jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Priyanka Dhiman | Neelam Malik | Anurag Khatkar
Source: BMC Chemistry (article, 2019-03-26)
Field: Chemistry — Organic Chemistry

Lead optimization for promising monoamine oxidase inhibitor from eugenol for the treatment of neurological disorder: synthesis and in silico based study Natural based inhibitors of monoamine oxidase are promising drug candidates for the treatment of several neurodegenerative and neuropsychological disorders including depression, anxiety, Parkinson's disease and Alzheimer's disease. In the present study we designed and synthesized the eugenol based derivatives and investigated them for human MAO inhibitory potential as promising candidates for therapeutics of neurological disorders. Moreover, radical scavenging activity of designed derivatives was tested by and H<sub>2</sub>O<sub>2</sub> and DPPH scavenging methods. Eugenol based derivatives were designed and synthesized for human MAO inhibitory action. The in silico and in vitro models were utilized for the evaluation of hMAO inhibition. The insight into molecular interactions among the compounds and both hMAO-A and hMAO-B active site was achieved by molecular docking studies. The two spectrophotometric titrations techniques were used to evaluate antioxidant potential. Compounds <b>5b</b> and <b>16</b> were found as most active hMAO-A inhibitors with IC<sub>50</sub> values of 5.989 ± 0.007 µM and 7.348 ± 0.027 µM respectively, through an appreciable selectivity index value of 0.19 and 0.14 respectively. In case of hMAO-B inhibition compounds <b>13a</b> and <b>13b</b> were found as most active hMAO-B inhibitors with IC<sub>50</sub> values of 7.494 ± 0.014 µM and 9.183 ± 0.034 µM receptively and outstanding value of selectivity index of 5.14 and 5.72 respectively. Radical scavenging assay showed that compounds <b>5b</b>, <b>5a</b>, <b>9b</b>, <b>9a</b> were active antioxidants. The findings of present study indicated excellent correlation among dry lab and wet lab hMAO inhibitory experiments. Interestingly, the compounds exhibiting better MAO inhibition activity was also appeared as good antioxidant agents. Monoamine oxidase ; Chemistry ; Eugenol ; In silico ; Pharmacology ; Monoamine oxidase B ; IC50 ; Monoamine neurotransmitter ; In vitro ; Biochemistry ; Enzyme ; Medicine ; Organic chemistry ; Gene Free Radicals and Antioxidants ; Cholinesterase and Neurodegenerative Diseases ; Electrochemical sensors and biosensors
Authors: Shuailong Jia | Runjing Wang | Kui Wu | Hongliang Jiang | Zhifeng Du
Source: Molecules (review, 2019-02-06)
Field: Chemistry — Spectroscopy

Elucidation of the Mechanism of Action for Metal Based Anticancer Drugs by Mass Spectrometry-Based Quantitative Proteomics The discovery of the anticancer activity of cisplatin and its clinical application has opened a new field for studying metal-coordinated anticancer drugs. Metal-based anticancer drugs, such as cisplatin, can be transported to cells after entering into the human body and form metal⁻DNA or metal⁻protein adducts. Then, responding proteins will recognize adducts and form stable complexes. The proteins that were binding with metal-based anticancer drugs were relevant to their mechanism of action. Herein, investigation of the recognition between metal-based anticancer drugs and its binding partners will further our understanding about the pharmacology of cytotoxic anticancer drugs and help optimize the structure of anticancer drugs. The "soft" ionization mass spectrometric methods have many advantages such as high sensitivity and low sample consumption, which are suitable for the analyses of complex biological samples. Thus, MS has become a powerful tool for the identification of proteins binding or responding to metal-based anticancer drugs. In this review, we focused on the mass spectrometry-based quantitative strategy for the identification of proteins specifically responding or binding to metal-based anticancer drugs, ultimately elucidating their mechanism of action. Proteomics ; Mass spectrometry ; Mechanism of action ; Chemistry ; Mechanism (biology) ; Computational biology ; Biochemistry ; Chromatography ; Biology Mass Spectrometry Techniques and Applications ; Advanced Proteomics Techniques and Applications ; Computational Drug Discovery Methods
Authors: Zhiyuan Fang | Yanan Li | Yuan-Yuan Zheng | Xiaomei Li | Yu‐Jing Lu | Siu‐Cheong Yan | Wing‐Leung Wong | Kin‐Fai Chan | Kwok‐Yin Wong | Ning Sun
Source: RSC Advances (article, 2019-01-01)
Field: Chemistry — Organic Chemistry

