Faculty Opinions recommendation of Kinetics of registry selection of chimeric peptides binding to MHC II.

Author(s):  
Peter Jensen
Biochemistry ◽  
2001 ◽  
Vol 40 (34) ◽  
pp. 10284-10292 ◽  
Author(s):  
Michael P. Belmares ◽  
Harden M. McConnell

2010 ◽  
Vol 72 ◽  
pp. 46-52 ◽  
Author(s):  
Laurent Royer ◽  
Stéphane Mathieu ◽  
Christophe Liebaut ◽  
Pierre Steinmetz

For energy production and also for the glass industry, finding new refractory alloys which could permit to increase the process temperatures to 1200°C or more is a permanent challenge. Chromium base alloys can be good candidates, considering the melting point of Cr itself, and also its low corrosion rate in molten glass. Two families of alloys have been studied for this purpose, Cr-Mo-W and Cr-Ta-X alloys (X= Mo, Si..). A finer selection of compositions has been done, to optimize their chemical and mechanical properties. Kinetics of HT oxidation by air, of corrosion by molten glass and also creep properties of several alloys have been measured up to 1250°C. The results obtained with the best alloys (Cr-Ta base) give positive indications as regards the possibility of their industrial use.


1996 ◽  
Vol 184 (2) ◽  
pp. 485-492 ◽  
Author(s):  
M A Alexander-Miller ◽  
G R Leggatt ◽  
A Sarin ◽  
J A Berzofsky

Experimental data suggest that negative selection of thymocytes can occur as a result of supraoptimal antigenic stimulation. It is unknown, however, whether such mechanisms are at work in mature CD8+ T lymphocytes. Here, we show that CD8+ effector cytotoxic T lymphocytes (CTL) are susceptible to proliferative inhibition by high dose peptide antigen, leading to apoptotic death mediated by TNF-alpha release. Such inhibition is not reflected in the cytolytic potential of the CTL, since concentrations of antigen that are inhibitory for proliferation promote efficient lysis of target cells. Thus, although CTL have committed to the apoptotic pathway, the kinetics of this process are such that CTL function can occur before death of the CTL. The concentration of antigen required for inhibition is a function of the CTL avidity, in that concentrations of antigen capable of completely inhibiting high avidity CTL maximally stimulate low avidity CTL. Importantly, the inhibition can be detected in both activated and resting CTL. Blocking studies demonstrate that the CD8 molecule contributes significantly to the inhibitory signal as the addition of anti-CD8 antibody restores the proliferative response. Thus, our data support the model that mature CD8+ CTL can accommodate an activation signal of restricted intensity, which, if surpassed, results in deletion of that cell.


2021 ◽  
Vol 80 (3) ◽  
pp. 118-122
Author(s):  
V.P. Dorozhkin ◽  
◽  
E.G. Mokhnatkina ◽  
D.N. Zemsky ◽  
A.D. Valiev ◽  
...  

A method is proposed that allows us to obtain the values of the rate constants (CR) of the processes of mechanodestruction (mechanical cracking) of kм, oxidative destruction of kо, and recombination of kр macromolecules, as well as the mass fractions of the corresponding fractions of φм, φо, and φр,r involved in the plasticization process (P) of SKI-3 isoprene rubber. The method is based on the selection of the values of these parameters that correspond to the previously obtained experimental data, using the previously obtained recurrent equations and a specially developed program. The dependences of the CR on the time P at 30oC are obtained, which allows us to describe the kinetics of the processes accompanying P at this temperature, and the changes in molecular mass (MM) in this process. It is shown that constant values of CR are established at large times of P. Refined explanations of the nature of the kinetics of the CR change at P are proposed. The MM value of SKI-3 macromolecules that have not undergone destruction is calculated, depending on the time of plasticization.


