jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Christoph Wichmann | Florian Meier | Sebastian Virreira Winter | Andreas‐David Brunner | Jürgen Cox | Matthias Mann
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2018-10-15)
Field: Chemistry — Spectroscopy

MaxQuant.Live enables global targeting of more than 25,000 peptides ABSTRACT Mass spectrometry (MS)-based proteomics is often performed in a shotgun format, in which as many peptide precursors as possible are selected from full or MS1 scans so that their fragment spectra can be recorded in MS2 scans. While achieving great proteome depths, shotgun proteomics cannot guarantee that each precursor will be fragmented in each run. In contrast, targeted proteomics aims to reproducibly and sensitively record a restricted number of precursor/fragment combinations in each run, based on pre-scheduled mass-to-charge and retention time windows. Here we set out to merge these two concepts by a global targeting approach in which an arbitrary number of precursors of interest are detected in real-time, followed by standard fragmentation or advanced peptide-specific analyses. We made use of a fast application programming interface to a quadrupole Orbitrap instrument and real-time recalibration in mass, retention time and intensity dimensions to predict precursor identity. MaxQuant.Live is freely available ( www.maxquant.live ) and has a graphical user interface to specify many pre-defined data acquisition strategies. Acquisition speed is as fast as with the vendor software and the power of our approach is demonstrated with the acquisition of breakdown curves for hundreds of precursors of interest. We also uncover precursors that are not even visible in MS1 scans, using elution time prediction based on the auto-adjusted retention time alone. Finally, we successfully recognized and targeted more than 25,000 peptides in single LC-MS runs. Global targeting combines the advantages of two classical approaches in MS-based proteomics, while greatly expanding the analytical toolbox. Computer science ; Orbitrap ; Shotgun proteomics ; Proteome ; Mass spectrometry ; Software ; Fragmentation (computing) ; Proteomics ; Merge (version control) ; Chemistry ; Computer hardware ; Chromatography ; Operating system ; Parallel computing ; Biochemistry Advanced Proteomics Techniques and Applications ; Mass Spectrometry Techniques and Applications ; Advanced biosensing and bioanalysis techniques
Authors: Horacio Ahuett‐Garza | Juan I. Melecio | Pedro Orta
Source: Mathematical Problems in Engineering (article, 2018-07-16)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Modal Analysis of a New Thermosensitive Actuator Design for Circuit Breakers Based on Mesoscale U-Shaped Compliant Mechanisms A new mesoscale thermosensitive actuator design for circuit breakers based on a U-shaped compliant mechanism was introduced as a potential replacement for bimetal strips in miniature circuit breakers. In a previous study, the response of this design to the thermal fields produced by a steady current flow was analyzed. This article presents a modal analysis of the compliant mechanism. The goal of the analysis is to compare the natural frequencies of the mechanism with the frequency of the magnetic loads caused by the flow of the alternating currents. Simulations with simple beam elements and 3D elements are presented and results are compared with experimental measurements. The study finds that the natural frequency of the mechanism differs by a factor of about 8 with the AC frequency. The conclusion is that the proposed compliant mechanism design’s performance as a thermal actuator will not be affected by the cyclic loads generated by the forces induced by the AC magnetic fields. Mechanism (biology) ; Actuator ; Modal analysis ; Natural frequency ; Circuit breaker ; Flow (mathematics) ; Mesoscale meteorology ; Thermal ; Modal ; Mechanical engineering ; Structural engineering ; Engineering ; Acoustics ; Materials science ; Mechanics ; Electrical engineering ; Finite element method ; Physics ; Vibration Magnetic Properties and Applications ; Piezoelectric Actuators and Control ; Electric Motor Design and Analysis
Authors: Ștefania Racoviță | Ana‐Lavinia Vasiliu | Adrian Bele | Dana Schwarz | Christine Steinbach | Regine Boldt | Simona Schwarz | Marcela Mihai
Source: RSC Advances (article, 2018-01-01)
Field: Materials Science — Surfaces, Coatings and Films

