Tertiary amines as vinyl source for the formations of aryl or pyrrole ring on amido-substitued 1,4-quinone with the assistance of palladium salt

The one-pot synthesis of 3-isopropyl-6-methyl-1H-benzo[f]indole-4,9-dione ( 3e ), N-(4-[isopentylamino]-3,6-dioxocyclohexa-1,4-dien-1-yl)acetamide ( 4d ), 2-(isopentylamino)-6-methylnaphthalene-1,4-dione ( 5b ), and 2-(4-acetamido-3,6-dioxocyclohexa-1,4-dien-1-yl)-N,N-diisopentyl-3-methylbutanamide ( 6a ) has been achieved via either pyrrol/aryl ring formations or amination reactions from the Pd(II)-catalyzed reaction of N-(3,6-dioxocyclohexa-1,4-dien-1-yl)acetamide ( 2a_BQ ) and in the presence of triisopentylamine. More 3 -, 4 -, 5 -, and 6 -like derivatives were obtained while other trialkylamines were used. Crystal structures of 3d_O , 3e , 4b , 4c , 4d , 5b, and 6a were determined by single-crystal X-ray diffraction methods. The 3 - and 5 -like products reveal the formations of newly generated benzene rings with/without substitutions. The formation of 6a also implies an unusual reaction pathway of its generation. Based on the structural conformations of various 3 -like products, as well as 6a , mechanisms were proposed to account for the formations of these compounds. Various fascinating conformations of products observed in this work demonstrate the diversities of this type of reactions.     

Rhodamine‐Ethylenediol,A Novel Vital Fluorescent Probe for Labelling Alkaline Phosphatase‐Rich Organelles

Zebrafish have received considerable attention as an organism‐based model in the development of pharmacological agents.^1,2 Many small molecules applied to zebrafish show important behaviours and may constitute new kinds of markers for clinical purposes.³ Analysis of these molecules can facilitate the development of useful tools for monitoring environmental changes.⁴ Many chemicals that are toxic to the environment are known to influence the sensory systems of humans⁵ and fish.⁶ One important sensory system in all fish is the lateral line organ,⁷ which is readily accessible for the assessment of environmental changes.⁸ Neuromasts, which are located on the surface of the fish body, are one of the major components of the lateral lines of the zebrafish.⁹ Copper‐enriched water is known to affect the olfactory system in fish. Therefore, small molecules that induce specific patterns in the neuromasts of zebrafish should provide an important animal model with which to explore the effects of environmental changes on the sensory system.^10,11 Recently, chemical sensors based on the rhodamine skeleton¹² have been designed to specifically detect metal ions, such as Cu(II)¹³ and Fe(III)/Hg(II),¹⁴ in zebrafish. However, there has been no report of these rhodamine derivatives used in the specific recognition of the sensory system of zebrafish. Commonly, the sensory system is studied with antibody staining assays of scarified fish. Here, we report that a new rhodamine derivative can be used as a fluorescent chemical probe to visualize the neuromasts and intestinal villi of living zebrafish. Based on the specific recognition of this area in zebrafish, we narrowed the possible enzymes targeted by this rhodamine probe to alkaline phosphatase and confirmed this with a binding assay. It is a well‐recognized challenge to develop a fluorescent chemical probe that specifically recognizes a particular enzyme. Furthermore, the transfer of phosphate groups to certain enzymes can activate their catalytic reactivity, triggering a cascade reaction in a signal transduction pathway. The alkaline‐phosphatase‐specific recognition by this rhodamine derivative may be applicable to clinical purposes.     

