Fibrils, mixed

Figure 2.79. Hollow graphite fibrils (left) and fibrils mixed with carbon black (right). Courtesy of Hyperion Catalysis International, Cambridge, MA, USA.

Figure 9 Covariance-processed correlation spectra obtained in C-labeled samples of Ap42 fibril mixed with curcumin. Reprinted with permission from Ref. [76], Copyright 2011 Elsevier.

Figure 10 Mixing-time dependence of covariance spectra in C-labeled samples of Ap42 fibril mixed with curcumin. (A) and (B) were obtained with a mixing time of 50 ms in Ap42 labeled at the 17-21 residues and at the N-terminus (see Fig. 8). (C) and (D) were obtained with a mixing time of 500 ms. Reprinted with permission from Ref. [76], Copyright 2011 Elsevier.

Since the processing conditions and mixing equipment have a crucial effect on the morphology of immiscible polymer blends [45], experiments were carried out in four different types of extruders to find optimal conditions for blend preparation and fibrillation. Nevertheless, the morphologies of PP-LCP blends produced by... 

Preparation of mixed peptide fibrils was similar for both of these labelled peptides 1% (by weight) was incubated at 37 °C with the other, unlabelled peptide in 10% CH3CN/H20atpH2.ForTTRio i9with l%dansyl-TTRio5 n5, a blue shift and dansyl anisotropy increase were observed, indicating the inclusion of dansyl-TTRios-i 15 into fibrils. CD spectroscopy proved that the stmcture was primarily p-sheet. 

Here, two different sequences from transth3Tetin were successfully combined into mixed fibrils [54], This is not always the case, however. For amyloidogenic proteins, the ability of other fibrils to act as cross-seeds for growth is known to depend on sequence similarity [55]. Seeding hen lysozyme solutions with seeds formed from closely related sequences (e.g. hen and other lysozymes) led to the largest increases in the rate of formation of fibrils. Consequently, there may be some restrictions on the selection of distinct peptide sequences to produce scaffolds. 

CD, TEM and a thioflavin binding assay (binding to fibrils results in a characteristic fluorescence emission) were used to confirm the existence of mixed fibrils (width roughly 20 nm, lengths ranging from hundreds of nanometres to several micrometres) prepared from the two peptides (pi6 and B2x-pl6) and consisting of p-sheets. 

Mixtures of three peptides were also screened for their ability to form fibrils containing all three. Rather than testing all possibilities, carefully selected mixtures were used. Peptides in the equimolar mixtures were charged, but the overall sum of the peptide charges was zero, to build in chain-chain electrostatic attractions. If individual peptides or a peptide pair in a mixture formed fibrils, the mixture was not studied. Application of these criteria led to six possible mixtures these were mixed at 4 pM each at pH 7.4 and left for several days at room temperature to self-assemble. 

The lack of lateral aggregation of Ap(io 35)-PEG fibrils is striking compared with the dense networks of fibrils seen in pure Apdo ss). A 1 1 ratio mixture produced fibrils that exhibited association somewhere between these two extremes (Fig. 22). The change in morphology implies that the two species are forming mixed fibrils. It is thought that the PEG block prevents fibrils from lateral aggregation because... 

To avoid the interference from intramolecular REDOR dephasing, peptides with 15NH, labels could be mixed with peptides with 13COy labels in a 1 1 ratio before fibrillization, where i and j denote the residues with isotopic enhancement at the amide and carbonyl sites, respectively. If an in-register parallel (3-sheet is considered as the hypothetical structure, the most adequate model for the analysis of the 13C 15N REDOR data measured for the case of i = j should be a 15N-13C-15N spin system, where the NCN angle is ca. 127° and the two 15N-13C distances are 5.3 and 5.5 A (Fig. 4a). For the case of i = j + 1, the NCN angle should be 154° and the two 15N-13C distances 4.2 and 5.6 A. Other combinations of i and j for an... 

Fig. 8 Pulse sequence for the measurement of homonuclear correlation spectra with 7 filtering. Narrows bars indicate 7t/2 pulses and broad bars indicate 71 pulses. Experimental conditions employed for a-synuclein fibrils samples static field strength 9.4 T temperature —5 °C spinning frequency 8 kHz T2 filter 100 ms CP contact time 2.5 ms TOBSY mixing time 6 ms. The rf phases can be found in the original figure and caption. (Figure and caption adapted from the Supporting Information of [134]. Copyright (2005) National Academy of Sciences, USA)...

There is no glycemic response to glucagon or epinephrine (Fig. 42-1), whereas a galactose load causes a normal glycemic response. Forearm ischemic exercise produces a blunted venous lactate rise or no response. Serum CK activity is variably, often markedly, increased. The ECG shows left ventricular or biventricular hypertrophy in most patients, and the EMG may show myopathic features alone or associated with fibrillations, positive sharp waves and myotonic discharges. This mixed EMG pattern in patients with weakness and distal wasting often reinforces... 

Fig. 1. Cross-/] structure of amyloid fibrils. (A) Cartoon representation of a cross-/] X-ray diffraction pattern. The defining features are a meridional reflection at 4.7 A and an equatorial reflection on the order of 10 A. The 4.7-A reflection is generally much brighter and sharper than the reflection at 10 A. (B) The cross-/] core structure of amyloid fibrils. Parallel /(-sheets are depicted, but the structure could equivalendy be composed of antiparallel /(-sheets or a mix of parallel and antiparallel. The 4.7-A spacing of /(-strands within each /(-sheet is parallel to the long fibril axis. The depicted 10-A sheet-to-sheet spacing actually ranges from about 5 to 14 A (Fandrich and Dobson, 2002), depending on the size and packing of amino acid side chains. Amyloid fibrils have diameters on the order of 100 A.

Pharmacokinetic/pharmacodynamic model using nonlinear, mixed-effects model in two compartment, best described time course of concentration strong correlation with creatinine clearance predicted concentration at the efi ect site and in reduction of heart rate during atrial fibrillation using population kinetic approach... 

Tn the last decades many attempts have been made to obtain attractive - materials by intimate mixing of two polymers with opposite or complementary properties. For example, the impact resistance of brittle polystyrene is increased by mixing with a rubber the wettability of polyacrylonitrile fiber is increased by mixing with hydrophilic saponified cellulose acetate, and the inconvenient flat-spotting of nylon-reinforced tires is suppressed by mixing stiffer polyester fibrils into the nylon fibers. In practically all cases these products acquire their final shape via the liquid state. Thus, the viscous properties of these liquid mixtures are important. 

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