jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Katarína Maráková
Source: LCGC North America (article, 2022-07-01)
Field: Chemistry — Spectroscopy

The Crucial Step in Every Analytical Workflow: Sample Preparation—Are We Ready For a Growing Area of Intact Protein Analysis? Proteins are biomolecules with a lot of essential functions in a human body. Their varied expression during complex disorders, including cancer, predicts their potential use as biomarkers. Therefore, there is a need for reliable analytical workflows for their analysis in complex biological matrices. Despite the very sensitive and advanced instrumentation we have available for protein analysis today, sample preparation still remains one of the biggest challenges. Workflow ; Instrumentation (computer programming) ; Computational biology ; Sample (material) ; Computer science ; Biomolecule ; Sample preparation ; Data science ; Nanotechnology ; Bioinformatics ; Biology ; Chemistry ; Chromatography ; Programming language ; Materials science ; Database Advanced Proteomics Techniques and Applications ; Mass Spectrometry Techniques and Applications ; Molecular Biology Techniques and Applications
Authors: María Elena Manríquez-Ramírez | C. Reza-San Germán | Miriam Estrada Flores
Source: Superficies y Vacío (article, 2022-11-30)
Field: Materials Science — Materials Chemistry

Intercalation of p-toluenesulfonic acid into Mg-Al layered double hydroxide Layered double hydroxide represents a class of materials for selective adsorption and catalysis. In the present work, anionic p-toluenesulfonic acid (PTSA) was successfully incorporated into the interlayer domain of Mg-Al layered double hydroxide (LDH), synthesized by the co-precipitation route. Materials were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, magic angle nuclear magnetic resonance (13C MAS-NMR) spectroscopy and UV-Visible diffuse reflectance (UV-VIS/DR). All samples supported PTSA intercalation at room temperature in the basal space, the interlayer distance increased by the intercalations of the above mentioned according to the arrangement of PTSA molecules in the interlayer. The LDH-PTSA structure collapsed at 400 °C and the organic portion of those materials occurred by partial combustion, which in turn gives rise to reduced species, such as carbon and sulfide anions. Intercalation (chemistry) ; Diffuse reflectance infrared fourier transform ; Layered double hydroxides ; Fourier transform infrared spectroscopy ; Raman spectroscopy ; Hydroxide ; p-Toluenesulfonic acid ; Materials science ; Spectroscopy ; Chemistry ; Inorganic chemistry ; Catalysis ; Photocatalysis ; Chemical engineering ; Organic chemistry Layered Double Hydroxides Synthesis and Applications ; Polyoxometalates: Synthesis and Applications ; Inorganic Chemistry and Materials
Authors: Po Yuen Ho | Evgenia Dmitrieva | Ningwei Sun | Olga Guskova | Franziska Lissel
Source: Advanced Materials Technologies (article, 2022-08-05)
Field: Materials Science — Polymers and Plastics

Synthesis of Novel Ruthenium‐Polymetallaynes and Their Application in Multistate Electrochromic Memory Abstract Multilevel (or multistate) electrochromic devices have the potential to achieve highly compact memory capacity while instantaneously transferring data between memory and processing units. In this article, three novel solution‐processable ruthenium‐polymetallaynes (i.e., P1, P2, and P3), in which the redox‐addressable Ru center is covalently embedded into a conjugated organic polymer, are discussed. In pursuit of higher functionality (e.g., stable multistate behavior, low operating voltage), the organic ligand bridging the metal centers is systematically varied. The previously reported P1 has a bithiophene (BT) bridging ligand with a high degree of rotational freedom. By replacing BT with cyclopenta‐dithiophene in P2 and dithieno‐pyrrole (DTP) in