406 research outputs found
Rapid, photoinduced electron transfer-modulated, turn-on fluorescent probe for detection and cellular imaging of biologically significant thiols
© 2014 American Chemical Society. There is a very limited number of existing probes whose fluorescence is turned on in the presence of the class of biological thiols made up of glutathione, cysteine, and homocysteine. The extant probes for this class of biological thiols commonly have poor aqueous solubility and long analyte response times, and they demand a very high probe/thiol ratio for decreased time of significant reporter signal generation; knowledge regarding their selectivity with respect to other sulfur-based analytes is unclear. Described here is a previously unreported photoinduced electron-transfer-quenched probe (HMBQ-Nap 1) that offers highly selective and rapid in vitro detection of this class of biologically important thiols at low concentrations and low probe/thiol ratio, and importantly, very rapid imaging of these biological thiols in human cells. (Chemical Presented)
A Multi-Party Conversation-Based Effective Robotic Navigation System for Futuristic Vehicle
In response to the growing need for advanced in-car navigation systems that prioritize user experience and aim to reduce driver cognitive workload, this study addresses the research question of how to enhance the interaction between drivers and navigation systems. The focus is on minimizing distraction while providing personalized and geographically relevant information. The research introduces an innovative in-car robotic navigation system comprising three subsystem models: geofencing,personalization, and conversation. The dynamic geofencing model acquires geographic details related to the user's current location and provides information about required destinations. The personalization model tailors suggestions based on user preferences, while the conversation model, employing two virtual robots, fosters interactive multiparty conversations aligned with the driver's interests. The study's scope is specifically confined to interactive conversations centered on nearby restaurants and the driver's dietary preferences. Evaluation of the system indicates a notable prevalence of neutral expressions amongparticipants during interaction, suggesting that the implemented system successfully mitigates cognitive workload. Participants in the experiments express higher usability and interactivity levels, as evidenced by feedback collected at the study's conclusion, affirming the system's effectiveness in enhancing the user experience while maintaining a driver-friendly environment.
Keywords: Human-Robot Interaction, Multiparty Conversation, In-Car Navigatio
Ticarcillin hypersusceptibility in pseudomonas aeruginosa in cystic fibrosis
Background: A subpopulation of Pseudomonas aeruginosa (PsA) exists in cysticfibrosis (CF) patients that is hypersusceptible to ticarcillin, a carboxypenicillin, in vitro (Tichs strain) defined as a minimum inhibitory concentration (MIC) ≤4μg/ml. Methods: In a retrospective cohort study, isolates of PsA from CF (23), non-cystic fibrosis bronchiectasis (NCFB) (17) and control (18) patients were analysed. MICs for each isolate were determined using agar dilution against six antibiotics and interpreted using EUCAST breakpoints. Prevalence of Tichs in each cohort was calculated. A point prevalence survey was conducted in CF to review the patients’ clinical progress following PsA isolation. Results: Prevalence of the Tichs strain in PsA was 48%, 76% and 0% in the CF, NCFB and control cohorts respectively. A statistically significant difference in geometric mean MIC was seen between the Tichs and non-Tichs cohorts in CF for ticarcillin (as expected) and temocillin (p=0.041and p=0.036 respectively). A similar trend was observed in NCFB for ticarcillin (p=0.038) and temocillin (p=0.067), although statistical significance was not reached for the latter.In CF, the Tichs strain demonstrated lower MICs to all antibiotics tested apart from gentamicin compared to their non-Tichs counterparts. Those who had the Tichs strain in CF had fewer antibiotics (13.9 days versus 23.5 days, Tichs and non-Tichs respectively) although this result was not statistically significant p=0.202. Conclusion: Our data supports the existence of a Tichs strain of PsA in our CF and NCFB patient populations. This strain correlated with reduced MICs to temocillin in CF, to which PsA would normally be resistant, which may be of clinical relevance.</p
Valuation study for a preference-based quality of life measure for dental caries (Dental Caries Utility Index - DCUI) among Australian adolescents - study protocol.
