Heating events in the nascent solar system recorded by rare earth element isotopic fractionation in refractory inclusions.

Equilibrium condensation of solar gas is often invoked to explain the abundance of refractory elements in planets and meteorites. This is partly motivated, by the observation that the depletions in both the least and most refractory rare earth elements (REEs) in meteoritic group II calcium-aluminum-rich inclusions (CAIs) can be reproduced by thermodynamic models of solar nebula condensation. We measured the isotopic compositions of Ce, Nd, Sm, Eu, Gd, Dy, Er, and Yb in eight CAIs to test this scenario. Contrary to expectation for equilibrium condensation, we find light isotope enrichment for the most refractory REEs and more subdued isotopic variations for the least refractory REEs. This suggests that group II CAIs formed by a two-stage process involving fast evaporation of preexisting materials, followed by near-equilibrium recondensation. The calculated time scales are consistent with heating in events akin to FU Orionis- or EX Lupi-type outbursts of eruptive pre-main-sequence stars.

Ultrathin Y2O3:Eu3+nanodiscs: spectroscopic investigations and evidence for reduced concentration quenching.

Here, we report the synthesis and spectral properties of ultrathin nanodiscs (NDs) of Y2O3:Eu3+. It was found that the NDs of Y2O3:Eu3+ with a thickness of about 1 nm can be fabricated in a reproducible, facile and self-assembling process, which does not depend on the Eu3+ concentration. The thickness and morphology of these NDs were determined with small angle x-ray scattering and transmission electron microscopy. We found that the crystal field in these nanoparticles deviates from both the cubic and monoclinic characteristics, albeit the shape of the 5D0 â†’ 7F J (J = 0, 1, 2) transitions shows some similarity with the transitions in the monoclinic material. The Raman spectra of the non-annealed NDs manifest various vibration modes of the oleic acid molecules, which are used to stabilise the NDs. The annealed NDs show two very weak Raman lines, which may be assigned to vibrational modes of Y2O3 NDs. The concentration quenching of the Eu3+ luminescence of the NDs before annealing is largely suppressed and might be explained in terms of a reduction of the phonon density of states.

Are people with an orofacial cleft at a higher risk of dental caries? A systematic review and meta-analysis.

Objective To establish whether children born with an orofacial cleft have a higher risk of dental caries than individuals without cleft.Design A systematic review and meta-analysisMethods The search strategy was based on the key words 'cleft lip palate' and 'oral hygiene caries decay'. Ten databases were searched from their inception to April 2016 to identify all relevant studies. All data were extracted by two independent reviewers. The primary outcome measure was caries measured by the decayed, missing, filled surfaces/teeth index (dmfs/dmft or DMFS/DMFT).Results Twenty-four studies met the selection criteria. All of the studies were observational. Twenty-two studies were suitable for inclusion in the meta-analysis. The overall pooled mean difference in dmft was 0.63 (95% CI: 0.47 to 0.79) and in DMFT was 0.28 (95% CI: 0.22 to 0.34).Conclusion Individuals with cleft lip and/or palate have higher caries prevalence, both in the deciduous and the permanent dentitions.

Using service rationalisation to build a research network: lessons from the centralisation of UK services for children with cleft lip and palate.

In the UK around a thousand children are born annually with a cleft lip and/or palate that requires treatment. In the last decade services have been centralised in the UK reducing the 57 centres operating on these children in 1998, down to 11 centres or managed clinical networks in 2011. While the rationale for centralisation was to improve the standard of care (and in so doing the outcome) for children born with cleft lip and/or palate, research was central to this process. We illustrate how research informed and shaped this service rationalisation and how it facilitated the emergence of a research culture within the newly configured teams. We also describe how these changes in service provision were linked to the development of a national research strategy and to the identification of the resources necessary to support this strategy.

Neutron activation analysis of a particle returned from asteroid Itokawa.

A single grain (~3 micrograms) returned by the Hayabusa spacecraft was analyzed by neutron activation analysis. This grain is mainly composed of olivine with minor amounts of plagioclase, troilite, and metal. Our results establish that the Itokawa sample has similar chemical characteristics (iron/scandium and nickel/cobalt ratios) to chondrites, confirming that this grain is extraterrestrial in origin and has primitive chemical compositions. Estimated iridium/nickel and iridium/cobalt ratios for metal in the Itokawa samples are about five times lower than CI carbonaceous chondrite values. A similar depletion of iridium was observed in chondrule metals of ordinary chondrites. These metals must have condensed from the nebular where refractory siderophile elements already condensed and were segregated.

Light-emitting nanocasts formed from bio-templates: FESEM and cathodoluminescent imaging studies of butterfly scale replicas.

