a natureza dúbia do poder do Anel, que tanto destrói quanto cria; e contribuir para diminuir a escassez desta linha de produções acadêmicas.
Desenvolvimento profissional para os servidores técnico-administrativos em educação com deficiência na Universidade Federal de Juiz de Fora
Authors:   , Metri Clarice Ferreira
Published: July 2021

A presente dissertação é desenvolvida no âmbito do Mestrado Profissional em Gestão e Avaliação da Educação (PPGP) do Centro de Políticas Públicas e Avaliação da Educação da Universidade Federal de Juiz de Fora (CAEd/UFJF). O caso de gestão a ser estudado irá discutir o desenvolvimento profissional dos Técnico-Administrativos em Educação (TAE) com deficiência da Universidade Federal de Juiz de Fora (UFJF). Dessa forma, a questão da pesquisa enfatiza: quais são os desafios enfrentados pela Pró-Reitoria de Gestão de Pessoas (PROGEPE) e pelo Núcleo de Apoio à Inclusão (NAI) na criação de ações afirmativas para promover o desenvolvimento profissional dos TAE com deficiência da UFJF? O objetivo geral deste estudo é analisar quais os desafios enfrentados pela PROGEPE e pelo NAI no planejamento e execução de ações afirmativas para o desenvolvimento profissional dos TAE com deficiência da UFJF, bem como propor ações para que elas sejam criadas e executadas. Para tanto, pretendemos especificamente: i) descrever os desafios enfrentados pela PROGEPE e pelo NAI na promoção de ações afirmativas para o desenvolvimento profissional dos TAE com deficiência da UFJF; ii) analisar o processo de elaboração de ações afirmativas de desenvolvimento profissional dos TAE com deficiência na UFJF e iii) propor um plano de ação educacional (PAE) que contribua para a criação de ações afirmativas que promovam o desenvolvimento profissional dos TAE com deficiência da UFJF. Do ponto de vista metodológico, trata-se de uma pesquisa qualitativa, de estudo de caso. Além da revisão de literatura, foi aplicado questionário e realizadas entrevistas semiestrututradas para a coleta de dados. Por fim, foi proposto um PAE que está estruturado em cinco ações com o objetivo de auxiliar os setores envolvidos a promover equidade no desenvolvimento profissional dos TAE com deficiência da UFJF.
Students’ Attitudes and Perceptions of ICT: Weblog Application in Improving Methods of SCL on Writing Class 2: Online Exploration of Global Issues
Authors: Radjuni Marleiny
Published: July 2021

In this digitized era, English as a Foreign Languag (EFL) teachers in Indonesia, as in many other countries are anxious to exploit the potential of Information and Communication Technology (ICT) to enhance the teaching and learning process. Given the increasing pressure exerted by technological developments on language education, it is important to understand the underlying factors behind teachers’ decisions regarding ICT. Regarding this matter, this study investigates the development as well as the effects of ICT applied in English Department in teaching and learning process. The use of weblog is being applied in the Academic Writing classes for a couple of years now. Students are equipped with the method of teaching through blog. So far, the use of ICT in the classroom often part of a teacher-centered class but it is easy to exploit these tools in learner-centered activities. For this particular case, students have freedom to control themselves in using the internet technology, even though it is still under teachers instructions. The method applied in this study is combination of the qualitative and quantitative. Evidence has been collected through a literature search, students questionnaires and semi interviews designed. The factors which was found to be most importans to these students were; having the lesson more interesting, easier, more fun for them, more diverse, more enjoyable and on top of that is more motivating.
Workshop Pelatihan Learning Management System Secara Online Dengan Menggunakan Google Classroom Untuk Guru SMAK St. Albertus, Malang.
Authors: Basatha Rizky , Soedargo David Saputra Octadianto , Wirapraja Alexander
Published: July 2021

Proses pembelajaran adalah salah satu aspek yang terdampak perkembangan teknologi, seorang guru dituntut tidak hanya mampu menyampaikan materi dengan baik tapi sekaligus juga menjadi fasilitator yang baik dalam menyampaikan materi sebagai bentuk proses pembejaran yang efektif dan efisien, kendala dari permasalahan pembelajaran konvensional dapat diatasi dengan menyediakan sarana pembelajaran yang baik dan fleksibel menggunakan aplikasi berbasis Learning Management System (LMS), dalam proses pengabdian masyarakat dilakukan proses pelatihan kepada para guru SMA dari SMAK St. Albertus Malang dan fasilitator dari pelatihan ini adalah dosen Institut Informatika Indonesia, pada pelatihan ini menggunakan metode interaktif dan praktek langsung dengan menggunakan salah satu aplikasi LMS yaitu Google Classroom. Aplikasi ini dipilih karena mudah digunakan dan telah dikenal secara umum, selain pelatihan dengan menggunakan Google Classroom, para peserta juga dibekali dengan pengetahuan umum tentang fitur dan fasilitas google lainnya, hasil dari pelatihan ini adalah adanya penambahan wawasan baru yang dapat digunakan guru untuk meningkatkan proses pembelajaran dikelas dan meningkatkan interaksi antara para guru dan murid sehingga kualitas pembelajaran pada kelas tersebut menjadi lebih baik.