32 results on '"Wong NH"'
Search Results
2. Interaction of Acinetobacter sp. RIT 592 induces the production of broad-spectrum antibiotics in Exiguobacterium sp. RIT 594.
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Parthasarathy A, Miranda RR, Bedore TJ, Watts LM, Mantravadi PK, Wong NH, Chu J, Adjei JA, Rana AP, Savka MA, Bulman ZP, Borrego EJ, and Hudson AO
- Abstract
Antimicrobial resistance (AMR) is one of the most alarming global public health challenges of the 21st century. Over 3 million antimicrobial-resistant infections occur in the United States annually, with nearly 50,000 cases being fatal. Innovations in drug discovery methods and platforms are crucial to identify novel antibiotics to combat AMR. We present the isolation and characterization of potentially novel antibiotic lead compounds produced by the cross-feeding of two rhizosphere bacteria, Acinetobacter sp. RIT 592 and Exiguobacterium sp. RIT 594. We used solid-phase extraction (SPE) followed by liquid chromatography (LC) to enrich antibiotic extracts and subsequently mass spectrometry (MS) analysis of collected fractions for compound structure identification and characterization. The MS data were processed through the Global Natural Product Social Molecular Networking (GNPS) database. The supernatant from RIT 592 induced RIT 594 to produce a cocktail of antimicrobial compounds active against Gram-positive and negative bacteria. The GNPS analysis indicated compounds with known antimicrobial activity in the bioactive samples, including oligopeptides and their derivatives. This work emphasizes the utility of microbial community-based platforms to discover novel clinically relevant secondary metabolites. Future work includes further structural characterization and antibiotic activity evaluation of the individual compounds against pathogenic multidrug-resistant (MDR) bacteria., Competing Interests: Author PM was employed by the company Agilent Technologies. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Parthasarathy, Miranda, Bedore, Watts, Mantravadi, Wong, Chu, Adjei, Rana, Savka, Bulman, Borrego and Hudson.)
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- 2024
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3. Surface Reconstruction of La 2 CuO 4 during the Electrochemical Reduction of Carbon Dioxide to Ethylene and Its Benefits for Enhanced Performance.
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Sha Y, Sunarso J, Wong NH, Gu Y, Wu X, Li Y, Ran R, Zhou W, and Shao Z
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Electrochemical reduction (ECR) of CO
2 to C2 H4 has a potential key role in realizing the carbon neutral future, which ultimately relies on the availability of an efficient electrocatalyst that can exhibit a high Faradaic efficiency (FE) for C2 H4 production and robust, long-term operational stability. Here, for the first time, we report that upon applying reductive potential and electrolyte to the benchmark La2 CuO4 catalyst, surface reconstruction occurred, i.e., the appearance of a distinctive phase evolution process over time, which was successfully monitored using ex situ powder XRD and operando Mott-Schottky (M-S) measurements of La2 CuO4 samples that were soaked into the electrolyte and subjected to CO2 -ECR for different durations. At the end of such a reconstruction process, an outermost layer consisting of lanthanum carbonate, a thin outer layer made of an amorphous Cu+ material formed over the core bulk La2 CuO4 , as confirmed by various characterization techniques, which resulted in the redistribution of interfacial electrons and subsequent formation of electron-rich and electron-deficient interfaces. This contributed to the enhancement in FE for C2 H4 , reaching as much as 58.7%. Such surface reconstruction-induced electronic structure tuning gives new explanations for the superior catalytic performance of La2 CuO4 perovskite and also provides a new pathway to advance CO2 -ECR technology.- Published
- 2024
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4. Physicochemical characteristics of grease-trap wastewater with different potential mechanisms of FOG solid formation, separation, and accumulation inside grease traps.
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Tang LY, Wong NH, Chieng TA, Kiu AKJ, Choo CS, Li Y, Tan CP, Yaser AZ, Khaerudini DS, Chen GH, and Sunarso J
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- Wastewater chemistry, Sewage chemistry, Waste Disposal, Fluid
- Abstract
This work investigates the physicochemical characteristics of grease-trap wastewater discharged from a large community market. It proposes potential mechanisms of fat, oil, and grease (FOG) solid formation, separation, and accumulation inside grease traps. Sixty-four samples, i.e., the floated scum, suspended solid-liquid wastewater, and settled sludge, were collected from the grease-trap inlet and outlet chambers. A lower pH of 5-6 at 25-29 °C inside the grease trap than those reported under the sewer conditions (pH 6-7) was revealed. A significant difference in solid and dissolved constituents was also discovered between the inlet and outlet chambers, indicating that the baffle wall could affect the separation mechanism. The sludge samples had 1.5 times higher total solids (TS) than the scum samples, i.e., 0.225 vs. 0.149 g g
-1 TS, revealing that the sludge amount impacted more significantly the grease trap capacity and operation and maintenance. In contrast, the scum samples had 1.4 times higher volatile solids (VS) than the sludge samples, i.e., 0.134 vs. 0.096 g g-1 VS, matching with the 64.2 vs. 29.7% of carbon content from CHN analysis. About 2/3 of the free fatty acids (FFAs) with palmitic acids were the primary saturated FFAs, while the remaining 1/3 of unsaturated FFAs were found in the solid and liquid samples. Although up to 0.511 g g-1 FOG can be extracted from the scum samples, none from the sludge samples. More diverse minerals/metals other than Na, Cl, and Ca were found in the sludge samples than in the scum samples. Grease-trap FOG solids and open drain samples exhibited similar physicochemical properties to those reported in the literature. Four potential mechanisms (crystallization, emulsification, saponification, and baffling) were presented. This work offers insights into the physicochemical properties of grease-trap wastewater that can help explore its FOG solid formation, separation, and accumulation mechanisms inside a grease trap., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ngie Hing Wong reports financial support was provided by Malaysia Ministry of Higher Education. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)- Published
- 2024
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5. Fabricating an adsorbent and micro-nano bubble catalyst through confining maghemite in the β cage of NaY zeolite.