Nanocasts comprising of red-light-emitting cubic Y(2)O(3):Eu phosphors were made from butterfly wing scale bio-templates. We report herein the first cathodoluminescent images made from such nanocasts and show that valuable insights into the nature of the internal structure of the casts can be gained by the use of this technique. The casts faithfully reproduced the fine sub-micrometre size detail of the scales, as was made evident by both FESEM and cathodoluminescent images that were collected from the same sample areas using a hyphenated FESEM-CL instrument. There was excellent agreement between the FESEM and cathodoluminescent images, the image quality of the latter indicating that the Eu(3+) activator ions were evenly dispersed in the Y(2)O(3):Eu phosphor on a sub-micrometre scale. The casts were made by infilling the natural moulds with a Y(2)O(3):Eu precursor solution that was subsequently dried and fired to convert it into the phosphor material. This method provides a simple, low cost route for fabricating nanostructures having feature dimensions as small as 20 nm in size, and it has the potential to be applied to other metal oxide systems for producing nano-and micro-components for electronic, magnetic or photonic integrated systems.

The importance of timing: the varying impact of childhood and adolescent maltreatment on multiple problem outcomes.

A substantial body of literature suggests that childhood maltreatment is related to negative outcomes during adolescence, including delinquency, drug use, teenage pregnancy, and school failure. There has been relatively little research examining the impact that variation in the developmental stage during which the maltreatment occurs has on these relationships, however. In this paper, we reassess the impact of maltreatment on a number of adverse outcomes when developmentally specific measures of maltreatment-maltreatment that occurs only in childhood, only in adolescence, or in both childhood and adolescence-are considered. Data are drawn from the Rochester Youth Development Study, a broad-based longitudinal study of adolescent development. The analysis examines how maltreatment affects delinquency, drug use, alcohol-related problems, depressive symptoms, teen pregnancy. school dropout, and internalizing and externalizing problems during adolescence. We also examine whether the type of maltreatment experienced at various developmental stages influences the outcomes. Overall, our results suggest that adolescent and persistent maltreatment have stronger and more consistent negative consequences during adolescence than does maltreatment experienced only in childhood.

Preparation of new chiral borane-protected P,N-ferrocenyl ligands via a methoxy directed ortho-lithiation.

We have shown that the readily prepared (ferrocenyl)benzylic methyl ethers of type 1 can be ortho-metalated with tert-BuLi with high diastereoselectivity. This reaction has been used to prepare new borane-protected P,N-substituted ferrocenes of type 2 in high diastereomeric and enantiomeric purity. The chiral heterocyclic aminophosphines 2 may be of interest as chelating ligands for asymmetric metal catalysis.

The role of vaterite and aragonite in the formation of pseudo-biogenic carbonate structures: implications for Martian exobiology.

A simple synthesis of various forms of calcium carbonate with spherical and 'floral' morphologies is reported. Vaterite formation occurs at approximately 25 degrees C, aragonite at approximately 70 degrees C and calcite at about approximately 80 degrees C. These are produced when CO2 is reacted with an aqueous solution of calcium chloride in the presence of ammonia. These conditions may have existed at the surface of Mars in the past, leading us to conclude that such mineral formations may be common there. Although the initial phases are modified over time with changing temperature and pressure conditions, they still influence the final morphology of the carbonates observed. A comparison of these structures with those found in the Martian meteorite ALH84001 suggests, but does not confirm, a non-biogenic origin for the ALH84001 carbonates.

Ferrocenyl Ligands with Two Phosphanyl Substituents in the alpha,varepsilon positions for the Transition Metal Catalyzed Asymmetric Hydrogenation of Functionalized Double Bonds.

The choice of the substituents at the benzylic position of diphosphane 1 allows the selection of the absolute configuration of the product that is obtained from the transition metal catalyzed enantioselective hydrogenation of various beta-dicarbonyl compounds, alpha-acetamidocinnamic acid derivatives, and dimethyl itaconate (see scheme).

Isotopic anomalies in extraterrestrial grains.

