95 research outputs found
Lavandula stoechas L alleviates dementia by preventing oxidative damage of cholinergic neurons in mice brain
Purpose: To ascertain if there is any scientific evidence for the folkloric use of Lavandula stoechas as a nootropic substance for memory-related disorders.Methods: Aqueous and n-hexane fractions of methanol extract of aerial parts of L. stoechas were used to explore their anti-amnesic activity. Male albino mice weighing 25 - 30 g were organized in ten groups (G-I to G-X) and treated for seven days. On 7th and 8th day, behavioral studies were conducted using elevated plus maze, hole-board and light-dark paradigms. Furthermore, biochemical studies were performed on brain homogenates of mice.Results: Half-maximal inhibitory concentration (IC50) values for aqueous and n-hexane fractions of L. stoechas were recorded as 35.14 and 357.42 μg/mL respectively, as compared to the standard, ascorbic acid (51.39 μg/mL). Behavioral test results indicate that the aqueous fraction showed significant (p < 0.001) build-up of memory in mice, compared to n-hexane fraction. Similarly, the aqueous fraction significantly (p < 0.001) reduced the level of acetylcholinesterase and malondialdehyde as well as elevation of natural antioxidants, viz, superoxide dismutase, catalase and glutathione in brain tissues.Conclusion: The aqueous fraction of L. stoechas is a memory-enhancing agent. Its antioxidant activity prevents the loss of memory by providing defense against neurodegeneration.Keywords: Acetylcholinesterase, Elevated plus maze, Behavioral studies, Lavandula stoechas, Malondialdehyd
Methane and n-hexane ignition in a newly developed diaphragmless shock tube
Shock tubes have been routinely used to generate reliable chemical kinetic
data for gas-phase chemistry. The conventional diaphragm-rupture mode for shock
tube operation presents many challenges that may ultimately affect the quality
of chemical kinetics data. Numerous diaphragmless concepts have been developed
to overcome the drawbacks of using diaphragms. Most of these diaphragmless
designs require significant alterations in the driver section of the shock tube
and, in some cases, fail to match the performance of the diaphragm-mode of
operation. In the present work, an existing diaphragm-type shock tube is
retrofitted with a fast-acting valve, and the performance of the diaphragmless
shock tube is evaluated for investigating the ignition of methane and n-hexane.
The diaphragmless shock tube reported here presents many advantages, such as
eliminating the use of diaphragms, avoiding substantial manual effort during
experiments, automating the shock tube facility, having good control over
driver conditions, and obtaining good repeatability for reliable gas-phase
chemical kinetic studies. Ignition delay time measurements have been performed
in the diaphragmless shock tube for three methane mixtures and two n-hexane
mixtures at = 10 - 20 bar and = 738 - 1537 K. The results obtained
for fuel-rich, fuel-lean, and oxygen-rich (undiluted) mixtures show very good
agreement with previously reported experimental data and literature kinetic
models (AramcoMech 3.0 [1] for methane and Zhang et al. mechanism [2] for
n-hexane). The study presents an easy and simple method to upgrade conventional
shock tubes to a diaphragmless mode of operation and opens new possibilities
for reliable chemical kinetics investigations.Comment: 22 pages, 9 figure
Design a Robust RST Controller for Stabilization of a Tri-Copter UAV
Research on the tri-rotor aerial robot is due to extra efficiency over other UAV’s regarding stability, power and size requirements. We require a controller to achieve 6-Degree Of Freedom (DOF), for such purpose, we propose the RST controller to operate our tri-copter model. A MIMO model of a tri-copter aerial robot is challenged in the area of control engineering. Ninestates of output control dynamics are treated individually. We designed dynamic controllers to stabilize the parameters of an UAV. The resulting system control algorithm is capable of stabilizing our UAV to perform numerous operations autonomously. The estimation and simulation implemented inMATLAB, Simulink to verify the results. All real flight test results are presented to prove the success of the planned control structure
Dual-camera high-speed imaging of n-hexane oxidation in a high-pressure shock tube
Shock tubes are widely used in the study of chemical kinetics. Its benefits
rely on the almost ideal shock-heating process that provides high temperatures
and pressures to a chemical system for a limited test time. Just like any
reactor, shock tubes are not immune to non-ideal effects. The study of
conditions that might deviate experiments from ideal conditions is thus of the
utmost importance. High-speed imaging has been proven to be a powerful bytool
to analyze non-ideal / non-homogenous combustion in shock tubes. In this work,
dual-camera high-speed imaging experiments were performed at 10, 15 and 20 bar
in a high-pressure shock tube (HPST). An optical section was designed as an
extension of the HPST which enabled simultaneous visualization from the endwall
and the sidewall of the driven section of the shock tube. n-Hexane, a fuel with
a negative temperature coefficient (NTC) behavior that has been identified as
prone to non-homogenous ignition, is used as a test fuel. Reactive mixtures and
thermodynamic conditions were selected to visually analyze ignition processes
at the high-temperature, NTC and low-temperature regimes. Non-homogeneous
ignition was observed mostly at the local maximum of the IDT, which is
comprised by the high-temperature and NTC regions. Stoichiometric n-hexane
mixture with high fuel loading (5% n-hexane) presented the highest deviation
from constant volume chemical kinetic simulations. The inclusion of helium as a
bath gas to mitigate preignition was tested and it showed to improve the
susceptibility of the mixtures to develop reaction fronts. The modified
Sankaran criterion for the identification of ignition regimes in shock tubes
