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The purpose of this study was to assess the efficacy of desocclusol, eucalyptol and d-limonene on removal of gutta-percha, their effect on microhardness of dentin, and the antibacterial properties against Enterococcus faecalis (E. faecalis) during root canal retreatment. Forty single-canal roots, obturated with gutta-percha, were prepared and randomly divided into 4 groups (n=10). Group that free of any solvent was control group. Three of experimental groups were exposed to desocclusol, eucalyptol and d-limonene respectively during endodontic retreatment. Efficacy of each solvent was assessed by comparation of time duration, amount of apical extrusion and residual debris in the root canals. Vickers microhardness of each sample was recorded. Antibacterial activity on E. faecalis was also observed. The data were subjected to repeated statistical analysis. All three organic solvents were found to be effective in the removal of root canal filling material compared with control group (p<0.05). D-limonene was more effective in significantly increasing the microhardness of dentin compared with desocclusol, which decreased the microhardness of root canal dentin (p<0.05). In the meantime, d-limonene had a stronger antibacterial activity than eucalyptol, while desocclusol had no obvious bacterial inhibition. These three organic solvents are all effective in removing gutta-percha in endodontic retreatment. D-limonene can increase the microhardness of dentin and has a stronger inhibitory effect on E. faecalis than desocclusol and eucalyptol. [ABSTRACT FROM AUTHOR]

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Counseling psychology has demonstrated leadership on multicultural issues through serious and committed attention to diversity in scholarship, conferences, and training and recruitment. Yet a survey of the literature on trainees with competence problems resulted in limited references to race/ethnicity and/or gender (REG). Using transcripts of phone interviews, we examined the degree to which Training Directors from 14 counseling psychology doctoral programs included REG in their conceptualizations of trainee remediation. REG conceptualizations differed in terms of (a) definitional clarity and conceptual sophistication about RE, (b) differential integration of approaches to diversity and remediation, and (c) strong emotions associated with race/ethnicity in trainee remediation. Implications for training and research are discussed. [ABSTRACT FROM AUTHOR]

The diagnosis of renal cell carcinoma (RCC) remains problematic, especially in the context of metastasis or small needle biopsy specimens. The renal cell carcinoma marker (RCCM) and kidney-specific cadherin (KSC) are considered specific markers for RCC but are expressed preferentially in specific subtypes of RCC of lower grades. This study was aimed at evaluating the usefulness of PAX-2 in the diagnosis of renal tumors and comparing it with that of RCCM and KSC. Immunostaining for PAX-2, RCCM, and KSC was performed on consecutive tissue sections of 130 renal tumors. PAX-2 was successfully detected in routine tissue specimens. Although PAX-2 seems to be more sensitive than RCCM and KSC, there is significant staining overlap in relation to histologic subtypes, justifying the use of all 3 markers, which helps detect the vast majority of renal neoplasms. PAX-2 seems to have a significant role in renal neogenesis and may represent a novel therapeutic target. [ABSTRACT FROM AUTHOR]

Abstract  THz spectra for some amino acids, peptide and protein have been measured by use of commercial and optically compensated FTS spectrometers. A lot of sharp spectral lines have been observed below 7 THz and attributed, tentatively and in general, to hydrogen bonds and weak intermolecular interactions for the amino-acids and simple peptides, but the detailed explanation is still lack and leaving a big room for further investigation. [ABSTRACT FROM AUTHOR]

The article presents a study of the influence of pollution on human health, investigations and epidemiological survey were carried out in a polluted area and a controlled area. The investigation was carried out in two towns (named Town A and B). Town A has about 20 small to medium-size disassembling workshops which are open to air, consequently, this town is considered to be polluted. Town B, which is about 50 miles away from town A, does not have heavy metal pollutants and is thus assumed to be unpolluted. 60 disassembling workers and 60 residents who had never done disassembling work were selected from town A. Another control group of 60 residents chosen from Town B.

Abstract   Bacillus subtilis KB-1111 and KB-1122 were studied to illustrate their phenotypic and biological properties. Comparison of KB-1111 with KB-1122 in morphology was carried out by microscopy and agar plate assays. Biological assay of the test strains showed that they may possess different physiological pathways from those of reference strain ATCC6501. The assessment of antagonism against the indicator fungi showed that both test strains had broad antifungal characteristics against eight phytopathogenic fungi. Of those fungal species, Magnaporthe grisea P131, Sclerotinia sclerotiorum, and F. oxysporium exhibited high sensitivity to the test strains. [ABSTRACT FROM AUTHOR]

