[Deng, Ye; Van Nostrand, Joy D.; Xue, Kai; Zhou, Jizhong; Wu, Liyou; Xie, Jianping; He, Zhili] Univ Oklahoma, Inst Environm Genom, Norman, OK 73019 USA.;[Deng, Ye; Van Nostrand, Joy D.; Fei, Shenfeng; Xue, Kai; Luo, Yiqi; Zhou, Jizhong; Wu, Liyou; Xie, Jianping; Cheng, Xiaoli; He, Zhili] Univ Oklahoma, Dept Bot & Microbiol, Norman, OK 73019 USA.;[Zhou, Jizhong] Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94270 USA.;[Zhou, Jizhong] Tsinghua Univ, Sch Environm, State Key Joint Lab Environm Simulat & Pollut Con, Beijing 100084, Peoples R China.;[Xie, Jianping] Cent S Univ, Sch Mineral Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
[Zhou, Jizhong] Univ Oklahoma, Inst Environm Genom, Norman, OK 73019 USA.
Understanding the mechanisms of biospheric feedbacks to climate change is critical to project future climate warming(1-3). Although microorganisms catalyse most biosphere processes related to fluxes of greenhouse gases, little is known about the microbial role in regulating future climate change(4). Integrated metagenomic and functional analyses of a long-term warming experiment in a grassland ecosystem showed that microorganisms play crucial roles in regulating soil carbon dynamics through three primary feedback mechanisms: shifting microbial community composition, which most likely led to the reduced temperature sensitivity of heterotrophic soil respiration; differentially stimulating genes for degrading labile but not recalcitrant carbon so as to maintain long-term soil carbon stability and storage; and enhancing nutrient-cycling processes to promote plant nutrient-use efficiency and hence plant growth. Elucidating microbially mediated feedbacks is fundamental to understanding ecosystem responses to climate warming and provides a mechanistic basis for carbon-climate modelling.
Nannochloropsis oculata CCMP 525, Dunaliella salina FACHB 435, and Chlorella sorokiniana CCTCC M209220 were compared in mixotrophic and photoautotrophic cultures in terms of growth rate, protein, and lipid content. Growth improved in glucose, and the biomass productivities of N. oculata, D. salina, and C. sorokiniana were found to be 1.4-, 2.2- and 4.2-fold that observed photoautotrophically. However, biomass and lipid production decreased at the highest glucose concentrations. Meanwhile, the content of protein and lipid were significantly augmented for mixotrophic conditions at least for some species. C. sorokiniana was found to be well suited for lipid production based on its high biomass production rate and lipid content reaching 51% during mixotrophy. Expression levels of accD (heteromeric acetyl-CoA carboxylase beta subunit), acc1 (homomeric acetyl-CoA carboxylase), rbcL (ribulose 1, 5-bisphosphate carboxylase/oxygenase large subunit) genes in C. sorokiniana were studied by real-time PCR. Increased expression levels of accD reflect the increased lipid content in stationary phase of mixotrophic growth, but expression of the acc1 gene remains low, suggesting that this gene may not be critical to lipid accumulation. Additionally, reduction of expression of the rbcL gene during mixotrophy indicated that utilization of glucose was found to reduce the role of this gene and photosynthesis.
Halloysite nanotubes (HNTs) showed natural nanotubular structures with similar chemical composition to kaolin. This paper reviewed the exciting applications of HNTs due to their abundantly deposit, nanoscale lumens, high length-to-diameter ratios, and relatively low surface hydroxyl group density. HNTs have been used as ideal templates for conveniently immobilizing nanoparticles, which could enable the construction of designed nanoarchitectures that are extremely attractive as supports for heterogeneous catalysts and for use in the fuel cells and related technologies that exploited the inherent 'smallness' and hollow characteristics of the nanoparticles. The recent developments in this area by exploring the various techniques with which HNTs could be functionalized with metal nanoparticles, and the diverse applications of the resulting materials overviewed in detail. The corresponding interfacial characteristics of the nanocomposites were emphasized. (C) 2015 Elsevier B.V. All rights reserved.
An, Xiuli;Schulz, Vincent P.;Li, Jie;Wu, Kunlu;Liu, Jing;Xue, Fumin;Hu, Jingping;Mohandas, Narla;Gallagher, Patrick G.*
Gallagher, Patrick G.
[An, Xiuli; Hu, Jingping; Xue, Fumin] New York Blood Ctr, Lab Membrane Biol, New York, NY 10021 USA.;[Liu, Jing; Li, Jie; An, Xiuli; Mohandas, Narla; Wu, Kunlu] New York Blood Ctr, Red Cell Physiol Lab, New York, NY 10021 USA.;[An, Xiuli] Zhengzhou Univ, Coll Life Sci, Zhengzhou 450052, Henan, Peoples R China.;[Schulz, Vincent P.; Gallagher, Patrick G.] Yale Univ, Sch Med, Dept Pediat, New Haven, CT 06520 USA.;[Liu, Jing; Wu, Kunlu] Cent S Univ, Mol Biol Res Ctr, Sch Biol Sci & Technol, Changsha, Hunan, Peoples R China.