Complex calcium carbonate/polymer microparticles as carriers for aminoglycoside antibiotics Composite microparticles of CaCO<sub>3</sub> and two pectin samples (which differ by the functional group ratio) or corresponding nonstoichiometric polyelectrolyte complexes with different molar ratios (0.5, 0.9 and 1.2) are obtained, characterized and tested for loading and release of streptomycin and kanamycin sulphate. The synthesized carriers were characterized before and after drug loading in terms of morphology (by SEM using secondary electron and energy selective backscattered electron detectors), porosity (by water sorption isotherms) and elemental composition (by elemental mapping using energy dispersive X-ray and FTIR spectroscopy). The kinetics of the release mechanism from the microparticles was investigated using Higuchi and Korsmeyer-Peppas mathematical models. Chemistry ; Sorption ; Porosity ; Dissolution ; Distilled water ; Fourier transform infrared spectroscopy ; Polymer ; Chemical engineering ; Pectin ; Polyelectrolyte ; Calcium carbonate ; Kanamycin ; Controlled release ; Calcium ; Nuclear chemistry ; Scanning electron microscope ; Materials science ; Chromatography ; Organic chemistry ; Antibiotics ; Composite material Polymer Surface Interaction Studies ; Drug Solubulity and Delivery Systems ; Advanced Drug Delivery Systems
Authors: Flavio della Sala | Wessel Verbeet | Simone Silvestrini | Ilaria Fortunati | Camilla Ferrante | Leonard J. Prins
Source: ChemNanoMat (article, 2018-04-14)
Field: Materials Science — Biomaterials

Stepwise Hierarchical Self‐Assembly of Supramolecular Amphiphiles into Higher‐Order Three‐Dimensional Nanostructures Abstract Hierarchical self‐assembly describes the spontaneous formation of large well‐defined molecular structures through a sequence of spontaneous processes driven by noncovalent interactions between molecules and intermediate structures. The chemical information embedded in the initial molecules determines the structural outcome of the overall assembly process. This is clearly advantageous in terms of product accessibility, but poses limits to the extent of control that can be exerted over the process. Here we report the stepwise hierarchical self‐assembly of well‐defined three‐dimensional organic nanostructures with dimensions of over 100 nm in each single xyz ‐direction and a total volume of up to 1.5×10 −2 μm 3 . These structures are formed through three consecutive processes that rely exclusively on the establishment of noncovalent interactions between the components: (1) complex formation between Zn 2+ and a macrocyclic ligand, (2) association of the amphiphiles in disk‐like micellar structures and, finally, (3) ATP ‐induced stacking of the disks into large hexagonal prisms. The top and bottom surface of these structures are flat multivalent cationic surfaces covered with ATP with dimensions in the order of 2×10 5 nm 2 onto which nanometer‐sized gold nanoparticles can be deposited through a final self‐assembly process. The stepwise hierarchical process bears a close analogy with a multistep covalent synthetic pathway with the difference that all steps rely exclusively on noncovalent interactions. Supramolecular chemistry ; Stacking ; Non-covalent interactions ; Self-assembly ; Molecule ; Nanostructure ; Nanotechnology ; Amphiphile ; Covalent bond ; Chemical physics ; Cationic polymerization ; Materials science ; Chemistry ; Crystallography ; Copolymer ; Organic chemistry ; Polymer chemistry Supramolecular Self-Assembly in Materials ; Surface Chemistry and Catalysis ; Surfactants and Colloidal Systems
Authors: Alex Avdeef
Source: ADMET & DMPK (article, 2018-04-22)
Field: Chemistry — Organic Chemistry

