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11.
To investigate the bleaching mechanism, a lignincarbohydrate complex (LCC) model compound, a vinyl ether-type lignin model dimer, and a hexeneuronic acid model compound were treated with dilute sulfuric acid of different pHs. Beech kraft pulp and red pine kraft pulp were also treated with dilute sulfuric acid and then extracted with aqueous alkali. The amount of hexeneuronic acid degradation products in acid effluents and lignin dissolved in alkali effluents were determined. It was found that the benzyl ether-type LCC bond and the vinyl ether bond in lignin were effectively cleaved under the pH where sulfuric acid bleaching of kraft pulp was effective. Hexeneuronic acid group was also effectively degraded during sulfuric acid bleaching. In beech kraft pulp bleaching, both lignin removal and hexeneuronic acid removal contributed to the kappa number reduction. In red pine bleaching, the contribution of hexeneuronic acid removal was negligible, and most of the kappa number reduction was achieved by the lignin removal.Part of this report was presented at the 9th International Symposium on Wood and Pulping Chemistry, Montreal, July 1997  相似文献   
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13.
This study evaluated methane (CH4) emission, intake, digestibility, and nitrogen efficiency in sheep fed diets containing replacement levels (0%, 33%, 50%, and 67% of soybean meal with euglena). In this experiment, four Corriedale wether sheep with an initial body weight of 53.8 ± 4.6 were arranged in a 4 × 4 Latin square design. This experiment lasted 84 days, divided into four experimental periods. Each period lasted 21 days, which consists of 14 days of adaptation to the diets, 5 days to collect samples, and 2 days to collect gas emission from sheep. Methane emission expressed as L/kg DM intake or g/kg DM intake reduced by up to 37% and the energy loss via CH4 (% of GE intake) reduced by up to 34%. No differences (> 0.05) were observed in DM and OM intake and whole tract apparent DM digestibility due to substitution of soybean meal with euglena. The total CP loss reduced significantly (linear, < 0.001) and CP efficiency increased linearly (= 0.03) with increasing concentration of euglena. As a result, nitrogen balance and average daily weight gain remained unchanged despite higher nitrogen concentration in soybean supplemented group. In conclusion, substitution of soybean meal with euglena reduced methane emission without affecting the performance of animals.  相似文献   
14.
Japanese cedar (Cryptomeria japonica) preheated at 700°C was subsequently heated to 1800°C and characterized by electron microscopy, X-ray diffraction, and micro-Raman spectroscopy. The degree of disorder of carbon crystallites and the amount of amorphous phase decreased considerably with an increase in heat treatment temperature to 1400°C, while carbon crystallites clearly developed above this temperature, showing that the microstructure of carbonized wood undergoes drastic changes around 1400°C. Besides showing the bands for sp2-bonded carbon, the Raman spectra showed a shoulder near 1100 cm−1 assigned to sp3-bonded carbon. With an increase of heat treatment temperature, the peak position of the Raman sp3 band shifted to a lower frequency from 1190 to 1120 cm−1, which is due to the transformation of sp3-bonded carbon from an amorphous phase to a nanocrystalline phase. These data showed that the microstructure of carbonized wood from 700° to 1800°C consisted of the combination of sp2- and sp3-bonded carbon, which is probably due to the disordered microstructure of carbonized wood. It is suggested that the sp3-bonded carbon is transformed from an amorphous structure to a nanocrystalline structure with the growth of polyaromatic stacks at temperatures above 1400°C.  相似文献   
15.
Qo inhibitor (QoI) fungicides are used to control gray blight caused by Pestalotiopsis longiseta in Japanese tea cultivation. However, field isolates of P. longiseta highly resistant to QoI fungicides were found in 2008, resulting in failure of QoI fungicidal control. This resistance was attributed to a mutation in the cytochrome b gene (cytb) in which alanine was substituted for glycine at position 143 (G143A). In 2009–2010, we detected field isolates that had an intermediate reaction between sensitive and resistant isolates in a preliminary assay. These isolates showed intermediate sensitivity to azoxystrobin and kresoxim-methyl on PDA plates. The intermediate reaction to azoxystrobin was also confirmed on detached tea leaves. Consequently, they were considered moderately resistant to QoI fungicides. Nucleotide sequencing of cytb showed that moderate resistance correlated with a single point mutation; leucine was substituted for phenylalanine at amino acid position 129 (F129L). Sequence analysis also revealed two types of cytb, with or without an intron between codons 131 and 132, in P. longiseta. F129L and G143A mutations were detected in both types of cytb according to their QoI resistance. This result suggests that G143A and F129L mutations have each occurred at least twice in the P. longiseta population.  相似文献   
16.
