jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Olli-Pekka Koistinen | Vilhjálmur Ásgeirsson | Aki Vehtari | Hannes Jónsson
Source: Journal of Chemical Theory and Computation (article, 2019-12-04)
Field: Materials Science — Materials Chemistry

Minimum Mode Saddle Point Searches Using Gaussian Process Regression with Inverse-Distance Covariance Function The minimum mode following method can be used to find saddle points on an energy surface by following a direction guided by the lowest curvature mode. Such calculations are often started close to a minimum on the energy surface to find out which transitions can occur from an initial state of the system, but it is also common to start from the vicinity of a first-order saddle point making use of an initial guess based on intuition or more approximate calculations. In systems where accurate evaluations of the energy and its gradient are computationally intensive, it is important to exploit the information of the previous evaluations to enhance the performance. Here, we show that the number of evaluations required for convergence to the saddle point can be significantly reduced by making use of an approximate energy surface obtained by a Gaussian process model based on inverse interatomic distances, evaluating accurate energy and gradient at the saddle point of the approximate surface and then correcting the model based on the new information. The performance of the method is tested with start points chosen randomly in the vicinity of saddle points for dissociative adsorption of an H<sub>2</sub> molecule on the Cu(110) surface and three gas phase chemical reactions. Saddle point ; Covariance ; Saddle ; Inverse ; Maxima and minima ; Curvature ; Gaussian process ; Gaussian ; Computer science ; Statistical physics ; Mathematics ; Physics ; Mathematical optimization ; Mathematical analysis ; Geometry ; Statistics ; Quantum mechanics Machine Learning in Materials Science ; Advanced Multi-Objective Optimization Algorithms ; Advanced Chemical Physics Studies
Authors: Patricia Shapley
Source: Online Learning (article, 2019-03-19)
Field: Chemistry — Physical and Theoretical Chemistry

Online Education to Develop Complex Reasoning Skills in Organic Chemistry Chemistry 331 is an upper level organic chemistry course for students interested in health-related careers with an enrollment of approximately 150 students per semester. It assumes that students have a basic knowledge of organic chemistry principles and concepts and it builds on this base with advanced concepts in organic synthesis, mechanism of reactions, and spectroscopy with a biological perspective. Three years ago we moved to an online format to better serve the needs of students with disparate backgrounds and to help them master the concepts and applications of organic chemistry at an advanced level. The course includes online lectures with embedded problems, computer-graded quizzes, and online discussion sections. he exams are in the standard format and are proctored on campus or in off-campus testing centers. The format of the course increases flexibility for the students, increases interaction among students and between students and faculty, and improves student performance on examinations that require complex reasoning skills. Flexibility (engineering) ; Mathematics education ; Perspective (graphical) ; Chemistry education ; Chemistry ; Computer science ; Psychology ; Mathematics ; Artificial intelligence Various Chemistry Research Topics ; Innovative Teaching Methods ; Problem and Project Based Learning
Authors: Victoria Borkovskaya | Elena Lyapuntsova | Maxim A. Nogovitsyn
Source: E3S Web of Conferences (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Risks and safety in construction by increasing efficiency of investments This study focuses on enhancing the effectiveness of investment in construction given the constant threat of new risks. We investigate the types and causes of risks of firms working in the construction industry, draw conclusions about the importance of risks associated with the investment attractiveness of projects, as well as responsibility for the environmental safety. Urbanization and changes in the surrounding area are the dominant trend in the development of modern society. The constant demand of business for commercial real estate, as well as the increase in population growth demands enhanced effectiveness in the construction market, where supply in construction market depends on the economic conditions. The relevance of the research topic is due to the fact that the increasing capital flows in the construction industry pose new challenges for forecasting, statistics and risk control, and a focus on the rates of return mechanisms to hedge against the uncertainty of the future. The aim of the study is a systematic integrated approach to solving problems to improve the efficiency and effectiveness of investments and their protection using a methodological systematic approach, which considers the components of an integrated investment process. We propose a model of risk hedging management, and focus on an analytical methodology of the most relevant risks in modern construction. Hedge ; Real estate ; Investment (military) ; Attractiveness ; Risk analysis (engineering) ; Business ; Risk management ; Population ; Industrial organization ; Environmental economics ; Economics ; Finance Structural mechanics and materials ; Educational Methods and Teacher Development ; Advanced Energy Technologies and Civil Engineering Innovations
Authors: Hui Wang | Du Lv | Nan Dong | Sijie Wang | Jia Liu
Source: Food Science and Biotechnology (article, 2019-02-23)
Field: Chemistry — Analytical Chemistry

