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  • Krause Estes posted an update 1 week, 1 day ago

    The detection and analysis of circulating tumor cells (CTCs) from cancer patients’ blood samples present a powerful means to monitor cancer progression. In this work, an antifouling nanostructure substrate made of hydrogel nanoparticles was fabricated for an effective capture of CTCs from the blood samples. The hydrogel nanoparticles were synthesized by zwitterionic sulfobetaine methacrylate (SBMA), methacrylic acid (MAA) and N, N’-methylene bisacrylamide (MBA) through a simple polymerization. SBMA could provide an effective antifouling layer for the substrate to prevent nonspecific cell adhesion, MAA could afford active carboxyl groups for the immobilization of antibody to achieve specific CTC capture, and the nanostructured surface could improve the interaction of the target cells with the antibody modified substrate surface to enhance the capture efficiency of CTCs. Moreover, it was not necessary to further modify the antifouling molecules on the hydrogel nanoparticle substrate’s surface, reducing the complexity and difficulty of the substrate preparation. The results showed that about 87 % of target cells (MCF-7 cells) were captured on the antibody modified hydrogel nanoparticle substrate. In contrast, the substrate showed little adhesive capacity for the nonspecific cells (K562 cells), and only 0.15 % of cells were captured. And 98 % of the captured cells kept good cell viability. Finally, 1-32 CTCs/mL were detected from the blood samples of five cancer patients, while no CTC was found in five healthy samples. It is envisaged that the new hydrogel nanostructure substrate is capable of capturing CTCs efficiently and specifically from patient blood samples to be used in cancer treatment.Although considerable efforts have been made to vary the alkyl chain length in the quaternary ammonium compounds (QACs) for optimizing the antibacterial activity, only few researchers have systematically investigated the combinatory effects of alkyl chain length and another acryl monomers with the different chemical configuration on the antibacterial activity of the modified substrate. In this study, by surface grafting of various copolymeric brushes, different modified cotton substrates were prepared by surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization reaction for exploring the effects of alkyl chain length of QACs and the fluorine content on antibacterial and anti-microbial adhesion characteristics. The quaternized monomers used were prepared by quaternization of 2-(dimethylamino) ethyl methacrylate (DMAEMA) with 1-bromooctane (DMAEMA + 8), and 1-bromopropane (DMAEMA + 3). The fluoro-containing monomer was 2,2,2-Trifluoroethyl methacrylate (TFEMA). Ethyl methacrylate (EMA) was also used for comparison. Results have shown that the optimal antibacterial and anti-microbial adhesion characteristics were noted on the substrates grafted with DMAEMA + 8 and TFEMA. This can be attributed to the enhanced degree of surface quaternization due to the hydrophobic interactions between the grafted TFEMA and DMAEMA + 8 chains, leading to an increase in antibacterial efficacy of modified cotton substrates.In this study, a laccase from Madurella mycetomatis (MmLac) was produced heterologously in Pichia pastoris; the initial immobilization in a metal-organic framework (MOF) (MmLac/ZIF-8) was achieved using zinc nitrate and 2-methylimidazole. Due to the instability of MmLac/ZIF-8 in an acidic medium, a silica layer was created on the surface of MmLac/MOF-8. The immobilized laccase composite (silica@MmLac/ZIF-8) obtained was further treated with glutaraldehyde (silica@Glu-MmLac/ZIF-8) to increase stability of composite. Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy techniques were used to confirm the immobilization of MmLac and to investigate the morphology of the immobilized laccase samples. The MmLac samples were also characterised in terms of optimum pH, temperature and thermal stability. The optimum pH of all the MmLac samples was determined to be 4.0. The free MmLac showed maximum activity at 55 °C, whereas both silica@MmLac/ZIF-8 and silica@Glu-MmLac/ZIF-8 were maximumly active at 65 °C. The silica@MmLac/ZIF-8 and silica@Glu-MmLac/ZIF-8 were 9.3- and 11.8-fold higher in stability, respectively, than the free MmLac at 65 °C. Selleckchem Foscenvivint Furthermore, both silica@MmLac/ZIF-8 and silica@Glu-MmLac/ZIF-8 showed a higher bleaching performance than free MmLac on cotton woven fabric. According to these results, silica@MmLac/ZIF-8 and silica@Glu-MmLac/ZIF-8 may be promising candidates for biocatalysts in laccase-based biotechnological applications.In current study, the enhancement effect of magnetite on anaerobic digestion was evaluated at increased organic loading rate (OLR) from 1.6 to 25.6 kg COD·m-3·d-1. The supplement of magnetite enhanced the methane yield by 7-483% accompanied with faster VFAs conversion. Microbial analysis suggested the varied enhancing effect achieved at different OLRs was attributed to different syntrophic interactions triggered by magnetite. More specially, an electroactive syntropy was established between Trichococcus with Methanobacterium at OLR lower than 6.4 kg COD·m-3·d-1, while with the OLR increase, more acid fermentative bacteria (Propionimicrobium, Syner-01) were enriched and further enhanced methanogenesis in a syntrophic way with Methanosaeta. Overall, the incorporation of magnetite was a promising approach to achieve efficient anaerobic digestion, OLR was also critical factor affecting the methanogenesis and should be carefully regulated in future application.The objective of this study was to understand how lactate-to-butyrate ratio and substrates concentrations affect the caproate production and product structure. The results showed that a higher butyrate-to-lactate ratio is beneficial to caproate production at low initial lactate concentration. Low pH (5.0) and low substrate concentration (20 mM and 40 mM) effectively decreased propionate production via restrained acrylate pathway, resulting in higher electron efficiency of caproate. With the optimum mole ratio of lactate to butyrate (14) and 80 mM initial butyrate concentration, the electron efficiency of caproate reached the maximum (43.10%). Moreover, high butyrate concentration suppressed the production of odd-carbon-number carboxylates while promoting the production of caproate. Compared with the batch operation, the caproate production in semi-continuous operation was enhanced by 3.45 times to 30.91 ± 1.07 mM as the acrylate pathway was successfully inhibited in semi-continuous experiments due to low pH and low lactate concentration.