jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ashlyn R. Hale | Lucas E. Aebersold | Juan E. Peralta | Dolos Foguet‐Albiol | Khalil A. Abboud | George Christou
Source: Polyhedron (article, 2022-07-16)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Analysis of spin frustration in an FeIII7 cluster using a combination of computational, experimental, and magnetostructural correlation methods Chemistry ; Frustration ; Antiferromagnetism ; Ground state ; Octahedron ; Magnetization ; Crystallography ; Spin (aerodynamics) ; Magnetic susceptibility ; Diethanolamine ; Analytical Chemistry (journal) ; Condensed matter physics ; Crystal structure ; Atomic physics ; Physics ; Thermodynamics ; Magnetic field Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Metal-Catalyzed Oxygenation Mechanisms
Authors: Tianlu Li | Tong Li | Yue Yang | Haoru Zhuang | Fengshan Wang | Hong‐Xiang Lou | Richard R. Schmidt | Peng Peng
Source: ChemRxiv (preprint, 2022-03-13)
Field: Chemistry — Organic Chemistry

Gold(III) Chloride─tert-Butyl Cyanide Catalyzed Glycosidations with O-Glycosyl Trihaloacetimidates Activation of O-glycosyl trihaloacetimidates as glycosyl donors with AuCl3 as a catalyst and pivalonitrile (tert-BuCN) as a cocatalyst led to excellent glycosylation results in terms of yield and anomeric selectivity. This way, independent of the glycosyl donor anomeric configuration and without the support of neighboring group or remote group participation, various β-gluco- and β-galactopyranosides were obtained conveniently and efficiently. Also glycoalkaloid solamargine could be readily prepared with this methodology. Studies to the reaction course support adduct formation of the glycosyl donor with the tert-BuCN─AuCl3 complex leading to anomerisation and formation of the thermodynamically most stable anomer prior to the glycosidation event. Then, via hydrogen-bonding of the acceptor to this adduct, intramolecular SN2-type reaction takes place that provides the β-glycoside. This course is closely related to the sequence of events in glycosyltransferase-catalyzed enzymatic glycoside bond formations. Anomer ; Chemistry ; Glycosyl ; Glycosyl donor ; Adduct ; SN2 reaction ; Intramolecular force ; Catalysis ; Glycosylation ; Hydrogen bond ; Yield (engineering) ; Stereochemistry ; Medicinal chemistry ; Acceptor ; Organic chemistry ; Molecule ; Biochemistry Carbohydrate Chemistry and Synthesis ; Enzyme Production and Characterization ; Glycosylation and Glycoproteins Research
Authors: Sayani Bhattacharyya | H. Adhikari | D. Regmi | R. R. V. Hosuru
Source: Indian Journal of Pharmaceutical Sciences (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

A Study on Solubility Enhancement of Etravirine by Crystal Engineering Method Etravirine, an antiretroviral agent, used in the treatment of human immunodeficiency virus belongs to biopharmaceutical classification system classification IV. The reported solubility of the drug is 0.0169 mg/ ml. In the present study, an attempt was made to enhance the solubility of etravirine by crystal engineering technique. The cocrystallization method was carried out using 12 different coformers and each coformer was studied in two different stoichiometric ratios. A preliminary screening of all the cocrystals was done by determination of melting point and solubility. A statistical evaluation of all the cocrystals on solubility was carried out at a significance level of p<0.05. The best cocrystals were subjected to drug content, in vitro drug release, solid-state study (fourier transform infrared spectroscopy, differential scanning calorimetry, powder x-ray diffraction) and stability study for 3 mo. Coformer benzoic acid showed a significant improvement in etravirine solubility in the drug:coformer ratio of 1:1 and 1:2. The drug:benzoic acid ratio of 1:2 was found to have more solubility and showed enhanced dissolution compared to pure drug. The in vitro dissolution rate of the drug:benzoic acid ratio of 1:2 was found to be more than 90 % in 60 min. Therefore, it can be concluded that the cocrystallization method with benzoic acid as coformer can be a promising approach for solubility improvement of etravirine. Solubility ; Etravirine ; Benzoic acid ; Dissolution ; Differential scanning calorimetry ; Chemistry ; Fourier transform infrared spectroscopy ; Nuclear chemistry ; Organic chemistry ; Chemical engineering ; Biochemistry Crystallization and Solubility Studies ; Crystallography and molecular interactions ; Pharmacological Effects of Natural Compounds
Authors: Pratik Kumar | Jason Vevea | Ariana N. Tkachuk | Kirby Campbell | Emma T. Watson | Anthony X. Ayala | Jonathan B. Grimm | Edwin R. Chapman | David J. Solecki | Luke D. Lavis
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2022-07-03)
Field: Chemistry — Organic Chemistry

