jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: James P. Shanahan | Cameron M. Moore | Jeff W. Kampf | Nathaniel K. Szymczak
Source: Chemical Communications (article, 2021-01-01)
Field: Chemistry — Organic Chemistry

Modulation of H<sup>+</sup>/H<sup>−</sup> exchange in iridium-hydride 2-hydroxypyridine complexes by remote Lewis acids A series of iridium hydride complexes featuring dihydrogen bonding are presented and shown to undergo rapid H<sup>+</sup>/H<sup>-</sup> exchange (1240 s<sup>-1</sup> at 25 °C). We demonstrate that the H<sup>+</sup>/H<sup>-</sup> exchange rate can be modified by post-synthetic modification at a remote site using BH<sub>3</sub>, Zn(C<sub>6</sub>F<sub>5</sub>)<sub>2</sub>, and [Me<sub>3</sub>O][BF<sub>4</sub>]. This route provides a complementary strategy to traditional methods that rely on pre-metalation modifications to a metal's primary sphere. Iridium ; Metalation ; Hydride ; Chemistry ; Lewis acids and bases ; Metal ; Inorganic chemistry ; Medicinal chemistry ; Organic chemistry ; Catalysis Coordination Chemistry and Organometallics ; Asymmetric Hydrogenation and Catalysis ; Hydrogen Storage and Materials
Authors: Florian Kleemiss | Pim Puylaert | Daniel Duvinage | Malte Fugel | Kunihisa Sugimoto | Jens Beckmann | Simon Grabowsky
Source: Acta Crystallographica Section B Structural Science Crystal Engineering and Materials (article, 2021-11-12)
Field: Chemistry — Physical and Theoretical Chemistry

Ibuprofen and sila-ibuprofen: polarization effects in the crystal and enzyme environments Sila-ibuprofen is a new potential nonsteroidal anti-inflammatory drug which deviates from its parent ibuprofen in terms of the electrostatic potential around the carbon/silicon-switched C/Si—H group. Therefore, sila-ibuprofen is more water soluble and has a lower melting enthalpy. However, its binding and inhibition properties of cyclooxygenases appear to be very similar to regular ibuprofen. Therefore, in this study, intermolecular interactions and interaction densities of both ibuprofen and sila-ibuprofen in their biologically active forms, i.e. deprotonated and as the pure S -enantiomers are investigated. Quantum-crystallographically refined salts with argininium and 1-phenylethan-1-amoninium (PEA) counter-cations as crystalline models of the interactions with the guanidine functional group of arginine inside cyclooxygenases are presented. The similarities and differences between the polarization of ibuprofen and sila-ibuprofen in the crystal, enzyme, solvent and isolated environments are discussed based on quantum-chemical calculations. For the explicit crystal and enzyme environments, specifically, molecular dynamics simulations starting from the crystal models were combined with QM/MM calculations. Ibuprofen ; Chemistry ; Enthalpy ; Crystal (programming language) ; Molecular dynamics ; Crystallography ; Computational chemistry ; Intermolecular force ; Polymorphism (computer science) ; Stereochemistry ; Organic chemistry ; Thermodynamics ; Molecule ; Biochemistry Crystallography and molecular interactions ; Crystal structures of chemical compounds ; Enzyme Structure and Function
Authors: Mareike Pfeil | Tobias A. Engesser | Jan Krahmer | Christian Näther | Felix Tuczek
Source: Zeitschrift für anorganische und allgemeine Chemie (article, 2021-07-07)
Field: Chemistry — Organic Chemistry

