11,824 research outputs found
Expression of human soluble tumor necrosis factor (TNF)-related apoptosis-inducing ligand in transplastomic tobacco
The soluble extracellular domain of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (sTRAIL) can, as the whole length TRAIL protein, bind with its receptors and specifically induce the apoptosis of cancer cells; therefore, it has been developed as a potential therapeutic agent for various cancer treatments. As it has become an attractive technology for foreign protein production, especially for production of biopharmaceuticals, chloroplast engineering was applied in this study to express human sTRAIL protein in tobacco. Two transplastomic lines were obtained. Southern blot showed that sTRAIL gene was inserted into the right site of the tobacco chloroplast genome. RT-PCR results also confirmed that the foreign gene is transcribed in both lines. However, western blot showed that only one line accumulated sTRAIL protein stably, while the other line lost the ability to accumulate this protein after several rounds of subcultures. The possible reason for this unexpected phenomenon is discussed.Key words: Chloroplast transformation, sTRAIL, pharmaceutical protein, expression, tobacco chloroplast
Inelastic X-Ray Scattering Study of Exciton Properties in an Organic Molecular crystal
Excitons in a complex organic molecular crystal were studied by inelastic
x-ray scattering (IXS) for the first time. The dynamic dielectric response
function is measured over a large momentum transfer region, from which an
exciton dispersion of 130 meV is observed. Semiempirical quantum chemical
calculations reproduce well the momentum dependence of the measured dynamic
dielectric responses, and thus unambiguously indicate that the lowest Frenkel
exciton is confined within a fraction of the complex molecule. Our results
demonstrate that IXS is a powerful tool for studying excitons in complex
organic molecular systems. Besides the energy position, the IXS spectra provide
a stringent test on the validity of the theoretically calculated exciton wave
functions.Comment: 4 pages, 4 figure
Lyapunov exponents for products of complex Gaussian random matrices
The exact value of the Lyapunov exponents for the random matrix product with each , where
is a fixed positive definite matrix and a complex Gaussian matrix with entries standard complex normals, are
calculated. Also obtained is an exact expression for the sum of the Lyapunov
exponents in both the complex and real cases, and the Lyapunov exponents for
diffusing complex matrices.Comment: 15 page
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