jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Akmal Z. Umarov | Evgeniia A. Nikitina | A. A. Piryazev | Ioannis Moutsios | Martin Rosenthal | Andrey O. Kurbatov | Yulia D. Gordievskaya | Elena Yu. Kramarenko | Erfan Dashtimoghadam | Mitchell Maw | Sergei S. Sheiko | Dimitri A. Ivanov
Source: Polymers (article, 2024-11-27)
Field: Chemistry — Organic Chemistry

Revealing Long-Range Order in Brush-like Graft Copolymers Through In Situ Measurements of X-Ray Scattering During Deformation Brush-like graft copolymers (A-g-B), in which linear A-blocks are randomly grafted onto the backbone of a brush-like B-block, exhibit intense strain-stiffening and high mechanical strength on par with load-bearing biological tissues such as skin and blood vessels. To elucidate molecular mechanisms underlying this tissue-mimetic behavior, in situ synchrotron X-ray scattering was measured during uniaxial stretching of bottlebrush- and comb-like graft copolymers with varying densities of poly(dimethyl siloxane) and poly(isobutylene) side chains. In an undeformed state, these copolymers revealed a single interference peak corresponding to the average spacing between the domains of linear A-blocks arranged in a disordered, liquid-like configuration. Under uniaxial stretching, the emergence of a distinct four-spot pattern in the small-angle region indicated the development of long-range order within the material. According to the affine deformation of a cubic lattice, the four-spot pattern's interference maxima correspond to 110 reflections upon stretching along the [111] axis of the body-centered unit cell. The experimental findings were corroborated by computer simulations of dissipative particle dynamics that confirmed the formation of a <i>bcc</i> domain structure. Materials science ; Dissipative particle dynamics ; Copolymer ; Scattering ; Small-angle X-ray scattering ; Synchrotron ; Deformation (meteorology) ; Optics ; Crystallography ; Composite material ; Molecular physics ; Polymer ; Chemistry ; Physics Advanced Polymer Synthesis and Characterization ; Polymer Surface Interaction Studies ; Hydrogels: synthesis, properties, applications
Authors: Lilith Schwartz | Jordan O. Norman | Sharika Hasan | Olive E. Adamek | Elisa Dzuong | John M. Lowenstein | Olivia G. Yost | Banumathi Sankaran | Krystle J. McLaughlin
Source: Biochemistry (article, 2024-12-12)
Field: Materials Science — Materials Chemistry

Carbohydrate Deacetylase Unique to Gut Microbe Bacteroides Reveals Atypical Structure <i>Bacteroides</i> are often the most abundant, commensal species in the gut microbiome of industrialized human populations. One of the most commonly detected species is <i>Bacteroides ovatus</i>. It has been linked to benefits like the suppression of intestinal inflammation but is also correlated with some autoimmune disorders, for example irritable bowel disorder (IBD). Bacterial cell surface carbohydrates, like capsular polysaccharides (CPS), may play a role in modulating these varied host interactions. Recent studies have begun to explore the diversity of CPS loci in <i>Bacteroides</i>; however, there is still much unknown. Here, we present structural and functional characterization of a putative polysaccharide deacetylase from <i>Bacteroides ovatus</i> (<i>Bo</i>PDA) encoded in a CPS biosynthetic locus. We solved four high resolution crystal structures (1.36-1.56 Å) of the enzyme bound to divalent cations Co<sup>2+</sup>, Ni<sup>2+</sup>, Cu<sup>2+</sup>, or Zn<sup>2+</sup> and performed carbohydrate binding and deacetylase activity assays. Structural analysis of <i>Bo</i>PDA revealed an atypical domain architecture that is unique to this enzyme, with a carbohydrate esterase 4 (CE4) superfamily catalytic domain inserted into a carbohydrate binding module (CBM). Additionally, <i>Bo</i>PDA lacks the canonical CE4 His-His-Asp metal binding motif and our structures show it utilizes a noncanonical His-Asp dyad to bind metal ions. <i>Bo</i>PDA is the first protein involved in CPS biosynthesis from <i>B. ovatus</i> to be characterized, furthering our understanding of significant biosynthetic processes in this medically relevant gut microbe. Bacteroides ; Microbiology ; Bacteroides fragilis ; Carbohydrate ; Chemistry ; Computational biology ; Biology ; Bacteria ; Biochemistry ; Genetics ; Antibiotics Enzyme Structure and Function ; Microbial Metabolites in Food Biotechnology ; Gut microbiota and health
Authors: Jayaprakash Rao Yerrabelly | Mohan Babu Bommagani | Hemasri Yerrabelly | Sai Charitha Mullaguri | Rama Krishna Kancha
Source: Journal of Heterocyclic Chemistry (article, 2024-03-31)
Field: Chemistry — Organic Chemistry

