Bar-Ilan University

About: Bar-Ilan University is a education organization based out in Ramat Gan, Israel. It is known for research contribution in the topics: Population & Poison control. The organization has 12835 authors who have published 34964 publications receiving 995648 citations. The organization is also known as: Bar Ilan University & BIU.

Self-assembly of polyhedral shells: a molecular dynamics study.

Abstract: The use of reduced models for investigating the self-assembly dynamics underlying protein shell formation in spherical viruses is described. The spontaneous self-assembly of these polyhedral, supramolecular structures, in which icosahedral symmetry is a conspicuous feature, is a phenomenon whose dynamics remain unexplored; studying the growth process by means of computer simulation provides access to the mechanisms underlying assembly. In order to capture the more universal aspects of self-assembly, namely the manner in which component shapes influence structure and assembly pathway, in this exploratory study low-resolution approximations are used to represent the basic protein building blocks. Alternative approaches involving both irreversible and reversible assembly are discussed, models based on both schemes are introduced, and examples of the resulting behavior described.

MicroRNA-137 is downregulated in glioblastoma and inhibits the stemness of glioma stem cells by targeting RTVP-1

Abstract: // Ariel Bier, 1 Nis Giladi, 1 Noam Kronfeld, 1 Hae Kyung Lee, 2 Simona Cazacu, 2 Susan Finniss, 2 Cunli Xiang, 2 Laila Poisson, 3 Ana C. deCarvalho 2 , Shimon Slavin 4 , Elad Jacoby, 5 Michal Yalon, 5 Amos Toren, 5 Tom Mikkelsen 2 and Chaya Brodie 1,2 1 Everard and Mina Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel, 2 Davidson Laboratory of Cell Signaling and Tumorigenesis, Hermelin Brain Tumor Center, Department of Neurosurgery, Henry Ford Hospital, Detroit MI USA. 3 Department of Public Health Sciences, Tel Aviv, Israel 4 The International Center for Cell Therapy and Cancer Immunotherapy (CTCI), Tel Aviv, Israel, 5 Pediatric Hemato-Oncology, The Edmond and Lilly Safra Children’s Hospital, Sheba Medical Center, Tel-Hashomer and The Sackler School of Medicine, Tel-Aviv University, Israel. Correspondence: Chaya Brodie, email: // Keywords : Glioma stem cells, self renewal, miR-137, RTVP-1, CXCR4 Received : March 12, 2013 Accepted : April 7, 2013 Published : April 9, 2013 Abstract Glioblastomas (GBM), the most common and aggressive malignant astrocytic tumors, contain a small subpopulation of cancer stem cells (GSCs) that are implicated in therapeutic resistance and tumor recurrence. Here, we study the expression and function of miR-137, a putative suppressor miRNA, in GBM and GSCs. We found that the expression of miR-137 was significantly lower in GBM and GSCs compared to normal brains and neural stem cells (NSCs) and that the miR-137 promoter was hypermethylated in the GBM specimens. The expression of miR-137 was increased in differentiated NSCs and GSCs and overexpression of miR-137 promoted the neural differentiation of both cell types. Moreover, pre-miR-137 significantly decreased the self-renewal of GSCs and the stem cell markers Oct4, Nanog, Sox2 and Shh. We identified RTVP-1 as a novel target of miR-137 in GSCs; transfection of the cells with miR-137 decreased the expression of RTVP-1 and the luciferase activity of RTVP-1 3’-UTR reporter plasmid. Furthermore, overexpression of RTVP-1 plasmid lacking its 3’-UTR abrogated the inhibitory effect of miR-137 on the self-renewal of GSCs. Silencing of RTVP-1 decreased the self-renewal of GSCs and the expression of CXCR4 and overexpression of CXCR4 abrogated the inhibitory effect of RTVP-1 silencing on GSC self-renewal. These results demonstrate that miR-137 is downregulated in GBM probably due to promoter hypermethylation. miR-137 inhibits GSC self-renewal and promotes their differentiation by targeting RTVP-1 which downregulates CXCR4. Thus, miR-137 and RTVP-1 are attractive therapeutic targets for the eradication of GSCs and for the treatment of GBM.

Effect of 5.3-GeV Pb-ion irradiation on irreversible magnetization in Y-Ba-Cu-O crystals.

Abstract: We report a dramatic change in the irreversibility line of Y-Ba-Cu-O crystals after irradiation with Pb ions. Near the transition temperature, following irradiation, the irreversibility temperature increases and the curvature of the irreversibility line changes sign. These changes are accompanied by a strong enhancement of critical current density and a decrease in flux creep rate. Pb irradiation induces damage in the form of amorphous tracks which penetrate throughout the thickness of the sample. We maintain that these defects are most efficient in terms of flux trapping and are responsible for the observed changes in irreversible magnetic features in the irradiated sample.

Suppressing epidemics with a limited amount of immunization units

Abstract: The way diseases spread through schools, epidemics through countries, and viruses through the internet is crucial in determining their risk. Although each of these threats has its own characteristics, its underlying network determines the spreading. To restrain the spreading, a widely used approach is the fragmentation of these networks through immunization, so that epidemics cannot spread. Here we develop an immunization approach based on optimizing the susceptible size, which outperforms the best known strategy based on immunizing the highest-betweenness links or nodes. We find that the network's vulnerability can be significantly reduced, demonstrating this on three different real networks: the global flight network, a school friendship network, and the internet. In all cases, we find that not only is the average infection probability significantly suppressed, but also for the most relevant case of a small and limited number of immunization units the infection probability can be reduced by up to 55%.