2,811 research outputs found
Enhancement of anammox performance in a novel non-woven fabric membrane bioreactor (nMBR)
Š 2015 The Royal Society of Chemistry. To reduce operating costs and membrane fouling of conventional membrane bioreactors (cMBR), a novel MBR using a non-woven fabric membrane (nMBR) was constructed and the performance of the two MBRs was compared for anaerobic ammonium oxidation (anammox) cultivation. The results showed that the start-up period for the nMBR (44 days) was notably shorter than that for the cMBR (56 days), meanwhile the nMBR achieved a 2-times higher nitrogen removal rate (231.5 mg N per L per d) compared to the cMBR (112.3 mg N per L per d). Illumina MiSeq sequencing showed that Candidatus Kuenenia and Candidatus Jettenia were the main distinguished anammox bacteria. FISH analysis revealed that anammox bacteria predominated in both reactors, especially in the nMBR (58%) corresponding to a qPCR analysis of 1.07 à 109 copies per mL (day 120). N2O emission analysis confirmed the advantage of the nMBR in N2O reduction to reduce the influence of greenhouse gas emission while treating identical nitrogen. These results clearly demonstrated that nMBRs could be a prospective choice for anammox start-up and performance enhancement
Co3O4 particles grown over nanocrystalline CeO2: influence of precipitation agents and calcination temperature on the catalytic activity for methane oxidation
Crystalline cobalt oxides were prepared by a precipitation method using three different precipitation
agents, IJNH4)2CO3, Na2CO3 and COIJNH2)2. Cobalt oxide nanoparticles corresponding to a Co3O4 loading
of 30 wt% were also deposited over high-surface area nanocrystalline ceria by the same precipitation
agents. The effect of calcination temperature, 350 or 650 °C, on the morphological and structural properties
was evaluated. Characterization by BET, XRD, SEM, TEM, Raman spectroscopy, H2-TPR, XPS and
NH3-TPD was performed and the catalytic properties were explored in the methane oxidation reaction.
The nature of the precipitation agent strongly influenced the textural properties of Co3O4 and the
Co3O4âCeO2 interface. The best control of the particle size was achieved by using COIJNH2)2 that
produced small and regular crystallites of Co3O4 homogeneously deposited over the CeO2 surface. Such a
Co3O4âCeO2 system precipitated by urea showed enhanced low-temperature reducibility and high surface
Co3+ concentration, which were identified as the key factors for promoting methane oxidation at
low temperature. Moreover, the synergic effect of cobalt oxide and nanocrystalline ceria produced stable
full conversion of methane in the entire range of investigated temperature, up to 700â800 °C, at which
Co3O4 deactivation usually occurs
Atropselective syntheses of (-) and (+) rugulotrosin A utilizing point-to-axial chirality transfer
Chiral, dimeric natural products containing complex structures and interesting biological properties have inspired chemists and biologists for decades. A seven-step total synthesis of the axially chiral, dimeric tetrahydroxanthone natural product rugulotrosin A is described. The synthesis employs a one-pot Suzuki coupling/dimerization to generate the requisite 2,2'-biaryl linkage. Highly selective point-to-axial chirality transfer was achieved using palladium catalysis with achiral phosphine ligands. Single X-ray crystal diffraction data were obtained to confirm both the atropisomeric configuration and absolute stereochemistry of rugulotrosin A. Computational studies are described to rationalize the atropselectivity observed in the key dimerization step. Comparison of the crude fungal extract with synthetic rugulotrosin A and its atropisomer verified that nature generates a single atropisomer of the natural product.P50 GM067041 - NIGMS NIH HHS; R01 GM099920 - NIGMS NIH HHS; GM-067041 - NIGMS NIH HHS; GM-099920 - NIGMS NIH HH
The electrochemical behaviour of magnetocaloric alloys La(Fe,Mn,Si)13Hx under magnetic field conditions
The degradation mechanism of La(Fe,Mn,Si)13Hx has been examined under conditions representative of the complex operating parameters of a refrigeration cycle. The magnetic field effects are found to be dominated by magneto-transport and are most significant when the material is in its paramagnetic state - resulting in significantly accelerated corrosion rates
Research on the Security of Cold-Chain Logistics
In this paper, the definition of cold-chain logistics and security features are analyzed. Based on overview of China's cold-chain logistics, cold chain, through the status quo at home and abroad contrast, we present some of China's food chain problems. With security control system of thought, and risk management theory, the establishment of a more comprehensive evaluation of cold chain logistics system, through a cold-chain business case analysis, put forward suggestions to solve a few cold-chain logistics security strategy
