26 results on '"W C Wong"'
Search Results
2. Effectiveness of motivational interviewing to reduce illicit drug use in adolescents: a systematic review and meta-analysis
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Lili Li, Samson Tse, Paul W. C. Wong, Nick Tse, and Shimin Zhu
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050103 clinical psychology ,Funnel plot ,medicine.medical_specialty ,business.industry ,05 social sciences ,Motivational interviewing ,Medicine (miscellaneous) ,Publication bias ,medicine.disease ,Confidence interval ,law.invention ,Substance abuse ,03 medical and health sciences ,Psychiatry and Mental health ,0302 clinical medicine ,Randomized controlled trial ,law ,Meta-analysis ,Medicine ,0501 psychology and cognitive sciences ,030212 general & internal medicine ,Brief intervention ,business ,Psychiatry ,Clinical psychology - Abstract
Aims Motivational interviewing (MI) is a commonly used intervention approach to promote reduction or cessation of substance abuse. Effects may be different for adolescents, so it is useful to assess the state of the evidence in this subpopulation. This paper aimed to assess evidence for MI effectiveness in adolescents. Method EBSCOhost, ProQuest and Digital Dissertation Consortium were searched using keywords. Ten randomized trials from the United Kingdom, United States and Taiwan, including 1466 participants, were identified and analysed using a random effects model. Primary outcome measures captured were: the extent of drug use, intention to use drugs and readiness to change. Each study received a high-quality score based on the Miller Quality Scoring Coding System. Moderator analyses were also conducted to examine the impacts of follow-up period, delivery setting and study design on the effectiveness of MI. Results No statistically significant effect of MI on was found change of drug use behaviours [d = 0.05, 95% confidence interval (CI) = −0.06, 0.17, P = 0.36]. A significant effect was found on attitude change (d = 0.44, 95% CI = 0.20, 0.67, P = 0.0002). The funnel plot was asymmetrical, suggesting publication bias favouring small studies with higher effect sizes. Conclusion Motivational interviewing has not been found thus far to reduce adolescent use of illicit drugs. It may influence intentions to change, but evidence of publication bias weakens confidence in this conclusion.
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- 2016
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3. Multicomponent intervention on enhancing dementia caregiver well-being and reducing behavioral problems among Hong Kong Chinese: a translational study based on REACH II
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Karen Siu-Lan Cheung, Bobo Hi-Po Lau, Vivian W. Q. Lou, Paul W. C. Wong, Grace Man-Yee Chan, Angela Y. M. Leung, and Richard Schulz
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Gerontology ,Service delivery framework ,media_common.quotation_subject ,Translational research ,Context (language use) ,Disease ,medicine.disease ,Psychiatry and Mental health ,Intervention (counseling) ,Perception ,Well-being ,medicine ,Dementia ,Geriatrics and Gerontology ,Psychology ,Clinical psychology ,media_common - Abstract
Objective This study examined the effectiveness of a translated version of Resources for Enhancing Alzheimer's Caregiver Health (REACH) II in Hong Kong's service delivery context. Method The localized intervention was adapted from REACH II with 12 individual-based sessions, which addressed multiple domains including disease education, safety, caregiver (CG) well-being, and care recipients' problem behavior. Two-hundred and one dementia family dyads completed the intervention. Results The efficacy of the intervention was demonstrated by the significant improvement in the perception of positive aspects of caregiving, reduction in depressive symptoms, subjective burden, bother and caregiving risks among CGs, and abatement in behavioral problems among care recipients. Treatment implementation was reflected from the high rate of adoption of each intervention component by interventionists and satisfactory reception from CGs. Promises in reach and adoption were demonstrated by the participation of 85 interventionists from 11 NGOs across 18 districts and CGs of a variety of demographic characteristics. Discussion This study is the first attempt to translate a highly successful evidence-based dementia CG intervention developed in the USA into the Hong Kong service delivery context. The current results echoed the success of REACH II. The values and challenges of translational research are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
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- 2014
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4. Screening options for Down syndrome: how women choose in real clinical setting
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Robert Kien Howe Chin, F. K. Lai, W.L. Lau, H. Choi, Y. C. Yee, L. S. Ng, W. C. Wong, A. S. Y. Sham, Tsz Kin Lo, Lawrence Chang Hung Tang, W. C. Leung, S. S. Tam, and H. Lam
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Gynecology ,medicine.medical_specialty ,business.industry ,Reproductive medicine ,Obstetrics and Gynecology ,Prenatal diagnosis ,Test (assessment) ,medicine ,Advanced maternal age ,Family history ,business ,Socioeconomic status ,Genetics (clinical) ,Mass screening ,Multinomial logistic regression ,Demography - Abstract
OBJECTIVE: To study pregnant women's preference among various screening options for Down syndrome (DS) in routine clinical setting, and its potential association with women's demographic characteristics. METHODS: Women aged 35 years and older carrying singleton pregnancy were offered a variety of screening tests for DS before 14 weeks of gestation. Their preference was confirmed by the test they actually underwent. The association between women's choice of test and a number of demographic characteristics was studied using multinomial regression. RESULTS: Among 1967 eligible women, 619 opted for first-trimester screening test (FTS), 924 for partial integrated test (PIT), and 424 for full integrated test (FIT). Nulliparous women and working mothers were more likely to choose FTS and FIT. Women with history of subfertility were more likely to choose FIT. Women with family history of chromosomal abnormalities were more likely to choose FTS. The choice of screening test could be predicted for 49.9% of women using four demographic characteristics. CONCLUSIONS: Among older women of predominantly Chinese ethnicity, integrated test is a favorite alternative to FTS. Their choice of DS screening test can be predicted by their obstetric and socioeconomic characteristics. Many women show willingness to pay for a test with a lower false-positive rate.
