Browsing by Author "Can M."
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Item Preoperative staging of rectal carcinoma by endorectal ultrasonography(2000) Can M.; Dural T.; Aydede H.; Ermete M.; Guney S.Purpose: To evaluate the efficacy and accuracy of endorectal ultrasonography (EUS) in detecting preoperatively rectal wall invasion and nodal involvement in patients with rectal carcinoma. Materials and methods: EUS was applied to 27 patients prediagnosed as having rectal carcinoma by using a 7.5 MHz endorectal transducers with water bag. Sonographic evaluation consisted of estimation of tumour invasion into the rectal wall and adjacent lymph node involvement. All of the patients were operated on with curative intend and the sonographic stage was compared with the postoperative pathologic stage. Results: The accuracy rates of EUS compared with the postoperative pathologic staging were 81%, 70.3% and 59.3% in determining wall invasion, nodal involvement and overall tumour stage, respectively. The most frequent factor leading to false-positive results was the abnormally reactive-hyperplastic lymph nodes which were hypoechoic and larger than 5 mm in diameter. Conclusion: It is concluded that EUS is a moderately reliable imaging method for local tumour staging, mainly due to its relatively high rate of nodal imaging failure.Item Blue naevus with satellitosis mimicking malignant melanoma(2001) Sahin M.T.; Demir M.A.; Yoleri L.; Can M.; Öztürkcan S.Blue naevus is an acquired benign melanocytic naevus. It is a firm, sharply defined dark blue to grey-black papule or nodule, which is likely to arise from the arrested dermal melanocytes in the dermis. In the last few years, blue naevus has attracted much attention due to the recognition of new entities and to its confusion with malignant melanoma. We report a 69-year-old man who developed a blue-black nodular lesion with satellitosis on his scalp. Although clinically it was thought to be a malignant melanoma, histopathological investigation and conservative methods such as dermatoscopy and power Doppler ultrasonography did not confirm this diagnosis. Histopathological examination excluded malignant melanoma, as there were no cellular atypia and mitotic activity in either the nodular lesion or the satellitosis. Doppler ultrasonography confirmed the benign nature of the lesion. Dermatoscopic examination showed homogeneous steel-blue pigmentation with individual blue globules, dots and some brown veils, and confirmed the histopathological diagnosis. To the best of our knowledge, our case is the third reported case of a blue naevus with satellitosis mimicking malignant melanoma.Item Lumbar stiffness but not thoracic radiographic changes relate to alteration of lung function tests in ankylosing spondylitis(2002) Cerrahoglu L.; Unlu Z.; Can M.; Goktan C.; Celik P.Involvement of the costovertebral (CV) and costotransverse (CT) as well as the sacroiliac (SI) joints is known to occur in patients with ankylosing spondylitis (AS). The functional significance of these changes is not clear. We have performed clinical and radiological evaluations and assessed the effect of joint involvement on pulmonary function. We detected radiologic evidence of involvement of the CV joint in 80% of patients and of the CT joint in 60 %. We found a direct relation between the severity of CV, CT and SI joint affliction, and the severity of CV and SI joints were related to time of evolution of the disease. Pulmonary function tests revealed neither restrictive nor obstructive defects. No relation was found between pulmonary function and CV and CT joint affliction. Patients with stiffer spines had a tendency to have pulmonary function tests within the lower limit of the normal range. In patients with AS diaphragmatic breathing might compensate the chest respiration to some extent.Item Inguinal keratotic basal cell carcinoma mimicking giant solitary trichoepithelioma(Japanese Dermatological Association, 2003) Şahin M.T.; Demir M.A.; Kaya Y.; Can M.; Inanir I.; Öztürkcan S.Keratotic basal cell carcinoma may not only clinically but also histologically share more or less the same features with giant solitary trichoepithelioma. It can be difficult to distinguish these two entities from each other, even for an experienced dermatopathologist. We present an unusual case of inguinal keratotic basal cell carcinoma mimicking giant solitary trichoepithelioma in a 56-year-old woman with a finger-like tumor of 20 years duration. The patient presented with an asymptomatic, skin colored, firm, nonulcerative, nodular