Effect of Heat Processing on IgE Reactivity and Cross‐Reactivity of Tropomyosin and Other Allergens of Asia‐Pacific Mollusc Species: Identification of Novel Sydney Rock Oyster Tropomyosin Sac g 1

1 Scope

Shellfish allergy is an increasing global health priority, frequently affecting adults. Molluscs are an important shellfish group causing food allergy but knowledge of their allergens and cross‐reactivity is limited. Optimal diagnosis of mollusc allergy enabling accurate advice on food avoidance is difficult. Allergens of four frequently ingested Asia‐Pacific molluscs are characterized: Sydney rock oyster (Saccostrea glomerata), blue mussel (Mytilus edulis), saucer scallop (Amusium balloti), and southern calamari (Sepioteuthis australis), examining cross‐reactivity between species and with blue swimmer crab tropomyosin, Por p 1.

2 Methods and results

IgE ELISA showed that cooking increased IgE reactivity of mollusc extracts and basophil activation confirmed biologically relevant IgE reactivity. Immunoblotting demonstrated strong IgE reactivity of several proteins including one corresponding to heat‐stable tropomyosin in all species (37–40 kDa). IgE‐reactive Sydney rock oyster proteins were identified by mass spectrometry, and the novel major oyster tropomyosin allergen was cloned, sequenced, and designated Sac g 1 by the IUIS. Oyster extracts showed highest IgE cross‐reactivity with other molluscs, while mussel cross‐reactivity was weakest. Inhibition immunoblotting demonstrated high cross‐reactivity between tropomyosins of mollusc and crustacean species.

3 Conclusion

These findings inform novel approaches for reliable diagnosis and improved management of mollusc allergy.     

Prediction of metal deposition from arc sound and weld temperature signatures in pulsed MIG welding

The weld deposition efficiency is an important economic factor like productivity and weld quality in gas metal arc welding (GMAW). There is a strong relationship between arc sound signals and arc stability (or deposition efficiency) in GMAW. In this work, the variation of weld deposition efficiency with various pulse parameters in pulsed metal inert gas welding was investigated. The arc sound signal along with current and voltage signals were acquired and analyzed in time domain as well as in frequency domain. The sound signal kurtosis and arc power were found to be highly correlated with welding process stability. The weld deposition efficiency was also related to weld surface peak temperature. Finally, an attempt was made to correlate the sound time domain as well as frequency domain features of sound signal with the deposition efficiency. The variation of pulse shape with the duty factor also influenced the deposition efficiency as evidenced by in fast Fourier transform analysis.     

Photoconductive optically driven deformable membrane for spatial light modulator applications utilizing GaAs substrates

The fabrication and characterization of an optically addressable deformable mirror for a spatial light modulator is described. Device operation utilizes an electrostatically driven pixellated aluminized polymeric membrane mirror supported above an optically controlled photoconductive GaAs substrate. A 5 microm thick grid of patterned photoresist supports the 2 microm thick aluminized Mylar membrane. A conductive ZnO layer is placed on the back side of the GaAs wafer. A standard Michelson interferometer is used to measure mirror deformation data as a function of illumination, applied voltage, and frequency. A simplified analysis of device operation is also presented.     

Synthesis and characterization of metal selenide (ZnSe, CdSe, HgSe) nanoparticles

Thermolysis of [M(SeCH2CH2CH2NMe2)2] (M = Zn, Cd, Hg), prepared by the reactions of sodium salt of 3-(N,N-dimethylamino)propaneselenolate with metal acetates, afforded metal selenides (MSe). The metal selenides were characterized by XRD, EDAX, SEM, AFM, and TEM techniques. Nanoparticles of HgSe were prepared by pyrolysis in a quartz boat, solvothermal, and sonochemical methods. EDAX showed 1:1 Hg/Se ratio, while XRD and SAED patterns confirmed the formation of cubic HgSe. These particles are spherical in nature with an average diameter of 15 nm (from TEM).     

Correlation of Microstructure and Texture in a Two-Phase High-Mn Twinning-Induced Plasticity Steel During Cold Rolling

Metallurgical and Materials Transactions A - The evolution of microstructure and texture of a two-phase austenite-ferrite twinning-induced plasticity steel during cold rolling was investigated and...     

Nanohardness of Sintered and Shock Deformed Alumina

To understand how high–strain rate, flyer-plate impact affects the nanohardness of a coarse (~10 μm) grain, high-density (~3.978 gm cc^–1) alumina, load controlled nanoindentation experiments were conducted with a Berkovich indenter on as-sintered disks and shock-recovered alumina fragments obtained from an earlier flyer-plate shock impact study. The nanohardness of the shock-recovered alumina was much lower than that of the as-sintered alumina. The indentation size effect was severe in the shock-recovered alumina but only mild in the as-sintered alumina. Extensive additional characterization by field emission scanning electron microscopy, transmission electron microscopy, and analysis of the experimental load depth data were used to provide a new explanation for the presence of strong indentation size effect in the shock-recovered alumina. Finally, a qualitative model was proposed to provide a rationale for the whole scenario of nanoindentation responses in the as-sintered and shock-recovered alumina ceramics.     

