Search

Robots, as the creation of human, became an irreplaceable component in human society. With the advancement of technologies, robots become more and more intelligent and have been widely used in many fields, such as disease diagnosis, customer services, healthcare for the older people, and so on. As robots made our lives much more convenient than ever before, they also brought many potential risks and challenges in technology, security, and ethic. To better understand the development of robots, we proposed a concept of a robot’s living space and analyzed the role of robots in our society. In this paper, we focus on setting a theoretical framework of the robot’s living space to further understand the human-robot relationship. The research in this paper contains three central aspects. First, we interpret the concept of the robot’s living space and functions of each space. Second, we analyze and summarize the relative technologies which support robots living well in each space. Finally, we provide advice and improvement measures based on a discussion of potential problems caused by the developments of robots. With the trend of robots humanization and human-robot society integration, we should seriously consider how to make a collaboration with intelligent robots to achieve hybrid intelligence. To build a harmonious human-robot integrated society, studying the robot’s living space and its relationship with humans is the pre-requisite and roadmap.

Nitrate transporters (NRTs) participate in nitrate uptake, transport and allocation within the plant. However, this gene family has not been studied thoroughly in spinach. This study provided the general information about spinach SoNRTs and their transcriptional and functional responses to different levels of nitrate supplies. Resultes showed that fifty-seven NPF (also known as NRT1), nine NRT2 and one NRT3 were identified in spinach homologous to characterized Arabidopsis NRT genes. Phylogenetic analysis organized the SoNRT family into three clades: NPF with three subclades, NRT2, and NRT3. The tested SoNRT genes showed the various expression profiles in relation to tissue specificity and nitrate supply, indicating their functional diversity in response to external nitrate supply. Among them, transgenic Arabidopsis plants overexpressing SoNPF30 showed improved biomass, decreased shoot nitrate contents but no significant difference of 15NO3- uptake rates when compared with those of the wild type in response to high N treatment. Under low N treatment, overexpressing of SoNRT3 significantly increased whole plant biomass, root nitrate contents and 15NO3- uptake rates. These demonstrated that SoNPF30 and SoNRT3 confer greater capacity for nitrate translocation or nitrate uptake, and could help to improve the ability of plant nitrogen utilization under those conditions. Our findings provide a valuable basis for future research on this family of genes in spinach.

A sensitive, accurate and rapid UHPLC–MS/MS method was developed and validated for the simultaneous determination of EVT201 and its two metabolites, Ro46-1927 and Ro18-5528, in human plasma. D6-EVT201 was used as the internal standard (IS). Plasma samples were extracted using ethyl acetate after being alkalized with saturated sodium carbonate solution. Chromatographic separation was carried out on an Acquity BEH C18 column (2.1 × 50 mm, 1.7 μm) with a gradient mobile phase at a flow-rate of 0.50 mL/min. The analytical run time was 5.5 min. For mass spectrometric detection, multiple reaction monitoring (MRM) was used. The MRM ion transitions were m/z 373.2 → 58.0 for EVT201, m/z 359.2 → 316.1 for Ro46-1927, m/z 291.2 → 274.1 for Ro18-5528 and m/z 379.3 → 64.0 for the IS. The linear range was 0.2–200 ng/mL for each analyte, with a correlation coefficient (r) over 0.9900. The intra-/inter- precision was within 7.9% and 4.5% for EVT201, 13.2% and 6.3% for Ro46-1927, 3.7% and 4.1% for Ro18-5528. For the accuracy, the relative bias of intra-/inter- run was no more than 6.4% and 4.6% for EVT201, 9.4% and 7.9% for Ro46-1927, −6.9% and −7.5% for Ro18-5528. The validated method was successfully applied to the analysis of more than 1500 samples from a Phase I clinical trial. The incurred sample reanalysis (ISR) of 146 samples from the study was evaluated and the results met the acceptance criteria. It indicated that the method could be used for the pharmacokinetic study of EVT201.

