Istanbul Technical University

About: Istanbul Technical University is a education organization based out in Istanbul, Turkey. It is known for research contribution in the topics: Fuzzy logic & Large Hadron Collider. The organization has 12889 authors who have published 25081 publications receiving 518242 citations. The organization is also known as: İstanbul Teknik Üniversitesi & Technical University of Istanbul.

Interaction of multi-functional silver nanoparticles with living cells

Abstract: Silver nanoparticles (AgNPs) are widely used in household products and in medicine due to their antibacterial and to wound healing properties. In recent years, there is also an effort for their use in biomedical imaging and photothermal therapy. The primary reason behind the effort for their utility in biomedicine and therapy is their unique plasmonic properties and easy surface chemistry for a variety of functionalizations. In this study, AgNPs modified with glucose, lactose, oligonucleotides and combinations of these ligands are investigated for their cytotoxicity and cellular uptake in living non-cancer (L929) and cancer (A549) cells. It is found that the chemical nature of the ligand strongly influences the toxicity and cellular uptake into the model cells. While the lactose-and glucose-modified AgNPs enter the L929 cells at about the same rate, a significant increase in the rate of lactose-modified AgNPs into the A549 cells is observed. The binding of oligonucleotides along with the carbohydrate on the AgNP surfaces influences the differential uptake rate pattern into the cells. The cytotoxicity study with the modified AgNPs reveals that only naked AgNPs influence the viability of the A549 cells. The findings of this study may provide the key to developing effective applications in medicine such as cancer therapy.

Perceived security determinants in e-commerce among Turkish university students

Abstract: Perceived security is defined as the level of security that users feel while they are shopping on e-commerce sites. The aims of this study were to determine items that positively influence this feeling of security by users during shopping, and to develop guidelines for perceived security in e-commerce. An experiment allowed users with different security assurances to shop on simulated e-commerce sites. The participants were divided into three groups, shopping for cheap, mid-range, and expensive products, respectively. Following the shopping environment, the virtual shopping security questionnaire (VSSQ), consisting of fourteen perceived security items, was presented to the users. The VSSQ was presented to the participants to validate these perceived security items. The VSSQ had a Cronbach's alpha internal reliability value of 0.70. With the exception of two items, there were no significant differences in item ratings between the groups of different shopping item values. A factor analysis procedure determi...

Production of epoxy composites reinforced by different natural fibers and their mechanical properties

Abstract: The aim of this research is the production of epoxy resin composites reinforced by birch, palm, and eucalyptus fibers with resin transfer molding technique and molded fiber production technique combination. The tensile stress of birch, palm, and eucalyptus reinforced epoxy composites were determined as 29.53, 42.24, and 45.28 MPa, respectively. Bending stress of birch, palm and eucalyptus reinforced epoxy composites were found as 58.83, 68.58, and 79.92 MPa, respectively. The birch epoxy composite had 0.105 J impact energy while palm and eucalyptus epoxy composites were determined as 0.130 and 0.124 J, respectively. It is clearly observed that fiber type was very effective on the mechanical properties of composites. The results of studies showed that molded fiber production method had a very promising future for the development of natural fiber reinforced composites.