jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Anna S. Bondarenko | Ilias Patmanidis | Riccardo Alessandri | Paulo C. T. Souza | Thomas L. C. Jansen | Alex H. de Vries | ‪Siewert J. Marrink | Jasper Knoester
Source: Chemical Science (article, 2020-01-01)
Field: Materials Science — Biomaterials

Multiscale modeling of molecular structure and optical properties of complex supramolecular aggregates Supramolecular aggregates of synthetic dye molecules offer great perspectives to prepare biomimetic functional materials for light-harvesting and energy transport. The design is complicated by the fact that structure-property relationships are hard to establish, because the molecular packing results from a delicate balance of interactions and the excitonic properties that dictate the optics and excited state dynamics, in turn sensitively depend on this packing. Here we show how an iterative multiscale approach combining molecular dynamics and quantum mechanical exciton modeling can be used to obtain accurate insight into the packing of thousands of cyanine dye molecules in a complex double-walled tubular aggregate in close interaction with its solvent environment. Our approach allows us to answer open questions not only on the structure of these prototypical aggregates, but also about their molecular-scale structural and energetic heterogeneity, as well as on the microscopic origin of their photophysical properties. This opens the route to accurate predictions of energy transport and other functional properties. Supramolecular chemistry ; Multiscale modeling ; Molecular model ; Materials science ; Nanotechnology ; Biological system ; Chemical physics ; Chemistry ; Molecule ; Computational chemistry ; Stereochemistry ; Biology Supramolecular Self-Assembly in Materials ; Luminescence and Fluorescent Materials ; Porphyrin and Phthalocyanine Chemistry
Authors: C. Montella
Source: Journal of Electroanalytical Chemistry (article, 2020-10-21)
Field: Chemistry — Electrochemistry

Voigt circuit representation model for electrochemical impedances under finite-length diffusion conditions Chemistry ; Equivalent circuit ; Electrical impedance ; Diffusion ; Electrolyte ; Electrochemistry ; Electrode ; Representation (politics) ; Steady state (chemistry) ; Capacitance ; Constant (computer programming) ; Reaction rate constant ; Time constant ; Thermodynamics ; Analytical Chemistry (journal) ; Mechanics ; Kinetics ; Electrical engineering ; Physical chemistry ; Physics ; Voltage ; Quantum mechanics Electrochemical Analysis and Applications ; Corrosion Behavior and Inhibition ; Conducting polymers and applications
Authors: Francesca Seghetti | Rita Maria Concetta Di Martino | Elena Catanzaro | Alessandra Bisi | Silvia Gobbi | Angela Rampa | Barbara Canonico | Mariele Montanari | Dmitri V. Krysko | Stefano Papa | Carmela Fimognari | Federica Belluti
Source: Molecules (article, 2020-07-05)
Field: Chemistry — Organic Chemistry

Curcumin-1,2,3-Triazole Conjugation for Targeting the Cancer Apoptosis Machinery The burden of neoplastic diseases is widely recognized as a severe cause of mortality. The clinical inadequacy of most anticancer therapeutics urgently prompted intense drug discovery efforts toward the identification of new chemical entities endowed with a potent and safe antitumor profile. In this scenario, targeting cancer cells apoptosis machinery has emerged as a relevant strategy, useful for tackling the emergence of drug resistance. On this basis, a small library of naturally inspired hybrid molecules was obtained by combining, through a click chemistry approach, "privileged" synthons such as curcumin scaffold and 1,2,3-triazole building block. Compound <b>1</b>, bearing a <i>para</i>-fluoro phenyl moiety, showed low-micromolar potency against T acute lymphoblastic leukemia cell growth. More in-depth biologic studies demonstrated, for this analog, cell death-inducing properties associated with its capability to simultaneously activate both the receptor and the mitochondrial apoptosis cascades. This peculiar behavior offers promises for achieving an expanded anticancer effect, namely intense cytotoxic response coupled with reduced predisposition of chemoresistance insurgence. Altogether, this study allowed the identification of compound <b>1</b> as a lead compound worth to be progressed as an anticancer drug candidate. Curcumin ; Apoptosis ; Drug discovery ; Synthon ; Cancer ; Cancer cell ; Programmed cell death ; Cancer research ; Chemistry ; Drug ; Pharmacology ; Biology ; Biochemistry ; Stereochemistry ; Genetics Synthesis and Characterization of Heterocyclic Compounds ; Curcumin's Biomedical Applications ; Synthesis and biological activity
Authors: Thanh Q. Bui | Huynh Thi Phuong Loan | Tran Thi Ai My | Dương Tuấn Quang | Bùi Thị Phương Thuý | Vo Duy Nhan | Phan Tứ Quý | Phạm Văn Tất | Duy Quang Dao | Nguyễn Tiến Trung | Lam K. Huynh | Nguyen Thi Ai Nhung
Source: RSC Advances (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

