Browsing by Author "Yildirim Y."
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Item The concentration of insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 in maternal sera during pregnancy with normal and growth retarded fetuses; [Normal ve yetersiz fetal gelisim gosteren gebelerde gebelik suresince serum insulin benzeri buyume faktoru-1 (IGF-1) ve insulin benzeri buyume faktoru baglayici protein-3 (IGFBP-3) konsantrasyonlari](2000) Lacin S.; Oruc S.; Kuscu K.; Ersoy B.; Tansug N.; Uyanik B.S.; Yildirim Y.; Koyuncu F.Objective: To determine the concentrations of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 in maternal sera of pregnancies with normal and growth retarded fetuses and investigate the relationship between these substances and fetal growth. Materials and Methods: Blood samples of 148 pregnant women were collected at 14-16 and 30-31 weeks and during delivery. Also cord blood samples were obtained during delivery. For the determination of IGF-1 and IGFBP-3, double-sided IRMA method was used. Infants were divided into two groups as normal and growth retarded fetuses based upon their patterns of growth using the percentile curves and the serum levels were compared. Correlation analysis and Mann-Whitney U test were used as statistical calculations. Results: Both IGF-1 and IGFBP-3 levels increased while approaching term in all pregnant women. In growth retarded cases, maternal IGF-1 levels were found to be significantly lower than pregnancies with normal fetuses (p< 0.005), but maternal IGFBP-3 levels were not different between two groups. IGF-1 levels in cord blood during delivery were not different while IGFBP-3 levels were significantly higher in growth retarded fetuses. Conclusion: Our study did not support the hypothesis that fetal growth retardation is due to IGF-1 deficiency. High binding protein levels may cause a relative free IGF-1 deficiency, but the levels of binding protein is probably secondary to metabolic changes or placental insufficiency. Low levels of IGF-1 and high levels of binding proteins implies the necessity of further investigation of placental transfer.Item Immunolocalization of transforming growth factor-β3 in pregnant human myometrium: Possible associations with labor(2001) Kuşcu N.K.; Laçin S.; Vatansever S.; Yildirim Y.; Var A.; Uyanik B.S.; Koyuncu F.Background. Transforming growth factor-β3 is a cytokine which is involved in cell growth regulation and differentiation, stimulation of extracellular matrix and modulation of immune responses. The goal of this study was to detect the presence of this cytokine in the myometrium of preterm and term, nonlaboring and laboring patients, and to measure serum levels of interleukin-1β (IL-1β), IL-6 and IL-8 before cesarean section. Methods. In this prospective study, we obtained samples of myometrium from the lower uterine segment during elective and emergency cesarean sections (term non-laboring, n=8; term laboring, n=7; preterm non-laboring, n=3; and preterm laboring, n=19) and stained for transforming growth factor-β3. Blood was also sampled from the same patients to determine IL-1β, IL-6 and IL-8 levels. Results. Different intensities of staining were detected in preterm laboring, term nonlaboring and term laboring groups, but there was no staining in preterm nonlaboring group. We also found a statistically significant difference in IL-6 levels between laboring and nonlaboring groups (p=0.028). Conclusion. Different intensities of TGF-β3 which appeared in different stages of myometrium made us consider that TGF-β3 might prepare myometrium to labor, and IL-6 was more important than the other interleukins in initiation of labor.Item Relationship of sexuality with psychological and hormonal features in the menopausal period(2003) Danaci A.E.; Oruç S.; Adigüzel H.; Yildirim Y.; Aydemir Ö.Women may experience some mental and sexual problems between the ages of 40 years and 60 years due to serious changes in the hormonal system. The aim of this study was to examine the relationships between the changes in sex hormones, sexual behaviours, depression and anxiety levels of women who were in either the premenopausal, perimenopausal or postmenopausal period. The subjects of this cross-sectional study consisted of 324 women who attended the Gynaecology and Obstetrics Out-Patient Ward of Celal Bayar University Hospital. Of this group, 37.0% (n = 124) were postmenopausal, 27.2% (n = 84) perimenopausal and 35.8% (n = 116) premenopausal. Beck Depression Inventory (BDI), State and Trait Anxiety Inventories (STAI-I and II) and a questionnaire on sexual behaviour which was prepared for this study by the authors, were applied to all of the attendees and serum sex hormone levels were analyzed. Beck Depression Anxiety, STAI-I and STAI-II scores and sexual behaviours did not show any statistically significant difference among these three groups. The frequency of sexual intercourse was lower in women with high BDI scores. The rate of painful intercourse was higher in women with high STAI-I scores. The frequency of sexual intercourse, sexual desire and orgasm decreased and painful intercourse increased in women with high STAI-II scores. The frequency of sexual intercourse decreased significantly as the age or follicle stimulating hormone level of women increased. These findings have revealed that the menopausal state did not affect the sexual behaviour, and psychological state of women between the ages of 40 and 60 years, but the increase in anxiety and depression scores affected the sexual life in a negative manner.Item Detection of endothelial dysfunction in preeclamptic patients by using color Doppler sonography(Springer Verlag, 2003) Kuscu N.K.; Kurhan Z.; Yildirim Y.; Tavli T.; Koyuncu F.Our goal in this study was to detect endothelial function in normal and preeclamptic patients by using color Doppler sonography and plasma fibronectin levels. The increased ratio of the brachial artery diameter during shear stress, and plasma fibronectin levels were measured in 15 preeclamptic and 11 normal, gestational-age matched pregnant patients. The test was repeated at the postpartum second and sixth weeks in the preeclamptic group. In addition, the plasma fibronectin levels of all patients were measured. The increased ratios were 4.26±0.69% vs 12.18±1.97% in the preeclamptic and normal patients, respectively (P=0.003). At the second and sixth postpartum weeks, the ratios were 6.67±0.89% and 9.27±1.16% in the preeclamptic group, revealing a significant improvement in the sixth week (P=0.001). Fibronectin levels were 0.80±0.11 g/L vs 0.45±0.06 g/L in preeclamptic and normal patients (P=0.01). The correlation coefficient between the fibronectin levels and increase rate was r=-0.38 and P=0.05. We conclude that endothelial dysfunction, which is fundamental to preeclampsia, can be detected by using color Doppler sonography.Item Interleukin-6 levels in hyperemesis gravidarum(2003) Kuscu N.K.; Yildirim Y.; Koyuncu F.; Var A.; Uyanik B.S.Introduction: Hyperemesis gravidarum (HG) is associated with higher levels of serum β-hCG levels and hyperthyroidism. Interleukin-6 (IL-6), a pro-inflammatory cytokine, is reported to enhance secretion of β-hCG from trophoblastic cell line. Methods: We measured serum levels of IL-6, thyroid hormones and β-hCG of hyperemetic patients and gestational age-matched controls to search for a difference between the two groups. Results: There was a significant difference in β-hCG (p=0.028), though IL-6 levels were higher in the hyperemetic group, it did not reach a significant level. Interleukin-6 positively correlated with β-hCG (r=0.38 and p=0.13).Item Endothelial dysfunction in preeclampsia: Increased homocysteine and decreased nitric oxide levels(2003) Var A.; Yildirim Y.; Onur E.; Kuscu N.K.; Uyanik B.S.; Goktalay K.; Guvenc Y.Endothelial dysfunction underlies the pathogenesis of preeclampsia, but its mechanism has not yet been completely understood. Elevated oxygen free radicals may partially explain the endothelial cell damage. In this study, we have aimed to measure homocysteine (Hcy) and nitric oxide (NO) levels as endothelial dysfunction markers in preeclamptic women. Nineteen preeclamptic (33.9 ± 1.4 weeks) and 15 gestational-age-matched normal pregnant women (35.5 ± 0.7 weeks) were included in the study. Mean NO level was significantly lower (p < 0.001) and mean Hcy level was significantly higher (p < 0.001) in the preeclamptic group. Elevated Hcy and oxygen free radical levels could decrease NO levels due to the reaction with each other and reduced NO may increase blood pressure and ischemia in preeclamptic patients. We have concluded that increased Hcy and oxygen free radical levels, and decreased NO levels are closely associated with preeclampsia-related endothelial dysfunction. Copyright © 2003 S. Karger AG, Basel.Item