Solutions consisting of single proteins and mixtures at different pH values have been subjected to both positive ion negative nanoelectrospray ionization study the influence solvent protein pI on responses proteins. As has noted previously, it is possible form ions one polarity despite fact that are present as opposite in solution. However, total response under this condition tends be least an order magnitude less than which same net charge Furthermore, maximum signals mode were when value...

Solutions consisting of protein and small molecule mixtures have been subjected to electrospray ionization study the influence molecule/cation components at high concentrations on responses proteins. Emphasis was placed solutions equal parts methanol water containing 1 vol % acetic acid. The results, therefore, are relevant low pH with significant organic content, a commonly used set conditions in mass spectrometry that tends denature A variety cations/molecules were selected sample range...

The prevention of adventitious agent contamination is a top priority throughout the entire biopharmaceutical production process. For example, although viral cell banks or cultures rare, it can result in serious consequences (e.g., shutdown and decontamination manufacturing facilities). To ensure virus free production, numerous vivo vitro assays biophysical characterizations such as electron microscopy are conducted on banks, raw materials, process drug substances Molecular PCR other...

In the elastic regime, GIFAD is equivalent to TEAS with an effective energy <italic>E</italic>_⊥ between 1 meV and eV providing a high sensitivity topology attractive forces. The inelastic regime merges classical limit still in development.

The transmission characteristics of circular–linear edge dislocation vortex (CLEDV) beams in optical nonlocal medium is investigated analytically and numerically detail. analytical expression for the CLEDV derived, are illustrated figures. influence various parameters on discussed, including statistical spot size, input power, topological charge, etc. results indicate that main transverse intensity can maintain a crescent shaped distribution rotate periodically under charges. For different...

Solutions composed of single proteins and mixtures are subjected to electrospray ionization study the influence protein components on responses one another. Protein matrix effects in particularly relevant development top-down identification methodologies involving mixtures, whereby whole ions tandem mass spectrometry. Emphasis is placed largely solutions equal parts methanol water 1% acetic acid. The results, therefore, low-pH with significant organic content, a commonly used set conditions...

Electrochemical reduction of the iron bound in heme group cytochrome c is shown to occur nano-electrospray capillary if protein sprayed from neutral water using a steel wire as electrical contact. Quadrupole ion trap collisional activation used study dissociation reactions function oxidation state iron. Oxidized (Fe(III)) dissociates via sequence-specific amide bond cleavage, while reduced (Fe(II)) form almost exclusively by loss protonated heme. Apo-cytochrome c, which has been removed...

Elastic diffraction of fast atoms at crystal surfaces under grazing incidence $\ensuremath{\theta}\ensuremath{\approx}1$\ifmmode^\circ\else\textdegree\fi{} has strong similarities with atomic thermal energies discovered almost hundred years ago. Here, we focus on the polar scattering profile, which does not exhibit features but shows well-defined elastic and inelastic components that are found to be essentially independent crystallographic axis. The width...

Grazing incidence fast-atom diffraction (GIFAD) uses keV atoms to probe the topmost layer of crystalline surfaces. The are scattered by potential energy landscape surface onto elastic spots located at Bragg angles and on Laue circle. However, transfer a significant momentum surface, giving rise possible phonon excitation. This causes inelastic intensity spread above below circle along direction normal. relative contribution is well fitted Debye-Waller model adapted GIFAD, but composite...

Aim: The study aimed to develop an LC–MS/MS assay measure dermatan sulfate (DS) in human cerebrospinal fluid (CSF). Methods & results: DS was quantified by ion pairing analysis of the major disaccharides derived from chondroitinase B digestion. Artificial CSF utilized as a surrogate for calibration curve preparation. fully validated, with linear range 20.0–4000 ng/ml, accuracy within ±20%, and precision ≤20%. samples mucopolysaccharidoses (MPS) II patients showed average 11-fold increase...

