jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Shohei Nakamura | Mizuno Nakura | Takatoshi Sakamoto
Source: Chemical and Pharmaceutical Bulletin (article, 2022-08-31)
Field: Materials Science — Biomaterials

The Effect of Cellulose Nanofibers on the Manufacturing of Mini-Tablets by Direct Powder Compression Mini-tablets (MTs) contain a small amount of active pharmaceutical ingredients in one small tablet. MTs are advantageous because they can be fine-tuned according to the age and weight of pediatric patients and they are easy for children and the elderly to swallow. However, there are manufacturing concerns such as the difficulty in achieving both hardness and disintegration of a small tablet and it is difficult to keep the tablet weight and drug content consistent in MTs because the mold used for its production is special. In this study, we aimed to determine if an additive such as cellulose nanofibers (CNF), which has been studied in various fields in recent years, could be used to manufacture MTs without difficulties. In this study, an MT was manufactured using a rotary tableting press with a compression force of 2, 5, and 8 kN, and the weight variation, drug content variation, tensile strength, friability, disintegration time, and drug dissolution were evaluated. Of note, the tensile strength of MTs produced with a compression force of ≥5 kN was ≥1.3 MPa, which was comparable to that of an ordinary tablet with an 8 mm diameter and a hardness of ≥30 N. The disintegration time of the MT which was 20-30% CNF was ≤30 s at any compression force. MTs with CNF showed similar disintegration to MTs with other common disintegrants. Therefore, we found that CNF is a functional additive capable of manufacturing MTs by direct powder compression which has both strength and disintegration. Friability ; Tableting ; Ultimate tensile strength ; Compression (physics) ; Dissolution ; Nanofiber ; Chemistry ; Composite material ; Cellulose ; Materials science ; Organic chemistry Advanced Cellulose Research Studies ; Electrospun Nanofibers in Biomedical Applications ; biodegradable polymer synthesis and properties
Authors: Mengjia Yin | Xiao‐Hong Xiong | Lipeng Zhang | Lele Gong | Dan Zhao | Feng Luo
Source: Cell Reports Physical Science (article, 2022-05-31)
Field: Chemistry — Inorganic Chemistry

Luminescence modulation by twisting the branches of organic building blocks in uranyl-organic frameworks Twisting the branches of an organic molecule will enhance luminescence; however, this is often accompanied by the rotation of the branches that will reduce luminescence, offering a contradiction. Thus, deep insight into this contradiction and creating some effective solutions to make a good trade-off have become critical but challenging. Here, we report a smart structural design to fine-tune the twisting of the branches of triangular organic building blocks through steric hindrance, including anchoring of organic units or further construction of uranyl-organic metal-organic frameworks (U-MOFs). Both theoretical calculations and experimental results disclose that the fluorescence performance in the solid for both organic ligands and corresponding U-MOFs highly correlates with the twisting of the branches, and both the anchoring of organic units and the construction of U-MOFs would be effective tools to modulate the trade-off between twisting and rotation, and that rotation could play a key role in promoting a turn-on antenna effect. Luminescence ; Metal-organic framework ; Contradiction ; Steric effects ; Rotation (mathematics) ; Template ; Antenna (radio) ; Nanotechnology ; Anchoring ; Materials science ; Uranyl ; Chemistry ; Optoelectronics ; Computer science ; Organic chemistry ; Telecommunications ; Engineering ; Philosophy Metal-Organic Frameworks: Synthesis and Applications ; Luminescence and Fluorescent Materials ; Lanthanide and Transition Metal Complexes
Authors: Michal Knapek | Peter Minárik | Adam Greš | Mária Zemková | František Lukáč | Jan Bohlen | František Chmelı́k | Róbert Král
Source: Materials Science and Engineering A (article, 2022-06-17)
Field: Materials Science — Biomaterials

