摘要 :
Prochloraz is a fungicide that is widely used in citrus storage for attaining fruit disinfection.
In this study, a gas chromatography method for determining prochloraz
residues in mandarin orange by derivatization reaction of proc...
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Prochloraz is a fungicide that is widely used in citrus storage for attaining fruit disinfection.
In this study, a gas chromatography method for determining prochloraz
residues in mandarin orange by derivatization reaction of prochloraz into its main
metabolite, 2,4,6-trichlorophenol, was validated. Prochloraz residue levels in postharvest
mandarin oranges at room temperature and cold storage were examined at
recommended label use and exaggerated dosage.
The results showed that the residue of prochloraz was found to be mostly distributed
in mandarin orange peel. The decay rate of prochloraz in mandarin orange
stored at room temperature was slightly faster than that in a refrigerator. It demonstrated
that residue decay in pulp was slightly slower than that in the whole fruit.
When treated with dipping application at 0.5 or 1 g/L dosage, final residues of
prochloraz in mandarin oranges were found to be from 0.09 to 1.29 mg/kg at different
storage conditions and intervals, whichwere far belowtheCodexMRLof 10 mg/
kg. Residues at intervals of more than 7 days would be unlikely to pose any public
health concerns if prochloraz was used according to the recommended use pattern at
room temperature or cold storage.
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摘要 :
Phosphocholine (PC) is the immunodominant epitope found on the surface of Streptococcus pneumoniae (SPn). T15-idiotype Abs. whose heavy (H) chain variable region is encoded by the V1 gene. are dominant in the anti-PC response in a...
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Phosphocholine (PC) is the immunodominant epitope found on the surface of Streptococcus pneumoniae (SPn). T15-idiotype Abs. whose heavy (H) chain variable region is encoded by the V1 gene. are dominant in the anti-PC response in adult mice and protect mice from lethal pneumococcal infection. The ability of anti-PC Abs using H chains other than the V1 H chain to protect against pneumococcal infection remains controversial. We generated V1/ knockout mice to determine whether protective anti-PC Abs could be produced in the absence of the V1 gene. No anti-PC Abs were produced in V1~-/- mice immunized with avirulent SPn, however, PC-BSA binding Abs were induced after immunization with PC-keyhole limpet hemocyanin but at significantly lower levels than those in wild-type mice. These Abs provided poor protection against virulent SPn, thus. <25/100 of V1~-/-, mice survived challenge with 10~4 bacteria as compared with 100/100 survival of V1+/+ mice. The anti-PC Abs in V1~-/- mice were heteroclitic. binding to nitrophenyl-PC better than to PC. None of nine hybrid- omas produced from V1~-/- mice provided passive protection. However. the V1~-/- mice produced normal amounts of Ab to SPn proteins that can partially protect mice against SPn. These data indicate that the V1 gene is critical for the production of anti-PC Abs providing optimum protection against infection with SPn. and the V1~-/- mice could be useful in unmasking epitopes other than the immunodominant PC epitope on SPn capable of providing cross protection.
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摘要 :
The use of highly specific and highly sensitive immunofluorescent probes is a promising approach for biomedical imaging in living tissue. We focus on immunofluorescence with quantum dot bioconjugates for hepatoma detection in vivo...
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The use of highly specific and highly sensitive immunofluorescent probes is a promising approach for biomedical imaging in living tissue. We focus on immunofluorescence with quantum dot bioconjugates for hepatoma detection in vivo. We synthesized specific immunofluorescent probes by linking quantum dots to AFP (alpha-fetoprotein) antibody for specific binding AFP-an important marker for hepatocellular carcinoma cell lines. In in vivo studies, the characteristic quantum dot (QD) fluorescent property is exhibited by the QDs-Anti-AFP probes in tumor and they demonstrate active tumor targeting and spectroscopic hepatoma imaging with an integrated fluorescence imaging system. We investigate the inhomogeneous distribution of the QDs-Anti-AFP probes in tumor by using a site-by-site measurement method to test their ability for distribution studies of cancer cells. These results demonstrate the practicality of QD bioconjugates as attractive fluorescent probes for biomedical detection.
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摘要 :
The composition, morphology, crystalline structure and formation and evolution of X phase in a Cu-12.3Al- 2Ni-2Mn-1Ti alloy were studied. The results show that the X phase is a Ti-rich phase with atomic ratio of (Cu + Ni): Ti: Al ...
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The composition, morphology, crystalline structure and formation and evolution of X phase in a Cu-12.3Al- 2Ni-2Mn-1Ti alloy were studied. The results show that the X phase is a Ti-rich phase with atomic ratio of (Cu + Ni): Ti: Al = 2:1:1 and DO_3 or L2_1 structure; it is directly formed in the liquid phase by crystallization in the process of solidi- fication of the alloy; there forms free particle X phase through the progressive dissolution and breakdown of the inter-den- dritic microstructure in the following homogenization process. The X phase has three different morphologies, i.e.X_L, X_Ls and Xs, whose contents in the matrix rely on the heat-treatment conditions.
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摘要 :
In order to establish a simple and useful way for preimplantation genetic diagnosis (PGD) of chromosomal diseases in general FVF laboratory, the methods that are most commonly used in the embryo biopsy, fixation of blastomere and ...
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In order to establish a simple and useful way for preimplantation genetic diagnosis (PGD) of chromosomal diseases in general FVF laboratory, the methods that are most commonly used in the embryo biopsy, fixation of blastomere and fluorescence in situ hybridization were compared. The three aspects of PGD were analyzed respectively. There was no significant difference in further development capacity of embryos between mechanical (79.7%) and chemical biopsy group (78.6%) (P> 0.05). In this study, more cells were successfully fixed with the Tween/HCL method (93.8%) than with the methanol/acetic acid method (80.5%, P< 0.05). There was no significant difference in cytoplasm remains between methanol/acetic acid method and Tween/HCL method (P> 0.05). The hybridization efficiency of fluorescence in situ hybridization was 89.5% in successive denaturation method and 90.9% in codenaturation method with the difference being not significant (P> 0.05). In conclusion, the mechanical or chemical method, Tween/HCL fixation method and codenaturation fluorescence in situ hybridization method can constitute a simple and useful way for PGD of chromosomal diseases.
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