2002 ◽  
Vol 46 (4-5) ◽  
pp. 441-446 ◽  
Author(s):  
T. Sobisch ◽  
D. Lerche

This paper reports on lab-scale investigations in relation to pre-selection of flocculants for sludge dewatering with decanter centrifuges. Results obtained were compared with CST-measurements and discussed in relation to findings under field conditions. Experiments were carried out with sewage sludges of different origin and characteristics and a number of commercial flocculants. Kinetics of sedimentation and clarification were measured as well as the compression behaviour and shear sensitivity of sludge sediments. To measure flocculant performance stability against intensive shearing, total solids in the sludge cake obtained and dewaterability of the sludge cake during the first 20-50 s of centrifugation were compared. A screening test procedure was developed. Efficient flocculants should produce high residual total solids and good initial compressibility. Lab-scale investigations deliver more reliable results if the dynamic behaviour of the sludge under centrifugal acceleration is also investigated. The separation analyser LUMiFuge 114 can provide results about the compression behaviour of sludges in the range between 10 and 100 s. So far no other method or device is known which can deliver such results.


1997 ◽  
Vol 64 (1) ◽  
pp. 63-69 ◽  
Author(s):  
A. Amici ◽  
S. Bartocci ◽  
S. Terramoccia ◽  
F. Martillotti

AbstractFive mathematical models were compared to select the most satisfactory model to describe digesta kinetics of solids and fluids in the gastrointestinal tract of buffaloes (Mediterranean bulls), cattle (Friesian bulls) and sheep (Delle Langhe rams) given food at maintenance level, according to a Latin-square arrangement for four consecutive periods of 21 days. Chromium mordanted alfalfa hay and cobalt-ethylenediamine tetraacetic acid were used as nonabsorbable markers and were administered through the rumen cannula in a single dose. Four different isonitrogenous diets (N × 6·25 = 140 g/kg dry matter) with different concentrate:forage ratios (12·5:87·5, 25:75, 37·5:62·5, 50:50) were used.Faecal chromium and cobalt concentration curves were fitted with five non-linear models: three gamma (G2, G3, G4) age-dependent one-compartment, one gamma age-dependent/age-independent two-compartment (G2G1) and one multicompartment (MC).Wilcoxon tests on residual sums of squares of the different models for solids showed that MC and G4 gave a better fit than G2G1, G2, G3 for all the data and within the species. The comparison of MC v. G4 did not show any significant difference (P > 0·05) for all the data computed together or within each species. Nevertheless, MC had a higher number of curves with lower residual sums of squares in comparison with G4 and was also able to produce estimates of digesta kinetics in the second compartment.The cobalt excretion curves for fluids, considering all the data, and only within sheep, showed G4 as the best fitting model. When G4 was compared with other models no significant differences were recorded either for cattle: G4 v. G2 (F = 0·6645), G4 v. G2G1 (P = 0·0620) and for buffalo: G4 v. G2 (P = 0·1575), G4 v.G3(P = 0·0796) and G4 v. G2G1 (P = 0·1641).It is concluded that the multicompartment model (MC) and G4 model were the best fits for solids and for fluids respectively.


2013 ◽  
Vol 23 (07) ◽  
pp. 1177-1215 ◽  
Author(s):  
THIERRY GOUDON ◽  
FRÉDÉRIC LAGOUTIÈRE ◽  
LÉON MATAR TINE

We consider the Lifshitz–Slyozov system that describes the kinetics of precipitation from supersaturated solid solutions. We design specific Finite Volume schemes and we investigate numerically the behavior of the solutions, in particular the large time asymptotics. Our purpose is two-fold: first, we introduce an adapted scheme based on downwinding techniques in order to reduce the numerical diffusion; second, we discuss the influence of coagulation effects on the selection of the asymptotic profile.


