jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ishtiyaq Ahmad | Asif A. Malik | Aijaz A. Dar
Source: Crystal Growth & Design (article, 2022-10-11)
Field: Chemistry — Spectroscopy

Multi-Stimuli-Responsive Organo-Sulfonated Anil and Its Organic Complex Sensing by molecules is an intriguing phenomenon that can lead to next-generation intelligent materials. Stimuli-responsive organic molecules or molecular complexes, although less reported, can open up new avenues and opportunities in the area of artificial intelligence and memory. Extending the scope of organo-sulfonated Anils as stimuli-responsive materials, we report hydrated sulfonated Anil 1 and its nonstoichiometric bipyridyl complex 1.BPY. The formation of new materials is well supported and further substantiated through the solid-state structural elucidation of 1. Thermal and crystallographic studies validate the presence of two lattice water molecules each in 1 and 1.BPY. Structural studies also indicate that 1 undergoes intramolecular proton transfer between sulfonate and imine groups and exists in the zwitterionic form. Both 1 and 1.BPY respond to external stimuli: temperature, solvent polarity, and ammonia vapor. The thermochromism in both forms is reversible and interestingly triggered by the breathing of lattice water, a rare phenomenon in organic materials, supported by Fourier-transform infrared (FT-IR), thermal, and diffraction studies. Compared with the transition temperature of 130 °C for 1, 1.BPY undergoes a color change at 65 °C, and their heated forms, 1-Heat and 1.BPY-Heat, in turn, can be used as humidity sensors. Both solid forms exhibit solvatochromism and show emission turn-on in nonprotic polar solvents, dimethyl sulfoxide (DMSO) and dimethylformamide (DMF). The incipience of emission of 1.BPY in highly polar solvents DMSO (φ = 12%) and DMF (φ = 46%), and its absence in the solvents of relatively lower polarity such as H2O and MeOH as well as in solid forms, may be attributed to aggregation-induced quenching, which is supported by the solubility and DLS studies of 1 and 1.BPY in the solvents. Very interestingly and to the best of our knowledge, molecular solids 1 and 1.BPY represent the first examples of organic materials that exhibit emission turn-on on exposure to fumes of a base. When exposed to the fumes of ammonia, 1 and 1.BPY undergo a color change from maroon and orange to yellow, respectively, and the 1.NH3 and 1.BPY-NH3 forms show a striking green emission, which may be attributed to proton transfer within the molecular systems most likely involving the excited-state intermolecular proton-transfer (ESIPT) pathway. The overall analyses of the results indicate that the molecular complex 1.BPY is a better material vis-à-vis its response time (thermochromism), intensity (solvatochromic), and fatigue (vapochromism) and substantiate the scope of the crystal-engineering principles in designing next-generation smart materials. Solvatochromism ; Chemistry ; Intramolecular force ; Thermochromism ; Molecule ; Photochemistry ; Solvent ; Organic chemistry Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials ; Sulfur-Based Synthesis Techniques
Authors: Ganapathi Rao Kandregula | Dhinesh Kumar Murugaiah | N. Arul Murugan | Kothandaraman Ramanujam
Source: New Journal of Chemistry (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Data-driven approach towards identifying dyesensitizer molecules for higher power conversion efficiency in solar cells Machine learning (ML) research based on the quantitative structure–property relationship (QSPR) has been applied for the development of highly efficient dye-sensitized solar cells (DSSCs). Chemistry ; Quantitative structure–activity relationship ; Energy conversion efficiency ; Dye-sensitized solar cell ; Molecule ; Property (philosophy) ; Nanotechnology ; Biochemical engineering ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Physical chemistry ; Optoelectronics Quantum Dots Synthesis And Properties ; TiO2 Photocatalysis and Solar Cells ; Advanced Nanomaterials in Catalysis
Authors: Manu Veliparambil Subrahmanian | KowsalyaDevi Pavuluri | Cristina Olivieri | Gianluigi Veglia
Source: PNAS Nexus (article, 2022-08-05)
Field: Chemistry — Spectroscopy