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- 2009
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5. An Integrative Suicide Prevention Program for Visitor Charcoal Burning Suicide and Suicide Pact
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Wincy S. C. Chan, Yik-wa Law, Patricia M. Y. Liu, Paul W. C. Wong, Steven C. K. Law, Annette L. Beautrais, M. K. Tso, King-wa Fu, Paul S. F. Yip, and Hana S. H. Li
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Adult ,Male ,Mental Health Services ,Suicide Prevention ,Program evaluation ,Gerontology ,Charcoal-burning suicide ,health care facilities, manpower, and services ,education ,Poison control ,Suicide, Attempted ,Suicide prevention ,Suicide pact ,health services administration ,Injury prevention ,Humans ,Medicine ,health care economics and organizations ,business.industry ,Visitor pattern ,Public Health, Environmental and Occupational Health ,Human factors and ergonomics ,Suicide ,Psychiatry and Mental health ,Clinical Psychology ,Charcoal ,Hong Kong ,Female ,business ,Program Evaluation ,Demography - Abstract
An integrative suicide prevention program was implemented to tackle an outbreak of visitor charcoal burning suicides in Cheung Chau, an island in Hong Kong, in 2002. This study evaluated the effectiveness of the program. The numbers of visitor suicides reduced from 37 deaths in the 51 months prior to program implementation to 6 deaths in the 42 months post-implementation period. The number of visitor suicide pacts decreased from 7 pacts (15 individuals) to 1 pact (2 individuals). No statistically significant differences in the numbers of visitor suicide attempts and resident suicides were observed in the two time periods. No statistically significant changes in visitor suicides during the study period were observed on the comparison islands. The consistency and timing of reduction in visitor suicides correlated with the development and delivery of the integrative program on the intervention island, suggesting a causal association between program delivery and reduction of visitor suicides. The possibility of displacement seems small because there was no increase in visitor suicides on the comparison islands during the study period. This integrative approach in preventing target-specific suicides may serve as an example for other communities to develop suicide prevention programs that make use of the existing local resources.
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- 2009
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6. Emergency transcatheter embolization of ruptured hepatocellular carcinomas with tortuous conventional or aberrant hepatic vascular anatomy, or parasitic supply
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L T Lee, J K W Chan, KY Lau, W W C Wong, G Y K Lee, W. K. Kan, A S L Lee, and J L Y Leung
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Male ,medicine.medical_specialty ,Carcinoma, Hepatocellular ,Vascular anatomy ,Transcatheter embolization ,medicine.medical_treatment ,Treatment outcome ,Hepatic Artery ,medicine ,Carcinoma ,Humans ,Radiology, Nuclear Medicine and imaging ,Embolization ,Aged ,Aged, 80 and over ,Rupture, Spontaneous ,business.industry ,Liver Neoplasms ,Middle Aged ,medicine.disease ,Embolization, Therapeutic ,Surgery ,Treatment Outcome ,medicine.anatomical_structure ,Liver ,Hepatocellular carcinoma ,Female ,Radiology ,Emergencies ,business ,Artery - Abstract
Emergency transcatheter embolization is a well-recognized measure to manage patients with life-threatening haemoperitoneum due to spontaneous ruptured hepatocellular carcinoma. Traditional embolization technique is to embolize the proper hepatic artery or the segmental hepatic artery by femoral approach using gelfoam pledgets. From 1997 to 2004, in 19 out of 96 embolizations, the embolization technique had to be modified because of tortuous conventional or aberrant hepatic vascular anatomy or parasitic supply to achieve successful embolization.
