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5-Methylhydantoin: From isolated molecules in a low-temperature Aaon matrix to solid state polymorphs characterization
(2017-12) Öğrüç Ildız, Gülce; Nogueira, Bernardo.A.; Canotilho J.; Eusébio MES; Henriques MSC; Paixão JA; Fausto R.
The molecular structure, vibrational spectra and photochemistry of 5-methylhydantoin (C4H6N2O2; 5-MH) were studied by matrix isolation infrared spectroscopy and theoretical calculations at the DFT(B3LYP)/6-311++G(d,p) theory level. The natural bond orbital (NBO) analysis approach was used to study in detail the electronic structure of the minimum energy structure of 5-MH, namely the specific characteristics of the σ and π electronic systems of the molecule and the stabilizing orbital interactions. UV irradiation of 5-MH isolated in argon matrix resulted in its photofragmentation through a single photochemical pathway, yielding isocyanic acid, ethanimine, and carbon monoxide, thus following a pattern already observed before for the parent hydantoin and 1-methylhydantoin molecules. The investigation of the thermal properties of 5-MH was undertaken by differential scanning calorimetry (DSC), polarized light thermal microscopy (PLTM) and Raman spectroscopy. Four different polymorphs of 5-MH were identified. The crystal structure of one of the polymorphs, for which it was possible to grow up suitable crystals, was determined by X-ray diffraction (XRD). Two of the additional polymorphs were characterized by powder XRD, which confirmed the molecules pack in different crystallographic arrangements.
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5-Methylhydantoin: from isolated molecules in a low-temperature argon matrix to solid state polymorphs characterization
(Amer Chemical Soc, 1155 16th St, Nw, Washington, Dc 20036 USA, 2017-07-20) Nogueira, Bernardo A.; Öğrüç Ildız, Gülce; Canotilho, J.; Eusebio, M. E. S.; Henriques, M. S. C.; Paixao, J. A.; Fausto, Rui; 107326
The molecular structure, vibrational spectra and photochemistry of 5-methylhydantoin (C4H6N2O2; 5-MH) were studied by matrix isolation infrared spectroscopy and theoretical calculations at the DFT(B3LYP)/6-311++G(d,p) theory level. The natural bond orbital (NBO) analysis approach was used to study in detail the electronic structure of the minimum energy structure of 5-MH, namely the specific characteristics of the sigma and pi electronic systems of the molecule and the stabilizing orbital interactions. UV irradiation of 5-MH isolated in argon matrix resulted in its photofragmentation through a single photochemical pathway, yielding isocyanic acid, ethanimine, and carbon monoxide, thus following a pattern already observed before for the parent hydantoin and 1-methylhydantoin molecules. The investigation of the thermal properties of 5-MH was undertaken by differential scanning calorimetry (DSC), polarized light thermal microscopy (PLTM) and Raman spectroscopy. Four different polymorphs of 5-MH were identified. The crystal structure of one of the polymorphs, for which it was possible to grow up suitable crystals, was determined by X-ray diffraction (XRD). Two of the additional polymorphs were characterized by powder XRD, which confirmed the molecules pack in different crystallographic arrangements.