Atherogenic profile in preeclampsia(Springer Verlag, 2003) Var A.; Kuşcu N.K.; Koyuncu F.; Uyanik B.S.; Onur E.; Yildirim Y.; Oruç S.Atherosis is accepted to underlie the pathogenesis of preeclampsia, therefore we aimed to determine malonyldialdehyde (MDA) levels as a marker of lipid peroxidation, and lipoprotein(a) (Lp(a)), apolipoprotein A-1 (Apo A-1) and apolipoprotein B (Apo B) levels as a marker of atherogenic profile in preeclamptic and normal pregnant women. Twenty preeclamptic and 20 gestational-age matched normal pregnant patients were enrolled in the study, mean gestational ages for the preeclamptic and the control group were 33.9±1.4 and 35.5±0.7 weeks, respectively. Blood was withdrawn from the patients soon after diagnosis, and from the controls at their routine prenatal visits. MDA levels was significantly higher in preeclamptic patients (P=0.0003), but no difference was observed in Apo A-1 and Apo B and Lp(a) levels between the 2 groups. We consider that higher MDA was due to oxidative stress seen in preeclampsia, and similar Apo A-1 and Apo B and Lp(a) levels were due to lack of systemic atherosis.Item Comparison of the radiopharmaceutical potentials of dithizone radiolabeled with 131I and with 99mTc(2007) Ünak T.; Yildirim Y.; Avcibasi U.; Biber Z.; Duman Y.; Ünak P.In this study, dithizone (diphenylthiocarbazone) has been separately radiolabeled with 131I and with 99mTc for preliminarily testing their radiopharmaceutical potentials on male albino rabbits. 131I-dithizone and 99mTc-dithizone were intravenously injected to rabbits via their ear veins after anesthetizing with a mixture of Alfazyne and Alfamine (Serva) to determine their dynamic and static statuses in the metabolism. Also, 99mTc as pertechnetate and 131I as iodate were administered to rabbits as controls. Dynamic and static scintigrams were obtained using a gamma camera (Diacan Instruments). Dynamic scintigrams were obtained over the first half hour with frames of 1 minute following the administrations of the labeled compounds. Static images were obtained from posterior projection at different time intervals up to about 3 hours following the administration of the radiolabeled compounds. 99mTc-dithizone was significantly uptaken by the pancreas in contrast to free 99mTc. In the case of 131I-dithizone, the distribution of 131I activity in the metabolism was clearly different than the case of free 131I and the uptake of 131I-dithizone at the pancreas zone was also significant. These preliminary tests have clearly indicated that especially 99mTc-dithizone has a significant potential to be used as a pancreatic radiopharmaceutical. © 2007 Springer Science+Business Media, Inc.Item Metabolic comparison of radiolabeled aniline- and phenol-phthaleins with 131I(2008) Avcibaşi U.; Avcibaşi N.; Ünak T.; Ünak P.; Müftüler F.Z.; Yildirim Y.; Dinçalp H.; Gümüşer F.G.; Dursun E.R.The metabolic comparison of aniline- and phenol-phthaleins radiolabeled with 131I (131I-APH and 131I-PPH, respectively) has been investigated in this study. To compare the metabolic behavior of these phthaleins and their glucuronide conjugates radiolabeled with 131I, scintigraphic and biodistributional techniques were applied using male Albino rabbits. The results obtained have shown that these compounds were successfully radioiodinated with a radioiodination yield of about 100%. Maximum uptakes of 131I-APH and 131I-PPH, which were metabolized as N- and O-glucuronides, were observed within 2 h in the bladder and in the small intestine, respectively. In the case of verification of considerably up taking of these compounds also by tumors developed in the small intestine and in the bladder tissues, these results can be expected to be encouraging to test these compounds, which will be radiolabeled with other radioiodines such as 125I, 123I and 124I as imaging and therapeutic agents in nuclear medical applications. © 2008 Elsevier Inc. All rights reserved.Item Isotopic dilution analysis of zinc in some tissue samples of urogenital systems of rats using 65Zn(2009) Ünak T.; Çal Ç.; Yildirim Y.; AvcIbaşI U.; Ünak G.Zinc plays an important role in prostate functions. For this reason, in this study some rats have been nourished with foods containing different zinc levels and some tissue samples removed at different intervals of time from their prostate, testis, and seminal vesicle. The zinc contents of these samples have been determined