Synthesis and optical properties of Eu3+ -substituted glaserite-type orthovanadates CsK2 Y[VO4 ]2.

A new Eu3+ -substituted CsK2 Y[VO4 ]2 glaserite-type orthovanadate phosphor was synthesized by the conventional high temperature solid-state reaction method. The phase purity was confirmed by powder X-ray diffraction study and it reveals that all the compositions crystallize in the hexagonal structure. The morphology and elemental composition were measured by FE-SEM with Energy Dispersive Analysis Of X Rays (EDAX). The band gap is determined by diffuse reflectance spectra. The self-activated luminescence of the host and Eu3+ -substituted luminescence behaviours were studied in detail by photoluminescence spectra. The host CsK2 Y[VO4 ]2 shows green emission, whereas the Eu3+ -substituted compositions show red emission. Effect of Eu3+ concentrations on the photoluminescence behaviour were also been studied. The Eu3+ -doped samples show not only several sharp emission lines but also a broad emission band due to presence of the [VO4 ]3- in the host, which clearly indicates that there is incomplete energy transfer from (VO4 ) charge transfer band to Eu3+. The life time of the phosphors also been studied. The Commission Internationale de l'Eclairage (CIE) chromaticity colour coordinates were calculated and it is very much closer to the National Television Standard Committee (NTSC) standards. These investigations evidently reveal that the self-activated and Eu3+ -activated phosphors show a great potential applications as a red phosphor for solid-state lighting includes white light-emitting diodes (wLEDs).

Sphagnum mosses from 21 ombrotrophic bogs in the athabasca bituminous sands region show no significant atmospheric contamination of "heavy metals".

Sphagnum moss was collected from 21 ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca bituminous sands in Alberta (AB). In comparison to contemporary Sphagnum moss from four bogs in rural locations of southern Germany (DE), the AB mosses yielded lower concentrations of Ag, Cd, Ni, Pb, Sb, and Tl, similar concentrations of Mo, but greater concentrations of Ba, Th, and V. Except for V, in comparison to the "cleanest", ancient peat samples ever tested from the northern hemisphere (ca. 6000-9000 years old), the concentrations of each of these metals in the AB mosses are within a factor of 3 of "natural, background" values. The concentrations of "heavy metals" in the mosses, however, are proportional to the concentration of Th (a conservative, lithophile element) and, therefore, contributed to the plants primarily in the form of mineral dust particles. Vanadium, the single most abundant trace metal in bitumen, is the only anomaly: in the AB mosses, V exceeds that of ancient peat by a factor of 6; it is therefore enriched in the mosses, relative to Th, by a factor of 2. In comparison to the surface layer of peat cores collected in recent years from across Canada, from British Columbia to New Brunswick, the Pb concentrations in the mosses from AB are far lower.

The impact of implementation of the Canadian regulatory requirements on the quality of natural health products: the glucosamine case.

PURPOSE: We investigated whether the recent implementation of the regulatory requirements for the entry to the Canadian market of natural products has resulted in improved quality of the available glucosamine products. METHODS: Eleven available products, of which 8 had been tested in 2002 (7 had contained substantially lower than the label claim of the active ingredient), and a European pharmaceutical grade tablet were assayed for their glucosamine content. The potassium and sodium contents of the products were also tested. RESULTS: Nine of the 11 Canadian products and the European tablet had more than 91% of the label claim of the active ingredient, hence, met the criterion. Two products contained 71 and 78% label claim. The electrolyte contents were very variable but constituted only a small fraction of the daily requirements. CONCLUSION: Most tested glucosamine products passed the Health Canada requirements. This improvement is likely due to the publicity regarding the low quality of the products in the past and also a result, at least in part, of the introduction of the new regulatory requirements. The sub-standard quality of a few tested products is still of concern.

Identifying the arrival of extensional and flexural wave modes using wavelet decomposition of ultrasonic signals.

In health monitoring applications of composite materials, the health state of specimens is often evaluated using naturally occurring and simulated Acoustic Emission stress waves. For such applications, identifying the arrival times of the extensional and flexural wave modes from acquired signals is a crucial step, and must be performed reliably and potentially on large sets of signals. This article proposes using the wavelet decomposition of a signal to develop a fast, algorithmic and automated approach to estimate the arrival times of the extensional and flexural wave modes. Algorithms are developed that estimate the two arrival times using wavelet decomposition data, and which can be employed to consistently and reliably identify the arrival times from large sets of signals iteratively. MATLAB scripts to automatically execute the algorithms are also developed, and are made available online.