A density functional theory study on silver and bis-silver complexes with lighter tetrylene: are silver and bis-silver carbenes candidates for SARS-CoV-2 inhibition? Insight from molecular docking simulation Ribavirin and remdesivir have been preclinically reported as potential drugs for the treatment of SARS-CoV-2 infection, while light silver tetrylene complexes (NHE<sub>Ph</sub>-AgCl and (NHE<sub>Ph</sub>-AgCl)<sub>2</sub> with E = C, Si, and Ge) have gained significant interest due to their promising applicability on the cytological scale. Firstly, the structures and bonding states of silver-tetrylene complexes (NHE-Ag) and bis-silver-tetrylene complexes (NHE-Ag-bis) were investigated using density functional theory (DFT) at the BP86 level with the def2-SVP and def2-TZVPP basis sets. Secondly, the inhibitory capabilities of the carbene complexes (NHC-Ag and NHC-Ag-bis) and the two potential drugs (ribavirin and remdesivir) on human-protein ACE2 and SARS-CoV-2 protease PDB6LU7 were evaluated using molecular docking simulation. The carbene ligand NHC bonds in a head-on configuration with AgCl and (AgCl)<sub>2</sub>, whereas, the other NHE (E = Si and Ge) tetrylene ligands bond in a side-on mode to the metal fragments. The bond dissociation energy (BDE) of the NHE-Ag bond in the complex families follows the order of NHC-Ag > NHSi-Ag > NHGe-Ag and NHSi-Ag-bis > NHGe-Ag-bis > NHC-Ag-bis. The natural bond orbital analysis implies that the [NHE<sub>Ph</sub>→AgCl] and [(NHE<sub>Ph</sub>)<sub>2</sub>→(AgCl)<sub>2</sub>] donations are derived mainly from the σ- and π-contributions of the ligands. The docking results indicate that both the ACE2 and PDB6LU7 proteins are strongly inhibited by silver-carbene NHC-Ag, bis-silver-carbene NHC-Ag-bis, ribavirin, and remdesivir with the docking score energy values varying from -17.5 to -16.5 kcal mol<sup>-1</sup> and -16.9 to -16.6 kcal mol<sup>-1</sup>, respectively. The root-mean-square deviation values were recorded to be less than 2 Å in all the calculated systems. Thus, the present study suggests that silver-carbene NHC-Ag and bis-silver-carbene NHC-Ag-bis complexes are potential candidates to inhibit ACE2 and PDB6LU7, and thus potentially conducive to prevent infection caused by the SARS-CoV-2 virus. Density functional theory ; Docking (animal) ; Chemistry ; Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ; Coronavirus disease 2019 (COVID-19) ; Nanotechnology ; Stereochemistry ; Computational chemistry ; Materials science ; Infectious disease (medical specialty) ; Medicine N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Catalytic Cross-Coupling Reactions ; Organometallic Complex Synthesis and Catalysis
Authors: Andrés Luengo | Isabel Marzo | Matthew L. Reback | Isabelle Marie Daubit | Vanesa Fernández‐Moreira | Nils Metzler‐Nolte | M. Concepción Gimeno
Source: Chemistry - A European Journal (article, 2020-06-16)
Field: Chemistry — Organic Chemistry

