Semi-Classical Wavefunction Perspective to High-Harmonic Generation

We introduce a semi-classical wavefunction (SCWF) model for strong-field physics and attosecond science. When applied to high harmonic generation (HHG), this formalism allows one to show that the natural time-domain separation of the contribution of ionization, propagation and recollisions to the HHG process leads to a frequency-domain factorization of the harmonic yield into these same contributions, for any choice of atomic or molecular potential. We first derive the factorization from the natural expression of the dipole signal in the temporal domain by using a reference system, as in the quantitative rescattering (QRS) formalism [J. Phys. B. 43, 122001 (2010)]. Alternatively, we show how the trajectory component of the SCWF can be used to express the factorization, which also allows one to attribute individual contributions to the spectrum to the underlying trajectories

Allergens and molecular diagnostics of shellfish allergy

In recent years, there has been a steady growth in the production and consumption of shellfish due to its important role in human nutrition and health. This increased consumption has led to an increase in adverse health problems among consumers including immunoglobulin E (IgE)-mediated allergic reactions. Approximately 2 % of the world population is affected by shellfish allergy, which includes the crustacean and mollusk groups. The allergenic proteins present in the shellfish group have variable primary structures and often present a challenge in allergen detection and diagnosis. The distinction of crustacean from mollusk is important from clinical point of view, as molecular cross-reactivity, particularly between crustaceans, seems to be determined by the close relationship to insects and mites. Currently, at least seven different shellfish allergens have been identified, mostly from crustaceans; however, only three recombinant allergens are available for IgE-based routine diagnostic, including tropomyosin, arginine kinase, and sarcoplasmic Ca++-binding protein. Other allergens include myosin light chain, troponin C, triose-phosphate isomerase, and actin. This chapter describes current information on shellfish allergy, the allergenic proteins involved, and diagnostic approaches

High-harmonic spectroscopy of transient two-center interference calculated with time-dependent density-functional theory

We demonstrate high-harmonic spectroscopy in many-electron molecules using time-dependent density-functional theory. We show that a weak attosecond-pulse-train ionization seed that is properly synchronized with the strong driving mid-infrared laser field can produce experimentally relevant high-harmonic generation (HHG) signals, from which we extract both the spectral amplitude and the target-specific phase (group delay). We also show that further processing of the HHG signal can be used to achieve molecular-frame resolution, i.e., to resolve the contributions from rescattering on different sides of an oriented molecule. In this framework, we investigate transient two-center interference in CO2 and OCS, and how subcycle polarization effects shape the oriented/aligned angle-resolved spectra. (C) 2019 Author(s)

Characterization of Seafood Proteins Causing Allergic Diseases

[Extract] Food allergy is increasing at a faster rate than any other allergic disorder (Gupta et al., 2007). In the last few decades, a large movement toward healthier eating makes seafood one of the major foods consumed worldwide (Wild & Lehrer, 2005). Consequently, the international trade of seafood has been growing rapidly, which reflects the popularity and frequency of consumption worldwide. The United States has become the third largest consumer of seafood in the world, with 1.86 billion kg of crustaceans in 2007 (6.04 kg/capita/year)(Food and Agriculture Organisation, 2007). Since seafood ingestion can cause severe acute hypersensitivity reactions and is recognized as one of the most common food allergies, the increased production and consumption of seafood has resulted in more frequent health problems (Lopata & Lehrer, 2009; Lopata et al., 2010). Exposure to seafood can cause a variety of health problems, including gastrointestinal disorders, urticaria, immunoglobulin E (IgE)-mediated asthma and anaphylaxis (Bang et al., 2005; Lopata & Lehrer, 2009; Malo & Cartier, 1993; Sicherer et al., 2004; Wild & Lehrer, 2005)

Electron Beam Cured Epoxy Resin Composites for High Temperature Applications

Electron beam curing of Polymer Matrix Composites (PMC's) is a nonthermal, nonautoclave curing process that has been demonstrated to be a cost effective and advantageous alternative to conventional thermal curing. Advantages of electron beam curing include: reduced manufacturing costs; significantly reduced curing times; improvements in part quality and performance; reduced environmental and health concerns; and improvement in material handling. In 1994 a Cooperative Research and Development Agreement (CRADA), sponsored by the Department of Energy Defense Programs and 10 industrial partners, was established to advance the electron beam curing of PMC technology. Over the last several years a significant amount of effort within the CRADA has been devoted to the development and optimization of resin systems and PMCs that match the performance of thermal cured composites. This highly successful materials development effort has resulted in a board family of high performance, electron beam curable cationic epoxy resin systems possessing a wide range of excellent processing and property profiles. Hundreds of resin systems, both toughened and untoughened, offering unlimited formulation and processing flexibility have been developed and evaluated in the CRADA program

