TR-Dizin

Permanent URI for this collectionhttps://ada.atilim.edu.tr/handle/123456789/21

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Citation Count: 0
Anticipatory effect of execution on observation: an approach using ExoPinch finger robot
(Tubitak Scientific & Technological Research Council Turkey, 2019) Arıkan, Kutluk Bilge; Zadeh, Hassan Gol Mohammad; Turgut, Ali Emre; Zinnuroğlu, Murat; Bayer, Gözde; Günendi, Zafer; Cengiz, Bülent; Department of Mechatronics Engineering
Background/aim: This study aims to explore the mirror neuron system (MNS) involvement using mu (8–12 Hz)/beta (15–25 Hz) bandsuppression in an action observation-execution paradigm.Materials and methods: Electrophysiological (EEG) data from 16 electrodes were recorded while 8 participants observed video clips ofa hand squeezing a spring. Specifically, the effect of anticipated execution on observation was studied. For this purpose, a fully actuatedfinger exoskeleton robot was utilized to synchronize observation and execution and to control the execution condition for the participants. Anticipatory effect was created with a randomized robot accompany session.Results: The results showed that the observational condition (with or without anticipation) interacted with hemisphere at central channels near somatosensory cortex. Additionally, we explored the response of MNS on the kinetics features of visual stimuli (hard or softspring).Conclusion: The results showed an interaction effect of kinetics features and hemisphere at frontal channels corresponding nearly tothe ventral premotor cortex area of the brain. The activation of mirror neurons in this area plays a crucial role in observational learning.Based on our results, we propose that specific type of visual stimuli can be combined with the functional abilities of the MNS in the action observation based treatment of hand motor dysfunction of stroke patients to have a positive additional impact.
Citation Count: 0
Association between monocyte to high-density lipoprotein cholesterol ratio and bicuspid\raortic valve degeneration
(Tubitak Scientific & Technological Research Council Turkey, 2020) Karaduman, Bilge Duran; Ayhan, Hüseyin; Keles, Telat; Bozkurt, Engin
Background/aim: From a pathophysiological point of view, inflammation is thought to be more dominant in bicuspid aortic valve\r(BAV) stenosis than tricuspid aortic valve (TAV) stenosis. Our study aimed to determine the association between monocyte to highdensity lipoprotein cholesterol (HDL-C) ratio (MHR), a new inflammatory marker, and the speed of progression of stenosis and\rpathophysiology of BAV stenosis.\rMaterials and methods: A total of 210 severe aortic stenosis patients (70 consecutive BAV patients, 140 matched TAV patients) were\rretrospectively enrolled in the study. Clinical and echocardiographic data and laboratory results related to our research were collected\rretrospectively from the patients’ records. MHR was measured as the ratio of the absolute monocyte count to the HDL-C value.\rResults: Seventy BAV (mean age: 72.0 ± 9.1 years, 42.9% female) and 140 TAV patients (mean age: 77.9 ± 8.3 years, 51.4% female)\rwith severe aortic stenosis were enrolled in this study. There was no difference between the two groups in terms of another baseline\rdemographic or clinic findings except age (P < 0.001). Monocyte count, hemoglobin level, mean platelet volume was significantly\rhigher, and HDL-C level was significantly lower in the BAV group, while other lipid and CBC parameters were found to be similar. In\rthe multivariate analysis, MHR (P = 0.005, 95% CI: 0.90–0.98) and, as expected, age (P = 0.001, 95% CI: 1.02–1.11) were found to be\rsignificant as the independent predictor of BAV, after adjusting for other risk factors.\rConclusion: Our study showed a significant correlation between increased MHR and BAV. MHR was determined as a significant\rindependent predictor for the speed of progression and diagnosis of severe BAV stenosis in multivariate analysis.