was tested and it showed an overall good agreement against the experimental
observations.Comment: 23 pages, 11 figures, 1 tabl
Lavandula stoechas (L) a Very Potent Antioxidant Attenuates Dementia in Scopolamine Induced Memory Deficit Mice
The objective of the current project was to explore the pharmacotherapeutic role of Lavandula stoechas (L) for the management of dementia. Dementia is considered a global challenge of current century seeking special attention of pharmacologists to explore its best remedies. Methanolic extract of aerial parts of L. stoechas was tested for phytochemical analysis along with free radical scavenging activity. Behavioral studies were performed on scopolamine induced amnesic mice by using elevated plus maze (EPM), light and dark test and hole board paradigms. Biochemical investigations were made after decapitating the mice. Their brains were isolated for biochemical estimation of acetylcholinesterase (AChE), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Phytochemical study ensured the presence of total phenolic contents (285.91 ± 0.75 mg of GAE/g of extract), total flavonoids (134.06 ± 0.63 mg of RE/g of extract), total tannins (149.60 ± 0.93 mg of TAE/g of extract) and free radical scavenging activity (IC50 value = 76.73 μg/ml found by DPPH method). Behavioral studies indicated that animals of GVII showed higher inflexion ratio (0.40 ± 0.03) for EPM, spent most of time (227.17 ± 2.13 s) in dark area of light dark test and had many hole pockings (39.83 ± 1.88) for hole board paradigm. Moreover, biochemical studies revealed that methanolic extract of L. stoechas (800 mg/kg/p.o.) significantly (P < 0.001) reduced brain AChE and MDA levels while improved SOD, CAT, and GSH levels. Thus the findings suggest that L. stoechas stabilizes memory by enhancing cholinergic neurotransmission and by providing defense against oxidative stress in mice brain
Exploring the Effects of Globalization on Social Development: A Study of Punjab, Pakistan
Globalization is a multidimensional concept that relates to the various aspects of life such as social, cultural, political and economic. The social perspective of globalization means an exchange of cultural values and ideas that contribute to the global culture. However, it is still unclear to decide, whether globalization brings various communities close to each other or creates a gap between them. Although, globalization relates to better living standards of people but also leaves some negative impact on their social life. Therefore, the present research aimed to investigate the relationship between globalization and social developments of Pakistan. A household survey from 480 respondents was conducted from three districts of Punjab, Pakistan by using the multi-stage sampling technique. The analysis shows that globalization has introduced the new trends in the education, health and economic domain. The overall findings show that globalization has a positive correlation with the social development of Pakistan
A proposed framework for developing user-centred mobile healthcare applications for the biggest annual mass gathering (Hajj) post COVID-19
The Hajj pilgrimage being the largest annual mass gathering globally with two to three million participants from over 180 counties, will remain a high priority for diseases surveillance for future epidemics or any other international public health emergencies with rapid scalability. This paper highlights the importance of monitoring mass gatherings during a pandemic and how mHealth applications can reduce the burden on health facilities during a mass gathering and tackle future infectious diseases outbreaks. The paper also highlights the importance of developing a user-centred application when designing for a diverse group of users with a shared purpose. As a result, a framework has been proposed to update the current applications or design and develop future mobile health applications. The framework has been developed based on the rationale and evidence found in the literature
Potential Economic and Household Income Gains from Trade Liberalization by Using MyGTAP Model
The current study attempted to calculate the potential gains/losses to the household income in Pakistan. The study has employed MyGTAP model which was initially developed by Minor & Walmsley (2012) and is extension of standard GTAP model. The standard GTAP model was linked with a representative household model by using the Social Accounting Matrix (SAM) to capture the effects of trade liberalization on economic growth and income distribution. The study used eight different simulations to calculate the impact of trade agreements with EU, SAARC, China and India and found a significant rise in economic growth. Regardless of some limitations, the model developed in this study produced significant results that may help to explain the current debate on trade liberalization. The results of the study conclude that it is manufacturing sector that may help to improve the income of all types of household and economic growth
Potential Economic and Household Income Gains from Trade Liberalization by Using MyGTAP Model
The current study attempted to calculate the potential gains/losses to the household income in Pakistan. The study has employed MyGTAP model which was initially developed by Minor & Walmsley (2012) and is extension of standard GTAP model. The standard GTAP model was linked with a representative household model by using the Social Accounting Matrix (SAM) to capture the effects of trade liberalization on economic growth and income distribution. The study used eight different simulations to calculate the impact of trade agreements with EU, SAARC, China and India and found a significant rise in economic growth. Regardless of some limitations, the model developed in this study produced significant results that may help to explain the current debate on trade liberalization. The results of the study conclude that it is manufacturing sector that may help to improve the income of all types of household and economic growth
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