7,280 research outputs found

    Development of a Thiol-capped Core/Shell Quantum Dot Sensor for Acetaminophen

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    Acetaminophen (AC) is a frequently used pharmaceutical which has been detected in water systems and is of concern due to its potential environmental impacts. In this study, three quantum dot (QD)-ligand systems, namely L-cysteine (L-cys)-, N-acetyl- L-cysteine (NAC)- and glutathione (GSH)-capped CdSe/ZnS quantum dots, were synthesized and tested for the fluorescence detection of acetaminophen. Among the synthesized aqueous core/shell quantum dots, L-cys-CdSe/ZnS QDs were found to be optimal with high sensitivity for the fluorescence detection of acetaminophen. The L-cys-CdSe/ZnS QDs were of a zinc blende crystal structure and displayed excellent fluorescence intensity and photostability and provided a photoluminescence quantum yield of 77 % . The fluorescence of L-cys-CdSe/ZnS QDs was enhanced by the introduction of AC enabling the development of a fast and simple method for the detection of AC. Under optimal conditions, F-F0 was linearly proportional to the concentration of AC from 3.0–100 nmol L–1 with limits of detection and quantification of 1.6 and 5.3 nmol L–1, respectively. Some related pharmaceutical compounds including epinephrine hydrochloride (EP), L-ascorbic acid (AA), uric acid (UA), dopamine hydrochloride (DA) and 4-aminophenol (4-AP) did not interfere with the sensing ofAC. The probe was also successfully applied in the determination of AC in tap and river water matrices.The University of Pretoria, the Water Research Commission (Grant K5/2438/1 and K5/2752) as well as the Photonics Initiative of South Africa (Grant PISA-15-DIR-06).http://www.journals.co.za/sajchemam2019Chemistr

    Does Habitat Management for Northern Bobwhites Benefit the Red Imported Fire Ant?

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    Red imported fire ants (Solenopsis invicta) have caused damage to agricultural, economic, and wildlife resources since their accidental introduction. Previous studies have suggested that red imported fire ant (RIFA) mound densities are positively correlated to habitats maintained through disturbance. Prescribed burning and disking are two techniques commonly used to disturb portions of the landscape to maintain early successional habitats for northern bobwhite (Colinus virginianus). We tested the hypothesis that prescribed burning and disking would increase RIFA mound densities. This study was conducted in Refugio County, Texas in the Texas Coastal Prairie on Loamy Prairie range sites. Red imported fire ant mound densities were different between years (F = 5.05, df = 2, P = 0.0148). However, burning and disking had no impact (F = 0.22, df = 2, P = 0.8044) on RIFA mound densities. Initially high RIFA mound densities in our study area coupled with the territoriality of predominantly monogyne (single-queen) colonies may have limited increases in RIFA mound density in response to treatments on these study sites

    Current practice of preparing morphine infusions for nurse/patient-controlled analgesia in a UK paediatric hospital: healthcare professionals' views and experiences

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    Objective To explore the views and experiences of healthcare professionals (HCPs) regarding the preparation of morphine infusions for nurse/patient-controlled analgesia (N/PCA). Methods Three focus groups were conducted with HCPs (anaesthetists, nurses in theatres and wards) at one UK children's hospital. Focus groups were transcribed verbatim and content analysis was used to identify themes. Results A variety of approaches are used to prepare morphine infusions. A lack of appreciation of the excess volume present in morphine ampoules that nominally contain 1 or 2 mL was identified. Other sources of error were miscalculation, complexity of the multistep procedure, distractions and time pressure. Participants suggested that ‘ready-to-use’ prefilled syringes and preprogrammed syringe pumps would improve practice and minimise the risk of error. Conclusions Risks associated with the preparation of infusions for paediatric N/PCA, in particular non-appreciation of the overage (excess volume) in morphine ampoules, raise concerns about the accuracy of current practices

    The Fate of Nephrons in Congenital Obstructive Nephropathy: Adult Recovery is Limited by Nephron Number Despite Early Release of Obstruction

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    Urinary tract obstruction and reduced nephron number often occur together as a result of maldevelopment of kidneys and urinary tract. We wished to determine the role of nephron number on the adaptation of remaining nephrons of mice subjected to neonatal partial unilateral ureteral obstruction (UUO) and followed through adulthood

    Political attitudes of the young electorate in the 2016 presidential election and parental influences on political identity formation.

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    We examined the political attitudes of college-aged students and the political identities of their parents to better understand the role that both parent-child political socialization and the liberal university environment play in political identity formation. We compared students explicit and implicit political attitudes and examined the relationships of these attitudes to the political identities of their parents. We also explored the uniqueness of two candidates, Bernie Sanders and Donald Trump in the 2016 Presidential election. Our results supported the existing notion of parental influences on political identity formation and revealed that the university environment may not play as large of a role in shifting first and second year university students away from political identities established at home. However, data revealed greater support for the non-traditional candidate in our left-leaning participants, suggesting that factors other than parent influence could be at play in forming the political identities of the youth

    Quantum diffusion on a cyclic one dimensional lattice

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    The quantum diffusion of a particle in an initially localized state on a cyclic lattice with N sites is studied. Diffusion and reconstruction time are calculated. Strong differences are found for even or odd number of sites and the limit N->infinit is studied. The predictions of the model could be tested with micro - and nanotechnology devices.Comment: 17 pages, 5 figure

    Measuring the Non-Separability of Optical Fields

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    Across various areas in the optical world, there has been a growing interest in exploiting the properties of non-separable optical fields. A class of non-separable fields, known as vector modes, exhibit a coupling between the spatial and polarisation degrees of freedom that is akin of entanglement in quantum mechanics. These vector modes, however, are typically characterized using qualitative measurements which are inadequate in determining to what extent an optical field is non-separable. Here, we present tools to characterize the degree of non-separability of an arbitrary optical field, exploiting the similarities between vector modes and quantum entangled states. As an example, we use vector modes carrying orbital angular momentum to demonstrate the effectiveness of our scheme, and note that the approach can be generalized to vector modes as a whole

    A randomized, blinded, controlled trial investigating the gastrointestinal health effects of drinking water quality.

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    A double-blinded, randomized, controlled trial was carried out in in Melbourne, Australia, to determine the contribution of drinking water to gastroenteritis. Melbourne is one of the few major cities in the world that draws drinking water from a protected forest catchment with minimal water treatment (chlorination only). Six hundred families were randomly allocated to receive either real or sham water treatment units (WTUs) installed in their kitchen. Real units were designed to remove viruses, bacteria, and protozoa. Study participants completed a weekly health diary reporting gastrointestinal symptoms during the 68-week observation period. There were 2,669 cases of highly credible gastroenteritis (HCG) during the study (0.80 cases/person/year). The ratio of HCG episode rates for the real WTU group compared to the sham WTU group was 0.99 (95% confidence interval, 0.85-1.15, p = 0.85). We collected 795 fecal specimens from participants with gastroenteritis, and pathogens were not more significantly common in the sham WTU group. We found no evidence of waterborne disease in Melbourne. The application of this methodology to other water supplies will provide a better understanding of the relationship between human health and water quality
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