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A breakthrough in neuroscience needs a "Nebulous Cartesian System" Oscillations, quantum dynamics and chaos in the brain and vegetative system
(ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2007-04) Başar, Erol; Güntekin, Bahar; TR142226; TR204666
The Cartesian System is a fundamental conceptual and analytical framework related and interwoven with the concept and applications of Newtonian Dynamics. In order to analyze quantum processes physicist moved to a Probabilistic Cartesian System in which the causality principle became a probabilistic one. This means the trajectories of particles (obeying quantum rules) can be described only with the concept of cloudy wave packets. The approach to the brain-body-mind problem requires more than the prerequisite of modem physics and quantum dynamics. In the analysis of the brain-body-mind construct we have to include uncertain causalities and consequently multiple uncertain causalities. These multiple causalities originate from (1) nonlinear properties of the vegetative system (e.g. irregularities in biochemical transmitters, cardiac output, turbulences in the vascular system, respiratory apnea, nonlinear oscillatory interactions in peristalsis); (2) nonlinear behavior of the neuronal electricity (e.g. chaotic behavior measured by EEG), (3) genetic modulations, and (4) additional to these physiological entities nonlinear properties of physical processes in the body. The brain shows deterministic chaos with a correlation dimension of approx. D-2=6, the smooth muscles approx. D-2=3. According to these facts we propose a hyper-probabilistic approach or a hyper-probabilistic Cartesian System to describe and analyze the processes in the brain-body-mind system. If we add aspects as our sentiments, emotions and creativity to this construct, better said to this already hyper-probabilistic construct, this "New Cartesian System" is more than hyper-probabilistic, it is a nebulous system, we can predict the future only in a nebulous way; however, despite this chain of reasoning we can still provide predictions on brain-body-mind incorporations. We tentatively assume that the processes or mechanisms of the brain-body-mind system can be analyzed and predicted similar to the metaphor of '' finding the walking path in a cloudy or foggy day". This is meant by stating "The Nebulous Cartesian System" (NCS). Descartes, at his time undertaking his genius step, did not possess the knowledge of today's physiology and modem physics; we think that the time has come to consider such a New Cartesian System. To deal with this, we propose the utilization of the Heisenberg S-Matrix and a modified version of the Feynman Diagrams which we call "Brain Feynman Diagrams". Another metaphor to consider within the oscillatory approach of the NCS is the "string theory". We also emphasize that fundamental steps should be undertaken in order to create the own dynamical framework of the brain-body-mind incorporation; suggestions or metaphors from physics and mathematics are useful; however, the grammar of the brains intrinsic language must be understood with the help of a new biologically founded, adaptive-probabilistic Cartesian system. This new Cartesian System will undergo mutations and transcend to the philosophy of Henri Bergson in parallel to the Evolution theory of Charles Darwin to open gateways for approaching the brain-body-mind problem. (c) 2006 Published by Elsevier B.V.
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A comparison of Gordon's functional health patterns model and standard nursing care in symptomatic heart failure patients: A randomized controlled trial
(W.B. Saunders, 2020-06) Türen, Sevda; Enç, Nuray
Background Heart failure (HF) is associated with poor quality of life and increased morbidity and mortality. Aim This study aimed to investigate effect of application of Gordon's functional health pattern (FHP) model in nursing care of symptomatic HF patients on quality of life, morbidity and mortality in the post-discharge 30-day. Methods This is a prospective randomized controlled study conducted in a single center. Experimental group received nursing care planned in accordance with Gordon's FHP model. 60 control and 60 experimental HF patients were included in the study. In the control group nursing care was given according to the standard protocol of the hospital whereas in the experimental group nursing care was given in accordance with Gordon's FHP model. Patients in both groups were followed up after discharge at 30th day. Results Mean Minnesota Living with Heart Failure Questionnaire score improved significantly in the experimental group compared to the control group at 30th day (40.2 ± 23.5 vs 62.3 ± 22.9 respectively, p = 0.001). Seven patients (11.7%) in the experimental group and 17 patients (28.3%) in the control group were readmitted in the post discharge 30-day (p = 0.02). Kaplan-Meier survival curve analysis revealed significant difference in 30-day event free survival rates between groups (log-rank p = 0.31). Conclusion Application of Gordon's FHP model in the nursing care of HF patients was associated with significantly improved quality of life, and reduced hospital readmission rates at 30th day. This was the only independent predictor of 30-day event free survival.
