Fabrication of submicron structures in nanoparticle/polymer composite by holographic lithography and reactive ion etching

We report on the fabrication of nanoparticle/polymer submicron structures by combining holographic lithography and reactive ion etching. Silica nanoparticles are uniformly dispersed in a (SU8) polymer matrix at a high concentration, and in situ polymerization (cross-linking) is used to form a nanoparticle/polymer composite. Another photosensitive SU8 layer cast upon the nanoparticle/SU8 composite layer is structured through holographic lithography, whose pattern is finally transferred to the nanoparticle/SU8 layer by the reactive ion etching process. Honeycomb structures in a submicron scale are experimentally realized in the nanoparticle/SU8 composite.This work was supported in part by the US Air Force Office for Scientific Research and in part by National Basic Research Program 973 of China No. 2004CB719800

A measurement of the evolution of Interatomic Coulombic Decay in the time domain

During the last 15 years a novel decay mechanism of excited atoms has been discovered and investigated. This so called ''Interatomic Coulombic Decay'' (ICD) involves the chemical environment of the electronically excited atom: the excitation energy is transferred (in many cases over long distances) to a neighbor of the initially excited particle usually ionizing that neighbor. It turned out that ICD is a very common decay route in nature as it occurs across van-der-Waals and hydrogen bonds. The time evolution of ICD is predicted to be highly complex, as its efficiency strongly depends on the distance of the atoms involved and this distance typically changes during the decay. Here we present the first direct measurement of the temporal evolution of ICD using a novel experimental approach.Comment: 6 pages, 4 figures, submitted to PR

Interatomic-Coulombic-decay-induced recapture of photoelectrons in helium dimers

We investigate the onset of photoionization shakeup induced interatomic Coulombic decay (ICD) in He2 at the He+*(n = 2) threshold by detecting two He+ ions in coincidence. We find this threshold to be shifted towards higher energies compared to the same threshold in the monomer. The shifted onset of ion pairs created by ICD is attributed to a recapture of the threshold photoelectron after the emission of the faster ICD electron.Comment: 5 Pages, 2 Figure

Peripheral Nα\alpha Scattering: A Tool For Identifying The Two Pion Exchange Component Of The NN Potential

We study elastic N$\alpha$ scattering and produce a quantitative correlation between the range of the effective potential and the energy of the system. This allows the identification of the waves and energies for which the scattering may be said to be peripheral. We then show that the corresponding phase shifts are sensitive to the tail of the NN potential, which is due to the exchange of two pions. However, the present uncertainties in the experimental phase shifts prevent the use of N$\alpha$ scattering to discriminate the existing models for the NN interaction.Comment: 19 pages, 6 PostScript figures, RevTeX, to be appear in Phys. Rev.

Arm bone loading index predicts DXA musculoskeletal outcomes in two samples of post-menarcheal girls

Abstract Objective: A site-specific bone loading index was developed to predict post-menarcheal arm bone mass, geometry, areal density and non-bone lean mass using organized activity records. Methods: Two cohorts of post-menarcheal girls (A= 55, B= 48) met analysis inclusion criteria: 1) Whole body and non-dominant radius DXA scans +1.0 to +2.6 years post-menarche; 2) detailed, organized activity records available for 36 months prior to the focal DXA scan; 3) accompanying anthropometric data. DXA non-dominant arm and radius regions of interest (1/3, Ultradistal (UD)) were evaluated. An arm bone loading index (arm totBLI) was developed and refined to describe >50 activities. Separate regression analyses for Cohorts A&B tested explanatory value of arm totBLI for DXA outcomes, accounting for gynecological age, height and whole body non-bone lean mass. Results: In both cohorts, arm totBLI reflecting 3 years of peri-menarcheal activity exposure exhibited strong explanatory value for post-menarcheal radius and arm outcomes (squared semi-partial r =0.07-0.34, p<0.05), except Arm Area. For both cohorts and most outcomes, arm totBLI explained significant variance, even after adjusting for local muscle mass. Conclusions: In two independent cohorts, arm totBLI may consistently indicate osteogenic and sarcogenic properties of represented activities; additional research is necessary for further refinement and validation

Fine mapping of the 9q31 Hirschsprung’s disease locus

Hirschsprung’s disease (HSCR) is a congenital disorder characterised by the absence of ganglia along variable lengths of the intestine. The RET gene is the major HSCR gene. Reduced penetrance of RET mutations and phenotypic variability suggest the involvement of additional modifying genes in the disease. A RET-dependent modifier locus was mapped to 9q31 in families bearing no coding sequence (CDS) RET mutations. Yet, the 9q31 causative locus is to be identified. To fine-map the 9q31 region, we genotyped 301 tag-SNPs spanning 7 Mb on 137 HSCR Dutch trios. This revealed two HSCR-associated regions that were further investigated in 173 Chinese HSCR patients and 436 controls using the genotype data obtained from a genome-wide association study recently conducted. Within one of the two identified regions SVEP1 SNPs were found associated with Dutch HSCR patients in the absence of RET mutations. This ratifies the reported linkage to the 9q31 region in HSCR families with no RET CDS mutations. However, this finding could not be replicated. In Chinese, HSCR was found associated with IKBKAP. In contrast, this association was stronger in patients carrying RET CDS mutations with p = 5.10 × 10−6 [OR = 3.32 (1.99, 5.59)] after replication. The HSCR-association found for IKBKAP in Chinese suggests population specificity and implies that RET mutation carriers may have an additional risk. Our finding is supported by the role of IKBKAP in the development of the nervous system

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Synchronizing Allelic Effects of Opposing Quantitative Trait Loci Confirmed a Major Epistatic Interaction Affecting Acute Lung Injury Survival in Mice

Increased oxygen (O2) levels help manage severely injured patients, but too much for too long can cause acute lung injury (ALI), acute respiratory distress syndrome (ARDS) and even death. In fact, continuous hyperoxia has become a prototype in rodents to mimic salient clinical and pathological characteristics of ALI/ARDS. To identify genes affecting hyperoxia-induced ALI (HALI), we previously established a mouse model of differential susceptibility. Genetic analysis of backcross and F2 populations derived from sensitive (C57BL/6J; B) and resistant (129X1/SvJ; X1) inbred strains identified five quantitative trait loci (QTLs; Shali1-5) linked to HALI survival time. Interestingly, analysis of these recombinant populations supported opposite within-strain effects on survival for the two major-effect QTLs. Whereas Shali1 alleles imparted the expected survival time effects (i.e., X1 alleles increased HALI resistance and B alleles increased sensitivity), the allelic effects of Shali2 were reversed (i.e., X1 alleles increased HALI sensitivity and B alleles increased resistance). For in vivo validation of these inverse allelic effects, we constructed reciprocal congenic lines to synchronize the sensitivity or resistance alleles of Shali1 and Shali2 within the same strain. Specifically, B-derived Shali1 or Shali2 QTL regions were transferred to X1 mice and X1-derived QTL segments were transferred to B mice. Our previous QTL results predicted that substituting Shali1 B alleles onto the resistant X1 background would add sensitivity. Surprisingly, not only were these mice more sensitive than the resistant X1 strain, they were more sensitive than the sensitive B strain. In stark contrast, substituting the Shali2 interval from the sensitive B strain onto the X1 background markedly increased the survival time. Reciprocal congenic lines confirmed the opposing allelic effects of Shali1 and Shali2 on HALI survival time and provide unique models to identify their respective quantitative trait genes and to critically assess the apparent bidirectional epistatic interactions between these major-effect loci