Silver chalcogenolate cluster assembled materials (SCAMs) are a category of promising light‐emitting materials the luminescence of which can be modulated by variation of their building blocks ...(cluster nodes and organic linkers). The transformation of a singly emissive Ag12(SBut)8(CF3COO)4(bpy)4n (Ag12bpy, bpy=4,4′‐bipyridine) into a dual‐emissive (Ag12(SBut)6(CF3COO)6(bpy)3)n (Ag12bpy‐2) via cluster‐node isomerization, the critical importance of which was highlighted in dictating the photoluminescence properties of SCAMs. Moreover, the newly obtained Ag12bpy‐2 served to construct visual thermochromic Ag12bpy‐2/NH2 by a mixed‐linker synthesis, together with dichromatic core–shell Ag12bpy‐2@Ag12bpy‐NH2‐2 via solvent‐assisted linker exchange. This work provides insight into the significance of metal arrangement on physical properties of nanoclusters.
Tandem varying of Ag cluster structure and tuning mixed linkers in a stepwise fashion are used to achieve dual‐emitting homogeneous and core–shell silver chalcogenolate cluster assembled materials. The arrangements of silver in the cluster are demonstrated to play a fundamentally important role in luminescence.
Locomotion mode identification is essential for the control of a robotic rehabilitation exoskeletons. This paper proposes an online support vector machine (SVM) optimized by particle swarm ...optimization (PSO) to identify different locomotion modes to realize a smooth and automatic locomotion transition. A PSO algorithm is used to obtain the optimal parameters of SVM for a better overall performance. Signals measured by the foot pressure sensors integrated in the insoles of wearable shoes and the MEMS-based attitude and heading reference systems (AHRS) attached on the shoes and shanks of leg segments are fused together as the input information of SVM. Based on the chosen window whose size is 200 ms (with sampling frequency of 40 Hz), a three-layer wavelet packet analysis (WPA) is used for feature extraction, after which, the kernel principal component analysis (kPCA) is utilized to reduce the dimension of the feature set to reduce computation cost of the SVM. Since the signals are from two types of different sensors, the normalization is conducted to scale the input into the interval of 0, 1. Five-fold cross validation is adapted to train the classifier, which prevents the classifier over-fitting. Based on the SVM model obtained offline in MATLAB, an online SVM algorithm is constructed for locomotion mode identification. Experiments are performed for different locomotion modes and experimental results show the effectiveness of the proposed algorithm with an accuracy of 96.00% ± 2.45%. To improve its accuracy, majority vote algorithm (MVA) is used for post-processing, with which the identification accuracy is better than 98.35% ± 1.65%. The proposed algorithm can be extended and employed in the field of robotic rehabilitation and assistance.
•The proposed online sparse GP algorithm is effective to approximate the HMI using the pHRI.•GRA method is capable of constructing the final training dataset.•Kalman smoother can eliminate noises ...meanwhile predict forward for the pHRI signal.•Laboratory experiment is conducted to validate the effectiveness of the proposed method.•The wearer wearing the robotic exoskeleton can walk on different terrains without any transition.
Human motion intent (HMI) acquiring by using physical human robot interaction (pHRI) information is one of the most crucial issues for lower extremity exoskeleton control. The mapping from the pHRI information to the HMI is complicated and nonlinear since the wearer is in the control loop, which is difficult to be modeled directly via mathematical tools. The nonlinear approximation can be learned by using machine learning approaches, e.g., Gaussian Process (GP) regression, which is suitable for high-dimensional and small-sample nonlinear regression problems. However, GP regression is restrictive for large scale datasets due to its computation complexity. In this paper, an online sparse GP algorithm is proposed to learn the HMI, where the input is the pHRI signal and the output is the angular increment of the active joints, i.e., the knee joints. The data of HRI is collected by the torque sensor and the angular position of the active joint is measured by the optical position sensor respectively. The pHRI signal is dealt with Kalman smoother to achieve the following functions, i.e., (1) eliminating noise and (2) predicting forward. The learned HMI via the online sparse GP regression algorithm is regarded as the reference trajectory of the lower extremity exoskeleton. A fuzzy-PID control strategy is designed to drive the robotic exoskeleton to follow the estimated HMI. Prototype experiments are performed on the subjects who wear the exoskeleton system to walk on different terrains without any transition. The experimental results validated the effectiveness of the proposed algorithm. The online sparse GP regression algorithm is capable of learning the HMI based on the pHRI and the fuzzy-PID can shadow the HMI quite well.