IntroductionA new health state classification system has been developed for dental caries - Dental Caries Utility Index (DCUI) to facilitate the assessment of oral health interventions in the cost-utility analysis (CUA). This paper reports the protocol for a valuation study, which aims to generate a preference-based algorithm for the classification system for the DCUI.Methods and analysisDiscrete choice experiments (DCEs) will be conducted to value health states generated by the DCUI classification system and preferences for these health states will be modelled to develop a utility algorithm. DCEs produce utility values on a latent scale and these values will be anchored into the full health-dead scale to calculate the quality-adjusted life years in CUA. There is no previous evidence for the most suitable anchoring method for dental caries health state valuation. Hence, we will first conduct pilot studies with two anchoring approaches; DCE including duration attribute and DCE anchoring to worst heath state in Visual Analogue Scale. Based on the pilot studies, the most suitable anchoring method among two approaches will be used in the main valuation survey, which will be conducted as an online survey among a representative sample of 2000 adults from the Australian general population. Participants will be asked to complete a set of DCE choice tasks along with anchoring tasks, basic social-demographic questions, DCUI, a generic preference-based measure and oral health quality of life instrument.Ethics and disseminationEthical approval for this study was obtained from the Human Research Ethics Committee, Griffith University (reference number HREC/2019/550). The generated algorithm will facilitate the use of the new dental caries preference-based measure in economic evaluations of oral health interventions. The results will be disseminated through journal articles and professional conferences
Antimicrobial Properties of Ethanolic and Methanolic Extracts of Finger millet (Eleusine coracana (L.) Gaertn.) Varieties Cultivated in Sri Lanka
The emerging significance of natural antimicrobial agents creates an imperative need to identify novel plant sources with antimicrobial activities. The objective of the present study was to evaluate antibacterial, antifungal and β-lactamase enzyme inhibitory activities of ethanolic and methanolic extracts of Ravi, Rawana and Oshadha finger millet varieties. Flours of whole grains of the finger millet varieties were extracted with absolute ethanol and methanol separately. Antibacterial activities against six antibiotic-sensitive and four antibiotic-resistant pathogenic bacterial strains were evaluated using the resazurin reduction assay. Antifungal activities against six antimicrobial-sensitive pathogenic fungal strains were evaluated using the agar tube dilution method. β-Lactamase enzyme inhibitory activity was evaluated using a standard method. Both ethanolic and methanolic extracts of the three finger millet varieties showed dose-dependent inhibitory activities against the tested antibiotic-sensitive and antibiotic-resistant bacterial strains while exhibiting high inhibitions against Gram-positive antibiotic-sensitive bacterial strains when compared to Gram-negative antibiotic-sensitive bacterial strains. The findings revealed the antibacterial potential of both ethanolic and methanolic extracts of the three finger millet varieties against antibiotic-sensitive Staphylococcus aureus (ATCC® 6538™) and Bacillus subtilis (ATCC® 23857™) strains and the minimum inhibitory concentrations of the extracts against S. aureus and B. subtilis were found to be 2.1 and 1.8 mg/ml, respectively. However, none of the extracts can be considered as significantly active against the tested antibiotic-sensitive and antibiotic-resistant bacterial strains when compared to the standard drugs. In addition, none of the extracts can be considered as active against the tested fungal strains at the tested concentrations. Nevertheless, all extracts showed more activities against the tested bacterial strains when compared to the tested fungal strains. Since all extracts showed less than 40% β-lactamase inhibitory activities even at 2 mg/ml concentration, they do not qualify as promising sources of β-lactamase inhibitors at the tested concentration.KEYWORDS: Antibacterial activity, Antifungal activity, Finger millet, β-Lactamase enzyme inhibitory activit
FACTORS LIMITING SEED GERMINATION IN Scyphiphora hydrophyllacea GAERTN f. AND Pempilis acidula J R & FORST
Scyphiphora hydrophyllacea is a highly threatened true mangrove confined to JafTna and asingle locality in Kalpitiya (Trimen 1974; Dassanayake and Clayton 1998). Pemphisacidula is restricted to small pockets in few coastal areas. Both produce fruits and seedsnevertheless, seedlings were not observed in their natural habitats. Factors governing seedgermination in these two species were studied. For all experiments, randomly collected ripe.seed samples were used within two weeks of collection. Moist filter paper method was usedand daily observations were recorded.In P. acidula, seed production was 100%. Percentage of fruit bearing seeds was 10% in S.hydrophyllacea, but none of them gave rise to healthy seedlings. Seed germination of bothspecies was 0% in water collected from respective natural habitats. In P. acidula%germination was 35% in 75% and 40% in 87.5% dilution of water from natural habitat.In distilled water, 65% of the seeds germinated. Continuous washing of seeds in runningtap water increased percentage germination to 75%.Dormancy breaking treatments such as heat treatment, seed nicking, acid base treatment,cold treatment and treatment with gibberellic acid did not increase germination abovenormal 65% value.Exposure to natural light, photoperiod and oxygen level also affected seed germination.Analysis of data consisted of ANa VA at 5% level of significance using Minitab package.In P. acidula, salinity of soil water (up to 34 ppt) and salt deposits on seed coat seem to bemajor causes hindering seed germination in natural habitat. Seeds buried ill sand may alsonot receive adequate amount of light (Isikawa 1962; Fujii 1962). Oxygen concentrationmay 1I0tbe enough when the ground is covered with water during tides. Lack of seedlingsmay therefore be due to lack of seed germination under natural conditions.In S. hydrophyllacea, very low percentage of seed bearing fruits and inability to producehealthy seedlings explain why it has become highly threatened. Production of large numberof seedless fruits and inability to produce normal seedlings could be due to genetic disorderin seeds, which is a very common phenomenon known as inbreeding depression inisolated, small populations.Presence of self-sterility and the absence of pollinator niight be some other reasons. Hence,studies on the possibility of propagating S. hydrophyllacea by vegetative means areurgently needed to conserve this highly threatened tree species.