In this paper, we develop a high order semi-Lagrangian (SL) discontinuous Galerkin (DG) method for nonlinear Vlasov-Poisson (VP) simulations without operator splitting. In particular, we combine two recently developed novel techniques: one is the high order non-splitting SLDG transport method [Cai, et al., J Sci Comput, 2017], and the other is the high order characteristics tracing technique proposed in [Qiu and Russo, J Sci Comput, 2017]. The proposed method with up to third order accuracy in both space and time is locally mass conservative, free of splitting error, positivity-preserving, stable and robust for large time stepping size. The SLDG VP solver is applied to classic benchmark test problems such as Landau damping and two-stream instabilities for VP simulations. Efficiency and effectiveness of the proposed scheme is extensively tested. Tremendous CPU savings are shown by comparisons between the proposed SL DG scheme and the classical Runge-Kutta DG method.

Time-frequency distributions (TFDs) are key indicators for inspecting debonding defects using ultrasonic nondestructive testing (NDT) or nondestructive examination (NDE). A novel algorithm combining empirical wavelet transform (EWT), Hilbert transform (HT) and short time Fourier transform (STFT) is presented to obtain the TFD of ultrasonic testing waves. First, we decompose the signal into mono-components by means of EWT to satisfy the mono-component requirement of HT. Next, correlation coefficients between the empirical modes and the decomposed signal are computed to extract valuable components. Further, the instantaneous amplitude (IA) of the extracted valuable components are calculated using HT. Finally, using the computed IAs, the peak time representing the arrival time of the component is obtained. To calculate the corresponding frequency, a method based on STFT is applied on the valuable components. The principle of the proposed method is illustrated by a numerical signal. The effectiveness of the proposed method in extracting the TFD of ultrasonic testing wave is validated by an experimental analysis of the ultrasonic NDT used for the detection of debonding defect in a composite construction. In comparison with STFT, smoothed pseudo Wigner-Ville distribution (SPWVD), and empirical mode decomposition (EMD), a higher accuracy of the TFD can be obtained using the proposed algorithm.

In this paper, a conservative semi-Lagrangian (CSL) kinetic scheme coupled with an implicit finite element method (IFEM) is developed for multidimensional electromagnetic plasma simulations. The present method (CSL-IFEM) enjoys the respective advantages of the CSL and IFEM, including mass conservation, high-order spatial accuracy, as well as being free from the Courant-Friedrichs-Lewy (CFL) condition. In present CSL-IFEM, the CSL scheme with a general high order positivity-preserving limiter is utilized for the spatial discretization of the Vlasov equation, which enables the proposed method to remove the CFL limitation in phase space, exactly conserve mass, and preserve the positivity of the distribution function. The IFEM solver is developed for the spatial discretization of the Maxwell equation, which makes the current method free from CFL limitation induced by the speed of light and easily handles general field boundary conditions. To make the proposed CSL-IFEM more efficient in multidimensional simulations, the dimensional splitting procedure and sparse matrix technology are implemented in CSL and IFEM, respectively. Then the Vlasov solver CSL and Maxwell solver IFEM are coupled via the current density calculated from the general Ohm law. Finally, several numerical experiments, including electromagnetic wave (2d0v), particle gyromotion (0d2v), streaming Weibel instability (1d2v) and magnetic reconnection (2d3v), are performed to demonstrate the capabilities of the proposed method.

In this paper, we propose a semi-Lagrangian discontinuous Galerkin method coupled with Runge-Kutta exponential integrators (SLDG-RKEI) for nonlinear Vlasov dynamics. The commutator-free Runge-Kutta (RK) exponential integrators (EI) were proposed by Celledoni, et al. (FGCS, 2003). In the nonlinear transport setting, the RKEI can be used to decompose the evolution of the nonlinear transport into a composition of a sequence of linearized dynamics. The resulting linearized transport equations can be solved by the semi-Lagrangian (SL) discontinuous Galerkin (DG) method proposed in Cai, et al. (JSC, 2017). The proposed method can achieve high order spatial accuracy via the SLDG framework, and high order temporal accuracy via the RK EI. Due to the SL nature, the proposed SLDG-RKEI method is not subject to the CFL condition, thus they have the potential in using larger time-stepping sizes than those in the Eulerian approach. Inheriting advantages from the SLDG method, the proposed SLDG-RKEI schemes are mass conservative, positivity-preserving, have no dimensional splitting error, perform well in resolving complex solution structures, and can be evolved with adaptive time stepping sizes. We show the performance of the SLDG-RKEI algorithm by classical test problems for the nonlinear Vlasov-Poisson system, as well as the Guiding center Vlasov model. Though that it is not our focus of this paper to explore the SLDG-RKEI scheme for nonlinear hyperbolic conservation laws that develop shocks, we show some preliminary results on schemes' performance on the Burgers' equation.