Spark plasma sintered Mg-4Y-3Nd with exceptional tensile performance Materials science ; Microstructure ; Spark plasma sintering ; Ultimate tensile strength ; Slip (aerodynamics) ; Ductility (Earth science) ; Electron backscatter diffraction ; Eutectic system ; Crystal twinning ; Texture (cosmology) ; Composite material ; Metallurgy ; Creep Magnesium Alloys: Properties and Applications ; Aluminum Alloys Composites Properties ; MXene and MAX Phase Materials
Authors: Marie Dallocchio | A. Boileau | Bernard Mercey | Adrian David | Ulrike Lüders | Sandrine Froissart | Xavier Larose | Bruno Bérini | Yves Dumont | Alain Pautrat | W. Prellier | Arnaud Fouchet
Source: Journal of Physics D Applied Physics (article, 2022-03-02)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Tunable magnetic and magnetotransport properties in locally epitaxial La<sub>0.67</sub>Sr<sub>0.33</sub>MnO<sub>3</sub> thin films on polycrystalline SrTiO<sub>3</sub>, by control of grain size Abstract La 0.67 Sr 0.33 MnO 3 (LSMO) thin films have been grown by pulsed laser deposition on SrTiO 3 using combinatorial substrate epitaxy (CSE) approach, i.e. polycrystalline substrates with micrometer-size grains. The crystallographic domains size of those polycrystalline substrates can be controlled between 2 and 45 µ m depending on the annealing temperature during synthesis. Each grain of the substrate acts as a single crystalline growth template promoting local epitaxy with a reproduction of the substrate grain structure in the thin film. Therefore, a fine-tuning of the substrate grain metrics and high crystalline quality of locally epitaxial LSMO film, allows to combine the advantages of polycrystalline, i.e. the presence of low field magnetoresistance (LFMR) and the possibility to use very thin films, with a pronounced magnetic shape anisotropy. For this, the magnetic and transport properties of the films are showing a strong influence with varying grain metrics of the substrate. High Curie temperatures, important values of the LFMR and anisotropy for optimized substrate grain metrics with the relative orientation of the magnetic field to the film plane underline the high quality of the films and the advantage of the CSE approach. The obtained LSMO thin films may have an interest for high-resolution low field magnetic sensors application. Materials science ; Crystallite ; Thin film ; Epitaxy ; Pulsed laser deposition ; Substrate (aquarium) ; Magnetoresistance ; Grain size ; Annealing (glass) ; Magnetic anisotropy ; Condensed matter physics ; Curie temperature ; Optoelectronics ; Magnetic field ; Magnetization ; Nanotechnology ; Composite material ; Ferromagnetism ; Metallurgy Magnetic and transport properties of perovskites and related materials ; Advanced Condensed Matter Physics ; Electronic and Structural Properties of Oxides
Authors: Saif Ullah | Stephanie Jensen | Kui Tan | Guoyu Zhang | Trevor Jenkins | Anthony Elias | Michael D. Gross | Jing Li | Timo Thonhauser
Source: Chemistry of Materials (article, 2022-03-23)
Field: Chemistry — Inorganic Chemistry

Decoding the Gate Opening Mechanism of the Flexible Framework RPM3–Zn upon Hydrocarbon Inclusion Although the existence of a gate-opening phenomenon in the flexible RPM3–Zn is well known, the actual mechanism remains a mystery. Here, we provide a full picture that unambiguously identifies and explains the gate-opening mechanism in RPM3–Zn upon exposure to various hydrocarbons─acetylene, ethylene, ethane, propane, and butane─by combining insights gained from calorimetry, adsorption isotherms, PXRD, in situ infrared spectroscopy, and ab initio simulations. We find that the key to gate opening in this framework is the stretching of a bond between an O and the Zn metal center (COO–Zn), acting as a “stabilizer”, which weakens the necessary support required for the structure to remain intact. Consequently, an increasing concentration of guest molecules exerts sufficient internal pressure to induce strong structural transformations in the unit cell shape and volume, thus triggering the gate opening. Our results are critical to understanding the gate opening in several other flexible frameworks and provide an opportunity to fine-tune hydrocarbon separation. Decoding methods ; Mechanism (biology) ; Inclusion (mineral) ; Hydrocarbon ; Computer science ; Chemistry ; Telecommunications ; Physics ; Organic chemistry ; Mineralogy Metal-Organic Frameworks: Synthesis and Applications ; Supramolecular Self-Assembly in Materials ; Advancements in Battery Materials
Authors: Emily K. Raulerson | Danielle M. Cadena | Mohammed A. Jabed | Christopher D. Wight | Inki Lee | Holden R. Wagner | James T. Brewster | Brent L. Iverson | Svetlana Kilina | Sean T. Roberts
Source: The Journal of Physical Chemistry Letters (article, 2022-02-04)
Field: Materials Science — Materials Chemistry