Cocrystal solubility-pH and drug solubilization capacity of sodium dodecyl sulfate – mass action model for data analysis and simulation to improve design of experiments This review discusses the disposition of the anionic surfactant, sodium dodecyl sulfate (SDS; i.e., sodium lauryl sulfate), to solubilize sparingly-soluble drugs above the surfactant critical micelle concentration (CMC), as quantitated by the solubilization capacity (k). A compilation of 101 published SDS k values of mostly poorly-soluble drug molecules was used to develop a prediction model as a function of the drug’s intrinsic solubility, S0, and its calculated H-bond acceptor/donor potential. In almost all cases, the surfactant was found to solubilize the neutral form of the drug. Using the mass action model, the k values were converted to drug-micelle stoichiometric binding constants, Kn, corresponding to drug-micelle equilibria in drug-saturated solutions. An in-depth case study (data from published sources) considered the micellization reactions as a function of pH of a weak base, B, (pKa 3.58, S0 52 μg/mL), where at pH 1 the BH.SDS salt was predicted to precipitate both below and above the CMC. At low SDS concentrations, two drug salts were predicted to co-precipitate: BH.Cl and BH.SDS. Solubility products of both were determined from the analysis of the reported solubility-surfactant data. Above the CMC, in a rare example, the charged form of the drug (BH+) appeared to be strongly solubilized by the surfactant. The constant for that reaction was also determined. At pH 7, the reactions were simpler, as only the neutral form of the drug was solubilized, to a significantly lesser extent than at pH 1. Case studies also featured examples of solubilization of solids in the form of cocrystals. For many cocrystal systems studied in aqueous solution, the anticipated supersaturated state is not long-lasting, as the drug component precipitates to a thermodynamically stable form, thus lowering the amount of the active ingredient available for intestinal absorption. Use of surfactant can prevent this. A recently-described method for predicting the solubility product of cocrystals (coupled with predicted k values described here) allowed for simulations of solubility-pH speciation profiles of cocrystal systems in the presence of SDS. Well in advance of any actual measurements, these simulations can be used to probe conditions favorable to the design of cocrystal experiments where SDS stabilizes cocrystal suspensions against drug precipitation over a predicted range of pH values. Chemistry ; Solubility ; Pulmonary surfactant ; Micelle ; Sodium dodecyl sulfate ; Critical micelle concentration ; Inorganic chemistry ; Stoichiometry ; Aqueous solution ; Chromatography ; Organic chemistry Surfactants and Colloidal Systems ; Crystallization and Solubility Studies ; Thermodynamic properties of mixtures
Authors: Maiko Kofu | Antonio Faraone | Madhusudan Tyagi | Michihiro Nagao | Osamu Yamamuro
Source: Physical review. E (article, 2018-10-05)
Field: Materials Science — Materials Chemistry

Two inherent crossovers of the diffusion process in glass-forming liquids We report on incoherent quasielastic neutron scattering measurements examining a self-diffusion process in two types of glass-forming liquids, namely a molecular liquid (3-methylpentane) and an ionic liquid [1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide]. We have experimentally demonstrated that both liquids exhibit two crossovers in the momentum transfer ($Q$) dependence of the self-correlation function, which is basically described by the stretched exponential function, $exp[\ensuremath{-}{(t/\ensuremath{\tau})}^{\ensuremath{\beta}}]$. The first crossover point ($Q\ensuremath{\approx}0.2\phantom{\rule{0.28em}{0ex}}{\AA{}}^{\ensuremath{-}1}$) corresponds to a crossover from Fickian ($\ensuremath{\beta}=1$) to non-Fickian ($\ensuremath{\beta}\ensuremath{\ne}1$) diffusion attributed to dynamical correlation. On the other hand, the second one at $Q\ensuremath{\approx}0.8\phantom{\rule{0.28em}{0ex}}{\AA{}}^{\ensuremath{-}1}$ is associated with the crossover from Gaussian to non-Gaussian behavior. It is remarkable that the stretching exponent $\ensuremath{\beta}$ gradually changes in between the two crossover points. We consider that the two crossovers are the universal feature for glass-forming liquids. Exponent ; Fick's laws of diffusion ; Physics ; Quasielastic neutron scattering ; Crossover ; Exponential function ; Diffusion ; Scaling ; Condensed matter physics ; Momentum transfer ; Ionic liquid ; Correlation function (quantum field theory) ; Exponential decay ; Relaxation (psychology) ; Neutron scattering ; Supercooling ; Scattering ; Thermodynamics ; Quantum mechanics ; Inelastic neutron scattering ; Chemistry ; Dielectric ; Mathematical analysis ; Mathematics Material Dynamics and Properties ; Advanced Neuroimaging Techniques and Applications ; NMR spectroscopy and applications
Authors: P.J. van Staden | Jochen Petersen
Source: Journal of the Southern African Institute of Mining and Metallurgy (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

First-order exchange and spherical diffusion models of heap leaching in PhreeqC Heap leaching ; Leaching (pedology) ; Heap (data structure) ; Materials science ; Metallurgy ; Computer science ; Environmental science ; Soil science ; Tailings ; Algorithm Fusion materials and technologies ; Molten salt chemistry and electrochemical processes ; Metallurgical Processes and Thermodynamics
Authors: A. Barba | Carolina Clausell
Source: Ceramics International (article, 2018-12-04)
Field: Materials Science — Ceramics and Composites

