Search

Aims We investigated the effects and underlying molecular mechanism of transient receptor potential vanilloid 1 ( TRPV1), a calcium (Ca2+)-permeable non-selective cation channel, on phosphorylation of endothelial nitric oxide synthase (e NOS) at threonine 497 (Thr497) in bovine aortic endothelial cells ( BAECs) and in mice. Methods Western blotting and immunoprecipitation were used for the evaluation of protein phosphorylation; protein phosphatase 2 B ( PP2B) activity was assessed by convention kit; Griess assay was for NO production; tube formation and Matrigel plug assay were used for angiogenesis. Results In BAECs, treatment with the TRPV1 ligand evodiamine decreased the phosphorylation of e NOS at Thr497, protein kinase Cα ( PKCα) at Serine 657 (Ser657) and PKCβ2 at Ser660. Evodiamine increased protein phosphatase 2B (PP2B) activity and promoted the formation of a PP2B- PKC complex. Inhibition of TRPV1 activation by the pharmacological antagonists, removal of extracellular Ca2+ or pharmacological inhibition of PI3K/Akt/calmodulin-dependent protein kinase II/ AMP-activated protein kinase signalling pathway abolished the evodiamine-induced alterations in phosphorylation of e NOS at Thr497, PKCα at Ser657, PKCβ2 at Ser660 and PP2B activity, as well as the formation of a PP2B- PKC complex. Inhibition of PP2B activation partially reduced the evodiamine-induced NO bioavailability and tube formation in endothelial cells ( ECs) and angiogenesis in mice. Moreover, evodiamine decreased the phosphorylation of e NOS at Thr497, PKCα at Ser657 and PKCβ2 at Ser660 in apolipoprotein E (ApoE)-deficient mouse aortas but not TRPV1-deficient or ApoE/ TRPV1 double-knockout mice. Conclusion TRPV1 activation in ECs may elicit a Ca2+-dependent effect on PP2B- PKC signalling, which leads to dephosphorylation of e NOS at Thr497 in ECs and in mice. [ABSTRACT FROM AUTHOR]

The most stable structures of gaseous Si m C n (3 ⩽ n+ m ⩽ 6) clusters in their ground electronic states are determined with the high level electronic correlation method QCISD(T)/g3large. Thermodynamic properties on heat capacity ( C ), entropy ( S ), Gibbs energy function (−[ G Θ − H Θ( T r )]/ T) and enthalpy function ( H Θ− H Θ( T r )) are predicted with standard statistical thermodynamics using the structure parameters and vibrational frequencies obtained with B3PW91/6-31G( d) method combined with the electronic excitation energies determined with time dependent density functional (TD DFT) method at B3PW91/6-31G( d) level. The electronic energies are calculated with the accurate model chemistry method at G3(QCI) level of theory and the Δ f H (0 K), Δ f H (298.15 K) and Δ f G (298.15 K) values are predicted. The heat capacities C ( T) as a function of temperature within 298.15-2000 K are fitted into analytical equations. The thermodynamic functions at higher temperatures are determined classically by using these equations. Most of the results obtained in this work are consistent with the available experiments. [ABSTRACT FROM AUTHOR]

Elastic, strength, electronic properties and vibrational spectra of Ne@C60 (Ih) in its ground electronic state (X 1Ag) were investigated with density functional theory at B3PW91/6-31G level via structure distortions. The elastic properties were obtained from the potential energy curves (PECs) in all of the five independent distortional directions of the molecule with symmetries of 1. D5d, 2. D3d, 3. D2h, 4. C2h(1) and 5. C2h(2). PECs were examined where the structure of Ne@C60 was destroyed. The necessary energies to destroy the structure were thus obtained, which illuminated the stability of Ne@C60. PECs were found to be anisotropic and were accurately fitted to polynomials. Elongations in the direction of D5d and compression in D2h encountered potential energy surface cross-linkages, which might be considered as a single electron pump for further application in the design of single electron devices. Time-dependent B3PW91/6-31G analysis predicted significant electronic spectra changes associated with structure distortions. Similarities and differences of the properties were compared with those in C60 and He@C60. [ABSTRACT FROM AUTHOR]