Antibacterial activity and mechanism of action of a thiophenyl substituted pyrimidine derivative The issue of multidrug resistant bacteria is a worldwide health threat. To develop new antibacterial agents with new mechanisms of action is thus an urgent request to address this antibiotic resistance crisis. In the present study, a new thiophenyl-pyrimidine derivative was prepared and utilized as an effective antibacterial agent against Gram-positive strains. In the tests against MRSA and VREs, the compound showed higher antibacterial potency than that of vancomycin and methicillin. The mode of action is probably attributed to the effective inhibition of FtsZ polymerization, GTPase activity, and bacterial cell division, which cause bactericidal effects. The compound could be a potential candidate for further development as an effective antibiotic to combat drug-resistant bacteria. FtsZ ; Antibacterial activity ; Pyrimidine ; Derivative (finance) ; Chemistry ; Mechanism (biology) ; Mechanism of action ; Combinatorial chemistry ; Stereochemistry ; Computational chemistry ; Bacteria ; Biochemistry ; Biology ; In vitro ; Cytoskeleton ; Philosophy ; Genetics ; Epistemology ; Business ; Cell Synthesis and biological activity ; Click Chemistry and Applications ; Synthesis of β-Lactam Compounds
Authors: Liam Yourston | Alexander Y. Lushnikov | О. А. Шевченко | Kirill A. Afonin | Alexey V. Krasnoslobodtsev
Source: Nanomaterials (article, 2019-04-13)
Field: Materials Science — Materials Chemistry

First Step Towards Larger DNA-Based Assemblies of Fluorescent Silver Nanoclusters: Template Design and Detailed Characterization of Optical Properties Besides being a passive carrier of genetic information, DNA can also serve as an architecture template for the synthesis of novel fluorescent nanomaterials that are arranged in a highly organized network of functional entities such as fluorescent silver nanoclusters (AgNCs). Only a few atoms in size, the properties of AgNCs can be tuned using a variety of templating DNA sequences, overhangs, and neighboring duplex regions. In this study, we explore the properties of AgNCs manufactured on a short DNA sequence-an individual element designed for a construction of a larger DNA-based functional assembly. The effects of close proximity of the double-stranded DNA, the directionality of templating single-stranded sequence, and conformational heterogeneity of the template are presented. We observe differences between designs containing the same AgNC templating sequence-twelve consecutive cytosines, (dC)<sub>12</sub>. AgNCs synthesized on a single "basic" templating element, (dC)<sub>12</sub>, emit in "red". The addition of double-stranded DNA core, required for the larger assemblies, changes optical properties of the silver nanoclusters by adding a new population of clusters emitting in "green". A new population of "blue" emitting clusters forms only when ssDNA templating sequence is placed on the 5' end of the double-stranded core. We also compare properties of silver nanoclusters, which were incorporated into a dimeric structure-a first step towards a larger assembly. Nanoclusters ; DNA ; Fluorescence ; Materials science ; Directionality ; Sequence (biology) ; Nanotechnology ; Nanomaterials ; Population ; Template ; Chemistry ; Physics ; Optics ; Biology ; Genetics Nanocluster Synthesis and Applications ; Advanced biosensing and bioanalysis techniques ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Jianqiao Hu | Hengxu Song | Zhanli Liu | Zhuo Zhuang | Xiaoming Liu | Stefan Sandfeld
Source: Scientific Reports (article, 2019-12-31)
Field: Materials Science — Materials Chemistry