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Duan Y, Zhang R, Han P, Wong NH, Sunarso J, Liu S, and Yu J
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- Ferric Compounds, Catalysis, Adsorption, Kinetics, Zeolites, Environmental Pollutants, Water Pollutants, Chemical analysis
- Abstract
This work reports the ion exchange fabrication of maghemite (γ-Fe
2 O3 ) modified NaY zeolite (Fe2 O3 @Y) with bifunction of adsorption and catalysis. The Fe3+ successfully replaced the Na+ in the β cage of zeolite in the ion exchange process and coordinated with framework oxygens to form magnetic γ-Fe2 O3 . Therefore, most of the γ-Fe2 O3 particles were confined in the β cages, which resulted in the high dispersal and stability of the catalyst. The Fe2 O3 @Y could remove methylene blue (MB) model pollutants up to 59.02 and 61.47% through the adsorption and catalysis process, respectively. The hydrogen bond between the OH- ions around the Fe2 O3 @Y surface and the N and O presented in the MB molecules enabled the chemical adsorption to MB, which accorded with the pseudo-second-order kinetic model. Further, the H+ existed in the solution and the β cage of zeolite promoted the collapse of micro-nano bubbles (MNBs). Then, the γ-Fe2 O3 catalyst would be activated by high temperature and oxidated OH- to produce hydroxyl radicals for pollutant degradation. Thus, pollutant removal was attributed to the combined effects of adsorption and catalysis in the Fe2 O3 @Y + MNB system. In this work, the Fe2 O3 @Y was demonstrated as a potentially magnetic adsorbent or MNB catalyst for wastewater treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)- Published
- 2024
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6. How adults understand what young children say.
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Meylan SC, Foushee R, Wong NH, Bergelson E, and Levy RP
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- Child, Adult, Humans, Child, Preschool, Bayes Theorem, Speech, Language Development, Language, Speech Perception
- Abstract
Children's early speech often bears little resemblance to that of adults, and yet parents and other caregivers are able to interpret that speech and react accordingly. Here we investigate how adult listeners' inferences reflect sophisticated beliefs about what children are trying to communicate, as well as how children are likely to pronounce words. Using a Bayesian framework for modelling spoken word recognition, we find that computational models can replicate adult interpretations of children's speech only when they include strong, context-specific prior expectations about the messages that children will want to communicate. This points to a critical role of adult cognitive processes in supporting early communication and reveals how children can actively prompt adults to take actions on their behalf even when they have only a nascent understanding of the adult language. We discuss the wide-ranging implications of the powerful listening capabilities of adults for theories of first language acquisition., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)
- Published
- 2023
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7. Revealing the enhanced photoelectrochemical water oxidation activity of Fe-based metal-organic polymer-modified BiVO 4 photoanode.
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Xiong X, Wong NH, Ernawati L, Sunarso J, Zhang X, Jin Y, Han D, Wu C, Yu B, Yang X, Wang Y, Chen G, and Yao J
- Abstract
Metal-organic polymers (MOPs) can enhance the photoelectrochemical (PEC) water oxidation performance of BiVO
4 photoanodes, but their PEC mechanisms have yet to be comprehended. In this work, we constructed an active and stable composite photoelectrode by overlaying a uniform MOP on the BiVO4 surface using Fe2+ as the metal ions and 2,5-dihydroxyterephthalic acid (DHTA) as ligand. Such modification on the BiVO4 surface yielded a core-shell structure that could effectively enhance the PEC water oxidation activity of the BiVO4 photoanode. Our intensity-modulated photocurrent spectroscopy analysis revealed that the MOP overlayer could concurrently reduce the surface charge recombination rate constant (ksr ) and enhance the charge transfer rate constant (ktr ), thus accelerating water oxidation activity. These phenomena can be ascribed to the passivation of the surface that inhibits the recombination of the charge carrier and the MOP catalytic layer that improves the hole transfer. Our rate law analysis also demonstrated that the MOP coverage shifted the reaction order of the BiVO4 photoanode from the third-order to the first-order, resulting in a more favorable rate-determining step where only one hole accumulation is required to overcome water oxidation. This work provides new insights into the reaction mechanism of MOP-modified semiconductor photoanodes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)- Published
- 2023
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8. Construction of Cu 7 S 4 @CuCo 2 O 4 Yolk-Shell Microspheres Composite and Elucidation of Its Enhanced Photocatalytic Activity, Mechanism, and Pathway for Carbamazepine Degradation.