A two-step approach has been developed for the growth of semi-polar (11–22) GaN on patterned (113) silicon substrates, which effectively eliminates Ga melt-back etching at a high temperature, one of the most challenging issues. A (113) Si substrate is patterned into groove trenches by means of using a standard photolithography technique and then anisotropic chemical etching, forming (111) facets with an inclination angle of 58˚ with respect to c-axis in addition to the un-etched (113) facets. A thick AlN layer is subsequently epitaxially grown on the patterned silicon to cover all the facets ensuring to eliminate the melt-back, followed by selectively depositing SiO2 masks on the (113) facets only. Further GaN overgrowth is performed only on the exposed (111) facets, forming (11–22) semi-polar GaN with high crystal quality along the vertical direction. Stimulated emission at room temperature has been observed with a low threshold. Low-temperature photoluminescence measurements confirm a significant reduction in basal stacking faults density. This method provides a promising approach to effectively suppress the Ga melt-back etching issue, which is particularly important for Al(Ga)N growth on semi-polar GaN that requires a high growth temperature. The presented results are crucially important for developing monolithic on-chip integration of electronics and photonics on silicon. [ABSTRACT FROM AUTHOR]

We use high-resolution cosmological hydrodynamical simulations of Milky-Way-sized galaxies with varying supernova feedback strengths and merger histories to investigate the formation of their gaseous halos and especially their hot (>106 K) X-ray-luminous coronae. Our simulations predict the presence of significant hot gas in the halos as early as z = 3–4, well before the halos ought to be able to sustain hot mode accretion in the conventional picture. The nascent coronae grow inside-out and initially do so primarily as a result of outflows from the central galaxies powered by merger-induced shock heating and strong supernova feedback, both of which are elemental features of today’s successful galaxy formation models. Furthermore, the outflows and the forming coronae also accelerate the transition from cold to hot mode accretion by contributing to the conditions for sustaining stable accretion shocks. They also disrupt the filamentary streams funneling cold gas onto the central galaxies by causing their mouths to fray into a broad delta, detach from the galaxies, and be pushed away to larger radii. And even though at early times the filaments repeatedly re-form, the hot gas and the outflows act to weaken the filaments and accelerate their ultimate disruption. Although galactic outflows are generally thought of as ejective feedback, we find that their action on the filaments suggests a preventive role as well. [ABSTRACT FROM AUTHOR]

Undoped and C-doped (C: Mg2+, Ni2+, Mn2+, Co2+, Cu2+, Cr3+) ZnO nanorods were synthesized by a hydrothermal method at temperatures as low as 60 °C. The effect of doping on the morphology of the ZnO nanorods was visualized by taking their cross section and top SEM images. The results show that the size of nanorods was increased in both height and diameter by cation doping. The crystallinity change of the ZnO nanorods due to each doping element was thoroughly investigated by an x-ray diffraction (XRD). The XRD patterns show that the wurtzite crystal structure of ZnO nanorods was maintained after cation addition. The optical Raman-active modes of undoped and cation-doped nanorods were measured with a micro-Raman setup at room temperature. The surface chemistry of samples was investigated by x-ray photoelectron spectroscopy and energy-dispersive x-ray spectroscopy. Finally, the effect of each cation dopant on band-gap shift of the ZnO nanorods was investigated by a photoluminescence setup at room temperature. Although the amount of dopants (Mg2+, Ni2+, and Co2+) was smaller than the amount of Mn2+, Cu2+, and Cr3+ in the nanorods, their effect on the band structure of the ZnO nanorods was profound. The highest band-gap shift was achieved for a Co-doped sample, and the best crystal orientation was for Mn-doped ZnO nanorods. Our results can be used as a comprehensive reference for engineering of the morphological, structural and optical properties of cation-doped ZnO nanorods by using a low-temperature synthesis as an economical mass-production approach. [ABSTRACT FROM AUTHOR]

A prototype photoelectrode has been fabricated using a GaN nano-pyramid array structure grown on a cost-effective Si (111) substrate, demonstrating a significant improvement in performance of solar-powered water splitting compared with any planar GaN photoelectrode. Such a nano-pyramid structure leads to enhanced optical absorption as a result of a multi-scattering process which can effectively produce a reduction in reflectance. A simulation based on a finite-difference time-domain approach indicates that the nano-pyramid architecture enables incident light to be concentrated within the nano-pyramids as a result of micro-cavity effects, further enhancing optical absorption. Furthermore, the shape of the nano-pyramid further facilitates the photo-generated carrier transportation by enhancing a hole-transfer efficiency. All these features as a result of the nano-pyramid configuration lead to a large photocurrent of 1 mA cm−2 under an illumination density of 200 mW cm−2, with a peak incident photon-to-current conversion efficiency of 46.5% at ∼365 nm, around the band edge emission wavelength of GaN. The results presented are expected to pave the way for the fabrication of GaN based photoelectrodes with a high energy conversion efficiency of solar powered water splitting. [ABSTRACT FROM AUTHOR]