using the isotopic dilution analysis technique applied with 65Zn. In this way, the zinc contents of tissues varying between 0.02-4.50 μg Zn/g wet tissue could be determined with good precision. As a result, the zinc content of the prostate was found to be considerably high with respect to the zinc contents of the testis and the seminal vesicle. It is also interesting to note that a high zinc level in foods results in the accumulation of zinc in the prostate rather than in the testis and the seminal vesicle. The zinc content of the seminal vesicle decreases with a function of time passed from the beginning of the diet which contrasts with the case of prostate. It is also very remarkable that when the level of zinc in the body is low, the content of zinc in the testis is considerably higher. © 2009 Akadémiai Kiadó, Budapest, Hungary.Item Chronic Cervical Perforation by an Intrauterine Device(2010) Koltan S.O.; Tamay A.G.; Yildirim Y.The intrauterine device (IUD) is a widely used, highly effective method of birth control. Uterine perforation is a rare yet serious complication and is usually seen during insertion of the IUD. A regular examination is necessary for follow-up. We present a patient with an IUD that had perforated the cervix. The diagnosis was made during routine gynecological examination, and the patient was treated in a timely manner before any complications such as ectopic pregnancy, intrauterine pregnancy, infection or irreversible harm to the cervix arose. This case stresses the importance of regular visits to maintain health and diagnose possible adverse effects of intrauterine contraceptive methods. © 2010 Elsevier.Item Evaluation of the effects of gonadotropin-relasing hormone antagonist (GnRH-ant) and agonist (GnRH-a) in the prevention of postoperative adhesion formation in a rat model with immunohistochemical analysis(2011) Tamay A.G.; Guvenal T.; Micili S.C.; Yildirim Y.; Ozogul C.; Koyuncu F.M.; Koltan S.O.Objective: To investigate the effects of GnRH antagonist (GnRH-ant) and agonist (GnRH-a) in the prevention of postoperative pelvic adhesions by a visual scoring system and immunohistochemical methods in a rat uterine horn model. Design: Controlled experimental animal study. Setting: Animal laboratory at an academic research environment. Animal(s): Twenty-one Wistar albino rats. Intervention(s): Rats were randomized into three groups. One week before the operation the rats received either GnRH-ant or GnRH-a or saline solution; they then underwent surgical laparotomy, and both uterine horns were traumatized by a scalpel. Three weeks later, all rats were sacrificed and extension and severity of the adhesions in each group were scored by a visual scoring system. Adhesion tissues were evaluated immunohistochemically for vitronectin and u-PAR. Main Outcome Measure(s): Scores of extend and severity of adhesions and staining of vitronectin and u-PAR. Result(s): The extent of adhesion scores were 1.85 ± 0.86, 0.78 ± 1.05, and 0.42 ± 0.64, and the severity of adhesion scores were 1.71 ± 0.91, 0.57 ± 0.85, 0.50 ± 0.75 for control, GnRH-ant, and GnRH-a groups, respectively. The extent and severity of adhesions were significantly lower in both GnRH-ant and GnRH-a groups when compared with the control group. Adhesion extent scores in the GnRH-a group were lower than in the GnRH-ant group, but this difference was not significant. vitronectin and u-PAR staining were significantly greater in both the GnRH-ant and GnRH-a groups than in the control group. Conclusion(s): GnRH-ant as well as GnRH-a reduced postoperative adhesion formation in a rat model. This finding was supported immunohistochemically by vitronectin and u-PAR staining. © 2011 American Society for Reproductive Medicine.Item Retrospective evaluation of the pregnant women consulted due to drug exposure during pregnancy; [Gebelikte İlaç Kullanimi Nedeni ile Başvuran Hastalarin Deǧerlendirilmesi](2012) Göker A.; Kadioǧlu Duman M.; Gürpinar T.; Muci E.; Yildirim Y.; Erköseoǧlu I.; Dikayak Ş.; Koyuncu F.M.Objective: Drug use in pregancy is a major obstetric issue due to the potential teratogenic effects. There are restricted studies about drug use during the first trimester in our country. The aim of this investigation is to evaluate pregnancies which applied to two reference hospitals of west and northeast of Turkey for drug use retrospectively and to initiate further studies in this field. Material and