Nicotinamide Mononucleotide Adenylyl Transferase 2 Inhibition Aggravates Neurological Damage after Traumatic Brain Injury in a Rat Model

Xiaoyu Gu,Haibo Ni,XuGang Kan,Chen Chen,Zhiping Zhou,Zheng Ding,Di Li,Bofei Liu 대한신경외과학회 2023 Journal of Korean neurosurgical society Vol.66 No.4

Objective : Nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2) is a crucial factor for the survival of neuron. The role of NMNAT2 in damage following traumatic brain injury (TBI) remains unknown. This study was designed to investigate the role of NMNAT2 in TBI-induced neuronal degeneration and neurological deficits in rats. Methods : The TBI model was established in Sprague-Dawley rats by a weight-dropping method. Real-time polymerase chain reaction, western blot, immunofluorescence, Fluoro-Jade C staining, and neurological score analyses were carried out. Results : NMNAT2 mRNA and protein levels were increased in the injured-side cortex at 6 hours and peaked 12 hours after TBI. Knocking down NMNAT2 with an injection of small interfering RNA in lateral ventricle significantly exacerbated neuronal degeneration and neurological deficits after TBI, which were accompanied by increased expression of BCL-2-associated X protein (Bax). Conclusion : NMNAT2 expression is increased and NMNAT2 exhibits neuroprotective activity in the early stages after TBI, and Bax signaling pathway may be involved in the process. Thus, NMNAT2 is likely to be an important target to prevent secondary damage following TBI.

Preparation of Intumescent Flame Retardant Poly(butylene succinate) Using Urea Intercalated Kaolinite as Synergistic Agent

Lingling Gu,Sheng Zhang,Hongfei Li,Jun Sun,WuFei Tang,Liqian Zhao,Xiaoyu Gu 한국섬유공학회 2019 Fibers and polymers Vol.20 No.8

Urea (U) was successfully intercalated into Kaolinite (Kaol) and the product K-U was introduced intopoly(butylene succinate) (PBS)/intumescent flame retardants (IFR) by melt blending. The structure of K-U was characterizedby X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The flame retardancy, thermal degradation,and combustion behavior of PBS composites were characterized by limiting oxygen index (LOI), vertical burning test to getUL-94 rating, thermogravimetricanalysis (TGA), and cone calorimeter test (Cone). With the introduction of K-U and IFRinto PBS, the LOI obviously increased from 21.9 % for neat PBS to 40.1 % for composite containing 20 wt% IFR/5 wt% KU;PBS cannot pass any UL-94 rating but the composite passed UL-94 V-0 rating. Similarly, the peak heat release rate(PHRR) in cone test decreased from 576 kW/m2 to 292 kW/m2. SEM results showed the char of the composite became morecompact and smooth.

CARBON DEPOSIT INCINERATION DURING ENGINE FLAMEOUT USING NON-THERMAL PLASMA INJECTION

Xiaoyu Pu,Yixi Cai,Yunxi Shi,Jing Wang,Linbo Gu,Jing Tian,Runlin Fan 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.3

−In order to investigate the influence of initial regeneration temperatures on diesel particulate filter (DPF) regeneration, an experimental study of DPF regeneration was implemented using a dielectric barrier discharge (DBD) reactor, aided by exhaust waste heat after engine flameout. DPF trapping characteristics and carbon deposit mass were discussed to facilitate further data analysis and calculation. DPF regeneration was then investigated by comparison analysis of deposit removal mass, backpressure drop, and internal temperature change. The results revealed that a large amount of particulate matter (PM) was deposited in DPF with a high filtration efficiency of about 90 %. The deposit removal rate and percentage drop of the backpressure both maximized at the initial temperature of 100 oC. During DPF regeneration, the sharp rise of internal temperature indicated vigorous PM incineration and high CO2 emission. The results successfully demonstrated DPF regeneration using non-thermal plasma injection during engine flameout, and prominent heat durability was achieved in this method.

Controlled self-assembly of low-dimensional Alq3 nanostructures from 1D nanowires to 2D plates via intermolecular interactions

Jianmin Gu,Baipeng Yin,Shaoyan Fu,Cuihong Jin,Xin Liu,Zhenpan Bian,Jianjun Li,Lu Wang,Xiaoyu Li 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.2

Due to the intense influence of the shape and size of the photon building blocks on the limitation and guidance of opticalwaves, an important strategy is the fabrication of different structures. Herein, organic semiconductor tris-(8-hydroxyquinoline)aluminium (Alq3) nanostructures with controllable morphology, ranging from one-dimensional nanowires to twodimensionalplates, have been prepared through altering intermolecular interactions with employing the anti-solvent diffusioncooperate with solvent-volatilization induced self-assembly method. The morphologies of the formed nanostructures, whichare closely related to the stacking modes of the molecules, can be exactly controlled by altering the polarity of anti-solventsthat can influence various intermolecular interactions. The synthesis strategy reported here can potentially be extended toother functional organic nanomaterials.

