Transient analysis of the nonmonotonic response of counterflow laminar diffusion flames in alternating current and step electric fields using a one-dimensional ionic transport model.

The electrohydrodynamic response of a counterflow laminar diffusion flame to applied alternating current (ac) electric fields is investigated experimentally and numerically. The flame positions are observed to show typical response to applied ac electric fields with high and moderate frequencies. The flame position does not respond above a threshold frequency corresponding to a certain collision response time, below which it oscillates in phase with the applied electric field. At a very low frequency (less than approximately 1 Hz), however, the flame position is observed to vary nonmonotonically as a function of time. To elucidate the nonmonotonic behaviors, a one-dimensional ionic transport model was employed by applying time-dependent electric fields. The responses of flame positions for ionized layers substituting for counterflow diffusion flames were systematically investigated with respect to one-way ionic wind (OIW) and two-way ionic wind (TIW) models. Consequently, it is demonstrated that the ionic models can produce not only harmonic flame oscillations for relatively low ac frequencies, but also free flame oscillations for stepwise voltages, which originated from the interaction between electrostatic force and ionic wind-induced force in the ionic system for both the OIW and TIW models.

Impacts of initial temperature and cylindrical obstacles on the dispersing flammable limits of accidental methane releases in an LNG bunkering terminal.

This paper presents a numerical study on the dispersing flammable limits with respect to the initial methane releases at TCH4,0 = -50 and -150 °C in the crosswind of ambient air according to the arrangement of (a) No Tank, (b) Tank I, (c) Tank II, and (d) Tank I and II on the ground. To provide a better physical insight on the dispersion behaviors of the methane releases, the spatial distributions of the quasi-averaged methane concentration and flow fields were mainly analyzed using 3-D large eddy simulations. Consequently, the results of both the parameters can be summarized in that the vortex characteristics of the rotating direction and vorticity generated by the interactions not only between the crosswind and cylindrical obstacles but also between the crosswind and releasing methane flows played important roles in determining the dispersing flammable limits depending on the mixing characteristics.

Effect of CO, NOx and SO2 on ROS production, photosynthesis and ascorbate-glutathione pathway to induce Fragaria×annasa as a hyperaccumulator.

A study was conducted to determine the effect of carbon monoxide (CO), nitroxide (NOx) and sulfur dioxide (SO2) on ROS production, photosynthesis and ascorbate-glutathione pathway in strawberry plants. The results showed that both singlet oxygen (O2(-1)) and hydrogen peroxide (H2O2) content increased in CO, NOx and SO2 treated strawberry leaves. A drastic reduction of primary metabolism of plants (photosynthesis), with the closure of stomata, resulted in a reduction of protein, carbohydrate and sucrose content due to production of reactive oxygen species (ROS) under prolonged exposure of gas stress. The resulting antioxidant enzymes were increased under a low dose of gas stress, whereas they were decreased due to a high dose of gas stress. Our results indicate that increased ROS may act as a signal to induce defense responses to CO, NOx and SO2 gas stress. The increased level of antioxidant enzymes plays a significant role in plant protection due to which strawberry plants can be used as a hyperaccumulator to maintain environmental pollution, however, the defense capacity cannot sufficiently alleviate oxidative damage under prolonged exposure of CO, NOx and SO2 stress.

MLCK and PKC Involvements via Gi and Rho A Protein in Contraction by the Electrical Field Stimulation in Feline Esophageal Smooth Muscle.

We have shown that myosin light chain kinase (MLCK) was required for the off-contraction in response to the electrical field stimulation (EFS) of feline esophageal smooth muscle. In this study, we investigated whether protein kinase C (PKC) may require the on-contraction in response to EFS using feline esophageal smooth muscle. The contractions were recorded using an isometric force transducer. On-contraction occurred in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME), suggesting that nitric oxide acts as an inhibitory mediator in smooth muscle. The excitatory composition of both contractions was cholinergic dependent which was blocked by tetrodotoxin or atropine. The on-contraction was abolished in Ca(2+)-free buffer but reappeared in normal Ca(2+)-containing buffer indicating that the contraction was Ca(2+) dependent. 4-aminopyridine (4-AP), voltage-dependent K(+) channel blocker, significantly enhanced on-contraction. Aluminum fluoride (a G-protein activator) increased on-contraction. Pertussis toxin (a G(i) inactivator) and C3 exoenzyme (a rhoA inactivator) significantly decreased on-contraction suggesting that Gi or rhoA protein may be related with Ca(2+) and K(+) channel. ML-9, a MLCK inhibitor, significantly inhibited on-contraction, and chelerythrine (PKC inhibitor) affected on the contraction. These results suggest that endogenous cholinergic contractions activated directly by low-frequency EFS may be mediated by Ca(2+), and G proteins, such as Gi and rhoA, which resulted in the activation of MLCK, and PKC to produce the contraction in feline distal esophageal smooth muscle.