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He Z, Yang H, Wong NH, Ernawati L, Sunarso J, Huang Z, Xia Y, Wang Y, Su J, Fu X, and Wu M
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Water pollution caused by the massive use of medicines has caused significant environmental problems. This work first reports the synthesis and characterization of the Cu
7 S4 /CuCo2 O4 (CS/CCO) yolk-shell microspheres via hydrothermal and annealing methods, and then investigates their photocatalytic performance in removing organic water pollutants. The 10-CS/CCO composite with yolk-shell microspheres exhibits the highest photodegradation rate of carbamazepine (CBZ), reaching 96.3% within 2 h. The 10-CS/CCO also demonstrates more than two times higher photodegradation rates than the pure (Cu7 S4 ) CS and (CuCo2 O4 ) CCO. This outstanding photocatalytic performance can be attributed to the unique yolk-shell structure and the Z-scheme charge transfer pathway, reducing multiple reflections of the acting light. These factors enhance the light absorption efficiency and efficiently transfer photoexcited charge carriers. In-depth, photocatalytic degradation pathways of CBZ are systematically evaluated via the identification of degradation intermediates with Fukui index calculation. The insights gained from this work can serve as a guideline for developing low-cost and efficient Z-scheme photocatalyst composites with the yolk-shell structure., (© 2023 Wiley-VCH GmbH.)- Published
- 2023
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9. Whole-Genome Sequence of Endophytic Bacteria Associated with Poison Ivy Vine (Toxicodendron radicans).
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Gan HM, Penix TS, Wengert PC, Wong NH, Hudson AO, Kumar G, and Savka MA
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Here, we report the genome assemblies of 11 endophytic bacteria, isolated from poison ivy vine (Toxicodendron radicans). Five species belonging to the genus Pseudomonas, two species of Curtobacterium , one strain of Pantoea agglomerans, and one species from the Bacillus , Cellulomonas , and Enterobacter genera were isolated from the interior tissue of poison ivy.
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- 2023
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10. The myth of regaining control: Ostracism increases superstitious tendencies.
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Poon KT, Wong NH, Lai HS, and Jiang Y
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- Humans, Superstitions, Social Isolation, Ostracism
- Abstract
Whether and how interpersonal experiences predispose people to show superstitious tendencies have been largely unexamined by past studies. By adopting a multimethod approach, three studies tested (a) whether ostracism increases superstitious tendencies through thwarted perceived control, (b) whether the dispositional need for closure moderates the effect of ostracism on superstitious tendencies and (c) whether restoring ostracized people's thwarted control weakens their superstitious tendencies. The results revealed that ostracized participants had higher superstitious tendencies than nonostracized participants did (Studies 1-3). Moreover, thwarted control mediated the effect of ostracism on superstitious tendencies (Study 2). In addition, the dispositional need for closure moderated the effect of ostracism on superstitious tendencies, such that the effect was stronger among participants with a high need for closure (Studies 1-2). Finally, restoring ostracized participants' perceived control weakened the effect of ostracism on superstitious tendencies (Study 3). Altogether, these findings feature the essential role of thwarted perceived control in understanding the link between ostracism and superstitious tendencies and the implication of control restoration in weakening the link. They also highlight the importance of dispositional characteristics in moderating people's responses to superstitions following ostracism and related forms of interpersonal maltreatment., (© 2022 The British Psychological Society.)
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- 2023
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11. Comparative analysis on indoor and outdoor thermal comfort in transitional seasons and summer based on multiple databases: Lessons learnt from the outdoors.
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Liu S, Xie Y, Zhu Y, Lin B, Cao B, Wong NH, Niu J, Fang Z, Lai D, Liu W, Wen J, Mou D, Tang H, Liu Z, and Ignatius M
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- Hong Kong, Humans, Learning, Seasons, Climate, Thermosensing
- Abstract
In environments with similar physical parameters, thermal comfort and sensation feelings may differ indoors and outdoors. How indoor and outdoor thermal perception differ from each other remains unclear. This study compared and discussed 29,536 field survey data, including 19,191 sets of indoor data, and 10,345 sets of outdoor data, covering five Köppen climate zones during transitional seasons and summer. Indoor data points were collected from two databases: the ASHRAE Global Thermal Comfort II and the SCATs (Smart Controls and Thermal Comfort), while outdoor data points were collected from the RUROS database (Rediscovering the Urban Realm and Open Spaces) and five individual projects executed in Singapore, Hong Kong, Guangzhou, Changsha, and Tianjin. The concepts of neutral rate (NR) and comfort rate (CR) were developed to help categorize "neutral" and "comfort" across different studies. The results of this study show that people are less sensitive to changes in thermal environment outdoors than indoors. Moreover, thermal comfort cannot be simply treated as thermal neutral, particularly for outdoor spaces. Compared with MM (mixed-mode) and NV (naturally ventilated) spaces, outdoor space does not have the highest NR, but its CR is much higher, with a wide range of SET* (Standard Effective Temperature) corresponding to CR over 80 %, from 15.5 °C to 23.4 °C. In the Cfa (humid subtropical) climate zone, significantly higher CR are recorded for outdoor spaces, although the NR are similar or even lower than those of indoors. Natural thermal resources in the outdoor thermal environment may hold the key to extending indoor comfort ranges., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
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12. Novel scheme towards interfacial charge transfer between ZnIn 2 S 4 and BiOBr for efficient photocatalytic removal of organics and chromium (VI) from water.
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He Z, Yang H, Sunarso J, Wong NH, Huang Z, Xia Y, Wang Y, Su J, Wang L, and Kang L
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- Bismuth, Software, Chromium, Water
- Abstract
Construction of Z-scheme heterostructure is an effective strategy to enhance the charge carriers' separation. However, successfully achieving this on the defect heterojunction to improve the photocatalytic activity remains challenging. This work successfully obtained sulfur vacancy in the ZnIn
2 S4 /BiOBr (SZIS/BOB) heterojunction composites with S-O covalent bonding using a hydrothermal method. As a result, they exhibited superior photocatalytic and stability performance. The optimized SZIS/BOB-10 exhibited excellent rhodamine B degradation (95.2%) and chromium (VI) reduction (97.8%) within 100 min under visible light. The enhanced composites with S-vacancies, S-O bond, and internal electric field induced the Z-scheme charge transfer mechanism. We had verified this mechanism based on the surface photovoltage spectra, electron spin response spectra, and density functional theory calculations. This work not only provides valuable insights into designing photocatalysts with a direct Z scheme heterostructure but also delineates a promising strategy for developing efficient photocatalysts to degrade organic pollutants., (Copyright © 2022 Elsevier Ltd. All rights reserved.)- Published
- 2022
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13. Lay awake with a racing mind: The associations between sexual objectification, insomnia, and affective symptoms.
