Ischemia-Induced Apoptosis of Intestinal Epithelial Cells Correlates with Altered Integrin Distribution and Disassembly of F-Actin Triggered by Calcium Overload

The present study examined intestinal epithelial cell (IEC) integrin distribution and disassembly of actin cytoskeleton in response to ischemia-anoxia. Protective effects of calcium channel blocker(CCB) were further examined to explore underlying mechanisms of cellular injury. Materials and Methods. Primary cultures of rat IECs and an in vitro model of ischemia/anoxia were established. IECs were exposed to ischemia/anoxia in the presence and absence of verapamil. The extent of exfoliation was determined using light microscopy while apoptosis rate was measured using flow cytometry. Changes in intracellular calcium, the distribution of integrins and the morphology of F-actin were assessed by confocal microscopy. Results. Detachment and apoptosis of IECs increased following ischemia/anoxia-induced injury. Treatment with verapamil inhibited the detachment and apoptosis. Under control conditions, the strongest fluorescent staining for integrins appeared on the basal surface of IECs while this re-distributed to the apical membrane in response to ischemic injury. Depolymerization of F-actin was also observed in the injured cells. Verapamil attenuated both changes of integrins and F-actin. Conclusions. Redistribution of integrins and disruption of F-actin under ischemia/anoxia injury is associated with IEC detachment and increased apoptosis. These events appeared to be triggered by an increase in Ca2+i suggesting a potential use for CCB in prevention and treatment of intestinal injury

Interactive mobile information hub

This project studied and developed a mobile information hub that transforms a mobile device into a portable information terminal which provides various information services. Two applications, i.e. augmented-reality campus guide and mobile phone logo recognition, have been selected from a wide range of mobile phone information services for implementation. A Layar browser was built to provide augmented-reality campus guide services in Nanyang Technological University. Based on GPS localization technique, this application presents augmented information, i.e. nearby landmark description and contact information, on top of the real world if viewing from the mobile phone camera after identifying the mobile phone’s location. Designed for fresh students and visitors, this augmented-reality service greatly enhances the perception of the real world and provides convenience. Website, database and mobile phone programming were involved in this part.Bachelor of Engineerin

Research on 3D Design of High-Load Counter-Rotating Compressor Based on Aerodynamic Optimization and CFD Coupling Method

In view of the flow instability problem caused by the strong shock wave and secondary flow in the channel of the high-load counter-rotating compressor, this paper adopts the design method of coupling aerodynamic optimization technology and CFD and establishes a three-dimensional aerodynamic optimization design platform for the blade channel based on an artificial neural network and genetic algorithm. The aerodynamic optimization design and internal flow-field diagnosis of a high-load counter-rotating compressor with a 1/2 + 1 aerodynamic configuration are carried out. The research indicates that the optimized blade channel can drive and adjust the flow better, and the expected supercharging purpose and efficient energy conversion process are achieved by controlling the intensity of the shock wave and secondary flow in the channel. The total pressure ratio at the design point of the compressor exceeds 2.9, the adiabatic efficiency reaches 87%, and the aerodynamic performance is excellent at the off-design condition, which is on the advanced design level of the same type of axial compressor. The established aerodynamic optimization design platform has important practical engineering applications for the development of high thrust-to-weight ratio aero-engine compression systems

Design and Ground Verification of Space Station Manipulator Control Method for Orbital Replacement Unit Changeout

Chinese space station has been in construction phase, and it will be launched around 2020. Lots of orbital replacement units (ORUs) are installed on the space station, and they need to be replaced on orbit by a manipulator. In view of above application requirements, the control method for ORU changeout is designed and verified in this paper. Based on the analysis of the ORU changeout task flow, requirements of space station manipulator’s control algorithms are presented. The open loop path planning algorithm, close loop path planning algorithm based on visual feedback, and impedance control algorithm are researched. To verify the ORU changeout task flow and corresponding control algorithms, a ground experiment platform is designed, which includes a 6-DOF manipulator with a camera and a force/torque sensor, an end effector with clamp/release and screwing function, ORU module, and ORU store. At last, the task flow and control algorithms are verified on the test platform. Through the research, it is found that the ORU changeout task flow designed in this paper is reasonable and feasible, and the control method can be used to control a manipulator to complete the ORU changeout task

Research and Ground Verification of the Force Compliance Control Method for Space Station Manipulator

