Synthesis and Characterization of Oleophobic Fluorinated Polyester Films

The study presented in this dissertation is dedicated to the synthesis and characterization of oleophobic fluorinated polyester films. Specifically, the blending of oleophilic polyethylene terephthalate (PET) with low surface energy materials such as fluorinated polyesters has been used in order to fabricate oleophobic PET films. First, fluorinated polyesters (P(PF-oate-R)) possessing different end-groups (-COOH, -OH and -CF3) are synthesized via polycondensation reaction of isophthaloyl chloride with perfluoro ether alcohols. Then, they are solvent-blended with PET at various concentrations to obtain oleophobic polyester films of different compositions. In addition, the films are annealed to investigate the effect of annealing on surface properties of the films. The results show that the obtained PET/P(PF-oate-R) polyester films demonstrate low wettability that depended on the polyester end-groups, film compositions, and annealing. It is found that PET blended with fluorinated polyesters terminated with CF3 groups exhibit higher contact angle (CA) with water and oils than other polyesters. In addition, CA increases with increasing P(PF-oate-R) polyester content in blends. To facilitate the oleophobicity of PET films, the fluorinated polyesters terminated with -CF3 groups with two different Mw were synthesized and blended with PET. The results reveal that at low concentrations, low molecular weight polyesters migrate to the surface easily, resulting in higher surface coverage. Thus, it leads to higher water and oil repellency. On the other hand, when they are used at high concentrations, higher molecular weight polyesters in blends reduce the wettability of the surface to the higher level. It is found that the wettability of the PET film surface depends on not only the Mw of polyesters, but also on annealing protocol. To this end, the effects of the annealing temperature on surface wettability are also examined

Monitoring CO Concentration in Fuel Cells Using Microcantilever Sensors

Estimating the concentration of gases including carbon monoxide (CO) in the hydrogen fuel exiting the reformer and entering the fuel cell is imperative. A high concentration of CO can cause fuel-cell catalyst poisoning, which permanently destroys the cell. Current practices call for utilizing expensive and bulky spectral analyzers to achieve this task. In addition to their high cost, these methodologies, undoubtedly, hinder the portability and self-containment of the cell. To overcome these problems and achieve the desired objectives of a portable, self-contained, and real-time measurement module, this thesis presents and experimentally investigates a new enabling technology based on utilizing an array of microcantilever sensors to detect minute concentrations of CO in the fuel cell. Results of this study indicate that microcantilevers can be spin coated with homogenous layers of copper-exchanged Y zeolite (CuY). This zeolite is capable of adsorbing CO over a range pressures and fuel cell operating temperatures. As a result of this adsorption, the sensor experiences a shift in its resonance frequency, which can be measured and related to the concentration of CO. It is determined that maximum adsorption capacity of the sensor occurs at 40 oC using CuY zeolite that is loaded with 10 wt% Cu. Furthermore, experimental findings indicate that the sensitivity of the sensor increases as the number of zeolite layers is increased up to a certain threshold (4 layers). Beyond this threshold, adding more layers will only result in a less sensitive sensor. In the experiments described in this thesis, a maximum repeatable shift of 275 Hz in the first modal frequency of the microcantilevers is measured. Ultimately, such frequency shifts can be iii related to the concentration of CO in the gas mixture, allowing closed-loop, real-time control and diagnosis of the flow of gases into and out of the fuel cell. This can help avoid fuel-cell starvation and prevent catastrophic deactivation of the necessary fuel cell catalyst

Protective effect of astaxanthin and metformin in the liver of rats in which the polycystic ovary syndrome model was formed by giving letrozole

Objective(s): In this study, the effects of astaxanthin on liver tissue in rats with polycystic ovary syndrome (PCOS) were evaluated.Materials and Methods: Fifty-four Spraque-Dawley rats were divided into 9 groups: Groups: Control, PCOS, PCOS+Metformin (Met), PCOS+ Astaxanthin (ASX)10, PCOS+ASX20, PCOS+ASX40, PCOS+Met+ASX10, PCOS+Met+ASX20, and PCOS+Met+ASX40. PCOS was induced in female rats by oral administration of letrozole (1 mg/kg) for 21 days. Rats were treated with ASX (10 mg/kg), ASX (20 mg/kg), ASX (40 mg/kg), and metformin (20 mg/kg) for 7 days after PCOS induction. At the end of the experiment, malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured in the liver tissue. The liver was stained with hematoxylin/eosin for histological examination. Additionally, NF-kB and caspase 3 were analyzed immunohistochemically.Results: A remarkable abnormality was observed in the biochemical and histological parameters in the liver tissue of the PCOS model rats. Astaxanthin dose-dependently normalized the MDA level. Additionally, astaxanthin showed a protective effect by increasing the SOD level and increasing its antioxidant activities. We observed that administration of astaxanthin in addition to metformin applied in the standard was more effective. Caspase 3 and NF-kB immune positivity was lower in the groups given astaxanthin compared with PCOS. Histologically, it was observed that astaxanthin improved the deteriorated liver morphology in the letrozole-induced PCOS group.Conclusion: According to our results, it was observed that astaxanthin had antioxidant, anti-inflammatory and anti-apoptotic effects on PCOS in the treatment groups. Therefore, it was concluded that astaxanthin may have a protective effect against PCOS side effects

Evaluation of the safety of intracameral trypan blue injection on corneal tissue using oxidative stress parameters and apoptotic activity: an experimental study