Luminescent Bimetallic Ir<sup>III</sup>/Au<sup>I</sup> Peptide Bioconjugates as Potential Theranostic Agents Diverse iridium peptide bioconjugates and the corresponding iridium/gold bimetallic complexes have been synthesized starting from a cyclometallated carboxylic acid substituted Ir<sup>III</sup> complex [Ir(ppy)<sub>2</sub> (Phen-5-COO)] by solid phase peptide synthesis (SPPS). The selected peptide sequences were an enkephalin derivative Tyr-Gly-Gly-Phe-Leu together with the propargyl-substituted species Tyr-Gly-Pgl-Phe-Leu to allow gold coordination (Pgl: propyrgyl-glycine, HC≡C-Gly), and a specific short peptide, Ala-Cys-Ala-Phen, containing a cysteine residue. Introduction of the gold center has been achieved via a click reaction with the alkynyl group leading to an organometallic Au-C(triazole) species, or by direct coordination to the sulfur atom of the cysteine. The photophysical properties of these species revealed predominantly an emission originating from the Ir complex, using mixed metal-to-ligand and ligand-to-ligand charge transfer excited states of triplet multiplicity. The formation of the peptide bioconjugates caused a systematic redshift of the emission profiles. Lysosomal accumulation was observed for all the complexes, in contrast to the expected mitochondrial accumulation triggered by the gold complexes. Only the cysteine-containing Ir/Au bioconjugate displayed cytotoxic activity. The absence of activity may be related to the lack of endosomal/lysosomal escape for the cationic peptide conjugates. Interestingly, the different coordination sphere of the gold atom may play a crucial role, as the Au-S(cysteine) bond may be more readily cleaved in a biological environment than the Au-C(triazole) bond, and thus the Au fragment could be released from or trapped in the lysosomes, respectively. This work represents a starting point in the development of bimetallic peptide bioconjugates as theranostics and in the knowledge of factors that contribute to anti-proliferative activity. Chemistry ; Peptide ; Cysteine ; Ligand (biochemistry) ; Stereochemistry ; Iridium ; Residue (chemistry) ; Coordination sphere ; Combinatorial chemistry ; Covalent bond ; Conjugated system ; Bimetallic strip ; Metal ; Organic chemistry ; Enzyme ; Biochemistry ; Catalysis ; Receptor Click Chemistry and Applications ; Chemical Synthesis and Analysis ; Advanced biosensing and bioanalysis techniques
Authors: Sogol Lotfi | Jakoah Brgoch
Source: Chemistry - A European Journal (review, 2020-03-18)
Field: Materials Science — Materials Chemistry

Discovering Intermetallics Through Synthesis, Computation, and Data‐Driven Analysis Intermetallics adopt an array of crystal structures, boast diverse chemical compositions, and possess exotic physical properties that have led to a wide range of applications from the biomedical to aerospace industries. Despite a long history of intermetallic synthesis and crystal structure analysis, identifying new intermetallic phases has remained challenging due to the prolonged nature of experimental phase space searching or the need for fortuitous discovery. In this Minireview, new approaches that build on the traditional methods for materials synthesis and characterization are discussed with a specific focus on realizing novel intermetallics. Indeed, advances in the computational modeling of solids using density functional theory in combination with structure prediction algorithms have led to new high-pressure phases, functional intermetallics, and aided experimental efforts. Furthermore, the advent of data-centered methodologies has provided new opportunities to rapidly predict crystal structures, physical properties, and the existence of unknown compounds. Describing the research results for each of these examples in depth while also highlighting the numerous opportunities to merge traditional intermetallic synthesis and characterization with computation and informatics provides insight that is essential to advance the discovery of metal-rich solids. Intermetallic ; Characterization (materials science) ; Merge (version control) ; Computer science ; Computation ; Aerospace ; Materials science ; Nanotechnology ; Engineering ; Algorithm ; Metallurgy ; Aerospace engineering Machine Learning in Materials Science ; X-ray Diffraction in Crystallography ; Crystallography and molecular interactions
Authors: N. V. Skripnyak | Alena V. Ponomareva | M. P. Belov | E.A. Syutkin | Alexandra Khvan | Alan Dinsdale | Igor A. Abrikosov
Source: Acta Materialia (article, 2020-02-01)
Field: Materials Science — Materials Chemistry

