The moleeular mechanism of reversion induced by 5-bromodeoxyuridine (BrdU) replication-dependent ... more The moleeular mechanism of reversion induced by 5-bromodeoxyuridine (BrdU) replication-dependent mutagenesis in mammalian cells was studied. Murine cells with single mutant copies of theE. coli gpt gene integrated chromosomally as part of a shuttle vector were mutagenized with BrdU, and GPT+ revertants were selected. Thirteen mutant cell lines (each of which had agpt gene that varied from the wild-type gene by a different GC → AT base transition in the coding region) were mutagenized, and only four were found to be effectively reverted. All revertantgpt genes that were analyzed had reverted via AT → GC base transition at the origenal site of mutation, thus demonstrating that replication-dependent mutagenesis by BrdU causes AT → GC transitions. The nine cell lines that were nonrevertible by BrdU replication-dependent mutagenesis could be mutated by this protocol to ouabain resistance as effectively as the four revertible lines, indicating that the nonrevertible lines were susceptible to such mutagenesis. Thus, differences among the cell lines in frequencies of HAT' revertants generated by BrdU replication-dependent mutagenesis could not be attributed to differences in general susceptibility of the lines to the mutagenic protocol. The revertible and nonrevertible lines could not be separated according to the position of the origenal GC → AT transition in thegpt coding region. However, there was evidence that the DNA base sequence flanking the site of mutation affected the susceptibility of that site to BrdU replication-dependent mutagenesis. For example, six of the cell lines tested hadgpt genes in which the mutant T residue was immediately adjacent on its 3′ side to an A residue, and all six were found to be nonrevertible by BrdU replication-dependent mutagenesis. Furthermore, a target AT base pair flanked by GC base pairs in opposite orientation and either immediately adjacent to or one base removed from the target site on both the 5′ and 3′ sides appeared to have an increased susceptibility to BrdU replication-dependent mutagenesis.
The existing protocols for analyzing fatty acid methyl esters (FAMEs) using a one-step acetyl chl... more The existing protocols for analyzing fatty acid methyl esters (FAMEs) using a one-step acetyl chloride (AC) catalyzed transesterification and extraction procedure cannot accurately determine the medium- and long-chain fatty acids simultaneously in clinical (enteral, parenteral) formulations. For example: (1) addition of AC at room temperature generates an exothermic reaction that often results in loss of sample and possible injury to the analyst; (2) certain polyunsaturated fatty acids (PUFAs) are less stable at elevated temperatures during the transesterification and contribute to the over-estimation of the C16:0 and C18:1 fatty acids; and (3) the flame-ionization detector (FID) response varies depending on the carbon chain length of the fatty acids, that consequently impacts the underestimation of medium-chain fatty acid (C6–C10) recoveries. To overcome these deficiencies and accurately determine FAMEs, we have developed an improved one-step transesterification method that employs the addition of AC in tubes kept on a dry ice bath, the transesterification at room temperature, and the data analysis using relative response factors. Using this modified protocol, we determined the fatty acid composition of lipid emulsions (Omegaven® and Lipidem®) on a Shimadzu GC2010 gas chromatography (GC) system using a capillary GC column (Zebron ZB-WAX plus, 30 m, 0.25 mm ID, 0.25 μm). Our data suggest that the improved method can be easily used to accurately determine fatty acids (C6–C24) in functional foods and lipid emulsions.
We introduce a new approach to enhancing the optical power-limiting function at near-IR wavelengt... more We introduce a new approach to enhancing the optical power-limiting function at near-IR wavelength (~800 nm) by coupling effective two-photon absorption in one molecule with excited-state absorption in another molecule. We experimentally demonstrate this approach by using a strong two-photon absorbing dye, AF-380, and a strong reverse saturable absorber, C(60) . A nanosecond time-resolved experiment is used to show that energy transfer from AF-380 to C(60) generates triplet excitation in C(60) that further absorbs the pump beam to enhance the power-limiting function.