Synthesis and anticancer activity of cinnoline sulphonamides and 4‐heteroyclic derivatives: Cross‐coupling approach Abstract A series of novel cinnoline sulphonamide derivatives and 4‐substuted cinnoline derivatives ( 13a‐h , 16a‐h and 17–31 total 33 analogues) were designed based on scaffold hopping techniques and evaluated for their antileukemic activity on wild type K562 as well as imatinib resistant cell lines (K562‐IR1 and K562‐IR2). Out of 33 analogues, five compounds ( 19 , 22 , 23 , 28 , and 31 ) exhibited potent antileukemic activity. An easy and efficient approach to synthesize numerous cinnoline derivatives by the various cross‐coupling reactions of 4‐chlorocinnoline has been developed and also demonstrated that metal‐free cross couplings give high product yield compared with metal catalyzed cross couplings. Cinnoline ; Chemistry ; Combinatorial chemistry ; K562 cells ; Stereochemistry ; Yield (engineering) ; Sonogashira coupling ; Organic chemistry ; In vitro ; Catalysis ; Palladium ; Biochemistry Synthesis and biological activity ; Cancer therapeutics and mechanisms ; Chemical synthesis and alkaloids
Authors: Kevin Synnatschke | Alina Müller | Cian Gabbett | Michael J. Mohn | Adam G. Kelly | Kseniia Mosina | Bing Wu | Eoin Caffrey | Oran Cassidy | Claudia Backes | Zdeněk Sofer | Ute Kaiser | Jonathan N. Coleman
Source: ACS Nano (article, 2024-10-09)
Field: Materials Science — Materials Chemistry

Inert Liquid Exfoliation and Langmuir-Type Thin Film Deposition of Semimetallic Metal Diborides Graphite is one of only a few layered materials that can be exfoliated into nanosheets with semimetallic properties, which limits the applications of nanosheet-based electrodes to material combinations compatible with the work function of graphene. It is therefore important to identify additional metallic or semimetallic two-dimensional (2D) nanomaterials that can be processed in solution for scalable fabrication of printed electronic devices. Metal diborides represent a family of layered non-van der Waals crystals with semimetallic properties for all nanosheet thicknesses. While previous reports show that the exfoliated nanomaterial is prone to oxidation, we demonstrate a readily accessible inert exfoliation process to produce quasi-2D nanoplatelets with intrinsic material properties. For this purpose, we demonstrate the exfoliation of three representative metal diborides (MgB<sub>2</sub>, CrB<sub>2</sub>, and ZrB<sub>2</sub>) under inert conditions. Nanomaterial is characterized using a combination of transmission electron microscopy, scanning electron microscopy, atomic force microscopy, IR, and UV-vis measurements, with only minimal oxidation indicated postprocessing. By depositing the pristine metal diboride nanoplatelets as thin films using a Langmuir-type deposition technique, the ohmic behavior of the networks is validated. Furthermore, the material decomposition is studied by using a combination of electrical and optical measurements after controlled exposure to ambient conditions. Finally, we report an efficient, low-cost approach for sample encapsulation to protect the nanomaterials from oxidation. This is used to demonstrate low-gauge factor strain sensors, confirming metal diboride nanosheets as a suitable alternative to graphene for electrode materials in printed electronics. Materials science ; Inert ; Exfoliation joint ; Deposition (geology) ; Thin film ; Chemical engineering ; Metal ; Langmuir ; Nanotechnology ; Metallurgy ; Physical chemistry ; Chemistry ; Organic chemistry ; Graphene ; Geology Graphene research and applications ; Semiconductor materials and devices ; Semiconductor materials and interfaces
Authors: Daiki Kobayashi | Shuntaro Nagashima | Shin‐ichi Ohkoshi | Junhao Wang | Hiroko Tokoro
Source: European Journal of Inorganic Chemistry (article, 2024-12-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Molecular Alloying of Three Different Organic Ligands within a Spin‐Transitional and SHG‐Active Fe<sup>II</sup>‐W<sup>IV</sup>(CN)<sub>8</sub> 3‐D Coordination Framework Abstract The effect of ligand‐based molecular alloying on spin crossover (SCO) materials has been studied using various polydentate organic ligands; however, this effect using small monodentate ligands has not been explored. To design a proper structure that can accommodate a variety of small ligands, we employed the structural matrix of a three‐dimensional cyanido‐bridged coordination framework, [Fe II (L mix ) 4 ] 2 [W IV (CN) 8 ] ( FeW ; L mix =a mixture of different ligands). We found that three different ligands of 4‐chloropyridine (4‐Clpy), 4‐iodopyridine (4‐Ipy), and pyrazole (pz) were able to be alloyed at the L mix site of the Fe II ion. Our obtained FeW framework had a 4‐Clpy:4‐Ipy:pz alloying ratio of 1.32 : 1.56 : 1.12 per Fe II ion, and it demonstrated a gradual SCO phenomenon in response to temperature change. Furthermore, the chiral structure of FeW allows the observation of second‐harmonic generation (SHG) signal; however, the SHG signal was quite weak owing to the racemic twinning of the mirrored enantiomers. This work demonstrates that the Fe II –W IV (CN) 8 structural matrix provides a viable approach to investigating the molecular alloying effect of various types of small organic ligands on magneto‐optical properties. Chemistry ; Coordination complex ; Crystallography ; Spin crossover ; Stereochemistry ; Metal ; Organic chemistry Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Raktim Baruah | Munira Dilshad | Marco Diegel | Jan Dellith | Jonathan Plentz | Andreas Undisz | Adriana Szeghalmi | Maria Wächtler
Source: Materials (article, 2024-09-05)
Field: Materials Science — Materials Chemistry