Ambargolu
A decision support system to determine optimal ventilator settings
(Biomed Central Ltd, 236 Grays Inn Rd, Floor 6, London Wc1X 8Hl, England, 2014) Patlar Akbulut, Fatma; Akkur, Erkan; Akan, Aydın; Yarman, B. Sıddık
Background: Choosing the correct ventilator settings for the treatment of patients with respiratory tract disease is quite an important issue. Since the task of specifying the parameters of ventilation equipment is entirely carried out by a physician, physician ' s knowledge and experience in the selection of these settings has a direct effect on the accuracy of his/her decisions. Nowadays, decision support systems have been used for these kinds of operations to eliminate errors. Our goal is to minimize errors in ventilation therapy and prevent deaths caused by incorrect configuration of ventilation devices. The proposed system is designed to assist less experienced physicians working in the facilities without having lung mechanics like cottage hospitals. Methods: This article describes a decision support system proposing the ventilator settings required to be applied in the treatment according to the patients ' physiological information. The proposed model has been designed to minimize the possibility of making a mistake and to encourage more efficient use of time in support of the decision making process while the physicians make critical decisions about the patient. Artificial Neural Network (ANN) is implemented in order to calculate frequency, tidal volume, FiO(2) outputs, and this classification model has been used for estimation of pressure support /volume support outputs. For the obtainment of the highest performance in both models, different configurations have been tried. Various tests have been realized for training methods, and a number of hidden layers mostly affect factors regarding the performance of ANNs. Results: The physiological information of 158 respiratory patients over the age of 60 and were treated in three different hospitals between the years 2010 and 2012 has been used in the training and testing of the system. The diagnosed disease, core body temperature, pulse, arterial systolic pressure, diastolic blood pressure, PEEP, PSO2, pH, pCO(2), bicarbonate data as well as the frequency, tidal volume, FiO(2), and pressure support / volume support values suitable for use in the ventilator device have been recommended to the physicians with an accuracy of 98,44%. Performed experiments show that sequential order weight/bias training was found to be the most ideal ANN learning algorithm for regression model and Bayesian regulation backpropagation was found to be the most ideal ANN learning algorithm for classification models. Conclusions: This article aims at making independent of the choice of parameters from physicians in the ventilator treatment of respiratory tract patients with proposed decision support system. The rate of accuracy in prediction of systems increases with the use of data of more patients in training. Therefore, non-physician operators can use systems in determination of ventilator settings in case of emergencies.
Açık Erişim
A New Interpretation Of P300 Responses Upon Analysis Of Coherences
(Springer, Van Godewijckstraat 30, 3311 Gz Dordrecht, Netherlands, 2010-06) Güntekin, Bahar; Başar, Erol; TR142226; TR204666
Previous studies on cognitive dynamics showed that oscillatory responses of P300 are composed of mainly delta and theta responses. In the present study, for the first time, the long-distance intra-hemispheric event related coherence (auditory oddball paradigm) and evoked coherence (simple sound) were compared in order to evaluate the effects of cognitive tasks on the long-distance coherences. Seventeen healthy subjects (8 female, 9 male) were included in the study. The coherence was analyzed for delta (1-3.5 Hz), theta (4-7.5 Hz) and alpha (8-13 Hz) frequency ranges for (F(3)-P(3), F(4)-P(4), F(3)-T(7), F(4)-T(8), F(3)-O(1,) F(4)-O(2)) electrode pairs. The coherence to target responses were higher than the non-target and simple auditory response coherence. This difference is significant for the delta coherence for both hemispheres and for theta coherences over the left hemisphere. The highest coherences were recorded at fronto-temporal locations for all frequency bands (delta, theta, alpha). Furthermore, fronto-parietal coherences were higher than the fronto-occipital coherences for all frequency bands (delta, theta, alpha).These results show that the fronto-temporal and fronto-parietal connections are most relevant for the identification of the target signal. This analysis open the way for a new interpretation of dynamic localization results during cognitive tasks.