Application of near-infrared spectroscopy for screening the potato flour content in Chinese steamed bread Chemometrics ; Partial least squares regression ; Near-infrared spectroscopy ; Spectroscopy ; Chemistry ; Calibration ; Analytical Chemistry (journal) ; Food science ; Coefficient of determination ; Content (measure theory) ; Mathematics ; Water content ; Chromatography ; Statistics ; Biology Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Water Quality Monitoring and Analysis
Authors: Aakash Gupta | Agni Raj Koirala | Bikash Gupta | Niranjan Parajuli
Source: Acta Chemica Malaysia (article, 2019-06-01)
Field: Materials Science — Materials Chemistry

Improved method for separation of silver nanoparticles synthesized using the Nyctanthes arbor-tristis shrub Abstract Plant-mediated synthesis of silver nanoparticles through green chemistry approach has evolved into a new era of research; however, the heterogeneous size and dispersity of silver nanoparticles have limited its applications, such as surface-enhanced Raman scattering, plasmon resonance, and more specifically in the medical field of target drug delivery and therapeutic activity. Here-we investigated the effect of purification and separation modes on the dispersity, size, and morphology of silver nanoparticles, synthesized by plant extract ( Nyctanthes arbor-tristis ). Transmission electron microscopy revealed silver nanoparticles with an average diameter of 13.0 nm when synthesized through ethanol precipitation, which is advantageously smaller. This result suggests that the silver nanoparticles size can be fine-tuned by changing the separation mode during purification from plant extract. Due to uniformity, our obtained nanoparticles can be expected to show higher catalytic activity towards photochemical reactions, drug delivery and antibacterial activity due to the absence of inactive coating layer (capping agent). Dispersity ; Silver nanoparticle ; Nanoparticle ; Transmission electron microscopy ; Surface plasmon resonance ; Drug delivery ; Nanotechnology ; Precipitation ; Chemical engineering ; Materials science ; Catalysis ; Coating ; Nuclear chemistry ; Chemistry ; Organic chemistry ; Polymer chemistry Nanoparticles: synthesis and applications
Authors: Junji Li | Xiaoyang Tian | Li-Ping Zong | Qiang Zhang | Xueji Zhang | Robert S. Marks | Serge Cosnier | Dan Shan
Source: ACS Applied Materials & Interfaces (article, 2019-08-09)
Field: Materials Science — Surfaces, Coatings and Films

Uniform and Easy-To-Prepare Glycopolymer-Brush Interface for Rapid Protein (Anti-)Adhesion Sensing Glycopolymers have emerged as powerful and versatile glycan analogues for the investigation of cellular signal transduction. In this study, a layer of the glycopolymer-brush (GlyB) interface was functionalized on the surface of gold substrates. In order to enhance the capability and accessibility of this transducer interface, a combined protocol of copper(0)-mediated living radical polymerization (Cu(0)-LRP) with subsequent "CuAAC" click reaction was utilized to synthesize a set of novel glycopolymer precursors with a tunable scaffold structure and pyranose ligands. The resulting glycopolymer exhibited a fine-tuned molecular weight with a minor dispersity of 1.27. Through surface plasmon resonance (SPR) analysis, various GlyB interfaces exhibiting different saccharide moieties (glucose, mannose, and galactose) were examined to study their adhesion or antiadhesion potential toward three types of proteins, concanavalin A, bovine serum albumin, and peanut agglutinin (PNA). The strong affinity between poly(galactose) and PNA was further employed to construct a proof-of-concept aggregation-mediated sensing system. This minimal naked-eye sensor that consisted of only two substances, namely, gold nanoparticles and glycopolymers, was characterized and tested for its potential in protein quantification. Glycopolymer ; Surface plasmon resonance ; Materials science ; Peanut agglutinin ; Adhesion ; Concanavalin A ; Glycan ; Dispersity ; Biophysics ; Nanotechnology ; Lectin ; Combinatorial chemistry ; Polymerization ; Polymer chemistry ; Nanoparticle ; Chemistry ; Polymer ; Biochemistry ; Glycoprotein ; Biology Polymer Surface Interaction Studies ; Advanced biosensing and bioanalysis techniques ; Molecular Junctions and Nanostructures
Authors: Vishwanath Hiremath | Virendrakumar G. Deonikar | Hern Kim | Jeong Gil Seo
Source: Colloids and Surfaces A Physicochemical and Engineering Aspects (article, 2019-11-05)
Field: Materials Science — Materials Chemistry

