New data for vitamin D in Australian foods of animal origin: impact on estimates of national adult vitamin D intakes in 1995 and 2011-13.

OBJECTIVES: To assess the potential dietary supply of vitamin D to Australian adults by application of new data for Australian primary foods of animal origin. METHODS: New published analytical data on the vitamin D contents of Australian primary foods from animal products were obtained and assessed for reliability. Using food consumption data from Australian population dietary surveys for 1995 and 2011-2013, estimates were made of the likely average daily intakes of vitamin D equivalents from these sources by Australian adults. RESULTS: Meats, chicken, fish, eggs and dairy produce may alone have contributed about 4.2 µg vitamin D equivalents per day to average Australian diets of adults >18 years in 1995 and 4.3 µg in 2011-2013. CONCLUSIONS: Dietary vitamin D intake in Australia is likely to be higher than previously estimated because new data from improved analytical methods reveal the contributions to vitamin D supply from foods of animal origin. Absence of reliable vitamin D data for milk and milk products, and the gaps in vitamin D data for many commonly consumed seafood, poultry, eggs and processed animal products greatly limit estimation of dietary vitamin D intakes by Australians.

Ultrafast nonlinear mirrors with broad spectral and angular bandwidths in the visible spectral range.

A novel nonlinear mirror structure is presented. A 23 nm-thick Au thin film separated from a 100 nm-thick Ag film by a dielectric spacer is used to drive the nonlinear optical response of the mirror. The linear and nonlinear optical properties of the mirror can be tuned by optimizing its layer thickness distribution. A figure-of-merit for the change in reflectance is derived for the nonlinear mirror and the nonlinear refractive index change of the Au layer is shown to be significantly enhanced in the mirror structure. The ultrafast reflectance change of the nonlinear mirror, studied using femtosecond white-light continuum pump-probe experiments, shows an extremely large magnitude and is both spectrally and angularly broad in the visible range.

Recyclable organic solar cells on cellulose nanocrystal substrates.

Solar energy is potentially the largest source of renewable energy at our disposal, but significant advances are required to make photovoltaic technologies economically viable and, from a life-cycle perspective, environmentally friendly, and consequently scalable. Cellulose nanomaterials are emerging high-value nanoparticles extracted from plants that are abundant, renewable, and sustainable. Here, we report on the first demonstration of efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. The solar cells fabricated on the CNC substrates display good rectification in the dark and reach a power conversion efficiency of 2.7%. In addition, we demonstrate that these solar cells can be easily separated and recycled into their major components using low-energy processes at room temperature, opening the door for a truly recyclable solar cell technology. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production.

Linear and nonlinear optical properties of Ag/Au bilayer thin films.

The linear and nonlinear optical properties of Ag/Au bilayer metallic thin films with a total thickness of around 20 nm and with different Ag/Au mass-thickness ratios were studied. This study shows that the spectral dispersion of the effective refractive index of bilayer films can be tuned by controlling the mass-thickness ratio between Au and Ag. Improvement of the figure-of-merit for potential plasmonic applications and linear optical filters in the visible spectral range are reported and discussed. The nonlinear optical properties of bilayer metal films studied using femtosecond white-light continuum pump-probe experiments are also shown to be tunable with this ratio. The nonlinear change of optical path length is extracted from the pump-probe data and agrees with simulated values derived from a combination of the two-temperature model, describing the ultrafast electron heating dynamics, and a physical model that describes the dielectric permittivity of Au as a function of electron and lattice temperature.

Designing an inducer-feeding schedule to enhance production of recombinant protein in Escherichia coli by microbial reaction engineering.

