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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The Effect Of Diabetes On Rat Skeletal Muscle Tissues At Molecular Level

Bozkurt, Ozlem 01 September 2006 (has links) (PDF)
In the present study Fourier Transform Infrared Spectroscopy was used to examine the effects of streptozotocin-induced diabetes mellitus on the structural components of slow- and fast-twitch rat skeletal muscles, at molecular level. Diabetes mellitus is a chronic disorder of carbohydrate, fat and protein metabolism, which is characterized by hyperglycemia caused by a defective or deficient insulin secretory response. The effect of diabetes is seen on a variety of tissues leading to important secondary complications such as kidney failure, liver dysfunction, cardiac disorders, etc. Skeletal muscle is one of the major tissues determining carbohydrate and lipid metabolism in the body / therefore, is one of the target tissues of diabetes. The two main types of muscle fibers are type I (slow-twitch) and type II (fast-twitch) fibers / having different structural organization and metabolic features. The FTIR spectra revealed a considerable decrease in lipid and protein content of diabetic skeletal muscles, indicating an increased lipolysis and protein breakdown or decreased protein synthesis. Moreover changes in protein structure and conformation were observed. In diabetes, muscle membrane lipids were more ordered and the amount of unsaturated lipids was decreased possibly due to lipid peroxidation. Diabetes caused a decrease in the content of nucleic acids, especially RNA, and hydrogen bonded phospholipids in the membrane structures of skeletal muscles. In all of the spectral parameters investigated slow-twitch muscle was more severely affected from diabetes. Thus, FTIR spectroscopy appears to be a useful method to evaluate the effect of diabetes on skeletal muscle tissues at molecular level.
22

The Effects Of Selenium On Stz-induced Diabetic Rat Kidney Plasma Membrane

Gurbanov, Rafig 01 January 2010 (has links) (PDF)
The kidney is one of the most affected organs of body from diabetes. Diabetic kidney disease is a complication of diabetes seen in 30-40% of diabetic person. The aim of this work is to contribute the useful information in the therapy of diabetes. It is very important to know the role of antioxidants at the molecular level during diabetes. The protecting role of antioxidants against lipid peroxidation, the effect of cellular antioxidant enzyme systems, understanding the changes of membrane fluidity, lipid order and protein structure which are resulted from antioxidant treatment, determining the effective therapeutic dose with the help of biochemical methods are very important in order to understand the effect of antioxidants at molecular level. In this thesis work, the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) was used in order to study the diabetic kidney disease at the molecular level, which is encountered as a complication of diabetes. Furthermore, the protecting and possible therapeutic role of selenium in the course of diabetic kidney disease was investigated. To conclude, the kidney plasma membranes were severely deteriorated due to diabetes with respect to its lipid, protein and carbohydrate structure and content, which were corrected after selenium treatment. The diabetes causes diminishment of whole membrane fluidity, which was normalized with the selenium administration. This is the first study demonstrating the effect of diabetes on kidney plasma membrane and the effect of selenium on stz-induced diabetic kidney plasma membranes using spectroscopic tools. The study revealed serious therapeutic and preventing capacities of selenium on diabetic kidney plasma membranes which needs confirmation of future researches. Furthermore, the dosage of selenium given to diabetics should be investigated in detail and proved with biochemical and clinical data.
23

Interactions Of Cholesterol Reducing Agent Simvastatin With Charged Phospholipid Model Membranes

Sariisik, Ediz 01 February 2010 (has links) (PDF)
Interactions of cholesterol reducing agent simvastatin with charged model membranes were investigated. Effects of cholestrol reducing agent simvastatin on the phase transition behaviour and physical properties of the anionic dipalmitoyl phosphatidylglycerol (DPPG) multilamellar liposome were studied as a function of temperature and simvastatin concentration. Moreover the effect of acyl chain length on the simvastatin model membrane interactions was monitored using dipalmitoyl phosphatidylglycerol (DPPG) and dimyristoyl phosphatidylglycerol (DMPG) lipids. All experiments were carried out by two non-invasive techniques namely Fourier Transform Infrared (FTIR) Spectroscopy and Differential Scanning Calorimetry (DSC). The observations made in the this study clearly showed that simvastatin interacts with the lipids of multilamellar liposomes and induces some variations in the structure of membranes. These effects are seen in the thermotropic phase transition profile of the membranes, on membrane order, acyl chain flexibility, lipid head group structures and membrane fluidity. The analysis of the C-H stretching region of FTIR spectra showed that, as simvastatin concentration increased, the phase transition curve broadened, pretransition temperature diminished, membrane order and membrane fluidity increased for anionic DPPG membrane. Moreover analysis of the C=O stretching and PO2 - stretching bands showed that simvastatin caused dehydration effect by decreasing of hydrogen bonding capacity in the glycerol backbone and also around the lipid head groups. DSC studies showed that as the simvastatin concentration increased, DSC curves broadened. In addition, simvastatin-induced lateral phase separation was observed in the DSC thermograms. In the second part of the study, the effect of acyl chain length on the simvastatin - membrane interactions was investigated for DPPG and DMPG lipid membranes. All parameters used in the FTIR studies are compared for DMPG and DPPG membranes. Similar results were observed for both membranes, except for the CH2 antisymmetric stretching band frequency at gel phase. Results showed that there are no significant effect of acyl chain length on simvastin - membrane interactions.
24