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- 2007
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7. Emergency embolization of spontaneous ruptured hepatocellular carcinoma: Correlation between survival and Child−Pugh classification
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Le Thanh Tan, A S L Lee, KY Lau, W W C Wong, J K W Chan, and T.P. Wong
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medicine.medical_specialty ,Cirrhosis ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,medicine.disease ,Surgery ,medicine.anatomical_structure ,Hepatocellular carcinoma ,Angiography ,medicine ,Carcinoma ,Radiology, Nuclear Medicine and imaging ,Radiology ,Embolization ,Complication ,business ,Survival rate ,Artery - Abstract
From February 1994 to April 2000, 29 emergency gelfoam embolizations for spontaneous ruptured hepatocellular carcinoma (HCC) performed in 28 patients were retrospectively reviewed. There were 11 patients in Child's A, 11 in Child's B and six in Child's C classification of cirrhosis. The duration of the procedure, artery embolized and complications were reviewed, and the Child-Pugh classification of each patient was correlated with their mean survival period. Embolization was done in 12 right hepatic arteries, two left hepatic arteries and 15 proper hepatic arteries. In one patient, the left hepatic artery was embolized initially but the proper hepatic artery was also embolized because another subcapsular liver tumour was found after reviewing the preangiogram CT scan. The entire procedure took 40-170 min (mean = 86 min) with no periprocedural complication. Following embolization, the mean survival period for Child's A class was 218.3 days, Child's B class was 83.4 days and Child's C class was 11.0 days. Transcatheter embolization is an effective treatment to arrest bleeding in spontaneous ruptured HCC. Patients with Child's A class cirrhosis have the longest survival. Selective embolization of either the right or the left hepatic artery alone carries the potential risk of missing multifocal HCC that might not be easily appreciated during angiography.
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- 2003
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8. Vegetation Response to Lime and Manure Compost Amendments on Acid Lead/Zinc Mine Tailings: A Greenhouse Study
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Ming Hung Wong, Zhihong Ye, and Jonathan W C Wong
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Ecology ,biology ,Compost ,Amendment ,engineering.material ,Cynodon dactylon ,biology.organism_classification ,Manure ,Tailings ,Soil conditioner ,Agronomy ,engineering ,Environmental science ,Fertilizer ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,Lime - Abstract
Land disturbed by mining in China is a serious problem and lead/zinc (Pb/Zn) mine tailings constitute the majority of the metal mine tailings produced in Guangdaong Province, China. A greenhouse study was therefore conducted to evaluate the effects of lime (40, 80, 120, and 160 t/ha) and manure compost (50 and 100 t/ha) amendment on the revegetation of the Pb/Zn mine tailings using Cynodon dactylon (Bermuda grass) and Agropyron elongatum (tall wheatgrass). The results showed that a combination of lime and manure compost amendment together with deionized water leachating was able to increase pH, reduce electrical conductivity and diethylenetraminepentaacetic acid (DTPA)-extractable concentrations of Zn and Pb in tailings. Using ≥80 t/ha lime amendment with the supplement of fertilizer or manure compost was able to effectively improve germination of both C. dactylon and A. elongatum. The highest dry weight yields were obtained in tailings receiving ≥80 t lime/ha and 100 t manure compost/ha for both plant species. Plant tissue analysis showed that lime amendment at 120-160 t/ha reduced Zn accumulation in both shoot and root of C. dactylon. However, this trend was not observed for Pb.
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- 2000
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9. Revegetation of Pb/Zn Mine Tailings, Guangdong Province, China
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C. Y. Lan, Ming Hung Wong, Jonathan W C Wong, Zhihong Ye, Alan J. M. Baker, and Wen-Sheng Shu
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Ecology ,biology ,Environmental remediation ,Lolium multiflorum ,Cynodon dactylon ,biology.organism_classification ,Manure ,Tailings ,Agronomy ,Dry weight ,Trifolium repens ,Environmental science ,Revegetation ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation - Abstract
The Lechang lead/zinc mine is located in the north part of Guangdong Province, southern China. The tailings residue from the extraction of lead/zinc ores was permanently stored in tailings ponds, which required revegetation to reduce the environmental impact. A field study was, therefore, conducted to evaluate the effects of different ameliorants, including: (1) pig manure (PM); (2) mushroom compost (MC); (3) burnt coal residue (BC); (4) fly ash (FA); and (5) surface soil on the growth of Agropyron elongatum (tall wheat grass), Cynodon dactylon (Bermuda grass), Lolium multiflorum (Italian ryegrass), and Trifolium repens (clover) in the tailings residue. The results from the core profiles indicated that adding FA (10 cm) or BC (15 cm) as a barrier layer between the cover soil and the tailings could increase pH, compared to the treatment with soil only. C. dactylon grew well and had a high cover (90‐100%) in all the treatment plots except the control plots without any amendment. A. elongatum and L. multiflorum had a higher cover when grown in plots covered with a barrier layer using FA or BC (both with surface soil), than those grown in plots covered with surface soil only. Treatment plots receiving a thicker soil cover (30 cm) had a better dry weight yield than those with a thinner soil cover (15 cm), regardless of the barrier layer. The results from this study indicate that the use of either 15 cm BC or 10 cm FA as a barrier layer with surface soil, or the use of 38 tonnes PM/ha and 6 cm MC, were effective for the revegetation of Pb/Zn mine tailings. C. dactylon was the best species among the four species used for revegetation.