Hierarchically assembled porous TiO2 nanoparticles with enhanced photocatalytic activity towards Rhodamine-B degradation Photocatalysis ; Rhodamine B ; Materials science ; Anatase ; Crystallite ; Chemical engineering ; Adsorption ; Mesoporous material ; Hydrothermal circulation ; Nanoparticle ; Titanium ; Porosity ; Nanotechnology ; Chemistry ; Catalysis ; Organic chemistry ; Metallurgy ; Composite material Advanced Nanomaterials in Catalysis ; Advanced Photocatalysis Techniques ; TiO2 Photocatalysis and Solar Cells
Authors: Martin Petr | Petr Jakubec | Václav Ranc | Veronika Šedajová | Rostislav Langer | Miroslav Medveď | Piotr Błoński | Josef Kašlík | Vojtěch Kupka | Michal Otyepka | Radek Zbořil
Source: Nanoscale (article, 2019-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Thermally reduced fluorographenes as efficient electrode materials for supercapacitors There is an urgent need for a simple and up-scalable method for the preparation of supercapacitor electrode materials due to increasing global energy consumption worldwide. We have discovered that fluorographene exhibits great potential for the development of new kinds of supercapacitors aimed at practical applications. We have shown that time control of isothermal reduction of fluorographite at 450 °C under a hydrogen atmosphere led to the fine-tuning of fluorine content and electronic properties of the resulting fluorographene derivatives. Charge transfer resistances (R<sub>ct</sub>) of the thermally reduced fluorographenes (TRFGs) were decreased with respect to the pristine fluorographene; however, the R<sub>ct</sub>vs. time-of-reduction plot showed a v-shaped profile. The specific capacitance vs. time-of-reduction of TRFG followed the v-shaped trend, which could be the result of the decreasing content of sp<sup>3</sup> carbons and increasing content of structural defects. An optimized material exhibited values of specific capacitance up to 539 F g<sup>-1</sup> recorded at a current density of 0.25 A g<sup>-1</sup> and excellent cycling durability with 100% specific capacitance retention after 1500 cycles in a three-electrode configuration and 96.7% of specific capacitance after 30 000 cycles in a two-electrode setup. Supercapacitor ; Materials science ; Electrode ; Nanotechnology ; Scalability ; Simple (philosophy) ; Capacitance ; Computer science ; Chemistry Supercapacitor Materials and Fabrication ; Advanced Sensor and Energy Harvesting Materials ; Graphene research and applications
Authors: Kun Zhang | Gao‐Peng Li | Cheng Zhang | Yao‐Yu Wang
Source: Dalton Transactions (article, 2019-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Dramatic impact of auxiliary ligands on the two-step magnetic relaxation process in Dy<sub>4</sub>(<scp>iii</scp>) single-molecule magnets To better understand the factors determining the multi-step relaxation processes in polynuclear lanthanide single molecule magnets (SMMs), two Dy(iii)4 SMMs showing two-step relaxation processes were elaborately designed and investigated for their structure-dependent magnetic properties. Through targetedly fine-tuning the auxiliary ligand (from the anion of 1-phenylbutane-1,3-dione to 2-acetylcyclopentanone) on specific Dy(iii) sites while retaining the same type of coordination atoms, one of the two relaxation processes shifted to higher temperature with an increase of energy barrier, which permits the unambiguous assignment of the relaxation processes to specific metal sites. Therefore, the present {Dy4} systems provide a good example to probe the factors determining the relaxation dynamics, and point to a simple way to optimize the magnetic performance of polynuclear dysprosium SMMs. Magnetic relaxation ; Magnet ; Relaxation (psychology) ; Lanthanide ; Molecule ; Crystallography ; Chemistry ; Single-molecule magnet ; Process (computing) ; Materials science ; Nanotechnology ; Magnetization ; Physics ; Magnetic field ; Ion ; Computer science ; Organic chemistry ; Quantum mechanics Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Advanced NMR Techniques and Applications
Authors: Sangheon Lee | Joseph C. Flanagan | Jaewook Kim | Alan Jiwan Yun | Byung-Ho Lee | Moonsub Shim | Byungwoo Park
Source: ACS Applied Materials & Interfaces (article, 2019-05-08)
Field: Materials Science — Materials Chemistry

