1,117 research outputs found
Isolated foetal ascites.
The prenatal diagnosis and perinatal outcome of two patients with isolated foetal ascites compatible with chyloperitoneum is described. The foetal ascites resolved spontaneously after delivery with good perinatal outcome in both cases. A good prognosis can be anticipated in such cases. Antepartum and intrapartum interventions are seldom necessary.published_or_final_versio
Adsorption and desorption behaviors of selected endocrine disrupting chemicals in simulated gastrointestinal fluids
postprin
Frequency of angiotensin-converting enzyme DD genotype is decreased in patients with hypertension and left ventricular hypertrophy
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Is syndrome X related to antiogensin-converting enzyme gene polymorphism?
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Synthesis and properties of ZnO nano-ribbon and comb structures
ZnO is of great interest for photonic applications due to its wide band gap (3.37 eV) and large exciton binding energy (60 meV). A large variety of fabrication methods and nanostructure morphologies was reported up to date for this material. Obtained morphologies include nanobelts or nanoribbons, nanowires, nanorods, tetrapod nanostructures, etc. Novel nanostructures like hierarchical nanostructures, nanobridges and nanonails have also been fabricated. In this work, we report a simple method for fabrication of nanoribbon and nanocomb structures. The structures are fabricated by evaporation of a mixture of ZnO and carbon nanotubes (CNT) at 1050°C, and the deposition products have been collected on Si substrates in the temperature range 750-800°C. The growth mechanism of obtained structures is discussed. © 2005 American Institute of Physics.published_or_final_versio
Strategy for introducing antibacterial activity under ambient illumination in titania nanoparticles
Titanium dioxide (TiO2) is a wide bandgap (∼3.4 eV) semiconductor material which is commonly used as a photocatalyst and antibacterial material. UV illumination with energy similar to the bandgap is often needed to make the material active. It would be favorable for practical applications, if its action can also be activated under ambient. Recently, robust antibacterial action was demonstrated on ZnO nanoparticles under ambient illumination. In this study, we demonstrated robust antibacterial activity of TiO2 nanoparticles induced by annealing under ambient illumination. It was found that the antibacterial activity could be significantly changed by tuning the annealing temperatures and using different crucibles containing the nanoparticles. Bacterium Escherichia coli was used as the model organism in the test. It was observed that although no significant antibacterial activity was observed on the starting material (untreated commercial TiO2 nanoparticles), the activity increases significantly if the nanoparticles were annealed above 650 °C with crucible lined with copper foil. The survival rate of E. coli bacteria approaches to zero if the nanoparticles annealing temperature reaches 850 °C. Under optimized conditions, three different titania nanoparticle samples exhibited antibacterial activity under ambient illumination. This work sheds light on the development of ambient-active antibacterial coating and in particular, on the modification of any TiO2 material to become ambient-active with a suitable treatment. © 2015 SPIE.published_or_final_versio
Growth of N, N′-di(naphthalene-1-yl)-N, N′-diphenyl-benzidine dome structures
N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine samples exhibiting interesting nano/microstructure were fabricated by thermal evaporation in a tube furnace under Ar gas flow. We investigated the influence of the substrate type, substrate temperature, source temperature, and the gas flow rate on the obtained morphology. The deposited material was investigated using scanning electron microscopy, x-ray diffraction, and photoluminescence. We found that the substrate temperature was the factor which significantly affected the obtained morphology, while other factors such as substrate type, source temperature, and gas flow mainly affected the size distribution of the features but not the type of morphology observed. © 2005 American Institute of Physics.published_or_final_versio
Sequential approaches for resection of clival chordoma
Free Paper 7Conference Theme: Degenerative Lumbar SpineINTRODUCTION: Chordomas are extra-axial tumours that originate from the primitive notochord. They are rare diseases that present mostly between the third and the fifth decades of life with an incidence rate of 0.08 per 100,000 in the United States. Approximately 35% of chordomas arise in the clivus of the skull base (clival chordoma). In spite of their slow-growing and non-malignant histopathological appearance, they are potentially life threatening due to their locally destructive and invasive nature. Clival chordomas are located near the spheno-occipital junction at the base of the skull, behind the sphenoid sinuses. Involvement of the surrounding cranial nerves accounts for their symptomatology. It is notorious for its high tendency of recurrence following treatment, with a reported recurrence rate of 68%. Therefore, gross total resection in combination with adjuvant radiotherapy is the standard mode of treatment …published_or_final_versio
Visible photoluminescence in ZnO tetrapod and multipod structures
The investigation of the properties of ZnO tetrapod and multipod structures using scanning electron microscopy, X-ray diffraction, photoluminescence (PL) and electron paramagnetic resonance (EPR) spectroscopy was discussed. The ZnO samples were fabricated by heating a mixture of ZnO, GeO2 and graphite at 1100°C in order to modify the morphology of the fabricated structures. The room temperature of PL was measured by using a HeCd laser excitation source (325 nm). It was found that the green PL was due to transition between a shallow donor and deep acceptor in the absence of g ≈ 1.96 EPR signal and transition between the conduction band and deep acceptor in the absence of g ≈ 1.96 EPR signal.published_or_final_versio
Zinc oxide tetrapods as efficient photocatalysts for organic pollutant degradation
Bisphenol A (BPA) and other organic pollutants from industrial wastewater have drawn increasing concern in the past decades regarding their environmental and biological risks, and hence developing strategies of effective degradation of BPA and other organic pollutants is imperative. Metal oxide nanostructures, in particular titanium oxide (TiO2) and zinc oxide (ZnO), have been demonstrated to exhibit efficient photodegradation of various common organic dyes. ZnO tetrapods are of special interest due to their low density of native defects which consequently lead to lower recombination losses and higher photocatalytic efficiency. Tetrapods can be obtained by relatively simple and low-cost vapor phase deposition in large quantity; the micron-scale size would also be advantageous for catalyst recovery. In this study, the photodegradation of BPA with ZnO tetrapods and TiO2 nanostructures under UV illumination were compared. The concentration of BPA dissolved in DI water was analyzed by high-performance liquid chromatography (HPLC) at specified time intervals. It was observed that the photocatalytic efficiency of ZnO tetrapods eventually surpassed Degussa P25 in free-standing form, and more than 80% of BPA was degraded after 60 min. Photodegradation of other organic dye pollutants by tetrapods and P25 were also examined. The superior photocatalytic efficiency of ZnO tetrapods for degradation of BPA and other organic dye pollutants and its correlation with the material properties were discussed. © 2015 SPIE.published_or_final_versio
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