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- 2000
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10. Synthesis of medium-chain glycerides using lipase from Candida rugosa
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Abu Bakar Salleh, Mahiran Basri, W. C. Wong, and Che Nyonya Abdul Razak
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Chromatography ,biology ,Water activity ,General Chemical Engineering ,Glyceride ,Organic Chemistry ,Triacylglycerol lipase ,Candida rugosa ,Enzyme catalysis ,chemistry.chemical_compound ,chemistry ,Capric Acid ,Glycerol ,biology.protein ,Lipase - Abstract
Enzymatic synthesis of medium-chain glycerides (MCG) from capric acid and glycerol was studied using lipase from Candida rugosa. The effects of various reaction parameters such as time, molar ratio of substrates (mmol capric acid/mmol glycerol), amount of lipase, type of organic solvents, and initial water activity (a w ) were studied. The best conditions tested for MCG synthesis at 37°C were, respectively, time, 24 h; molar ratio of substrates, 2.5; and amount of lipase, 100.0 mg. The use of organic solvents greatly influenced the activity of lipase in the synthesis of MCG. Generally, activity of lipase was high in nonpolar solvents with log P values from 3.50 to 4.50, where P is the partition coefficient between water and 1-octanol. The enzymatic synthesis of MCG was preferably carried out at an initial a w of 0.328, which resulted in maximal yield. Analysis of the products of reaction using gas chromatography showed that lipase from Candida rugosa seemed to produce more dicaprin and tricaprin than monocaprin.
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- 2000
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11. Cation Exchange Behavior of Bauxite Refining Residues from Western Australia
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Goen Ho and Jonathan W C Wong
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chemistry.chemical_classification ,Plant growth ,Environmental Engineering ,Chromatography ,Chemistry ,Sodium ,Inorganic chemistry ,chemistry.chemical_element ,Management, Monitoring, Policy and Law ,engineering.material ,Pollution ,Red mud ,Divalent ,Bauxite ,Adsorption ,parasitic diseases ,Cation-exchange capacity ,engineering ,Selectivity ,Waste Management and Disposal ,Water Science and Technology - Abstract
Over 60 million tonnes per year of bauxite refining residue (red mud) is produced worldwide. Its high Na concentration inhibits plant growth and hence reclamation. The cation-exchange capacity (CEC) of red mud and the cation exchange equilibria between Na+ and several other cations were measured to elucidate the mechanism of Na release from red mud. The CECs obtained by using K+ and NH4/+ were significantly higher than those obtained using Ca2+ and Ba2+. This unusual cation exchange phenomenon can be attributed to the presence of zeolitic minerals in red mud. Cation exchange equilibria show that Na+ originally present hi red mud was preferentially adsorbed by the mud over other cations. At high cation fractions in red mud (>0.1), the mud selectively sorbed monovalent over divalent cations, with the following order of selectivity: K+ > Li+ > NH4/+ > Ba2+ ≥ Ca2+ > Mg2+. The exchange of Na+ has been found to have significant negative correlations with the radius of hydration and Debye-Huckel parameter. Divalent cations have little ability to exchange Na+ from zeolitic exchange sites. Incremental extraction of Na+ in red mud shows that K+ and NH4/+ displaced 99 (63%) and 57 (44%) cmol(c) kg-1 red mud whereas Ca2+ and Mg2+ could only displace 33 and 29 cmol(c) kg-1 red mud, respectively, out of a total of 99 cmol(c) Na kg-1 red mud. In a reverse process 95% of K+ adsorbed on red mud was readily replaced by Na+. The experimental evidence suggests that the release of Na+ from red mud is due to cation exchange. Over 60 million tonnes per year of bauxite refining residue (red mud) is produced worldwide. Its high Na concentration inhibits plant growth and hence reclamation. The cation-exchange capacity (CEC) of red mud and the cation exchange equilibria between Na+ and several other cations were measured to elucidate the mechanism of Na release from red mud. The CECs obtained by using K+ and NH4+ were significantly higher than those obtained using Ca2+ and Ba2+. This unusual cation exchange phenomenon can be attributed to the presence of zeolitic minerals in red mud. Cation exchange equilibria show that Na+ originally present in red mud was preferentially adsorbed by the mud over other cations. At high cation fractions in red mud (>0.1), the mud selectively sorbed monovalent over divalent cations, with the following order of selectivity: K+>Li+>NH 4+>Ba2+≥Ca2+>Mg2+. The exchange of Na+ has been found to have significant negative correlations with the radius of hydration and Debye-Huckel parameter. Divalent cations have little ability to exchange Na+ from zeolitic exchange sites. Incremental extraction of Na+ in red mud shows that K+ and NH4+ displaced 99 (63%) and 57 (44%) cmolc kg-1 red mud whereas Ca2+ and Mg2+ could only displace 33 and 29 cmolc kg-1 red mud, respectively, out of a total of 99 cmolc Na kg-1 red mud. In a reverse process 95% of K+ adsorbed on red mud was readily replaced by Na+. The experimental evidence suggests that the release of Na+ from red mud is due to cation exchange.
