From collagen-chitosan blends to three-dimensional scaffolds: the influences of chitosan on collagen nanofibrillar structure and mechanical property.

The nanofibrillar feature of native type I collagen is of great importance in maintaining its functions in vivo. In the field of engineering collagen-based materials in vitro, different fabrications may yield differences in collagen organization and thus affect the nanofibrous structure. Two approaches of fabricating collagen-chitosan (Col-Chi) scaffolds were presented in this study to investigate the respective impacts especially on nanostructures.

High-repetition-rate, high-peak-power, linear-polarized 473 nm Nd:YAG/BiBO blue laser by extracavity frequency doubling.

We report on a high-repetition-rate, high-peak-power, linear-polarized 473 nm blue laser. A high-power 946 nm fundamental laser was obtained based on a diode-pumped acousto-optically (AO) Q-switched Nd:YAG laser using a thermal-compensating resonator and a microchannel heat sink for thermal dissipation. A pulsed 473 nm laser was generated using a BiB(3)O(6) (BiBO) crystal as an extracavity frequency doubler.

Bone-like nanocomposites based on self-assembled protein-based matrices with Ca2+ capturing capability.

In the present work, bone-like nanocomposites have been successfully synthesized based on the mineralization of self-assembled protein-based microgels. Such mircogels were achieved by the in vitro reconstitution of collagen monomeric solutions in the presence of alginate in a microemulsion system. Microstructural observations revealed that the collagen-alginate composite beads possessed a nanofibrous three dimensional (3D) interconnected porous microstructure.

Use of a bioactive scaffold for the repair of bone defects in a novel reproducible vertebral body defect model.

Bone defects in vertebral bodies (VB) usually occur after the reduction of fractures or are caused by bone disease. Besides the treatment of original disease, repair of the bone defect can restore the structure of VB and improve stabilization of the spine to protect the spinal cord nerves. To aid studies of the efficacy of bioengineering techniques for repair of VB, we developed a rat model with a critical size bone defect in VB.

Myc is required for the maintenance of Kaposi's sarcoma-associated herpesvirus latency.

Myc is deregulated by Kaposi's sarcoma-associated herpesvirus (KSHV) latent proteins, but its role in KSHV latency is not clear. We found that Myc knockdown with RNA interference (RNAi) induced KSHV reactivation and increased the protein and mRNA levels of RTA, a key viral regulator of KSHV reactivation. Myc knockdown increased, whereas Myc overexpression inhibited, RTA promoter activity.

SOD2 V16A SNP in the mitochondrial targeting sequence is associated with noise induced hearing loss in Chinese workers.

Objective: To investigate whether single nucleotide polymorphisms (SNPs) in the Mn-superoxide dismutase gene (SOD2) underlie the susceptibility to noise-induced hearing loss (NIHL).

Methods: Audiometric data from 2400 Chinese Han workers who exposed to occupational noise were analyzed. DNA samples were collected from the 10% most susceptible and the 10% most resistant individuals, and five SNPs (SOD2 rs2842980, rs5746136, rs2758331, rs4880 and rs5746092) were genotyped by Taqman SNP Genotyping Kits.

Inactivation of PI3k/Akt signaling pathway and activation of caspase-3 are involved in tanshinone I-induced apoptosis in myeloid leukemia cells in vitro.

Tanshinone I (Tan I), a diterpene quinone extracted from herbal medicine Salvia miltiorrhiza Bunge, has recently been reported to have antitumor effects. As the mechanism of its proapoptotic effects on human myeloid leukemia cells has not been extensively studied, we performed an in-depth evaluation of the effects of Tan I on apoptosis in human K562 and HL-60 cells. The results revealed that Tan I could inhibit the growth of leukemia cells and cause apoptosis in a time- and dose-dependent manner.

Controlled mineralization by extracellular matrix: monodisperse, colloidally stable calcium phosphate-hyaluronan hybrid nanospheres.

Uniform, monodisperse calcium phosphate nanospheres (40 nm) were prepared using a simple co-precipitation method via the segregation crystallization imposed by hyaluronan molecules. The nanospheres exhibit excellent colloidal/storage stability in water due to the incorporated extracellular substance.

Transcriptional alteration of matrix-related gene expression in cultured human disc cells by nanoparticles of a bismethanophosphonate fullerene.

