<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

(SoNS) School of Natural Sciences

We calculate loop-induced Higgs production and decay processes which are relevant for the LHC in various six-dimensional Universal Extra Dimension models. More concretely, we focus on the Higgs production through gluon fusion and the Higgs decay into two photons induced by loop diagrams. They are one-loop leading processes and the contribution of Kaluza-Klein particles is considered to be significant. These processes are divergent in six dimensions. Therefore, we employ a momentum cutoff, whose size is fixed from the validity of perturbative calculation through naive dimensional analysis. In these six-dimensional Universal Extra Dimension models, the Higgs production cross section through gluon fusion is highly enhanced and the Higgs decay width into two photons is suppressed. In particular in the case of the compactification on Projective Sphere, these effects are remarkable. The deviation of the h (0) → 2γ signal from the prediction of the Standard model is much greater than that in the case of the five-dimensional minimal UED model. We also consider threshold corrections in the two processes and these effect are noteworthy even when we take a higher cutoff and/or a heavy KK scale. Comparing our calculation to the recent LHC results which were published at the Lepton-Photon 2011 and at the December of 2011 is performed briefly. © 2012 SISSA.

Physics

Fulltext

Journal of High Energy Physics

Higgs production and decay processes via loop diagrams in various 6D Universal Extra Dimension models at LHC

We work out the strongly interacting sector of a non-minimal Universal Extra Dimension (nmUED) scenario with one flat extra spatial dimension orbifolded on S 1 /Z 2 in the presence of brane-localized kinetic and Yukawa terms. On compactification, these terms are known to have significant, nontrivial impact on the masses and the couplings of the Kaluza-Klein (KK) excitations. We study the masses of the level '1' KK gluon and the quarks and find the modified strong interaction vertices involving these particles. The scenario conserves KK parity. Possibility of significant level-mixing among the quarks from different KK-levels is pointed out with particular reference to the top quark sector. Crosssections for various generic final states involving level '1' KK-gluon and KK-quarks from first two generations are estimated at the Large Hadron Collider (LHC) via an implementation of the scenario in MadGraph-5 with the help of FeynRules. The decay branching fractions of both strong and weakly interacting KK excitations are studied to estimate yields in various different final states involving jets, leptons and missing energy. These are used to put some conservative constraints on the nmUED parameter space using the latest LHC data. Nuances of the scenario are elucidated with reference to the minimal Universal Extra Dimension (mUED) and Supersymmetry (SUSY) and their implications for the LHC are discussed. © 2012 SISSA, Trieste, Italy.

World University root node

Non-minimal universal extra dimensions: The strongly interacting sector at the Large Hadron Collider

Time-resolved fluorescence Stokes shift and anisotropy measurements using a solvation probe in 0.78CH 3CONH 2 0.22{f LiBr (1-f) LiNO 3} melts reveal a strong decoupling of medium dynamics from viscosity. Interestingly, this decoupling has been found to occur at temperatures ∼50-100 K above the glass transition temperatures of the above melt at various anion concentrations (f LiBr). The decoupling is reflected via the following fractional viscosity dependence (η) of the measured average solvation and rotation times (τ s and τ r, respectively): τ x (ηT) p (x being solvation or rotation), with p covering the range, 0.20 p 0.70. Although this is very similar to what is known for deeply supercooled liquids, it is very surprising because of the temperature range at which the above decoupling occurs for these molten mixtures. The kinship to the supercooled liquids is further exhibited via p which is always larger for τ r than for τ s, indicating a sort of translation-rotation decoupling. Multiple probes have been used in steady state fluorescence measurements to explore the extent of static heterogeneity. Estimated experimental dynamic Stokes shift for coumarin 153 in these mixtures lies in the range, 1000 Δν tcm -1 1700, and is in semi-quantitative agreement with predictions from our semi-molecular theory. The participation of the fluctuating density modes at various length-scales to the observed solvation times has also been investigated. © 2012 American Institute of Physics.

