Queen Mary's College

About: Queen Mary's College is a based out in . It is known for research contribution in the topics: Ring (chemistry) & Crystal. The organization has 254 authors who have published 276 publications receiving 3755 citations.

Aspirin and non-steroidal anti-inflammatory drugs for cancer prevention: an international consensus statement

Abstract: Evidence clearly shows a chemopreventive effect for aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) on colorectal cancer and probably other cancer types; however, data on the risk-benefit profile for cancer prevention are insufficient and no definitive recommendations can be made. Aspirin has emerged as the most likely NSAID for use in chemoprevention because of its known cardiovascular benefit and available safety and efficacy data. Other traditional NSAIDs, particularly sulindac, and selective COX-2 inhibitors are now given to patients at high risk of colorectal cancer, although these drugs do not provide cardioprotection. More studies of aspirin and cancer prevention are needed to define the lowest effective dose, the age at which to initiate therapy, the optimum treatment duration, and the subpopulations for which the benefits of chemoprevention outweigh the risks of adverse side-effects. Although it might be possible to answer some of these questions with longer follow-up of existing clinical trials, randomised controlled trials with new study designs will be needed. Future projects should investigate the effects of aspirin treatment on multiple organ systems. Cancers of interest are colorectal, breast, prostate, lung, stomach, and oesophageal. The main side-effect of aspirin is peptic ulcers; therefore coadministration of aspirin with a proton-pump inhibitor is an attractive option and is under investigation in the AspECT trial.

The Loss of Telomerase Activity in Highly Differentiated CD8+CD28−CD27− T Cells Is Associated with Decreased Akt (Ser473) Phosphorylation

Abstract: The enzyme telomerase is essential for maintaining the replicative capacity of memory T cells. Although CD28 costimulatory signals can up-regulate telomerase activity, human CD8 + T cells lose CD28 expression after repeated activation. Nevertheless, telomerase is still inducible in CD8 + CD28 − T cells. To identify alternative costimulatory pathways that may be involved, we introduced chimeric receptors containing the signaling domains of CD28, CD27, CD137, CD134, and ICOS in series with the CD3 zeta (ζ) chain into primary human CD8 + T cells. Although CD3 ζ-chain signals alone were ineffective, triggering of all the other constructs induced proliferation and telomerase activity. However, not all CD8 + CD28 − T cells could up-regulate this enzyme. The further fractionation of CD8 + CD28 − T cells into CD8 + CD28 − CD27 + and CD8 + CD28 − CD27 − subsets showed that the latter had significantly shorter telomeres and extremely poor telomerase activity. The restoration of CD28 signaling in CD8 + CD28 − CD27 − T cells could not reverse the low telomerase activity that was not due to decreased expression of human telomerase reverse transcriptase, the enzyme catalytic subunit. Instead, the defect was associated with decreased phosphorylation of the kinase Akt, that phosphorylates human telomerase reverse transcriptase to induce telomerase activity. Furthermore, the defective Akt phosphorylation in these cells was specific for the Ser 473 but not the Thr 308 phosphorylation site of this molecule. Telomerase down-regulation in highly differentiated CD8 + CD28 − CD27 − T cells marks their inexorable progress toward a replicative end stage after activation. This limits the ability of memory CD8 + T cells to be maintained by continuous proliferation in vivo.

Synthesis and characterization of metal oxides (CeO2, CuO, NiO, Mn3O4, SnO2 and ZnO) nanoparticles as photo catalysts for degradation of textile dyes.

Abstract: The progress of the enriched photocatalytic degradation predominantly depends on materials fabrication. In the recent times, the outcomes of nanomaterials show extraordinary efficiency due to its shape and size. In this connection, the present work concentrates on the fabrication of single digit metal oxides (CeO2, CuO, NiO, Mn3O4, SnO2 and ZnO) through precipitation method. The structural information of different metal oxides (MOs) and their crystallite size were estimated via XRD analysis and their consistent results revealed that the crystalline sizes of the prepared metal oxide were exhibited in nano size. The morphology and dimension of the synthesized MOs were identified through FE-SEM and TEM techniques. The FE-SEM images were apparently defined that the actual morphology of each metal oxide expresses different dimension due to nucleation and growth process. The result of UV-vis absorption spectra was helped to identify the band gap of MOs and a suitable light for photocatalytic irradiation. Additionally, the synthesized single digit MOs nanoparticles were magnificently applied for the degradation of methyl orange and methylene blue under UV light irradiation.

Synthesis and Characterization of Rare Earth Ion Doped Nano ZnO

Abstract: Zinc oxide (ZnO) doped with erbium at different concentrations was synthesized by solid-state reaction method and characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM), UV-absorption spectroscopy, photoluminescence (PL) study and vibrating sample magnetometer. The XRD studies exhibit the presence of wurtzite crystal structure similar to the parent compound ZnO in 1% Er3+ doped ZnO, suggesting that doped Er3+ ions sit at the regular Zn2+ sites. However, same studies spread over the samples with Er3+ content>1% reveals the occurrence of secondary phase. SEM images of 1% Er3+ doped ZnO show the polycrystalline nature of the synthesized sample. UV-visible absorption spectrum of Er3+ doped ZnO nanocrystals shows a strong absorption peak at 388 nm due to ZnO band to band transition. The PL study exhibits emission in the visible region, due to excitonic as well as defect related transitions. The magnetization-field curve of Er3+ doped ZnO nanocrystals showed ferromagnetic property at room-temperature.