Classification of Verbal and Quantitative Mental Tasks Using Phase Locking Values between EEG Signals

Huseyin Atasoy,Esen Yildirim 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.7

In this study, electroencephalography signals recorded while participants were doing verbal and quantitative tasks, are classified. A dataset containing 1044 records obtained from 18 participants are used for subject-dependent classifications. Features are derived from phase locking values calculated between all channel pairs. Features are reduced before the classification process by using both analysis of variance and correlation based feature selection methods. Instances in the dataset are classified by using the nearest neighbor algorithm. An average classification accuracy of 92.35% is achieved over 18 participants. It is shown that phase locking value is distinctive especially when it is calculated on delta and gamma frequency bands measured between frontal and occipital regions.

Evaluation of Patients Treated in Intensıve Care Due to COVID-19: A Retrospective Study

Kılınç Gökhan,Atasoy Aslı Akcan 대한감염학회 2022 Infection and Chemotherapy Vol.54 No.2

Background The aim of this study is to report the demographic characteristics, clinical features, treatment protocols, comorbidities, imaging findings, prognosis and factors affecting mortality in critically ill patients with coronavirus disease 2019 (COVID-19) in the intensive care unit. Materials and Methods This retrospective cohort study consists of adult (≥18 years old) patients hospitalized in a tertiary hospital intensive care unit of with COVID-19. The independent effects of possible factors identified in previous analyzes on survival were analyzed using univariate and multivariate logistic regression analysis. Results The mean age of all patients was 70.2 ± 13.9 years. Of the 200 patients, 139 (69.5%) had died. White blood cells (19.2 ± 76.1 × 109 per L), neutrophil/lymphocyte ratio (15.4 ± 65.1), d-dimer (2,558.4 ± 4,574.2 ng/mL), ferritin (1,481.2 ± 4,447.4 μg/L) and C-reactive protein (CRP) (12.1 ± 11.9 mg/dL) levels were high at the time of admission. According to the results of univariate regression analysis; presence of additional disease (odds ratio [OR]: 3.837; P = 0.015), older age (OR: 1.027; P = 0.015), reverse transcriptase-polymerase chain reaction (RT-PCR) positivity (OR: 2.58; P = 0.019), higher heart rate (OR = 1.027; P = 0.028), higher APACHE II score (OR: 1.049; P = 0.012), higher sequential organ failure assessement (SOFA) score(OR: 1.479; P = 0.014), high d-dimer levels (OR: 3.180; P <0.001) and high CRP levels (OR: 1.035; P = 0.028) increases the risk of death. When patients with full data for all variables in the multivariate logistic regression model were evaluated; positive RT-PCR (OR=4.105; P = 0.005), older age (OR: 1.033; P = 0.024), higher heart rate (OR: 1.042; P = 0.006), higher (SOFA) score (OR: 1.477; P <0.001), high d-dimer levels at admission (OR: 3.459; P = 0.002) and diabetes mellitus (OR: 3.433; P = 0.035) increase the risk of death. Conclusion Mortality of critically ill patients with COVID-19 pneumonia was high (69.5%). Older patients and acute respiratory distress syndrome were at higher risk of death. High SOFA score, high d-dimer at admission, and presence of diabetes mellitus were associated with high mortality. Background The aim of this study is to report the demographic characteristics, clinical features, treatment protocols, comorbidities, imaging findings, prognosis and factors affecting mortality in critically ill patients with coronavirus disease 2019 (COVID-19) in the intensive care unit. Materials and Methods This retrospective cohort study consists of adult (≥18 years old) patients hospitalized in a tertiary hospital intensive care unit of with COVID-19. The independent effects of possible factors identified in previous analyzes on survival were analyzed using univariate and multivariate logistic regression analysis. Results The mean age of all patients was 70.2 ± 13.9 years. Of the 200 patients, 139 (69.5%) had died. White blood cells (19.2 ± 76.1 × 109 per L), neutrophil/lymphocyte ratio (15.4 ± 65.1), d-dimer (2,558.4 ± 4,574.2 ng/mL), ferritin (1,481.2 ± 4,447.4 μg/L) and C-reactive protein (CRP) (12.1 ± 11.9 mg/dL) levels were high at the time of admission. According to the results of univariate regression analysis; presence of additional disease (odds ratio [OR]: 3.837; P = 0.015), older age (OR: 1.027; P = 0.015), reverse transcriptase-polymerase chain reaction (RT-PCR) positivity (OR: 2.58; P = 0.019), higher heart rate (OR = 1.027; P = 0.028), higher APACHE II score (OR: 1.049; P = 0.012), higher sequential organ failure assessement (SOFA) score(OR: 1.479; P = 0.014), high d-dimer levels (OR: 3.180; P <0.001) and high CRP levels (OR: 1.035; P = 0.028) increases the risk of death. When patients with full data for all variables in the multivariate logistic regression model were evaluated; positive RT-PCR (OR=4.105; P = 0.005), older age (OR: 1.033; P = 0.024), higher heart rate (OR: 1.042; P = 0.006), higher (SOFA) score (OR: 1.477; P <0.001), high d-dimer levels at admission (OR: 3.459; P = 0.002) and diabetes mellitus (OR: 3.433; P = 0.035) increase the risk of death. Conclusion Mortality of critically ill patients with COVID-19 pneumonia was high (69.5%). Older patients and acute respiratory distress syndrome were at higher risk of death. High SOFA score, high d-dimer at admission, and presence of diabetes mellitus were associated with high mortality.

