1,236 research outputs found
Natural Photosensitizers in Constructed Unit Process Wetlands: Photochemical Characterization and Inactivation of Pathogen Indicator Organisms
Mixed-phase titania foams via 3D-printing for pharmaceutical degradation
The continuing accumulation of organic micropollutants, particularly pharmaceuticals, in water is now considered an urgent threat to human health and the environment. Although the photocatalytic degradation of these compounds using slurries of photoactive nanoparticles has been proven to be highly effective at laboratory scale, this technology has not been implemented in industry due to cost and safety concerns. Here, 3D printed titania foams which are nanoparticle-free, mechanically robust and photoactive, are presented for the first time as a viable alternative to slurries for the photocatalytic degradation of pharmaceuticals. By optimizing the resin used to 3D print highly porous gyroid structures and the subsequent sintering conditions, it was possible to obtain a pure titania foam with a high anatase content, leading to the high photoactivity observed. Using carbamazepine, the pharmaceutical most found in waterways around the world, as a model pollutant, the 3D printed foams were tested in a recirculating flow reactor, with a quantum yield and electrical energy per order of 7.6 × 10−3 and 67.6 kW h m−3, respectively, outperforming literature results for titania nanoparticle slurries. These results, along with the reproducibility afforded by 3D printing methods, shows a clear pathway for photocatalysts to be implemented in practice, helping to solve an urgent health problem while addressing the risk of nanoparticulate release in the environment
Generation and quality control of lipidomics data for the alzheimers disease neuroimaging initiative cohort.
Alzheimers disease (AD) is a major public health priority with a large socioeconomic burden and complex etiology. The Alzheimer Disease Metabolomics Consortium (ADMC) and the Alzheimer Disease Neuroimaging Initiative (ADNI) aim to gain new biological insights in the disease etiology. We report here an untargeted lipidomics of serum specimens of 806 subjects within the ADNI1 cohort (188 AD, 392 mild cognitive impairment and 226 cognitively normal subjects) along with 83 quality control samples. Lipids were detected and measured using an ultra-high-performance liquid chromatography quadruple/time-of-flight mass spectrometry (UHPLC-QTOF MS) instrument operated in both negative and positive electrospray ionization modes. The dataset includes a total 513 unique lipid species out of which 341 are known lipids. For over 95% of the detected lipids, a relative standard deviation of better than 20% was achieved in the quality control samples, indicating high technical reproducibility. Association modeling of this dataset and available clinical, metabolomics and drug-use data will provide novel insights into the AD etiology. These datasets are available at the ADNI repository at http://adni.loni.usc.edu/
Neutral magic-angle bilayer graphene: Condon instability and chiral resonances
We discuss the full optical response of twisted bilayer graphene at the
neutrality point close to the magic angle within the continuum model. (i)
First, we define the full optical response consistent with the underlying
symmetry, yielding the total, magnetic, and chiral response that transform
according to the irreducible representations , , and ,
respectively. Then, we numerically calculate the dissipative and reactive
response for twist angles around the magic angle and comment on the
possibility of a Condon instability. (ii) Second, we numerically calculate the
full optical response {\it almost at} . The total response is
characterized by three universal plateaus which can be obtained from an
analytical calculation. The magnetic and the chiral response, however, is given
by corresponding non-universal plateaus depending on the twist angle
via the dimensionless parameter . (iii) Following
the discussion on the large magnetic response, we calculate the plasmonic
excitations at the neutrality point inside the optical gap of relaxed twisted
bilayer graphene. We find that acoustic plasmons extend over almost the whole
optical gap and carry the largest oscillator strength. (iv) Finally, we discuss
symmetry relations for the response functions as function of the chemical
potential and highlight the consequences of the approximate particle-hole
symmetry of the continuum model for twisted bilayer graphene. We then discuss a
detailed balance relation where the chiral response at charge neutrality can be
understood in terms of electron (hole) transitions for which the initial
(final) states are energetically closer to charge neutrality than the final
(initial) states.Comment: 17 pages, 7 figure
Shoot growth of woody trees and shrubs is predicted by maximum plant height and associated traits
1. The rate of elongation and thickening of individual branches (shoots) varies across plant species. This variation is important for the outcome of competition and other plant-plant interactions. Here we compared rates of shoot growth across 44 species from tropical, warm temperate, and cool temperate forests of eastern Australia.2. Shoot growth rate was found to correlate with a suite of traits including the potential height of the species, xylem-specific conductivity, leaf size, leaf area per xylem cross-section, twig diameter (at 40 cm length), wood density and modulus of elasticity.3. Within this suite of traits, maximum plant height was the clearest correlate of growth rates, explaining 50 to 67% of the variation in growth overall (p p 4. Growth rates were not strongly correlated with leaf nitrogen or leaf mass per unit leaf area.5. Correlations between growth and maximum height arose both across latitude (47%, p p p p < 0.0001), reflecting intrinsic differences across species and sites
Bolivian health and social care professionals' experiences of decision-making in oncology and palliative care
Ablation of Dihydroceramide Desaturase Confers Resistance to Etoposide-Induced Apoptosis In Vitro
10.1371/journal.pone.0044042PLoS ONE79
A Colorimetric Chemosensor Based on a Nozoe Azulene That Detects Fluoride in Aqueous/Alcoholic Media
Colorimetry is an advantageous method for detecting fluoride in drinking water in a resource-limited context, e. g., in parts of the developing world where excess fluoride intake leads to harmful health effects. Here we report a selective colorimetric chemosensor for fluoride that employs an azulene as the reporter motif and a pinacolborane as the receptor motif. The chemosensor, NAz-6-Bpin, is prepared using the Nozoe azulene synthesis, which allows for its rapid and low-cost synthesis. The chemosensor gives a visually observable response to fluoride both in pure organic solvent and also in water/alcohol binary solvent mixtures
The initiation and development of metamorphic foliation in the Otago Schist, Part 2: evidence from quartz grain-shape data
Shape, size and orientation measurements of quartz grains sampled along two transects that cross zones of increasing metamorphic grade in the Otago Schist, New Zealand, reveal the role of quartz in the progressive development of metamorphic foliation. Sedimentary compaction and diagenesis contributed little to the formation of a shape-preferred orientation (SPO) within the analysed samples. Metamorphic foliation was initiated at sub-greenschist facies conditions as part of a composite S1-bedding structure parallel to the axial planes of tight to isoclinal F1 folds. An important component of this foliation is a pronounced quartz SPO that formed dominantly by the effect of dissolution?precipitation creep on detrital grains in association with F1 strain. With increasing grade, the following trends are evident from the SPO data: (i) a progressive increase in the aspect ratio of grains in sections parallel to lineation, and the development of blade-shaped grains; (ii) the early development of a strong shape preferred orientation so that blade lengths define the linear aspect of the foliation (lineation) and the intermediate axes of the blades define a partial girdle about the lineation; (iii) a slight thinning and reduction in volume of grains in the one transect; and (iv) an actual increase in thickness and volume in the survivor grains of the second transect. The highest-grade samples, within the chlorite zone of the greenschist facies, record segregation into quartz- and mica-rich layers. This segregation resulted largely from F2 crenulation and marks a key change in the distribution, deformation and SPO of the quartz grains. The contribution of quartz SPO to defining the foliation lessens as the previously discrete and aligned detrital quartz grains are replaced by aggregates and layers of dynamically recrystallized quartz grains of reduced aspect ratio and reduced alignment. Pressure solution now affects the margins of quartz-rich layers rather than individual grains. In higher-grade samples, therefore, the rock structure is characterized increasingly by segregation layering parallel to a foliation defined predominantly by mica SPO
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