Electron-phonon and electron-electron interactions in organic field effect transistors

Recent experiments have demonstrated that the performances of organic FETs strongly depend on the dielectric properties of the gate insulator. In particular, it has been shown that the temperature dependence of the mobility evolves from a metallic-like to an insulating behavior upon increasing the dielectric constant of the gate material. This phenomenon can be explained in terms of the formation of small polarons, due to the polar interaction of the charge carriers with the phonons at the organic/dielectric interface. Building on this model, the possible consequences of the Coulomb repulsion between the carriers at high concentrations are analyzed.Comment: proceedings of the SMEC'07 conference, submitted to the Journal of Physics and Chemistry of Solid

Surfactant Sensors in Biotechnology; Part 1 – Electrochemical Sensors

An overview on electrochemical surfactant sensors is given with special attention to papers published since 1993. The importance of surfactants in modern biotechnology is stressed out. Electrochemical sensors are usually divided according to the measured physical quantity to potentiometric, amperometric, conductometric and impedimetric surfactant sensors. The last ones are very few. Potentiometric surfactant sensors are the most numerous due to their simplicity and versatility. They can be used either as end-point titration sensors or as direct EMF measurement sensors, in batch or flow-through mode. Some amperometric surfactant sensors are true biosensors that use microorganisms or living cells

Application of a New Potentiometric Sensor for Determination of Anionic Surfactants in Wastewater

A new screen-printed potentiometric microsensor (SPMS) for the determination of anionic surfactants (ASs) based on the dimethyldioctadecylammonium-tetraphenylborate (DDA-TPB) ion pair as a sensing material was applied to real industrial effluents. The sensor is accurate, inexpensive, simple and very sensitive. The solutions of cetylpyridinium chloride (CPC) of the concentrations down to 5· 10–5 mol dm–3 were used as a titrant. Standard addition method was used for checking the precision and accuracy of measurements providing satisfactory results with recoveries between 98.3 to 102.0 % in pure AS solutions and 99.0 to 114.5 % in wastewater. Standard spectrophotometric method Methylene Blue Active Substances (MBAS) was used as control for comparison of the results obtained with the new sensor. The results obtained using SPMS were compared with those obtained by the polymeric membrane ion-selective electrodes (ISEs), containing the same sensing material, and exhibited good mutual agreement

Editor\u27s Introduction to the 10th Anniversary Volume of the Journal of Southeast Asian American Education and Advancement

Editor\u27s Introduction to the 10th Anniversary Volum

A multisite study of performance drivers among institutional review boards.

Introduction:The time required to obtain Institutional Review Board (IRB) approval is a frequent subject of efforts to reduce unnecessary delays in initiating clinical trials. This study was conducted by and for IRB directors to better understand factors affecting approval times as a first step in developing a quality improvement framework. Methods:807 IRB-approved clinical trials from 5 University of California campuses were analyzed to identify operational and clinical trial characteristics influencing IRB approval times. Results:High workloads, low staff ratios, limited training, and the number and types of ancillary reviews resulted in longer approval times. Biosafety reviews and the need for billing coverage analysis were ancillary reviews that contributed to the longest delays. Federally funded and multisite clinical trials had shorter approval times. Variability in between individual committees at each institution reviewing phase 3 multisite clinical trials also contributed to delays for some protocols. Accreditation was not associated with shorter approval times. Conclusions:Reducing unnecessary delays in obtaining IRB approval will require a quality improvement framework that considers operational and study characteristics as well as the larger institutional regulatory environment

The role of the train station in the image formation of the early Republican Ankara

Depending on the assumption that buildings play the fundamental role in the formation of cities and their image, this study investigates the contribution of the Train Station to the formation of Ankara and its image in the early years of the Turkish Republic. The spatial entity of the station reflected the intended modern identity of the new state. Orienting the movement and development within its setting, the building constituted an indispensable element of the structure of the city. It acted as an immediate stimulus for the perception of the city and as a mediator for the creation of city's image. As a building of prestige, it accommodated contemporary practices and provided civilized conditions for the whole public. Consequently, the station had a significant effect on the social and spatial formation and mental re-formation of Ankara. © 2012 SAGE Publications

