jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zoltán Gáspári
Source: Alkalmazott Matematikai Lapok (article, 2019-01-01)
Field: Materials Science — Biomaterials

Kísérletileg meghatározott, belső dinamikát tükröző fehérjeszerkezeti sokaságok: előállítás, elemzés és biológiai relevancia Az utbbi vtizedekben nyilvnvalv vlt, hogy a fehrjk trszerkezete mellett bels dinamikjuk is kulcsfontossg szerepet jtszik biolgiai funkcijuk meghatrozsban s finomhangolsban. A bels mozgsok atomi szint reprezentcijra olyan j modellek kerltek eltrbe, amelyek ugyanannak a molekulnak nagyszm klnbz trszerkezeteit tartalmazzk, amelyek kztti klnbsgek nem elssorban bizonytalansgbl addnak Chemistry ; Physics Collagen: Extraction and Characterization
Authors: Sarah Schiffers
Source: Electronic Theses of LMU Munich (Ludwig-Maximilians-Universität München) (article, 2019-01-01)
Field: Chemistry — Spectroscopy

Mass spectrometric analysis of modified nucleotides in embryonic development and disease Nucleotide ; Embryonic stem cell ; Chemistry ; Computational biology ; Biology ; Biochemistry ; Gene Mass Spectrometry Techniques and Applications
Authors: Yanuar Setiadi | ⁠Muhamad Basit Febrian | Ahmad Mudzakir | Azmairit Aziz | Duyeh Setiawan | Anna Kurnia Illahi | Dwi Ayu Rahmawati
Source: Jurnal Sains dan Teknologi Nuklir Indonesia (article, 2019-11-10)
Field: Chemistry — Inorganic Chemistry

SYNTHESIS AND CHARACTERIZATION OF BENZOTRIAZOLIUM-BASED IONIC LIQUIDS FOR TECHNETIUM-99M SEPARATION FROM MOLYBDENUM BY IL-MEDIATED EXTRACTION PROCESS Various separation techniques for separation of technetium-99m ( 99m Tc) from molybdenum-99 ( 99 Mo) are being developed to overcome the drawbacks of using 99 Mo from neutron activation technique. Ionic liquids (ILs) were used in many extraction processes in metal separation due to their high selectivity. In this research, two benzotriazolium-based ionic liquids were used as co-extractant in 99m Tc/ Mo separation process via liquid-liquid extraction. 1-octyl-3-methyl-benzotriazolium iodide ([MeOcBtu]I) and 1-octyl-3-methyl-benzotriazolium bis (trifluoromethanesulfonyl) imide ([MeOcBtu]TF 2 N) were successfully synthesized and analyzed by FTIR, 1 H-NMR and 13 C-NMR. Extraction processes were conducted in various organic solvents, pH, and extraction time without/ with ionic liquids addition. The data of ratio between 99m Tc distribution coefficient compared to Mo distribution coefficient showed that the addition of ionic liquids exhibited significant improvement of separation factor. The separation factor of extraction using conventional water immiscible solvent ranged between 0 – 8 and increased to 30 – 600 as ILs were added. The optimum conditions which achieved highest separation factor were pH 14 using [MeOcBtu]I-chloroform. Benzotriazolium-based ionic liquid potential to be developed as extractant in the separation of 99m Tc from 99 Mo. Keywords : Ionic liquids, benzotriazolium, technetium-99m, molybdenum, liquid-liquid extraction. Ionic liquid ; Extraction (chemistry) ; Molybdenum ; Chemistry ; Partition coefficient ; Chloroform ; Separation process ; Liquid–liquid extraction ; Solvent ; Selectivity ; Inorganic chemistry ; Chromatography ; Organic chemistry ; Catalysis Radioactive element chemistry and processing ; Chemical Synthesis and Characterization ; Radiopharmaceutical Chemistry and Applications
Authors: Prabha Chuphal | Ishwar Venugopal | Snigdha Thakur
Source: arXiv (Cornell University) (preprint, 2019-10-01)
Field: Materials Science — Materials Chemistry