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A novel EOG-based wireless rapid communication device for people with motor neuron diseases
(Taylor and Francis Online, 2018-11-22) Uşaklı, Ali Bülent; Gürkan, Serkan; Gürkan, Güray; 118889; 244333; 113297
In this study, a new electrooculography (EOG) based system that provides efficient communication for people suffered from motor neuron diseases is presented. The system consists of two distinct devices. The first device operates as a main unit that is activated by the subject’s eye movements. This unit is capable of transmitting 10 different command/state messages. These messages enable subject to choose his/her situation such as “I’m fine”, “I feel bad”, “I’m hungry” and “I’m thirsty”. Commands such as “Come”, “Go”. The number of messages can be increased. The main unit acquires the EOG signal from the subject. Newly developed analogue and digital signal conditioning interprets the eye movements as specific messages and transmits them to the second unit (receiver) using radio frequency transmitter. The messages related to the subject’s demands and situation can be heard from both main and receiver unit speakers. The wireless receiver unit is capable of notifying the patient’s command by auditory and visual indicators. The realised device was tested by 2 healthy and 2 ALS patients and confirmed to be successful with 100% performance for sending correct messages.
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A review of alpha activity in integrative brain function: Fundamental physiology, Sensory coding, cognition and pathology
(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2012-10) Başar, Erol; TR142226
Aim of the review: Questions related to the genesis and functional correlates of the brain's alpha oscillations around 10 Hz (Alpha) are one of the fundamental research areas in neuroscience. In recent decades, analysis of this activity has been not only the focus of interest for description of sensory-cognitive processes, but has also led to trials for establishing new hypotheses. The present review and the companion review aim to constitute an ensemble of "reasonings and suggestions" to understand alpha oscillations based on a wide range of accumulated findings rather than a trial to launch a new "alpha theory". Surveyed descriptions related to physiology and brain function: The review starts with descriptions of earlier extracellular recordings, field potentials and also considers earlier alpha hypotheses. Analytical descriptions of evoked and event-related responses, event-related desynchronization, the relationship between spontaneous activity and evoked potentials, aging brain, pathology and alpha response in cognitive impairment are in the content of this review. In essence, the gamut of the survey includes a multiplicity of evidence on functional correlates in sensory processing, cognition, memory and vegetative system, including the spinal cord and heart. (C) 2012 Elsevier B.V. All rights reserved.
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A review of brain oscillations in cognitive disorders and the role of neurotransmitters
(ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2008-10-15) Başar, Erol; Güntekin, Bahar; TR142226; TR204666
The analysis of the functional correlates of "brain oscillations" has become an important branch of neuroscience. Although research on the functional correlates of brain oscillation has progressed to a high level, studies on cognitive disorders are rare and mainly limited to schizophrenia patients. The present review includes the results of the changes in brain oscillations in patients with Alzheimer's, schizophrenia, bipolar disorders, mild cognitive impairment, attention-deficit hyperactivity disorder (ADHD), alcoholism and those with genetic disorders. Furthermore, the effects of pharmaca and the influence of neurotransmitters in patients with cognitive disorders are also reviewed. Following the review, a short synopsis is given related to the analysis of brain oscillations. (c) 2008 Elsevier B.V. All rights reserved.
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A Review of Brain Oscillations in Perception of Faces and Emotional Pictures
(Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1Gb, England, 2014-05) Güntekin, Bahar; Başar, Erol; 204666; 142226
The differentiation of faces, facial expressions and affective pictures involves processes of higher mental activity that have considerable applications in the psychology of moods and emotions. At present, the search for functional correlates of brain oscillations is an important trend in neuroscience. Furthermore, analyses of oscillatory responses provide key knowledge on the physiology of brain dynamics. Studies analysing oscillatory dynamics in face perception and emotional pictures have increased in recent years; however, the literature lacks a review of the current state of the art. This study provides a comprehensive review of the delta, theta, alpha, beta and gamma oscillatory responses on presentation of faces, facial expressions and affective pictures (International Affective Picture System, IAPS). The reviewed literature revealed that the brain is more sensitive to emotional stimuli than neutral stimuli. A common and reliable finding from all reviewed studies was the increased brain responsiveness towards negative emotional pictures (face expression or IAPS). (C) 2014 Elsevier Ltd. All rights reserved.