Chemistry

Journal of Chemical Physics

Medium decoupling of dynamics at temperatures ∼100 K above glass-transition temperature: A case study with (acetamide + lithium bromidenitrate) melts

Steady state and time resolved fluorescence emission spectroscopy have been employed to investigate the effects of solvent confinement and electrolyte concentration on excited state intramolecular charge transfer (ICT) reaction in 4-(1-pyrrolidinyl) benzonitrile (P5C), 4-(1-piperidinyl) benzonitrile (P6C), and 4-(1-morpholenyl) benzonitrile (M6C) in AOT/n-heptane/acetonitrile and AOT/n-heptane/methanol reverse micelles. Dramatic confinement effects have been revealed via a huge reduction (factor ranging between 100 and 20) over bulk values of both equilibrium and reaction rate constants. A strong dependence on the size of the confinement (W s ) of these quantities has also been observed. W s dependent average static dielectric constant, viscosity and solvation time-scale have been determined. Estimated dielectric constants for confined methanol and acetonitrile show a decrease from the respective bulk values by a factor of 3-5 and viscosities increased by a factor of 2 at the highest W s considered. Addition of electrolyte at W s =5 for acetonitrile is found to produce a linear increase of confined solvent viscosity but leads to a non-monotonic electrolyte concentration dependence of average solvation time. Reaction rate constant is found to decrease linearly with electrolyte concentration for P5C and P6C but non-monotonically for M6C, the highest decrease for all the molecules being ∼ 20% over the value in the absence of added electrolyte in the solvent pool. The observed huge reduction in reaction rate constant is attributed to the effects of decreased solution polarity, enhanced viscosity and slowed-down solvent reorganization of the solvent under confinement in these non-aqueous reverse micelles. © 2011 Indian Academy of Sciences.

Journal of Chemical Sciences

Excited state intramolecular charge transfer reaction in non-aqueous reverse micelles: Effects of solvent confinement and electrolyte concentration#

Herein, we report a diversity-oriented-synthesis (DOS) approach for the synthesis of biologically relevant molecular scaffolds. Our methodology enables the facile synthesis of fused N-heterocycles, spirooxoindolones, tetrahydroquinolines, and fused N-heterocycles. The two-step sequence starts with a chiral-bicyclic-lactam-directed enolate-addition/substitution step. This step is followed by a ring-closure onto the built-in scaffold electrophile, thereby leading to stereoselective carbocycle- and spirocycle-formation. We used in silico tools to calibrate our compounds with respect to chemical diversity and selected drug-like properties. We evaluated the biological significance of our scaffolds by screening them in two cancer cell-lines. In summary, our DOS methodology affords new, diverse scaffolds, thereby resulting in compounds that may have significance in medicinal chemistry. Uno, DOS, tres: An enolate-mediated strategy was used to synthesize biologically relevant cyclic scaffolds. In silico analysis was used to evaluate the compounds in terms of, for example, polar surface area and chemical diversity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemistry - An Asian Journal

Reagent-based DOS: Developing a diastereoselective methodology to access spirocyclic- and fused heterocyclic ring systems

We discuss the choice of input parameters for the renormalization of the chargino and neutralino sector in the minimal supersymmetric standard model in the on-shell scheme. We show that one should choose the masses of a bino-like, a wino-like and a Higgsino-like state as inputs in order to avoid large corrections to the masses of the other eigenstates in this sector. We also show that schemes where the Higgsino-like input state is a neutralino are more stable than those where the mass of the Higgsino-like chargino is used as input. The most stable scheme uses the masses of the wino-like chargino as well as the masses of the bino- and Higgsino-like neutralinos as inputs. {\textcopyright} 2012 American Physical Society.

Physical Review D - Particles, Fields, Gravitation and Cosmology

On-shell renormalization of the chargino and neutralino masses in the MSSM

Recent advances in radical azidation using sulfonyl azides are presented. For instance, radical carboazidation using $\alpha$-iodoketones, desulfitative carboazidation and anti- Markovnikov hydroazidation of alkenes are described. These novel methods tolerate a large number of functional groups and allow the synthesis of organic azides that would be difficult to synthesize otherwise. The transformation of the azides using reductive processes as well as a Schmidt reaction under nonacidic conditions were used to synthesize alkaloids including indolizidine 167B, monomorine I, cylindricine C and lepadiformine C. {\textcopyright} 2012 IUPAC.