Leaves of tomato and barley were inoculated with conidia of Blumeria graminis f. sp. hordei race 1 (R1) or Oidium neolycopersici (KTP-01) to observe cytological responses in search of resistance to powdery mildew. Both conidia formed appressoria at similar rates on tomato or barley leaves, indicating that no resistance was expressed during the prepenetration stage of these fungi. On R1-inoculated tomato leaves, appressoria penetrated the papillae, but subsequent haustorium formation was inhibited by hypersensitive necrosis in the invaded epidermal cells. On the other hand, KTP-01 (pathogenic to tomato leaves) successfully developed functional haustoria in epidermal cells to elongate secondary hyphae, although the hyphal elongation from some conidia was later suppressed by delayed hypersensitive necrosis in some haustorium-harboring epidermal cells. Thus, the present study indicated that the resistance of tomato to powdery mildew fungi was associated with a hypersensitive response in invaded epidermal cells but not the prevention of fungal penetration through host papilla.  相似文献   
17.
The infectivity of a Japanese isolate of tomato powdery mildew, Oidium neolycopersici KTP-01, to tomato cultivars was examined using a resistant cultivar Grace bred in The Netherlands to O. lycopersici, which was recently proposed to be renamed O. neolycopersici. Grace was severely infected with KTP-01, and its susceptibility was similar to that on susceptible tomato cultivars Moneymaker and Ponderosa, suggesting that KTP-01 differs in pathogenicity on tomatoes from those of European and American isolates.  相似文献   
18.
The cathelicidin family is one of the several families of antimicrobial peptides (AMPs). A bovine myeloid antimicrobial peptide (BMAP‐28) belongs to this family. Recently, the emergence of drug‐resistant bacteria such as methicillin‐resistant Staphylococcus aureus (MRSA) has become a big problem. AMPs are expected to be leading compounds of new antibiotics against drug‐resistant bacteria. In this study, we focused on the activity of BMAP‐28 against bacterial cell surfaces. First, we observed morphological change of MRSA caused by BMAP‐28 using a scanning probe microscope. We also studied activities of BMAP‐28 against adherence of S. aureus to fibronectin, collagen type I, collagen type IV. We confirmed whether BMAP‐28 can bind to lipoteichoic acid (LTA) of S. aureus. BMAP‐28 was indicated as damaging the cell surface of MRSA. In a particular range of concentrations, BMAP‐28 promoted adherence of S. aureus against fibronectin and collagens. It was revealed that BMAP‐28 and LTA of S. aureus bound with each other. Our study showed the potential of BMAP‐28 which can damage MRSA and interact with LTA of S. aureus but promote its adherence in some concentrations. This study provides new points of which to take notice when we use AMPs as medicines.  相似文献   
19.
Through the use of a number of bioconversion experiments we demonstrated that P450 proteins (CYP1A9 and CYP1C1) from Japanese eel (Anguilla japonica) metabolized a number of herbicides and the drug phenacetin. We performed bioconversion experiments in which substrates were added directly to incubation medium. The resulting metabolites were extracted and analyzed by high-performance liquid chromatography. Proteins CYP1A9 and CYP1C1 metabolized 50 nmol of the drug phenacetin to yield 12.1 and 1.1 nmol of product (acetaminophen), respectively. Further incubation of CYP1A9 with 50 nmol of the herbicides chlorotoluron, diuron, linuron, simazine, or atrazine yielded 16.5, 18.5, 7.3, 1.6, or 0.8 nmol of product, respectively. CYP1C1 also metabolized linuron, diuron, and simazine yield 5.4, 4.6, or 0.7 nmol of product, respectively. Next, polyclonal antibody was isolated by immunizing with two conjugated-peptides (amino acid residues 272–290 and 294–310) of CYP1A9. This antibody did not recognize human CYP1A2 or CYP1C1. Western blotting using the antibody revealed one band in the livers of Japanese eel and tilapia (Oreochromis niloticus). Theses results suggest that CYP1A9 and CYP1C1 metabolize herbicides, and that CYP1A9 is an useful biomarker of contamination when detected with this antibody.  相似文献   
20.
Carbohydrates are main compositions for wood (Menachem et al. 1991). The chemical components of poplar I-214 and Chinese fir have been reported (Huang Luohua et al. 2002; Qin Tefu et al. 2003). Through the studies of carbohydrate compositions of poplar I-214 and Chinese fir, different composition of monosaccharides can be found in both poplar I-214 and Chinese fir. 1 MATERIALS AND METHODS 1.1 Materials Wood samples of Chinese fir (Cunninghamia lancedata) and poplar I-214 (Populus…  相似文献   
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