Purpose: The present experimental study aimed to investigate the effects of intracameral trypan blue (TB) on oxidative stress parameters and apoptosis in corneal tissue. Methods: Thirty rats were randomly assigned to three groups of 10 rats each: the sham group (Group 1); control group (Group 2); and treatment group (Group 3). The control group was administered 0.01 cc of balanced salt solution. The treatment group was administered 0.006 mg/0.01 cc of TB. The total antioxidant status (TAS) and total oxidant status (TOS) in corneal tissue and blood were measured and the oxidative stress index (OSI) was calculated. Finally, corneal tissue histopathology was evaluated using staining for caspase-3 and -8, and apoptotic activity was examined. Results: The TAS, TOS and OSI levels in the blood samples were not significantly different (p>0.05 for all). Compared with the sham and control groups, the TOS and OSI levels in corneal tissue were significantly different in the treatment group (p<0.05 for all). No significant difference was observed between the sham group and the control group (p>0.05). Immunohistochemical staining for caspase-3 and caspase-8 demonstrated higher apoptotic activity in the TB group than in the sham and control groups. Conclusion: The present study showed that intracameral TB injection is safe systematically but may be toxic to corneal tissue, as demonstrated using oxidative stress parameters and histopathological evaluation

Renal complications of lipodystrophy: A closer look at the natural history of kidney disease

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144612/1/cen13732_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144612/2/cen13732.pd

Bioaffinity immobilization and characterization of alpha-galactosidase on aminophenylboronicacid derivatized chitosan and Sepabeads EC-FA

WOS: 000426535600075Enzyme immobilization with affinity binding which is based on the specific affinity interactions have an important advantage as; high selectivity. In the present study, chitosan and Sepabeads EC-EA were derivatized with aminophenylboronicacid(APBA) for the affinity immobilization of alpha-galactosidase. The influence of various process parameters on immobilization of the enzyme is investigated to get high immobilization yields. Under optimized immobilization conditions, the chitosan and Sepabeads EC-EA immobilized enzymes exhibited activity yield of 89.5% and 72%, respectively. The maximum activities were detected at 40 degrees C for free and Sepabeads EC-EA immobilized enzyme and 55 degrees C for chitosan immobilized enzyme. The optimum pH was found as pH 5.0 for free and Sepabeads EC-EA immobilized enzyme and pH 5.5 for chitosan immobilized enzyme. Both immobilized enzymes were very stable at temperature ranged from 4 to 55 degrees C and also in a pH range of 2.6-7.0. The immobilized alpha-galactosidases were also used in the hydrolysis of raffinose. The chitosan and Sepabeads EC-EA immobilized enzymes hydrolysed 55% and 42% of raffinose in 32 hat 50 degrees C, respectively. The obtained results shed light for the useability of these immobilized enzymes in the hydrolysis of raffinose in food industry and make these immobilized enzymes good candidates for their various biotechnological applications.Ege University Research FoundationEge University [2011 FEN 034]This work has been funded by the Ege University Research Foundation under Project 2011 FEN 034. We also thank to Dr. Caimi (Resindion S.R.L.) for providing us Sepabeads EC-EA support and for technical help

Conservative management of iatrogenic tracheal rupture in a 19-month-old child

Up to date, only five cases of iatrogenic tracheal rupture during rigid bronchoscopy have been reported in children. Herein, we report the first case who has recovered with spontaneous respiration without intubation. Rigid bronchoscopy of a 19-month-old girl revealed a foreign body at the right main bronchus. While the bronchoscope was being withdrawn, we identified a 0.5-cm longitudinal mucosal laceration along the right wall of the membranous trachea. As her spontaneous respiration was adequate, she was treated conservatively. For the treatment of tracheal lacerations, while early surgical repair has traditionally been acceptable, evidence supporting conservative treatment is increasing, particularly in paediatric cases. If spontaneous respiration is sufficient, bridging the laceration with an endotracheal tube may not be required

The relation of novel cardiovascular risk parameters in patients with familial Mediterranean fever

Objective In this study, we aimed at correlating the thickness of epicardial adipose tissue and levels of Vitamin D with cardiac risk in patients with familial Mediterranean fever. Methods Sixty-five patients with familial Mediterranean fever and 38 healthy controls with matching age and sex were included in the study. The patients with a history of familial Mediterranean fever attacks within the previous two weeks or with any history of inflammatory or cardiovascular disease were excluded. Data regarding age, gender, weight, height, waist circumference, body mass index (calculated as weight/height 2 ), pulse wave velocity, serum Vitamin D levels from fasting blood samples, and Homeostatic Model Assessment for insulin resistance were obtained for the patients and controls. The epicardial adipose tissue was visualized as an echo-free space between the outer surface of myocardium and visceral pericardium using two-dimensional echocardiography, and the thickness of epicardial adipose tissue was measured in parasternal long-axis view at the end of diastole. Results The patients with familial Mediterranean fever had significantly higher levels of C-reactive protein, epicardial adipose tissue, and pulse wave velocity (p < 0.001, <0.05, <0.005, respectively) as compared with the control group. However, the serum Vitamin D levels in the two groups were observed to be similar (p = 0.486). Weak but significant positive correlations were observed between epicardial adipose tissue thickness and C-reactive protein (r = 0.302, p < 0.005), epicardial adipose tissue thickness and pulse wave velocity (r = 0.263, p < 0.01), and C-reactive protein and pulse wave velocity (r = 0.235, p < 0.05). Conclusion Thickness of epicardial adipose tissue and pulse wave velocity were observed to increase in patients with familial Mediterranean fever