jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: S. Turnage | M. Rajagopalan | K. Darling | Pulkit Garg | C. Kale | B. Gholami Bazehhour | I. Adlakha | B.C. Hornbuckle | Cyril L. Williams | Pedro Peralta | K.N. Solanki
Source: Nature Communications (article, 2018-07-06)
Field: Materials Science — Materials Chemistry

Anomalous mechanical behavior of nanocrystalline binary alloys under extreme conditions Fundamentally, material flow stress increases exponentially at deformation rates exceeding, typically, ~10<sup>3</sup> s<sup>-1</sup>, resulting in brittle failure. The origin of such behavior derives from the dislocation motion causing non-Arrhenius deformation at higher strain rates due to drag forces from phonon interactions. Here, we discover that this assumption is prevented from manifesting when microstructural length is stabilized at an extremely fine size (nanoscale regime). This divergent strain-rate-insensitive behavior is attributed to a unique microstructure that alters the average dislocation velocity, and distance traveled, preventing/delaying dislocation interaction with phonons until higher strain rates than observed in known systems; thus enabling constant flow-stress response even at extreme conditions. Previously, these extreme loading conditions were unattainable in nanocrystalline materials due to thermal and mechanical instability of their microstructures; thus, these anomalies have never been observed in any other material. Finally, the unique stability leads to high-temperature strength maintained up to 80% of the melting point (~1356 K). Materials science ; Strain rate ; Nanocrystalline material ; Dislocation ; Microstructure ; Deformation (meteorology) ; Flow stress ; Instability ; Brittleness ; Plasticity ; Stress (linguistics) ; Arrhenius equation ; Portevin–Le Chatelier effect ; Composite material ; Condensed matter physics ; Mechanics ; Dynamic strain aging ; Nanotechnology ; Physics ; Classical mechanics Microstructure and mechanical properties ; Advanced materials and composites ; High-Velocity Impact and Material Behavior
Authors: Yuan Ou | Kai Chen | Hao Cai | Hu Zhang | Qiyong Gong | Jian Wang | Wei Chen | Kui Luo
Source: Biomaterials Science (article, 2018-01-01)
Field: Materials Science — Biomaterials

Enzyme/pH-sensitive polyHPMA–DOX conjugate as a biocompatible and efficient anticancer agent In this study, to enhance the therapeutic function and reduce the side-effects of doxorubicin (DOX), a biodegradable N-(2-hydroxypropyl) methacrylamide (HPMA) polymer-DOX conjugate has been prepared through reversible addition fragmentation chain transfer (RAFT) polymerization and conjugation chemistry, and the anticancer agent DOX was covalently linked to the polymeric vehicle through a pH-responsive hydrazone bond. The cellular mechanisms of the conjugate were explored, and the therapeutic indexes were studied as well. The high molecular weight (MW) polymeric conjugate (94 kDa) was degraded into products with low MW (45 kDa) in the presence of lysosomal cathepsin B and also showed pH-responsive drug release behavior. In vitro cellular mechanism studies revealed that the polymeric conjugate was uptaken by the 4T1 cells, leading to cell apoptosis and cytotoxicity to cancer cells, while the polymeric conjugate demonstrated excellent in vivo biosafety even at a high dose. Compared to free DOX, the conjugate has a much longer half-life in pharmacokinetics and accumulates in tumors with a much higher amount. The conjugate therefore has a much greater in vivo anticancer efficacy against 4T1 xenograft tumors and shows subtle side-effects, which were confirmed via tumor size and weight, immunohistochemistry and histological studies. Overall, this polymeric conjugate may be used as an enzyme/pH-sensitive anticancer agent. Biocompatible material ; Conjugate ; Enzyme ; Chemistry ; Combinatorial chemistry ; Biochemistry ; Medicine ; Biomedical engineering Nanoparticle-Based Drug Delivery ; Graphene and Nanomaterials Applications ; Nanoplatforms for cancer theranostics
Authors: Shuang‐Shuang Hou | Bien Tan
Source: Macromolecules (article, 2018-04-04)
Field: Materials Science — Materials Chemistry

