Stomach One-Point Cancer: One Case Report and Literature Review

Gastric cancer is one of the most common cancers and one of themost frequent causes of cancer deaths worldwide. Early detection andaccurate preoperative staging of gastric cancer is essential for planning optimal therapy such as endoscopic mucosal resection or gastric resection and offers the best prognosis. With advanced technology in diagnostic instruments and the mass screening, early gastric cancer has been detected easier. One-point cancer of gastric is a special type of early gastric cancer[1]. Diagnosis of one-point cancer of gastric is important for both the immediate treatment and the prognosis. There is still no consensus on the operation extent and postoperative treatment for patients with one-point cancer of gastric. Learned from previous reports[2-5], we know that existed in the superfi cial layer of the gastric mucosa and the superfi cial ulcer is one of the important characteristics of one point cancer of gastric. Herein, we report a case of one point cancer of gastric with the appearance of a deep infi ltrating ulcer. To the best of our knowledge, no such type of one point cancer of gastric has been reported

Anomalous Heat Conduction and Anomalous Diffusion in Low Dimensional Nanoscale Systems

Thermal transport is an important energy transfer process in nature. Phonon is the major energy carrier for heat in semiconductor and dielectric materials. In analogy to Ohm's law for electrical conductivity, Fourier's law is a fundamental rule of heat transfer in solids. It states that the thermal conductivity is independent of sample scale and geometry. Although Fourier's law has received great success in describing macroscopic thermal transport in the past two hundreds years, its validity in low dimensional systems is still an open question. Here we give a brief review of the recent developments in experimental, theoretical and numerical studies of heat transport in low dimensional systems, include lattice models, nanowires, nanotubes and graphenes. We will demonstrate that the phonon transports in low dimensional systems super-diffusively, which leads to a size dependent thermal conductivity. In other words, Fourier's law is breakdown in low dimensional structures

Electronic Structures of Shallow Acceptors Confined in Si/SiGe Quantum Well Structures

AbstractEnergy levels of the shallow acceptor states have been calculated for center-doped Si/Si1−xGex/Si quantum wells (QWs). The impurity states were calculated using an effective-mass theory that accounts for valence-band mixing as well as the mismatch of band parameters and dielectric constants between well and barrier materials. Acceptor binding energies and splitting between the acceptor 1S3/2(Γ7) and 1S3/2(Γ6) ground states were studied at various Ge concentrations and well widths. The results are discussed in comparison with the recent experimental data from the lateral transport measurements in boron-doped Si/SiGe quantum wells.</jats:p

Characteristics of water transport through the membrane in direct methanol fuel cells operating with neat methanol

The water required for the methanol oxidation reaction in a direct methanol fuel cell (DMFC) operating with neat methanol can be supplied by diffusion from the cathode to the anode through the membrane. In this work, we present a method that allows the water transport rate through the membrane to be in-situ determined. With this method, the effects of the design parameters of the membrane electrode assembly (MEA) and operating conditions on the water transport through the membrane are investigated. The experimental data show that the water flux by diffusion from the cathode to the anode is higher than the opposite flow flux of water due to electro-osmotic drag (EOD) at a given current density, resulting in a net water transport from the cathode to the anode. The results also show that thinning the anode gas diffusion layer (GDL) and the membrane as well as thickening the cathode GDL can enhance the water transport flux from the cathode to the anode. However, a too thin anode GDL or a too thick cathode GDL will lower the cell performance due to the increases in the water concentration loss at the anode catalyst layer (CL) and the oxygen concentration loss at the cathode CL, respectively. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

Coupled Quantum Wells

Properties of quantum-well (QW) structures have proved useful in providing enhanced device characteristics and even in generating new device applications. This book presents a theory needed to understand the properties of QW structures, as well as the rules employed in the design of photodetectors based on QWs. A theoretical model is presented evaluating gain from the QW structure based on IV-VI semiconductor materials. The experimental and theoretical results concerning coupled QW structures are discussed. Semimagnetic quantum wells attract great attention due to potential device application in the field of spintronics. A study of three groups of semimagnetic structures is presented. Magnetoexcitons dispersion in coupled quantum wells are discussed using the Bethe-Salpeter formalism. Also presented are: high-resolution electron energy loss spectroscopy measurements on surface plasmon dispersion in systems exhibiting quantum well states; a review of different ways to achieve a spin splitting of two-dimensional electron and hole sub-bands; a review of two approaches to the quantisation of the particle motion in an infinite square; a study of the different disordered electron systems with various disorder strengths; and a study of quantum states of Double Quantum Wells and hydrogen-like molecules. An optical gain using the new material system InGaAsN for the operation of QW based semiconductor lasers is evaluated as well.Show more Show less</p