thermal stability of the nanostructured powder mixtures prepared by mechanical alloying

... energy of the balls) and the properties of the powders The temperature of the powder can affect the diffusivity and defect concentration in the powder and thus the phase transformation during the ... increase the kinetic energy of the balls and therefore the impact force of the ball Both the frictional and the kinetic energy can be controlled by the magnet at position M3 By relocating the magnet ... between the powders and the balls, the impellers and the container wall [36, 37] Because of the high rotation speed of the central shaft, the capacity of the attritor is somewhat limited The relatively...

Ngày tải lên: 17/09/2015, 17:19

... decrease in the thermal stability observed by DSC on actin species cleaved within the D-loop is associated with opening of the cleft Does the thermal stability of G-actin reflect the conformational ... Thus, the increased thermal stability of G-actin appears to correspond to the closed conformation of the nucleotide-binding cleft, whereas the decreased thermal stability is a feature of the actin ... transitions of the nucleotide-binding cleft For this purpose, we studied the effects of the D-loop cleavage on the thermal unfolding of G- and F-actin Previously, the thermal unfolding of G-actin...

Ngày tải lên: 06/03/2014, 22:21

... compare the thermal stability of AOPTP with that of other peroxidases In our previous publication [8] we reported the results of a detailed investigation of the thermal denaturation of horseradish ... reversibility of the thermal transitions was checked by examining the reproducibility of the calorimetric trace in a second heating of the sample immediately after cooling from the rst scan The experimental ... Kinetics of AOPTP thermal inactivation are, respectively, the experimental and where yi and calculated values of C ex ; y m is the mean of the experimental p i values of C ex , and n is the number of...

Ngày tải lên: 31/03/2014, 15:20

... black-box methods, the thermal conductance of the wall With this particular type of construction of the monitored walls, it is not possible to use other methods of determination of thermal conductance ... and the knowledge of the temperature coefficient of the material of which it is made A single measure allows for the determination of diffusivity, thermal conductivity, and specific heat of the ... if the present structures are characterized with local materials, namely, “Tufo of Matera” for the structures of the "Sassi of Matera," and “Stone of Fasano” for the structures of the "Trulli of...

Ngày tải lên: 05/09/2013, 14:58

... table The calculating results based on the elastic theory are presented in table Figure is graph of the elasto-plastic instability case The comparison between the elasto-plastic instability and the ... value, the difference between the critical loads found by basing on two theories is very little Therefore for the slender cylindrical shells, calculating based on the elastic theory is reliable c) The ... remarks as follows a) The critical loads determined according to the elastic theory are much greater than those according to the theory of elasto-plastic processes when the thickness of cylindrical...

Ngày tải lên: 13/02/2014, 04:20

... binding of the polyadenylated rpsO RNA We have shown that the presence of the remainder of the acidic tail results in the thermodynamic stabilization of Hfq by 1.8 kcalÆmol)1 A comparison of the ... than the full-length protein Based on the analysis of the transition region, the conformational stability of the proteins can be calculated [29]: the free energy when Ó FEBS 2004 The role of the ... °C The spectra are the average of 125 scans Spectra were corrected for the linear dependence of the absorption measured by ATR on the wavelength The water signal was removed by subtraction of...

Ngày tải lên: 19/02/2014, 12:20

... [8,37] Thermally induced denaturation curves monitored by farUV CD The thermal denaturation curves obtained in the presence of urea can be obtained by using Eqn (1) and the expression of the DGÂ ... from the tting of the CD thermal denaturation data to Eqn (1) Fitting of the thermal and urea-denaturation data (using the approach of Pace and Laurents [39]) yielded similar values, within the ... Application of the LEM to the thermodynamic data of scHPr accounts well for the measurement of scHPr stability, as shown by the agreement between the chemical- (where LEM was used to analyse the data)...

Ngày tải lên: 19/02/2014, 12:20

... of wild-type ALP I On the other hand, the Tm of D266N/Y269A-ALP I increased by only °C The denaturation temperature indicates the stability of the structure of the protein The difference of the ... residues of the depression, and the side chain of the mutated residue might restrain the mobility of the N-terminal region on the surface by interaction with the main chain of Lys26 by van der ... enzyme, the side chain of Asp266 interacted with the amino group of the main chain at Glu268 The oxygen of the main chain at Asp266 was bound to amino groups of main chain of Tyr269 and Ala270 by...

Ngày tải lên: 21/02/2014, 03:20

... study, the current authors have shown that the mutation of Thr15 to Ala in the vicinity of the hydrophobic core induces a tighter binding of the cofactor in C freundii TPL, thereby reducing the ... (pH 8.0), the thermal stability of both mutants was confirmed to be up to 10 °C higher than that of the wild-type (Fig 2B) When the pH properties of the purified enzymes were investigated, the AS4 ... higher for the stability mutants than for the wildtype enzyme Meanwhile, the activities of A1 and A2 were two-fold greater than that of the wild-type enzyme, whereas the activity of the stability...

Ngày tải lên: 07/03/2014, 00:20

... This paper is based on the talk given at the Conference on Mathematics, Mechanics, and Informatics, Hanoi, 7/10/2006, on the occasion of 50th Anniversary of Department of Mathematics, Mechanics ... Tran Kim Thanh, On the characterization of the distribution of the composed random variables and their stabilities Dotor thesis, Hanoi 2000 [2] Tran Kim Thanh, Nguyen Huu Bao, On the geometric composed ... composed variables and the estimate of the stable degree of the Renyi’s characteristic theorem, Acta Mathemaica Vietnamica 21 (1996) 269 [3] C G Essen, Fourier analysis of distribution functions,...

