FUZZY D-CONTINUOUS FUNCTIONS

Akdag, Metin The Youngnam Mathematical Society Korea 2001 East Asian mathematical journal Vol.17 No.1

In this paper, fuzzy D-continuous function is defined. Some basic properties of this continuity are summarized; and sufficient conditions on domain and/or ranges implying fuzzy D-continuity of fuzzy D-continuous functions are given. Also fuzzy D-regular space is defined and by using fuzzy D-continuity, the condition which is equivalent to fuzzy D-regular space, is given.

On Upper and Lower Z-supercontinuous Multifunctions

Akdag, Metin Department of Mathematics 2005 Kyungpook mathematical journal Vol.45 No.2

In this paper, we define a multifunction $F:X{\rightarrow}Y$ to be upper (lower) Z -supercontinuous if $F^{+}(V)(F^{-}(V))$ is z-open in X for every open set V of Y. We obtain some characterizations and several properties concerning upper (lower) Z-supercontinuous multifunctions.

A novel echocardiographic method for assessing arterial stiffness in obstructive sleep apnea syndrome

Serkan Akdag,Aytac Akyol,Huseyin Altug Cakmak,Hulya Gunbatar,Muntecep Asker,Naci Babat,Aydin Rodi Tosu,Mehmet Yaman,Hasan Ali Gumrukcuoglu 대한심장학회 2015 Korean Circulation Journal Vol.45 No.6

Background and Objectives: Obstructive sleep apnea syndrome (OSAS) is associated with increased arterial stiffness and cardiovascularcomplications. The objective of this study was to assess whether the color M-mode-derived propagation velocity of the descendingthoracic aorta (aortic velocity propagation, AVP) was an echocardiographic marker for arterial stiffness in OSAS. Subjects and Methods: : The study population included 116 patients with OSAS and 90 age and gender-matched control subjects. Thepatients with OSAS were categorized according to their apnea hypopnea index (AHI) as follows: mild to moderate degree (AHI 5-30) andsevere degree (AHI≥30). Aortofemoral pulse wave velocity (PWV), carotid intima-media thickness (CIMT), brachial artery flow-mediateddilatation (FMD), and AVP were measured to assess arterial stiffness. Results: AVP and FMD were significantly decreased in patients with OSAS compared to controls (p<0.001). PWV and CIMT were increasedin the OSAS group compared to controls (p<0.001). Moreover, AVP and FMD were significantly decreased in the severe OSAS groupcompared to the mild to moderate OSAS group (p<0.001). PWV and CIMT were significantly increased in the severe group compared tothe mild to moderate group (p<0.001). AVP was significantly positively correlated with FMD (r=0.564, p<0.001). However, it was found tobe significantly inversely related to PWV (r=-0.580, p<0.001) and CIMT (r=-0.251, p<0.001). Conclusion: The measurement of AVP is a novel and practical echocardiographic method, which may be used to identify arterial stiffnessin OSAS

Direct Immunofluorescence in Behçet’s Disease: A Controlled Study with 108 Cases

Afet Akdag Kose 연세대학교의과대학 2009 Yonsei medical journal Vol.50 No.4

Purpose: Behçet’s disease (BD) is a disease of unknown etiology, which has multisystemic involvement. This multisystemic involvement might be the clue for an autoimmune pathogenesis. In order to evaluate an autoimmune pathogenesis, we examined immunoreactans depositions in the skin of BD patients. Materials and Methods: The skin samples of 108 BD patients (28 perilesional skin, 44 positive pathergy test site, 22 negative pathergy test site, 14 normal skin) were examined for the depositions of immunoglobulin (Ig)M, IgG, IgA, complement 3 (C3), and fibrinogen (F) using direct immunofluorescence (DIF). The data were statistically compared to the DIF of 36 systemic lupus erythematosus (SLE) patients and 20 healthy controls using χ2 Fisher exact test. Results: Highly significant immunoreactans depositions were obtained in BD (deposition rates: IgM 70.3%, IgG 0%, IgA 20.3%, C3 62.9%, F 83.3%). The comparison with SLE revealed no differences in IgM, IgA, and C3. However, IgG deposition was higher in SLE while F deposition was higher in BD. In both BD and SLE, the Ig depositions were highly significant when the data were compared with the healthy controls. Conclusion: The significant deposition of immunoreactans in BD, especially in the negative pathergy and the normal skin sites, were observed. This study is the first controlled study revealing positive Ig depositions in BD, and it is expected to help us to reconsider the autoimmune pathogenesis in BD. Purpose: Behçet’s disease (BD) is a disease of unknown etiology, which has multisystemic involvement. This multisystemic involvement might be the clue for an autoimmune pathogenesis. In order to evaluate an autoimmune pathogenesis, we examined immunoreactans depositions in the skin of BD patients. Materials and Methods: The skin samples of 108 BD patients (28 perilesional skin, 44 positive pathergy test site, 22 negative pathergy test site, 14 normal skin) were examined for the depositions of immunoglobulin (Ig)M, IgG, IgA, complement 3 (C3), and fibrinogen (F) using direct immunofluorescence (DIF). The data were statistically compared to the DIF of 36 systemic lupus erythematosus (SLE) patients and 20 healthy controls using χ2 Fisher exact test. Results: Highly significant immunoreactans depositions were obtained in BD (deposition rates: IgM 70.3%, IgG 0%, IgA 20.3%, C3 62.9%, F 83.3%). The comparison with SLE revealed no differences in IgM, IgA, and C3. However, IgG deposition was higher in SLE while F deposition was higher in BD. In both BD and SLE, the Ig depositions were highly significant when the data were compared with the healthy controls. Conclusion: The significant deposition of immunoreactans in BD, especially in the negative pathergy and the normal skin sites, were observed. This study is the first controlled study revealing positive Ig depositions in BD, and it is expected to help us to reconsider the autoimmune pathogenesis in BD.