A general method to determine optimal thermal cycles based on solid-state sintering fundamentals Sintering ; Materials science ; Grain growth ; Crystallite ; Microstructure ; Dwell time ; Grain size ; Ceramic ; Thermal ; Process (computing) ; Metallurgy ; Thermodynamics ; Computer science Advanced ceramic materials synthesis ; Aluminum Alloys Composites Properties ; Advanced materials and composites
Authors: Abir Nachawaty | Ming Yang | Sébastien Nanot | Dimitrios Kazazis | Rositsa Yakimova | Walter Escoffier | B. Jouault
Source: Physical review. B./Physical review. B (article, 2018-07-03)
Field: Materials Science — Materials Chemistry

Large nonlocality in macroscopic Hall bars made of epitaxial graphene We report on nonlocal transport in large-scale epitaxial graphene on silicon carbide under an applied external magnetic field. The nonlocality is related to the emergence of the quantum Hall regime and persists up to the millimeter scale. The nonlocal resistance reaches values comparable to the local (Hall and longitudinal) resistances. At moderate magnetic fields, it is almost independent on the in-plane component of the magnetic field, which suggests that spin currents are not at play. The nonlocality cannot be explained by thermoelectric effects without assuming extraordinary large Nernst and Ettingshausen coefficients. A model based on counterpropagating edge states backscattered by the bulk reproduces quite well the experimental data. Quantum nonlocality ; Condensed matter physics ; Magnetic field ; Quantum Hall effect ; Physics ; Spin (aerodynamics) ; Hall effect ; Quantum ; Quantum mechanics ; Quantum entanglement Graphene research and applications ; Quantum and electron transport phenomena ; Topological Materials and Phenomena
Authors: Sobia Noreen | Ishtiaq Hussain | Muhammad Ilyas Tariq | Shahid Iqbal | Fozia Batool | Shazia Akram Ghumman | Shazia Noureen | Tusneem Kausar
Source: Notulae Scientia Biologicae (article, 2018-09-27)
Field: Materials Science — Biomaterials

Influence of Extraction Scheme on the Antioxidant Potential of Caralluma tuberculata Herbal industry of developing countries is facing several technical issues related to the extraction conditions in order to attain the maximum yield of a plant extract with maximum therapeutic attributes. Therefore the present study was aimed to investigate the best technique for respective herbal products. The effect of three different extraction techniques: ultrasonic assisted extraction, microwave assisted and orbital shaker assisted extraction, by using three solvents (80% methanol, ethanol, and ethyl acetate) on the antioxidant potential of Caralluma tuberculata stem (non-conventional vegetable) extracts were investigated. Folin-Ciocalteu method was applied on tested samples in order to find the concentration of total phenols. Therefore, the optimized extract of high yield and maximum total phenolic content was selected for further analysis like total flavonoid contents, FRAP, DPPH and ABTS scavenging potential. Quantification of phenolic acids in the extracts was also carried out by HPLC. Significant variation was observed in the yield of total phenols within the extracts, but better results were obtained in aqueous methanolic extract of ultrasonic assisted extraction, followed by microwave assisted and orbital shaker assisted extraction. Present findings supported the view that ultrasonic assisted extraction can be used for phytochemicals profiling, activity guided assays and the development of herbal products. Correlation coefficients of active principles indicated a significant relationship to antioxidant capacity P &lt; 0.05. DPPH ; ABTS ; Extraction (chemistry) ; Phenols ; Chemistry ; Chromatography ; Ethyl acetate ; Flavonoid ; Antioxidant ; Yield (engineering) ; Methanol ; Organic chemistry ; Materials science Phytochemistry and Bioactive Compounds ; Phytochemicals and Antioxidant Activities ; Phytochemistry and Biological Activities
Authors: Musiliyu A. Musa | Veera L. D. Badisa | Lekan M. Latinwo | Elizabeth Ntantie
Source: Anticancer Research (article, 2018-11-01)
Field: Chemistry — Organic Chemistry

