Expression and Functional Studies on the Noncoding RNA,PRINS

PRINS, a noncoding RNA identified earlier by our research group, contributes to psoriasis susceptibility and cellular stress response. We have now studied the cellular and histological distribution of PRINS by using in situ hybridization and demonstrated variable expressions in different human tissues and a consistent staining pattern in epidermal keratinocytes and in vitro cultured keratinocytes. To identify the cellular function(s) of PRINS, we searched for a direct interacting partner(s) of this stress-induced molecule. In HaCaT and NHEK cell lysates, the protein proved to be nucleophosmin (NPM) protein as a potential physical interactor with PRINS. Immunohistochemical experiments revealed an elevated expression of NPM in the dividing cells of the basal layers of psoriatic involved skin samples as compared with healthy and psoriatic uninvolved samples. Others have previously shown that NPM is a ubiquitously expressed nucleolar phosphoprotein which shuttles to the nucleoplasm after UV-B irradiation in fibroblasts and cancer cells. We detected a similar translocation of NPM in UV-B-irradiated cultured keratinocytes. The gene-specific silencing of PRINS resulted in the retention of NPM in the nucleolus of UV-B-irradiated keratinocytes; suggesting that PRINS may play a role in the NPM-mediated cellular stress response in the skin.     

Thiourea and Guanidine Compounds and Their Iridium Complexes in Drug-Resistant Cancer Cell Lines: Structure-Activity Relationships and Direct Luminescent Imaging

Thiourea and guanidine units are found in nature, medicine, and materials. Their continued exploration in applications as diverse as cancer therapy, sensors, and electronics means that their toxicity is an important consideration. Iridium complexes present new opportunities for drug development and imaging in terms of structure and photoactivity. We have systematically synthesised a set of thiourea and guanidine compounds and iridium complexes thereof, and elucidated structure–activity relationships for cellular toxicity in three ovarian cancer cell lines and their cisplatin-resistant sub-lines. We have been able to use the intrinsic luminescence of iridium complexes to visualise the effect of both structure alteration and cellular resistance mechanisms. These findings provide starting points for the development of new drugs and consideration of safety issues for novel thiourea-, guanidine-, and iridium-based materials.     

Dynamic target tracking with fringe-adjusted joint transform correlation and template matching

Target tracking in forward-looking infrared (FLIR) video sequences is a challenging problem because of various limitations such as low signal-to-noise ratio (SNR), image blurring, partial occlusion, and low texture information, which often leads to missing targets or tracking nontarget objects. To alleviate these problems, we developed a novel algorithm that involves local-deviation-based image preprocessing as well as fringe-adjusted joint-transform-correlation--(FJTC) and template-matching--(TM) based target detection and tracking. The local-deviation-based preprocessing technique is used to suppress smooth texture such as background and to enhance target edge information. However, for complex situations such as the target blending with background, partial occlusion of the target, or proximity of the target to other similar nontarget objects, FJTC may produce a false alarm. For such cases, the TM-based detection technique is used to compensate FJTC breaking points by use of cross-correlation coefficients. Finally, a robust tracking algorithm is developed by use of both FJTC and TM techniques, which is called FJTC-TM technique. The performance of the proposed FJTC-TM algorithm is tested with real-life FLIR image sequences.     

Prediction of the resonance characteristics of combustion chambers on the basis of large-eddy simulation

In the last few years intensive experimental investigations were performed at the University of Karlsruhe to develop an analytical model for the Helmholtz resonator-type combustion system. In the present work the resonance characteristics of a Helmholtz resonator-type combustion chamber were investigated using large-eddy simulations (LES), to understand better the flow effects in the chamber and to localize the dissipation. In this paper the results of the LES are presented, which show good agreement with the experiments. The comparison of the LES study with the experiments sheds light on the significant role of the wall roughness in the exhaust gas pipe.     

Investigations on polyurethane ionomers. II. 3,4-dihydroxycinnamic acid-based anionomers

Polyurethanes of different compositions were synthesized by chain extending the prepolymer formed by the reaction of various polyols and diisocyanate with 3,4-dihydroxycinnamic acid. The polyurethanes were converted to their anionomers by treating with metal acetates. The polyurethanes were characterized using FTIR, FTNMR, TGA, and DSC analysis. The molecular weights of the polymers were determined using GPC. A detailed study of the effect of variation of molecular weight of the polyols and mol ratio of the various reactants on the glass transition temperature and molecular weight of the polyurethanes was made. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2105–2109, 1997     