High-fidelity control of spin ensemble dynamics via artificial intelligence: from quantum computing to NMR spectroscopy and imaging High-fidelity control of spin ensemble dynamics is essential for many research areas, spanning from quantum computing and radio-frequency (RF) engineering to NMR spectroscopy and imaging. However, attaining robust and high-fidelity spin operations remains an unmet challenge. Using an evolutionary algorithm and artificial intelligence (AI), we designed new RF pulses with customizable spatial or temporal field inhomogeneity compensation. Compared with the standard RF shapes, the new AI-generated pulses show superior performance for bandwidth, robustness, and tolerance to field imperfections. As a benchmark, we constructed a spin entanglement operator for the weakly coupled two-spin-1/2 system of <sup>13</sup>CHCl<sub>3</sub>, achieving high-fidelity transformations under multiple inhomogeneity sources. We then generated band-selective and ultra-broadband RF pulses typical of biomolecular NMR spectroscopy. When implemented in multipulse NMR experiments, the AI-generated pulses significantly increased the sensitivity of medium-size and large protein spectra relative to standard pulse sequences. Finally, we applied the new pulses to typical imaging experiments, showing a remarkable tolerance to changes in the RF field. These AI-generated RF pulses can be directly implemented in quantum information, NMR spectroscopy of biomolecules, magnetic resonance imaging techniques for in vivo and materials sciences. Robustness (evolution) ; Spectroscopy ; Radio frequency ; Nuclear magnetic resonance spectroscopy ; Computer science ; Nuclear magnetic resonance ; Physics ; Computational physics ; Materials science ; Biological system ; Chemistry ; Telecommunications ; Quantum mechanics Advanced NMR Techniques and Applications ; Electron Spin Resonance Studies ; Advanced MRI Techniques and Applications
Authors: Wei Han | Fei Jiang | Zhiyuan Zhu
Source: Foods (article, 2022-04-14)
Field: Chemistry — Analytical Chemistry

Detection of Cherry Quality Using YOLOV5 Model Based on Flood Filling Algorithm Presently, the quality of cherries in the market is uneven, because human senses are used to distinguish cherry quality, which consumes a lot of time and energy and does not achieve good results in terms of accuracy. If the internal quality indices, such as the PH value, sugar-acid ratio, and vitamin C content, of cherries are extracted using chemical methods, the detection speed will decrease. With the development of artificial intelligence (AI), image processing by AI algorithms has attracted broad attention. The YOLOv5 model in the YOLO series has many advantages, such as high detection accuracy, fast speed, small size, and so on, and has been used in face recognition, image recognition and other fields. However, owing to the influence of seasonal weather, the environment and other factors, the dataset used in the training model decreases the accuracy of image recognition. To improve the accuracy, a large amount of data must be used for model training, but this will decrease the model training speed. Because it is impossible to use all data in training, there will inevitably be recognition errors in the detection process. In this study, the cherry images in a dataset were extracted by the flooding filling algorithm. The extracted cherry images were used as a new dataset for training and recognition, and the results were compared to those obtained with non-extracted images. The dataset generated by the flooding filling algorithm was used for model training. After 20 training epochs, the accuracy rate reached 99.6%. Without using the algorithm to extract images, the accuracy rate was only 78.6% after 300 training epochs. Algorithm ; Quality (philosophy) ; Flood myth ; Computer science ; Mathematics ; Geography ; Physics ; Archaeology Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Date Palm Research Studies
Authors: Nikos Nikolopoulos | Renata C. Matos | Pascal Courtin | Isabel Ayala | Houssam Akherraz | Jean‐Pierre Simorre | Marie‐Pierre Chapot‐Chartier | François Leulier | Stéphanie Ravaud | Christophe Grangeasse
Source: Scientific Reports (article, 2022-07-30)
Field: Materials Science — Materials Chemistry

DltC acts as an interaction hub for AcpS, DltA and DltB in the teichoic acid d-alanylation pathway of Lactiplantibacillus plantarum Teichoic acids (TA) are crucial for the homeostasis of the bacterial cell wall as well as their developmental behavior and interplay with the environment. TA can be decorated by different modifications, modulating thus their biochemical properties. One major modification consists in the esterification of TA by D-alanine, a process known as D-alanylation. TA D-alanylation is performed by the Dlt pathway, which starts in the cytoplasm and continues extracellularly after D-Ala transportation through the membrane. In this study, we combined structural biology and in vivo approaches to dissect the cytoplasmic steps of this pathway in Lactiplantibacillus plantarum, a bacterial species conferring health benefits to its animal host. After establishing that AcpS, DltB, DltC1 and DltA are required for the promotion of Drosophila juvenile growth under chronic undernutrition, we solved their crystal structure and/or used NMR and molecular modeling to study their interactions. Our work demonstrates that the suite of interactions between these proteins is ordered with a conserved surface of DltC1 docking sequentially AcpS, DltA and eventually DltB. Altogether, we conclude that DltC1 acts as an interaction hub for all the successive cytoplasmic steps of the TA D-alanylation pathway. Cytoplasm ; Teichoic acid ; Biology ; Cell biology ; Biochemistry ; Bacterial cell structure ; Computational biology ; Genetics ; Bacteria ; Cell wall ; Peptidoglycan Enzyme Structure and Function ; Polyamine Metabolism and Applications ; Enzyme Production and Characterization
Authors: Amir H. Farmahini | Khalid Limbada | Lev Sarkisov
Source: Adsorption (article, 2022-08-01)
Field: Chemistry — Inorganic Chemistry