Modeling and Verification of a Contactless Air Film Conveyor Using a Viscous Traction Principle

Wei Zhong,Xiaoyu Gu,Ke Xu,Fanghua Liu,Xin Li,Toshiharu Kagawa 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.12

Many industries require contactless transport of delicate or clean products such as silicon wafers, flat foodstuffs and freshly painted objects. In this study, a contactless air film conveyor for flat objects is introduced. The object is supported by a thin film formed between the object and the conveyor surface and transported by viscous traction which is generated by controlled airflow underneath the object. Experiments are conducted to investigate the film pressure distribution and viscous force. The results show that the film pressure is symmetrically distributed along the direction perpendicular to the airflow in the actuating cells and non-symmetrically distributed along the airflow direction. The viscous force decreases as the increase of gap thickness. A simplified model is established to help understand and characterize the viscous force. The calculated results show a good agreement with the experimental data. It is revealed that the viscous force is the resultant of an actuating force in the pocket and side areas and a drag force from airflow across the dam area. Simulation and experiments are conducted using a PID controller for one dimension position control and position tracking. The results verify the effectiveness of the theoretical modeling and control method.

Characterizing nonlinear oscillation behavior of an MRF variable rotational stiffness device

Yang Yu,Yancheng Li,Jianchun Li,Xiaoyu Gu 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.3

Magneto-rheological fluid (MRF) rotatory dampers are normally used for controlling the constant rotation of machines and engines. In this research, such a device is proposed to act as variable stiffness device to alleviate the rotational oscillation existing in the many engineering applications, such as motor. Under such thought, the main purpose of this work is to characterize the nonlinear torque-angular displacement/angular velocity responses of an MRF based variable stiffness device in oscillatory motion. A rotational hysteresis model, consisting of a rotatory spring, a rotatory viscous damping element and an error function-based hysteresis element, is proposed, which is capable of describing the unique dynamical characteristics of this smart device. To estimate the optimal model parameters, a modified whale optimization algorithm (MWOA) is employed on the captured experimental data of torque, angular displacement and angular velocity under various excitation conditions. In MWOA, a nonlinear algorithm parameter updating mechanism is adopted to replace the traditional linear one, enhancing the global search ability initially and the local search ability at the later stage of the algorithm evolution. Additionally, the immune operation is introduced in the whale individual selection, improving the identification accuracy of solution. Finally, the dynamic testing results are used to validate the performance of the proposed model and the effectiveness of the proposed optimization algorithm.

Surface Modification of Cellulose Microcrystalline with Aluminate Coupling Agent and Its Effects on Flame Retardant and Mechanical Properties of Epoxy Resin

Minghang Wang,Quan Wu,Zhengyu Feng,Xiaoyu Gu,Hongfei Li,Jun Sun,Bin Fei,Sheng Zhang 한국섬유공학회 2020 Fibers and polymers Vol.21 No.10

Cellulose microcrystalline (CMC), a linear polysaccharide with glucosidic bond, was successfully extracted frombamboo powder and modified by aluminate coupling agent (ACA) to prepare ACA-CMC. The chemical structure of asdesignedACA-CMC was characterized by scanning electron microscopy and Fourier transform infrared spectra. ACACMC,in association with ammonium polyphosphate (APP), was introduced into epoxy resin (EP) by casting process toobtain flame-resistant composites. The fire performance evaluation indicated that the presence of 10 phr APP and 5 phrACA-CMC in EP achieved the maximal LOI value of 29.0 %, passed the UL-94 V-0 rating, and significantly decreased thepeak heat release rate from 1055 kW·m-2 of neat EP to 294 kW·m-2. The introduction of ACA-CMC could also improve themechanical properties of EP composites due to the strengthening effect of CMC and better interfacial compatibility aftermodification with ACA. Moreover, the relative mechanisms were also proposed.

EFFECTS OF RESIDUAL ASH ON DPF CAPTURE AND REGENERATION

Yingxin Cui,Yixi Cai,Runlin Fan,Yunxi Shi,Linbo Gu,Xiaoyu Pu,Jing Tian 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.5

To study the effects of residual ash on the capture and regeneration of a diesel particulate filter (DPF), repeated capture and complete regeneration experiments were conducted. An engine exhaust particulate sizer was used to measure the particle size distribution of diesel in the front and back of DPF. Discrepancies in the size distribution of the particulate matter in repeated trapping tests were analyzed. To achieve complete DPF regeneration, a DPF regeneration system using nonthermal plasma technology was established. The regeneration carbon removal mass and peak temperatures of DPF internal measuring points were monitored to evaluate the effect of regeneration. The mechanism explaining the influence of residual ash on DPF capture and regeneration was thoroughly investigated. Results indicate that the DPF trapping efficiencies of the nuclear-mode particles and ultrafine particles have significant improvements with the increase quantity of residual ash, from 90 % and 96.01 % to 94.17 % and 97.27 %, respectively. The exhaust backpressure of the DPF rises from 9.41 kPa to 11.24 kPa. Heat transfer in the DPF is improved with ash, and the peak temperatures of the measuring points accordingly increase. By comparing the regeneration trials, the elapsed time for complete regeneration and time difference for reaching the peak temperature between adjacent reaction interfaces are extended with increased quantity of ash. The carbon removal mass rises by 34.00 %.