Indirect evaluation of hardness and delamination strength of Akoya cultured pearl nacre based on UV fluorescence intensity     

Hiramatsu  Junichi  Iwahashi  Yasunori  Nagai  Kiyohito 《Fisheries Science》2022,88(6):805-813

The durability of Akoya pearls is closely related to the mechanical strength of the nacre. Therefore, obtaining information about the mechanical strength of the nacre is very important in the quality control of pearls. The nacre of Akoya pearls is composed of aragonite contained within an organic matrix. The presence of the organic matrix provides mechanical strength and fracture toughness much higher than that of monolithic aragonite. In this study, we investigated the hardness and delamination strength of Akoya cultured pearls classified into four levels by “Gray Value (GV)”, a score given by a non-destructive inspection method based on UV fluorescence intensity that provides an indication of the condition of the nacre’s organic components. Pearl hardness decreased significantly with decreasing GV. Furthermore, delamination strength of the pearl surface layer was very low when the GV was very low. These results suggest that the GV indirectly represents the mechanical strength of the nacre and could be used as a non-destructive quality-control method to maintain the quality of pearls used as jewelry.

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Nursery‐Box Total Fertilization Technology (NBTF) Application for Increasing Nitrogen Use Efficiency in Chinese Irrigated Riceland: N–Soil Interactions     

Aiping Zhang  Ji Gao  Ruliang Liu  Zhe Chen  Shiqi Yang  Zhengli Yang  Hongbo Shao  Qingwen Zhang  Nagai Yoshikazu 《Land Degradation \u0026amp; Development》2016,27(4):1255-1265

High N fertilizer and flooding irrigation applied to rice in anthropogenic‐alluvial soil often result in N leaching and low use efficiency of applied fertilizer N from the rice field in Ningxia irrigation region in the upper reaches of the Yellow River. Sound N management practices need to be established to improve N use efficiency while sustaining high grain yield levels and minimize fertilizer N loss to the environment. We investigated the effects of Nursery Box Total Fertilization technology (NBTF) on N leaching at different rice growing stages, N use efficiency and rice yield in 2010 and 2011. The four fertilizer N treatments were 300 kg N ha⁻¹ (CU, Conventional treatment of urea at 300 kg N ha⁻¹), 120 kg N ha⁻¹ (NBTF120, NBTF treatment of controlled‐release N fertilizer at 120 kg N ha⁻¹), 80 kgN ha⁻¹ (NBTF80, NBTF treatment of controlled‐release N fertilizer at 80 kg N ha⁻¹) and no N fertilizer application treatment (CK). The results showed that the NBTF120 treatment increased N use efficiency, maintained crop yields and substantially reduced N losses to the environment. Under the CU treatment, the rice yield was 9634 and 7098 kg ha⁻¹, the N use efficiency was 31·6% and 34·8% and the leaching losses of TN were 44·51 and 39·89 kg ha⁻¹; NH₄⁺‐N was 5·26 and 5·49 kg ha⁻¹, and NO₃⁻‐N was 27·94 and 26·22 kg ha⁻¹ during the rice whole growing period in 2010 and 2011, respectively. Compared with CU, NBTF120 significantly increased the N use efficiency and decreased the N losses from the paddy field. Under NBTF120, the N use efficiency was 56·3% and 51·4%, which was 24·7% and 16·6% higher than that of CU, and the conventional fertilizer application rate could be reduced by 60% without lowering the rice yield while decreasing the leaching losses of TN by 16·27 and 14·36 kg ha⁻¹, NH₄⁺‐N by 0·90 and 1·84 kg ha⁻¹, NO₃⁻‐N by 110·6 and 10·14 kg ha⁻¹ in 2010 and 2011, respectively. Our results indicate that the CU treatment resulted in relatively high N leaching losses, and that alternative practice of NBTF which synchronized fertilizer application with crop demand substantially reduced these losses. We therefore suggest the NBTF120 be a fertilizer application alternative which leads to high food production but low environmental impact. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Partial purification of polyphenol oxidase from Chinese cabbage Brassica rapa L   总被引：1，自引：0，他引：1  

Nagai T  Suzuki N 《Journal of agricultural and food chemistry》2001,49(8):3922-3926

