Search results for "Nod"
showing 10 items of 4007 documents
<p class="HeadingRunIn"><strong>Reinterpretation of the enigmatic Ordovician genus <em>Bolboporites </em>(Echinodermata)</…
2019
Bolboporites is an enigmatic Ordovician cone-shaped fossil, the precise nature and systematic affinities of which have been controversial over almost two centuries. For the first time, a wide range of techniques (CT-scan, SEM, cathodoluminescence, XPL, UV epifluorescence, EBSD, FT-IR and XRF spectrometry) were applied to well-preserved specimens of Bolboporites from Norway and Russia. Our main finding confirms its echinoderm affinities, as shown by its stereomic microstructure and by the first definitive evidence of its monocrystalline nature. Each cone consists in a single, microporous calcitic crystal with a narrow longitudinal internal canal. These results are combined with all previous …
MYC Activates Stem-like Cell Potential in Hepatocarcinoma by a p53-Dependent Mechanism
2014
Activation of c-MYC is an oncogenic hallmark of many cancers including liver cancer, and is associated with a variety of adverse prognostic characteristics. Despite a causative role during malignant transformation and progression in hepatocarcinogenesis, consequences of c-MYC activation for the biology of hepatic cancer stem cells (CSCs) are undefined. Here, distinct levels of c-MYC over-expression were established by using two dose-dependent tetracycline inducible systems in 4 hepatoma cell lines with different p53 mutational status. The CSCs were evaluated using side-population approach as well as standard in vitro and in vivo assays. Functional repression of p53 was achieved by lentivira…
A distributed data storage and retrieval scheme in unattended WSNs using Homomorphic Encryption and secret sharing
2009
Many data storage schemes have been proposed in the past for keeping dependable data storage, but they are not designed for Unattended Wireless Sensor Networks (UWSNs). When applying these schemes to UWSNs, most of them have limitations such as high storage requirement, transmission cost, and not resilient to a large number of node compromises. To address the problem of data storage, transmission cost, and resilience of node compromise in UWSNs, we propose a novel Homomorphic Encryption and Homomorphic Secret Sharing based scheme (HEHSS) to accomplish the goals of confidentiality, resilience to node compromises, reliability, and efficiency of storage and transmission. Our scheme exploits th…
Two-photon laser dynamics.
1995
Degenerate as well as nondegenerate three-level two-photon laser (TPL) models are derived. In the limit of equal cavity losses for both fields, it is shown that the nondegenerate model reduces to the degenerate one. We also demonstrate the isomorphism existing between our degenerate TPL model and that of a dressed-state TPL. All these models contain ac-Stark and population-induced shifts at difference from effective Hamiltonian models. The influence of the parameters that control these shifts on the nonlinear dynamics of a TPL is investigated. In particular, the stability of the periodic orbits that arise at the Hopf bifurcation of the system and the extension of the self-pulsing domains of…
Micropropagation ofAgeratum houstonianumby nodal segments
2017
Ageratum houstonianum is a bedding and flowering potted plant originated from Central America which is generally propagate by seed. In this report a preliminary in vitro technique for propagation of A. houstonianum was investigated. In vitro germinated seeds were used to establish aseptic shoot cultures of several clones. Seedling stem segments bearing 3-4 nodes were placed on Murashige and Skoog (MS) basal medium plus 20 g L-1 sucrose, 8.0 g L-1 Agar to induce axillary shoot development. Axillary shoots were subcultured into the same medium and nodal segments were sectioned and subcultured to increase the stock of shoot cultures. Shoot cultures of the selected clone AG14 were used to accom…
Human cytomegalovirus (HCMV)-specific CD4+ T lymphocyte response in AIDS patients with no past or current HCMV disease following HAART.
2003
Abstract Background: The incidence of Human Cytomegalovirus (HCMV) end-organ disease has dramatically decreased since the implementation of highly active antiretroviral therapies (HAARTs), but the precise immune mechanism whereby HCMV is controlled remains to be elucidated. Objectives: To investigate the effect of (HAART) on CD4 + T-cell immunity to HCMV in AIDS patients with no past or current HCMV disease. Study design: Seventeen patients were prospectively examined for CD4 + (CD45RO + and CD45 RA + ) T-cell counts (flow cytometry), HIV RNA load (Amplicor HIV test), HCMV leukoDNAemia and HCMV DNA in urine (nested PCR), lymphoproliferative response (LPR) to HCMV, phytohemagglutinin (PHA) a…
Application of a 5-bromo-2′-deoxyuridine ELISA for measuring the lymphoproliferative response to human cytomegalovirus in HIV-1-infected patients
2002
Assessment of the lymphoproliferative response to human cytomegalovirus (HCMV) may help to identify human immunodeficiency virus (HIV)-1-infected patients at high risk of developing HCMV end-organ disease. The tritiated thymidine ([3H]-TdR)-incorporation assay is the gold standard for measuring lymphoproliferative responses, though it is unsuitable as a routine laboratory procedure. An alternative non-radioactive technique, a 5-bromo-2'-deoxyuridine (BrdU) enzyme-linked immunosorbent assay, was applied for measuring T-cell proliferation in response to HCMV. Stimulation of either 1 x 10(5) or 5 x 10(4) peripheral blood mononuclear cells (PBMCs)/well with 10 PFU/well (before inactivation) of …
Presence of Epstein-Barr virus, cytomegalovirus and human papillomavirus in normal oral mucosa of HIV-infected and renal transplant patients
2001
OBJECTIVES: To determine the prevalence of EBV-DNA,CMV-DNA and HPV-DNA in oral healthy mucosa of HIV-infected and renal transplant patients. To associate the detection of viral genomes with laboratory parameters of immunodeficiency, gender, antiretroviral and immunosuppressive therapy. DESIGN: A cross-sectional analysis of lingual and buccal cytobrushings from HIV-infected and renal transplant patients. SUBJECTS AND METHODS: Lingual and buccal cytobrushings were obtained from clinically normal oral mucosa of 57 HIV+, 40 renal transplant patients and 30 healthy uninfected controls, all matched for age at baseline of examination. Presence of EBV-, CMV- and HPV-DNA was assessed by polymerase c…
Frequent coinfection of cells explains functional in vivo complementation between cytomegalovirus variants in the multiply infected host.
2005
In contrast to many other virus infections, primary cytomegalovirus (CMV) infection does not fully protect against reinfection. Accordingly, clinical data have revealed a coexistence of multiple human CMV variants/ strains in individual patients. Notably, the phenomenon of multiple infection was found to correlate with increased virus load and severity of CMV disease. Although of obvious medical relevance, the mechanism underlying this correlation is unknown. A weak immune response in an individual could be responsible for a more severe disease and for multiple infections. Alternatively, synergistic contributions of variants that differ in their biological properties can lead to qualitative…
Experimental Preemptive Immunotherapy of Murine Cytomegalovirus Disease with CD8 T-Cell Lines Specific for ppM83 and pM84, the Two Homologs of Human …
2001
ABSTRACTCD8 T cells are the principal antiviral effectors controlling cytomegalovirus (CMV) infection. For human CMV, the virion tegument protein ppUL83 (pp65) has been identified as a source of immunodominant peptides and is regarded as a candidate for cytoimmunotherapy and vaccination. Two sequence homologs of ppUL83 are known for murine CMV, namely the virion protein ppM83 (pp105) expressed late in the viral replication cycle and the nonstructural protein pM84 (p65) expressed in the early phase. Here we show that ppM83, unlike ppUL83, is not delivered into the antigen presentation pathway after virus penetration before or in absence of viral gene expression, while other virion proteins o…