79 resultados para Facilitated Uptake


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Trace metals are required for many cellular processes. The acquisition of trace elements from the environment includes a rapid adsorption of metals to the cell surface, followed by a slower internalization. We investigated the uptake of the trace elements Co2+, Cu2+, Mn2+, Ni2+, and Zn2+ and the non-essential divalent cation Cd2+ in the cyanobacterium Nostoc punctiforme. For each metal, a dose response study based on cell viability showed that the highest non-toxic concentrations were: 0.5 μM Cd2+, 2 μM Co2+, 0.5 μM Cu2+, 500 μM Mn2+, 1 μM Ni2+, and 18 μM Zn2+. Cells exposed to these non-toxic concentrations with combinations of Zn2+ and Cd2+, Zn2+ and Co2+, Zn2+ and Cu2+ or Zn2+ and Ni2+, had reduced growth in comparison to controls. Cells exposed to metal combinations with the addition of 500 μM Mn2+ showed similar growth compared to the untreated controls. Metal levels were measured after one and 72 h for whole cells and absorbed (EDTA-resistant) fractions and used to calculate differential uptake rates for each metal. The differences in binding and internalisation between different metals indicate different uptake processes exist for each metal. For each metal, competitive uptake experiments using 65Zn showed that after 72 h of exposure Zn2+ uptake was reduced by most metals particularly 0.5 μM Cd2+, while 2 μM Co2+ increased Zn2+ uptake. This study demonstrates that N. punctiforme discriminates between different metals and favourably substitutes their uptake to avoid the toxic effects of particular metals.

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Aim
To examine the uptake of religious rituals of the Greek Orthodox Church by relatives of patients in critical condition in Greece and to explore their symbolic representations and spiritual meanings.
Background
Patients and their relatives want to be treated with respect and be supported for their beliefs, practices, customs and rituals. However nurses may not be ready to meet the spiritual needs of relatives of patients, while the health-related religious beliefs, practices and rituals of the Greek Orthodox Christian denomination have not been explored.
Method
This study was part of a large study encompassing 19 interviews with 25 informants, relatives of patients in intensive care units of three large hospitals in Athens, Greece, between 2000 and 2005. In this paper data were derived from personal accounts of religious rituals given by six participants.
Results
Relatives used a series of religious rituals, namely blessed oil and holy water, use of relics of saints, holy icons, offering names for pleas and pilgrimage.
Conclusion
Through the rituals, relatives experience a sense of connectedness with the divine and use the sacred powers to promote healing of their patients.
Implications for nursing management
Nurse managers should recognize, respect and facilitate the expression of spirituality through the practice of religious rituals by patients and their relatives.

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Sustainable management of the coastal zone represents a considerable challenge to Australian society. This challenge is rooted in the complexity of the biophysical and sociocultural characteristics of coastal areas, including uncertainty about system characteristics and processes, and the diversity of stakeholders, their interests, values and perspectives, and the jurisdictions involved in coastal governance and management. Given this complexity of coastal zone management, scientific and other forms of knowledge can affect decision-making and human action in diverse ways, which will often depend on the ability of scientists to engage effectively with relevant stakeholders.

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Introduction
Throughout the world, alcohol consumption is common among adolescents. Adolescent alcohol use and misuse have prognostic significance for several adverse long-term outcomes, including alcohol problems, alcohol dependence, school disengagement and illicit drug use. The aim of this study was to evaluate whether randomisation to a community mobilisation and social marketing intervention reduces the proportion of adolescents who initiate alcohol use before the Australian legal age of 18, and the frequency and amount of underage adolescent alcohol consumption.
Method and analysis
The study comprises 14 communities matched with 14 non-contiguous communities on socioeconomic status (SES), location and size. One of each pair was randomly allocated to the intervention. Baseline levels of adolescent alcohol use were estimated through school surveys initiated in 2006 (N=8500). Community mobilisation and social marketing interventions were initiated in 2011 to reduce underage alcohol supply and demand. The setting is communities in three Australian states (Victoria, Queensland and Western Australia). Students (N=2576) will complete school surveys in year 8 in 2013 (average age 12). Primary outcomes: (1) lifetime initiation and (2) monthly frequency of alcohol use. Reports of social marketing and family and community alcohol supply sources will also be assessed. Point estimates with 95% CIs will be compared for student alcohol use in intervention and control communities. Changes from 2006 to 2013 will be examined; multilevel modelling will assess whether random assignment of communities to the intervention reduced 2013 alcohol use, after accounting for community level differences. Analyses will also assess whether exposure to social marketing activities increased the intervention target of reducing alcohol supply by parents and community members.