Formation of self-propelling clusters starting from randomly dispersed\n Brownian particles We present a simple chemical strategy for the formation of a self-propelling\ncluster via the process of capture and assembly of passive colloids on the\nsurface of a chemically active colloid. The two species of colloids that are\nisotropic and Brownian otherwise interact to form propelling cluster. With the\nhelp of coarse-grained numerical simulations, we show that a chemically active\ncolloid can induce diffusiophoretic motility to nearby chemically inert\ncolloids towards itself. This propulsion and then self-assembly can then lead\nto the formation of active cluster. We observe the formation of propelling\ndimers, trimers, tetramers, etc. depending on the chemical activity and size of\nthe colloids.\n Colloid ; Cluster (spacecraft) ; Brownian motion ; Chemical physics ; Brownian dynamics ; Active matter ; Isotropy ; Chemistry ; Nanotechnology ; Chemical engineering ; Materials science ; Physics ; Physical chemistry ; Optics ; Computer science Pickering emulsions and particle stabilization ; Micro and Nano Robotics ; Diffusion and Search Dynamics
Authors: Teresa Mendes Maia | An Staes | Kim Plasman | Jarne Pauwels | Katie Boucher | Andrea Argentini | Lennart Martens | Tony Montoye | Kris Gevaert | Francis Impens
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2019-07-16)
Field: Chemistry — Spectroscopy

A simple approach for accurate peptide quantification in MS-based proteomics ABSTRACT Despite its growing popularity and use, bottom-up proteomics remains a complex analytical methodology. Its general workflow consists of three main steps: sample preparation, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and computational data analysis. Quality assessment of the different steps and components of this workflow is instrumental to identify technical flaws and to avoid loss of precious measurement time and sample material. However, assessment of the extent of sample losses along the sample preparation protocol, in particular after proteolytic digestion, is not yet routinely implemented because of the lack of an accurate and straightforward method to quantify peptides. Here, we report on the use of a microfluidic UV/visible spectrophotometer to quantify MS-ready peptides directly in MS loading solvent, consuming only 2 μl of sample. We determined the optimal peptide amount for LC-MS/MS analysis on a Q Exactive HF mass spectrometer using a dilution series of a commercial K562 cell digest. Careful evaluation of selected LC and MS parameters allowed us to define 3 μg as an optimal peptide amount to be injected on this particular LC-MS/MS system. Finally, using tryptic digests from human HEK293T cells, we showed that injecting equal peptide amounts, rather than approximated ones, results into less variable LC-MS/MS and protein quantification data. The obtained quality improvement together with easy implementation of the approach makes it possible to routinely quantify MS-ready peptides as a next step in daily proteomics quality control. Chromatography ; Mass spectrometry ; Sample preparation ; Proteomics ; Workflow ; Tandem mass spectrometry ; Chemistry ; Peptide ; Bottom-up proteomics ; Sample (material) ; Quantitative proteomics ; Protocol (science) ; Liquid chromatography–mass spectrometry ; Shotgun proteomics ; Computer science ; Database ; Protein mass spectrometry ; Biochemistry Advanced Proteomics Techniques and Applications ; Mass Spectrometry Techniques and Applications ; Metabolomics and Mass Spectrometry Studies
Authors: Azim Uddin | Faxiang Qin | Diana Estévez | Shang Jiang | Syed Arsalan Jawed | L.V. Panina | Hua‐Xin Peng
Source: arXiv (Cornell University) (preprint, 2019-04-13)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Microwave programmable response of Co-based microwire polymer composites through wire microstructure and arrangement optimization Traditional approaches to realize microwave tunability in microwire polymer composites which mainly rely on topological factors, magnetic field/stress stimuli, and hybridization prove to be burdensome and restricted to rather narrow band frequencies. This work presents a novel yet facile strategy based on a single component tunable medium to program the transmission response over wide frequency bands. To this end, we demonstrated that structural modification of one type of microwire through suitable current annealing and arrangement of the annealed wires in multiple combinations were sufficient to distinctly red-shift the transmission dip frequency of the composites. Such one wire control-strategy endorsed a programmable multivariable system grounded on the variations in both the overall array conductivity or "effectiv" area determined by the wires arrangement and the relaxation time dictated by the annealing degree of microwires. These results can be used to prescribe transmission frequency bands of desired features via diverse microwire arrays and microwave performance from a single component to a composite system design. Materials science ; Microwave ; Microstructure ; Annealing (glass) ; Composite number ; Composite material ; Simulated annealing ; Polymer ; Optoelectronics ; Electronic engineering ; Computer science ; Telecommunications Electromagnetic wave absorption materials ; Advanced Antenna and Metasurface Technologies ; Metamaterials and Metasurfaces Applications
Authors: David Serantes | Daniel Faílde | D. Baldomir | Beatriz Pelaz | Pablo del Pino | R.W. Chantrell
Source: arXiv (Cornell University) (preprint, 2019-09-23)
Field: Materials Science — Materials Chemistry

