Noncommutative Stein's maximal spherical means

Based on a proper hypothesis on the noncommutative Fourier integral operators, we establish in this paper the strong-type $(p,p)$ (with $2\leq p\leq \infty$) estimates for the operator-valued Stein's maximal spherical means

Construction of a 7-fold BAC library and cytogenetic mapping of 10 genes in the giant panda (Ailuropoda melanoleuca)

BACKGROUND: The giant panda, one of the most primitive carnivores, is an endangered animal. Although it has been the subject of many interesting studies during recent years, little is known about its genome. In order to promote research on this genome, a bacterial artificial chromosome (BAC) library of the giant panda was constructed in this study. RESULTS: This BAC library contains 198,844 clones with an average insert size of 108 kb, which represents approximately seven equivalents of the giant panda haploid genome. Screening the library with 15 genes and 8 microsatellite markers demonstrates that it is representative and has good genome coverage. Furthermore, ten BAC clones harbouring AGXT, GHR, FSHR, IRBP, SOX14, TTR, BDNF, NT-4, LH and ZFX1 were mapped to 8 pairs of giant panda chromosomes by fluorescence in situ hybridization (FISH). CONCLUSION: This is the first large-insert genomic DNA library for the giant panda, and will contribute to understanding this endangered species in the areas of genome sequencing, physical mapping, gene cloning and comparative genomic studies. We also identified the physical locations of ten genes on their relative chromosomes by FISH, providing a preliminary framework for further development of a high resolution cytogenetic map of the giant panda

Fabrication and magnetic properties of Sm2Co17 and Sm2Co17/Fe7Co3 magnetic nanowires via AAO templates

AbstractThe Sm2Co17 single-phase and Sm2Co17/Fe7Co3 double-phase nanowire arrays with smaller diameter (around 50nm) have been fabricated into the anodic aluminum oxide (AAO) templates by direct-current electrodeposition. The crystal structure and micrograph of these nanowire arrays were characterized by X-ray diffraction, field-emission scanning electron microscopy and transmission electron microscopy (TEM). It is found that the as-deposited Sm2Co17 nanowires have the amorphous microstructure. The magnetic hysteresis loops obtained by vibrating sample magnetometer (VSM) show that the easily magnetized direction of the Sm2Co17 single-phase and Sm2Co17/Fe7Co3 double-phase nanowire arrays is parallel to the nanowire arrays and the exchange coupling interaction in nanocomposite Sm2Co17/Fe7Co3 is discussed. The study of the Sm2Co17 single-phase and Sm2Co17/Fe7Co3 double-phase nanowires with small diameter may open up new opportunities for the design and control of nanostructures such as the fabrication of magnetic recording devices

Postbiotics Derived from L. paracasei ET-22 Inhibit the Formation of S. mutans Biofilms and Bioactive Substances: An Analysis

Globally, dental caries is one of the most common non-communicable diseases for patients of all ages; Streptococcus mutans (S. mutans) is its principal pathogen. Lactobacillus paracasei (L. paracasei) shows excellent anti-pathogens and immune-regulation functions in the host. The aim of this study is to evaluate the effects of L. paracasei ET-22 on the formation of S. mutans biofilms. The living bacteria, heat-killed bacteria, and secretions of L. paracasei ET-22 were prepared using the same number of bacteria. In vitro, they were added into artificial-saliva medium, and used to coculture with the S. mutans. Results showed that the living bacteria and secretions of L. paracasei ET-22 inhibited biofilm-growth, the synthesis of water-soluble polysaccharide and water-insoluble polysaccharide, and virulence-gene-expression levels related to the formation of S. mutans biofilms. Surprisingly, the heat-killed L. paracasei ET-22, which is a postbiotic, also showed a similar regulation function. Non-targeted metabonomics technology was used to identify multiple potential active-substances in the postbiotics of L. paracasei ET-22 that inhibit the formation of S. mutans biofilms, including phenyllactic acid, zidovudine monophosphate, and citrulline. In conclusion, live bacteria and its postbiotics of L. paracasei ET-22 all have inhibitory effects on the formation of S. mutans biofilm. The postbiotics of L. paracasei ET-22 may be a promising biological anticariogenic-agent

Pseudo-solidification of dredged marine soils with cement - fly ash for reuse in coastal development

The dislodged and removed sediments from the seabed, termed dredged marine soils, are generally classified as a waste material requiring special disposal procedures. This is due to the potential contamination risks of transporting and disposing the dredged soils, and the fact that the material is of poor engineering quality, unsuitable for usage as a conventional good soil in construction. Also, taking into account the incurred costs and risk exposure in transferring the material to the dump site, whether on land or offshore, it is intuitive to examine the possibilities of reusing the dredged soils, especially in coastal development where the transportation route would be of shorter distance between the dredged site and the construction location. Pseudo-solidification of soils is not a novel idea though, where hydraulic binders are injected and mixed with soils to improve the inherent engineering properties for better load bearing capacity. It is commonly used on land in areas with vast and deep deposits of soft, weak soils. However, to implement the technique on the displaced then replaced dredged soil would require careful study, as the material is far more poorly than their land counterparts, and that the deployment of equipment and workforce in a coastal environment is understandably more challenging. The paper illustrates the laboratory investigation of the improved engineering performance of dredged marine soil sample with cement and fly ash blend. Some key findings include optimum dosage of cement and fly ash mix to produce up to 30 times of small strain stiffness improvement, pre-yield settlement reduction of the treated soil unaffected by prolonged curing period, and damage of the cementitious bonds formed by the rather small dosage of admixtures in the soil post-yield. In short, the test results show a promising reuse potential of the otherwise discarded dredged marine soils

Characterization of a sensitive biosensor based on an unmodified DNA and gold nanoparticle composite and its application in diquat determination

AbstractDNA usually adsorbs gold nanoparticles by virtue of mercapto or amino groups at one end of a DNA molecule. However, in this paper, we report a sensitive biosensor constructed using unmodified DNA molecules with consecutive adenines (CA DNA) and gold nanoparticles (GNPs). The CA DNA–GNP composite was fabricated on gold electrodes and characterized by using of scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and the electrochemical method. Using an electrochemical quartz crystal microbalance (EQCM), the mechanism by which the CA DNA and GNPs combined was also studied. The modified electrode exhibited an ultrasensitive response to diquat. Differential pulse voltammetry (DPV) was used to study the linear relationships between concentrations and reduction peak currents, ranging from 1.0×10−9M to 1.2×10−6M. The detection limit of it is 2.0×10−10M. The feasibility of the proposed assay for use in human urine and grain was investigated, and the satisfactory results were obtained