Browsing by Author "Demir, Y."

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The Application of Shewhart Cusum and Ewma Control Graphics on Machine Industry
(Centenary University, 2016) Demir, Y.; Mirtagioğlu, H.
In this study, Shewhart (control charts for variable quantities), CUSUM (cumulative sum control charts), EWMA (exponential weighted moving average control charts) control graphics and data belonging to cable taken from Gebze Organized Industrial Zone is used with the purpose of determination of big or small drifts occurring in targeted average within the process. Respectively, by applying Shewhart, CUSUM and EWMA control graphics to the coordinated data set, information about the process has been obtained, temporary control limits have been determined, deviation from general average has been identified, and prospective predictions have been made for production process. In application result, 2 points in the mean control graphic and 1 point in range and standard deviation control graphics signaled to be “out of control” exceeding designated control limits. Considering 3σ deviation, having exceeded the control limits, 11 points in the CUSUM control graphic and also 1 point in the EWMA control graphic have shown that the process was “out of control” As a result, quality control graphics are being used in many different areas such as agricultural production process, food and machine industry and as using one of the following graphics; Shewhart, CUSUM and EWMA could be misleading in terms of giving an idea about the process, it could be suggested that it will be more proper if decisions are made based on two of above mentioned graphics at least. © 2016, Centenary University. All rights reserved.
Brain Scintigraphy in Brain Death: the Experience of Nuclear Medicine Department in Dokuz Eylul University, School of Medicine
(Yuzuncu Yil Universitesi Tip Fakultesi, 2014) Sürücü, E.; Aslan, M.; Demir, Y.; Durak, H.
We investigated the propriety between the findings of brain death scintigraphy and the patient outcomes after the scan. We figured out the benefits of scintigraphic findings to the diagnosis. This study was performed in our department between 2006-2011 and patients were evaluated retrospectively. Pre-diagnosis of brain death and final diagnosis were compared. 24 patients were referred to our nuclear medicine department between 2006-2011. All patients underwent brain scintigraphy following IV injection of 20 mCi of Tc 99m DTPA or 10 mCi Tc 99m HMPAO with one-second dynamic images in 128x128 matrix for a period of 60 seconds. Anterior, posterior, right and left lateral static images were obtained with 5-minute in 256x256 matrix after dynamic images. Patients were referred by the departments of internal medicine intensive care and anaesthesiology intensive care. No blood flow into the middle, anterior and posterior cerebral arteries and no activity in the venous sinuses were accepted as showing the brain death. 22 of 24 patients were reported that findings in brain scan were consistent with brain death as in the prediagnosis. Brain death was not reported in two patients with Tc-99m HMPAO scan and brain death was suspicious in one patient with Tc-99m DTPA scan. Two patients with Tc-99m HMPAO scan were died two weeks after the brain scan and the patient with Tc-99m DTPA was died one day after the brain scan. Brain scintigraphy is a non-invasive procedure supporting the clinical diagnosis and it can be also easily performed and can exclude the negative and suspicious patients. © 2014, Yuzuncu Yil Universitesi Tip Fakultesi, Universitas Indonesia. All rights reserved.
Comment on "analysis of the Diastolic Function by Myocardial Perfusion Gated Spect After Coronary Revascularization in Acute Myocardial Infarction
(Elsevier Doyma Sl, 2014) Demir, Y.; Aydin, M.
Contra Lateral Parotideal Lymph Node Metastasis Detected by Pet/Ct in a Female Patient With Locally Advanced Breast Cancer
(Elsevier Doyma Sl, 2013) Demir, Y.; Surucu, E.; Durak, M. G.; Balci, P.; Saydam, S.; Bekis, R.
Dyke-Davidoff Syndrome With Cerebral Hypometabolism and Unique Crossed Cerebellar Diaschisis in 18f-Fdg Pet/Ct
(2015) Demir, Y.; Sürücü, E.; Çilingir, V.; Bulut, M.D.; Tombul, T.
A 23-year-old man with Dyke-Davidoff-Masson syndrome (DDMS) was admitted to the hospital with increasing frequency of epileptic seizures. Physical examination revealed mental retardation, left facial asymmetry, and left-sided spastic hemiparesis. Dysdiadochokinesia on the left upper limb was detected, and there was no dysmetria. MRI confirmed the well-known radiological features of DDMS. PET/CT demonstrated cerebral and contralateral cerebellar hypometabolism. We present DDMS with crossed cerebellar diaschisis, which was demonstrated by PET/CT.
An Evaluation of Thyrotoxic Autoimmune Thyroiditis Patients With Triplex Doppler Ultrasonography
(2014) Karakas, O.; Karakas, E.; Cullu, N.; Demir, Y.; Kucukyavas, Y.; Surucu, E.; Igci, E.