Numerical solution of beam equation using neural networks and evolutionary optimization tools

Babaei, Mehdi,Atasoy, Arman,Hajirasouliha, Iman,Mollaei, Somayeh,Jalilkhani, Maysam Techno-Press 2022 Advances in computational design Vol.7 No.1

In this study, a new strategy is presented to transmit the fundamental elastic beam problem into the modern optimization platform and solve it by using artificial intelligence (AI) tools. As a practical example, deflection of Euler-Bernoulli beam is mathematically formulated by 2nd-order ordinary differential equations (ODEs) in accordance to the classical beam theory. This fundamental engineer problem is then transmitted from classic formulation to its artificial-intelligence presentation where the behavior of the beam is simulated by using neural networks (NNs). The supervised training strategy is employed in the developed NNs implemented in the heuristic optimization algorithms as the fitness function. Different evolutionary optimization tools such as genetic algorithm (GA) and particle swarm optimization (PSO) are used to solve this non-linear optimization problem. The step-by-step procedure of the proposed method is presented in the form of a practical flowchart. The results indicate that the proposed method of using AI toolsin solving beam ODEs can efficiently lead to accurate solutions with low computational costs, and should prove useful to solve more complex practical applications.

Effect of MCI-186 on Lipid Peroxidation in Experimental Traumatic Brain Damage in Rats

Murat Baloglu,Metin Ant Atasoy 대한신경손상학회 2022 Korean Journal of Neurotrauma Vol.18 No.2

Objective: Brain damage occurs in many clinical conditions, including trauma, ischemia, and hypertension. Reactive oxygen products and lipid peroxidation are responsible for the brain damage that occurs in these clinical conditions. We investigated whether MCI-186 (3-methyl-1-phenyl-2-pyrazoline-5-one), a free radical binding agent on lipid peroxidation, affects malondialdehyde (MDA), glutathione (GSH), and glutathione peroxidase (GPx) levels in traumatic brain damage. Methods: The traumatic brain damage model, modified by Feeney, was performed on 28 male Wistar rats separated into 4 groups. The MDA, GSH, and GPx levels in the brain tissues of each group were studied. Results: MDA levels in the traumatized group were significantly higher than those in the sham and MCI-186 groups (p<0.05), while GSH levels were significantly higher in the sham group than in the trauma and solvent groups (p<0.05). No significant difference was observed between the sham and MCI-186 groups (p>0.05). Although the average GPx level was higher in the sham and MCI-186 groups, no significant difference was found between groups. Conclusion: Reactive oxidation products significantly decreased in the MCI-186 group. Thus, MCI-186 can be used as a free radical-binding agent in traumatic brain damage.

Experience of the Endoscopists Matters in Endoscopic Retrograde Cholangiopancreatography in Billroth II Gastrectomy Patients

Erkan Caglar,Deniz Atasoy,Mukaddes Tozlu,Engin Altınkaya,Serkan Dogan,Hakan Senturk 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.1

Background/Aims: Altered anatomy is a challenge in endoscopic retrograde cholangiopancreatography (ERCP) for patients withBillroth II anastomosis. In this study, we investigated the overall success and role of endoscopist experience. Methods: Data of patients who underwent ERCP between 2014 and 2018 after a previous Billroth II operation were retrievedretrospectively from 2 tertiary ERCP centers. The procedures were performed by 2 endoscopists with different levels of experience. Clinical success was defined as extraction of the stone, placement of a stent through a malignant stricture, and clinical and laboratoryimprovements in patients. Results: Seventy-five patients were included. The technical success rate was 83% for the experienced endoscopist and 75% for theinexperienced endoscopist (p=0.46). The mean (±standard deviation) procedure time was 23.8±5.7 min for the experienced endoscopistand 40.68±6.07 min for the inexperienced endoscopist (p<0.001). In total, 3 perforations (4%) were found. The rate of afferent loopperforation was 6.25% (1/16) for the inexperienced endoscopist and 0% (0/59) for the experienced endoscopist (p=0.053). Conclusions: ERCP in patients who had undergone Billroth II gastrectomy was time consuming for the inexperienced endoscopistwho should beware of the unique adverse events related to ERCP in patients with altered anatomy.