Ngày tải lên: 14/03/2014, 13:20

... between the two proteins (as indicated by the values of DGwater, Cm and Tg) hence arise from the changes in the surface of the protein because of the interactions of the cofactor with the protein ... conformational stability of holo-ACP and apoACP was determined by chaotrope-dependent unfolding at different temperatures The reversibility of the isothermal denaturation of ACP was shown by the return of ... bonds The 4Â-PP group is linked to the protein by the Ser37 O-c atom Only residues 3138 of the protein make extensive contacts with the cofactor For the sake of better understanding of the interactions,...

Ngày tải lên: 16/03/2014, 10:20

... not the clarification of the overall mechanism of thermal unfolding We have restricted ourselves to the question of whether unfolding of the two domains is (even slightly) separated Therefore, thermal ... Simultaneous protection by the two substrates against thermal unfolding The thermal stability of PGK was further increased in the ternary complexes, i.e in the simultaneous presence of two substrates ... favour of a highly co-operative thermal unfolding of the two domains in case of both enzyme forms, although the stabilities of the whole molecules differ from each other and from that of the wild-type...

Ngày tải lên: 16/03/2014, 18:20

... cannot form tetramers in vivo Nevertheless, whether the lack of expression of the tetramer is caused by the absence of the tetramerization domain or by misfolding of the monomers before tetramer assembly ... thermostabilities of the wild-type and mutant KcsA constructs were compared at basic and acidic pHs because the stability of KcsA depends on the pH of the solution: the tetrameric form of the wild-type ... control of the excitability of membrane, release of neurotransmitter, regulation of osmotic pressure and regulation of the size of cell) A structural and functional understanding of these channels...

Ngày tải lên: 23/03/2014, 06:20

... responsible for the higher stability of the wild-type protein compared to the mutant Thus, the value of 1.8 kJÆmol)1 could be taken as being the maximum cost of the disruption of the K13-E34 salt ... Nevertheless, there is no commonly held view in the literature on the energetic advantages of solvent-exposed salt bridges as the disruption of a salt bridge by the substitution of one of the ... spectroscopy The combination of these two techniques allowed us to determine the thermodynamic parameters of the native, dimeric structure and its thermal unfolding, and to describe some of the experimental...

Ngày tải lên: 23/03/2014, 12:20

... Reversibility of the HK022 Xis_wt thermal denaturation The first scan is shown by a dashed line, the second scan by a solid line (B) pH dependence of HK022 Xis_wt thermal denaturation The partial ... Data for the Xis_wt thermal denaturation in the presence of 400 mM NaCl b Data for the Xis_C28S thermal denaturation 4850 V V Rogov et al (Eur J Biochem 270) Fig DSC data of HK022 Xis_wt thermal ... also supported by NMR data (not shown) The influence of pH on the Xis_wt thermal denaturaion is illustrated in Fig 1B A visible increase of the protein stability was observed when the pH was raised...

Ngày tải lên: 23/03/2014, 15:21

... the absence (s) or in the presence of 0.5 (n) or (h) mM Zn2+ The continuous lines correspond to the fit of the experimental data to a sigmoidal function Table Thermodynamic parameters of the thermal ... ellipticity below 250 nm These changes reflect the loss of tertiary structure of the protein Monitoring of the decrease with temperature of the ellipticity at 268 nm facilitated tracing of the denaturalization ... ± 0.3 °C), thus serving as a useful gauge of the heterodimer thermostability DSC data confirmed that, in the presence of ZnCl2, the thermal stability of PSP-I ⁄ PSP-II was substantially FEBS Journal...

Ngày tải lên: 23/03/2014, 15:21

... that the mutant enzyme exhibits unusual electrostatic potential The basis of thermal stability of the Asp133Val mutant The thermal stability of the purified Asp133Val mutant enzyme was assessed by ... 50% of the initial enzyme activity is lost after heat treatment The kinetics of thermal inactivation of the wild-type and Asp133Val was monitored at 50 °C The kinetics of thermal inactivation of ... characterization of a thermostable mutant One of the most important goals of protein engineering is to produce modified enzymes with improved thermostability However, the thermal stability of a protein...

Ngày tải lên: 30/03/2014, 02:20

... without changing the shape of the denaturation curve Complementary to the CD experiments, the thermal denaturation of S100A2-DCys was followed by FT-IR The absorbance change at the amide I (1600– ... thermodynamic stability of the Ca2+- and Zn2+-loaded mutants can be retrieved from the analysis of metallation effects within the background of the same mutation (Table 2) With the exception of Zn2+-loaded ... aggregation The formation of insoluble b-sheet-containing aggregates is most certainly an important contributor to the irreversibility of the thermal denaturation The denaturation curves of the above-mentioned...

Ngày tải lên: 30/03/2014, 02:20

... that the stability of the cluster is essential for the correct quaternary assembly of the enzyme and is increased by the binding of PLP and substrates Indeed, the two helices that form the cluster ... cofactor binding, substrate binding and catalysis (Fig 1) On the other hand, the mutations did not affect either the capability to bind the cofactor or the catalytic activity of the enzyme The ... together, these observations suggest that, in the mutant enzymes, the urea-induced dissociation of PLP is favoured by the disruption of the third cluster of CHCs The mutations introduced with the...

Ngày tải lên: 30/03/2014, 02:20

... considered the role of the degree of glycosylation and the secondary structure variability on the observed differences in stability Results The thermal stability of the FUs was monitored by FTIR ... that the glycan chains are involved in the antigenicity of R thomasiana hemocyanin [15] In the present study, we investigated the thermal stability of the homologous FUs of b-hemocyanin of H ... series of homologous proteins rather than a single protein with or without glycans To examine the effect of glycosylation on the thermal stability of homologous FUs, we plotted the Tm values of the...

Ngày tải lên: 30/03/2014, 04:20