P3, both of which are more planar than BT, the degree of freedom is decreased. By using DTP, redox‐matching is achieved between the metal center and organic ligand, leading to extra stability of the mixed‐valence (MV) state in P3. In‐depth experimental (i.e., in situ electron paramagnetic resonance and UV–vis–NIR spectroelectrochemistry) and theoretical studies (i.e., DFT calculations) are carried out on the polymer thin‐films, showing enhanced metal–metal (M–M) interaction in P2 and P3 and stable Robin–Day class III MV compound in P3. These polymers are also first time fabricated into solid‐state electrochromic devices and the stability of each oxidation state is characterized by tracing the change of transmittance over time, showing satisfactory cyclic stability and retention behavior (≈90% retention after 30 min). Electrochromism ; Materials science ; Ruthenium ; Valence (chemistry) ; Bridging ligand ; Polymer ; Electrochromic devices ; Redox ; Metal ; Photochemistry ; Electrode ; Physical chemistry ; Organic chemistry ; Chemistry Conducting polymers and applications ; Photochromic and Fluorescence Chemistry ; Perovskite Materials and Applications
Authors: Flavien Zannini | Sandrine Mathiot | Jérémy Couturier | Claude Didierjean | Nicolas Rouhier
Source: Inorganics (article, 2022-02-17)
Field: Chemistry — Inorganic Chemistry

Structural Insights into a Fusion Protein between a Glutaredoxin-like and a Ferredoxin-Disulfide Reductase Domain from an Extremophile Bacterium In eukaryotic photosynthetic organisms, ferredoxin–thioredoxin reductases (FTRs) are key proteins reducing several types of chloroplastic thioredoxins (TRXs) in light conditions. The electron cascade necessary to reduce oxidized TRXs involves a pair of catalytic cysteines and a [4Fe–4S] cluster present at the level of the FTR catalytic subunit, the iron–sulfur cluster receiving electrons from ferredoxins. Genomic analyses revealed the existence of FTR orthologs in non-photosynthetic organisms, including bacteria and archaea, referred to as ferredoxin-disulfide reductase (FDR) as they reduce various types of redoxins. In this study, we describe the tridimensional structure of a natural hybrid protein formed by an N-terminal glutaredoxin-like domain fused to a FDR domain present in the marine bacterium Desulfotalea psychrophila Lsv54. This structure provides information on how and why the absence of the variable subunit present in FTR heterodimer which normally protects the Fe–S cluster is dispensable in FDR proteins. In addition, modelling of a tripartite complex based on the existing structure of a rubredoxin (RBX)–FDR fusion present in anaerobic methanogen archaea allows recapitulating the electron flow involving these RBX, FDR and GRX protein domains. Ferredoxin ; Glutaredoxin ; Archaea ; Ferredoxin-thioredoxin reductase ; Protein subunit ; Sulfite reductase ; Biochemistry ; Thermophile ; Thioredoxin ; Oxidoreductase ; Biology ; Chemistry ; Reductase ; Thioredoxin reductase ; Enzyme ; Gene Metal-Catalyzed Oxygenation Mechanisms ; Metalloenzymes and iron-sulfur proteins ; Mass Spectrometry Techniques and Applications
Authors: Ouahab Zakaria | Karima Bounab | Necira Zoulikha
Source: Revue des composites et des matériaux avancés (article, 2022-12-31)
Field: Chemistry — Inorganic Chemistry

Investigation of the Impact of Magnesium Doping on the Structural and Dielectric Properties of the Compound: (Na0.5Bi0.5)1-xMgx[(Ti0.8Zr0.2)0.9(Nb2/3Zn1/3)0.1]O3 (NBMTZNZ) Our research is based on the production of BNT ceramics, abbreviated as NBMTZNZ.And study its structural and electrical properties.Using x-rays, electronic scanning, and non-electrical measurements, we analyzed the samples.The results obtained are of considerable value, allowing them to be exploited to develop the use of our compound . Magnesium ; Dielectric ; Doping ; Materials science ; Analytical Chemistry (journal) ; Mineralogy ; Metallurgy ; Chemistry ; Environmental chemistry ; Optoelectronics Inorganic Chemistry and Materials ; Ferroelectric and Piezoelectric Materials ; Microwave Dielectric Ceramics Synthesis
