In this contribution the emission of gold-molecule cluster ions from self-assembled monolayers (SAMs) of alkanethiols on gold is investigated using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Layers of alkanethiols [CH3(CH2)nSH] with various chain lengths (n 1⁄4 8, 12, 16) have been chosen because they form well-ordered molecular monolayers on gold. First, we compare and interpre...

MALDI imaging as a molecular mass spectrometry imaging technique (MSI) can provide accurate information about molecular composition on a surface. The last decade of MSI development has brought the technology to clinical and biomedical applications as a complementary technique of MRI and other molecular imaging. Then, this IMS technique is used for endogenous and exogenous molecule detection in ...

Phlorotannins are a group of complex polymers of phloroglucinol (1,3,5-trihydroxybenzene) unique to macroalgae. These phenolic compounds are integral structural components of the cell wall in brown algae, but also play many secondary ecological roles such as protection from UV radiation and defense against grazing. This study employed Ultra Performance Liquid Chromatography (UPLC) with tandem m...

Using a newly developed gradient chamber to provide independent measurements of chemokinesis (stimulated motility) and chemotaxis (stimulated motility up a concentration gradient) of individual T-helper cells, it was recently demonstrated that HIV-induced T-cell syncytia release two distinct chemotactic activities that are separable by their rates of diffusion. The molecular masses of the two c...

The combination of HPLC and mass spectrometry has great promise for the toxicology laboratory. In the past five years, significant progress has been made toward producing a reliable interface for these techniques. Thermospray, liquid ion evaporation, ion-spray, and the particle beam separator are all viable "second generation" approaches with significant advantages and disadvantages. I review t...

A new strategy for the structural characterisation of human albumin variants has been developed which makes extensive use of mass spectrometric methodologies. The rationale behind the method is to provide a rapid and effective screening of the entire albumin structure. The first step in this strategy consists in the attempt to determine the accurate molecular mass of the intact variant by elect...

Hypoallergenic antibacterial low-molecular-mass peptides were produced from defatted soybean meal in a membrane bioreactor. In the first step, soybean meal proteins were digested with trypsin in the bioreactor, operated in batch mode. For the tryptic digestion of soybean meal protein, optimum initial soybean meal concentration of 75 g/L, temperature of 40 °C and pH=9.0 were determined. After en...

phytochemical investigation of the aerial parts of euphorbia erythradenia bioss. (euphorbiaceae), one of iranian endemic euphorbias, with particular attention to triterpene constituents, using methanol solvent extraction was carried out. five known triterpenes, including four cycloartanes and oleanolic acid, were isolated for the first time and identified using nmr and mass techniques. anti hiv...

serum albumin is the most abundant protein in blood plasma. its two major roles are maintaining osmoticpressure and depositing and transporting compounds. in this paper albumin-ethanol/water solutionssimulations are carried out by three techniques including monte carlo (mc), molecular dynamic (md) andlangevin dynamic (ld) simulations in aqueous solutions. investigation the energy changes with t...

background: melon (cucumis melo) allergy is one of the most common food allergies, characterized by oral allergy syndrome. to date, two allergen molecules, cuc m 1 and cuc m 2, have been fully characterized in melon pulp, but there are few reports about the molecular characteristics of cuc m 3. methods:the cuc m 3 cdna has been characterized by rapid amplification of cdna ends (race), which rev...