Using Spectator Ligands to Enhance Nanocrystal-to-Molecule Electron Transfer Semiconductor nanocrystals (NCs) have emerged as promising photocatalysts. However, NCs are often functionalized with complex ligand shells that contain not only charge acceptors but also other "spectator ligands" that control NC solubility and affinity for target reactants. Here, we show that spectator ligands are not passive observers of photoinduced charge transfer but rather play an active role in this process. We find the rate of electron transfer from quantum-confined PbS NCs to perylenediimide acceptors can be varied by over a factor of 4 simply by coordinating cinnamate ligands with distinct dipole moments to NC surfaces. Theoretical calculations indicate this rate variation stems from both ligand-induced changes in the free energy for charge transfer and electrostatic interactions that alter perylenediimide electron acceptor orientation on NC surfaces. Our work shows NC-to-molecule charge transfer can be fine-tuned through ligand shell design, giving researchers an additional handle for enhancing NC photocatalysis. Ligand (biochemistry) ; Nanocrystal ; Molecule ; Acceptor ; Dipole ; Electron transfer ; Chemical physics ; Charge (physics) ; Semiconductor ; Materials science ; Electron acceptor ; Marcus theory ; Photocatalysis ; Chemistry ; Photochemistry ; Nanotechnology ; Optoelectronics ; Organic chemistry ; Kinetics ; Physics ; Reaction rate constant Quantum Dots Synthesis And Properties ; Nanocluster Synthesis and Applications ; Chalcogenide Semiconductor Thin Films
Authors: Torben Steenbock | Lawrence Rybakowski | Dominik Benner | Carmen Herrmann | Gabriel Bester
Source: Journal of Chemical Theory and Computation (article, 2022-07-07)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Exchange Spin Coupling in Optically Excited States In optically excited states in molecules and materials, coupling between local electron spins plays an important role for their photoemission properties and is interesting for potential applications in quantum information processing. Recently, it was experimentally demonstrated that the photogenerated local spins in donor-acceptor metal complexes can interact with the spin of an attached radical, resulting in a spin-coupling-dependent mixing of excited doublet states, which controls the local spin density distributions on donor, acceptor, and radical subunits in optically excited states. In this work, we propose an energy-difference scheme to evaluate spin coupling in optically excited states, using unrestricted and spin-flip simplified time-dependent density functional theory. We apply it to three platinum complexes which have been studied experimentally to validate our methodology. We find that all computed coupling constants are in excellent agreement with the experimental data. In addition, we show that the spin coupling between donor and acceptor in the optically excited state can be fine-tuned by replacing platinum with palladium and zinc in the structure. Besides the two previously discussed excited doublet states (one bright and one dark), our calculations reveal a third, bright excited doublet state which was not considered previously. This third state possesses the inverse spin polarization on donor and acceptor with respect to the previously studied bright doublet state and is by an order of magnitude brighter, which might be interesting for optically controlling local spin polarizations with potential applications in spin-only information transfer and manipulation of connected qubits. Excited state ; Acceptor ; Spin states ; Spin (aerodynamics) ; Spins ; Density functional theory ; Atomic physics ; Chemistry ; Molecular physics ; Spin polarization ; Physics ; Electron ; Condensed matter physics ; Quantum mechanics ; Computational chemistry Magnetism in coordination complexes ; Photochemistry and Electron Transfer Studies ; Lanthanide and Transition Metal Complexes
Authors: Ramazan Paşahan | Mitat Akkoç | Şeyma Yaşar | Tuğba Kul Köprülü | Şaban Teki̇n | Sedat Yaşar | İsmaıl Özdemır
Source: TURKISH JOURNAL OF CHEMISTRY (article, 2022-01-01)
Field: Chemistry — Organic Chemistry

Synthesis and investigation of antiproliferative activity of Ru-NHC complexes against C6 and HeLa cancer cells The 2-methylpyridine, 2-diethylaminoethyl, and isopentyl linked a series of symmetric and unsymmetric benzimidazolium salts 2a-e were prepared and used in the synthesis of silver-N-heterocyclic carbene (NHC) complexes (3a-e). The Ru(II)-NHC complexes (4a-h) were synthesized via transmetalation reaction from 3a-e. 4a-h complexes were converted to Ru(II)-NHC.HCl complexes (5ah) by HCl solution of diethyl ether and characterized by different spectroscopic techniques such as <sup>1</sup>H and <sup>13</sup>C NMR, LC/MS-Q-TOF, FT-IR, elemental analysis, and melting point detection. We examined the effect of the structural difference of complexes on anticancer activity via different arenes and metal centers. Antiproliferative activity of 5a-h and 3a was tested against human cervix adenocarcinoma (HeLa) and rat glioblastoma (C6) cell lines by ELISA assay. The IC<sub>50</sub> value of 5b, 5c and 5e complexes exhibited good cytotoxic activity than cisplatin on C6 (14.2 ± 0.5 mM; 16.2 ± 0.4 mM; 24.2 ± 0.7 mM, respectively) and HeLa (11.1 ± 0.5 mM; 13.7 ± 0.3 mM; 22.8 ± 0.8 mM, respectively) cell lines. Chemistry ; HeLa ; Transmetalation ; Diethyl ether ; Carbene ; Ether ; Stereochemistry ; Cisplatin ; Medicinal chemistry ; In vitro ; Organic chemistry ; Biochemistry ; Catalysis N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Synthetic Organic Chemistry Methods ; Catalytic Cross-Coupling Reactions
Authors: Agnes Chacor de Figueiredo | Javier Mauricio Anaya‐Mancipe | Aline Oliveira da Silva De Barros | Ralph Santos‐Oliveira | Marcos L. Dias | Rossana Mara da Silva Moreira Thiré
Source: Preprints.org (preprint, 2022-07-01)
Field: Materials Science — Biomaterials

