jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Khadiga M. Kelani | Maha A. Hegazy | Amal M. Hassan | Mahmoud A. Tantawy
Source: BMC Chemistry (article, 2022-04-04)
Field: Chemistry — Spectroscopy

A green TLC densitometric method for the simultaneous detection and quantification of naphazoline HCl, pheniramine maleate along with three official impurities Impurity profiling of a pharmaceutical compound is now taking great attention during quality assessment of pharmaceuticals, as presence of small amount of impurities may affect safety and efficacy. In this work, a novel TLC chromatographic method coupled with densitometric detection was established for the simultaneous quantification of naphazoline HCl, pheniramine maleate and three of their official impurities, namely; naphazoline impurity B, pheniramine impurities; A & B. Chromatographic separation was carried out on TLC aluminum silica plates F254, as a stationary phase, using methanol: ethyl acetate: 33.0% ammonia (2.0: 8.0: 1.0, by volume), as a mobile phase. Plates were examined at 260.0 nm and International Council for Harmonisation (ICH) guidelines were followed for method's validation. Important factors, such as; composition of mobile phase and detection wavelengths were optimized. Linearity was achieved over the ranges of 2.0-50.0 µg band<sup>-1</sup> for naphazoline, 10.0-110.0 µg band<sup>-1</sup> for pheniramine, 0.1-10.0 µg band<sup>-1</sup> for naphazoline impurity B and 2.0-50.0 µg band<sup>-1</sup> for both pheniramine impurities. The proposed method was assessed in terms of accuracy, precision and robustness where satisfactory results (recovery % ≈ 100% and RSD < 2) were obtained. The method was also applied for the simultaneous determination of naphazoline HCl and pheniramine maleate, in Naphcon-A<sup>®</sup> eye drops, with respective recoveries of 101.36% and 100.94%. Method greenness was evaluated and compared to the reported HPLC one via environmental, health and safety tool. The developed method has much potential over the reported one of being simple, selective, economic and time saving for the analysis of the five cited compounds. Impurity ; Chromatography ; Silica gel ; Detection limit ; Chemistry ; Methanol ; Stationary phase ; Materials science ; Organic chemistry Analytical Chemistry and Chromatography ; Analytical Methods in Pharmaceuticals ; Pharmacological Effects and Assays
Authors: Davis Unruh | Reza Vatan Meidanshahi | Stephen M. Goodnick | Gábor Cśanyi | Gergely T. Zimányi
Source: Physical Review Materials (article, 2022-06-27)
Field: Materials Science — Materials Chemistry

Gaussian approximation potential for amorphous Si : H Hydrogenation of amorphous silicon $(a\text{\ensuremath{-}}\mathrm{Si} : \mathrm{H})$ is critical for reducing defect densities, passivating midgap states and surfaces, and improving photoconductivity in silicon-based electro-optical devices. Modeling the atomic-scale structure of this material is critical to understanding these processes, which in turn is needed to describe $c\text{\ensuremath{-}}\mathrm{Si}/a\text{\ensuremath{-}}\mathrm{Si} : \mathrm{H}$ heterojunctions that are at the heart of modern solar cells with world-record efficiency. Density functional theory (DFT) studies achieve the required high accuracy but are limited to moderate system sizes of 100 atoms or so by their high computational cost. Simulations of amorphous materials have been hindered by this high cost because large structural models are required to capture the medium-range order that is characteristic of such materials. Empirical potential models are much faster, but their accuracy is not sufficient to correctly describe the frustrated local structure. Data-driven, machine-learned interatomic potentials have broken this impasse and have been highly successful in describing a variety of amorphous materials in their elemental phase. Here, we extend the Gaussian approximation potential (GAP) for silicon by incorporating the interaction with hydrogen, thereby significantly improving the degree of realism with which amorphous silicon can be modeled. We show that our Si : H GAP enables the simulation of hydrogenated silicon with an accuracy very close to DFT but with computational expense and run times reduced by several orders of magnitude for large structures. We demonstrate the capabilities of the Si : H GAP by creating models of hydrogenated liquid and amorphous silicon and showing that their energies, forces, and stresses are in excellent agreement with DFT results, and their structure as captured by bond and angle distributions are in agreement with both DFT and experiments. Materials science ; Amorphous silicon ; Atomic units ; Amorphous solid ; Silicon ; Heterojunction ; Density functional theory ; Crystalline silicon ; Condensed matter physics ; Chemical physics ; Optoelectronics ; Physics ; Crystallography ; Quantum mechanics ; Chemistry Machine Learning in Materials Science ; Thin-Film Transistor Technologies ; Phase-change materials and chalcogenides
Authors: Rongling Zhang | Xinyan Wu | Yujie Chen | Yang Xiang | Dan Liŭ | Xihui Bian
Source: Molecules (article, 2022-08-12)
Field: Chemistry — Analytical Chemistry

