Protective effects of aqueous extract from Cudrania tricuspidata on oxidative stress-induced neurotoxicity

Total phenolics and flavonols of aqueous extract from different parts of Cudrania tricuspidata (fruit, root, leaf, and stem) and neuronal cell protective effects against oxidative stress-induced cytotoxicity were investigated. The neuronal cell protective effects of aqueous extract from different parts of C. Tricuspidata was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction, lactate dehydrogenase (LDH) release, and neutral red uptake assay. The overall relative neuronal cell protective effects of C. tricuspidata root by 3 assays were much higher than those of leaf, stem, and fruit. The aqueous extract of C. Tricuspidata root also showed higher total phenolics than those of different parts. Therefore, our study suggested that the aqueous extract of root has strong protective effect on oxidative stress-induced neurotoxicity which is correlated with its high level of phenolics, particularly kaempferol, quercetin, and myricetin.     

Copper(II) acetate-induced hydrolytic C–N bond cleavage of a topologically constrained tetraaza macrotricycle

A topologically constrained tetraaza macrotricycle, 2,2,4,10,10,12-hexamethyl-1,5,9,13-tetraazatricyclo[11.3.2.2^5.9]eicosane (L²), has been prepared by the reaction of 5,7,7,12,14,14-hexaazamethyl-1,4,8,11-tetraazacyclotetradecane (L¹) with 1,3-dibromopropane. Interestingly, L² reacts with Cu(OAc)₂ · H₂O to produce [CuL³]²⁺ (L³ = 2,2,4,10,10,12-hexamethyl-1,5,9,13-tetraazabicyclo[11.3.2]octadecane) as the only product under mild conditions, showing that the C–N bonds at one of the two N–CH₂CH₂–N linkages of the macrotricycle are readily broken in the presence of the metal salt. The complex [CuL³]²⁺ exhibits stronger ligand field strength than other related copper(II) complexes with a 5-6-6-6 chelate ring sequence and is unusually inert against decomposition in acid solutions.     

Fault tolerant attitude estimation for an LEO satellite using a multi-hypothesis filter

The aim of this paper is to improve state estimation and FDI performance. We proposed an algorithm using a model based multi-hypothesis filter (MHF). With this method, we can detect and identify the fault on a satellite actuator. Also, we can improve the attitude estimation performance of a satellite attitude control system. In this method, there are several models for a possible failure situation and the model probabilities are decided from the residuals of each filter. The master filter finds the most suitable state estimation result from the weighting sum of each filter based on probabilities. And a probability crossing detection algorithm and thresholding algorithm based on probabilities are introduced for fault detection and identification of satellite actuators. The simulation results demonstrate the advantages of the MHF-based method proposed.     

A comparison of some imidazoles in the curing of epoxy resin

An epoxy-imidazole resin system was used to form an anisotropic conducting film (ACF) for electronic equipment applications. In this study, the curing behaviors of an epoxy resin with imidazole, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 1-methylimidazole, 2-ethyl-4(5)-methylimidazole, and 1-(2-cyanoethyl)-2-ethyl-4(5)-methylimidazole were investigated using differential scanning calorimetry (DSC), and the curing times were determined at 150 and 180 °C. The polymerization mechanism for the epoxy resin with imidazoles was examined, and the DSC results matched the mechanism. 2-Methylimidazole exhibited the fastest reaction time among the imidazoles used in this study.     

Preparation of TiO<Subscript>2</Subscript>/SiO<Subscript>2</Subscript> hollow spheres and their activity in methylene blue photodecomposition

PSA [poly-(styrene-methyl acrylic acid)] latex particle has been taken into account as template material in SiO₂ hollow spheres preparation. TiO₂-doped SiO₂ hollow spheres were obtained by using the appropriate amount of Ti(SO₄)₂ solution on SiO₂ hollow spheres. The photodecomposition of the MB (methylene blue) was evaluated on these TiO₂-doped SiO₂ hollow spheres under UV light irradiation. The catalyst samples were characterized by XRD, UV-DRS, SEM and BET. A TiO₂-doped SiO₂ hollow sphere has shown higher surface area in comparison with pure TiO₂ hollow spheres. The 40 wt% TiO₂-doped SiO₂ hollow sphere has been found as the most active catalyst compared with the others in the process of photodecomposition of MB (methylene blue). The BET surface area of this sample was found to be 377.6 m²g⁻¹. The photodegradation rate of MB using the TiO₂-doped SiO₂ catalyst was much higher than that of pure TiO₂ hollow spheres.     

Lower critical solution temperature behavior of amphiphilic copolymers based on polyaspartamide derivatives

Novel copolymers consisting of poly(N‐isopropylaminoethyl‐co‐6‐hydroxyhexyl aspartamide) and poly (N‐isopropylaminoethyl‐co‐hexyl aspartamide) were prepared from polysuccinimide, which was the thermal polycondensation product of L ‐aspartic acid, via a ring‐opening reaction with 6‐amino‐L ‐hexanol (AH) or hexylamine (HA) and N‐isopropylethylenediamine at different ratios. The copolymers, containing 75–90 mol % of AH and 35–45 mol % of HA, produced thermoresponsive polymers through their lower critical solution temperatures (LCSTs) in aqueous solution. We could control the LCST could be controlled by modifying the hydrophobic–hydrophilic balance by changing the content of AH or HA. The pH dependencies of the LCST were opposite in these two different copolymer systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