Rigidity of SU(2,2|2)-symmetric solutions in Type IIB
We investigate the existence of half-BPS solutions in Type IIB supergravity
which are invariant under the superalgebra SU(2,2|2) realized on either AdS_5 x
S^2 x S^1 or AdS_5 x S^3 warped over a Riemann surface \Sigma with boundary. We
prove that, in both cases, the only solution is AdS_5 x S^5 itself. We argue
that this result provides evidence for the non-existence of fully back-reacted
intersecting D3/D7 branes with either AdS_5 x S^2 x S^1 x \Sigma or AdS_5 x S^3
x \Sigma near-horizon limits.Comment: 55 page
KIAA0101 (OEACT-1), an expressionally down-regulated and growth-inhibitory gene in human hepatocellular carcinoma
BACKGROUND: Our previous cDNA array results indicated KIAA0101 as one of the differentially expressed genes in human hepatocellular carcinoma (HCC) as compared with non-cancerous liver. However, it is necessary to study its expression at protein level in HCC and its biological function for HCC cell growth. METHOD: Western blot and tissue array were performed to compare KIAA0101 protein expression level in paired human HCC and non-cancerous liver tissues from the same patients. Investigation of its subcellular localization was done by using dual fluorescence image examination and enriched mitochondrial protein Western blot analysis. The in vitro cell growth curve was used for examing the effect of over-expression of KIAA0101 in HCC cells. FACS was used to analyze the cell cycle pattern in KIAA0101 expression positive (+) and negative (-) cell populations isolated by the pMACSKK(II )system after KIAA0101 cDNA transfection. RESULTS: Western blot showed KIAA0101 protein expression was down-regulated in HCC tissues as compared with their counterpart non-cancerous liver tissues in 25 out of 30 cases. Tissue array also demonstrated the same pattern in 161 paired samples. KIAA0101 was predominantly localized in mitochondria and partially in nuclei. KIAA0101 cDNA transfection could inhibit the HCC cell growth in vitro. In cell cycle analysis, it could arrest cells at the G(1 )to S phase transition. CONCLUSION: KIAA0101 protein expression was down-regulated in HCC. This gene could inhibit the HCC cell growth in vitro and presumably by its blocking effect on cell cycle
HLA-A Confers an HLA-DRB1 Independent Influence on the Risk of Multiple Sclerosis
A recent high-density linkage screen confirmed that the HLA complex contains the strongest genetic factor for the risk of multiple sclerosis (MS). In parallel, a linkage disequilibrium analysis using 650 single nucleotide polymorphisms (SNP) markers of the HLA complex mapped the entire genetic effect to the HLA-DR-DQ subregion, reflected by the well-established risk haplotype HLA-DRB1*15,DQB1*06. Contrary to this, in a cohort of 1,084 MS patients and 1,347 controls, we show that the HLA-A gene confers an HLA-DRB1 independent influence on the risk of MS (Pâ=â8.4Ă10â10). This supports the opposing view, that genes in the HLA class I region indeed exert an additional influence on the risk of MS, and confirms that the class I allele HLA-A*02 is negatively associated with the risk of MS (ORâ=â0.63, Pâ=â7Ă10â12) not explained by linkage disequilibrium with class II. The combination of HLA-A and HLA-DRB1 alleles, as represented by HLA-A*02 and HLA-DRB1*15, was found to influence the risk of MS 23-fold. These findings imply complex autoimmune mechanisms involving both the regulatory and the effector arms of the immune system in the triggering of MS
SL(2,R) Chern-Simons, Liouville, and Gauge Theory on Duality Walls
We propose an equivalence of the partition functions of two different 3d
gauge theories. On one side of the correspondence we consider the partition
function of 3d SL(2,R) Chern-Simons theory on a 3-manifold, obtained as a
punctured Riemann surface times an interval. On the other side we have a
partition function of a 3d N=2 superconformal field theory on S^3, which is
realized as a duality domain wall in a 4d gauge theory on S^4. We sketch the
proof of this conjecture using connections with quantum Liouville theory and
quantum Teichmuller theory, and study in detail the example of the
once-punctured torus. Motivated by these results we advocate a direct
Chern-Simons interpretation of the ingredients of (a generalization of) the
Alday-Gaiotto-Tachikawa relation. We also comment on M5-brane realizations as
well as on possible generalizations of our proposals.Comment: 53+1 pages, 14 figures; v2: typos corrected, references adde
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