Grey Wolf Optimizer for Variable Selection in Quantification of Quaternary Edible Blend Oil by Ultraviolet-Visible Spectroscopy A novel swarm intelligence algorithm, discretized grey wolf optimizer (GWO), was introduced as a variable selection tool in edible blend oil analysis for the first time. In the approach, positions of wolves were updated and then discretized by logical function. The performance of a wolf pack, the iteration number and the number of wolves were investigated. The partial least squares (PLS) method was used to establish and predict single oil contents in samples. To validate the method, 102 edible blend oil samples containing soybean oil, sunflower oil, peanut oil and sesame oil were measured by an ultraviolet-visible (UV-Vis) spectrophotometer. The results demonstrated that GWO-PLS models can provide best prediction accuracy with least variables compared with full-spectrum PLS, Monte Carlo uninformative variable elimination-PLS (MCUVE-PLS) and randomization test-PLS (RT-PLS). The determination coefficients (R<sup>2</sup>) of GWO-PLS were all above 0.95. Therefore, the research indicates the feasibility of using discretized GWO for variable selection in rapid determination of quaternary edible blend oil. Partial least squares regression ; Mathematics ; Feature selection ; Biological system ; Selection (genetic algorithm) ; Monte Carlo method ; Variable elimination ; Sunflower oil ; Statistics ; Computer science ; Chemistry ; Artificial intelligence ; Food science ; Biology Spectroscopy and Chemometric Analyses ; Advanced Chemical Sensor Technologies ; Water Quality Monitoring and Analysis
Authors: Nuerguli Kari | Marco Zannotti | Rita Giovannetti | David Řeha | Babak Minofar | Shawket Abliz | Abliz Yimit
Source: Nanomaterials (article, 2022-03-13)
Field: Materials Science — Materials Chemistry

Metallic Effects on p-Hydroxyphenyl Porphyrin Thin-Film-Based Planar Optical Waveguide Gas Sensor: Experimental and Computational Studies Metal effects on the gas sensing behavior of metal complexes of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (THPP) thin film was investigated in terms of detecting NO2 gas by the planar optical waveguide. For this purpose, several THPP and metal complexes were synthesized with different central metal ions: Co(II), Ni(II), Cu(II), and Zn(II). Planar optical gas sensors were fabricated with the metalloporphyrins deposited on K+ ion-exchanged soda-lime glass substrate with the spin coating method serving as host matrices for gas interaction. All of the THPP complex’s films were fully characterized by UV-Vis, IR and XPS spectroscopy, and the laser light source wavelength was selected at 520 and 670 nm. The results of the planar optical waveguide sensor show that the Zn–THPP complex exhibits the strongest response with the lowest detectable gas concentration of NO2 gas for both 520 nm and 670 nm. The Ni–THPP and Co–THPP complexes display good efficiency in the detection of NO2, while, on the other hand, Cu–THPP shows a very low interaction with NO2 gas, with only 50 ppm and 200 ppm detectable gas concentration for 520 nm and 670 nm, respectively. In addition, molecular dynamic simulations and quantum mechanical calculations were performed, proving to be coherent with the experimental results. Materials science ; Porphyrin ; X-ray photoelectron spectroscopy ; Thin film ; Waveguide ; Planar ; Metal ; Metal ions in aqueous solution ; Spin coating ; Analytical Chemistry (journal) ; Optoelectronics ; Nanotechnology ; Photochemistry ; Chemical engineering ; Chemistry ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Analytical Chemistry and Sensors ; Advanced Chemical Sensor Technologies
Authors: Eslam Salama | Ali Hamdy | Hassan Samy Hassan | Wael A. Amer | El‐Zeiny M. Ebeid | Mona Ossman | Marwa Elkady
Source: Adsorption Science & Technology (article, 2022-01-01)
Field: Chemistry — Inorganic Chemistry

