TR Dizin İndeksli Yayınlar Koleksiyonu / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14365/4
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Article Citation - WoS: 9Citation - Scopus: 9Classical Heart Rate Variability and Non-Linear Heart Rate Analysis in Mice Under Na-Pentobarbital and Ketamine/Xylazine Anesthesia(Tubitak Scientific & Technical Research Council Turkey, 2022-01-01) Kazdagli, Hasan; Ozel, Hasan Fehmi; Ozbek, Mustafa; Alpay, Suheda; Alenbey, MuruvvetBackground/aim: Anesthetics are often used in animal experiments to achieve immobilization and relieve pain. However, many anesthetics can alter the dynamics of cardiovascular systems. We aimed to compare the effects of two frequently used anesthetics agents on heart rate variability (HRV) parameters in mice. Materials and methods: This observational study was performed between May and June 2014 in 21 male BALB/c mice aged 16-20 weeks. The animals were divided into three groups: pentobarbital (P), (n = 7); pentobarbital+fentanyl (P+ F), (n = 7); and ketamine+xylazine (K+X), (n = 7). Surface electrocardiography (ECG) electrodes were placed in lead II configuration. 'the tachogram of RR intervals was obtained after R waves were detected using the Pan-Tompkins real-time QRS recognition algorithm. Frequency-domain, time-domain, and nonlinear HRV analyses were performed. Results: The bradycardia effect was higher in the K+X group (p < 0.01). Time-domain indices were higher in group K+X compared to group P (p < 0.01) and group P+F (p < 0.001). Very low frequency (VLF) power was significantly lower in group K+X compared to group P and group P+F (p < 0.01). Low frequency (LF) power, low frequency/high frequency (LF/HF) ratio, and total power (TP) were higher in group K+X compared to group P (p < 0.01) and group P+F (p < 0.001). The detrended fluctuation analysis short-term parameter (DFA alpha(1)) was significantly higher in group K+X compared to group P+F (p < 0.05) and the long-term parameter (DFA alpha(2)) was lower in group K+X compared to group P (p < 0.05). Standard deviations SD1 and SD2 were higher in group K+X compared to group P (p < 0.001) and group P+F (p < 0.001), SD2/SD1 ratio was lower in group K+X compared to group P (p < 0.05) and group P+F (p < 0.05). Entropy measures did not differ between groups. Conclusion: HRV analyses, including nonlinear methods, indicated that a K+X combination reduces imbalance and disorder in the regulation of the autonomic nervous system (ANS) in comparison to both P and the P+F combination.Article Citation - WoS: 3Citation - Scopus: 6Effects of Bevacizumab Administration on the Hypoxia- Induced Pulmonary Hypertension Rat Model(Tubitak Scientific & Technical Research Council Turkey, 2021-10-21) Demir, Canan; Karaman, Meral; Ucan, Eyup Sabri; Gokmen, Ali Necati; Gurel, Duygu; Coker, Sadiye Canan; Adali, Yasemen; Yilmaz, Osman; Gokmen, Necati; Coker, CananBackground/aim: Bevacizumab is a chemotherapeutic drug, which selectively binds to vascular endothelial growth factor (VEGF) and mainly inhibits angiogenesis and neovascularization. We aimed to study the possible effects of bevacizumab on right ventricular pressure (RVP), right ventricular hypertrophy, and VEGF, in hypoxia -induced pulmonary hypertension (PH) rat model. Materials and methods: 24 adult Wistar Albino rats were randomly divided into four groups: control group -saline; Bevacizumab Group; PH Group; PH + Bevacizumab Group. In hypoxia -induced model, 10% oxygen and 90% nitrogen were applied in a plexiglas box for eight days to PH Group and PH + Bevacizumab Group. On day eight, RVPs were measured directly from the heart, and then animals were sacrificed. Heart and lung tissues were examined, and Fulton index was measured. Results: RVP, Fulton index, and tissue VEGF scores were significantly lower in PH + Bevacizumab group than PH group: median (ranges), RVP, mmHg, 37.8 (33.0-39.0) and 32.3 (28.0-35.0), p: 0.01; Fulton index: 0.30 (0.29-0.33) and 0.25 (0.24-0.26), p: 0.003; tissue VEGF scores: 5.1 (4.8-5.3) and 4.0 (3.8 4.1), p: 0.004, respectively. Conclusion: Bevacizumab, which is indeed an antineoplastic agent, might have a favorable effect on hypoxia -induced pulmonary hypertension.Article Citation - WoS: 5Citation - Scopus: 5The Validity and Reliability of the Turkish Version of the Physical Activity Scale for Individuals With Physical Disabilities (pasipd)(Tubitak Scientific & Technical Research Council Turkey, 2019) Ulas, Kardem; Topuz, Semra; Dinc Horasan, Gonul; Horasan, Gönül DinçBackground/aim: The aim of this study is to assess the validity and reliability of Turkish translation of the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) in a disabled Turkish population. Materials and methods: Following the translation protocol of the PASIPD, the Turkish version of the PASIPD, Short Form-36, and International Physical Activity Questionnaire were administered to 198 developmentally and physically disabled individuals. Results: The Turkish version of the PASIPD was found to be reliable. The domains of the Turkish version of the PASIPD were also found to be valid. Pour factors were obtained from the questionnaire. The ICC was 1.0 since all the respondents reported the same answers in the test and retest. The Cronbach alpha for the PASIPD was 0.60. Conclusion: The Turkish version of the PASIPD survey is valid and reliable for developmentally and physically disabled Turkish individuals and professionals can use it to assess physical activity level.Article Citation - WoS: 