Authors: Lebogang N. Maruma | Anou M. Somboro | Daniel G. Amoako | Hezekiel M. Khumalo | René B. Khan
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2022-03-06)
Field: Chemistry — Organic Chemistry

Molecular mechanisms underlying Warburgia salutaris effects on oxidative stress and apoptotic parameters in Human Hepatoma Cells Abstract This study aims to determine the molecular effects of Warburgia salutaris extract in HepG2 cells and elucidate the possible mechanisms. The MTT assay was employed to determine cell viability and the half maximal inhibitory concentration (IC 50 ) of Warburgia salutaris-treated in HepG2 cells (0-5mg/ml). Extracellular lactate dehydrogenase and ATP were also quantified as a measure of cell viability. The production of reactive oxygen species (ROS) was assessed by quantifying lipid peroxidation and oxidative DNA damage, and reactive nitrogen species (RNS) in treated HepG2 cells. The cells response to free radicals was assessed by measuring GSH. Stress response antioxidant and apoptotic markers were detected using western blotting and /or qPCR. Cell death parameters assayed included annexin V, caspase activity and necrosis. Single-cell gel electrophoresis (SCGE) was used to visualise DNA damage in the HepG2 cells and confirmed with DNA fragmentation assay. The Hoechst assay allowed the visualisation of the nucleus to assess cell growth and apoptosis. Decreased cell viability was associated with a decreased level of ATP. The presence of oxidative stress was suggested by increased HSP70 and Nrf2 protein expression and confirmed by increase ROS, RNS, GPx and catalase; and a corresponding decrease of SOD2 and glutathione. Caspase 8 showed no significant difference between treatment concentrations, caspase 9 was decreased and caspase 3/7 increased. A reduction in p53 correlated with chromatin changes, increase in comet lengths and DNA fragmentation. NFκB protein was significantly decreased at the IC 50 , along with decreased cMyc protein expression. Our findings shows that Warburgia salutaris promotes apoptosis by inducing oxidative stress in HepG2 cells and may be a potential anti-cancer agent that would serve as an alternative to conventional therapeutic agents. Viability assay ; Oxidative stress ; Molecular biology ; DNA fragmentation ; Comet assay ; Apoptosis ; Biology ; Reactive oxygen species ; Lipid peroxidation ; Lactate dehydrogenase ; Glutathione ; DNA damage ; Fragmentation (computing) ; Biochemistry ; Programmed cell death ; Enzyme ; DNA Synthesis and biological activity ; Marine Sponges and Natural Products ; Microbial Natural Products and Biosynthesis
Authors: Maria J. Lopera
Source: Optica Pura y Aplicada (article, 2022-03-28)
Field: Chemistry — Physical and Theoretical Chemistry

Polarimetric microscope web application for simulated and experimental retrieval of polarimetric properties of biological samples Polarimetric microscope web application for simulated and experimental retrieval of polarimetric properties of Polarimetry ; Microscope ; Remote sensing ; Computer science ; Materials science ; Information retrieval ; Optics ; Geology ; Physics thermodynamics and calorimetric analyses
Authors: Nan Zhao
Source: Digital Archive @ GSU (article, 2022-04-13)
Field: Materials Science — Materials Chemistry

