10 research outputs found

    Comparison of mesoporous silicate supports for the immobilisation and activity of cytochrome c and lipase

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    The activity and stability of Candida antartica lipase B (CALB) and cytochrome c immobilised on to, SBA-15 and a porous spherical silicate material (PPS), were examined. The materials possess similar pore diameters but have different morphologies, pore volumes and surface areas. CALB exhibited higher catalytic activity and stability on SBA-15 when compared to PPS, while cytochrome c showed similar catalytic activity on both materials. The activity of CALB immobilised on SBA-15 was retained (95%) after 7 uses, while CALB immobilised on PPS retained only 43% activity. Such changes can be mainly ascribed to the different physical properties (pore volume, surface area and pore shape) of the supports

    Pore expansion in mesoporous silicas using supercritical carbon dioxide

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    In this paper we report the controlled expansion of pores within mesoporous silicas using supercritical carbon dioxide (sc-CO2). Our method uses the tunable density of sc-CO2 to induce the controlled swelling of the triblock copolymer surfactant templating agents, P123 (PEO20PPO69PEO20) and P85 (PEO26PPO39PEO26). This swelling process ultimately leads to the control of pore diameters and hexagonal spacing within the mesoporous silicas. At pressures of approximately 482 bar, pore diameters of up to 100 Ã… can be achieved representing a pore expansion of 54 % compared to the conventionally formed mesoporous silicas. Powder X-ray diffraction (PXRD), transmission electron microscopy (TEM) and nitrogen adsorption techniques were used to establish pore diameters, silica wall widths and the hexagonal packing of the pores within the sc-CO2 treated mesoporous silicas. The sc-CO2 was shown not to effect the hexagonal ordering of the silica, a distinct advantage over conventional pore swelling techniques

    Cervical mucus sialic acid content determines the ability of frozen-thawed ram sperm to migrate through the cervix

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    The aim of this study was to investigate the properties and to functionally characterize the cervical mucus that modulates sperm transport through the cervix by using ewe breeds with a divergent pregnancy rate (Belclare and Suffolk; high and low, respectively) following cervical insemination using frozen-thawed semen. Sperm number, as well as sialic acid and fricose content in both the channels and in the lumen of different regions of the cervix were quantified in inseminated Belclare and Suffolk ewes. Expression of glycosyltransferase and MUC genes, glycosidase activity and sialic acid speciation in follicular phase cervical tissue and mucus were assessed. More spermatozoa were found in the cervical channels in the region dosest to the cervical os in Belclare than Suffolk ewes (P 0.05). Levels of Neu5Ac were higher in Belclare than Suffolk ewes (P < 0.05) and levels of Neu5Gc was higher in Suffolk than Belclare ewes (P < 0.05). Competitive sperm penetration assays demonstrated that frozen-thawed sperm progression increased when cervical mucus was incubated with sialyllactose prior to a sperm penetration test (P < 0.05). These results suggest that the difference between Belclare and Suffolk ewes in sperm transport with frozen-thawed semen is due to the higher concentration of sialic acid within channels, which binds to spermatozoa and reduces their ability to traverse the cervix

    Effect of siRNA-mediated <i>SPATS2L</i> knockdown on β<sub>2</sub>-adrenergic receptor levels in HASM cells.

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    <p>(A) Knockdown efficiency of two <i>SPATS2L</i> siRNAs. Quantitative real-time PCR was done on RNAs extracted from HASM cells transfected with control non-targeting (NT) or <i>SPATS2L</i>-specific siRNAs. (B) Western blot analysis of β<sub>2</sub>AR protein in <i>SPATS2L</i> knockdown HASM cells. Three independent experiments (siRNA transfection and Western blot analysis) were done in HASM cells. The upper panel is a representative of the three Western blots. Quantification of the β<sub>2</sub>AR protein amount (normalized against the control β-actin protein) from three Western blots is shown in the lower panel.</p

    Study overview.

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    <p>(A) Primary GWAS was conducted using subjects from CAMP, LOCCS, LODO, Sepracor, ACRN, and CARE cohort. Samples genotyped on Illumina platforms (i.e. CAMP/LOCCS/LODO/Sepracor) were pooled and analyzed first. Results from samples genotyped on Affymetrix platforms were analyzed separately and then combined to obtain the primary GWAS results. 1000GP imputed data was utilized to expand the primary GWAS association results. (B) Replication of the top (i.e. P-value<1E-04) SNPs from the primary GWAS were attempted in two independent populations: SARP and DAG. (C) The <i>SPATS2L</i> gene was selected for functional validation based on nominal replication of association results in SARP and analysis of publicly available resources.</p
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