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Biomedical subjects

F C Wu

Publications and source records attributed to F C Wu.

At least 19 recordsLinked to original sources
PubMed2005

Effects of light and oxygen on the uptake and distribution of phosphorus at the sediment-water interface.

Effects of oxygen and light on the uptake and distribution of phosphorus at the sediment-water interface were investigated in this study. The experimental water and sediment samples were collected from East Taihu Lake, China. The results show that phosphorus can be taken up from the overlying water to the sediments with high nutrient loading in both anoxic and aerobic conditions. The transformation between different phosphorus fractions in the sediments and in the overlying water was observed. Effects of dissolved oxygen on the phosphorus distribution at the sediment and overlying water interface were mainly due to the inorganic processes, while effects of light were mainly due to the biological activity. This study indicates that oxygen concentration had a predominant control on the distribution and uptake of phosphorus in the sediments, and light had obvious effect on the dissolved inorganic phosphorus (DIP) concentration in the overlying water.

China↗
PubMed2003

Separation and characterization of NOM by high-performance liquid chromatography and on-line three-dimensional excitation emission matrix fluorescence detection.

By using high-performance size exclusion chromatography (HPSEC) and reversed-phase high-performance liquid chromatography with on-line three-dimensional excitation emission matrix fluorescence detection, we measured fluorescence properties of natural organic matter (NOM) as a function of molecular size (MS) and polarity. The work was carried out with Suwannee River Fulvic Acid, Aldrich Humic Acid, and a naturally occurring river NOM sample. Significant differences in fluorescence maximum pattern were found as NOM was separated chromatographically based on MS and polarity. There existed a strong relationship between MS, fluorescence pattern, and polarity. Humic-, fulvic-, and protein-like fluorescence fractions had distinct hydrophilic/hydrophobic nature. The results suggest that HPSEC may be better for characterizing major fulvic-like fluorescence and smaller MS fractions but not those having humic- and protein-like fluorescence and larger MS, which may be strongly adsorbed onto the HPSEC column because of their hydrophobic nature. This study has significant implications for further understanding the nature of NOM and its complexation with trace metals.

Benzopyrans↗
PubMed2003

Dietary docosahexaenoic acid is more optimal than eicosapentaenoic acid affecting the level of cellular defence responses of the juvenile grouper Epinephelus malabaricus.

The combined effects of dietary docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids on phagocytic, respiratory burst, and leucocyte proliferative activities of the juvenile grouper, Epinephelus malabaricus, were investigated. The test fish were fed for 12wk on test diets containing 1g 100g(-1) diet of DHA and EPA in combinations (DHA/EPA: 3/1, 2/1, 1/1, 0.7/1, 0.3/1). In addition to promoting fish growth, high dietary DHA/EPA ratio significantly enhanced phagocytic and respiratory burst activities of grouper head-kidney leucocytes compared with low ratio. Significant correlations were found between leucocyte phagocytic or respiratory burst activities and concentrations of 20:3(n-3), DHA and EPA in fish liver and muscle tissues. Leucocyte proliferation was significantly higher (P< 0.05) when the diets were high in DHA/EPA ratio than low in DHA/EPA ratio, when stimulated by Con A and PHA-P, but not by LPS. Tissue DHA concentrations and leucocyte proliferation were significantly and positively correlated. Fortification of dietary DHA, thus increased T-cell proliferation and phagocytic function of grouper leucocytes. DHA is the only member in the (n-3) highly unsaturated fatty acid family that stimulated phagocytic functions of leucocytes and T-cell proliferation, and is more optimal than EPA affecting the cellular defence responses of the E. malabaricus juveniles.

Animals↗
PubMed2003

Pollutant sources investigation and remedial strategies development for the Kaoping River Basin, Taiwan.

