Early Stages Of Uptake Research Articles

Growth and phosphate uptake of microalgae under different phosphate conditions

Microalgae could utilize the nutrients in the environment and therefore are widely used in wastewater treatment. The variety and complexity of phosphates in the water column and different types of wastewater can affect the growth of microalgae, which further affects the treatment efficiency of phosphorus- containing wastewater. In this study, phosphate uptake and microalgal growth were investigated under different phosphate conditions. The results showed that the increase of phosphate concentration could promote the growth of microalgae. Phosphate species affected the phosphate uptake and transformation process. Orthophosphate and polyphosphate were first adsorbed on the surface of microalgae and then transported inside the cell. Polyphosphates produce desorption in the early stages of uptake. The adsorbed polyphosphates were released back into the culture medium and were taken up and utilized again in the later stages of incubation. Polyphosphates were taken up and utilized by microalgae for a longer period of time than orthophosphates. It was also found that orthophosphate was more readily utilized by microalgae compared to polyphosphate. An increase in phosphate concentration promotes the growth of microalgae.

Abstract 211: A novel FRET assay for the intracellular activation of ADC linkers

Abstract Evaluating the intracellular activation of ADC by a novel FRET assay. Despite the recent success of ADCs as cancer therapeutics, their mechanisms of action are not fully understood. In this study, we developed ADCs using a novel fluorescence resonance energy transfer (FRET) linker in order to facilitate monitoring the details of intracellular uptake, vesicular trafficking and payload release. In the FRET linker, the cathepsin-cleavable dipeptide of val-cit was inserted between a fluorescence donor Alexa Fluor 488 (or later, fluorescein) and an acceptor tetramethylrhodamine (TAMRA). Upon cleavage of the val-cit linker, a fluorescence signal from Alexa Fluor 488 or fluorescein is expected to appear as a probe for monitoring intracellular activation of ADC. We used two in-vitro human cancer cell lines, SKBR3 and PC3. SKBR3 is a Her2-positive breast cancer cell line and PC3 is a prostate cancer cell line that has been engineered to express a prostate cancer-specific growth factor receptor, tomoregulin-2 (TenB2). We assessed the intracellular processing of the FRET conjugates using flow cytometry. We found that 74% and 41% of the linker was cleaved in PC3 and SKBR3 cells after 20 hours of treatment, respectively. In the live-celling imaging of the FRET probe in SKBR3 and PC3 cells, Anti-Her2 and TenB2 FRET ADCs showed a remarkable difference of internalization pathways and cleavage following receptor-mediated endocytosis. In PC3 cells, FRET ADCs were internalized and congregated into a certain localized area during the early stage of uptake in 2 to 3 hours. The ADC-containing vesicles were spread over the cytosol and near the plasma membrane in a subset of cells. A similar directed localization at the early stage of uptake was not observed for the SKBR3 cells. The endosomal vesicles in SKBR3s were spread over the cytosol during the course of ADC internalization. The amount of the release payload in the cytosol of SKBR3s was 3-fold greater than that of PC3 cells, suggesting that the endosomal/lysosomal membrane of SKBR3 may be more permeable than that of PC3. In summary, our ADC FRET probes allowed for the facile, robust and non-invasive evaluation of intracellular processing for ADC linkers. Quantitative measurements for the rate of antigen-mediated intracellular cleavage of the FRET linker as well as cytosolic release could be evaluated by our FRET probes. Citation Format: Byoung-Chul Lee, Cecile Chalouni, Sam Nalle, Sophia Doll, Martine Darwish, Ira Mellman, Richard Vandlen. A novel FRET assay for the intracellular activation of ADC linkers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 211. doi:10.1158/1538-7445.AM2015-211

Systematic reviews on child welfare services: identifying and disseminating the evidence.