Inhibitory interactions between perigeniculate GABAergic neurons

Perigeniculate neurons form an interactive sheet of cells that inhibit one another as well as thalamocortical neurons in the dorsal lateral geniculate nucleus (LGNd). The inhibitory influence of the GABAergic neurons of the perigeniculate nucleus (PGN) onto other PGN neurons was examined with intracellular recordings in vitro. Intracellular recordings from PGN neurons during the generation of spindle waves revealed barrages of EPSPs and IPSPs. The excitation of local regions of the PGN with the local application of glutamate resulted in activation of IPSPs in neighboring PGN neurons. These IPSPs displayed an average reversal potential of -77 mV and were blocked by application of bicuculline methiodide or picrotoxin, indicating that they are mediated by GABAA receptors. In the presence of GABAA receptor blockade, the activation of PGN neurons with glutamate could result in slow IPSPs that were mediated by GABAB receptors in a subset (40%) of cells. Similarly, application of specific agonists muscimol and baclofen demonstrated that PGN neurons possess both functional GABAA and GABAB receptors. Examination of the axon arbors of biocytin-filled PGN neurons often revealed the presence of beaded axon collaterals within the PGN, suggesting that this may be an anatomical substrate for PGN to PGN inhibition. Functionally, activation of inhibition between PGN neurons could result in a shortening or a complete abolition of the low threshold Ca2+ spike or an inhibition of tonic discharge. We suggest that the mutual inhibition between PGN neurons forms a mechanism by which the excitability of these cells is tightly controlled. The activation of a point within the PGN may result in the inhibition of neighboring PGN neurons. This may be reflected in the LGNd as a center of inhibition surrounded by an annulus of disinhibition, thus forming a "center-surround" mechanism for thalamic function.     

Variation of magnetic properties of two-layer carbon-steel products under tension

Evolution of magnetic properties during tension of multilayer products have been studied on two-layer specimens composed of low-carbon and medium-carbon steel plates with different values of magnetic hardness. The magnetic properties were measured in a loaded state. A model of the stress-strain state of a two-layer specimen has been designed. A technique for restoring stress-strain curves of multicomponent steel products from magnetic characteristics of its components determined directly during tension has been suggested. The values of the field of the maximum magnetic permeability of the components have been recommended as a parameter for nondestructive testing of stresses and strains, namely, at small deformations, the field of the maximum magnetic permeability of the magnetically soft component and at higher deformations, the field of the maximum magnetic permeability of the magnetically hard component. The results obtained are of considerable interest for technical diagnostics of loaded two-layer elements of constructions, including surface-hardened, welded, and bimetallic ones.     

FTIR investigation of the influence of diisocyanate symmetry on the morphology development in model segmented polyurethanes

Novel segmented polyurethanes with hard segments based on a single diisocyanate molecule with no chain extenders were prepared by the stoichiometric reactions of poly(tetramethylene oxide)glycol (M_n=1000 g/mol) (PTMO-1000) and 1,4-phenylene diisocyanate (PPDI), trans-1,4-cyclohexyl diisocyanate (CHDI), bis(4-isocyanatocyclohexyl)methane (HMDI) and bis(4-isocyanatophenyl)methane (MDI). Time dependent microphase separation and morphology development in these polyurethanes were studied at room temperature using transmission FTIR spectroscopy. Solvent cast films on KBr discs were annealed at 100 °C for 15 s and microphase separation due to self organization of urethane hard segments was followed by FTIR spectroscopy, monitoring the change in the relative intensities of free and hydrogen-bonded carbonyl (CO) peaks. Depending on the structure of the diisocyanate used, while the intensity of free CO peaks around 1720-1730 cm⁻¹ decreased, the intensity of H-bonded CO peaks around 1670-1690 cm⁻¹, which were not present in the original samples, increased with time and reached saturation in periods ranging up to 5 days. Structure of the diisocyanate had a dramatic effect on the kinetics of the process and the amount of hard segment phase separation. While PPDI and CHDI based polyurethanes showed self-organization and formation of well ordered hard segments, interestingly no change in the carbonyl region or no phase separation was observed for MDI and HMDI based polyurethanes. Quantitative information regarding the relative amounts of non-hydrogen bonded, loosely hydrogen bonded and strongly hydrogen bonded and ordered urethane hard segments were obtained by the deconvolution of CO region and analysis of the relative absorbances in CO region.     

Investigation of liquid diffusion into contact lenses using an electron spin resonance technique

In this study, electron spin resonance (ESR) spectroscopy was used for the first time to investigate liquid diffusion into contact lenses. As contact lenses are not paramagnetic substances, they were labeled with nitroxide spin probes to get an ESR spectrum. Thus, it gives a solid spin‐labeled ESR spectrum. The shape and intensity of the ESR signals depend on the environment of these spin probes. The spin probe environment began to change from solid to liquid if liquid were dropped into the system. Consequently the ESR spectra began to change with time, too. By following these changes, three distinct steps were found. Their diffusion coefficients were determined to be 6.38 × 10^?8 cm²/s for the first step (rapid decay region) and 0.37 × 10^?8 cm²/s for the second step (slow decay region), and 2.50 × 10^?8 cm²/s for the third and last step (desorption region). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2942–2946, 2006