jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Benedito Roberto de Alvarenga | Renato Lajarim Carneiro
Source: Molecules (review, 2019-10-22)
Field: Chemistry — Analytical Chemistry

Chemometrics Approaches in Forced Degradation Studies of Pharmaceutical Drugs Chemometrics is the chemistry field responsible for planning and extracting the maximum of information of experiments from chemical data using mathematical tools (linear algebra, statistics, and so on). Active pharmaceutical ingredients (APIs) can form impurities when exposed to excipients or environmental variables such as light, high temperatures, acidic or basic conditions, humidity, and oxidative environment. By considering that these impurities can affect the safety and efficacy of the drug product, it is necessary to know how these impurities are yielded and to establish the pathway of their formation. In this context, forced degradation studies of pharmaceutical drugs have been used for the characterization of physicochemical stability of APIs. These studies are also essential in the validation of analytical methodologies, in order to prove the selectivity of methods for the API and its impurities and to create strategies to avoid the formation of degradation products. This review aims to demonstrate how forced degradation studies have been actually performed and the applications of chemometric tools in related studies. Some papers are going to be discussed to exemplify the chemometric applications in forced degradation studies. Forced degradation ; Chemometrics ; Biochemical engineering ; Context (archaeology) ; Degradation (telecommunications) ; Chemistry ; Impurity ; Process engineering ; Computer science ; Biological system ; Chromatography ; Organic chemistry ; Engineering ; Calibration curve Spectroscopy and Chemometric Analyses ; Analytical Methods in Pharmaceuticals ; Analytical Chemistry and Chromatography
Authors: Daniel M. Sussman | Daniel A. Beller
Source: Frontiers in Physics (article, 2019-12-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Fast, Scalable, and Interactive Software for Landau-de Gennes Numerical Modeling of Nematic Topological Defects Numerical modeling of nematic liquid crystals using the tensorial Landau-de Gennes (LdG) theory provides detailed insights into the structure and energetics of the enormous variety of possible topological defect configurations that may arise when the liquid crystal is in contact with colloidal inclusions or structured boundaries. However, these methods can be computationally expensive, making it challenging to predict (meta)stable configurations involving several colloidal particles, and they are often restricted to system sizes well below the experimental scale. Here we present an open-source software package that exploits the embarrassingly parallel structure of the lattice discretization of the LdG approach. Our implementation, combining CUDA/C++ and OpenMPI, allows users to accelerate simulations using both CPU and GPU resources in either single- or multiple-core configurations. We make use of an efficient minimization algorithm, the Fast Inertial Relaxation Engine (FIRE) method, that is well-suited to large-scale parallelization, requiring little additional memory or computational cost while offering performance competitive with other commonly used methods. In multi-core operation we are able to scale simulations up to supra-micron length scales of experimental relevance, and in single-core operation the simulation package includes a user-friendly GUI environment for rapid prototyping of interfacial features and the multifarious defect states they can promote. To demonstrate this software package, we examine in detail the competition between curvilinear disclinations and point-like hedgehog defects as size scale, material properties, and geometric features are varied. We also study the effects of an interface patterned with an array of topological point-defects. Computer science ; Computational science ; Scalability ; Software ; Discretization ; Topology (electrical circuits) Liquid Crystal Research Advancements ; Photonic Crystals and Applications ; Advanced Materials and Mechanics
Authors: Zhiqian Liu | Jian Hao | Ruijin Liao | Jian Li | Zhen Gao | Zhengbo Liang