Naphthyl Substitution-Induced Fine Tuning of Porosity and Gas Uptake Capacity in Microporous Hyper-Cross-Linked Amine Polymers Exploring the effect of functional group substitution on the porous structure and gas adsorption performance of polymer materials is becoming much fascinating. Here, three novel polymers, based on various amine building blocks, were efficiently prepared by the solvent knitting method. It is intriguingly found that with the gradual functional group substitution of phenyl by naphthyl in building blocks both porosity and gas uptake capacity of these hyper-cross-linked polymers can be finely tuned, with SBET increased from 874 to 1717 m2 g–1, and CO2 adsorption capacity tuned from 12.76 to 18.85 wt % (273.15 K/1.00 bar). Besides, these polymers could reveal CO2/N2 selectivity up to 24.9 and CO2/CH4 selectivity of 6.3 at 298.15 K. This work has proved that increasing the number of naphthyl in precursors will be in favor of knitting microporous with improved porosity and enhanced gas uptake ability, and naphthyl outweighs phenyl in their contributions to bettering the porosity parameters and gas uptake capacity of synthesized polymers, which is crucially important for the further research. Microporous material ; Polymer ; Porosity ; Selectivity ; Amine gas treating ; Solvent ; Chemical engineering ; Adsorption ; Materials science ; Polymer chemistry ; Chemistry ; Porous medium ; Organic chemistry ; Catalysis Covalent Organic Framework Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Membrane Separation and Gas Transport
Authors: Naoki Hashimoto | Rika Umano | Yusuke Ochi | Kiyoka Shimahara | Jun Nakamura | Shigeki Mori | Hidetoshi Ohta | Yutaka Watanabe | Minoru Hayashi
Source: Journal of the American Chemical Society (article, 2018-02-05)
Field: Chemistry — Spectroscopy

Synthesis and Photophysical Properties of λ<sup>5</sup>-Phosphinines as a Tunable Fluorophore A practical synthesis of a variety of λ<sup>5</sup>-phosphinines, which show distinct fluorescence both in solution and solid state, is described. Both C4-selective electrophilic substitutions and the following conversions realized an easy preparation of a wide range of derivatives having several substituents for electronic modification, which provides the potential for fine-tuning of the photophysical properties. Chemistry ; Fluorophore ; Electrophile ; Fluorescence ; Solid-state ; Photochemistry ; Combinatorial chemistry ; Range (aeronautics) ; Organic chemistry ; Physical chemistry ; Catalysis Molecular Sensors and Ion Detection ; Organophosphorus compounds synthesis ; Luminescence and Fluorescent Materials
Authors: Zong‐Ying Liu | Jiun‐Wei Hu | Chi‐Lin Chen | Yi‐An Chen | Kew‐Yu Chen | Pi‐Tai Chou
Source: The Journal of Physical Chemistry C (article, 2018-09-05)
Field: Chemistry — Physical and Theoretical Chemistry

Correlation among Hydrogen Bond, Excited-State Intramolecular Proton-Transfer Kinetics and Thermodynamics for −OH Type Proton-Donor Molecules A series of new molecules bearing alkyl-substitutes on the parent molecule 1-hydroxy-11H-benzo[b]fluoren-11-one (HBF) has been designed and synthesized, which possesses an intramolecular hydrogen bond (H-bond) between −OH proton donor and carbonyl proton acceptor. All studied molecules present an equilibrium type of excited-state intramolecular proton transfer (ESIPT) at 298 K. The alkyl-substitutions at various positions subtly alter the intramolecular H-bond strength, which then fine-tune the excited-state equilibrium and hence thermodynamics between normal and tautomer species. These, in combination with finite rates of ESIPT resolved by femtosecond fluorescence upconversion techniques, lead to the establishment of an empirical relationship among H-bond strengths, ESIPT kinetics, and thermodynamics for HBF series of molecules, in which the stronger H-bond is, the faster and more exergonic ESIPT is. The intensity ratio for normal versus proton-transfer tautomer emission can be systematically tuned, demonstrating the harness of −OH type ESIPT reaction via facile alkyl-substituent perturbation. Intramolecular force ; Exergonic reaction ; Tautomer ; Chemistry ; Hydrogen bond ; Molecule ; Photochemistry ; Alkyl ; Substituent ; Excited state ; Proton ; Stereochemistry ; Organic chemistry ; Catalysis ; Atomic physics Photochemistry and Electron Transfer Studies ; Porphyrin and Phthalocyanine Chemistry ; Free Radicals and Antioxidants
Authors: Zemin Xu | Chaonan Chen | Zhewei Wang | Ke Wu | Haining Chong | Hui Ye
Source: RSC Advances (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