Isotopic compositions are referred to as anomalous if the isotopic ratios measured cannot be related to the terrestrial (solar) composition of a given element. While small effects close to the resolution of mass spectrometric techniques can have ambiguous origins, the discovery of large isotopic anomalies in inclusions and grains from primitive meteorites suggests that material from distinct sites of stellar nucleosynthesis has been preserved. Refractory inclusions, which are predominantly composed of the refractory oxides of Al, Ca, Ti, and Mg, in chondritic meteorites commonly have excesses in the heaviest isotopes of Ca, Ti, and Cr which are inferred to have been produced in a supernova. Refractory inclusions also contain excess 26Mg from short lived 26Al decay. However, despite the isotopic anomalies indicating the preservation of distinct nucleosynthetic sites, refractory inclusions have been processed in the solar system and are not interstellar grains. Carbon (graphite and diamond) and silicon carbide grains from the same meteorites also have large isotopic anomalies but these phases are not stable in the oxidized solar nebula which suggests that they are presolar and formed in the circumstellar atmospheres of carbon-rich stars. Diamond has a characteristic signature enriched in the lightest and heaviest isotopes of Xe, and graphite shows a wide range in C isotopic compositions. SiC commonly has C and N isotopic signatures which are characteristic of H-burning in the C-N-O cycle in low-mass stars. Heavier elements such as Si, Ti, Xe, Ba, and Nd, carry an isotopic signature of the s-process. A minor population of SiC (known as Grains X, ca. 1%) are distinct in having decay products of short lived isotopes 26Al (now 26Mg), 44Ti (now 44Ca), and 49V (now 49Ti), as well as 28Si excesses which are characteristic of supernova nucleosynthesis. The preservation of these isotopic anomalies allows the examination of detailed nucleosynthetic pathways in stars.

Alcohol abuse in abused and neglected children followed-up: are they at increased risk?

OBJECTIVE: To examine whether childhood victimization leads to increased risk of alcohol abuse in young adulthood and whether there are differential responses by gender and type of abuse. METHOD: Substantiated cases of child abuse and/or neglect from 1967 to 1971 in a midwestern metropolitan county area were matched on the basis of age, race, sex and approximate family social class with a group of nonabused and nonneglected children and followed prospectively into young adulthood. Subjects were located and administered a 2-hour interview consisting of a series of structured and semistructured questions, rating scales and a psychiatric assessment using the NIMH Diagnostic Interview Schedule. Findings are based on completed interviews with 1,068 subjects (611 abused and/or neglected and 457 controls). RESULTS: No relationship between childhood victimization and subsequent alcohol abuse in men. A significant bivariate relationship for women was found, and the relationship persists when controlling for parental alcohol and/or drug problems, childhood poverty, race and age. CONCLUSIONS: The connection between early childhood victimization and subsequent alcohol abuse seems less robust and more complex than hypothesized.

Childhood victimization and risk for alcohol and drug arrests.

Using data from a prospective cohorts design study, this paper examines the relationship between early childhood victimization and subsequent arrest for alcohol- and/or drug-related offenses. Complete official criminal histories are compared for cases of childhood physical and sexual abuse and neglect (n = 908) and a control sample (n = 667). After controlling for relevant demographic characteristics, logistic regression analyses indicate that childhood maltreatment is a significant predictor of adult, but not juvenile, arrests for alcohol- and/or drug-related offenses. Differential responses to maltreatment by race and gender are discussed as well as limitations of the findings and future directions for research.

Cardiopulmonary resuscitation in hospitalized patients: continuing problems of decision-making.

Disturbingly low survival rates after CPR prompted us to carry out a series of studies. Of 272 patients receiving CPR at our 600-bed community hospital in 1984, 102 (37.5%) patients survived initial resuscitation and 30 (11%) survived their hospitalization. Of the 102 initial survivors, only 15 patients had received full CPR including cardiac compression and/or defibrillation, endotracheal intubation, and cardiotonic drugs. These data were compared with those for 129 patients admitted to our critical care units in 1982 and 1983 in whom CPR was withheld. These patients had been designated "No CPR" primarily because of their poor response to therapy. There was an 11% survival rate for patients who had received CPR compared to a 16% survival rate for the "No CPR" group. These data suggest that criteria for administering CPR to hospitalized patients should be improved.

Characteristics of children with endoscopically proved chronic bronchitis.

This study evaluated by chart review the clinical, allergic, pathologic, and immunologic characteristics of 20 children found to have chronic bronchitis (CB) by bronchoscopic evaluation, including 13 children in whom CB was documented by endobronchial biopsy. Two additional children likely to have had CB also are described. In this study group, all of the patients were believed to have asthma as well. Chronic bronchitis was predicted by chronicity of symptoms and incomplete response to bronchodilators and corticosteroids, but it was not predicted by a history of allergy or laboratory evidence of systemic infection or inflammation. In the children described herein, CB often was associated with an IgG subclass abnormality. Bronchoscopic evaluation documented CB and provided biopsy and secretion samples. Although the histomorphic findings were heterogeneous, patients with CB usually had white blood cells present on Gram stains of secretions in addition to mononuclear cell infiltrates on biopsy specimens. Chronic bronchitis in these children seems to be distinct from CB in adults. Further studies will be needed to define CB in children.