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Biomedical subjects

C M Wang

Publications and source records attributed to C M Wang.

At least 19 recordsLinked to original sources
PubMed2006

Morphological evolution of Ba(NO3)2 supported on alpha-Al2O3(0001): an in situ TEM study.

A key question for the BaO-based NOx storage/reduction catalyst system is the morphological evolution of the catalyst particles during the uptake and release of NOx. Notably, because the formed product during NOx uptake, Ba(NO3)2, requires a lattice expansion from BaO, one can anticipate that significant structural rearrangements are possible during the storage/reduction processes. Associated with the small crystallite size of high-surface area gamma-Al2O3, it is difficult to extract structural and morphological features of Ba(NO3)2 supported on gamma-Al2O3 by any direct imaging method, including transmission electron microscopy. In this work, by choosing a model system of Ba(NO3)2 particles supported on single-crystal alpha-Al2O3, we have investigated the structural and morphological features of Ba(NO3)2 as well as the formation of BaO from Ba(NO3)2 during the thermal release of NOx, using ex-situ and in-situ TEM imaging, electron diffraction, energy dispersive spectroscopy (EDS), and Wulff shape construction. We find that Ba(NO3)2 supported on alpha-Al2O3 possesses a platelet morphology, with the interface and facets being invariably the eight [111] planes. Formation of the platelet structure leads to an enlarged interface area between Ba(NO3)2 and alpha-Al2O3, indicating that the interfacial energy is lower than the Ba(NO3)2 surface free energy. In fact, Wulff shape constructions indicate that the interfacial energy is approximately 1/4 of the [111] surface free energy of Ba(NO3)2. The orientation relationship between Ba(NO3)2 and the alpha-Al2O3 is alpha-Al2O3[0001]//Ba(NO3)2[111] and alpha-Al2O3(1-210)//Ba(NO3)2(110). Thus, the results clearly demonstrate dramatic morphology changes in these materials during NOx release processes. Such changes are expected to have significant consequences for the operation of the practical NOx storage/reduction catalyst technology.

Journal Article↗
PubMed2006

Characterization of two parvalbumin genes and their association with growth traits in Asian seabass (Lates calcarifer).

Parvalbumins are extremely abundant in fish muscle and play an important role in muscle relaxation. In this study, two parvalbumin genes (PVALB1 and PVALB2) were cloned from Asian seabass (Lates calcarifer). The cDNAs for PVALB1 and PVALB2 were 840 and 667 bp respectively. Both genes consisted of five exons and four introns, encoded 109 amino acids, and were of beta lineage. Using real-time polymerase chain reaction, expression of PVALB1 was detected in all 10 tissues tested, with expression in brain, kidney, muscle and small intestine being 15- to 322-fold higher than in the other tissues. Expression of PVALB2 was detected only in muscle, brain and intestine, and was up to 10-fold lower than PVALB1 expression. A (CT)(17) microsatellite in the 3'-untranslated region of PVALB1 and three single nucleotide polymorphisms (SNPs) in the third intron of PVALB2 were identified. The microsatellite in PVALB1 was significantly associated with body weight and body length at 90 days post-hatch (P < 0.01), whereas the SNPs in PVALVB2 were not associated with these traits.

3' Untranslated Regions↗
PubMed2006

Isolation, characterization, and linkage analyses of 74 novel microsatellites in Barramundi (Lates calcarifer).

Barramundi (Lates calcarifer) is an important marine food fish species in Southeast Asia and Australia. Seventy-four novel microsatellites were isolated from a genomic DNA library enriched for CA repeats and were characterized in 24 unrelated individuals. Among the 74 microsatellites, 71 were polymorphic, with an average allele number of 7.0 +/- 3.6/locus. The average expected heterozygosity of these polymorphic markers was 0.66. Sixty-three of the 71 polymorphic microsatellites conformed to Hardy-Weinberg equilibrium. Linkage analyses were conducted in a reference family, leading to the assignment of 34 novel microsatellites and 16 published markers in 16 linkage groups. The novel microsatellites developed in this study will contribute significantly to the construction of a first-generation linkage map for mapping of quantitative trait loci in Barramundi, and supply a large choice of markers for studies on population genetics, stock management, and pedigree reconstruction.

