From rods to helices: evidence of a screw-like nematic phase

Evidence of a special chiral nematic phase is provided using numerical simulation and Onsager theory for systems of hard helical particles. This phase appears at the high density end of the nematic phase, when helices are well aligned, and is characterized by the C$_2$ symmetry axes of the helices spiraling around the nematic director with periodicity equal to the particle pitch. This coupling between translational and rotational degrees of freedom allows a more efficient packing and hence an increase of translational entropy. Suitable order parameters and correlation functions are introduced to identify this screw-like phase, whose main features are then studied as a function of radius and pitch of the helical particles. Our study highlights the physical mechanism underlying a similar ordering observed in colloidal helical flagella [E. Barry et al. \textit{Phys. Rev. Lett.} \textbf{96}, 018305 (2006)] and raises the question of whether it could be observed in other helical particle systems, such as DNA, at sufficiently high densities.Comment: List of authors correcte

Development and validation of new analytical method for the estimation of fluoxetine in bulk and dosage form by UV spectrophotometry

A simple, rapid and precise method is developed for the quantitative determination of Fluoxetine in combined pharmaceutical-dosage forms. The method was based on UV Spectrophotometric determination of Fluoxetine drug using Beer-Lamberts Law. It involves absorbance measurement at 224 nm (λmax of Fluoxetine) in water. For UV Spectrophotometric method, linearity was obtained in concentration range of 5-30 mcg/ml with regression 0.999 for Fluoxetine respectively. Recovery was in the range of 98 -102%; the value of standard deviation and %R.S.D was found to be < 2 shows high precision of the method.

Enhanced dispersibility of carbon black particles by PVA encapsulation using combined heating method

Carbon black (CB) nanoparticles were prepared by incomplete combustion of petroleum in the presence of air. CB, both hydrous and non-hydrous were encapsulated by poly vinyl alcohol (PVA) using a simple method of combined heating. The resultant powder was characterized by XRD, SEM and FTIR. The particle-size distribution measurements of the obtained PVA-encapsulated CB (CB@PVA) nanoparticles show that the diameters of were distributed within the nanoscale dimension. Simple water dispersibility test was done to check for the changes. Using this strategy, complicated polymerization process involved in the counterpart of polymer coating applications can be avoided and it is much cheaper compared to any other techniques

Characterization of calcium and magnesium binding domains of human 5-lipoxygenase

Two calcium binding sites, separated by about 9.3 Å, present in the loops that connect the β-sheets of N-terminal domain contain the ligating residues F14, A15, G16, D79, and D18, D19, L76, respectively. Magnesium is found to bind in regions, which are marginally different owing to the disparity in the ionic radii of Ca<SUP>2+</SUP> and Mg<SUP>2+</SUP>. The entropy analysis on the loops of 5-lipoxygenase, implementing the wormlike chain model, explains that the N-terminal β-barrel is well suited to accommodate calcium binding sites. The large buried side chain area of W102 (compared to W13 and W75) and comparatively smaller fraction of side chain exposed to polar atoms corroborate the calcium induced higher affinity to phosphatidylcholine (PC). However, W80 lying in close proximity of the calcium binding sites is expected to have considerable PC affinity but negligible calcium induced effect on PC binding

Influence of ZrO2_{2} Addition on Structural and Biological Activity of Phosphate Glasses for Bone Regeneration

Zirconium doped calcium phosphate-based bioglasses are the most prominent bioactive materials for bone and dental repair and regeneration implants. In the present study, a 8ZnO-22Na2O-(24 - x)CaO-46P2O5-xZrO2 (0.1 ≤ x ≤ 0.7, all are in mol%) bioglass system was synthesized by the conventional melt-quenching process at 1100 °C. The glass-forming ability and thermal stability of the glasses were determined by measuring the glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm), using differential thermal analysis (DTA). The biological activity of the prepared samples was identified by analyzing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy-energy dispersive spectra (SEM-EDS), before and after immersion in simulated body fluid (SBF) for various intervals of 0, 1 and 5 days, along with the magnitude of pH and the degradation of glasses also evaluated. The obtained results revealed that the glass-forming ability and thermal stability of glasses increased with the increase in zirconia mol%. The XRD, FTIR, and SEM-EDS data confirmed a thin hydroxyapatite (HAp) layer over the sample surface after incubation in SBF for 1 and 5 days. Furthermore, the development of layer found to be increased with the increase of incubation time. The degradation of the glasses in SBF increased with incubation time and decreased gradually with the increase content of ZrO2 mol% in the host glass matrix. A sudden rise in initial pH values of residual SBF for 1 day owing to ion leaching and increase of Ca2+ and PO43- ions and then decreased. These findings confirmed the suitability of choosing material for bone-related applications

Vanitha et.al Indian Journal of Research in Pharmacy and Biotechnology ISSN: 2321-5674(Print) ISSN: 2320 – 3471(Online) Applications of organogels in drug delivery

An organogel is a class of gel composed of a liquid organic phase within a three-dimensional, crosslinked network. In the pharmaceutical field, organogels can be used for drug and vaccine delivery via different administration routes, although relatively few such formulations have investigated only a few organogels have been investigated for drug delivery despite the very large number of organogels under study. Organogels present very interesting advantages as drug delivery formulations, amongst which their ease of preparation and administration. This article will discuss the details of organogels formation and its applications in the drug delivery. Key Word: Gel, cross-linked, drug deliver

Randomly Directed Exploration Protocol for Clone Detection in Wireless Sensor Networks

ABSTRACT: Wireless sensor networks are resource constrained and vulnerable to various kinds of attacks. In this paper we study node clone attack. Many solutions came into existence and for detecting this attack. Many solutions need assumptions to have the problem solved in large-scale deployment of sensors. They have tradeoffs between the solutions provided and network conditions. Recently Li and Gong proposed two protocols for node clone detection with different tradeoffs with network conditions. Distributed Hash Table (DHT) was used to have distributed mechanisms for node clone detection. Due to the overhead caused by DHT, they proposed another protocol that overcomes this problem. In this paper, we implement a novel mechanism that can detect node clone attack in wireless sensor networks. We made simulations in NS2 to demonstrate the proof of concept

Enhancing Renewable Energy Capture with Fuzzy Logic MPPT Control in PV and Wind Power Systems

There are many natural resources available in the nature to produce power like solar, wind, bio-gas and hydel etc. By producing power through these resources, we can decrease the burden to the other power generation units. In this project we are using the application based on the hybrid power systems like (SWHPS). It includes solar radiations, solar panels, turbine, permanent magnet synchronous generator (PMSG), controller, converter and finally inverter. In this photovoltaic method the algorithm used is (P&O) for both power systems as a control logic for increasing the power generated using the method called maximum power point tracking system (MPPT). In this project we will show the total survey of power controller is done by P&O algorithm for both hybrid power systems, the MPPT controller is executed through Fuzzy Logic Controller (FLC) by both renewable sources in hybrid power systems. MPPT controlled boost converter is common for both power generation units. The voltage and current are the common inputs for the hybrid power systems but the wind generation unit has the extra input known as speed related to the PMSG device. The SWHPS with the Fuzzy Logic Control based MPPT exhibits for having a greater and quick run when related with the other controllers. In this the presentation of the various implementations (solar, wind) of MPPT controller are explored through this project are shown in Matrix laboratory application through simulation. Simulated outputs are in the load voltage, load current and load power of SWHPS