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Jiang Y, Wong NH, Chan YC, and Poon KT
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- Affective Symptoms, Anxiety, Female, Humans, Sleep Quality, Wakefulness, Sleep Initiation and Maintenance Disorders
- Abstract
Background: Sexual objectification is a form of interpersonal maltreatment that women may experience in daily life. Research has focused on testing how it leads to various psychological distresses. However, little research has examined its influences on women's sleep quality, the underlying psychological mechanisms, and the potential implications for affective symptoms. We addressed this research gap by testing whether sexual objectification predicted perceived stress and insomnia, thereby predicting affective symptoms (i.e., depression and anxiety). We further examined whether sex-is-power beliefs moderated these associations., Methods: Participants completed validated measures of sex-is-power beliefs, sexual objectification, perceived stress, insomnia, depression, and anxiety. We conducted regression analyses, structural equation modeling, and bootstrapping analyses to test the associations between these psychological constructs., Results: As predicted, the results showed that sexual objectification was positively associated with perceived stress, insomnia, and affective symptoms. Moreover, perceived stress and insomnia serially mediated the association between sexual objectification and affective symptoms. Furthermore, sex-is-power beliefs moderated the serial mediation effect, such that the effect was only observed among participants with weak sex-is-power beliefs., Conclusions: These findings advanced current theories and knowledge of sexual objectification by demonstrating that sexual objectification is associated with perceived stress and insomnia, thereby predicting affective symptoms. The findings also highlighted the role of beliefs in weakening the negative consequences of sexual objectification., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2022
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14. Exiguobacterium sp. is endowed with antibiotic properties against Gram positive and negative bacteria.
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Cavanaugh NT, Parthasarathy A, Wong NH, Steiner KK, Chu J, Adjei J, and Hudson AO
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- Bacteria, Escherichia coli, Gram-Negative Bacteria, Microbial Sensitivity Tests, Staphylococcus aureus, Anti-Bacterial Agents pharmacology, Exiguobacterium
- Abstract
Objective: In order to isolate and identify bacteria that produce potentially novel bactericidal/bacteriostatic compounds, two ponds on the campus of the Rochester Institute of Technology (RIT) were targeted as part of a bioprospecting effort., Results: One of the unique isolates, RIT 452 was identified as Exiguobacterium sp. and subjected to whole-genome sequencing. The genome was assembled and in silico analysis was performed to predict the secondary metabolite gene clusters, which suggested the potential of Exiguobacterium RIT452 for producing antibiotic compounds. Extracts of spent growth media of RIT452 were active in disc diffusion assays performed against four reference strains, two Gram-negative (E. coli ATCC 25922 and P. aeruginosa ATCC 27853) and two Gram-positive (B. subtilis BGSC 168 and S. aureus ATCC 25923). Differential extraction and liquid chromatography was used to fractionate the extracts. Efforts to identify and elucidate the structure of the active compound(s) are still ongoing.
- Published
- 2021
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15. Whole-Genome Sequencing and Annotation of 10 Endophytic and Epiphytic Bacteria Isolated from Lolium arundinaceum.
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Gaeth VA, Domondon CJ, Podbielski PA, Aswad VX, Wrightstone EA, Wong NH, Burke WH, Melita J, Murray KM, and Hudson AO
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We report the whole-genome sequence and annotation of 10 endophytic and epiphytic bacteria isolated from the grass Lolium arundinaceum as part of a laboratory exercise in a Fundamentals of Plant Biochemistry and Pathology undergraduate course (BIOL403) at the Rochester Institute of Technology in Rochester, New York., (Copyright © 2021 Gaeth et al.)
- Published
- 2021
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16. Genomic characterization of bacteria from the ultra-oligotrophic Madison aquifer: insight into the archetypical LuxI/LuxR and identification of novel LuxR solos.
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Wengert PC, Wong NH, Barton HA, Gan HM, Hudson AO, and Savka MA
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- Bacteria genetics, Bacterial Proteins genetics, Genomics, Repressor Proteins, Groundwater, Trans-Activators
- Abstract
Objectives: To characterize the bacterial community of Wind Cave's Madison aquifer through whole-genome sequencing, and to better understand the bacterial ecology by identifying genes involved in acyl-homoserine lactone (AHL) based quorum-sensing (QS) systems., Results: Genome-based taxonomic classification revealed the microbial richness present in the pristine Madison aquifer. The strains were found to span eleven genera and fourteen species, of which eight had uncertain taxonomic classifications. The genomes of strains SD129 and SD340 were found to contain the archetypical AHL QS system composed of two genes, luxI and luxR. Surprisingly, the genomes of strains SD115, SD129, SD274 and SD316 were found to contain one to three luxR orphans (solos). Strain SD129, besides possessing an archetypical AHL QS luxI-luxR pair, also contained two luxR solos, while strain SD316 contained three LuxR solos and no luxI-luxR pairs. The ligand-binding domain of two LuxR solos, one each from strains SD129 and SD316, were found to contain novel substitutions not previously reported, thus may represent two LuxR orphans that detection and response to unknown self-produced signal(s), or to signal(s) produced by other organisms.
