MolecularWebXR is a new web-based platform for education, science communication and scientific peer discussion in chemistry and biology, based on modern web-based Virtual Reality (VR) and Augmented Reality (AR). With no installs as it is all web-served, MolecularWebXR enables multiple users to simultaneously explore, communicate and discuss concepts about chemistry and biology in immersive 3D environments, by manipulating and passing around objects with their bare hands and pointing at different elements with natural hand gestures. Users may either be present in the same physical space or distributed around the world, in the latter case talking naturally with each other thanks to built-in audio.
View Article and Find Full Text PDFThe comprehension of molecular structure is pivotal in chemistry education. Over the past decade, Mahidol University International College has employed various teaching tools for the introductory chemistry laboratory class. This paper outlines our evolutionary shift from traditional tools, such as plastic and plasticine models, to the integration of computer software, and ultimately to augmented reality (AR) and virtual reality (VR) tools-specifically, MoleculARweb and MolecularWebXR developed by École Polytechnique Fédérale de Lausanne researchers.
View Article and Find Full Text PDFNucleophilic substitution of pertosylated pillar[5]arene (P-OTs) with commercially available sulfur containing nucleophiles (KSCN, KSAc, and thiophenol), yields a series of sulfur-functionalised pillar[5]arenes. DLS results and SEM images imply that these pillararene macrocycles self-assemble in acetonitrile solution, while X-ray crystallographic evidence suggests solvent-dependent assembly in the solid state. The nature of the sulfur substituents decorating the rim of the pillararene controls binding affinities towards organic guest encapsulations within the cavity and dictates metal-ion binding properties through the formation of favorable S-M coordination bonds outside the cavity, as determined by H NMR and fluorescence spectroscopic experiments.
View Article and Find Full Text PDFCaffeine, quinic acid, and nicotinic acid are among the significant chemical determinants of coffee quality. This study develops a chemometric model to quantify these compounds in ternary mixtures analyzed by terahertz time-domain spectroscopy (THz-TDS). A data set of 480 THz spectra was obtained from 80 samples.
View Article and Find Full Text PDFLactose plays a significant role in daily lives as a constituent of various food and pharmaceutical products. Yet, lactose intolerance conditions demand low-lactose and lactose-free products in the market. These increasing nutritional claims and labels on food products entail simple and reliable methods of analysis that can be used for meeting quality standards, nutritional claims and legal requirements.
View Article and Find Full Text PDFA quantum chemical investigation of the stability of compounds with identical formulas was carried out on 23 classes of compounds made of C, N, P, O and S atoms as core structures and halogens H, F, Cl, Br and I as substituents. All possible structures were generated and investigated by quantum mechanical methods. The prevalence of a formula in which its configuration, conformation or isomer is the most stable form is calculated and discussed.
View Article and Find Full Text PDFIntermolecular interactions between an electron-rich aromatic hydroquinone (HQ) with its electron deficient counterpart, benzoquinone (BQ), result in the formation of a quinhydrone charge-transfer complex. Herein, we report a novel quinhydrone-type complex between pillar[5]quinone (P[5]Q) and HQ. Characterized by a suite of spectroscopic techniques including H NMR, UV-visible, and FTIR together with PXRD, SEM, BET, CV, and DFT modeling studies, the stability of the complex is determined to be due to an electron-proton transfer reaction coupled with a complementary donor-acceptor interaction.
View Article and Find Full Text PDFThe exhaustive enumeration of 3D chemical structures based on Z-matrix templates has recently been used in the quantum chemical investigation of constitutional isomers, diastereomers and rotamers. This simple yet powerful initial structure generation approach can apply beyond the investigation of compounds of identical formula by quantum chemical methods. This paper provides a comprehensive description of the overall concept followed by a practical tutorial to the approach.
View Article and Find Full Text PDFThe azygos lobe (AL) is an accessory lobe of the right lung with prevalence between 0.4 and 1.2%.
View Article and Find Full Text PDFObjective: The application of molecular graphics software as a simple and free alternative to molecular model sets for introductory-level chemistry learners is presented.
Results: Based on either Avogadro or IQmol, we proposed four sets of tasks for students, building basic molecular geometries, visualizing orbitals and densities, predicting polarity of molecules and matching 3D structures with bond-line structures. These topics are typically covered in general chemistry for first-year undergraduate students.
Surgeon
December 2021
Background: Anconeus epitrochlaeris muscle and Osborne's ligament are anatomical variants that are occasionally found at the cubital tunnel of the elbow. In certain individuals, these two structures may compress the ulnar nerve resulting in a cubital tunnel syndrome. Although these variants have been reported extensively, its prevalence is still unclear and its contribution to cubital tunnel syndrome is debatable.
View Article and Find Full Text PDFAll the possible polychlorinated aromatic compounds in the classes of dibenzodioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) were studied by the quantum chemical methods of HF/6-311++G(d,p), B3LYP/6-311++G(d,p), and MP2/cc-pVTZ. The calculated stabilities and structures of these compounds were compared with the available data on their abundance and toxicity. Prediction models for trends in energy and planarity among these congeners were proposed.
