3,759 research outputs found
Teeth bleaching effect and anti-oral microbial activity of water-extracted apple (Malus asiatica)
Apple contains nutrients such as sugars, dietary fiber, and vitamins as well as bioactive phytochemicals such as organic acid, fatty acid and phenolic compounds. This study was conducted to confirm the applicability of apples as a bleaching agent and functional substances for the prevention of oral infectious diseases and maintenance of oral health by investigating the bovine teeth bleaching effect, anti-oral microbial activity, and inhibitory effect of halitosis of water-extracted apple (WEA). From the results of quantitative analysis of the surface color of bovine teeth, the application of WEA significantly increased the ΔE value, indicating a bleaching effect. In the case of 100mg/ml, the ΔE value increased as the WEA application time increased, and the bleaching effect was the greatest. Based on the results of the disk diffusion test and selective culture using CRT bacteria test kit, WEA showed anti-oral microbial activity against the dental caries bacteria, Streptococcus mutans and Latobacillus casei, the periodontal bacteria, Aggregatibacter actinomycetemcomitans, and Eschericha coli, but showed no antifungal effect against Candida albicans, causing oral candidiasis. From the results of colony formation and generation of halitosis from salivary microorganisms, WEA inhibited the growth of salivary microorganisms and generation of components inducing halitosis such as hydrogen sulfide, methyl mercaptan and dimethyl sulfide, that occur during the metabolic process of oral microorganisms. Therefore, WEA is a functional substance derived from a safe and useful natural product that can be used for the prevention of oral infectious diseases and maintenance of oral healt
Physiological and biochemical responses to cadmium exposure in Fucus serratus (Phaeophyceae)
Marine macroalgae can accumulate metals from the surrounding waters. But their responses to metals, especially non-essential metals like cadmium, are not well known and require further investigation. Therefore, the effects of cadmium exposure on the physiology and biochemistry of Fucus serratus collected from metal-contaminated (Restronguet Point) and clean (Bantham Quay) habitats were investigated. Therefore F. serratus demonstrates strong cadmium tolerance to cadmium exposure resulting from the production of antioxidative enzymes, glutathione and phytochelatine.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Characterization of copy numbers of 16S rDNA and 16S rRNA of Candidatus Liberibacter asiaticus and the implication in detection in planta using quantitative PCR
<p>Abstract</p> <p>Background</p> <p>Citrus Huanglongbing (HLB) is one of the most devastating diseases on citrus and is associated with <it>Candidatus </it>Liberibacter spp.. The pathogens are phloem limited and have not been cultured <it>in vitro</it>. The current management strategy of HLB is to remove infected citrus trees and reduce psyllid populations with insecticides to prevent the spreading. This strategy requires sensitive and reliable diagnostic methods for early detection.</p> <p>Results</p> <p>We investigated the copy numbers of the 16S rDNA and 16S rRNA of the HLB pathogen and the implication of improving the diagnosis of HLB for early detection using Quantitative PCR. We compared the detection of HLB with different Quantitative PCR based methods with primers/probe targeting either 16S rDNA, beta-operon DNA, 16S rRNA, or beta-operon RNA. The 16S rDNA copy number of <it>Ca</it>. Liberibacter asiaticus was estimated to be three times of that of the beta-operon region, thus allowing detection of lower titer of <it>Ca</it>. L. asiaticus. Quantitative reverse transcriptional PCR (QRT-PCR) indicated that the 16S rRNA averaged 7.83 times more than that of 16S rDNA for the same samples. Dilution analysis also indicates that QRT-PCR targeting 16S rRNA is 10 time more sensitive than QPCR targeting 16S rDNA. Thus QRT-PCR was able to increase the sensitivity of detection by targeting 16S rRNA.</p> <p>Conclusion</p> <p>Our result indicates that <it>Candidatus </it>Liberibacter asiaticus contains three copies of 16S rDNA. The copy number of 16S rRNA of <it>Ca</it>. L. asiaticus <it>in planta </it>averaged about 7.8 times of 16S rDNA for the same set of samples tested in this study. Detection sensitivity of HLB could be improved through the following approaches: using 16S rDNA based primers/probe in the QPCR assays; and using QRT-PCR assays targeting 16S rRNA.</p
Effect of Photonic Structures in Organic Light-Emitting Diodes – Light Extraction and Polarization Characteristics
Edited by Jai Sing
Academic experiences of international PhD students in Australian higher education: from an EAP program to a PhD program
