Epstein-Barr virus (EBV) is an oncogenic γ-herpes virus associated with malignancies that develop in both lymphoid and epithelial cells including nasopharyngeal carcinoma (NPC). The EBV protein, ...latent membrane protein 2A (LMP2A), is expressed in NPC and can modulate epithelial proliferation, transformation and differentiation, and as such may promote malignancy. A key regulator of epithelial-cell differentiation is the transcription factor p63, a member of the p53 family. This study examines the potential contribution of p63 to LMP2A-mediated inhibition of epithelial-cell differentiation. Stable expression of LMP2A increased the protein level and stability of the ΔNp63α isoform and in two epithelial cell lines, LMP2A interacted with ΔNp63α under stable- and transient-expression systems. LMP2A and ΔNp63α were localized to the cytoplasm and nuclear membrane and co-immunoprecipitated in the same fractions. Following induction of epithelial-cell differentiation by calcium, expression of differentiation markers was impaired in both ΔNp63α- and LMP2A-expressing cells. Induction of p63α, association of p63α with LMP2A and impairment of differentiation required the PY and immunoreceptor tyrosine-based activation motif (ITAM) signaling motif of LMP2A. By associating with and being regulated by LMP2A, ΔNp63α may function as a unique regulator of LMP2A effects on epithelial differentiation and contribute to EBV-associated epithelial cancers.
Redox-based resistive switching is one of the most-promising concepts in the focus of research to meet the ever-growing demand for faster and smaller non-volatile memory devices. In this work we ...present detailed studies of the impact of cation stoichiometry and surface segregation effects on the performance of the valence change memory model material SrTiO3. In order to clarify if the enhanced switching performance of Sr-rich SrTiO3 devices can be attributed to SrO segregation or to the formation of Sr-rich extended defects, we artificially engineered the formation of SrO islands by depositing additional SrO on top of stoichiometric SrTiO3. We thereby unravel that the enhanced switching performance is solely accounted for by the formation of SrO islands and not influenced by extended defects. Consequently following our findings, we design devices with a further improved retention by tailoring the amount of SrO on the surface.
Opportunistic DNA viruses, particularly members of the herpesvirus family, are frequently the aetiological agents of HIV‐associated oral lesions. Oral lesions common to the early phase of the AIDS ...epidemic, including Kaposi's sarcoma (KS), oral aphthous ulceration, AIDS‐associated oral lymphoma, and oral hairy leukoplakia (OHL), have been tested for the prevalence of Epstein–Barr virus (EBV) and Kaposi's sarcoma‐associated herpesvirus (KSHV). While EBV DNA is detected by PCR in all of these lesions, abundant viral replication can only be detected in OHL. In OHL, a novel state of EBV infection has been discovered with concurrent expression of replicative and transforming proteins, with all of these proteins contributing to the development of the lesion. Activation of signalling pathways and up‐regulation of the viral receptor, proliferative and antiapoptotic genes by these proteins induce several of the histological features common to OHL, such as acanthosis and hyperproliferation. In contrast to other permissive herpesvirus infections, expression of EBV transforming proteins within the permissively infected OHL tissue enables epithelial cell survival and may enhance viral replication. Detection of KSHV in these HIV‐infected individuals has been localized only to their saliva. Replicative and latent KSHV gene products have been detected in association with the development of oral KS lesions. EBV, but not human cytomegalovirus (HCMV), has been detected by PCR in minor salivary gland biopsies of HIV‐associated salivary gland disease. Human papillomaviruses (HPV) are associated with oral warts in HIV‐positive individuals; a diagnosis that appears to be increasing in frequency in the era of highly active antiretroviral therapy. To date, there appears to be little increase in the incidence of HPV‐associated oral cancer. The mechanisms of interaction between HIV and HPV are not fully understood. Expression of viral gene products is clearly important and necessary for the development of multiple AIDS‐associated oral lesions.
