Development and characterization of yttria stabilized zirconia and Al2O3 thin films by pulsed laser deposition:Special Issue

The present study concerns development of yttria stabilized zirconia (YSZ), Al2O3 and a multilayer of Al2O3-YSZ thin film deposition by pulsed laser deposition (PLD) technique for its application as thermal barrier coating (TBC). The detailed study included characterization (microstructure, composition, phase and surface topography) of the thin film. The phase analysis of the YSZ films deposited at room temperature showed amorphous feature, while the film deposited at high temperature showed the formation of tetragonal phase. Residual stress analysis of the coating showed the presence of compressive stress and was maximum at 573 K (sigma(11) = -8.1 GPa and sigma(22) = -6.4 GPa). Residual stress was found to decease with increase in substrate temperature and was found to be lowest at 973 K (sigma(11) = -3.0 GPa and sigma(22) = -1.7 GPa). The cross-sectional morphology of the YSZ and Al2O3 thin films deposited at room temperature showed presence of inter-columnar porosities which changed to a dense structure with increase in substrate temperature

Behandlung verschluckter zahnprothesen:Erfahrungen mit 34 patienten

Background: Swallowed dentures can present with upper aerodigestive tract obstruction needing urgent intervention. Removing such an ingested denture can prove challenging and needs careful planning.Aim: To share our experience of managing patients with a swallowed denture focusing on the practical aspects of denture removal along with relevant literature review. We aim to raise a public health message on the safety aspect of usage of dentures.Subjects and methods: A retrospective analysis of the patients managed by our team in the ENT department at two hospitals in Scotland, over 10 years (2009–2019), who were found to have swallowed a denture. Data on demographics, clinical history, examination findings and management of patients were collected and analysed using Microsoft Excel.Results: A total of 34 patients were admitted with a swallowed denture, of which 24 (71%) were male and 10 (29%) were female. The mean age was 60 years (range 17–83). Of the 34 patients, 2 had a feeling of something stuck in the throat but were able to eat and drink; the rest of the patients complained about dysphagia and pain in the throat, with 2 patients also showing signs of respiratory distress. Twenty-four (71%) patients required denture removal under general anaesthetic in the theatre; 20 (59%) by rigid oesophagoscopy, 1 with tracheostomy (3%), 1 with (3%) laparoscopy and gastrostomy, and 2 (6%) with external neck exploration. Seven (20%) patients were taken to the theatre and the denture was removed with Magill forceps under light sedation using intubating laryngoscope or video laryngoscope. In 1 patient (3%), the denture material was successfully removed under flexible pharyngoly guidance in the clinic without sedation. The final 2 (6%) patients were reassured as no foreign body was seen on flexible laryngoscopy.Conclusion: In the absence of a clear evidence of denture ingestion, a detailed history and examination are needed to identify this serious pathology. Once confirmed, the ingested denture should be removed as soon as possible to minimize the risk of serious complications

Collet-Sicard Syndrome from Thrombosis of the Sigmoid-Jugular Complex: A Case Report and Review of the Literature

Purpose. Collet-Sicard syndrome is a very rare condition characterised by unilateral palsy of the IX–XII cranial nerves. It is distinguished from Villaret syndrome by lack of presence of sympathetic involvement. Current literature contains only two cases of Collet-Sicard syndrome due to idiopathic internal jugular vein thrombosis. Method and Results. We report the case of Collet-Sicard syndrome in a 30-year-old man who presented with delayed development of XIth nerve dysfunction, due to internal jugular vein-sigmoid sinus thrombosis. A multidisciplinary team approach was employed in the management of this patient. At three-month followup, he had significantly improved swallowing, and repeat computed tomography neck scan showed partial recanalisation of the right internal jugular vein. Conclusion. In suspected Collet-Sicard syndrome, a focal primary lesion or metastasis to the temporal bone must be excluded, and sigmoid-jugular complex thrombosis should be considered in the differential diagnosis. Early recognition and treatment may result in significant functional recovery

Interpreting the HI 21-cm cosmology maps through Largest Cluster Statistics -- I: Impact of the synthetic SKA1-Low observations

We analyse the evolution of the largest ionized region using the topological and morphological evolution of the redshifted 21-cm signal coming from the neutral hydrogen distribution during the different stages of reionization. For this analysis, we use the "Largest Cluster Statistics" - LCS. We mainly study the impact of the array synthesized beam on the LCS analysis of the 21-cm signal considering the upcoming low-frequency Square Kilometer Array (SKA1-Low) observations using a realistic simulation for such observation based on the 21cmE2E-pipeline using OSKAR. We find that bias in LCS estimation is introduced in synthetic observations due to the array beam. This in turn shifts the apparent percolation transition point towards the later stages of reionization. The biased estimates of LCS, occurring due to the effect of the lower resolution (lack of longer baselines) and the telescope synthesized beam will lead to a biased interpretation of the reionization history. This is important to note while interpreting any future 21-cm signal images from upcoming or future telescopes like the SKA, HERA, etc. We conclude that one may need denser $uv$-coverage at longer baselines for a better deconvolution of the array synthesized beam from the 21-cm images and a relatively unbiased estimate of LCS from such images.Comment: 37 pages, 14 figures, text revised, Comments are welcom