Search results for "defects"

Dynamic tuning of the director field in liquid crystal shells using block copolymers

2020

When an orientationally ordered system, like a nematic liquid crystal (LC), is confined on a self-closing spherical shell, topological constraints arise with intriguing consequences that depend critically on how the LC is aligned in the shell. We demonstrate reversible dynamic tuning of the alignment, and thereby the topology, of nematic LC shells stabilized by the nonionic amphiphilic block copolymer Pluronic F127. Deep in the nematic phase, the director (the average molecule orientation) is tangential to the interface, but upon approaching the temperature TNI of the nematic– isotropic transition, the director realigns to normal. We link this to a delicate interplay between an interfacial …

Novel missense mutation of the TP63 gene in a newborn with Hay-Wells/Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) syndrome: clinical rep…

2021

Abstract Introduction Ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome, also known as Hay-Wells syndrome, is a rare genetic syndrome with ectodermal dysplasia. About 100 patients have been reported to date. It is associated to a heterozygous mutation of the tumor protein p63 (TP63) gene, located on chromosome 3q28. Typical clinical manifestations include: filiform ankyloblepharon adnatum (congenital adherence of the eyelids), ectodermal abnormalities (sparse and frizzy hair, skin defects, nail alterations, dental changes and hypohidrosis), and cleft lip/palate. Diagnostic suspicion is based on clinical signs and confirmed by genetic testing. Patient’s presentation We hereb…

Nickel release after implantation of the Amplatzer occluder.

2003

Background Transcatheter closure of atrial septal defects is a new and less traumatic technique than open heart surgery. In recent years, patients with a patent foramen ovale sustaining potential paradoxical embolism have also become candidates for interventional closure devices. One of the more popular occluding devices is the Amplatzer septal occluder, which, like many other occluders, is made of nitinol. Nitinol-based alloys are widely used in medical products, for example, in orthopedics and orthodontics. However, the clinical use of nitinol, which contains 55% nickel, is still controversial because of concerns about its biocompatibility. Therefore, we examined the systemic nickel relea…

Perturbed Glucose Metabolism: Insights into Multiple Sclerosis Pathogenesis

2014

Multiple sclerosis (MS) is a complex debilitating disease of the central nervous system perceived to result from the autoimmune effect of T cells in damaging myelin sheath. However, the exact pathogenesis of the disease remains elusive. Initial studies describing the possibility of defective pyruvate metabolism in MS were performed in 1950s. The group observed elevated blood pyruvate level in both fasting and postprandial times in MS patients with relapse. Similarly, other investigators also reported increased fasting pyruvate level in this disease. These reports hint to a possible abnormality of pyruvate metabolism in MS patients. In addition, increase in levels of Krebs cycle acids like a…

Transcatheter Vs. Surgical Closure of Atrial Septal Defects in Adults

2018

Abstract Percutaneous transcatheter device closure of secundum atrial septal defects (ASD) has now largely replaced surgical closure in most centres. The aim of this study was to compare results of transcatheter and surgical ASD closure in adults in Latvia during the years 2002–2014 and to analyse long-term outcomes of transcatheter closure. We analysed data from 334 patients with secundum ASD who underwent ASD closure in Pauls Stradiņš Clinical University Hospital. Patients were included into device or surgical closure groups. In the device group, three follow-ups were made 1, 6, and 12 months after the procedure. No follow-up data were available for surgical arm patients beyond their hosp…

Catheter-based closure of a large atrial septal defect with inferior rim deficiency using pulmonary vein slide-out assisted implantation technique: a…

2021

Abstract Background Transcatheter approach for large and complex atrial septal defects may represent a therapeutic challenge, particularly when the postero-inferior rim is deficient and floppy. Case summary Here, we describe a successful catheter-based closure of a large (>30 mm) secundum atrial septal defect associated with postero-inferior rim deficiency in a 35-year-old female with congestive heart failure using pulmonary vein slide-out assisted implantation technique. Discussion Inferior–posterior rim deficiency is a well-known risk factor for device instability or embolization. Transcatheter closure may represent a safe and effective alternative to the traditional surgical appro…

Endokarditische Restzust�nde und Klappenfehler

1954

Pulsed radiofrequency energy device (PEAK plasmablade™) and CustomBone® Cranioplasty: an appealing surgical rendez-vous

2019

Background: CustomBone® prosthesis is a widely recognized effective and successful technique for the reconstruction of cranial bone defects. Prior the cranioplasty implant, meticulous dissection wi...

Color-discrimination threshold determination using pseudoisochromatic test plates

2014

We produced a set of pseudoisochromatic plates for determining individual color-difference thresholds to assess test performance and test properties, and analyzed the results. We report a high test validity and classification ability for the deficiency type and severity level [comparable to that of the fourth edition of the Hardy–Rand–Rittler (HRR) test]. We discuss changes of the acceptable chromatic shifts from the protan and deutan confusion lines along the CIE xy diagram, and the high correlation of individual color-difference thresholds and the red–green discrimination index. Color vision was tested using an Oculus HMC anomaloscope, a Farnsworth D15, and an HRR test on 273 schoolchildr…

Origins of radiation-induced attenuation in pure-silica-core and Ge-doped optical fibers under pulsed x-ray irradiation

2020

We investigated the nature, optical properties, and decay kinetics of point defects causing large transient attenuation increase observed in silica-based optical fibers exposed to short duration and high-dose rate x-ray pulses. The transient radiation-induced attenuation (RIA) spectra of pure-silica-core (PSC), Ge-doped, F-doped, and Ge + F-doped optical fibers (OFs) were acquired after the ionizing pulse in the spectral range of [∼0.8–∼3.2] eV (∼1500–∼380 nm), from a few ms to several minutes after the pulse, at both room temperature (RT) and liquid nitrogen temperature (LNT). Comparing the fiber behavior at both temperatures better highlights the thermally unstable point defects contribut…