FORMULATION AND EVALUATION OF ACARBOSE PELLETS BY EXTRUSION SPHERONIZATION TECHNIQUE

Objective: The objective of our work is to formulate and evaluate acarbose pellets for sustain drug delivery. The present study was aimed to develop sustain drug delivery system of acarbose pellets by extrusion spheronization technique using different polymers like Hydroxypropyl methyl cellulose, chitosan, ethylcellulose, microcrystalline cellulose. Pelletization of acarbose was done to achieve sustain drug release profile suitable for oral administration. Methods: The acarbose pellets were prepared by extrusion spheronization technique. The Fourier transform-infrared spectrum (FT-IR) and Differential scanning calorimetry thermogram of pure drug and drug-polymer blend showed the stable character of acarbose in the pellets. The prepared pellets were evaluated for different quality control parameters like particle size analysis, drug content, and Drug release characteristics. Results: The results obtained from different quality control parameters are within acceptable range and In vitro dissolution studies indicated that drug release from pellets follows zero-order kinetics with sustain release drug release up to 12 h with the use of ethyl cellulose as a sustain release polymer and mechanism of drug release is non-fickian. The formulated pellets were stable with respect to their physicochemical characters and drug content over a period of 60 d at accelerated stability condition. Conclusion: From present study, it was concluded that formulation of acarbose pellets by this will be a promising technique for the preparation of pellets to sustain drug release for the treatment of diabetes with better patient compliance

Probing the CP-violating light neutral higgs in the charged higgs decay at the LHC

The CP-violating MSSM allows existence of a light neutral Higgs boson (MH150 GeV) in the CPX scenario in the low tan β (5)region, which could have escaped the LEP searches due to a strongly suppressed H1ZZ coupling. This parameter space corresponds to a relatively light H+ (MH+<Mt), which is predicted to decay dominantly into the WH1 channel. Thus one expects to see a striking tt- signal at the LHC, where one of the top quarks decays into the bbb-W channel, via t→bH±, H±→WH1 and H1→bb-. The characteristic correlation between the bb-,bb-W and bbb-W invariant mass peaks is expected to make this signal practically free of the SM background. Our parton level Monte Carlo simulation yields upto 5000 events, for L=30 fb-1, over the parameter space of interest, after taking into account the b-tagging efficiency for three or more b-tagged jets

Comparison of 16S rRNA gene sequences of genus Methanobrevibacter

BACKGROUND: The phylogeny of the genus Methanobrevibacter was established almost 25 years ago on the basis of the similarities of the 16S rRNA oligonucleotide catalogs. Since then, many 16S rRNA gene sequences of newly isolated strains or clones representing the genus Methanobrevibacter have been deposited. We tried to reorganize the 16S rRNA gene sequences of this genus and revise the taxonomic affiliation of the isolates and clones representing the genus Methanobrevibacter. RESULTS: The phylogenetic analysis of the genus based on 786 bp aligned region from fifty-four representative sequences of the 120 available sequences for the genus revealed seven multi-member groups namely, Ruminantium, Smithii, Woesei, Curvatus, Arboriphilicus, Filiformis, and the Termite gut symbionts along with three separate lineages represented by Mbr. wolinii, Mbr. acididurans, and termite gut flagellate symbiont LHD12. The cophenetic correlation coefficient, a test for the ultrametric properties of the 16S rRNA gene sequences used for the tree was found to be 0.913 indicating the high degree of goodness of fit of the tree topology. A significant relationship was found between the 16S rRNA sequence similarity (S) and the extent of DNA hybridization (D) for the genus with the correlation coefficient (r) for logD and logS, and for [ln(-lnD) and ln(-lnS)] being 0.73 and 0.796 respectively. Our analysis revealed that for this genus, when S = 0.984, D would be <70% at least 99% of the times, and with 70% D as the species "cutoff", any 16S rRNA gene sequence showing <98% sequence similarity can be considered as a separate species. In addition, we deduced group specific signature positions that have remained conserved in evolution of the genus. CONCLUSIONS: A very significant relationship between D and S was found to exist for the genus Methanobrevibacter, implying that it is possible to predict D from S with a known precision for the genus. We propose to include the termite gut flagellate symbiont LHD12, the methanogenic endosymbionts of the ciliate Nyctotherus ovalis, and rat feces isolate RT reported earlier, as separate species of the genus Methanobrevibacter

Neutrino masses along with fermion mass hierarchy

Recently a new mechanism has been proposed to cure the problem of fermion mass hierarchy in the Standard Model (SM) model. In this scenario, all SM charged fermions other than top quark arise from higher dimensional operators involving the SM Higgs field. This model also predicted some interesting phenomenology of the Higgs boson. We generalize this model to accommodate neutrino masses (Dirac & Majorana) and also obtain the mixing pattern in the leptonic sector. To generate neutrino masses, we add extra three right handed neutrinos $(N_{iR})$ in this model.Comment: 20 pages, the content on results and phenomenology have been expanded, a new section on UV completion of the model has been added and also some new references, this version has been accepted by Physical Review