Comment on the applicability of the Gurvich rule for estimation of pore volume in microporous zeolites Abstract This comment seeks to establish a relation between two definitions of the pore volume of a microporous crystalline material. According to the first definition based on the Gurvich rule, the volume of the pores can be estimated from the saturated amount of vapour adsorbed, using the bulk liquid density of adsorbate as the conversion factor. The second definition is based on a purely geometric consideration of the porous space. With argon as the adsorbate and all-silica zeolite structures from the International Zeolite Association (IZA) database as the model adsorbents, we generate adsorption data using Grand Canonical Monte Carlo simulations and structural characteristics of the materials from the Poreblazer PB4.0 software. Under confinement in zeolitic pores, adsorbed argon forms structures very different from the liquid-like configurations. However, the pore volumes of these materials obtained from the Gurvich may deviate positively or negatively from the reference geometric value. Considering simply the geometric features of the materials, such as the pore volume itself or the pore size distribution, it proved to be difficult to anticipate how the volume from the Gurvich rule would deviate from the geometric volume for a particular structure. Overall, volume from the Gurvich rule agrees with the geometric volume within 25% error for 82% of the structures from the IZA database. As an additional outcome of this study, we provide a comprehensive database of textural characteristics and simulated argon adsorption data for all-silica zeolites, which can be used as reference values for the assessment of the quality of the microporous samples of all-silica zeolites in future experimental studies. Microporous material ; Volume (thermodynamics) ; Adsorption ; Zeolite ; Argon ; Porosity ; Thermodynamics ; Materials science ; Chemistry ; Statistical physics ; Mineralogy ; Physical chemistry ; Physics ; Organic chemistry ; Catalysis Zeolite Catalysis and Synthesis ; Mesoporous Materials and Catalysis ; Catalysis and Oxidation Reactions
Authors: Sidharth Mehan | Navneet Arora | Sonalika Bhalla | Andleeb Khan | Muneeb U. Rehman | Badrah S. Alghamdi | Torki A. Zughaibi | Ghulam Md Ashraf
Source: Molecules (review, 2022-06-01)
Field: Materials Science — Biomaterials

Involvement of Phytochemical-Encapsulated Nanoparticles’ Interaction with Cellular Signalling in the Amelioration of Benign and Malignant Brain Tumours Brain tumours have unresolved challenges that include delay prognosis and lower patient survival rate. The increased understanding of the molecular pathways underlying cancer progression has aided in developing various anticancer medications. Brain cancer is the most malignant and invasive type of cancer, with several subtypes. According to the WHO, they are classified as ependymal tumours, chordomas, gangliocytomas, medulloblastomas, oligodendroglial tumours, diffuse astrocytomas, and other astrocytic tumours on the basis of their heterogeneity and molecular mechanisms. The present study is based on the most recent research trends, emphasising glioblastoma cells classified as astrocytoma. Brain cancer treatment is hindered by the failure of drugs to cross the blood-brain barrier (BBB), which is highly impregnableto foreign molecule entry. Moreover, currently available medications frequently fail to cross the BBB, whereas chemotherapy and radiotherapy are too expensive to be afforded by an average incomeperson and have many associated side effects. When compared to our current understanding of molecularly targeted chemotherapeutic agents, it appears that investigating the efficacy of specific phytochemicals in cancer treatment may be beneficial. Plants and their derivatives are game changers because they are efficacious, affordable, environmentally friendly, faster, and less toxic for the treatment of benign and malignant tumours. Over the past few years, nanotechnology has made a steady progress in diagnosing and treating cancers, particularly brain tumours. This article discusses the effects of phytochemicals encapsulated in nanoparticles on molecular targets in brain tumours, along with their limitations and potential challenges. Phytochemical ; Nanoparticle ; Signalling pathways ; Chemistry ; Cancer research ; Neuroscience ; Medicine ; Pharmacology ; Nanotechnology ; Biology ; Biochemistry ; Signal transduction ; Materials science Nanoparticle-Based Drug Delivery ; Curcumin's Biomedical Applications ; Retinoids in leukemia and cellular processes
Authors: Hele Guo | Yali Liu | Hongliang Dong | Wei Zong | Kaibin Chu | Weiwei Li | Zhongli Fan | Guanjie He | Yue‐E Miao | Ivan P. Parkin | Feili Lai | Tianxi Liu
Source: Science Bulletin (article, 2022-11-14)
Field: Chemistry — Organic Chemistry

