jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Y Zhao | Yi Shen | Yurong Wen | Robert E. Campbell
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2020-04-13)
Field: Chemistry — Spectroscopy

High performance intensiometric direct- and inverse-response genetically encoded biosensors for citrate Abstract Motivated by the growing recognition of citrate as a central metabolite in a variety of biological processes associated with healthy and diseased cellular states, we have developed a series of high-performance genetically encoded citrate biosensors suitable for imaging of citrate concentrations in mammalian cells. The design of these biosensors was guided by structural studies of the citrate-responsive sensor histidine kinase, and took advantage of the same conformational changes proposed to propagate from the binding domain to the catalytic domain. Following extensive engineering based on a combination of structure guided mutagenesis and directed evolution, we produced an inverse-response biosensor (ΔF/F min ~ 18) designated Citroff1 and a direct-response biosensor (ΔF/F min ~ 9) designated Citron1. We report the x-ray crystal structure of Citron1 and demonstrate the utility of both biosensors for qualitative and quantitative imaging of steady-state and pharmacologically-perturbed citrate concentrations in live cells. Biosensor ; Histidine ; Mutagenesis ; Chemistry ; Biochemistry ; Genetically engineered ; Computational biology ; Biophysics ; Biology ; Enzyme ; Mutation ; Gene Mass Spectrometry Techniques and Applications ; Enzyme Structure and Function ; Advanced biosensing and bioanalysis techniques
Authors: Petar Žutinić | Antonija Kulaš | Zlatko Levkov | Mirela Šušnjara | Sandi Orlić | Stefani Kukić | Gordana Goreta | Damir Valić | Marija Gligora Udovič
Source: Macedonian Journal of Ecology and Environment (article, 2020-01-01)
Field: Materials Science — Biomaterials

Ecological status assessment using periphytic diatom communites - case study Krka River In the light of ever-growing issue of climate changes, a special focus has been directed towards freshwater periphytic algal communities. Diatoms, a commonly dominant group of protists in periphytic assemblages, are frequently used for ecological water-quality assessments of rivers. Diatom-based indices for ecological status assessment are based on a weighted-averaging model using relative abundances and the environmental optima of taxa. The aim of this study was to assess the ecological status of the Krka River based on taxonomic analyses of its periphytic communities. Sampling of periphytic and environmental variables was carried out in September 2017 and September 2018 on nine stations along the Krka River course, with 3 microhabitats at each station. Taxonomic analysis of samples in 2017 revealed a total of 120 diatom species, whilst in 2018 a total of 226 diatom species was noted. Ecological status of the Krka River, evaluated using TDIHR (Croatian Trophic Diatom Index) and the corresponding ecological quality ratio (EQR), was classified as high in most of the watercourse of the Krka River. Diatom ; Ecology ; Trophic level ; Environmental science ; River ecosystem ; Water quality ; Periphyton ; Geography ; Biomass (ecology) ; Biology ; Habitat Diatoms and Algae Research ; Aquatic Invertebrate Ecology and Behavior ; Freshwater macroinvertebrate diversity and ecology
Authors: K. Sooryakala | S. Ramalingam | R. Maheswari | R. Aarthi
Source: Heliyon (article, 2020-10-01)
Field: Chemistry — Physical and Theoretical Chemistry