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- 1995
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12. Upgrading the Activated-Sludge Process for Total Nitrogen Removal in Hong Kong
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K. W. Law, W. C. Wong, H. C. Lai, and D. K. C. Wu
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Environmental Engineering ,Denitrification ,business.industry ,Environmental engineering ,Sewage ,chemistry.chemical_element ,Management, Monitoring, Policy and Law ,Pollution ,Nitrogen ,Anoxic waters ,Activated sludge ,chemistry ,Nitrification ,Sewage treatment ,Eutrophication ,business ,Water Science and Technology - Abstract
In order to protect the sensitive waters in Tolo harbour (Hong Kong), Sha Tin and Tai Po sewage-treatment works were first designed to remove 70% of the nitrogen load from the sewage. Since then, due to continuing serious eutrophication problems in the harbour, both plants have been modified to increase the removal efficiency to 90%. The modifications were based on the Bardenpho process. However, the designers of the two plants adopted different approaches to process intensity, complexity and control of bacterial foam. At Sha Tin, the average monthly results have shown an increase of total nitrogen removal from 60–70% to about 80% since its completion. The addition of methanol was found to be ineffective on further enhancement of the denitrification rate due to difficulties in the apportioning of the second anoxic zone. The overall monthly results for Tai Po have also shown an increase in the removal rate to about 80%, even though 90% was achieved for a short period of time. The major problem encountered at the latter plant was that the process design did not provide an effective control on bacterial foaming, which had affected the smooth operation of the process.
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- 1995
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13. Production and Use of Monoclonal Antibodies to Pseudomonas andropogonis
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Xiang Li, A. C. Hayward, and W. C. Wong
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biology ,medicine.diagnostic_test ,Physiology ,Pseudomonas ,Plant Science ,Immunogold labelling ,Ribosomal RNA ,biology.organism_classification ,Immunofluorescence ,Microbiology ,Pseudomonadales ,Genetics ,medicine ,Agronomy and Crop Science ,Pathogen ,Bacteria ,Pseudomonadaceae - Abstract
Pseudomonas andropogonis is an important pathogen of worldwide distribution in ornamental and other plant species from 15 families. This paper reports the production and characterization of monoclonal antibodies (MAbs) to P. andropogonis and evaluation of their use in the detection of the pathogen in carnation cuttings. Ten stable hybridoma cell lines were produced. Results of indirect ELISA and indirect immuno-fluorescence showed that MAb 6B3 was specific for P. andropogonis; MAb 3D5W1 reacted with both P. andropogonis and P. caryophylli; six other MAbs reacted with all strains of seven species of rRNA group II pseudomonads tested except P. solanacearum and P. pickettii. Eight of the ten MAbs failed to cross-react with other non-fluorescent or fluorescent pseudomonads, xanthomonads and other bacteria tested. P. andropogonis was similar in protein profile to other rRNA group II pseudomonads tested except P. solanacearum and P. pickettii. Epitopes were clearly located within the cell by immunogold labelling. Of four MAbs that were isotyped, two possessed IgGl and two the IgM heavy chain. P. andropogonis was readily detected by combining immunofluorescence and detached carnation leaf assay using an initial inoculum of 4 × 10° colony forming units (cfu) ml−1 after enrichment at room temperature for 4 days.
