A Mathematical Model Of Blood Flow Of A Stenosed Artery In Variable Shape

In this theoretical study, a mathematical model is developed to carry out a systematic analysis of flow behaviour in a two-dimensional vessel (modeled as artery) with a locally variable shaped constriction. An artificial artery, which containing a viscous incompressible fluid that representing the flowing blood can be treated as inflexible vessel. The shape of the stenosis in the arterial lumen is chosen to be symmetric as well as asymmetric about the middle cross section is perpendicular to the axis of the vessel. The constricted vessel is resolved into a straight vessel and the entire resulting equations are solved by a numerical method with Reynolds number and ‘n’, a number giving the shape of the constriction as parameters. The impacts of these parameters on wall shear stress, pressure gradient and velocity have been analysed. It is found that the flow resistance decreases as the shape of a smooth stenosis changes and extreme resistance is attained for the symmetric stenosis. But the length of separation increases for the asymmetric constrictions and the oscillation in the shear layer appears earlier for asymmetric constriction than that in the case of symmetric constriction. The extreme resistance is attained for inflexible stenosed vessel rather than the flexible one

Implementation of Energy Saver Circuit using 8051 Microcontroller

In this paper, we have proposed the development of a module based on 8051 microcontroller that allows us to operate a 220V AC lamp with a remote control and regulate the intensity of the lamp as per our needs. The ability to control the intensity of the lamp according to our requirement waives of unwanted wastage of energy thus providing an economic relief and reducing wastage of primary energy sources at this hour of shortage of non-renewable energy sources. Remote control provides an interface to the system that is simple to understand, operate, reliable and durable irrespective of usage and also economical. It adds comfort to our daily life by eliminating unwanted movement to operate the appliances. Remote control facilitates controlling various appliances from a convenient distance. The module is easy to install,convenient to use, energy saving and also cost effective without allowing compensation of efficiency

Discovery of highly spin-polarized conducting surface states in the strong spin-orbit coupling semiconductor Sb2_2Se3_3

Majority of the A$_2$B$_3$ type chalcogenide systems with strong spin-orbit coupling, like Bi$_2$Se$_3$, Bi$_2$Te$_3$ and Sb$_2$Te$_3$ etc., are topological insulators. One important exception is Sb$_2$Se$_3$, where a topological non-trivial phase was argued to be possible under ambient conditions, but such a phase could be detected to exist only under pressure. In this Letter, we show that like Bi$_2$Se$_3$, Sb$_2$Se$_3$, displays generation of highly spin-polarized current under mesoscopic superconducting point contacts as measured by point contact Andreev reflection spectroscopy. In addition, we observe a large negative and anisotropic magnetoresistance in Sb$_2$Se$_3$, when the field is rotated in the basal plane. However, unlike in Bi$_2$Se$_3$, in case of Sb$_2$Se$_3$ a prominent quasiparticle interference (QPI) pattern around the defects could be obtained in STM conductance imaging. Thus, our experiments indicate that Sb$_2$Se$_3$ is a regular band insulator under ambient conditions, but due to it's high spin-orbit coupling, non-trivial spin-texture exists on the surface and the system could be on the verge of a topological insulator phase.Comment: 5 pages, 4 figures, supplemental material not include

Antidiabetic effect of various fractions of Habenaria plantaginea root in streptozotocine-induced diabetic rats

The aim of this study is to evaluate the antidiabetic effect of methanolic extract of Habenaria plantaginea and its various fractions in different animal models. The effect of repeated oral administration of methanolic extract along with its n-hexane, ethyl acetate and n-butanol fractions on serum lipid profile and plasma enzyme levels in diabetic rats was also examined. The effect was found to be pronounced in n-butanol fraction. In oral glucose tolerance test, reduction of fasting blood glucose levels took place from 60 min on administration of methanolic extract and its various fractions. The n-butanol fraction has almost similar effect as that of standard drug Glibenclamide (10 mg/kg b. w). After 15 days of treatment, n-butanol fraction showed maximum reduction of blood glucose levels (64.28 %).  Total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and very low density lipoprotein (VLDL) levels were found to be decreased by 38.98, 28.06, 56.26 and 37.77% respectively in diabetic rats whereas, cardioprotective, high density lipoprotein (HDL) was increased by 31.65%. The n-butanol fraction also restored the altered plasma enzyme such as serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and alkaline phosphatase (ALP) levels to near normal. These results clearly indicate that n-butanol fraction of methanolic extract of Habenaria plantaginea possess high antidiabetic potential along with significant hypoglycaemic and hypolipidemic effects