We investigate the influence of temperature in Fast Atom Diffraction at surfaces. The inelastic profiles broaden rapidly while elastic one is constant but its intensity decreases with a Debye-Waller factor adapted to grazing incidences.

The time evolution of the trajectories, angular distributions, and two-dimensional images intermediate-energy protons being transmitted through a conical capillary was simulated. simulation results indicate that charge deposited in significantly enhances probability surface specular scattering thus greatly transmission rate. Furthermore, this deposited-charge-assisted reflection causes rate to exhibit an energy dependence proportional ${E}^{\ensuremath{-}1}$, which is very consistent with...

In recent years, the guiding effect of highly charged ions (HCIs) through insulating nanocapillary membrane has received extensive attention. It is found that slow at keV energies can be guided along capillary even when title angle a few degrees and larger than geometry opening capillary. Initially, Stolterfoht et al. (2002 Phys. Rev. Lett. 88 133201), according to incident deposit positive charges on surface in self-organizing manner, proposed scattering regions explain this phenomenon....

We describe a UHV setup for grazing incidence fast atom diffraction (GIFAD) experiments. The overall geometry is simply source of keV atoms facing an imaging detector. Therefore, It very similar to the RHEED experiments, reflection high energy electron used monitor growth at surfaces. Several custom instrumental developments are described making GIFAD operation efficient and straightforward. difficulties associated with accurately measuring small scattering angle related calibration...

Aim: Myostatin (MSTN) is an attractive therapeutic target for the treatment of muscle degeneration-related diseases and being evaluated as a engagement biomarker. Methods: A sensitive 2D-LC-MS/MS assay was developed to quantify MSTN in different animal species. Sample preparation involved SDS denaturation serum proteins followed by tryptic digestion peptide enrichment SPE. Results: The validated with LLOQ 2.5 ng/ml rat monkey serum. precision within 13.7%, bias ±12.6% all quality control...

The quantitation of PTH-Fc in circulation by ligand binding assay presented a significant challenge due to the extremely low doses administration, interference from endogenous. A robust LC-MS/MS method quantify concentration human serum utilized sequential immunoaffinity enrichment at PTH and Fc domains conjunction with microflow technology significantly improved sensitivity selectivity. displayed range 0.025-5.0 ng/ml acceptable intraday interday precision (%CV ≤ 15%) accuracy (%bias ±15%)...

In recent years, by using the etching techniques with great precision, ion tracks in materials were converted into insulator and metal nanocapillaries. The physical chemical properties of inner surface on micro nano-scales these capillaries can be investigated interaction ions surfaces. Stolterfoht et al. (2002 Phys. Rev. Lett. 88 133201) have found evidence for capillary guiding studying transmission 3 keV Ne7+ (energy/charge E/q100 kV) through polymer self-organized charge-up process was...

Aimed at the problem of low accuracy rate for face recognition and speaker in noisy environment, a multi-biometric model fusing features speech is presented by combining Normalization SVM theory based on research feature level fusion. Face are first extracted pulse coupled neural network VQ-SVM respectively. Then distance between tested people template calculated after getting fused In order to reduce computational cost improve performance, matching normalized finally recognized SVM....

Grazing incidence fast atom diffraction has mainly been investigated with helium atoms, considered as the best possible choice for surface analysis. This article presents experimental profiles recorded neon projectile, between 300 eV and 4 keV kinetic energy angles $\theta_i$ 0.3$^\circ$ 1.5$^\circ$ along three different directions of a LiF(001) crystal surface. These correspond to perpendicular ranging from few meV up almost 1 eV. A careful analysis scattering profile allows us extract...

Grazing incidence fast atom diffraction has mainly been investigated with helium atoms, considered as the best possible choice for surface analysis. This article presents experimental profiles recorded neon projectile, between 300 eV and 4 keV kinetic energy angles θi 0.3 1.5° along three different directions of a LiF(001) crystal surface. These correspond to perpendicular ranging from few meV up almost 1 eV. A careful analysis scattering profile allows us extract diffracted intensities even...