Broadband One Way Propagation via Dielectric Waveguides with Unequal Effective Index

We present an efficient approach for broad band one way propagation of light by parallel and unequal dielectric waveguides leading different effective phase shifts. Three dimensional numerical simulations show that 30% operating bandwidth is achieved

The Effects of Riluzole on Cisplatin-induced Ototoxicity

Introduction Riluzole (2-amino-6-trifluoromethoxy benzothiazole) is known as a neuroprotective, antioxidant, antiapoptotic agent. It may have beneficial effects on neuronal cell death due to cisplatin-induced ototoxicity. Objective To evaluate the effect of riluzole on cisplatin-induced ototoxicity in Guinea pigs. Methods Twenty-four Guinea pigs, studied in three groups, underwent auditory brainstem response evaluation using click and 8 kHz tone burst stimuli. Subsequently, 5 mg/kg of cisplatin were administered to all animals for 3 days intraperitoneally (i.p.) to induce ototoxicity. Half an hour prior to cisplatin, groups 1, 2 and 3 received 2 ml of saline i.p., 6 mg/kg of riluzole hydrochloride i.p., and 8 mg/kg of riluzole hydrochloride i.p., respectively, for 3 days. The auditory brainstem responses were repeated 24 hours after the last drug administration. The cochleae were analyzed by transmission electron microscopy (TEM). Results After drug administiration, for 8,000 Hz stimulus, group 1 had significantly higher threshold shifts when compared with groups 2 (p 0.05). Transmission electron microscopy findings demonstrated the protective effect of riluzole on the hair cells and the stria vascularis, especially in the group treated with 8 mg/kg of riluzole hydrochloride. Conclusion We can say that riluzole may have a protective effect on cisplatin- induced ototoxicity. However, additional studies are needed to confirm these results and the mechanisms of action of riluzole. Copyright © 2019 by Thieme Revinter Publicações Ltda, Rio de Janeiro, Brazi

Renal access in PNL under sonographic guidance: Do we really need to insert an open end ureteral catheter in dilated renal systems? A prospective randomized study

Purpose: To evaluate the true necessity of open end ureteral catheter insertion in patients with moderate to severe pelvicalyceal system dilation treated with percutaneous nephrolithotomy (PNL) under sonographic guidance. Patients and methods: 50 cases treated with PNL under sonographic guidance in prone position for solitary obstructing renal stones were evaluated. Patients were randomly divided into two groups; Group 1: Patients in whom a open end ureteral catheter was inserted prior to the procedure; Group 2: Patients receiving no catheter before PNL. In addition to the duration of the procedure as a whole and also all relevant stages as well, radiation exposure time, hospitalization period, mean nephrostomy tube duration, mean drop in Hb levels and all intra and postoperative complications have been evaluated. Results: Mean size of the stones was 308.5 ± 133.2 mm2. Mean total duration of the PNL procedure in cases with open end ureteral catheter was significantly longer than the other cases (p < 0.001). Evaluation of the outcomes of the PNL procedures revealed no statistically significant difference between two groups regarding the stone-free rates (86% vs 84%). Additionally, there was no significant difference with respect to the duration of nephrostomy tube, hospitalization period and secondary procedures needed, complication rates as well as the post-operative Hb drop levels in both groups (p = 0.6830). Conclusions: Our results indicate that the placement of an open end ureteral catheter prior to a PNL procedure performed under sonographic access may not be indicated in selected cases presenting with solitary obstructing renal pelvic and/or calyceal stones

What is the rate of tobacco usage among dental school students?

Kuru, Leyla/0000-0002-7599-2409;WOS: 000467864900002

Association Between Endocrine Diseases and Serous Otitis Media in Children

Objective: Otitis media with effusion (OME) is a condition in which fluid is retained in the middle ear cavity. The association between endocrine disorders and OME has not yet been determined. This study aimed to investigate the presence of OME in children diagnosed with an endocrine disease and the relationship between these two conditions

What is the rate of tobacco usage among dental school students?

Introduction This survey aimed to investigate the rate of students in dental schools that use various tobacco products and possible factors affecting their attitudes towards tobacco products. Methods The survey was conducted between May 1 and June 30, 2018 and participants were from ten dental schools in Turkey. First year students and fifth year students were compared in terms of tobacco product usage and their attitudes towards tobacco. Data were tested statistically using Statistical Package for Social Sciences (SPSS) 15.0 program and chi-square test. Results A total of 1228 students from eleven different dental schools completed the online survey. Majority of the participants were females (62.1 %) and males were less (37.9 %). Mean age of the participants was 21.8±2.9 years (min-max; 18-54 years). The overall rate of current smokers was 38.11%, but 56.6% of the participants have inhaled tobacco smoke. More than half (55.3%) of the current smokers stated that they wish to quit and 36.7% of these students have attempted to quit within the last six months. More than 10% of all participants defined themselves as highly addicted to cigarette smoking. The rate of waterpipe smokers were 41.2% and 83.7% of these students were not willing to stop waterpipe smoking. Conclusions The rate of current tobacco smokers is rather high among dental school students and this finding points out the need for more effective precautions against tobacco. Funding This study has been funded solely by the institutions of the authors