Relaxor ferroelectric single crystals Pb((Mg1/3Nb2/3)1-x Ti x )O3 (PMNT 100(1-x)/100x) were grown directly from melt by a modified Bridgman technique. The segregation during the growth of PMNT single crystals was studied by means of differential thermal analysis (TGA), thermogravimetric analysis (DTA), X-ray diffraction (XRD) and X-ray fluorescence analyzer (XRFA). The results show that PbTiO3 content increases throughout the crystal growth. The segregation coefficient is about 0.95 during the growth of PMNT 76/24 directly from melt. Therefore, the electric properties of PMNT single crystals vary even in the same boule. It was demonstrated that the homogeneity of PMNT single crystals can be improved by optimizing growth parameters, but it cannot be eliminated because of the effect of segregation during the crystal growth. We have recently improved the growth process of the modified Bridgman technique to increase the homogeneity of the crystals. Good-quality single crystals with a boule size of more than φ40×80 mm or 30×30×1 mm plates have been achieved. For PMNT 67/33 crystals, their coupling factors are k 33≈94% for the longitudinal mode, k 33 ′≈86% for the beam mode, and k t≈62% for the thickness mode, and they have the piezoelectric constant d 33=1500–3000 pC/N, and dielectric constant ε 33/ε 0=3500–5500.

Investigating the structure, modification, interaction, and function of biomolecules in their native cellular environment leads to physiologically relevant knowledge about their mechanisms, which will benefit drug discovery and design. In recent years, nuclear and electron magnetic resonance (NMR) spectroscopy has emerged as a useful tool for elucidating the structure and function of biomacromolecules, including proteins, nucleic acids, and carbohydrates in living cells at atomic resolution. In this review, we summarize the progress and future of in-cell NMR as it is applied to proteins, nucleic acids, and carbohydrates.

In the principle of optical crystallography and crystal symmetry, it is found that at room temperature, the 0.67 PMN-0.33 PT crystals near the morphotropic phase boundary composition present not only a rhombohedral 3m phase but also a monoclinic m phase with various angles of polarization rotation, the third ferroelectric phase in the PMN-PT solid solution system. The polarization rotation readily driven by composition suggests that it can be easily induced by electric field as well, thereby providing the structure base of the ultrahigh piezoelectric performance of 0.67 PMN-0.33 PT single crystals.

A conserved guanine-rich sequence could be a new target for anti–hepatitis C virus drug development.

In the present study, our bioinformatics analysis first reveals the existence of a conserved guanine-rich sequence within the Zaire ebolavirus L gene. Using various methods, we show that this sequence tends to fold into G-quadruplex RNA. TMPyP4 treatment evidently inhibits L gene expression at the RNA level. Moreover, the mini-replicon assay demonstrates that TMPyP4 effectively inhibits the artificial Zaire ebolavirus mini-genome and is a more potent inhibitor than ribavirin. Although TMPyP4 treatment reduced the replication of the mutant mini-genome when G-quadruplex formation was abolished in the L gene, its inhibitory effect was significantly alleviated compared with wild-type. Our findings thus provide the first evidence that G-quadruplex RNA is present in a negative-sense RNA virus. Finally, G-quadruplex RNA stabilization may represent a new therapeutic strategy against Ebola virus disease.

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Lead-free potassium sodium niobate piezoelectric single crystals substituted with lithium 0.95(K0.5Na0.5)NbO3–0.05LiNbO3 have been grown by Bridgman method and their dielectric and piezoelectric properties were studied. The orthorhombic-tetragonal and tetragonal-cubic phase transition temperatures of the single crystal appear at 192 and 426°C according to the dielectric constant versus temperature loops, respectively, and the (001) plates show good piezoelectric properties with piezoelectric constant d33 as high as 405pC∕N, large thickness electromechanical coupling factor kt=61%, and low dielectric constant of 185 at room temperature. These excellent properties show that the 0.95(K0.5Na0.5)NbO3–0.05LiNbO3 single crystal is a good lead-free piezoelectric material.