PECVD‐based nanocrystalline‐silicon TFT backplanes for large‐sized AMOLED displays

Abstract— A 14.1‐in. AMOLED display using nanocrystalline silicon (nc‐Si) TFTs has been developed. Nanocrystalline silicon was deposited using conventional 13.56‐MHz plasma‐enhanced chemical vapor deposition (PECVD). Detailed thin‐film characterization of nc‐Si films was followed by development of nc‐Si TFTs, which demonstrate a field‐effect mobility of about 0.6–1.0 cm²/V‐sec. The nc‐Si TFTs show no significant shift in threshold voltage when over 700 hours of constant current stress is applied, indicating a stable TFT backplane. The nc‐Si TFTs were successfully integrated into a 14.1‐in. AMOLED display. The display shows no significant current decrease in the driving TFT of the 2T‐1cap circuit because the TFTs are highly stable. In addition to the improved lifetime of AMOLED displays, the development of nc‐Si TFTs using a conventional 13.56‐MHz PECVD system offers considerable cost advantages over other laser and non‐laser polysilicon‐TFT technologies for large‐sized AMOLEDs.     

Inhibition of major histocompatibility complex class I antigen presentation in pig and primate cells by herpes simplex virus type 1 and 2 ICP47

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) express an immediate-early protein, ICP47, that effectively inhibits the human transporter associated with antigen presentation (TAP), blocking major histocompatibility complex (MHC) class I antigen presentation to CD8+ T cells. Previous work indicated that the mouse TAP is relatively resistant to inhibition by the HSV-1 and HSV-2 ICP47 proteins (ICP47-1 and ICP47-2) and that mouse cells infected with HSV-1 are lysed by anti-HSV CD8+ cytotoxic T lymphocytes (CTL). Therefore, mice are apparently not suitable animals in which to study the in vivo effects of ICP47. In order to find an animal model, we introduced ICP47-1 and ICP47-2 into cells from various animal species-mice, rats, guinea pigs, rabbits, dogs, pigs, cows, monkeys, and humans-and measured TAP activity in the cells. Both proteins were unable to inhibit TAP in mouse, rat, guinea pig, and rabbit cells. In contrast, ICP47-1 and ICP47-2 inhibited TAP in pig, dog, cow, and monkey cells, and the TAP in pig and dog fibroblasts was often more sensitive to both proteins than TAP in human fibroblasts. These results were extended by measuring CD8+-T-cell recognition (CTL lysis) of cells from various species. Cells were infected with recombinant HSV-1 constructed to express murine MHC class I proteins so that the cells would be recognized and lysed by well-characterized murine anti-HSV CTL unless antigen presentation was blocked by ICP47. Anti-HSV CD8+ CTL effectively lysed pig and primate cells infected with a recombinant HSV-1 ICP47- mutant but were unable to lyse pig or primate cells infected with a recombinant HSV-1 that expressed ICP47. Therefore, pigs, dogs, and monkeys may be useful animal models in which to test the effects of ICP47 on HSV pathogenesis or the use of ICP47 as a selective immunosuppressive agent.     

Vitamin A and Retinoids in Bladder Cancer Chemoprevention and Treatment: A Narrative Review of Current Evidence,Challenges and Future Prospects

Bladder cancer (BC) is the tenth most common cancer worldwide with a high recurrence rate, morbidity and mortality. Therefore, chemoprevention and improved treatment of BC are of paramount importance. Epidemiological studies suggest that adequate vitamin A intake may be associated with reduced BC risk. In addition, retinoids, natural and synthetic derivatives of vitamin A, are intensively studied in cancer research due to their antioxidant properties and their ability to regulate cell growth, differentiation, and apoptosis. Findings from in vivo and in vitro models of BC show great potential for the use of retinoids in the chemoprevention and treatment of BC. However, translation to the clinical practice is limited. In this narrative review we discuss: (i) vitamin A and retinoid metabolism and retinoic acid signalling, (ii) the pathobiology of BC and the need for chemoprevention, (iii) the epidemiological evidence for the role of dietary vitamin A in BC, (iv) mechanistic insights obtained from in vivo and in vitro models, (v) clinical trials of retinoids and the limitations of retinoid use, (vi) novel systems of retinoid delivery, and (vii) components of retinoid signalling pathways as potential novel therapeutic targets.     

Dynamic behavior of capillary-driven encapsulation flow characteristics for different injection types in flip chip packaging

This study investigated the influence of different injection types, such as I-type, L-type, and U-type, on the dynamic behavior of capillary-driven encapsulation flows for a commercially available flip chip. The dynamic filling behavior of underfill encapsulation was visualized experimentally, and numerical simulations were conducted for three-dimensional flows in a flip chip package by using commercial software (ANSYS FLUENT Ver. 13.0). Numerical results were compared with experimental data for the filling time and the rate of change in underfill volume fraction with different injection types. At the early stage of underfill injection, the estimated flow characteristics exhibited high capillary acceleration that rapidly decreased with time, which indicates that capillary force was dominant in underfill encapsulation. The capillary pressure drop effect was dominant at the early stage. Thus, the injection method for underfill encapsulation inside the flip chip should be carefully controlled for faster and more stable encapsulation to avoid void formation in the chips.