A Novel Data-Driven Fault Detection Method Based on Stable Kernel Representation for Dynamic Systems.

With the steady improvement of advanced manufacturing processes and big data technologies, modern industrial systems have become large-scale. To enhance the sensitivity of fault detection (FD) and overcome the drawbacks of the centralized FD framework in dynamic systems, a new data-driven FD method based on Hellinger distance and subspace techniques is proposed for dynamic systems. Specifically, the proposed approach uses only system input/output data collected via sensor networks, and the distributed residual signals can be generated directly through the stable kernel representation of the process. Based on this, each sensor node can obtain the identical residual signal and test statistic through the average consensus algorithms. In addition, this paper integrates the Hellinger distance into the residual signal analysis for improving the FD performance. Finally, the effectiveness and accuracy of the proposed method have been verified in a real multiphase flow facility.

The role of activated monocyte IFN/SIGLEC1 signalling in Graves' disease.

Graves' disease (GD) is characterized by dysregulation of the immune system with aberrant immune cell function. However, there have been few previous studies on the role of monocytes in the pathology of GD. The object of this study was to investigate whether and how monocytes participate in GD pathology. CD14+ monocytes were isolated from untreated initial GD patients and healthy controls. Then, RNA-seq was performed to investigate changes in global mRNA expression in monocytes and found that type I interferon (IFN) signalling was among the top upregulated signalling pathways in GD monocytes. Type I IFN-induced sialic acid-binding immunoglobulin-like lectin1 (SIGLEC1) expression was significantly upregulated in untreated GD patients and correlated with thyroid parameters. Patient serum SIGLEC1 concentrations were reduced after anti-thyroid drug treatment. Inhibiting SIGLEC1 expression could inhibit proinflammatory cytokine (IL-1ß, IL-6, IL-8, IL-10 and M-CSF) expression in monocytes. In conclusion, our study suggested that type I IFN-mediated monocyte activation could have a deleterious effect on the pathogenesis of GD. These observations indicated that the inhibition of type I IFN-activated monocytes/macrophages could have a therapeutic effect on GD remission.

One-pot catalyst-free synthesis of benzopyrroxazine derivatives by a mutually activated sequential annulation process.

A one-pot catalyst-free reaction of o-hydroxyaryl azomethine ylides, vinyl pyridines and paraformaldehyde for the synthesis of benzopyrroxazines is reported, which offers a straightforward and atom-economical procedure for the preparation of benzopyrroxazine derivatives in moderate to excellent yields under mild conditions. A self-catalyzed [3 + 2] annulation through a mutual activation method and a sequential non-catalyzed [5 + 1] annulation process contribute to this strategy. The corresponding control experiments have been conducted to reveal the mechanism of this reaction.

High-Content Lithium Aluminum Titanium Phosphate-Based Composite Solid Electrolyte with Poly(ionic liquid) Binder.

Solid electrolytes have been regarded as the most promising electrolyte materials for the next generation of flexible electronic devices due to their excellent safety and machinability. Herein, composite solid electrolytes (CSE) with "polymer in ceramic" are prepared by using lithium aluminum titanium phosphate (LATP) as a matrix and modified poly(ionic liquid) as a binder. The results revealed that adding a poly(ionic liquid)-based binder not only endowed good flexibility for solid electrolytes, but also significantly improved the ionic conductivity of the electrolytes. When the content of LATP in the CSE was 50 wt.%, the electrolyte obtained the highest ionic conductivity (1.2 × 10-3 S·cm-1), which was one order of magnitude higher than that of the pristine LATP. Finally, this study also characterized the compression resistance of the composite solid-state electrolyte by testing the Vickers hardness, and the results showed that the hardness of the composite solid-state electrolyte can reach 0.9 ± 0.1 gf/mm2 at a LATP content of 50 wt.%.

Slow feature analysis-aided detection and diagnosis of incipient faults for running gear systems of high-speed trains.