lesion. Scanty mitotic activity and apoptotic cells were the histopathologic findings against basal cell carcinoma, whereas absence of papillary mesenchymal bodies, presence of peritumoral lacunae detected only around the solid areas, and accumulation of amyloid-like hyalinized material were the findings in favor of basal cell carcinoma. This case illustrates that keratotic basal cell carcinoma must be taken into account in the differential diagnosis of inguinally located solitary, polypoid masses, especially giant solitary trichoepithelioma.Item The association of dehydroepiandrosterone, obesity, waist-hip ratio and insulin resistance with fatty liver in postmenopausal women - A hyperinsulinemic euglycemic insulin clamp study(2003) Saruç M.; Yüceyar H.; Ayhan S.; Türkel N.; Tuzcuoglu I.; Can M.Background/Aims: The relationship between insulin resistance and the occurrence of fatty acid has been documented. Recently DHEA (dehydroepiandrosterone) was shown to have a protective effect against development of fatty liver in rats. We aimed to investigate the association of nonalcoholic fatty liver and serum levels of DHEA, obesity, fat distribution and insulin resistance and to evaluate the effect of DHEA on fatty liver, obesity and insulin resistance. Methodology: Thirteen postmenopausal women with nonalcoholic fatty liver and 14 postmenopausal women with normal liver histology were included into the study. Body mass index, waist-hip ratio, serum DHEA, DHEAS, triglyceride, cholesterol levels and insulin resistance were determined. Fatty liver was determined by ultrasound and established by liver biopsy and histology. Hyperinsulinemic euglycemic clamp studies were performed. Results: The subjects in both groups were age matched (p>0.05). Body mass index showed obesity in patients with fatty liver but not in control group (p=0.01). Central obesity was present in women with fatty liver (p=0.039). As expected, insulin resistance was significantly present in patients with fatty liver (p=0.001). DHEA and DHEAS levels of women with fatty liver were greater than those of control group (p1=0.001 and p2=0.0001, respectively). DHEA and DHEAS were positively correlated with both body mass index and waist-hip ratio. However, glucose disposal rate was inversely and significantly correlated with DHEA and DHEAS levels. Conclusions: These data do not support the hypothesis that DHEA or DHEAS protect postmenopausal women against fatty liver, diabetes and obesity. Indeed, DHEA and DHEAS may be the cause of fatty liver, obesity (especially abdominal obesity) and diabetes in estrogen-deficient women.Item Effect of mesh and its localisation on testicular flow and spermatogenesis in patients with Groin Hernia(ARSMB-KVBMG, 2003) Aydede H.; Erhan Y.; Sakarya A.; Kara E.; Ilkgül Ö.; Can M.In this study, the long-term effects of mesh and its localisation (i.e. anterior or posterior) on testicular perfusion and testicular function were evaluated in groin hernia patients. Testicular function has been evaluated with spermiogram and testicular perfusion with colour Doppler ultrasonography. Group I: consisted of 30 posterior preperitoneal mesh repair patients Group II: consisted of 30 anterior tension-free repair patients. The operation types were randomised with a systematic sampling method. There was no statistically significant difference between pre-operative and postoperative spermiogram results for both groups. No statistically significant difference was found between the two groups in terms of Doppler flow parameters (PSV, EDV, RI and PI) for pre-operative, early and late postoperative periods. When Doppler flow parameters were compared for group I, statistically significant differences were found between pre-operative and early postoperative values. No statistically significant difference was found between pre-operative and late postoperative values. This is also true for early postoperative values versus late postoperative values. When Doppler flow parameters were compared for group II, statistically significant differences were found between pre-operative and early postoperative values. No statistically significant difference was found between pre-operative and late postoperative values. This is also true for early postoperative values versus late postoperative values. These results support the idea that inguinal mesh application is still a safe procedure in patients with no children or who are undergoing infertility treatment, where testicular function is important.Item Somatostatin infusion and hemodynamic changes in patients with non-variceal