Endoscopic Ultrasound-Guided Fine Needle Aspiration Using a 22-G Needle for Hepatic Lesions: Single-Center Experience

Ebru Akay,Deniz Atasoy,Engin Altınkaya,Ali Koç,Tamer Ertan,Hatice Karaman,Erkan Caglar 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.3

Background/Aims: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been accepted as a reliable tool indiagnosing and staging intra-abdominal tumors. In this study, we aimed to investigate the performance of EUS-FNA in theevaluation of liver masses and its impact on patient management and procedure-related complications retrospectively. Methods: Data of patients who underwent EUS-FNA biopsies due to liver masses between November 2017 and July 2018 wereretrieved retrospectively. Biopsies were performed using 22-G needles. The demographics, EUS-FNA results, sensitivity andspecificity of the procedure, negative predictive value, positive predictive value, and specimen sufficiency rates were assessed. Results: A total of 25 patients (10 females) were included in the study. The mean age was 62.73±15.2 years. The mean size of themasses was 34.50±16.04 mm. The technical success rate was 88%. During the EUS-FNA procedure, each patient had only one passwith 94.45% of aspirate sufficiency rate and 86.3% of biopsy sufficiency rate. The diagnostic accuracy rate was 86.3%. There were nocomplications. Conclusions: For the evaluation of liver masses, EUS-FNA using a 22-G needle with even one pass had high aspiration and biopsysuccess rates accompanied with high diagnostic accuracy rates.

Reparative, Neuroprotective and Anti-neurodegenerative Effects of Granulocyte Colony Stimulating Factor in Radiation-Induced Brain Injury Model

Gökhan Gürkan,Özüm Atasoy,Nilsu Çini,İbrahim Halil Sever,Bahattin Özkul,Gökhan Yaprak,Cansın Şirin,Yiğit Uyanıkgil,Ceren Kızmazoğlu,Mümin Alper Erdoğan,Oytun Erbaş 대한신경외과학회 2023 Journal of Korean neurosurgical society Vol.66 No.5

Objective : This animal model aimed to compare the rat group that received brain irradiation and did not receive additional treatment (only saline) and the rat group that underwent brain irradiation and received Granulocyte colony stimulating factor (G-CSF) treatment. In addition, the effects of G-CSF on brain functions were examined by magnetic resonance (MR) imaging and histopathologically. Methods : This study used 24 female Wistar albino rats. Drug administration (saline or G-CSF) was started at the beginning of the study and continued for 15 days after whole-brain radiotherapy (WBRT). WBRT was given on day 7 of the start of the study. At the end of 15 days, the behavioral tests, including the three-chamber sociability test, open field test, and passive avoidance learning test, were done. After the behavioral test, the animals performed the MR spectroscopy procedure. At the end of the study, cervical dislocation was applied to all animals. Results : G-CSF treatment positively affected the results of the three-chamber sociability test, open-space test and passive avoidance learning test, cornu Ammonis (CA) 1, CA3, and Purkinje neuron counts, and the brain levels of brain-derived neurotrophic factor and postsynaptic density protein-95. However, G-CSF treatment reduced the glial fibrillary acidic protein immunostaining index and brain levels of malondialdehyde, tumor necrosis factor-alpha, nuclear factor kappa-B, and lactate. In addition, on MR spectroscopy, G-CSF had a reversible effect on brain lactate levels. Conclusion : In this first designed brain irradiation animal model, which evaluated G-CSF effects, we observed that G-CSF had reparative, neuroprotective and anti-neurodegenerative effects and had increased neurotrophic factor expression, neuronal counts, and morphology changes. In addition, G-CSF had a proven lactate-lowering effect in MR spectroscopy and brain materials.