Management and Outcome of Intracranial Dural Arteriovenous Fistulas That Have Caused a Hemorrhage in the Posterior Fossa : A Clinical Study

Rıfat Akdag,Uğur Soylu,Ergün Dağlıoğlu,İlkay Akmangit,Vedat Açık,Ahmet Deniz Belen 대한신경외과학회 2023 Journal of Korean neurosurgical society Vol.66 No.6

Objective : We evaluated the diagnosis, treatment, and long-term results of patients with dural arteriovenous fistula (dAVF), which is a very rare cause of posterior fossa hemorrhage. Methods : This study included 15 patients who underwent endovascular, surgical, combined, or Gamma Knife treatments between 2012 and 2020. Demographics and clinical features, angiographic features, treatment modalities, and outcomes were analyzed. Results : The mean age of the patients was 40±17 years (range, 17–68), and 68% were men (11/15). Seven of the patients (46.6%) were in the age group of 50 years and older. While the mean Glasgow coma scale was 11.5±3.9 (range, 4–15), 46.3% presented with headache and 53.7% had stupor/coma. Four patients (26.6%) had only cerebellar hematoma and headache. All dAVFs had cortical venous drainage. In 11 patients (73.3%), the fistula was located in the tentorium and was the most common localization. Three patients (20%) had transverse and sigmoid sinus localizations, while one patient (6.7%) had dAVF located in the foramen magnum. Eighteen sessions were performed on the patients during endovascular treatment. Sixteen sessions (88.8%) were performed with the transarterial (TA) route, one session (5.5%) with the transvenous (TV) route, and one session (5.5%) with the TA+TV route. Surgery was performed in two patients (14.2%). One patient (7.1%) passed away. While there were nine patients (64.2%) with a Rankin score between 0 and 2, the total closure rate was 69.2% in the first year of control angiograms. Conclusion : In the differential diagnosis of posterior fossa hemorrhages, the differential diagnosis of dAVFs, which is a very rare entity, should be considered, even in the middle and elderly age groups, in patients presenting with good clinical status and pure hematoma. The treatment of such patients can be done safely and effectively in a multidisciplinary manner with a good understanding of pathological vascular anatomy and appropriate endovascular treatment approaches.

Do All Antioxidant Supplements Have the Same Potential Effect on Preventing Myringosclerosis?

Seden Akdagli,Arzu Tuzuner,Sule Demirci,Hatice Karadas,Kamil Gökce Tulaci,Mehmet Dogan,Refik Caylan 대한이비인후과학회 2015 Clinical and Experimental Otorhinolaryngology Vol.8 No.1

Objectives. Myringosclerosis is an irreversible pathological healing mechanism of the tympanic membrane which can result in the formation of sclerotic plaques. Antioxidant treatment is a recognised prevention therapy and coenzyme Q10 (CoQ10), lycopene, and grape seed extract (GSE), were used in this manner. Methods. Forty-four Wistar rats were used in this experiment, and, following myringotomies, the animals were randomly divided into four groups. CoQ10, lycopene or GSE was administered orally to the respective groups, starting from the day of surgery. Otomicroscopy examination was performed on the 14th day. All tympanic membrane lesions were evaluated and compared otomicroscopically and histopathologically. Results. The otomicroscopy and histopathological findings, compared against a control (saline) group, showed the CoQ10, lycopene, and GSE groups had statistically significant differences of degree of sclerosis (P<0.001). Conclusion. CoQ10, lycopene, and GSE were compared against a saline group and their antioxidative and anti-inflammatory effects were similar. The formation of myringosclerotic plagues after experimental myringotomy in rats significantly decreased and diminished after systemic administration of the three different antioxidant supplements.