The Effects Of Radioprotectant Amifostine On Irradiated Rat Brain And Liver Tissues

Cakmak, Gulgun 01 September 2010 (has links) (PDF)
Amifostine is the only approved radioprotective agent by the Food and Drug Administration for reducing the damaging effects of radiation on healthy tissues. In this study, the effects of ionizing radiation on rat liver microsomal membrane and brain tissue and the protecting effects of amifostine on these systems were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated and liver microsomal membranes and different regions of the brain of these rats were analyzed using FTIR spectroscopy, FTIR microspectroscopy and synchrotron FTIR microspectroscopy. The first part of this study revealed that ionizing radiation caused a decrease in the total lipid content and CH2 groups of lipids, an increase in the carbonyl esters, olefinic=CH and CH3 groups of lipids in the white matter and grey matter regions of the brain, which could be interpreted as a result of lipid peroxidation. In addition, radiation altered the protein structure of the brain. Amifostine caused significant protective effect against all the radiation induced damages in the brain. In the second part of the study, FTIR results showed that radiation induced a decrease in the lipid/protein ratio and a degradation of lipids into smaller fragments that contain less CH2 and more carbonyl esters, olefinic=CH and CH3 groups in microsomal membranes. In addition, radiation caused an alteration in the secondary structure of proteins, an increase in lipid order and a decrease in the membrane dynamics. Amifostine prevented all the radiation induced compositional, structural and functional damages in the liver microsomal membranes.
25

Macromolecular Characterization Of Adipose Tissues In Inbred Obese Mouse Models

Sen, Ilke 01 August 2012 (has links) (PDF)
Obesity is a metabolic disorder that results in elevated levels of free fatty acids and triglycerides in the blood circulation, which further leads to accumulation of lipids within various tissues. Like in other similar metabolic disorders, obesity is thought to be originated from structural and regulatory changes in macromolecular assemblies. This current study aims to investigate the effects of obesity on macromolecular alterations in order to characterize Berlin fat mouse inbred (BFMI) lines which arenew models for the obesity research that may contribute to understanding of spontaneous obesity without induction of a high fat diet. Attenuated Total Reflectance - Fourier Transform Infrared (ATR-FTIR) spectroscopy was used to characterize content and structure of macromolecules in male and female control (DBA/2J) and BFMI lines / namely BFMI856, BFMI860 and BFMI861, in two different adipose tissues / inguinal fat (IF) which is subcutaneous adipose tissue (SAT), gonadal fat (GF) which is visceral adipose tissue (VAT). Structural and compositional alterations in proteins, lipids, saturated and unsaturated lipid contents, nucleic acid, collagen and glycogen contents and variations in the lipid chain length were determined. BFMI860 and BFMI861 lines were found to be the most affected lines since they showed the indications of lipid peroxidation and insulin resistance more severely as they had lower glycogen content in all tissues and lower unsaturated lipid content especially in IF adipose tissues. Moreover, structural changes in lipids were observed especially in male GF adipose tissues of BFMI856 and BFMI861 lines. Protein content decreased significantly specifically in female IF adipose tissues but no change was observed in the structure. Furthermore, BFMI852 line was found to be affected different than other lines and had an effect on especially female IF. To conclude, obesity induced changes differ in BFMI lines according to the gender, adipose tissue type and distinctness in the strains.
26

Schwingungsdynamik in O−H···O-verbrückten Aggregaten: FTIR-Spektroskopie vom Nah- bis zum Ferninfraroten / Vibrational dynamics in O–H···O connected aggregates: FTIR spectroscopy from the near to the far infrared

Kollipost, Franz 08 June 2015 (has links)
No description available.
27

Surveillance of c-allocation in microalgal cells

Wagner, Heiko, Jungandreas, Anne, Wilhelm, Christian 02 July 2014 (has links) (PDF)
When microalgae are exposed to changing environmental conditions, e.g., light-dark cycles or oscillations in nutrient availability (CO2, nitrogen, phosphate or silicate) they respond with metabolic changes in the carbon allocation pattern. Short time regulations in the time range of few seconds to minutes can be mirrored best by mass spectroscopy based metabolomics. However, these snap shots do not reflect the alterations in the carbon flow to the cellular macromolecules like protein, carbohydrate or lipid. In this review it is shown how the combination of FTIR spectroscopy and Chla-in-vivo-fluorescence based electron transport rates can reveal changes in the metabolic flux rates of carbon during a shift of the environmental conditions. The review will demonstrate in which time range FTIR spectroscopy can deliver significant information and how FTIR spectroscopy data can synergistically support metabolome analysis by mass-spectroscopy.
28