- Published
- 2021
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17. Exploration of the Neisseria Resistome Reveals Resistance Mechanisms in Commensals That May Be Acquired by N. gonorrhoeae through Horizontal Gene Transfer.
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Fiore MA, Raisman JC, Wong NH, Hudson AO, and Wadsworth CB
- Abstract
Nonpathogenic Neisseria transfer mutations encoding antibiotic resistance to their pathogenic relative Neisseria gonorrhoeae . However, the resistance genotypes and subsequent phenotypes of nonpathogens within the genus have been described infrequently. Here, we characterize the minimum inhibitory concentrations (MICs) of a panel of Neisseria ( n = 26)-including several commensal species-to a suite of diverse antibiotics. We furthermore use whole genome sequencing and the Comprehensive Antibiotic Resistance Database Resistance Gene Identifier (RGI) platform to predict putative resistance-encoding mutations. Resistant isolates to all tested antimicrobials including penicillin ( n = 5/26), ceftriaxone ( n = 2/26), cefixime ( n = 3/26), tetracycline ( n = 10/26), azithromycin ( n = 11/26), and ciprofloxacin ( n = 4/26) were found. In total, 63 distinct mutations were predicted by RGI to be involved in resistance. The presence of several mutations had clear associations with increased MIC such as DNA gyrase subunit A ( gyrA ) (S91F) and ciprofloxacin, tetracycline resistance protein ( tetM ) and 30S ribosomal protein S10 ( rpsJ ) (V57M) and tetracycline, and TEM-type β-lactamases and penicillin. However, mutations with strong associations to macrolide and cephalosporin resistance were not conclusive. This work serves as an initial exploration into the resistance-encoding mutations harbored by nonpathogenic Neisseria , which will ultimately aid in prospective surveillance for novel resistance mechanisms that may be rapidly acquired by N. gonorrhoeae .
- Published
- 2020
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18. Isolation and whole-genome sequencing of Pseudomonas sp. RIT 623, a slow-growing bacterium endowed with antibiotic properties.
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Steiner KK, Parthasarathy A, Wong NH, Cavanaugh NT, Chu J, and Hudson AO
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- Bacteria, Escherichia coli, Microbial Sensitivity Tests, Staphylococcus aureus, Technology, Anti-Bacterial Agents pharmacology, Pseudomonas genetics
- Abstract
Objective: There is an urgent need for the discovery and/or development of novel antibiotics. We report an exploration of "slow"-growing bacteria, which can be difficult to isolate using rich media as they are usually outcompeted by "fast"-growing bacteria, as potential sources of novel antimicrobials., Results: Pseudomonas sp. RIT 623 was isolated using pond water agar from a pond located on the campus of the Rochester Institute of Technology (RIT). The genome was sequenced and analyzed for potential secondary metabolite gene clusters. Bioinformatics analysis revealed 14 putative gene clusters predicted to encode pathways for the anabolism of secondary metabolites. Ethyl acetate extracts from spent growth medium of Pseudomonas sp. RIT 623 were tested against two Gram-negative (E. coli ATCC 25922 and P. aeruginosa ATCC 27853) and two Gram-positive (B. subtilis BGSC 168 and S. aureus ATCC 25923) type strains to assess antibiotic activity. The antibiotic assays demonstrated that extracts of Pseudomonas sp. RIT 623 were able to inhibit the growth of the four strains. The active compound was separated using diethyl ether in a multi-solvent extraction and reverse phase chromatography. The bioactive compound/s were subsequently eluted in two consecutive fractions corresponding to approximately 16-22% acetonitrile, indicative of polar compound/s.
- Published
- 2020
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19. Expression of a Shiga-Like Toxin during Plastic Colonization by Two Multidrug-Resistant Bacteria, Aeromonas hydrophila RIT668 and Citrobacter freundii RIT669, Isolated from Endangered Turtles ( Clemmys guttata ).
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Thomas SG, Glover MA, Parthasarathy A, Wong NH, Shipman PA, and Hudson AO
- Abstract
Aeromonas hydrophila RIT668 and Citrobacter freundii RIT669 were isolated from endangered spotted turtles ( Clemmys guttata ). Whole-genome sequencing, annotation and phylogenetic analyses of the genomes revealed that the closest relative of RIT668 is A. hydrophila ATCC 7966 and Citrobacter portucalensis A60 for RIT669. Resistome analysis showed that A. hydrophila and C. freundii harbor six and 19 different antibiotic resistance genes, respectively. Both bacteria colonize polyethylene and polypropylene, which are common plastics, found in the environment and are used to fabricate medical devices. The expression of six biofilm-related genes-biofilm peroxide resistance protein ( bsmA ), biofilm formation regulatory protein subunit R ( bssR ), biofilm formation regulatory protein subunit S ( bssS ), biofilm formation regulator ( hmsP ), toxin-antitoxin biofilm protein (tabA) and transcriptional activator of curli operon ( csgD )-and two virulence factors-Vi antigen-related gene ( viaB ) and Shiga-like toxin ( slt - II )-was investigated by RT-PCR. A. hydrophila displayed a >2-fold increase in slt-II expression in cells adhering to both polymers, C. freundii adhering on polyethylene displayed a >2-fold, and on polypropylene a >6-fold upregulation of slt-II . Thus, the two new isolates are potential pathogens owing to their drug resistance, surface colonization and upregulation of a slt-II -type diarrheal toxin on polymer surfaces.
- Published
- 2020
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20. Transpiration and cooling potential of tropical urban trees from different native habitats.
