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91.
To determine whether olive flounder (Paralichthys olivaceus) immunized with lysate of Philasterides dicentrarchi could be protected immobilization antigen (i-antigen) type independently, fish were immunized with lysate of ciliates obtained from in vitro cultures or ciliates obtained from infected fish. Fish immunized with ciliates obtained from infected fish were completely protected against artificial infection with in vitro cultured P. dicentrarchi, in spite of a weak or no serum agglutination activity against in vitro cultured ciliates. The present results indicate that i-antigen-independent protection was elicited by immunization of fish with the ciliates lysate, and the cultured ciliates would provide a good source for preparation of vaccines, which are cross-protective against various i-antigen types of P. dicentrarchi.  相似文献   
92.
Vibrio anguillarum , an opportunistic fish pathogen, is the main species responsible for vibriosis, a disease that affects feral and farmed fish and shellfish, and causes considerable economic losses in marine aquaculture. In this study, we used polymerase chain reaction (PCR) to detect V. anguillarum . PCR specificity was evaluated by amplifying the rpoS gene, a general stress regulator, in six strains of V. anguillarum and 36 other bacterial species. PCR amplified a species-specific fragment (689 bp) from V. anguillarum . Furthermore, the PCR assay was sensitive enough to detect rpoS expression from 3 pg of genomic DNA , or from six colony-forming units (CFU) mL−1 of cultured V. anguillarum . However, the assay was less sensitive when genomic DNA from the infected flounder and prawn was used (limit of detection, 50 ng and 10 ng g−1 tissue, respectively). These data demonstrate that PCR amplification of the rpoS gene is a sensitive and species-specific method to detect V. anguillarum in practical situations.  相似文献   
93.
ABSTRACT:   As part of this study on the isolation of cholinesterase inhibitors from natural marine products, the bioactivity of the ethanolic extracts from 27 Korean seaweeds were screened using acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory assays. Ecklonia stolonifera exhibited promising inhibitory properties against both AChE and BChE. Bioassay-guided fractionation of the active n -hexane and ethyl acetate (EtOAc) soluble fractions, obtained from the ethanolic extract of E. stolonifera , resulted in the isolation of the sterols; fucosterol ( 1 ) and 24-hydroperoxy 24-vinylcholesterol ( 2 ), from the n -hexane fraction and the phlorotannins; phloroglucinol ( 3 ), eckstolonol ( 4 ), eckol ( 5 ), phlorofucofuroeckol-A ( 6 ), dieckol ( 7 ), triphlorethol-A ( 8 ), 2-phloroeckol ( 9 ) and 7-phloroeckol ( 10 ), from the EtOAc fraction. Of these, compounds 2 , 9 and 10 were isolated from E. stolonifera for the first time. Compounds 4 – 7 , 9 and 10 exhibited inhibitory potential against AChE, with 50% inhibition concentration (IC50) values of 42.66 ± 8.48, 20.56 ± 5.61, 4.89 ± 2.28, 17.11 ± 3.24, 38.13 ± 4.95 and 21.11 ± 4.16 μM, respectively; whereas, compounds 1 , 2 , 4 and 6 were found to be active against BChE, with IC50 values of 421.72 ± 1.43, 176.46 ± 2.51, 230.27 ± 3.52 and 136.71 ± 3.33 μM, respectively. It has been suggested that the inhibition of these enzymes by the sterols and phlorotannins derived from marine brown algae could be a useful approach for the treatment of Alzheimer's disease.  相似文献   
94.
ABSTRACT

Long-term fertilization tests evaluated rice (Oryza sativa) productivity in relation to application of nitrogen (N)-phosphorus (P)-potassium (K) (120-34.9-66.7 kg ha? 1, respectively) during 1967–1972 and N-P-K (150-43.7-83.3 kg ha? 1, respectively) during 1973–2000. The comparison treatments (NP, PK, and NK) and the control (not fertilized) were selected for calculating nutrient efficiency. Rice grain yield increased at a 17.78 kg ha? 1 yr? 1 in the control, mainly due to development of improved cultivars. Phosphorus management was found to be important for indigenous fertility and rice productivity in this paddy soil. Yield increased significantly with P fertilization. Without N fertilization (PK), rice productivity increased 56.85 kg ha? 1 yr? 1 from 62% of NPK at the initial stage to 74% after passing 34 years, which might be affected by increasing biological N fixation with P accumulation in soil. In NK treatment, rice yield increased at a relatively low rate (37.82 kg hr? 1 yr? 1) from the same rice productivity with that of NPK in 1967 to 91% after 34 years. In comparison, yield increased at a high rate (62.82 kg hr? 1 yr? 1) without K fertilization (NP) from ca. 90% of NPK and might exceed the yield of NPK after 64 years of long-term fertilization. Therefore, K fertilization level might be readjusted after long-term fertilizing in paddy soil.  相似文献   
95.
A multifunctional heat pulse probe (MFHPP) can measure soil thermal and hydraulic properties. Though its successful implementation has been documented, previous studies have reported some limitations. One specific cause of the limitations is the absorption of the generated heat pulse within the probe itself, which creates error in the measurements. The objective of this study was to develop and evaluate a new calibration method to account for measurement error due to heat loss to the probe. A MFHPP was constructed and tested in six soil types using both a traditional method and the newly developed calibration method. The new calibration utilizes heat pulse response curves from real soils with thermal conductivities similar to that of the MFHPP rather than the traditional agar-stabilized water solution. This new approach significantly reduced average measurement errors from 9.1% to 2.4% for heat capacity and 13.5% to 4.5% for volumetric water content.  相似文献   
96.
