SÜPER KRİTİK CO2’nin P3HT/PCBM ve PVP-AgNP MALZEMELERDE NANOPARTİKÜL DAĞILIMININ KONTROLÜ

Günümüzde, polimerik nanokompozit malzemeler kompozit malzemeler içinde öncelikli olarak tercih edilen malzeme grubunda ilk sırada bulunmaktadır. Nano boyutta takviye taneciklerinin yer aldığı kompozit malzemelerin niteliklerinin bulunması, geliştirilmesi, ve üretilmesi oldukça önem arzetmektedir. Bu çalışmada, P3HT-PCBM, ve PVP-Ag nanotoz (PVP-AgNP) ince filmleri döndürmeli kaplama yöntemi ile hazırlandıktan sonra süoer kritik CO₂ tavlaması yapılmıştır. Üretilen filmlerin daha sonra optik mikroskop, taramalı elektron mikroskobu ve atomik kuvvet mikroskop ile analizleri yapılmıştır. Bu araştırmaların sonucunda, P3HT-PCBM ve PVP-AgNP numunelerinde, CO₂ tavlama değişkenleri üzerinden partiküllerin yüzelsey faz ayrışması ile yüzey göçü kontrolünün kapsamlı bir şekilde yapılabildiği gözlenmiştir. Polimer içinde yer alan CO2 miktarına bağlı olarak partikül konsantrasyon dağılımının değişkenlik gösterdiği saptanmıştır. Böylelikle polimer nanokompozitlerin özelliklerinin anlaşılarak kullanım alanlarının genişletilmesi, düşük maliyete sahip yeni malzemelerin üretilmesi ve CO2 kritik ıslatma mekanizmasının farklı sistemler ile en iyi şekilde kullanılabileceği anlaşılmıştır.Today, polymeric nanocomposite materials are in the first place in the group of primarily preferred materials among composite materials. It is very important to find, develop, and produce the properties of composite materials with nano-sized reinforcement particles. In this study, supercritical CO₂ annealing was performed after P3HT-PCBM and PVP-Ag nanopowder (PVP-AgNP) thin films were prepared by spin coating method. The produced films were then analyzed with optical microscope, scanning electron microscope, and atomic force microscope. As a result of these investigations, it has been observed that surface migration control can be made comprehensively by superficial phase separation of particles over CO₂ annealing variables in P3HT-PCBM and PVP-AgNP samples. It has been determined that the particle concentration distribution varies depending on the amount of CO2 in the polymer. Thus, by understanding the properties of polymer nanocomposites, it has been understood that expanding the usage areas, producing new materials with low cost and the CO2 critical wetting mechanism can be used in the best way with different systems

Flame-Sprayed Pure and Ce-Doped TiO2 Photocatalysts

Pure and Ce-doped TiO2 nanoparticles were successfully synthesized in one step by means of the scalable flame spray pyrolysis (FSP) process. Complete structural and chemical characterization of these materials revealed that the majority of the nanoparticles are crystalline and spherical, ranging from 5 to 45 nm in diameter. The band gap of TiO2 was reduced by doping with Ce from 2.43 to 3.06 eV and the Ce-TiO2 nanoparticles exhibit a strong photoelectrical response to visible light illumination. Ce-TiO2 nanoparticles obtained with this scalable method are trivially scalable to industrial level manufacturing, granting and enabling additional approaches for the actual application of ceramic oxide nanomaterials to combat challenges such as environmental cleanup and energy production from the visible part of solar inputs

Isolation and analysis of bioactive diterpenoids in Salvia species (Salvia chionantha and Salvia kronenburgiii) by micellar electrokinetic capillary chromatography

In the present work, we isolated two bioactive diterpenoids, horminone and 7-O-acetylhorminone and developed a micellar electrokinetic chromatography (MEKC) method for the simultaneous quantitative analysis of them in Turkish Salvia Species. The optimal separation electrolyte was 50 mmol/L SDS and 25% methanol at pH 11.5. The limits of detection (S/N=3) were 3.269 and 4.518 mu g/mL for horminone and 7-O-acetylhorminone, respectively. The method has been applied successfully to analyze these two components in Salvia chionantha and Salvia kronenburgii acetone extracts. (C) 2009 Elsevier B.V. All rights reserved

Effect of rosuvastatin on spatial learning, memory, and anxiety-like behaviour in ovariectomized rats