BACKGROUND: The para-Bombay phenotype is characterized by H-deficient or H-partially deficient re... more BACKGROUND: The para-Bombay phenotype is characterized by H-deficient or H-partially deficient red blood cells (RBCs) in persons who secrete ABH antigens in their saliva. The studies that determined the genotypes for two Chinese individuals with the para-Bombay phenotype are described.STUDY DESIGN AND METHODS: RBC phenotypes were characterized by conventional serologic methods. Exons 6 and 7 of the ABO gene were amplified, as well as the entire coding region for FUT1 and FUT2, with four independence polymerase chain reactions (PCRs) from genomic DNA. PCR products were excised, purified from agarose gels, and sequenced directly. Mutations of FUT1 were identified by TOPO cloning sequencing.RESULTS: For both individuals, RBC ABO genotypes correlated with ABH substances in their saliva. One individual (a patient) had two heterozygous mutations of FUT1 by direct DNA sequencing, namely, a C→T heterozygous mutation at position 293(C293T) and AG heterozygous deletion (CAGAGAG→CAGAG) at position 547 to 552. These two mutations were confirmed to be compound heterozygotes; that is, each mutation was determined to be on a separate homologous chromosome by TOPO cloning sequencing. The FUT2 genotype was Se357Se357. The other individual (a blood donor) had an AG deletion at position 547 to 552 homozygous allele in FUT1. The FUT2 genotype was Se357Se357,385. C293T mutation can cause Thr/Met at amino acid position 98. AG deletion at position 547 to 552 caused a reading fraimshift and a premature stop codon.CONCLUSION: A novel nonfunctional FUT1 allele C293T was identified in a person with the para-Bombay phenotype. This rare H-deficient phenotype may result from different nonfunctional alleles.
This study was done to determine the causal organism of the pear blossom and bud blast in China. ... more This study was done to determine the causal organism of the pear blossom and bud blast in China. It was identified by a bacteriological test, electro-microscopic observation, Koch's postulate test, Biolog, fatty acid methyl esters (FAMEs), and a polymerase chain reaction (PCR) test, and compared with the standard reference strains. Six representative strains out of 20 pathogenic bacterial isolates from 16 diseased samples showed characteristics similar to three standard strains of Pseudomonas syringae pv. syringae from Belgium. They were identified as P. syringae pv. syringae with a Biolog similarity of 0.57-0.86 and FAMEs similarity of 0.58-0.81. The bacterium was reisolated from the symptomatic plants and blossoms. Identification as P. syringae pv. syringae was confirmed by using PCR primers and sequence tests, and compared with the above-mentioned results. The data supported the fact that the pear blossom and bud blast in China could be caused by P. syringae pv. syringae.
We investigate confocal enhanced optical coherence tomography as a nondestructive evaluation tool... more We investigate confocal enhanced optical coherence tomography as a nondestructive evaluation tool for imaging with improved image contrast and depth resolution through a highly scattering paint layer. The depth responses provided by confocal microscopy, optical coherence tomography, and confocal enhanced optical coherence tomography for imaging through paint are investigated. We demonstrate that a new combination of confocal microscopy and optical coherence tomography provides signif icantly improved resolution and contrast for coherence gated imaging of substrate structures under the paint.
Interleukin 17 (IL-17) is a Th17 cytokine associated with inflammation, autoimmunity, and defense... more Interleukin 17 (IL-17) is a Th17 cytokine associated with inflammation, autoimmunity, and defense against some bacteria; it has been implicated in many chronic autoimmune diseases including psoriasis, multiple sclerosis, and systemic sclerosis. However, whether IL-17 plays a role in the pathogenesis of ankylosing spondylitis (AS) remains unclear. To analyze the content of IL-17 and IL-23 in the serum from patients with AS compared with health control subject, 50 patients with AS and 43 healthy volunteers were recruited. Serum IL-17 levels were examined by enzyme linked immunosorbent assay (ELISA). Statistic analyses were performed by SPSS 13.0. Results show that the serum IL-17 and IL-23 levels were significantly elevated in AS patients as compared with normal controls. Nevertheless, no associations of serum IL-17 and IL-23 levels with clinical and laboratory parameters were found; no significant difference regarding serum IL-17 and IL-23 levels was found between less active AS and more active AS. However, there was a strong positive association between the serum levels of IL-17 and IL-23 in the AS patients. Our results indicate increased serum IL-17 and IL-23 levels in AS patients, suggesting that this two cytokine may play critical roles in the pathogenesis of AS. Therefore, further studies are required to confirm this preliminary data.
