Papers by Feride Severcan
The Turkish Journal Of Occupational / Environmental Medicine and Safety, Jun 5, 2015
Murine macrophage-like RAW 264.7 cells studied with ATR-FTIR. Control group was treated with phos... more Murine macrophage-like RAW 264.7 cells studied with ATR-FTIR. Control group was treated with phosphate-buffered saline (0.9% PBS; Sigma, USA), CpG DNA stimulated group was treated with 1 µM K3 ODN (Endotoxin-free; Integrated DNA Technologies, Belgium), and LPS stimulated group was treated with 0.5 µg/ml LPS (Sigma, USA). Four different times points following treatment were used for measurements to evaluate the kinetics of induced effects: 10 min, 30 min, 2 h, and 6 h.
The HKU Scholars Hub (University of Hong Kong), Nov 24, 2013
Zhengyuan Xia had served as a Cardiovascular Anesthetist for more than 10 years in China before h... more Zhengyuan Xia had served as a Cardiovascular Anesthetist for more than 10 years in China before he completed his Ph.D. study at the University of British Columbia (UBC), in Canada in 2004 and postdoctoral studies at UBC
IOS Press eBooks, Jun 1, 2012
Biophysical Journal, 2015
Journal of Biomedical Optics, Jul 25, 2013
The disease-and drug-related bone disorders are rapidly increasing in the population. It is previ... more The disease-and drug-related bone disorders are rapidly increasing in the population. It is previously reported that anti-epileptic drugs (AEDs) may cause osteopenia, osteoporosis, and fractures in epilepsy patients. However, it cannot be determined whether the bone disorders in epileptic patients are due to AED therapy and/or to epilepsy and epileptic seizures. There is no study in the literature which investigates the sole effects of epilepsy and epileptic seizures on bone tissues. The current study provides the first report on determination of the possible effects of epilepsy and epileptic seizures on long bone tissues. Wistar Albino Glaxo/Rijswijk rats, which are accepted as genetic rat models for human absence epilepsy, were compared with the healthy Wistar rats to get information about the sole effects of epilepsy and epileptic seizures on bones. Cortical regions of tibia and femur bones were studied by Fourier transform infrared microspectroscopy (FTIRM). According to FTIRM parameters, variation on bone mineral and matrix composition, including decreased mineral content, decreased collagen cross-links, increased carbonate substitution, and larger crystals in epileptic group compared to the healthy one, show severe effects of epilepsy and seizures on bone tissues for the first time.
Journal of Biophotonics, Jan 27, 2017
Biochimica Et Biophysica Acta: Molecular Basis Of Disease, Oct 1, 2022
Bioscience Reports, Aug 1, 1989
The effect of α-tocopherol (αT) on partitioning and fluidity changes occurring in phospholipid li... more The effect of α-tocopherol (αT) on partitioning and fluidity changes occurring in phospholipid liposomes have been investigated by monitoring the X-band ESR spectrum of the high resolution amphiphilic spin probe perdeutero-di-t-butyl nitroxide (PDDTBN), which partitions in the lipid and water phase of liposomes, showing all the three resonances from each phase well resolved.
InTech eBooks, May 30, 2018
Adipose tissue is a metabolically active endocrine organ having a distribution in a variety of lo... more Adipose tissue is a metabolically active endocrine organ having a distribution in a variety of locations in whole body; therefore, it is crucial to understand the adipocyte metabolism in health and disease. Spectroscopic techniques such as Fourier transform infrared (FTIR), Raman, nuclear magnetic resonance (NMR) are widely used to characterize biological systems by monitoring cellular molecules such as lipids, carbohydrates, and proteins. Obesity or insulin resistance-induced molecular alterations in adipose tissue can be detected using these techniques. Spectral imaging of adipose tissue provides high-quality information involving molecular compositional, structural, and functional alterations for characterization and differentiation of adipocytes (brown, white) in different adipose tissue regions (visceral, subcutaneous, etc.). In this chapter, applications of spectroscopic and spectral imaging techniques for characterization and differentiation of various adipose tissues will be discussed, which will shed light to better understand adipose tissue metabolism and provide new insight into diagnosis and treatment of some metabolic diseases such as obesity.
