61 research outputs found

    Overexpression of a mutant form of TGFBI/BIGH3 induces retinal degeneration in transgenic mice

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    PURPOSE: Despite ubiquitous expression of the keratoepithelin (KE) protein encoded by the transforming growth factor beta induced/beta induced gene human clone 3 (TGFBI/BIGH3) gene, corneal dystrophies are restricted to the cornea, and no other tissues are affected. We investigated the role of TGFBI/BIGH3 in Groenouw corneal dystrophies by generating transgenic mice overexpressing TGFBI/BIGH3 containing the R555W mutation. METHODS: Transgenic animals expressing the Groenouw mutation of human TGFBI/BIGH3 were generated using lentiviral vectors. The line expressed TGFBI/BIGH3 containing the R555W mutation under the control of the phosphoglycerate kinase (PGK) promoter. Expression of the transgene was monitored by Southern and western blotting and by RT-PCR. Electroretinogram analysis was performed and four mice were subjected to complete necroscopy. RESULTS: Transgene expression was observed in different organs although without specific expression in the cornea. The overall morphology of the transgenic animals was not severely affected by KE overexpression. However, we observed an age-dependent retinal degeneration both functionally and histologically. Female-specific follicular hyperplasia in the spleen and increased levels of lipofuscin in the adrenal gland were also seen in transgenic animals. CONCLUSIONS: Cellular degeneration in the retina of transgenic animals suggest that perturbation of the transforming growth factor beta (TGFbeta) family regulation may affect photoreceptor survival and may induce possible accelerated aging in several tissues. No corneal phenotype could be observed, probably due to the lack of transgene expression in this tissue

    Theory Meets Experiment for Noncovalent Complexes: The Puzzling Case of Pnicogen Interactions

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    A gas-phase nitrogen\u2013nitrogen noncovalent interaction has been unveiled in the nitroethane\u2013trimethylamine complex in an environment free from solvent and matrix effects using rotational spectroscopy in supersonic expansion. Different quantum chemical models (NOCV/CD and NBO) agree in indicating that this interaction largely prevails over the C 12H c5 c5 c5O and C 12H c5 c5 c5N hydrogen bonds. Furthermore, a SAPT analysis shows that electrostatic and dispersion interactions play a comparable role in stabilizing the complex. The conformational landscape exploration and stationary points characterization have been performed using state-of-the-art quantum-chemical computations providing significant insights on structure determination

    Understanding the complex organisational processes that help and hinder creativity and innovation

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    This study looks at the topics of creativity and innovation and how they are experienced as ordinary, everyday work. In business publications there is much hype and hope around the words “creativity” and “innovation”, but there is also a limited understanding of how creativity and innovation are enacted in organisations. Consequently, academics have stressed the need for ‘opening the black box’ of the firm and understanding how innovation really works (Birdi et al, 2003). This research uses the Complex Responsive Processes approach to understand the ordinary, everyday experiences of people involved in work which was novel for the organisations concerned. I selected three organisational cases from the health and education sectors. I selected these because, in each case, people were working on complex challenges which had no single, obvious solution and which required the generation and development of new and useful ideas. The research makes a novel contribution to knowledge in three ways. First, it has been unusual in that it has extended the application of complex responsive processes to understand the processes which impact on creativity and innovation in the health and education sectors. While complex responsive processes thinking has been applied to these sectors before, to my knowledge, this is the first time it has been applied to understand processes impacting on creativity and innovation in these sectors. Second, this research finds a pattern of dynamics between trust and a paradoxical concept of diversity, comprising both sufficient difference and sufficient common-ground between organizational members. In this research, trust was a necessary foundation for the exploration of ideas. However, for risks to be taken and ideas to be implemented, in contexts of high uncertainty and risk, trust alone was insufficient. The quality of conversational life flourished where both trust and diversity were present. Finally, this research makes a methodological contribution through using Stacey’s five areas for focusing attention as a conceptual framework. The use of this framework helps provide a depth of compelling detail and insights which would not have been obtained through traditional lenses from the domains of creativity and innovation. This is the first time this framework for focusing attention has been applied in this way to understanding creativity and innovation in empirical settings.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    An integrated experimental and quantum-chemical investigation on the vibrational spectra of chlorofluoromethane