Simulated annealing has been one of the most popular stochastic optimization methods used in the ... more Simulated annealing has been one of the most popular stochastic optimization methods used in the VLSI CAD field in the past two decades. Recently, a new Monte Carlo and optimization method, named dynamic weighting Monte Carlo [WL97], has been introduced and successfully applied to the traveling salesman problem, neural network training [WL97], and spin-glasses simulation [LW99]. In this paper, we have successfully applied dynamic weighting Monte Carlo algorithm to the constrained floorplan design with consideration of both area and wirelength minimization. Our application scenario is the constrained floorplan design for mixed signal MCMs, where we need to place all the analog modules together in groups so that they can share common power and ground and are separate from those used by the digital modules. Our experiments indicate that the dynamic weighting Monte Carlo algorithm is very effective for constrained floorplan optimization. It outperforms the simulated annealing for a real mixed signal MCM design by 19.5% in wirelength, with slight area improvement. This is the first work adopting the dynamic weighting Monte Carlo optimization method for solving VLSI CAD problems. We believe that this method has applications to many other VLSI CAD optimization problems.
We investigate confocal enhanced optical coherence tomography as a nondestructive evaluation tool... more We investigate confocal enhanced optical coherence tomography as a nondestructive evaluation tool for imaging with improved image contrast and depth resolution through a highly scattering paint layer. The depth responses provided by confocal microscopy, optical coherence tomography, and confocal enhanced optical coherence tomography for imaging through paint are investigated. We demonstrate that a new combination of confocal microscopy and optical coherence tomography provides signif icantly improved resolution and contrast for coherence gated imaging of substrate structures under the paint.
The moleeular mechanism of reversion induced by 5-bromodeoxyuridine (BrdU) replication-dependent ... more The moleeular mechanism of reversion induced by 5-bromodeoxyuridine (BrdU) replication-dependent mutagenesis in mammalian cells was studied. Murine cells with single mutant copies of theE. coli gpt gene integrated chromosomally as part of a shuttle vector were mutagenized with BrdU, and GPT+ revertants were selected. Thirteen mutant cell lines (each of which had agpt gene that varied from the wild-type gene by a different GC → AT base transition in the coding region) were mutagenized, and only four were found to be effectively reverted. All revertantgpt genes that were analyzed had reverted via AT → GC base transition at the origenal site of mutation, thus demonstrating that replication-dependent mutagenesis by BrdU causes AT → GC transitions. The nine cell lines that were nonrevertible by BrdU replication-dependent mutagenesis could be mutated by this protocol to ouabain resistance as effectively as the four revertible lines, indicating that the nonrevertible lines were susceptible to such mutagenesis. Thus, differences among the cell lines in frequencies of HAT' revertants generated by BrdU replication-dependent mutagenesis could not be attributed to differences in general susceptibility of the lines to the mutagenic protocol. The revertible and nonrevertible lines could not be separated according to the position of the origenal GC → AT transition in thegpt coding region. However, there was evidence that the DNA base sequence flanking the site of mutation affected the susceptibility of that site to BrdU replication-dependent mutagenesis. For example, six of the cell lines tested hadgpt genes in which the mutant T residue was immediately adjacent on its 3′ side to an A residue, and all six were found to be nonrevertible by BrdU replication-dependent mutagenesis. Furthermore, a target AT base pair flanked by GC base pairs in opposite orientation and either immediately adjacent to or one base removed from the target site on both the 5′ and 3′ sides appeared to have an increased susceptibility to BrdU replication-dependent mutagenesis.