upper gastrointestinal bleeding: A pilot study(2003) Saruç M.; Can M.; Küçükmetin N.; Tuzcuoglu I.; Tarhan S.; Göktan C.; Yüceyar H.Background: Intravenous somatostatin decreases acid secretion, splanchnic blood flow, and portal pressure, but the evidence for its efficacy in the treatment of non-variceal upper gastrointestinal bleeding has been mixed. We aimed to evaluate the vasoactive effect and possible mechanisms of somatostatin infusion in the cessation of non-variceal upper gastrointestinal bleeding. Material/Methods: Patients with non-variceal upper gastrointestinal bleeding without portal hypertension were enrolled in the study. They were given somatostatin infusion in a dose of 250 μgr/hour for 72 hours. Superior mesenteric arterial average flow velocity (SMA-V), SMA pulsatility index (SMA-PI), portal venous volume flow (PV-F), and renal artery resistance index (RA-RI) were measured two times for each patient by Doppler ultrasound; oncee on the first day of infusion therapy and again 6 hours or more after stopping the infusion. Results: 21 patients (12 male, mean age 44.1±9.9) with bleeding peptic ulcer were enrolled. During somatostatin infusion, PV-F was 33.7±19.7 cm3/sec. After stopping infusion, it increased to 56.3±16.0 cm3/sec (p=0.001). SMA-V was 39.7±13.1 cm/ sec and 64.4±15.1 cm/sec during somatostatin infusion and after cessation of somatostatin respectively (p=0.01). SMA-PI was 2.0±0.8 during somatostatin infusion but 2.8±0.8 without somatostatin infusion (p=0.02). However, RA-RI showed no difference between states with or without somatostatin infusion (p>0.05). Conclusions: Somatostatin infusion causes a decrease in arterial blood flow to the stomach and duodenum in patients with non-variceal upper gastrointestinal bleeding without portal hypertension. Somatostatin therapy also decreases portal blood flow while not altering renal blood.Item Highly soluble polyoxyethylene-perylene diimide: Optical, electrochemical and photovoltaic studies(2011) Birel O.H.; Zafer C.; Dincalp H.; Aydin B.; Can M.The synthesis and optical properties of a new dye molecule [PERKAT] were reported. The molecular structure of PERKAT was characterized by FT-IR and 1H NMR. Optical properties of PERKAT were investigated by UV-Vis absorption, fluorescence spectroscopy. The effect of the solvent polarity on the spectral characteristics has been investigated in five common organic solvents of different polarity. PERKAT is highly soluble in common organic solvents such as chloroform, dichloromethane due to the polyoxyethylene chains. The fluorescence quantum yields of PERKAT in all solvents is very low (10 -2 -10-3). Cyclic Voltammetry (CV) analysis was performed to determine the HOMO and LUMO energy levels of the PERKAT. PERKAT was used as electron acceptor material in organic solar cell.Item A multicenter nationwide reference intervals study for common biochemical analytes in Turkey using Abbott analyzers(Walter de Gruyter GmbH, 2014) Ozarda Y.; Ichihara K.; Aslan D.; Aybek H.; Ari Z.; Taneli F.; Coker C.; Akan P.; Sisman A.R.; Bahceci O.; Sezgin N.; Demir M.; Yucel G.; Akbas H.; Ozdem S.; Polat G.; Erbagci A.B.; Orkmez M.; Mete N.; Evliyaoglu O.; Kiyici A.; Vatansev H.; Ozturk B.; Yucel D.; Kayaalp D.; Dogan K.; Pinar A.; Gurbilek M.; Cetinkaya C.D.; Akin O.; Serdar M.; Kurt I.; Erdinc S.; Kadicesme O.; Ilhan N.; Atali D.S.; Bakan E.; Polat H.; Noyan T.; Can M.; Bedir A.; Okuyucu A.; Deger O.; Agac S.; Ademoglu E.; Kaya A.; Nogay T.; Eren N.; Dirican M.; Tuncer G.; Aykus M.; Gunes Y.; Ozmen S.U.; Kawano R.; Tezcan S.; Demirpence O.; Degirmen E.Background: A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality. Methods: Blood samples were collected nationwide in 28 laboratories from the seven regions (≥400 samples/region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and analyzer. Reference materials were used for standardization of test results. After secondary exclusion using the latent abnormal values exclusion method, RIs were derived by a parametric method employing the modified Box-Cox formula and compared with the RIs by the non-parametric method. Three-level nested ANOVA was used to evaluate variations among sexes, ages and regions. Associations between test results and age, body mass index (BMI) and region were determined by multiple regression analysis (MRA). Results: By ANOVA, differences of reference values among seven regions were significant in none of the 25 analytes. Significant sex-related and age-related differences were observed for 10 and seven analytes, respectively. MRA revealed BMI-related