Optimizing multifunctional fluorescent ligands for intracellular labeling Abstract Enzyme-based self-labeling tags enable covalent attachment of synthetic molecules to proteins inside living cells. A frontier of this field is designing multifunctional ligands that contain both fluorophores and affinity tags or pharmacological agents and can still efficiently enter cells. Self-labeling tag ligands with short linkers can enter cells readily but often show less activity due to steric issues; ligands with long linkers can be more potent but show lower cell permeability. Here, we overcome this tug-of-war between efficacy and cell-permeability by devising a rational strategy for making cell permeable multifunctional ligands for labeling HaloTag fusions. We found that the lactone–zwitterion equilibrium sconstant ( K L–Z ) of rhodamines inversely correlates with their distribution coefficients (log D 7.4 ), suggesting that ligands based on dyes exhibiting low K L–Z and high log D 7.4 values, such as Si-rhodamines, would efficiently enter cells. We designed cell-permeable multifunctional HaloTag ligands with a biotin moiety to purify mitochondria or a JQ1 appendage to translocate BRD4 from euchromatin to the nucleolus or heterochromatin. We discovered that translocation of BRD4 to constitutive heterochromatin in cells expressing HaloTag–HP1a fusion proteins can lead to apparent increases in transcriptional activity. These new reagents enable affinity capture and translocation of intracellular proteins in living cells and the use of Si-rhodamines and other low K L– Z /high log D 7.4 dye scaffolds will facilitate the design of new multifunctional chemical tools for biology. SIGNIFICANCE STATEMENT Understanding cellular processes requires tools to measure and manipulate proteins in living cells. Self- labeling tags, such as the HaloTag and SNAP-tag, enable modification of cellular proteins with synthetic molecules. Creating ligands for these systems that have more than one chemical motif remains challenging, however, due to competing demands between cell permeability and functionality. We discovered that multifunctional ligands based on Si-rhodamines efficiently entered cells and enabled affinity purification of mitochondria or translocation of nuclear proteins; the performance of these molecules could be verified by fluorescence microscopy. These compounds should be useful for a variety of biological experiments and our general framework will allow the design of other multifunctional ligands to study living systems. Fluorophore ; Rhodamine ; Biotin ; Fluorescence ; Ligand (biochemistry) ; Chemistry ; Fluorescence microscope ; Cell permeability ; Biophysics ; Avidin ; Nanotechnology ; Live cell imaging ; Cell ; Materials science ; Biochemistry ; Biology Click Chemistry and Applications ; Biotin and Related Studies ; Monoclonal and Polyclonal Antibodies Research
Authors: Sylvestre P. J. T. Bachollet | Yuriy Shpinov | Fanny Broch | Hela Benaissa | Arnaud Gautier | Jean‐Maurice Mallet | Blaise Dumat
Source: ChemRxiv (preprint, 2022-02-08)
Field: Materials Science — Materials Chemistry

An expanded palette of fluorogenic HaloTag probes with enhanced contrast for targeted cellular imaging We report the development of HaloTag fluorogens based on dipolar flexible molecular rotor structures. By modulating the electron donating and withdrawing groups, we have tuned the absorption and emission wavelengths to design a palette of fluorogens with emissions spanning the green to red range. The probes were studied in glycerol and in presence of HaloTag and exhibited good fluorogenic properties thanks to a viscosity-sensitive emission. In live-cell confocal imaging, the fluorogens yielded only a very low non-specific signal that enabled wash-free targeted imaging of intracellular organelles and proteins with good contrast. Confocal ; Fluorescence ; Biophysics ; Palette (painting) ; Chemistry ; Live cell imaging ; Intracellular ; Molecular probe ; Materials science ; Cell ; Optics ; Biochemistry ; DNA Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics ; Supramolecular Chemistry and Complexes
Authors: Joshua Kyle Stanfield | Osami Shoji
Source: Journal of the Japan Petroleum Institute (article, 2022-04-30)
Field: Chemistry — Inorganic Chemistry