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    The vibrational analysis of the gas-phase infrared spectra of chlorofluoromethane (CH2ClF, HCFC-31) was carried out in the range 200-6200 cm(-1). The assignment of the absorption features in terms of fundamental, overtone, combination, and hot bands was performed on the medium-resolution (up to 0.2 cm(-1)) Fourier transform infrared spectra. From the absorption cross section spectra accurate values of the integrated band intensities were derived and the global warming potential of this compound was estimated, thus obtaining values of 323, 83, and 42 on a 20-, 100-, and 500-year horizon, respectively. The set of spectroscopic parameters here presented provides the basic data to model the atmospheric behavior of this greenhouse gas. In addition, the obtained vibrational properties were used to benchmark the predictions of state-of-the-art quantum-chemical computational strategies. Extrapolated complete basis set limit values for the equilibrium geometry and harmonic force field were obtained at the coupled-cluster singles and doubles level of theory augmented by a perturbative treatment of triple excitations, CCSD(T), in conjunction with a hierarchical series of correlation-consistent basis sets (cc-pVnZ, with n = T, Q, and 5), taking also into account the core-valence correlation effects and the corrections due to diffuse (aug) functions. To obtain the cubic and quartic semi-diagonal force constants, calculations employing second-order Moller-Plesset perturbation (MP2) theory, the double-hybrid density functional B2PLYP as well as CCSD(T) were performed. For all anharmonic force fields the performances of two different perturbative approaches in computing the vibrational energy levels (i.e., the generalized second order vibrational treatment, GVPT2, and the recently proposed hybrid degeneracy corrected model, HDCPT2) were evaluated and the obtained results allowed us to validate the spectroscopic predictions yielded by the HDCPT2 approach. The predictions of the deperturbed second-order perturbation approach, DVPT2, applied to the computation of infrared intensities beyond the double-harmonic approximation were compared to the accurate experimental values here determined. Anharmonic DFT and MP2 corrections to CCSD(T) intensities led to a very good agreement with the absorption cross section measurements over the whole spectral range here analysed. (C) 2013 AIP Publishing LLC

    The Italian National Project of Astrobiology-Life in Space-Origin, Presence, Persistence of Life in Space, from Molecules to Extremophiles

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    The \u2018\u2018Life in Space\u2019\u2019 project was funded in the wake of the Italian Space Agency\u2019s proposal for the development of a network of institutions and laboratories conceived to implement Italian participation in space astrobiology experiments

    Targeting Sphingosine Kinase 1 in Carcinoma Cells Decreases Proliferation and Survival by Compromising PKC Activity and Cytokinesis

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    Sphingosine kinases (SK) catalyze the phosphorylation of proapoptotic sphingosine to the prosurvival factor sphingosine 1-phosphate (S1P), thereby promoting oncogenic processes. Breast (MDA-MB-231), lung (NCI-H358), and colon (HCT 116) carcinoma cells were transduced with shRNA to downregulate SK-1 expression or treated with a pharmacologic SK-1 inhibitor. The effects of SK-1 targeting were investigated by measuring the level of intracellular sphingosine, the activity of protein kinase C (PKC) and cell cycle regulators, and the mitotic index. Functional assays included measurement of cell proliferation, colony formation, apoptosis, and cell cycle analysis. Downregulation of SK-1 or its pharmacologic inhibition increased intracellular sphingosine and decreased PKC activity as shown by reduced phosphorylation of PKC substrates. In MDA-MB-231 cells this effect was most pronounced and reduced cell proliferation and colony formation, which could be mimicked using exogenous sphingosine or the PKC inhibitor RO 31-8220. SK-1 downregulation in MDA-MB-231 cells increased the number of cells with 4N and 8N DNA content, and similar effects were observed upon treatment with sphingosine or inhibitors of SK-1 or PKC. Examination of cell cycle regulators unveiled decreased cdc2 activity and expression of Chk1, which may compromise spindle checkpoint function and cytokinesis. Indeed, SK-1 kd cells entered mitosis but failed to divide, and in the presence of taxol also failed to sustain mitotic arrest, resulting in further increased endoreduplication and apoptosis. Our findings delineate an intriguing link between SK-1, PKC and components of the cell cycle machinery, which underlines the significance of SK-1 as a target for cancer therapy