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A Review of Gamma Oscillations in Healthy Subjects and in Cognitive Impairment
(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2013-11) Başar, Erol; 142226
This review describes a wide range of functional correlates of gamma oscillations in whole-brain work, in neuroethology, sensory-cognitive dynamics, emotion, and cognitive impairment. This survey opens a new window towards understanding the brain's gamma activity. Gamma responses are selectively distributed in the whole brain, and do not reflect only a unique, specific function of the nervous system. Sensory responses from cortex, thalamus, hippocampus, and reticular formations in animal and human brains, and also cognitive responses, were described by several authors. According to reviewed results, it becomes obvious that cognitive disorders, and medication which influence the transmitter release change entirely the understanding of the big picture in cognitive processes. Gamma activity is evoked or induced by different sensory stimuli or cognitive tasks. Thus, it is argued that gamma-band synchronization is an elementary and fundamental process in whole-brain operation. In conclusion, reasoning and suggestions for understanding gamma activity are highlighted. (C) 2013 Elsevier B.V. All rights reserved.
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A short review of alpha activity In cognitive processes and in cognitive impairment
(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2012-10) Başar, Erol; Güntekin, Bahar; TR142226; TR204666
Aim of the report: In the companion report (Basar, this volume), the physiological fundaments of alpha activity in integrative brain function are described. The present report is a review of the significant role of alpha activity in memory and cognitive processes in healthy subjects, and in cognitive impairment. The role of neurotransmitters is also described, briefly, in this context. Towards an understanding of brain alpha: Despite numerous experimental studies, it is indicated that the presented results are only appropriate to establish an ensemble of reasonings and suggestions for analyzing "alphas" in the whole brain. In turn, in the near future, these reasonings and suggestions may serve (or are indispensable to serve) as fundaments of more general and tenable hypotheses on the genesis and function of "alphas". (C) 2012 Elsevier B.V. All rights
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A vibrational spectroscopy study on 3-aminophenylacetic acid by DFT calculations
(Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1Gb, England, 2015-08-05) Akkaya, Yasemin; Balcı, Kubilay; Gören, Yeliz; Akyüz, Sevim; 175409; 54889; 263178; 10127
In this study, in which the group vibrations of 3-aminophenylacetic acid were investigated by electronic structure calculations based on Density Functional Theory (DFT), the possible stable conformers of the molecule were searched through a relaxed "potential energy surface scan" carried out at B3LYP/6-31G(d) level of theory. The corresponding equilibrium geometrical and vibrational spectral data for each of the determined stable conformers and for their ipossible dimer structures were obtained through "geometry optimisation" and "frequency" calculations carried out at B3LYP/6-31G(d) and B3LYP/6-311G++(d,p) levels of theory. The obtained results confirmed that anharmonic wavenumbers calculated at B3LYP/6-311G++(d,p) level generally quite well agree with the experimental wavenumbers, however, harmonic wavenumbers calculated at both levels of theory need an efficient refinement for a satisfactory agreement with experiment. In particular, the harmonic wavenumbers, IR and Raman intensities refined within Scaled Quantum Mechanical Force Field (SQM FF) methodology constituted the primary data set in the interpretatiori of the experimental FT-IR, FT-Raman and dispersive Raman spectra of 3-aminophenylacetic acid. By the help of these refined spectral data, the effects of conformation and intermolecular hydrogen bonding on the fundamental bands observed in the experimental spectra could be correctly predicted. (C) 2015 Elsevier B.V. All rights reserved.