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Tan PY, Wong NH, Tan CL, Jusuf SK, Schmiele K, and Chiam ZQ
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- Forests, Plant Leaves, Vapor Pressure, Water, Plant Transpiration, Trees
- Abstract
Urban trees are widely promoted as a solution to cool the urban environment because of shading and evaporative cooling provided by tree canopies. The extent to which the cooling benefits are realized is dependent not just on the genetically determined traits of trees, but also by their interactions with the atmospheric and edaphic conditions in urban areas, for which there is currently a paucity of information. We conducted a field experiment to compare whole-tree transpiration (E
t ) of tropical urban species from seasonally dry forest (SDF) (Tabebuia rosea, Lagerstroemia speciosa, Delonix regia, Caesalpinia ferrea, Dalbergia sissoo, Samanea saman) and aseasonal evergreen forest (AEF) (Peltophorum pterocarpum, Sindora wallichii). We examined the dependence of Et on atmospheric conditions (solar radiation (Rn ) and vapor pressure deficit (VPD)), as well as on soil moisture level (θv ). Daily Et differences between species were large but not statistically significant overall: 2000-3200 g m-2 (leaf area) under sunny conditions and 980-2000 g m-2 under cloudy conditions. The led to a daily latent heat flux (LE) of 770 W m-2 between the species with the highest (2136 W m-2 ) and lowest (1369 W m-2 ) daily Et . SDF species had higher daily Et than AEF species, but the difference was only significant under cloudy condition. Rn had a slightly stronger role in influencing transpiration compared to VPD, and species responses to drought stress differed marginally between the two groups. We assessed if two plant functional traits, wood density (ρw ) and leaf stomatal conductance (gs ), could be used to predict Et . Only gs was shown to be moderately correlated with Et , but more studies are needed to assess this given the limited number of species used in the study., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2020
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21. Isolation and Whole-Genome Sequencing of 12 Mushroom-Associated Bacterial Strains: an Inquiry-Based Laboratory Exercise in a Genomics Course at the Rochester Institute of Technology.
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Wong NH, Rosato AJ, Rose YM, Penix TS, Fung JB, Vanitski AL, Goossen CJ, Bradshaw SG, Lopp SM, Pennington AD, Darmohray VM, Steiner KK, Kersey GE, Brylow KB, Pridmore MV, Hedges JS, Rynkiewicz P, and Hudson AO
- Abstract
Here, we report the isolation, identification, and whole-genome sequences of 12 bacterial strains associated with four mushroom species. The study was done as an inquiry-based exercise in an undergraduate genomics course (BIOL 340) in the Thomas H. Gosnell School of Life Sciences at the Rochester Institute of Technology., (Copyright © 2020 Wong et al.)
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- 2020
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22. Isolation, Whole-Genome Sequencing, and Annotation of Yimella sp. RIT 621, a Strain That Produces Antibiotic Compounds against Escherichia coli ATCC 25922 and Bacillus subtilis BGSC 168.
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Parthasarathy A, Wong NH, Burns ND, Aziz-Dickerson AH, Dweh J, Buchanan D, Savka MA, and Hudson AO
- Abstract
Here, we report the isolation, identification, whole-genome sequencing, and annotation of the bacterium Yimella sp. strain RIT 621. Concentrated spent medium extract treated with ethyl acetate was found to produce bactericidal compounds against the Gram-positive bacterium Bacillus subtilis BGSC 168 and the Gram-negative bacterium Escherichia coli ATCC 25922., (Copyright © 2019 Parthasarathy et al.)
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- 2019
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23. SELfies and CELLfies: Whole Genome Sequencing and Annotation of Five Antibiotic Resistant Bacteria Isolated from the Surfaces of Smartphones, An Inquiry Based Laboratory Exercise in a Genomics Undergraduate Course at the Rochester Institute of Technology.
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Parthasarathy A, Wong NH, Weiss AN, Tian S, Ali SE, Cavanaugh NT, Chinsky TM, Cramer CE, Gupta A, Jha R, Johnson LK, Tuason ED, Klafehn LM, Krishnadas V, Musich RJ, Pfaff JM, Richman SC, Shumway AJ, and Hudson AO
- Abstract
Are touchscreen devices a public health risk for the transmission of pathogenic bacteria, especially those that are resistant to antibiotics? To investigate this, we embarked on a project aimed at isolating and identifying bacteria that are resistant to antibiotics from the screens of smartphones. Touchscreen devices have become ubiquitous in society, and it is important to evaluate the potential risks they pose towards public health, especially as it pertains to the harboring and transmission of pathogenic bacteria that are resistant to antibiotics. Sixteen bacteria were initially isolated of which five were unique (four Staphylococcus species and one Micrococcus species). The genomes of the five unique isolates were subsequently sequenced and annotated. The genomes were analyzed using in silico tools to predict the synthesis of antibiotics and secondary metabolites using the anti biotics and S econdary M etabolite A nalysis SH ell (antiSMASH) tool in addition to the presence of gene clusters that denote resistance to antibiotics using the R esistance G ene I dentifier (RGI) tool. In vivo analysis was also done to assess resistance/susceptibility to four antibiotics that are commonly used in a research laboratory setting. The data presented in this manuscript is the result of a semester-long inquiry based laboratory exercise in the genomics course (BIOL340) in the Thomas H. Gosnell School of Life Sciences/College of Science at the Rochester Institute of Technology., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.
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- 2019
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24. Whole-Genome Sequencing and Annotation of Exiguobacterium sp. RIT 452, an Antibiotic-Producing Strain Isolated from a Pond Located on the Campus of the Rochester Institute of Technology.
