2,529 research outputs found

    Controlling the Ultrafast Dynamics of HD+ by the Carrier-Envelope Phases of an Ultrashort Laser Pulse: A Quasi-Classical Dynamics Study

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    A theoretical study on the coupled electron-nuclear dynamics of HD+ molecular ions under ultrashort, intense laser pulses is performed by employing a well-established quasi-classical model. The influence of the laser carrier-envelope phase on various channel (H + D+, D + H+, and H+ + D+) probabilities is investigated at different laser field intensities. The carrier-envelope phase is found to govern the dissociation (H + D+ and D + H+) and Coulomb explosion (H+ + D+) channel probabilities. The kinetic energy release distributions of the fragments are also found to be sensitive to the carrier-envelope phase of the laser pulse. Our results are in agreement with the previously reported quantum dynamics studies and experiments

    Pulmonary Echinococcal Cyst with a Filamentous Fungus Co-Infection

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    Fungal infections are known to colonize the preexisting lung cavities formed as a result of diseases like tuberculosis, sarcoidosis, bronchiectasis and cavitatary neoplasia, mostly encountered in immunocompromised patients. Pulmonary echinococcal cysts have been reported coexistent with cryptococcosis and other saprophytic mycosis, but the coexistence of aspergillosis and echinococcal cyst is extremely rare and occasionally been reported in English literature. Active invasion and proliferation of the fungi in the laminated ectocyst of the echinococcal cyst is very unusual. We report a case of 60 years old immunocompetent female, presented with cough, chest pain and shortness of breath. The chest X- ray showed a large thick walled cavity in the lower and mid zone of right lung with positive water lily sign. Surgical enucleation of the echinococcal cyst revealed aspergilloma involving the cavity with massive invasion of laminated ectocyst by filamentous fungus, morphologically resembling an Aspergillus species and was further treated with Itraconazole for 3 months. This unique coexistence of active pulmonary echinococcosis and aspergillosis is being reported because of its rarity and clinical importance for its management.Keywords: Aspergillosis, echinococcosis, echinococcal cyst, pulmonary, mycosis

    Assessment of genetic and biochemical diversity of ecologically variant ectomycorrhizal Russula sp. from India

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    The aim of this study was to develop the phylogenetic relationship amongst the ecologically variant Russula species by using polymerase chain reaction (PCR) based technique, random amplified polymorphic DNA (RAPD) and isozyme analyses. Two groups could be characterized amongst the total isolates by cluster analyses. Protease, cellulase, glutamate dehydrogenase,  pectinase and acid phosphatase designated band P220.16, C472.18, GLD130.21, Pe569.12 and AP472.12, respectively, were common in all the isolates and four monomorphic RAPD bands viz; 818, 512, 298 and 201 bp were also diversified in the isolates. This common band reveals that diversity of these alleles or loci in all ecologically variant isolates. Thus, the present studies discuss the genetic diversity of ecologically variant Russula species on the basis of RAPD and isozyme analysis

    Alu-miRNA interactions modulate transcript isoform diversity in stress response and reveal signatures of positive selection

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    Primate-specific Alus harbor different regulatory features, including miRNA targets. In this study, we provide evidence for miRNA-mediated modulation of transcript isoform levels during heat-shock response through exaptation of Alu-miRNA sites in mature mRNA. We performed genome-wide expression profiling coupled with functional validation of miRNA target sites within exonized Alus, and analyzed conservation of these targets across primates. We observed that two miRNAs (miR-15a-3p and miR-302d-3p) elevated in stress response, target RAD1, GTSE1, NR2C1, FKBP9 and UBE2I exclusively within Alu. These genes map onto the p53 regulatory network. Ectopic overexpression of miR-15a-3p downregulates GTSE1 and RAD1 at the protein level and enhances cell survival. This Alu-mediated fine-tuning seems to be unique to humans as evident from the absence of orthologous sites in other primate lineages. We further analyzed signatures of selection on Alu-miRNA targets in the genome, using 1000 Genomes Phase-I data. We found that 198 out of 3177 Alu-exonized genes exhibit signatures of selection within Alu-miRNA sites, with 60 of them containing SNPs supported by multiple evidences (global-FST > 0.3, pair-wise-FST > 0.5, Fay-Wu's H  2.0, high ΔDAF) and implicated in p53 network. We propose that by affecting multiple genes, Alu-miRNA interactions have the potential to facilitate population-level adaptations in response to environmental challenges

    Numerical and experimental assessment of the modal curvature method for damage detection in plate structures

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    This paper is concerned with the use of numerically obtained modal curvatures for damage detection in both isotropic and composite laminated plates. Numerical simulations are carried out by using COMSOL Multiphysics as FEM solver of the governing equations, in which a Mindlin-Reissner plate model is assumed and defects are introduced as localized smoothed variations of the baseline (healthy) configuration. Experiments are also performed on steel and aluminum plates using scanning laser vibrometry. This study confirms that the central difference method greatly amplifies the measurement errors and its application leads to ineffective predictions for damage detection, even after denoising. As a consequence, different numerical techniques should be explored to allow the use of numerically obtained modal curvatures for structural health monitoring. Herein, the Savitzky-Golay filter (or least-square smoothing filter) is considered for the numerical differentiation of noisy data

    Numerical and experimental assessment of the modal curvature method for damage detection in plate structures

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    Use of modal curvatures obtained from modal displacement data for damage detection in isotropic and composite laminated plates is addressed through numerical examples and experimental tests. Numerical simulations are carried out employing COMSOL Multiphysics as finite element solver of the equations governing the Mindlin-Reissner plate model. Damages are introduced as localized non-smooth variations of the bending stiffness of the baseline (healthy) configuration. Experiments are also performed on steel and aluminum plates using scanning laser vibrometry. The obtained results confirm that use of the central difference method to compute modal curvatures greatly amplifies the measurement errors and its application leads to unreliable predictions for damage detection, even after denoising. Therefore, specialized ad hoc numerical techniques must be suitably implemented to enable structural health monitoring via modal curvature changes. In this study, the Savitzky-Golay filter (also referred to as least-square smoothing filter) is considered for the numerical differentiation of noisy data. Numerical and experimental results show that this filter is effective for the reliable computation of modal curvature changes in plate structures due to defects and/or damages

    Assessment and Localization of Active Discontinuities Using Energy Distribution Between Intrinsic Modes

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    A method for localization and severity assessment of structural damages is proposed. The algorithm works based on nonlinear behavior of certain type of damages such as breathing cracks which are called active discontinuities in this paper. Generally, nonlinear features are more sensitive to such damages although their extraction is sometimes controversial. A major controversy is the imposition of spurious modes on the expansion of the signal which needs to be addressed for an effective application and robustness of the method. The energy content of Intrinsic Mode Functions (IMFs), which are the resultants of Empirical Mode Decomposition (EMD), and also the shape of energy distribution between these modes before and after damage, are used for localization and severity assessment of the damages. By using EMD, we preserve the nonlinear aspects of the signal while avoiding imposition of spurious harmonics on its expansion without any assumption of stationarity. The developed algorithms are used to localize and assess the damage in a steel cantilever beam. The results show that the method can be used effectively for detecting active structural discontinuities due to damage
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