Nitrogen and carbon mineralisation of leather meal in soil as affected by particle size of fertiliser and microbiological activity of soil     

Maria?Teresa?Dell'AbateEmail author  Anna?Benedetti  Alessandra?Trinchera  Daniele?Galluzzo 《Biology and Fertility of Soils》2003,37(2):124-129

Carbon and nitrogen mineralisation of leather meal fertilisers were studied in two soils characterised by different respiration activity. Both C and N mineralisation were highest in the most active soil, and when leather meal was added as a powder rather than as 2- to 4- and 4- to 6-mm particles. Fast and slow soluble N pools were determined after extraction with cold water and with hot buffer, respectively. The N remaining after the second extraction with hot buffer was named slow-release N. The percentage of slow-release N rose as the size of the applied leather meal particles increased, whereas fast soluble N was highest in the coarsest (4-6 mm) fertiliser.  相似文献   

Forms of Cd,Cu, Pb,and Zn in soil and their uptake by cereal crops when applied jointly as carbonates     

Anna Chlopecka 《Water, air, and soil pollution》1996,87(1-4):297-309

The cereal crops (barley -Hordeum vulgare L., maize -Zea mays L., wheat -Triticum vulgare L.) were grown in a greenhouse using a sandy soil type treated with various doses of cadmium carbonate (salt), copper carbonate (malachite), lead carbonate (cerussite), and zinc carbonate (smithsonite), added jointly. The following levels of these metals were used: Cd ? 5, 10, 50μg g^?1 soil; Cu and Pb - 50,100, 500 μg g^?1 soil; Zn-150, 300, 1500 μg g-1 soil. Sequential extraction was adopted to partition the metals into five operationally-defined fractions: exchangeable, carbonate, Fe-Mn oxides, organic, and residual. The residual was the most abundant fraction in the untreated (control) soil for all the metals studied (50 to 60% of the total metal content). The concentrations of exchangeable Cd, Cu, Pb, and Zn were relatively low in untreated soil but increased (over the three year period) in treated soils for Cd, Zn, and Cu, whereas only small changes were observed for Ph. This experiment showed a significant increase in Cd, Zn, and Cu in tissue of plants grown on the treated soil, but a non-significant change in plant tissue with respect to Pb concentration.  相似文献   

Examples of 'loaded' terms     

Bedford AM 《Public health nutrition》2005,8(7):928

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Fluorescence polarization immunoassay based on a monoclonal antibody for the detection of the organophosphorus pesticide parathion-methyl   总被引：11，自引：0，他引：11  

Kolosova AY  Park JH  Eremin SA  Kang SJ  Chung DH 《Journal of agricultural and food chemistry》2003,51(5):1107-1114

A fluorescence polarization immunoassay (FPIA) based on a monoclonal antibody for the detection of parathion-methyl (PM) was developed and optimized. Fluorescein-labeled PM derivatives (tracers) with different structures were synthesized and purified by thin-layer chromatography. The influence of immunogen and tracer structures on the assay characteristics was investigated. PM concentration determinable by the FPIA ranged from 25 to 10000 ppb. The detection limit was 15 ppb. Methanol extracts of vegetable, fruit, and soil samples were diluted 1/10 for the analysis. Recovery in spiked samples averaged between 85 and 110%. The method developed is characterized by high specificity and reproducibility (CV ranged from 1.5 to 9.1% for interassay and from 1.8 to 14.1% for intra-assay). The FPIA method can be applied to the screening of food and environmental samples for PM residues without complicated cleanup.  相似文献   

Regeneration of peroxiredoxins by p53-regulated sestrins, homologs of bacterial AhpD     

Budanov AV  Sablina AA  Feinstein E  Koonin EV  Chumakov PM 《Science (New York, N.Y.)》2004,304(5670):596-600