Polyphenol oxidase (PPO) was purified and characterized from Chinese cabbage by ammonium sulfate precipitation and DEAE-Toyopearl 650M column chromatography. Substrate staining of the crude protein extract showed the presence of three isozymic forms of this enzyme. The molecular weight of the purified enzyme was estimated to be approximately 65 kDa by gel filtration on Toyopearl HW-55F. On SDS-PAGE analysis, this enzyme was composed of a subunit molecular weight of 65 kDa. The optimum pH was 5.0, and this enzyme was stable at pH 6.0 but was unstable below pH 4.0 or above pH 7.0. The optimum temperature was 40 degrees C. Heat inactivation studies showed temperatures >40 degrees C resulted in loss of enzyme activity. PPO showed activity to catechol, pyrogallol, and dopamine (K(m) and V(max) values were 682.5 mM and 67.6 OD/min for catechol, 15.4 mM and 14.1 OD/min for pyrogallol, and 62.0 mM and 14.9 OD/min for dopamine, respectively). The most effective inhibitor was 2-mercaptoethanol, followed in decreasing order by ascorbic acid, glutathione, and L-cysteine. The enzyme activity of the preparation was maintained for 2 days at 4 degrees C but showed a sudden decreased after 3 days.  相似文献   

Negative regulation of Wingless signaling by D-axin, a Drosophila homolog of axin     

Hamada F  Tomoyasu Y  Takatsu Y  Nakamura M  Nagai S  Suzuki A  Fujita F  Shibuya H  Toyoshima K  Ueno N  Akiyama T 《Science (New York, N.Y.)》1999,283(5408):1739-1742

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Dynamics of Nrf2 and Keap1 in ARE-mediated NQO1 expression by wasabi 6-(methylsulfinyl)hexyl isothiocyanate     

Hou DX  Korenori Y  Tanigawa S  Yamada-Kato T  Nagai M  He X  He J 《Journal of agricultural and food chemistry》2011,59(22):11975-11982

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Plectosporium blight of monkshood caused by <Emphasis Type="Italic">Plectosporium tabacinum</Emphasis>     

Keisuke Tomioka  Yuuri Hirooka  Toshirou Nagai  Hiroyuki Sawada  Takayuki Aoki  Toyozo Sato 《Journal of General Plant Pathology》2011,77(4):266-268

Severe blight of potted seedlings of monkshood caused by Plectosporium tabacinum was found in glasshouses in Kagawa Prefecture in southwest Japan in May 2001. Root rot and browning of stem bases were followed by wilting and yellowing of leaves, then blighting of leaves, flower buds and stems. A fungus was isolated from diseased plants and confirmed to cause the disease. The new disease was named “Plectosporium blight of monkshood”.  相似文献   

Molecular and biological characterization of <Emphasis Type="Italic">Chrysanthemum stem necrosis virus</Emphasis> isolates from distinct regions in Japan     

Minoru?TakeshitaEmail author  Naoko?Nagai  Mitsuru?Okuda  Shohei?Matsuura  Shiori?Okuda  Naruto?Furuya  Kenichi?Tsuchiya 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(1):9-14

Three isolates of Chrysanthemum stem necrosis virus (CSNV) were obtained from chrysanthemum plants in distinct regions of Japan in 2006 and 2007. All the original host plants showed severe necrotic symptoms on the leaves and stems. Amino acid sequence data of the nucleocapsid protein genes of the three isolates (CbCh07A, TcCh07A, and GnCh07S) showed high identities with those of two other CSNV isolates, HiCh06A L1 from Japan and Chry1 from Brazil. Furthermore, for the first time the complete nucleotide sequence of the S RNA was determined for CSNV (isolate HiCh06A). In phylogenetic analysis based on the non-structural protein genes from the genus Tospovirus, HiCh06A L1 was placed in the same genetic group as Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus. Host range examination for isolates HiCh06A L1 and CbCh07A showed that green pepper (cv. ‘Kyoyutaka’, ‘Saitamawase’, ‘Tosakatsura’, ‘L3 sarara’ and ‘L3 miogi’) and tomato (cv. ‘Sekaiichitomato’) were systemically susceptible hosts, whereas TSWV-resistant Solanaceae species, Capsicum chinense, Lycopersicon peruvianum and a TSWV-resistant cultivar of green pepper (cv. TSR miogi), were resistant.  相似文献   