Author(s):  
Е.Г. Раковская ◽  
О.А. Кудряшова

Исследование посвящено изучению возможности применения преобразователя ржавчины П-2 при подготовке поверхности стали к окрашиванию с целью замены экологически вредных механических способов очистки и улучшения его защитных свойств путем введения органических ингибиторов. При механической обработке металлов в больших количествах выделяются мелкодисперсные частички лака, мелкодисперсная металлическая пыль, оксиды металлов (Fe, Al), которые негативно действуют на человека. Для замены вредных для окружающей среды механических способов очистки металлической поверхности предлагается подготовка без удаления продуктов коррозии, которая заключается в нанесении на ржавую поверхность модификаторов или грунтов модификаторов ржавчины. Суть действия модификаторов ржавчины состоит в их способности стабилизировать состояние ржавчины и обезвреживать агрессивные примеси. Ингибиторы коррозии с каждым годом приобретают все большее значение в противокоррозионной защите металлических изделий. Успехи в области разработки научных основ действия ингибиторов и создания новых ингибиторов различного назначения позволили предложить метод противокоррозионной защиты, который основан на введении ингибиторов в лакокрасочные покрытия. Преобразователи ржавчины преобразуют продукты коррозии в нерастворимые соединения, образующие защитные слои, на которые затем наносятся лакокрасочные материалы. Для исследования кинетики электрохимических реакций использовался метод снятия поляризационных кривых с помощью потенциостата П-5828 М. Испытания проводились на стали 3 и стали У8А. Кинетика процессов, протекающих при пассивации, изучалась методом снятия анодных потенциостатических кривых, также определялись сопротивление защитных пленок, выход по току и скорость коррозии. Исследование влияния N- и S-содержащих органических соединений на параметры пассивации стальных образцов в среде преобразователя ржавчины П-2 показало, что данные добавки способствуют переходу стали в пассивное состояние, уменьшают ток пассивации, способствуют увеличению сопротивления пассивных пленок. Следствием такого влияния органических добавок на параметры пассивации является уменьшение выхода металла по току, а следовательно, и уменьшение скорости коррозии. Результаты исследования могут быть использованы при подборе ингибиторов, вводимых в преобразователь ржавчины П-2, для более эффективной защиты металла от коррозии и безопасности здоровья человека. The real work is devoted to studying of a possibility of use of the P-2 rust solvent for preparation of a surface of steel for coloring for the purpose of replacement of ecologically harmful mechanical ways of cleaning and improvement of its protective properties by introduction of organic inhibitors. When machining metals in large numbers fine parts of a varnish, fine metal dust, oxides of metals (Fe, Al) which negatively affect the person are allocated. For replacement of mechanical ways of cleaning of a metal surface, harmful to the environment, preparation without removal of products of corrosion which consists in drawing on the rusty surface of modifiers or soil of modifiers of a rust is offered. The essence of operation of modifiers of a rust consists in ability to stabilize their condition of a rust and to neutralize aggressive impurity. Corrosion inhibitors gain the increasing value in anticorrosive protection of metal products every year. Achievements in the field of development of scientific bases of effect of inhibitors and creation of new inhibitors of different function have allowed to offer a method of anticorrosive protection which is based on introduction of inhibitors to paint and varnish coverings. Rust solvents will transform corrosion products to the insoluble connections forming protective layers on which then paints and varnishes are applied. For a research of kinetics of electrochemical reactions the method of removal of polarizing curves by means of a potentsiostat of P-5828 of M was used. Tests were carried out on steel 3 and U8A steel. The kinetics of the processes proceeding at passivation was studied by method of removal the anodic potentiostatic curves, resistance of protective films, an exit was also determined by current and corrosion speed. The research of influence of N-and S-of the containing organic compounds on parameters of passivation of steel samples in the environment of the P-2 rust solvent has shown that these additives promote transition of steel to a passive state, reduce passivation current, promote increase in resistance of passive films. Reduction of an exit of metal on current and consequently, and reduction of speed of corrosion is a consequence of such influence of organic additives on parameters of passivation. Results of work can be used at selection of the inhibitors entered into the P-2 rust solvent for more effective protection of metal against corrosion and safety of health of the person.


Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 163
Author(s):  
Mitko Petrov

Ten unstructured models of Monod, Mink, Tessier, Moser, Aiba, Andrews, Haldane, Luong, Edward, and Han-Levenspiel are considered in this paper to explain the kinetics of cell growth for batch cultivation of the yeast Kluyweromyces marxianus var. lactis MC 5. For the first time, two independent kinetic models are used to model the process for the two basic substrates—lactose and oxygen. The selection of the most appropriate growth rate models has been made through a new multi-criteria decision-making approach called the Inter-Criteria Decision Analysis (ICDA) method. The application of ICDA to the growth rate of lactose and oxygen alone has shown that there have been many correlations between the studied models. Thus, the models for the growth rate, depending only on lactose, are reduced to one—Monod model and there are two models—Monod and Mink—depending on oxygen only. Separate kinetic process models have been developed for the combination of Monod–Monod and Monod–Mink models. For the first time, in addition to the multiplicative form, the additive form of a specific growth rate has been studied. The comparison of the obtained results has shown that the additive form has shown better results than the multiplicative one. For this reason, the additive form of the Monod–Monod model will be used to model the process.


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