Animals↗
PubMed2005

Negligible magnetism in excellent structural quality Cr(x)Ti(1-x)O(2) anatase: contrast with high-T(C) ferromagnetism in structurally defective Cr(x)Ti(1-x)O(2).

We reexamine the mechanism of ferromagnetism in doped TiO(2) anatase, using epitaxial Cr:TiO(2) with excellent structural quality as a model system. In contrast to highly oriented but defective Cr:TiO(2) (approximately 0.5 micro(b)/Cr), these structurally superior single crystal films exhibit negligible ferromagnetism. Similar results were obtained for Co:TiO(2). We show for the first time that charge-compensating oxygen vacancies alone, as predicted by F-center mediated exchange, are not sufficient to activate ferromagnetism. Instead, the onset of ferromagnetism correlates with the presence of structural defects.

Journal Article↗
PubMed2005

Intrinsic ferromagnetism in insulating cobalt doped anatase TiO2.

Using complementary experiments we show that the room temperature ferromagnetism observed in anatase Co:TiO(2) films is not carrier mediated, but coexists with the dielectric state. TEM and x-ray absorption spectroscopy reveal a solid solution of Co in anatase, where Co is not metallic but in the +2 state substituting for Ti. Measurements at 300 K yield a M(S) of 1.1 mu(B)/Co atom, while all films are highly insulating. The evidence of intrinsic ferromagnetism in the dielectric ground state of Co:TiO(2) leads to new considerations for the origin of ferromagnetism in transition metal doped oxides.

Journal Article↗
PubMed2005

Stability of QTLs for rice grain dimension and endosperm chalkiness characteristics across eight environments.

Rice appearance quality, including traits specifying grain dimension and endosperm chalkiness, represents a major problem in many rice-producing areas of the world. In this study, the genetic basis of six appearance quality traits of milled rice was dissected into quantitative trait loci (QTL) main effects, and the stability of these QTLs was assessed in a population of 66 chromosome segment substitution lines (CSSLs) across eight environments. The CSSLs showed transgressive segregation for many of the traits, and significant correlations were detected among most of the traits. Twenty-two QTLs were identified on eight chromosomes, and numerous QTLs affecting related traits were mapped in the same regions, probably reflecting pleiotropic effects. Nine QTLs, namely qGL-1,qGL-3, qGW-5,qLWR-3, qLWR-5,qPGWC-8, qPGWC-9, qACE-8, and qDEC-8, were consistently detected across the eight environments. The additive main effect and multiplicative interaction (AMMI) analysis showed that genotype (G) x environment (E) interaction was significant for all six traits, with the first three iPCA terms accounting for over 80% of the G x E variance. Both D(I) values and the iPCA1-iPCA2 biplots showed that the CSSLs harboring the nine QTL alleles were more stable than those carrying any of the additional 13 QTL alleles, thereby confirming their environmental stability and pointing to their appropriateness as targets for marker-assisted selection for high-quality rice varieties.

Analysis of Variance↗
PubMed2005

Limiting burn extension by transient inhibition of Connexin43 expression at the site of injury.

Extension of a burn wound over the first 24h following injury is recognised clinically, and leads to diagnostic and therapeutic dilemmas. In the central nervous system, a similar spread of damage, beyond the initial injury, can occur via the spread of death signals from injured cells to their healthy neighbours via Connexin43 (Cx43) gap junction channels. In the skin, Cx43 is expressed in the basal epidermis and in fibroblasts and dermal appendages. We have used Cx43 specific antisense oligodeoxynucleotide approach to transiently down-regulate Cx43 protein in the early stages of partial thickness cutaneous burn wound healing. Antisense ODNs reduce the spread of tissue damage and neutrophil infiltration around the wound following injury. Epithelial cell proliferation is increased and the rate of wound closure is accelerated, compared to controls. Resultant scarring is smaller with less granulation tissue and more dermal appendages than controls. These findings suggest that Cx43 antisense treatment speeds partial thickness burn wound healing and reduces scarring. We suggest that this approach may provide an effective adjunct to managing partial thickness burn wounds.

