Publications by authors named "Alexandrou I"

Introduction: The treatment of children with pelviureteric junction obstruction (PUJO) has naturally progressed from open, to minimally invasive approaches, including laparoscopic pyeloplasty and robot-assisted laparoscopic pyeloplasty (RALP). The RALP is now considered to be the gold standard for paediatric patients with PUJO, except for smaller infants due to size limitations. Our systematic review aims to synthesise all the available evidence regarding key postoperative outcomes for the three surgical approaches to pyeloplasties in children.

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The main strengthening mechanism for Inconel 718 (IN718), a Ni-based superalloy, is precipitation hardening by γ' and γ″ particles. It is thus essential, for good alloy performance, that precipitates with the desired chemical composition have adequate size and dispersion. The distribution of the γ' and γ″ phases and their chemical composition were investigated in the nickel-based Inconel 718 superalloy by taking advantage of the new capabilities of scanning transmission electron microscopy and energy-dispersive X-ray spectrometry using a windowless multiple detector, a high-brightness Schottky electron gun, and a spherical aberration corrector in the illumination probe optics.

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Article Synopsis
  • Pelvi-ureteric junction obstruction (PUJO) is a condition that hinders urine flow at the junction where the kidney's pelvis connects to the ureter, affecting both adults and children.
  • The obstruction can be caused by either external pressure or blockages within the body that impact urinary drainage.
  • Traditionally, surgical intervention has been the primary treatment, with the open Anderson-Hynes dismembered pyeloplasty being the standard procedure for correcting this issue.
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DPC in Scanning Transmission Electron Microscopy (STEM) is a valuable method for mapping the electric fields in semiconductor materials. However, optimising the experimental conditions can be challenging. In this paper, we test and compare critical experimental parameters, including the convergence angle, camera length, acceleration voltage, sample configuration, and orientation using a four-quadrant segmented detector and a Si specimen containing layers of different As concentrations.

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Pockels and Kerr effects are linear and nonlinear electro-optical effects, respectively, used in many applications. The modulation of the refractive index is employed in different photonic circuits. However, the greatest challenge is in photonic elements for quantum computing at room temperature.

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Pediatric Crohn's disease (CD) is a chronic inflammatory bowel disease considered to impair the growth of children and adolescents. Since CD commonly presents perianal manifestations, general surgeons may play a crucial role in its diagnosis and treatment. Detailed history, along with a thorough clinical examination, is mandatory for the management of CD perianal lesions.

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Williams-Beuren syndrome (WBS) is a rare neurodevelopmental disorder characterized by supravalvular aortic stenosis (SVAS), intellectual disability, overfriendliness and dysmorphic features. It is typically caused by 1.5-1.

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We present an extremely rare case of inguinal hernia coexisting with testicular ectopia in a child. Male infant 9.5 month old presented with an empty scrotum and the ipsilateral intravaginal testis lying in a high iliac crest position.

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We describe a female with Rett syndrome carrying a rare de novo mosaic nonsense mutation on gene, with random X-chromosome inactivation. Rett syndrome severity in females depends on mosaicism level and tissue specificity, X-chromosome inactivation, epigenetics and environment. Rett syndrome should be considered in both males and females.

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Article Synopsis
  • Sperm cell granuloma, known as epididymitis nodosa, is a condition that can happen after injury, inflammation, or a vasectomy, and it affects the epididymis (a part of the male reproductive system).
  • A 13-year-old boy was treated for a related issue called epididymo-orchitis, but after his symptoms got worse, he needed surgery.
  • The surgery revealed damage and dead tissue in the testicle, and doctors found that epididymitis nodosa was the cause, showing that this condition should be checked for in boys with testicle swelling when other treatments don’t work.
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Haploinsufficiency of the short stature homeobox contaning SHOX gene has been shown to result in a spectrum of phenotypes ranging from Leri-Weill dyschondrosteosis (LWD) at the more severe end to SHOX-related short stature at the milder end of the spectrum. Most alterations are whole gene deletions, point mutations within the coding region, or microdeletions in its flanking sequences. Here, we present the clinical and molecular data as well as the potential molecular mechanism underlying a novel microdeletion, causing a variable SHOX-related haploinsufficiency disorder in a three-generation family.

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Prader-Willi syndrome is a rare syndrome characterized by hypotonia, developmental delay and excessive appetite. This syndrome is caused by the loss of function of paternally-expressed genes located in an imprinting centre in 15q11-q13. Here, we report the case of a patient who was referred to us with Prader-Willi syndrome-like symptoms including obesity and developmental delay.

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The optical properties of zinc oxide nanowires are critically influenced by the growth process. Herein, we describe a metal-organic chemical vapour deposition (MOCVD) process for the growth of ZnO nanowires with improved optical properties. A tetrahydrofuran adduct is used to control the reactivity of dimethylzinc to enable this.

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Nowadays, organic solar cells have the interest of engineers for manufacturing flexible and low cost devices. The considerable progress of this nanotechnology area presents the possibility of investigating new effects from a fundamental science point of view. In this letter we highlight the influence of the concentration of fullerene molecules on the ultrafast transport properties of charged electrons and polarons in P3HT/PCBM blended materials which are crucial for the development of organic solar cells.

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Charge exchange at the bulk heterojunctions of composites made by mixing single wall nanotubes (SWNTs) and polymers show potential for use in optoelectronic devices such as solar cells and optical sensors. The density/total area of these heterojunctions is expected to increase with increasing SWNT concentration but the efficiency of solar cell peaks at low SWNT concentrations. Most researchers use current-voltage measurements to determine the evolution of the SWNT percolation network and optical absorption measurements to monitor the spectral response of the composites.

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Oleuropein, a novel immunomodulator derived from olive tree, was assessed in vitro and in experimental sepsis by Pseudomonas aeruginosa. After addition in monocyte and neutrophil cultures, malondialdehyde, TNF-alpha, IL-6, and bacterial counts were estimated in supernatants. Acute pyelonephritis was induced in 70 rabbits after inoculation of pathogen in the renal pelvis.

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Annular pancreas is the rare congenital anomaly where the pancreas forms a full or incomplete ring around the second segment of the duodenum, causing various degrees of stenosis or atresia. It is estimated that it appears in 1 out of 12 000-15 000 births of living neonates and until now, in the literature, only 6 cases have been reported among individuals of the same family. We present the case of two siblings, a boy and a girl, with annular pancreas from consecutive pregnancies of the same couple.

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Since carbon nanotubes and onions were discovered, many methods have been proposed for their production. For applications the main requirements are low capital cost, high purity of the produced material, simplicity of technique, and its potential for scale up. Recently a cathodic arc between two graphitic electrodes immersed in liquids has been demonstrated to be a simple method to produce carbon nanoparticles such as nanotubes and onions.

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The fabrication of carbon nanomaterials usually calls for expensive vacuum systems to generate plasmas and yields are disappointingly low. Here we describe a simple method for producing high-quality spherical carbon nano-'onions' in large quantities without the use of vacuum equipment. The nanoparticles, which have C60 cores surrounded by onion-like nested particles, are generated by an arc discharge between two graphite electrodes submerged in water.

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