jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Thibaut Préfol
Source: theses.fr (ABES) (preprint, 2020-12-11)
Field: Materials Science — Biomaterials

Optimisation des propriétés de transport de films respirants à base de poly(éther-b-amide) par ajout de polyéthylène glycols et cyclodextrines pour des applications liées à l’emballage alimentaire : relations structure-propriétés de fonction De nombreux produits alimentaires frais rapidement périssables tels que les fruits et les légumes présentent une activité respiratoire élevée qu’il est nécessaire d’optimiser une fois conditionnés dans un emballage pour prolonger leur durée de vie. Cette optimisation passe généralement par la maîtrise des flux gazeux au travers de l’emballage, ce qui reste à l’heure actuelle un véritable challenge. Ainsi, les acteurs du secteur sont à la recherche de nouveaux emballages polymères qui présentent des niveaux de perméabilité élevés et bien définis, notamment vis-à-vis des gaz respiratoires CO2 et O2. Dans ce contexte, le poly(éther-bloc-amide) (Pebax®) a été identifié comme un candidat prometteur pour l’application visée de par son caractère respirant et CO2-phile. Dans ce travail, les propriétés de transport aux gaz CO2 et O2 de films Pebax® élaborés par voie solvant, ont cherché à être améliorées via l’incorporation d’espèces CO2-philes de faible masse molaire de type polyéthylène glycol et/ou de molécules cages de type cyclodextrine – agents modifiants tous deux habilités au contact alimentaire. Les effets de la quantité et de la nature des agents modifiants sur les propriétés de fonction du film ont été étudiés. La stabilité des films a également été suivie dans le temps et une attention particulière a été portée sur l’éventuelle migration des agents incorporés. La caractérisation approfondie des matériaux élaborés a permis in fine d’établir des relations structure-propriétés pour chacun des systèmes étudiés. Polyethylene ; Food packaging ; Materials science ; Polymer chemistry ; Ether ; Chemical engineering ; Amide ; Polymer science ; Chemistry ; Organic chemistry ; Composite material ; Food science biodegradable polymer synthesis and properties ; Synthesis and properties of polymers ; Membrane Separation and Gas Transport
Authors: Kamal Haji Karim | Shuela Sheikh-Abdullah | Sairan Ali
Source: Tikrit Journal for Agricultural Sciences (article, 2020-03-01)
Field: Materials Science — Biomaterials

Kinetics of copper release in some calcareous soils from Sulaimani governorate, Iraqi Kurdistan Region This study was conducted to estimate copper release kinetic in five calcareous soils includes (Sharazor, Qaradagh, Bazian, Mawat, and Surdash) at the Sulaimani governorate, Iraqi Kurdistanregion. The highest amount of Cu release during 48 hours was least in soil Qaradagh (0.75mg kg -1 ). While Soil Mawat exhibited the highest release (2.272mg kg -1 ). The value of diffusion rate constant (kp) from parabolic diffusion varied from 0.123 to 0.321 with a mean of (0.221). The initial Cu release constant (s) and Cu release rate coefficient ( s ) from simple Elovich model, ranged from 0.42 to 1.164 with a mean of 0.6856, and from 2.197 to 5.952 with a mean of 3.6918. While the values of the rate constant (a and b) from the power function model with the mean were (0.249 and 0.605) respectively varied widely with the five soil. The parabolic diffusion was the best-fitted model used to describe Cu release process very well in the studied soils. Copper ; Soil water ; Calcareous ; Diffusion ; Calcareous soils ; Reaction rate constant ; Chemistry ; Mineralogy ; Animal science ; Nuclear chemistry ; Kinetics ; Soil science ; Environmental science ; Botany ; Biology ; Thermodynamics ; Physics Clay minerals and soil interactions ; Heavy metals in environment ; Mine drainage and remediation techniques
Authors: D. Schumann | Martin Heule
Source: CHIMIA International Journal for Chemistry (review, 2020-12-23)
Field: Materials Science — Materials Chemistry

