C2-substituted indoles were efficiently prepared with excellent regio-selectivity from N-phenylpyridin-2-amines and sulfoxonium ylides via cascade reaction of C–H alkylation/nucleophilic cyclization.
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Rhodium(III)-catalyzed synthesis of indole derivatives has been realized via cascade reaction of CH alkylation/nucleophilic cyclization starting from readily available N-phenylpyridin-2-amines and sulfoxonium ylides. Notably, this transformation could smoothly proceed with high yields, good regioselectivity, and feature broad group tolerance and under redox-neutral condition to avoid external oxidant. The titled products are potentially important building blocks in the organic synthesis through various chemical transformations.
Vesicular stomatitis virus (VSV) is an archetypal member of Mononegavirales which causes important diseases in cattle, horses and pigs. The matrix protein (M) of VSV plays critical roles in the ...replication, assembly/budding and pathogenesis of VSV. To further investigate the role of M during viral growth, we used a two-hybrid system to screen for host factors that interact with the M protein. Here, NADH: ubiquinone oxidoreductase complex assembly factor 4 (Ndufaf4) was identified as an M-binding partner, and this interaction was confirmed by yeast cotransformation and GST pulldown assays. The globular domain of M was mapped and shown to be critical for the M–Ndufaf4 interaction. Two double mutations (E156A/H157A, D180A/E181A) in M impaired the M–Ndufaf4 interaction. Overexpression of Ndufaf4 inhibited VSV propagation, and knockdown of Ndufaf4 by short hairpin RNA (shRNA) markedly promoted VSV replication. Finally, we also demonstrate that the anti-VSV effect of Ndufaf4 is independent of activation of the type I IFN response. These results indicated that Ndufaf4 might exploit other mechanisms to affect VSV replication. In summary, we identify Ndufaf4 as a potential target for the inhibition of VSV propagation. These results provided further insight into the study of VSV pathogenesis.
Polymers with a carbon–carbon (C–C) backbone are an important class of polymers, which can be regarded as the derivatives of polyethylene (PE). To investigate the effect of side chains on the ...single-chain enthalpic elasticity (SCEE) of polymers with a C–C backbone, several polymers with pendants or side chains of different lengths and shapes have been studied by single-molecule AFM. We find that both length and shape of the side chains count: only the side chains that are both long and bulky (i.e., bulky dendrons of second or higher generation as side chains) affect the SCEE. Thus, only rare polymers have special SCEE. For the vast majority of polymers, the SCEE is identical to that of PE, which means that the SCEE is determined by the nature of the C–C backbone. It is expected that this conclusion can also be popularized to all polymers with various backbones. This study is an important update to the understanding of polymers at the single-chain level.
Cerussite is a lead oxide mineral resource that is typically enriched through sulfidization flotation. The surface sulfidation degree and the high solubility of cerussite strongly affect the ...flotation ability of cerussite. In the current work, lead ions were used to pretreat cerussite to intensify its sulfidization flotation. The sulfidization mechanism regulating the lead ions pretreatment on cerussite was investigated by the micro-flotation test, ToF-SIMS, zeta potential measurement, adsorption test, and XPS. The results from the micro-flotation test demonstrated that the floatability of cerussite could be improved by adding an appropriate amount of lead ions. Compared with the treatment involving only Na
S, the maximum recovery increased by 17.57%. Adsorption experiments showed that lead modification improved the stability of xanthate products on the surface of cerussite. According to the measurement of zeta potential and the results of ToF-SIMS, the addition of lead ion Pb pretreatment increased the number of active Pb sites adsorbed by xanthate, thereby improving the formation of hydrophobic Pb-dilute precipitate. Therefore, the interaction between lead ions and the surface of cerussite enhances the strength and stability of the hydrophobic layer, resulting in enhanced hydrophobicity of cerussite.