Predicting the flow stress and dominant yielding mechanisms: analytical models based on discrete dislocation plasticity Dislocations are the carriers of plasticity in crystalline materials. Their collective interaction behavior is dependent on the strain rate and sample size. In small specimens, details of the nucleation process are of particular importance. In the present work, discrete dislocation dynamics (DDD) simulations are performed to investigate the dominant yielding mechanisms in single crystalline copper pillars with diameters ranging from 100 to 800 nm. Based on our simulations with different strain rates and sample size, we observe a transition of the relevant nucleation mechanism from "dislocation multiplication" to "surface nucleation". Two physics-based analytical models are established to quantitatively predict this transition, showing a good agreement for different strain rates with our DDD simulation data and with available experimental data. Therefore, the proposed analytical models help to understand the interplay between different physical parameters and nucleation mechanisms and are well suitable to estimate the material strength for different material properties and under given loading conditions. Nucleation ; Plasticity ; Dislocation ; Materials science ; Stress (linguistics) ; Flow stress ; Strain rate ; Work (physics) ; Statistical physics ; Thermodynamics ; Composite material ; Physics Microstructure and mechanical properties ; High-Velocity Impact and Material Behavior ; Aluminum Alloys Composites Properties
Authors: Aktham E. Shoukry | Ahmed H. El-Banbi | Helmy Sayyouh
Source: Petroleum Science (article, 2019-10-15)
Field: Chemistry — Analytical Chemistry

Enhancing asphaltene precipitation modeling by cubic-PR solid model using thermodynamic correlations and averaging techniques Abstract Cubic equation-of-state solid models are one of the most widely used models to predict asphaltene precipitation behavior. Thermodynamic parameters are needed to model precipitation under different pressures and temperatures and are usually obtained through tuning with multi asphaltene onset experiments. For the purpose of enhancing the cubic Peng–Robinson solid model and reducing its dependency on asphaltene experiments, this paper tests the use of aromatics and waxes correlations to obtain these thermodynamic parameters. In addition, weighted averages between both correlations are introduced. The averaging is based on reported saturates, aromatics, resins, asphaltene (SARA) fractions, and wax content. All the methods are tested on four oil samples, with previously published data, covering precipitation and onset experiments. The proposed wax-asphaltene average showed the best match with experimental data, followed by a SARA-weighted average. This new addition enhances the model predictability and agrees with the general molecular structure of asphaltene molecules. Asphaltene ; Wax ; Thermodynamics ; Precipitation ; Predictability ; Materials science ; Chemistry ; Organic chemistry ; Mathematics ; Statistics ; Physics ; Meteorology Petroleum Processing and Analysis ; Enhanced Oil Recovery Techniques ; Hydrocarbon exploration and reservoir analysis
Authors: Weiheng Xu | Sayli Jambhulkar | Rahul Verma | Rahul Franklin | Dharneedar Ravichandran | Kenan Song
Source: Nanoscale Advances (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

<i>In situ</i> alignment of graphene nanoplatelets in poly(vinyl alcohol) nanocomposite fibers with controlled stepwise interfacial exfoliation Hierarchically microstructured tri-axial poly(vinyl alcohol)/graphene nanoplatelet (PVA/GNP) composite fibers were fabricated using a dry-jet wet spinning technique. The composites with distinct PVA/GNPs/PVA phases led to highly oriented and evenly distributed graphene nanoplatelets (GNPs) as a result of molecular chain-assisted interfacial exfoliation. With a concentration of 3.3 wt% continuously aligned GNPs, the composite achieved a ∼73.5% increase in Young's modulus (∼38 GPa), as compared to the pure PVA fiber, and an electrical conductivity of ∼0.38 S m<sup>-1</sup>, one of the best mechanical/electrical properties reported for polymer/GNP nanocomposite fibers. This study has broader impacts on textile engineering, wearable robotics, smart sensors, and optoelectronic devices. Vinyl alcohol ; Exfoliation joint ; Nanocomposite ; Exfoliated graphite nano-platelets ; Materials science ; In situ ; Graphene ; Chemical engineering ; Composite material ; Nanotechnology ; Polymer ; Chemistry ; Organic chemistry Graphene research and applications ; Graphene and Nanomaterials Applications ; Carbon Nanotubes in Composites
Authors: Lucie Brès | Audrey Sanchot | Bertrand Rives | Nicolas Ghérardi | Nicolas Naudé | Maëlenn Aufray
Source: Surface and Coatings Technology (article, 2019-01-29)
Field: Materials Science — Surfaces, Coatings and Films