7,8-Dihydroxy-3-arylcoumarin Induces Cell Death Through S-Phase Arrest in MDA-MB-231 Breast Cancer Cells These results suggest that 7h could serve as a valuable template for the development of novel synthetic compounds for breast cancer treatment. Programmed cell death ; Breast cancer ; Cancer research ; Apoptosis ; Medicine ; Cancer ; Internal medicine ; Oncology ; Biology ; Biochemistry Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Synthesis of Organic Compounds
Authors: Iara S. Santos | Fabiana Sélos Guerra | Lucas Ferreira Bernardino | Patrícia Dias Fernandes | Lidilhone Hamerski | Bárbara V. Silva
Source: Journal of the Brazilian Chemical Society (article, 2018-01-01)
Field: Chemistry — Organic Chemistry

A Facile Synthesis of Novel Isatinspirooxazine Derivatives and Potential in vitro Anti-Proliferative Activity Novel isatinspirooxazine derivatives were designed and synthesized as potential anti-proliferative agents. The new compounds were obtained from aldol condensation reactions between isatin and 3-(hydroxyimino)butan-2-one in the presence of an organic base in order to generate an aldol adduct, followed by cyclization in trifluoroacetic acid, providing the desired isatinspirooxazines in 30 to 80% yield. All the synthesized compounds, including the starting material and the synthetic intermediates, were tested for in vitro anti-proliferative activity against cell lines MCF-7 and MDA-MB231 (breast cancer) and A549 (lung cancer), highlighting the compound 4-methyl,5'-methyl-spiro[(5-aza-4-eno-3-one-cyclohexane)-1,3'-(1H-indol-one)] with an IC 50 (half maximal inhibitory concentration) = 0.34 M, more potent than the reference drug, doxorubicin (IC 50 = 1.88 M), in breast cancer line MDA-MB231. Trifluoroacetic acid ; Isatin ; Chemistry ; In vitro ; Aldol condensation ; Cyclohexane ; IC50 ; Aldol reaction ; Combinatorial chemistry ; Stereochemistry ; Biochemistry ; Organic chemistry ; Catalysis Synthesis and Biological Evaluation ; Phenothiazines and Benzothiazines Synthesis and Activities ; Synthesis and biological activity
Authors: L. Chafki | El Housseine Rifi | R. Touir | M. Ebn Touhamı | Z. Hatim
Source: The Open Materials Science Journal (article, 2018-07-31)
Field: Materials Science — Materials Chemistry

Corrosion Inhibition of Mild Steel in 1.0 M HCl Solution by Anhydrous Tricalcium Phosphate Objective: In this study, electrochemical measurements were used to characterize Anhydrous Tricalcium Phosphate (ATP) as a corrosion inhibitor for mild steel in 1.0 M HCl. Method: The potentiodynamic polarization curves indicated that the ATP reacts as an anodic type inhibitor. In addition, it has been found that the electrochemical impedance confirms the inhibitor character of ATP obtained by the potentiodynamic polarization curves where the inhibition efficiency increases by its concentration to reach a maximum of 93.79 % at 10 -4 M. The temperature solution influence indicated that the corrosion rate increases with temperature while the inhibitor acts actively. Thermodynamic adsorption and activation parameters indicated that the ATP acts by physical adsorption on the metallic surface with an endothermic process of metal dissolution. Result: Additionally, it was found that the adsorption of ATP molecules obeyed to the Langmuir isotherm. Surface analyses via scanning electron microscopy (SEM) was used to investigate the morphology of mild steel before and after immersion in 1.0 M HCl solution without and with 10 -4 M of ATP. It is revealed that the ATP acted by the formation of a protective layer on the mild steel. Anhydrous ; Adsorption ; Corrosion ; Materials science ; Langmuir adsorption model ; Endothermic process ; Scanning electron microscope ; Electrochemistry ; Metal ; Phosphate ; Inorganic chemistry ; Electrolyte ; Nuclear chemistry ; Polarization (electrochemistry) ; Dielectric spectroscopy ; Dissolution ; Chemistry ; Metallurgy ; Physical chemistry ; Organic chemistry ; Electrode ; Composite material Corrosion Behavior and Inhibition ; Hydrogen embrittlement and corrosion behaviors in metals ; Concrete Corrosion and Durability