Evaluation of Zn Adenine-Based Bio-MOF for Efficient Remediation of Different Types of Dyes As an eco-friendly material, Zn-adeninate bio-metal-organic framework (bio-MOF) was investigated as an efficient adsorbent for both anionic and cationic dyes. The adsorption capability of the synthesized Zn-adeninate bio-MOF was confirmed by its notable surface area of 52.62 m 2 g −1 and total pore volume of 0.183 cm 3 g −1 . The bio-MOF adsorption profiles of anionic direct red 81 (DR-81) and cationic methylene blue (MB) dyes were investigated under different operating parameters. The optimum dosages of Zn-adeninate bio-MOF were 0.5 g L −1 and 1 g L −1 for MB and DR-81 decolorization, respectively. The pH PZC of Zn-adeninate bio-MOF was 7.2, and maximum monolayer adsorption capacity was 132.15 mg g –1 for MB, which decreased to 82.54 mg g –1 for DR-81 dye. Thermodynamic data indicated the spontaneous and endothermic nature of the decolorization processes. Additionally, the adsorption processes were in agreement with the Langmuir and pseudo-second-order kinetic models. The synthesized Zn-adeninate bio-MOF could be reused several times with high decolorization ability. These findings demonstrated that the synthesized Zn bio-MOF is an effective and promising adsorbent material for the removal of both cationic and anionic dyes from polluted water. Chemistry ; Cationic polymerization ; Adsorption ; Langmuir adsorption model ; Methylene blue ; Endothermic process ; Nuclear chemistry ; Langmuir ; Monolayer ; Inorganic chemistry ; Organic chemistry ; Catalysis ; Photocatalysis Metal-Organic Frameworks: Synthesis and Applications ; Advanced Nanomaterials in Catalysis ; Adsorption and biosorption for pollutant removal
Authors: Adam S. Braegelman | Rachel C. Ollier | Bo Su | Christopher J. Addonizio | Lei Zou | Sara L. Cole | Matthew J. Webber
Source: ACS Applied Bio Materials (review, 2022-05-27)
Field: Chemistry — Organic Chemistry

Macromolecular Solute Transport in Supramolecular Hydrogels Spanning Dynamic to Quasi-Static States Hydrogels prepared from supramolecular cross-linking motifs are appealing for use as biomaterials and drug delivery technologies. The inclusion of macromolecules (e.g., protein therapeutics) in these materials is relevant to many of their intended uses. However, the impact of dynamic network cross-linking on macromolecule diffusion must be better understood. Here, hydrogel networks with identical topology but disparate cross-link dynamics are explored. These materials are prepared from cross-linking with host-guest complexes of the cucurbit[7]uril (CB[7]) macrocycle and two guests of different affinity. Rheology confirms differences in bulk material dynamics arising from differences in cross-link thermodynamics. Fluorescence recovery after photobleaching (FRAP) provides insight into macromolecule diffusion as a function of probe molecular weight and hydrogel network dynamics. Together, both rheology and FRAP enable the estimation of the mean network mesh size, which is then related to the solute hydrodynamic diameters to further understand macromolecule diffusion. Interestingly, the thermodynamics of host-guest cross-linking are correlated with a marked deviation from classical diffusion behavior for higher molecular weight probes, yielding solute aggregation in high-affinity networks. These studies offer insights into fundamental macromolecular transport phenomena as they relate to the association dynamics of supramolecular networks. Translation of these materials from in vitro to in vivo is also assessed by bulk release of an encapsulated macromolecule. Contradictory in vitro to in vivo results with inverse relationships in release between the two hydrogels underscores the caution demanded when translating supramolecular biomaterials into application. Macromolecule ; Self-healing hydrogels ; Fluorescence recovery after photobleaching ; Supramolecular chemistry ; Rheology ; Diffusion ; Molecular dynamics ; Chemistry ; Materials science ; Nanotechnology ; Chemical physics ; Molecule ; Polymer chemistry ; Computational chemistry ; Thermodynamics ; Organic chemistry ; Biochemistry Supramolecular Chemistry and Complexes ; Advanced NMR Techniques and Applications ; Supramolecular Self-Assembly in Materials
Authors: Liangyi Yao | Xiangyuan Zou | Shuqi Zhou | Hongxiang Zhu | Guoning Chen | Shuangfei Wang | Xiuyu Liu | Yan Jiang
Source: Polymers (article, 2022-02-24)
Field: Materials Science — Biomaterials