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Parthasarathy A, Wong NH, Cavanaugh NT, Steiner KK, Wengert PC, Savka MA, and Hudson AO
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Exiguobacterium sp. RIT 452 is of biotechnological importance given its potential for antibiotic production. Bactericidal activity was detected using spent medium extract in a disk diffusion assay against Escherichia coli. The genome consists of 3,246 protein-coding sequences, including a variety of gene clusters involved in the synthesis of antibacterial compounds.
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- 2018
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25. Isolation and genomic characterization of six endophytic bacteria isolated from Saccharum sp (sugarcane): Insights into antibiotic, secondary metabolite and quorum sensing metabolism.
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Parthasarathy A, Gan HM, Wong NH, Savka MA, Steiner KK, Henry KR, and Hudson AO
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Six endophytic bacteria were isolated from Saccharum sp (sugarcane) grown in the parish of Westmoreland on the island of Jamaica located in the West Indies. Whole genome sequence and annotation of the six bacteria show that three were from the genus Pseudomonas and the other three were from the genera Pantoea , Pseudocitrobacter , and Enterobacter . A scan of each genome using the antibiotics and secondary metabolite analysis shell (antiSMASH4.0) webserver showed evidence that the bacteria were able to produce a variety of secondary metabolites. In addition, we were able to show that one of the organisms, Enterobacter sp RIT418 produces N -acyl-homoserine lactones (AHLs), which is indicative of cell-cell communication via quorum sensing (QS)., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.
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- 2018
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26. Optical side scattering radiometry for high resolution, wide dynamic range longitudinal assessment of optical fibers.
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Sandoghchi SR, Petrovich M, Gray DR, Chen Y, Wheeler NV, Bradley TD, Wong NH, Jasion GT, Hayes J, Fokoua EN, Alonso MB, Mousavi SM, Richardson DJ, and Poletti F
- Abstract
Current optical reflectometric techniques used to characterize optical fibers have to trade-off longitudinal range with spatial resolution and therefore struggle to provide simultaneously wide dynamic range (>20dB) and high resolution (<10cm). In this work, we develop and present a technique we refer to as Optical Side Scattering Radiometry (OSSR) capable of resolving discrete and distributed scattering properties of fibers along their length with up to 60dB dynamic range and 5cm spatial resolution. Our setup is first validated on a standard single mode telecoms fiber. Then we apply it to a record-length 11km hollow core photonic band-gap fiber (HC-PBGF) the characterization requirements of which lie far beyond the capability of standard optical reflectometric instruments. We next demonstrate use of the technique to investigate and explain the unusually high loss observed in another HC-PBGF and finally demonstrate its flexibility by measuring a HC-PBGF operating at a wavelength of 2µm. In all of these examples, good agreement between the OSSR measurements and other well-established (but more limited) characterization methods, i.e. cutback loss and OTDR, was obtained.
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- 2015
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27. Cladding pumped few-mode EDFA for mode division multiplexed transmission.
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Jung Y, Lim EL, Kang Q, May-Smith TC, Wong NH, Standish R, Poletti F, Sahu JK, Alam SU, and Richardson DJ
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- Spectrum Analysis, Amplifiers, Electronic, Erbium chemistry, Optical Fibers, Signal Processing, Computer-Assisted
- Abstract
We experimentally demonstrate a few-mode erbium doped fiber amplifier (FM-EDFA) supporting 6 spatial modes with a cladding pumped architecture. Average modal gains are measured to be >20dB between 1534nm-1565nm with a differential modal gain of ~3dB among the mode groups and noise figures of 6-7dB. The cladding pumped FM-EDFA offers a cost effective alternative to core-pumped variant as low cost, high power multimode pumps can be used, and offers performance, scalability and simplicity to FM-EDFA design.
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- 2014
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28. A comparative analysis of human thermal conditions in outdoor urban spaces in the summer season in Singapore and Changsha, China.
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Yang W, Wong NH, and Zhang G
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- Adult, China epidemiology, Female, Humans, Male, Middle Aged, Singapore epidemiology, Young Adult, Body Temperature physiology, Seasons, Urban Population statistics & numerical data
- Abstract
This paper presents the comparative analysis between the findings from two field surveys of human thermal conditions in outdoor urban spaces during the summer season. The first survey was carried out from August 2010 to May 2011 in Singapore and the second survey was carried out from June 2010 to August 2010 in Changsha, China. The physiologically equivalent temperature (PET) was utilized as the thermal index to assess the thermal conditions. Differences were found between the two city respondents in terms of thermal sensation, humidity sensation, and wind speed sensation. No big difference was found between the two city respondents regarding the sun sensation. The two city respondents had similar neutral PET of 28.1 °C for Singapore and 27.9 °C for Changsha, respectively. However, Singapore respondents were more sensitive to PET change than Changsha respondents and the acceptable PET range for Changsha respondents was wider than that for Singapore respondents. Besides, the two city respondents had different thermal expectations with the preferred PET of 25.2 °C and 22.1 °C for Singapore and Changsha, respectively. The results also reveal that Changsha respondents were more tolerant than Singapore respondents under hot conditions. Finally, two regression models were proposed for Singapore and Changsha to predict the human thermal sensation in a given outdoor thermal environment.
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- 2013
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29. Securing and sustaining employment: concerns of HIV patients in Singapore.