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A Vibrational Spectroscopy Study on Anserine and Its Aqueous Solutions
(Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1Gb, England, 2015-10-05) Akkaya, Yasemin; Balcı, Kubilay; Gören, Yeliz; Akyüz, Sevim; Stricker, Moogega C.; Ritzhaupt, G.; Stover, D. D.; Collier, W. B.; 175409; 54889; 10127
In this study based on vibrational spectroscopic measurements and Density Functional Theory (OFF), we aimed for a reliable interpretation of the IR and Raman spectra recorded for anserine in the solid phase and water (H2O) and heavy water (D2O) solutions. Initial DFT calculations at the B3LYP/6-31G(d) searched possible conformers of the anserine zwitterion using a systematic conformational search. The corresponding equilibrium geometrical parameters and vibrational spectral data were determined for each of the stable conformers (in water) by the geometry optimization and hessian calculations performed at the same level of theory using the polarized continuum model (PCM). The same calculations were repeated to determine the most energetically preferred dimer structure for the molecule and the associated geometry, force field and vibrational spectral data. The harmonic force constants obtained from these calculations were scaled by the Scaled Quantum Mechanical Force Field (SQM) method and then used in the calculation of the refined wavenumbers, potential energy distributions, IR and Raman intensities. These refined theoretical data, which confirm the zwitterion structure for anserine in the solid phase or aqueous solvents, revealed the remarkable effects of intermolecular hydrogen bonding on the structural properties and observed IR and Raman spectra of this molecule. (C) 2015 Elsevier B.V. All rights reserved.
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Activation of polyamine catabolic enzymes involved in diverse responses against epibrassinolide-induced apoptosis in LNCaP and DU145 prostate cancer cell lines
(Springer Wien, Sachsenplatz 4-6, Po Box 89, A-1201 Wien, Austria, 2014-03) Obakan, Pınar; Arısan, Elif Damla; Palavan Unsal, Narçin; Calcabrini, Annarica; Agostinelli, Enzo; Bolkent, Şehnaz; 156421; 113920; 6125; 3894
Epibrassinolide (EBR) is a biologically active compound of the brassinosteroids, steroid-derived plant growth regulator family. Generally, brassinosteroids are known for their cell expansion and cell division-promoting roles. Recently, EBR was shown as a potential apoptotic inducer in various cancer cells without affecting the non-tumor cell growth. Androgen signaling controls cell proliferation through the interaction with the androgen receptor (AR) in the prostate gland. Initially, the development of prostate cancer is driven by androgens. However, in later stages, a progress to the androgen-independent stage is observed, resulting in metastatic prostate cancer. The androgen-responsive or -irresponsive cells are responsible for tumor heterogeneity, which is an obstacle to effective anti-cancer therapy. Polyamines are amine-derived organic compounds, known for their role in abnormal cell proliferation as well as during malignant transformation. Polyamine catabolism-targeting agents are being investigated against human cancers. Many chemotherapeutic agents including polyamine analogs have been demonstrated to induce polyamine catabolism that depletes polyamine levels and causes apoptosis in tumor models. In our study, we aimed to investigate the mechanism of apoptotic cell death induced by EBR, related with polyamine biosynthetic and catabolic pathways in LNCaP (AR+), DU145 (AR-) prostate cancer cell lines and PNT1a normal prostate epithelial cell line. Induction of apoptotic cell death was observed in prostate cancer cell lines after EBR treatment. In addition, EBR induced the decrease of intracellular polyamine levels, accompanied by a significant ornithine decarboxylase (ODC) down-regulation in each prostate cancer cell and also modulated ODC antizyme and antizyme inhibitor expression levels only in LNCaP cells. Catabolic enzymes SSAT and PAO expression levels were up-regulated in both cell lines; however, the specific SSAT and PAO siRNA treatments prevented the EBR-induced apoptosis only in LNCaP (AR+) cells. In a similar way, MDL 72,527, the specific PAO and SMO inhibitor, co-treatment with EBR during 24 h, reduced the formation of cleaved fragments of PARP in LNCaP (AR+) cells.