The Kaoping River Basin, located in southern Taiwan, flows through approximately 171 km and drains towards the South Taiwan Strait. It is the largest and the most intensively used river basin in Taiwan. Based on the results from the pollutant sources investigation and water quality analysis, the main water pollution sources of the Kaoping River were livestock wastewater from hog farms, municipal wastewater, industrial wastewater, leachate from riverbank landfills, and non-point source (NPS) pollutants from agricultural areas in the upper catchment. Concern about the deteriorating condition of the river led the Government of Taiwan to amend the relevant legislation and strengthen the enforcement of the discharge regulations to effectively manage the river and control the pollution. The following remedial strategies have been taken to improve the river water quality since 2001: (1) hog ban in the upper catchment of the Kaoping River Basin, thus, 510 thousand hogs have been removed/relocated; (2) removal of riverbank landfills; (3) enforcement of the industrial wastewater discharge standards; (4) sewer system construction in five cities along the river corridor; (5) application of best management practices for NPS pollutant control; (6) application of natural wastewater treatment systems (e.g. land treatment, constructed wetland, overland flow, riverbank sedimentation/aeration pond) for domestic wastewater treatment in rural areas; and (7) construction of the watershed geographical information system (GIS) and real time water quality monitoring system to effectively monitor and manage the watershed. Recent water quality investigation results indicate that the biochemical oxygen demand (BOD) and nutrient loadings to the Kaoping River have been significantly reduced and the water quality has been improved after the implementation of the remedial strategies described above. Results and experience obtained from this study will be helpful in designing the watershed management strategies for other similar river basins.

Animals↗
PubMed2001

Enhanced abilities of highly swollen chitosan beads for color removal and tyrosinase immobilization.

The enhancement of abilities for the removal of reactive dyes and immobilization of tyrosinase onto highly swollen chitosan beads was demonstrated compared to the use of common chitosan flakes. Chitosan was prepared from natural cuttlebone wastes. It was shown that the adsorption capacity of dyes at 30 degrees C using swollen chitosan beads was around five times greater than that using common chitosan flakes. The adsorption of dyes using swollen beads was faster by 10-40% depending on the types of dyes. Finally, the capacity of tyrosinase immobilization onto swollen beads was about 14 times greater than chitosan flakes, which was reflected by the higher yield of 3,4-dihydroxyphenylalanine from tyrosine and ascorbic acid in the heterogeneous catalytic system.

Adsorption↗
PubMed2001

Activational effects of testosterone on cognitive function in men.

OBJECTIVES: The effect of testosterone (T) on sexual function in men is well established. However, less is known about its effects on cognitive function. The aim of this study is to investigate the relationship between T levels and sex-typed cognitive abilities in both eugonadal and hypogonadal men. DESIGN: A single-blind placebo-controlled design was employed in this study. METHODS: Thirty healthy eugonadal men and seven hypogonadal men participated in the study. Eugonadal men were randomised into one of two treatment regimens: (1) active group--receiving 200 mg of T enanthate i.m. weekly for 8 weeks (raising T levels into the supraphysiological range) or (2) placebo group--receiving 200 mg of sodium chloride i.m. weekly for 8 weeks. The hypogonadal group received the physiological replacement dose of 200 mg T enanthate i.m. bi-weekly for 8 weeks. All groups underwent a battery of neuropsychological tests and had circulating T measured at baseline, and at weeks 4 and 8 during treatment. RESULTS: A significant time by group interaction effect was found in the measure of spatial ability (i.e., block design test) indicating that the active group's performance declined significantly at week 4, compared to placebo group (F(4,64)=3.78, P<0.01). Conversely, the active group performed significantly better than the placebo group in the measure of verbal fluency (i.e., the Controlled Oral Word Association Test) at week 4 (F(4,64)=2.54, P<0.05). No significant changes were found on any of the other tests. Generally, the hypogonadal group performed less well than the eugonadal groups on all tests. CONCLUSIONS: These results offer support to the notion that increased T has a differential effect on cognitive function, inhibiting spatial abilities while improving verbal fluency in eugonadal men.

