The problem of finding an optimal vertex cover in a graph is a classic NP-complete problem, and is a special case of the hitting set question. On the other hand, the hitting set problem, when asked in the context of induced geometric objects, often turns out to be exactly the vertex cover problem on restricted classes of graphs. In this work we explore a particular instance of such a phenomenon...

EDITOR’S NOTE Geopersia is published biannually by the College of Science, University of Tehran, Iran. The College of Science published “Journal of Science”, which covered all fields of basic science, from 1968 to 2010. It was then decided that the College’s journals should be more specialized, and hence publication of Geopersia was launched. Geopersia aims to publish peer-reviewed original...

We use plasmon coupling between individual gold nanoparticle labels to monitor subdiffraction limit distances in live cell nanoparticle tracking experiments. While the resolving power of our optical microscope is limited to approximately 500 nm, we improve this by more than an order of magnitude by detecting plasmon coupling between individual gold nanoparticle labels using a ratiometric detect...

Objective(s): The use of new technologies, which can be realized as nanotechnology, is a novel approach in this sector. Covers made of silver nanoparticles effectively prevent and reduce invasion of microorganisms, compared with other conventional covers. This study was conducted to determine the effects of nanosilver covers in comparison with other conventional covers. <stron...

We demonstrate for the first time a new mechanical annealing method that can significantly improve the structural quality of self-assembled nanoparticle arrays by eliminating defects at room temperature. Using in situ high-pressure small-angle X-ray scattering, we show that deformation of nanoparticle assembly in the presence of gigapascal level stress rebalances interparticle forces within nan...

After introducing the operational principle of nanoparticle memory devices, their current status in silicon technology is briefly presented in this work. The discussion then focuses on hybrid technologies, where silicon and organic materials have been combined together in a nanoparticle memory device, and finally concludes with the recent development of organic nanoparticle memories. The review...

We developed a simple preparation procedure for the protein encapsulated nanoparticle and used the nanoparticle for spatiotemporal activity control of various proteins. We succeeded in the local protein activation within cells by light using the nanoparticle.

OBJECTIVE To evaluate the spermatotoxicity of gold nanoparticles. DESIGN Experimental study. SETTING A university in Thailand. PATIENT(S) Single-donor fresh semen sample. INTERVENTION(S) A mixture of gold nanoparticle solution and semen was prepared and further analyzed. MAIN OUTCOME MEASURE(S) Spermatozoa appearance. RESULT(S) After mixing the semen with a gold nanoparticle solutio...

We report a new self-assembly pathway that leads to supported and hierarchically organized gold nanoparticle mesostructure arrays on solid substrates such as glass slide, thermal oxide, photopolymer film, and mica. Using the nanoparticle micelle as a building block, hierarchical gold nanoparticle mesostructure arrays were prepared by a hydrothermal nucleation and growth process through self-ass...

AIM The aim of this work was to develop pH-responsive nanoparticles encapsulating CdtB and to demonstrate that these particles represent a potential therapeutic agent for gastric cancer. MATERIALS & METHODS Chitosan/heparin nanoparticle-encapsulated CdtB was prepared and the delivery efficiency was monitored by confocal laser scanning microscopy. The molecular basis of the nanoparticle-encaps...