For the last few decades, Australia has played a pivotal role in the supply of quality education to international students and other educational industries associated with them. In the higher education sector, in particular, international PhD student numbers continue to increase. However, the limited availability of resources for the students and the lack of investigation concerning the students indicate that there is a need for both higher education providers and other related stakeholders to understand and take into account the difficulties and challenges of international PhD students and their implications in the Australian academic context. While learning a new academic culture in a new country, international PhD students meet situations where they have to deal with a range of language problems, cultural differences and personal matters. The study reported in this article explores international non-English speaking background (NESB) students' experiences with university preparation programs and PhD programs and investigates the issues they face at an Australian university with a focus on factors affecting the NESB students' academic experiences. It provides implications for the teaching of postgraduate preparation programs and the supervision of international NESB PhD students at Australian universities
DECAY FACTOR WITH EXPERIMENTAL VARIABLES IN TWO CIRCULATING FLUIDIZED BED (CFB) RISERS
The effects of the riser inlet velocity, solid mass flux and particle size on the axial solid holdup profile and decay factor were investigated using two circulating fluidized beds (CFBs) with FCC (Geldart A) particles as the bed materials. Based on the experimental results from the two-CFBs, the axial solid holdup in the two CFBs were compared with the correlations of previous studies. Also, an empirical correlation was proposed for decay factor that exhibited a good agreement with experimental data
Genomic analysis of sorghum by fluorescence in situ hybridization
The reliability of genome analysis and proficiency of genetic manipulation in vivo and in vitro are increased by assignment of linkage groups to specific chromosomes, placement of centromeres, orientation with respect to telomeres, and linear alignment with respect to chromosomal features and dimensions. I undertook five studies aimed at integrating sorghum genomics and cytogenetics at several levels. The results help establish an entirely new "cyto-genomics" resource, impacts of which are likely to be broad. In the first study, I developed a FISH-based karyotyping system for Sorghum bicolor Moench. I used integrated structural genomic resources, including linkage maps and large-insert clonal libraries of sorghum genomic DNA to develop a 17-locus probe cocktail for simultaneous fluorescent in situ hybridization (FISH). This probe enabled facile identification of all chromosome pairs in mitotic chromosome spreads. Perhaps just as important, I established time-efficient means to select sorghum BAC clones for multi-probe FISH. Thus, an integrated cyto-genomics system for sorghum can be constructed without need of chromosome flow sorting or microdissection, both of which are difficult and costly. In the second study, hybridization of DNA clones from 37 different genomic regions enabled the assignment of linkage groups and orientation of linkage maps to chromosomes. Comparisons between genetic and physical distances throughout the genome enabled a new nomenclature for linkage group designation in sorghum. The results provide an integrated nomenclature system of Sorghum bicolor chromosomes and linkage groups. In the third study, I created high-resolution maps by FISH to pachytene bivalents for two linkage groups (B and H), and defined relationships between pericentromeric heterochromatin, centromeres, mapped markers and recombination rates. These relationships will help guide the development and use of sorghum genomics. In the fifth study, I used FISH in two ongoing gene-targeted efforts. For the maturity gene ma5 and fertility restoration gene rfl, I estimated physical lengths between currently available flanking molecular markers. This enables estimation of recombination densities in these regions and assessment of the applicability of map-based and -assisted cloning
Electroluminescent devices with function of electro-optic shutter
The polymer-dispersed liquid crystal (PDLC) was used as a dielectric layer of electroluminescent (EL) device to provide multi-function of electroluminescence and electro-optic shutter. A 50 μm-thick PDLC layer was formed between a transparent electrode and a ZnS:Cu phosphor layer. The electro-optic properties of the EL device were not distorted by the introduction of the PDLC layer. The extraction efficiency of luminescence was improved by more than 14% by PDLC layer. The transmittance of the PDLC was also founded not to be degraded significantly by excitation frequency. Therefore, the electroluminescence of the device was ignited by excitation frequency at a given voltage for full transparency of the PDLC. This device has great potential for applications in transparent displays with the function of a privacy window. © 2012 Optical Society of America.1
Discrete Time Iterative Negotiation Algorithm for Phosphorus Reductions in the Illinois River Basin
Economic
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