β‐Amino sulfones are commonly found structural motifs in biologically active compounds. Herein, we report a direct photocatalyzed amino‐sulfonylation reaction of alkenes for the efficicient ...production of important compounds by simple hydrolysis without the need for additional oxidants and reductants. In this transformation, the sulfonamides worked as bifunctional reagents, simultaneously generating sulfonyl radicals and N‐centered radicals which were added to alkene in a highly atom‐economical fashion with high regioselectivity and diastereoselectivity. This approach showed high functional group tolerance and compatibility, facilitating the late‐stage modification of some bioactive alkenes and sulfonamide molecules, thereby expanding the biologically relevant chemical space. Scaling up this reaction led to an efficient green synthesis of apremilast, one of the best‐selling pharmceuticals, demonstrating the synthetic utility of the applied method. Moreover, mechanistic investigations suggest that an energy transfer (EnT) process was in operation.
A benign method was developed for the economical and sustainable amino‐sulfonylation of alkenes with high regioselectivity and diastereoselectivity. This approach showed high functional group tolerance and compatibility, facilitating the late‐stage modification of some bioactive alkenes and sulfonamide molecules, thereby expanding the biologically relevant chemical space. Mechanistic investigations suggest that an energy transfer (EnT) process was in operation.
Abstract
We report on the results of a new spectroscopic monitoring campaign of the quasar PG 0026+129 at the Calar Alto Observatory 2.2 m telescope from 2017 July to 2020 February. Significant ...variations in the fluxes of the continuum and broad emission lines, including H
β
and He
ii
, were observed in the first and third years, and clear time lags between them are measured. The broad H
β
line profile consists of two Gaussian components: an intermediate-width H
with an FWHM of 1964 ± 18
and another very broad H
with an FWHM of 7570 ± 83
. H
has long time lags of ∼40–60 days in the rest frame, while H
shows nearly zero time delay with respect to the optical continuum at 5100 Å. The velocity-resolved delays show consistent results: lags of ∼30–50 days at the core of the broad H
β
line and roughly zero lags at the wings. H
has a redshift of ∼400
, which seems to be stable for nearly 30 yr by comparing with archived spectra, and may originate from an infall. The rms spectrum of H
shows a double-peaked profile with brighter blue peak and extended red wing in the first year, which matches the signature of a thin disk. Both the double-peaked profile and the near-zero lag suggest that H
comes from a region associated with the part of the accretion disk that emits the optical continuum. Adopting the FWHM (in the rms spectrum) and the time lag measured for the total H
β
line, and a virial factor of 1.5, we obtain a virial mass of
for the central black hole in this quasar.
In the present study, a novel amino-functionalized magnetic aerobic granular sludge-biochar (NH2-M-AGS) was successfully fabricated through magnetization and functional modification and applied for ...Pb(II) sorption. The composite was characterized by using scanning electron microscopy (SEM), energy dispersive spectrum (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Zeta potential analysis, vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS). The effects of adsorbent dosage, pH value, contact time and initial metal concentration on the adsorption of Pb(II) were investigated by using batch equilibrium experiments. It was concluded that the pseudo-second-order model was better to describe adsorption kinetic of Pb(II) onto NH2-M-AGS. The Langmuir model was more accorded with the experimental data, and the maximum adsorption capacity of Pb(II) was 127.0 mg/g. A possible adsorption mechanism could be mainly caused by surface complexation, electrostatic attraction and precipitation. In five adsorption-desorption cycles, the desorption efficiency of Pb(II) exhibited a slight decline and still reached at 88.14%. Furthermore, the good reproducibility indicated that NH2-M-AGS could be used a desirable, economic and recyclable adsorbent in practical metal-contaminated wastewater treatment.
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•NH2-M-AGS composite was fabricated with high removal efficiency for Pb(II).•The adsorption process follows the pseudo-second-order model and the Langmuir model.•The maximum adsorption capacity of NH2-M-AGS for Pb(II) was 127.0 mg/g.•In five adsorption-desorption cycles, the removal efficiency of NH2-M-AGS still reached at 88.14%.
Building blocks with multiple components are promising for the synthesis of complex molecular assemblies, but are rarely available. Herein, we report a modification procedure for a multi‐component ...building block Ln3Ti(HSA)6(SA)4(H2O)− ({Ln3Ti‐SA}, H2SA=salicylic acid, Ln=Eu/Gd) to form new building blocks {Ln3Tix‐MSA} (H2MSA=5‐methoxysalicylic acid, x=1, 2, 3) by constructing Ti(MSA)32− units. The obtained {Ln3Tix‐MSA} can further assemble into a chiral Ln22Ti14 ring with the formulae Eu22Ti14(MSA)48(HMSA)22(CH3COO)4(H2O)10(iPrOH) and Gd22Ti14(MSA)46(HMSA)26(CH3COO)4(H2O)8. Parallel experiments without Ti4+ result in linear Ln chains. Detailed analysis shows that the Ti(MSA)44− unit makes the originally variable Ln chains become available building blocks and the modified Ti(MSA)32− further triggers interesting chiral‐sorting behavior. Finally, the electronic adsorption and magneto‐optic responses of these molecular rings are investigated.
