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101.
102.
This study was undertaken to compare the chemical properties and yields of pineapple leaf residue (PLR) char produced by field burning (CF) with that produced by a partial combustion of air-dried PLR at 340 °C for 3 h in a furnace (CL). Higher total C, lignin content, and yield from CL as well as the presence of aromatic compounds in the Fourier Transform Infrared spectra of the char produced from CL suggest that the CL process was better in sequestering C than was the CF process. Although the C/N ratio of char produced from CL was low indicating a high N content of the char, the C in the char produced from CL was dominated by lignin suggesting that the decomposition of char produced from CL would be slow. To sequester C by char application, the PLR should be combusted in a controlled process rather than by burning in the field. 相似文献
103.
104.
采用盆栽试验,研究了中药渣蚓粪对玉米生长及土壤肥力的影响.结果表明: 随着蚓粪施用量的增加,玉米的株高、茎粗、叶面积、叶绿素含量均显著增加;生长60 d收获时,多数蚓粪处理的土壤容重显著降低;蚓粪处理的土壤pH显著高于对照和相应的化肥处理.蚓粪处理的土壤全氮、有机质含量也明显高于化肥处理,且随蚓粪施用量的增加,效果越趋显著.中药渣蚓粪可作为一种高效有机肥,其合理施用有助于改善土壤物理结构,缓解土壤的酸化进程,提高土壤有机质和氮素含量,有效促进作物生长. 相似文献
105.
Oxygen consumption in Mn-depleted photosystem II (PSII) preparations under continuous and pulsed illumination is investigated. It is shown that removal of manganese from the water-oxidizing complex (WOC) by high pH treatment leads to a 6-fold increase in the rate of O2 photoconsumption. The use of exogenous electron acceptors and donors to PSII shows that in Mn-depleted PSII preparations along with the well-known effect of O2 photoreduction on the acceptor side of PSII, there is light-induced O2 consumption on the donor side of PSII (nearly 30% and 70%, respectively). It is suggested that the light-induced O2 uptake on the donor side of PSII is related to interaction of O2 with radicals produced by photooxidation of organic molecules. The study of flash-induced O2 uptake finds that removal of Mn from the WOC leads to O2 photoconsumption with maximum in the first flash, and its yield is comparable with the yield of O2 evolution on the third flash measured in the PSII samples before Mn removal. The flash-induced O2 uptake is drastically (by a factor of 1.8) activated by catalytic concentration (5-10 μM, corresponding to 2-4 Mn per RC) of Mn2+, while at higher concentrations (> 100 μM) Mn2+ inhibits the O2 photoconsumption (like other electron donors: ferrocyanide and diphenylcarbazide). Inhibitory pre-illumination of the Mn-depleted PSII preparations (resulting in the loss of electron donation from Mn2+) leads to both suppression of flash-induced O2 uptake and disappearance of the Mn-induced activation of the O2 photoconsumption. We assume that the light-induced O2 uptake in Mn-depleted PSII preparations may reflect not only the negative processes leading to photoinhibition but also possible participation of O2 or its reactive forms in the formation of the inorganic core of the WOC. 相似文献
106.
107.
Reversible unfolding of the severe acute respiratory syndrome coronavirus main protease in guanidinium chloride 下载免费PDF全文
Chemical denaturant sensitivity of the dimeric main protease from severe acute respiratory syndrome (SARS) coronavirus to guanidinium chloride was examined in terms of fluorescence spectroscopy, circular dichroism, analytical ultracentrifuge, and enzyme activity change. The dimeric enzyme dissociated at guanidinium chloride concentration of <0.4 M, at which the enzymatic activity loss showed close correlation with the subunit dissociation. Further increase in guanidinium chloride induced a reversible biphasic unfolding of the enzyme. The unfolding of the C-terminal domain-truncated enzyme, on the other hand, followed a monophasic unfolding curve. Different mutants of the full-length protease (W31 and W207/W218), with tryptophanyl residue(s) mutated to phenylalanine at the C-terminal or N-terminal domain, respectively, were constructed. Unfolding curves of these mutants were monophasic but corresponded to the first and second phases of the protease, respectively. The unfolding intermediate of the protease thus represented a folded C-terminal domain but an unfolded N-terminal domain, which is enzymatically inactive due to loss of regulatory properties. The various enzyme forms were characterized in terms of hydrophobicity and size-and-shape distributions. We provide direct evidence for the functional role of C-terminal domain in stabilization of the catalytic N-terminal domain of SARS coronavirus main protease. 相似文献
108.