Redox-based resistive switching is one of the most-promising concepts in the focus of research to meet the ever-growing demand for faster and smaller non-volatile memory devices. In this work we ...present detailed studies of the impact of cation stoichiometry and surface segregation effects on the performance of the valence change memory model material SrTiO3. In order to clarify if the enhanced switching performance of Sr-rich SrTiO3 devices can be attributed to SrO segregation or to the formation of Sr-rich extended defects, we artificially engineered the formation of SrO islands by depositing additional SrO on top of stoichiometric SrTiO3. We thereby unravel that the enhanced switching performance is solely accounted for by the formation of SrO islands and not influenced by extended defects. Consequently following our findings, we design devices with a further improved retention by tailoring the amount of SrO on the surface.
•We unravel the enhanced performance of resistive switching Sr-rich SrTiO3 devices.•We engineer the segregation of SrO at the Pt/SrTiO3 interface by PLD.•We thereby mimic the performance of Sr-rich STO.•Following our findings, we design devices with a further improved retention.
Epstein–Barr virus (EBV) is consistently detected in nasopharyngeal carcinoma (NPC) from regions of high and low incidence. EBV DNA within the tumor is homogeneous with regard to the number of ...terminal repeats. The detection of a single form of viral DNA suggests that the tumors are clonal proliferations of a single cell that was initially infected with EBV. Specific EBV genes are consistently expressed within the NPC tumors and in early, dysplastic lesions. The viral proteins, latent membrane protein 1 and 2, have profound effects on cellular gene expression and cellular growth, resulting in the highly invasive, malignant growth of NPC tumors. In addition to potential genetic changes, the establishment of a latent, transforming infection in epithelial cells is likely to be a major contributing factor to the development of this tumor.
The physics of laser-plasma interactions has undergone dramatic improvements in recent years. By directing a multi-TW, ultrashort laser pulse onto a thin foil or a gas jet, it is nowadays possible to ...produce multi-MeV proton, ion and electron beams. Although much progress has been made in characterizing and improving the quality of such laser-generated beams, it is still an untouched issue whether the laser-generated beams are or can be spin-polarized and, thus, whether laser-based polarized sources are conceivable. To this end, one may either think of a selection of certain spin states through the huge magnetic field gradients that are inherently generated in the laser-generated plasmas, or of pre-polarized target particles which maintain their polarization during the rapid acceleration procedure. We have developed a method to measure the degree of polarization of protons that have been accelerated at the 200 TW laser facility ARCturus at Düsseldorf University. As a next step, measurements with unpolarized H2 (for proton acceleration) and 3He gas (for 3He ions) are planned and, finally, pre-polarized 3He will be used.
We prospectively evaluated adolescent organized physical activity (PA) as a factor in adult female bone traits. Annual DXA scans accompanied semiannual records of anthropometry, maturity, and PA for ...42 participants in this preliminary analysis (criteria: appropriately timed DXA scans at ~1 year premenarche predictor and ~5 years postmenarche dependent variable). Regression analysis evaluated total adolescent interscan PA and PA over 3 maturity subphases as predictors of young adult bone outcomes: 1) bone mineral content (BMC), geometry, and strength indices at nondominant distal radius and femoral neck; 2) subhead BMC; 3) lumbar spine BMC. Analyses accounted for baseline gynecological age (years pre- or postmenarche), baseline bone status, adult body size and interscan body size change. Gymnastics training was evaluated as a potentially independent predictor, but did not improve models for any outcomes (p > .07). Premenarcheal bone traits were strong predictors of most adult outcomes (semipartial r2 = .21-0.59, p ≤ .001). Adult 1/3 radius and subhead BMC were predicted by both total PA and PA 1-3 years postmenarche (p < .03). PA 3-5 years postmenarche predicted femoral narrow neck width, endosteal diameter, and buckling ratio (p < .05). Thus, participation in organized physical activity programs throughout middle and high school may reduce lifetime fracture risk in females.
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