Methods: This study was performed at Obstetrics and Gynecology and Pharmacology deaprtments of Celal Bayar University Hospital (CBU) in Manisa and Trabzon Technical University Hospital (KTU) in Trabzon. Pregnancies who applied between 2005-2010 at any week of gestation with a history of drug use were retrospectively evaluated. Results: A total of 811 records were analysed. The most frequent drug used in Manisa and Trabzon was antidepressants (19%, 38.3%) and antibiotics (17.8%, 32.9%). Antiepileptics ranked third at CBU (11.7%) and analgesics at KTU (23.3%). When the most freqently used drug groups were compared there was a significant difference. Pregnant women used drugs of Food and Drug Administration group C 58.1%, D 23.2%, B 14.2% and X 4.5% while in Trabzon there was a drug use of 82.7% low risk, 11.6% intermediate, 4.7% noncategorised and 0.9% high risk groups. Conclusion: There is a common belief that antidepressants and antibiotics are harmful for the fetus. Patients are more susceptible to consult a doctor when these two groups are consumed during pregnancy. It is important to raise awareness about planned pregnancies and educate women about medications during a possible pregnancy. Questioning about pregnancy before prescibing drugs will lower the risk of teratogenity. Copyright © 2012 by Türkiye Klinikleri.Item Cancer stem cell and embryonic development-associated molecules contribute to prognostic significance in ovarian cancer(2012) Oktem G.; Sanci M.; Bilir A.; Yildirim Y.; Kececi S.D.; Ayla S.; Inan S.Objectives: Embryonic molecules and cancer stem cell signaling resemble each other, and they organize cancer modality. We hypothesized that similar immunohistochemical expressions between tumor spheroids and patients' samples compared with clinical relevance would give an important clue in patients' prognosis. Methods: Immunohistochemical expression of c-kit, Notch1, Jagged1, and Delta1 in 50 cases of primary ovarian tumors (10 endometrioid, 10 serous, 10 mucinous adenocarcinoma, 10 borderline serous, and 10 borderline mucinous tumors) and MDAH-2774 spheroids were investigated. Results were compared in both spheroids and tumor samples with morphologic parameters (histological grade) and clinical data (age, stage, tumor size, and metastasis). Results: High c-kit and Notch1 immunoreactivity was shown in spheroids, but interestingly immunoreactivity of these molecules in tumor samples was different from patients' clinicopathological characteristics. In serous carcinoma, metastasis correlated with Notch1 immunoexpression; in mucinous carcinoma, Jagged1 immunohistochemistry correlated with grade, stage, and metastasis of tumor; in borderline serous and mucinous tumors, Jagged1 correlated with high grade.Moreover, Jagged1 correlated with stage and Notch1 with size in borderline mucinous tumor. Endometrioid carcinoma statistics showed that there was a correlation between age and Notch1 expression. Conclusion: Notch1, Jagged1, and Delta1 expressions might be useful markers for clinical prognosis of ovarian carcinomas; and Notch pathway, one of the most intensively studied putative therapeutic targets, may be a useful marker for cancer. Consequently, Jagged1 could be a marker for tumor grades and Notch1 as a marker for metastases. Copyright © 2012 by IGCS and ESGO.Item A Turkish Gynecologic Oncology Group study of fertility-sparing treatment for early-stage endometrial cancer(John Wiley and Sons Ltd, 2012) Dursun P.; Erkanli S.; Güzel A.B.; Gultekin M.; Tarhan N.C.; Altundag O.; Demirkiran F.; Beşe T.; Yildirim Y.; Bozdag G.; Yarali H.; Simsek T.; Ozcelik B.; Ortaç F.; Taskin S.; Guvenal T.; Ozgul N.; Haberal A.; Vardar M.A.; Dede M.; Yenen M.; Altintas A.; Arvas M.; Ayhan A.Objective: To analyze the results of fertility-sparing treatment of early-stage endometrial cancer (EC) in patients treated at Turkish gynecologic oncology centers, and to present a review of the literature. Methods: Thirteen healthcare centers in Turkey were contacted to determine if they were eligible to participate in the study. Centers that were eligible and agreed to participate were sent a database form to record the demographic characteristics, clinicopathologic findings, and follow-up results for their EC patients. Results: Eleven Turkish healthcare centers provided data on 43 EC patients. Mean duration of treatment was 5 months and mean follow-up was 49 months. In total, 35 (81.4%) patients were tumor free following primary progesterone therapy. Mean time from the end of progesterone therapy to pregnancy was 10.6 ± 4.3 months (range, 3-18 months). Two patients had tumor recurrence during follow-up. The pregnancy rate among the 31 women who actively sought pregnancy was 41.9% (n = 13). Conclusion: Conservative management of early-stage EC in women of reproductive age using oral progestins was effective and did not compromise oncological outcome. Pregnancy in the study patients was achieved spontaneously and artificially. © 2012 International Federation of Gynecology and Obstetrics.Item Immunolocalization of ERK1/2 and p-AKT in normal endometrium, endometrial hyperplasia, and early and advanced stage endometrioid endometrial adenocancer and their prognostic significance in malignant group(Elsevier Ireland Ltd, 2014) Gungorduk K.; Ertas I.E.; Sahbaz A.; Ozvural S.; Sarica Y.; Ozdemir A.; Sayhan S.; Gokcu M.; Yilmaz B.; Sanci M.; Inan S.; Harma M.; Yildirim Y.Objective: To analyze the expression patterns of extracellular signal-regulated kinase (ERK1/2) and phosphorylated (p)-AKT in the tissues of non-pathologic endometrium, endometrial hyperplasia, and early and advanced stage endometrioid endometrial adenocancer using indirect immunohistochemistry, and also to investigate the effect of ERK1/2 and p-AKT expression patterns on prognosis in endometrioid adenocancer. Study design: Immunolocalization of ERK1/2 and p-AKT was examined in six different types of endometrial tissues: proliferative endometrium (PE; n = 10, 11.2%), secretuar endometrium (SE; n = 10, 11.2%), simple hyperplasia (SH; n = 15, 16.9%), complex hyperplasia (CH; n = 3, 3.4%) and atypical complex hyperplasia (ACH; n = 10, 11.2%), which were obtained from endometrial biopsies, curettage materials, and hysterectomy specimens and classified as the benign group; and both early stage endometrioid (n = 21, 23.6%) and advanced stage endometrioid adenocancer (AC; n = 20, 22.5%), which were obtained from complete surgical staging materials and classified as the malignant group. All specimens were fixed in 10% formalin and processed using routine paraffin protocols. Immunostaining intensities were evaluated as negative or weak (assigned as low expression) and moderate or strong (assigned as high expression). Results: In the malignant group, 23 of 41 patients (56.1%) had high ERK1/2 and p-AKT expression, whereas only three of 48 patients in the benign group (6.3%) had high ERK1/2 and p-AKT expression (P < 0.0001 and P < 0.0001, respectively). p-AKT expression was significantly higher in women with positive lymph nodes (OR 9.0; 95% CI: 1.2-100.0; P = 0.03). Higher expression of p-AKT was significantly associated with poor progression-free survival (PFS) and overall survival (OS). In contrast, ERK1/2 expression was not associated with PFS or OS.Conclusions ERK1/2 and p-AKT can be useful in the differential diagnosis of benign vs. malignant endometrial lesions, as well as early vs. advanced stage endometrioid endometrial adenocancer. Additionally, higher p-AKT expression could be used as a marker of poor prognosis in the management of patients with endometrioid endometrial adenocancer. © 2014 Elsevier Ireland Ltd. All rights reserved.Item Preparation and characterization of novel boron containing nanocomposites with neutron radiation shielding properties(John Wiley and Sons Inc, 2023) Saltan F.; Şirin K.; Aydin S.; Yildirim Y.PVA/PEO/PVP-B4C and PVA/PEO/PVP-BN polymer nanocomposites were prepared using boron nitrite (BN), boron carbide (B4C), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and polyethylene oxide (PEO). B4C and BN nanopowders were added to the mixture at three different percentages: 5%, 10%, and 20%. Thermal characterization was performed by differential scanning calorimetry, differential thermal analysis and thermogravimetry. Scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were used for surface analysis and crystal structure characterization. The atomic distribution was determined by elemental analysis. Neutron shielding properties were performed at three different gamma peak areas, 1293.56 keV, 1097.33 keV, 416.86 keV, and calculated total macroscopic cross-section ∑T and half-value layer. The ∑T values were found to be in the range of 7.99–14.37 for all synthesized composites. B4C-doped composites show higher protection efficiency against slow thermal neutrons than