An adaptive fuzzy total-sliding-mode controller (AFTSMC) with a total switching surface is proposed to control the position of an electrical servodrive. The proposed controller comprises a special fuzzy total-sliding-mode controller (FTSMC) and an adaptive tuner. The FTSMC acts as the main tracking controller, which is designed via a fuzzy system to mimic the merits of a total-sliding-mode controller (TSMC). In addition, a translation width is embedded into fuzzy rules to reduce the chattering phenomena. The adaptive tuner, which is derived in the sense of Lyapunov stability theorem, is utilised to adjust the translation width on-line for further assuring robust and optimal performance. In the AFTSMC, the fuzzy-control-rules base is compact and only one parameter needs to be adjusted. An electrical servodrive with the proposed position-control system possesses the advantages of a simple control framework, reduced chattering, stable performance and robustness to uncertainties. The effectiveness is demonstrated by simulated and experimental results, and its advantages are indicated in comparison with conventional TSMC and adaptive TSMC for a field-oriented control induction-motor (IM) drive. [ABSTRACT FROM AUTHOR]

An alternative control scheme including an enhanced genetic algorithm controller (EGAC) and a supervisory controller is developed for nonlinear dynamical systems in this study. In the EGAC design, the spirit of gradient descent training is embedded in genetic algorithm (GA) to construct a main controller to search the optimum control effort under the possible occurrence of uncertainties. To ensure the system states around a defined bound region, a supervisory controller, which is derived in the sense of Lyapunov stability theorem, is added to adjust the control effort. Compared with enunciated GA control methods, the proposed control scheme possesses some salient advantages of simple framework, less executing time and good self-organising properties even for the time-varying system because the simple solution representation and the error backpropagation genetic operation are utilised in the GA process. In addition, the proposed scheme is applied to the position control of a decoupling induction motor (IM) drive, whose effectiveness is verified by the numerical simulation and experimental results and whose advantages are presented in comparison with existing position control schemes. [ABSTRACT FROM AUTHOR]

OBJECTIVE:: To investigate whether vitamin B6 supplementation had a beneficial effect on lowering fasting plasma homocysteine concentrations in coronary artery disease (CAD) patients. DESIGN:: A single-blind intervention study. SETTING:: The study was performed at the Taichung Veterans General Hospital, the central part of Taiwan. SUBJECTS:: A total of 50 subjects were identified by cardiac catheterization to have at least 70% stenosis of one major coronary artery. In all, 42 patients successfully completed this study. INTERVENTIONS:: Patients were randomly assigned to one of five groups and treated with a daily dose of placebo (n=8), 5?mg vitamin B6 (n=8), 10?mg vitamin B6 (n=8), 50?mg vitamin B6 (n=9), or 5?mg folic acid combined with 0.25?mg vitamin B12 (n=9) for 12 weeks. MAIN OUTCOME MEASURES:: Nutrient intakes were recorded by using 24-h diet recalls when patients returned to the cardiology clinic before the intervention (week 0) and at week 12. Vitamin B6 status was assessed by direct measures (plasma pyridoxal 5'-phosphate) and indirect measures (erythrocyte alanine and aspartate aminotransaminase activity coefficient). Fasting plasma homocysteine, serum folic acid, and vitamin B12 were measured. RESULTS:: Fasting plasma homocysteine concentration did not respond to high or low doses of vitamin B6 when compared with a placebo treatment after 12 weeks of supplementation. The mean fasting plasma homocysteine concentration, however, decreased significantly after 12 weeks of folic acid combined with vitamin B12 supplementation (P=0.047). Further, within group, mean fasting plasma homocysteine concentration was nonsignificantly increased by 25.5, 16.2, and 18.3% in placebo, 10?mg/day and 50?mg/day vitamin B6 supplemented groups, respectively; whereas folic acid combined with vitamin B12 supplementation significantly reduced fasting plasma homocysteine concentration by 32% (P<0.001). CONCLUSIONS:: Our results indicate that vitamin B6 supplementation alone is less effective than folic acid combined with vitamin B12 in lowering plasma homocysteine concentrations in CAD patients. SPONSORSHIP:: This study was supported by the National Science Council, Taiwan, Republic of China (NSC-91-2320-B-040-023).European Journal of Clinical Nutrition (2004) 58, 481-487. doi:10.1038/sj.ejcn.1601834 [ABSTRACT FROM AUTHOR]

High-temperature threshold characteristics of a symmetrically graded δ-doped InAlAs/InxGa1-xAs/GaAs (x=0.5→0.65→0.5) metamorphic high electron mobility transistor (MHEMT) have been investigated. The thermal threshold coefficients, defined as ∂Vth/∂T, are superiorly low at 0.9 mV/K from 300 to 420 K and at -0.75 mV/K from 420 to 500 K. An interesting polarity change of the thermal threshold coefficient was observed around 420 K due to the variation of thermal modulation effects. The present MHEMT device, with stabilized thermal threshold variations and superior high-temperature linearity characteristics, is promising for high-temperature circuit applications. [ABSTRACT FROM AUTHOR]

