Immobilization of proteolytic enzyme on highly porous activated carbon derived from rice bran

Highly porous activated carbon (HPAC) was used as carrier matrix for immobilization of acid protease (AP). Immobilization of acid protease on mesoporous activated carbon (AP-HPAC) performs as best enzyme carrier. At pH 6.0, 250 mg acid protease g⁻¹ HPAC was immobilized. The optimum temperature for both free and immobilized AP activities were 50 °C. After incubation at 50 °C, the immobilized AP maintained about 50% of its initial activity, while the free enzyme was completely inactivated. When testing the reusability of AP-HPAC combination immobilized system, a significant catalytic efficiency was maintained along more than five consecutive reaction cycles. The highly porous nature of the carbon permits significant higher loadings of enzyme, which results in a higher enzyme-support strength and increased stability. The changes in the AP, HPAC and AP-HPAC were confirmed by Fourier Transform Infrared spectroscopy (FT-IR). Furthermore, scanning electron microscopy (SEM) allowed us to observe that the morphology of the surface of HPAC and the AP-HPAC.     

Virtualization layer security challenges and intrusion detection/prevention systems in cloud computing: a comprehensive review

Virtualization plays a vital role in the construction of cloud computing. However, various vulnerabilities are existing in current virtualization implementations, and thus there are various security challenges at virtualization layer. In this paper, we investigate different vulnerabilities and attacks at virtualization layer of cloud computing. We examine the proposals of cloud intrusion detection system (IDS) and intrusion detection and prevention system frameworks. We recommend the cloud IDS requirements and research scope to achieve desired level of security at virtualization layer of cloud computing.     

Planar perovskite solar cells: eco-friendly synthesized cone-like ZnO nanostructure for efficient interfacial electron transport layer

The process of interfacial engineering in planar perovskite solar cells (PPSCs) plays an important role not only in transferring charges from active perovskite layer but also in enhancing the device performance. Considering this, the present study aims to synthesize an eco-friendly solution processed ZnO nanostructure interfacial electron transport layer (ETL) in PPSCs. The optical, structural, morphological and chemical properties of the prepared ZnO nanostructured material are analysed using ultraviolet–visible spectroscopy (UV–Vis), X-ray diffraction analysis (XRD), field emission-scanning electron microscopy (FE-SEM), energy-dispersive X-ray analysis (EDX), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analysis, respectively. Under ambient conditions, the device performance in terms of efficiency, stability and device degradation are investigated for both single layer (c-TiO₂ and cone-like ZnO nanostructure) and bilayer (c-TiO₂/cone-like ZnO nanostructure) ETL. Furthermore, the effective way of constructing cone-like nanostructured ZnO ETL on top of c-TiO₂ surface, found to be improved in faster charge transfer at the ETL/perovskite interfaces and reduced recombination losses. As a result, it exhibits maximum power conversion efficiency (PCE), short-circuit current density, fill factor and open-circuit voltage as 8.02%, 15.33 mA cm^?2, 0.52% and 0.99 V, respectively. Besides, the stability of PPSCs fabricated with bilayer exhibits better air stability of?~?87.40% with retained rate of 250 h from its initial value.

     

Opposition-based equilibrium optimizer algorithm for identification of equivalent circuit parameters of various photovoltaic models

Journal of Computational Electronics - The simulation, assessment, and harvesting of maximum energy of the solar photovoltaic (PV) system require accurate and fast parameter estimation for solar...     

Selective Laser Sintering of Alumina Using Aluminum Binder

Selective Laser Sintering (SLS) process has been used to make shapes from Al₂0₃ using Al as binder. SLS is a rapid manufacturing process that uses data from Solid Modeling systems to guide a laser beam and rapidly form 3-D shapes from powder without any part specific tooling. The aluminum melts under the laser and bonds the alumina particles. Some of the aluminum reacts with the ambient (air) to form alumina. The residual aluminum is oxidized in a subsequent he at-treatment step. The effect of parameters in the SLS step and heat-treating step on the mechanical properties and density of the part is examined. Linear expansion of the parts with oxidation heat-treatment is also examined.     