Nanostructured Electrospun Polycaprolactone - Propolis Films Composed of Different Morphologies for Potential Use in Wound Healing The structure of wound dressing materials presents one of the most relevant characteristics for effective skin tissue repair. Electrospinning is a common technique used to produce polymeric fibres that can mimic fibrillar disposition of skin extracellular matrix, favouring cell migration, and thus regeneration of the damaged tissue. Moreover, beads, also known as by-products of electrospinning, have potential as reservoirs for sustained drug release. Processing parameters, such as molecular weight and viscosity of the polymer solution, can affect the desirable morphologies of electrospun films. Thereby, this work had the purpose of producing and characterized electrospun polycaprolactone (PCL) mats loaded with propolis, a popular extract in traditional medicine with potential for skin repair aid. Films with different morphologies were obtained depending on the storage period of the solution prior to the lectrospinning, probably due to the PCL hydrolysis. FTIR analyses of the extract confirmed propolis composition. GPC and viscosity analyses demonstrated that the decrease in molar mass over the storage period was responsible for nanostructure diversity. Propolis acts as a lubricant agent, affecting the spun solutions' viscosity and the thermal properties and hydrophilicity of the films. All films are within the value range of the water vapour transpiration rate of the commercial products. The presence of beads did not affect the propolis release pattern. However, &amp;quot;in vitro&amp;quot; wound healing assay showed that propolis-loaded films composed by beaded fibres increased the cell migration process. Thus, it can be inferred that these films presented the potential for wound dressing application. Propolis ; Polycaprolactone ; Electrospinning ; Materials science ; Chemical engineering ; Wound healing ; Polylactic acid ; Nanofiber ; Polymer ; Composite material ; Chemistry ; Surgery ; Food science Electrospun Nanofibers in Biomedical Applications ; Bee Products Chemical Analysis
Authors: Chinna Ayya Swamy P | Archana V. Raveendran | Sivakrishna Narra | Rajendra Prasad Nandi
Source: Dalton Transactions (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Triarylborane-triphenylamine based luminophore for the mitochondria targeted live cell imaging and colorimetric detection of aqueous fluoride Bioimaging of subcellular organelles such as mitochondria is crucial for detecting physiological abnormalities induced by fluctuations in the levels of various analytes. Herein, we report the design and synthesis of two novel water-soluble cationic Lewis acid triarylborane-triarylamine conjugates 1 and 2. The optical characteristics of 1 and 2 and their precursor compounds BTPA-NMe2 and BTPA-2NMe2 were evaluated, which show similar absorption and fluorescence spectra, with 1 and 2 exhibiting higher quantum yields of 0.73 and 0.64, respectively, than those of the precursors BTPA-NMe2 and BTPA-2NMe2, indicating the partial disruption of the ICT process and the activation of alternative emission bands in 1 and 2. The live cell imaging ability of compound 2 was examined in HeLa cells using a confocal microscope. Moreover, mitochondrial internalisation using compound 2 was effective and it was found to have high photostability under UV light conditions. Furthermore, compound 2 demonstrated an evident colorimetric response with a colour change to dark yellow in aqueous environments, indicating that it could be used for anion sensing. The spectral changes were observed in UV-visible and fluorescence titration experiments, which were strongly supported by DFT calculations. In short, compound 2 synthesized by us can be exclusively utilized for the selective localization of mitochondria with less cytotoxicity and shows excellent colorimetric response to aqueous inorganic fluoride at levels as low as 0.1 ppm with high selectivity. Fluorescence ; Chemistry ; Triphenylamine ; Photochemistry ; Luminophore ; Aqueous solution ; HeLa ; Fluoride ; Absorption (acoustics) ; Titration ; Nuclear chemistry ; Biophysics ; Combinatorial chemistry ; Luminescence ; Materials science ; Inorganic chemistry ; Cell ; Organic chemistry ; Biochemistry Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Sashi Debnath | Ganesh Masilamani | Abhijeet R. Agrawal | Neha Rani Kumar | Chandan Kumar | Sanjio S. Zade | Anjan Bedi
Source: Organic Materials (article, 2022-12-01)
Field: Materials Science — Polymers and Plastics