Autologous anti-SOX2 antibody responses reflect intensity but not frequency of antigen expression in small cell lung cancer

Background: Anti-SOX2 antibody responses are observed in about 10 to 20% of small cell lung cancer (SCLC) patients. The aim of this study was to determine whether such responses reflect a particular pattern of SOX2 protein expression in the tumor and whether this pattern associates with clinical outcome. Methods. Paraffin embedded tumor tissues, obtained from SCLC patients who had no evidence of paraneoplastic autoimmune degeneration, were evaluated for SOX2 expression by immunohistochemistry for both intensity and extent of staining. Sera from the same patients were tested for autologous antibodies against recombinant SOX2 by enzyme-linked immunosorbent assay (ELISA). Correlates between overall survival and various clinical parameters including SOX2 staining and serology were determined. Results: SOX2 protein expression was observed in tumor tissue in 89% of patients. Seventeen patients (29%) were seropositive for SOX2 antibodies and, in contrast to SOX2 staining, the presence of antibody correlated with limited disease stage (p = 0.05). SOX2 seropositivity showed a significant association with the intensity of SOX2 staining in the tumor (p = 0.02) but not with the frequency of SOX2 expressing cells. Conclusion: Anti-SOX2 antibodies associate with better prognosis (limited stage disease) while SOX2 protein expression does not; similar to reports from some earlier studies. Our data provides an explanation for this seemingly contrasting data for the first time as SOX2 antibodies can be observed in patients whose tumors contain relatively few but strongly staining cells, thus supporting the possible presence of active immune-surveillance and immune-editing targeting SOX2 protein in this tumor type. © 2014 Atakan et al.; licensee BioMed Central Ltd

Autologous anti-SOX2 antibody responses reflect intensity but not frequency of antigen expression in small cell lung cancer

Cataloged from PDF version of article.Background: Anti-SOX2 antibody responses are observed in about 10 to 20% of small cell lung cancer (SCLC) patients. The aim of this study was to determine whether such responses reflect a particular pattern of SOX2 protein expression in the tumor and whether this pattern associates with clinical outcome. Methods. Paraffin embedded tumor tissues, obtained from SCLC patients who had no evidence of paraneoplastic autoimmune degeneration, were evaluated for SOX2 expression by immunohistochemistry for both intensity and extent of staining. Sera from the same patients were tested for autologous antibodies against recombinant SOX2 by enzyme-linked immunosorbent assay (ELISA). Correlates between overall survival and various clinical parameters including SOX2 staining and serology were determined. Results: SOX2 protein expression was observed in tumor tissue in 89% of patients. Seventeen patients (29%) were seropositive for SOX2 antibodies and, in contrast to SOX2 staining, the presence of antibody correlated with limited disease stage (p = 0.05). SOX2 seropositivity showed a significant association with the intensity of SOX2 staining in the tumor (p = 0.02) but not with the frequency of SOX2 expressing cells. Conclusion: Anti-SOX2 antibodies associate with better prognosis (limited stage disease) while SOX2 protein expression does not; similar to reports from some earlier studies. Our data provides an explanation for this seemingly contrasting data for the first time as SOX2 antibodies can be observed in patients whose tumors contain relatively few but strongly staining cells, thus supporting the possible presence of active immune-surveillance and immune-editing targeting SOX2 protein in this tumor type. © 2014 Atakan et al.; licensee BioMed Central Ltd

Surfactant Sensors in Biotechnology; Part 2 – Non-Electrochemical Sensors

An overview on non-electrochemical surfactant sensors is given with special attention to work published since 1993. In the first part the importance of surfactants in modern biotechnology is stressed out and works on electrochemical surfactant sensors have been summarised. In this part the research of non-electrochemical surfactant sensors is reported, primarily optochemical and piezoelectric surfactant sensors. Papers investigating some specific interactions of potential interest for surfactant sensors are reported as well