Evaluation of Hearing and Outer Hair Cell Function of Cochlea in Patients With Psoriatic Arthritis

Mehmet Akdag,Derya Uçmak,Fazıl Emre Özkurt,Mehtap Bozkurt,Zeynep Meltem Akkurt,İsmail Topçu 대한이비인후과학회 2015 Clinical and Experimental Otorhinolaryngology Vol.8 No.3

Objectives. The aim of this study was to investigate hearing and outer cells function in patients with psoriatic arthritis. Our investigation was a prospective case control study. Methods. A total of 31 psoriatic arthritis patients (62 ears) and 31 healthy control subjects (62 ears) were enrolled in the study. We investigated hearing changes of patients and controls via pure tone audiometry, speech discrimination scores, tympanometry, acoustic reflex, and transient product otoacoustic emission. Results. The mean age of psoriatic arthritis patients was 36.1±8.5 years (range, 14 to 62 years). The average age of the control group was 37.9±8.1 years (range, 16 to 62 years). There were statistically significant differences between pure tone audiometry in all frequencies and right and left emission at the 4.0 and 1.0 in psoriatic arthritis patients versus controls (P<0.05). This difference was evident, especially at high frequencies. There was no statistically significant difference between the ages and genders of the patient and control groups (P>0.05). Both audiological and otoacoustic emissions were not significantly different between right and left ear (P>0.05). Conclusion. Based on the audiological and otoacoustic findings; it is likely that the cochlear outer hair cells become subtly damaged in psoriatic arthritis patients, consequently leading to changes in hearing thresholds. These data suggest that it is important to screen psoriatic arthritis patients for hearing changes with otoacoustic emissions and audiologic tests regularly.

Early and Late Complications after Inguinofemoral Lymphadenectomy for Vulvar Cancer

Cirik, Derya Akdag,Karalok, Alper,Ureyen, Isin,Tasci, Tolga,Kalyoncu, Rukiye,Turkmen, Osman,Kose, M Faruk,Tulunay, Gokhan,Turan, Taner Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.13

Background: We aimed to determine the frequency of early and late complications following groin surgery for vulvar cancer and analyze possible risk factors. Materials and Methods: This retrospective cohort study included 99 women who underwent for vulvar cancer. The early (${\leq}1$ month) complications were wound infection, breakdown and lymphocyst and late (>1 month) complications were lower limb lymphedema, incontinence and erysipelas. The risk factors for developing each of the complications were analyzed with regression analysis. Results: In the entire cohort, 29 (29.3%) women experienced early and 12 (12.1%) had late complications. Wound complications including infection and breakdown were the leading early complications (23.2%). In the multivariate analysis, both obesity (body mass index ${\geq}30kg/m^2$) and advanced age (${\geq}65years$) were found as independent predictive factors for early complications. Obese women of advanced age had 6.32 times more risk of experiencing any of the early complications, when compared to non-obese and young women (55.6% vs 8.7%). The most common late complication was lower limb lymphedema (10.1%) that was more frequently seen in young women. However, neither age nor lymph node count were significantly associated with the occurrence of lower limb lymphedema. Conclusions: More than 40% of the women suffered from postoperative complications after inguinofemoral lymphadenectomy in the current study. While advanced age and obesity were the significant predictors for any of the early complications, there was no identified risk factor for lower limb lymphedema.

Approximate Expression of Bit Error Rate in Uplink MC-CDMA Systems with Equal Gain Combining

Develi, Ibrahim,Akdagli, Ali The Korea Institute of Information and Commucation 2013 Journal of communications and networks Vol.15 No.1

Uplink multicarrier code-division multiple-access (MC-CDMA) with equal gain combining (EGC) over Nakagami fading channels is considered. An improved expression which is a feasible alternative for the bit error rate (BER) performance evaluation of MC-CDMA signals is proposed. Simulated annealing algorithm is employed to obtain the optimum value of the coefficients belonging to the proposed expression. Numerical examples show that the performance curves computed by the improved expression are in good agreement with the results obtained by the exact expression. Thus, the proposed expression can improve the accuracy of BER performance evaluation that has been realized by the approximate expression.

Approximate Expression of Bit Error Rate in Uplink MC-CDMA Systems with Equal Gain Combining

Ibrahim Develi,Ali Akdagli 한국통신학회 2013 Journal of communications and networks Vol.15 No.1

Uplink multicarrier code-division multiple-access (MCCDMA)with equal gain combining (EGC) over Nakagami fading channels is considered. An improved expression which is a feasible alternative for the bit error rate (BER) performance evaluation of MC-CDMA signals is proposed. Simulated annealing algorithm is employed to obtain the optimum value of the coefficients belonging to the proposed expression. Numerical examples show that the performance curves computed by the improved expression are in good agreement with the results obtained by the exact expression. Thus,the proposed expression can improve the accuracy of BER performance evaluation that has been realized by the approximate expression.