Fine-tuning of chemical and physical polymer surface modifications by atmospheric pressure post-discharge plasma and its correlation with adhesion improvement Materials science ; Wetting ; Contact angle ; X-ray photoelectron spectroscopy ; Surface modification ; Polymer ; Adhesion ; Plasma ; Atmospheric-pressure plasma ; Composite material ; Plasma cleaning ; Atmospheric pressure ; Bending ; Chemical engineering ; Nanotechnology Surface Modification and Superhydrophobicity ; Fiber-reinforced polymer composites ; Graphene research and applications
Authors: Qi Qiao | Xiaobao Li | Liangliang Huang
Source: Journal of Chemical & Engineering Data (article, 2019-10-17)
Field: Materials Science — Biomaterials

Crystalline Cellulose under Pyrolysis Conditions: The Structure–Property Evolution via Reactive Molecular Dynamics Simulations As a primary component of cell walls of plants, algae, bacteria, and other natural biomaterials, cellulose has attracted research attention and is the key to effective conversion of natural biomaterial into processable advanced functional materials. From the chemistry point of view, a typical crystalline cellulose is composed of linear chains of hundreds of β-1,4-linker glucose units. Therefore, inter and intra hydrogen bonding interactions play a decisive role of the structure–property relationship of cellulose based materials. Despite research progress from past decades, the fundamental mechanism of how cellulose structure transforms under pyrolysis conditions and the practical guideline of how cellulose properties are fined tuned accordingly are still incomplete. In this work, a series of reactive molecular dynamics calculations has been designed to reveal the structural evolution of crystalline cellulose under pyrolysis treatments. Through the detailed analysis of cellulose configuration change, hydrogen bonding network variation, reaction and redistribution of carbon, oxygen and hydrogen elements, and Young’s modulus, a molecule level insight of crystalline cellulose and its structural evolution under pyrolysis conditions has been constructed via reactive molecular dynamics simulations. We anticipate those theoretical results could effectively promote the design, the manufacture, and the optimization of cellulose based materials for relevant emerging applications. Cellulose ; Bacterial cellulose ; Materials science ; Molecular dynamics ; Hydrogen bond ; Pyrolysis ; Chemical engineering ; Molecule ; Chemistry ; Organic chemistry ; Computational chemistry Advanced Cellulose Research Studies ; Lignin and Wood Chemistry ; Catalysis for Biomass Conversion
Authors: M. Mustafa Azeem | Qingyu Wang | Zhongyu Li | Yue Zhang
Source: Nuclear Engineering and Technology (article, 2019-07-09)
Field: Materials Science — Materials Chemistry