Soluble porous organic cages as homogenizers and electron-acceptors for homogenization of heterogeneous alloy nanoparticle catalysts with enhanced catalytic activity Catalysis ; Homogenization (climate) ; Homogenizer ; Alloy ; Materials science ; Nanoparticle ; Porosity ; Chemical engineering ; Composite material ; Nanotechnology ; Chemistry ; Organic chemistry ; Chromatography Nanomaterials for catalytic reactions ; Catalytic Processes in Materials Science ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Qingxiang Li | Xuemin Lü | Zhiguo Lv | Bangshang Zhu | Qinghua Lu
Source: ACS Nano (article, 2022-11-08)
Field: Chemistry — Organic Chemistry

Full-Color and Switchable Circularly Polarized Light from a Macroscopic Chiral Dendritic Film through a Solid-State Supramolecular Assembly Chiral materials displaying chirality across multiple length scales have attracted increasing interest due to their potential applications in diverse fields. Herein, we report an efficient approach for the construction of macroscopic crystal dendrites with hierarchical chirality based on an <i>in situ</i> solid assembly in a block copolymer film. Chiral fluorescent crystals are formed by enantiopure d-/l-dibenzoyl tartaric acid and pyrenecarboxylic acid in a poly(1,4-butadiene)-<i>b</i>-poly(ethylene oxide) film. The chiro-optical activity of the crystalline dendrites can be greatly amplified in the absorption and scattering regions and goes along with the dimension of dendrites. Notably, the chiral dendrites exhibited strong circularly polarized luminescence emission with a high dissymmetric factor (0.03). The enhancement of the quantum yield of the chiral film was up to 28%, which was 14 times higher that of the corresponding fluorescent molecules. The circularly polarized emission bands of the films can be fine-tuned by contriving the emissive bands of fluorescent molecules. More importantly, the chiral signals are able to be wiped when the fluorescent group photodimerizes under UV irradiation. This work provides an efficient way to develop functional materials through solid self-assembly. Materials science ; Enantiopure drug ; Supramolecular chirality ; Fluorescence ; Chirality (physics) ; Circular polarization ; Luminescence ; Quantum yield ; Molecule ; Tetraphenylethylene ; Self-assembly ; Supramolecular chemistry ; Photochemistry ; Chemical physics ; Crystallography ; Optoelectronics ; Nanotechnology ; Crystal structure ; Aggregation-induced emission ; Optics ; Chiral symmetry breaking ; Chemistry ; Organic chemistry ; Physics ; Enantioselective synthesis Synthesis and Properties of Aromatic Compounds ; Supramolecular Self-Assembly in Materials ; Luminescence and Fluorescent Materials
Authors: Qi Mou | Ruyuan Zhao | Bo Sun
Source: Chemistry - An Asian Journal (review, 2022-09-01)
Field: Chemistry — Organic Chemistry

Recent Advances in Transition‐Metal‐Catalyzed C−H Functionalization of Ferrocene Amides During the past decades, in synthetic organic chemistry, directing-group-assisted C-H functionalization is found to be a key tool for the expedient and site-selective construction of C-C and hybrid bonds. Among C-H functionalization of ferrocene derivatives, the directed group strategy is undoubtedly the most commonly used method. Compared to the other directing groups, ferrocene amides can be synthesized easily and are now recognized as one of the most efficient tools for the selective functionalization of certain positions because its metal centre permits fine, tuneable and reversible coordination. The family of amide directing groups mainly comprises monodentate and bidentate directing groups, which are categorized on the basis of coordination sites. In this review, various C-H bond functionalization reactions of ferrocene using amide directing groups are broadly discussed. Surface modification ; Ferrocene ; Catalysis ; Transition metal ; Combinatorial chemistry ; Chemistry ; Organic chemistry ; Electrochemistry ; Physical chemistry Catalytic C–H Functionalization Methods ; Asymmetric Hydrogenation and Catalysis ; Synthesis and Catalytic Reactions
Authors: Victoria N. Drago | Steven Dajnowicz | Jerry M. Parks | Matthew P. Blakeley | David A. Keen | Nicolas Coquelle | Kevin L. Weiss | Oksana Gerlits | Andrey Kovalevsky | Timothy C. Mueser
Source: Chemical Science (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