Two novel caffeoylmalic acid methyl esters, 2-O-(trans-caffeoyl)malic acid 1-methyl ester (6) and 2-O-(trans-caffeoyl)malic acid 4-methyl ester (7), were isolated from pear (Pyrus pyrifolia Nakai cv. Chuhwangbae) fruit peels. In addition, 5 known hydroxycinnamoylmalic acids and their methyl esters were identified: 2-O-(trans-coumaroyl)malic acid (1), 2-O-(cis-coumaroyl)malic acid (2), 2-O-(cis-coumaroyl)malic acid 1-methyl ester (3), 2-O-(trans-coumaroyl)malic acid 1-methyl ester (4), and 2-O-(trans-caffeoyl)malic acid (phaselic acid, 5). The chemical structures of these compounds were determined by spectroscopic data from ESI MS and NMR. Of all the isolated compounds, five hydroxycinnamoylmalic acids and their methyl esters (2-4, 6, 7) were identified in the pear for the first time.  相似文献   
97.
Legumes, including soybeans ( Glycine max ), are deficient in sulfur-containing amino acids, which are required for the optimal growth of monogastric animals. This deficiency can be overcome by expressing heterologous proteins rich in sulfur-containing amino acids in soybean seeds. A maize 27 kDa γ-zein, a cysteine-rich protein, has been successfully expressed in several crops including soybean, barley, and alfalfa with the intent to biofortify these crops for animal feed. Previous work has shown that the maize 27 kDa zein can withstand digestion by pepsin and elicit an immunogenic response in young pigs. By use of sera from patients who tested positive by ImmunoCAP assay for elevated IgE to maize proteins, specific IgE binding to the 27 kDa γ-zein is demonstrated. Bioinformatic analysis using the full-length and 80 amino acid sliding window FASTA searches identified significant sequence homology of the 27 kDa γ-zein with several known allergens. Immunoblot analysis using human serum that cross-reacts with maize seed proteins also revealed specific IgE-binding to the 27 kDa γ-zein in soybean seed protein extracts containing the 27 kDa zein. This study demonstrates for the first time the allergenicity potential of the 27 kDa γ-zein and the potential that this protein has to limit livestock performance when used in soybeans that serve as a biofortified feed supplement.  相似文献   
98.
Soil vapor extraction (SVE) is one of the most effective remediation technologies for soil and groundwater contamination. Soil particles can be mobilized by air perturbation during SVE, resulting in the differentiation of porous media, which has not been well addressed. This paper developed a numerical method to study the flow pattern and quantify the change of porous media for the first time. Based on the mass equilibrium and Darcy’s law, a two-phase water–air flow model was constructed with integration of saturation, relative permeability, and capillary pressure during SVE. Relationship between porosity and saturation was deduced and coupled with the two-phase flow model for quantifying change of porous media in real time. Results reveal that both porosity and permeability increase sharply in the early stage of SVE then gradually to a quasi-steady state. These increases in vadose zone tapered off with distance from the SVE screen and the steady period occurred later as well. The influence radius of a single SVE well and the change degree in porosity and permeability of media were proportional to the extraction vacuum and the driving coefficient C, which is more sensitive than extraction vacuum according to the simulation results. Knowledge from this modeling exercise provides a useful tool to estimate the change of remediated zone and assess the environmental risk of remedial activities at real-world contamination sites.  相似文献   
99.
Increased calcium (Ca) in potatoes may increase the production rate by enhancing tuber quality and storability. Additionally, increased Ca levels in important agricultural crops may help ameliorate the incidence of osteoporosis. However, the capacity to alter Ca levels in potato tubers through genetic manipulations has not been previously addressed. Here we demonstrate that potato tubers expressing the Arabidopsis H+/Ca2+ transporter sCAX1 (N-terminal autoinhibitory domain truncated version of CAtion eXchanger 1) contain up to 3-fold more Ca than wild-type tubers. The increased Ca appears to be distributed throughout the tuber. The sCAX1-expressing potatoes have normally undergone the tuber/plant/tuber cycle for three generations; the trait appeared stable through successive generations. The expression of sCAX1 does not appear to alter potato growth and development. Furthermore, increased Ca levels in sCAX1-expressing tubers do not appear to alter tuber morphology or yield. Given the preponderance of potato consumption worldwide, these transgenic plants may be a means of marginally increasing Ca intake levels in the population. To our knowledge, this study represents the first attempts to use biotechnology to increase the Ca content of potatoes.  相似文献   
100.
There are several strategies that can be applied in SNP discovery, as for example the locus-specific amplification of target genome regions (Primmer et al., 2002; Van et al., 2004) or simultaneous assembly of anonymous sequences which are the product of whole genome shotgun sequencing (Webber and Myers, 1997) or reduced representation shotgun sequencing (Altshuler et al., 2000). The majority of these methods are highly cost-prohibitive, however, and there is a necessity for development of new strategies that would be more suitable for small and medium-scale laboratories.  相似文献   
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