Vibrational Properties of Quinones in Photosynthetic Reaction Centers Fourier transform infrared difference spectroscopy (FTIR DS) is widely used to study the structural details of electron transfer cofactors in photosynthetic protein complexes. In photosynthetic proteins quinones play an important role, functioning as a cofactor in light-driven electron transfer. In photosystem I (PS I) phylloquinone (PhQ) functions as an intermediary in electron transfer. To investigate the properties of PhQ that occupies the, so called, A1 binding site in PS I, time-resolved step-scan FTIR DS, with 5æs time resolution at 77K has been used. By replacing PhQ in the A1 binding site with specifically isotope labeled version, information on the vibrational frequencies associated specifically with the quinone in the binding site were obtained, which could be compared to the vibrational properties of quinone in solution or quinones in other protein binding sites. To further aid in assessing the origin of bands in the spectra, quantum mechanics /molecular mechanics (QM/MM) ONIOM type calculations were undertaken. ONIOM is an acronym for Our own N-layered Integrated molecular Orbital and molecular Mechanics. We find that the phytyl tail of PhQ does not play an important role in the orientation of PhQ in the A1 binding site. We also find that PhQ, in both neutral and reduced states, is strongly hydrogen bonded. To test and verify the applicability of our QM/MM approach, ONIOM calculations were also undertaken for ubiquinone and a variety of other quinones incorporated into the, so called, QA binding site in purple bacteria photosynthetic reaction centers. The calculated and experimental spectra agree well, demonstrating the utility and applicability of our ONIOM approach. Hydrogen bonding to the carbonyl groups of quinones in the QA binding site was shown to be relatively weak, and it was found that hydrogen bonding to neutral ubiquinone in purple bacterial reaction centers can be considered in purely electrostatic terms, contrary to the widely held belief that the hydrogen bonding amino acids should be treated quantum mechanically. Photosynthesis ; Photosynthetic reaction centre ; Chemistry ; Photochemistry ; Biochemistry Porphyrin and Phthalocyanine Chemistry ; Photosynthetic Processes and Mechanisms ; Photochemistry and Electron Transfer Studies
Authors: Yi-nuo WEN | Liu-yan ZHOU | Yanling Chen | Jianhua Lin | Jie Fu | Shuyang Chen | Ming-xiao HAN | Jie Li | De-gang DENG | Liang CHEN
Source: Chinese Journal of Luminescence (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Up-conversion Luminescence and Temperature Sensing Properties of La&lt;sub&gt;2&lt;/sub&gt;&lt;italic&gt;A&lt;/italic&gt;TiO&lt;sub&gt;6&lt;/sub&gt;（&lt;italic&gt;A&lt;/italic&gt;=Mg, Zn） Phosphor Er3+çä¸è½¬æ¢æ§è½å¼ºçä¾èµå±é¨ä½ç½®å¯¹ç§°ç¸åãå¨æ¬ç ç©¶ä¸­ï¼éç¨é«æ¸©åºç¸æ³å¶å¤äºLa2Mgï¼1-wï¼ZnwTiO6â¶xEr3+ï¼x=0ï¼0.02ï¼0.04ï¼0.06ï¼0.08ï¼0.10ï¼w=0ï¼0.3ï¼0.5ï¼0.7ï¼1.0ï¼ç³»åè§å ç²ãåºäºXRDç²¾ä¿®ï¼Zn2+çæºææ¹åäºLa2MgTiO6æ¶ä½çé ä½ç¯å¢ï¼æ¶ç¸ç±Pbnmè½¬åä¸ºP21/nãå¨980 nmæ¿å æ¿åä¸ï¼æ ·åä¸è½¬æ¢è§å å¼ºåº¦éEr3+ç¦»å­æµåº¦æ¹åï¼å½Er3+ç¦»å­æµåº¦ä¸ºx=0.06æ¶æ ·åçä¸è½¬æ¢è§å å¼ºåº¦æå¼ºãåºäºè§å å¼ºåº¦æ¯ææ¯ç ç©¶äºæ ·åLa2Mgï¼1-wï¼ZnwTiO6â¶xEr3+ï¼x=0.06ï¼w=0ï¼0.3ï¼0.5ï¼0.7ï¼1.0ï¼å¨303ï½583 Kæ¸©åº¦èå´å çä¸è½¬æ¢è§å æ¸©åº¦ä¼ æç¹æ§ãå®éªç»æè¡¨æï¼çµæåº¦éçMg2+åZn2+æºææµåº¦æ¯ä¾çæ¹åèæ¹åï¼å¨w=1.0æ¶è¾¾å°æå¤§ç»å¯¹çµæåº¦0.90%Â·K-1ï¼è¯´æZn2+çæºææé«äºLa2MgTiO6ççµæåº¦ã Materials science ; Luminescence ; Optoelectronics Luminescence Properties of Advanced Materials ; Acoustic Wave Resonator Technologies ; Microwave Dielectric Ceramics Synthesis
Authors: Kinjal Gandha | Rakesh P. Chaudhary | M. J. Kramer | Ryan Ott | Durga Paudyal | Ikenna C. Nlebedim
Source: Materials Chemistry and Physics (article, 2022-04-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Microstructural evolutions, phase transformations and hard magnetic properties in polycrystalline Ce–Co–Fe–Cu alloys Materials science ; Coercivity ; Curie temperature ; Microstructure ; Solubility ; Phase (matter) ; Crystallite ; Homogeneity (statistics) ; Magnetization ; Homogeneous ; Analytical Chemistry (journal) ; Metallurgy ; Condensed matter physics ; Thermodynamics ; Ferromagnetism ; Chemistry ; Magnetic field ; Physical chemistry Magnetic Properties of Alloys ; Magnetic and transport properties of perovskites and related materials ; Rare-earth and actinide compounds