Radioanalytics – An Indispensable Tool for Radiological and Nuclear Safety The exact knowledge on the inventory of a radioactive sample is a precondition to act appropriately in terms of nuclear safety. Radioanalytical methods aimed to determine the radionuclide content of activated material play therefore a central role regarding safe operation of nuclear installations, protection of personnel, inhabitants and environment as well as for the design and construction of new facilities. The article gives an overview on the broad variety of analysis and measurement methods, describes necessary chemical separation procedures and explains the impact for nuclear safety assessment in the field of radioanalytics at the Paul Scherrer Institut Villigen, Switzerland. It addresses both the safe routine operation of nuclear installations, which can be a challenge to our radiometric capabilities and refers to selected radioanalytical research projects. Radiological weapon ; Radionuclide ; Precondition ; Risk analysis (engineering) ; Construction engineering ; Computer science ; Environmental science ; Nuclear engineering ; Engineering ; Business ; Radiochemistry ; Physics ; Chemistry ; Nuclear physics Graphite, nuclear technology, radiation studies ; Nuclear and radioactivity studies ; Radioactive contamination and transfer
Authors: M. Szurgot
Source: TU repository (Lodz University of Technology) (article, 2020-03-30)
Field: Materials Science — Materials Chemistry

Growth velocities and sectorial and zonal distributions of impurities in crystals Formulae for relative impurity content in various parts of a crystal have been derived and analysis of sectorial and zonal distributions of impurities conducted. Contribution of volume diffusion controlled crystal growth for sectorial and zonal distributions of impurities in lopezite crystals has been evaluated as small in comparison with surface diffusion. Impurity ; Geology ; Geophysics ; Geodesy ; Physics Solidification and crystal growth phenomena ; Solid-state spectroscopy and crystallography
Authors: Rebecca deGraffenried | Nicolas Cluzel | Thomas Shea | J. E. Hammer
Source: Goldschmidt Abstracts (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Experimental Examination of the Melt Embayment Method for Determining Magma Decompression Rate Magma ; Decompression ; Geology ; Petroleum engineering ; Petrology ; Geochemistry ; Surgery ; Volcano ; Medicine Graphite, nuclear technology, radiation studies ; Iron and Steelmaking Processes ; Metallurgical Processes and Thermodynamics
Authors: Nikunj B. Patel | Nayan D. Prajapati | LENSI PATEL | Khushi Patel | Haresh S. Kalasariya
Source: INTERNATIONAL JOURNAL OF PHARMACEUTICAL SCIENCE AND HEALTH CARE (article, 2020-01-01)
Field: Chemistry — Spectroscopy

SILICO MOLECULAR DOCKING &amp; ADMET STUDY OF PHYCOCOMPONENTS ISOLATED FROM PADINATETRASTROMATICA AND CAULERPAPELTATA Brown algae, P. tetrastromaticaand Green algae C. peltata belong to the family Dictyotaceae&Caulerpaceae. This present study was carried out by taking GC-MS data performed by M. Uma Maheswari et al.(2017) & K. Murugan and V. V. Iyer (2014). In silico ; Docking (animal) ; Computational biology ; Chemistry ; Computer science ; Biology ; Biochemistry ; Medicine ; Gene Analytical Chemistry and Chromatography
Authors: Norma Aurea Rangel-Vázquez
Source: Polímeros (article, 2020-01-01)
Field: Materials Science — Surfaces, Coatings and Films