Citation Count: 0
Card spending dynamics in Turkey during the COVID-19 pandemic
(Central Bank Republic Turkey, 2021) Kantur, Zeynep; Özcan, Gülserim; Economics
This paper provides an extensive analysis of card spending during the COVID-19 pandemic in Turkey by using weekly aggregated and sectoral credit and debit card spending data from March 2014 to December 2020. At an aggregated level, we show that aggregate demand decreases significantly at the early stages of COVID-19 and seems to reinstate its pre-COVID trend. However, when we include the pre-existing conditions of Turkey, the 2018 currency crisis, we observe that the recovery in demand is not that strong. To highlight the underlying reasons for structural change in aggregate demand, we estimate the model with stringency index and unemployment-related search index. The estimated model indicates that containment measures and restrictions and fear of job/income loss mainly explain the overall impact of COVID-19 on aggregate demand. We also examined sectoral data to understand aggregate demand dynamics better. Only stable and delayable sector groups have reached a trend above their pre-pandemic trajectories. However, the social and work-related sectors are far from their respective pre-pandemic trend.
Citation Count: 0
The clinical and demographical characteristics of Turkish pediatric lymphedema patients: a multicenter study
(Tubitak Scientific & Technological Research Council Turkey, 2022) Borman, Pinar; Balcan, Aysegul; Eyigor, Sibel; Coskun, Evrim; Ayhan, Figen; Cakit, Burcu Duyur; Dogan, Sevil Ceyhan
Background/aim: Reducing lymphedema-associated burden and disability in the pediatric setting requires improved awareness and understanding clinical properties of the lymphedema. The aim of this study was to evaluate the clinical and demographic characteristics of patients with pediatric lymphedema presented to different lymphedema centers in Turkey. Materials and methods: The socio-demographic and clinical characteristics of the children including age, gender, presence of genetic syndromes, duration of edema, site and stage of lymphedema and the received therapies were determined. Parental and children education on self-management techniques were recorded. Results: A total of 122 children (female: 66, male: 56) with a mean age of 120.7 +/- 71.2 months were included from 7 centers. Of them; 92% had primary, 8% had secondary lymphedema mostly due to infection and trauma. Lymphedema was part of a syndrome in 18% of the children. The most common site of involvement was the lower extremity, followed by upper extremity and genital involvement. Lymphedema was complicated in 17 % of children, mainly with a clinical picture of cellulitis, infection, and pain. The median duration of lymphedema was 41 (5-216) months. Although most of the children had stage 2 lymphedema, only 40% of them received treatment. The most commonly received treatment was compression therapy. No family or child was educated for self-care management before. Conclusion: In conclusion, pediatric lymphedema has a comparable gender distribution and usually involves the lower extremities. Although most of the children had advanced disease, more than half of the patients did not receive any treatment indicating the unmet need for management of lymphedema. The education of patients and/or children about self-management methods were lacking. We suggest educational activities for both families of children with lymphedema and health care providers, in order to facilitate early reference to lymphedema units and to receive prompt preventive and therapeutic approaches for this suffering condition.
Citation Count: 1
Impact of hospital-acquired acute kidney injury on Covid-19 outcomes in patients with and without chronic kidney disease: a multicenter retrospective cohort study
(Tubitak Scientific & Technological Research Council Turkey, 2021) Ozturk, Savas; Turgutalp, Kenan; Arıcı, Mustafa; Çetinkaya, Hakkı; Altıparmak, Mehmet Rıza; Aydın, Zeki; Ateş, Kenan