Authors: Van Liem Bui | Phan Xuan Le
Source: Indonesian Journal of Electrical Engineering and Computer Science (article, 2022-08-10)
Field: Materials Science — Materials Chemistry

The impacts of green Cs2ZnSi5O12:Eu2+ phosphor for white light emitting diode We created the green-light phosphor Cs&lt;sub&gt;2&lt;/sub&gt;ZnSi&lt;sub&gt;5&lt;/sub&gt;O&lt;sub&gt;12&lt;/sub&gt; (CZSO) with Eu&lt;sup&gt;2+&lt;/sup&gt; replacement for the practical use of ultraviolet white illumination through the solid-state technique. The phosphor displays many different forms and crystallizes in the space group &lt;em&gt;Pbca&lt;/em&gt; along with &lt;em&gt;Pa&lt;/em&gt; , with formation resembling CsAlSi&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;6&lt;/sub&gt;, the leucite in cube form. We utilized the X-ray powder diffraction as well as the spectroscopic knowledge to validate that the crystal formation in the phosphor CZSO:Eu&lt;sup&gt;2+&lt;/sup&gt; belongs to the space group &lt;em&gt;Pa&lt;/em&gt; . CZSO can generate wide green emission with a wavelength of 504 nm when excited by ultraviolet. We enveloped the blend using the translucent silicone resin and the red-light phosphor Sr&lt;sub&gt;2&lt;/sub&gt;Si&lt;sub&gt;5&lt;/sub&gt;N&lt;sub&gt;8&lt;/sub&gt;:Eu&lt;sup&gt;2+&lt;/sup&gt; as well as excited it using an ultraviolet light emitting diode (LED) device with a wavelength of 370 nm to generate white illumination that yields remarkable chromatic output. The generation of illumination utilizing the phosphor CZSO benefits from the wide green emission, which does not require the integration of the three phosphors that are critical to the ultraviolet pumping. Such benefit will allow the model of the apparatus to become simpler and simultaneously create a desirable ultraviolet white illumination. When the augmentation the emission efficacy as well as the heat consistency for the phosphor CZSO is realized, we can easily incorporate the ultraviolet LED devices to create better white illumination. Phosphor ; Ultraviolet ; Light-emitting diode ; Excited state ; Materials science ; Analytical Chemistry (journal) ; Physics ; Chemistry ; Optoelectronics ; Atomic physics Luminescence Properties of Advanced Materials ; Advanced Energy Technologies and Civil Engineering Innovations
Authors: Aiji Liang | Zhilin Li | Shihao Zhang | Shucui Sun | Shuai Liu | Cheng Chen | Haifeng Yang | Shengtao Cui | Sung‐Kwan Mo | Shuai Yang | Yongqing Li | Meixiao Wang | Lexian Yang | Jianpeng Liu | Zhongkai Liu | Yu-Lin Chen
Source: arXiv (Cornell University) (preprint, 2022-11-30)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Electronic Origin of Half-metal to Semiconductor Transition and Colossal Magnetoresistance in Spinel HgCr2Se4 Half-metals are ferromagnets hosting spin-polarized conducting carriers and crucial for spintronics applications. The chromium spinel HgCr2Se4 represents a unique type of half-metal, which features a half-metal to semiconductor transition (HMST) and exhibits colossal magnetoresistance (CMR) across the ferromagnetic-paramagnetic (FM-PM) transition. Using angle-resolved photoemission spectroscopy (ARPES), we find that the Fermi surface of n-type HgCr2Se4 (n-HgCr2Se4) consists of a single electron pocket which moves above the Fermi level (EF) upon the FM-PM transition, leading to the HMST. Such a Lifshitz transition manifests a giant band splitting which originates from the exchange interaction unveiled with a specific chemical nonstoichiometry. The exchange band splitting and the chemical nonstoichiometry are two key ingredients to the HMST and CMR, consistent with our ab-initio calculation. Our findings provide spectroscopic evidences of the electronic origin of the anomalous properties