Protein-Protein Affinity Determination by Quantitative FRET Quenching.

The molecular dissociation constant, Kd, is a well-established parameter to quantitate the affinity of protein-protein or other molecular interactions. Recently, we reported the theoretical basis and experimental procedure for Kd determination using a quantitative FRET method. Here we report a new development of Kd determination by measuring the reduction in donor fluorescence due to acceptor quenching in FRET. A new method of Kd determination was developed from the quantitative measurement of donor fluorescence quenching. The estimated Kd values of SUMO1-Ubc9 interaction based on this method are in good agreement with those determined by other technologies, including FRET acceptor emission. Thus, the acceptor-quenched approach can be used as a complement to the previously developed acceptor excitation method. The new methodology has more general applications regardless whether the acceptor is an excitable fluorophore or a quencher. Thus, these developments provide a complete methodology for protein or other molecule interaction affinity determinations in solution

Nexus between financial development, FDI, industrial structure change and innovation in the post-financial crisis era: Evidence from China

China began to strive for innovation-driven economic growth by encouraging technological progress since the recent world financial crisis. Further, Chinese economy exhibited several different features since the crisis. Its financial credits surged. Meanwhile, it began to adjust its industrial structures. In order to test the effect of these policies, this paper investigates whether financial development, FDI and industrial structure changes affect innovation in this new era. The results find that provincial variation in innovation performance enlarged during this period. Further, financial development significantly improves innovation. However, FDI hampers innovation. Lastly, industrial structure adjustment promotes innovation. The paper suggests that China improve the technological skills of local firms and its human capital and introduce high-quality and efficient foreign direct investment to achieve an innovation-driven economic growth

Preparation and Characterization of an Antibody Antagonist That Targets the Porcine Growth Hormone Receptor

A series of antagonists specifically targeting growth hormone receptors (GHR) in different species, such as humans, rats, bovines, and mice, have been designed; however, there are currently no antagonists that target the porcine growth hormone (GH). Therefore, in this study, we developed and characterized a porcine GHR (pGHR) antibody antagonist (denoted by AN98) via the hybridoma technique. The results from enzyme-linked immunosorbent assay, fluorescence activated cell sorter, indirect immunoinfluscent assay, and competitive receptor binding analysis showed that AN98 could specifically recognize pGHR, and further experiments indicated that AN98 could effectively inhibit pGH-induced signalling in CHO-pGHR cells and porcine hepatocytes. In addition, AN98 also inhibited GH-induced insulin-like growth factor-1 (IGF-1) secretion in porcine hepatocytes. In summary, these findings indicated that AN98, as a pGHR-specific antagonist, has potential applications in pGH-pGHR-related research on domestic pigs

Spin selection rules on the quantum tunneling of magnetization in Mn

By means of low-temperature magnetic measurements, it is seen that, quantum spin selection rules also apply to the Mn3 molecule magnets which have intermolecular exchange couplings. The absence of two splitting steps of the tunneling from |6〉 to |−5〉 indicates that the transitions are confined to the C3 molecular symmetry. This is the first manifestation of quantum phase interference in the molecule magnets with intermolecular exchange couplings

CHIP regulates AKT/FoxO/Bim signaling in MCF7 and MCF10A cells.

A number of studies have shown that apoptosis resistance can be observed in multiple human tumors; however the detailed mechanism remains unclear. In the present study, we demonstrated that the abnormal overexpression of the C terminus of Hsc70-interacting protein (CHIP) induced apoptosis resistance by regulating the AKT/FoxO/Bim signaling pathway in the breast cancer cell MCF7 and the human non-tumorigenic cell MCF10A. We found that CHIP overexpression in MCF7 and MCF10A cells activated AKT and inhibited the Forkhead box O (FoxO) transcription factors FoxO1, FoxO3, and FoxO4, thereby inhibiting transcription of the target genes bim and pten. Inhibition of PI3K by a chemical reagent revealed that these events may be critical for CHIP-induced apoptosis resistance. We also determined that inhibition of FoxO3 by CHIP led to the decrease in PTEN and further activated the AKT survival pathway. We corroborated our findings in breast cancer tissues. In general, the CHIP-modulated AKT/FoxO/Bim signaling pathway was shown to induce apoptosis resistance by decreasing the protein level of the tumor suppressor PTEN in both transcriptional and post-translational regulations

Polarized operation of Yb:YAl₃(BO₃)₄ CW and mode-locked lasers

We present a diode-pumped Yb³⁺: YAl₃(BO₃)₃ (Yb:YAB) laser system and measured the polarized outputs of the CW and femtosecond mode-locked lasers with semiconductor saturable-absorber mirrors (SESAM) at the fundamental wavelength. For the CW output, polarization ratios were 88.1% and 87.2% . For the mode-locked system, polarization ratio reached 38.5%.5 page(s

The Evolution of Intumescent Char in Flame-Retardant Coatings Based on Amino Resin

Intumescent flame-retardant (IFR) coatings have been gaining more attention. The behaviors of intumescent char in IFR coatings play the most important role in its flame-retardant properties. However, the evolution of intumescent char throughout the whole process of protection is still unclear. In this study, both the formation and shrinkage of char were studied. The formulation of IFR includes melamine modified urea-formaldehyde resin (MUF), ammonium polyphosphate (APP) and pentaerythritol (PER). The flame-retardant properties of the coating were measured by the cone calorimeter (CONE). The evolution of the volume and the pore size distribution of char were monitored. The morphological and chemical structures were characterized by the scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that the evolution of intumescent char could be divided into three stages. More than 50% shrinkage of char occurs in the second stage. There are obvious transformations of the morphological and chemical structures of char between the different stages

Cavity design of a Yb:YAl3(BO3)4 Kerr lens mode-locked laser

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