Synthesis opto-electronic characterization and NLO evaluation of 6-methyl 5-nitro Uracil crystal using XRD, spectroscopic and theoretical tools The organic composite crystal for 6-methyl 5-nitro Uracil was grown using slow-evaporation method and the crystal quality was checked by observing the peaks in XRD pattern. The molecular structure of 6-methyl 5-nitro Uracil was used to find crystal parameters for determining NLO activity. The appropriate electronic geometrical structure was keenly noted and the transitional energy exchange was studied and thereby fine-tuning of crystal performance was made by adopting suitable electron-accepting and with-drawing substitutional groups. The crystal parameters; a≠b≠c confirmed the orthorhombic lattice pattern. The space group was found as P<sub>21/a</sub> and Transparency range was observed as 409-1256 nm. The laser measurements were made and laser Damage threshold was estimated at 10 ns[1.08-3 GW/cm<sup>2</sup>]. The scattering characteristics of bond networks over the molecule were observed by studying vibrational characteristics of elemental bonds. The hybrid calculations on DFT methods were made using B3LYP/6-311++(D,P) basis set. The chemical shift was observed and retracing chemical potential was identified from the parametric oscillation. The frontier molecular interactions between ground and excited orbital lobe overlapping segments were noted and type of interaction system was identified. The electronic and protonic transfer energy was measured and the origination point of equivalent chemical potential was acknowledged. The NBMO profile was keenly grafted and the transitional energy was measured at every consumed electronic energy band. The vibrational circular dichroic image for all vibrational regions was sketched and the rate of transmission and absorption ratio was verified from peak intensity. Chemistry ; Crystal (programming language) ; Crystal structure ; Excited state ; Analytical Chemistry (journal) ; Crystallography ; Materials science ; Atomic physics ; Physics ; Organic chemistry Crystallography and molecular interactions ; Nonlinear Optical Materials Research ; Crystal structures of chemical compounds
Authors: Mingxiao Gao | Xinyuan Zhang | Yangwu Guo | Jiyong Yao | Guochun Zhang | Zhanggui Hu | Yicheng Wu
Source: CrystEngComm (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Rational structure design of isoxazolone-based crystals with large second-order optical nonlinearity Two new acentric isoxazolone-based organic crystals of C<sub>24</sub>H<sub>17</sub>NO<sub>3</sub> (MPFI) and C<sub>18</sub>H<sub>15</sub>NO<sub>3</sub>S (MPMI) were designed and synthesized by a structure fine-tuning strategy. Acentric factor ; Order (exchange) ; Nonlinear optical ; Crystallography ; Chemistry ; Crystal structure ; Nonlinear system ; Physics ; Quantum mechanics Nonlinear Optical Materials Research ; Crystal structures of chemical compounds ; Crystallography and molecular interactions
Authors: Patrícia Silva | Ricardo F. Mendes | Carlos Fernandes | Ana C. Gomes | Duarte Ananias | Fernando Remião | Fernanda Borges | Anabela A. Valente | Filipe A. Almeida Paz
Source: Dalton Transactions (article, 2020-01-01)
Field: Chemistry — Inorganic Chemistry

Multifunctionality and cytotoxicity of a layered coordination polymer This work reports the synthesis and multifunctionality of 2D layered coordination polymers formulated as [Ln<sub>2</sub>(H<sub>3</sub>nmp)<sub>2</sub>]·xH<sub>2</sub>O (1, where Ln = Sm<sup>3+</sup>, Eu<sup>3+</sup>, Tb<sup>3+</sup>, Dy<sup>3+</sup>, Ho<sup>3+</sup>, Er<sup>3+</sup> and Y<sup>3+</sup>) (x = 1 to 4). We describe detailed synthesis of the materials using various methods [typical hydrothermal reaction (HT), microwave-assisted synthesis (MWAS) and one-pot method (OP)], while discussing the various crystal morphologies which can be fine tuned by varying systematically the conditions. We further explore the multifunctionality of this material by studying its heterogeneous catalytic activity in the ring opening of styrene oxide, its photoluminescence behaviour and its cytotoxicity. A conversion of 88%/100% yield at 4 h/24 h reaction respectively, with excellent selectivity towards 2-methoxy-2-phenylethanol product (100%) was observed. Photoluminescence properties of the optically-active [Eu<sub>2</sub>(H<sub>3</sub>nmp)<sub>2</sub>]·xH<sub>2</sub>O (1Eu) and the mixed-lanthanide [(Gd<sub>0.95</sub>Eu<sub>0.5</sub>)<sub>2</sub>(H<sub>3</sub>nmp)<sub>2</sub>]·xH<sub>2</sub>O (1GdEu), on the other hand, show potential use for UV-to-visible light converters, with lifetimes of 2.31 ± 0.01 and 2.61 ± 0.01 ms at ambient temperature for 1Eu and 1GdEu samples. Preliminary cytotoxic studies showed no effects on metabolic activity of both in vitro human epithelial kidney (HK-2) and human hepatocellular carcinoma (HepG2) cell lines. A reduction of NR uptake was, however, observed indicating some cytotoxic effect on lysosomal activity. Crystallography ; Polymer ; X-ray crystallography ; Physics ; Chemistry ; Materials science ; Stereochemistry ; Nuclear magnetic resonance Metal-Organic Frameworks: Synthesis and Applications ; Lanthanide and Transition Metal Complexes ; Covalent Organic Framework Applications
Authors: Jacob T. Trotta | Tarek A. Zeidan | Pranoti A. Tilak | Bruce M. Foxman | Örn Almarsson | Mark A. Oliveira | Renato A. Chiarella | Magali B. Hickey | Julius F. Remenar
Source: Crystal Growth & Design (article, 2020-05-01)
Field: Chemistry — Physical and Theoretical Chemistry

Aripiprazole and Dehydro-Aripiprazole Solid Solutions: Crystalline Combinations of Drug and Active Metabolite in Tailored Compositions Solid solutions of aripiprazole (APZ) and its active metabolite, dehydro-aripiprazole (dAPZ), have been prepared as free form (neat or nonsolvated), hydrated, or alcohol- solvated modifications with methanol (MeOH), ethanol, propan-1-ol, isopropyl alcohol, and propylene glycol, and full physiochemical characterization of these materials was performed. The various compositions of the free solid solutions were isomorphous with the thermodynamically stable form of dAPZ, form V, and the hydrated solid solution was isomorphous throughout its compositional range. Dissolution studies of the hydrated system demonstrated the ability to deliver varying drug content from a single phase of two molecules, potentially paving the way for the treatment of CYP2D6-deficient patients without the need for dose adjustments. The set of all alcohol solvate solids are nearly isomorphous on the basis of PXRD patterns, and upon desolvation, the MeOH-solvated solid solution in the range of 25–60% APZ showed a new powder diffraction pattern distinct from that of any known APZ or dAPZ crystal form. The emergence of the new diffraction pattern suggests that solid solutions can be used to generate previously unknown phases. Crystal structure and powder diffraction pattern analysis of the solid solutions revealed that subtle shifting in distances of the crystal planes was a function of APZ and dAPZ content, controlled by the cumulative effects of hydrogen bonding and steric bulk in these molecules. Melting temperatures and other transitions of the solid material can be finely tuned while a single phase is maintained through tailoring the APZ and dAPZ composition. This study illustrates that, despite the extreme conformational flexibility and dissimilar crystal form diversity of APZ and dAPZ, isomorphous compositions combining both APZ and dAPZ in a single phase can be prepared as a way of fine-tuning physicochemical properties. Chemistry ; Solid solution ; Steric effects ; Powder diffraction ; Molecule ; Dissolution ; Crystallography ; Phase (matter) ; Hydrogen bond ; Crystal structure ; Stereochemistry ; Organic chemistry Crystallography and molecular interactions ; Crystallization and Solubility Studies ; X-ray Diffraction in Crystallography
Authors: Anette Löfstrand | Johannes Svensson | Lars‐Erik Wernersson | Ivan Maximov
Source: Nanotechnology (article, 2020-04-24)
Field: Materials Science — Materials Chemistry