Abstract Purpose This study aimed to compare the effects of conventional surgery and three-dimension (3D) printing technology-assisted surgery in the treatment of posterolateral tibial plateau ...fractures (PTPF). Methods A cohort of 61 patients afflicted with PTPF, spanning from June 2015 to October 2021, was enrolled. They were divided randomly into two groups: 31 cases of 3D printing group, 30 cases of conventional group. The personalized 3D-printed models were used to simulate the surgical procedures in 3D printing group. The demographic characteristics and clinical data were recorded, encompassing operation duration, intraoperative blood loss, intraoperative fluoroscopy shoots and fracture union time. The radiographic outcomes were gauged, encompassing tibiofemoral angle (FTA), tibial plateau angle (TPA), posterolateral slope angle (PSA) and Rasmussen’s anatomical score. The functional outcomes were assessed at the 12-month postoperative juncture, encompassing range of motion, Hospital for Special Surgery (HSS) score and Rasmussen’s functional score. Furthermore, fracture complications were evaluated,, encompassing infections, traumatic osteoarthritis, and delayed union. Results The 3D printing group exhibited the operation time of 95.8 ± 30.2 min, intraoperative blood loss of 101.1 ± 55.3 ml, and intraoperative fluoroscopy shoots of 6.3 ± 2.3 times, while the conventional group recorded respective values of 115.5 ± 34.0 min, 137.0 ± 49.2 ml and 9.13 ± 2.5 times. Noteworthy disparities were evident between the conventional and 3D printing groups (p < 0.05). Furthermore, in comparison to the conventional group, the 3D printing group exhibited commendable radiological and functional outcomes both immediately and 12 months post-surgery, although statistical significance was not attained. Moreover, the 3D printing group experienced a paucity of complications compared to the conventional group, although without achieving statistical significance. Conclusion This study demonstrated the clinical feasibility of 3D printing combined with anteroposterior cannulated screws for the treatment of posterolateral tibial plateau fracture.
In general, malachite is recovered via sulfidization–xanthate flotation, although many unsatisfactory flotation indexes are frequently obtained as a result of the presence of associated calcite. This ...phenomenon occurs because the dissolved components of malachite and calcite affect the flotation behavior of both minerals. In this study, the effect of the dissolved components derived from malachite and calcite on the flotation behavior and surface characteristics of both minerals was investigated. Flotation tests indicated that malachite recovery decreased when the calcite supernatant was introduced, while the presence of the malachite supernatant increased the recovery of calcite. Dissolution and adsorption tests, along with zeta potential measurements, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometry, and time-of-flight secondary ion mass spectrometry demonstrated that the Ca species in the calcite supernatant were adsorbed on the malachite surface, which hindered the interaction of Na
2
S with malachite, thereby resulting in the insufficient adsorption of sodium isoamyl xanthate (NaIX) on the surface of malachite. By contrast, the Cu species in the malachite supernatant were adsorbed on the calcite surface, and they provided active sites for the subsequent adsorption of Na
2
S and NaIX.
LiDAR occupies a vital position in self-driving as the advanced detection technology enables autonomous vehicles (AVs) to obtain much environmental information. Ground segmentation for LiDAR point ...cloud is a crucial procedure to ensure AVs’ driving safety. However, some current algorithms suffer from embarrassments such as unavailability on complex terrains, excessive time and memory usage, and additional pre-training requirements. The Jump-Convolution-Process (JCP) is proposed to solve these issues. JCP converts the segmentation problem of the 3D point cloud into the smoothing problem of the 2D image and takes little time to improve the segmentation effect significantly. First, the point cloud marked by an improved local feature extraction algorithm is projected onto an RGB image. Then, the pixel value is initialized with the points’ label and continuously updated according to image convolution. Finally, a jump operation is introduced in the convolution process to perform calculations only on the low-confidence points filtered by the credibility propagation algorithm, reducing the time cost. Experiments on three datasets show that our approach has a better segmentation accuracy and terrain adaptability than those of the three existing methods. Meanwhile, the average time for the proposed method to deal with one scan data of 64-beam and 128-beam LiDAR is only 8.61 ms and 15.62 ms, which fully meets the AVs’ requirement for real-time performance.