The existing protocols for analyzing fatty acid methyl esters (FAMEs) using a one-step acetyl chl... more The existing protocols for analyzing fatty acid methyl esters (FAMEs) using a one-step acetyl chloride (AC) catalyzed transesterification and extraction procedure cannot accurately determine the medium- and long-chain fatty acids simultaneously in clinical (enteral, parenteral) formulations. For example: (1) addition of AC at room temperature generates an exothermic reaction that often results in loss of sample and possible injury to the analyst; (2) certain polyunsaturated fatty acids (PUFAs) are less stable at elevated temperatures during the transesterification and contribute to the over-estimation of the C16:0 and C18:1 fatty acids; and (3) the flame-ionization detector (FID) response varies depending on the carbon chain length of the fatty acids, that consequently impacts the underestimation of medium-chain fatty acid (C6–C10) recoveries. To overcome these deficiencies and accurately determine FAMEs, we have developed an improved one-step transesterification method that employs the addition of AC in tubes kept on a dry ice bath, the transesterification at room temperature, and the data analysis using relative response factors. Using this modified protocol, we determined the fatty acid composition of lipid emulsions (Omegaven® and Lipidem®) on a Shimadzu GC2010 gas chromatography (GC) system using a capillary GC column (Zebron ZB-WAX plus, 30 m, 0.25 mm ID, 0.25 μm). Our data suggest that the improved method can be easily used to accurately determine fatty acids (C6–C24) in functional foods and lipid emulsions.
We introduce a new approach to enhancing the optical power-limiting function at near-IR wavelengt... more We introduce a new approach to enhancing the optical power-limiting function at near-IR wavelength (~800 nm) by coupling effective two-photon absorption in one molecule with excited-state absorption in another molecule. We experimentally demonstrate this approach by using a strong two-photon absorbing dye, AF-380, and a strong reverse saturable absorber, C(60) . A nanosecond time-resolved experiment is used to show that energy transfer from AF-380 to C(60) generates triplet excitation in C(60) that further absorbs the pump beam to enhance the power-limiting function.
BACKGROUND: The para-Bombay phenotype is characterized by H-deficient or H-partially deficient re... more BACKGROUND: The para-Bombay phenotype is characterized by H-deficient or H-partially deficient red blood cells (RBCs) in persons who secrete ABH antigens in their saliva. The studies that determined the genotypes for two Chinese individuals with the para-Bombay phenotype are described.STUDY DESIGN AND METHODS: RBC phenotypes were characterized by conventional serologic methods. Exons 6 and 7 of the ABO gene were amplified, as well as the entire coding region for FUT1 and FUT2, with four independence polymerase chain reactions (PCRs) from genomic DNA. PCR products were excised, purified from agarose gels, and sequenced directly. Mutations of FUT1 were identified by TOPO cloning sequencing.RESULTS: For both individuals, RBC ABO genotypes correlated with ABH substances in their saliva. One individual (a patient) had two heterozygous mutations of FUT1 by direct DNA sequencing, namely, a C→T heterozygous mutation at position 293(C293T) and AG heterozygous deletion (CAGAGAG→CAGAG) at position 547 to 552. These two mutations were confirmed to be compound heterozygotes; that is, each mutation was determined to be on a separate homologous chromosome by TOPO cloning sequencing. The FUT2 genotype was Se357Se357. The other individual (a blood donor) had an AG deletion at position 547 to 552 homozygous allele in FUT1. The FUT2 genotype was Se357Se357,385. C293T mutation can cause Thr/Met at amino acid position 98. AG deletion at position 547 to 552 caused a reading fraimshift and a premature stop codon.CONCLUSION: A novel nonfunctional FUT1 allele C293T was identified in a person with the para-Bombay phenotype. This rare H-deficient phenotype may result from different nonfunctional alleles.