Dislocation-oxide interaction in Y2O3 embedded Fe: A molecular dynamics simulation study Oxide dispersed strengthened (ODS) steel is an important candidate for Gen-IV reactors. Oxide embedded in Fe can help to trap irradiation defects and enhances the strength of steel. It was observed in this study that the size of oxide has a profound impact on the depinning mechanism. For smaller sizes, the oxide acts as a void; thus, letting the dislocation bypass without any shear. On the other hand, oxides larger than 2 nm generate new dislocation segments around themselves. The depinning is similar to that of Orowan mechanism and the strengthening effect is likely to be greater for larger oxides. It was found that higher shear deformation rates produce more fine-tuned stress-strain curve. Both molecular dynamics (MD) simulations and BKS (Bacon-Knocks-Scattergood) model display similar characteristics whereby establishing an inverse relation between the depinning stress and the obstacle distance. It was found that (110)oxide || (111)Fe (oriented oxide) also had similar characteristics as that of (100)oxide || (111)Fe but resulted in an increased depinning stress thereby providing greater resistance to dislocation bypass. Our simulation results concluded that critical depinning stress depends significantly on the size and orientation of the oxide. Keywords: Oxide dispersed strengthened (ODS) steel, Molecular dynamics (MD) simulation, Edge dislocation, Orowan loop, Dislocation dynamics Oxide ; Materials science ; Molecular dynamics ; Dislocation ; Void (composites) ; Composite material ; Stress (linguistics) ; Condensed matter physics ; Shear (geology) ; Shear stress ; Crystallography ; Metallurgy ; Physics ; Chemistry ; Computational chemistry Fusion materials and technologies ; Nuclear Materials and Properties ; Hydrogen embrittlement and corrosion behaviors in metals
Authors: A. Ghorbanpour Arani | Hassan Baba Akbar Zarei | Pouya Pourmousa
Source: International Journal of Applied Mechanics (article, 2019-11-01)
Field: Materials Science — Materials Chemistry

Free Vibration Response of FG Porous Sandwich Micro-Beam with Flexoelectric Face-Sheets Resting on Modified Silica Aerogel Foundation The free vibration analysis of sandwich micro-beam (SMB) which is subjected to electrical field is investigated by adopting the Euler–Bernoulli beam theory (EBBT) and modified strain gradient theory (MSGT). SMB is made of three layers, including a functionally graded (FG) porous core and two flexoelectric face-sheets. The porosities are assumed to be distributed over the beam thickness based on the two distribution functions. Also, due to the electric properties of flexoelectric materials, face-sheets of SMB are subjected to the external electric field. The modified Silica Aerogel foundation model is employed to consider the effects of elastic foundation on SMB. The size-dependent governing equations of motion are derived using Hamilton’s principle and solved by Navier’s solution method for a case of simply supported SMB. The effects of various parameters, such as length to thickness ratio, porosity index, flexoelectric loadings (the load applied to the flexoelectric face-sheets caused by external electric field), small scale parameter and foundation parameters on dimensionless frequency of SMB, are assessed. The results of this work can be used for optimum design and control of micro-electro-mechanical devices. Materials science ; Porosity ; Beam (structure) ; Electric field ; Timoshenko beam theory ; Composite material ; Vibration ; Aerogel ; Dimensionless quantity ; Mechanics ; Structural engineering ; Acoustics ; Physics Nonlocal and gradient elasticity in micro/nano structures ; Vibration Control and Rheological Fluids ; Composite Structure Analysis and Optimization
Authors: Noemí Contreras‐Pereda | Payam Hayati | Salvio Suárez–García | Leili Esrafili | Pascal Retailleau | Samia Benmansour | Fernando Novio | Ali Morsali | Daniel Ruiz‐Molina
Source: Ultrasonics Sonochemistry (article, 2019-02-19)
Field: Materials Science — Materials Chemistry

Delamination of 2D coordination polymers: The role of solvent and ultrasound Sonication ; Solvent ; Materials science ; Polymer ; Colloid ; Delamination (geology) ; Chemical engineering ; Yield (engineering) ; Fabrication ; Sonochemistry ; Nanotechnology ; Composite material ; Organic chemistry ; Chemistry Luminescence and Fluorescent Materials ; Metal-Organic Frameworks: Synthesis and Applications ; 2D Materials and Applications
Authors: Issraa Shahine | Nour Beydoun | Jean‐Jacques Gaumet | El‐Eulmi Bendeif | H. Rinnert | Pierre Magri | Aotmane En Naciri | Patrice Miska | Safi Jradi | Suzanna Akil
Source: Catalysts (article, 2019-02-07)
Field: Materials Science — Materials Chemistry