Feature size control using surface reconstruction temperature in block copolymer lithography for InAs nanowire growth Here we present a method to control the size of the openings in hexagonally organized BCP thin films of poly(styrene)-block-poly(4-vinylpyridine) (PS-b-P4VP) by using surface reconstruction. The surface reconstruction is based on selective swelling of the P4VP block in ethanol, and its extraction to the surface of the film, resulting in pores upon drying. We found that the BCP pore diameter increases with ethanol immersion temperature. In our case, the temperature range 18 to 60 °C allowed fine-tuning of the pore size between 14 and 22 nm. A conclusion is that even though the molecular weight of the respective polymer blocks is fixed, the PS-b-P4VP pore diameter can be tuned by controlling temperature during surface reconstruction. These results can be used for BCP-based nanofabrication in general, and for vertical nanowire growth in particular, where high pattern density and diameter control are of importance. Finally, we demonstrate successful growth of indium arsenide InAs vertical nanowires by selective-area metal-organic vapor phase epitaxy (MOVPE), using a silicon nitride mask patterned by the proposed PS-b-P4VP surface reconstruction lithography method. Materials science ; Nanowire ; Metalorganic vapour phase epitaxy ; Nanolithography ; Lithography ; Thin film ; Indium arsenide ; Epitaxy ; Copolymer ; Nanotechnology ; Polymer ; Optoelectronics ; Chemical engineering ; Composite material ; Gallium arsenide ; Fabrication ; Layer (electronics) Block Copolymer Self-Assembly ; Polymer Surface Interaction Studies ; Nanofabrication and Lithography Techniques
Authors: Xiangchun Li | Yibo Xue | Wan Song | Yan Yu | Jie Min | Fang Liu | Xu Liu | Wen‐Yong Lai | Wei Huang
Source: Research (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Highly Regioselective Direct C-H Arylation: Facile Construction of Symmetrical Dithienophthalimide-Based <i>π</i> -Conjugated Molecules for Optoelectronics Controllable direct C-H arylation with high regioselectivity is highly desirable yet remains a formidable challenge. Herein, a facile regioselective direct C-H arylation is developed for efficient construction of a variety of symmetrical dithienophthalimide-based <i>π</i>-conjugated molecules. The resulting methodology is applicable to a wide range of substrates, from electron-rich units to electron-deficient units with large steric end groups. Aryl halides have been confirmed to be able to couple with dithienophthalimide (DTI) via direct C-H arylation, showing high regioselectivity. Varying the functional end groups onto the DTI core has been demonstrated to fine tune the emission colors to cover most of the visible spectra. The results suggest a facile strategy towards highly selective direct C-H arylation, opening the prospects towards efficient construction of <i>π</i>-conjugated molecules for various potential optoelectronic applications. Regioselectivity ; Conjugated system ; Molecule ; Materials science ; Combinatorial chemistry ; Chemistry ; Nanotechnology ; Catalysis ; Organic chemistry ; Polymer Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Catalytic Cross-Coupling Reactions
Authors: Nur Zehan An'Nisa | Marlia Morsin | Rahmat Sanudin | Nur Liyana Razali | Suratun Nafisah
Source: Sensing and Bio-Sensing Research (article, 2020-06-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Controlled wet chemical synthesis of gold nanorods for triclopyr butotyl herbicide detection based-plasmonic sensor Gold nanorods (GNRs) have a unique optical property of metallic nanoparticles due to the localised surface plasmon resonance (LSPR) effect, which depends on the size, shape and dielectric property of the surrounding medium. Anisotropic GNRs optical behaviours are approximated based on Mie-Gans theory by predicting the presence of dual absorption bands, which are the transverse and longitudinal bands. This study discussed the investigation of the GNRs formation by controlling three process parameters; centrifugation speed, seed solution concentration and growth solution