The plasmon resonance of Au/SiO2 multilayered nanodisks was studied using light scattering spectroscopy and numerical calculations. Compared to single layered Au nanodisks, multilayered nanodisks exhibit several distinctive properties including significantly enhanced plasmon resonances and tunable resonance wavelengths which can be tailored to desired values by simply varying dielectric layer thickness while the particle diameter is kept constant. Numerical calculations show that slicing one metal layer into metal multilayers leads to higher scattering intensity and more “hot spots,” or regions of strong field enhancement. This tunable and augmented plasmon resonance holds a great potential in the applications of surface-enhanced Raman scattering (SERS). [ABSTRACT FROM AUTHOR]

Nutrient intake including iron and iron status indicators were investigated in 96 elderly subjects. Subjects were divided into 6 groups based on the sex and age. Each subject completed a 24-h diet recall and semi-quantitative food frequency questionnaire. Iron status indicators were measured. Body iron stores were calculated. The mean iron intake was higher than the current Taiwan Recommended Daily Nutrient Allowance of 10 mg in all groups. However, iron intake did not correlate with iron status indicators in any groups. Body iron stores significantly positively correlated with plasma ferritin (p < 0.05). One man in 65-69 y group, 2 men in 70-74 y group, 3 women in 65-69 y group, and 2 women in 70-74 y group were identified iron deficiency anemia. Elderly subjects had sufficient iron intakes, but iron deficiency still occurred in the elderly.

Objective: The purpose of this study was to measure and compare nutritional status of the functionally dependent elderly with those nonfunctionally dependent elderly by assessing nutrient intake, anthropometric measurements, hematological and biochemical parameters, and the nutritional risk index (NRI)., Methods: Ninety-six volunteers (42 functionally dependent elderly, 54 nonfunctionally dependent elderly) participated in this study. The items of activity of daily living (ADL) were assessed to determine functional status. Demographic and health data were collected at the time of interview. Subjects completed 24-hour diet recall and food frequency questionnaires. Height, weight and skinfold thickness measurements were taken. Hematological and biochemical parameters were measured. The NRI was then calculated., Results: Osteoporosis and hypertension were the most frequently reported chronic diseases. A small proportion of the elderly with functional dependence (9.5%) and with nonfunctional dependence (13%) had a body mass index (BMI) (< or = 21 kg/m2), indicating they were underweight. There were no significant differences in nutrient intake between the two groups. However, a higher percentage of the functionally dependent elderly had a nutrient intake of less than 75% of the Taiwan Recommended Daily Nutrient Allowance (RDNA). The functionally dependent group had a higher prevalence of malnutrition than the nonfunctionally dependent group (44.7% vs. 25%) based on the NRI., Conclusions: These functionally dependent elderly people exhibited a poorer nutritional status than the nonfunctionally dependent elderly. The elderly with functional dependence were at risk for inadequate iron intake and abnormal serum triglyceride concentrations: they were also at greater risk for chronic diseases and had a greater need for medications.

In this study, sexual risk behavior of 104 incarcerated female drug users is examined. Findings demonstrate that incarcerated women who use drugs are at high risk for human immunodeficiency virus (HIV) infection because of their behavior prior to arrest. During the month prior to arrest, the majority of respondents were sexually active. Half reported past sexual contacts with injecting drug users, and more than one-third had traded sex for money or drugs. Consistent with other studies, condom use was more frequent with casual or commercial partners. Those who traded sex for money were less likely to be white Anglo or regular heroin users, and more likely to be regular crack users and alcoholic, have fathers who were drug or alcohol users, and perceive themselves as at-risk for contracting HIV and other sexually transmitted diseases.

This study examines the predictors of alcoholism among 201 patients from three methadone maintenance treatment programs (MMTPs) in New York City. Using the Michigan Alcohol Screening Test, one-fifth of the sample met criteria for alcohol dependence. Few subjects were currently enrolled in any form of chemical dependency treatment other than MMTP. Alcoholics started to use alcohol at an early age, and almost every alcoholic subject admitted to alcohol abuse before entering MMTPs. More alcoholics than nonalcoholics reported symptoms of somatization, obsessive-compulsive behavior, depression, phobic anxiety, and psychosis. Logistic regression indicated that alcoholism among MMTP patients was associated with years drinking, years of sharing needles, utilization of drug abuse detoxification but not alcohol detoxification, smaller increases in methadone dosage over time, and psychiatric symptomatology. Findings are discussed in terms of their implications for designing more efficacious treatment approaches for dually addicted patients in MMTPs.