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Metal homoeostasis in cyanobacteria is based on uptake and export systems that are controlled by their own regulators. This study characterises the zinc uptake (Znu) system in Nostoc punctiforme. The system was found to comprise of three subunits in an ACB operon: a Zn2+-binding protein (ZnuA18), a transmembrane domain (ZnuB) and an ATPase (ZnuC). These proteins are encoded within the znu operon regulated by a zinc uptake transcription repressor (Zur). Interestingly, a second Zn2+-binding protein (ZnuA08) was also identified at a distal genomic location. Interactions between components of the ZnuACB system were investigated using knockouts of the individual genes. The znuA08-, znuA18-, znuB- and znuC- mutants displayed overall reduced znuACB transcript levels, suggesting that all system components are required for normal expression of znu genes. Zinc uptake assays in the Zn2+-binding protein mutant strains showed that the disruption of znuA18 had a greater negative effect on zinc uptake than disruption of znuA08. Complementation studies in Escherichia coli indicated that both znuA08 and znuA18 were able to restore zinc uptake in a znuA- mutant, with znuA18 permitting the highest zinc uptake rate. The N. punctiforme zur was also able to complement the E. coli zur- mutant.

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To investigate the importance of the glucose transporter GLUT-4 for muscle glucose uptake during exercise, transgenic mice with skeletal muscle GLUT-4 expression approximately 30–60% of normal (CON) and approximately 5–10% of normal (KO) were generated using the Cre/Lox system and compared with wild-type (WT) mice during approximately 40 min of treadmill running (KO: 37.7 ± 1.3 min; WT: 40 min; CON: 40 min, P = 0.18). In WT and CON animals, exercise resulted in an overall increase in muscle glucose uptake. More specifically, glucose uptake was increased in red gastrocnemius of WT mice and in the soleus and red gastrocnemius of CON mice. In contrast, the exercise-induced increase in muscle glucose uptake in all muscles was completely abolished in KO mice. Muscle glucose uptake increased during exercise in both red and white quadriceps of WT mice, while the small increases in CON mice were not statistically significant. In KO mice, there was no change at all in quadriceps muscle glucose uptake. No differences in muscle glycogen use during exercise were observed between any of the groups. However, there was a significant increase in plasma glucose levels after exercise in KO mice. The results of this study demonstrated that a reduction in skeletal muscle GLUT-4 expression to approximately 10% of normal levels completely abolished the exercise-induced increase in muscle glucose uptake.

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The purposes of this study were to provide data on the peak Vo 2 of 12-18-year-old boys from Hong Kong, a densely populated urban environment; to compare these data with those for other similarly aged populations; and to examine the correlations between peak Vo 2 and various anthropometric parameters of this group. A stratified, random sample of 86 ethnic Chinese boys had their peak Vo 2 determined using an on-line gas analysis system during incremental, treadmill running. The mean peak 17o2 of the boys was 2.7 SD 0.44 1- rain - 1 or, when expressed in relation to body mass, 52.0 SD 5-8 ml- kg- 1. min - 1. Peak Vo 2 (1. min - 1) was significantly correlated with body mass (r = 0.72, p < 0.001, age (r = 0.49, p < 0.001) and height (r = 0.71, p = 0-001). Peak Vo 2 (ml 'kg- 1. min- 1) showed no correlation with age or height. These data suggest that this population group has peak Vo 2 values very similar to those observed in boys from most other population groups.

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An institutional electronic portfolio called the "iPortfolio" had over 17,000 subscribers one year after its introduction at an Australian university. This paper reports on a study to determine how students use these "iPortfolio" accounts, and factors leading to uptake and effective use. Self-assessed competence with technology skills, factors motivating uptake, and barriers to adoption were examined using an online survey completed by 554 students. Of these, 339 had an "iPortfolio" at the time they completed the survey. Survey results were examined in the context of usage patterns based on data automatically collected for operational and administrative purposes. No statistically significant difference in prior technology use or self-assessed competence with information technology was observed when comparing students with "iPortfolio" accounts to those without. Assessment was found to be the principal driver of "iPortfolio" uptake. However, about two-fifths (42.9%) of students agreed that they were likely to use the "iPortfolio" in the future, even if it was not a course requirement. An additional 29.6% were neutral. Significant use of the "iPortfolio" to reflect on extracurricular activities was not observed. Improved employability outcomes were seen to be a benefit of "iPortfolio" adoption by about half (52%) of the students. Recommendations are made to promote "iPortfolio" uptake and encourage student reflection on "lifewide" experiences that enhance employability and augment learning within the formal curriculum.

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Monodispersed mesoporous silica nanoparticles (MSNs) of optimal size and configuration were synthesized for uptake by plant organs, tissues and cells. These monodispersed nanoparticles have a size of 20 nm with interconnected pores with an approximate diameter of 2.58 nm.