A phase sensitive optical rotation measurement in a scattered chiral medium using a Zeeman laser

A novel circular polarized optical heterodyne interferometer using a Zeeman laser to measure optical rotation both in nonscattered and scattered chiral medium is proposed. A pair of correlated orthogonal circular polarized light waves of different temporal frequency propagating in the chiral medium at different speed is studied. This results in phase retardation between circular polarized light waves of which the phase difference is proportional to the optical rotation angle of a linear polarized light in a chiral medium. In the mean time, two orthogonal circular polarized light waves can be treated as a circular polarized photon pair that is able to reduce the scattering effect in a scattered chiral medium. Then the optical rotation angle can be measured in the scattering medium. In addition, a common-path configuration with respect to circular polarized light waves immune the background noise. This further improves the sensitivity on optical rotation measurement based on phase difference detection.     

Synthesis of side chain liquid-crystalline polysiloxane containing trans-cyclohexane-based mesogenic side groups

The synthesis and characterization of nine new side chain liquid-crystalline polysiloxanes containing one cyclohexyl ring and another 2-4 aromatic rings in their mesogenic side groups are described. All synthesized polymers displayed nematic mesomorphism. Most of the polymers showed a very wide mesomorphic temperature range. The mesogenic core length has profound influence on the phase transitions of the polymers. The mesomorphic temperature range increased with increasing mesogenic core length.     

Trace analysis of vanadium as pentavalent vanadium using differential pulse polarography with a coupled catalytic homogeneous reaction

The differential pulse polarographic determination of the vanadium (V) ion coupled with a catalytic homogeneous reaction was carried out in a system containing the vanadium (V)-PAR complex and an oxidant in acetic/acetate buffer. On addition of the powerful oxidant, sodium bromate, the peak current for the reduction of the vanadium (V) complex was increased significantly by about 21 times. A calibration plot was found to be linear in the concentration range 0.05–0.25 g/ml and the detection limit was 5 ng/ml.     

Composites of UHMWPE fiber reinforced PU/epoxy grafted interpenetrating polymer networks

Several polyurethane-modified epoxy resins (PU/DGEBA-g-IPNs) were synthesized and characterized through a series tests, including differential scanning calorimetry and mechanical property measurements, such as tensile, Izod, bending and shear strengths were investigated in the study. The PU/DGEBA-g-IPNs and neat DGEBA as matrices for UHMWPE fiber-reinforced and aramid fiber-reinforced composites were prepared for comparison of their mechanical properties. The degree of plasma treatment, the polyurethane content, and the type of polyol in the polyurethane within the matrix of the composite were investigated through mechanical and bulletproof testing.     

Dose Dependencies and Biocompatibility of Renal Clearable Gold Nanoparticles: From Mice to Non‐human Primates

While dose dependencies in pharmacokinetics and clearance are often observed in clinically used small molecules, very few studies have been dedicated to the understandings of potential dose‐dependent in vivo transport of nanomedicines. Here we report that the pharmacokinetics and clearance of renal clearable gold nanoparticles (GS‐AuNPs) are strongly dose‐dependent once injection doses are above 15 mg kg^?1: high dose expedited the renal excretion and shortened the blood retention. As a result, the no‐observed‐adverse‐effect‐level (NOAEL) of GS‐AuNPs was >1000 mg kg^?1 in CD‐1 mice. The efficient renal clearance and high compatibility can be translated to the non‐human primates: no adverse effects were observed within 90 days after intravenous injection of 250 mg kg^?1 GS‐AuNPs. These fundamental understandings of dose effect on the in vivo transport of ultrasmall AuNPs open up a pathway to maximize their biomedical potentials and minimize their toxicity in the future clinical translation.     

Methyl side-chain dynamics in proteins using selective enrichment with a single isotopomer

13C relaxation studies on side-chain methyl groups in proteins typically involve measurements on (13)CHD(2) isotopomers, where the (13)C relaxation mechanism is particularly straightforward in the presence of a single proton. While such isotopomers can be obtained in proteins overexpressed in bacteria by use of (13)C enriched and fractionally deuterated media, invariably all possible (2)H isotopomers are obtained. This results in a loss of both resolution and sensitivity, which becomes particularly severe for larger proteins. We describe an approach that overcomes this problem by chemical synthesis of amino acids containing a pure (13)CHD(2) isotopomer. We illustrate the benefits of this approach in (13)C side-chain relaxation measurements on the mouse major urinary protein selectively enriched with [gamma(1),gamma(2)-(13)C(2),alpha,beta,gamma(1),gamma(1),gamma(2),gamma(2)-(2)H(6)] valine. Relaxation measurements in the absence and presence of pyrazine-derived ligands suggest that valine side-chain dynamics do not contribute significantly to binding entropy.