Three-level spin system under decoherence-minimizing driving fields: Application to nitrogen-vacancy spin dynamics

Within the framework of a general three-level problem, the dynamics of the nitrogen-vacancy (NV) spin is studied for the case of a special type of external driving consisting of a set of continuous fields with decreasing intensities. Such a set has been proposed for minimizing coherence losses. Each new driving field with smaller intensity is designed to protect against the fluctuations induced by the driving field at the preceding step with larger intensity. We show that indeed this particular type of external driving minimizes the loss of coherence, using purity and entropy as quantifiers for this purpose. As an illustration, we study the coherence loss of an NV spin due to a surrounding spin bath of $^{13}$C nuclei.Comment: 10 pages, 8 figures, to be published in Phys. Rev.

Sponge Biodiversity in Kerala and its Biotechnological Potentials

Animals which exist today may be classified under two categories; I) Protozoa or s ingle celled animals 2) Metazoa or multicellular animals. Metazoam in tum, may be divided into two groups: a) Diploblastic, with two germ layers (ectoderm and endoderm) and b) Triploblastic, with three germ layers (eetoderm, mesoderm and endoderm). I n sponges thcre are no layers as seen in diploblastic or triobl.astic or triploblastic groups, but the 'layers', in sponges, are made of loosely arranged cells which can even change their location at will

Pathological manifestations of sponge infestation in Perna indica Kuriakose & Nair 1976

Pathological manifestations of bioeroding sponges on the brown mussel, Perna indica were studied. The major manifestation was blister formation (46.3%). Nacre erosis was observed in 7.6% of the total infested population. Bifacial porosis was noted in 19.1% of infested shells; discolouration of shell was observed in 19.8 % and melanosis in 13.1 % of the infested population

The role of polar and facial amphipathic character in determining lipopolysaccharide-binding properties in synthetic cationic peptides

Two series of peptides, designated K and NK were synthesized and tested for lipid A binding and neutralizing properties. K2, which has an 11-residue amphiphilic core, and a branched N-terminus bearing two branched lysinyl residues does not bind lipid A, while NK2, also with an 11-residue amphiphilic core comprised entirely of non-ionizable residues, and a similarly branched, cationic N-terminus, binds lipid A very weakly. Both peptides do not inhibit lipopolysaccharide (LPS) activity in the Limulus assay, nor do they inhibit LPS-induced TNF-α and NO production in J774 cells. These results are entirely unlike a homologous peptide with an exclusively hydrophobic core whose LPS-binding and neutralizing properties are very similar to that of polymyxin B [David SA, Awasthi SK, Wiese A et al. Characterization of the interactions of a polycationic, amphiphilic, terminally branched oligopeptide with lipid A and lipopolysaccharide from the deep rough mutant of Salmonella minnesota . J Endotoxin Res 1996; 3: 369-379]. These data suggest that a clear segregation of charged and apolar domains is crucial in molecules designed for purposes of LPS sequestration and that head-tail (polar) orientation of the cationic/hydrophobic regions is preferable to molecules with mixed or facial cationic/amphipathic character

Evaluation of the Liquisolid Compacts Using Response Surface Methodology

Liquisolid Compacts technique has potential to develop sustained release formulations. It involves conversion of liquid drug (either solution or suspension) in non-volatile solvent into free-flowing, non adherent, dry looking and readily compressible powder. In the present work, an attempt was made to develop such formulation of Diltiazem HCl and evaluation using Response surface methodology. Liquisolid compacts were prepared by dissolving Diltiazem HCl in Polyethylene Glycol 400. Then a binary mixture of carrier-coating material, Avicel and Aerosil, was added to liquid medication under continuous mixing in mortar. The HPMC K4M was used as adjuvant for sustaining the drug release.  The pre-compression studies for all the formulations were also carried out. The Liquisolid compacts were evaluated in-vitro dissolution studies. The experimental data was evaluated using Design Expert Software. The % Drug Concentration, ratio of Carrier to Coating material and amount of HPMC K4M are taken as three factors. Response Surface methodology was used to study the influence of the each factor on the response. The present investigation showed that Polyethylene Glycol 400 has important role in release retardation of drug in Liquisolid compacts. The reduction in Tg can be reason for same. The Response surface methodology showed that all the factors were significantly affect the release at 16 hrs.

Lymphoproliferative disease in mice infected with murine gammaherpesvirus 68

Murine gammaherpesvirus is a natural pathogen of wild rodents. In the laboratory it establishes an infection of epithelial cells and persists in B lymphocytes in a latent form. Inbred mice chronically infected with the virus develop a lymphoproliferative disease (LPD) similar to that seen in patients infected with Epstein-Barr virus. The frequency of LPD over a period of 3 years was 9% of all infected animals, with 50% of these displaying high grade lymphomas. The incidence of LPD was greatly increased when infected mice were treated with cyclosporin A. The majority of mice used in the experiments were BALB/c, although lymphomas were detected in mice on other genetic backgrounds, ie, CBA and B10Br. Lymphomas were associated with both lymphoid and nonlymphoid tissues (liver, lung, and kidney). In all cases of lymphomas studied thus far, there was a mixed B cell (B220+ve) and T cell (CD3+ve) phenotype. The B cells were light chain restricted, indicative of a clonal origin. Variable numbers of virus genome-positive cells were detected by in situ hybridization in and around the lymphomas. In contrast, no lytic antigen-positive cells were detected, indicating that genome-positive cells were either latently infected or undergoing an abortive infection. These observations suggest that murine gammaherpesvirus-infected mice may be an important model to study the pathogenesis of LPD associated with other gammaherpesviruses, such as Epstein-Barr virus

HLA-DR phenotypes and lymphocyte response to M. tuberculosis antigens and in cured spinal tuberculosis patients and their contacts

Background: Our earlier studies on Human Leucocyte Antigens (HLA) in pulmonary tuberculosis patients revealed the association of HLA-DR2 antigen with susceptibility to pulmonary TB and DR2 antigen has been shown to influence the immunity to tuberculosis. Objectives: The present study was carried out to find out whether HLA-DR antigens are associated with susceptibility to spinal tuberculosis. Moreover, the role of HLA-DR antigens on lymphoproliferative response to Mycobacterium tuberculosis culture filtrate antigens was studied using Lymphocyte Transformation Test (LTT). Material and Methods: HLA-DR genotyping and lymphoproliferative response was carried out in 63 cured spinal TB patients and 63 control subjects (spouses of pulmonary and spinal TB patients). Results: A trend towards an increased frequency of HLA-DR9 antigen was observed in spinal TB patients compared to controls. A significantly decreased lymphocyte response to M. tuberculosis antigens was observed in HLA-DR9 antigen positive control subjects compared to HLA- DR9 antigen negative subjects (P=0.0009) whereas increased response was observed with DR9 positive cured spinal TB patients compared to HLA-DR9 antigen negative patients. Further, HLADR3 antigen positive patients showed a decreased lymphocyte response compared to HLA-DR3 antigen negative patients (P<0.05). Conclusion: The study suggests that HLA-DR9 antigen either alone or in combination with other HLA antigen as lhplotype and non-HLA genes may be associated with susceptibility to spinal TB and play a regulatory role on the immune response to M. tuberculosis in spinal tuberculosis patients