Efficient Type-II Heterojunction Nanorod Sensitized Solar Cells Realized by Controlled Synthesis of Core/Patchy-Shell Structure and CdS Cosensitization Here, we report the successful application of core/patchy-shell CdSe/CdSe <sub>x</sub>Te<sub>1- x</sub> type-II heterojunction nanorods (HNRs) to realize efficient sensitized solar cells. The core/patchy-shell structure designed to have a large type-II heterointerface without completely shielding the CdSe core significantly improves photovoltaic performance compared to other HNRs with minimal or full-coverage shells. In addition, cosensitization with CdS grown by successive ionic layer adsorption and reaction further improves the power conversion efficiency. One-diode model analysis reveals that the HNRs having exposed CdSe cores and suitably grown CdS result in significant reduction of series resistance. Investigation of the intercorrelation between diode quality parameters, diode saturation current density ( J<sub>0</sub>) and recombination order (β = (ideality factor)<sup>-1</sup>) reveals that HNRs with open CdSe cores exhibit reduced recombination. These results confirm that the superior performance of core/patchy-shell HNRs results from their fine-tuned structure: photocurrent is increased by the large type-II heterointerface and recombination is effectively suppressed due to the open CdSe core enabling facile electron extraction. An optimized power conversion efficiency of 5.47% (5.89% with modified electrode configuration) is reported, which is unmatched among photovoltaics utilizing anisotropic colloidal heterostructures as light-harvesting materials. Materials science ; Nanorod ; Heterojunction ; Nanotechnology ; Core (optical fiber) ; Optoelectronics ; Solar cell ; Shell (structure) ; Dye-sensitized solar cell ; Electrode ; Composite material Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Copper-based nanomaterials and applications
Authors: Jhen‐Yi Lee | Yong‐Siang Su | Yu‐Shan Wang | Hon Man Lee
Source: Advanced Synthesis & Catalysis (article, 2019-08-18)
Field: Chemistry — Organic Chemistry

