Supramolecular host–guest systems constructed of pyrrole derivatives and 3D-coordination polymers

Pyrrole derivatives have been shown to be completely or partially oxidized within the expandable channels of the 3D-coordination polymers [(R₃Sn)₃Fe(CN)₆] _n and [(R₃Sn)(R₃^′Sn)₂Fe(CN)₆] _n , R and R′ = Me, n-Bu, or Ph, to give novel class of supramolecular host–guest systems. The structures and physical properties of these host–guest systems depend on the reaction time, nature of the host and guest, the space empty within the network of the 3D-coordination polymers. Pyrrole undergoes oxidative polymerization in the channels of the 3D-coordination polymers to form semiconducting diamagnetic supramolecular host–guest systems. Whereas N-methylpyrrole and 2,5-dimethylpyrrole are not polymerized under these experimental conditions, but give paramagnetic charge transfer (CT) supramolecular host–guest systems.     

Extending and Enhancing the Properties of Porous Cordierite Ceramics by Mo6+ ion Incorporation via Facile Combined Synthesis Technique

Molybdenum‐doped cordierite ceramics have been fabricated through facile combined techniques, coprecipitation followed by solid state. XRD results revealed that α‐cordierite phase is predominated with increasing Mo⁶⁺ ion content. The density measurements showed that the bulk density reduced to the minimum value of 0.61 g/cm³, which corresponds to the maximum porosity of about 76.8% at 5% Mo⁶⁺ ion. The dielectric permittivity (ε) of pure cordierite is decreased with increasing Mo⁶⁺ ion content. The minimum dielectric loss of Mo‐doped cordierite at 1 MHz was equal 0.008 with 10% Mo⁶⁺, while at 1 GHz was equal 0.03 with 5% Mo⁶⁺.     

Direct use of solar energy for water desalination

Solar energy utilization in three different types of solar desalination systems is considered. The overall efficiency of a typical basin type solar desalination plant is 30 per cent or lower. The major design factors affecting energy utilization are basin temperature, condensing surface temperature and ambient air temperature. Basic reflection and thermal radiation from the evaporating surface and transparent cover are the major sources of heat energy loss in a solar still. The efficiency of a solar desalination plant can be improved by controlling radiation from the plant basin and by the reuse of the latent heat of condensation.     

Dual effect of erbB-2 depletion on the regulation of DNA repair and cell cycle mechanisms in non-small cell lung cancer cells

Overexpression of the erbB-2 tyrosine kinase receptor, p185erbB-2, is a common alteration in non-small cell lung cancer (NSCLC) and has been associated with poor prognosis and a tumor drug resistance phenotype. In this study, we have examined the consequences of erbB-2 depletion on DNA repair, cell cycle, and apoptosis using a panel of NSCLC cell lines constitutively overexpressing erbB-2 receptor. Depletion of the erbB-2 was achieved using the tyrosine kinase inhibitor CP127,374 which promotes erbB-2 degradation. Treatment with CP127,374 concentrations which deplete erbB-2 and inhibit tyrosine phosphorylation resulted in downregulation of DNA repair mechanisms and cell accumulation at G1 phase of the cell cycle. GI arrest was observed in cells with mutated p53 as well as cells lacking p53 protein, suggesting a p53-independent mechanisms. NSCLC cells which overexpress erbB-2 were more resistant to cisplatin-induced cytotoxicity in comparison to cells expressing low levels of erbB-2. Treatment with CP127,374 alone did not result in any induction of apoptosis. A combination of CP127,374 and cisplatin, however, was more potent in cell growth inhibition and induction of apoptosis compared to treatment with cisplatin alone. Together, our results further support a pivotal role of erbB-2 signaling in the regulatory balance between DNA repair, cell cycle checkpoints and apoptosis; all these mechanisms are essential determinants for tumor cell destiny following chemotherapy stress.     

Availability of K-out-of-N:G systems with M failure modes

Markov models for analyzing the availability of K-out-of-N systems subject to M failure modes are presented. Closed form solutions of the steady-state probabilities of the systems and hence the availability are calculated.     

Effects of design factors on the temperature profile of a partially charged thermal storage tank

Thermal storage is a key subsystem in any solar thermal application. It stores thermal energy during periods of high solar irradiation so it can be used when solar irradiation is low and during the night. The energy extraction efficiency is influenced by design and by such operational factors as the state of charge of the thermal storage under normal conditions, a solar thermal storage system is in a partially charged state. This study was aimed at developing charged thermal storage with emphasis on the effect of inlet design, storage tank wall material, and the presence of fluid dead zones.     

Practicable building frame analysis

The analysis of building frames is carried out using a two-stage finite element process, which considers a full three-dimensional model of the structure, including lateral and vertical loadings. Although the analysis process requires somewhat more data preparation than current design office methods, it does involve techniques which are considerably less expensive than full finite element analysis both in terms of CPU costs and data preparation, and it is amenable to fairly routine procedures which could be made automatic. The advantage is a rational analysis, which can take care of sidesway analysis in a realistic way, and can handle such complexities as holes for stairways, and offset columns. Dynamic analysis and stability analysis are also practicable extensions, since the displacement equations which must be solved are formulated for the model with reduced degrees of freedom, in a manner similar to the familiar substructure approach in matrix analysis. The authors also report an extension to the analysis in progress. The results of an analysis of a 10-storey building frame are presented and compared to earlier studies.     

The relation between scabies and hypersensitivity to antigens of house dust mites and storage mites

Twenty five non-atopic scabietic patients were examined to estimate their reaction to crude house dust mite Dermatophagoides farinae (D. farinae) and storage mite Tyrophagus putrescentia (T. putrescentiae) antigens. Skin prick testing (SPT) by extracts of both mites antigens showed significant higher positive results in scabietics when compared to non-scabietic control subjects. Moreover, 60% and 56% of scabietic patients showed positive levels of specific anti-D. farinae and T. putrescentia IgE respectively in comparison to 13.4% & 20% of control subjects. A significant difference has been obtained when the total number of positive results were compared to the total number of negative ones. The results revealed that there is an evidence of cross reactivity between Sarcoptes scabiei antigens and extracts of D. farinae and T. putrescentiae, and the hypersensitivity to house dust mite and storage mite antigens was significantly higher in scabietics than in controls. It could be concluded that there is some proof that other mites rather than Sarcoptes scabiei may have a role in the pathogenesis of scabies and the cross reactivity between S. scabiei and house dust mite and storage mite may explain the persistence of symptoms in some cases even after proper treatment of the disease.     

Comments on "Parameter estimation in multivariative stochastic difference equations"

In the above paper Kashyap and Nasburg introduced canonical forms II and III to represent multivariate systems. The limited informarion estimate to obtain the parameters of the system was presented, in which the system is decomposed by using either of the proposed canonical forms into subsystems. As a result the estimation problem was considerably simplified. In this correspondence, it is observed that the canonical form I which has the smallest number of parameters can be decomposed into subsystems just as well, and that the class of models in canonical form I, which is the usual representation, is wider than canonical forms II or III. The question therefore is: what is the real merit of implementing those new canonical forms II and III?