Adsorption of terbium ion on Fc/dymethylacrylamide: application of Monte Carlo simulation The crosslinking of the Fc fragment (IgG antibody) on a polymer matrix about of dimethylacrylamide (DMA), melamide group (MG) and n-acryloxy succinimide (NAS) was analyzed through Monte Carlo simulation at 277.15K and pH 7, in where Gibs free energy and the dipole moment indicated the spontaneity of the reaction through van der Waals interactions. In addition, the QSAR properties determinated that both the surface area and the volume allow to carry out the physical adsorption of the Fc fragment that was verified through the electronic distribution of the electrostatic potential maps (MESP) where the nucleophilic zones (blue color) and electrophilic (red color) were observed, while the partition coefficient (Log P) indicated the solubility of the process. Subsequently, the analysis of the adsorption of the terbium ion (Tb+3) at 277.15K and a pH 7 in Fc/polymeric matrix was carried out, observing that the Fc fragment presented a flat-on optimization geometry attributed to the Tb+3 that generates electronic repulsions, as well as van der Waals forces, hydrogen bonds derived from the Cys aminoacids formed a polar structure and that was corroborated by the Log P negative. Finally, the surface area and volume determined that Tb+3 adsorption showed an increase in surface area and volume with temperature. Terbium ; Adsorption ; van der Waals force ; Chemistry ; Physical chemistry ; Hydrogen bond ; Ion ; Computational chemistry ; Crystallography ; Molecule ; Organic chemistry Polymer Surface Interaction Studies ; Molecular Junctions and Nanostructures ; Analytical chemistry methods development
Authors: Tran Thi Ai My | Lê Trung Hiếu | Nguyễn Thị Thanh Hải | Tôn Nữ Mỹ Phương | Huynh Thi Phuong Loan | Bùi Thị Phương Thuý | Nguyen Thi Ai Nhung
Source: HUE UNIVERSITY JOURNAL OF SCIENCE NATURAL SCIENCE (article, 2020-06-30)
Field: Chemistry — Organic Chemistry

Antioxidant activity of some natural essential oils in Vietnam: Comparison between QSAR simulation and experimental study The antioxidant activity of essential oils from leaves of Piper betle L. (T) and Cleistocalyx operculatus L. (V) and aerial parts of Ageratum conyzoides L. (H), indigenously grown in Thua Thien Hue province, Vietnam, is investigated. The quantitative structure–activity relationship (QSAR) model comprising 4-hydroxy-chromene-2H-one and its 26 derivatives is used to predict the radical scavenging activity of T, V, and H. The radical scavenging activity of the oils is experimentally determined with DPPH (1,1-diphenyl-2-picrylhydrazyl) via IC50 values. The experimental IC50 values are in good agreement with those obtained from the QSAR model. The IC50 value of Piper betle L. is 3.71 mg/mL, comparable to that of the strong antioxidant ascorbic acid (3.03 mg /mL). Quantitative structure–activity relationship ; DPPH ; Antioxidant ; Ascorbic acid ; Piper ; Chemistry ; Ageratum conyzoides ; IC50 ; Traditional medicine ; Stereochemistry ; Organic chemistry ; Food science ; Botany ; Biology ; Biochemistry Free Radicals and Antioxidants ; Essential Oils and Antimicrobial Activity ; Phytochemicals and Antioxidant Activities
Authors: Andrew N. Dinh
Source: eScholarship (California Digital Library) (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Selective Methodologies for Direct Functionalization of Arenes and Heterocycles The functionalization of arenes and heterocycles via direct C-H activation is a valuable tool in medicinal chemistry as it allows for the manipulation of a diversity of complex structures without the need for de novo methodologies. It can be utilized as a late-stage strategy to address pharmacological problems such as pharmacokinetic profile, metabolism and on-off target activity of a lead compound. One of the drawbacks to current methodologies is the lack of regioselectivity, wherein a scaffold possesses multiple sites of reactivity, leading to multiple constitutional isomers. Our lab has developed a regioselective catalyst-controlled Lewis base halogenation of phenols and anilines, which is discussed in two manuscripts in Chapter 1 and 2. We also explore photoredox catalysis to explore the intramolecular synthesis of benzothiazoles and intermolecular sulfenylation of indoles, which is presented in Chapter 3. Last, Chapter 4 discusses an enantioselective functionalization of a diaryl ether naphthoquinone scaffold to access enantioenriched atropisomeric molecules. We believe these works can be utilized to obtain a diversity of highly regioselective and enantioselective heterocycle and arene motifs that are relevant towards drug discovery efforts. Regioselectivity ; Combinatorial chemistry ; Chemistry ; Intramolecular force ; Enantioselective synthesis ; Halogenation ; Surface modification ; Photoredox catalysis ; Catalysis ; Stereochemistry ; Organic chemistry Catalytic C–H Functionalization Methods ; Axial and Atropisomeric Chirality Synthesis ; Oxidative Organic Chemistry Reactions
Authors: Carlo Matera | N. Camarero | C. Masferrer | Eva Coll-de la Rubia | S. Vitiello | Alma Rus | Cristina Segovia | Carolina Rubio | Cristian Suárez-Cabrera | Aina Gomila‐Grange | M. Libergoli | Carlos Pacheco Soler | Ana Cristina Calpena | Helena Colom | Jesús M. Paramio | J.M. Carrascosa | Eva Martínez‐Cáceres | Eva Colás | Pau Gorostiza
Source: Archivio Istituzionale della Ricerca (Universita Degli Studi Di Milano) (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Phototrexate : a novel drug candidate for cancer and psoriasis Psoriasis ; Medicine ; Drug ; Cancer drugs ; Cancer ; Dermatology ; Pharmacology ; Internal medicine Synthesis and biological activity ; Click Chemistry and Applications ; Psoriasis: Treatment and Pathogenesis
Authors: Zhigang Liu | Wei Zhou | Ziyi Chen | Guohao Zhang
Source:  (preprint, 2020-03-03)
Field: Chemistry — Analytical Chemistry