changes in results for uric acid, glucose, triglycerides, high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase, and γ-glutamyltransferase. Their RIs were thus derived by applying stricter criteria excluding individuals with BMI >28 kg/m2. Ranges of RIs by non-parametric method were wider than those by parametric method especially for those analytes affected by BMI. Conclusions: With the lack of regional differences and the well-standardized status of test results, the RIs derived from this nationwide study can be used for the entire Turkish population. © by De Gruyter 2014.Item Surface modification of CdSeS nanocrystals for polymer hybrid solar cells(Royal Society of Chemistry, 2016) Erdogan A.; Karakaya C.; Gonce M.K.; Buyukcelebi S.; Yenel E.; Kara K.; Ozcivan A.N.; Can M.; Kus M.; Demic S.We report the synthesis of fluorene-carbazole derivatives as capping agents for CdSeS nanocrystals and present their performance in polymer hybrid solar cells. CdSeS nanocrystals and different ligands consisting of fluorene and carbazole units were synthesized and characterized. Both oleic acid and pyridine capped CdSeS nanocrystals were used as reference materials in polymer hybrid solar cells. We observed that our synthesized materials show better efficiencies depending on their structures. In comparison with the reference cells consisting of pyridine capped CdSeS nanocrystals, ligand capped CdSeS shows better efficiency due to electron withdrawing and accepting groups in its structure. The reason behind the superiority of our ligands compared to the reference pyridine is the donor and/or acceptor based compatibility of the combined structures and effective surface modification as well. © 2016 The Royal Society of Chemistry.Item Spectroscopic studies on 9H-carbazole-9-(4-phenyl) boronic acid pinacol ester by DFT method(Elsevier B.V., 2016) Sas E.B.; Kurt M.; Can M.; Horzum N.; Atac A.9H-Carbazole-9-(4-phenyl) boronic acid pinacol ester (9-CPBAPE) molecule was investigated by FT-IR, Raman, UV-vis, 1H and 13C NMR spectra. FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. 1H, 13C NMR and UV-vis spectra were recorded in dimethyl sulfoxide (DMSO) solution. The results of theoretical calculations for the spectra of the title molecule were compared with the experimental spectra. The highest occupied molecular orbital (HOMO) the lowest unoccupied molecular orbital (LUMO) and molecular electrostatic potential (MEP) analyses were performed. The theoretical calculations for the molecular structure and spectroscopic studies were performed with DFT (B3LYP) and 6-311G (d,p) basis set calculations using the Gaussian 09 program. The total (TDOS), partial (PDOS) density of state and overlap population density of state (OPDOS) diagrams analyses were performed using GaussSum 2.2 program. © 2016 Elsevier B.V. All rights reserved.Item Synthesis and spectroscopic characterization on 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid: A DFT approach(Elsevier, 2016) Kurt M.; Sas E.B.; Can M.; Okur S.; Icli S.; Demic S.; Karabacak M.; Jayavarthanan T.; Sundaraganesan N.Abstract A complete structural and vibrational analysis of the 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid (TPBA), was carried out by ab initio calculations, at the density functional theory (DFT) method. Molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO) 13C NMR and 1H NMR chemical shift values of (TPBA), in the ground state have been calculated by using ab initio density functional theory (DFT/B3LYP) method with 6-311G(d,p) as basis set for the first time. Comparison of the observed fundamental vibrational modes of (TPBA) and calculated results by DFT/B3LYP method indicates that B3LYP level of theory giving yield good results for quantum chemical studies. Vibrational wavenumbers obtained by the DFT/B3LYP method are in good agreement with the experimental data. The study was complemented with a natural bond orbital (NBO) analysis, to evaluate the significance of hyperconjugative interactions and electrostatic effects on such molecular structure. By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals analysis and thermodynamic properties of TPBA were investigated using theoretical calculations. © 2015 Elsevier B.V.Item Functionalized organic semiconductor molecules to enhance charge carrier injection in electroluminescent cell(Elsevier B.V., 2017) Yalcin E.; Kara D.A.; Karakaya C.; Yigit M.Z.; Havare A.K.; Can M.; Tozlu C.; Demic S.; Kus M.; Aboulouard A.Organic semiconductor (OSC) materials as a charge carrier interface play an important