Source: IEEE Access (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Morphological, Structural, and Dielectric Properties of Thermally Aged AC 500 kV XLPE Submarine Cable Insulation Material and Its Deterioration Condition Assessment Cross-linked polyethylene (XLPE) has been widely used as insulation material for cables. In 2019, the highest voltage level AC 500 kV XLPE submarine cable has been operated in Zhoushan, China. The irreversible degradation poses a safety hazard to the operation of submarine cable. Therefore, it is necessary to investigate the physical, chemical and electrical properties of XLPE submarine cable insulation under aging condition and explore the method for its deterioration degree assessment. In this paper, the AC 500 kV XLPE submarine cable insulation material was thermally aged at 130 °C. The deterioration characteristics of materials were analyzed based on morphology, chemical structure, mechanical property, thermal property and dielectric properties. Multiple characteristic parameters were extracted and new deterioration condition assessment model was established. Results show that the physicochemical characteristic parameters including retention rate of elongation at break, carbonyl index (CI) based on FTIR, full-width at half-maximum (FWHM) of the diffraction peak based on XRD, melting enthalpy based on DSC analysis, and the dielectric characteristic parameters including modified Cole-Cole model parameter χ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sα</sub> and AC breakdown strength are sensitive to deterioration condition of XLPE material. According to the change of elongation retention at break, the deterioration condition of XLPE sample was divided into enhanced stage, wear-out stage and disposal stage. The new multi-factor deterioration condition assessment model including six characteristic parameters (retention rate of elongation at break, CI, FWHM, melting enthalpy, modified Cole-Cole model parameter χ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sα</sub> , AC breakdown strength) was successfully established by grey correlation analysis. The new model can reflect the property of mechanical, chemical, thermal and dielectric property and has prominent effect in differentiating deterioration degree of the AC 500 kV XLPE submarine cable insulation material. Materials science ; Composite material ; Dielectric ; Polyethylene ; Dielectric strength ; Electrical insulation paper ; Voltage ; Electrical engineering ; Optoelectronics ; Engineering High voltage insulation and dielectric phenomena ; Power Transformer Diagnostics and Insulation ; Electrical Fault Detection and Protection
Authors: Mohammad Iman Mokhlespour Esfahani | Maury A. Nussbaum
Source: Sensors (article, 2019-07-16)
Field: Materials Science — Polymers and Plastics

Classifying Diverse Physical Activities Using “Smart Garments” Physical activities can have important impacts on human health. For example, a physically active lifestyle, which is one of the most important goals for overall health promotion, can diminish the risk for a range of physical disorders, as well as reducing health-related expenditures. Thus, a long-term goal is to detect different physical activities, and an important initial step toward this goal is the ability to classify such activities. A recent and promising technology to discriminate among diverse physical activities is the smart textile system (STS), which is becoming increasingly accepted as a low-cost activity monitoring tool for health promotion. Accordingly, our primary aim was to assess the feasibility and accuracy of using a novel STS to classify physical activities. Eleven participants completed a lab-based experiment to evaluate the accuracy of an STS that featured a smart undershirt (SUS) and commercially available smart socks (SSs) in discriminating several basic postures (sitting, standing, and lying down), as well as diverse activities requiring participants to walk and run at different speeds. We trained three classification methods-K-nearest neighbor, linear discriminant analysis, and artificial neural network-using data from each smart garment separately and in combination. Overall classification performance (global accuracy) was ~98%, which suggests that the STS was effective for discriminating diverse physical activities. We conclude that, overall, smart garments represent a promising area of research and a potential alternative for discriminating a range of physical activities, which can have positive implications for health promotion. Linear discriminant analysis ; Promotion (chess) ; Computer science ; Clothing ; Artificial intelligence ; Health promotion ; Machine learning ; Sitting ; Medicine ; Public health Textile materials and evaluations ; Thermoregulation and physiological responses ; Physical Activity and Health
Authors: Juan Fernández‐Novales | Javier Tardáguila | Salvador Gutiérrez | María P. Diago
Source: Molecules (article, 2019-07-31)
Field: Chemistry — Analytical Chemistry

