3,905 research outputs found
In vitro inhibitory potential of selected Malaysian plants against key enzymes involved in hyperglycemia and hypertension.
Introduction: This study was conducted to determine the inhibitory potential of
selected Malaysian plants against key enzymes related to type 2 diabetes and
hypertension. Methods: The samples investigated were pucuk ubi (Manihot
esculenta), pucuk betik (Carica papaya), ulam raja (Cosmos caudatus), pegaga (Centella
asiatica) and kacang botol (Psophocarpus tetragonolobus). The inhibitory potential of
hexane and dichloromethane extracts against the enzymes were determined by
using α-amylase, α-glucosidase and angiotensin I-converting enzyme (ACE)
inhibition assay. Results: In α-amylase inhibition assay, the inhibitory potential
was highest in pucuk ubi for both hexane (59.22%) and dichloromethane extract
(54.15%). Hexane extract of pucuk ubi (95.01%) and dichloromethane extract of
kacang botol (38.94%) showed the highest inhibitory potential against α-
glucosidase,while in ACE inhibition assay, the inhibitory potential was highest
in hexane extract of pegaga (48.45%) and dichloromethane extract of pucuk betik
(59.77%). Conclusion: This study suggests a nutraceutical potential of some of
these plants for hyperglycemia and hypertension prevention associated with
type 2 diabetes
The Santa Fe Light Cone Simulation Project: I. Confusion and the WHIM in Upcoming Sunyaev-Zel'dovich Effect Surveys
We present the first results from a new generation of simulated large sky
coverage (~100 square degrees) Sunyaev-Zeldovich effect (SZE) cluster surveys
using the cosmological adaptive mesh refinement N-body/hydro code Enzo. We have
simulated a very large (512^3h^{-3}Mpc^3) volume with unprecedented dynamic
range. We have generated simulated light cones to match the resolution and
sensitivity of current and future SZE instruments. Unlike many previous studies
of this type, our simulation includes unbound gas, where an appreciable
fraction of the baryons in the universe reside.
We have found that cluster line-of-sight overlap may be a significant issue
in upcoming single-dish SZE surveys. Smaller beam surveys (~1 arcmin) have more
than one massive cluster within a beam diameter 5-10% of the time, and a larger
beam experiment like Planck has multiple clusters per beam 60% of the time. We
explore the contribution of unresolved halos and unbound gas to the SZE
signature at the maximum decrement. We find that there is a contribution from
gas outside clusters of ~16% per object on average for upcoming surveys. This
adds both bias and scatter to the deduced value of the integrated SZE, adding
difficulty in accurately calibrating a cluster Y-M relationship.
Finally, we find that in images where objects with M > 5x10^{13} M_{\odot}
have had their SZE signatures removed, roughly a third of the total SZE flux
still remains. This gas exists at least partially in the Warm Hot Intergalactic
Medium (WHIM), and will possibly be detectable with the upcoming generation of
SZE surveys.Comment: 14 pages, 13 figures, version accepted to ApJ. Major revisions mad
An overview of heavy oil properties and its recovery and transportation methods
Unconventional oils - mainly heavy oils, extra heavy oils and bitumens - represent a significant share of the total oil world reserves. Oil companies have expressed interest in unconventional oil as alternative resources for the energy supply. These resources are composed usually of viscous oils and, for this reason, their use requires additional efforts to guarantee the viability of the oil recovery from the reservoir and its subsequent transportation to production wells and to ports and refineries. This review describes the main properties of high-viscosity crude oils, as well as compares traditional and emergent methods for their recovery and transportation. The main characteristics of viscous oils are discussed to highlight the oil properties that affect their flowability in the processes of recovery and pipeline transportation. Chemical composition is the starting point for the oil characterization and it has major impact on other properties, including key properties for their dynamics, such as density and viscosity. Next, enhanced oil recovery (EOR) methods are presented, followed by a discussion about pipeline and transportation methods. In addition, the main challenges to achieve viable recovery and transportation of unconventional oils are compared for the different alternatives proposed. The work is especially focused on the heavy oils, while other hydrocarbon solid sources, such as oil sands and shale oil, are outside of the scope of this review31357159
Study of composition of cosmic rays with energy .7 E 3 Ee
The longitudinal shower development of extensive air showers (EAS) observed in the fly's eye is used to determine the distribution of X sub max, the depth in the atmosphere of the EAS maximum. Data and Monte Carlo simulations of proton and iron primaries are compared. A substantial contribution from light primaries is noted
Accurate Antenna Gain Estimation Using the Two-Antenna Method
This paper demonstrates a simulation-assisted measurement technique to determine the gain of an antenna accurately in an open test site or anechoic chamber. The proposed technique is based on the two-antenna gain measurement method using Friis equation in far-field free-space conditions, with the actual measurement test setup modelled in CST Studio Suite for
simulation. An LTE-reject UHF TV log-periodic dipole antenna is used to validate the gain measurement technique in this paper. The simulation of the two-antenna gain measurement method is used in order to estimate an appropriate minimum separation distance between the two antennas that needs to be used for actual measurements to ensure far-field free-space conditions. Determining this minimum separation distance using several simulations instead of actual measurements saves time and effort because it eliminates the need to perform measurements at various separation distances. The measured realized gain obtained using this technique provides a good agreement with the simulation and thus validates the accuracy of this technique
Self-esteem and its associated factors among secondary school students in Klang District, Selangor.
Self-esteem is an important determinant of psychological well-being that is particularly problematic during adolescent life stage. There is a correlation between low self-esteem and other social problems among today's adolescents. This study was conducted to determine the mean self-esteem score, and to determine the association between self-esteem and age, sex, race, religion, number of siblings, ranking among siblings, family function, parental marital status and smoking among adolescents aged 12 to 20-years-old. A cross sectional study design using random cluster sampling method was done. Four out of a total of 35 secondary schools in Klang District, Selangor were selected. Respondents consisted of individual students in selected classes from the four selected schools. Data was collected using a self-administered, structured, pre-tested questionnaire and was analyzed using the SPSS version 12.0. Out of 1089 respondents, 793 completed the questionnaire (response rate 73.82%). The overall mean self-esteem score was 27.65. The mean self-esteem score for males (27.99) was slightly higher than females (27.31). The differences in the mean scores by race were statistically significant. There was a statistically significant relationship between mean self-esteem scores and sex, age, race, religion, number of siblings, smoking and family function. There was no statistically significant difference between mean self-esteem score with parental marital status and with ranking among siblings. The overall mean self-esteem score was 27.65. Self-esteem was associated with sex, age, race, religion, number of siblings, smoking and family function
Multiple wavelength Er-doped twincore fibre loop laser
Multiwavelength laser operation of an inhomogeneously broadened Er-doped twincore fibre loop laser is demonstrated. Equal output power, separation 0.5nm and linewidth <10kHz was confirmed for each mode in a 3 wavelength laser. Up to 8 wavelength operation has been observed, demonstrating that twincore EDFAs can provide channel equalisation in an 8-channel multi-amplifier optical network
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