ageing period to overcome the limitations of rod-shaped nanoparticles due to inhomogeneity, uncontrollable shape and aspect ratio. Bottom-up synthesis has been used to produce fine-tuning gold nanostructures. High yield and aspect ratio of GNRs are achieved at 20 h with 10 μl seed solution concentration and 5000 rpm centrifugation speed for particles separation; a longer growth ageing period caused the uncontrollable formation of GNRs with stacking nanoparticles. Therefore, the optimized GNRs with an aspect ratio of 4.23 ± 0.36 and the yields 74.81% are used as sensing material to detect the targeted herbicide analyte, namely triclopyr butotyl. The concentration of triclopyr butotyl can be detected as low as 3% ~ 1.03 mg/l using the sensing mechanism that was based on the plasmonic effect; which was resulting from the collective oscillations of conduction band electrons in a rod nanoparticle. Nanorod ; Materials science ; Plasmon ; Nanoparticle ; Colloidal gold ; Surface plasmon resonance ; Nanotechnology ; Chemical engineering ; Analytical Chemistry (journal) ; Optoelectronics ; Chemistry ; Chromatography Gold and Silver Nanoparticles Synthesis and Applications ; Advanced biosensing and bioanalysis techniques ; Biosensors and Analytical Detection
Authors: Sijie Wu | Chengyu Liang | Jiaxu Zhang | Zhou Wu | Xiaoli Wang | Rui Zhou | Yaxing Wang | Shuao Wang | Dong‐Sheng Li | Tao Wu
Source: Angewandte Chemie (article, 2020-08-10)
Field: Materials Science — Materials Chemistry

A Photoconductive X‐ray Detector with a High Figure of Merit Based on an Open‐Framework Chalcogenide Semiconductor A wide range of tunability in the physical parameters of a semiconductor used for X-ray detection is desirable to achieve targeted performance optimization. However, in a dense-phase semiconductor, fine-tuning one parameter often leads to unwanted changes in other parameters. Herein, the intrinsic openness in an open-framework semiconductor has been confirmed, for the first time, to be a key structural factor that weakens the mutual exclusivity of the adjustable physical parameters owing to a non-linear control mechanism. The controllable doping of S in a zeolitic In-Se host results in an optimal balance between resistivity, band gap, and carrier mobility, which finally results in an excellent X-ray detector with a high figure of merit for the mobility-lifetime product (7.12×10<sup>-4</sup> cm<sup>2</sup> V<sup>-1</sup> ); this value is superior to that of a commercial α-Se detector. The current strategy of choosing open-framework semiconductor materials opens a new window for targeting high-performance X-ray detection. Figure of merit ; Semiconductor ; Optoelectronics ; Detector ; Chalcogenide ; Materials science ; Semiconductor detector ; Doping ; Nanotechnology ; Optics ; Physics 2D Materials and Applications ; Chalcogenide Semiconductor Thin Films ; Advanced Semiconductor Detectors and Materials
Authors: Wanchai Deeloed | Worawat Wattanathana | Pongsakorn Jantaratana | Panida Prompinit | Suttipong Wannapaiboon | Suparat Singkammo | Suchinda Sattayaporn | Apirat Laobuthee | Songwut Suramitr | Yuranan Hanlumyuang
Source: Materials Research Express (article, 2020-09-01)
Field: Materials Science — Materials Chemistry

A systematic variation in cationic distribution and its influence on the magnetization of mixed-metal (nickel and zinc) cobaltite spinels Abstract Cobaltite oxide spinel (CoCo 2 O 4 ) is one promising material that has been extensively studied for decades due to its versatile applications. Revealing the correlation among chemical compositions, cationic distributions, and physical properties are crucial for exploring its novel application. Here, a series of nickel/zinc co-substituted cobaltite spinels, Zn 1−X Ni X Co 2 O 4 (ZNCO-X; where X = 0.00, 0.25, …, 1.00), was synthesized by calcining the hydrothermal-derived precursors and their magnetic properties have been investigated. Multiple