Deposition of CdSe Nanocrystals in Highly Porous SiO2 Matrices—In Situ Growth vs. Infiltration Methods Embedding quantum dots into porous matrices is a very beneficial approach for generating hybrid nanostructures with unique properties. In this contribution we explore strategies to dope nanoporous SiO<sub>2</sub> thin films made by atomic layer deposition and selective wet chemical etching with precise control over pore size with CdSe quantum dots. Two distinct strategies were employed for quantum dot deposition: in situ growth of CdSe nanocrystals within the porous matrix via successive ionic layer adsorption reaction, and infiltration of pre-synthesized quantum dots. To address the impact of pore size, layers with 10 nm and 30 nm maximum pore diameter were used as the matrix. Our results show that though small pores are potentially accessible for the in situ approach, this strategy lacks controllability over the nanocrystal quality and size distribution. To dope layers with high-quality quantum dots with well-defined size distribution and optical properties, infiltration of preformed quantum dots is much more promising. It was observed that due to higher pore volume, 30 nm porous silica shows higher loading after treatment than the 10 nm porous silica matrix. This can be related to a better accessibility of the pores with higher pore size. The amount of infiltrated quantum dots can be influenced via drop-casting of additional solvents on a pre-drop-casted porous matrix as well as via varying the soaking time of a porous matrix in a quantum dot solution. Luminescent quantum dots deposited via this strategy keep their luminescent properties, and the resulting thin films with immobilized quantum dots are suited for integration into optoelectronic devices. Nanoporous ; Nanocrystal ; Materials science ; Porosity ; In situ ; Deposition (geology) ; Quantum dot ; Infiltration (HVAC) ; Nanostructure ; Chemical engineering ; Nanotechnology ; Porous medium ; Composite material ; Chemistry ; Organic chemistry Quantum Dots Synthesis And Properties ; Copper-based nanomaterials and applications ; Chalcogenide Semiconductor Thin Films
Authors: Eduard Monaico | Vadim Morari | Stepan Buiucli | V.V. Zalamai | V. V. Ursaki | I. M. Tiginyanu
Source: Coatings (article, 2024-11-02)
Field: Materials Science — Materials Chemistry

Impact of Substrate upon Morphology, Luminescence, and Wettability of ZnMgO Layers Deposited by Spray Pyrolysis In this work, we report on a comparative study of the topology, luminescence, and wettability properties of ZnMgO films prepared by a cost-effective spray pyrolysis technology on GaAs substrates with (100), (001), and (111) crystallographic orientations, as well as on Si(100) substrates. Deposition on nanostructured GaAs substrates was also considered. It was found that film growth is not epitaxial or conformal, but rather, it is granular, depending on the nucleating sites for the crystallite growth. The distribution of nucleation sites ensured the preparation of nanostructured films with good uniformity of their topology. The observed difference in columnar growth on Si substrates and pyramidal growth on GaAs ones was explained in terms of the impact of chemical bonding in substrates. The films grown on GaAs substrates with a (001) orientation were found to be made of larger crystallites compared to those deposited on substrates with a (111) orientation. These effects resulted in a difference in roughness of a factor of 1.5, which correlates with the wetting properties of films, with the most hydrophobic surface being found on films deposited on GaAs substrates with a (111) orientation. The prospects for photocatalytic and gas sensor applications of films produced on flat substrates, as well as for plasmonic and other applications of films deposited on nanostructured substrates, are discussed, taking into account the results of the analysis of their photoluminescence properties. Wetting ; Materials science ; Spray pyrolysis ; Substrate (aquarium) ; Morphology (biology) ; Luminescence ; Chemical engineering ; Pyrolysis ; Nanotechnology ; Optoelectronics ; Composite material ; Thin film ; Geology ZnO doping and properties ; Gas Sensing Nanomaterials and Sensors ; Copper-based nanomaterials and applications
Authors: Nannapat Kaewnukulkit | Nisanart Traiphol | Rakchart Traiphol
Source: Heliyon (article, 2024-09-27)
Field: Chemistry — Organic Chemistry