32Citation - Scopus: 32Covid-19 Anxiety in People Living With Hiv: an Online Cross-Sectional Study(Tubitak Scientific & Technical Research Council Turkey, 2020-12-17) Kuman Tuncel, Ozlem; Pullukcu, Husnu; Erdem, Huseyin Aytac; Kurtaran, Behice; Tasbakan, Selin Ece; Isikgoz Tasbakan, Meltem; Tuncel, Ozlem KumanBackground/aim: The emergence of the coronavirus disease 2019 (COVID-19) outbreak has had an enormous emotional impact on sonic vulnerable groups, such as people living with human immunodeficiency virus (HIV) (PLHIV). This study was planned with the aim of assessing the anxiety levels of PLHIV and the sources of their anxiety. Materials and methods: A web-based questionnaire was sent to PLHIV using the virtual snowball sampling method. The questionnaire included questions about sociodemographic status, information about HIV infection, and the Beck Anxiety Inventory (BAI). Additionally, some opinions of the participants about COVID-19 were asked. Results: A total of 307 respondents, with a median age of 33 years, from 32 different cities, participated in the study. More than half of the respondents reported the belief that COVID-19 was not sufficiently well-known by the medical community and nearly 45% believed that they would have snore complications if they contracted COVID-19. One-fourth of the participants had anxiety. Having a preexisting psychiatric disorder, perceiving that they were practicing insufficient preventive measures, not being sure about the presence of any individuals with COVID-19 in their environment, and living with a household member with a chronic disease were found to be the risk factors of PLHIV for having anxiety during this pandemic. The BAI scores were correlated with the patient-reported anxiety levels about the spread of COVID-19 in Turkey, acquiring COVID-19, transmitting COVID-19 to another person, and transmitting HIV to another person. Among the stated conditions, the most common concern was the spread of COVID-19 all over the country, while the least common was transmitting HIV to someone else. Conclusion: The results revealed that a significant proportion of the sample had anxiety, and the findings were essential for developing evidence-based strategies for decreasing the anxiety of PLHIV, especially for those who had risk factors and to provide them with better health care during this pandemic or other pandemic-like crises.Article Citation - WoS: 20Citation - Scopus: 20The Incidence of Pressure Ulcer in Patients on Mechanical Ventilation and Effects of Selected Risk Factors on Pressure Ulcer Development(Tubitak Scientific & Technical Research Council Turkey, 2016) Karayurt, Ozgul; Akyol, Ozay; Kilicaslan, Necmiye; Akgun, Nuray; Sargin, Umran; Kondakci, Melike; Ekinci, Hanim; Kondakçı, B Melike; Sarı, B NeslihanBackground/aim: This study aimed to determine the incidence of pressure ulcers in patients on mechanical ventilation and selected risk factors likely to play a role in pressure ulcer development. Materials and methods: The study included 110 patients recruited from an anesthesia critical care unit of a university hospital. Data were collected with a demographic and clinical characteristics form. The form was composed of questions about demographic characteristics and clinical features including diagnosis, duration of mechanical ventilation, general well-being, oxygenation, perfusion, and skin condition. Results: The incidence of pressure ulcer was 15.5%. Duration of mechanical ventilation was longer and the body mass index was higher in patients developing pressure ulcers than in those without pressure ulcers. Additionally, 90.11% of patients with pressure ulcers had edema and 82.35% of patients with pressure ulcers received vasopressin. The patients with pressure ulcers had higher PH levels, lower PaO2 levels, higher PCO2 levels, lower SaO2 levels, and higher urine output. Conclusion: It can be recommended that nurses and other health professionals should be aware of factors playing a role in pressure ulcer development and should be able to conduct appropriate interventions to prevent pressure ulcers.Article Citation - Scopus: 1Effects of 1-(2 (trim) on Receptor-Independent And-Dependent Contractile Responses in Rat Aorta(Tubitak Scientific & Technical Research Council Turkey, 2016) Selli, Cigdem; Erac, Yasemin; Tosun, MetinerBackground/aim: This study investigates whether 1-(2-trifluoromethylphenyl)-imidazole (TRIM), originally proposed as a nitric oxide synthase inhibitor and also suggested to be an inhibitor of store-operated calcium entry in mouse anococcygeal muscle, inhibits receptor-independent and -dependent responses in rat thoracic aorta. Materials and methods: Cyclopiazonic acid-and serotonin-induced vascular responses were investigated in aortic segments isolated from male Sprague Dawley rats using isolated tissue experiments. Changes in intracellular calcium levels were also monitored via front surface fluorescence measurements in fura-2-loaded embryonic rat vascular smooth muscle cell line A7r5. Results: TRIM inhibited serotonin-mediated vascular contractions without affecting cyclopiazonic acid-induced responses. In addition, TRIM caused a nonlinear rightward shift in the serotonin concentration-response curve, possibly via serotonin receptor modulation. Conclusion: TRIM may have an impact on investigation of tissue-specific receptor-independent and -dependent vascular responses. It may also be used as a lead compound in the development of selective serotonin receptor modulators.Article Citation - WoS: 11Citation - Scopus: 14Evaluation of Mother Wavelets on Steady-State Visually-Evoked Potentials for Triple-Command Brain-Computer Interfaces(Tubitak Scientific & Technical Research Council Turkey, 2021-09-23) Sayilgan, Ebru; Yuce, Yilmaz Kemal; Isler, YalcinWavelet transform (WT) is an important tool to analyze the time-frequency structure of a signal. The WT relies on a prototype signal that is called the mother wavelet. However, there is no single universal wavelet that fits all signals. Thus, the selection of mother wavelet function might be challenging to represent the signal to achieve the optimum performance. There are some studies to determine the optimal mother wavelet for other biomedical signals; however, there exists no evaluation for steady-state visually-evoked potentials (SSVEP) signals that becomes very popular among signals manipulated for brain-computer interfaces (BCIs) recently. This study aims to explore, if any, the mother wavelet that suits best to represent SSVEP signals for classification purposes in BCIs. In this study, three common wavelet-based features (variance, energy, and entropy) extracted from SSVEP signals for five distinct EEG frequency bands (delta, theta, alpha, beta, and gamma) were classified to determine three different user commands using six fundamental classifier algorithms. The study was repeated for six different commonly-used mother wavelet functions (haar, daubechies, symlet, coiflet, biorthogonal, and reverse biorthogonal). The best discrimination was obtained with an accuracy of 100% and the average of 75.85%. Besides, ensemble learner gives the highest accuracies for half of the trials. Haar wavelet had the best performance in representing SSVEP signals among other all mother wavelets adopted in this study. Concomitantly, all three features of energy, variance, and entropy should be used together since none of these features had superior classifier performance alone.Article A Convergent Algorithm for a Cascade Network of Multiplexed Dual Output Discrete Perceptrons for Linearly Nonseparable Classification(Tubitak Scientific & Technical Research Council Turkey, 2014) Genc, Ibrahim; Guzelis, CuneytIn this paper a new discrete perceptron model is introduced. The model forms a cascade structure and it is capable of realizing an arbitrary classification task designed by a constructive learning algorithm. The main idea is to copy a discrete perceptron neuron's output to have a complementary dual output for the neuron, and then to select, by using a multiplexer, the true output, which might be 0 or 1 depending on the given input. Hence, the problem of realization of the desired output is transformed into the realization of the selector signal of the multiplexer. In the next step, the selector signal is taken as the desired output signal for the remaining part of the network. The repeated applications of the procedure render the problem into a linearly separable one and eliminate the necessity of using the selector signal in the last step of the algorithm. The proposed modification to the discrete perceptron brings universality with the expense of getting just a slight modification in hardware implementation.Article Citation - WoS: 2Citation - Scopus: 2Model-Based Robust Chaotification Using Sliding Mode Control(Tubitak Scientific & Technical Research Council Turkey, 2014) Kocaoglu, Aykut; Guzelis, CuneytChaos is a complex behavior of dynamical nonlinear systems that is undesirable in most applications and should be controlled; however, it is desirable in some situations and should be generated. In this paper, a robust chaotification scheme based on sliding mode control is proposed for model based chaotification. A continuous time single input observable system is considered such that it is subject to parameter uncertainties, nonlinearities, noises, and disturbances, which are all additive to the input and can be modeled as an unknown function but bounded by a known function. The designed dynamical state feedback control law forces the system to match a reference chaotic system in finite time irrespective of the mentioned uncertainties, noises, and disturbances, as provided by the developed sliding mode control scheme. Simulation results are provided to illustrate the robustness of the proposed scheme against parameter uncertainties and noises. The results are compared with those of other model-based methods and Lyapunov exponents are calculated to show whether the closed-loop control systems exhibit chaotic behavior or not.Article Citation - WoS: 1G-Quadruplex Enrichment Analysis Reveals Their Role as Intronic Regulatory Elements in Plants(Tubitak Scientific & Technical Research Council Turkey, 2019-03-07) Doluca, OsmanG-Quadruplexes, a class of noncanonical but highly stable nucleic acid structures, have the potential to be part of the regulatory mechanism of cells. They can form in the genome where the double-stranded helix is unwound to facilitate formation of a G-quadruplex. The biological significance of these structures is yet to be understood entirely. This work presents a novel approach and investigates common characteristics in the distribution of G-quadruplexes relative to genes in plants through analysis of genomes and gene expressions. The results indicate that G-quadruplex distribution has gone through significant changes with the evolution of higher plants and, for the first tune, that G-quadruplexes enriched at the beginning of introns may have a regulatory role during transcription.