Incipient faults in running gear systems corrupt the overall performance of high-speed trains, increasing the necessity of fault detection and diagnosis whose purpose is to maintain the safe and stable operation of high-speed trains. For this purpose, a novel data-driven method, that utilizes Hellinger distance and slow feature analysis, is proposed in this study. By integrating Hellinger distance into slow feature analysis, a new test statistic is defined for detecting incipient faults in running gear systems. Furthermore, the hidden Markov method is developed for performing reliable fault diagnosis tasks. The salient strengths of the proposed method lie in its satisfactory fault detectability on the one hand and the considerable robustness against high-level noises on the other hand. Finally, the effectiveness of the proposed method is verified through a numerical example and a running gear system of high-speed trains under actual working conditions.

A Review of Intelligent Fault Diagnosis for High-Speed Trains: Qualitative Approaches.

For ensuring the safety and reliability of high-speed trains, fault diagnosis (FD) technique plays an important role. Benefiting from the rapid developments of artificial intelligence, intelligent FD (IFD) strategies have obtained much attention in the field of academics and applications, where the qualitative approach is an important branch. Therefore, this survey will present a comprehensive review of these qualitative approaches from both theoretical and practical aspects. The primary task of this paper is to review the current development of these qualitative IFD techniques and then to present some of the latest results. Another major focus of our research is to introduce the background of high-speed trains, like the composition of the core subsystems, system structure, etc., based on which it becomes convenient for researchers to extract the diagnostic knowledge of high-speed trains, where the purpose is to understand how to use these types of knowledge. By reasonable utilization of the knowledge, it is hopeful to address various challenges caused by the coupling among subsystems of high-speed trains. Furthermore, future research trends for qualitative IFD approaches are also presented.

Performance improvement of N-doped carbon ORR catalyst via large through-hole structure.

N-doped carbon-based materials are crucial electrically conductive additives and non-metal electrocatalysts for the oxygen reduction reaction. At present, many pieces of research are focused on the effects of micropore, mesopore and hierarchical pore structure on the catalytic activity, however, there are few works concerning the role of large-dimension through-hole structure. Hence, in this work, we prepare two kinds of carbon materials with large through-hole structure, i.e. N-doped carbon hollow-spheres and hollow-tubes, as the oxygen reduction catalysts. The synthesis follows template-free morphology-controlled pyrolysis, which is more convenient than the preparation of conventional N-doped nanotubes and graphene. The resultant N-doped carbon hollow-spheres and hollow-tubes evidently enhanced their ORR catalytic activity, remarkable long-term stability and methanol resistance. The large-dimension through-hole structure is found to account for the increase in mass transfer.

Rhodol-based fluorescent probes for the detection of fluoride ion and its application in water, tea and live animal imaging.

Herein, we presented two novel turn-on colorimetric and fluorescent probes based on a F- triggered SiO bond cleavage reaction, which displayed several desired properties for the quantitative detection for F-, such as high specificity, rapid response time (within 3 min) and naked-eye visualization. The fluorescence intensity at 574 nm (absorbance at 544 nm) of the solution was found to increase linearly with the concentration of F- (0.00-30.0 µM) with the detection limit was estimated to be 0.47 µM/0.48 µM. Based on these excellent optical properties, the probes were employed to monitor F- in real water samples and tea samples with satisfactory. Furthermore, it was successfully applied for fluorescent imaging of F- in living nude mice, suggesting that it could be used as a powerful tool to predict and explore the biological functions of F- in physiological and pathological processes.

A facile and scalable process to synthesize flexible lithium ion conductive glass-ceramic fibers.

Solid-state electrolytes have emerged as a promising alternative to existing liquid electrolytes for next-generation flexible Li metal batteries with enhanced safety and stability. Nevertheless, the brittleness and inferior room temperature conductivity are major obstacles for practical applications. Herein, for the first time, we have fabricated a flexible lithium ion conductive glass-ceramic fiber by using a melt-spun homogeneous NASICON-type structured Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass melt and annealed at 825 °C. The annealed samples exhibited a higher lithium ion conductivity than the air-quenched sample due to the presence of a well-crystallized crystal grain in the annealed sample. Meanwhile, the ionic conductivity has shown an inverse relationship with the diameter of annealed LAGP glass-ceramic fibers. The results revealed that the annealed glass-ceramic fiber, with a diameter of 10 µm, resulted in lithium ion conductivity of 8.8 × 103 S cm-1 at room temperature.

