Comparative DSC study of human and bovine serum albumin

The thermal denaturation process of bovine and human both fatty acid containing and fatty acid free albumins in aqueous solution was studied by use of differential scanning calorimetry. Human serum albumins were found to be more stable than their bovine counterparts. Fatty acid free albumins were characterized as generally less stable, more susceptible to aggregation, their unfolding endothermic transition was less cooperative and with the smaller degree of reversibility. Deconvolution analysis with using a non-two-state model with two component transitions showed essential differences in the thermodynamic parameters between all studied albumins, particularly regarding the high-temperature component transition.     

Weighted Influence Non-linear Gauge System (WINGS) – An analysis method for the systems of interrelated components

The WINGS method has been derived from DEMATEL and can be widely used as a structural model for analysis of intertwined factors and causal relations between them. Its novelty comes from an idea of including in one mathematical mechanism both strength (importance) and influence of the system components. In particular, WINGS can be applied as the MCDA method for evaluating alternatives when interrelations between criteria cannot be neglected. For the problem with independent criteria, WINGS reproduces the additive aggregation of preferences, a classical method in MCDA.     

Blood serum DSC analysis of well-trained men response to CrossFit training and green tea extract supplementation

Differential scanning calorimetry (DSC) has been used for the detection of post-exercise changes in blood serum resulting from participation in the CrossFit (CF) training combined with green tea extract (GTE) supplementation. Blood samples from 20 well-trained men were collected at rest, immediately post-exercise and after 1 h of recovery in two trials: first before and second after CF training combined with GTE or placebo administration in the supplemented (S) and control (C) groups, respectively. Selected muscle damage biomarkers have been compared in different phases of the experiment. A significant increase in blood lactate content has been observed post-exercise in both trials in both participants’ groups. The opposite trends have been noted for the C and S groups in creatine kinase (CK) activity changes recorded during the first to the second trial: an increase in CK for the control and a decrease for the supplemented group in all phases of the experiment: pre-exercise, post-exercise and after recovery. In the second trial, all CK values for the S group have been found significantly lower than the corresponding values recorded in the C group. These results suggest a mitigate effect of GTE supplementation on post-training muscle damage. DSC results did not reveal clear effects of training nor GTE supplementation on serum denaturation transition. However, interesting dependences of thermodynamic parameters describing this transition have been observed in different phases of the experiment. Statistically significant negative correlations have been found between post-training VO_2max and post-exercise thermodynamic parameters associated with haptoglobin contribution to serum denaturation transition.     

Comparison of human blood serum DSC profiles in aqueous and PBS buffer solutions

Journal of Thermal Analysis and Calorimetry - The results of studies of physiological fluids by differential scanning calorimetry (DSC) for the purpose of diagnosis and monitoring of diseases are...     

Effect of UVC radiation on conformational restructuring of human serum albumin

The study of the influence of UVC-254 nm radiation on spectroscopic and calorimetric properties of human serum albumin in aqueous solutions was conducted. This radiation did not only accelerate aging of albumin solutions but also caused the other qualitative changes. The dose dependent effect on conformational restructuring and thermal stability of albumin for exposure periods from 10 to 60 min was shown. The differences in response to UVC-irradiation between non-defatted and fatty acid-free albumins were found.     

The influence of radio-frequency radiation on thermal stability of bovine serum albumin in aqueous solution

Protein unfolding events were studied by differential scanning calorimetry (DSC) for bovine serum albumin (BSA) aqueous solutions exposed to radio-frequency radiation. No immediate effect of this radiation on thermal unfolding of BSA was observed. The differences between irradiated and control samples have appeared during the storage of BSA solution. The irradiated samples changed faster than non-irradiated. Our results indicated that the age-related changes were stronger for 3.5 and 5 MHz than for 247 MHz frequency and dependent on energy power of radiation. Deconvolution of DSC traces allowed to study the effect of radio-frequency radiation on each component transition. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of ethanol on the thermal stability of human serum albumin

The effect of ethanol on human serum albumin stability in aqueous solution was studied by use of differential scanning calorimetry. A deconvolution of DSC traces in 2-state model with ΔC _p=0 and ΔC _p≠0 was performed and analysed to obtain information on the interaction of ethanol with different parts of albumin molecule both fatty acid containing and fatty acid free. The differences in ethanol binding affinity for both kinds of albumin were found. At very low concentrations ethanol was observed to be a stabilizer of the folded state of albumin contrary to the higher concentration where its binding to the unfolded protein predominates.     

DSC study of the association of ethanol with human serum albumin

Human serum albumin unfolding in ethanol/water mixtures was studied by use of differential scanning calorimetry. Ethanol-induced changes in DSC curves of defatted and non-defatted albumin were markedly different. In the presence of ethanol, bimodal denaturation transition for fatty acid free albumin was observed while that for albumin containing endogenous fatty acids was single and more sharpen than in aqueous solution. Ethanol was found to decrease the thermal stability of albumin due to the binding to the unfolded state to a higher degree than to the native state, thus favouring unfolding. The binding with different affinities has been suggested depending on ethanol concentration range.     

The assessment of the information quality with the aid of multiple criteria analysis

The virtual business work flow depends on the information quality (IQ) which is essential attribute of information. The IQ depends strongly on organization of the information system (IS) and how the information is processed. In our approach we incorporate the four-aspect representation of IQ: (1) intrinsic, (2) contextual, (3) representational, and (4) accessibility. These four-aspects are divided into several criteria at the next level of hierarchy. The weights, representing the relative importance of criteria, have been assessed by pair-wise comparisons made by group of experts. Based on discussion with experts, six alternative strategies, that could be used for improving the IQ, were designed. For each given criterion, the group of subjects revealed the opinion about the level of achievement of every alternative. The set of scores, assigned to the alternative by different subjects, formed the discrete distribution that is used for a comparison of alternatives with the aid of stochastic dominances. In analogy to the Electre I methodology, the simple algorithm for the aggregate evaluation of analyzed alternatives was proposed. The benefits of proposed approach were demonstrated in a case study of the semiconductor industry. The results of our study suggest, that in case of matured company, the external strategies, that point out to the information exchange and strategic networked alliance with customers and suppliers, are preferred to the internal ones. The latter ones might be of greater importance for the new set up or for a young company.     

Differential scanning calorimetry study of blood serum in chronic obstructive pulmonary disease

Differential scanning calorimetry (DSC) has been applied for studies of blood serum from patients sick with chronic obstructive pulmonary disease (COPD). The denaturation of serum proceeds as endothermic process over the temperature range 45–85 °C. Distinct changes in the shape of DSC curves have been observed for serum from patients with severe stage of COPD (treated with inhaled corticosteroids) relative to serum from healthy individuals. The first moment of the thermal transition with respect to the temperature axis shifts from the normal value of 63.9 ± 0.3 to 65.3 ± 0.7 °C and to 67.6 ± 1.6 °C for early and advanced stages of disease, respectively. The results of our studies suggest age dependence of blood serum denaturation transition.