Tetranuclear Palladium Complexes of Abnormal <i>N</i>‐Heterocyclic Carbene Ligands and their Catalytic Activities in Mizoroki‐Heck Coupling Reaction of Electron‐Rich Aryl Chlorides Abstract Based on the ligand scaffold of an imidazolyl/benziimidazolyl moiety and a N ‐CH 2 C(=O)NHPh substituent, two series of ligand precursors with ortho hydroxy groups incorporated on the N ‐phenyl rings were prepared. The structural fine tuning of the ligand scaffold allowed the synthesis of tetranuclear palladium complexes with abnormal N ‐heterocyclic carbene ( a NHC) ligands. For precursors with C2‐methyl blocking groups, pyridine‐assisted C−H bond activation led to the formation of mononuclear tridentate palladium a NHC complexes or tetranuclear complexes with tridentate CNO donors. Representative mononuclear and tetranuclearpalladium a NHC complexes were structurally characterized by X‐ray diffraction studies, revealing very short Pd−C bond distances. The tetranuclear palladium a NHC complexes were very effective in catalyzing Mizoroki‐Heck coupling reaction, and were capable of employing a range of aryl chlorides including deactivated substrates with low palladium loading of 0.2 mol%. magnified image Chemistry ; Palladium ; Carbene ; Aryl ; Heck reaction ; Moiety ; Ligand (biochemistry) ; Substituent ; Pyridine ; Medicinal chemistry ; Migratory insertion ; Coupling reaction ; Catalysis ; Stereochemistry ; Combinatorial chemistry ; Organic chemistry Catalytic Cross-Coupling Reactions ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Catalytic C–H Functionalization Methods
Authors: Monica Lestari | Matteo Lusi
Source: Chemical Communications (article, 2019-01-01)
Field: Chemistry — Organic Chemistry

A mixed molecular salt of lithium and sodium breaks the Hume-Rothery rules for solid solutions The first molecular solid solution of lithium and sodium ions is reported. In spite of the different chemical and structural properties of the parent compounds, the two cations form a homogeneous mixed phase with the isoorotate ion. Such observation appears in contrast with the Hume-Rothery principles for solid solutions. Furthermore the mixed salts in the series are thermally stable up to 100 °C and non-hygroscopic, which makes them relevant for their potential use as a lithium drug substance. Lithium (medication) ; Salt (chemistry) ; Sodium ; Sodium salt ; Chemistry ; Inorganic chemistry ; Materials science ; Chemical engineering ; Organic chemistry ; Psychology Coordination Chemistry and Organometallics ; Crystallography and molecular interactions ; Crystallization and Solubility Studies
Authors: Michael Sun | Anirban Sen Gupta
Source: Seminars in Thrombosis and Hemostasis (review, 2019-06-14)
Field: Materials Science — Biomaterials

Vascular Nanomedicine: Current Status, Opportunities, and Challenges The term "nanotechnology" was coined by Norio Taniguchi in the 1970s to describe the manipulation of materials at the nano (10<sup>-9</sup>) scale, and the term "nanomedicine" was put forward by Eric Drexler and Robert Freitas Jr. in the 1990s to signify the application of nanotechnology in medicine. Nanomedicine encompasses a variety of systems including nanoparticles, nanofibers, surface nano-patterning, nanoporous matrices, and nanoscale coatings. Of these, nanoparticle-based applications in drug formulations and delivery have emerged as the most utilized nanomedicine system. This review aims to present a comprehensive assessment of nanomedicine approaches in vascular diseases, emphasizing particle designs, therapeutic effects, and current state-of-the-art. The expected advantages of utilizing nanoparticles for drug delivery stem from the particle's ability to (1) protect the drug from plasma-induced deactivation; (2) optimize drug pharmacokinetics and biodistribution; (3) enhance drug delivery to the disease site via passive and active mechanisms; (4) modulate drug release mechanisms via diffusion, degradation, and other unique stimuli-triggered processes; and (5) biodegrade or get eliminated safely from the body. Several nanoparticle systems encapsulating a variety of payloads have shown these advantages in vascular drug delivery applications in preclinical evaluation. At the same time, new challenges have emerged regarding discrepancy between expected and actual fate of nanoparticles in vivo, manufacturing barriers of complex nanoparticle designs, and issues of toxicity and immune response, which have limited successful clinical translation of vascular nanomedicine systems. In this context, this review will discuss challenges and opportunities to advance the field of vascular nanomedicine. Nanomedicine ; Drug delivery ; Nanotechnology ; Context (archaeology) ; Biodistribution ; Drug ; Nanoparticle ; Materials science ; Medicine ; Pharmacology ; In vivo ; Biotechnology ; Biology Nanoparticle-Based Drug Delivery ; Electrospun Nanofibers in Biomedical Applications ; Extracellular vesicles in disease