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Adsorption Of Isoniazid Onto Sepiolite-Palygorskite Group Of Clays: An IR Study
(Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1Gb, England, 2010-04) Akyüz, Sevim; Akyüz, Tanıl; Akalın, Elif; TR10127; TR111424; TR46357
The adsorption of isoniazid (INH) on sepiolite, loughlinite (natural Na-sepiolite) and palygorskite from Anatolia was investigated by FT-IR spectroscopy. Experimental results indicated that INH molecules, adsorbed on sepiolite-palygorskite group of clays, are coordinated to surface hydroxyls by H-bonding interaction through the pyridine ring nitrogen lone pairs. Moreover, some of the adsorbed INH molecules may enter the interior channels of the sepiolite-palygorskite structure and involve H-bonding interaction with zeolitic water. Some intensity and frequency changes in the OH stretching band of surface hydroxyls (Si-OH) of the INH-treated sepiolite and loughlinite were observed. However, this band is found to be less affected by the adsorption of isoniazid in the case of palygorskite, probably because the surface Si-OH groups in palygorskite appear to be less abundant than in sepiolite or loughlinite. (C) 2010 Elsevier B.V. All rights reserved.
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Affective pictures processing is reflected by an increased long-distance EEG connectivity
(Springer, Van Godewijckstraat 30, 3311 Gz Dordrecht, Netherlands, 2017-08) Güntekin, Bahar; Femir, Banu; Turp Gölbaşı, Bilge; Tülay, Elif; Başar, Erol; 204666; 142226
Analysis of affective picture processing by means of EEG has invaded the literature. The methodology of event-related EEG coherence is one of the essential methods used to analyze functional connectivity. The aims of the present study are to find out the long range EEG connectivity changes in perception of different affective pictures and analyze gender differences in these long range connected networks. EEGs of 28 healthy subjects (14 female) were recorded at 32 locations. The participants passively viewed emotional pictures (IAPS, unpleasant, pleasant, neutral). The long-distance intra-hemispheric event-related coherence was analyzed for delta (1-3.5 Hz), theta (4-7.5 Hz), and alpha (8-13 Hz) frequency ranges for F-3-T-7, F-4-T-8, F-3-TP7, F-4-TP8, F-3-P-3, F-4-P-4, F-3-O-1, F-4-O-2, C-3-O-1, C-4-O-2 electrode pairs. Unpleasant pictures elicited significantly higher delta coherence values than neutral pictures (p < 0.05), over fronto-parietal, fronto-occipital, and centro-occipital electrode pairs. Furthermore, unpleasant pictures elicited higher theta coherence values than pleasant (p < 0.05) and neutral pictures (p < 0.05). The present study showed that female subjects had higher delta (p < 0.05) and theta (p < 0.05) coherence values than male subjects. This difference was observed more for emotional pictures than for neutral pictures. This study showed that the brain connectivity was higher during emotional pictures than neutral pictures. Females had higher connectivity between different parts of the brain than males during emotional processes. According to these results, we may comment that increased valence and arousal caused increased brain activity. It seems that not just single sources but functional networks were also activated during perception of emotional pictures.
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Analysis of linear lung models based on state-space models
(Elsevier Ireland Ltd., 2020-01) Saatçi, Esra; Saatçi, Ertuğrul; Akan, Aydın
Background and Objectives: Linear parametric respiratory system models have been used in the model-based analysis of the respiratory system. Although there are studies exploring the physiological correctness and fitting accuracy of the models, they are not analysed in terms of interaction between parameters and dynamics of the model. In this study we propose to use state-space modelling to yield the time-varying nature of the system incorporated by the parameters. Methods: We tested controllability, observability and stability characteristics of the equation of motion, 2-comp. parallel, 2-comp. series, viscoelastic, 6-element and mead models while using the parameters given in the literature. In the sensitivity analysis we proposed to use dual Desensitized Linear Kalman Filter (DKF) and Extended Kalman Filter (EKF) method. In this method, state error covariance revealed the parameter sensitivities for each model. Results: Results showed that all models, except 2-comp. parallel and mead models, are both controllable and observable models. On the other hand all models, except mead model, are stable models. Regarding to the sensitivity analysis, dual DKF - EKF method estimated states of the models successfully with a low estimation error. Sensitivity analysis results showed that airway parameters have higher effects on the state estimation than the other parameters have. Conclusion: We proved that state-space evaluation of the previously proposed parametric models of the respiratory system led us to quantitative and qualitative assessments of the respiratory models. Moreover parameter values found in the literature have different effects on the models. (C) 2019 Elsevier B.V. All rights reserved.