Objective: This study aimed to investigate the usefulness of blood flow parameters obtained from STA and CCA with Triplex Doppler ultrasonography (TDU) on patients with thyrotoxicosis. Materials and methods: This cross-sectional study included consecutive 24 patients with thyrotoxicosis and 18 healthy controls. The thyroid gland blood flow parameters were evaluated with TDU. Results: The thyroid volumes and FT3, TRAb, 4-h and 24-h radioactive iodine uptake (RAIU) levels of Group 1 were significantly high compared to those of Group 2. The thyroid volumes and FT3, FT4 and TSH levels of both Group 1 and Group 2 showed a statistically significant difference compared to Group 3. STA-PSV values for Group 1, Group 2 and Group 3 were 138 cm/s, 54 cm/s and 37 cm/s, respectively. STA-EDV values for these groups were 60 cm/s, 25 cm/s and 15 cm/s, respectively. PSVR values for these groups were 1.01, 0.45, 0.34 cm/s, respectively. EDVR values for these groups were 1.29, 0.70 and 0.49 cm/s, respectively. In Group 1, STA-PSV, STA-EDV, PSVR and EDVR values were significantly high compared to those of Group 2. RAIU levels showed a significant positive correlation with the STA-PSV, STA-EDV and PSVR. Conclusion: The thyroid gland blood flow parameters may be used in clinical diagnosis of patients with thyrotoxicosis. © 2014 Elsevier Inc.
Examining Periodic Differences of Suicide Cases With Circular Data Analysis
(Yuzuncu Yil Universitesi Tip Fakultesi, 2021) Demir, Y.
The aim of this study is to analyze suicide cases with circular data analysis and to compare them with the standard linear analysis method and to guide the implementation of long-term social protective programs. Circular data analysis was used as method. However, standard linear statistics method was also used to compare the results of circular data analysis. Men constitute 74.91% of 15731 cases included in the study. Disease (39.84%) has been identified as the highest risk factor. Despite having a low concentration, the most suicide occurred in May (9.43%). Furthermore, a significant relationship was found between suicide causes and gender and suicide causes and months (p<0.05). In the analyses performed by circular data analysis, although the mean direction of suicides indicated May 29 (148.11°), suicides spread throughout the year according to circular variance (0.96). It was determined that the mean directions of suicide causes among from 1 April (90.02°) to 19 July (199.69°), so the concentration of suicide was in this interval. However, according to the distribution measures, all causes of suicide, except educational failure, showed a multimodal distribution. It can be stated that at least one sample distribution, mean direction, condensation parameter differs from other sample parameters in terms of itself species (p<0.05). Suicide cases were seen more common among men and during the spring-summer months. It is recommended to take preventive measures according to risk factors in order to prevent suicides, especially in periods determined. © 2021, Yuzuncu Yil Universitesi Tip Fakultesi. All rights reserved.
The Value of F-18 Fdg Pet/Ct for Detecting Primary Foci in the Metastatic Cancer of Unknown Primary Origin
(Yuzuncu Yil Universitesi Tip Fakultesi, 2014) Sürücü, E.; Aşcıoğlu, M.Ş.; Şengöz, T.; Demir, Y.; Durak, H.
Cancers of unknown primary origin (CUP) have poor prognosis and the median survival for patients with CUP is approximately 1 year. This survival can be extended by the identification of the primary origin and treating with specific therapy. F-18 FDG PET/CT scans of 75 patients (39 female, 36 male, mean age 60 ±12) with CUP referred to our clinic between January 2009 and January 2011 were evaluated retrospectively. Whole body images were obtained 60 minutes after the injection of approximately 370 MBq (10 mCi) F-18 FDG by PET/CT (Gemini-TOF-Philips). Emission scans were obtained for 1.5 min per bed position and transmission scans were obtained with low dose CT using 50 mA and 120 kvp. The tumor was identified histopathologically in 58 of 75 patients. 4 of 58 patients were treated as CUP. 17 of 75 patients could not be followed, so final diagnosis could not be made. In 54 patients, the primary was identified as 17 lung, 8 colorectal, 7 breast, 3 stomach, 3 pancreas, 2 endometrial, 2 nasopharynx, 2 gallbladder cancers, 2 lymphoma, 2 peritoneum, 1 maxillary sinus, 1 salivary gland carcinoma, 1 brain tumor, 1 leiomyosarcoma, 1 ovary cancer and 1 multiple myeloma. If reports are considered, F-18 FDG PET/CT helped to detect primary origin in 65% of these 58 patients, 38 of 54 primary sites were true positive (70%). There were 6 false positive sites (10.3%), 16 false negative (27.5%) results in F-18 FDG PET/CT. After the retrospective evaluation of the false negative patients, we have realized that primary sites were ignored in 5 of 14 patients, so actually F-18 FDG PET/CT helped in 74% of the patients showing 43 of 54 primary sites (80%). In first evaluation, F-18 FDG PET/CT missed 2 breast cancers, 1 lymphoma, 1 colon cancer and 1 intra maxillary sinus cancer. F-18 FDG PET/CT is an important imaging tool for detecting primary origin in the patients with CUP. F-18 FDG PET/CT helped in 74% of the patients showing the primary sites. In the patients with CUP, lung, breast, colon and the physiologic uptake areas should be scrutinized carefully for any tumor location. © 2014, Yuzuncu Yil Universitesi Tip Fakultesi, Universitas Indonesia. All rights reserved.