Replication of period-doubling route to chaos in impulsive systems

In this study, we investigate the dynamics of impulsive systems driven by a chaotic system. It is shown that the response impulsive system replicates the sensitivity and the period-doubling cascade of the drive. Illustrative examples that support the theoretical results are provided

Unpredictable Event during EUS-Guided Hepaticojejunostomy

Endoscopic ultrasound (EUS)-guided biliary drainage is a therapeutic alternative method in patients with cholestasis where the ampulla of Vater cannot be reached because several reasons. An unfortunate complication during EUS-guided biliary drainage was presented in this report. A 53-year-old male patient presented with jaundice and pruritus. He had a history of total gastrectomy due to gastric cancer. An abdominal tomography scan detected a tumoral mass in the common bile duct due to the recurrence of gastric cancer. We decided to perform EUS-guided hepaticojejunostomy because biliary drainage cannot be obtained by conventional methods and percutaneous drainage impairs patient comfort. A double pigtail plastic stent was placed from the jejunum into the segment-3 bile duct towards the hilus. After that echoduodenoscope was removed to the outside gently. We noticed that the stent was stuck in the echoduedonoscope elevator. We reached into the bile duct again and placed a double-pigtail plastic stent successfully

Replication of period-doubling route to chaos in impulsive systems

In this study, we investigate the dynamics of impulsive systems driven by a chaotic system. It is shown that the response impulsive system replicates the sensitivity and the period-doubling cascade of the drive. Illustrative examples that support the theoretical results are provided

Does progesterone therapy increase nuchal translucency in women with threatened miscarriage?

Objectives: The effect of exogenous progesterone on fetal nuchal translucency (NT) has been proposed recently. In this study, we aimed to compare the thickness of NT of patients receiving and not receiving progesterone for threatened miscarriage. Material and methods: This study was designed as a retrospective comparative study. Ninety five women treated with progesterone constituted the study group whereas 97 women who were not treated with progesterone constituted the control group. An ultrasonographic examination was performed on all of the women to measure NT. All patients were treated with oral micronized progesterone in the study group. The main parameters recorded for each woman were; age, body mass index (BMI), obstetrical characteristics, and gestational age at first examination, treatment duration of progesterone therapy, and results of combined and triple tests. Results: A total of 192 pregnant women with threatened miscarriage were included in this study. The mean NT thickness was statistically significantly higher in the study group (p < 0.001), and mean serum level of human chorionic gonadotropin (hCG) was also higher in this group (p < 0.05). There was no statistically significant difference between groups in terms of age, BMI, and gestational age at first examination. ROC curve analysis demonstrated that only increased NT (area under the curve: 0.634, p = 0.005, 95% CI: 0.541–0.727) was a discriminative factor for women receiving progesterone for threatened miscarriage. Also there was a positive correlation between NT and treatment duration (r = 0.269; p < 0.001). Conclusions: We think that oral progesterone therapy may increase NT depending on treatment duration without causing abnormal prenatal screening test results

Morphometric analysis of the arteries of Willis Polygon

Objective: Willis polygon forms the basis of the arterial circulation of the cerebrum. Willis polygon is a vascular structure whom variations are not rare. Knowledge of the anatomy and preservation of its integrity is crucial for performing neurovascular surgery and intracranial tumour surgery. Because of the important vascular and neurological structures, approaches to this region are considered extremely risky. One of the main variations in-person basis is the diameter differences of the arteries, which forms Willis polygon, between the left and right hemispheres. About structure and variations, studies of Rhoton and Yasargil had formed the touchstone.Our aim is to contribute to the literature and clinical studies, to be done in the future, by comparing our results with previous studies about variations and morphometric features of Willis polygon.Methods: Arteries of 30 fresh cadaver brains were examined during autopsies in T.C. Ministry of Justice Istanbul Forensic Science Institute. Bilaterally anterior cerebral artery A1 segment lengths, distance between anterior communicating artery-callosomarginal artery outputs, posterior cerebral artery P1 segment lengths were measured using a digital calliper. After dissections and measures, photos of the region were taken and vascular anatomy and variations noted. From every single cerebrum samples were obtained from bilaterally A1, A2, callosomarginal artery, middle cerebral artery, posterior communicant artery, P1 and basilar artery. Samples were fixed by using 10% buffered-formalin. Taken samples were transported to Marmara University Faculty of Medicine, Department of Anatomy Laboratory. Samples were examined and interior diameters were measured under the microscope.Results: Our results with artery diameters and lengths were similar with literature. Different from literature, in anterior cerebral artery A1 segment, posterior cerebral artery P1 segment and posterior communicant artery no aplasia were noted. In 50% of the samples, callosomarginal artery were originate from A2 segment. In one case, we observed left and right pericallosal arteries were joined together at the end of the A2 segment and continued as a single pericallosal artery. We could not find any information about this variation in the literature.Conclusion: Before surgical operations, detailed knowledge of Willis polygon and evaluation of the pre-op cerebral angiography considering possible variations, reduce mortality and morbidity ratios. In addition, because of the role of flow gradients of Willis polygon in aneurysm formation, and in terms of better understanding the collateral circulation which is important in vascular occlusive diseases and vascular surgery, we believe, more anatomic studies about this region needed

Statistical analysis of associated vertebra and costal anomalies in spina bifida patients

Objective: Spina bifida is one of the most severe birth defects and can happen as a result of disrupted primary neurulation. Congenital vertebra and costa anomalies are more frequently seen with spina bifida, and associated anomalies significantly affect the prognosis of affected children. In this study, we aimed to determine the incidence of scoliosis, costal anomalies, and vertebral deformations seen at the time of diagnosis and to statistically evaluate their concomitancies. Methods: Gender and mean ages of the patients were determined. The spina bifida patients were examined for deformation anomalies, butterfly vertebra, hemivertebra, wedge vertebra, costal anomalies and scoliosis. The relationships between these anomalies were evaluated. Results: 94 patients with a mean age of 11,5 months examined. The incidence of scoliosis was 21.8% among female infants and 17.9% among males. Rates of scoliosis with vertebra anomalies (hemivertebra, wedge vertebra) and costal anomalies did not differ significantly (P > 0.05). Wedge vertebra were the most frequent vertebra anomaly type with 38.2% ratio. Costal anomalies were detected in 25.5% of females and 20.5% of male infants. Hemivertebra and wedge vertebra were seen significantly more frequently in this group. Gender distribution did not differ between with and without any vertebra types. Conclusion: Congenital vertebra and costa anomalies are more frequently seen with spina bifida. We believe that these anomalies and relationship with spina bifida may demonstrate differences among different ethnic groups or locations. More detailed multi-centered studies performed on this issue will aid in the determination of etiologies, genetics, and treatment principles of these congenital anomalies

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