Spectroscopy, 2002
In the present work, the interaction of calcium-phosphate with DPPC (dipalmitoyl phosphatidylchol... more In the present work, the interaction of calcium-phosphate with DPPC (dipalmitoyl phosphatidylcholine) model membranes has been studied in the presence and absence of vitamin D2 by using Fourier Transform Infrared (FTIR) spectroscopy. Calcium and phosphorus are the most abundant elements in the body. They combine in the form of calcium phosphate salt, called hydroxyapatite. Hydroxyapatite is the major structural component of the bone. Calcium phosphate assists with the digestion and absorption of food and is vitally important for the building of sturdy bone and body structures and a robust constitution. Phosphorus is extracted from foods and its use is controlled by vitamin D and calcium. FTIR spectral analysis results suggested that, calcium-phosphate complex, which is the major component of the bones, decreases the phase transition temperature to lower values, causes a loss in cooperativity of the acyl chains, decreases the order of the membrane in both phases and decreases the dynamics of the membrane in the liquid crystalline phase, increases the flexibility of the chains in the center of the bilayer in both phases, and increases the mobility of the head group of DPPC in the gel phase. The effect of calcium-phosphate on DPPC liposomes diminishes with the addition of vitamin D2 into the liposomes. Our results suggest how calcium-phosphate and/or vitamin D2, which have indispensable role for the functioning of the bone tissue, affect the thermal behaviour of DPPC liposomes at molecular level.
Chemistry and Physics of Lipids, Mar 1, 1990
An investigation into the effect of alpha-tocopherol on phospholipid model membranes has been car... more An investigation into the effect of alpha-tocopherol on phospholipid model membranes has been carried out by electron spin resonance (ESR) and saturation transfer ESR. The use of stearic acid and of perdeutero -di-t-butyl nitroxide spin probes has allowed us to monitor, in particular, the effect of alpha-tocopherol on both the phospholipid chain order and the phospholipid chain mobility. The results obtained are mainly consistent with a differing action of alpha-tocopherol in the gel and in the liquid crystalline phases: in the former it induces a decrease of order and an increase in fluidity; while in the latter phase an indication of a slight increase in ordering and a clear decrease in fluidity are registered.
Chemistry and Physics of Lipids, Jun 1, 1988
The high resolution (narrow linewidth) amphiphilic spin probe perdeutero all-t-butyl nitroxide (P... more The high resolution (narrow linewidth) amphiphilic spin probe perdeutero all-t-butyl nitroxide (PDDTBN) has been used to investigate the effect of a-tocopherol on lecithin liposomes. The electron spin resonance (ESR) results obtained as a function both of a-tocopherol concentration and of temperature indicate the presence of two different hydrophobic sites for the spin probe molecules. The presence of two distinct phases, one a-tocopherol-poor and the other a-tocopherol-rich, is suggested in these phosphofipid bilayers.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2018
Rapid, cost-effective, sensitive and accurate methodologies to classify bacteria are still in the... more Rapid, cost-effective, sensitive and accurate methodologies to classify bacteria are still in the process of development. The major drawbacks of standard microbiological, molecular and immunological techniques call for the possible usage of infrared (IR) spectroscopy based supervised chemometric techniques. Previous applications of IR based chemometric methods have demonstrated outstanding findings in the classification of bacteria. Therefore, we have exploited an IR spectroscopy based chemometrics using supervised method namely Soft Independent Modeling of Class Analogy (SIMCA) technique for the first time to classify heavy metal-exposed bacteria to be used in the selection of suitable bacteria to evaluate their potential for environmental cleanup applications. Herein, we present the powerful differentiation and classification of laboratory strains (Escherichia coli and Staphylococcus aureus) and environmental isolates (Gordonia sp. and Microbacterium oxydans) of bacteria exposed to growth inhibitory concentrations of silver (Ag), cadmium (Cd) and lead (Pb). Our results demonstrated that SIMCA was able to differentiate all heavy metal-exposed and control groups from each other with 95% confidence level. Correct identification of randomly chosen test samples in their corresponding groups and high model distances between the classes were also achieved. We report, for the first time, the success of IR spectroscopy coupled with supervised chemometric technique SIMCA in classification of different bacteria under a given treatment.
Analytical Biochemistry, Sep 1, 2004
Secondary structures of proteins have been predicted using neural networks from their Fourier tra... more Secondary structures of proteins have been predicted using neural networks from their Fourier transform infrared spectra. To improve the generalization ability of the neural networks, the training data set has been artificially increased by linear interpolation. The leave-one-out approach has been used to demonstrate the applicability of the method. Bayesian regularization has been used to train the neural networks and the predictions have been further improved by the maximum-likelihood estimation method. The networks have been tested and standard error of prediction (SEP) of 4.19% for a helix, 3.49% for b sheet, and 3.15% for turns have been achieved. The results indicate that there is a significant decrease in the SEP for each type of structure parameter compared to previous works.
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Papers by Feride Severcan