Animals↗
PubMed2005

Effects of artificial supplemental light on the reproductive season of geese kept in open houses.

1. New lighting programmes were designed to change the pattern of goose reproduction, based on the response of predictable avian photoperiodic stimulation. The objective of this study was to evaluate the efficiency of a long photoperiod of 20L on shifting goose reproduction to the non-breeding season in an open housing system. 2. Eighty mature White Roman geese were randomly allocated into 4 groups (male:female = 1:4). The supplemental lighting programmes with a daily photoperiod of 20 h were initiated on 22 November and withdrawn when 90% of geese were moulting in the treatment groups. Artificial light intensities of 220, 120 and 20 lux were provided to experimental groups A, B and C, respectively. In contrast, the geese in control group D were kept under natural lighting conditions throughout this study. 3. The annual reproductive curves of all the experimental groups consisted of two separate laying periods. The first period was induced by the supplemental lighting programme while the second was induced by the naturally increasing photoperiod in this subtropical region. The first laying period of the experimental groups occurred in the breeding season, and the second was relocated to the non-breeding season. 4. The supplemental lighting could shift the laying periods of geese to the non-breeding season and had no significant effect on annual reproductive performance. The supplemental light programmes described here were able to manipulate the reproductive season of geese reared in open houses, which would be of practical value.

Animal Husbandry↗
PubMed2004

QTL detection for eating quality of cooked rice in a population of chromosome segment substitution lines.

The genetic mechanism underlying six palatability properties of cooked rice and three physico-chemical traits was dissected in 66 BC(3)F(2) chromosome segment substitution lines (CSSLs), using a complete linkage map in three successive years. The CSSLs showed transgressive segregation for all traits studied. Significant correlation was detected among most palatability traits. A total of 25 QTLs for the nine traits were identified on nine chromosomes, and many QTLs affecting different quality traits were mapped in the same regions. Six QTLs--qLT-8 for luster, qTD-6 and qTD-8 for tenderness, qIVOE-6 and qIVOE-8 for integrated value of organoleptic evaluation, and qAC-8 for amylose content--were repeatedly detected across the 3 years. Phenotypic values were significantly different between the recurrent parent, cultivar Asominori, and the CSSLs harboring any of the six QTL alleles across the three environments, indicating that these six QTLs were non-environment-specific and could be used for marker-assisted selection in rice quality improvement.

Chromosome Mapping↗
PubMed2004

Prediction of apatite lattice constants from their constituent elemental radii and artificial intelligence methods.

Lattice constants (LCs) of all possible 96 apatite compounds, A(5)(BO(4))(3)C, constituted by A[double bond]Ba(2+), Ca(2+), Cd(2+), Pb(2+), Sr(2+), Mn(2+); B[double bond]As(5+), Cr(5+), P(5+), V(5+); and C[double bond]F(1-), Cl(1-), Br(1-), OH(1-), are predicted from their elemental ionic radii, using pattern recognition (PR) and artificial neural networks (ANN) techniques. In particular, by a PR study it is demonstrated that ionic radii predominantly govern the LCs of apatites. Furthermore, by using ANN techniques, prediction models of LCs a and c are developed, which reproduce well the measured LCs (R(2)=0.98). All the literature reported on 30 pure and 22 mixed apatite compounds are collected and used in the present work. LCs of all possible 66 new apatites (assuming they exist) are estimated by the developed ANN models. These proposed new apatites may be of interest to biomedical research especially in the design of new apatite biomaterials for bone remodeling. Similarly these techniques may also be applied in the study of interface growth behaviors involving other biomaterials.

Algorithms↗
PubMed2004

Fcgamma receptor IIa, IIIa, and IIIb polymorphisms of systemic lupus erythematosus in Taiwan.