3D N-doped carbon framework with embedded CoS nanoparticles as highly active and durable oxygen reduction and evolution electrocatalyst.

Development of bifunctional non-metal electrocatalyst for oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) with high efficiency, durable stability and low cost is a crucial and challenging issue. However, the heteroatom-doped carbon material including a carbon-based conductive additive would be easily oxidized under the high potential needed for driving the OER. Besides, the interaction between the heteroatom-doped carbon material that possesses electrocatalyst activity and a carbon-based conductive additive is weak, affecting the performance of the electrocatalyst. In this context, we introduce CoS nanoparticles into a three-dimensional N-doped carbon framework (CoS/NCF) by a morphology-retaining pyrolysis of polyaniline/CoS framework precursor, in which the polyaniline framework provides abundant functional groups to nucleate and grow CoS nanoparticles while retaining its interconnected three-dimensional porous structure. Benefiting from (i) the lower OER potential of CoS nanoparticles than the electro-oxidation decomposition potential of a carbon material and (ii) the strong affinity of CoS nanoparticles for a N-doped carbon framework, higher stability than commercial Pt/C system and greater catalytic activity towards ORR with an onset potential of about 0.921 V versus reversible hydrogen electrode (RHE) are observed. Furthermore, only a potential of 1.515 V versus RHE is required for achieving a current density of 10 mA cm-2.

Dual-functional probe based on rhodamine for sequential Cu2+ and ATP detection in vivo.

A rhodamine-based fluorescent probe for Cu2+ and ATP has been designed. The fluorescence intensity/absorbance was significantly enhanced upon the addition of Cu2+ owning to the opening of the spiro-ring of rhodamine, which quickly returned to the original level due to the reconstruction of the probe by the reacting with ATP. Cu2+/ATP-induced fluorescent intensity/aborbance changes showed a good linear relationship with the concentration of Cu2+/ATP in the range of 2-20 µM/0-10 µM with a detection limit of 0.1 µM/1.0 µM. The proposed method is simple in design and fast in operation, and is suitable for the reversible monitoring of Cu2+ and ATP in bioanalytical applications.

Dual-Functional Fluorescein-Based Chemosensor for Chromogenic Detection of Fe3+ and Fluorgenic Detection of HOCl.

A novel fluorescein-based dual probe was designed and synthesized. The probe exhibited highly sensitive and selective colormetric response to Fe3+ and turn-on fluorescence response towards OCl- with very low detection limits of 100 and 50 nM, respectively. It was successfully applied for quantitative detection of Fe3+ and OCl- in real water samples. Moreover, probe 1 was expected to be a potentially powerful tool for studying and providing further insights into OCl- and Fe3+ chemistry in the near future.

Synthesis and in vitro antitumor activity of (1E,4E)-1-aryl-5-(2-((quinazolin-4-yl)oxy)phenyl)-1,4-pentadien-3-one derivatives.

BACKGROUND: Cancer is one of the leading causes of death and only second to heart diseases. Recently, preclinical studies have demonstrated that curcumin had a number of anticancer properties. Thus, we planned to synthesize a series of curcumin analogs to assess their antiproliferation efficacy. RESULTS: A series of (1E,4E)-1-aryl-5-(2-((quinazolin-4-yl)oxy)phenyl)-1,4-pentadien-3-one derivatives (curcumin analogs) were synthesized and characterized by IR, NMR, and elemental analysis techniques. All of the prepared compounds were screened for antitumor activities against MGC-803, PC3, and Bcap-37 cancer cell lines. A significant inhibition for cancer cells were observed with compound 5f and also less toxic on NIH3T3 normal cells. The mechanism of cell death induced by compound 5f was further investigated by acridine orange/ethidium bromide staining, Hoechst 33,258 staining, TUNEL assay, and flow cytometry cytometry, which revealed that the compound can induce cell apoptosis in MGC-803 cells. CONCLUSIONS: This study suggests that most of the derivatives could inhibit the growth of human cancer cell lines. In addition, compound 5f could induce apoptosis of cancer cells, and it should be subjected to further investigation as a potential anticancer drug candidate.