Metabolic constraints during the production of recombinant protein in Escherichia coli impede the efficient utilization of resources by the cells, thus reducing their production potential. In order to minimize these adverse effects, we have proposed to segregate the cell population into two groups: the first one formed by non-induced cells, growing at a high specific growth rate and rapidly contributing cells to the system, and the second one formed by fully induced cells, growing slowly but using the cell machinery to express the target protein. An adequate balance between these two populations should maximize the protein expression in a given system. This segregation is accomplished experimentally by taking advantage of the "all or none" phenomenon, in which at subsaturated inducer conditions the cells are either fully induced or fully uninduced. Based on this two-population theory, a mathematical model was developed in which a parameter alpha was defined as the fraction of the fully induced cells in the total population. In this study three different induction strategies were investigated and their effect on the protein production was established. It was found that the linear increase of this fraction, achieving maximum induction (alpha = 1) only at the end of the fermentation and with a slope m = 0.15 gave the best results. Finally these results were validated experimentally with the finding that they closely match the mathematical simulation with a 26% increase in protein production with respect to the conventional induction approach described.

Insight into the permeation barrier of glued Langmuir-Blodgett bilayers.

Permeation measurements have been made for He, CO2, and N2 across single Langmuir-Blodgett (LB) bilayers derived from 1,2,4,5-tetrakis[(N-(undecanoamidoethyl)-N,N-dimethyl ammonium) methyl]benzene tetrabromide (2) and 1,2,4,5-tetrakis[(N-(perfluoroundecanoamidoethyl)-N,N-dimethyl ammonium)methyl]benzene tetrabromide (3) in the absence and in the presence of entrapped poly(acrylic acid) (PAA). In the absence of PAA, single LB bilayers of 3 show a higher permeance for He and N2 but a lower permeation rate of CO2, as compared with analogous LB bilayers made from 2. The relatively low permeation rate of CO2 for the former has been attributed to reduced associative interactions with the fluorocarbon-rich bilayer. The same behavior has also been observed for LB bilayers containing PAA, formed under conditions that yield glued bilayers of 2 and 3 having similar diffusional pathways, as judged by He/N2 selectivities. These results, together with the fact that glued bilayers of 2 (having a thinner PAA layer as compared with those made from 3) exhibit lower He and N2 permeances, provide compelling evidence that the main barrier for gas transport is the combination of surfactant plus PAA and not simply a thin PAA layer that is encased within the surfactant bilayer.

O acetylation of the enterobacterial common antigen polysaccharide is catalyzed by the product of the yiaH gene of Escherichia coli K-12.

The carbohydrate component of the enterobacterial common antigen (ECA) of Escherichia coli K-12 occurs primarily as a water-soluble cyclic polysaccharide located in the periplasm (ECA(CYC)) and as a phosphoglyceride-linked linear polysaccharide located on the cell surface (ECA(PG)). The polysaccharides of both forms are comprised of the amino sugars N-acetyl-D-glucosamine (GlcNAc), N-acetyl-D-mannosaminuronic acid (ManNAcA), and 4-acetamido-4,6-dideoxy-D-galactose (Fuc4NAc). These amino sugars are linked to one another to form trisaccharide repeat units with the structure -->3-alpha-D-Fuc4NAc-(1-->4)-beta-D-ManNAcA-(1-->4)-alpha-D-GlcNAc-(1-->. The hydroxyl group in the 6 position of the GlcNAc residues of both ECA(CYC) and ECA(PG) are nonstoichiometrically esterified with acetyl groups. Random transposon insertion mutagenesis of E. coli K-12 resulted in the generation of a mutant defective in the incorporation of O-acetyl groups into both ECA(CYC) and ECA(PG). This defect was found to be due to an insertion of the transposon into the yiaH locus, a putative gene of unknown function located at 80.26 min on the E. coli chromosomal map. Bioinformatic analyses of the predicted yiaH gene product indicate that it is an integral inner membrane protein that is a member of an acyltransferase family of enzymes found in a wide variety of organisms. The results of biochemical and genetic experiments presented here strongly support the conclusion that yiaH encodes the O-acetyltransferase responsible for the incorporation of O-acetyl groups into both ECA(CYC) and ECA(PG). Accordingly, we propose that this gene be designated wecH.

Preparative fractionation of protein, RNA, and plasmid DNA using centrifugal precipitation chromatography with tubular dialysis membrane inside a convoluted tubing as separation channel.

