46 research outputs found
Wide-angle effects in multi-tracer power spectra with Doppler corrections
We examine the computation of wide-angle corrections to the galaxy power
spectrum including redshift-space distortions and relativistic Doppler
corrections, and also including multiple tracers with differing clustering,
magnification and evolution biases. We show that the inclusion of the
relativistic Doppler contribution, as well as radial derivative terms, are
crucial for a consistent wide-angle expansion for large-scale surveys, both in
the single and multi-tracer cases. We also give for the first time the
wide-angle cross-power spectrum associated with the Doppler
magnification-galaxy cross correlation, which has been shown to be a new way to
test general relativity. In the full-sky power spectrum, the wide-angle
expansion allows integrals over products of spherical Bessel functions to be
computed analytically as distributional functions, which are then relatively
simple to integrate over. We give for the first time a complete discussion and
new derivation of the finite part of the divergent integrals of the form
,
which are necessary to compute the wide-angle corrections when a general window
function is included. This facilitates a novel method for integrating a general
analytic function against a pair of spherical Bessel functions.Comment: 41 pages and 2 figures. V3 has substantial improvements and new
results. V4 is to appear in JCA
EVALUATING THE ANTI-MICROBIAL EFFECT OF EUGENOL EXTRACTED FROM OCIMUM SANCTUM
Eugenol is a phytochemical present in herbal and medicinal plants. It possess anti tubercular, anti-inflammatory, anti-mutagenic properties. Commercial or synthesised eugenol is used extensively in the market nowadays. The aim is to evaluate the anti-microbial property of eugenol extracted from both the powder and leaf samples of Ocimum sanctum (tulsi) and to have a comparative analysis of the synthetic eugenol and the naturally extracted eugenol from tulsi leaves. The eugenol is extracted from tulsi leaves by steam distillation. For quantitative analysis of the natural eugenol, HPLC and UV Spectroscopy are performed with commercial eugenol as the reference. While Raman Spectroscopy is performed for qualitative analysis of the constituents of tulsi leaves. Membrane casting is done with eugenol as the core ingredient and porosity of the membrane is checked by SEM. Further microbial assay is performed to evaluate the effect of eugenol. From the results it can be concluded that the eugenol extracted from the powder and fresh leaves of tulsi has anti-microbial effect and the membrane composed of eugenol has the capability to retain the eugenol. Keywords: Ocimum sanctum, eugenol, anti-microbial, membrane,anti-microbial
FAK Is a Critical Regulator of Neuroblastoma Liver Metastasis
Neuroblastomas express increased levels of gastrin-releasing peptide receptor (GRP-R). However, the exact molecular mechanisms involved in GRP-R-mediated cell signaling in neuroblastoma growth and metastasis are unknown. Here, we report that focal adhesion kinase (FAK), as a critical downstream target of GRP-R, is an important regulator of neuroblastoma tumorigenicity. We found that FAK expression correlates with GRP-R expression in human neuroblastoma sections and cell lines. GRP-R overexpression in SK-N-SH cells increased FAK, integrin α3 and ÎČ1 expressions and cell migration. These cells demonstrated flatter cell morphology with broad lamellae, in which intense FAK expression was localized to the leading edges of lamellipodia. Interestingly, FAK activation was, in part, dependent on integrin α3 and ÎČ1 expression. Conversely, GRP-R silencing decreased FAK as well as Mycn levels in BE(2)-C cells, which displayed a denser cellular morphology. Importantly, rescue experiments in GRP-R silenced BE(2)-C cells showed FAK overexpression significantly enhanced cell viability and soft agar colony formation; similarly, FAK overexpression in SK-N-SH cells also resulted in increased cell growth. These effects were reversed in FAK silenced BE(2)-C cells in vitro as well as in vivo. Moreover, we evaluated the effect of FAK inhibition in vivo. FAK inhibitor (Y15) suppressed GRP-induced neuroblastoma growth and metastasis. Our results indicate that FAK is a critical downstream regulator of GRP-R, which mediates tumorigenesis and metastasis in neuroblastoma
Autocatalysis and CO2: Carbon Capture and Utilization (CCU) Meets Natural Processes
Autocatalytic reactions were proposed to play a key role at the beginning of life starting from the first reduction of CO2 to formate, acetate and C1 C4 hydrocarbons. In carbon capture and utilization (CCU) processes, the same reactions were demonstrated to be autocatalytic and, in some cases, promoted by catalysts of the same composition. Through evolution, CO2 reduction then turned into complex autocatalytic networks such as photosynthesis, where CCU chemists found inspiration for the development of more advanced systems for the synthesis of value-added chemicals. Less evolved systems than photosynthesis, however, may be easier to emulate and provide valuable inspiration into CO2 reduction chemistry for CCU. Other synthetic systems were also demonstrated to be autocatalytic demonstrating that CO2 reactions and autocatalysis are closely connected. In this concept article, the relationship between natural, artificial and bio-inspired autocatalytic CO2 reduction processes is summarized and discussed. The accomplishments resulting from the integration of autocatalysis and CCU strategies, along with their inherent benefits and future prospectives are also outlined.Fil: Gastelu, Gabriela. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Investigaciones en FĂsico-quĂmica de CĂłrdoba. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂmicas. Instituto de Investigaciones en FĂsico-quĂmica de CĂłrdoba; ArgentinaFil: Saha, Pritha. Charles University; RepĂșblica ChecaFil: Dyson, Paul. Ăcole Polytechnique FĂ©dĂ©rale de Lausanne; SuizaFil: Hulla, Martin. Charles University; RepĂșblica ChecaFil: Uranga, Jorge Gustavo. Universidad Nacional de CĂłrdoba; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Investigaciones en FĂsico-quĂmica de CĂłrdoba. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂmicas. Instituto de Investigaciones en FĂsico-quĂmica de CĂłrdoba; Argentin
Antimicrobial activity, biocompatibility and hydrogelation ability of dipeptide-based amphiphiles
The development of new antibiotics is of increasing importance due to the growing resistance power of microbes against conventional drugs. To this end, cationic peptides are emerging as clinically potent antimicrobial agents. In the present study, we have synthesized six dipeptide-based cationic amphiphiles with different head group structures by varying combinations of L-amino acid residues. These amphiphiles showed remarkable growth inhibiting activity on several Gram-positive (minimum inhibitory concentration (MIC) = 0.1â10 μg/mL) and Gram-negative (MIC = 5â150 μg/mL) bacteria as well as on fungus (MIC = 1â50 μg/mL). The inherent antimicrobial efficacies of these cationic dipeptides were influenced by the head group architecture of the amphiphiles. Encouragingly, these amphiphiles selectively attacked microbial cells, while showing biocompatibility toward mammalian cells. The results show that the rational designing of short peptide-based cationic amphiphiles might serve as a promising strategy in the development of antimicrobial agents with greater cell specificities. In addition, the amphiphiles showed water gelation ability at room temperature. The formation of non-covalent supramolecular networks in gelation was established by microscopic and spectroscopic studies