Micro-X-Ray Fluorescence, Micro-X-Ray Absorption Spectroscopy, and Micro-X-Ray Diffraction Investigation of Lead Speciation after the Addition of Different Phosphorus Amendments to a Smelter-Contaminated Soil
Citation: Baker, Lucas R., Gary M. Pierzynski, Ganga M. Hettiarachchi, Kirk G. Scheckel, and Matthew Newville. “Micro-X-Ray Fluorescence, Micro-X-Ray Absorption Spectroscopy, and Micro-X-Ray Diffraction Investigation of Lead Speciation after the Addition of Different Phosphorus Amendments to a Smelter-Contaminated Soil.” Journal of Environmental Quality 43, no. 2 (2014): 488–97. https://doi.org/10.2134/jeq2013.07.0281.The stabilization of Pb on additions of P to contaminated soils and mine spoil materials has been well documented. It is clear from the literature that different P sources result in different efficacies of Pb stabilization in the same contaminated material. We hypothesized that the differences in the efficacy of Pb stabilization in contaminated soils on fluid or granular P amendment addition is due to different P reaction processes in and around fertilizer granules and fluid droplets. We used a combination of several synchrotron-based techniques (i.e., spatially resolved micro-X-ray fluorescence, micro-X-ray absorption near-edge structure spectroscopy, and micro-X-ray diffraction) to speciate Pb at two incubation times in a smelter-contaminated soil on addition of several fluid and granular P amendments. The results indicated that the Pb phosphate mineral plumbogummite was an intermediate phase of pyromorphite formation. Additionally, all fluid and granular P sources were able to induce Pb phosphate formation, but fluid phosphoric acid (PA) was the most effective with time and distance from the treatment. Granular phosphate rock and triple super phosphate (TSP) amendments reacted to generate Pb phosphate minerals, with TSP being more effective at greater distances from the point of application. As a result, PA and TSP were the most effective P amendments at inducing Pb phosphate formation, but caution needs to be exercised when adding large amounts of soluble P to the environment
Tuning the properties of complex transparent conducting oxides: role of crystal symmetry, chemical composition and carrier generation
The electronic properties of single- and multi-cation transparent conducting
oxides (TCOs) are investigated using first-principles density functional
approach. A detailed comparison of the electronic band structure of
stoichiometric and oxygen deficient InO, - and
-GaO, rock salt and wurtzite ZnO, and layered InGaZnO
reveals the role of the following factors which govern the transport and
optical properties of these TCO materials: (i) the crystal symmetry of the
oxides, including both the oxygen coordination and the long-range structural
anisotropy; (ii) the electronic configuration of the cation(s), specifically,
the type of orbital(s) -- , or -- which form the conduction band;
and (iii) the strength of the hybridization between the cation's states and the
p-states of the neighboring oxygen atoms. The results not only explain the
experimentally observed trends in the electrical conductivity in the
single-cation TCO, but also demonstrate that multicomponent oxides may offer a
way to overcome the electron localization bottleneck which limits the charge
transport in wide-bandgap main-group metal oxides. Further, the advantages of
aliovalent substitutional doping -- an alternative route to generate carriers
in a TCO host -- are outlined based on the electronic band structure
calculations of Sn, Ga, Ti and Zr-doped InGaZnO. We show that the
transition metal dopants offer a possibility to improve conductivity without
compromising the optical transmittance
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