Mixing enthalpies of alloys with dynamical instability: bcc Ti-V system Materials science ; Thermodynamics ; Enthalpy ; Enthalpy of mixing ; Instability ; Ab initio quantum chemistry methods ; Lattice constant ; Lattice (music) ; Molecular dynamics ; Computational chemistry ; Physics ; Chemistry ; Molecule ; Mechanics Titanium Alloys Microstructure and Properties ; Chemical Thermodynamics and Molecular Structure ; Energetic Materials and Combustion
Authors: Shawn Zhang | Dan Wu | Liping Zhou
Source: AAPS PharmSciTech (article, 2020-07-01)
Field: Materials Science — Biomaterials

Characterization of Controlled Release Microspheres Using FIB-SEM and Image-Based Release Prediction Materials science ; Dissolution ; Dissolution testing ; Scanning electron microscope ; Porosity ; Polymer ; Controlled release ; Chemical engineering ; Characterization (materials science) ; Active ingredient ; Nanotechnology ; Composite material Nanoparticle-Based Drug Delivery ; Advanced Drug Delivery Systems ; Drug Solubulity and Delivery Systems
Authors: Susanne Sandell | Jérémie Maire | Emigdio Chávez‐Ángel | Clivia M. Sotomayor Torres | Helge Kristiansen | Zhiliang Zhang | Jianying He
Source: Nanomaterials (article, 2020-04-02)
Field: Materials Science — Materials Chemistry

Enhancement of Thermal Boundary Conductance of Metal–Polymer System In organic electronics, thermal management is a challenge, as most organic materials conduct heat poorly. As these devices become smaller, thermal transport is increasingly limited by organic-inorganic interfaces, for example that between a metal and a polymer. However, the mechanisms of heat transport at these interfaces are not well understood. In this work, we compare three types of metal-polymer interfaces. Polymethyl methacrylate (PMMA) films of different thicknesses (1-15 nm) were spin-coated on silicon substrates and covered with an 80 nm gold film either directly, or over an interface layer of 2 nm of an adhesion promoting metal-either titanium or nickel. We use the frequency-domain thermoreflectance (FDTR) technique to measure the effective thermal conductivity of the polymer film and then extract the metal-polymer thermal boundary conductance (TBC) with a thermal resistance circuit model. We found that the titanium layer increased the TBC by a factor of 2, from 59 × 10<sup>6</sup> W·m<sup>-2</sup>·K<sup>-1</sup> to 115 × 10<sup>6</sup> W·m<sup>-2</sup>·K<sup>-1</sup>, while the nickel layer increased TBC to 139 × 10<sup>6</sup> W·m<sup>-2</sup>·K<sup>-1</sup>. These results shed light on possible strategies to improve heat transport in organic electronic systems. Materials science ; Thermal conductivity ; Polymer ; Titanium ; Silicon ; Layer (electronics) ; Metal ; Composite material ; Nickel ; Conductance ; Thermal grease ; Chemical engineering ; Nanotechnology ; Optoelectronics ; Metallurgy Thermal properties of materials ; Thermal Radiation and Cooling Technologies ; Advanced Thermoelectric Materials and Devices
Authors: Benedikt Weggler | Lena Dubois | Nadine Gawlitta | Thomas Gröger | John Moncur | Luigi Mondello | Steven Reichenbach | Peter Q. Tranchida | Zhijun Zhao | Ralf Zimmermann | Mariosimone Zoccali | Jean-François Focant
Source: Journal of Chromatography A (article, 2020-11-14)
Field: Chemistry — Spectroscopy

