Fabrication of double nano-cup assemblies and their anomalous plasmon absorption

Double-cup assemblies of nanoscale gold semi-shells have been synthesized using a combination of thermal evaporation and chemical etching. The optical extinction of these structures peaked at 740 nm, but there was also evidence of additional extinction maxima at 560, 940 and 1110 nm. Numerical simulations of the optical properties revealed that the extinction was due mainly to scattering rather than to absorption In contrast, the extinction in simple single-shell nanocups was strongly absorptive in nature. Multiple plasmon resonances were identified in the double-cup structures, including an interesting quadrupole resonance in which oscillations of the inner and outer shells should operate 180° out-of-phase. © 2008 IEEE

Applications of nano- and mesoporous gold in electrodes and electrochemical sensors

A nano- or mesoporous sponge of Au is formed when the intermetallic compound AuAl2 is de-alloyed with NaOH. The large specific surface area of the sponge, and the unique surface chemical properties of Au indicate that this porous material might usefully serve as an electrode in capacitive sensors or other specialized electrochemical cells. Results for some prototype sensor and energy storage systems are presented, and methods of controlling the nature of the porosity presented. © 2006 IEEE

X-ray mapping of metallic elements in roll bonded metal laminates

Advanced metal laminates have experienced rapid development in functional engineering applications. In this study, copper/aluminium metal laminates were produced by the roll bonding technique at 430°C with a critical 40% rolling reduction and sintering treatment was applied at 450°C. Interface development of the samples was examined using scanning electron microscopy and the distribution of the metallic elements and the subsequent chemical phase formation in the interfacial region was investigated by x-ray mapping. It was found that movement of the copper atoms occurred at a faster diffusion rate into the aluminium region and resulted in a shift of the interface boundary. Growth rate of the interface was determined and its relationship with sintering time was formulated. Development of the metallic phases in the interfacial area of the metal laminates was observed and determined. © Institute of Materials Engineering Australasia Ltd

Histo-blood group glycans in the context of personalized medicine

General significance: Histo-blood group glycans have a unique linking position in the complex network of genes, oncodevelopmental biological processes, and disease mechanisms. Thus, they are highly promising targets for novel approaches in the field of personalized medicine. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc. (C) 2015 Elsevier B.V. All rights reserved.Proteomic

Software-Assisted Data Processing Workflow for Intact Glycoprotein Mass Spectrometry

Intact protein analysis by mass spectrometry is important for several applications such as assessing post-translational modifications and biotransformation. In particular, intact protein analysis allows the detection of proteoforms that are commonly missed by other approaches such as proteolytic digestion followed by bottom-up analysis. Two quantification methods are mainly used for intact protein data quantification, namely the extracted ion and deconvolution approaches. However, a consensus with regard to a single best practice for intact protein data processing is lacking. Furthermore, many data processing tools are not fit-for-purpose and, as a result, the analysis of intact proteins is laborious and lacks the throughput required to be implemented for the analysis of clinical cohorts. Therefore, in this study, we investigated the application of a software-assisted data analysis and processing workflow in order to streamline intact protein integration, annotation, and quantification via deconvolution. In addition, the assessment of orthogonal data sets generated via middle-up and bottom-up analysis enabled the cross-validation of cleavage proteoform assignments present in seminal prostate-specific antigen (PSA). Furthermore, deconvolution quantification of PSA from patients' urine revealed results that were comparable with manually performed quantification based on extracted ion electropherograms. Overall, the presented workflow allows fast and efficient processing of intact protein data. The raw data is available on MassIVE using the identifier MSV000086699.</p

Immunoglobulin G glycoprofiles are unaffected by common bottom-up sample processing

Immunoglobulin G (IgG) glycosylation is a key post-translational modification in regulating IgG function. It is therefore a prominent target for biomarker discovery and a critical quality attribute of antibody-based biopharmaceuticals. A common approach for IgG glycosylation analysis is the measurement of tryptic glycopeptides. Glycosylation stability during sample processing is a key prerequisite for an accurate and robust analysis yet has hitherto hardly been studied. Especially, acid hydrolysis of sialic acids may be a source for instability. Therefore, we investigated acid denaturation, centrifugal vacuum concentration, and glycopeptide storage regarding changes in the IgG glycosylation profile. Intravenous IgG was analyzed employing imaginable deviations from a reference method and stress conditions. All glycosylation features-sialylation, galactosylation, bisection, and fucosylation-remained unchanged for most conditions. Only with prolonged exposure to acidic conditions at 37 degrees C, sialylation decreased significantly and subtle changes occurred for galactosylation. Consequently, provided that long or intense heating in acidic solutions is avoided, sample preparation for bottom-up glycoproteomics does not introduce conceivable biases.Proteomic

Serum sialylation changes in cancer

Proteomic

Antibody glycosylation in COVID-19

Proteomic

Serum and plasma immunoglobulin G Fc N-glycosylation is stable during storage

Immunoglobulin G (IgG) glycosylation is studied in biological samples to develop clinical markers for precision medicine, for example, in autoimmune diseases and oncology. Inappropriate storage of proteins, lipids, or metabolites can lead to degradation or modification of biomolecular features, which can have a strong negative impact on accuracy and precision of clinical omics studies. Regarding the preservation of IgG glycosylation, the range of appropriate storage conditions and time frame is understudied. Therefore, we investigated the effect of storage on IgG Fc N-glycosylation in the commonly analyzed biofluids, serum and plasma. Short-term storage and accelerated storage stability were tested by incubating samples from three healthy donors under stress conditions of up to 50 degrees C for 2 weeks using -80 degrees C for 2 weeks as the reference condition. All tested IgG glycosylation features-sialylation, galactosylation, bisection, and fucosylation-remained unchanged up to room temperature as well as during multiple freeze-thaw cycles and exposure to light. Only when subjected to 37 degrees C or 50 degrees C for 2 weeks, galactosylation and sialylation subtly changed. Therefore, clinical IgG glycosylation analysis does not rely as heavily on mild serum and plasma storage conditions and timely analysis as many other omics analyses.Proteomic