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排序方式: 共有207条查询结果,搜索用时 15 毫秒
1.
We estimated the genetic parameters of fat‐to‐protein ratio (FPR) and the genetic correlations between FPR and milk yield or somatic cell score in the first three lactations in dairy cows. Data included 3 079 517 test‐day records of 201 138 Holstein cows in Japan from 2006 to 2011. Genetic parameters were estimated with a multiple‐trait random regression model in which the records within and between parities were treated as separate traits. The phenotypic values of FPR increased soon after parturition and peaked at 10 to 20 days in milk, then decreased slowly in mid‐ and late lactation. Heritability estimates for FPR yielded moderate values. Genetic correlations of FPR among parities were low in early lactation. Genetic correlations between FPR and milk yield were positive and low in early lactation, but only in the first lactation. Genetic correlations between FPR and somatic cell score were positive in early lactation and decreased to become negative in mid‐ to late lactation. By using these results for genetic evaluation it should be possible to improve energy balance in dairy cows.  相似文献   
2.
This study reexamined the kinetics of the condensation reactions of hydroxymethylphenols with the purpose of elucidating the reaction mechanisms. This report discusses experimental results on the self-condensations of 2,4-dihydroxymethylphenols (2,4-DHMP) and 2,4,6-trihydroxymethylphenol (THMP), focusing on the order of reaction. The relations between the initial rates of reaction and the initial concentrations of reactants were investigated. Results quite different from those of previous reports were obtained. The order of reaction of the selfcondensation of 2,4-DHMP was found to be 1.1, which did not change with the alkali/2,4-DHMP molar ratio. The order of reaction of the self-condensation of THMP was found to vary with both the concentration of THMP and the alkali/THMP molar ratio. In the region of THMP concentrations above 1.5mol/l, the order of reaction was confirmed to be 2.0, which did not change with the alkali/THMP molar ratio. In the region of THMP concentrations below 1.0mol/l, the order of reaction varied with the alkali/THMP molar ratio, showing fractional numbers of 1.2–1.6. These results indicate that unimolecular reaction(s) and bimolecular reaction(s) take place simultaneously as the ratedetermining step in the condensation reactions of 2,4-DHMP and THMP and that the reaction mechanism changes with the species of reactant and, in some cases, with the reaction conditions.Part of this study was presented at the Wood Adhesives 2000 symposium, South Lake Tahoe, Nevada, USA, June 2000  相似文献   
3.
Propylene carbonate (PC) is known as one of the cure accelerators for alkaline phenol–formaldehyde resins. To elucidate the cure-acceleration mechanisms, the effects of PC on the condensation reactions of monomeric hydroxymethylphenols (HMPs) were investigated and compared with those of PC hydrolysate, sodium bicarbonate (NaHCO3) and ethyl formate. Immediately after the reaction started, PC, decomposing itself simultaneously, accelerated the formation of the ortho-para methylene-bonded dimer of 2,4,6-trihydroxymethylphenol. This effect of PC was very similar to that of ethyl formate. To the contrary, PC hydrolysate accelerated the formation of the para-para methylene-bonded dimer throughout the course of the reaction. This effect of PC hydrolysate was identical to that of NaHCO3. These results indicate that PC increases the reactivity of the ortho-hydroxymethyl group, presumably through transesterification. On the other hand, NaHCO3 is formed by the hydrolysis of PC or decomposition of the transesterified HMPs and it increases the reactivity of the para-hydroxymethyl group.  相似文献   
4.
Summary A new lignin isolation method has been developed. Wood and pulp were subjected to ball milling, swelled in an organic solvent, and then treated with a cellulase. The enzyme digestion time could be shortened to 1 day with this method. The lignin obtained has been named Swelled Enzyme Lignin (SEL). Swelling and enzyme digestion conditions and their effects on lignins were investigated. The SEL's from wood could be directly washed with water, while those from pulp had to be washed with aqueous acetic acid because they were water soluble. The purification of crude SEL's was accomplished by extracting them with dioxane-water, and then precipitating and washing with ethyl ether. Lignin yields were 24–67% based on the total amount of lignin present. The characteristics of the SEL's were further investigated by gel-permeation chromatography (GPC), infrared and 13C nuclear magnetic resonance (NMR) spectroscopy.Symbols SUKP Softwood Unbleached Kraft Pulp - BUKP Birch Unbleached Kraft Pulp - TD Todomatsu (Abies sachalinensis) wood - MWL Milled Wood Lignin - MWLS (BK, TD) Milled Wood Lignin of SUKP (BUKP, TD) - SEL-C Swelled Enzyme Lignin (crude) - SELS-C SEL-C of SUKP, other materials named in the same way - SELS-90 SEL-C of SUKP and extracted with 90% dioxane-water - SELS-96 SEL-C of SUKP and extracted with 96% dioxane-water, other materials named in the same way  相似文献   
5.