A unique data analysis framework and open source benchmark data set for the analysis of comprehensive two-dimensional gas chromatography software Software ; Benchmarking ; Benchmark (surveying) ; Set (abstract data type) ; Gas chromatography–mass spectrometry ; Data mining ; Data set ; Computer science ; Gas chromatography ; Mass spectrometry ; Chemistry ; Chromatography ; Database ; Artificial intelligence Analytical Chemistry and Chromatography ; Advanced Chemical Sensor Technologies ; Mass Spectrometry Techniques and Applications
Authors: Mohammad Avzayesh | Mamoun F. Abdel–Hafez | Wasim M. F. Al-Masri | Mohammad Al‐Shabi | Ayman El‐Hag
Source: IEEE Transactions on Instrumentation and Measurement (article, 2020-06-01)
Field: Materials Science — Materials Chemistry

A Hybrid Estimation-Based Technique for Partial Discharge Localization This article demonstrates the use of five different methods to estimate partial discharge (PD) location in an oil insulation system from noisy measurements. The measurements are obtained from three ultrasonic sensors located in three different places. The sensors map the PD location utilizing a nonlinear model. The estimation techniques used in this article are the extended Kalman filter (EKF), the unscented Kalman filter (UKF), the smooth variable structure filter (SVSF), the EK-SVSF, and the UK-SVSF. The last two filters use the combination of EKF or UKF with SVSF, respectively, to consider possible PD model uncertainty. The proposed integrated UK-SVSF algorithm achieves the following objectives. First, the use of the Kaman-based filter enhances the optimality of the filter to system dynamics and measurements noise. Second, the use of the UKF reduces the calculation complexity and errors by replacing the Jacobian calculation with statistical linearization. Finally, the use of the SVSF enhances the estimate's robustness to model uncertainty. The experimental results verify the claim that the PD location estimate with minimum error is achieved by the UK-SVSF. Jacobian matrix and determinant ; Robustness (evolution) ; Control theory (sociology) ; Extended Kalman filter ; Kalman filter ; Linearization ; Nonlinear system ; Invariant extended Kalman filter ; Filter (signal processing) ; Unscented transform ; Computer science ; Mathematics ; Applied mathematics ; Physics High voltage insulation and dielectric phenomena ; Water Systems and Optimization ; Power Transformer Diagnostics and Insulation
Authors: Fan Yu | Guoqiang He | Xue‐Xia Yang | Jinxin Du | Steven Gao
Source: Applied Sciences (article, 2020-11-13)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Polarization-Insensitive Metasurface for Harvesting Electromagnetic Energy with High Efficiency and Frequency Stability over Wide Range of Incidence Angles In this paper, a polarization-insensitive metasurface, harvesting electromagnetic (EM) energy with high efficiency and frequency stability over a wide range of incidence angles, is proposed. The previously reported metasurfaces suffer from their maximum efficiencies shifting with the frequency when the incidence angle increases. By introducing a square-shaped metal via ring around the elements, the mutual coupling among adjacent cells is reduced so that the proposed metasurface can maintain maximum efficiency at the fixed operation frequency over a wide range of incidence angles. Furthermore, with one single harvesting via in the proper position for the connection of a harvesting load, the metasurface can collect EM energy effectively with both transverse electric (TE) and transverse magnetic (TM) polarizations in one single harvesting load. Compared with the reported metasurfaces, this proposed metasurface has a higher efficiency and fixed operation frequency within a wide incidence range. The energy distribution, harvesting efficiency, and surface current are simulated to investigate the operation mechanism of the proposed metasurface. The simulation results show that the maximum harvesting efficiency is 91% at 5.8 GHz for both TE and TM polarizations at the normal incidence. When the incident angle increases to 75°, the maximum efficiency is achieved at 5.79 GHz (0.19% shift), and the maximum efficiencies of TM and TE polarizations are 91% and 68%, respectively. A 5 × 5 array is fabricated and tested. The experimental results are in good agreement with the simulated ones. Polarization (electrochemistry) ; Optics ; Materials science ; Energy harvesting ; Range (aeronautics) ; Transverse plane ; Inductive coupling ; Optoelectronics ; Energy (signal processing) ; Physics ; Electrical engineering ; Engineering Metamaterials and Metasurfaces Applications ; Antenna Design and Analysis ; Energy Harvesting in Wireless Networks
Authors: Ana Maria Faísca Phillips | Armando J. L. Pombeiro
Source: Organic & Biomolecular Chemistry (review, 2020-01-01)
Field: Chemistry — Organic Chemistry