Background/aim: Hospital-acquired acute kidney injury (HA-AKI) may commonly develop in Covid-19 patients and is expected to have higher mortality. There is little comparative data investigating the effect of HA-AKI on mortality of chronic kidney disease (CKD) patients and a control group of general population suffering from Covid-19. Materials and methods: HA-AKI development was assessed in a group of stage 3–5 CKD patients and control group without CKD among adult patients hospitalized for Covid-19. The role of AKI development on the outcome (in-hospital mortality and admission to the intensive care unit [ICU]) of patients with and without CKD was compared. Results: Among 621 hospitalized patients (age 60 [IQR: 47–73]), women: 44.1%), AKI developed in 32.5% of the patients, as stage 1 in 84.2%, stage 2 in 8.4%, and stage 3 in 7.4%. AKI developed in 48.0 % of CKD patients, whereas it developed in 17.6% of patients without CKD. CKD patients with HA-AKI had the highest mortality rate of 41.1% compared to 14.3% of patients with HA-AKI but no CKD (p < 0.001). However, patients with AKI+non-CKD had similar rates of ICU admission, mechanical ventilation, and death rate to patients with CKD without AKI. Adjusted mortality risks of the AKI+non-CKD group (HR: 9.0, 95% CI: 1.9–44.2) and AKI+CKD group (HR: 7.9, 95% CI: 1.9–33.3) were significantly higher than that of the non-AKI+non-CKD group. Conclusion: AKI frequently develops in hospitalized patients due to Covid-19 and is associated with high mortality. HA-AKI has worse outcomes whether it develops in patients with or without CKD, but the worst outcome was seen in AKI+CKD patients.Key words: Acute kidney injury, chronic kidney disease, Covid-19, hospitalization, mortality
Citation Count: 0
Investigation of the effect of hyperthyroidism on endoplasmic reticulum stress and transient receptor potential canonical 1 channel in the kidney
(Tubitak Scientific & Technological Research Council Turkey, 2021) Aykanat, Nuriye Ezgi Bektur; Şahin, Erhan; Kaçar, Sedat; Bağcı, Rıdvan; Karakaya, Şerife; Dönmez, Dilek Burukoğlu; Şahintürk, Varol; Basic Sciences
Background/aim: Hyperthyroidism is associated with results in increased glomerular filtration rate as well as increased renin-angiotensin-aldosterone activation. The disturbance of Ca2+ homeostasis in the endoplasmic reticulum (ER) is associated with many diseases, including diabetic nephropathy and hyperthyroidism. Transient receptor potential canonical 1 (TRPC1) channel is the first cloned TRPC family protein. Although it is expressed in many places in the kidney, its function is uncertain. TRPC1 is involved in regulating Ca2+ homeostasis, and its upregulation increases ER Ca2+ level, activates the unfolded protein response, which leads to cellular damage in the kidney. This study investigated the role of TRPC1 in the kidneys of hyperthyroid rats in terms of ER stress markers that are glucose-regulated protein 78 (GRP78), activating transcription factor 6 (ATF6), (protein kinase R (PKR)-like endoplasmic reticulum kinase) (PERK), Inositol-requiring enzyme 1 (IRE1). Materials and methods: Twenty male rats were assigned into control and hyperthyroid groups (n = 10). Hyperthyroidism was induced by adding 12 mg/L thyroxine into the drinking water of rats for 4 weeks. The serum-free T3 and T4 (fT3, fT4), TSH, blood urea nitrogen (BUN), and creatinine levels were measured. The histochemical analysis of kidney sections for morphological changes and also immunohistochemical and western blot analysis of kidney sections were performed for GRP78, ATF6, PERK, IRE1, TRPC1 antibodies. Results: TSH, BUN, and creatinine levels decreased while fT3 and fT4 levels increased in the hyperthyroid rat. The morphologic analysis resulted in the capillary basal membrane thickening in glomeruli and also western blot, and immunohistochemical results showed an increase in TRPC1, GRP78, and ATF6 in the hyperthyroid rat (p < 0.05). Conclusion: In conclusion, in our study, we showed for the first time that the relationship between ER stress and TRPC1, and their increased expression caused renal damage in hyperthyroid rats.Key words: Hyperthyroidism, endoplasmic reticulum (ER) stress, transient receptor potential canonical 1 (TRPC1), kidney, rat
Citation Count: 0
The role of anakinra in the modulation of intestinal cell apoptosis and inflammatory response during ischemia/reperfusion
(Tubitak Scientific & Technological Research Council Turkey, 2021) Kandemir, Muhammed; Yaşar, Necdet Fatih; Özkurt, Mete; Özyurt, Rumeysa; Aykanat, Nuriye Ezgi Bektur; Erkasap, Nilüfer; Basic Sciences