Fullerene and its derivatives have been extensively studied in the biomedical field. Their biological activities towards various cell types have been reported, and previous results have implicated their potential uses as photosensitizers in photodynamic therapy of tumour and photoinactivation of bacteria and viruses, antioxidative/cytoprotective reagents and carriers for drug delivery. We describe here the effects of a BMPF (bismethanophosphonate fullerene) on matrix-related gene expression in cultured human disc cells by real-time reverse transcriptase PCR.

[Enhancement of laccase activity by combining white rot fungal strains].

The method of combining white rot fungal strains was used to enhance laccase activity, and the interaction mechanism between strains was also studied. The laccase activity of combined fungi of strain 55 (Trametes trogii) and strain m-6 (Trametes versicolor) were 24.13 and 4.

Power scaling of directly dual-end-pumped Nd:GdVO4 laser using grown-together composite crystal.

Power scaling of end-pumped Nd:GdVO(4) laser was realized by direct pumping, grown-together composite crystal and dual-end-pumping. A maximum CW output power of 46.0W with M(2)<1.

Correlations between Z-scores of VSRAD and regional cerebral blood flow of SPECT in patients with Alzheimer's disease and mild cognitive impairment.

Aims: The purpose of the present study was to investigate whether there were correlations between atrophy of the entorhinal cortex and individual regional cerebral blood flow (rCBF) in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (MCI) to better clarify the relationships between morphological and functional changes in AD.

Methods: Twenty-six patients including sixteen AD and 10 amnestic MCI patients were enrolled. Z scores of voxel-based specific regional analysis system for AD (VSRAD) were determined to assess the degree of atrophy of the entorhinal cortex.

Dipeptide-based polyphosphazene and polyester blends for bone tissue engineering.

Polyphosphazene-polyester blends are attractive materials for bone tissue engineering applications due to their controllable degradation pattern with non-toxic and neutral pH degradation products. In our ongoing quest for an ideal completely miscible polyphosphazene-polyester blend system, we report synthesis and characterization of a mixed-substituent biodegradable polyphosphazene poly[(glycine ethyl glycinato)(1)(phenyl phenoxy)(1)phosphazene] (PNGEG/PhPh) and its blends with a polyester. Two dipeptide-based blends namely 25:75 (Matrix1) and 50:50 (Matrix2) were produced at two different weight ratios of PNGEG/PhPh to poly(lactic acid-glycolic acid) (PLAGA).

Multipotential differentiation of human anulus fibrosus cells: an in vitro study.

Background: The existence of fibrocartilage, bone-like tissues, nerves, and blood vessels in the anulus fibrosus during intervertebral disc degeneration has been well documented. Migration of differentiated cells from outside the intervertebral disc has been hypothesized as a possible mechanism for the formation of these tissues. We hypothesized that the normal anulus fibrosus tissue contains multipotent progenitor cells, which are able to differentiate into cartilage and/or fibrocartilage cells, osteoblasts, neurons, and blood vessel cells.

Quantification of anaerobic ammonium-oxidizing bacteria in enrichment cultures by quantitative competitive PCR.

The anaerobic ammonium-oxidizing (ANAMMOX) bacteria were enriched from a sequencing batch biofilm reactor (SBBR). A quantitative competitive polymerase chain reaction (QC-PCR) system was successfully developed to detect and quantify ANAMMOX bacteria in environmental samples. For QC-PCR system, PCR primer sets targeting 16S ribosomal RNA genes of ANAMMOX bacteria were designed and used.

Investigations on the mechanical properties of conducting polymer coating-substrate structures and their influencing factors.

This review covers recent advances and work on the microstructure features, mechanical properties and cracking processes of conducting polymer film/coating- substrate structures under different testing conditions. An attempt is made to characterize and quantify the relationships between mechanical properties and microstructure features. In addition, the film cracking mechanism on the micro scale and some influencing factors that play a significant role in the service of the film-substrate structure are presented.

Tpl2/AP-1 enhances murine gammaherpesvirus 68 lytic replication.

How cellular factors regulate gammaherpesvirus lytic replication is not well understood. Here, through functional screening of a cellular kinase expression library, we identified mitogen-activated protein kinase kinase kinase 8 (MAP3K8/Tpl2) as a positive regulator of murine gammaherpesvirus 68 (MHV-68 or gammaHV-68) lytic gene expression and replication. Tpl2 enhances MHV-68 lytic replication by upregulating lytic gene expression and promoter activities of viral lytic genes, including RTA and open reading frame 57 (ORF57).