A system-level investigation into the pharmacological mechanisms of flavor compounds in Maotai liquor <title>Abstract</title> Maotai-flavor liquor, one of the world’s famous natural fermentation food product plays a significant role in traditional Chinese culture and people’s daily lives for a long time due to its good taste. However, the pharmacological activities of flavor compounds in Maotai liquor has not been fully elucidated. In answering this question, a system-level analysis was developed by combining in silico ADME evaluation, multi-target prediction, GO enrichment analysis, network pharmacology technology, pathway analysis, as well as experimental verification to elucidate the pharmacological effects of flavor compounds in Maotai liquor. Finally, 55 active compounds and 80 targets were identified to interpret the pharmacological effect of the flavor compounds. Moreover, the key active compounds was verified by in vitro experiments to validate the reliability of our approaches. Our study provides a novel integrated strategy to comprehensively understand the pharmacological activities of complex components in Maotai liquor. Flavor ; Business ; Chemistry ; Biochemical engineering ; Food science ; Engineering Chromatography in Natural Products ; Traditional Chinese Medicine Analysis ; Natural product bioactivities and synthesis
Authors: Samar Abd Alelah
Source: Journal of International Crisis and Risk Communication Research (article, 2020-01-01)
Field: Chemistry — Physical and Theoretical Chemistry

