An Assessment of the Surgical Results of the Site-Directed Surgical Treatment in Obstructive Sleep Apnoea Syndrome

Background: Obstructive sleep apnea (OSA) has cardiovascular, neurological, and social complications. Surgical treatment has the potential to improve airway patency but when and which surgery should be done is a controversy. Aims and objectives: To estimate the site of obstruction in patients with OSAS and to assess the surgical results of the site (of obstruction) directed surgical treatment. Methodology: Twenty patients with OSAS were included in the study with Eight adults and Twelve children. It was a prospective study. All patients were assessed for the airway collapse and surgery was done accordingly. Repeat PSG was done after surgery for success rate after 4 months of follow up. Result: 17 patients successfully completed the follow-up. Four (50%) adults and Two (17%) children have grade I or II tonsils while Four (50%) of adults and Ten (83%) children have tonsil size grade III or IV. Seven (88%) adults and one (8%) of the children have adenoid hypertrophy up to grade II. One adult (12%) and nine children (75%) have grade III Adenoid size. Two children (17%) have Adenoid grade IV size. In Four patients retropalatal more than retroglossal collapse was found (50%). One patient (12%) had retroglossal more than retropalatal collapse other one had only retropalatal collapse, and the other one had retroglossal collapse. ESS (Epworth sleepiness scale) decreased postoperatively in both groups. There is a significant change in AHI with the median pre-op AHI being 40.19 to median post-op AHI being 11.35 with a p-value 0.017. Apnea-hypopnea index (AHI) in children pre-operatively was 12.98 (median) changed to 2.15 (median) which is statistically significant. Only one adult patient (12%) is surgically cured while in five patients (63%) surgical success achieved with a surgical success rate of 5/8 (63%). Whereas only one patient is surgically cured 1/8 (13%). Eight patients achieved surgical success with a total success rate of 8/9 (89%). While only two patients achieved surgical cure (23%) among children. Conclusion: The outcome of site-directed surgical treatment is that it is a satisfactory way of treatment of OSAS with an overall success rate of 76%.

Mechanical behavior of organo-modified Indian bentonite nanoclay fiber-reinforced plastic nanocomposites

The aim of the research was to examine the influence of organo-modified Indian bentonite （IB） nanoclay dispersed in vinyisster on the mechanical properties of nanoclaylvinylesterlglass nanocomposRes. Nanoclay was organically modified using cationic surfactant hexadecyltrimethylammonium bromide （HDTMA-Br） by cation exchange method and dispersed in vinylester using ultrasonication and twin screw extrusion. XRD of nanoclaylvinylester revealed exfoliaUon at 4 wt.% nanoclay indicating uniform dispersion in the polymer. DSC results showed improvement in glass transition temperature by 22.3% in 4 wt.% nanoclaylvinylester/glass when compared with that of vinylester/glass. Nanoclay/vinylester/glass with 4 wt,% nanoclay showed 29.23%, 23.84% and 60.87% improvement in ultimate tensile strength （UTS）, fiexural strength （FS） and interlaminar shear strength （ILSS） respectively when compared with those of vinylester! glass. The mode of tensile failure examined by SEM showed no agglomeration of nanoclay in 4 wt.% nanoclayNinylester/glass specimens.

Mechanical, thermal and fire nanoclay/vinylester retardation behaviours of nanocomposites

The dispersion of montmorillonite （MMT） in vinylester for preparing nanoclay/vinylester gel coat was reported. Two sets of MMT/vinylester specimens, namely Type I and Type 2, were prepared for comparative studies. Type I specimens were prepared using ultrasonication only, and Type 2 specimens were prepared using both ultrasonication and twin-screw extrusion. According to XRD and TEM results, Type 2 specimens showed lower levels of nanoclay agglomeration and higher levels o! exfoliation. DSC results showed that the glass transition temperatures of Type 2 specimens are higher than those of Type 1 specimens. TGA results showed that the residual weight of 4 wt.% MMT/vinylester of Type 1 was 7.38%, while the corresponding value of Type 2 was 13,5%, indicating lower thermal degradation in the latter. MMTt vinylester/glass and MMT/vinylester/carbon specimens were fabricated and tested for mechanical and fire retardation behaviours. Type 2 based nanocomposite laminates showed greater values of ultimate tensile strength, flexural strength, interlaminar shear strength, impact strength, horizontal burning rate, and vertical burning rate than Type 1 based laminates. SEM images of tensile fractured surfaces revealed that Type 2 based laminates have no or less agglomeration of nanoclay than Type 1 based laminates.