D-limonene Inhibits Pentylenetetrazole-Induced Seizure via Adenosine A2A Receptor Modulation on GABAergic Neuronal Activity

Background: Epilepsy is a chronic neurological disorder characterized by the recurrence of seizures. One-third of patients with epilepsy may not respond to antiseizure drugs. Purpose: We aimed to examine whether D-limonene, a cyclic monoterpene, exhibited any antiseizure activity in the pentylenetetrazole (PTZ)-induced kindling mouse model and in vitro. Methods: PTZ kindling mouse model was established by administering PTZ (30 mg/kg) intraperitoneally to mice once every 48 h. We performed immunoblot blots, immunohistochemistry (IHC), and high-performance liquid chromatography (HPLC) analysis after the behavioral study. Results: An acute injection of PTZ (60 mg/kg) induced seizure in mice, while pretreatment with D-limonene inhibited PTZ-induced seizure. Repeated administration of PTZ (30 mg/kg) increased the seizure score gradually in mice, which was reduced in D-limonene (10 mg/kg)-pretreated group. In addition, D-limonene treatment increased glutamate decarboxylase-67 (GAD-67) expression in the hippocampus. Axonal sprouting of hippocampal neurons after kindling was inhibited by D-limonene pretreatment. Moreover, D-limonene reduced the expression levels of Neuronal PAS Domain Protein 4 (Npas4)-induced by PTZ. Furthermore, the adenosine A2A antagonist {"type":"entrez-protein","attrs":{"text":"SCH58261","term_id":"1052882304","term_text":"SCH58261"}}SCH58261 and ZM241385 inhibited anticonvulsant activity and gamma-aminobutyric acid (GABA)ergic neurotransmission-induced by D-limonene. Conclusion: These results suggest that D-limonene exhibits anticonvulsant activity through modulation of adenosine A2A receptors on GABAergic neuronal function.     

Texturing behaviours of (K0.47Na0.51Li0.02)(Nb0.8Ta0.2)O3 piezoelectric ceramics produced using NaNb1-xTaxO3 templates

Textured (K_0.47Na_0.51Li_0.02)(Nb_0.8Ta_0.2)O₃ (KNLNT20) piezoelectric ceramics were prepared using NaNb_1?xTa_xO₃ templates. The highest degree of grain orientation (97%) and piezoelectric constant (342 pC/N) were obtained upon adding 3 wt% of the NaNb_0.8Ta_0.2O₃ (NNT20) template and sintering at 1150 °C for 1 h. Back-scattered scanning electron micrographs of the textured KNLNT20 samples sintered at 1150 °C for 1 h indicated the presence of templates similar in size to the original ones within the cores of the textured grains. The peak value of the dielectric constant corresponding to the NNT20 core decreased after prolonged holding at 1150 °C, owing to a decrease in the size of the NNT20 core because of the interdiffusion of K, Na, and Li ions between the NNT20 core and KNLNT20 shell. This interdiffusion also decreased the piezoelectric constant, d₃₃ value of the textured KNLNT20 samples by inducing a change in the chemical composition of the shell region.     

弯管塑性极限载荷分析

利用Von-Mises屈服准则,推导出内压和扭矩联合载荷以及内压、弯矩与扭矩联合载荷作用下弯管的塑性极限载荷方程,经过简化后可得到任一单个载荷、两个或3个载荷共同作用下的塑性极限载荷.有关实验验证了理论的正确,为充分挖掘弯管的塑性极限承载能力提供了理论依据,也为研究有缺陷弯管塑性极限载荷提供了方法.     

Development and evaluation of Zigbee node module for USN

This study aims at securing technology to develop a multisensor and complex position-tracking Zigbee node module for USN (ubiquitous sensor network). In a concrete way, it aims at developing military (invader detection module and system) and industrial (transformer-tracking and thermo-measurement module and system) Zigbee telecommunication node module, and developing wireless monitoring and tracking technology based on such modules. In addition, it aims at building up the foundation of interface test for various sensors (thermo sensors, pressure sensors, vibration sensors and vision sensors) and the foundation of a comprehensive interlocking device to which GIS (Geographic Information System) and GPS (Global Positioning System) were applied, for industrial devices are mostly installed in mountains. Moreover, it aims at developing a roaming-type variable Zigbee node module to the end that it stands against unfavorable conditions (extreme temperatures, dust, winds, electromagnetism, noise, etc.). In case such aims are achieved, Zigbee communications will not be limited to normal and stable conditions (home networks, building automation, etc.) but will be applied to the industrial field under noises and unfavorable conditions. In such a case, the application of Zigbee node modules is expected to be unlimited.     

Electrochemical performance, biocompatibility, and adhesion of new polymer matrices for solid-state ion sensors.