On-The-Go VIS + SW − NIR Spectroscopy as a Reliable Monitoring Tool for Grape Composition within the Vineyard Visible-Short Wave Near Infrared (VIS + SW - NIR) spectroscopy is a real alternative to break down the next barrier in precision viticulture allowing a reliable monitoring of grape composition within the vineyard to facilitate the decision-making process dealing with grape quality sorting and harvest scheduling, for example. On-the-go spectral measurements of grape clusters were acquired in the field using a VIS + SW - NIR spectrometer, operating in the 570-990 nm spectral range, from a motorized platform moving at 5 km/h. Spectral measurements were acquired along four dates during grape ripening in 2017 on the east side of the canopy, which had been partially defoliated at cluster closure. Over the whole measuring season, a total of 144 experimental blocks were monitored, sampled and their fruit analyzed for total soluble solids (TSS), anthocyanin and total polyphenols concentrations using standard, wet chemistry reference methods. Partial Least Squares (PLS) regression was used as the algorithm for training the grape composition parameters' prediction models. The best cross-validation and external validation (prediction) models yielded determination coefficients of cross-validation (R<sup>2</sup><sub>cv</sub>) and prediction (R<sup>2</sup><sub>P</sub>) of 0.92 and 0.95 for TSS, R<sup>2</sup><sub>cv</sub> = 0.75, and R<sup>2</sup><sub>p</sub> = 0.79 for anthocyanins, and R<sup>2</sup><sub>cv</sub> = 0.42 and R<sup>2</sup><sub>p</sub> = 0.43 for total polyphenols. The vineyard variability maps generated for the different dates using this technology illustrate the capability to monitor the spatiotemporal dynamics and distribution of total soluble solids, anthocyanins and total polyphenols along grape ripening in a commercial vineyard. Vineyard ; Partial least squares regression ; Near-infrared spectroscopy ; Chemistry ; Ripening ; Wine ; Berry ; Polyphenol ; Environmental science ; Mathematics ; Horticulture ; Food science ; Statistics ; Physics Spectroscopy and Chemometric Analyses ; Horticultural and Viticultural Research ; Fermentation and Sensory Analysis
Authors: Jiajun Zhuang | Chaojun Hou | Yu Tang | Yong He | Qiwei Guo | Aimin Miao | Zhenyu Zhong | Shaoming Luo
Source: Sensors (article, 2019-07-01)
Field: Chemistry — Analytical Chemistry

Assessment of External Properties for Identifying Banana Fruit Maturity Stages Using Optical Imaging Techniques The maturity stage of bananas has a considerable influence on the fruit postharvest quality and the shelf life. In this study, an optical imaging based method was formulated to assess the importance of different external properties on the identification of four successive banana maturity stages. External optical properties, including the peel color and the local textural and local shape information, were extracted from the stalk, middle and tip of the bananas. Specifically, the peel color attributes were calculated from individual channels in the hue-saturation-value (HSV), the International Commission on Illumination (CIE) L*a*b* and the CIE L*ch color spaces; the textural information was encoded using a local binary pattern with uniform patterns (UP-LBP); and the local shape features were described by histogram of oriented gradients (HOG). Three classifiers based on the naïve Bayes (NB), linear discriminant analysis (LDA) and support vector machine (SVM) algorithms were adopted to evaluate the performance of identifying banana fruit maturity stages using the different optical appearance features. The experimental results demonstrate that overall identification accuracies of 99.2%, 100% and 99.2% were achieved using color appearance features with the NB, LDA and SVM classifiers, respectively; overall accuracies of 92.6%, 86.8% and 93.4% were obtained using local textural features for the three classifiers, respectively; and overall accuracies of only 84.3%, 83.5% and 82.6% were obtained using local shape features with the three classifiers, respectively. Compared to the complicated calculation of both the local textural and local shape properties, the simplicity and high accuracy of the peel color property make it more appropriate for identifying banana fruit maturity stages using optical imaging techniques. Artificial intelligence ; Local binary patterns ; Pattern recognition (psychology) ; Histogram ; Support vector machine ; Linear discriminant analysis ; Mathematics ; Histogram of oriented gradients ; Hue ; Naive Bayes classifier ; Postharvest ; Local color ; Color space ; Computer science ; Horticulture ; Biology ; Image (mathematics) Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Leaf Properties and Growth Measurement