Cobalt Complexes of Bulky PNP Ligand: H2 Activation and Catalytic Two-Electron Reactivity in Hydrogenation of Alkenes and Alkynes

The reactivity of cobalt pincer complexes supported by the bulky tetramethylated PNP ligands Me4PNPR(R = iPr, tBu) has been investigated. In these ligands, the undesired H atom loss reactivity observed earlier in some classical CH2-arm PNP cobalt complexes is blocked, allowing them to be utilized for promoting two-electron catalytic transformations at the cobalt center. Accordingly, reaction of the formally CoIMe complex 3 with H2 under ambient pressure and temperature afforded the CoIII trihydride 4-H, in a reaction cascade reasoned to proceed by two-electron oxidative addition and reductive eliminations. This mechanistic proposal, alongside the observance of alkene insertion and ethane production upon sequential exposure of 3 to ethylene and H2, prompted an exploration into 3 as a catalyst for hydrogenation. Complex 4-H, formed in situ from 3 under H2, was found to be active in the catalytic hydrogenation of alkenes and alkynes. The proposed two-electron mechanism is reminiscent of the platinum group metals and demonstrates the utility of the bulky redox-innocent Me4PNPR ligand in the avoidance of one-electron reactivity, a concept that may show broad applicability in expanding the scope of earth-abundant first-row transition-metal catalysis.journal articl

Unusual Charged Higgs Signals at LEP-2

We have made a detailed study of the signals produced at LEP-2 from charged scalar bosons whose dominant decay channels are into four fermions. The event rates as well as kinematics of the final states are discussed when such scalars are either pair-produced or are generated through a tree-level interaction involving a charged scalar, the W and the Z. The backgrounds in both cases are discussed. We also suggest the possibility of reconstructing the mass of such a scalar at LEP-2.Comment: 12 pages, LateX, 9 Postscript figures, uses eps

Chaos and localization in the wavefunctions of complex atoms NdI, PmI and SmI

Wavefunctions of complex lanthanide atoms NdI, PmI and SmI, obtained via multi-configuration Dirac-Fock method, are analyzed for density of states in terms of partial densities, strength functions ($F_k(E)$), number of principal components ($\xi_2(E)$) and occupancies (\lan n_\alpha \ran^E) of single particle orbits using embedded Gaussian orthogonal ensemble of one plus two-body random matrix ensembles [EGOE(1+2)]. It is seen that density of states are in general multi-modal, $F_k(E)$'s exhibit variations as function of the basis states energy and $\xi_2(E)$'s show structures arising from localized states. The sources of these departures from EGOE(1+2) are investigated by examining the partial densities, correlations between $F_k(E)$, $\xi_2(E)$ and \lan n_\alpha \ran^E and also by studying the structure of the Hamiltonian matrices. These studies point out the operation of EGOE(1+2) but at the same time suggest that weak admixing between well separated configurations should be incorporated into EGOE(1+2) for more quantitative description of chaos and localization in NdI, PmI and SmI.Comment: There are 9 figure

Multicomponent Click Synthesis of β-Hydroxy/Benzyl 1,2,3- Triazoles Catalyzed by Magnetically Recyclable Nano Iron Oxide in Water

Abstract: Iron oxide nanoparticles have been found to effectively catalyze the multicomponent synthesis of 1,2,3-triazoles from azide precursors, such as epoxides and organic halides in water. The formation of the product proceeds in one pot through a mechanism that involves in situ generated organic azide intermediate, followed by rapid ring closure of this intermediate with terminal alkynes. In the presence of nano-Fe 2 O 3 , click reaction proceeds in short reaction times and the resulting products are obtained in good yields. Aqueous reaction medium, easy recovery of catalyst, efficient recycling and high stability of the catalyst render the protocol sustainable and economic

Structural, optical and electronic properties of homoepitaxial GaN nanowalls grown on GaN template by laser molecular beam epitaxy

We have grown homoepitaxial GaN nanowall networks on GaN template using an ultra-high vacuum laser assisted molecular beam epitaxy system by ablating solid GaN target under a constant r.f. nitrogen plasma ambient. The effect of laser repetition rate in the range of 10 to 30 Hz on the structural properties of the GaN nanostructures has been studied using high resolution X-ray diffraction, field emission scanning electron microscopy and Raman spectroscopy. The variation of the laser repetition rate affected the tip width and pore size of the nanowall networks. The z-profile Raman spectroscopy measurements revealed the GaN nanowall network retained the same strain present in the GaN template. The optical properties of these GaN nanowall networks have been studied using photoluminescence and ultrafast spectroscopy and an enhancement of optical band gap has been observed for the nanowalls having a tip width of 10-15 nm due to the quantum carrier confinement effect at the wall edges. The electronic structure of the GaN nanowall networks has been studied using X-ray photoemission spectroscopy and it has been compared to the GaN template. The calculated Ga/N ratio is largest (similar to 2) for the GaN nanowall network grown at 30 Hz. Surface band bending decreases for the nanowall network with the lowest tip width. The homoepitaxial growth of porous GaN nanowall networks holds promise for the design of nitride based sensor devices