OBJECTIVE: To determine whether the distribution of Fcgamma receptor IIa, IIIa, and IIIb polymorphisms confers a risk factor for disease susceptibility, and correlates with the clinical characteristics and serological parameters of patients with SLE in Taiwan. METHODS: Genotyping of Fcgamma receptors IIa H/R131, IIIa F/V158, and IIIb NA1/NA2 was performed in 302 patients with SLE and 311 healthy blood donor controls. The distribution of Fcgamma receptor IIa, IIIa, and IIIb genotypes in patients and controls was analysed. Frequencies of three Fcgamma receptor polymorphisms were also compared between lupus patients with and without different clinical manifestations and autoantibodies. RESULTS: No significant skewing in the distribution of Fcgamma RIIa H/R131, Fcgamma RIIIa F/V158, and Fcgamma RIIIb NA1/NA2 was found between patients and controls in Taiwan. The following clinical associations were found: Fcgamma RIIIb NA1/NA1 protected against neuropsychiatric lupus (p = 0.028) but conferred susceptibility to discoid rash (p<0.005); increased Fcgamma RIIIa V/V158 was associated with infections (p = 0.039); increased Fcgamma RIIa H/H131 was associated with earlier onset of lupus (p = 0.01). CONCLUSION: Fcgamma receptor IIa, IIIa, and IIIb polymorphisms may be responsible for the development of distinct manifestations of lupus patients in Taiwan, but there is no significantly skewed distribution in the susceptibility to lupus as a whole.

Adult↗
PubMed2001

Comparison of different protein immobilization methods on quartz crystal microbalance surface in flow injection immunoassay.

In this study, a quartz crystal microbalance (QCM) system operated repetitively in flow injection analysis (FIA) mode, is reported. Four immobilization approaches of seven different methods include: (i) physical adsorption; (ii) two thioamine thiolation methods, using cysteamine and cystamine for gold chemisorption and further coupling; (iii) two oxidized dextran spacer methods, coupling of cysteamine and cystamine thiolated QCM surface with periodate-oxidized dextran for further Schiff acid-base reaction; and (iv) two thiol-gold chemisorption-based self-assembled monolayer (SAM), applying short-chain, C(3), and long-chain, C(11), mercapto fatty acids to insolubilize human serum albumin (HSA) on QCM surface. Effects of these protein immobilization methods on FIA immunoassay of anti-HSA were compared. At the 0.01 mg/ml anti-HSA level, the lowest analyte concentration tested, the SAM using 11-mercaptoundecanoic acid as QCM surface activating agent generated a larger frequency shift than the other immobilization methods. This implied that the use of thiolated long-chain fatty acid constructed as self-assembled monolayer may thereby potentially be a useful protein immobilization method in QCM-FIA application.

Absorption↗
PubMed2001

Phase determination and extension using X-ray multiple diffraction and the maximum-entropy method.

The extension of the phases of the structure factors of the organic crystal C(25)H(25)NO(2) from 77 starting individual phases using the maximum-entropy method is reported. These starting phases were determined from 90 experimental triplet phases calculated from 215 measured psi-scan three-beam and four-beam diffraction profiles obtained with a rotating-anode X-ray source, where the psi scans were around the reciprocal-lattice vectors of the 001, 002 and 003 reflections. The extension of the structure factors with phase values was carried out using the maximum-entropy method for 2040 measured two-beam Bragg diffraction intensities with 77 starting phases and the symmetry of the space group as the constraints. Use of structure-factor triplets as constraints for entropy maximization was also attempted. The minimum chi(2) criteria were applied to the maximum-entropy extrapolation to discern the best phase set to be used as the new constraints for the next step of generating new phases. With this phase-extension procedure, more than 100 phases were determined and an electron-density map at 1.97 A was deduced.

Journal Article↗
PubMed2001

Epidemiology of extraspinal fractures associated with acute spinal cord injury.