A remarkably rich variety of nanophase-separated structures and various order–order transitions are observed in a series of low-molecular weight (MW) rod–coil block copolymers (BCPs) with the rod ...blocks of different lengths (L Rod’s). The rod–coil diblock copolymer studied herein is poly(dimethylsiloxane)-b-poly{2,5-bis(4-methoxyphenyl)oxycarbonylstyrene} (PDMS-b-PMPCS), in which PMPCS is a rod-like polymer and exhibits an MW-dependent liquid crystalline (LC) phase behavior. When the polymerization degree of the PMPCS rod block (N Rod) is less than 32 (L Rod < 8 nm), the PMPCS block is always amorphous in the entire temperature range. And the corresponding PDMS-b-PMPCS BCPs with N Rod from 11 to 29 and the volume fraction of the PMPCS rod (f Rod) from 43% to 67% self-assemble into various equilibrium nanostructures after annealed at temperatures above the glass transition temperatures of the PMPCS blocks. When N Rod = 11 and f Rod = 43%, the BCP forms a lamellar structure (LAM); when N Rod = 15 and f Rod = 51%, the BCP forms a double gyriod structure (GYR) ; when N Rod = 20 and f Rod = 57%, the BCP forms a GYR structure after annealed below 180 °C and transforms to the Fddd structure after annealed above 180 °C; when N Rod = 29 and f Rod = 67%, the nanostructure of the BCP after annealed below 180 °C is hexagonally packed cylinders (HEX) and changes to a body centered cubic structure (BCC) after annealed above 180 °C. When N Rod > 32 (L Rod > 8 nm), the PMPCS rod block is amorphous at low temperatures and transforms to a stable columnar LC phase after annealed at high temperatures. Correspondingly, the PDMS-b-PMPCS BCP with N Rod = 44 and f Rod = 75% forms a HEX structure after annealed at lower temperatures at which the PMPCS block is amorphous, and the nanostructure transforms to LAM after the sample is annealed at higher temperatures at which the PMPCS block enters into the LC phase. Therefore, only by a small change of the rod length in the low-MW PDMS-b-PMPCS rod–coil BCPs, various nanostructures including LAM, GYR, Fddd, HEX, and BCC are obtained. In addition, by increasing annealing temperatures, GYR-to-Fddd and HEX-to-BCC transitions are observed in the BCPs with the amorphous PMPCS, and a HEX-to-LAM transition occurs in the BCP when the LC PMPCS block undergoes an isotropic-to-LC phase transformation.
With the increasing presence of robots in our daily life, there is a strong need and demand for the strategies to acquire a high quality interaction between robots and users by enabling robots to ...understand usersʼ mood, intention, and other aspects. During human-human interaction, personality traits have an important influence on human behavior, decision, mood, and many others. Therefore, we propose an efficient computational framework to endow the robot with the capability of understanding the userʼ s personality traits based on the userʼ s nonverbal communication cues represented by three visual features including the head motion, gaze, and body motion energy, and three vocal features including voice pitch, voice energy, and mel-frequency cepstral coefficient ( MFCC ) . We used the Pepper robot in this study as a communication robot to interact with each participant by asking questions, and meanwhile, the robot extracts the nonverbal features from each participantʼ s habitual behavior using its on-board sensors. On the other hand, each participantʼ s personality traits are evaluated with a questionnaire. We then train the ridge regression and linear support vector machine ( SVM ) classifiers using the nonverbal features and personality trait labels from a questionnaire and evaluate the performance of the classifiers. We have verified the validity of the proposed models that showed promising binary classification performance on recognizing each of the Big Five personality traits of the participants based on individual differences in nonverbal communication cues.
A novel sugar-appended low-molecular-mass gelator, 4′′-butoxy-4-hydroxy-p-terphenyl-β-d-glucoside (BHTG), was synthesized. It formed thermally reversible gels in a variety of aqueous and organic ...solvents. Three-dimensional networks made up of helical ribbons were observed in the mixture of H2O/1,4-dioxane (40/60 v/v). The handedness of the ribbons depended on the rate of gel formation. Fast-cooling process led to right-handed ribbons, while slow-cooling process led to left-handed ones. A combinatory analyses of microscopic, spectroscopic, and diffraction techniques revealed that BHTG formed a twisted interdigitated bilayer structure with a d spacing of 3.1 nm in gels through a kinetically controlled nucleation−growth process. There were two kinds of molecular orientations of BHTG in the nuclei, clockwise and anticlockwise, which dictated the growth of ribbons. One was metastable and formed first during the cooling process of gel formation. It was able to gradually transform into the more stable latter one with further decreasing temperature. Fast-cooling process did not leave enough time for the nuclei to evolve from metastable to stable state and the ribbons grown from them exhibited right-handedness. However, the metastable nuclei transformed into the stable one when cooled slowly and directed the molecules of BHTG to grow into left-handed aggregates.
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