Production of waste hair in the leather manufacturing industry is increasing every year due to the adoption of hair-save unhairing
techniques, leaving the tanners with the problem of coping with yet another solid by-product. Numerous potential strategies
for hair utilisation have been proposed. However, the use of hair waste as agricultural fertiliser is one of its most promising
applications due to the high nitrogen content of hair. Agricultural value of hair can be increased by composting. This paper
deals with the composting of hair from the unhairing of bovine hide. Results indicated that hair cannot be either composted
on its own or co-composted with de-inking sludge, a chemical complementary co-substrate. However, good results were obtained
when co-composted with raw sludge from a municipal wastewater treatment plant at hair:raw sludge weight ratios 1:1, 1:2 and,
1:4 in lab scale and pilot plant scale composters. In all cases, a more stable product was achieved at the end of the process.
Composting in the pilot plant composter was effectively monitored using Static Respiration Indices determined at process temperature
at sampling (SRI
T
) and at 37°C (SRI37). Notably, SRI
T
values were more sensitive to changes in the biological activity. In contrast, Respiratory Quotient (RQ) values were not
adequate to follow the development of the process. 相似文献
109.
Michal Ciolkowski Monika Rozanek Maria BryszewskaBarbara Klajnert 《Biochimica et Biophysica Acta - Proteins and Proteomics》2013,1834(10):1982-1987
In this study the ability of three polyamidoamine (PAMAM) dendrimers with different surface charge (positive, neutral and negative) to interact with a negatively charged protein (porcine pepsin) was examined. It was shown that the dendrimer with a positively charged surface (G4 PAMAM-NH2), as well as the dendrimer with a neutral surface (G4 PAMAM-OH), were able to inhibit enzymatic activity of pepsin. It was also found that these dendrimers act as mixed partially non-competitive pepsin inhibitors. The negatively charged dendrimer (G3.5 PAMAM-COOH) was not able to inhibit the enzymatic activity of pepsin, probably due to the electrostatic repulsion between this dendrimer and the protein. No correlation between changes in enzymatic activity of pepsin and alterations in CD spectrum of the protein was observed. It indicates that the interactions between dendrimers and porcine pepsin are complex, multidirectional and not dependent only on disturbances of the secondary structure. 相似文献
110.
Jonathan R. Mielenz John S. Bardsley Charles E. Wyman 《Bioresource technology》2009,100(14):3532-3539
Soybean hulls were evaluated as a resource for production of ethanol by the simultaneous saccharification and fermentation (SSF) process, and no pretreatment of the hulls was found to be needed to realize high ethanol yields with Saccharomyces cerevisiae D5A. The impact of cellulase, β-glucosidase and pectinase dosages were determined at a 15% biomass loading, and ethanol concentrations of 25–30 g/L were routinely obtained, while under these conditions corn stover, wheat straw, and switchgrass produced 3–4 times lower ethanol yields. Removal of carbohydrates also concentrated the hull protein to over 25% w/w from the original roughly 10%. Analysis of the soybean hulls before and after fermentation showed similar amino acid profiles including an increase in the essential amino acids lysine and threonine in the residues. Thus, eliminating pretreatment should assure that the protein in the hulls is preserved, and conversion of the carbohydrates to ethanol with high yields produces a more concentrated and valuable co-product in addition to ethanol. The resulting upgraded feed product from soybean hulls would likely to be acceptable to monogastric as well as bovine livestock. 相似文献