Gaseous Alkane Hydroxylation by Deceiving Cytochrome P450BM3 Using Decoy Molecules Cytochrome P450BM3 (P450BM3) catalyses the monooxygenation of fatty acids. However, in the case of non-native substrates possessing different structures from fatty acids, P450BM3 remains in an inactive state and catalysis does not proceed. This review will introduce a unique approach, wherein native substrate mimics (decoy molecules) are employed to trick P450BM3 into mistakenly hydroxylating non-native substrates. The decoy molecule system has the advantage that wild-type enzyme can be employed and catalytic activity improved by developing appropriate decoy molecules. With a focus on the hydroxylation of gaseous alkanes, key developments since the first discovery of decoy molecules to the present day will be covered briefly herein. Notably, ethane was efficiently hydroxylated by wild-type P450BM3 with assistance of the systematically evolved N-substituted dipeptidic decoy molecule N-enanthoyl-L-pipecolyl-L-phenylalanine (C7AMPipPhe), achieving a TOF of 82.7 min−1 P450−1, representing the highest TOF among reported values catalysed by P450s including engineered P450s. Hydroxylation ; Decoy ; Chemistry ; Molecule ; Catalysis ; Cytochrome ; Substrate (aquarium) ; Biocatalysis ; Cytochrome P450 ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Enzyme ; Biochemistry ; Reaction mechanism ; Biology ; Ecology Metal-Catalyzed Oxygenation Mechanisms ; Pharmacogenetics and Drug Metabolism ; Asymmetric Hydrogenation and Catalysis
Authors: Ashanul Haque | Khalaf M. Alenezi | Hani El Moll | Muhammad S. Khan | Wai‐Yeung Wong
Source: Molecules (article, 2022-07-01)
Field: Chemistry — Inorganic Chemistry

Synthesis of Mixed Arylalkyl Tertiary Phosphines via the Grignard Approach Trialkyl and triaryl phosphines are important classes of ligands in the field of catalysis and materials research. The wide usability of these low-valent phosphines has led to the design and development of new synthesis routes for a variety of phosphines. In the present work, we report the synthesis and characterization of some mixed arylalkyl tertiary phosphines via the Grignard approach. A new asymmetric phosphine is characterized extensively by multi-spectroscopic techniques. IR and UV-Vis spectra of some selected compounds are also compared and discussed. Density functional theory (DFT)-calculated results support the formation of the new compounds. Phosphine ; Chemistry ; Combinatorial chemistry ; Catalysis ; Organic chemistry ; Computational chemistry Asymmetric Hydrogenation and Catalysis ; Organoboron and organosilicon chemistry ; Asymmetric Synthesis and Catalysis
Authors: Jesús Sanmartín‐Matalobos | Pilar Bermejo–Barrera | Ignacio Pérez‐Juste | Matilde Fondo | Ana M. Garcı́a-Deibe | Yeneva Alves-Iglesias
Source: Chemosensors (article, 2022-09-28)
Field: Materials Science — Materials Chemistry

Detecting CdSe Nanomaterials with a Fluorescent Schiff Base Ligand We investigated the easily synthesized ligand H3L as a fluorescent chemosensor for the detection of CdSe nanoparticles (CdSe NPs) and L-cysteine-capped CdSe quantum dots (CdSe-Cys QDs) in ethanol–water samples. A drastic quenching of the fluorescence emission of H3L at 510 nm occurred, as a result of the addition of CdSe NPs and CdSe-Cys QDs. A solution of H3L (1.26 ppb) showed sensitive responses to both CdSe NPs and CdSe-Cys QDs, with limits of detection (LOD) as low as 40 and 62 ppb, respectively. Moreover, using a smartphone color recognizer application, the fluorescence intensity response of H3L-modified cellulose paper to CdSe-Cys QDs was recorded on a red channel (R), which allowed us to detect CdSe-Cys QDs with LOD = 15 ppb. Interference of some common metal nanomaterials (NMs), as well as metal ions, in the determination of CdSe NMs in solution was studied. The affinity of H3L to CdSe NPs and CdSe-Cys QDs was spectroscopically determined. Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX), micro-X-ray fluorescence (µ-XRF), 1H-NMR, attenuated total reflection infrared spectroscopy (ATR-IR), and density functional theory (DFT) were also used to investigate the interaction of H3L with CdSe NMs. Fluorescence ; Nanomaterials ; Quantum dot ; Spectroscopy ; Materials science ; Analytical Chemistry (journal) ; Quenching (fluorescence) ; Scanning electron microscope ; Nanoparticle ; Metal ions in aqueous solution ; Chemistry ; Nuclear chemistry ; Photochemistry ; Metal ; Nanotechnology ; Organic chemistry Quantum Dots Synthesis And Properties ; Advanced biosensing and bioanalysis techniques ; Nanocluster Synthesis and Applications
Authors: Junyan Li | Álvaro Mayoral | Yoshihiro Kubota | Satoshi Inagaki | Jihong Yu | Osamu Terasaki
Source: Angewandte Chemie (article, 2022-10-04)
Field: Chemistry — Inorganic Chemistry

