University of Ioannina

About: University of Ioannina is a education organization based out in Ioannina, Greece. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 7654 authors who have published 20594 publications receiving 671560 citations. The organization is also known as: Panepistimio Ioanninon.

Selective Removal of Cs+, Sr2+, and Ni2+ by K2xMgxSn3–xS6 (x = 0.5–1) (KMS-2) Relevant to Nuclear Waste Remediation

Abstract: 137Cs and 90Sr, both byproducts of the uranium and plutonium fission processes, make up the majority of high-level waste from nuclear power plants. 63Ni is a byproduct of the erosion-corrosion process of the reactor components in nuclear energy plants. The concentrations of these ions in solution determine the Waste Class (A, B, or C); thus, their selective removal in the presence of large excesses of nonradioactive ions is necessary to reduce waste volume and cut disposal costs. We report the new material K2xMgxSn3–xS6 (x = 0.5–1, KMS-2) and its application for the ion exchange of Cs+, Sr2+, and Ni2+ in varying conditions. This compound crystallizes in the hexagonal space group P63/mmc with cell parameters a = b = 3.6749(8) A and c = 16.827(4) A. The difference in crystal structure between KMS-2, the previously reported Mn analog K2xMnxSn3–xS6 (KMS-1), and their parent SnS2 is also described. Distribution coefficients for KMS-2 are high for Cs+ (7.1 × 103 mL/g) and Sr2+ (2.1 × 104 mL/g) at neutral pH (∼ ...

The Rab5 effector Rabankyrin-5 regulates and coordinates different endocytic mechanisms.

Abstract: The small GTPase Rab5 is a key regulator of clathrin-mediated endocytosis. On early endosomes, within a spatially restricted domain enriched in phosphatydilinositol-3-phosphate [PI(3)P], Rab5 coordinates a complex network of effectors that functionally cooperate in membrane tethering, fusion, and organelle motility. Here we discovered a novel PI(3)P-binding Rab5 effector, Rabankyrin-5, which localises to early endosomes and stimulates their fusion activity. In addition to early endosomes, however, Rabankyrin-5 localises to large vacuolar structures that correspond to macropinosomes in epithelial cells and fibroblasts. Overexpression of Rabankyrin-5 increases the number of macropinosomes and stimulates fluid-phase uptake, whereas its downregulation inhibits these processes. In polarised epithelial cells, this function is primarily restricted to the apical membrane. Rabankyrin-5 localises to large pinocytic structures underneath the apical surface of kidney proximal tubule cells, and its overexpression in polarised Madin-Darby canine kidney cells stimulates apical but not basolateral, non-clathrin-mediated pinocytosis. In demonstrating a regulatory role in endosome fusion and (macro)pinocytosis, our studies suggest that Rab5 regulates and coordinates different endocytic mechanisms through its effector Rabankyrin-5. Furthermore, its active role in apical pinocytosis in epithelial cells suggests an important function of Rabankyrin-5 in the physiology of polarised cells.

Selective Reporting Biases in Cancer Prognostic Factor Studies

Abstract: Background: Nonreported and selectively reported information and the use of different defi nitions may introduce biases in the literature of prognostic factors. We probed these biases in a meta-analysis of a prognostic factor for head and neck squamous cell cancer (HNSCC) mortality that has drawn wide attention — the status of the tumor suppressor protein TP53. Methods: We compared results of meta-analyses that included published data plus unpublished data retrieved from investigators; published data; and only published data indexed with “ survival ” or “ mortality ” in MEDLINE/ EMBASE, with or without standardized defi nitions. We also evaluated whether previously published meta-analyses on mortality predictors for various malignancies addressed issues of retrieval and standardized information. All statistical tests were two-sided. Results: For the 18 studies with 1364 patients that included published and indexed data, we obtained a highly statistically signifi cant association between TP53 status and mortality. When we used the defi nitions preferred by each publication, the association was stronger (risk ratio [RR] = 1.38, 95% confi dence interval [CI] = 1.13 to 1.67; P = .001) than when we standardized defi nitions (RR = 1.27, 95% CI = 1.06 to 1.53; P = .011). The addition of 13 studies with 1028 subjects that included published but not indexed data reduced the observed association (RR = 1.23, 95% CI = 1.03 to 1.47; P = .02). Finally, when we obtained data from investigators (11 studies with 996 patients) and analyzed it with all other data, statistical signifi cance was lost (RR = 1.16, 95% CI = 0.99 to 1.35; P = .06). Among 18 published meta- analyses of 37 cancer prognostic factors, 13 (72%) did not use standardized defi nitions and 16 (89%) did not retrieve additional information. Conclusions: Selective reporting may spuriously infl ate the importance of postulated prognostic factors for various malignancies. We recommend that meta-analyses thereof should maximize retrieval of information and standardize defi nitions. [J Natl Cancer Inst 2005;97:1043 – 55]

Search for dark matter and large extra dimensions in monojet events in pp collisions at √s = 7 TeV

Abstract: A search has been made for events containing an energetic jet and an imbalance in transverse momentum using a data sample of pp collisions at a center-of-mass energy of 7 TeV. This signature is common to both dark matter and extra dimensions models. The data were collected by the CMS detector at the LHC and correspond to an integrated luminosity of 5.0 inverse femtobarns. The number of observed events is consistent with the standard model expectation. Constraints on the dark matter-nucleon scattering cross sections are determined for both spin-independent and spin-dependent interaction models. For the spin-independent model, these are the most constraining limits for a dark matter particle with mass below 3.5 GeV, a region unexplored by direct detection experiments. For the spin-dependent model, these are the most stringent constraints over the 0.1-200 GeV mass range. The constraints on the Arkani-Hamed, Dimopoulos, and Dvali model parameter MD determined as a function of the number of extra dimensions are also an improvement over the previous results.