Epley’s maneuver versus Semont’s maneuver in treatment of posterior canal benign positional paroxysmal vertigo

Background: Benign paroxysmal positional vertigo (BPPV) is characterized by brief but violent attacks of paroxysmal vertigo provoked by certain positions of the head. BPPV is the most common cause of vertigo, resulting from migration of otoconia into the semicircular canals. Majority of patients have posterior canal BPPV. Epley’s Canalith Repositioning and Semont Liberatory Maneuver have been shown to be highly efficacious in the successfultreatment of posterior canal BPPV. The main objective of this study was to compare the efficacy of Epley’s maneuver versus Semont’s maneuver in the management of benign paroxysmal positional vertigo.Methods: This study was conducted in the Department of Otorhinolaryngology of a rural Medical College in Kerala, for a period of one and half year, from January 2015 to June 2016. It was an observational prospective cohort study. 200 patients with posterior canal BPPV were enrolled in this study based on inclusion and exclusion criteria. Patients were allotted alternatively to Epley’s group and Semont’s group, 100 patients in each group based on the treatment maneuvers they underwent. Efficacy of maneuvers were assessed at the end of 1st week, 1st month and 3rd month on the basis of resolution of symptoms and Dix-Hallpike negativity.Results: Of the 100 cases managed by Epley’s maneuver 95 cases showed complete relief of symptoms after 3 months. Out of 100 cases managed by Semont’s maneuver, 94 cases showed complete recovery after 3 months. The results were compared by Chi square test, as the data was mainly qualitative in nature. The results of both the groups were compared at the end of 1st week, 1st month and 3rd month, which revealed that both the Semont’s and Epley’s maneuver are equally effective in the treatment of posterior canal BPPV.Conclusions: Both Epley’s and Semont’s maneuver are equally effective for treating the patients of posterior canal benign paroxysmal positional vertigo

A study on the effect of adenoidectomy with tonsillectomy in otitis media with effusion in children

Background: The aural symptoms attributed to adenoid hypertrophy are Eustachian tube block (ET) and otitis media with effusion (OME). It is thought that adenoid hypertrophy causes a block in air flow through the ET, thus creating a negative pressure in the middle ear leading to effusion which acts as a focus of infection. The role of hypertrophied tonsils in the aetiology of OME is controversial. Adenoid and tonsillar hypertrophy and associated inflammation continue to be a major problem in paediatric age group despite the advances in medicine. Otitis media with effusion is a treatable cause of deafness which may hamper the learning ability of a child. This study was undertaken to study the effect of adenoidectomy with tonsillectomy on established otitis media with effusion in children.Methods: 35 children presenting to the department of ENT, Government Medical College, Thrissur, Kerala, India over one and a half years with features suggestive of secretory otitis media, tonsillar and adenoid hypertrophy who underwent adenoidectomy with tonsillectomy in Government Medical College, Thrissur, Kerala, India were included in the study. A predesigned questionnaire was prepared which included details on clinical symptoms, relevant investigations and preoperative and postoperative evaluation of hearing after 6 weeks and 3 months. Data collected was analyzed using paired t-test and chi square test to determine the improvement in hearing after 6 weeks and 3 months following surgery.Results: Out of the 35 children included in the study, it was seen that 56% of cases, after 6 weeks showed complete resolution of OME which improved to 67% after 3 months. This was assessed by PTA and tympanometry. 33% showed partial improvement with Type C curve in tympanometry and improvement in PTA values.Conclusions: All cases of OME associated with adenoid and tonsillar hypertrophy responded to our treatment with 67% showing complete cure of the condition. It can be assumed that, in the 33% partial responders there may be other factors like allergy, anatomical deformities, immunological which prevented the complete resolution of symptoms in OME.

