Fault Diagnosis Reasoning Algorithm for Electromechanical Actuator Based on an Improved Hybrid TFPG Model

As a new generation of power-by-wire actuators, electromechanical actuators are finding increasingly more applications in the aviation field. Aiming at the application problem of the fault diagnosis of the electromechanical actuator, an improved diagnosis reasoning algorithm based on a hybrid timed failure propagation graph (TFPG) model is proposed. On the basis of this hybrid TFPG model, the activation conditions of OR and causality among nodes are given. The relationship discrepancy node is transformed into a relationship node and discrepancy node, which unifies the model storage process. The backward and forward extension operations of hypothesis generation and updating are improved. In the backward expansion operation, the specific process of backward update from non-alarm nodes is given, and the judging logic of the branch of relationship nodes is added, which guarantees the unity of the algorithm framework and the accuracy of the time update. In the forward expansion operation, the update order is adjusted to ensure the accuracy of the node update for the case of multiple parents. A hybrid TFPG model of the electromechanical actuator is established in the general modeling environment (GME), and a systematic verification scheme with two simulation types is tested with the application of the P2020 reference design board (RDB) and VxWorks 653 system. The results show that the proposed algorithm can realize the fault diagnosis of the electromechanical actuator as well as fault propagation prediction

Organic photodynamic nanoinhibitor for synergistic cancer therapy

Despite its great potential in cancer treatment, photodynamic therapy (PDT) often exacerbates hypoxia and subsequently compromises its therapeutic efficacy. To overcome this issue, an organic photodynamic nanoinhibitor (OPNi) has been synthesized that has the additional ability to counteract carbonic anhydrase IX (CA‐IX), a molecular target in the hypoxia‐mediated signalling cascade. OPNi is composed of a metabolizable semiconducting polymer as the photosensitizer and a CA‐IX antagonist conjugated amphiphilic polymer as the matrix. This molecular structure allows OPNi not only to selectively bind CA‐IX positive cancer cells to facilitate its tumor accumulation but also to regulate the CA‐IX‐related pathway. The integration of CA‐IX inhibition into the targeted PDT process eventually has a synergistic effect, leading to superior antitumor efficacy over that of PDT alone, as well as the reduced probability of hypoxia‐induced cancer metastasis. This study thus proposes a molecular strategy to devise simple yet amplified photosensitizers to conquer the pitfalls of traditional PDT.Ministry of Education (MOE)Nanyang Technological UniversityAccepted versionThis work was supported by Nanyang Technological University (NTU-SUG:M4081627) and Singapore Ministry of Education Academic Research Fund Tier 1(RG133/ 15M4011559, 2017-T1-002-134-RG147/17) and Tier 2 (MOE2016-T2-1-098

Cell membrane coated semiconducting polymer nanoparticles for enhanced multimodal cancer phototheranostics

Phototheranostic nanoagents are promising for early diagnosis and precision therapy of cancer. However, their imaging ability and therapeutic efficacy are often limited due to the presence of delivery barriers in tumor microenvironment. Herein, we report the development of organic multimodal phototheranostic nanoagents that can biomimetically target cancer-associated fibroblasts in tumor microenvironment for enhanced multimodal imaging-guided cancer therapy. Such biomimetic nanocamouflages comprise a near-infrared (NIR) absorbing semiconducting polymer nanoparticle (SPN) coated with the cell membranes of activated fibroblasts. The homologous targeting mechanism allows the activated fibroblast cell membrane coated SPN (AF-SPN) to specifically target cancer-associated fibroblasts, leading to enhanced tumor accumulation relative to the uncoated and cancer cell membrane coated counterparts after systemic administration in living mice. As such, AF-SPN not only provides stronger NIR fluorescence and photoacoustic (PA) signals to detect tumors, but also generates enhanced cytotoxic heat and single oxygen to exert combinational photothermal and photodynamic therapy, ultimately leading to an antitumor efficacy higher than the counterparts. This study thus introduces an organic phototheranostic system that biomimetically target the component in tumor microenvironment for enhanced multimodal cancer theranostics.MOE (Min. of Education, S’pore)Accepted versio

A renal-clearable duplex optical reporter for real-time imaging of contrast-induced acute kidney injury

Despite its high morbidity and mortality, contrast‐induced acute kidney injury (CIAKI) remains a diagnostic dilemma because it relies on in vitro detection of insensitive late‐stage blood and urinary biomarkers. We report the synthesis of an activatable duplex reporter (ADR) for real‐time in vivo imaging of CIAKI. ADR is equipped with chemiluminescence and near‐infrared fluorescence (NIRF) signaling channels that can be activated by oxidative stress (superoxide anion, O2.−) and lysosomal damage (N‐acetyl‐β‐d‐glucosaminidase, NAG), respectively. By virtue of its high renal clearance efficiency (80 % injected doses after 24 h injection), ADR detects sequential upregulation of O2.− and NAG in the kidneys of living mice prior to a significant decrease in glomerular filtration rate (GFR) and tissue damage in the course of CIAKI. ADR outperforms the typical clinical assays and detects CIAKI at least 8 h (NIRF) and up to 16 h (chemiluminescence) earlier.MOE (Min. of Education, S’pore)Accepted versio

