A fast and convenient soil analytical technique is needed for soil quality assessment and precision soil management. The main objective of this study was to evaluate the ability of near-infrared reflectance spectroscopy (NIRS) to predict diverse soil properties. Near-infrared reflectance spectra, obtained from a Perstrop NIR Systems 6500 scanning monochromator (Foss NIRSystems, Silver Spring, MD), and 33 chemical, physical, and biochemical properties were studied for 802 soil samples collected from four Major Land Resource Areas (MLRAs). Calibrations were based on principal component regression (PCR) using the first derivatives of optical density [log(1/R)] for the 1300-to 2500-nm spectral range. Total C, total N, moisture, cation-exchange capacity (CEC), 1.5 MPa water, basal respiration rate, sand, silt, and Mehlich III extractable Ca were successfully predicted by NIRS (r 2 > 0.80). Some Mehlich III extractable metals (Fe, K, Mg, Mn) and exchangeable cations (Ca, Mg, and K), sum of exchangeable bases, exchangeable acidity, clay, potentially mineralizable N, total respiration rate, biomass C, and pH were also estimated by NIRS but with less accuracy (r 2 = 0.80∼0.50). The predicted results for aggregation (wt% > 2, 1, 0.5, 0.25 mm, and macroaggregation) were not reliable (r 2 = 0.46∼0.60). Mehlich III extractable Cu, P, and Zn, and exchangeable Na could not be predicted using the NIRS-PCR technique (r 2 < 0.50). The results indicate that NIRS can be used as a rapid analytical technique to simultaneously estimate several soil properties with acceptable accuracy in a very short time.

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Fucosylated glycoconjugates have critical roles in biological processes, but a limited availability of alpha-l-fucosidase has hampered research on this human enzyme (h-Fuc) at a molecular level. After overexpressing h-Fuc in Escherichia coli as an active form, we investigated the catalytic function of this recombinant enzyme. Based on sequence alignment and structural analysis of close homologues of h-Fuc, nine residues of glutamate and aspartate in h-Fuc were selected for mutagenic tests to determine the essential residues. Among the mutants, D225N, E289Q, and E289G lost catalytic activity significantly; their k(cat) values are 1/5700, 1/430, and 1/340, respectively, of that of the wild-type enzyme. The Brønsted plot for k(cat)/K(m) for the E289G mutant is linear with beta(lg) = -0.93, but that for k(cat) is biphasic, with beta(lg) for poor substrates being -0.88 and for activated substrates being -0.11. The small magnitude of beta(lg) for the activated substrates may indicate that the rate-limiting step of the reaction is defucosylation, whereas the large magnitude of the latter beta(lg) value for the poor substrates indicates that the rate-limiting step of the reaction becomes fucosylation. The kinetic outcomes support an argument that Asp(225) functions as a nucleophile and Glu(289) as a general acid/base catalyst. As further evidence, azide significantly reactivated D225G and E289G, and (1)H NMR spectral analysis confirmed the formation of beta-fucosyl azide and alpha-fucosyl azide in the azide rescues of D225G and E289G catalyses, respectively. As direct evidence to prove the function of Glu(289), an accumulation of fucosyl-enzyme intermediate was detected directly through ESI/MS analysis.

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New organic dyes comprising carbazole, iminodibenzyl, or phenothiazine moieties, respectively, as the electron donors, and cyanoacetic acid or acrylic acid moieties as the electron acceptors/anchoring groups were synthesized and characterized. The influence of heteroatoms on carbazole, iminodibenzyl and phenothiazine donors, and cyano-substitution on the acid acceptor is evidenced by spectral, electrochemical, photovoltaic experiments, and density functional theory calculations. The phenothiazine dyes show solar-energy-to-electricity conversion efficiency (η) of 3.46–5.53%, whereas carbazole and iminodibenzyl dyes show η of 2.43% and 3.49%, respectively.

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