The described TROSY-based experiments for investigating backbone dynamics of proteins make it possible to elucidate internal motions in large proteins via measurements of T(1), T(2), and NOE of backbone (15)N nuclei. In our proposed sequences, the INEPT sequence is eliminated and the PEP sequence is replaced by the ST2-PT sequence from the HSQC-based experiments. This has the benefit of shortening the pulse sequences by 5.4 ms (=1/2J) and results in an increase in the intrinsic sensitivity of the proposed TROSY-based experiments. The TROSY-based experiments are on average of 13% more sensitive than the corresponding HSQC-based experiments on a uniformly (15)N-labeled Xenopus laevis calcium-bound calmodulin sample on a 750-MHz spectrometer at 5 degrees C. The amide proton linewidths of the TROSY-based experiments are 2-13 Hz narrower than those of the HSQC experiments. More sensitivity gain and higher resolution are expected if the protein sample is deuterated. 相似文献
Three different approaches, including (1) manipulating the site chemistry, (2) controlling the spacing between neighbouring sites and (3) altering the adsorbates by the use of chelates, were successfully used to prepare MCM-41 adsorbents with excellent selectivity for silver adsorption from solutions containing copper. 相似文献
Let T and be arbitrary nonnegative, irreducible, stochastic matrices corresponding to two ergodic Markov chains on n states. A function κ is called a condition number for Markov chains with respect to the (α, β)–norm pair if . Here π and are the stationary distribution vectors of the two chains, respectively. Various condition numbers, particularly with respect
to the (1, ∞) and (∞, ∞)-norm pairs have been suggested in the literature. They were ranked according to their size by Cho
and Meyer in a paper from 2001. In this paper we first of all show that what we call the generalized ergodicity coefficient
, where e is the n-vector of all 1’s and A# is the group generalized inverse of A = I − T, is the smallest condition number of Markov chains with respect to the (p, ∞)-norm pair. We use this result to identify the smallest condition number of Markov chains among the (∞, ∞) and (1, ∞)-norm
pairs. These are, respectively, κ3 and κ6 in the Cho–Meyer list of 8 condition numbers. Kirkland has studied κ3(T). He has shown that and he has characterized transition matrices for which equality holds. We prove here again that 2κ3(T) ≤ κ(6) which appears in the Cho–Meyer paper and we characterize the transition matrices T for which . There is actually only one such matrix: T = (Jn − I)/(n − 1), where Jn is the n × n matrix of all 1’s.
This research was supported in part by NSERC under Grant OGP0138251 and NSA Grant No. 06G–232. 相似文献
Although extensive previous studies have shown that strained [1]ferrocenophanes predominantly undergo ring-opening chemistry at the bridging atom E-cyclopentadienyl (E-Cp) bond, recent reports have highlighted that reactivity at the Fe-Cp bond can also occur, especially on photoactivation. We provide an overview of recent results from our group and those of other researchers. In addition, the development of photocontrolled living polymerizations of sila[1]ferrocenophanes using Fe-Cp bond cleavage chemistry is described. 相似文献
Bifurcations and route to chaos of the Mathieu–Duffing oscillator are investigated by the incremental harmonic balance (IHB)
procedure. A new scheme for selecting the initial value conditions is presented for predicting the higher order periodic solutions.
A series of period-doubling bifurcation points and the threshold value of the control parameter at the onset of chaos can
be calculated by the present procedure. A sequence of period-doubling bifurcation points of the oscillator are identified
and found to obey the universal scale law approximately. The bifurcation diagram and phase portraits obtained by the IHB method
are presented to confirm the period-doubling route-to-chaos qualitatively. It can also be noted that the phase portraits and
bifurcation points agree well with those obtained by numerical time-integration. 相似文献
Summary: A novel experimental set‐up has been devised to measure simultaneously, in real time, the conversion and shrinkage of multi‐acrylates during photopolymerization. The data show that the current practice of assigning the excess volume entirely as excess free volume is inappropriate as this leads to an increasing fractional free volume with conversion. We propose to partition the excess volume into free and occupied volume components. The new model produces satisfactory results.
Experimental set‐up for the simultaneous collection of shrinkage and conversion data. 相似文献
A hyperbolic Lindstedt-Poincare method is presented to determine the homoclinic solutions of a kind of nonlinear oscillators, in which critical value of the homoclinic bifurcation parameter can be determined. The generalized Lienard oscillator is studied in detail, and the present method's predictions are compared with those of Runge-Kutta method to illustrate its accuracy. 相似文献
Journal of Radioanalytical and Nuclear Chemistry - [177Lu]Lu-DOTA-PSMA-617 for PRRT is subject to radiolysis and therefore loses receptor affinity. This will be detrimental for treatment efficacy.... 相似文献