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

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

An integrated approach to the management of meningoencephalocoeles

Meningoencephalocoeles are congenital herniations of meningeal and cerebral tissues through a cranial defect. They occur most commonly in South-East Asia, and are relatively rare amongst European ancestry populations, with an estimated prevalence of 1/40,000 live births. The treatment of congenital meningoencephalocoeles is primarily surgical and are best managed by dedicated multi-disciplinary craniofacial teams. The authors performed a retrospective case review of all primary meningoencephalocoeles managed in the Oxford University Hospitals NHS Foundation Trust between 1986 and 2012. Twenty-nine cases (13 frontal, 9 occipital, 2 parietal, and 5 basal) were included in this study. The median age at presentation was 11 months (range 0–60 years). Twenty-five cases presented with an external mass; 3 with recurrent meningitis and 1 with otorrhoea. Twenty-six cases underwent surgery, and 17 of these were managed by an integrated approach between 2 or more surgical specialties. Twenty out of 26 operations were performed via a transcranial approach. The authors describe a particularly complex case in order to highlight the challenges associated with management of meningoencephalocoeles, the surgical technique employed, and the importance of a multidisciplinary surgical approach. This is the largest reported case series of meningoencephalocoeles managed in a single hospital in the United Kingdom. Designated craniofacial units with access to multidisciplinary surgical specialties provide a safe and optimal setting for the management of meningoencephalocoeles

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

Preferentially oriented m-tuned WO3 thin-films photocatalysts for the multitargeted degradation of organic molecules

In this work, morphology-tuned tungsten oxide (m-tuned WO3) thin films are deposited on a glass substrate by a simple and cost-effective chemical bath deposition (CBD) method. The deposition pH is varied to tune the physicochemical properties of m-tuned WO3 thin films. The m-tuned WO3 thin films show an orthorhombic crystal structure with a preferred orientation along the (020) plane. The morphological study demonstrated the conversion of ‘rice hull’ to ‘interlocked nanosheets’ to ‘reticulated nanosheets composed of nanorods’ upon changing pH, highlighting the significant role of pH in m-tuned WO3 thin film synthesis. The m-tuned WO3 thin films show good absorption in the visible-light region (390–780 nm) of the solar spectrum. The m-tuned WO3 thin films are used for the visible light active photocatalytic degradation of organic molecules such as methylene blue (MB), rhodamine B (Rh B), and tetracycline hydrochloride (TC). The optimized m-tuned WO3 thin film shows maximum photocatalytic performance of 95, 94, and 86 % in 180 min for MB, Rh B, and TC, respectively. The present study demonstrates the usefulness of the CBD method for the deposition of m-tuned WO3 and improved photocatalytic performance