The space station manipulator does lots of tasks with contact force/torque on orbit. To ensure the safety of the space station and the manipulator, the contact force/torque of manipulator must be controlled. Based on analyzing typical tasks’ working flows and force control requirements, such as ORU (orbit replacement unit) changeout and dual arm collaborative payload transport, an impedance control method based on wrist 6 axis force/torque feedback is designed. For engineering implementation of the impedance control algorithm, the discretization method and impedance control parameters selection principle are also studied. To verify the compliance control algorithm, a ground experiment platform adopting industrial manipulators is developed. In order to eliminate the influence of gravity, a real-time gravity compensation algorithm is proposed. Then, the correctness of real-time gravity compensation and force compliance control algorithm is verified on the experiment platform. Finally, the ORU replacement and dual arm collaborative payload transport experiments are done. Experimental results show that the force compliance control method proposed in this paper can control the contact force and torque at the end of the manipulator when executing typical tasks

<i>Clostridium butyricum</i> Potentially Improves Immunity and Nutrition through Alteration of the Microbiota and Metabolism of Elderly People with Malnutrition in Long-Term Care

Recent research advances examining the gut microbiome and its association with human health have indicated that microbiota-targeted intervention is a promising means for health modulation. In this study, elderly people in long-term care (aged 83.2 ± 5.3 year) with malnutrition (MNA-SF score ≤ 7) were recruited in a community hospital for a 12-week randomized, single-blind clinical trial with Clostridium butyricum. Compared with the basal fluctuations of the control group, an altered gut microbiome was observed in the intervention group, with increased (p Coprobacillus species, Carnobacterium divergens, and Corynebacterium_massiliense, and the promoted growth of the beneficial organisms Akketmanse muciniphila and Alistipes putredinis. A concentrated profile of 14 increased Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologs (KOs) that were enriched in cofactor/vitamin production and carbohydrate metabolism pathways were discovered; the genes were found to be correlated (p p p = 0.059), and the sensitive nutrition biomarker prealbumin improved, in contrast to the opposite changes in control. Based on our results obtained during a relatively short intervention time, C. butyricum might have great potential for improving nutrition and immunity in elderly people in long-term care with malnutrition through the alteration of gut microbiota, increasing the abundance of beneficial bacteria and activating the metabolism in SCFA and cofactor/vitamin production, bile acid metabolism, along with efficient energy generation

Mobilization of Au and Ag during Supergene Processes in the Linglong Gold Deposit: Evidence from SEM and LA&ndash;ICP&ndash;MS Analyses of Sulfides

Precious metals can be mobilized during supergene processes, which are important for the formation of high-grade or high-purity ores. The world-class Linglong gold deposit has high-grade ores that have undergone supergene processes in the near-surface zone. Under which conditions the supergene modification occurred and how Au and Ag behaved during the supergene processes have been poorly studied in this deposit. Here, we performed scanning electron microscope (SEM) and laser ablation&ndash;inductively coupled plasma&ndash;mass spectrometry (LA&ndash;ICP&ndash;MS) analyses on samples from the supergene enrichment zone of the Linglong gold deposit. The results show that secondary minerals were formed sequentially from magnetite-goethite-limonite to marcasite-acanthite, and finally to siderite after the primary minerals of pyrite-pyrrhotite-chalcopyrite. These mineral assemblages and variations indicate that the supergene modification by groundwater occurred under oxidative and weakly acidic conditions in the near-surface zone and evolved to reductive and near neutral conditions in the supergene enrichment zone. The newly formed marcasite has much higher Au (0.003&ndash;23.5 ppm, mean of 1.33 ppm) and Ag (81.7&ndash;6021 ppm, mean of 1111 ppm) concentrations than those of the primary pyrite (Au of 0.004&ndash;0.029 ppm and Ag of 0.22&ndash;4.14 ppm), which together with the formation of independent Ag&ndash;S mineral (acanthite), indicates that Au and Ag were significantly mobilized and fractionated during the supergene processes. These processes improved the Au and Ag grades in the supergene enrichment zone and thus facilitate their extraction

UAV Path Planning Based on Improved Artificial Potential Field Method

The obstacle avoidance system of a drone affects the quality of its flight path. The artificial potential field method can react quickly when facing obstacles; however, the traditional artificial potential field method lacks consideration of the position information between drones and obstacles during flight, issues including local minima, unreachable targets, and unreasonable obstacle avoidance techniques that lengthen flight times and consume more energy get encountered. Therefore, an improved artificial potential field method is proposed. First, a collision risk assessment mechanism was introduced to avoid unreasonable obstacle avoidance actions and reduce the length of unmanned aerial vehicle flight paths. Then, to solve the problem of local minimum values and unreachable targets, a virtual sub-target was set up and the traditional artificial potential field model was modified to enable the drone to avoid obstacles and reach the target point. At the same time, a virtual sub-target evaluation factor was set up to determine the reasonable virtual sub-target, to achieve a reasonable obstacle avoidance path compared to the traditional artificial potential field method. The proposed algorithm can plan a reasonable path, reduce energy consumption during flight, reduce drone turning angle changes in the path, make the path smoother, and can also be applied in complex environments