Design and Performance of a Multipurpose 2-D Photonic Crystal Device Based on Y Couplers

Plasmonics - This paper reports on the design of a multipurpose photonic device based on 2-D photonic crystals which uses Y couplers in its structure that is very efficient when employed as a...     

Pd(II)-catalysed and Hg(II)-co-catalysed oxidation of D-glucose and D-fructose by N-bromoacetamide in the presence of perchloric acid: a kinetic and mechanistic study

The kinetics of Pd(II)-catalysed and Hg(II)-co-catalysed oxidation of D-glucose (Glc) and D-fructose (Fru) by N-bromoacetamide (NBA) in the presence of perchloric acid using mercury(II) acetate as a scavenger for Br- ions have been studied. The results show first-order kinetics with respect to NBA at low concentrations, tending to zero order at high concentrations. First-order kinetics with respect to Pd(II) and inverse fractional order in Cl- ions throughout their variation have also been noted. The observed direct proportionality between the first-order rate constant (k1) and the reducing sugar concentration shows departure from the straight line only at very higher concentration of sugar. Addition of acetamide (NHA) decreases the first-order rate constant while the oxidation rate is not influenced by the change in the ionic strength (mu) of the medium. Variation of [Hg(OAc)2] shows a positive effect on the rate of reaction. The observed negative effect in H+ at lower concentrations tends to an insignificant effect at its higher concentrations. The first-order rate constant decreases with an increase in the dielectric constant of the medium. The various activation parameters have also been evaluated. The products of the reactions were identified as arabinonic acid and formic acid for both the hexoses. A plausible mechanism involving HOBr as the reactive oxidising species, Hg(II) as co-catalyst, and [PdCl3.S]-1 as the reactive Pd(II)-sugar complex in the rate-controlling step is proposed.     

Concomitant replacement of language and mtDNA in South Caspian populations of Iran

The Gilaki and Mazandarani occupy the South Caspian region of Iran and speak languages belonging to the North-Western branch of Iranian languages . It has been suggested that their ancestors came from the Caucasus region, perhaps displacing an earlier group in the South Caspian . Linguistic evidence supports this scenario, in that the Gilaki and Mazandarani languages (but not other Iranian languages) share certain typological features with Caucasian languages . We analyzed patterns of mtDNA and Y chromosome variation in the Gilaki and Mazandarani. Based on mtDNA HV1 sequences, the Gilaki and Mazandarani most closely resemble their geographic and linguistic neighbors, namely other Iranian groups. However, their Y chromosome types most closely resemble those found in groups from the South Caucasus. A scenario that explains these differences is a south Caucasian origin for the ancestors of the Gilaki and Mazandarani, followed by introgression of women (but not men) from local Iranian groups, possibly because of patrilocality. Given that both mtDNA and language are maternally transmitted, the incorporation of local Iranian women would have resulted in the concomitant replacement of the ancestral Caucasian language and mtDNA types of the Gilaki and Mazandarani with their current Iranian language and mtDNA types. Concomitant replacement of language and mtDNA may be a more general phenomenon than previously recognized.     

Chitinozoaires ashgilliens de l'Anti-Atlas (Maroc)

Thirty three species of Chitinozoans are recorded inthe Upper Ktaoua and in the Lower Deuxième Bani Formations (Anti-Atlas, Morocco). These two lithological units have been refered to the upper part of the Ashgill Series on Trilobite, Brachiopod and Echinoderm evidence. This age assignment is well supported by the present study of the Chitinozoans. Strong affinities with North american Chitinozoan assemblages (Anticosti Island, Québec; Oklahoma, U.S.A.) are pointed out. The Upper Ktaoua Formation can be correlated with part of the Vaureal Formation (Richmodian of Quebec); the Lower Deuxième Bani Formation seems to be of the same age as the lower part of the Ellis-Bay Formation (Gamachian of Quebec).     

Partial physical map of human chromosome 21 from fibroblast and lymphocyte DNA

A partial physical map of the human chromosome 21 including 26 genes and anonymous sequences was established by pulsed-field gel electrophoresis analysis of restriction fragments obtained from lymphocyte and fibroblast DNAs. The sizes of the restriction fragments obtained by total digestion with eight different enzymes were compared in these two tissues. Differences resulting from the variations in the methylation state of the restriction sites were frequently observed. These differences and partial digestions were used to estimate the order and the distances between genes and sequences. Six linkage groups were defined: D21S13-D21S16, D21S1-D21S11, D21S65-D21S17, (D21S55,ERG)-ETS2, BCEI-D21S19-D21S42-D21S113-CBS-CRYA1, and COL6A2-S100B. For six intergenic distances the resolution of previous maps was significantly increased.     

Present status of the application of cryopreserved hepatocytes in the evaluation of xenobiotics: consensus of an international expert panel.

Successful cryopreservation of freshly isolated hepatocytes would significantly decrease the need for freshly-procured livers for the preparation of hepatocytes for experimentation. Hepatocytes can be prepared, cryopreserved, and used for experimentation as needed at different times after isolation. Cryopreservation is especially important for research with human hepatocytes because of the limited availability of fresh human livers. Based on the cumulative experience of this international expert panel, a consensus was reached on the various aspects of hepatocyte cryopreservation, including cryopreservation and thawingprocedures and applications of the cryopreserved hepatocytes. Key to successful cryopreservation includes slow addition of cryopreservants, controlled-rate freezing with adjustment for the heat of crystallization, storage at -150 degrees C, and rapid thawing. There is a general consensus that cryopreserved hepatocytes are useful for short-term xenobiotic metabolism and cytotoxicity evaluation.     

In vivo induction of CTL responses by recombinant adenylate cyclase of Bordetella pertussis carrying multiple copies of a viral CD8+ T-cell epitope

Bordetella pertussis adenylate cyclase toxin (ACT) is one of the few known protein toxins penetrating directly into the cytosol of target cells across their cytoplasmic membrane without the need for endocytosis. This capacity of ACT was recently exploited for in vivo delivery of single viral CD8(+) T-epitopes into MHC class I-presenting cells and induction of protective antiviral cytotoxic T-cell (CTL) responses. Here, we have explored the potential of the cell-invasive adenylate cyclase domain of the toxin to deliver larger antigens by evaluating the epitope-specific CTL responses induced by constructs bearing one to four copies of the CD8(+) T-epitope from the nucleoprotein of the lymphocytic choriomeningitis virus. The increase in the number of copies of the epitope was accompanied by a moderate decrease of the specific cell invasiveness of the ACT protein and did not lead to further enhancement of the level of induced epitope-specific CTL cells in mice, as compared to ACT with a single copy of the epitope. These results demonstrate the capacity of ACT to deliver larger heterologous antigens comprising several epitopes for antigenic presentation in vivo.