Photoactivatable organic semiconducting pro-nanoenzymes

Therapeutic enzymes hold great promise for cancer therapy; however, in vivo remote control of enzymatic activity to improve their therapeutic specificity remains challenging. This study reports the development of an organic semiconducting pro-nanoenzyme (OSPE) with a photoactivatable feature for metastasis-inhibited cancer therapy. Upon near-infrared (NIR) light irradiation, this pro-nanoenzyme not only generates cytotoxic singlet oxygen (1O2) for photodynamic therapy (PDT), but also triggers a spontaneous cascade reaction to induce the degradation of ribonucleic acid (RNA) specifically in tumor microenvironment. More importantly, OSPE-mediated RNA degradation is found to downregulate the expression of metastasis-related proteins, contributing to the inhibition of metastasis after treatment. Such a photoactivated and cancer-specific synergistic therapeutic action of OSPE enables complete inhibition of tumor growth and lung metastasis in mouse xenograft model, which is not possible for the counterpart PDT nanoagent. Thus, our study proposes a phototherapeutic-proenzyme approach toward complete-remission cancer therapy.MOE (Min. of Education, S’pore)Accepted versio

Statistical optimization and batch studies on adsorption of phosphate using Al-eggshell

This work provides a simple and convenient method to manufacture the sorbent of Al-eggshell. The influence of AlCl 3 concentration and pH values as well as the dosage of sorbent and their interactions on adsorption of phosphate was investigated. Therefore, Box–Behnken design coupled with response surface method was adopted to explore the empirical model for phosphate species removal. It was observed that there is an optimal point, C(AlCl 3 )(0.29 mol/l)–pH(6.12)–dosage(6.72 g/l), for the goal of maximizing phosphate species removal. The second-order polynomial model for phosphate reduction was given as Removal(%) = 96.43 +10.82X1 + 4.29X2 − 0.70X3 + 2.06X1X2 − 1.72X1X3 +8.24X2X3 − 13.10X1 2  − 17.26X2 2  − 1.72X3 2 . Contour pictures implied that the interaction between pH values and sorbent dosage was the strongest, followed by C(AlCl 3 ) versus dosage and C(AlCl 3 ) versus pH. The adsorption of phosphate data had a good agreement with the Freundlich isotherm equation at 313 and 323 K. Otherwise, Langmuir–Freundlich model described the best fitness at the temperature of 293, 298, and 303 K. The process of adsorption of phosphate on Al-eggshell fitted a pseudo-second-order kinetic equation, which indicates the exothermic reaction. In conclusion, the present work suggests Al-eggshell as an efficient and environmental friendly sorbent for phosphate species adsorption from aqueous solutions

A new species of the genus Hebius (Squamata: Colubridae: Natricinae) from Hunan Province, China

Zhou, Zhengyan, Sun, Zhiyong, Qi, Shuo, Lu, Yuyan, Lyu, Zhitong, Wang, Yingyong, Li, Pipeng, Ma, Jianzhang (2019): A new species of the genus Hebius (Squamata: Colubridae: Natricinae) from Hunan Province, China. Zootaxa 4674 (1): 68-82, DOI: https://doi.org/10.11646/zootaxa.4674.1.

Scalable Electrophysiology of Millimeter-Scale Animals with Electrode Devices

Millimeter-scale animals such as Caenorhabditis elegans, Drosophila larvae, zebrafish, and bees serve as powerful model organisms in the fields of neurobiology and neuroethology. Various methods exist for recording large-scale electrophysiological signals from these animals. Existing approaches often lack, however, real-time, uninterrupted investigations due to their rigid constructs, geometric constraints, and mechanical mismatch in integration with soft organisms. The recent research establishes the foundations for 3-dimensional flexible bioelectronic interfaces that incorporate microfabricated components and nanoelectronic function with adjustable mechanical properties and multidimensional variability, offering unique capabilities for chronic, stable interrogation and stimulation of millimeter-scale animals and miniature tissue constructs. This review summarizes the most advanced technologies for electrophysiological studies, based on methods of 3-dimensional flexible bioelectronics. A concluding section addresses the challenges of these devices in achieving freestanding, robust, and multifunctional biointerfaces

Impact of urbanization on baseflow characteristics in the central catchment of North China Plain, China

Study area: The Dawenhe River and Xiaoqinghe River Basins (116°21′–118°41′E, 35°43′–37°15′N) in the center of the North China Plain (NCP), China. Study focus: To quantitatively assess the influence of urbanization (two indicators including Impervious Surface Percentage (ISP) and Average Night Light Index (ANLI)) on baseflow hydrological behavior (nine baseflow signatures), this study selects the typical urbanized catchment (nine sub-catchments) within the central NCP, where the baseflow was estimated from the total daily streamflow from 2006 to 2016. New hydrological insights for the region: Findings show that: (i) Baseflow signatures had a notable spatial variability, in which the magnitude baseflow signatures (Qb10, Qb25, Qb50, Qb90), Baseflow Index (BFI), Concavity Index (CI), and Slope of the baseflow duration curve (SBDC) demonstrated greater values in the north versus the south. (ii) Both ISP and ANLI exhibited an upward trend over time with some fluctuations (R2 > 0.65, p < 0.05). For ANLI, there were higher values in the northwest and northeast regions, and the higher ISP values were mainly located in the northern region. (iii) Overall, the effects of two urbanization indicators on baseflow signatures exhibited catchment-variability, and model performance between ISP and baseflow signatures is better than ANLI. This study provides a scientific reference to elucidate the water balance of the central NCP under the background of urbanization