The novel adiponectin-resistin (AR) and insulin resistance (IR~AR~) indexes

Serum hypoadiponectinemia and hyperrestinemia independently links insulin resistance to type 2 diabetes (T2DM) and metabolic syndrome (MS). Thus, the aim of this study was propose a novel adiponectin-resistin (AR) index by unifying the effect of adiponectin and resistin. Then, a novel insulin resistance (IR~AR~) index was proposed by taking into account the AR index. Serum adiponectin and resistin levels as well as other insulin resistance, T2DM and MS risk factors were tested. Experimental results showed the AR index was more stronger correlated with insulin resistance risk factors and had stronger association (df=5; F=51.154; P<0.001) with T2DM and MS susceptibility rather than the serum adiponectin (df=5; F=15.680; P<0.001) and resistin (df=5; F=40.648; P<0.001) levels alone. Therefore, the AR index looks very strongly links insulin resistance to T2DM and MS. Meanwhile, the IR~AR~ index (df=5; F=78.396; P<0.001) is a potent useful index of insulin sensitivity in subjects with T2DM and MS

Changes Of The Blood-Brain Barrier Permeability, Ultrastructure, And Protein And Gene Expressions In A Rat Model Of Cerebral Hypoperfusion

Cerebral hypoperfusion is a condition where there is reduced blood flow to the brain. This condition is observed in patients with cardiovascular diseases, hypertension and among the aging population. Cerebral hypoperfusion leads to more severe neurological diseases including vascular dementia, Alzheimer’s disease and multiple sclerosis. Cerebral hypoperfusion induces damages to the blood-brain barrier (BBB) and this detailed study was carried out to understand the BBB behavior during cerebral hypoperfusion. In this study, two-vessel occlusion (2VO) model was used to mimic cerebral hypoperfusion in rats. Using exogenous tracers of different molecular weight i.e. Evans blue dye (69 kDa) as a marker for macromolecule leakage, and sodium fluorescein (376 Da) as a marker for small molecule leakage, BBB leakages to Evans blue dye was observed during the early phase of cerebral hypoperfusion, 1-day post-surgery in the brain regions frontal cortex, posterior cortex and thalamus-midbrain. Using transmission electron microscopy, vesicles and formation of fenestration in endothelial cells, and swelling of astrocyte end-feet were observed, indicating cellular damages leading to BBB leakages during cerebral hypoperfusion

EFFECTS OF INTERNAL FIELDS IN QUANTUM DOTS

In this work we study the effect of built in electrostatic fields in Quantum Dots. Built-in electrostatic fields in Zincblende quantum dots originate mainly from--(1) the fundamental crystal atomicity and the interfaces between two dissimilar materials, (2) the strain relaxation, and (3) the piezoelectric polarization. We also study the geometric dependence of built in fields on 3 shapes namely Box, Dome and Pyramid. The main objectives are 3 fold they are (1) Explore the nature and the role of crystal atomicity at the interfaces and built-in fields (strain-field, and piezoelectric polarization) in determining the energy spectrum and the wave functions. (2) To identify the shift in the one-particle energy states, symmetry-lowering and non-degeneracy in the first excited state and strong band-mixing in the overall conduction band electronic states. (3) Finally geometric dependence of the above-mentioned phenomena. We discuss the importance atomistic effects and the need for 3 dimensional atomistic simulator NEMO 3D. We also discuss the effect of built in fields in HEMT (High Electron Mobility Transistor)

The evolutionary nature of RV Tauri stars in the SMC and LMC

Based on their stellar parameters and the presence of a mid-IR excess due to circumstellar dust, RV Tauri stars have been classified as post-AGB stars. Our recent studies, however, reveal diverse SEDs among RV Tauri stars, suggesting they may occupy other evolutionary channels as well. The aim of this paper is to present the diverse SED characteristics of RV Tauri stars and investigate their evolutionary nature as a function of their SEDs. We carried out a systematic study of RV Tauri stars in the SMC and LMC because of their known distances and hence luminosities. Their SEDs were classified in three groups: dusty (disc-type), non-dusty (non-IR) and uncertain. A period-luminosity- colour (PLC) relation was calibrated. The luminosities from the PLC were complemented with the ones found using their SEDs and the stars were placed on the HR-diagram. The four main results from this study are: 1) RV Tauri stars with a clear IR-excess have disc-type SEDs, which indicates that the dust is trapped in a stable disc. Given the strong link between disc-type SEDs and binarity in the Galaxy, we postulate that these are binaries as well. These cover a range of luminosities and we argue that the more luminous ones are post-AGB stars while the lower luminosity ones are likely post-Red Giant Branch (post-RGB) stars. 2) Two of these objects have variable mean brightness with periods of 916 and 850 days, respectively, caused by variable extinction during orbital motion. 3) The non-dusty RV Tauri stars and the objects with an uncertain SED evolve such that the circumstellar dust has dispersed. If they are single stars, they are post-AGB objects of low initial mass ($<$ 1.25 M$_\odot$), while if they are binaries, the low-luminosity part of the sample are likely post-RGB stars. 4) We find that RV Tauri stars with dust are on average more luminous than the rest of the sample.Comment: 32 Pages, Accepted to be published in A&

Analysis of Instabilities and Their Impact on Friction Factor in Hole-Pattern Seals

The determination of the leakage and consequently the friction factor is an important part of analyzing the flow through a seal. This is done experimentally by means of a flat plate tester, which allows for the simplified representation of the seal pattern on a flat plate surface tested under a range of clearances and pressure drops. The setup mounts a smooth plate opposite a second plate which may be smooth or have a roughened surface while the separation between plates is held constant. The present study analyzes the phenomenon of friction factor 'upset' ? wherein it was seen that as the pressure drop across the parallel plates is increased, there is a sudden increase in the friction factor (i.e. a decrease in flow rate) at a certain Reynolds number and for any further increase in the pressure differential, the friction factor shows the expected trend and decreases slowly. This phenomenon was initially believed to be an anomaly in the rig and was attributed to choking at an upstream flow control valve. The present author differs from that view and hypothesized that the reason for the abrupt change is linked to the flow mechanics of the system and the current study analyzes the same. Preliminary analysis of available data has established that the cause for the 'upset' was not related to the switch from a normal mode resonance driven by the Helmholtz frequency of the cavities on the stator to a shear layer instability, as was seen earlier by Ha. The friction factor jump for this case is therefore proposed to be due to a change of the instability modes as the fluid passes over the cavities in the plate. A detailed analysis of the physics of the flow will be carried out via a numerical simulation using a Large Eddy Simulation (LES) model from ANSYS Fluent. Results will be validated through comparisons with experimental data from the flat plate test rig