An Exponential Filtering Based Inversion Method for Microwave Imaging

In this paper, a new methodology based on the exponential filtering of singular values is adopted to solve the linear ill-posed problem of microwave imaging. This technique filters out the insignificant singular values and works as an efficient low pass filter to eliminate high-frequency noise from the estimated solution. Standard Tikhonov regularization has also proven to be a special case of this method. To show the effectiveness of this approach, various numerical examples of synthetic data and experimental data of Fresnel's Institute are considered for the study. The reconstruction performance of this algorithm is quantified using the mean square error (MSE) and Pearson's correlation coefficient (PCC). Further, the effect of noise on these metrics is presented. The results are compared with the standard Tikhonov regularization method, and it is observed that the proposed reconstruction algorithm provides accurate results compared to the standard Tikhonov regularization method

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Comparison of Endothelial Cell Loss by Specular Microscopy between Phacoemulsification and Manual Small-Incision Cataract Surgery

Aim: To compare the endothelial cell loss between phacoemulsification and manual small‑incision cataract surgery (SICS). Endothelial cell loss was also compared in phacoemulsification group by temporal clear corneal incision (CCI) and by superior scleral incision (SI) technique.Materials and Methods: A total of 200 eyes of 200 patients were included in the study. Cases were randomly divided into two equal groups. Group A had undergone phacoemulsification and Group B had under gone manual SICS. In Group A 50 cases were performed by temporal CCI and remaining 50 cases were performed by superior SI technique. Endothelial cell count was evaluated by using a noncontact specular microscope.Results: Mean endothelial cell loss (cells/mm2) in Group A was 307.80 (12.33%), 397.79 (15.93%), and 421.69 (16.89%) on 1 week, 6 week, and 3 month postoperative period, respectively. In Group B, it was 270.86 (10.63%), 385.22 (15.12%), and 413.68 (16.24%) on 1 week, 6 week, and 3 month postoperative period, respectively. There was no clinical and statistically significant difference (P > 0.05) between the two groups. The mean endothelial cell loss in Group A by CCI was 340.68 (13.61%), 427.80 (17.08%), and 448.70 (17.92%) and by SI was 274.92 (11.05%), 367.78 (14.78%), and 394.68 (15.83%) on 1 week, 6 week, and 3 month postoperative period respectively. There was statistically significant difference in endothelial cell loss at 1 week (P < 0.05) but it was not statistically significant on 6 week and 3 month postoperatively (P > 0.05).Conclusion: There was no clinically or statistically significant difference in endothelial cell loss or visual acuity between phacoemulsification and manual SICS at 3 month postoperative period.Keywords: Endothelial cell count, manual small incision cataract surgery, phacoemulsification, specular microscop

A Novel Negative Meander Line Design of Microstrip Antenna for 28 GHz mmWave Wireless Communications

In this paper, we propose a fractional regularized distorted Born iterative method (DBIM) to solve non-linear ill-posed problems of microwave imaging. Fractional regularization is a modification to Tikhonov regularization, where singular values are weighed with fractional power. As a result, the well-known effect of oversmoothing present in Tikhonov regularization is reduced, thereby the output image quality is improved. The results of this method are compared with standard DBIM using Tikhonov regularization. Various numerical examples of simulated and experimental datasets containing homogeneous as well as heterogeneous scatterers are considered to validate the effectiveness of the proposed approach. It is found that the proposed method improves the accuracy of estimated images over conventional DBIM

Formulation and characterization of oxiconazole-loaded emulgel for topical application

Background: Oxiconazole nitrate is a new topical broad spectrum antifungal agent used to treat superficial fungal infections. It has a low aqueous solubility due to which different techniques are employed to enhance its bioavailability. Emulgel has emerged as one of the most interesting topical drug delivery system for hydrophobic drugs like Oxiconazole as it has dual release control systems i.e. emulsion and gel. Objective: In the present work an attempt was made to prepare Emulgel of Oxiconazole nitrate for enhancing its topical delivery. Materials and Methods: Emulgel formulations were characterized by various parameters like pH, viscosity, spreadability, extrudability, in vitro drug release. Skin irritation test on wistar rats and in vitro antifungal test on Candida albicans were performed. Results: Optimized formulation F5 showed 92.06% release at the end of 12 hrs. It showed no skin irritation and observed with maximum zone of inhibition when compared with marketed cream of Oxiconazole nitrate. Conclusion: The optimized emulgel formulation F5 showed better antifungal activity in comparison to the marketed formulation

Should all paediatric patients with presumed idiopathic scoliosis undergo MRI screening for neuro-axial disease?

Background: Idiopathic scoliosis is a relatively common childhood condition affecting 0.47–5.2% of the population. Traditional interventions focus on orthopaedic correction of the curve angle. There is a spectrum of patients with scoliosis who are found to have neuro-axial abnormality on full MRI of the spine, but not all surgeons request imaging in the absence of neurological symptoms. There is evidence to suggest that treatment of neuro-axial disease may improve scoliosis curve outcome. We therefore sought to estimate what proportion of patients with normal neurology and scoliosis are found to have neuro-axial abnormality on full MRI imaging of the spine, in particular Chiari malformation and syringomyelia. Results: Out of 11 identified studies consisting of 3372 paediatric patients (age 20°) and normal neurological examination will demonstrate a neuro-axial abnormality on full MRI imaging of the spine. Of patients, 8.3 and 8.4% were found to have Chiari malformation and syringomyelia, respectively. Conclusions: Up to one in seven paediatric patients with scoliosis and normal neurological examination will demonstrate neuro-axial disease on MRI imaging of the spine. Given that younger age and earlier age of decompression is associated with improvement in curve angle, it seems important that MRI screening be considered in all patients regardless of neurological examination findings. There is a potentially long-term benefit in these patients. Multi-cross institutional prospective studies are encouraged to further investigate effect on curve angle

Language development, hearing loss, and intracranial hypertension in children with TWIST1-confirmed Saethre-Chotzen syndrome

Saethre-Chotzen syndrome (SCS) is an autosomal dominant condition defined by mutations affecting the TWIST1 gene on chromosome 7p21.1. Previous research has identified an elevated prevalence of intracranial hypertension and hearing impairment associated with this syndrome. This study aimed to investigate the influence of hearing history and presence of intracranial hypertension on language development in children with SCS. A retrospective study note analysis was performed for all patients with a confirmed TWIST1 gene abnormality who attended the Oxford Craniofacial Unit and underwent a language assessment over a 22-year period. Intracranial pressure monitoring, hearing status, and language outcomes were examined in detail. Thirty patients with genetically confirmed SCS and language assessment data were identified. Twenty-eight patients underwent surgical intervention; 10 presented with intracranial hypertension (5 prior to, and 5 after primary surgical intervention). Language data coinciding with the presentation of intracranial hypertension were available for 8 children. About 44% of children with intracranial hypertension presented with concurrent receptive and expressive language delay (n = 4/8). For both children (n = 2) with longitudinal language data available, the onset of intracranial hypertension reflected a concurrent decline in language skills. Audiometric data were available for 25 children, 80% (n = 20/25) had a history of hearing loss. About 50% of these had confirmed conductive hearing loss with middle ear effusion and the other 50% had presumed conductive hearing loss with middle ear effusion. About 100% of the children with available hearing data in our study had evidence of middle ear effusion in at least 1 ear. Results also indicated that 43% (n = 13/30) of the children presented with receptive and/or expressive language delay during childhood. Given the importance of hearing for language development and the preliminary findings of a potential decline in language skills in children during periods of intracranial hypertension, regular follow-up of hearing, language, and intracranial hypertension are indicated in children with SCS.</p