Fluoresence Spectra Study of Sterically Strained Isomers of C24H14 polycyclic aromatic (PAHs) & Characterization of a Bio-sourced, Fluoresent, Ratiometric pH Indicator with Alkaline pKa This thesis is composed to two studies, each of which relies on recent advances in time-dependent density functional theory (TD-DFT) to accurately model fluorescence spectra. The first study focuses on evaluating the fluorescence spectrum of polycyclic aromatic hydrocarbons (PAHs) having a molecular weight of 302. Three isomers are analyzed including dibenzo[a,j]fluoranthene, dibenzo[a,k]fluoranthene and dibenzo[a,l]fluoranthene. These isomers differ in the placement of one of six aromatic rings and in the amount that each molecule deviates from planarity. The TD-DFT methods are used to compute spectra in an environment that simulates solvent (n-hexane). These computed spectra are compared to vibronically resolved experimental data obtained at cryogenic temperatures. Computed spectra for dibenzo[a,j]fluoranthene and dibenzo[a,k]fluoranthene are blue shifted versus experimental data. Conversely, the computed spectra of dibenzo[a,l]fluoranthene is red shifted. This difference is attributed to steric interactions in dibenzo[a,l]fluoranthene that creates a deviation from planarity. The second project describes the characterization of a pH-responsive fluorophore from an endophytic fungus isolated from sand pine. The endogenous fluorescence of the live organism was measured using fluorescence microscopy. Computational interpretation of the spectra was accomplished with the TD-DFT methods and include solvent effects. The combined use of experimental and theoretically predicted spectra revealed the pH dependent equilibria and photo-excited tautomerization of the natural product, 5-methylmellein. This product shows promise both as a stand-alone pH-indicating fluorophore with alkaline pKa, and as "green" feedstock for synthesis of custom fluorophores. Fluorescence ; Steric effects ; Fluorophore ; Spectral line ; Characterization (materials science) ; Molecule ; Tautomer Photochemistry and Electron Transfer Studies ; Advanced Fluorescence Microscopy Techniques ; Advanced Physical and Chemical Molecular Interactions
Authors: Huynh Thi Phuong Loan | Hoàng Văn Đức | Nguyen Thi Ai Nhung
Source: HUE UNIVERSITY JOURNAL OF SCIENCE NATURAL SCIENCE (article, 2020-03-20)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A theoretical study of structure, bonding and property of platinum(II)-8-hydroxyquinolines complexes with carbene and heavier homologues &lt;p&gt;In this work, a theoretical study for platinum(II)-8-hydroxyquinolines-tetrylene complexes [{PtCl-C&lt;sub&gt;9&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;NO}-NHE&lt;sub&gt;Ph&lt;/sub&gt;] (&lt;strong&gt;Pt-EPh&lt;/strong&gt;)&lt;strong&gt; &lt;/strong&gt;are investigated for the first time using density functional theory (DFT). Quantum chemical calculations using DFT and charge methods at the BP86 level with basic sets SVP, TZVPP have been carried out to get insight into the structures and property for &lt;strong&gt;Pt-EPh&lt;/strong&gt;. The optimization of equilibrium geometries of the ligands&lt;strong&gt; EPh&lt;/strong&gt; in &lt;strong&gt;Pt-EPh&lt;/strong&gt; are bonded in distorted end-on way to &lt;strong&gt;Pt&lt;/strong&gt; fragment with the bending angle, a, slightly decreases from carbene &lt;strong&gt;Pt-CPh&lt;/strong&gt; to germylene &lt;strong&gt;Pt-GePh&lt;/strong&gt;. Quantum chemical parameters such as &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;HOMO&lt;/sub&gt;, &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;LUMO&lt;/sub&gt;, the energy gap (&lt;em&gt;E&lt;/em&gt;&lt;sub&gt;LUMO &lt;/sub&gt;– &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;HOMO&lt;/sub&gt;), electronegativity (χ), global hardness (η), and global softness (&lt;em&gt;S&lt;/em&gt;) in the neutral molecules have been calculated and discussed. Bond dissociation energies (BDEs), D&lt;sub&gt;e &lt;/sub&gt;(kcal.mol&lt;sup&gt;-1&lt;/sup&gt;), decrease from the slighter to the heavier homologues. The hybridization of atoms E have large p characters while the hybridization of atom Pt has greater d character which lead to the Pt-E bond possesses not only NHE&lt;sub&gt;Ph&lt;/sub&gt;→{ PtCl-C&lt;sub&gt;9&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;NO} strong σ-donation but also a significant contribution π-donation NHE&lt;sub&gt;Ph&lt;/sub&gt;→{PtCl-C&lt;sub&gt;9&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;NO} and a weak π-backdonation metal-ligand NHE&lt;sub&gt;Ph&lt;/sub&gt;←{PtCl-C&lt;sub&gt;9&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;NO} in complexes &lt;strong&gt;Pt-Eph &lt;/strong&gt;was also considered.&lt;/p&gt; Chemistry ; HOMO/LUMO ; Electronegativity ; Crystallography ; Platinum ; Stereochemistry ; Molecule ; Catalysis ; Organic chemistry Magnetism in coordination complexes ; Metal complexes synthesis and properties ; Organometallic Complex Synthesis and Catalysis
Authors: Yogesh D. Mane
Source: Biomedical Journal of Scientific & Technical Research (article, 2020-08-17)
Field: Chemistry — Organic Chemistry