of HgCr2Se4, which address the unique phase transition in half-metals. Condensed matter physics ; Colossal magnetoresistance ; Angle-resolved photoemission spectroscopy ; Spintronics ; Magnetoresistance ; Ferromagnetism ; Fermi level ; Materials science ; Transition metal ; Paramagnetism ; Electronic structure ; Giant magnetoresistance ; Fermi surface ; Photoemission spectroscopy ; Spinel ; X-ray photoelectron spectroscopy ; Chemistry ; Electron ; Physics ; Superconductivity ; Nuclear magnetic resonance ; Magnetic field Magnetic and transport properties of perovskites and related materials ; Advanced Condensed Matter Physics ; Magnetic Properties and Synthesis of Ferrites
Authors: Ariel Ashkenazy | Racheli Ron | Tchiya Zar | Hannah Aharon | Adi Salomon | Dror Fixler | Eliahu Cohen
Source: IEEE photonics journal (article, 2022-08-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Measurement of the Second-Order Polarizability of Silver Nanoparticles With Reference-Free Hyper-Rayleigh Scattering for Entangled Photon Pair Interaction Two-photon interactions of entangled-photon pairs with metallic nanoparticles (NPs) can be enhanced by localized surface-plasmon resonance. Recently, we have described how the properties of this quantum light-matter interaction can be deduced from classical second-harmonic generation measurements performed using a reference-free hyper-Rayleigh scattering method. Herein, we report the results of such classical-light characterization measurements. We obtain a large hyperpolarizability for the NPs, present the dependence of the hyperpolarizability on the NPs' spectral features, and show a dipolar emission pattern for the second-harmonic signal. Our results can be used to optimize entangled-photon pair interactions with metallic NPs to enable first ever detection of this process. Moreover, these results suggest that NPs may be used as source for ultra-broadband entangled-photon pairs through nonphase-matched spontaneous parametric down-conversion. Polarizability ; Rayleigh scattering ; Scattering ; Photon ; Order (exchange) ; Physics ; Molecular physics ; Light scattering ; Nanoparticle ; Optics ; Atomic physics ; Quantum mechanics Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Thermal Radiation and Cooling Technologies
Authors: Julien Acquadro | Sophie Noël | Pascal Chrétien | Frédéric Houzé | Ph. Teste | Corine Genet | Hiba Azougaghe | F. Ansart | Marie Gressier | Marie‐Joëlle Menu | Robin Montpellaz | Olivier Gavard | R. Leroy | G. Tredan | S. Demarthon | T. Pichot | F. Raoul | M. Ladire
Source:  (preprint, 2022-10-23)
Field: Materials Science — Materials Chemistry

Innovative sol-gel coatings for corrosion protection of connector housings This paper presents the electrical properties of innovative sol-gel coatings for connectors. A first study has shown the feasibility of developing a conducting and anti-corrosion coating for connector housing based on sol-gel chemistry. Such coatings aimed at replacing cadmium and chromium (VI) as recommended by REACH and RoHS regulations must have equivalent properties. A large consortium has been established in order to tackle aspects of the project from the formulation, the characterizations and the scale-up phases. The electrical properties of the coatings are obtained with conductive fillers of various types. We present here electrical characterizations both at the macroscopic scale and at the microscopic scale and try to correlate the conduction to the various parameters involved in the complex mechanisms ruling the film formation. Corrosion ; Materials science ; Coating ; Cable gland ; Sol-gel ; Electrical conductor ; Metallurgy ; Scale (ratio) ; Composite material ; Nanotechnology ; Mechanical engineering ; Engineering ; Physics Corrosion Behavior and Inhibition ; Molecular Junctions and Nanostructures ; Polyoxometalates: Synthesis and Applications