1,726 research outputs found

    Novel missense mutation in the FH gene in familial renal cell cancer patients lacking cutaneous leiomyomas

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    BACKGROUND: Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare tumor predisposition syndrome characterized by cutaneous and uterine leiomyomas and papillary type 2 renal cell cancer. Germline mutation of the fumarate hydratase (FH) gene is known to be associated with HLRCC. CASE PRESENTATION: We describe a 64-year-old father and his 39-year-old son with HLRCC who developed papillary type 2 RCCs lacking cutaneous leiomyomas at any site. A common missense mutation in the FH gene, (c.1021G > A, p.D341N) in exon 7, was detected in the 2 cases. Functional prediction with the bioinformatics programs, SIFT and Polyphen-2, reported “damaging (SIFT score 0.00)” and “probably damaging (PSIC score 1.621)” values, respectively. In 162 healthy individuals, there were no cases of a G transition to any base. Finally, (c.1021G > A) in exon 7, was identified as a point mutation. CONCLUSION: We report a family with HLRCC in which a novel missense mutation was detected. A familial papillary type 2 renal cancer should be considered HLRCC unless typical cutaneous leiomyomas do not occur

    Photocatalytic evidence of the rutile-to-anatase electron transfer in titania

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    Layered anatase-rutile titania thin-films were synthesized via atmospheric-pressure chemical vapor deposition and characterized using X-ray diffraction, Raman spectroscopy and electron microscopy. The interposition of an amorphous TiO2-based interlayer allowed direct vapor deposition of anatase on a rutile substrate, which is otherwise hindered by templating. This resourceful approach and the subsequent crystallization of the amorphous layer after annealing of the films allowed investigation on the impact of an efficient interface of the two anatase-rutile phases in the photodegradation of a model organic pollutant. Clear evidence is presented on the synergy between the two polymorphs and more importantly, on the charge flow across the interface, which, against much conventional understanding, it involves electron transfer from rutile to anatase and is in agreement with a recent theoretical model and electron paramagnetic resonance data. Here, an increasing density of trapped electrons on the anatase surface of the A/R film is confirmed by photoreduction of silver. This observation is attributed to a defect-free efficient contact between the two phases and the presence of small rutile particles that promote rapid electron transfer at the A-R interface of the films

    Evolution of the electronic structure with size in II-VI semiconductor nanocrystals

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    In order to provide a quantitatively accurate description of the band gap variation with sizes in various II-VI semiconductor nanocrystals, we make use of the recently reported tight-binding parametrization of the corresponding bulk systems. Using the same tight-binding scheme and parameters, we calculate the electronic structure of II-VI nanocrystals in real space with sizes ranging between 5 and 80 {\AA} in diameter. A comparison with available experimental results from the literature shows an excellent agreement over the entire range of sizes.Comment: 17 pages, 4 figures, accepted in Phys. Rev.

    Experimental variable effects on laser heating of inclusions during Raman spectroscopic analysis

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    Raman spectroscopy for fluid, melt, and mineral inclusions provides direct insight into the physicochemical conditions of the environment surrounding the host mineral at the time of trapping. However, the obtained Raman spectral characteristics such as peak position are modified because of local temperature enhancement of the inclusions by the excitation laser, which might engender systematic errors and incorrect conclusions if the effect is not corrected. Despite the potentially non-negligible effects of laser heating, the laser heating coefficient (B) (°C/mW) of inclusions has remained unsolved. For this study, we found B from experiments and heat transport simulation to evaluate how various parameters such as experimental conditions, mineral properties, and inclusion geometry affect B of inclusions. To assess the parameters influencing laser heating, we measured B of a total of 19 CO2-rich fluid inclusions hosted in olivine, orthopyroxene, clinopyroxene, spinel, and quartz. Our results revealed that the measured B of fluid inclusions in spinel is highest (approx. 6 °C/mW) and that of quartz is lowest (approx. 1 × 10−2 °C/mW), consistent with earlier inferences. Our simulation results show that the absorption coefficient of the host mineral is correlated linearly with B. It is the most influential parameter when the absorption coefficient of the host mineral (αh) is larger than that of an inclusion (αinc). Furthermore, although our results indicate that both the inclusion size and depth have little effect on B if αh > αinc, the thickness and radius of the host mineral slightly influence B. These results suggest that the choice of inclusion size and depth to be analyzed in a given sample do not cause any systematic error in the Raman data because of laser heating, but the host radius and thickness, which can be adjusted to some degree at the time of sample preparation, can cause systematic errors between samples.Our results demonstrate that, even with laser power of 10 mW, which is typical for inclusion analysis, the inclusion temperature rises to tens or hundreds of degrees during the analysis, depending especially on the host mineral geometry and optical properties. Therefore, correction of the heating effects will be necessary to obtain reliable data from Raman spectroscopic analysis of inclusions. This paper presents some correction methods for non-negligible effects of laser heating

    Improvement of photoluminescence stability of ZnS-AgInS2 nanoparticles through interactions with ionic liquids

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    Photoluminescence (PL) stability of ZnS-AgInS2 (ZAIS) nanoparticles (NPs) prepared via thermal decomposition of (AgIn)xZn2(1-x)(S2CN(C2H5)2)4 (x = 0.5, 0.8 and 1.0) was improved by ionic liquids (ILs) of 1-ethyl-3-metylimidazolium ethylsulfate (EMI-es) and tris (2-hydroxyethyl) methylammonium methylsulfate (HEMA-mes). Through ligand exchange processes from oleylamine (OLA) to sodium 2-mercaptoethanesulfonic acid (MES), hydrophilic NP’s surfaces changed into hydrophobic ones, resulting in that the ZAIS NPs could be dispersed in the ILs. UV irradiation caused the PL deterioration of ZAIS NPs in solutions, but MES-ZAIS NPs in the ILs exhibited higher PL stability than the OLA-ZAIS NPs in chloroform, the degree being more remarkable for NPs dispersed in HEMA-mes than in EMI-es. The improvement of PL stability could be interpreted as a result of stabilization of MES adsorbed on the NPs through electrostatic interaction between MES and the ILs. Exposing to the air and mixing with the water accelerated the PL deterioration of the NPs.journal articl
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