Fabrication and structural, electrical characterization of i-ZnO/n-ZnO nanorod homojunctions

S. Yılmaz,E. Bacaksız,İ. Polat,Y. Atasoy 한국물리학회 2012 Current Applied Physics Vol.12 No.5

Well-aligned ZnO nanorods were synthesized by a vapor phase transport method on ZnO buffer layer coated n-Si substrates. X-ray diffraction and scanning electron microscopy results showed that the deposited ZnO nanorods crystallize in the wurtzite structure and are highly textured with their c-axes normal to the substrate and show a clearly hexagonal morphology. A heavily compensated and intrinsic ZnO layer (i-ZnO) doped with both Mg and Na was deposited on the nominally undoped ZnO nanorods (which show a natural n-type behavior) to produce an i-ZnO/n-ZnO homojunction. The i-ZnO layer consisted of the grainy shape nano-crystallites with the wavy surface morphology. The currentevoltage (I-V) characteristics of these structures in the temperature range of 150e300 K have been analyzed in the framework of standard thermionic emission (TE) theory with the assumption of a Gaussian distribution of the barrier heights. The values of zero bias barrier height (Φb0) and ideality factor (n) were found to be strongly temperature dependent whereby n decreases while Φb0 increases with increasing temperature. The ln(I0/T2) vs q/kT plot shows a straight line behavior and the values of activation energy (Ea = Φb0) and the Richardson constant (A*) determined from the intercept and slope of the plot were 0.926 eV and 2.61 × 10-8 A cm-2 K-2, respectively. This value of A* is much lower than the known value of 32 A cm-2 K-2 for ZnO. Thus, a modified ln(0=T2)-(σ20q2=2k2T2)vs. q/kT plot based on a Gaussian distribution of barrier heights was used which yields a mean barrier height (Φb)and modified effective Richardson (A**) of 1.032 eV and 34.85 A cm- K-, respectively. This value of A** is much closer to the theoretical value of 32 A cm-2K-2 for ZnO.

Novel 3D micro- and nanofabrication method using thermally activated selective topography equilibration (TASTE) of polymers

Schleunitz Arne,Guzenko Vitaliy A,Messerschmidt Martin,Atasoy Hakan,Kirchner Robert,Schift Helmut 나노기술연구협의회 2014 Nano Convergence Vol.1 No.7

Micro- and nanostructures with three-dimensional (3D) shapes are needed for a variety of applications in optics and fluidics where structures with both smooth and sharp features enhance the performance and functionality. We present a novel method for the generation of true 3D surfaces based on thermally activated selective topography equilibration (TASTE). This technique allows generating almost arbitrary sloped, convex and concave profiles in the same polymer film with dimensions in micro- and nanometer scale. We describe its principal mechanism exemplified by pre-patterned poly (methyl methacrylate) resist which is exposed to high energy electrons prior to a thermal annealing step enabling the selective transformation of stepped contours into smooth surfaces. From this we conclude, that TASTE not only offers an enormous degree of freedom for future process variations, but also will advance the patterning capabilities of current standard 3D micro- and nanofabrication methods.

Prognostic impact of p16 and p53 gene expressions in stage 1a epithelial ovarian cancer

( Emre Gunakan ),( Yusuf Aytac Tohma ),( Latife Atasoy Karakaş ),( Huseyin Akıllı ),( Asuman Nihan Haberal ),( Ali Ayhan ) 대한산부인과학회 2020 Obstetrics & Gynecology Science Vol.63 No.4

Objective Epithelial ovarian cancer (EOC) is rarely detected at stage 1a. Most of the patients have a good prognosis and there are limited factors that affect their survival. In the present study, we evaluated the p16 and p53 gene expressions of stage 1a EOC patients. Prognostic effects of these gene expressions, as well as those of other factors on short term survival were analyzed. Methods Our study included 29 patients. The specimens of the ovary with cancer were stained for p16 and p53. Gene expressions and other prognostic factors were evaluated. Results The median age of the patients was 51 years (27-84). The mean numbers of dissected pelvic and paraaortic lymph nodes were 27 and 12, respectively. The mean follow-up time was 33.7±18.9 months. During this period, recurrence occurred in two patients. One of the patients had grade 2 mucinous carcinoma and died of the disease at month 12 after the recurrence occurred at month 7. The second patient had clear cell carcinoma and recurrence occurred at month 34. p16 and p53 gene expressions or other factors were not associated with overall survival (OS) or diseasefree survival in the short term. The lower p16 positivity rate in the non-clear cell group was found to be statistically significant (P=0.003). Both p53 and p16 positivity rates were higher in the high-grade carcinoma. Conclusion The levels of none of the common prognostic factors, including those of p16 and p53 gene expression, were associated with the progression-free survival or OS of stage 1a in the short term. Appropriate surgical staging and non-omission of subclinical metastases seem to be of central importance.