Topological Defects, Orientational Order, and Depinning of the Electron Solid in a Random Potential

We report on the results of molecular dynamics simulation (MD) studies of the classical two-dimensional electron crystal in the presence disorder. Our study is motivated by recent experiments on this system in modulation doped semiconductor systems in very strong magnetic fields, where the magnetic length is much smaller than the average interelectron spacing $a_0$, as well as by recent studies of electrons on the surface of helium. We investigate the low temperature state of this system using a simulated annealing method. We find that the low temperature state of the system always has isolated dislocations, even at the weakest disorder levels investigated. We also find evidence for a transition from a hexatic glass to an isotropic glass as the disorder is increased. The former is characterized by quasi-long range orientational order, and the absence of disclination defects in the low temperature state, and the latter by short range orientational order and the presence of these defects. The threshold electric field is also studied as a function of the disorder strength, and is shown to have a characteristic signature of the transition. Finally, the qualitative behavior of the electron flow in the depinned state is shown to change continuously from an elastic flow to a channel-like, plastic flow as the disorder strength is increased.Comment: 31 pages, RevTex 3.0, 15 figures upon request, accepted for publication in Phys. Rev. B., HAF94MD

Nanoparticles for Applications in Cellular Imaging

In the following review we discuss several types of nanoparticles (such as TiO2, quantum dots, and gold nanoparticles) and their impact on the ability to image biological components in fixed cells. The review also discusses factors influencing nanoparticle imaging and uptake in live cells in vitro. Due to their unique size-dependent properties nanoparticles offer numerous advantages over traditional dyes and proteins. For example, the photostability, narrow emission peak, and ability to rationally modify both the size and surface chemistry of Quantum Dots allow for simultaneous analyses of multiple targets within the same cell. On the other hand, the surface characteristics of nanometer sized TiO2allow efficient conjugation to nucleic acids which enables their retention in specific subcellular compartments. We discuss cellular uptake mechanisms for the internalization of nanoparticles and studies showing the influence of nanoparticle size and charge and the cell type targeted on nanoparticle uptake. The predominant nanoparticle uptake mechanisms include clathrin-dependent mechanisms, macropinocytosis, and phagocytosis

A Dynamic Key Infrastructure for Grid

Abstract. This paper introduces the concept of a dynamic key infrastructure for Grid. It utilises the properties of Identity-based Cryptography (IBC) to simplify key management techniques used in current Public Key Infrastructure (PKI) settings for Grid. This approach can offer greater simplicity, flexibility, and enhanced computation trade-offs.

A Screen-Printed Electrode Modified With Graphene/Co3O4 Nanocomposite for Electrochemical Detection of Tramadol

In this paper, graphene (Gr)/Co3O4 nanocomposite was synthesized and utilized for the development of a novel electrochemical sensor to detect tramadol. Tramadol determination was examined by linear sweep voltammetry, differential pulse voltammetry, cyclic voltammetry, and chronoamperometry on Gr/Co3O4 nanocomposite-modified screen-printed electrode (Gr/Co3O4/SPE) in phosphate-buffered saline (PBS). Under the optimized condition, the detection limit of tramadol is 0.03 μM (S/N = 3) in the linear ranges of 0.1�500.0 μM. Furthermore, Gr/Co3O4/SPE was satisfactorily utilized to detect tramadol in tramadol tablet and urine specimens. © Copyright © 2020 Aflatoonian, Tajik, Aflatoonian, Beitollahi, Zhang, Le, Cha, Jang, Shokouhimehr and Peng

Supplementary Material for: Assessment of Adjuvant Trastuzumab-Associated Cardiac Toxicity in Korean Patients with Breast Cancer: A Single-Center Analysis

<b><i>Background</i></b>: We performed this analysis to investigate the clinical presentation of trastuzumab-associated cardiac toxicity in Korean women. <b><i>Method:</i></b> 124 patients treated in a single institute from January 2006 to November 2011 with adjuvant trastuzumab therapy following primary surgery were identified from a database. We evaluated the cumulative incidence of cardiac toxicity, associated risk factors, and changes in cardiac function during trastuzumab treatment. <b><i>Results:</i></b> The median age of patients was 50 years (range 27-73). After 12 months of follow-up, the cumulative incidence of cardiac toxicity was 12.1% (grade I: 8.1%, grade II: 0.8%, grade III: 3.2%). In total, 4% of patients discontinued treatment due to cardiac dysfunction. The left ventricular ejection fraction (LVEF) recovered in all patients who discontinued or delayed treatment due to cardiac dysfunction following treatment discontinuation. The degree of the decrease in LVEF was large at 6 months after the initiation of treatment. A lower LVEF at baseline (<65%) was associated with cardiac toxicity. <b><i>Conclusions:</i></b> The low incidence of cardiac toxicity and the reversibility of cardiac dysfunction may validate the safety of trastuzumab treatment in Korean women with an acceptable baseline LVEF

Reconfigurable photo-induced doping of two-dimensional van der Waals semiconductors using different photon energies

Few-layer molybdenum ditelluride and tungsten diselenide field-effect transistors can be reversibly doped with different carrier types and concentrations using pulses of ultraviolet and visible light, allowing reconfigurable complementary metal-oxide-semiconductor circuits to be created. Two-dimensional semiconductors have a range of electronic and optical properties that can be used in the development of advanced electronic devices. However, unlike conventional silicon semiconductors, simple doping methods to monolithically assemble n- and p-type channels on a single two-dimensional semiconductor are lacking, which makes the fabrication of integrated circuitry challenging. Here we report the reversible photo-induced doping of few-layer molybdenum ditelluride and tungsten diselenide, where the channel polarity can be reconfigured from n-type to p-type, and vice versa, with laser light at different frequencies. This reconfigurable doping is attributed to selective light-lattice interactions, such as the formation of tellurium self-interstitial defects under ultraviolet illumination and the incorporation of substitutional oxygen in tellurium and molybdenum vacancies under visible illumination. Using this approach, we create a complementary metal-oxide-semiconductor (CMOS) device on a single channel, where the circuit functions can be dynamically reset from a CMOS inverter to a CMOS switch using pulses of different light frequencies.11Nsciescopu