Direct TEM Observation of Vacancy‐Mediated Heteroatom Incorporation into a Zeolite Framework: Towards Microscopic Design of Zeolite Catalysts Abstract Incorporating hetero‐metal‐atom, e.g., titanium, into zeolite frameworks can enhance the catalytic activity and selectivity in oxidation reactions. However, the rational design of zeolites containing titanium at specific sites is difficult because the precise atomic structure during synthesis process remained unclear. Here, a titanosilicate with predictable titanium distribution was synthesized by mediating vacancies in a defective MSE ‐type zeolite precursor, based on a pre‐designed synthetic route including modification of vacancies followed by titanium insertion, where electron microscopy (EM) plays a key role at each step resolving the atomic structure. Point defects including vacancies in the precursor and titanium incorporated into the vacancy‐related positions have been directly observed. The results provide insights into the role of point defects in zeolites towards the rational synthesis of zeolites with desired microscopic arrangement of catalytically active sites. Zeolite ; Heteroatom ; Titanium ; Vacancy defect ; Catalysis ; Rational design ; Materials science ; Selectivity ; Chemistry ; Chemical engineering ; Nanotechnology ; Crystallography ; Organic chemistry ; Metallurgy Zeolite Catalysis and Synthesis ; Catalytic Processes in Materials Science ; Polyoxometalates: Synthesis and Applications
Authors: Weiwei Guo | Yinping Ma | Lei Hu | Yujie Feng | Yanmiao Liu | Xuedong Yi | Wenzhi Zhang | Fushan Tang
Source: Preprints.org (preprint, 2022-11-23)
Field: Materials Science — Biomaterials

Modification Strategies for Ionic Complementary Self-Assembling Peptides: Taking RADA16-Ⅰ as an Example Ion-complementary self-assembling peptides have been studied in many fields for their distinct advantages mainly due to their self-assembly properties. However, their shortcomings, such as insufficient specific activity and poor mechanical properties, also limited their application. For better and wider application of this kind of promising biomaterials, ion-complementary self-assembling peptides can be modified with their self-assembly properties not being destroyed to the greatest extent. The modification strategies were reviewed by taking RADA16-Ⅰ as an example. For the insufficient specific activity, RADA16-Ⅰ can be structurally modified with active motifs derived from the active domain of the extracellular matrix or other related active factors. For weak mechanical properties, materials with strong mechanical properties or materials that can undergo chemical crosslinking were used to mix with RADA16-Ⅰto enhance the mechanical properties of RADA16-Ⅰ. To improve the performance of RADA16-Ⅰ as drug carriers, appropriate adjustment of the RADA16-Ⅰ sequence and/ or modification of the RADA16-Ⅰ-related delivery system with polymer materials or specific molecules can be considered to achieve sustained and controlled release of specific drugs or active factors. The modification strategies reviewed in this paper may provide some references for the further basic research and clinical application of ion-complementary self-assembling peptides and their derivatives. Nanotechnology ; Self-assembly ; Self-healing hydrogels ; Materials science ; Chemistry ; Polymer chemistry Supramolecular Self-Assembly in Materials ; Biopolymer Synthesis and Applications ; Chemical Synthesis and Analysis
Authors: Joscha Kruse | María Sanromán-Iglesias | Aimar Marauri | Iván Rivilla | Marek Grzelczak
Source: ChemSystemsChem (article, 2022-12-15)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Coupling Reversible Clustering of DNA‐Coated Gold Nanoparticles with Chemothermal Cycloaddition Reaction Abstract Stimuli‐responsive, optically‐active colloidal systems are convenient signal transducers capable of monitoring environmental changes at the nanoscale. We report on the coupling of chemo‐thermal cycloaddition reaction with temperature‐sensitive, DNA‐coated gold nanoparticles. We found that the concentration of chemical fuel, dictating the temperature of the mixture, is a primary ingredient in controlling the extent of the reversible clustering of gold nanoparticles. Our results show that rational coupling of chemical and colloidal systems can open up new possibilities in tracking the change of local temperature using aggregation/redispersion of nanoparticles. Colloidal gold ; Cycloaddition ; Nanoparticle ; Materials science ; Coupling (piping) ; Colloid ; Nanoscopic scale ; Nanotechnology ; Molecule ; Cluster analysis ; Chemical physics ; Chemical engineering ; Chemistry ; Catalysis ; Organic chemistry ; Composite material Gold and Silver Nanoparticles Synthesis and Applications ; Machine Learning in Materials Science ; Computational Drug Discovery Methods
Authors: Junbo Chen | Chenhui Wang | Hao Li | Xin Xu | Jiangang Yang | Zhe Huo | Lixia Wang | Weifeng Zhang | Xudong Xiao | Yaping Ma
Source: Preprints.org (preprint, 2022-12-14)
Field: Materials Science — Materials Chemistry