Cationic Lignocellulose Nanofibers from Agricultural Waste as High-Performing Adsorbents for the Removal of Dissolved and Colloidal Substances The accumulation of dissolved and colloidal substances (DCS) in the increasingly closed paper circulating water system can seriously lower the productivity and safety of papermaking machines, and it has been a challenge to develop an adsorbent with low cost, high adsorption efficiency and large adsorption capacity for DCS removal. In this study, cationic lignocellulose nanofibers (CLCNF) were obtained by cationic modification of agricultural waste bagasse in deep eutectic solvents (DES) followed by mechanical defibrillation, and then CLCNF were employed as an adsorbent for DCS model contaminant polygalacturonic acid (PGA) removal. CLCNF was characterized by transmission electron microscopy, Fourier transform infrared, elemental analysis, X-ray diffraction, and thermogravimetric analysis. The analytical results confirmed the successful preparation of CLCNF with 4.6-7.9 nm diameters and 0.97-1.76 mmol/g quaternary ammonium groups. The effects of quaternary ammonium group contents, pH, contact time and initial concentration of PGA on the adsorption were investigated in a batch adsorption study. According to the results, the cationic modification significantly enhanced the adsorption of PGA by CLCNF and the adsorption performance increased with the increase of the quaternary ammonium group contents. The adsorption of PGA on CLCNF followed the pseudo-second-order and the fitted Langmuir isotherm model. The adsorption showed fast initial kinetics and the experimental maximum adsorption capacity was 1054 mg/g, which is much higher than PGA adsorbents previously reported in the literature. Therefore, CLCNF with high cationic group content developed in this paper is a promising adsorbent for DCS removal. Adsorption ; Cationic polymerization ; Nanofiber ; Colloid ; Cellulose ; Materials science ; Agricultural waste ; Chemical engineering ; Waste management ; Pulp and paper industry ; Chemistry ; Organic chemistry ; Nanotechnology Advanced Cellulose Research Studies ; Electrospun Nanofibers in Biomedical Applications ; Aerogels and thermal insulation
Authors: A. Zafra | Zachary D. Harris | Evžen Korec | Emilio Martínez‐Pañeda
Source: International Journal of Hydrogen Energy (article, 2022-10-25)
Field: Materials Science — Metals and Alloys

On the relative efficacy of electropermeation and isothermal desorption approaches for measuring hydrogen diffusivity The relative efficacy of electrochemical permeation (EP) and isothermal desorption spectroscopy (ITDS) methods for determining the hydrogen diffusivity is investigated using cold-rolled pure iron. The diffusivities determined from 13 first transient and 8 second transient EP experiments, evaluated using the conventional lag and breakthrough time methods, are compared to the results of 10 ITDS experiments. Results demonstrate that the average diffusivity is similar between the second EP transient and ITDS, which are distinctly increased relative to the first EP transient. However, the coefficient of variation for the ITDS experiments is reduced by 2 and 3-fold relative to the first and second EP transients, confirming the improved repeatability of ITDS diffusivity measurements. The source of the increased error in EP measurements is systematically evaluated, revealing an important influence of assumed electrochemical boundary conditions on the analysis and interpretation of EP experiments. Thermal diffusivity ; Isothermal process ; Repeatability ; Chemistry ; Transient (computer programming) ; Thermodynamics ; Desorption ; Analytical Chemistry (journal) ; Materials science ; Chromatography ; Physical chemistry ; Physics ; Adsorption Hydrogen embrittlement and corrosion behaviors in metals ; Corrosion Behavior and Inhibition ; Nuclear Materials and Properties
Authors: Ranjana Aggarwal | Mona Hooda | Prince Kumar | Garima Sumran
Source: Topics in Current Chemistry (review, 2022-02-05)
Field: Chemistry — Organic Chemistry

Vision on Synthetic and Medicinal Facets of 1,2,4-Triazolo[3,4-b][1,3,4]thiadiazine Scaffold Chemistry ; Scaffold ; Stereochemistry ; Combinatorial chemistry ; Nanotechnology ; Programming language Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and biological activity ; Phenothiazines and Benzothiazines Synthesis and Activities
Authors: Vera L. M. Silva | Rita Silva‐Reis | Alexandra Moreira‐Pais | Tiago Ferreira | Paula A. Oliveira | Rita Ferreira | Susana M. Cardoso | Javad Sharifi‐Rad | Monica Butnariu | Maria Alina Costea | Ioana Grozea
Source: Chinese Medicine (review, 2022-12-27)
Field: Chemistry — Organic Chemistry