Fractionation of clarified E. coli lysate components in bench-scale and preparative-scale centrifugal precipitation chromatography (CPC), using a solution of cationic surfactant cetyltrimethylammonium bromide (CTAB) containing 0.5 M NaCl as precipitant, are compared here. Step gradient of CTAB from 0.50% to 0.16% (w/v) gave a successful fractionation in bench-scale CPC; however, a linear gradient of lower CTAB concentration, 0.20-0% (w/v), was used in the preparative scale and resulted in similar fractionation. The preparative-scale CPC has a superior sample loading capacity by the use of tubular dialysis membrane inside convoluted tubing as the separation channel. In this study, the quantity of the sample loaded into the preparative CPC was about 15 times more than that in the bench scale, and in a single run the preparative CPC could prepare approximately 3 mg of plasmid DNA with about 96% of RNA removed. The higher surface area per length of the separation channel in the preparative CPC was believed to benefit mass transfer of CTAB across the membrane, leading to less CTAB being required in the process.

Identification of Klebsiella pneumoniae virulence determinants using an intranasal infection model.

Klebsiella pneumoniae is a Gram-negative enterobacterium that has historically been, and currently remains, a significant cause of human disease. It is a frequent cause of urinary tract infections and pneumonia, and subsequent systemic infections can have mortality rates as high as 60%. Despite its clinical significance, few virulence factors of K. pneumoniae have been identified or characterized. In this study we present a mouse model of acute K. pneumoniae respiratory infection using an intranasal inoculation method, and examine the progression of both pulmonary and systemic disease. Wild-type infection recapitulates many aspects of clinical disease, including significant bacterial growth in both the trachea and lungs, an inflammatory immune response characterized by dramatic neutrophil influx, and a steady progression to systemic disease with ensuing mortality. These observations are contrasted with an infection by an isogenic capsule-deficient strain that shows an inability to cause disease in either pulmonary or systemic tissues. The consistency and clinical accuracy of the intranasal mouse model proved to be a useful tool as we conducted a genetic screen to identify novel virulence factors of K. pneumoniae. A total of 4800 independent insertional mutants were evaluated using a signature-tagged mutagenesis protocol. A total of 106 independent mutants failed to be recovered from either the lungs or spleens of infected mice. Small scale independent infections proved to be helpful as a secondary screening method, as opposed to the more traditional competitive index assay. Those mutants showing verified attenuation contained insertions in loci with a variety of putative functions, including a large number of hypothetical open reading frames. Subsequent experiments support the premise that the central mechanism of K. pneumoniae pathogenesis is the production of a polysaccharide-rich cell surface that provides protection from the inflammatory response.

Fractionation of protein, RNA, and plasmid DNA in centrifugal precipitation chromatography using cationic surfactant CTAB containing inorganic salts NaCl and NH(4)Cl.

Centrifugal precipitation chromatography (CPC) is a separation system that mainly employs a moving concentration gradient of precipitating agent along a channel and solutes of interest undergo repetitive precipitation-dissolution, fractionate at different locations, and elute out from the channel according to their solubility in the precipitating agent solution. We report here for the first time the use of a CPC system for fractionation of protein, RNA, and plasmid DNA in clarified lysate produced from bacterial culture. The cationic surfactant cetyltrimethylammonium bromide (CTAB) was initially used as a precipitating agent; however, all biomolecules showed no differential solubility in the moving concentration gradient of this surfactant and, as a result, no separation of protein, RNA, and plasmid DNA occurred. To overcome this problem, inorganic salts such as NaCl and NH(4)Cl were introduced into solution of CTAB. The protein and RNA were found to have higher solubility with the addition of these salts and separated from the plasmid DNA. Decreasing surface charge density of CTAB upon addition of NaCl and NH(4)Cl was believed to lead to lower surfactant complexation, and therefore caused differential solubility and fractionation of these biomolecules. Addition of CaCl(2) did not improve solubility and separation of RNA from plasmid DNA.

Exceptional gas permeation selectivity of a glued Langmuir-Blodgett bilayer by pH control.

