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.

Sonochemical coating of textiles with hybrid ZnO/chitosan antimicrobial nanoparticles.

Abstract: Textiles are good substrates for growth of microorganisms especially under moisture and temperature conditions found in hospitals. Microbial shedding from the body occurs continuously at contact of the patient with textile materials used in medical practices, contributing to the occurrence of hospital acquired infections. Thus, the use of efficient antimicrobial textiles is necessary to prevent the transfer of pathogens and the infection incidence. In this work, hybrid antimicrobial coatings were generated on cotton fabrics by means of a one-step simultaneous sonochemical deposition of ZnO nanoparticles (NPs) and chitosan. The process was further optimized in terms of reagents concentration and processing time in order to improve the antibacterial properties of the fabric and ensure their biocompatibility. The highest antibacterial activity of the fabrics against two medically relevant bacterial species was achieved in a 30 min sonochemical coating process using 2 mM ZnO NPs suspension. When chitosan was ...

Scaling Behavior in Economics: I. Empirical Results for Company Growth

Abstract: We address the question of the growth of rm size. To this end, we analyze the Compustat data base comprising all publicly-traded United States manufacturing rms within the years 1974-1993. We nd that the distribution of rm sizes remains stable for the 20 years we study, i.e., the mean value and standard deviation remain approximately constant. We study the distribution of sizes of the ew" companies in each year and nd it to be well approximated by a log-normal. We nd (i) the distribution of the logarithm of the growth rates, for a xed growth period of one year, and for companies with approximately the same size S ,d isplays an exponential form, and (ii) the fluctuations in the growth rates | measured by the width of this distribution 1 | scale as a power law withS, 1S. We nd that the exponent takes the same value, within the error bars, for several measures of the size of a company. In particular, we obtain: =0 :20 0:03 for sales, =0 :18 0:03 for number of employees, =0 :18 0:03 for assets, =0 :18 0:03 for cost of goods sold, and =0 :20 0:03 for property, plant, and equipment.

Cell fusion induced by ERVWE1 or measles virus causes cellular senescence.

Abstract: Cellular senescence limits proliferation of potentially detrimental cells, preventing tumorigenesis and restricting tissue damage. However, the function of senescence in nonpathological conditions is unknown. We found that the human placental syncytiotrophoblast exhibited the phenotype and expressed molecular markers of cellular senescence. During embryonic development, ERVWE1-mediated cell fusion results in formation of the syncytiotrophoblast, which serves as the maternal/fetal interface at the placenta. Expression of ERVWE1 caused cell fusion in normal and cancer cells, leading to formation of hyperploid syncytia exhibiting features of cellular senescence. Infection by the measles virus, which leads to cell fusion, also induced cellular senescence in normal and cancer cells. The fused cells activated the main molecular pathways of senescence, the p53- and p16–pRb-dependent pathways; the senescence-associated secretory phenotype; and immune surveillance-related proteins. Thus, fusion-induced senescence might be needed for proper syncytiotrophoblast function during embryonic development, and reuse of this senescence program later in life protects against pathological expression of endogenous fusogens and fusogenic viral infections.

Geometric phase from Aharonov–Bohm to Pancharatnam–Berry and beyond

Abstract: Whenever a quantum system undergoes a cyclic evolution governed by a slow change of parameters, it acquires a phase factor: the geometric phase. Its most common formulations are known as the Aharonov–Bohm phase and the Pancharatnam and Berry phase, but both earlier and later manifestations exist. Although traditionally attributed to the foundations of quantum mechanics, the geometric phase has been generalized and become increasingly influential in many areas from condensed-matter physics and optics to high-energy and particle physics and from fluid mechanics to gravity and cosmology. Interestingly, the geometric phase also offers unique opportunities for quantum information and computation. In this Review, we first introduce the Aharonov–Bohm effect as an important realization of the geometric phase. Then, we discuss in detail the broader meaning, consequences and realizations of the geometric phase, emphasizing the most important mathematical methods and experimental techniques used in the study of the geometric phase, in particular those related to recent works in optics and condensed-matter physics. The geometric phase is a deep and influential concept in modern physics and related sciences. This Review briefly discusses its origin, mathematical formulation and various forms, some of which are topological; then elaborates on contemporary optical and condensed-matter applications.