x-ray based characterization techniques (XRD, XRF, XPS, and XAS) were applied to determine the crystalline structure and appropriated compositions of cation species (Zn 2+ , Ni 2+ , Ni 3+ , Co 2+ , and Co 3+ ). In conjunction with Neel’s theory of antiferromagnetism, the theoretical magnetization of the spinel series was calculated based on the assumption that Zn 2+ ion was located in tetrahedral (A site) while nickel cations (Ni 2+ and Ni 3+ ) occupying the octahedral (B site). The theoretical magnetization profile exhibited a good correlation. Superparamagnetic effect and cationic site exchange can be used to explain the discrepancies between the measured and calculated magnetizations. This work reported a systematic controlling of materials structure and cationic distribution, which are crucial for fine-tuning the magnetic property of the Zn 1−X Ni X Co 2 O 4 cobaltite system. Cobaltite ; Spinel ; Magnetization ; Nickel ; Materials science ; Cationic polymerization ; Zinc ; Antiferromagnetism ; Inorganic chemistry ; Crystallography ; Chemistry ; Metallurgy ; Condensed matter physics ; Physics ; Magnetic field Magnetic Properties and Synthesis of Ferrites ; Magnetic and transport properties of perovskites and related materials ; Advanced Condensed Matter Physics
Authors: V. G. Suchithra | P. Prabhakar Rao | B. A. Aswathy
Source: Journal of Materials Science Materials in Electronics (article, 2020-02-21)
Field: Materials Science — Materials Chemistry

New full color emitting phosphor through energy transfer in Bi3+ and Eu3+ co-doped La3TaO7 weberite system Phosphor ; Chromaticity ; Photoluminescence ; Luminescence ; Orthorhombic crystal system ; Materials science ; Doping ; Ion ; Analytical Chemistry (journal) ; Optoelectronics ; Chemistry ; Crystal structure ; Optics ; Crystallography ; Physics Luminescence Properties of Advanced Materials ; Radiation Detection and Scintillator Technologies ; Perovskite Materials and Applications
Authors: Thu‐Hong Doan | Aurélien Chardon | Arnaud Osi | Damien Mahaut | Nikolay Tumanov | Johan Wouters | Benoı̂t Champagne | Guillaume Berionni
Source: Chemistry - A European Journal (article, 2020-08-27)
Field: Chemistry — Organic Chemistry

Methylene Bridging Effect on the Structures, Lewis Acidities and Optical Properties of Semi‐planar Triarylboranes Three synthetic methods towards semi-planar triarylboranes with two aryl rings connected by a methylene bridge have been developed. The fine-tuning of their stereoelectronic properties and Lewis acidities was achieved by introducing fluorine, methyl, methoxy, n-butyl and phenyl groups either at their exocyclic or bridged aryl rings. X-ray diffraction analysis and quantum-chemical calculations provided quantitative information on the structural distortion experienced by the near planar hydro-boraanthracene skeleton during the association with Lewis bases such as NH<sub>3</sub> and F<sup>-</sup> . Though the methylene bridge between the ortho-positions of two aryl rings of triarylboranes decreased the Gibbs free energies of complexation with small Lewis bases by less than 5 kJ mol<sup>-1</sup> relative to the classical Lewis acid BAr<sub>3</sub> , the steric shielding of the CH<sub>2</sub> bridge is sufficient to avoid the formation of Lewis adducts with larger Lewis bases such as triarylphosphines. A newly synthesized spirocyclic amino-borane with a long intramolecular B-N bond that could be dissociated under thermal process, UV-irradiation, or acidic conditions might be a potential candidate in Lewis pairs catalysis. Lewis acids and bases ; Chemistry ; Methylene bridge ; Steric effects ; Borane ; Intramolecular force ; Adduct ; Aryl ; Methylene ; Crystallography ; Polymer chemistry ; Stereochemistry ; Medicinal chemistry ; Catalysis ; Organic chemistry Organoboron and organosilicon chemistry ; Sulfur-Based Synthesis Techniques ; Synthesis and characterization of novel inorganic/organometallic compounds