Determination of polysorbates in foods by colorimetry with confirmation by infrared spectrophotometry, thin-layer chromatography, and gas chromatography   总被引：1，自引：0，他引：1  

H Kato  Y Nagai  K Yamamoto  Y Sakabe 《Journal of the Association of Official Analytical Chemists》1989,72(1):27-29

A method is presented for the detection of polysorbates (PSs) in 8 kinds of processed foods by colorimetric and thin-layer chromatographic (TLC) techniques. The PSs are extracted from processed foods with a mixture of methylene chloride and ethanol by using an Extrelut column. The extract is further purified by using a silica gel column. The PS extract is complexed with cobalt-thiocyanate (Cothiocyanate) reagent and is determined spectrophotometrically at 620 nm. The recoveries and coefficients of variation for 8 kinds of processed foods fortified with 0.1% PS 80 were 67.9-94.6% and 4.0-11.3%, respectively. The detection limit of TLC corresponded to 50 mg PS 80/kg. PS identity was confirmed by infrared spectrophotometry of PS extract, and gas chromatography of fatty acids and thin layer chromatography of POE-sorbitan residues after saponification.  相似文献   

Development of a genetically modified nontoxigenic Pasteurella multocida toxin as a candidate for use in vaccines against progressive atrophic rhinitis in pigs   总被引：1，自引：0，他引：1  

To H  Someno S  Nagai S 《American journal of veterinary research》2005,66(1):113-118

OBJECTIVE: To construct a genetically modified nontoxigenic Pasteurella multocida toxin (PMT) and examine its immunoprotective activity against challenge exposure with wild-type PMT in pigs. ANIMALS: 5 healthy pigs. PROCEDURE: A nontoxigenic PMT was created by replacing the serine at position 1164 with alanine (S1164A) and the cysteine at position 1165 with serine (C1165S). Toxic activity was determined by use of the guinea pig skin test and mouse lethality test. Three pigs were vaccinated twice with the modified PMT, and the remaining 2 pigs served as nonvaccinated control animals. Vaccinated and control pigs were challenge exposed with wild-type PMT. Pigs were euthanatized and necropsied on day 14 after challenge exposure. Turbinate atrophy was examined macroscopically and assigned a score. Serum anti-PMT antibodies were determined by use of an ELISA. RESULTS: The genetically modified PMT was characterized by a total lack of toxic activity. Pigs vaccinated with the modified PMT became seropositive; in contrast, control pigs remained seronegative. Necropsy revealed that the 2 control pigs had moderate and severe turbinate atrophy, respectively, whereas the 3 vaccinated pigs did not have any lesions in the turbinates or abnormalities in other organs. CONCLUSIONS AND CLINICAL RELEVANCE: Modification by use of S1164A and C1165S leads to a complete loss of toxic effects of PMT without impairment of the ability to induce protective immunity in pigs. Analysis of these results suggests that genetically modified PMT may represent a good candidate for use in developing a vaccine against progressive atrophic rhinitis in pigs.  相似文献   

Genetic control of egg quality. I. Sources of variation     

J Nagai  R S Gowe 《British poultry science》1969,10(4):337-350

Measurements of specific gravity, egg weight and albumen height of eggs from three consecutive trap days were taken at approximately 225, 350 and 450 d of age, for three years, from three strains of the White Leghorns. Haugh units were calculated for each egg. From these data estimates of genetic parameters were derived.

Pooled estimates within the 27 strain‐period‐year subclasses for heritability of single egg records from sire components of variance for specific gravity, egg weight, albumen height and Haugh units were 0.36, 0.48, 0.46 and 0.45, and repeatability within periods for the four traits were 0.68, 0.74, 0.76 and 0.74 respectively. The intra‐class correlations (repeatabilities) between period‐means of the same hen expressed in standard deviation units for each subclass were 0.58, 0.71, 0.74 and 0.69 respectively. Genetic correlations between adjacent periods were high varying from 0.91 to 0.96 while those between non‐adjacent periods varied from 0.76 to 0.87 for the four traits.

It was suggested from the size of these estimates that annual performance for a quality trait could be improved by selecting pullets on the basis of a small number of egg measurements taken at early periods in the laying year.  相似文献