    Collision induced broadening of ν1 band and ground state spectral lines of sulfur dioxide perturbed by N2 and O2

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    To monitor the constituents and trace pollutants of Earth atmosphere and understand its evolution, ac- curate spectroscopic parameters are fundamental information. SO 2 is produced by both natural and an- thropogenic sources and it is one of the principal causes of acid rains as well as an important component of fine aerosol particles, once oxidized to sulfate. The present work aims at determining SO 2 broaden- ing parameters using N 2 and O 2 as atmospherically relevant damping gases. Measurements are carried out in the infrared (IR) and mm-/sub-mm wave regions, around 8.8 μm and in the 104 GHz–1.1 THz in- terval, respectively. IR ro-vibrational transitions are recorded by using a tunable diode laser spectrometer, whereas the microwave spectra are recorded by using a frequency-modulated millimeter-/submillimeter- wave spectrometer. SO 2 -N 2 and SO 2 -O 2 collisional cross sections are retrieved for several ν1 band ro- vibrational transitions of 32 S 16 O 2 , for some transitions belonging to either ν1 + ν2 −ν2 of 32 S 16 O 2 or ν1 of 34 S 16 O 2 as well as for about 20 pure rotational transitions in the vibrational ground state of the main isotopic species. From N 2 - and O 2 - broadening coefficients the broadening parameters of SO 2 in air are derived. The work is completed with the study of the dependence of foreign broadening coefficients on the rotational quantum numbers

    The Spectroscopic Characterization of Halogenated Pollutants through the Interplay between Theory and Experiment: Application to R1122

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    In the last decade, halogenated ethenes have seen an increasing interest for different applications; in particular, in refrigeration, air-conditioning and heat pumping. At the same time, their adverse effects as atmospheric pollutants require environmental monitoring, especially by remote sensing spectroscopic techniques. For this purpose, an accurate characterization of the spectroscopic fingerprint—in particular, those of relevance for rotational–vibrational spectroscopy—of the target molecules is strongly needed. This work provides an integrated computational–theoretical investigation on R1122 (2-Chloro-1,1-difluoro-ethylene, ClHC=CF2), a compound widely employed as a key intermediate in different chemical processes. State-of-the-art quantum chemical calculations relying on CCSD(T)-based composite schemes and hybrid CCSD(T)/DFT approaches are used to obtain an accurate prediction of the structural, rotational and vibrational spectroscopic properties. In addition, the equilibrium geometry is obtained by exploiting the semi-experimental method. The theoretical predictions are used to guide the analysis of the experimentally recorded gas-phase infrared spectrum, which is assigned in the 400–6500 cm−1 region. Furthermore, absorption cross sections are accurately determined over the same spectral range. Finally, by using the obtained spectroscopic data, a first estimate of the global warming potential of R1122 vibrational spectra is obtained

    Study of the Vibrational Spectra and Absorption Cross Sections of 1-Chloro-1-fluoroethene by a Joint Experimental and Ab Initio Approach

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    The gas-phase infrared spectra of 1-chloro-1-fluoroethene (geminal chloro-fluoroethene, ClFC=CH2, 1,1-C2H2ClF) were recorded at medium resolution in the range of 400-6400 cm(-1), and the vibrational analysis led to revised assignments for the nu(11) (A '' symmetry), nu(2) (A' symmetry), and nu(1) (A' symmetry) bands. Besides the fundamentals, all the most important spectral features were interpreted in terms of overtone and combination bands, thus obtaining an accurate description of the vibrational structure of ClFC=CH2. Accurate measurements of absorption cross-sectional spectra were carried out, and integrated band intensity data were determined. High-level ab initio calculations of harmonic and anharmonic force fields thoroughly supported and guided the analysis and the disentangling of the several strongly coupled polyads involving many vibrational levels. Diagonalization of the effective Hamiltonian with the off-diagonal elements involving several Fermi and Darling-Dennison resonance coefficients computed by the theoretical cubic and quartic force constants provided the predicted energy levels in good agreement with the vibrational assignments. The calculated infrared intensities, obtained by taking into account anharmonic corrections, were compared to the accurate experimental absorption cross-sectional data determined here
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