Carbon nanotube alignment driven rapid actuations.

Suspended micro-beams made from aligned carbon nanotubes and parylene deflect reversibly in an ac field and the deflection rate is three orders of magnitude greater than those for existing devices. The direction of beam deflection is determined by the area moment of inertia and the actuation mechanism involves rapid accumulation of charges at tube surfaces, the creation of Coulomb repulsive forces between tubes, beam dilation and the formation of compressive stresses at beam ends. Tube alignment plays a crucial role in the first step as is verified by experimental data and calculation.

Ag-catalyzed growth of Ge nanostructures via the thermal evaporation of Ge powder.

The Ag-catalyzed growth of straight Ge nanowires (GeNWs), serrated Ge nanobelts (GeNBs), and hexagonal Ge nanotowers (GeNTs) by thermal evaporation of Ge powder at 950 degrees C in Ar was studied. The growth of GeNWs and GeNBs at 550-600 degrees C followed the top-growth mode via the vapor-solid-solid process, while that of GeNTs at 700-750 degrees C followed the bottom-growth mode via the vapor-liquid-solid process. This result shows that the growth mode of Ge nanostructures catalyzed by Ag nanoparticles is temperature-dependent. The larger size of AgGe droplets assembled at high temperatures is beneficial to the growth of GeNTs with the bottom-growth mode. In addition, the growth mechanisms of Ge nanostructures are discussed.

"A real-world evidence" in reduction of volatile anesthetics by BIS-guided anesthesia.

Many well-controlled clinical studies have shown that BIS-guided anesthesia could prevent intraoperative awareness and improve postoperative morbidity and mortality, by optimizing the amount of volatile anesthetics administered to patients. However, we questioned if the previously reported advantages of BIS-guided anesthesia in controlled studies would still apply in real-world settings. This retrospective study based on real-world settings clarified the role of BIS-guided anesthesia in reducing anesthetic consumption. We obtained anesthesia records from an electronic database of a medical center in southern Taiwan. A total of 6,713 cases were enrolled, where 1,324 cases receiving sevoflurane underwent BIS-guided anesthesia and 378 received desflurane; further, 3,819 receiving sevoflurane underwent standard anesthesia practice and 1,192 cases received desflurane. The median (25-75% interquartile values) of the average hourly consumption of sevoflurane or desflurane decreased significantly under BIS-guided anesthesia [10.5 (8.7-13.0) mL/h and 17.4 (13.7-21.1) mL/h, respectively] compared to that under standard anesthesia practice [11.4 (9.0-14.5) mL/h, and 20.2 (15.8-25.0), mL/h, respectively]. Furthermore, the average hourly consumption of these two volatile anesthetics varied inversely with age and anesthesia time in both groups. A significant reduction was found in the hourly consumption of volatile anesthetics in patients under BIS-guided anesthesia compared to standard anesthesia practice in different age groups or different anesthesia time. We concluded that BIS-guided anesthesia could reduce consumption of volatile anesthetics in real-world settings as well.

Lignin valorization meets synthetic biology.

Lignin, an abundant renewable resource in nature, is a highly heterogeneous biopolymer consisting of phenylpropanoid units. It is essential for sustainable utilization of biomass to convert lignin to value-added products. However, there are technical obstacles for lignin valorization due to intrinsic heterogeneity. The emerging of synthetic biology technologies brings new opportunities for lignin breakdown and utilization. In this review, we discussed the applications of synthetic biology on lignin conversion, especially the production of value-added products, such as aromatic chemicals, ring-cleaved chemicals from lignin-derived aromatics and bio-active substances. Synthetic biology will offer new potential strategies for lignin valorization by optimizing lignin degradation enzymes, building novel artificial converting pathways, and improving the chassis of model microorganisms.

Hexagonal Boron Nitride Coated Carbon Nanotubes: Interlayer Polarization Improved Field Emission.

Coating of h-BN onto carbon nanotubes induces polarization at interfaces, and charges become localized at N and C atoms. Field emission of coated tubes is found to be highly stable, and current density fluctuates within 4%. Study further reveals that the electric field established between coatings and tubes facilitates charge transfer across interfaces and electrons are emitted through occupied and unoccupied bands of N and B atoms.

Inhibition of chemokine (C-C motif) receptor 7 sialylation suppresses CCL19-stimulated proliferation, invasion and anti-anoikis.

Chemokine (C-C motif) receptor 7 (CCR7) is involved in lymph-node homing of naive and regulatory T cells and lymphatic metastasis of cancer cells. Sialic acids comprise a group of monosaccharide units that are added to the terminal position of the oligosaccharide chain of glycoproteins by sialyation. Recent studies suggest that aberrant sialylation of receptor proteins contributes to proliferation, motility, and drug resistance of cancer cells. In this study, we addressed whether CCR7 is a sialylated receptor protein and tried to elucidate the effect of sialylation in the regulation of signal transduction and biological function of CCR7. Our results demonstrated that α-2, 3-sialyltransferase which catalyze sialylation reaction in vivo was overexpressed in breast tumor tissues and cell lines. Lectin blot analysis clearly demonstrated that CCR7 receptor was sialyated in breast cancer cells. Chemokine (C-C motif) ligand 19 (CCL19), the cognate ligand for CCR7, induced the activation of extracellular signal-regulated kinase (ERK) and AKT signaling and increased the expression of cell cycle regulatory proteins and proliferation of breast cancer cells. When cells were pre-treated with a sialyltransferase inhibitor AL10 or sialidase, CCL19-induced cell growth was significantly suppressed. CCL19 also increased invasion and prevented anoikis by up-regulating pro-survival proteins Bcl-2 and Bcl-xL. Inhibition of sialylation by AL10 totally abolished these effects. Finally, we showed that AL10 inhibited tumorigenicity of breast cancer in experimental animals. Taken together, we demonstrate for the first time that CCR7 receptor is a sialylated protein and sialylation is important for the paracrine stimulation by its endogenous ligand CCL19. In addition, inhibition of aberrant sialylation of CCR7 suppresses proliferation and invasion and triggers anoikis in breast cancer cells. Targeting of sialylation enzymes may be a novel strategy for breast cancer treatment.