Adult↗
PubMed2001

Kinetic modeling of liquid-phase adsorption of reactive dyes and metal ions on chitosan.

The rates of adsorption of three commercial reactive dyes and Cu(II) from water in the absence and presence of complexing agents using chitosan were measured at 30 degrees C. Three simplified kinetic models, i.e., pseudo-first-order, pseudo-second-order, and intraparticle diffusion, were tested to investigate the adsorption mechanisms. It was shown that the adsorption of reactive dyes and Cu(II) in the absence of complexing agents could be best described by the intraparticle diffusion model, whereas that of Cu(II) in the absence of complexing agents such as EDTA, citric acid, and tartaric acid by the pseudo-second-order equation. Kinetic parameters of the three models and the normalized standard deviations between the measured and predicted results were also calculated and discussed.

Adsorption↗
PubMed2001

Solute adsorption and enzyme immobilization on chitosan beads prepared from shrimp shell wastes.

The equilibrium and kinetics of adsorption of reactive dye RR222 and Cu2+, and the activity of immobilization of acid phosphatase, on highly swollen chitosan beads were examined at 30 degrees C. The chitosan was prepared from shrimp shell wastes and was cross-linked with different dosages of glutaraldehyde or glyoxal (100-80,000 mg/l). It was shown that the amounts of solute adsorption and the immobilization capacity of acid phosphatase on cross-linked chitosan beads were substantially affected by their degree of cross-linking. The cross-linking rate of chitosan with glutaraldehyde could be described by a pseudo-second-order equation and the cross-linking equilibrium by the Freundlich equation. This provided an experimental method to control the degree of cross-linking of chitosan beads. Finally, the activity and lifetime of the immobilized enzyme were measured to evaluate the application potential.

Adsorption↗
PubMed2001

Kinetics of color removal by adsorption from water using activated clay.

Kinetics and mechanism of adsorption of one commercial basic dye (BB69) and one direct dye (DR227) from aqueous solutions using day were studied in the temperature range 15-75 degrees C. The clay was activated by treatment with sulfuric add. Two simplified kinetic models, pseudo first- and second-order equations, were tested. It was shown that the adsorption of both dyes could be well described by the pseudo second-order equation. Rate constants of the best-fit model were calculated, and the related apparent activation energies were also evaluated and discussed.

Adsorption↗
PubMed2001

Adsorption of dyes and phenols from water on the activated carbons prepared from corncob wastes.

Pore structures and physical properties of the activated carbons prepared from corncob wastes at various activation temperatures (830, 860, 890 degrees C.) were first studied. Equilibria and rates of adsorption of two commercial dyes, phenol, and 3-chlorophenol from water on such activated carbons were then measured at 30 degrees C. All adsorption isotherms of the solutes could be well fitted by the Langmuir equation. Three simplified kinetic models including pseudo-first-order equation, pseudo-second-order equation, and intraparticle diffusion model were selected to follow the adsorption processes. It was shown that the adsorption of both phenols could be best described by the pseudo second-order equation, but that of both dyes best by the intraparticle diffusion model. Kinetic parameters of each best-fit model were calculated and discussed.

Adsorption↗
PubMed2001

A novel male contraceptive pill-patch combination: oral desogestrel and transdermal testosterone in the suppression of spermatogenesis in normal men.

This study investigated the effect of transdermal T and oral desogestrel on the reproductive axis of healthy men. Twenty-three men were randomized to 1 of 3 treatment groups and received a daily transdermal T patch plus oral desogestrel at a dose of 75, 150, or 300 microg/d for 24 wk. Baseline blood and semen samples were obtained and then every 4 wk thereafter for 32 wk. The outcome measures were sperm density and plasma levels of FSH, LH, total and free T. The results show a dose-dependent suppression of spermatogenesis and gonadotropins. Seven of the 17 subjects became azoospermic. Desogestrel (300 microg daily) in combination with 5 mg daily transdermal T was the most effective (57% azoospermic), whereas a dose of 75 microg was ineffective (0% azoospermic). Total and free plasma T were reduced by approximately 30%. High density lipoprotein cholesterol was significantly reduced. No serious side-effects were encountered. We conclude that daily self-administered desogestrel with transdermal T is capable of suppressing the male reproductive axis, although the efficacy was less marked and less consistent than injectable regimens. The lower efficacy is likely to be due to failure of the transdermal T system to maintain circulating T levels consistently in the required range.