View Article and Find Full Text PDFThis article presents theoretical data on geometric and energetic features of halogenated rotamers of the following backbone structures, C-C, N-N, P-P, O-O, S-S, N-P, O-S, C-N, C-P, C-O, C-S, N-O, N-S, P-O and P-S. The data is considered to be comprehensive combinations of non-metal elements in the form abcx-ydef whereby a,b,c,d,e,f are halogen (fluorine to iodine), hydrogen or a lone pair and x,y are carbon, nitrogen, phosphorus, oxygen and sulfur. Data were obtained from geometry optimization and frequency calculations at HF, B3LYP, MP2 and CCSD levels of theory on 6-311++G(d,p) basis set.
View Article and Find Full Text PDFThis article presents theoretical data on geometric and energetic features of halobenzenes and xylenes. Data were obtained from geometry optimization and frequency calculations at HF, B3LYP, MP2 and CCSD levels of theory on 6-311++G(d,p) basis set. In total, 1504 structures of halobenzenes, three structures of xylenes and one structure of benzene were generated and processed by custom-made codes in Mathematica.
View Article and Find Full Text PDFThis article presents theoretical data on geometric and energetic features of halogenated compounds of ethene (C[bond, double bond]C), imine (C[bond, double bond]N), methylenephosphine (C[bond, double bond]P), iminophosphine (N[bond, double bond]P), diazene (N[bond, double bond]N), diphosphene (P[bond, double bond]P) and cyclopropane (Δ). The data were obtained from geometric optimization and frequency calculations at HF, B3LYP, MP2 and CCSD levels of theory on 6-311++G(d,p) basis set. Input structures were generated by shell scripts and run by Q-Chem quantum chemical package.
View Article and Find Full Text PDFPrevalence of mentholated products for consumption has brought great importance to studies on menthol's metabolic pathways to ensure safety, design more potent derivatives, and identify therapeutic benefits. Proposed pathways of (-)-menthol metabolism based on metabolites found experimentally in previous works by Yamaguchi, Caldwell & Farmer, Madyastha & Srivatsan and Hiki et al. were not in agreement.
View Article and Find Full Text PDFWe present simple and effective experiments to produce intricate chemical patterns from common chemicals in a classroom setting. Students selected an independent variable of their interest, designed their experiment, and investigated its effect on chemical patterns in a four-hour activity. Photographs and videos were taken, while the identity and the concentration of chemicals in the reaction mixture, the concentration of oxygen gas above the solution, the depth of the solution, the shape and the total area of container's cross section, and the temperature were varied.
View Article and Find Full Text PDFObjective: Mitragynine is the main active compound of Mitragyna speciose (Kratom in Thai). The understanding of mitragynine derivative metabolism in human body is required to develop effective detection techniques in case of drug abuse or establish an appropriate dosage in case of medicinal uses. This in silico study is based upon in vivo results in rat and human by Philipp et al.
View Article and Find Full Text PDFForty anatomy articles were sampled from English Wikipedia and assessed quantitatively and qualitatively. Quantitatively, each article's edit history was analyzed by Wikipedia X-tools, references and media were counted manually, and two readability indices were used to evaluate article readability. This analysis revealed that each article was updated 8.
View Article and Find Full Text PDFThe blue bottle experiment is a collective term for autoxidation reactions catalysed by redox indicators. The reactions are characterized by their repeatable cycle of colour changes when shaken/left to stand and intricate chemical pattern formation. The blue bottle experiment is studied based on calculated solution-phase half-cell reduction potential of related reactions.
View Article and Find Full Text PDFUse of the modern parallel programming language X10 for computing long-range Coulomb and exchange interactions is presented. By using X10, a partitioned global address space language with support for task parallelism and the explicit representation of data locality, the resolution of the Ewald operator can be parallelized in a straightforward manner including use of both intranode and internode parallelism. We evaluate four different schemes for dynamic load balancing of integral calculation using X10's work stealing runtime, and report performance results for long-range HF energy calculation of large molecule/high quality basis running on up to 1024 cores of a high performance cluster machine.
View Article and Find Full Text PDFUse of the resolution of Ewald operator method for computing long-range Coulomb and exchange interactions is presented. We show that the accuracy of this method can be controlled by a single parameter in a manner similar to that used by conventional algorithms that compute two-electron integrals. Significant performance advantages over conventional algorithms are observed, particularly for high quality basis sets and globular systems.
View Article and Find Full Text PDFA synthetic method that relies on NIS (N-iodosuccinimide)-mediated cycloisomerization reactions of 1-(2'-anilinyl)prop-2-yn-1-ols to gem-3-(diiodomethyl)indolin-2-ones and 2-(iodomethylene)indolin-3-ones has been developed. The reactions were shown to be chemoselective, with secondary and tertiary alcoholic substrates exclusively giving the 3- and 2-oxindole products, respectively. In the case of the latter, the transformation features an unprecedented double 1,2-OH and 1,2-alkyl migration relay.
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