BN-doped samples. Highlights: Poly(vinyl alcohol)/poly(ethylene oxide)/polyvinylpyrrolidone composites containing boron nanoparticles are flexible and workable. Nanocomposites were prepared with a simple, cheap, and fast method. Prepared boron nanocomposites exhibit slow thermal neutron stopping even at 3 mm thickness. PVA90/PEO5/PVP5-BN and PVA90/PEO5/PVP5-B4C composites are good candidates for demanding military applications such as vehicle and body armor. © 2023 Society of Plastics Engineers.Item Nationwide prospective audit for the evaluation of appendicitis risk prediction models in adults: Right iliac fossa treatment (RIFT) - Turkey(Oxford University Press, 2024) Yalcinkaya A.; Yalcinkaya A.; Balci B.; Keskin C.; Erkan I.; Yildiz A.; Kamer E.; Leventoglu S.; Caglikulekci M.; Zarbaliyev E.; Sevmis M.; Ulgen Y.; Altinel Y.; Meric S.; Akbas A.; Hacim N.A.; Vartanoglu Aktokmanyan T.; Aktimur Y.E.; Calikoglu F.; Gullu H.F.; Durma A.G.; Acar S.; Ciftci E.; Balik E.; Kulle C.B.; Ozata I.H.; Tufekci T.; Tatar C.; Sevinc M.M.; Sevik H.; Ertürk C.; Kiraz I.N.; Ozben V.; Aytac E.; Aliyeva Z.; Mutlu A.U.; Tanal M.; Celayir M.F.; Bozkurt E.; Yetkin S.G.; Ergin E.; Attaallah W.; Uprak T.K.; Omak A.; Simsek O.; Bozkurt M.A.; Kara Y.; Bozdag E.; Yirgin H.; Ozcan A.; Okkabaz N.; Ozdenkaya Y.; Haksal M.C.; Pekuz C.K.; Duru S.; Sivrikoz E.; Ozdemir Y.; Tan N.; Yarbug Karayali F.; Taghiyeva A.; Tirnova I.; Erenler Bayraktar I.; Bayraktar O.; Emsal E.Z.; Dalkilic M.I.; Yesiltas M.; Tok H.; Karakas D.O.; Pusane A.; Demirer A.I.; Sahin H.B.; Gok A.F.K.; Bozkurt H.A.; Yildirim M.; Uzunyolcu G.; Yanar H.T.; Ergun S.; Kutluk F.; Uludag S.S.; Zengin A.K.; Ozcelik M.F.; Sanli A.N.; Altuntas Y.E.; Memisoglu E.; Sari R.; Akdogan O.; Kucuk H.F.; Ozkan O.F.; Ulgur H.S.; Kirkan E.F.; Yuksekdag S.; Rencuzogullari A.; Aktas M.K.; Aba M.; Demirel A.O.; Eray I.C.; Aydogan B.; Cetinkunar S.; Yener K.; Sozutek A.; Irkorucu O.; Bayrak M.; Altintas Y.; Alabaz O.; Atasever A.; Erdogrul G.; Kupeli A.H.; Muhammedoglu B.; Kokdas S.; Kaya M.; Uysal E.; Yildirim A.C.; Zeren S.; Ekici M.F.; Algin M.C.; Kucuk G.O.; Eraslan H.; Aybar E.; Polat S.; Ceylan A.; Isik O.; Kural S.; Aktas A.; Bakar B.; Uzunoglu M.Y.; Gulcu B.; Ozturk E.; Devay A.O.; Taspinar E.; Balcin O.; Aksoy F.; Garip G.; Yalkin O.; Iflazoglu N.; Yigit D.; Kaya R.B.; Ugur M.; Kilic E.; Dedemoglu A.; Arslan R.E.; Temiz M.; Aydin C.; Demirli Atici S.; Kaya T.; Ozturk S.; Calik B.; Kilinc G.; Acar T.; Acar N.; Cengiz F.; Ureyen O.; Tan S.; Ilhan E.; Turk Y.; Durak A.T.; Yilmaz M.; Mercan M.; Atci R.; Sokmen S.; Bisgin T.; Egeli T.; Yildirim Y.; Safak T.; Celik K.; Yilmaz E.M.; Kirnap M.; Demirkiran A.E.; Sekerci U.U.; Karacan E.; Bilgic E.; Ozmen M.M.; Guldogan C.E.; Gundogdu E.; Moran M.; Erol T.; Dincer H.A.; Kirimtay B.; Yilmaz S.; Cennet O.; Yildiz A.; Sahin C.; Akyol C.; Koc M.A.; Ersoz S.; Turhan A.; Konca C.; Tezcaner T.; Erkent M.; Aydin O.; Avci T.; Altiner S.; Osmanov I.; Emral A.C.; Cetinkaya G.; Lapsekili E.; Sakca M.; Cimen S.; Ozen D.; Kozan E.B.; Dogan L.; Haberal E.; Kayhan O.; Aksel B.; Karabacak H.; Azili C.; Yazici F.; Apaydin M.; Kaya I.O.; Cetinkaya E.; Akin T.; Gunes G.; Turap H.; Aslan D.; Demirbag A.E.; Bolukbasi B.; Karaca B.E.; Ozturk E.; Ozeller E.; Kayacan G.S.; Borcek A.O.; Ece I.; Yormaz S.; Colak B.; Calisir A.; Sahin M.; Arslan K.; Hasirci I.; Ulutas M.E.; Metin S.H.; Gultekin F.A.; Ozkan Z.; Ilhan O.; Gundogdu T.; Liman R.K.; Kanat B.H.; Aydin A.; Sungurtekin U.; Ozgen U.; Aykota M.R.; Altintoprak F.; Gonullu E.; Cakmak G.; Dulger U.C.; Mantoglu B.; Demir H.; Akin E.; Eroz E.; Nazli O.; Dere O.; Dadasoglu M.A.; Kara E.; Tutcu S.; Solak I.; Gencer I.; Dalkiran A.; Sevinc B.; Karahan O.; Damburaci N.; Sari E.; Akay T.; Calta A.F.; Ozdemir A.; Ohri N.; Ermis I.; Bozbiyik O.; Ozdemir M.; Goktepe B.; Demir B.; Kilincarslan O.; Gunduz U.R.; Olcum M.; Dincer O.I.; Cakir R.C.; Dinc B.; Sahin E.; Uludag E.; Arslan Y.; Posteki G.; Oktay A.; Tatar O.C.; Guler S.A.; Utkan N.Z.; Tayar S.; Copelci Y.; Kartal M.; Kalayci T.; Yeni M.; Buyukkasap A.C.; Vural S.; Kesicioglu T.; Aydin I.; Gulmez M.; Saracoglu C.; Topcu O.; Kurt A.; Soylu S.; Kurt B.; Serin M.; Basceken S.I.; Gundes E.; Savda M.; Balkan A.Z.A.; Yildiz M.N.; Uzunkoy A.; Karaca E.; Berkan A.; Isik A.; Yildiz Y.A.; Ergul Z.; Yasar N.F.; Badak B.; Ozen A.; Velipasaoglu M.; Ure I.Background: Appendicitis is the most prevalent surgical emergency. The negative appendicectomy