Bonding and Activation of N<sub>2</sub> in Molybdenum(0) Complexes Supported by Tripod Ligands with Phospholane End Groups Abstract Tripod ligands with a neopentyl backbone and one ( trpd‐1 pln ), two ( trpd‐2 pln ) or three ( trpd‐3 pln ) phospholane end groups are synthesized and used for the synthesis of MoX 3 (X=Cl, Br, I) complexes supported by these ligands. Na x Hg reduction of [MoBr 3 ( trpd‐3 pln )], in the presence of N 2 and the bidentate coligand dppm leads to the molybdenum(0) mono(dinitrogen) complex [Mo(N 2 )( trpd‐3 pln )(dppm)] with a moderately activated N 2 ligand. An attempt to further increase the activation by using dmpm as coligand leads to a mixture containing desired [Mo(N 2 )( trpd‐3 pln )(dmpm)], but also the bis(dinitrogen) complex [Mo(N 2 ) 2 ( κ 2 ‐ trpd‐3 pln ) 2 ] and the homoleptic complex [Mo( trpd‐3 pln ) 2 ]. Protonation of [Mo(N 2 )( trpd‐3 pln )(dppm)] with [H(OEt 2 ) 2 ][Al{OC(CF 3 ) 3 } 4 ] generates the hydrazido(2‐) complex [Mo(NNH 2 )( trpd‐3 pln )(dppm)][Al{OC(CF 3 ) 3 } 4 ] 2 . Denticity ; Molybdenum ; Chemistry ; Protonation ; Ligand (biochemistry) ; Tripod (photography) ; Stereochemistry ; Medicinal chemistry ; Crystallography ; Crystal structure ; Inorganic chemistry ; Receptor Organometallic Complex Synthesis and Catalysis ; Asymmetric Hydrogenation and Catalysis ; Metalloenzymes and iron-sulfur proteins
Authors: Ji-Xiang He | Zhengcong Fei | Ling Fu | Caiping Tian | Fuchu He | Hao Chi | Jing Yang
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2021-09-24)
Field: Chemistry — Organic Chemistry

pChem: a modification-centric assessment tool for the performance of chemoproteomic probes Chemoproteomics has emerged as a key technology to expand the functional space in complex proteomes for probing fundamental biology and for discovering new small molecule-based therapies. Here we report a modification-centric computational tool termed pChem to provide a streamlined pipeline for unbiased performance assessment of chemoproteomic probes. The pipeline starts with an experimental setting for isotopically coding probe-derived modifications (PDMs) that can be automatically recognized by pChem, with masses accurately calculated and sites precisely localized. Further, pChem exports on-demand reports by scoring the profiling efficiency, modification-homogeneity and proteome-wide residue selectivity of a tested probe. The performance and robustness of pChem were benchmarked by applying it to eighteen bioorthogonal probes. Of note, the analyses reveal that the formation of unexpected PDMs can be driven by endogenous reactive metabolites (e.g., bioactive aldehydes and glutathione). Together, pChem is a powerful and user-friendly tool that aims to facilitate the development of probes for the ever-growing field of chemoproteomics. Bioorthogonal chemistry ; Proteome ; Computer science ; Robustness (evolution) ; Nanotechnology ; Computational biology ; Proteomics ; Chemistry ; Combinatorial chemistry ; Biology ; Materials science ; Biochemistry ; Gene ; Click chemistry Click Chemistry and Applications ; Advanced Proteomics Techniques and Applications ; Chemical Synthesis and Analysis
Authors: Lars Banko | Phillip M. Maffettone | Dennis Naujoks | Daniel Olds | Alfred Ludwig
Source: npj Computational Materials (preprint, 2021-07-09)
Field: Materials Science — Materials Chemistry

Deep learning for visualization and novelty detection in large X-ray diffraction datasets Abstract We apply variational autoencoders (VAE) to X-ray diffraction (XRD) data analysis on both simulated and experimental thin-film data. We show that crystal structure representations learned by a VAE reveal latent information, such as the structural similarity of textured diffraction patterns. While other artificial intelligence (AI) agents are effective at classifying XRD data into known phases, a similarly conditioned VAE is uniquely effective at knowing what it doesn’t know: it can rapidly identify data outside the distribution it was trained on, such as novel phases and mixtures. These capabilities demonstrate that a VAE is a valuable AI agent for aiding materials discovery and understanding XRD measurements both ‘on-the-fly’ and during post hoc analysis. Novelty ; Diffraction ; Similarity (geometry) ; Novelty detection ; Computer science ; Artificial intelligence ; Pattern recognition (psychology) ; On the fly ; Visualization ; Materials science ; Physics ; Image (mathematics) ; Optics ; Psychology Machine Learning in Materials Science ; X-ray Diffraction in Crystallography ; Radiomics and Machine Learning in Medical Imaging
Authors: Sebastian Ament | Maximilian Amsler | Duncan R. Sutherland | Ming-Chiang Chang | Dan Guevarra | Aine Connolly | John M. Gregoire | Michael O. Thompson | Carla P. Gomes | R. B. van Dover
Source: arXiv (Cornell University) (preprint, 2021-01-19)
Field: Materials Science — Materials Chemistry

