Untersuchung der Isomerisierungsdynamik von Azobenzolen und der strahlungslosen Desaktivierung von Nukleobasen mit Hilfe der Femtosekunden-Fluoreszenzspektroskopie

The isomerization dynamics of azobenzenes (AB) and the electronic deactivation dynamics of adenine (Ade) and adenosine (Ado) were investigated by femtosecond fluorescence upconversion. Trans- or \cis-AB molecules were excited to the S1 potential surface at 475 nm. Fluorescence was detected between 560 and 708 nm. Biexponential fits to the fluorescence time profiles of trans-AB yielded two time constants, which were in the range of 0.24 - 0.91 ps and 1.8 - 4.9 ps depending on the solvent and detection wavelength. For cis-AB the fluorescence time profiles could only be fitted with three exponentials with 269 nm. In the cases of 7H-Ade and Ado no dependence on excitation energy could be observed. The averrage values were 8.4 ps (7H-Ade) and 0.31 ps (Ado). The Ade lifetimes in dioxane were constant (0.38 ps for 9H-Ade and 15.3 ps for 7H-Ade). The localization of a step in the 9H-Ade lifetimes in aqueous solution at 265 nm may hint at the opening of a pi\sigma* relaxation channel predicted in that energy range

Femtosecond fluorescence up-conversion spectroscopy of a rotation-restricted azobenzene after excitation to the S1 state

Femtosecond time-resolved fluorescence up-conversion spectroscopy has been used in a study of the photo- induced isomerization reactions of a rotation-restricted trans-azobenzene (trans-AB) derivative capped by a crown ether (1), a chemically similar open derivative (2), and unsubstituted trans-AB (3) after excitation to the S 1 (np*) state at l ¼ 475 nm in dioxane solution. The observed biexponential temporal fluorescence profiles for 1 and 2 were almost indistinguishable within experimental error. The fitted fast fluorescence decay times (2s) for the two compounds were t 1 (1) ¼ (0.79 0.20) and t 1 (2) ¼ (1.05 0.20) ps, compared to t 1 (3) ¼ (0.37 0.06) ps. The second decay components could be described with t 2 (1) ¼ (20.3 9.5) resp. t 2 (2) ¼ (19.0 6.0) ps, vs. t 2 (3) ¼ (3.26 0.85) ps. The very similar lifetimes strongly suggest that trans–cis isomerization of 1 and 2 after S 1 excitation is governed by the same mechanism. Since 1 cannot isomerize by a simple large-amplitude rotation of one of the phenyl rings about the central NN bond, the isomerization dynamics of both ABs should be better described as ‘‘inversion’’ at the N atom(s) rather than large-amplitude ‘‘rotation’’

Democratized image analytics by visual programming through integration of deep models and small-scale machine learning

Analysis of biomedical images requires computational expertize that are uncommon among biomedical scientists. Deep learning approaches for image analysis provide an opportunity to develop user-friendly tools for exploratory data analysis. Here, we use the visual programming toolbox Orange (http://orange.biolab.si) to simplify image analysis by integrating deep-learning embedding, machine learning procedures, and data visualization. Orange supports the construction of data analysis workflows by assembling components for data preprocessing, visualization, and modeling. We equipped Orange with components that use pre-trained deep convolutional networks to profile images with vectors of features. These vectors are used in image clustering and classification in a framework that enables mining of image sets for both novel and experienced users. We demonstrate the utility of the tool in image analysis of progenitor cells in mouse bone healing, identification of developmental competence in mouse oocytes, subcellular protein localization in yeast, and developmental morphology of social amoebae

Errors in the use of Verbs Caused by the Interference of Bahasa Indonesia as the First Language in the Writing of Final Project Abstracts Done by the Batam Polytechnic Students

Polytechnic is one of the colleges that requires the writing of the final project as one of the important graduation requirements for its students in the end of their three years study. Batam Polytechnic, as a college located in the region which directly borders with Singapore and Malaysia and whose graduates are mostly employed by multinational companies encourages its students to write their final project abstracts in English. This research was done to investigate the errors in the use of verbs in the final project abstracts done by the Batam Polytechnic students. The result of this inquiry is assumed to reveal the properness level of the English abstract of the final project in Polytechnic. Besides, it is also supposed to contribute to determine the standard of the final project writing in Polytechnic, especially in writing its English abstract

The comparison of the parameters of the lespilation functions in voice education (spirometer) and the data acquired from interdisciplinary studies

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Sosyal Bilimler Enstitüsü, 2005Thesis (M.A.) -- İstanbul Technical University, Institute of Social Sciences, 2005Yüksek LisansM.A

The Effect of Type 2 Diabetes Mellitus on the Development of Alzheimer's Disease and Its Molecular Mechanism

Following increased epidemiological studies indicating the relationship between diabetes and Alzheimer's disease (AD), Type 2 diabetes has been reported to be a risk factor for the progress of AD pathology. Insulin resistance that develops in the brain, impairment in the insulin signal delivery system and glucose metabolism have been shown among the most likely pathophysiological causes of AD. It has been reported that the increase in AD markers such as phospho tau and A beta in the type 2 diabetes model of rats is associated with the decrease in the insulin receptor (IR) signaling and insulin-like growth factor-1 receptors (IGF-1R) ratio. Furthermore, intracellular components such as phospho-AKT (protein kinase B) and phospho-glycogen synthase kinase-3 beta (GSK3 beta), which are members of IR pathway, have been proved to be reduced in AD. Due to the common molecular mechanisms underlying the pathological development of Type 2 Diabetes and AD, treatment protocols indicated in diabetes have been used in the treatment of AD