Authors: Rafat M. Amin | Mohamed Taha | S. A. Abdel Moaty | Fatma I. Abo El‐Ela | Hossam F. Nassar | Yasser GadelHak | Rehab Mahmoud
Source: RSC Advances (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Gamma radiation as a green method to enhance the dielectric behaviour, magnetization, antibacterial activity and dye removal capacity of Co–Fe LDH nanosheets Nowadays, improving the physico-chemical properties of nanomaterials to enhance their performance towards various applications is urgent. Accordingly, gamma irradiation (GI) has evolved and attracted wide attention as a promising green technique to meet this need. In the current study, a Co-Fe LDH was used as a model 2D nanomaterial and was irradiated by GI (dose = 100 kGy). The sample was characterized <i>via</i> XRD, FTIR, FESEM, HRTEM, hydrodynamic size, zeta potential, and BET surface area measurements. The results showed that after irradiation, the surface area of the sample increased from 83 to 89 m<sup>2</sup> g<sup>-1</sup>. Moreover, irradiation increased its dielectric constant, dielectric loss and AC conductivity. In addition, the sample showed superparamagnetic behavior, where its saturation magnetization increased from 1.28 to 52.04 emu g<sup>-1</sup> after irradiation. Furthermore, the adsorption capacity of the irradiated LDH towards malachite green (MG) and methylene blue (MB) as model wastewater pollutants was also studied. The exposure of LDH to GI enhanced its adsorption capacity for MG from 44.73 to 54.43 mg g<sup>-1</sup>. The Langmuir-Freundlich, Sips, and Baudu models were well suited for both MG and MB adsorption among the six fitted isotherm models. The pseudo-first and second order models fit the adsorption kinetics better than the intraparticle diffusion model for both dyes. The interaction of MB and MG with the LDH surface was further investigated in dry and aqueous solution using Grand canonical Monte Carlo and molecular dynamics simulations. These two techniques provided insight into the adsorption mechanism, which is vital to understand the adsorption process by the LDH nanosheets and their possible use in practical applications. Moreover, the Co-Fe LDH showed good antibacterial activity against both Gram-positive and Gram-negative bacteria strains. Furthermore, due to its magnetic property, the Co-Fe LDH could be simply recovered from water by magnetic separation at a low magnetic field after the adsorption process. Adsorption ; Malachite green ; Freundlich equation ; Langmuir ; Zeta potential ; Dielectric ; Irradiation ; Materials science ; Nuclear chemistry ; Aqueous solution ; Brilliant green ; BET theory ; Specific surface area ; Nanomaterials ; Chemical engineering ; Langmuir adsorption model ; Nanoparticle ; Analytical Chemistry (journal) ; Chemistry ; Nanotechnology ; Chromatography ; Organic chemistry Layered Double Hydroxides Synthesis and Applications ; Adsorption and biosorption for pollutant removal ; Nanomaterials for catalytic reactions
Authors: Anni Wang | Guijun Xian | Hui Li
Source: Polymers (article, 2019-07-31)
Field: Materials Science — Polymers and Plastics

Effects of Fiber Surface Grafting with Nano-Clay on the Hydrothermal Ageing Behaviors of Flax Fiber/Epoxy Composite Plates Flax fiber has high sensitivity to moisture, and moisture uptake leads to the decrease of mechanical properties and distortion in shape. This paper attempts to graft flax fabric with nano-clay, with assistance from a silane-coupling agent, in order to improve hygrothermal resistance. The nano-clay grafted flax fabric reinforced epoxy (FFRP) composite produced through vacuum assisted resin infusion (VARI) process were subjected to 80% RH chamber for 12 weeks at 20, 40 and 70 °C, respectively. Moisture uptake, dimensional stability, and tensile properties was studied as a function of humidity exposure. Through SEM and FTIR, the effects of hygrothermal exposure was elucidated. In comparison to control FFRP plates, nano-clay grafting decreases saturation moisture uptake and the coefficient of diffusion of FFRP by 38.4% and 13.2%, respectively. After exposure for six weeks, the retention rate of the tensile modulus of the nano-clay grafted flax fiber based FFRP increased by 33.8% compared with that of the control ones. Nano-clay grafting also reduces the linear moisture expansion coefficient of FFRPs by 8.4% in a radial direction and 10.9% in a weft direction. Materials science ; Composite material ; Ultimate tensile strength ; Grafting ; Fiber ; Epoxy ; Moisture ; Composite number ; Nano- ; Natural fiber ; Polymer Natural Fiber Reinforced Composites ; Textile materials and evaluations ; Mechanical Behavior of Composites
Authors: Terry Shing‐Bong Lou | Scott W. Bagley | Michael C. Willis