The monolayer properties of 5,11,17,23,29,35-hexakis[(N,N,N-trimethylamonium)-N-methyl-37,38,39,40,41,42-hexakis-n-hexadecyloxy-calix[6]arene hexachloride (1) have been characterized over aqueous solutions of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) as a function of pH. At high pH values (e.g., pH 10), such monolayers show relatively low surface viscosities. At low pH (e.g., pH 4.4), these monolayers exhibit relatively high surface viscosities. The barrier properties of single Langmuir-Blodgett bilayers of 1, which have been ionically cross-linked (i.e., "glued together") with PAA were found to correlate with changes in surface viscosity. Thus, bilayers that were fabricated under low pH conditions exhibited high permeation barriers and high permeation selectivity with respect to He and N(2). Given the extreme thinness of these glued bilayers (ca. 6 nm), the optimized He/N(2) selectivity of ca. 1000 is extraordinary. These results, taken together, demonstrate the feasibility of fine tuning the surface viscosity of monolayers of 1, and also the barrier properties of corresponding glued bilayers, by adjusting the pH of an aqueous subphase that contains a weak polyacid.

Glued Langmuir-Blodgett bilayers from porous versus nonporous surfactants.

Poly(4-styrenesulfonate) (PSS) has been used to ionically cross-link (glue together) single Langmuir-Blodgett bilayers derived from 1,2,4,5-tetrakis[N,N-dimethyl-N-(1-hexadecyl)-ammoniummethyl]benzene (2a) and tris(N,N-dimethyl-N-hexadecylammoniummethyl)mesitylene (3). The resulting films are of high quality as judged by He/N2 permeation selectivities of ca. 100. Such selectivity is well in excess of the Knudsen diffusion limit of 2.6 and approaches that which has been found for glued bilayers of 5,11,17,23,29,35-hexakis[(N,N,N-trimethylamonium)-N-methyl-37,38,39,40,41,42-hexakis-n-hexamedecyloxy-calix[6]arene hexachloride (1). The significance of these findings to LB technology, in general, is briefly discussed.

The gluing of a Langmuir-Blodgett bilayer.

Poly(4-styrenesulfonate) has been used to ionically cross-link (glue together) a single Langmuir-Blodgett bilayer derived from an amphiphilic calix[6]arene bearing six hexadecyl and six methylene-trimethylammonium groups. The resulting film is of high quality and robustness, as judged by its He/N2 permeation selectivity and by its ability to withstand exposure to chloroform solvent. The creation of a stable organic membrane, having a thickness that is less than 6 nm and a He/N2 permeation selectivity of ca. 305, represents a milestone for LB technology.

The Lichtman classification for Kienböck's disease: an assessment of reliability.

PURPOSE: The correct identification of Lichtman stage 3A and 3B Kienböck's disease is crucial for treatment purposes. The present study evaluates the reliability of the Lichtman classification, with specific attention to differentiating stage 3A and 3B. METHODS: Four reviewers evaluated wrist radiographs from 39 patients with Kienböck's disease. Radiographs were graded according to the traditional Lichtman classification, a modification of the Lichtman classification using a radioscaphoid angle of 60 degrees to subdivide stage 3, and 8 other radiographic measures. RESULTS: The interobserver reliability of the Lichtman classification was substantial (kappa coefficient 0.63), but Stage 3A was less reliably identified (kappa 0.38). The new modification of the Lichtman classification increased both the overall (kappa 0.81) and the stage 3A (kappa 0.75) interobserver reliability. CONCLUSION: The use of the radioscaphoid angle increases the interobserver reliability of the Lichtman classification. This should allow a better understanding of the clinically important distinction between stage 3A and 3B disease.

A polymerized calix[6]arene monolayer having gas permeation selectivity that exceeds Knudsen diffusion.

A polymerized monolayer of 5,11,17,23,29,35-hexamercaptomethyl-37,38,40,41,42-hexakis-(1-n hexadecyloxy)calix[6]arene (1) has been synthesized on the surface of an ca. 15 mum-thick film derived from poly[1-(trimethylsilyl)-1-propyne] (PTMSP). This monolayer exhibits a permeation selectivity toward He and SF6 that exceeds Knudsen diffusion. Analogous membranes made from a calix[6]arene that contains amidoxime headgroups (i.e., 2) showed Knudsen diffusion characteristics.