The Inhibitory Effect of Quercetin-3-O-beta-D-Glucuronopyranoside on Gastritis and Reflux Esophagitis in Rats.

It was evaluated the inhibitory action of quercetin-3-O-beta-D-glucuronopyranoside (QGC) on reflux esophagitis and gastritis in rats. QGC was isolated from the herba of Rumex Aquaticus. Reflux esophagitis or gastritis was induced surgically or by administering indomethacin, respectively. Oral QGC decreased ulcer index, injury area, gastric volume, and acid output and increased gastric pH as compared with quercetin. Furthermore, QGC significantly decreased gastric lesion sizes induced by exposing the gastric mucosa to indomethacin. Malondialdehyde levels were found to increase significantly after inducing reflux esophagitis, and were reduced by QGC, but not by quercetin or omeprazole. These results show that QGC can inhibit reflux esophagitis and gastritis in rats.

Preparation, characterization and in vitro intestinal absorption of a dry emulsion formulation containing atorvastatin calcium.

A redispersible dry emulsion (DE) formulation of atorvastatin calcium (AC) was developed to enhance the in vitro dissolution of AC, thereby increasing its gastrointestinal absorption. The spray-drying technology was used where Plurol Oleique CC 497 was chosen as the oil phase. Effects of carriers, surfactants, and homogenizers on the characteristics of DE containing AC were systematically investigated. The final formulation consisted of dextrin and Poloxamer 188 as carrier and surfactant, respectively, and was homogenized by a high pressure homogenizer before spray drying. The in vitro release of AC from the optimized DE was significantly higher than that of pure AC powder (76% vs. 30% at 24 hr). The in vitro intestinal absorption of AC from the DE formulation was 0.77 microg/cm(2) at 2 hr, which was a 2.33-fold increase compared to the pure unformulated AC powder. These results suggest that the oral dry emulsion formulation could improve the intestinal absorption of AC.

Effect of resveratrol on the pharmacokinetics of oral and intravenous nicardipine in rats: possible role of P-glycoprotein inhibition by resveratrol.

The present study aimed to assess the effect of resveratrol on the bioavailability of nicardipine in rats. Nicardipine was administered orally (12 mg kg(-1)) or intravenously (4 mg kg(-1)) with or without oral administration of resveratrol (0.5, 2.5 or 10 mg kg(-1)). The oral administration of 2.5 or 10 mg kg(-1) of resveratrol significantly increased both the area under the plasma concentration-time curve (AUC) (P < 0.01, 111-126%) and the peak plasma concentration (Cmax) (P < 0.01, 105-121%), and significantly decreased the total body clearance (CL/F) (P < 0.01, 52.8-55.8%) of orally administered nicardipine. In contrast, resveratrol did not significantly change the pharmacokinetic parameters of i.v. nicardipine. Resveratrol significantly reduced rhodamine123 efflux via P-gp in MCF-7/ADR cells overexpressing P-gp. Resveratrol also inhibits CYP3A4, suggesting that the enhanced oral bioavailability of nicardipine by resveratrol may result from decreased P-gp-mediated efflux or inhibition of intestinal CYP3A4 metabolism. Based on these results, nicardipine dosage should be adjusted when given with supplements containing resveratrol.

Novel porous matrix of hyaluronic acid for the three-dimensional culture of chondrocytes.

A novel three-dimensional (3D) scaffold of chemically unmodified hyaluronic acid (HA) with minimum cross-linkage was developed for the culture of chondrocytes, thereby to promote cartilage repair. The porous structure of the scaffold was observed by scanning electron microscopy (SEM), and the pore size was controlled by fabrication conditions including swelling time and composition of the HA matrix. Rabbit primary chondrocytes and human chondrocytic cell lines (C-20/A4) were cultured in the HA matrix to investigate whether they can be applied to construct the cartilage tissue in vitro. The chondrocytes retained chondrocytic spherical morphology in this HA matrix. Moreover, results from the MTT assay showed good cellular viability within the HA matrix; optical density increased for up to 28 days, demonstrating that the cells continued to proliferate inside the HA matrix. Phenotypic analysis (RT-PCR, Alcian blue staining and quantification of s-GAG) showed that chondrocytes, when three-dimensionally cultured within the HA matrix, expressed transcripts encoding collagen type II and aggrecan, and produced sulfated glycosaminoglycans (s-GAG), indicating chondrogenic differentiation. The new HA matrix therefore appears as a potentially promising scaffold for the three-dimensional culture of chondrocytes for cartilage tissue engineering.