Source: Angewandte Chemie (article, 2019-10-15)
Field: Chemistry — Organic Chemistry

Cyclic Alkenylsulfonyl Fluorides: Palladium‐Catalyzed Synthesis and Functionalization of Compact Multifunctional Reagents Abstract A series of low‐molecular‐weight, compact, and multifunctional cyclic alkenylsulfonyl fluorides were efficiently prepared from the corresponding alkenyl triflates. Palladium‐catalyzed sulfur dioxide insertion using the surrogate reagent DABSO effects sulfinate formation, before trapping with an F electrophile delivers the sulfonyl fluorides. A broad range of functional groups are tolerated, and a correspondingly large collection of derivatization reactions are possible on the products, including substitution at sulfur, conjugate addition, and N‐functionalization. Together, these attributes suggest that this method could find new applications in chemical biology. Reagent ; Palladium ; Surface modification ; Electrophile ; Derivatization ; Chemistry ; Catalysis ; Combinatorial chemistry ; Sulfonyl ; Sulfur ; Organic chemistry ; Polymer chemistry ; Alkyl Sulfur-Based Synthesis Techniques ; Click Chemistry and Applications ; Chemical Synthesis and Reactions
Authors: Aisen Li | Hao Liu | Chongping Song | Yijia Geng | Shuping Xu | Hongyu Zhang | Houyu Zhang | Haining Cui | Weiqing Xu
Source: Materials Chemistry Frontiers (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Flexible control of excited state transition under pressure/temperature: distinct stimuli-responsive behaviours of two ESIPT polymorphs The conversion between normal emission and ESIPT can be successfully achieved under pressure and temperature. Excited state ; Materials science ; Transition (genetics) ; Control (management) ; State (computer science) ; Chemical physics ; Photochemistry ; Chemistry ; Computer science ; Atomic physics ; Artificial intelligence ; Physics Luminescence and Fluorescent Materials ; Photochemistry and Electron Transfer Studies ; Photoreceptor and optogenetics research
Authors: Cecilia Cerretani | Tom Vosch
Source: ACS Omega (article, 2019-04-30)
Field: Materials Science — Materials Chemistry

Switchable Dual-Emissive DNA-Stabilized Silver Nanoclusters We investigated an ss-DNA sequence that can stabilize a red- and a green-emissive silver nanocluster (DNA-AgNC). These two emitters can convert between each other in a reversible way. The change from red- to green-emitting DNA-AgNCs can be triggered by the addition of H<sub>2</sub>O<sub>2</sub>, while the opposite conversion can be achieved by the addition of NaBH<sub>4</sub>. Besides demonstrating the switching between red- and green-emissive DNA-AgNCs and determining the recoverability, we fully characterized the photophysical properties, such as steady-state emission, quantum yield, fluorescence lifetime, and anisotropy of the two emissive species. Understanding the mechanism behind the remarkable conversion between the two emitters could lead to the development of a new range of DNA-AgNC-based ratiometric sensors. Nanoclusters ; Quantum yield ; DNA ; Materials science ; Fluorescence ; Optoelectronics ; Nanotechnology ; Photochemistry ; Chemistry ; Optics ; Physics Nanocluster Synthesis and Applications ; Gold and Silver Nanoparticles Synthesis and Applications ; Advanced biosensing and bioanalysis techniques
Authors: Prashant Bhardwaj | G. P. Biswas | Biswanath Bhunia
Source: Chemosphere (article, 2019-07-04)
Field: Chemistry — Organic Chemistry

Docking-based inverse virtual screening strategy for identification of novel protein targets for triclosan Docking (animal) ; Triclosan ; Virtual screening ; Chemistry ; Computational biology ; Biochemistry ; Drug discovery ; Biology ; Medicine Click Chemistry and Applications ; Computational Drug Discovery Methods ; Chemical Synthesis and Analysis
Authors: Yeo Jin Kim | Md. Mujibur Rahman | Sang Min Lee | Jung Min Kim | Kwangsik Park | Joo‐Hyon Kang | Young Rok Seo
Source: International Journal of Nanomedicine (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Assessment of in vivo genotoxicity of citrated-coated silver nanoparticles via transcriptomic analysis of rabbit liver tissue Our investigation highlights the risk associated with a single cAgNP exposure with unrepaired damage persisting for at least a month. In vivo ; Genotoxicity ; Toxicity ; Transcriptome ; Nanotoxicology ; Silver nanoparticle ; Pharmacology ; Carcinogen ; Pathology ; Comet assay ; Biology ; Toxicology ; Chemistry ; Medicine ; Nanoparticle ; DNA damage ; Gene expression ; Materials science ; Gene ; Nanotechnology ; Biochemistry ; Biotechnology ; Internal medicine ; DNA Nanoparticles: synthesis and applications ; Anesthesia and Neurotoxicity Research