Effective macrospin model for $Co_{x}Fe_{3-x}O_{4}$ nanoparticles: decreasing the anisotropy by Co-doping? $Co$-doping of $Fe_{3}O_{4}$ magnetic nanoparticles is an effective way to tailor their magnetic properties. When considering the two extreme cases of the $Co_{x}Fe_{3-x}O_{4}$ series, i.e. the $x=0$ and $x=1$ values, one finds that the system evolves from a negative cubic-anisotropy energy constant, $K_{C}^{-}&lt;0$, to a positive one, $K_{C}^{+}&gt;0$. Thus, what happens for intermediate $x$-compositions? In this work we present a very simple phenomenological model for the anisotropy, under the \textit{macrospin} approximation, in which the resultant anisotropy is just directly proportional to the amount of $Co$. First, we perform a detailed analysis on a rather ideal system in which the extreme values have the same magnitude (i.e. $|K_{C}^{-}|=|K_{C}^{+}|$) and then we focus on the real $Co_{x}Fe_{3-x}O_{4}$ system, for which $|K_{C}^{+}|\sim 18|K_{C}^{-}|$. Remarkably, the approach reproduces rather well the experimental values of the heating performance of $Co_{x}Fe_{3-x}O_{4}$ nanoparticles, suggesting that our simple approach may in fact be a good representation of the real situation. This gives rise to an intriguing related possibility arises: a $Co$-doping composition should exist for which the effective anisotropy tends to zero, estimated here as 0.05. Anisotropy ; Doping ; Condensed matter physics ; Magnetic anisotropy ; Phenomenological model ; Nanoparticle ; Physics ; Materials science ; Analytical Chemistry (journal) ; Magnetization ; Nanotechnology ; Chemistry ; Magnetic field ; Quantum mechanics Chemical and Physical Properties of Materials ; Copper-based nanomaterials and applications ; Magnetic properties of thin films
Authors: Erika Lisztes
Source: University of Debrecen Electronic Archive (University of Debrecen) (article, 2019-11-20)
Field: Materials Science — Biomaterials

Új, komplex mechanizmusok felderítése a hajnövekedés szabályozásában – fókuszban a külső gyökérhüvely keratinociták A haj- és szőrnövekedés rendellenességei emberek sokaságának okoznak életminőségbeli romlást világszerte. Nem meglepő tehát, hogy napjainkban a szőrnövekedési rendellenességek kezelése érdekében világszerte számos kutatócsoport tesz erőfeszítéseket a „szőrbiológia” alaposabb megismerésére.Az adenozin, egy lokálisan termelődő esszenciális mediátor, mely szerteágazó fiziológiai funkciói (angiogenezis, vazodilatáció) mellett speciális szerepet tölt be az energiatranszferben és neurotranszmisszióban is. A hajnövekedésre gyakorolt jótékony hatását, úgymint a hajszál átmérőjének vastagodását és hosszának növekedését, már korábban leírták.Az adenozin hajciklusra gyakorolt moduláló hatása részben ismert, ennek ellenére azonban számos nyitott kérdés vár megválaszolásra a pontos hatást, illetve a szabályozást illetően.A koffein napjaink egyik legismertebb alkaloid vegyülete, mely ismertségét elsősorban kulináris élvezeteket nyújtó természetes forrásának, a kávécserjének köszönheti, és a legszélesebb körben felhasznált természetes, farmakológiailag aktív vegyületek közé tartozik a világon.A koffein szőrnövekedésre kifejtett „pozitív” hatása abban rejlik, hogy a férfias típusú hajhullásban fokozott tesztoszteron (TST) szint által telogén fázisban „megragadt” HF-k újbóli anagén fázisba lépésének indukálásában játszik szerepet. Ezen nyomvonalon elindulva kísérleteink során szerettünk volna mélyebb betekintést nyerni az adenozin és koffein hajciklust reguláló hatásába humán HF-kön; vizsgálatainkat HF-eredetű ORS keratinociták bevonásával terjesztettük ki. Physics ; Medicine Collagen: Extraction and Characterization
Authors: H. Suzuki | T. Kobayashi | S. Miyasaka | K. Okazaki | T. Yoshida | M. Horio | L. C. C. Ambolode | Y. Ota | H. Yamamoto | S. Shin | M. Hashimoto | D. H. Lu | Z.-X. Shen | S. Tajima | A. Fujimori
Source: Scientific Reports (article, 2019-11-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Band-dependent superconducting gap in SrFe2(As0.65P0.35)2 studied by angle-resolved photoemission spectroscopy The isovalent-substituted iron pnictide compound SrFe<sub>2</sub>(As<sub>1-x</sub>P<sub>x</sub>)<sub>2</sub> exhibits multiple evidence for nodal superconductivity via various experimental probes, such as the penetration depth, nuclear magnetic resonance and specific heat measurements. The direct identification of the nodal superconducting (SC) gap structure is challenging, partly because the presence of nodes is not protected by symmetry but instead caused by an accidental sign change of the order parameter, and also because of the three-dimensionality of the electronic structure. We have studied the SC gaps of SrFe<sub>2</sub>(As<sub>0.65</sub>P<sub>0.35</sub>)<sub>2</sub> in three-dimensional momentum space by synchrotron and laser-based angle-resolved photoemission spectroscopy. The three hole Fermi surfaces (FSs) at the zone center have SC gaps with different magnitudes, whereas the SC gaps of the electron FSs at the zone corner are almost isotropic and k<sub>z</sub>-independent. As a possible nodal SC gap structure, we propose that the SC gap of the outer hole FS changes sign around the Z-X [(0, 0, 2π) - (π, π, 2π)] direction. Superconductivity ; Photoemission spectroscopy ; Angle-resolved photoemission spectroscopy ; Synchrotron radiation ; Fermi level ; Band gap ; Fermi surface ; Isotropy ; Electron Iron-based superconductors research ; Superconductivity in MgB2 and Alloys ; Physics of Superconductivity and Magnetism
Authors: Jussi Peltonen
Source: Työväentutkimus Vuosikirja (article, 2019-10-31)
Field: Materials Science — Materials Chemistry