Biophysical Investigation Of The Effects Of Antioxidants On Normal And Diabetic Rat Bone Tissues At Molecular Level

Boyar, Handan 01 June 2004 (has links) (PDF)
In the first part of this study, the effect of diabetes mellitus on the long bones (femur and tibia) of the streptozocin induced diabetic rats and the effect of selenium (Se) treatment on these bones are investigated at molecular level by Fourier transform infrared (FTIR) spectroscopy, light and electron microscopy. In the second part of this study, the effect of selenium and vitamin E deficiency or selenium toxicity on rat bones have been studied by FTIR spectroscopy. The results of the first part of the present study revealed that the changes observed in the mineral and matrix phases of diabetic bones, briefly, the increase in the mineral crystal size, the decrease in the acid phosphate and carbonate content, the increase in the ratio of pyridinoline [Pyr] cross-links to dihydroxylysinonorleucine [DHLNL] cross-links present in collagen I of the bone tissue as well as the increase in the lipid to protein ratio of the matrix are quite similar to those seen in osteoporotic patients and animal models and confirms the evidence of diabetic osteoporosis. Histologic studies carried out with light and electron microscopy supported these findings. FTIR spectroscopic analysis revealed that sodium selenite treatment had some restoring effects on the deviated properties of the microstructure of diabetic bones. The results of the second part of this study revealed that the deficiency of selenium led to increase in the crystal size of the bone minerals, decreases in acid phosphate and labile carbonate content and increase in the Pyr to DHLNL ratio as in the case of diabetic bones. These results can be indicative of the importance of selenium in glucose metabolism.The results of Se excess group are similar to those of Se deficient group except that toxic amount of selenium led to increase in the relative amount of acid phosphate. This can affect the pH of the mineral environment and lead to deformation of the bone tissue. It can be concluded from FTIR spectroscopic and light microscopic findings that both antioxidant deficient and excess diets cause almost similar defects in the mineral matrix phases of rat long bones. Overall results may reflect the importance of antioxidants for human life and if they are used in proper amounts they can be preventive for the complications of diabetes seen in bones as well as other organs. However, further investigations are necessary for the therapeutic usage of selenium, since the treatment of control group rat femurs with sodium selenite led to some structural defects.
29

Preliminary Approch For The Determination Of Fish Exuded Kairomone Using Fourier Transform Infrared Spectroscopy

Kepenek, Ayse Ozge 01 January 2006 (has links) (PDF)
Chemical communication in aquatic organisms has been topic of a large number of studies focusing interactions between organisms via info chemicals. Diel Vertical Migration (DVM) is commonly observed among zooplankton and consists of a single daily ascent with minimum depth reached between sunset and sunrise and a descent with maximum depth attained during the day. DVM was absent or reduced when predators were absent and well developed in their presence. Species of the Daphnia are one of the well investigated group in freshwater environments. Variation in DVM of Daphnia in response to fish kairomone is one of the best studied behavioral strategies. Kairomone, as a term, is described interspecific chemical messengers, the adaptive benefit of which falls on the recipient rather than the emitter. As a result, nature and origin of kairomone is still unclear and needs to be investigated. It was decided that FT-IR technique would be favorable tool for this aim. In this frame, it was conceived that the occurrence of migration adaptation relevant to the seasonal changes in the presence of fish kairomone could be proved and characterized by FT-IR technique. Results of the present study indicate that non-aromatic, secondary amine compound has significant contribution to fish cue. Since other sources other than fish can contribute the natural amine compounds level in fresh water environment, origin and concentration of amines are needed further investigation to determine ecological function of amine.
30

Studium molekulární struktury různých forem vodivých polymerů metodami FTIR a Ramanovy spektroskopie / The Study of the Molecular Structure of Various Forms of Conducting Polymers using FTIR and Raman Spectroscopies

Morávková, Zuzana January 2013 (has links)
In this Thesis, the structure of thin films formed by a conducting polymer, polyaniline, was studied using mainly infrared and Raman spectroscopies. That led to the study of aniline oligomers. The oligomers play a key role in the formation of thin films and nanostructures of polyaniline. Furthermore, the Thesis deals with the carbonization of various forms of polyaniline (granular polyaniline base, thin films of polyaniline salt, multi-wall carbon nanotubes coated with polyaniline salt or base, polyaniline nanotubes/nanorods prepared in the presence of ethanol). The two topics, aniline oligomers and carbonization of polyaniline, are connected by a paper concerning the carbonization of microspheres formed during oxidation of aniline in alkaline medium. Optical microscopy, transmission and scanning electron microscopy, UV-Vis spectroscopy, spectroscopic ellipsometry, wide angle X-ray scattering and thermogravimetric analysis were used.

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