Recent Advances in Surface Modifications of Elemental Two-Dimensional Materials: Structures, Properties, and Applications The advent of graphene opens up the research into two-dimensional (2D) material, which is considered as a revolutionary material in the future. Due to its unique geometric structure, graphene exhibits a series of exotic physical and chemical properties. Besides, single-element-based 2D materials (Xenes) have garnered tremendous interest. At present, 16 kinds of Xenes (silicene, borophene, germanene, phosphorene, tellurene, etc.) have been explored, mainly distributed in the third, fourth, fifth and sixth main groups. The current methods to prepare monolayer or few-layer 2D materials include epitaxy growth, mechanical exfoliation, and liquid phase exfoliation. Although two Xenes (aluminene and indiene) have not been synthesized due to the limitations of synthetic methods or stability of Xenes, other Xenes have been successfully realized by elaborately artificial design and synthesis. Focusing on elemental 2D materials, this review mainly summarizes the recently reported work about tuning the electronic, optical, mechanical, or chemical properties of Xenes via surface modifications achieved by controllable approaches (doping, adsorption, strain, intercalation, phase transition, etc.) to broaden the applications in various fields, including spintronics, electronics, optoelectronics, superconducting, photovoltaics, sensors, catalysis, and biomedicines. These advances in surface modification of Xenes have laid a theoretical and experimental foundation for the development of 2D materials and their practical applications in diverse fields. Germanene ; Materials science ; Nanotechnology ; Silicene ; Exfoliation joint ; Graphene ; Spintronics ; Phosphorene ; Monolayer ; Surface modification ; Ferromagnetism ; Chemistry Graphene research and applications ; 2D Materials and Applications ; Advanced Photocatalysis Techniques
Authors: Daria Vladikova | Blagoy Burdin | Asrar Sheikh | Paolo Piccardo | Milena Krapchanska | Dario Montinaro | Roberto Spotorno
Source: Energies (article, 2022-04-30)
Field: Materials Science — Materials Chemistry

Accelerated Stress Tests for Solid Oxide Cells via Artificial Aging of the Fuel Electrode Solid Oxide Cells (SOCs) are under intensive development due to their great potential to meet the 2030 targets for decarbonization. One of their advantages is that they can work in reversible mode. However, in respect to durability, there are still some technical challenges. Although the quick development of experimental and modeling approaches gives insight into degradation mechanisms, an obligatory step that cannot be avoided is the performance of long-term tests. Taking into account the target for a commercial lifetime is 80,000 h, experiments lasting years are not acceptable for market needs. This work aims to develop accelerated stress tests (ASTs) for SOCs by the artificial aging of the fuel electrode via redox cycling, which follows the degradation processes of calendar aging (Ni coarsening and migration). However, it can cause irreversible damage by the formation of cracks at the interface anode/electrolyte. The advantages of the developed procedure are that it offers a mild level of oxidation, which can be governed and regulated by the direct impedance monitoring of the Ni network resistance changes during oxidation/reduction on a bare anode sample. Once the redox cycling conditions are fixed and the anode/electrolyte sample is checked for cracks, the procedure is introduced for the AST in full-cell configuration. The developed methodology is evaluated by a comparative analysis of current voltage and impedance measurements of pristine, artificially aged, and calendar-aged button cells, combined with microstructural characterization of their anodes. It can be applied in both fuel cell and electrolyzer mode. The results obtained in this study from the electrochemical tests show that the artificially aged experimental cell corresponds to at least 3500 h of nominal operation. The number of hours is much bigger in respect to the microstructural aging of the anode. Taking into consideration that the duration of the performed 20 redox cycles is about 50 to 60 working hours, the acceleration factor in respect to experimental timing is estimated to be higher than 60, without any damaging of the sample. This result shows that the selected approach is very promising for a large decrease in testing times for SOCs. Anode ; Electrolyte ; Materials science ; Durability ; Oxide ; Degradation (telecommunications) ; Accelerated aging ; Electrode ; Electrolysis ; Stress (linguistics) ; Redox ; Solid oxide fuel cell ; Composite material ; Metallurgy ; Electrical engineering ; Chemistry ; Engineering Advancements in Solid Oxide Fuel Cells ; Fuel Cells and Related Materials ; Electrocatalysts for Energy Conversion