An N⋯H⋯N low-barrier hydrogen bond preorganizes the catalytic site of aspartate aminotransferase to facilitate the second half-reaction Pyridoxal 5'-phosphate (PLP)-dependent enzymes have been extensively studied for their ability to fine-tune PLP cofactor electronics to promote a wide array of chemistries. Neutron crystallography offers a straightforward approach to studying the electronic states of PLP and the electrostatics of enzyme active sites, responsible for the reaction specificities, by enabling direct visualization of hydrogen atom positions. Here we report a room-temperature joint X-ray/neutron structure of aspartate aminotransferase (AAT) with pyridoxamine 5'-phosphate (PMP), the cofactor product of the first half reaction catalyzed by the enzyme. Between PMP N<sub>SB</sub> and catalytic Lys258 Nζ amino groups an equally shared deuterium is observed in an apparent low-barrier hydrogen bond (LBHB). Density functional theory calculations were performed to provide further evidence of this LBHB interaction. The structural arrangement and the juxtaposition of PMP and Lys258, facilitated by the LBHB, suggests active site preorganization for the incoming ketoacid substrate that initiates the second half-reaction. Catalysis ; Chemistry ; Active site ; Hydrogen bond ; Pyridoxal ; Pyridoxamine ; Enzyme ; Pyridoxal phosphate ; Phosphate ; Stereochemistry ; Biochemistry ; Molecule ; Organic chemistry ; Cofactor Enzyme Structure and Function ; Amino Acid Enzymes and Metabolism ; Biochemical and Molecular Research
Authors: Ying Wan | Jian Li | Jitong Ma | Yanan Li | Ren Wang | Zhengxing Chen | Tao Wang
Source: Food Chemistry (article, 2022-08-06)
Field: Materials Science — Materials Chemistry

Fixing zein at the fibrillar carboxymethyl cellulose toward an amphiphilic nano-network Carboxymethyl cellulose ; Amphiphile ; Dispersity ; Circular dichroism ; Chemical engineering ; Pickering emulsion ; Materials science ; Cellulose ; Nanoparticle ; Polysaccharide ; Chemistry ; Polymer ; Polymer chemistry ; Nanotechnology ; Crystallography ; Organic chemistry ; Copolymer ; Sodium ; Composite material Pickering emulsions and particle stabilization ; Proteins in Food Systems ; Polysaccharides Composition and Applications
Authors: Mengqi Sun | Zixin Wang | Hui Wang
Source: Chemistry of Materials (article, 2022-02-07)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Chemically Driven Phase Segregation of Alloy Nanoparticles: A Versatile Route to Dual-Plasmonic Gold@Copper Chalcogenide Heteronanostructures Multicomponent heteronanostructures have emerged as a class of structurally and compositionally tunable multifunctional nanomaterials whose electronic, optical, and catalytic properties can be fine-engineered for targeted applications. Heteronanostructures composed of Au and copper chalcogenide domains represent a unique hybrid material system that integrates two distinct types of plasmon resonances arising from the conduction electrons and valence holes, respectively, in a single nanoscale entity. Success in fine-tuning the optical properties of these dual-plasmonic heteronanostructures relies critically on our capabilities to precisely tailor not only the structural arrangements but also the crystalline phases of the constituent domains. Here, we report a robust and versatile colloidal synthetic approach that allows us to selectively access a series of Au@copper chalcogenide heteronanostructures with tailored intraparticle architectures, tunable domain sizes, and targeted crystalline phases through chemically triggered phase segregation of Au–Cu bimetallic alloy and intermetallic nanoparticles. Under our reaction conditions, the chalcogen precursor concentration and the reaction temperature serve as two fine-adjustable synthetic knobs that enable us to deliberately control the crystalline phases of the copper chalcogenide domains, while the relative domain dimensions in the heteronanostructures can be precisely preprogrammed by tuning the Cu/Au stoichiometries of the parental bimetallic nanoparticles. Both the Cu/Au stoichiometries and atomic ordering in the bimetallic nanoparticles are found to be key structural factors that kinetically maneuver the phase segregation process and thereby profoundly influence the structure-transforming behaviors of the nanoparticles. Bimetallic strip ; Chalcogenide ; Materials science ; Nanoparticle ; Plasmon ; Copper ; Nanotechnology ; Alloy ; Nanomaterials ; Stoichiometry ; Metal ; Optoelectronics ; Chemistry ; Metallurgy ; Physical chemistry Gold and Silver Nanoparticles Synthesis and Applications ; Nanocluster Synthesis and Applications ; Copper-based nanomaterials and applications