Ammonium and potassium ion-selective membranes formulated with PVC/hydroxylated PVC, polyurethane/hydroxylated PVC, and moisture-curable silicone rubber matrices are studied in an effort to extend the lifetime of solid-state ion sensors through improved membrane adhesion. The PVC/membranes exhibit electrochemical performance equivalent to that of conventional PVC membranes in terms of slope, detection limit, and selectivity. The polyurethane- and silicone-rubber-based membranes have better adhesion to silicon nitride than do PVC or hydroxylated PVC matrices. Incorporating a silanizing reagent (silicon tetrachloride) significantly improves the adhesion of the polyurethane matrix. The use of silicon tetrachloride in membrane matrices also enhances the electrochemical stability of the interfacial potential between ion-selective polymer-matrix membranes and silver epoxy inner reference electrodes of solid-state sensors. The biocompatibility of the polymer matrices is examined via radiotracer protein adsorption studies and whole blood clotting time measurements. The polyurethane- and silicone-rubber-based membranes exhibit less overall nonspecific protein adsorption than the PVC or hydroxylated PVC matrices.     

Electrolyte optimization for a Li ion battery by charge profile analysis

Electrolyte design for Li ion batteries was approached by means of comparison of faradaic and non-faradaic currents. The faradaic current by the movement of Li⁺ ions was dependent on the composition of the electrolyte and was related to the battery capacity; the higher the capacity, the greater the current by the faradaic reaction. The open circuit potential of the electrode with a greater faradaic current decreased at a slower rate than that of the electrode with a smaller faradaic current. This analysis method can be used to prepare an optimal electrolyte of an actual Li ion battery, especially when developing batteries with excellent high-rate discharge capabilities and low temperature discharge properties.     

High-resolution crystal structures of delta5-3-ketosteroid isomerase with and without a reaction intermediate analogue

Bacterial Delta5-3-ketosteroid isomerase (KSI) catalyzes a stereospecific isomerization of steroid substrates at an extremely fast rate, overcoming a large disparity of pKa values between a catalytic residue and its target. The crystal structures of KSI from Pseudomonas putida and of the enzyme in complex with equilenin, an analogue of the reaction intermediate, have been determined at 1.9 and 2.5 A resolution, respectively. The structures reveal that the side chains of Tyr14 and Asp99 (a newly identified catalytic residue) form hydrogen bonds directly with the oxyanion of the bound inhibitor in a completely apolar milieu of the active site. No water molecule is found at the active site, and the access of bulk solvent is blocked by a layer of apolar residues. Asp99 is surrounded by six apolar residues, and consequently, its pKa appears to be elevated as high as 9.5 to be consistent with early studies. No interaction was found between the bound inhibitor and the residue 101 (phenylalanine in Pseudomonas testosteroni and methionine in P. putida KSI) which was suggested to contribute significantly to the rate enhancement based on mutational analysis. This observation excludes the residue 101 as a potential catalytic residue and requires that the rate enhancement should be explained solely by Tyr14 and Asp99. Kinetic analyses of Y14F and D99L mutant enzymes demonstrate that Tyr14 contributes much more significantly to the rate enhancement than Asp99. Previous studies and the structural analysis strongly suggest that the low-barrier hydrogen bond of Tyr14 (>7.1 kcal/mol), along with a moderate strength hydrogen bond of Asp99 ( approximately 4 kcal/mol), accounts for the required energy of 11 kcal/mol for the transition-state stabilization.     

Plasma etching optimization of oxide/nitride/oxide interpolydielectric breakdown time in flash memory devices

The breakdown time of flash memory oxide/nitride/oxide (ONO) layer t_bd under positive constant current stressing has been found to be closely related to the cumulative extent of (over)etch of the tungsten silicide, control polysilicon, and ONO layers, i.e., Σ(ΛOE). An empirical first-order relation between t_bd and Σ(ΛOE) has been derived to facilitate the plasma etch recipe optimization. This has led to a four-fold increase in the average t_bd across a 200-mm wafer to 208 s. More importantly, the spread in t_bd has been tightened to ~5%, which is down from ~54%     

Microstructure and mechanical properties of Ti 45Al 5Nb + (0–0.5C) sheets

The possible application of gamma titanium aluminides in aerospace industry requires a detailed understanding of the microstructure–property relationship of sheets made from this material. This paper reports the mechanical properties of sheets up to 1000 °C, based on alloy concepts with high Nb concentrations and small additions of C. Sheets were manufactured by rolling powder metallurgical compacts with compositions Ti 45Al 5Nb and Ti 45Al 5Nb 0.5C. The microstructures of both sheets are “near gamma” and consist of γ-TiAl and ₂-Ti₃Al phases. The texture of both phases is very weak. The strengths levels are very high and that of the C-containing sheet exceeds that of the C-free material at RT by 200 MPa. The mechanical properties of Ti 45Al 5Nb are independent of the direction in the sheet, in the whole temperature range from RT to 1000 °C. However, for the C-containing sheet this is true only in the upper temperature range.     

陶瓷树脂内衬复合钢管介绍

采用树脂材料密暑离心铝热法制备陶瓷瓷钢管内衬层气孔，从而获得具有防护耐磨双重功能的复合管材。产品内衬层与钢管基体结合强度高，可在真空状态下长期运行，在高温下内初不鼓泡、不折皱。