The amount of heavy metals discharged from daily life was estimated in order to know the origin of the metals contained in the sewage sludge which is produced in the wastewater treatment plant treating only domestic wastewater. The amounts of the metals discharged from our daily life were estimated to be in the range of 0.2 to 0.3 for Cd, 1.6 to 1.9 for Ni, 3.5 to 6.8 for Pb, 0.8 to 1.4 for Cr, 8.2 to 19.3 for Mn 9.4 to 55.8 for Cu, 44.3 to 62.7 for Zn and 111 to 293 for Fe in mg.d–1 per person, Using these data, the cycle of the metals in our daily life was discussed in relation to land application of sewage sludge.  相似文献   
6.
The methanol extract from Uncaria sinensis showed a suppressive effect on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen 3-amino-1,4-dimethyl-5H-pyrido[4,3b]indole (Trp-P-1), which requires liver metabolizing enzymes. The methanol extract from U. sinensis was re-extracted with hexane, CH2Cl2, BuOH, and water, respectively. CH2Cl2 extract showed a suppressive effect. A suppressive compound 1 in CH2Cl2 extract was isolated by SiO2 column chromatography. Compound 1 was identified as ursolic acid by IR, electron ionization EI-MS, and NMR spectroscopy. Suppressive effects of ursolic acid (1) and its derivatives, methyl ursolate (1M), acetylursolic acid (1A), and methyl acetylursolate (1MA), were determined in the umu test. These compounds suppressed 61.3, 37.7, 71.5, and 37.8% of the Trp-P-1-induced SOS response at a concentration of 0.4 micromol/mL, respectively. The ID50 values of compounds 1 and 1A were 0.17 and 0.20 micromol/mL. In addition, these compounds were assayed with the activated Trp-P-1. Suppressive effects on activated Trp-P-1 were decreased as compared with those of Trp-P-1.  相似文献   
7.
Biotransformation of alpha-terpineol by the common cutworm (Spodoptera litura) larvae was investigated. alpha-Terpineol was mixed in an artificial diet, and the diet was fed to the larvae (fourth-fifth instar) of S. litura. Metabolites were isolated from the frass and analyzed spectroscopically. Main metabolites were 7-hydroxy-alpha-terpineol (p-menth-1-ene-7,8-diol) and oleuropeic acid (8-hydroxy-p-menth-1-en-7-oic acid). Intestinal bacteria from the frass of larvae did not participate in the metabolism of alpha-terpineol. alpha-Terpineol was preferentially oxidized at the C-7 position (allylic methyl group) by S. litura larvae.  相似文献   
8.
Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The endothelial differentiation , sphingolipid G-protein-coupled receptor , 1 ( EDG1 ) gene has been considered as a positional functional candidate for the gene responsible for marbling. We have recently reported that 2 single nucleotide polymorphisms (SNPs), c.-312A > G in the 5' untranslated region (UTR) and c.*446G > A in the 3' UTR in EDG1 were associated with marbling in Japanese Black beef cattle, but this was not functional and a causal mutation for marbling. In the present study, we detected 2 novel SNPs, referred to as g.1475435G > A and g.1471620G > T , in the 5' flanking region of the EDG1 between low-marbled and high-marbled steer groups, which were previously shown to have EDG1 expression differences in musculus longissimus muscle. The g.1475435G > A SNP seemed not to segregate in Japanese Black beef cattle. The g.1471620G > T SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. Based on these findings, we hypothesized that the g.1471620G > T SNP might have an impact on EDG1 expression and also marbling.  相似文献   
9.
10.
Pathogenic characters of Japanese potato strains of Ralstonia solanacearum   总被引:1,自引:0,他引:1  
Ralstonia solanacearum (Rs) strains in phylotypes I and IV isolated from potato in Japan were investigated for pathogenicity on potato, tomato, eggplant, Solanum integrifolium, tobacco, groundnut, and pumpkin. The strains were divided into 17 types based on differences in their pathogenicity on the tested plants. Particularly, the pathogenicity of most phylotype I strains on eggplant was distinctly different from that of the phylotype IV strains. When nine potato varieties (included two breeding lines) were inoculated with several Rs strains, phylotype IV strains were highly virulent on the breeding lines that are regarded as resistant to phylotype I strains.  相似文献   
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