Optical constants acquisition and phase change properties of Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub> thin films based on spectroscopy In this work, phase change chalcogenide Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub> (GST) thin films were fabricated by magnetron sputtering. The optical properties, especially the optical constants (refractive index and extinction coefficient), of such alloys were systematically studied by investigating their thermally and photo-thermally induced switching between different phases. The results show that GST films are highly tunable in microstructure and optical constants, either by post-annealing at 160 °C, 200 °C, 250 °C and 350 °C, respectively, or by laser irradiation of 1 mW, 3 mW, 5 mW and 10 mW power with beam diameter of 7 μm at 532 nm, respectively. From the structural analysis, we can clearly observe different crystallinities and chemical bonding in the different post-treated GST films. The optical constants of GST films under various phases were obtained from spectrophotometry, by fitting their transmittance data with the Tauc-Lorentz (TL) dispersion model. The refractive index and extinction coefficient exhibit notable change upon annealing and laser irradiation, specifically at 1550 nm, from 3.85 (amorphous) to 6.5 (crystalline) in refractive index. The optical constants have been proved capable of fine tuning <i>via</i> the laser irradiation method. Hence, the pronounced adjustability in optical properties due to rapid and repeatable phase change render GST suitable for tunable photonic devices. Spectroscopy ; Phase change ; Materials science ; Analytical Chemistry (journal) ; Phase (matter) ; Thin film ; Constant (computer programming) ; Chemistry ; Physics ; Engineering physics ; Nanotechnology ; Computer science ; Environmental chemistry Phase-change materials and chalcogenides ; Nonlinear Optical Materials Studies ; Chalcogenide Semiconductor Thin Films
Authors: Justin M. Di Trani | Stéphane De Cesco | Rebecca O’Leary | Jessica Plescia | Cláudia Jorge do Nascimento | Nicolas Moitessier | Anthony Mittermaier
Source: Nature Communications (article, 2018-02-23)
Field: Chemistry — Physical and Theoretical Chemistry

Rapid measurement of inhibitor binding kinetics by isothermal titration calorimetry Although drug development typically focuses on binding thermodynamics, recent studies suggest that kinetic properties can strongly impact a drug candidate's efficacy. Robust techniques for measuring inhibitor association and dissociation rates are therefore essential. To address this need, we have developed a pair of complementary isothermal titration calorimetry (ITC) techniques for measuring the kinetics of enzyme inhibition. The advantages of ITC over standard techniques include speed, generality, and versatility; ITC also measures the rate of catalysis directly, making it ideal for quantifying rapid, inhibitor-dependent changes in enzyme activity. We used our methods to study the reversible covalent and non-covalent inhibitors of prolyl oligopeptidase (POP). We extracted kinetics spanning three orders of magnitude, including those too rapid for standard methods, and measured sub-nM binding affinities below the typical ITC limit. These results shed light on the inhibition of POP and demonstrate the general utility of ITC-based enzyme inhibition kinetic measurements. Isothermal titration calorimetry ; Kinetics ; Calorimetry ; Titration ; Chemistry ; Isothermal process ; Biophysics ; Thermodynamics ; Physical chemistry ; Biology ; Physics thermodynamics and calorimetric analyses ; Computational Drug Discovery Methods ; Protein purification and stability
Authors: Lan Yang | Changhua Zhu | Ye Sheng | Hongqiang Nian | Qian Li | Peng Song | Wencong Lu | Jiong Yang | Bin Liu
Source: Journal of the American Ceramic Society (article, 2018-09-16)
Field: Materials Science — Materials Chemistry

Investigation of mechanical and thermal properties of rare earth pyrochlore oxides by first‐principles calculations Abstract The pyrochlore‐type rare‐earth oxides attract considerable attentions due to their outstanding properties and extensive applications. In this work, contour maps of mechanical/thermal properties as a function of A and B cation radii across a wide variety of A 2 B 2 O 7 ( A = La‐Lu and Y; B = Ti, Sn, Hf, Zr, Pr and Ce) pyrochlore oxides are studied using the first‐principles calculations. The mechanical/thermal properties vary dramatically with increasing of the B cation sizes but do not show a strong systematic dependence on the A cation sizes. Furthermore, the machine learning algorithm is performed for the large family of pyrochlores and the parameters playing key role on mechanical/thermal properties are clarified. Besides, the expressions of focused mechanical and thermal properties are constructed. These results are expected to guide the future material design through composition tailoring. Pyrochlore ; Thermal ; Materials science ; Rare earth ; Work (physics) ; Thermodynamics ; Mineralogy ; Metallurgy ; Chemistry ; Physics Nuclear materials and radiation effects ; Nuclear Materials and Properties ; Advanced Condensed Matter Physics
Authors: Noryani Muhammad | S.M. Sapuan | Mastura Mohammad Taha
Source: JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES (review, 2018-03-31)
Field: Materials Science — Materials Chemistry