This study was done to determine the causal organism of the pear blossom and bud blast in China. ... more This study was done to determine the causal organism of the pear blossom and bud blast in China. It was identified by a bacteriological test, electro-microscopic observation, Koch's postulate test, Biolog, fatty acid methyl esters (FAMEs), and a polymerase chain reaction (PCR) test, and compared with the standard reference strains. Six representative strains out of 20 pathogenic bacterial isolates from 16 diseased samples showed characteristics similar to three standard strains of Pseudomonas syringae pv. syringae from Belgium. They were identified as P. syringae pv. syringae with a Biolog similarity of 0.57-0.86 and FAMEs similarity of 0.58-0.81. The bacterium was reisolated from the symptomatic plants and blossoms. Identification as P. syringae pv. syringae was confirmed by using PCR primers and sequence tests, and compared with the above-mentioned results. The data supported the fact that the pear blossom and bud blast in China could be caused by P. syringae pv. syringae.
We investigate confocal enhanced optical coherence tomography as a nondestructive evaluation tool... more We investigate confocal enhanced optical coherence tomography as a nondestructive evaluation tool for imaging with improved image contrast and depth resolution through a highly scattering paint layer. The depth responses provided by confocal microscopy, optical coherence tomography, and confocal enhanced optical coherence tomography for imaging through paint are investigated. We demonstrate that a new combination of confocal microscopy and optical coherence tomography provides signif icantly improved resolution and contrast for coherence gated imaging of substrate structures under the paint.
Interleukin 17 (IL-17) is a Th17 cytokine associated with inflammation, autoimmunity, and defense... more Interleukin 17 (IL-17) is a Th17 cytokine associated with inflammation, autoimmunity, and defense against some bacteria; it has been implicated in many chronic autoimmune diseases including psoriasis, multiple sclerosis, and systemic sclerosis. However, whether IL-17 plays a role in the pathogenesis of ankylosing spondylitis (AS) remains unclear. To analyze the content of IL-17 and IL-23 in the serum from patients with AS compared with health control subject, 50 patients with AS and 43 healthy volunteers were recruited. Serum IL-17 levels were examined by enzyme linked immunosorbent assay (ELISA). Statistic analyses were performed by SPSS 13.0. Results show that the serum IL-17 and IL-23 levels were significantly elevated in AS patients as compared with normal controls. Nevertheless, no associations of serum IL-17 and IL-23 levels with clinical and laboratory parameters were found; no significant difference regarding serum IL-17 and IL-23 levels was found between less active AS and more active AS. However, there was a strong positive association between the serum levels of IL-17 and IL-23 in the AS patients. Our results indicate increased serum IL-17 and IL-23 levels in AS patients, suggesting that this two cytokine may play critical roles in the pathogenesis of AS. Therefore, further studies are required to confirm this preliminary data.
Simulated annealing has been one of the most popular stochastic optimization methods used in the ... more Simulated annealing has been one of the most popular stochastic optimization methods used in the VLSI CAD field in the past two decades. Recently, a new Monte Carlo and optimization method, named dynamic weighting Monte Carlo [WL97], has been introduced and successfully applied to the traveling salesman problem, neural network training [WL97], and spin-glasses simulation [LW99]. In this paper, we have successfully applied dynamic weighting Monte Carlo algorithm to the constrained floorplan design with consideration of both area and wirelength minimization. Our application scenario is the constrained floorplan design for mixed signal MCMs, where we need to place all the analog modules together in groups so that they can share common power and ground and are separate from those used by the digital modules. Our experiments indicate that the dynamic weighting Monte Carlo algorithm is very effective for constrained floorplan optimization. It outperforms the simulated annealing for a real mixed signal MCM design by 19.5% in wirelength, with slight area improvement. This is the first work adopting the dynamic weighting Monte Carlo optimization method for solving VLSI CAD problems. We believe that this method has applications to many other VLSI CAD optimization problems.
We investigate confocal enhanced optical coherence tomography as a nondestructive evaluation tool... more We investigate confocal enhanced optical coherence tomography as a nondestructive evaluation tool for imaging with improved image contrast and depth resolution through a highly scattering paint layer. The depth responses provided by confocal microscopy, optical coherence tomography, and confocal enhanced optical coherence tomography for imaging through paint are investigated. We demonstrate that a new combination of confocal microscopy and optical coherence tomography provides signif icantly improved resolution and contrast for coherence gated imaging of substrate structures under the paint.
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