Dicoumarol: from chemistry to antitumor benefits Dicoumarol, a coumarin-like compound, is known for its anticoagulant properties associated with the ability to inhibit vitamin K, being prescribed as a drug for several decades. The pharmaceutical value of dicoumarol turned it into a focus of chemists' attention, aiming its synthesis and of dicoumarol derivatives, bringing to light new methodologies. In recent years, several other bioactive effects have been claimed for dicoumarol and its derivatives, including anti-inflammatory, antimicrobial, antifungal, and anticancer, although the mechanisms of action underlying them are mostly not disclosed and additional research is needed to unravel them. This review presents a state of the art on the chemistry of dicoumarols, and their potential anticancer characteristics, highlighting the mechanisms of action elucidated so far. In parallel, we draw attention to the lack of in vivo studies and clinical trials to assess the safety and efficacy as drugs for later application. Dicoumarol ; Coumarin ; Pharmacology ; Antifungal ; Medicine ; Chemistry ; Biochemistry ; Organic chemistry Multicomponent Synthesis of Heterocycles ; Oxidative Organic Chemistry Reactions ; Synthesis of Organic Compounds
Authors: Jonas F. Goebel | Julian Löffler | Zhongyi Zeng | Jens Handelmann | Albert Hermann | Ilja Rodstein | Tobias Gensch | Viktoria H. Gessner | Lukas J. Gooßen
Source: Angewandte Chemie International Edition (article, 2022-12-20)
Field: Chemistry — Organic Chemistry

Computer‐Driven Development of Ylide Functionalized Phosphines for Palladium‐Catalyzed Hiyama Couplings Palladium-catalyzed couplings of silicon enolates with aryl electrophiles are of great synthetic utility, but often limited to expensive bromide substrates. A comparative experimental study confirmed that none of the established ligand systems allows to couple inexpensive aryl chlorides with α-trimethylsilyl alkylnitriles. In contrast, ylide functionalized phosphines (YPhos) led to encouraging results. A statistical model was developed that correlates the reaction yields with ligand features. It was employed to predict catalyst structures with superior performance. With this cheminformatics approach, YPhos ligands were tailored specifically to the demands of Hiyama couplings. The newly synthesized ligands displayed record-setting activities, enabling the elusive coupling of aryl chlorides with α-trimethylsilyl alkyl nitriles. The preparative utility of the catalyst system was demonstrated by the synthesis of pharmaceutically meaningful α-aryl alkylnitriles, α-arylcarbonyls and biaryls. Aryl ; Chemistry ; Ylide ; Electrophile ; Palladium ; Trimethylsilyl ; Catalysis ; Combinatorial chemistry ; Ligand (biochemistry) ; Bromide ; Alkyl ; Organic chemistry Catalytic Cross-Coupling Reactions ; Catalytic C–H Functionalization Methods ; Asymmetric Hydrogenation and Catalysis
Authors: Kasturee Chakraborty | Archana Tripathi | Sukumar Mishra | Argha Mario Mallick | Rituparna Sinha Roy
Source: Bioscience Reports (review, 2022-05-31)
Field: Materials Science — Biomaterials

Emerging concepts in designing next-generation multifunctional nanomedicine for cancer treatment Abstract Nanotherapy has emerged as an improved anticancer therapeutic strategy to circumvent the harmful side effects of chemotherapy. It has been proven to be beneficial to offer multiple advantages, including their capacity to carry different therapeutic agents, longer circulation time and increased therapeutic index with reduced toxicity. Over time, nanotherapy evolved in terms of their designing strategies like geometry, size, composition or chemistry to circumvent the biological barriers. Multifunctional nanoscale materials are widely used as molecular transporter for delivering therapeutics and imaging agents. Nanomedicine involving multi-component chemotherapeutic drug-based combination therapy has been found to be an improved promising approach to increase the efficacy of cancer treatment. Next-generation nanomedicine has also utilized and combined immunotherapy to increase its therapeutic efficacy. It helps in targeting tumor immune response sparing the healthy systemic immune function. In this review, we have summarized the progress of nanotechnology in terms of nanoparticle designing and targeting cancer. We have also discussed its further applications in combination therapy and cancer immunotherapy. Integrating patient-specific proteomics and biomarker based information and harnessing clinically safe nanotechnology, the development of precision nanomedicine could revolutionize the effective cancer therapy. Nanomedicine ; Cancer therapy ; Medicine ; Immunotherapy ; Cancer ; Drug delivery ; Cancer immunotherapy ; Therapeutic index ; Nanotechnology ; Biomarker ; Drug ; Pharmacology ; Nanoparticle ; Materials science ; Internal medicine ; Chemistry Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics ; RNA Interference and Gene Delivery