Multi-criteria decision-making tools for material selection of natural fibre composites: A review Materials selection in manufacturing process is an important stage and should be performed in parallel with selection of manufacturing process. In automotive industry, production of green automotive component could utilize the natural sources such as plant fibres. In recent years, several multi-criteria decision-making (MCDM) techniques are suggested to choose the best materials for particular application. Materials selection tools for natural fibre composites are studied from past researchers with the summary of the advantage and disadvantages. In addition, new optimization approach in materials selection by using statistical analysis such as multiple linear regression (MLR), responsesurface methodology (RSM) and Taguchi method (TM) is proposed in this study. The proposed method could evaluate the criteria or attribute in materials selection precisely by analyse the relationship of the parameters, goodness of fit, correlation, analysis of variance (ANOVA), determination of coefficient and the significant criteria in to the desired goal of the design problem. Taguchi methods ; Multiple-criteria decision analysis ; Automotive industry ; Selection (genetic algorithm) ; Design of experiments ; Computer science ; Process (computing) ; Orthogonal array ; Material selection ; Manufacturing engineering ; Process engineering ; Engineering ; Operations research ; Machine learning ; Materials science ; Mathematics ; Statistics ; Composite material Material Selection and Properties ; Natural Fiber Reinforced Composites ; Multi-Criteria Decision Making
Authors: Oliver M. Crook | Claire M. Mulvey | Paul Kirk | Kathryn S. Lilley | Laurent Gatto
Source: PLoS Computational Biology (article, 2018-11-27)
Field: Chemistry — Spectroscopy

A Bayesian mixture modelling approach for spatial proteomics Analysis of the spatial sub-cellular distribution of proteins is of vital importance to fully understand context specific protein function. Some proteins can be found with a single location within a cell, but up to half of proteins may reside in multiple locations, can dynamically re-localise, or reside within an unknown functional compartment. These considerations lead to uncertainty in associating a protein to a single location. Currently, mass spectrometry (MS) based spatial proteomics relies on supervised machine learning algorithms to assign proteins to sub-cellular locations based on common gradient profiles. However, such methods fail to quantify uncertainty associated with sub-cellular class assignment. Here we reformulate the framework on which we perform statistical analysis. We propose a Bayesian generative classifier based on Gaussian mixture models to assign proteins probabilistically to sub-cellular niches, thus proteins have a probability distribution over sub-cellular locations, with Bayesian computation performed using the expectation-maximisation (EM) algorithm, as well as Markov-chain Monte-Carlo (MCMC). Our methodology allows proteome-wide uncertainty quantification, thus adding a further layer to the analysis of spatial proteomics. Our framework is flexible, allowing many different systems to be analysed and reveals new modelling opportunities for spatial proteomics. We find our methods perform competitively with current state-of-the art machine learning methods, whilst simultaneously providing more information. We highlight several examples where classification based on the support vector machine is unable to make any conclusions, while uncertainty quantification using our approach provides biologically intriguing results. To our knowledge this is the first Bayesian model of MS-based spatial proteomics data. Markov chain Monte Carlo ; Computer science ; Bayesian probability ; Proteomics ; Artificial intelligence ; Machine learning ; Mixture model ; Proteome ; Context (archaeology) ; Support vector machine ; Bioinformatics ; Biology Advanced Proteomics Techniques and Applications ; Metabolomics and Mass Spectrometry Studies ; Identification and Quantification in Food
Authors: Ya Guo | Tianjun Sun | Xiaowei Liu | Quanli Ke | Xiaoli Wei | Yiming Gu | Shudong Wang
Source: Chemical Engineering Journal (article, 2018-10-03)
Field: Chemistry — Inorganic Chemistry

