Feasibility of Protein a for the Oriented Immobilization of Immunoglobulin on Silicon Surface for a Biosensor with Imaging Ellipsometry

The feasibility of using protein A to immobilize antibody on silicon surface for a biosensor with imaging ellipsometry was presented in this study. The amount of human IgG bound with anti-IgG immobilized by the protein A on silicon surface was much more than that bound with anti-IgG immobilized by physical adsorption. The result indicated that the protein A could be used to immobilize antibody molecules in a highly oriented manner and maintain antibody molecular functional configuration on the silicon surface. High reproducibility of the amount of antibody immobilization and homogenous antibody adsorption layer on surfaces could be obtained by this immobilization method. Imaging ellipsometry has been proven to be a fast and reliable detection method and sensitive enough to detect small changes in a molecular monolayer level. The combination of imaging ellipsometry and surface modification with protein A has the potential to be further developed into an efficient immunoassay protein chip.

Low-temperature hydrothermal growth of oriented [0001] ZnO film

Well-aligned ZnO films have been successfully prepared by using low-temperature hydrothermal approach on (0001) sapphire substrates that were pre-coated with a ZnO nano-layer by dip-coating. The characterizations of scanning electron microscopy (SEM) and X-ray diffraction (XRD) indicate that the ZnO films consist of hexagonal rods that grow along the c axis based on the sapphire substrates. It is found that the size of ZnO rods can be adjusted by an aqueous solution with some methenamine. (c) 2006 Elsevier B.V. All rights reserved.

Low temperature growth of c-axis oriented AlN films on gamma-LiAlO2 by radio frequency magnetron sputtering

Aluminum nitride (AlN) films were prepared on gamma-LiAlO2 substrates by radio frequency (rf) magnetron sputtering. The influence of substrate temperature (T-s) and nitrogen (N-2) concentration on film growth was investigated. The X-ray diffraction (XRD) results reveal that highly c-axis oriented AlN films can be obtained in the temperature range from room temperature (RT) to 300 degrees C. A smoother surface and a crystalline quality decrease with increasing N-2 concentration have been observed by XRD and atomic force microscopy (AFM) for the films deposited at lower substrate temperature. On the contrary, the degradation of the surface smoothness and the higher crystalline quality can be observed for the films deposited at a higher substrate temperature with N-2-rich ambient. The growth mechanism which leads to different crystalline quality of the films is discussed. (C) 2008 Elsevier B.V. All rights reserved.

Trade-off between reciprocal mutualists: local resource availability-oriented interaction in fig/fig wasp mutualism

The mechanisms that prevent competition (conflict) between the recipient and co-operative actor in co-operative systems remain one of the greatest problems for evolutionary biology. Previous hypotheses suggest that self-restraint, dispersal or spatial con

Xanthohumol, a novel anti-HIV-1 agent purified from Hops Humulus lupulus

Xanthohumol, prenylchacone flavonoid, is a natural product with multi-biofunctions purified from Hops Humulus lupulus. Its anti-HIV-1 activity was tested in the present study. Results showed that xanthohumol inhibited HIV-1 induced cytopathic effects, the production of viral p24 antigen and reverse transcriptase in C8166 lymphocytes at non-cytotoxic concentration. The EC50 values were 0.82, 1.28 and 0.50 mug/ml, respectively. The therapeutic index (TI) was about 10.8. Xanthohumol also inhibited HIV-1 replication in PBMC with EC50 value of 20.74 mug/ml. The activity of recombinant HIV-1 reverse transcriptase and the HIV-1 entry were not inhibited by xanthohumol. The results from this study suggested that xanthohumol is effective against HIV-1 and might serve as an interesting lead compound. It may represent a novel chemotherapeutic agent for HIV-1 infection. However, the mechanism of its anti-HIV-1 effect needs to be further clarified. (C) 2004 Elsevier B.V. All rights reserved.

Concentricolide, an anti-HIV agent from the ascomycete Daldinia concentrica

A novel benzofuran lactone, named concentricolide (=rel-(6R)-6-ethylbenzo[2.1-b:3,4-c']difuran-8(6H)-one; 1), was isolated along with four known compounds (friedelin, cytochalasin L-696.474, armillaramide, and russulamide) from the fruiting bodies of the

Nonpolar growth and characterization of InN overlayers on vertically oriented GaN nanorods

Nanostructured hexagonal InN overlayers were heteroepitaxially deposited on vertically oriented c-axis GaN nanorods by metal-organic chemical vapor deposition. InN overlayers grown in radial directions are featured by a nonpolar heteroepitaxial growth mode on GaN nanorods, showing a great difference from the conventional InN growth on (0001) c-plane GaN template. The surface of InN overlayers is mainly composed of several specific facets with lower crystallographic indices. The orientation relationship between InN and GaN lattices is found to be [0001](InN) parallel to [0001](GaN) and [1100](InN)parallel to[1100](GaN). A strong photoluminescence of InN nanostructures is observed. (C) 2009 American Institute of Physics. [DOI 10.1063/1.3177347]

Growth of c-oriented ZnO films on (001) SMO3 substrates by MOCVD

The growth direction of ZnO thin films grown by metal-organic chemical vapor deposition (MOCVD) is modulated by pretreatment of (001) SMO3 (STO) substrates. ZnO films show a-oriented smooth surface with epitaxial relationship of < 001 > ZnO//< 110 > STO on as-received SfO, and c-axis columnar growth with < 010 > ZnO//< 110 > STO on etched STO, respectively. The orientation alteration of ZnO films is supposed to be caused by the change of STO surface polarity. In addition, the c-ZnO films exhibit an enhanced photoluminescence (PL) intensity due to the improved crystal quality, while the blueshift of PL peak is attributed to the smaller tensile strain. These results show that high quality c-ZnO, which is essential for electronic and optoelectronic device applications, can be grown on (001) SfO by MOCVD. (C) 2008 Elsevier B.V. All rights reserved.

Effect of ion flux on recrystallization and resistance lowering in phosphorus-implanted (0001)-oriented 4H-SiC

High-dose ion implantation of phosphorus into 4H-SiC (0001) has been investigated with three different ion fluxes ranging from 1.0 to 4.0 x 10(12) P(+)cm(-2.)s(-1) and keeping the implantation dose constant at 2.0 x 10(15) P(+)cm(-2). The implantations are performed at room temperature and subsequently annealed at 1500 degrees C. Photoluminescence and Raman scattering are employed to investigate the implantation-induced damages and the residual defects after annealing. The electrical properties of the implanted layer are evaluated by Hall effect measurements on the sample with a van der Pauw configuration. Based on these results, it is revealed that the damages and defects in implanted layers can be greatly reduced by decreasing the ion flux. Considering room temperature implantation and a relatively low annealing temperature of 1500 degrees C, a reasonably low sheet resistance of 106 Omega/square is obtained at ion flux of 1.0 x 10(12) P(+)cm(-2.)s(-1) with a donor concentration of 4.4 x 10(19)cm(-3).