Ascorbic acid differentially modulates the induction of heme oxygenase-1, NAD(P)H:quinone oxidoreductase 1 and glutathione S-transferase Ya by As(3+), Cd(2+) and Cr(6+).

The induction of phase II drug metabolizing enzymes serves as a detoxification mechanism for many mutagens, carcinogens and other toxic compounds. Specifically, NAD(P)H:quinone oxidoreductase 1 (Nqo1) and glutathione S-transferase Ya subunit (Gst ya) are key enzymes involved in cellular defense against reactive forms of oxygen and the inhibition of carcinogenesis. As(3+), which induces these enzymes, has been proven to have a role in the treatment of acute promyelocytic leukemia. Ascorbic acid (AA) potentiates the anticancer effect of As(3+) and thus it is expected that this antioxidant will have a paradoxical effect on the ability of heavy metals, specifically As(3+), to induce Nqo1 and Gst ya. We have shown that As(3+) and Cd(2+) induce heme oxygenase-1 (HO-1), Nqo1 and Gst ya mRNA levels but Cr(6+) decreases Nqo1 and Gst ya mRNA. Surprisingly, AA superinduced the induction of HO-1, Nqo1 and Gst ya mRNA by As(3+), while inhibiting the induction of HO-1 mRNA by Cd(2+) and Cr(6+). Hence, it is tempting to speculate that AA may potentiate the therapeutic efficacy of As(3+) by enhancing the expression of HO-1, Nqo1, and Gst ya while acting as a potent antioxidant.

Metallic copper as a fiducial marker for both CT and PET.

There is great interest in augmenting computed tomography (CT) with information gained from other imaging modalities. Positron emission tomography (PET) provides valuable data related to patient physiology to aid in the delineation of tumor volumes. Combining the information provided by these imaging modalities requires accurate spatial registration of the two data sets. Fiducial based mapping provides straightforward registration based on corresponding landmark points or fiducials in the two image sets. When external fiducials are employed, consistent intermodality marker placement and centroid identification are essential to achieving an accurate and reliable registration. Similarity of marker design between modalities greatly aides in achieving this goal. Solid copper may serve as a fiducial marker in both CT and PET. Small spheres or wires of copper are readily visible in CT while neutron activation of these same markers produces positron emitting Copper-64 for detection by PET. The use of identical shaped markers in both imaging modalities greatly simplifies the task of intermodality centroid matching. Copper has excellent machining properties and, prior to activation, is easy and safe to handle. The feasibility of Cu as a marker for both CT and PET is demonstrated using imaging phantoms.

Modeling enzootic raccoon rabies from land use patterns - Georgia (USA) 2006-2010.

We analyzed how land-use patterns and changes in urbanization influence reported rabid raccoons in Georgia from 2006 - 2010.  Using Geographical Information Systems and rabies surveillance data, multivariate analysis was conducted on 15 land-use variables that included natural topography, agricultural development, and urbanization to model positive raccoon rabies cases while controlling for potential raccoon submission bias associated with higher human population densities.  Low intensity residential development was positively associated with reported rabid raccoons while a negative association was found with evergreen forest.  Evergreen forests may offer a barrier effect where resources are low and raccoon populations are not supported.  Areas with pure stands of upland evergreen forest might be utilized in baiting strategies for oral rabies vaccination programs where fewer or no baits may be needed.  Their use as a barrier should be considered carefully in a cost-effective strategy for oral rabies vaccination (ORV) programs to contain the western spread of this important zoonotic disease.

Phylogenetic relationships within the tribe Malveae (Malvaceae, subfamily Malvoideae) as inferred from ITS sequence data.

Phylogenetic relationships among genera of tribe Malveae (Malvaceae, subfamily Malvoideae) were reconstructed using sequences of the internal transcribed spacer (ITS) region of the 18S-26S nuclear ribosomal repeat. Newly generated sequences were combined with those available from previous generic level studies to assess the current circumscription of the tribe, monophyly of some of the larger genera, and character evolution within the tribe. The ITS data do not support monophyly of most generic alliances as presently defined, nor do the data support monophyly of several Malveae genera. Two main well-supported clades were recovered, which correspond primarily to taxa that either possess or lack involucral bracts, respectively. Chromosomal evolution has been dynamic in the tribe with haploid numbers varying from n = 5 to 36. Aneuploid reduction, hybridization, and/or polyploidization have been important evolutionary processes in this group.