Autonomous synthesis of metastable materials Autonomous experimentation enabled by artificial intelligence (AI) offers a new paradigm for accelerating scientific discovery. Non-equilibrium materials synthesis is emblematic of complex, resource-intensive experimentation whose acceleration would be a watershed for materials discovery and development. The mapping of non-equilibrium synthesis phase diagrams has recently been accelerated via high throughput experimentation but still limits materials research because the parameter space is too vast to be exhaustively explored. We demonstrate accelerated synthesis and exploration of metastable materials through hierarchical autonomous experimentation governed by the Scientific Autonomous Reasoning Agent (SARA). SARA integrates robotic materials synthesis and characterization along with a hierarchy of AI methods that efficiently reveal the structure of processing phase diagrams. SARA designs lateral gradient laser spike annealing (lg-LSA) experiments for parallel materials synthesis and employs optical spectroscopy to rapidly identify phase transitions. Efficient exploration of the multi-dimensional parameter space is achieved with nested active learning (AL) cycles built upon advanced machine learning models that incorporate the underlying physics of the experiments as well as end-to-end uncertainty quantification. With this, and the coordination of AL at multiple scales, SARA embodies AI harnessing of complex scientific tasks. We demonstrate its performance by autonomously mapping synthesis phase boundaries for the Bi$_2$O$_3$ system, leading to orders-of-magnitude acceleration in establishment of a synthesis phase diagram that includes conditions for kinetically stabilizing $δ$-Bi$_2$O$_3$ at room temperature, a critical development for electrochemical technologies such as solid oxide fuel cells. Computer science ; Chemical space ; Metastability ; Phase diagram ; Artificial intelligence ; Nanotechnology ; Materials science ; Phase (matter) ; Physics ; Chemistry ; Drug discovery Machine Learning in Materials Science
Authors: Nickolas Gantzler | Min‐Bum Kim | Alexander Robinson | Maxwell W. Terban | Sanjit Ghose | Robert E. Dinnebier | Arthur H. P. York | Davide Tiana | Cory M. Simon | Praveen K. Thallapally
Source: ChemRxiv (preprint, 2021-12-03)
Field: Chemistry — Inorganic Chemistry

Computation-informed optimization of Ni(PyC)₂ functionalization for noble gas separations Metal-organic frameworks (MOFs) are promising nanoporous materials for the adsorptive capture and separation of noble gases at room temperature. Among the numerous MOFs synthesized and tested for noble gas separations, Ni(PyC)₂ (PyC = pyridine-4-carboxylate) exhibits one of the highest xenon/krypton selectivities at room temperature. Like lead-optimization in drug discovery, here we aim to tune the chemistry of Ni(PyC)₂, by appending a functional group to its PyC ligands, to maximize its Xe/Kr selectivity. To guide experiments in the laboratory, we virtually screen Ni(PyC-X)₂ (X=functional group) structures for noble gas separations by (i) constructing a library of Ni(PyC-X)₂ crystal structure models then (ii) using molecular simulations to predict noble gas (Xe, Kr, Ar) adsorption and selectivity at room temperature in each structure. The virtual screening predicts several Ni(PyC-X)₂ structures to exhibit a higher Xe/Kr, Xe/Ar, and Kr/Ar selectivity than the parent Ni(PyC)₂ MOF, with Ni(PyC-m-NH₂)₂ among them. In the laboratory, we synthesize Ni(PyC-m-NH₂)₂, determine its crystal structure by X-ray powder diffraction, and measure its Xe, Kr, and Ar adsorption isotherms (298 K). In agreement with our molecular simulations, the Xe/Kr, Xe/Ar, and Kr/Ar selectivities of Ni(PyC-m-NH₂)₂ exceed those of the parent Ni(PyC)₂. Particularly, Ni(PyC-m-NH₂)₂ exhibits a [derived from experimental, equilibrium adsorption isotherms] Xe/Kr selectivity of 20 at dilute conditions and 298 K, compared to 17 for Ni(PyC)₂. According to in situ X-ray diffraction, corroborated by molecular models, Ni(PyC-m-NH₂)₂ presents well-defined binding pockets tailored for Xe and organized along its one-dimensional channels. In addition to discovering the new, performant Ni(PyC-m-NH₂)₂ MOF for noble gas separations, our study illustrates the computation-informed optimization of the chemistry of a "lead" MOF to target adsorption of a specific gas. Krypton ; Xenon ; Selectivity ; Noble gas ; Nanoporous ; Adsorption ; Noble metal ; Chemistry ; Pyridine ; Crystal structure ; Physical chemistry ; Inorganic chemistry ; Materials science ; Crystallography ; Metal ; Organic chemistry ; Catalysis Metal-Organic Frameworks: Synthesis and Applications ; Machine Learning in Materials Science ; Boron and Carbon Nanomaterials Research
Authors: Andrew Johnston | Edward H. Sargent
Source: ACS Photonics (article, 2021-03-17)
Field: Materials Science — Materials Chemistry