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Tan SY, Ow Yong LM, Foong JY, Wong NH, Chew LL, and Koh YL
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- Adult, Comorbidity, Female, HIV Infections economics, HIV Infections therapy, Humans, Interviews as Topic, Male, Middle Aged, Qualitative Research, Singapore, Social Discrimination economics, Confidentiality psychology, Disclosure, Employment, HIV Infections psychology, Health Services Accessibility economics, Social Determinants of Health, Social Discrimination psychology, Social Stigma
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Employment sustainability is one of the most pressing issues inflicting people living with HIV (PLHIV). A qualitative approach was used to elucidate the perceived challenges in sustaining their employment and the perceived barriers in re-entering the workforce for HIV patients. In-depth interviews were conducted with 16 patients from an acute hospital in Singapore. The main challenges raised in sustaining employment were: (1) ability to ensure secrecy of diagnosis from employers, (2) ability to secure financial resources for treatment and sustenance, (3) ability to ensure stable health to meet job requirements, (4) ability to cognitively sit with the concerns of uncertainty and limitations in career, and (5) ability to work through discriminatory workplace practices. The perceived barriers in gaining workforce re-entry were: (1) fear of pre-employment medical screening and potential discriminatory practices at workplace, (2) concerns over health (frequent hospital admissions, physical weakness, and existing medical co-morbidities), and (3) psychosocial challenges (unstable accommodation, older age, financial issues, and trade skills limitation). The overarching factor that influences the success of sustaining and securing an employment among HIV patients is secrecy of the diagnosis. The individuals' health status, financial status and access to healthcare, and other psychosocial challenges further compound the issue.
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- 2013
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30. A three-year retrospective study of emergency visits at an oral health clinic in south-east Queensland.
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Wong NH, Tran C, Pukallus M, Holcombe T, and Seow WK
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- Adolescent, Chi-Square Distribution, Child, Child, Preschool, Dental Caries epidemiology, Female, Humans, Male, Periapical Abscess epidemiology, Queensland epidemiology, Retrospective Studies, Social Class, Tooth Injuries epidemiology, Toothache epidemiology, Dental Care for Children statistics & numerical data, Dental Clinics statistics & numerical data, Emergency Medical Services statistics & numerical data
- Abstract
Background: There is little information available regarding dental emergencies for children in Australia. The aim of this study was to investigate the reasons for dental emergency cases which were treated at a public oral health clinic in a low socioeconomic district in south-east Queensland., Methods: From a register kept at a public oral health clinic, we analysed the monthly number of emergency visits for children over a three-year period (January 2008 to August 2010) with respect to numbers treated, reasons for presentation and types of treatment rendered., Results: During the period 2008-2010, there was a mean of 196 ± 86 cases presenting for emergency care each month. The proportions of the various types of emergencies remained fairly consistent over the three-year period, with the majority presenting for caries related problems (74-75%), followed by trauma (8-9%), orthodontic treatment related (2-5%) and other reasons (16-11%). Between 8-11% of cases were preschool children who were added to the waitlist for treatment for caries under general anaesthesia at the public hospital., Conclusions: Trends in the past three years at a public oral health clinic in a low socioeconomic district in south-east Queensland show that dental caries constitute nearly three-quarters of all paediatric emergency appointments., (© 2012 Australian Dental Association.)
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- 2012
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31. Attitudes of Hong Kong nurses toward cadaveric organ donation.
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Chan YM, Po-lin PL, Lee WK, and Wong NH
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- Adult, Cadaver, Female, Health Knowledge, Attitudes, Practice, Hong Kong, Humans, Male, Attitude of Health Personnel, Nurses psychology, Tissue Donors psychology
- Abstract
Objectives: The objectives of this descriptive correlational study were to (a) examine Hong Kong nurses' attitudes toward cadaveric organ donation, and (b) determine if there were any relationships among the nurses' attitudes and their behaviors, or knowledge regarding cadaveric organ donation, or their experience in caring for cadaveric organ donors/recipients, in order to identify any obstacles in promoting organ donation in Hong Kong., Design: The Bidigare and Oermann (1991) Questionnaire and Chiu et al. (1991) Questionnaire were modified to a five-section questionnaire used in the study., Sample/setting: The sample consisted of 60 registered nurses from the intensive care unit (ICU), operation room (OR), or renal and surgical units in one of the public hospitals under the Hong Kong Hospital Authority., Methods: Questionnaires were given to the selected participants through their wards. The registered nurses returned completed questionnaires to their wards which were collected by the researchers., Results: Most of the nurses (84.6%) supported the concept of cadaveric donation but only 23.5% had signed the donor card. It also revealed that nurses attitudes and behaviors regarding cadaveric organ donation were positively correlated to their knowledge and experience of caring for organ donors and recipients and there was knowledge deficit among the nurses concerning cadaveric organ donation., Conclusion: While nurses with knowledge and previous experience in caring for cadaveric organ donors and recipients had a more positive attitude toward cadaveric organ donation, there is a knowledge deficit among the nurses. An educational program about organ donation is suggested to change their attitudes and hence increase organ procurement.
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- 1997
32. Patient response to PMMA contact lenses.
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Harris MG, Wong NH, and Low AW
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- Humans, Consumer Behavior, Contact Lenses adverse effects
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This study was designed to determine patient response to hard (PMMA) contact lenses and evaluate how lens modifications and refitting affect success. The subjects of this study were 178 randomly selected contact lens patients fitted at the University of California School of Optometry. Six to nine months after the patients were examined and fitted, their response to contact lenses was evaluated using the standard of Sarver and Harris. 44.4% of the patients were successful with the initial lenses while an additional 35.4% of the patients became successful after appropriate lens changes were made. The majority of the changes made were to eliminate ocular tissue changes. Our results indicate that lens modifications or refittings are often necessary to achieve a successful response to contact lenses.
- Published
- 1975
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