Inhibition of neuronal Na+ channels by antidepressant drugs

Although tricyclic antidepressant (TCA) blockade of cardiac Na+ channels is appreciated, actions on neuronal Na+ channels are less clear. Therefore, the effects of TCAs (amitriptyline, doxepin and desipramine) as well as trazdone and fluoxetine on voltage-gated Na+ current (INa) were examined in bovine adrenal chromaffin cells using the whole-cell patch-clamp method. Amitriptyline produced concentration-dependent depression of peak INa evoked from a holding potential of -80 mV with KD value of 20.2 microM and a Hill coefficient of 1.2. Although 20 microM amitriptyline induced no change in the rate or voltage dependence of INa activation, steady-state inactivation demonstrated a 15-mV hyperpolarizing shift. Similar results were observed for doxepin and desipramine. This shift in steady-state inactivation was associated with a slowed rate of recovery from the inactivated state. Contrasting results were observed with the atypical antidepressants: while 20 microM fluoxetine depressed peak INa by 61% and caused a 7-mV hyperpolarizing shift in steady-state inactivation, 100 microM trazodone decreased peak INa by only 19% and caused only a 3-mV shift. Although the magnitude of fluoxetine effects was similar to those of the TCAs, the onset of fluoxetine effects was substantially slower than for amitriptyline. In voltage-clamp and current-clamp measurements from neonatal rat dorsal root ganglion neurons, 20 microM amitriptyline decreased INa by 52% and depressed action potential dynamics consistent with enhanced Na+ channel inactivation. The effects of the TCAs on INa are similar to local anesthetic behavior and could contribute to certain analgesic actions.     

Microplasma illumination enhancement of vertically aligned conducting ultrananocrystalline diamond nanorods

Vertically aligned conducting ultrananocrystalline diamond (UNCD) nanorods are fabricated using the reactive ion etching method incorporated with nanodiamond particles as mask. High electrical conductivity of 275 Ω·cm⁻¹ is obtained for UNCD nanorods. The microplasma cavities using UNCD nanorods as cathode show enhanced plasma illumination characteristics of low threshold field of 0.21 V/μm with plasma current density of 7.06 mA/cm² at an applied field of 0.35 V/μm. Such superior electrical properties of UNCD nanorods with high aspect ratio potentially make a significant impact on the diamond-based microplasma display technology.     

Investigations on pool boiling critical heat flux,transient characteristics and bonding strength of heater wire with aqua based reduced graphene oxide nanofluids

In the present work, the pool boiling critical heat flux, transient heat transfer characteristics, and bonding strength of thin Ni-Cr wire with aqua based reduced graphene oxide(r GO) nanofluids are experimentally studied. Results indicate:(i) the critical heat flux(CHF) of 0.01, 0.05, 0.1, 0.2, and 0.3 g·L~(-1) concentrations of r GO-water nanofluids varies from 1.42 to 2.40 MW·m~(-2);(ii) the CHF remains same for the tested samples during transient heat transfer studies and(iii) a constant value of CHF upto 10 tests when the nanocoated Ni-Cr wire is tested with DI water and deterioration occurs beyond this which implies a chance of peel off of r GO layer below the critical coating thickness.     

Volatile anaesthetics have differential effects on recombinant m1 and m3 muscarinic acetylcholine receptor function

Muscarinic acetylcholine signalling plays major roles in regulation of consciousness, cognitive functioning, pain perception and circulatory homeostasis. Halothane has been shown to inhibit m1 muscarinic signalling. However, no comparative data are available for desflurane, sevoflurane or isoflurane, nor have the anaesthetic effects on the m3 subtype (which is also prominent in the brain) been studied. Therefore, we have investigated the effects of these compounds on isolated m1 and m3 muscarinic receptor function. Defolliculated Xenopus oocytes expressing recombinant m1 or m3 muscarinic or (for comparison) AT1A angiotensin II receptors were voltage clamped, and Ca(2+)-activated Cl- currents (ICl(Ca)) induced by acetyl-beta-methylcholine (Mch) or angiotensin II were measured in the presence of clinically relevant concentrations of halothane, sevoflurane, desflurane or isoflurane. To determine the site of action of the volatile anaesthetics we compared anaesthetic effects on m1, m3 and AT1A receptor function and studied the effects of volatile anaesthetics on signalling induced by intracellular injection of the second messenger IP3. Desflurane had a biphasic effect on m1 signalling, enhancing at a concentration of 0.46 mmol litre-1 but depressing at 0.92 mmol litre-1. A similar, although not significant, trend was observed with m3 signalling. Isoflurane had no effect on m1 signalling, but profoundly inhibited m3 signalling. Sevoflurane depressed the function of m1 and m3 signalling in a dose-dependent manner. Halothane, similar to its known effect on m1 signalling, dose-dependently depressed m3 function. ICl(Ca) induced by intracellular injections of IP3 were unaffected by all four anaesthetics. Similarly, none of the anaesthetics tested affected AT1A signalling. Absence of interference with AT1A signalling and intracellular pathways suggest that the effects of anaesthetics on muscarinic signalling most likely result from interactions with the m1 or m3 receptor molecule. Multiple interaction sites with different affinities may explain the biphasic response to desflurane. Anaesthetic-specific effects on closely related receptor subtypes suggest defined sites of action for volatile anaesthetics on the receptor protein.