role to improve the device performance of organic electroluminescent cells. In this study, 4,4″-bis(diphenyl amino)-1,1':3′,1″-terphenyl-5'-carboxylic acid (TPA) and 4,4″-di-9H-carbazol-9-yl-1,1':3′,1″-terphenyl-5'-carboxylic acid (CAR) has been designed and synthesized to modify indium tin oxide (ITO) layer as interface. Bare ITO and PEDOT:PSS coated on ITO was used as reference anode electrodes for comparison. Furthermore, PEDOT:PSS coated over CAR/ITO and TPA/ITO to observe stability of OSC molecules and to completely cover the ITO surface. Electrical, optical and surface characterizations were performed for each device. Almost all modified devices showed around 36% decrease at the turn on voltage with respect to bare ITO. The current density of bare ITO, ITO/CAR and ITO/TPA were measured as 288, 1525 and 1869 A/m2, respectively. By increasing current density, luminance of modified devices showed much better performance with respect to unmodified devices. © 2017 Elsevier B.V.Item Experimental and computational investigation of graphene/SAMs/n-Si Schottky diodes(Elsevier B.V., 2018) Aydin H.; Bacaksiz C.; Yagmurcukardes N.; Karakaya C.; Mermer O.; Can M.; Senger R.T.; Sahin H.; Selamet Y.We have investigated the effect of two different self-assembled monolayers (SAMs) on electrical characteristics of bilayer graphene (BLG)/n-Si Schottky diodes. Novel 4″bis(diphenylamino)-1, 1′:3″-terphenyl-5′ carboxylic acids (TPA) and 4,4-di-9H-carbazol-9-yl-1,1′:3′1′-terphenyl-5′ carboxylic acid (CAR) aromatic SAMs have been used to modify n-Si surfaces. Cyclic voltammetry (CV) and Kelvin probe force microscopy (KPFM) results have been evaluated to verify the modification of n-Si surface. The current–voltage (I–V) characteristics of bare and SAMs modified devices show rectification behaviour verifying a Schottky junction at the interface. The ideality factors (n) from ln(I)–V dependences were determined as 2.13, 1.96 and 2.07 for BLG/n-Si, BLG/TPA/n-Si and BLG/CAR/n-Si Schottky diodes, respectively. In addition, Schottky barrier height (SBH) and series resistance (R s ) of SAMs modified diodes were decreased compared to bare diode due to the formation of a compatible interface between graphene and Si as well as π–π interaction between aromatic SAMs and graphene. The CAR-based device exhibits better diode characteristic compared to the TPA-based device. Computational simulations show that the BLG/CAR system exhibits smaller energy-level-differences than the BLG/TPA, which supports the experimental findings of a lower Schottky barrier and series resistance in BLG/CAR diode. © 2017 Elsevier B.V.Item Rate of Overlap between ICD-11 Gaming Disorder and DSM-5 Internet Gaming Disorder along with Turkish Reliability of the Gaming Disorder Scale for Adolescents (GADIS-A)(S. Karger AG, 2023) Tuncturk M.; Karacetin G.; Ermis C.; Ciray R.O.; Can M.; Yesilkaya C.; Atay A.; Alkas G.E.; Kasap D.; Guney O.; Alarslan S.; Cakir B.; Halac E.; Tonyall A.; Elmas F.N.; Turan S.Introduction: The main aims of the current study were (i) to explore the overlap between Internet gaming disorder (IGD) and gaming disorder (GD) diagnoses, (ii) to identify clinical characteristics in clinical settings, and (iii) to measure psychometric properties of the Gaming Disorder Scale for Adolescents (GADIS-A). Methods: 222 adolescents who were followed up within a tertiary-care mental health hospital, were included (IGD/GD group [n = 111], clinical comparison group [n = 90], healthy controls [n = 21]). The tools used were the GADIS-A, Internet Gaming Disorder Scale-Short-Form, The Difficulties in Emotion Regulation Scale (DERS-36), Children's Global Assessment Scale, and a semistructured interview for DSM-5 diagnoses. Results: The overlap rate of IGD and GD is 73%. Comorbid ADHD diagnoses were more commonly found in the IGD group compared to the clinical comparison group. Patients who met GD and IGD diagnoses revealed higher scores in DERS-36. Turkish GADIS-A Item-Total score correlation coefficients were between 0.627 and 0.860. In the sample, there was a high level of correlation between the number of DSM-5 and ICD-11 diagnostic criteria met and GADIS-A scale scores. The Cronbach's alphas if item deleted ranged between 0.942 and 0.954. In addition, treatment refusal was more frequent in the IGD group than in the clinical comparison group. Conclusion: The GADIS-A had good to excellent psychometric properties in Turkish adolescents. Despite having a stricter diagnostic criterion, GD overlapped with IGD in a clinical population. © 2023 S. Karger AG. All rights reserved.