A modification procedure on a 15‐component building block of achiral Ln24Ti8 wheel‐like assemblies has been developed to obtain new accessible building blocks, resulting in a pair of new chiral enantiomers in elusive Ln–Ti systems.
Drug discovery is important in cancer therapy and precision medicines. Traditional approaches of drug discovery are mainly based on in vivo animal experiments and in vitro drug screening, but these ...methods are usually expensive and laborious. In the last decade, omics data explosion provides an opportunity for computational prediction of anti-cancer drugs, improving the efficiency of drug discovery. High-throughput transcriptome data were widely used in biomarkers' identification and drug prediction by integrating with drug-response data. Moreover, biological network theory and methodology were also successfully applied to the anti-cancer drug discovery, such as studies based on protein-protein interaction network, drug-target network and disease-gene network. In this review, we summarized and discussed the bioinformatics approaches for predicting anti-cancer drugs and drug combinations based on the multi-omic data, including transcriptomics, toxicogenomics, functional genomics and biological network. We believe that the general overview of available databases and current computational methods will be helpful for the development of novel cancer therapy strategies.
Abstract
In this work, we present the first results of the long-term high-cadence spectroscopic monitoring of 15 PG quasars with relatively strong Fe
ii
emission, as a part of a broader reverberation ...mapping campaign performed using the Calar Alto Observatory’s 2.2 m telescope. The
V
-band, 5100 Å continuum, and H
β
broad emission line light curves are measured for a set of quasars for periods ranging from dozens to more than a hundred epochs between 2017 May and 2020 July. Accurate time lags between the variations of the H
β
broad-line fluxes and the optical continuum strength are obtained for all 15 quasars, ranging from
17.0
−
3.2
+
2.5
to
95.9
−
23.9
+
7.1
days in the rest frame. The virial masses of the central supermassive black holes are derived for all 15 quasars, ranging between
0.50
−
0.19
+
0.18
and
19.17
−
2.73
+
2.98
in units of 10
7
M
⊙
. For 11 of the objects in our sample, this is the first reverberation analysis to be published. Of the rest, two objects have been the subject of previous reverberation studies, but we determine time lags for these that are only half as long as those found in the earlier investigations, which had only been able to sample much more sparsely. The remaining two objects have previously been monitored with high sampling rates. Our results here are consistent with the earlier findings, in the sense that the time lag and the line width vary inversely, consistent with virialization.
The targeted therapy for triple-negative breast cancer (TNBC) is a great challenge due to our poor understanding on its molecular etiology. In the present study, our clinical data showed that the ...expression of G-protein coupled estrogen receptor (GPER) is negatively associated with lymph node metastasis, high-grade tumor and fibronectin (FN) expression while positively associated with the favorable outcome in 135 TNBC patients. In our experimental studies, both the in vitro migration and invasion of TNBC cells were inhibited by GPER specific agonist G-1, through the suppression of the epithelial mesenchymal transition (EMT). The G-1 treatment also reduced the phosphorylation, nuclear localization, and transcriptional activities of NF-κB. While over expression of NF-κB attenuated the action of G-1 in suppressing EMT. Our data further illustrated that the phosphorylation of GSK-3β by PI3K/Akt and ERK1/2 mediated, at least partially, the inhibitory effect of G-1 on NF-κB activities. It was further confirmed in a study of MDA-MB-231 tumor xenografts in nude mice. The data showed that G-1 inhibited the in vivo growth and invasive potential of TNBC via suppression of EMT. Our present study demonstrated that an activation of GPER pathway elicits tumor suppressive actions on TNBC, and supports the use of G-1 therapeutics for TNBC metastasis.
•GPER is negatively correlated with the progression of TNBC.•G-1 inhibits the in vitro motility of TNBC cells via suppression of EMT.•The inhibition of NF-κB mediates G-1 induced EMT suppression.•GSK-3β is involved in G-1 suppressed NF-κB activities.•PI3K/Akt and ERK1/2 are involved in G-1 induced phosphorylation of GSK-3β.
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