Colorimetric sensing of fatty acids in organic solvents using polydiacetylene-based nanocomposites Colorimetric detection of long chain fatty acids by polydiacetylenes (PDAs)-based sensors is quite a challenge, mainly due to their relatively low solubility in aqueous media. In this study, we developed PDA/Zn<sup>2+</sup>/ZnO nanocomposites in various organic solvents for detecting fatty acids. Oleic acid and steric acid were used as representatives of fatty acids with bent and linear structures, respectively. The nanocomposites dispersed in ethanol exhibited blue-to-red color transition upon increasing the concentration of oleic acid. The use of other solvents including 1-butanol, 1-hexanol, 1-octanol, 1,4-dioxane, hexane, octane and toluene affected the sensitivity of nanocomposites. Furthermore, incorporating cetyltrimethylammonium bromide (CTAB) into the structure of the nanocomposites resulted in a systematic increase of sensitivity. The use of organic solvents simplified the method and allowed direct sensing of the fatty acids. Paper-based sensor was fabricated and utilized as a mobile test kit. This class of colorimetric sensors can also distinguish the bent and linear structures of fatty acids. Our study extends the utilization of PDA-based materials as colorimetric sensors of fatty acids in food industries. Nanocomposite ; Organic chemistry ; Chemistry ; Polydiacetylenes ; Materials science ; Nanotechnology ; Chemical engineering ; Polymer ; Conjugated system Polydiacetylene-based materials and applications ; Antimicrobial Peptides and Activities ; Advanced Chemical Sensor Technologies
Authors: Liying Zhang | Wenxiu He | Hehe Yuan | Lei Shao | Huan Chen | Yu Fu
Source: Chemistry - A European Journal (article, 2024-07-01)
Field: Chemistry — Inorganic Chemistry

Superlong Metal–Organic Framework Nanowire Fabricated via Steam‐Assisted Conversion 1D nanomaterials have attracted great attention due to their outstanding anisotropic and linear structures. A facile method is developed to fabricate 1D copper metal-organic framework nanowires (Cu-MOF-NW) through steam-assisted conversion from Cu-MOF precursors. During the steam-assisted conversion, Cu-MOF precursor gradually dissolves in methanol steam, and then recrystallized into Cu-MOF-NW, which shows high aspect ratio of about 600 and identical crystal structure of MOF-74. As-prepared Cu-MOF-NW with multiscale porous structure can effectively remove cationic dyes even in dye mixture. Moreover, Cu-MOF-NW, as an ideal template, is calcined to form Cu nanoparticle-doped carbon nanofiber with maintaining its 1D morphology, which shows excellent electrocatalytic activity for the non-enzymatic sensing of glucose. Nanowire ; Materials science ; Metal ; Nanotechnology ; Chemical engineering ; Metallurgy ; Engineering Metal-Organic Frameworks: Synthesis and Applications ; Dendrimers and Hyperbranched Polymers ; Conducting polymers and applications
Authors: K.A. Prokop | Sandrine Cottrino | Vincent Garnier | Gilbert Fantozzi | Y. Guyot | G. Boulon | M. Guzik
Source: Ceramics (article, 2024-04-30)
Field: Materials Science — Materials Chemistry