Cost-effective synthesis of CHA zeolites with controllable morphology and size Tetramethylammonium hydroxide ; Microporous material ; Zeolite ; Chemical engineering ; Morphology (biology) ; Crystallization ; Materials science ; Nanotechnology ; Adsorption ; Crystal (programming language) ; Chemistry ; Catalysis ; Organic chemistry ; Composite material Zeolite Catalysis and Synthesis ; Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications
Authors: Kun Zhang | Vincent Montigaud | Olivier Cador | Gao‐Peng Li | Boris Le Guennic | Jinkui Tang | Yao‐Yu Wang
Source: Inorganic Chemistry (article, 2018-07-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Tuning the Magnetic Interactions in Dy(III)<sub>4</sub> Single-Molecule Magnets The study of mononuclear lanthanide-based systems, where the observed single-molecule magnets (SMMs) properties originate from the local description of the magnetic properties of the lanthanide ion, has been widely investigated through the literature. The case of polynuclear SMMs becomes more challenging both experimentally and theoretically due to the complexity of such architectures involving interactions between the magnetic centers. Many efforts have been focused on the understanding of the nature of these interactions and their effects on the SMM properties. In this work, a series of three structurally related tetranuclear dysprosium(III) SMMs, namely, [Dy<sub>4</sub>(L)<sub>4</sub>(OH)<sub>2</sub>(DMF)<sub>4</sub>(NO<sub>3</sub>)<sub>2</sub>]·2(DMF)·(H<sub>2</sub>O) (1), [Dy<sub>4</sub>(L)<sub>4</sub>(OH)<sub>2</sub>(DMF)<sub>2</sub>(tfaa)<sub>2</sub>]·2(CH<sub>3</sub>CN) (2), and [Dy<sub>4</sub>(L)<sub>4</sub>(OH)<sub>2</sub>(DMF)<sub>2</sub>(acac)<sub>2</sub>]·2(DMF) (3) (H<sub>2</sub>L = 2-(2-hydroxy-3-methoxybenzylideneamino)phenol, Htfaa = trifluoroacetylactone, Hacac = acetylacetonate), has been synthesized and investigated. By a fine-tuning of the ligands on the changeable coordination sites in these Dy(III)<sub>4</sub> SMMs, the intramolecular magnetic interactions can be modified, switching from antiferromagnetic (for 1 and 2) to ferromagnetic (for 3). Ab initio calculations support these statements. In addition, the formation of 1 has been analyzed by ESI-MS analysis of the reaction mixture, indicating rather quick and high-yield formation of the [Dy<sub>4</sub>] framework in solution. The combination of experimental work and ab initio calculations offers further insight into the relationship between structures and magnetic properties and sheds light on how to tune magnetic interactions in future polynuclear dysprosium complexes. Chemistry ; Magnet ; Molecule ; Single-molecule magnet ; Molecular magnets ; Crystallography ; Nanotechnology ; Chemical physics ; Condensed matter physics ; Magnetic field ; Magnetization ; Organic chemistry ; Quantum mechanics ; Physics Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Advanced NMR Techniques and Applications
Authors: Johannes J. Möller | Wolfgang Körner | Georg Krugel | Daniel F. Urban | Christian Elsässer
Source: Acta Materialia (article, 2018-04-17)
Field: Materials Science — Materials Chemistry

Compositional optimization of hard-magnetic phases with machine-learning models Materials science ; Magnet ; Property (philosophy) ; Density functional theory ; Machine learning ; Computer science ; Biological system ; Statistical physics ; Nanotechnology ; Mechanical engineering ; Physics Machine Learning in Materials Science ; X-ray Diffraction in Crystallography
Authors: Kasra Momeni | Yanzhou Ji | Kehao Zhang | Joshua A. Robinson | Long‐Qing Chen
Source: npj 2D Materials and Applications (article, 2018-07-20)
Field: Materials Science — Materials Chemistry

Multiscale framework for simulation-guided growth of 2D materials Abstract Chemical vapor deposition (CVD) is a powerful technique for synthesizing monolayer materials such as transition metal dichalcogenides. It has advantages over exfoliation techniques, including higher purity and the ability to control the chemistry of the products. However, controllable and reproducible synthesis of 2D materials using CVD is a challenge because of the complex growth process and its sensitivity to subtle changes in growth conditions, making it difficult to extend conclusions obtained in one CVD chamber to another. Here, we developed a multiscale model linking CVD control parameters to the morphology, size, and distribution of synthesized 2D materials. Its capabilities are experimentally validated via the systematic growth of MoS 2 . In particular, we coupled the reactor-scale governing heat and mass transport equations with the mesoscale phase-field equations for the growth morphology considering the variation of edge energies with the precursor concentration within the growth chamber. The predicted spatial distributions of 2D islands are statistically analyzed, and experiments are then performed to validate the predicted island morphology and distributions. It is shown that the model can be employed to predict and control the morphology and characteristics of synthesized 2D materials. Exfoliation joint ; Chemical vapor deposition ; Materials science ; Monolayer ; Morphology (biology) ; Mesoscale meteorology ; Deposition (geology) ; Enhanced Data Rates for GSM Evolution ; Nanotechnology ; Chemical physics ; Chemical engineering ; Computer science ; Chemistry ; Physics ; Meteorology 2D Materials and Applications ; MXene and MAX Phase Materials ; Graphene research and applications