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- 1993
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14. ChemInform Abstract: Unexpected Reactivity of Bifunctional Hexacoordinated Silicon Species
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G. Royo, C. Breliere, W. W. C. Wong Chi Man, Robert J. P. Corriu, and J. Zwecker
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chemistry.chemical_compound ,Silicon ,chemistry ,biology ,Polymer chemistry ,chemistry.chemical_element ,Organic chemistry ,Tetra ,Reactivity (chemistry) ,General Medicine ,Bifunctional ,biology.organism_classification - Abstract
The basic transformations of SiF, SiCl, and SiH in hexacoordinated silicon species are completely different from those observed with the corresponding tetra- and pentacoordinate compounds
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- 2010
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15. Comparative fate in soil of the enantiomers of triadimenol when applied individually to barley seed
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Wilson W.-C. Wong, Klaus Vogeler, and Terence Clark
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Fungicide ,chemistry.chemical_compound ,Chromatography ,Agronomy ,Chemistry ,Seed treatment ,Soil water ,Epimer ,Poaceae ,Hordeum vulgare ,Metabolism ,Enantiomer ,Applied Microbiology and Biotechnology - Abstract
The systemic fungicide triadimenol is a mixture of four enantiomers which have different biological activities. Dissipation and metabolism of the individual enantiomers in soil were investigated after seed treatment. Forty-nine days after 1R2S and 1S2S treatments, more of the radioactivity (87% for both) had dissipated from the seeds into the 0–10 cm soil layer than after the 1S2R (76%) and 1R2R (73%) treatments. After 1R2S treatment 56% of the radioactivity extracted from soil was accounted for as the parent isomer and 44% as its 1R2R epimer. After 1S2R treatment 76% of the radioactivity was in the parent form and 24% was converted to the 1S2S (17%) and 1R2R (7%) isomers.
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- 1991
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16. Effects of some nonionic polyoxyethylene surfactants on uptake of ethirimol and diclobutrazol from suspension formulations applied to wheat leaves
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Wilson W.-C. Wong, David Seaman, Richard B. Perry, Hazel J. Partridge, and Peter J. Holloway
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Active ingredient ,Chromatography ,Ethylene oxide ,Sorbitan ,Applied Microbiology and Biotechnology ,Agronomy ,Nonylphenol ,Hydrophobe ,Fungicide ,chemistry.chemical_compound ,Pulmonary surfactant ,chemistry ,Agricultural spray adjuvant ,Entomology - Abstract
The influence of a number of commercial nonionic polyoxyethylene surfactants on the foliar penetration and movement of two systemic fungicides, ethirimol and diclobutrazol, was studied in outdoor-grown wheat plants at different growth stages and post-treatment temperatures in two consecutive growing seasons. Both fungicides were applied as ca 0.2-mu-l droplets of aqueous suspension formulations containing 0.5 g litre-1 of C-14-labelled active ingredient; surfactants were added to these suspensions at concentrations ranging from 0.2-10 g litre-1. To achieve optimum uptake of each fungicide the use of surfactants with different physicochemical properties was required. For diclobutrazol, a lipophilic compound, uptake of radiolabel was best with surfactants of low mean molar ethylene oxide (E) content (5-6) but it was necessary to use concentrations of ca 5 g litre-1 to attain this. The surfactant threshold concentration for uptake enhancement of radiolabel from ethirimol formulations (< 1 g litre-1) was much lower than that for diclobutrazol but surfactants with E contents > 10 induced the greatest amount of uptake. For both fungicides, surfactants with an aliphatic alcohol hydrophobe were generally more efficient in promoting their uptake than those with a nonylphenol moiety. The sorbitan-based surfactant 'Tween 20' proved to be an effective adjuvant only for the ethirimol formulation; the uptake enhancing properties of the block copolymer 'Synperonic PE/F68' were weak. Uptake performance could not be related to the spreading properties of the respective formulations on the wheat leaf surface or to differences in solubilisation of the two fungicides by the surfactants. Although surfactants could substantially increase the amount of acropetal transport of radiolabel from both fungicides, none of those tested specifically promoted it; a constant proportion of the radioactive dose absorbed by a treated leaf was usually exported away from the site of application. The results are discussed in the light of current theories about the mode of action of surfactants as spray adjuvants.