Enhancing Transparency in Non-Cubic Calcium Phosphate Ceramics: Effect of Starting Powder, LiF Doping, and Spark Plasma Sintering Parameters Our objective is to achieve a new good-quality and mechanically durable high-transparency material that, when activated by rare earth ions, can be used as laser sources, scintillators, or phosphors. The best functional transparent ceramics are formed from high-symmetry systems, mainly cubic. Considering hexagonal hydroxyapatite, which shows anisotropy, the particle size of the initial powder is extremely important and should be of the order of several tens of nanometers. In this work, transparent micro-crystalline ceramics of non-cubic Ca10(PO4)6(OH)2 calcium phosphate were fabricated via Spark Plasma Sintering (SPS) from two types of nanopowders i.e., commercially available (COM. HA) and laboratory-made (LAB. HA) via the hydrothermal (HT) protocol. Our study centered on examining how the quality of sintered bodies is affected by the following parameters: the addition of LiF sintering agent, the temperature during the SPS process, and the quality of the starting nanopowders. The phase purity, microstructure, and optical transmittance of the ceramics were investigated to determine suitable sintering conditions. The best optical ceramics were obtained from LAB. HA nanopowder with the addition of 0.25 wt.% of LiF sintered at 1000 °C and 1050 °C. Materials science ; Spark plasma sintering ; Transparent ceramics ; Ceramic ; Microstructure ; Sintering ; Transmittance ; Doping ; Chemical engineering ; Composite material ; Optoelectronics Luminescence Properties of Advanced Materials ; Bone Tissue Engineering Materials ; Glass properties and applications
Authors: Deborah Giordano | Simone Bonora | Ilenia D’Orsi | Domenico D’Alelio | Angelo Facchiano
Source: Biomolecules (article, 2024-02-25)
Field: Chemistry — Spectroscopy

Structural and Functional Characterization of Lipoxygenases from Diatoms by Bioinformatics and Modelling Studies Lipoxygenases make several biological functions in cells, based on the products of the catalyzed reactions. In diatoms, microalgae ubiquitous in aquatic ecosystems, lipoxygenases have been noted for the oxygenation of fatty acids with the production of oxylipins, which are involved in many physiological and pathological processes in marine organisms. The interest in diatoms' lipoxygenases and oxylipins has increased due to their possible biotechnological applications, ranging from ecology to medicine. We investigated using bioinformatics and molecular docking tools the lipoxygenases of diatoms and the possible interaction with substrates. A large-scale analysis of sequence resources allowed us to retrieve 45 sequences of lipoxygenases from diatoms. We compared and analyzed the sequences by multiple alignments and phylogenetic trees, suggesting the possible clustering in phylogenetic groups. Then, we modelled the 3D structure of representative enzymes from the different groups and investigated in detail the structural and functional properties by docking simulations with possible substrates. The results allowed us to propose a classification of the lipoxygenases from diatoms based on their sequence features, which may be reflected in specific structural differences and possible substrate specificity. Phylogenetic tree ; Biochemistry ; Biology ; Computational biology ; Enzyme ; Lipoxygenase ; Substrate specificity ; Phylogenetics ; Chemistry ; Gene Analytical Chemistry and Chromatography ; Metabolomics and Mass Spectrometry Studies ; Advanced Proteomics Techniques and Applications
Authors: Yawen Yang | H. Wan | Qiang Xing | Xiao–Ping Zhang | Haili Xu
Source: Materials (article, 2024-09-23)
Field: Materials Science — Materials Chemistry

Continuous and Stable Printing Method of Planar Microstructure Based on Meniscus-Confined Electrodeposition The meniscus-confined electrodeposition (MCED) technique offers advantages such as low cost and wide applicability, making it a promising method in the field of micro/nanofabrication. However, unstable meniscal morphology and poor deposition quality during planar deposition in MCED necessitate the development of improved methods. Therefore, a planar adaptive micro-tuning deposition method (PAMTDM), which utilizes the positioning technology of scanning electrochemical cell microscopy (SECCM) and employs a singular value decomposition (SVD) planar fitting method to determine the flatness of the deposition plane, is proposed. An adaptive micro-tuning motion mode was proposed by analyzing the variation patterns of the meniscus. Moreover, a combination of multi-physics finite element simulations and orthogonal experimental methods was introduced to determine the optimal motion parameters. The experimental results demonstrate that the PAMTDM effectively addresses the issues encountered during planar growth. Compared to the point-by-point deposition method, the PAMTDM achieves a threefold increase in deposition speed for continuous deposition of 105-μm-long line segments in two-dimensional planes, with a deposition current error of less than 0.2 nA. In conclusion, the proposed method provides significant insights into the broad future applications of MCED. Meniscus ; Deposition (geology) ; Planar ; Materials science ; Flatness (cosmology) ; Singular value decomposition ; Nanotechnology ; Composite material ; Computer science ; Optics ; Algorithm ; Physics Anodic Oxide Films and Nanostructures ; Force Microscopy Techniques and Applications ; Electrodeposition and Electroless Coatings