[Finite element modeling of material property assignment based on CT gray value and its application in simulation of osteotomy for deformities].

OBJECTIVE: To explore a new method for finite element modeling to achieve material property assignment based on in situ CT gray value in simulated osteotomies for deformities. METHODS: A CT scan dataset of the lower limb of a patient with extorsion deformity was obtained for three-dimensional reconstruction using Mimics software and preparing a solid model. In the CAD software, the parameters for osteotomy simulation were defined including the navigation axis, rotation angle and reference plane. The tibia model was imported to the FEA pre-processing software for meshing procedure and then exported to Mimics. All the segments of the tibia meshed model were assigned uneven material properties based on the relationship between CT gray values and material properties in the Mimics software. Finally, all the segments of the tibia model, reference axis and reference plane were assembled in the pre-processing software to form a full finite element model of a corrected tibia, which was submitted to resolver for biomechanical analysis. RESULTS: The tibia model established using our modeling method had inhomogeneous material properties based on CT gray values, and was available for finite element analysis for the simulation of osteotomy. CONCLUSIONS: The proposed finite element modeling method, which retains the accuracy of the material property assignment based on CT gray value, can solve the reposition problem commonly seen in modeling via the routine method of property assignment and provides an efficient, flexible and accurate computational biomechanical analysis method for orthopedic surgery.

Metabonomic Study of Biochemical Changes in Human Hair of Heroin Abusers by Liquid Chromatography Coupled with Ion Trap-Time of Flight Mass Spectrometry.

Hair analysis is with the advantage of non-invasive collection and long surveillance window. The present study employed a sensitive and reliable liquid chromatography coupled with ion trap-time of flight mass spectrometry method to study the metabonomic characters in the hair of 58 heroin abusers and 72 non-heroin abusers. Results indicated that certain endogenous metabolites, such as sorbitol and cortisol, were accelerated, and the level of arachidonic acid, glutathione, linoleic acid, and myristic acid was decreased in hair of heroin abusers. The metabonomic study is helpful for further understanding of heroin addiction and clinical diagnosis.

Moisture Battery Formed by Direct Contact of Magnesium with Foamed Polyaniline.

The present communication reports a concept battery made by direct contact of magnesium foil with ultralight polyaniline (PANI) foam in the absence of additional electrolyte. Electrical current is allowed to be steadily released from the junction with a specific energy of 646 mWh g(-1) and specific capacity of 1247 mAh g(-1). Additionally, the battery offers an environmentally friendly route of hydrogen production along with discharging. Mechanistic studies indicated that the ubiquitous galvanic corrosion combined with decomposition of adsorbed trace water in the semi-conducting polymer foam enabled the generation of electricity, which overturns the traditional view. The higher moisture level is conducive to the discharge. This work is believed to open up new possibilities for the design of electrochemical batteries.

The Fluorescence Enhancement of Mercury Detected in Food Based on Rhodamine Derivatives.

