Application of terahertz spectroscopy and molecular modeling in isomers investigation: Glucose and fructose

Terahertz spectra of glucose and fructose have been measured by terahertz time-domain spectroscopy (THz-TDS) at room temperature. Because they have the same molecular formula, the differences of the THz spectra can be attributed to their molecular structures and the arrangement of molecules in unit cell. In this paper, gaseous-state theory has been employed to simulate the isolated molecule of these two isomers. The results indicate that experimental THz spectral features (0.5 – 4.0 THz) of glucose and fructose arise from the mixture of intramolecular and intermolecular modes, involving hydrogen bonds and covalent bonds, and with the intermolecular modes dominating.     

Synthesis and biological evaluation of a lipopeptide-based methamphetamine vaccine

We describe an application of carrier protein-free strategy in constructing a fully synthetic methamphetamine (METH) vaccine that contains three components: Toll-like receptor 2 ligand, Th2 epitope, and METH hapten. The immunological evaluation in mice revealed high titers of METH-specific antibodies induced by the construct and the activation of humoral immunity that would be beneficial for neutralization and clearance of the METH molecule. Behavioral experiments indicated that the synthetic vaccine attenuated the acquisition of METH-induced conditioned place preference and inhibited the initiation and expression of METH-induced locomotor sensitization. These results demonstrate that the lipopeptide-based vaccine has invoked an immune response and showed the potential of preventing the rewarding and psychoactive effects of METH.     

A Small-Molecule Diketopyrrolopyrrole-Based Dye for in vivo NIR-IIa Fluorescence Bioimaging

Organic small-molecule fluorophores with near-infrared IIa (NIR-IIa) emission have great potential in pre-clinical detection and inoperative imaging due to the high-spatial resolution and deep penetration. However, developments of the NIR-IIa fluorophores are still facing considerable challenges. In this work, a series of diketopyrrolopyrrole (DPP)-based fluorophores were designed and synthesized. Subsequently, nanomaterial T25@F127 with significant NIR-IIa emission properties was rationally prepared by encapsulating DPP-based fluorophore T25 , and was selected for fluorescence angiography and cerebral vascular microscopic imaging with nearly 800 μm penetrating depth and excellent signal-background ratio of 4.07 and 2.26 (at 250 and 400 μm), respectively. Furthermore, the nanomaterial T25@cRGD with tumor targeting ability can image tiny metastatic tumor on intestine with a small size of 0.3 mm×1.0 mm and high-spatial resolution (SBR=3.84). This study demonstrates that the nanomaterials which encapsulated T25 behave as excellent NIR-IIa fluorescence imaging agents and have a great potential for in vivo biological application.     

A Silicon Nanowire‐Based Electrochemical Sensor with High Sensitivity and Electrocatalytic Activity

A new kind of silicon nanowire (SiNWs)‐based nanoelectrode assembly, a gold‐nanoparticle‐decorated silicon nanowire array (AuNPs@SiNWsAr), is employed for the construction of high‐performance electrochemical sensors. Significantly, the electrochemical nanosensors are capable of sensitive detection of various electroactive molecules (e.g., dopamine (DA), ascorbic acid (AA), hydrogen peroxide (H₂O₂), and glucose). Further, DA molecules loaded on the surface of AuNPs@SiNWsAr preserve stable high electroactivity overnight without special protection, while free DA molecules may lose their biological activity due to severe oxidization in ambient environment. These findings may offer new opportunities for the design of high‐performance electrochemical nanosensors with high sensitivity and robust stability.     

The Generalized Thermo Jaynes–Cummings Model and?Its Energy Spectrum

By analyzing the characteristics of thermo field dynamics, we present a new generalized thermo Jaynes-Cummings (TJC) model at finite temperature including the thermal effects and expatiate on its physical explanation. By virtue of Lewis-Riesenfeld invariant method, we obtain its exact eigenenergy spectrum and the explicit expressions for the evolution operator of the wavefunctions. In addition, we evaluate various expectation values of physical quantities and find the pseudo-invariant eigen-operator for the generalized TJC Hamiltonian.     

Bipolar copolymers comprised mesogen‐jacketed polymer containing oxadiazole units and PVK as host materials for electroluminescent devices

Nonconjugated bipolar transport polymers have been developed as host materials for electroluminescent devices by incorporating both electron‐transporting and hole‐transporting functionalities into copolymers. The random copolymer PCt‐nvk3‐7 containing mesogen‐jacketed segment of P‐Ct have been synthesized and characterized. The effect of mesogen‐jacketed segment content of these bipolar copolymers on device performance has been investigated. The results of polymer light‐emitting diodes (PLEDs) show that the jacketed content of copolymers has a significant effect on device performance: lowering charge transport and facilitating the hole‐electron recombination leads to much higher current efficiency. Applying these high triplet random copolymers as host, the maximum current efficiency of 0.70 cd/A and the maximum brightness of 1872.8 cd/m² was achieved for PCt‐nvk3‐7 with an orange‐emitting complex dopant. The results suggest that the bipolar copolymers PCt‐nvks can be good host polymers for electrophosphorescent devices. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7861–7867, 2008     

水／离子液体两相体系中出芽短梗霉催化4-氯-乙酰乙酸乙酯不对称还原合成（S）-4-氯-3-羟基-丁酸乙酯

考察了水/离子液体两相体系中出芽短梗霉(Aureobasidium pullulansCGMCC1244)催化4-氯乙酰乙酸乙酯(COBE)不对称还原生成光学活性(S)-4-氯-3-羟基丁酸乙酯((S)-CHBE)的性能,并对反应条件如摇床转速、相体积比、温度、初始底物浓度和pH值等进行了优化.结果表明,在水/1-丁基-3-甲基咪唑六氟磷酸盐体系中,出芽短梗霉催化COBE不对称还原生成(S)-CHBE,在30℃,pH6·6,摇床转速180r/min和不对称反应8h条件下,反应物的转化率、产物ee值和浓度分别达到95·6%,98·5%和47·1g/L.在控制pH值为6·6的情况下,通过分添加底物可有效提高产物(S)-CHBE浓度至75·1g/L.