Acting as a signal, hydrogen peroxide circumvents antioxidant defense by overoxidizing peroxiredoxins (Prxs), the enzymes that metabolize peroxides. We show that sestrins, a family of proteins whose expression is modulated by p53, are required for regeneration of Prxs containing Cys-SO(2)H, thus reestablishing the antioxidant firewall. Sestrins contain a predicted redox-active domain homologous to AhpD, the enzyme catalyzing the reduction of a bacterial Prx, AhpC. Purified Hi95 (sestrin 2) protein supports adenosine triphosphate-dependent reduction of overoxidized PrxI in vitro, indicating that unlike AhpD, which is a disulfide reductase, sestrins are cysteine sulfinyl reductases. As modulators of peroxide signaling and antioxidant defense, sestrins constitute potential therapeutic targets.  相似文献   

Capping by branching: a new ribozyme makes tiny lariats     

Pyle AM 《Science (New York, N.Y.)》2005,309(5740):1530-1531

The number of naturally occurring RNA enzymes has just been expanded by the discovery of a new branching ribozyme. But this ribozyme has unexpected relatives: group I introns.  相似文献   

Endocannabinoid hydrolysis generates brain prostaglandins that promote neuroinflammation   总被引：2，自引：0，他引：2  

Nomura DK  Morrison BE  Blankman JL  Long JZ  Kinsey SG  Marcondes MC  Ward AM  Hahn YK  Lichtman AH  Conti B  Cravatt BF 《Science (New York, N.Y.)》2011,334(6057):809-813

Phospholipase A(2)(PLA(2)) enzymes are considered the primary source of arachidonic acid for cyclooxygenase (COX)-mediated biosynthesis of prostaglandins. Here, we show that a distinct pathway exists in brain, where monoacylglycerol lipase (MAGL) hydrolyzes the endocannabinoid 2-arachidonoylglycerol to generate a major arachidonate precursor pool for neuroinflammatory prostaglandins. MAGL-disrupted animals show neuroprotection in a parkinsonian mouse model. These animals are spared the hemorrhaging caused by COX inhibitors in the gut, where prostaglandins are instead regulated by cytosolic PLA(2). These findings identify MAGL as a distinct metabolic node that couples endocannabinoid to prostaglandin signaling networks in the nervous system and suggest that inhibition of this enzyme may be a new and potentially safer way to suppress the proinflammatory cascades that underlie neurodegenerative disorders.  相似文献   

Kinetics of morphogen gradient formation     

Kicheva A  Pantazis P  Bollenbach T  Kalaidzidis Y  Bittig T  Jülicher F  González-Gaitán M 《Science (New York, N.Y.)》2007,315(5811):521-525

In the developing fly wing, secreted morphogens such as Decapentaplegic (Dpp) and Wingless (Wg) form gradients of concentration providing positional information. Dpp forms a longer-range gradient than Wg. To understand how the range is controlled, we measured the four key kinetic parameters governing morphogen spreading: the production rate, the effective diffusion coefficient, the degradation rate, and the immobile fraction. The four parameters had different values for Dpp versus Wg. In addition, Dynamin-dependent endocytosis was required for spreading of Dpp, but not Wg. Thus, the cellular mechanisms of Dpp and Wingless spreading are different: Dpp spreading requires endocytic, intracellular trafficking.  相似文献   

Crystal structure of a self-spliced group II intron     

Toor N  Keating KS  Taylor SD  Pyle AM 《Science (New York, N.Y.)》2008,320(5872):77-82

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Flavonoids from Radix Astragali induce the expression of erythropoietin in cultured cells: a signaling mediated via the accumulation of hypoxia-inducible factor-1α   总被引：1，自引：0，他引：1  

Zheng KY  Choi RC  Cheung AW  Guo AJ  Bi CW  Zhu KY  Fu Q  Du Y  Zhang WL  Zhan JY  Duan R  Lau DT  Dong TT  Tsim KW 《Journal of agricultural and food chemistry》2011,59(5):1697-1704

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