Recently, the problem of food security is more and more serious, and people pay attention to mercury because of the toxic of it. A new approach for the determination of mercury content in foodstuff is devised. In this paper, first, we design and synthesis a new kind of fluorescent probe whose matrix based on rhodamine B, hydrazine hydrate and hydroxy benzaldehyde. Through the analysis of H-NMR spectra of the synthesized product L1, we confirm that the synthetic substance is the adjacent carboxyl benzaldehyde hydrazone structure generation of rhodamine B. Then, we measure the fluorescence signal intensity of the probe with different concentrations of mercury ions fully upon complexation by fluorescence spectrometer and we can study the relationship between the mercury ion concentration and the fluorescence intensity and draw the standard working curve. Following, It's time to discuss the microwave digestion processing of tea, after digestion we use the synthetic probe Li for determination of mercury content in tea. The experimental results show that the maximum excitation wavelength of the probe and coordination compound are 568. 05 and 560. 00 nm, the maximum emission wavelength are 587. 94 and 580. 00 nm. Then we can find the best testing conditions to improve the degree of accuracy, that is: room temperature, 50% the methanol solution, 3. 0 mL pH 4. 0 buffer solution, in the extent of 30 min. The experimental results show that Na+, K+, Ca2+, Cu2+, Zn2+, Al3+ have little impact on the fluorescence intensity of the:probe. Fe3+, Mg2+, Ba2+ has a weak enhancement to the fluorescence intensity of the probe. While a low concentrations of Hg2+ have an obviously enhanced effect on the fluorescence intensity of the probe. In contrast to other metal ions, the probe for Hg2+ has a good selectivity. Linear relationship between the magnitude of increase in fluorescence intensity and concentration of mercury ion was in the range of 5~20 ng . L-1 with detection limit (3S/N) of 1. 9 ng . L-1. The proposed method was applied to determination of mercury ion in samples of tea and sausage and the obtained result and sample recovery were all satisfactory. The methods of analysis instrument has the advantages of simple structure, sensitivity, high accuracy, good selectivity and less volume of simple, without the need for enrichment, being very practical.

Role of immune dysfunction in pathogenesis of type 1 diabetes mellitus in children.

OBJECTIVES: To investigate the function of cytokines, chemokines, and regulatory T cells (Tregs) in the pathogenesis of type 1 diabetes mellitus (T1DM) in children. METHODS: A total of 35 children with T1DM and 30 healthy controls were enrolled in this study. Levels of serum cytokines (IL-1α, IL-6, IL-10, IL-12, and TNF-α) and chemokines (MIP-1α, MIP-1α and MCP-1) were detected by enzyme-linked immunosorbent assay. Peripheral blood mononuclear cells (PBMCs) were isolated and culture supernatant of phytohaemagglutinin (PHA)-stimulated PBMCs was subjected to ELISA for levels of cytokines (IL-1α, IL-6, IL-10, IL-12 and TNF-α) in T1DM and control group. Furthermore, flow cytometry was used to determine the percentage of Tregs in PBMCs of two groups. RESULTS: Levels of serum cytokines including IL-1α, IL-6, IL-10 and TNF-α as well as chemokines, such as MIP-1α and MIP-1α in children with T1DM children were significantly higher than those in healthy controls (P<0.05, respectively). PBMCs with PHA stimulation in T1DM group secreted more IL-1α and TNF-α (P<0.05, respectively), but less IL-10 (P<0.05), as compared with control group. Furthermore, the proportion of CD4(+), CD25(+), Foxp3(+), Tregs in PBMCs isolated from children with T1DM was obviously lower than those in healthy controls (P<0.05). CONCLUSIONS: Immune dysfunction, with upregulation of inflammatory factors such as IL-1α, IL-6, TNF-α and MIP-1α, downregulation of IL-10 and Tregs, plays an important role in the pathogenesis of T1DM in children.

New phenanthrene derivatives with nitric oxide inhibitory and radical-scavenging activities from Pholidota imbricata Hook.

One new phenanthrene derivative phoimbrtol A (1) with seven known compounds, loddigesiinol B (2), shanciol B (3), (-)-medioresinol (4), (-)-pinoresinol (5), quercetin 3-O-ß-L-arabinofuranoside (6), luteolin 7-O-ß-glucoside (7) and platycaryanin D (8) have been isolated from the ethyl acetate extract of the air-dried whole plant of Pholidota imbricata Hook. Their inhibitory effects on nitric oxide (NO) production and 1,1-diphenyl-2-picrylhydrazil (DPPH) radical scavenging activity were examined. Among these compounds, 8 exhibited the most potent activity at NO production inhibitory assay and DPPH radical scavenging assay, stronger than those of the familiar antioxidative agents, quercetin and resveratrol.