Administration, Cutaneous↗
PubMed2001

[Analysis of genetic diversity of Bama miniature pigs and Guizhou miniature pigs by RAPD].

RAPD analysis was performed with 31 selected single primers to study genetic diversity of two strains of miniature pigs, The percentages of polymorphisic loic in or between two strains of miniature pigs were 30.9%, 29.2% and 25.7% respectively, and the average genetic distances in and between two strains of miniature pigs were 0.120, 0.072, and 0.067 respectively. These results suggested that genetic diversity and genetic variability were poorer in and between two strains of miniature pigs than ordinary breeds' pigs.

Animals↗
PubMed2000

Comparative adsorption of metal and dye on flake- and bead-types of chitosans prepared from fishery wastes.

The adsorption capacities and rates of Cu(II) and a commercial reactive dye RR222 on flake- and bead-types of chitosans prepared from three fishery wastes (shrimp, crab, and lobster shells) were compared at 30 degrees C. It was shown that all equilibrium isotherms could be well fitted by the Langmuir equation. The adsorption capacity of Cu(II) on flake- and bead-types of chitosans appeared to be comparable, but the adsorption capacity of RR222 on bead type was much larger than that on flake type by a factor of 2. 0-3.8. The rates of dye adsorption on both types of chitosans indicated different controlling mechanisms. In addition, the bead type of chitosans exhibited a greater rate compared to the flake type.

Adsorption↗
PubMed2000

Male hormonal contraception.

Male hormonal contraceptive methods are based on the principle of pituitary gonadotrophin suppression and intratesticular testosterone depletion, leading to suppression of spermatogenesis. Following the earlier contraceptive efficacy trials using testosterone alone, synergistic combination regimes using newer androgens and other agents are now being tested. The combination of a long-acting testosterone preparation with a progestogen appears to be the most promising, and will hopefully lead to an accepted product for clinical application early in the 21st century.

Androgens↗
PubMed2000

Male contraception: prospects for the new millennium.

Effective regulation of human fertility has global consequences in terms of resource depletion, pollution and poverty. Current family planning services predominantly target a female clientele with few significant developments in male fertility regulation for over a century. The last two decades have witnessed a gathering interest, initially from the scientific community, and laterally from industry, in the development of safe, reliable, reversible methods of contraception for men. This review summarises the methods of male fertility regulation which are currently available and critically examines the published data on novel developments in male hormonal contraception which offer the potential of improved contraceptive choice for all in new millennium.

Condoms↗
PubMed1999

Genetic variation at nine STR loci in populations from the Philippines and Thailand living in Taiwan.

In order to apply a set of nine STR loci and the amelogenin locus in forensic testing, we have performed a population study on individuals from the Philippines and Thailand living in Taiwan (273 Philippine and 146 Thai individuals were typed by commercially available kits and an automated sequencer). A total of 73 alleles for all systems for both populations could be observed in these two populations. No new intermediate fragments were found. Allele frequencies showed no deviation from Hardy-Weinberg equilibrium. The mean exclusion power (MEP) ranged from 0.327 (TPOX) to 0.706 (FGA), the discriminating power (DP) ranged from 0.790 (TPOX) to 0.963 (FGA) for Philippinos, MEP ranged from 0.247 (TPOX) to 0.723 (FGA), DP ranged from 0.761 (TPOX) to 0.968 (FGA) for Thais, the combined MEP is > 0.9988 and the combined DP is > 0.9999999993 for both Philippinos and Thais.

Alleles↗