STUDY DESIGN: A descriptive study of concurrent extraspinal fractures collected prospectively during initial hospital care. OBJECTIVES: To examine the frequency and related characteristics of concurrent extraspinal fractures among patients with a new onset of spinal cord injury (SCI). SETTING: Model SCI care systems throughout the United States. METHODS: A consecutive sample of 5711 subjects admitted to the National SCI Database between 1986-1995 was recruited to estimate the incidence of extraspinal fractures associated with acute SCI, stratified by anatomic sites, demographics, and injury related characteristics. RESULTS: Of 5711 subjects, 1585 (28%) patients had extraspinal fractures; 580 (37%) patients had more than one fracture site. The most common region of fractures was chest, followed by lower extremity, upper extremity, head, others, and pelvis. The overall incidence rate was higher for women than men, for whites than non-whites, for paraplegics than tetraplegics, and for those injured in motor vehicle crashes than others. Compared with patients having single fracture, those who had multiple fractures were likely to be white, paraplegic, and injured in motor vehicle crashes. There was no age difference in the incidence of concurrent fractures, single or multiple. CONCLUSIONS: Extraspinal fractures are not uncommon at the same time as SCI. The fracture occurrence varies by gender, race, injury level, and etiology of injury. The knowledge of these associated factors will aid in early recognition of fractures, preventing complications, and facilitating rapid mobilization and rehabilitation outcomes among persons with SCI.

Adolescent↗
PubMed2001

Allergic contact dermatitis to temporary tattoos with positive para-phenylenediamine reactions: report of four cases.

BACKGROUND: In recent years, temporary tattoos instead of permanent tattoos have become popular worldwide. Although contact allergy to temporary henna tattoos appears to be rare in the past, it is progressively more commonly reported. PATIENTS: Four Taiwanese patients of allergic contact dermatitis following application of temporary tattoos were patch tested and they were followed up for 1 year after treatment. RESULTS: All four of the tested patients were positive to paraphenylenediamine. At 1-year follow-up, all four patients still showed various degrees of remnant hyperpigmentation on their previous tattooed areas. CONCLUSION: Temporary tattoos may pose similar risks of allergic reactions associated with permanent tattoos. A high risk of prolonged post-inflammatory hyperpigmentation after allergic contact dermatitis from temporary tattoos should also be alerted, especially in Asian skin type.

Adult↗
PubMed2001

[Effects of corticosterone on the activity of the neurons in the rostral ventrolateral medulla of rats].

Spontaneous discharges of the rostral ventrolateral medulla (RVLM) neurons were extracellularly recorded by multi-barrelled microelectrodes in urethane-anesthetized rats. A total of 145 neurons were recorded: 33 were cardiovascular, 31 were nociceptive modulating, and 81 were unknown functional. The cardiovascular neurons were electrophysiologically identified through activating baroreceptor reflex by electrical stimulation of the aortic nerve and by intravenous injection of phenylephrine. Of the 33 cardiovascular neurons, 25 (76%) increased in firing rate after iontophoretical application of corticosterone sulfate (CORT), and 8 (24%) failed to respond. Of the 31 nociceptive modulating neurons excited by noxious stimulation, the firing rate decreased in 19 (64%), increased in 2 (6%), and did not respond in 10 (30%) after iontophoresis of CORT. Of the remaining 81 unknown functional neurons, 32 (40%) were excited, 5 (6%) inhibited, and 44 (54%) were not affected by CORT. These results demonstrate that CORT may modulate the activities of the neurons in RVLM through fast non-genomical effect, suggesting that the mechanism of the fast actions of CORT may play an important role in integration of the cardiovascular, nociceptive modulating activity under some conditions such as stress.

Animals↗
PubMed2001

Expression of the Recombinant Human Interleukin-11 in Pichia pastoris.

Full length cDNA of human IL-11 was synthesized by DNA synthesizer. An expression plasmid, pGENYk, containing the recombinant DNA fragment, was linearized and transformed into Pichia pastoris. This recombinant gene was highly expressed in this yeast, and the expression product was purified by a three-step chromatography method. Analysis of the purified recombination protein with SDS-PAGE, Western blot and biological activities showed that the activity of the protein was the same as the Neumega expressed in E.coli.

Journal Article↗