[Gallagher, Patrick G.] Yale Univ, Sch Med, Dept Pediat, 333 Cedar St,POB 208064, New Haven, CT 06520 USA.
We recently developed fluorescence-activated cell sorting (FACS)-based methods to purify morphologically and functionally discrete populations of cells, each representing specific stages of terminal erythroid differentiation. We used these techniques to obtain pure populations of both human and murine erythroblasts at distinct developmental stages. RNA was prepared from these cells and subjected to RNA sequencing analyses, creating unbiased, stage-specific transcriptomes. Tight clustering of transcriptomes from differing stages, even between biologically different replicates, validated the utility of the FACS-based assays. Bioinformatic analyses revealed that there were marked differences between differentiation stages, with both shared and dissimilar gene expression profiles defining each stage within transcriptional space. There were vast temporal changes in gene expression across the differentiation stages, with each stage exhibiting unique transcriptomes. Clustering and network analyses revealed that varying stage-specific patterns of expression observed across differentiation were enriched for genes of differing function. Numerous differences were present between human and murine transcriptomes, with significant variation in the global patterns of gene expression. These data provide a significant resource for studies of normal and perturbed erythropoiesis, allowing a deeper understanding of mechanisms of erythroid development in various inherited and acquired erythroid disorders.
[Yang, Huaming] Cent S Univ, Dept Inorgan Mat, Sch Minerals Proc & Bioengn, Changsha 410083, Peoples R China.
Palladium (Pd) nanoparticles were deposited on the surface of halloysite nanotubes (HNTs) modified with gamma-aminopropyltriethoxysilane (APTES) to produce Pd/NH2-HNTs nanocomposites. The results indicated that Pd nanoparticles were densely immobilized onto NH2-HNTs with an average diameter of similar to 3 nm. The Pd distribution on the surface of silanized HNTs showed much more uniform, and the Pd nanoparticle size became smaller compared with those directly deposited onto HNTs without silanization. Systematic characterization demonstrated that APTES were chemically bonded onto HNTs, and further confirmed the bond formation between Pd and -NH2 groups, which could ensure the firm deposit of Pd nanoparticles on the surface of silanized HNTs. The as-synthesized Pd/NH2-HNTs exhibited an excellent catalytic activity in the liquid-phase hydrogenation of styrene to ethylbenzene with full conversion within 30 min. The mechanism of the deposit of Pd nanoparticles on silanized HNTs was also investigated.
In this paper, the reduction roasting of laterite ore in the absence or presence of sodium sulfate was carried out for nickel beneficiation by wet magnetic separation. Sodium sulfate is found to be capable of enhancing the reduction of laterite ore through liberating iron and nickel from Ni/Fe substituted-lizardite, as well as increasing the size of ferronickel particles considerably. When the laterite pellets were reduced at 1100 degrees C for 60 min, the average particle size of ferronickel grains was approximately 50 mu m in the presence of sodium sulfate, which far exceeded the size of 5-10 mu m in the absence of sodium sulfate. Compared with those reduced without sodium sulfate, the Ni grade of ferronickel concentrate increased from 2.33% to 9.48%, and the magnetic separation recovery of Ni increased from 56.97% to 83.01% with the addition of 20 wt.% sodium sulfate. Experimental evidence showed that troilite (FeS) serves as an activating agent to accelerate melt phase formation via a low melting point (985 degrees C) Fe-FeS eutectic. This markedly facilitated the aggregation of ferronickel particles during reduction, along with the selective enrichment of Ni by suppressing the complete metallization of Fe. (c) 2012 Elsevier Ltd. All rights reserved.
MoS2/montmorillonite (MoS2/MMT) composite nanosheets have been successfully synthesized by a facile hydrothermal method, and the catalytic activities of composites are evaluated by reduction reaction of methyl orange in aqueous phase. A preparation strategy demonstrates that MoS2 can be in situ formed on the surface of MMT from Na2MoO4· and H2NCSNH2. The microstructures and morphologies characterization indicates that few‐layered MoS2 nanosheets are uniformly grown on the surface of montmorillonite, and the hydrogen bonds are formed at the interfaces. The catalytic activity of MoS2/MMT is enhanced by support of montmorillonite, which can be attributed to the large surface area, more reactive sites, dispersibility of MoS2/MMT, and the synergistic adsorption property of montmorillonite. Based on density functional theory calculations, the preferred adsorption configurations of MoS2 cluster on MMT are studied. The supporting effect of MMT on MoS2 nanoparticles will lead to the anchoring of these reactive MoS2 nanoparticles on clay surface and enhance the absorption ability of MoS2 to the organics and meanwhile improving the catalytic properties of the MoS2/MMT composite. The MoS2/MMT composite nanosheets show prospective application to treat effectively wastewater of dyes.