Pure, Size Tunable ZnO Nanocrystals Assembled into Large Area PMMA Layer as Efficient Catalyst Here, we demonstrate for the first time a strategy to self-assemble ZnO nanoparticles (NP) on a large area by a facile one-step process. First, rough and random ZnO nanocrystals (NC), were produced by free-stabilizing aqueous synthesis. Therefore, a post thermal treatment at various temperatures ranging from 80 to 800 °C was necessary to obtain size-tunable and photoluminescent crystalline NP. The fabricated NP had both efficient UV photoluminescence and photocatalytic activity by photo-degradation of Methylene Blue (MB) dye. The annealed NP showed an absorption blue shift in the UV region with decreasing size. This shift was attributed to high quantum confinement effect since ZnO NP diameter reached values lower than the Bohr radius of ZnO (~2.7 nm). The photocatalytic activity displayed dependency on the particle’s size, number, and crystallinity. Subsequently, the NP were self-assembled inside poly(methyl methacrylate) (PMMA) nanoholes. Subsequently, large area substrate of homogenous properties ZnO NP was obtained. Moreover, the synthesis facility, photoemission and photocatalytic properties of ZnO NP could be a new insight into the realization of high performance and low cost UV laser devices. Materials science ; Photocatalysis ; Photoluminescence ; Chemical engineering ; Crystallinity ; Nanotechnology ; Nanoparticle ; Particle size ; Aqueous solution ; Quantum dot ; Nanocrystal ; Optoelectronics ; Catalysis ; Composite material ; Organic chemistry ; Chemistry ZnO doping and properties ; Ga2O3 and related materials ; Advanced Photocatalysis Techniques
Authors: Eric R. Meshot | Sei Jin Park | Steven F. Buchsbaum | Melinda L. Jue | Tevye Kuykendall | Eric Schaible | L. B. Bayu Aji | S. O. Kucheyev | Kuang Jen Wu | Francesco Fornasiero
Source: Carbon (article, 2019-12-13)
Field: Materials Science — Materials Chemistry

High-yield growth kinetics and spatial mapping of single-walled carbon nanotube forests at wafer scale Wafer ; Materials science ; Carbon nanotube ; Yield (engineering) ; Substrate (aquarium) ; Silicon ; Nanotechnology ; Raman spectroscopy ; Synchrotron ; Analytical Chemistry (journal) ; Optoelectronics ; Chemical engineering ; Optics ; Composite material ; Chemistry ; Organic chemistry Carbon Nanotubes in Composites ; Graphene research and applications ; Advancements in Battery Materials
Authors: Yunqing Zhu | Alessandro Poma | Loris Rizzello | Virgínia M. Gouveia | Lorena Ruiz‐Pérez | Giuseppe Battaglia | Charlotte K. Williams
Source: Angewandte Chemie International Edition (article, 2019-02-05)
Field: Materials Science — Biomaterials

Metabolically Active, Fully Hydrolysable Polymersomes The synthesis and aqueous self-assembly of a new class of amphiphilic aliphatic polyesters are presented. These AB block polyesters comprise polycaprolactone (hydrophobe) and an alternating polyester from succinic acid and an ether-substituted epoxide (hydrophile). They self-assemble into biodegradable polymersomes capable of entering cells. Their degradation products are bioactive, giving rise to differentiated cellular responses inducing stromal cell proliferation and macrophage apoptosis. Both effects emerge only when the copolymers enter cells as polymersomes and their magnitudes are size dependent. Polymersome ; Polyester ; Amphiphile ; Chemistry ; Polycaprolactone ; Polyhydroxyalkanoates ; Ether ; Copolymer ; Organic chemistry ; Polymer ; Biology biodegradable polymer synthesis and properties ; Advanced Polymer Synthesis and Characterization ; Hydrogels: synthesis, properties, applications