Association between polymorphisms in SOD1 and noise-induced hearing loss in Chinese workers.

Conclusion: SOD1 is an important gene related to noise-induced hearing loss (NIHL), and its effect is dependent on noise exposure levels.

Objectives: To test whether the polymorphisms in the CuZn-superoxide dismutase gene (SOD1) are associated with susceptibility to NIHL in the Chinese population.

Methods: Audiometric data from 2400 Chinese Han people exposed to occupational noise were analyzed.

Inhibition of the phosphatidylinositol 3-kinase-Akt pathway enhances gamma-2 herpesvirus lytic replication and facilitates reactivation from latency.

Cellular signalling pathways are critical in regulating the balance between latency and lytic replication of herpesviruses. Here, we investigated the effect of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway on replication of two gamma-2 herpesviruses, murine gammaherpesvirus-68 (MHV-68) and human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus (HHV-8/KSHV). We found that de novo infection of MHV-68 induced PI3K-dependent Akt activation and the lytic replication of MHV-68 was enhanced by inhibiting the PI3K-Akt pathway with both chemical inhibitors and RNA interference technology.

Activation of peroxisome proliferator-activated receptor-gamma induces apoptosis on acute promyelocytic leukemia cells via downregulation of XIAP.

In the present study we investigated the in vitro apoptosis inducing effects of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligand ciglitazone (CGZ) on acute promyelocytic leukemia (APL) NB4 cells and its mechanisms of action. The results revealed that CGZ (10-50 micromol/l) inhibited the growth of leukemia NB4 cells and caused apoptosis in a time- and dose-dependent manner. Apoptosis was observed clearly by flow cytometry (FCM) and DNA fragmentation analysis.

Laser properties of continuous-grown Nd:GdVO4/GdVO4 and Nd:YVO4/YVO4 composite crystals under direct pumping.

We present the laser properties of continuous-grown Nd:GdVO(4)/GdVO(4) and Nd:YVO(4)/YVO(4) composite crystals under LD direct pumping . The maximum CW output powers of 20W with a slope efficiency of 74.9% to absorbed pump power and 32W with 82.

[Construction of genetically modified dendritic cell vaccine expressing bcr/abl fusion gene and inducing specific cytotoxic T lymphocytes to kill K562 cells in vitro].

Background And Objective: Specific immunological effect mediated by T lymphocytes plays an important role in treating chronic myelocytic leukemia (CML). Dendritic cells (DCs)-based immunotherapy has become popular in treating tumors. This study was to construct DC vaccines by transducing with replication-defective recombinant adenoviruses expressing bcr/abl fusion gene of CML, observe the lethal effects of specific cytotoxic T lymphocytes (CTLs) triggered by genetically modified DC vaccines expressing bcr/abl fusion gene against K562 cells in vitro.

Effect of organic carbon on nitrification efficiency and community composition of nitrifying biofilms.

The effects of organic carbon/inorganic nitrogen (C/N) ratio on the nitrification processes and the community shifts of nitrifying biofilms were investigated by kinetic comparison and denaturing gradient gel electrophoresis (DGGE) analysis. The results showed that the nitrification rate decreased with an increasing organic concentration. However, the effect became weak when the carbon concentration reached a sufficiently high level.

Nucleus pulposus tissue engineering: a brief review.

Symptomatic intervertebral disc degeneration is associated with several spinal diseases, which cause losses of life quality and money. Tissue engineering provides a promising approach to recover the functionality of the degenerative intervertebral disc. Most studies are directed toward nucleus pulposus (NP) tissue engineering because disc degeneration is believed to originate in NP region, and considerable progress has been made in the past decade.

[Property analysis of nanosized iron sulfide produced by sulfate reducing bacteria and its application in the treatment of wastewater containing high concentration of Cr (VI)].

The properties of novel nanosized iron sulphide produced by sulfate reducing bacteria (SRB) and its application to the removal of Cr (VI) from wastewater were studied. The structural properties were examined by transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The influences of pH, temperature and dosage on removal of Cr (VI) from wastewater by nanosized iron sulphide were investigated, and the effect comparison of nanosized iron sulphide and other traditional wastewater treatment was also evaluated.