We investigate the properties of halo gas using three cosmological “zoom-in” simulations of realistic Milky Way-galaxy analogs with varying sub-grid physics. In all three cases, the mass of hot (T > 106 K) halo gas is ∼1% of the host's virial mass. The X-ray luminosity of two of the runs is consistent with observations of the Milky Way, while the third simulation is X-ray bright and resembles more closely a very massive, star-forming spiral. Hot halos extend to 140 kpc from the galactic center and are surrounded by a bubble of warm-hot ( K) gas that extends to the virial radius. Simulated halos agree well outside 20–30 kpc with the β-model of Miller & Bregman based on O vii absorption and O viii emission measurements. Warm-hot and hot gas contribute up to 80% of the total gas reservoir, and contain nearly the same amount of baryons as the stellar component. The mass of warm-hot and hot components falls into the range estimated for galaxies. With key observational constraints on the density of the Milky Way corona being satisfied, we show that concealing of the ubiquitous warm-hot baryons, along with the ejection of just 20%–30% of the diffuse gas out of the potential wells by supernova-driven outflows, can solve the “missing baryon problem.” The recovered baryon fraction within 3 virial radii is 90% of the universal value. With a characteristic density of ∼10−4 cm−3 at 50–80 kpc, diffuse coronae meet the requirement for fast and complete ram-pressure stripping of the gas reservoirs in dwarf galaxy satellites. [ABSTRACT FROM AUTHOR]

Silicon nanocrystals embedded in an oxide matrix formed in a multilayer architecture were deposited by the magnetron sputtering method. By means of Raman spectroscopy we have found that compressive stress is exerted on the silicon nanocrystal core. The stress varies as a function of silicon concentration (O/Si ratio) in the silicon-rich oxide (SRO) layers, which can be attributed to the changing nanocrystal environment. By conducting the time-resolved spectroscopy experiment, we demonstrate that, depending on the nanocrystal surroundings, a different amount of nonradiative recombination sites participates in the excited carrier relaxation process, leading to changes of the relative quantum yield of photoluminescence. [ABSTRACT FROM AUTHOR]

The effects of the stoichiometry of the Si-rich oxide (SRO) layer, O/Si ratio, on the structural and optical properties of SRO/SiO2 multilayer films were investigated in this work. SRO/SiO2 multilayer films with different O/Si ratios were grown by a co-sputtering technique, and Si quantum dots (QDs) were formed with post-deposition annealing. By transmission electron microscopy (TEM) and glancing incidence x-ray diffraction (GIXRD), it was found that the Si QD size decreases with increases in O/Si ratio. The photoluminescence (PL) spectrum varies with the O/Si ratio in band position, shape and intensity. In addition, it was observed that the absorption edge blue-shifts with increases in the O/Si ratio. The change in the absorption edge is consistent with strengthening quantum confinement effects in Si QDs, as indicated by TEM and GIXRD. The optical properties were also investigated by 2D photoluminescence excitation (2D-PLE) and lifetime measurements. The origin of emission and absorption is discussed based on the absorption, PL, 2D-PLE and decay time measurements. [ABSTRACT FROM AUTHOR]

Doping of Si nanocrystals is an important topic in the emerging field of Si nanocrystals based all-Si tandem solar cells. Boron-doped Si nanocrystals embedded in a silicon dioxide matrix were realized by a co-sputtering process, followed by high temperature annealing. The x-ray photoelectron spectroscopy B 1s signal attributable to Si-B (187 eV) and/or B-B (188 eV) indicates that the boron may exist inside Si nanocrystals. A higher probability of effective boron doping was suggested for Si-rich oxide films with a low oxygen content, Then, structural and optical properties were characterized with a focus on the effects of the boron content on Si quantum dots. The results show that as the boron content increases, the nanocrystal size is slightly reduced and the Si crystallization is suppressed. The photoluminescence intensity of the films is decreased as the boron content increases. This is due to boron-induced defects and/or Auger processes induced by effective doping. These results can provide optimal conditions for future Si quantum dot based solar cells. [ABSTRACT FROM AUTHOR]

An optical refractometer using intensity measurement to detect minute changes in the refractive index (RI) of aqueous analyte is illustrated in this paper. In this sensor, the analyte, which is sealed by an O-ring between two metal films, serves as the guiding layer of a symmetric metal-clad waveguide. By using the free-space coupling technique, an incident laser beam is coupled into the sensor structure as the sensing probe. The reflected beam intensity is monitored to analysis the sample's RI change. Both theoretical analysis and experimental results show that, due to concentrated power in the sample layer, the sensor exhibits magnificent sensitivity improvement. Besides, it also presents polarization independence. [ABSTRACT FROM AUTHOR]