The electron beam cure of epoxy paste adhesives

Recently developed epoxy paste adhesives were electron beam cured and experimentally explored to determine their suitability for use in an aerospace-quality aircraft component. There were two major goals for this program. The first was to determine whether the electron beam-curable past adhesives were capable of meeting the requirements of the US Air Force T-38 supersonic jet trainer composite windshield frame. The T-38 windshield frame`s arch is currently manufactured by bonding thin stainless steel plies using an aerospace-grade thermally-cured epoxy film adhesive. The second goal was to develop the lowest cost hand layup and debulk process that could be used to produce laminated steel plies with acceptable properties. The laminate properties examined to determine adhesive suitability include laminate mechanical and physical properties at room, adhesive tack, out-time capability, and the debulk requirements needed to achieve these properties. Eighteen past adhesives and four scrim cloths were experimentally examined using this criteria. One paste adhesive was found to have suitable characteristics in each of these categories and was later chosen for the manufacture of the T-38 windshield frame. This experimental study shows that by using low-cost debulk and layup processes, the electron beam-cured past adhesive mechanical and physical properties meet the specifications of the T-38 composite windshield frame

Tracking Charge Migration with Frequency-Matched Strobo-Spectroscopy

We present frequency-matched strobo-spectroscopy (FMSS) of charge migration (CM) in bromodiacetylene, simulated with time-dependent density-functional theory. CM+FMSS is a pump-probe scheme that uses a frequency-matched HHG-driving laser as an independent probe step following the creation of a localized hole on the bromine atom that induces CM dynamics. We show that the delay-dependent harmonic yield tracks the phase of the CM dynamics through its sensitivity to the amount of electron density on the bromine end of the molecule. FMSS takes advantage of the intrinsic attosecond time resolution of the HHG process, in which different harmonics are emitted at different times and thus probe different locations of the electron hole. Finally, we show that the CM-induced modulation of the HHG signal is dominated by the recombination step of the HHG process, with negligible contribution from the ionization step

The Anisakis Transcriptome Provides a Resource for Fundamental and Applied Studies on Allergy-Causing Parasites.

BACKGROUND: Food-borne nematodes of the genus Anisakis are responsible for a wide range of illnesses (= anisakiasis), from self-limiting gastrointestinal forms to severe systemic allergic reactions, which are often misdiagnosed and under-reported. In order to enhance and refine current diagnostic tools for anisakiasis, knowledge of the whole spectrum of parasite molecules transcribed and expressed by this parasite, including those acting as potential allergens, is necessary. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we employ high-throughput (Illumina) sequencing and bioinformatics to characterise the transcriptomes of two Anisakis species, A. simplex and A. pegreffii, and utilize this resource to compile lists of potential allergens from these parasites. A total of ~65,000,000 reads were generated from cDNA libraries for each species, and assembled into ~34,000 transcripts (= Unigenes); ~18,000 peptides were predicted from each cDNA library and classified based on homology searches, protein motifs and gene ontology and biological pathway mapping. Using comparative analyses with sequence data available in public databases, 36 (A. simplex) and 29 (A. pegreffii) putative allergens were identified, including sequences encoding 'novel' Anisakis allergenic proteins (i.e. cyclophilins and ABA-1 domain containing proteins). CONCLUSIONS/SIGNIFICANCE: This study represents a first step towards providing the research community with a curated dataset to use as a molecular resource for future investigations of the biology of Anisakis, including molecules putatively acting as allergens, using functional genomics, proteomics and immunological tools. Ultimately, an improved knowledge of the biological functions of these molecules in the parasite, as well as of their immunogenic properties, will assist the development of comprehensive, reliable and robust diagnostic tools.This work was supported by a ‘Collaborations Across Boundaries’ grant and a seed grant from the Centre of Biodiscovery and Molecular Development of Therapeutics, James Cook University (FJB and CC). ALL is an Australian Research Council (ARC) Future Fellow and his laboratory is supported by grants from the National Health and Medical Research Council of Australia (NHMRC). Research in the CC laboratory is supported by grants from the Isaac Newton Trust/Wellcome Trust/University of Cambridge (grant number PNVM/GAAB) and the Royal Society (grant number PNAG/428)

All-Electron, Density Functional-Based Method for Angle-Resolved Tunneling Ionization in the Adiabatic Regime

We develop and test a method that integrates many-electron weak-field asymptotic theory (ME-WFAT) [Phys. Rev. A 89, 013421 (2014)] in the integral representation (IR) into the density functional theory (DFT) framework. In particular, we present modifications of the integral formula in the IR ME-WFAT to incorporate the potential terms unique to DFT. By solving an adiabatic rate equation for the angle-resolved ionization yield in our DFT-based ME-WFAT method, we show that the results are in excellent agreement with those of real-time time-dependent density functional theory (RT-TDDFT) simulations for NO, OCS, CH$_3$Br, and CH$_3$Cl interacting with one- and two- color laser fields with a fundamental wavelength of $800$ nm. This agreement is significant because the WFAT calculations take only a small fraction of the time of full TDDFT calculations. These results suggest that in the wavelength region commonly used in strong-field experiments ($800$ nm and longer), our DFT-based WFAT treatment can be used to rapidly screen for the ionization properties of a large number of molecules as a function of alignment or orientation between the molecule and the strong field