Antidiabetic effect of various fractions of Habenaria plantaginea root in streptozotocine-induced diabetic rats

The aim of this study is to evaluate the antidiabetic effect of methanolic extract of Habenaria plantaginea and its various fractions in different animal models. The effect of repeated oral administration of methanolic extract along with its n-hexane, ethyl acetate and n-butanol fractions on serum lipid profile and plasma enzyme levels in diabetic rats was also examined. The effect was found to be pronounced in n-butanol fraction. In oral glucose tolerance test, reduction of fasting blood glucose levels took place from 60 min on administration of methanolic extract and its various fractions. The n-butanol fraction has almost similar effect as that of standard drug Glibenclamide (10 mg/kg b. w). After 15 days of treatment, n-butanol fraction showed maximum reduction of blood glucose levels (64.28 %).  Total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and very low density lipoprotein (VLDL) levels were found to be decreased by 38.98, 28.06, 56.26 and 37.77% respectively in diabetic rats whereas, cardioprotective, high density lipoprotein (HDL) was increased by 31.65%. The n-butanol fraction also restored the altered plasma enzyme such as serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and alkaline phosphatase (ALP) levels to near normal. These results clearly indicate that n-butanol fraction of methanolic extract of Habenaria plantaginea possess high antidiabetic potential along with significant hypoglycaemic and hypolipidemic effects

Resensitization of Akt induced docetaxel resistance in breast cancer by ‘Iturin A’ a lipopeptide molecule from marine bacteria bacillus megaterium

Development of the resistance is the major problem in cancer therapy. Docetaxel is a taxol alkaloid that is frequently used in metastatic breast cancer. However, resistance often limits the usefulness of this drug in many breast cancer patients. Manipulation of resistant cells to re-sensitize to the therapeutic effect of docetaxel is current strategy to overcome this problem. Here, we have introduced ‘Iturin A’ as a potent chemosensitizer in docetaxel resistant breast cancer cells. Combination of Iturin A and docetaxel treatment significantly hampered the proliferation of docetaxel resistant MDA-MB-231 and MDA-MB-468 breast cancer cells. Cell cycle analysis also showed massive amount of apoptotic population (Sub G0G1) in combination therapy. A number of apoptotic and anti-apoptotic proteins were significantly altered in dual drug treated groups. Caspase 3 dependent cell death was observed in dual treatment. Molecular mechanism study showed that over-expression of Akt and its downstream signaling pathway was associated with docetaxel resistance. Iturin A significantly reduced Akt signaling pathway in resistant cells. This mechanistic action might be the reason behind the chemo-sensitization effect of Iturin A in docetaxel resistant breast cancer cells. In conclusion, Iturin A resensitized the resistant breast cancer cells to docetaxel therapy by inhibiting Akt activity

UV-vis-NIR and EPR characterisation of the redox series [MQ3]2+,+,0,−,2−, M = Ru or Os, and Q = o-quinone derivative

The neutral title compounds with Q = 3,5-di-tert-butyl-o-quinone or 4,6-di- tert-butyl-N-phenyl-o-iminobenzoquinone (Qx) were studied by UV-vis-NIR spectroelectrochemistry and by EPR spectroscopy in the case of the odd- electron monocation and monoanion intermediates. Supported by DFT and TD-DFT calculations, the results indicate stepwise electron removal from predominantly ligand-based delocalised MOs on oxidation whereas the stepwise electron uptake on reduction involves unoccupied MOs with considerably metal–ligand mixed character. In both cases, the strong near-infrared absorption of the neutral precursors diminishes. In comparison to the ruthenium series, the osmium analogues exhibit larger transition energies from enhanced MO splitting and a different EPR response due to the higher spin–orbit coupling. The main difference between the quinone (1nnn, 2nnn) and corresponding monoiminoquinone systems (3nnn, 4nnn) is the shift of about 0.6 V to lower potentials for the monoimino analogues. While the absorption features do not differ markedly, the EPR data reflect a higher degree of covalent bonding for the complexes with monoimino ligands