Cyclopenta[c]thiophene- and Diketopyrrolopyrrole-Based Red-Green-Blue Electrochromic Polymers Cyclopenta[c]thiophene (CPT)-based polymers are potential candidates in organic electronics. Here, we report the first solution-processable red homopolymer (P1) of a thiophene-capped derivative of CPT (DHTCPT), and a blue homopolymer (P2) of N-substituted thienodiketopyrrolopyrrole (DEHTDPP). Additionally, by alternatingly copolymerizing the DHTCPT and DEHTDPP units, we achieved the green copolymer P3, thus completing the red-green-blue color wheels. We have shown experimentally and computationally (time-dependent density functional theory and natural bond orbital calculations) that P1 and P2 have very different optoelectronic features. However, in a donor–acceptor (D–A) copolymer P3, the optoelectronic properties have been tuned significantly to keep it in an intermediate range of P1 and P2. P2 and P3 absorb throughout the whole UV-vis range of the solar spectrum. Furthermore, all polymers showed electrochromism to switch colors between neutral and polaronic states in solution. For P1, the maximum optical contrast (%ΔT) was observed for the SOMO→LUMO transition, whereas P3 displayed the maximum %ΔT at the HOMO→LUMO transition. Thiophene ; HOMO/LUMO ; Electrochromism ; Materials science ; Photochemistry ; Polymer ; Copolymer ; Density functional theory ; Electrochromic devices ; Acceptor ; Optoelectronics ; Molecule ; Chemistry ; Physical chemistry ; Computational chemistry ; Organic chemistry ; Physics ; Condensed matter physics Conducting polymers and applications ; Organic Electronics and Photovoltaics ; Perovskite Materials and Applications
Authors: ISHRAT GOWSIA | FEROZ MIR | JAVID BANDAY
Source: TURKISH JOURNAL OF CHEMISTRY (article, 2022-01-01)
Field: Materials Science — Biomaterials

Synthesis, characterization, and antimicrobial evaluation of polyvinylalcohol-osthol composite films Although poly-vinyl alcohol (PVA) has certain mechanical drawbacks such as a weak barrier, it has widely been used in food packaging over the last many years. To increase the suitability of PVA (C<sub>2</sub>H<sub>4</sub>O)<sub>n</sub> and render it ideal for food packaging, a diversity of studies have already been carried out. In the below-mentioned script, we, for the first time, report the use of natural product osthol in making a new composite with PVA for enhancing thermal, physicochemical, and antimicrobial properties. The significant aim of the report is the insertion of osthol (C<sub>15</sub>H<sub>16</sub>O<sub>3</sub>) into PVA polymer, which is to be subsequently used for antimicrobial applications. The synthesis of the polymer composite film is done by solvent casting method and is characterized by SEM, XRD, FT-IR, and UV-Vis spectroscopy analysis. The manifestation of antimicrobial activity against (<i>S. aureus</i>) (ATCC8738P), <i>E. coli</i> (ATCC8739), <i>Aspergillus niger</i>, <i>Alternaria alternata</i>, and <i>Fusarium solani</i> by the film composite is remarkable. The addition of osthol molecule increases the tensile strength of PVA films from 18.73 ± 0.56 Mpa (PVA) to 24.58 ± 0.49 Mpa (15 mL). As a result, tensile strength increases by 23.79% in a film containing a higher concentration of osthol (15 mL). The barrier properties of PVA osthol composite films improve with the incorporation of osthol. OTR and WVTR decrease by 43.03% and 30.24%, respectively, on the addition of 15 mL osthol. Reduction in OTR and WVTR of the films could increase their applicability in the food sector. An increase in contact angle from 43° (pure PVA) to 66.7° increases the hydrophobic character of the composite films which is desirable for food packaging. This noticeable enhancement of the properties of the PVA film like hydrophobicity, mechanical, barrier, and antimicrobial is supporting the potential application of achieved material in packaging of easily perishable foods like fruits and vegetables by extending their shelf life. Chemistry ; Vinyl alcohol ; Ultimate tensile strength ; Antimicrobial ; Composite number ; Food packaging ; Solvent ; Nuclear chemistry ; Polymer ; Composite material ; Food science ; Organic chemistry ; Materials science Nanocomposite Films for Food Packaging ; biodegradable polymer synthesis and properties ; Polymer Science and PVC