新开花粉蛋白的盐酸胍去折叠过程

本文利用荧光光谱和园二色光谱了新开花粉蛋白的盐酸胍去折叠过程。结果显示：新开花粉蛋白的盐酸胍去折叠是一个只包含天然蛋白和变性终态的二态过程,与已经报道的天花粉蛋白的盐酸胍去折叠的过程不同。     

Review of nanofluids for heat transfer applications

Research on nanofluids has progressed rapidly since its enhanced thermal conductivity was first repotted about a decade ago,though much controversy and inconsistency have been reported,and insufficient understanding of the formulation and mechanism of nanofluids further limits their applications.This work presents a critical review of research on heat transfer applications of nanofluids with the aim of identifying the limiting factors so as to push forward their further development.     

Monte-Carlo models of amorphous materials

A Monte-Carlo technique is described for the determination of atomic and molecular arrangements in simple amorphous solids. This method appears to be capable of describing configurations of atoms in glasses with sufficient detail to reproduce an experimental radial distribution function. The radial distribution function is combined with data on chemical bonding and with data on other physical properties to generate a model of the atomic arrangements which provides a view of the local order in an amorphous material. The entire procedure involves two steps. In the first, a quasi-random arrangement of atoms is constructed by a stochastic Monte-Carlo procedure. In the second stage the atomic arrangement is subjected to an extended Monte-Carlo perturbation, whereby the final configuration is described by the experimental radial distribution function.     

CD40mAb adjuvant induces a rapid antibody response that may be beneficial in post-exposure prophylaxis

Active vaccination can be effective as a post-exposure prophylaxis, but the rapidity of the immune response induced, relative to the incubation time of the pathogen, is critical. We show here that CD40mAb conjugated to antigen induces a more rapid specific antibody response than currently used immunological adjuvants, alum and monophosphoryl lipid A™.     

On the structure of glassy polymers. III. Small-angle x-ray scattering from amorphous polyethylene terephthalate

The small-angle x-ray scattering (SAXS) from glassy polyethylene terephthalate has been measured using a Bonse–Hart system. The data cover the angular range (2θ) between 20 sec and 2 deg. After correcting for absorption, background, and beam divergence, the data have been placed on an absolute basis by comparison with the scattering from a standard silica suspension. The corrected absolute intensity decreases strongly with increasing angle over the range between 20 sec and 15 min, decreases more gradually in the range between 15 min and 45 min, and reaches a nearly constant asymptotic value over the range between 45 min and 2 deg. The magnitude of the scattering in the constant range, about 0.4 (electrons)² Å^?3, is very close to the value predicted by the thermodynamic fluctuation theory for fluids applied at the glass-transition temperature [0.34 (electrons)² Å^?3]. The increase in intensity at angles smaller than about 45 min cannot be described by structures on the scale and volume fraction of the nodules reported in amorphous PET (50–100 Å), but can be well represented by small concentrations of heterogeneities, ranging in size from 100 to 2000 Angstroms, superimposed on the thermal density fluctuations frozen-in at the glass transition. The bulk structure of this material seems well described as a random amorphous solid, containing simple thermal fluctuations and a small concentration (<1 vol-%) of heterogeneities covering a range of sizes. The heterogeneities in the small end of the range may well be crystallites which formed on cooling.     

On the structure of glassy polymers. II. Small-angle x-ray scattering from poly(methyl methacrylate)

The small-angle x-ray scattering (SAXS) from glassy poly(methyl methacrylate) has been measured using a Bonse–Hart system. The data cover the angular range (2θ) between 20 sec and 2 deg. After correcting for absorption, background, and beam divergence, the data have been placed on an absolute basis by comparison with the scattering from a standard silica suspension. The corrected absolute intensity decreases strongly with increasing angle over the range between 20 sec and 30 min, and is nearly constant between 30 min and 2 deg. The magnitude of the scattering in the constant range, 0.6 (electrons)² Å^?3, is within a factor of 1.5 of the value predicted by the thermodynamic fluctuation theory for fluids applied at the glass transition temperature. The increase in intensity at smaller angles cannot be described by structures on the scale of the nodules reported in highly isotactic PMMA (150–200 Å), but can be well represented by small concentrations of heterogeneities, several thousand angstrom units in size, superimposed on the thermal density fluctuations frozen-in at the glass transition. The bulk structure of this material is well described as a random amorphous solid, containing simple thermal fluctuations and a small concentration of relatively large heterogeneities.     

All-normal-dispersion femtosecond fiber laser with pulse energy above 20 nJ

We report a study of the scaling and limits to pulse energy in an all-normal-dispersion femtosecond fiber laser. Theoretical calculations show that operation at large normal cavity dispersion is possible in the presence of large nonlinear phase shifts, owing to strong pulse shaping by spectral filtering of the chirped pulse in the laser. Stable pulses are possible with energies of tens of nanojoules. Experimental results from Yb-doped fiber lasers agree with the trends of numerical simulations. Stable and self-starting pulses are generated with energies above 20 nJ, and these can be dechirped to <200 fs duration. Femtosecond pulses with peak powers near 100 kW are thus available from this simple and practical design.