The effect of rosuvastatin (Ros) on cognitive function and anxiety-like behaviour in ovariectomized rats were evaluated. Eighteen female Wistar rats (218–310 g, 6–8 months old) were allocated into sham (n = 6), ovariectomy (Ovx, n = 6) or Ovx + Ros (up to eighth week n = 6, then n = 4) groups. Ros was administered at 20 mg/kg/day by oral gavage for 12 weeks. Behavioural tests were performed at 4, 8 and 12 weeks following Ovx. At 12 weeks, Ovx group had significantly longer escape latency than the sham group at the first day of the four-day training period of the Morris Water Maze test (p < .01). In the Elevated Plus Maze test, Ovx group spent significantly more time in the closed arms than the sham group (p < .01), and this anxiety-like behavioural effect of Ovx was prevented by 12-weeks Ros treatment (p < .05). In conclusion, Ros prevents memory deficit and anxiety-like behaviour in the ovariectomized rats, a model for human surgical menopause. Impact Statement What is already known on this subject? Reduced levels of oestrogen in surgical postmenopausal period has been linked to an increased risk of cognitive dysfunction. Although statins have been shown to improve cognitive function in experimental and clinical studies, there are limited studies evaluating the effect of statins on the cognitive decline and anxiety-like behaviour associated with surgical menopause. What do the results of this study add? Rosuvastatin, a long-acting statin, prevents learning and memory deficit and anxiety-like behaviour in the ovariectomized rat model. What are the implications of these findings for future clinical practice and/or future clinical research? These findings will form the basis for further experimental and clinical research on the effects of statins on cognitive functions and anxiety-like behaviour in the surgical menopause

The Effect of the Acute Submaximal Exercise on Thrombin Activatable Fibrinolysis Inhibitor Levels in Young Sedentary Males

Depending on type, duration, and intensity of the exercise, changes occur in hemostasis. In this study, we evaluated the changes in the parameters of coagulation and fibrinolytic systems that happened after the submaximal aerobic exercises by bicycle ergomater. Twelve healthy male participants whose ages were between 21 and 28 have been included. The venous samples have been drawn before the exercise as well as at the 0th, 15th, and 60th minutes after the submaximal exercise. The values of prothrombin time (PT), active partial thromboplastin time (aPTT), D-dimer, fibrinogen, plasminogen activator inhibitor 1 (PAI-1) and thrombin-activatable fibrinolysis inhibitor (TAFI) have been measured. Plasminogen activator inhibitor 1 values have shown an insignificant increase after exercise (P = .328), whereas, it has decreased significantly during the resting period (P = .033) Postexercise 15th and 60th minutes TAFI values have decreased significantly comparing to basal and postexercise (0th minute) values (P = .001). Fibrinolytic system activation is observed after acute submaximal aerobic exercise of sedentary healthy participants

The Spectrum Of Diseases Causing Fever Of Unknown Origin In Turkey: A Multicenter Study

Objective: The purpose of this trial was to determine the spectrum of diseases with fever of unknown origin (FUO) in Turkey. Methods: A prospective multicenter study of 154 patients with FUO in twelve Turkish tertiarycare hospitals was conducted. Results: The mean age of the patients was 42 +/- 17 years (range 17-75). Fifty-three (34.4%) had infectious diseases (ID), 47 (30.5%) had non-infectious inflammatory diseases (NIID), 22 (14.3%) had malignant diseases (MD), and eight (5.2%) had miscellaneous diseases (Mi). In 24 (15.6%) of the cases, the reason for high fever could not be determined despite intensive efforts. The most common ID etiologies were tuberculosis (13.6%) and cytomegalovirus (CMV) infection (3.2%). Adult Still's disease was the most common NIID (13.6%) and hematological malignancy was the most common MD (7.8%). In patients with NIID, the mean duration of reaching a definite diagnosis (37 +/- 23 days) was significantly longer compared to the patients with ID (25 +/- 12 days) (p = 0.007). In patients with MD, the mean duration of fever (51 +/- 35 days) was longer compared to patients with ID (37 +/- 38 days) (p = 0.052). Conclusions: Although infection remains the most common cause of FUO, with the highest percentage for tuberculosis, non-infectious etiologies seem to have increased when compared with previous studies. (C) 2007 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.WoSScopu