Objective To investigate the effect of Qiguiyishen decoction (QGYS) on the severity of nephropathy. Methods Twenty-four rats were randomly divided into four groups (I, II, III, IV) according to the random number table. Group I as control group did not establish nephropathy model. Groups II, III, and IV were intravenously administered Adriamycin (7.5 mg/kg) through the tail vein to establish nephropathy model. QGYS was prepared with the extracts of Huangqi ( Radix Astragali Mongolici ), Danggui ( Radix Angelicae Sinensis ), Niuxi ( Radix Achyranthis Bidentatae ), and Chuanxiong ( Rhizoma Chuanxiong ). Group IV was administered QGYS (2 mL · kg −1 · d −1 ), group III was administered benazepril (10 mL · kg −1 · d −1 ), and group I, II was administered water (2 mL · kg −1 · d −1 ) once daily for eight weeks. Results QGYS reduced the excretion of urinary protein and N-acetyl-β-D-glucosaminidase and alleviated the accumulation of extracellular matrix (ECM) in renal tissue. Additionally, QGYS effectively regulated the levels of transforming growth factor, tissue inhibitor of matrix metalloproteinase, and matrix metalloproteinases in the kidney of the rats. Conclusion QGYS may reduce the accumulation of ECM in the kidneys of rats with Adriamycin-induced nephropathy.

SummaryHormaomycin produced by Streptomyces griseoflavus is a structurally highly modified depsipeptide that contains several unique building blocks with cyclopropyl, nitro, and chlorine moieties. Within the genus Streptomyces, it acts as a bacterial hormone that induces morphological differentiation and the production of bioactive secondary metabolites. In addition, hormaomycin is an extremely potent narrow-spectrum antibiotic. In this study, we shed light on hormaomycin biosynthesis by a combination of feeding studies, isolation of the biosynthetic nonribosomal peptide synthetase (NRPS) gene cluster, and in vivo and in vitro functional analysis of enzymes. In addition, several nonnatural hormaomycin congeners were generated by feeding-induced metabolic rerouting. The NRPS contains numerous highly repetitive regions that suggest an evolutionary scenario for this unusual bacterial hormone, providing new opportunities for evolution-inspired metabolic engineering of novel nonribosomal peptides.

Mycobacterium goodii X7B, a facultative thermophilic bacterium, cleaving the C-S bond of dibenzothiophene via a sulfur-specific pathway, was investigated for DBT in tetradecane and crude oil desulfurization. The extent of growth was improved by fed-batch culture controlled at a constant pH. The total sulfur level of dibenzothiophene in tetradecane, was reduced by 99%, from 200 to 2 ppm within 24h at 40 degrees C. After 72 h treatment, 59% of the total sulfur content in Liaoning crude oil was removed, from 3600 to 1478 ppm.

Several methods to prepare a biodesulfurization (BDS) biocatalyst were investigated in this study using a strain of Rhodococcus sp. 1awq. This bacterium could selectively remove sulfur from dibenzothiophene (DBT) via the "4S" pathway. DBT, dimethylsulfoxide (DMSO), sodium sulphate and mixed sulfur sources were used to study their influence on cell density, desulfurization activity, desulfurization ability, and the cost of biocatalyst production. In contrast to that observed from bacteria cultured in DBT, only partial desulfurization activity of strain 1awq was induced by DBT after cultivation in a medium containing inorganic sulfur as the sole sulfur source. The biocatalyst, prepared from culture with mixed sulfur sources, was found to possess desulfurization activity. With DMSO as the sole sulfur source, the desulfurization activity was shown to be similar to that of bacteria incubated in medium with DBT as the sole sulfur source. The biocatalyst prepared by this method with the least cost could remove sulfur from hydrodesulfurization (HDS)-treated diesel oil efficiently, providing a total desulfurization percent of 78% and suggesting its cost-effective advantage.