Coolant-cladding interaction models in FINIX fuel behaviour module FINIX is a nuclear fission reactor fuel behaviour module developed at VTT Technical Research Centre of Finland since 2012. It has been simplified in comparison to the full-fledged fuel performance codes to improve its usability in coupled applications, by reducing the amount of required input information. While it has been designed to be coupled on a source-code level with other reactor core physics solvers, it can provide accurate results as a stand-alone solver as well.&#13;\n&#13;\nThe corrosion that occurs on the interface between nuclear fuel rod cladding and reactor coolant is a limiting factor for the lifespan of a fuel rod. Of several corrosion phenomena, oxidation of the cladding has been studied widely. It is modelled in other fuel performance codes using semiempirical models based on several decades of experimental data.&#13;\n&#13;\nThis work aims to implement cladding oxidation models in FINIX and validate them against reference data from experiments and the state-of-the-art fuel performance code FRAPCON-4.0. In addition to this, the models of cladding-coolant heat transfer and coolant conditions are updated alongside to improve the accuracy of the oxidation predictions in stand-alone simulations. The theory of the cladding oxidation, water coolant models and general structure of FINIX and reactor analysis will be studied and discussed.&#13;\n&#13;\nThe results of the initially implemented cladding oxidation models contain large errors, which indicates that FINIX does not account for the axial temperature difference between the bottom and the top of the rod in the coolant. This was corrected with the updates to the coolant models, which calculate various properties of a water coolant based on International Association for the Properties of Water and Steam (IAWPS) industrial water correlations to solve the axial temperature increase in a bulk coolant. After these updates the predictions of cladding oxidation improved and the validity of the different oxidation models were further analyzed in the context of FINIX. Cladding (metalworking) ; Coolant ; Nuclear engineering ; Environmental science ; Mechanical engineering ; Engineering ; Forensic engineering ; Materials science ; Waste management ; Metallurgy Nuclear Materials and Properties ; Nuclear reactor physics and engineering ; Heat transfer and supercritical fluids
Authors: Charles Paillard | Sergei Prokhorenko | L. Bellaïche
Source: npj Computational Materials (article, 2019-10-24)
Field: Materials Science — Polymers and Plastics

Author Correction: Strain engineering of electro-optic constants in ferroelectric materials An amendment to this paper has been published and can be accessed via a link at the top of the paper. Strain engineering ; Ferroelectricity ; Strain (injury) ; Materials science ; Engineering physics ; Engineering ; Theoretical physics ; Physics ; Mechanical engineering ; Optoelectronics ; Biology ; Dielectric Synthesis and properties of polymers ; Advanced Fiber Optic Sensors
Authors: Jill Farnsworth
Source: The Mathematics Enthusiast (article, 2019-01-01)
Field: Chemistry — Spectroscopy