Background/aim: Even though interleukin-1 receptor antagonist, IL-1Ra, is used in certain inflammatory diseases, its effect on ischemia-reperfusion injury is a current research topic. We aimed to investigate the protective effects of anakinra, an IL-1Ra, on the I/R induced intestinal injury. Materials and methods: The rat model of intestinal ischemia-reperfusion was induced. Rats were randomized into 4 groups: (group 1) control group, (group 2) I/R group, (group 3 and 4) treatment groups (50 mg/kg and 100 mg/kg, respectively). Gene expressions of caspase-3, TNF-α, IL-1α, IL-6, and apoptotic cells in tissue samples were evaluated by PCR and TUNEL methods, respectively. Plasma levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were studied by the ELISA method and tissue samples were examined histopathologically as well. Results: Anakinra inhibited the expression of IL-1α, IL-6, and TNF-α and decreased the SOD, CAT, and MDA caused by ischemiareperfusion injury in both treatment groups. Caspase-3 expression and TUNEL-positive cell number in treatment groups were also less. Histopathologically, anakinra better preserved the villous structure of the small intestine at a dose of 100 mg/kg than 50 mg/kg.Conclusion: Anakinra decreased the intestinal damage caused by ischemia-reperfusion and a dose of 100 mg/kg was found to be histopathologically more effective.Key words: Ischemia reperfusion injury, interleukin-1 receptor antagonist, anakinra
Citation Count: 0
TESTS OF RATIONALITY IN THE TURKISH FOREIGN EXCHANGE MARKET
(2014) Topbaş, Neslihan; International Trade and Logistics
Beklentilerin rasyonalitesi birçok döviz piyasasında, anket verileri kullanılmak suretiyle, test edilmiştir. BuçalışmadaTürkiye'de döviz piyasalarındakipiyasa oyuncularının beklentilerine ilişkin ampirik değerlendirmeler yapmak amaçlanmıştır. Türkiye Cumhuriyet Merkez Bankası tarafından yayımlanan ABD dolarkuruna ilişkin 1 yıl ve 1 ay vadeli beklentiler kapsamında piyasa oyuncularının ortalama beklentilerinin gerçekleşen değer kaybından yüksek olduğu tespit edilmiştir. Forward döviz kurlarının gelecekteki spot döviz kurunun tahmininde yansızlığına ilişkin testler ise olumsuz sonuçlanmıştır. Beklentilerin rasyonelliğini değerlendirmeküzere,gerçekleşen devalüasyon ile beklenen devalüasyon regresyon analizine tabi tutulmuş ve 1 ay vade için beklentilerin gerçekleşmeler ile ters yönlü olduğu tespit edilmiştir.
Citation Count: 0
The triglyceride-glucose index predicts peripheral artery disease complexity
(Tubitak Scientific & Technological Research Council Turkey, 2020) Karaduman, Bilge Duran; Ayhan, Hüseyin; Keles, Telat; Bozkurt, Engin
Background/aim: High levels of triglyceride (TG) and fasting blood glucose (FBG) values increase atherosclerosis risk. This study\revaluates the relationship between peripheral artery disease (PAD) severity and complexity, as assessed by TransAtlantic InterSociety\rConsensus-II (TASC-II) classification and the triglyceride-glucose (TyG) index.\rMaterials and methods: A total of 71 consecutive patients with PAD (males 93%, mean age 63.3 ± 9.7), who underwent percutaneous\rperipheral intervention were included retrospectively. The patients were divided into two groups according to the angiographically\rdetected lesions. Those with TASC A-B lesions were included in Group 1, and those with TASC C-D lesions were included in Group 2.\rTyG index was calculated as formula: ln[fasting TG (mg/dL) × fasting plasma glucose (mg/dL)/2].\rResults: There were 40 patients in Group 1 (90.3% men, with a mean age of 63.6 ± 9.3 years) and 31 patients in Group 2 (96.8% men,\rwith a mean age of 62.0 ± 8.6 years). In the majority of patients in both groups, the target vessels are iliac arteries and femoral arteries.\rIn Group 2, platelet count and TyG index were significantly high, according to Group 1. The TyG index was significantly correlated with\rTASC-II, Rutherford category, HbA1c, and HDL-C.\rConclusion: In this present study, we showed that the TyG index was an independent predictor of peripheral artery disease complexity,\raccording to TASC-II classification, for the first time in the literature.

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