Pure and Applied Chemistry

Radical azidation reactions and their application in the synthesis of alkaloids

Plasmodium falciparum origin recognition complex 1 (ORC1) protein has been implicated in DNA replication and silencing var gene family. However, the mechanism and the domain structure of ORC1 related to the regulation of var gene family are unknown. Here we show that the unique N-terminus of PfORC1 (PfORC1N1-238) is targeted to the nuclear periphery in vivo and this region binds to the telomeric DNA in vitro due to the presence of a leucine heptad repeats. Like PfORC1N1-238, endogenous full length ORC1, was found to be associated with sub telomeric repeat regions and promoters of various var genes. Additionally, binding and propagation of ORC1 to telomeric and subtelomeric regions was severely compromised in PfSir2 deficient parasites suggesting the dependence of endogenous ORC1 on Sir2 for var gene regulation. This feature is not previously described for Plasmodium ORC1 and contrary to yeast Saccharomyces cerevisiae where ORC function as a landing pad for Sir proteins. Interestingly, the overexpression of ORC1N1-238compromises the binding of Sir2 at the subtelomeric loci and var gene promoters consistent with de-repression of some var genes. These results establish role of the N-terminus of PfORC1 in heterochromatin formation and regulation of var gene expression in co-ordination with Sir2 in P. falciparum. © The Author(s) 2012. Published by Oxford University Press.

Life Sciences

Nucleic Acids Research

The role of N-terminus of Plasmodium falciparum ORC1 in telomeric localization and var gene silencing

We examined the effects of an inhibitor of PI3K, XL147, against human breast cancer cell lines with constitutive PI3K activation. Treatment with XL147 resulted in dose-dependent inhibition of cell growth and levels of pAKT and pS6, signal transducers in the PI3K/AKT/TOR pathway. In HER2-overexpressing cells, inhibition of PI3K was followed by up-regulation of expression and phosphorylation of multiple receptor tyrosine kinases, including HER3. Knockdown of FoxO1 and FoxO3a transcription factors suppressed the induction of HER3, InsR, IGF1R, and FGFR2 mRNAs upon inhibition of PI3K. In HER2 + cells, knockdown of HER3 with siRNA or cotreatment with the HER2 inhibitors trastuzumab or lapatinib enhanced XL147-induced cell death and inhibition of pAKT and pS6. Trastuzumab and lapatinib each synergized with XL147 for inhibition of pAKT and growth of established BT474 xenografts. These data suggest that PI3K antagonists will inhibit AKT and relieve suppression of receptor tyrosine kinase expression and their activity. Relief of this feedback limits the sustained inhibition of the PI3K/AKT pathway and attenuates the response to these agents. As a result, PI3K pathway inhibitors may have limited clinical activity overall if used as single agents. In patients with HER2- overexpressing breast cancer, PI3K inhibitors should be used in combination with HER2/HER3 antagonists.

Proceedings of the National Academy of Sciences of the United States of America

Feedback upregulation of HER3 (ErbB3) expression and activity attenuates antitumor effect of PI3K inhibitors

The peroxidase family of natural enzymes facilitate H2O 2 reduction by one electron transfer through aromatic substrates, if chromogenic, they can be used in the colorimetric detection of H 2O2 and subsequently glucose in tandem with glucose oxidase. Au nanoparticles encapsulated within porous silica exhibited peroxidase mimetic activity and kinetic parameter evaluation indicates an excellent affinity for H2O2. It is also shown to have a detection capability for glucose in very low concentrations and could be used for glucose detection in a one-pot assay. The material is synthesised by using cation-ended thiol-stabilised ultra small gold clusters as precursors. Removal of the thiols creates micropores within the silica, making this material unique in that the active centres are protected inside the silica, yet are accessible to reactant molecules. This characteristic makes the material ideal as a detection tool where attrition resistance will be advantageous. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2012.