- Published
- 1992
17. ChemInform Abstract: Pentacoordinated Silicon Anions: Synthesis and Reactivity
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Corriu Robert, W. W. C. Wong Chi Man, Bernard J. L. Henner, J.L. Brefort, and Christian Guerin
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Silicon ,Chemistry ,chemistry.chemical_element ,Reactivity (chemistry) ,General Medicine ,Medicinal chemistry - Abstract
Synthese des complexes Ph 3 Si(OMe) 2 − K + (18-crown-6), Ph 2 Si(OMe) 3 K + (18-crown-6), Ph 3 SiF 2 − K + (18-crown-6) et MePhSiF 3 − K + (18-crown-6) a partir de K.F (18-crown-6) et de Ph 3 SiF ou MePhSiF 2 , de KOMe (18-crown-6) et de Ph n Si(OMe) 4-n (n=1, 2 ou 3). Etude de la reactivite de ces complexes vis-a-vis de nucleophiles (RMgX, RLi, ROLi, LiAlH 4 )
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- 1990
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18. Plant Resources of South-East Asia. No. 5(2). Timber Trees: Minor Commercial Timbers
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Rudolf Schmid, R. H. M. J. Lemmens, I. Soerianegara, and W. C. Wong
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Geography ,Agroforestry ,Genetic resources ,Forestry ,Plant Science ,Minor (academic) ,South east asia ,Ecology, Evolution, Behavior and Systematics ,Woody plant - Published
- 1996
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19. Sclerotium cepivorumBerk. in onion (Allium cepaL.) crops: isolation and characterization of bacteria antagonistic to the fungus in Queensland
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W. C. Wong and I. K. Hughes
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Sclerotium ,biology ,fungi ,Pseudomonas ,food and beverages ,Fungus ,Fungi imperfecti ,Erwinia ,biology.organism_classification ,complex mixtures ,Applied Microbiology and Biotechnology ,Microbiology ,Botany ,Allium ,Bacteria ,Pseudomonadaceae - Abstract
Bacteria antagonistic to the fungal pathogen Sclerotium cepivorum Berk., which causes onion white rot disease, were isolated and characterized. Eighty percent of the bacterial antagonists isolated from soil samples and sclerotia of S. cepivorum recovered from soil were identified as belonging to the genus Bacillus. The other antagonists were coryneforms and Pseudomonas spp. In contrast, 90% of the antagonists isolated from onion roots were mostly Pseudomonas spp. and the remainder were Erwinia spp. The significance of these antagonistic bacteria is discussed in relation to the control of white rot disease of onion.
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- 1986
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20. A novel process for the manufacturing of porous grafts: Process description and product evaluation
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Gregory J. Wilson, Jacob Leidner, David C. MacGregor, and Edward W. C. Wong
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Pore size ,chemistry.chemical_classification ,Materials science ,Graft patency ,Polymers ,Biomedical Engineering ,Polymer ,Models, Biological ,Elasticity ,Blood Vessel Prosthesis ,Biomaterials ,Carotid Arteries ,Dogs ,chemistry ,Process description ,Animals ,MANDRIL ,Aorta, Abdominal ,Composite material ,Porosity ,Process (anatomy) ,Polymer melt - Abstract
A novel process has been developed for the manufacture of porous vascular grafts from solutions or melts of polymers. It allows the manufacture of grafts with controllable porosity, pore size, and mechanical properties. In this process, the polymer melt or polymer solution is extruded through fine orifices; the fibers are then fibers are then stretched and wound on a rotating mandril. Fiber-fiber bonding takes place, resulting in the formation of stable porous tubes. The effects of the process variables on the physical properties of the resulting graft have been studied and preliminary in vivo evaluation in dogs has demonstrated graft patency with a thin, stable neointima in both small (4 mm) and large (10 mm) caliber configurations.
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- 1983
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21. Sources of Verticillium fungicola on a commercial mushroom farm in England
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T. F. Preece and W. C. Wong
- Subjects
Mushroom ,Peat ,Compost ,fungi ,food and beverages ,Plant Science ,Horticulture ,engineering.material ,Biology ,Spore ,Edible mushroom ,Crop production ,Botany ,Genetics ,engineering ,Agronomy and Crop Science ,Agaricus bisporus ,Verticillium fungicola - Abstract
From 1979 to 1981 Verticillium fungicola, a pathogen to Agaricus bisporus, was detected in 47 out of 485 samples of baled peat and in one out of 126 samples of bagged limestone arriving at an isolated mushroom farm in the UK. The pathogen was not detected in 875 samples of water, soil, mushroom spawn or spawned compost. Casing (a mixture of peat and limestone) prepared and used on the farm contained detectable V. fungicola in 25 out of 108 samples. The primary sources of V fungicola were thus the two constituents of casing, especially peat. Secondary sources of V. fungicola were numerous and included symptomless and diseased mushrooms, pickers and other staff, floors and doors and the principal pests (sciarid flies and mites). Viable airborne spores of V. fungicola were detected with an Andersen sampler in farm buildings at all stages in crop production. The spore load increased with the age of the crop. Few airborne spores were detected immediately outside affected buildings, and very few at the farm entrance 30 m away. There was no evidence that V. fungicola reached the farm from the surrounding air. despite substantial soil disturbance nearby. Selective media for V. fungicola are described.