The Effect of Caffeic Acid on Wound Healing in Skin-incised Mice.

This study was carried out to investigate the wound healing effect of caffeic acid in skin-incised mice. Caffeic acid showed significant effects on anti-inflammatory activity and wound healing, such as myeloperoxidase activity, lipid peroxidation, phospholipase A(2) activity and collagen-like polymer synthesis, in incised-wound tissue. On the other hand, it significantly stimulated collagen-like polymer synthesis in NIH 3T3 fibroblast cells, while inhibited both silica-induced reactive oxygen species generation and melittin-induced arachidonic acid release and PGE(2) production in Raw 264.7 cells, and histamine release in RBL 2H3 cells stimulated by melittin or arachidonic acid. Therefore, caffeic acid appears to have a potent antioxidant and anti-inflammatory effect in cell culture system, which may be related to wound healing in skin-incised mice.

Altered pharmacokinetics of paclitaxel by the concomitant use of morin in rats.

The purpose of this study was to investigate the effect of morin on the pharmacokinetics of orally and intravenously administered paclitaxel in rats. Pharmacokinetic parameters of paclitaxel were determined in rats after an oral (30 mg kg(-1)) or intravenous (3 mg kg(-1)) administration of paclitaxel to rats in the presence and absence of morin (3.3 and 10 mg kg(-1)). Compared to the control given paclitaxel alone, pretreatment with morin 30 min prior to the oral administration of paclitaxel increased C(max) and AUC of paclitaxel by 70-90% and 30-70%, respectively, while there was no significant change in T(max) and terminal plasma half-life (T(1/2)) of paclitaxel. Consequently, absolute and relative bioavailability values of paclitaxel in the rats after the pretreatment with morin were significantly higher (p<0.05) than those from the control. In contrast, following an intravenous administration of paclitaxel (3.3 mg kg(-1)), the pharmacokinetic profiles of paclitaxel were not altered significantly in the presence of morin. Those results suggest that the enhanced oral exposure of paclitaxel should be mainly due to the inhibition effect of morin on the gastrointestinal extraction of paclitaxel during the intestinal absorption. Therefore, the concurrent use of morin or morin-containing dietary supplement may provide a therapeutic benefit in the oral delivery of paclitaxel.

Production of biodiesel fuel by transesterification of rapeseed oil.

Fatty acid methyl esters (FAMEs) show large potential applications as diesel substitutes, also known as biodiesel fuel. Biodiesel fuel as renewable energy is an alternative that can reduce energy dependence on petroleum as well as air pollution. Several processes for the production of biodiesel fuel have been developed. Transesterification processes under alkali catalysis with short-chain alcohols give high yields of methyl esters in short reaction times. We investigated transesterification of rapeseed oil to produce the FAMEs. Experimental reaction conditions were molar ratio of oil to alcohol, concentration of catalyst, type of catalyst, reaction time, and temperature. The conversion ratio of rapeseed oil was enhanced by the alcohol:oil mixing ratio and the reaction temperature.

[Screening for high risk population of dementia and development of the preventive program using web].

PURPOSE: This study was to develop a screening model for identifying a high risk group of dementia and to develop and evaluate the web-based prevention program. METHOD: It was conducted in 5 phases. 1) Data were collected from dementia patients and non-dementia patients in a community. 2) A screening model of the high risk population was constructed. 3) The validity test was performed and the model was confirmed. 4) Four weeks-prevention program was developed. 5) The program was administered, and evaluated the effects. RESULT: The model consisted of age, illiteracy, history of stroke and hypercholesterolemia. The program was designed with 12 sessions, group health education using web-based individual instruction program, and 12 sessions of low-intensity physical exercise program. After the completion, their self-efficacy, and health behaviors in experimental group were significantly improved over those in the control group. The perceived barrier in the treatment group is significantly decreased. CONCLUSION: The screening model developed is very simple and can be utilized in diverse community settings. And the web based prevention program will encourage individual learning and timely feedback, therefore it can facilitate their active participation and promote health management behaviors at home.

Design and synthesis of a piperazinylalkylisoxazole library for subtype selective dopamine receptor ligands.

A piperazinylbutylisoxazole libary was designed, synthesized and screened for the binding affinities to dopamine D2, D3, and D4 receptors. Several ligands were identified to possess high binding affinity and selectivity for the D3 and D4 receptors over the D2 receptor. Compounds 6s and 6t showed K(i) values of 2.6 nM and 3.9 nM for the D3 receptor with 46- and 50-fold selectivity over the D2 receptor, respectively.