Electrochemical asymmetric synthesis of biologically active substances Electrically driven oxidation and reduction reactions are well-established methods for synthesis even in the chemical industry, but asymmetric versions are still few. The mild conditions used, atom efficiency and low cost make these reactions a very attractive alternative to other methods of synthesis. Very fine tuning can be achieved based on minute changes in potentials, allowing only one functional group in a molecule to react in the presence of several others, which is ideal for applications in total synthesis. In this review, the literature in the field of asymmetric synthesis of biologically active substances over the last 10 years is surveyed. Biological activity ; Electrochemistry ; Chemistry ; Nanotechnology ; Combinatorial chemistry ; Materials science ; Biochemistry ; Electrode ; In vitro Radical Photochemical Reactions ; Advanced Chemical Sensor Technologies ; Electrochemical Analysis and Applications
Authors: Judith Stickdorn | Lutz Nuhn
Source: European Polymer Journal (article, 2020-01-07)
Field: Materials Science — Biomaterials

Reactive-ester derived polymer nanogels for cancer immunotherapy Cancer immunotherapy ; Immunotherapy ; Cancer ; Drug delivery ; Materials science ; Nanomedicine ; Nanogel ; Nanotechnology ; Nanoparticle ; Medicine Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics ; Immunotherapy and Immune Responses
Authors: P. K. Sajith | Aleksandar Staykov | Masataka Yoshida | Yoshihito Shiota | Kazunari Yoshizawa
Source: The Journal of Physical Chemistry C (article, 2020-05-22)
Field: Materials Science — Materials Chemistry

Theoretical Study of the Direct Conversion of Methane to Methanol Using H<sub>2</sub>O<sub>2</sub> as an Oxidant on Pd and Au/Pd Surfaces First-principle theoretical study was performed to elucidate the reaction mechanism of the direct conversion of methane to methanol using hydrogen peroxide as an oxidant over Pd and Au/Pd catalysts. We have investigated the effect of Au-Pd alloying and its effect on the reaction steps and energetics and we have provided an understanding of the contribution of surface-exposed Au centers to the overall reaction mechanism. The hydrogen peroxide decomposition reactions to OH groups or surface-adsorbed oxo species and water molecules were compared on the Pd and Au/Pd surfaces as an important preliminary process for the methane oxidation. We have evaluated the C–H bond cleavage energetics assisted by either the OH group or oxo species over Pd and Au/Pd surfaces and compared them to the C–H cleavage energy. Our results show that the products of hydrogen peroxide decomposition significantly reduce the high activation barrier for the hydrogen atom abstraction from methane. The recombination of methyl group and OH group was found to be the rate-determining step for the methanol formation. The proposed reaction pathway in our work provides important insights into the oxidation mechanism by hydrogen peroxide and the fine-tuning of the Pd catalyst by other alloying elements such as Au. Chemistry ; Catalysis ; Hydrogen peroxide ; Methanol ; Methane ; Adsorption ; Reaction mechanism ; Decomposition ; Hydrogen ; Inorganic chemistry ; Photochemistry ; Bond cleavage ; Hydrogen atom abstraction ; Peroxide ; Physical chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Electrocatalysts for Energy Conversion