Bundling up carbon nanotubes through Wigner defects

We show, using ab initio total energy density functional theory, that the so-called Wigner defects, an interstitial carbon atom right besides a vacancy, which are present in irradiated graphite can also exist in bundles of carbon nanotubes. Due to the geometrical structure of a nanotube, however, this defect has a rather low formation energy, lower than the vacancy itself, suggesting that it may be one of the most important defects that are created after electron or ion irradiation. Moreover, they form a strong link between the nanotubes in bundles, increasing their shear modulus by a sizeable amount, clearly indicating its importance for the mechanical properties of nanotube bundles.Comment: 5 pages and 4 figure

Growth of carbon nanotubes on quasicrystalline alloys

We report on the synthesis of carbon nanotubes on quasicrystalline alloys. Aligned multiwalled carbon nanotubes (MWNTs) on the conducting faces of decagonal quasicrystals were synthesized using floating catalyst chemical vapor deposition. The alignment of the nanotubes was found perpendicular to the decagonal faces of the quasicrystals. A comparison between the growth and tube quality has also been made between tubes grown on various quasicrystalline and SiO2 substrates. While a significant MWNT growth was observed on decagonal quasicrystalline substrate, there was no significant growth observed on icosahedral quasicrystalline substrate. Raman spectroscopy and high resolution transmission electron microscopy (HRTEM) results show high crystalline nature of the nanotubes. Presence of continuous iron filled core in the nanotubes grown on these substrates was also observed, which is typically not seen in MWNTs grown using similar process on silicon and/or silicon dioxide substrates. The study has important implications for understanding the growth mechanism of MWNTs on conducting substrates which have potential applications as heat sinks

Structural stability and energetics of single-walled carbon nanotubes under uniaxial strain

A (10x10) single-walled carbon nanotube consisting of 400 atoms with 20 layers is simulated under tensile loading using our developed O(N) parallel tight-binding molecular-dynamics algorithms. It is observed that the simulated carbon nanotube is able to carry the strain up to 122% of the relaxed tube length in elongation and up to 93% for compression. Young s modulus, tensile strength, and the Poisson ratio are calculated and the values found are 0.311 TPa, 4.92 GPa, and 0.287, respectively. The stress-strain curve is obtained. The elastic limit is observed at a strain rate of 0.09 while the breaking point is at 0.23. The frequency of vibration for the pristine (10x10) carbon nanotube in the radial direction is 4.71x10^3 GHz and it is sensitive to the strain rate.Comment: 11 pages, 8 figure

Aquaporin–graphene interface: relevance to point-of-care device for renal cell carcinoma and desalination

© 2018 The Author(s) Published by the Royal Society. All rights reserved. The aquaporin superfamily of hydrophobic integral membrane proteins constitutes water channels essential to the movement of water across the cell membrane, maintaining homeostatic equilibrium. During the passage of water between the extracellular and intracellular sides of the cell, aquaporins act as ultra-sensitive filters. Owing to their hydrophobic nature, aquaporins self-assemble in phospholipids. If a proper choice of lipids is made then the aquaporin biomimetic membrane can be used in the design of an artificial kidney. In combination with graphene, the aquaporin biomimetic membrane finds practical application in desalination and water recycling using mostly Escherichia coli AqpZ. Recently, human aquaporin 1 has emerged as an important biomarker in renal cell carcinoma. At present, the ultra-sensitive sensing of renal cell carcinoma is cumbersome. Hence, we discuss the use of epitopes from monoclonal antibodies as a probe for a point-of-care device for sensing renal cell carcinoma. This device works by immobilizing the antibody on the surface of a single-layer graphene, that is, as a microfluidic device for sensing renal cell carcinoma

van der Waals interaction in nanotube bundles : consequences on vibrational modes

We have developed a pair-potential approach for the evaluation of van der Waals interaction between carbon nanotubes in bundles. Starting from a continuum model, we show that the intertube modes range from $5 cm^{-1}$ to $60 cm^{-1}$. Using a non-orthogonal tight-binding approximation for describing the covalent intra-tube bonding in addition, we confirme a slight chiral dependance of the breathing mode frequency and we found that this breathing mode frequency increase by $\sim$ 10 % if the nanotube lie inside a bundle as compared to the isolated tube.Comment: 5 pages, 2 figure