Hybrid Basketball Game Outcome Prediction Model by Integrating Data Mining Methods for the National Basketball Association

The sports market has grown rapidly over the last several decades. Sports outcomes prediction is an attractive sports analytic challenge as it provides useful information for operations in the sports market. In this study, a hybrid basketball game outcomes prediction scheme is developed for predicting the final score of the National Basketball Association (NBA) games by integrating five data mining techniques, including extreme learning machine, multivariate adaptive regression splines, k-nearest neighbors, eXtreme gradient boosting (XGBoost), and stochastic gradient boosting. Designed features are generated by merging different game-lags information from fundamental basketball statistics and used in the proposed scheme. This study collected data from all the games of the NBA 2018–2019 seasons. There are 30 teams in the NBA and each team play 82 games per season. A total of 2460 NBA game data points were collected. Empirical results illustrated that the proposed hybrid basketball game prediction scheme achieves high prediction performance and identifies suitable game-lag information and relevant game features (statistics). Our findings suggested that a two-stage XGBoost model using four pieces of game-lags information achieves the best prediction performance among all competing models. The six designed features, including averaged defensive rebounds, averaged two-point field goal percentage, averaged free throw percentage, averaged offensive rebounds, averaged assists, and averaged three-point field goal attempts, from four game-lags have a greater effect on the prediction of final scores of NBA games than other game-lags. The findings of this study provide relevant insights and guidance for other team or individual sports outcomes prediction research.     

Formation of CC-type palladacycles with assistance from an apparently innocent NH(CO) functional group

A novel cyclometalation pathway to form CC-type palladacycles is reported. Unlike common donor-assisted cyclometalation, the NH(CO) auxiliary group undergoes a deprotonation step to form a palladalactam intermediate. The coordinating nitrogen atom functions as an intramolecular base promoting selective C-H bond cleavage. Without the NH proton, the ortho-N-phenyl C-H is activated instead.     

Scattering of sound from point sources by multiple circular cylinders using addition theorem and superposition technique

In this study, we use the addition theorem and superposition technique to solve the scattering problem with multiple circular cylinders arising from point sound sources. Using the superposition technique, the problem can be decomposed into two individual parts. One is the free‐space fundamental solution. The other is a typical boundary value problem (BVP) with specified boundary conditions derived from the addition theorem by translating the fundamental solution. Following the success of null‐field boundary integral formulation to solve the typical BVP of the Helmholtz equation with Fourier densities, the second‐part solution is easily obtained after collocating the observation point exactly on the real boundary and matching the boundary condition. The total solution is obtained by superimposing the two parts which are the fundamental solution and the semianalytical solution of the Helmholtz problem. An example was demonstrated to validate the present approach. The parameter study of size and spacing between cylinders are addressed. The results are well compared with the available theoretical solutions and experimental data. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2011     

Cellular Uptake of a Polypyridyl Ruthenium Complex Revealed Using a Fluorescent Rhodamine‐modified Ruthenium Complex

A fluorescent polypyridyl ruthenium complex was successfully prepared using an amide bond linkage to link two rhodamine moieties through bipyridine groups. Although photo‐induced electron transfer (PET) quenched the fluorescent intensity, the quantum yield of the rhodamine‐modified Ru(II) complex was 0.17 in water, sufficient for observing the fluorophore behaviour in biological systems. The rhodaminemodified Ru(II) complex was found to inhibit the bacterial growth of E. coli. In vitro fluorescence images of human hepatoma cells (SK‐Hep1) showed that a fluorescent polypyridyl ruthenium complex not only supported the above observation but also preferably accumulated in the cytoplasmic region inside the cell. These observations suggest that in addition to strong Ru–DNA interactions, Ru‐protein interactions in the cytoplasmic regions are strong and are therefore important to the development of metallopharmaceuticals.     

Optical anisotropy of ZnO nanocrystals on sapphire by thermoreflectance spectroscopy

The band-edge excitonic transitions of vertically aligned and tilted ZnO nanorods on sapphire have been characterized using thermoreflectance (TR) measurements in the temperature range between 30 and 300 K. The TR spectra of the nanorods with largely {0001} planes show considerable difference in energy and line shape with respect to those of the other sample with largely side planes of {1010}. The TR result at each temperature clearly indicates the band-edge excitons (A, B, and C) measured from the largely {0001} planes of the rods are lower in energy with respect to those obtained from the other sample dominated by the side planes of {1010}. Optical anisotropy in the transition amplitudes of the TR spectra for the vertically aligned and tilted ZnO nanorods is observed. The TR is shown to be very sensitive to the detection of the ZnO nanorods' alignment.