Preparation and characterization of spray-dried mucoadhesive microspheres of aceclofenac

Objective: Microencapsulation of the anti-inflammatory drug aceclofenac (ACE) was investigated as a means of controlling drug release and minimizing or eliminating local side effects. Method: Microspheres were prepared by a spray-drying technique using solutions of ACE and three polymers, namely, carbopol, chitosan, and polycarbophil, in different weight ratios. Results: The spray-dried mucoadhesive microspheres were characterized in terms of shape (scanning electron microscope), size (6.60–8.40 μm), production yield (34.10–55.62%), and encapsulation efficiency (58.14–90.57%). In vitro release studies were performed in phosphate buffer (pH 6.8) up to 10 hours. The spray-drying process of solutions of ACE with polymeric blends can give prolonged drug release. The in vitro release data were well fit into Higuchi and Korsmeyer–Peppas model and followed Fickian diffusion mechanism. In vivo data showed that the administration of ACE in polymeric microspheres prevented the gastric side effects. Conclusion: The formulations here described can be proposed for the oral administration of nonsteroidal anti-inflammatory drugs with minimal side effects on gastric mucosa.     

Effect of N3 modifications on the affinity of spin label ç for abasic sites in duplex DNA

Noncovalent site‐directed spin labeling (NC‐SDSL) of abasic sites in duplex DNAs with the spin label ç , a cytosine analogue, is a promising approach for spin‐labeling nucleic acids for EPR spectroscopy. In an attempt to increase the affinity of ç for abasic sites, several N3 derivatives were prepared, and their binding affinities were determined by EPR spectroscopy. Most of the N3 substituents had a detrimental effect on binding. The triazole‐linked polyethylene‐glycol derivative ( 12 a ) showed a 15‐fold decrease in affinity, whereas the binding affinities of ethyl azido ( 8 b ) and hydroxyl ( 8 c ) derivatives were five‐ to sixfold lower. The spin‐labeled nucleoside Ç showed only a twofold decrease, thus binding better than 8 c , even though it contains the larger 2′‐deoxyribose substituent at N3 instead of a 2‐hydroxyethyl group. N3 derivatives that contained the basic ethyl amino ( 9 ) or ethyl guanidino ( 10 ) substituents had both higher binding affinity and solubility, attributed to their cationic charge at neutral pH. Compounds 9 and 10 are promising candidates for NC‐SDSL of nucleic acids, for distance measurements by pulsed EPR spectroscopy.     

Development and application of a mobile laboratory for measuring emissions from diesel engines. 2. Sampling for toxics and particulate matter

Limited data are available on the emission rates of speciated volatile and semivolatile organic compounds, as well as the physical and chemical characteristics of fine particulate matter (PM) from mobile, in-use diesel engines operated on the road. A design for the sampling of these fractions and the first data from in-use diesel sources are presented in this paper. Emission rates for carbonyls, 1,3-butadiene, benzene, toluene, xylene, PM, and elemental and organic carbon (EC and OC) are reported for a vehicle driven while following the California Air Resources Board (ARB) four-mode heavy heavy-duty diesel truck (HHDDT) cycle and while transiting through a major transportation corridor. Results show that distance specific emission rates are substantially greater in congested traffic as compared with highway cruise conditions. Specifically, emissions of toxic compounds are 3-15 times greater, and PM is 7 times greater under these conditions. The dependence of these species on driving mode suggests that health and source apportionment studies will need to account for driving patterns in addition to emission factors. Comparison of the PM/NOx ratios obtained for the above tests provides insight into the presence and importance of "off-cycle" emissions during on-road driving. Measurements from a stationary source (operated and tested at constant engine speed) equipped with an engine similar to that in the HHDDT yielded a greater understanding of the relative dependence of emissions on load versus engine transients. These data are indicative of the type of investigations made possible by the development of this novel laboratory.     

Contactless measurement of surface dominated recombination in gold- and aluminum-catalyzed silicon vapor-liquid-solid wires

Carrier lifetimes of Si micro/nanowires grown by the vapor-liquid-solid method are measured using an extension of the classic contactless photoconductivity decay method. The samples measured consist of a thin aggregated film of oxide passivated wires on a fused silica carrier. Au catalyzed wires in the 392-730 nm diameter range are studied. Recombination in these wires is controlled by the surface or near surface effects, not bulk Au impurities. The lifetimes of Au- and Al-catalyzed wires of comparable diameter are measured. The Al wires are found to have slightly longer lifetimes than those grown with Au at a comparable diameter. Across all samples, the lifetimes measured range was from 0.2 to 1.0 ns. The surface controlled nature of the recombination measured implies larger diameter wires will offer better performance in devices that rely on minority carrier transport.