Accelerated Discovery of Optoelectronic Materials This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Photonics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see doi.org/10.1021/acsphotonics.0c01949. Citation ; Social media ; Library science ; Altmetrics ; Computer science ; World Wide Web Machine Learning in Materials Science ; Nanowire Synthesis and Applications ; Electronic and Structural Properties of Oxides
Authors: Altaf Hussain | Sofia Tahir | Naseeb Ahmad | Mohd Yussni Hashim | A.B. Ziya | Shahzadi Noreen
Source: Revista Mexicana de Física (article, 2021-04-30)
Field: Materials Science — Materials Chemistry

A study on microstructure and magnetic properties of nanostructured CoxNi1-xMn0.5Fe1.5O4(x=0,0.25,0.5,0.75,1) spinel ferrites A low-temperature synthesis of novel nanostructured CoxNi1-xMn0.5Fe1.5O4(x=0,0.25,0.5,0.75,1) ferrites was carried out by sol-gel auto-combustion technique. The obtained nanostructured ferrites were investigated by employing the techniques of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometry (VSM). The XRD diffractograms of the prepared ferrites revealed the formation of a spinel phase with face centered cubic (fcc) structure belonging to Fd- m space group. The average lattice parameter ‘a’ of ferrites exhibited a rise versus a rise in Co2+ concentration in accordance with the Vegard’s law. The SEM investigation of NiMn0.5Fe1.5O4 powder revealed an existence of octahedral-shaped morphology of ferrite grains. The TEM investigation of NiMn0.5Fe1.5O4 powder showed nanostructures of ferrite particles with sizes consistent with the crystallite sizes as estimated by Debye-Scherer’s formula. An EDX spectrum of NiMn0.5Fe1.5O4 powder confirmed its elemental composition. The M-H hysteresis loops recorded by VSM at room temperature revealed a dependence of coercivity (Hc), maximum magnetization (Mmax) and retentivity (Mr) on Co2+concentration. Due to the shape dependence of M-H loops on Co2+ concentration in compounds enabled their candidature for applications in memory devices and magnetic sensors. Materials science ; Crystallite ; Spinel ; Coercivity ; Ferrite (magnet) ; Microstructure ; Transmission electron microscopy ; Analytical Chemistry (journal) ; Scanning electron microscope ; Magnetization ; Lattice constant ; Diffraction ; Nanotechnology ; Condensed matter physics ; Metallurgy ; Composite material ; Optics ; Magnetic field ; Chemistry Magnetic Properties and Synthesis of Ferrites ; Multiferroics and related materials ; Magneto-Optical Properties and Applications
Authors: Tariq Aziz Tariq | Jieyuan Zheng | Muhammad Imran Jamil | Hong Fan | Roh Ullah | Mudassir Iqbal | Amjad Ali | Farman Ullah Khan | Asmat Ullah
Source: Research Square (preprint, 2021-02-15)
Field: Materials Science — Biomaterials

Enhancement in Adhesive and Thermal Properties of Bio-based Epoxy Resin by Using Eugenol Grafted Cellulose Nanocrystals Abstract Bio-based epoxy resins are being used due to their green chemistry. They have better properties than petroleum-based epoxy resins. Recently, environment friendly nanomaterials have been used for different industrial applications. Cellulose nanocrystals (CNCs) are among the best naturally occurring materials. Therefore, the surface of cellulose nanocrystals are modified by eugenol-based silane coupling agent (EBSCA). Chemical composition and surface morphologies of CNCs were analyzed and characterized by FTIR, AFM, SEM, TEM and 1 H-NMR. The SEM and AFM results confirmed eugenol-based silane coupling agent was successfully grafted on cellulose nanocrystals. Modified CNCs demonstrated an excellent tensile strength (2190 MPa) and modulus (16.00 MPa), as well as storage modulus (1622 MPa) exhibited by 1wt% modified cellulose nanocrystals composites. Additionally, modified CNCs displayed hydrophobic behavior (CA=102 ± 2°). The corresponding modified CNCs have significant applications in combination of high stiffness and strength to the epoxy resins. This study lays a foundation towards full bio-based, environment friendly polymers fabrication and consumptions most desirable in adhesive and mechanical industrial fields. Epoxy ; Materials science ; Adhesive ; Cellulose ; Ultimate tensile strength ; Polymer ; Eugenol ; Composite material ; Chemical engineering ; Silane ; Dynamic mechanical analysis ; Fourier transform infrared spectroscopy ; Nanocrystal ; Nanomaterials ; Organic chemistry ; Nanotechnology ; Chemistry ; Layer (electronics) Advanced Cellulose Research Studies ; Lignin and Wood Chemistry ; Polymer composites and self-healing
Authors: Фируза Ахметова | Yermek Aubakirov | Zheneta Kh. Tashmukhambetova | L.R. Sassykova | Hüseyin Arbağ | Ayazhan Kurmangaliyeva
Source: Chemical Bulletin of Kazakh National University (article, 2021-06-30)
Field: Chemistry — Inorganic Chemistry