Kısıtlı
Analyzing the Wastewater Treatment Facility Location/Network Design Problem via System Dynamics: Antalya, Turkey Case
(Academic Press Ltd. - Elsevier Science Ltd., 2022) DEMİREL, DUYGUN FATİH; Gönül-Sezer, Eylül Damla; Pehlivan, Seyda Alperen
Wastewater treatment facility location selection and network design issues have become attractive topics in the field of wastewater management due to increasing human population, resource scarcity, environmental concerns, and rise of necessity for sustainable solutions for future policy designs. Especially in areas where the demand for wastewater treatment increases dramatically over the years because of reasons such as high migration levels, rapid industrialization, and tourism activities, the problem turns out to be more critical and dynamic. The existing studies try to deal with the issue through mathematical modeling approaches based on optimization perspectives, which require significant computational effort. In this study, an alternative approach based on system dynamics (SD) method is proposed to examine the complex dynamic and nonlinear structure of waste-water treatment facility location selection and network design problems. The proposed SD simulation model is designed for a densely populated industrial and tourism spot, the city of Antalya, located on the Mediterranean coast of Turkey. The model is capable of determining where and when to build a new wastewater treatment facility as well as generating the generic wastewater network structure to be built for the five districts situated in the city center based on cost issues for 2015-2040 period. In addition, the impacts of demand level changes for wastewater treatment due to population variations are analyzed via several scenarios to help decision makers to develop sustainable and cost-efficient management policies. Although SD is a frequently utilized approach in the water/wastewater management arena, to the best of our knowledge, this study is the first attempt to examine the complex and dynamic nature of wastewater treatment facility location selection and network design problems through SD approach.
Kısıtlı
Anxiolytic-Like Effects of Extremely Low Frequency Electric Field in Stressed Rats: Involvement of 5-HT2C Receptors
(Taylor & Francis Ltd., 2022) Kantar, Deniz; Acun, Alev Duygu; AFŞAR, EBRU; Yargıçoğlu, Piraye
Background Possible modulatory effects of noninvasive brain stimulation have gained interest recently. In our study, the effect of low frequency electric fields (LF-EF) on stress-induced electrophysiological, behavioral changes and the possible involvement of serotonergic 5-HT2C receptors were investigated. Materials and methods A total of eight groups including the control groups were formed by applying LF-EF with or without a 5-HT2C receptor agonist to naive or acute stress exposed rats to demonstrate the effects of LF-EF. LF-EF administration at 10 kV/m was started 30 min before acute stress application and lasted for 1 h in total. Anxiety levels and social interaction were evaluated using the elevated plus maze test and social interaction test, respectively. Auditory evoked potentials (AEP) were recorded by using ascending loudness paradigms. Loudness dependence AEP (LDAEP) was calculated by using amplitude values to analyze serotonergic transmission. Serotonin and glucocorticoid levels were measured in the frontal cortex and hippocampus. Results It was observed that the applied LF-EF reduced the anxiety behavior, and attenuated the LDAEP responses in stress and/or 5-HT2C receptor agonist applied groups. In parallel, an increase in serotonin levels and a decrease in glucocorticoid levels were observed. However, LF-EF exposure was ineffective in impaired social interaction. Conclusions Our findings show that 10 kV/m LF-EF administration may modulate the neural network and physiological responses associated with mild acute stress. 5-HT2C receptor dependent functions are thought to play a role in the anxiolytic effect of LF-EF.

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