Synthesis and Antimicrobial Evaluation of Novel 4-phenylPyrrole-2-Carboxamides Ten novel 4-phenylpyrrole-2-carboxamide derivatives (5a-j) were synthesized and evaluated for their in vitro antibacterial activity... The arts ; Liberal arts education ; Psychology ; Art ; Higher education ; Visual arts ; Political science ; Law Synthesis and biological activity ; Synthesis and Characterization of Pyrroles ; Multicomponent Synthesis of Heterocycles
Authors: Tingting Qi | Jing Shi | Xishuo Wang | Kun Dong | Yongping Luo | Jiawei Teng | Guang Wen Chu | Liangliang Zhang | Hai Kui Zou | Bao‐Chang Sun
Source:  (preprint, 2020-06-26)
Field: Chemistry — Inorganic Chemistry

Effects of Enhancing Micromixing on Nucleation/Crystal Growth Process and Material Properties of Zeolite Hierarchical (micro/mesopore) ZSM-5 zeolites were hydrothermally synthesized with enhancing micromixing of the high viscosity reaction system in a rotating packed bed (RPB). Herein, the effects of four operating processes with different micromixing intensity on nucleation/crystal growth process as well as properties of ZSM-5 zeolites were investigated. Results indicated that enhancing micromixing by RPB in the zeolite synthesis could facilitate the formation of Al sites and shorten the nucleation and crystallization period. ZSM-5 samples prepared by the RPB premix process exhibit hierarchical structure, smaller average particle size, more uniform particle size distributions, larger specific surface areas, higher catalytic stability as well as more Brønsted and Lewis acid sites. While adopting the prepared ZSM-5 zeolites with RPB premix for catalyzing C4-olefin cracking reaction, the conversion of C4-olefin and yield of propylene were higher than that obtained by traditional stirring tank reactor premix. Micromixing ; Nucleation ; Zeolite ; Crystallization ; Chemical engineering ; Materials science ; Crystal (programming language) ; Particle size ; Catalysis ; Acicular ; Olefin fiber ; ZSM-5 ; Particle (ecology) ; Crystal growth ; Chemistry ; Viscosity ; Organic chemistry ; Crystallography ; Composite material ; Microstructure Zeolite Catalysis and Synthesis ; Catalysis and Hydrodesulfurization Studies ; Catalysis for Biomass Conversion
Authors: Mukhomorov Vladimir K
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2020-01-30)
Field: Chemistry — Organic Chemistry

Statistical modeling of antifungal activity of substituted benzo-1-thia- and selenium diazoles Statistical methods revealed a close relationship between antifungal activity (suppression of the growth of the mycelium of the fungi of the species <em>Venturia inaqualis</em>, <em>Aspergillus niger</em> and <em>Fusarium moniliforme</em>) and the molecular structure of the substituted benzo-1-thiadiazoles and benzo-1-seleniumdiazoles. The molecular pseudopotential is used as the explanatory variable in the regression equations. It was established the threshold dependence of the antifungal activity on the pseudopotential of the molecule. The explanatory variable exceeding of its threshold value leads to a rapid linear increase in bioactivity for all species of fungi. Antifungal activity of drugs is low to the threshold value of the molecular pseudopotential and does not have a significant relationship with the variability of the molecular structure of the chemical compounds. Selenium ; Antifungal ; Chemistry ; Biology ; Microbiology ; Organic chemistry Chemical Thermodynamics and Molecular Structure ; Thermodynamic properties of mixtures