Recycling of waste plastics to liquid fuel mixture over composite zeolites catalysts Plastic waste production and consumption is increasing at an alarming rate with the increase of the human population, rapid economic growth, continuous urbanization, and changes in lifestyle. In addition, the short life span of plastic accelerates the production of plastic waste on a daily basis. Plastic waste recycling is carried out in different ways, but in most developing countries, open or landfill disposal is a common practice for plastic waste management. Plastic recycling into feedstocks, also known as chemical recycling, is encouraged all over the world. One such area is the thermal and catalytic thermal degradation of plastics into hydrocarbon fractions, which can be used as high-quality motor fuel after appropriate processing. Hydrocracking in the presence of a catalyst is a promising method of converting waste plastic materials to high quality liquid transportation fuels with decreased amounts of olefins and heteroatoms such as S, N, Cl, N, and O. The article deals with the study of hydrocracking of waste plastic into high quality liquid fuel on various catalysts based on natural zeolite deposits Taizhuzgen. The aim of the work is to determine the effect of new composite catalysts on the yield of liquid products by studying the specific surface and porous structure based on natural zeolite modified with Mо salt. It is established that the modification of natural zeolite with Mo affects the morphology of the catalyst, therefore, the obtained catalysts have different effects on the yield and composition of liquid fractions during the hydrogenation thermocatalytic transformation of hydrocarbons. The highest yield of liquid products (61.56%) was achieved using the 2% Mo/Taizhuzgen zeolite catalyst, which was chosen as optimal. Zeolite ; Liquid fuel ; Waste management ; Catalysis ; Yield (engineering) ; Materials science ; Environmental pollution ; Chemistry ; Environmental science ; Organic chemistry ; Metallurgy ; Combustion Zeolite Catalysis and Synthesis ; Thermochemical Biomass Conversion Processes ; Catalysis and Hydrodesulfurization Studies
Authors: Essawi Sherif | Nasrat Loai | Hanafy Ismail | J. N. Asaad
Source: International Journal of Advanced Technology and Engineering Exploration (article, 2021-10-31)
Field: Materials Science — Polymers and Plastics

Effect of nanoparticles on dielectric, mechanical and thermal characteristics of XLPE/TiO2 nanocomposites Because of its high flexibility and mechanical strength, superior dielectric characteristics, strong chemical resistance, ease of processing, and low cost, Cross-Linked Polyethylene (XLPE) has been widely used as an insulating material in high-voltage underground cables Composite materials are made up of two or more components with drastically different physical and chemical characteristics. New materials with properties distinct from the individual components are created as a result of the controlled mixing of the components Nanocomposites are materials that have at least one component with nanometric dimensions [5]. Nanocomposite ; Materials science ; Dielectric ; Nanoparticle ; Composite material ; Thermal ; Nanotechnology ; Optoelectronics ; Thermodynamics Polymer Nanocomposites and Properties ; Polymer Nanocomposite Synthesis and Irradiation ; Dielectric materials and actuators
Authors: Krishna B. Singh | Eun‐Ryeong Hahm | Shivendra V. Singh
Source: Journal of Cancer Metastasis and Treatment (article, 2021-01-01)
Field: Chemistry — Spectroscopy

Leelamine suppresses cMyc expression in prostate cancer cells in vitro and inhibits prostate carcinogenesis in vivo The present study reveals that LLM inhibits cMyc expression in human prostate cancer cells <i>in vitro</i> but concentrations higher than 10 mg/kg may be required to achieve chemoprevention of prostate cancer. Prostate cancer ; LNCaP ; Carcinogenesis ; Cancer research ; Prostate ; Downregulation and upregulation ; Intraepithelial neoplasia ; Cancer ; In vivo ; Tramp ; Biology ; Medicine ; Internal medicine ; Biochemistry Mass Spectrometry Techniques and Applications ; Radiopharmaceutical Chemistry and Applications ; Redox biology and oxidative stress