rate and diagnostic uncertainty are important concerns. This study aimed to assess the effectiveness of current appendicitis risk prediction models in patients with acute right iliac fossa pain. Methods: A nationwide prospective observational study was conducted, including all consecutive adult patients who presented with right iliac fossa pain. Diagnostic, clinical and negative appendicectomy rate data were recorded. The Alvarado score, Appendicitis Inflammatory Response (AIR), Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA) and Adult Appendicitis Score systems were calculated with collected data to classify patients into risk categories. Diagnostic value and categorization performance were evaluated, with use of risk category-based metrics including 'true positive rate' (percentage of appendicitis patients in the highest risk category), 'failure rate' (percentage of patients with appendicitis in the lowest risk category) and 'categorization resolution' (true positive rate/failure rate). Results: A total of 3358 patients from 84 centres were included. Female patients were less likely to undergo surgery than men (71.5% versus 82.5% respectively; relative risk 0.866, 95% c.i. 0.834 to 0.901, P < 0.001); with a three-fold higher negative appendicectomy rate (11.3% versus 4.1% respectively; relative risk 2.744, 95% c.i. 2.047 to 3.677, P < 0.001). Ultrasonography was utilized in 56.8% and computed tomography in 75.2% of all patients. The Adult Appendicitis Score had the best diagnostic performance for the whole population; however, only RIPASA was significant in men. All scoring systems were successful in females patients, but Adult Appendicitis Score had the highest area under the receiver operating characteristic curve value. The RIPASA and the Adult Appendicitis Score had the best categorization resolution values, complemented by their exceedingly low failure rates in both male and female patients. Alvarado and AIR had extremely high failure rates in men. Conclusion: The negative appendicectomy rate was low overall, but women had an almost three-fold higher negative appendicectomy rate despite lower likelihood to undergo surgery. The overuse of imaging tests, best exemplified by the 75.2% frequency of patients undergoing computed tomography, may lead to increased costs. Risk-scoring systems such as RIPASA and Adult Appendicitis Score appear to be superior to Alvarado and AIR. © 2024 The Author(s). Published by Oxford University Press on behalf of BJS Foundation Ltd.Item Thermal decomposition kinetics and mechanical analysis of boron carbide-reinforced polymer nanocomposites(John Wiley and Sons Inc, 2025) Yildirim Y.; Saltan F.; Şirin K.; Küçük V.A.In the present study, the mechanical properties and thermal degradation kinetics of PVA/PVP/PEO (polyvinyl alcohol/polyvinyl pyrrolidone/polyethylene oxide) blend, along with their composites containing various percentages of boron carbide (B4C), are examined. The solvent-casting method is used for preparing the composites. Thermal degradation is analyzed using both Kissinger and FWO (Flynn-Wall-Ozawa) methods to determine the activation energies (Ea). The Ea varied with the B4C content, with higher B4C percentages leading to increased thermal stability. Dynamic mechanical analysis (DMA) was employed to evaluate the mechanical properties, revealing that B4C addition enhances the Young's modulus (E) while decreasing strain. The highest strain (ε) was observed in the PVA/PEO/PVP blend, reaching 184%. The ε values for PVA/PEO/PVP-B4C%5, PVA/PEO/PVP-B4C%10, and PVA/PEO/PVP-B4C%20 composites were determined as 45.30%, 29.15%, and 16.48%, respectively. The E was measured as 0.12 MPa for PVA/PEO/PVP, while the highest E value of 0.64 MPa was observed in the PVA/PVP/PEO-B4C20% composite. Additionally, chemometric analysis using FTIR data and clustering algorithms confirmed the homogeneity of the blends. These findings indicate that B4C-reinforced PVA/PVP/PEO composites could serve as alternatives to conventional polymers, particularly in applications requiring enhanced thermal and mechanical stability. Highlights: B4C addition increases the thermal stability of the PVA/PVP/PEO blend. DMA analysis shows that B4C addition increases the elastic modulus. Activation energies were calculated by the Kissinger and FWO methods. PVA/PVP/PEO-B4C composites offer superior mechanical resistance. © 2025 Society of Plastics Engineers.