- Published
- 1987
- Full Text
- View/download PDF
22. Nuclei of the diencephalon of Hylobatidae
- Author
-
R. Kanagasuntheram and W. C. Wong
- Subjects
Primates ,Thalamus ,Hypothalamus ,Hylobatidae ,Prosimian ,Macaque ,film.subject ,Diencephalon ,biology.animal ,Hylobates ,medicine ,Animals ,biology ,General Neuroscience ,Geniculate Bodies ,Hominidae ,Haplorhini ,Anatomy ,biology.organism_classification ,Anatomy, Comparative ,medicine.anatomical_structure ,film ,Nucleus - Abstract
The nuclear organization of the diencephalon of the gibbon is described and a comparison is made with that of prosimian primates, macaque and chimpanzee. The nuclear configuration is generally similar in Hylobates and Symphalangus except that in the latter genus the lateral geniculate body becomes six layered in the caudal third of the nucleus while the four laminar pattern prevails throughout the entire nucleus in Hylobates. The thalamus of gibbon shows an advance over that of the macaque in the enlargement of the nucleus medialis dorsalis, the centrum medianum and the pulvinar. The nucleus ventralis intermedius, composed of large cells assumes remarkable proportions in the gibbon while the nucleus ventralis posterior shows a corresponding reduction. In the hypothalamus the nucleus hypothalamicus ventromedialis and the nucleus mammillaris medialis are very large but the nucleus hypothalamicus dorsomedialis shows a marked reduction in size.
- Published
- 1968
- Full Text
- View/download PDF
23. Infection of Cricket Bat Willow (Salix alba var. caerulea) Sm. by Erwinia salicis (Day) Chester detected in the Field by the Use of a Specific Antiserum
- Author
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W. C. Wong and T. F. Preece
- Subjects
Salix caprea ,Willow ,food and beverages ,Plant Science ,Horticulture ,Biology ,Erwinia ,biology.organism_classification ,Staining ,Cricket ,Shoot ,Botany ,Genetics ,Agronomy and Crop Science ,Caerulea ,Leafy - Abstract
SUMMARY The use of a slide agglutination test on squeezed-out sap of cultivated cricket bat willow trees allowed rapid diagnosis of infection by Erwinia salicis in the field. By this means, infection of “classically” diseased willow trees with both red leaf and wood staining was confirmed. Trees with either red leaf or wood stain, but not both symptoms, were also shown to be infected. Symptomless infection of cricket bat willow trees was detected. E. salicis was viable in the stumps of trees felled five years previously. Some of these stumps were in an advanced state of decay and some were producing symptomless leafy shoots. Trees dying with severe die-back symptoms and infected with Armil- laria mellea, were shown to be infected with E. salicis. Salix caprea and S. vitellina, two wild species of willow, were also shown to be infected.
- Published
- 1973
- Full Text
- View/download PDF
24. ChemInform Abstract: TOTAL SYNTHESIS OF (.+-.)-CORYDALIC ACID METHYL ESTER
- Author
-
M. CUSHMAN and W. C. WONG
- Subjects
General Medicine - Published
- 1984
- Full Text
- View/download PDF
25. ChemInform Abstract: Synthesis of Bis(trifluoromethylated)Pyrazine-containing Nitrogen Heterocycles from Hexafluorobiacetyl and ortho-Diamines. Stabilization of the Covalent Dihydrates of Pteridines and Pyrido[3,4-b]pyrazines by Trifluoromethyl Groups
- Author
-
M. CUSHMAN, W. C. WONG, and A. BACHER
- Subjects
General Medicine - Published
- 1986
- Full Text
- View/download PDF
26. ChemInform Abstract: Synthesis of 6,7-Bis(trifluoromethyl)-8-substituted Pteridine-2,4(1H,3H)-dione (Lumazine) Hydrates from 4,5-Diaminouracil Hydrochlorides and Perfluorobutane- 2,3-dione. Stabilization of the Transmolecular Covalent Hydrates of 8-Substi
- Author
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A. Bacher, W. C. Wong, and M. Cushman
- Subjects
chemistry.chemical_compound ,Trifluoromethyl ,chemistry ,Perfluorobutane ,Covalent bond ,medicine ,Organic chemistry ,General Medicine ,Pteridine ,medicine.drug - Published
- 1986
- Full Text
- View/download PDF
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