NEGATIVE ALLOSTERIC MODULATION OF NMDA RECEPTORS WITH GLUN2A GAIN-OF-FUNCTION MUTATIONS N-methyl D-aspartate (NMDA) receptors are calcium permeable, glutamate-gated ion channels that mediate many forms of synaptic plasticity in the central nervous system. Due to their pivotal role in regulating synaptic plasticity, a canonical correlate of the molecular and cellular basis for learning and memory, they are implicated in the pathophysiology of various neurological disorders. Recently, advances in genome sequencing has identified the NMDA receptor to be intolerant to genetic variation, as variation often leads to disease. For example, mutations in the GluN2A subunit of the NMDA receptor are implicated in the etiology of severe epilepsy-aphasia spectrum disorders. Here we selected six gain-of-function mutations identified in patients with epilepsy-aphasia spectrum disorders and characterized their sensitivity to inhibition by GluN2A-selective negative allosteric modulators. We found that GluN2A-selective negative allosteric modulators can inhibit all the GluN2A gain-of-function-containing NMDA receptors tested, despite the location of the mutation in the receptor. However, we also found no clear evidence that transfection of GluN2A gain-of-function mutations is toxic or causes overt hyperexcitability in cultured cortical neurons or CA1 pyramidal neurons of the hippocampus. These data indicate that while GluN2A-selective negative allosteric modulators can inhibit NMDA receptors harboring GluN2A gain-of-function mutations, the presence of mutated GluN2A may not directly cause cell toxicity or hyperexcitability, at least in cultured neuronal systems. Allosteric regulation ; NMDA receptor ; Receptor ; Gain of function ; Neuroscience ; Modulation (music) ; Biology ; Chemistry ; Mutation ; Genetics ; Physics ; Gene Analytical Chemistry and Chromatography
Authors: Ionel Bogdan Guster
Source: LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) (article, 2019-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A bird's-eye view of charge and spin density waves from first principles calculations Aquesta tesi te com a objecte l'estudi de l'estructura electrònica de metalls de baixa dimensionalitat tant en la forma de monocapes com en el bulk. Aquest tipus de metalls sovint presenten inestabilitats electròniques del tipus ona de densitat de càrrega (CDW) o de espí (SDW). La major part dels esquemes teòrics utilitzats per entendre l'origen d'aquestes inestabilitats es basen en la noció de nesting de la superfície de Fermi. Tanmateix, si es considera en detall la informació experimental, en un nombre important dels materials que exhibeixen aquestes inestabilitats no es gens clar que aquest tipus de mecanisme sigui apropiat. L'objecte d'aquest treball es el de reconsiderar críticament aquesta situació, basant-se en el càlcul precís per mètodes de primers principis DFT de la funció de resposta de Lindhard i/o l'estructura de bandes de fonons.Hem estudiat un nombre considerable de materials d'aquest tipus: dicalcogenurs de metalls de transició (TiSe2, TiTe2 i NbSe2), òxids i bronzes ( bronze blau, bronzes monofosfats de tungstè, perovskites laminars AnBnO3n+2, amb B: Nb, Ti, fases de Magnéli com Mo4O11 i Mo8O23), tricalgogenurs (NbS3, NbSe3, TaS3, ZrTe3) i tetracalcogenurs de metalls de transició (TaTe4, (TaSe2)4I), conductors moleculars com les sals de Bechgaard (TMTSF)2X amb X = ClO4, NO3, PF6 ) i compostos intermetàl·lics de terres rares (LaAgSb2). En aquest document exposem en detall els nostres resultats per sis d'aquests materials: TiSe2, TiTe2, NbSe2, els bronzes blaus, les salts de Bechgaard i TaTe4.Com a resultat d'aquest treball hem pogut demostrar que: 1) El mecanisme de formació de CDW a TiSe2, TiTe2, NbSe2 i TaTe4 es degut a una inestabilitat de fonons que no te rés a veure amb el nesting de la superfície de Fermi; 2) fins a sis diferents estructures poden coexistir en l'estat CDW del NbSe2; 3) en el cas del bronze blau, es pot explicar la seva transició de Peierls sobre la base d'un mecanisme basat en un acoblament electrò-fonò feble dins l'aproximació adiabàtica i 4) la funció de resposta de Lindhard de les sals de Bechgaard canvia considerablement amb la temperatura I aquests canvis estan clarament associats amb variacións de la dimensionalitat del gas d'electrons. Humanities ; Physics ; Philosophy Organic and Molecular Conductors Research ; 2D Materials and Applications ; Molecular Junctions and Nanostructures