Rationale, aims and objectivesEvidence‐based practice is at an early stage of uptake within child welfare services. To facilitate well‐informed decisions, we disseminated evidence from systematic reviews (SR) to local child welfare stakeholders in Norway through plain language summaries on a website (http://www.r‐bup.no).MethodWe developed and implemented our dissemination strategy through seven steps: (1) systematic literature search; (2) selection of relevant SRs; (3) assembly of an advisory board; (4) selection of child welfare SRs relevant to Norway; (5) prioritization of the included SRs; (6) development of a plain language summary (PLS) after feedback from the advisory board; and (7) implementation of website.ResultsA total of 9266 potentially relevant records were screened and 120 SRs were included. The advisory board was assembled from local policymakers, practitioners, researchers, carers and consumers. The advisory board members independently ranked the 120 SRs according to relevance and prioritized 20 SRs that were written up into the PLS. The format of the PLS was tested and agreed with the board members. A website was developed and the PLSs were published starting September 2014.ConclusionWe think that the PLSs will be valuable resources to practitioners and it will be easily accessible to caregivers and consumers. This knowledge will inform research priorities and practice in Norway, leading the way to the use of evidence‐based decisions in local child welfare services.

Building a Facebook Strategy: Some Insights From Australian Accommodation Small Tourism Enterprises (STEs)

Social media has become a major information platform allowing businesses to engage with tourists. Small Tourism Enterprises (STEs) have commenced using social media for tourism purposes by maintaining a brand page on Facebook. The literature on Facebook adoption by STEs is expanding but limited, especially the discussion around building Facebook presence and strategy. Indeed, Facebook use by STEs is at an early stage of uptake hence the early adopters of this relatively new phenomenon can provide important insights regarding their Facebook use and strategy. The article examines separate case studies of eight Australian accommodation STEs and reports insights into Facebook use and implementation. Notably, even with early adopters, a pre-planned Facebook strategy was found to be poorly understood and in many instances had not been developed and implemented appropriately. Although focused on Australia, the findings have the potential to be related to small tourism operators in other countries.

The strength model of self-regulation failure and health-related behaviour

Successful self-regulation is associated with adherence to health-related behaviour in many domains. In contrast, self-regulatory failure is linked to poor adherence and drop-out. This review presents the strength model of self-control as a framework to explain self-regulation in health-related behaviour contexts. In the model, self-regulation is conceptualised as a limited resource that once depleted results in reduced capacity to further regulate the self. We provide an overview of the hypotheses of the strength model and review research applying the model to self-regulation in four health-related behaviour domains: dietary restraint and eating behaviour, alcohol consumption, smoking cessation and physical activity. Based on our review, we recommend practitioners adopt strategies to minimise self-regulatory failure in people engaging in health-related behaviours such as minimising demands on self-control resources in the early stages of uptake and eating regularly to prevent hypoglycaemia. We advocate techniques to improve self-control strength through rest and training on self-control tasks. Suggestions on how these techniques can be integrated into health-related behaviour-change interventions are provided. Recommendations for future research to identify the mechanisms underpinning self-control resource depletion, conduct further randomised controlled interventions using the model, and integrate strength model hypotheses into existing models of health-related behaviour are proposed.

Uptake of trifluralin and lindane from water by ryegrass

Understanding of the plant uptake of organic chemicals is essential to assessing contaminant mobility in the ecosystem, exposure to humans, and phytoremediation technologies. In this study, we measured the uptake of trifluralin and lindane from water by ryegrass as a function of uptake time for periods of 96 and 120 h, respectively. Trifluralin concentration in ryegrass increased sharply at the early stage of uptake and reached the maximum at 10 h, and then decreased with uptake time. 14C-labelled trifluralin uptake displayed a similar trend but a higher 14C-concentration than that of extracted parent compound, indicating metabolism and formation of bound residues following trifluralin uptake. Lindane concentration in ryegrass slowly increased with uptake time and approached a plateau, indicating minimal metabolism and formation of bound residues. The difference in the uptake characteristics of these two chemicals may be related to the differences in their lipophilicity, and chemical and biological reactivities. A two-compartment model accounting for the contributions of transpiration, metabolism and formation of bound residues to overall uptake was developed to assess the uptake kinetics. The model adequately described the uptake of trifluralin and lindane into ryegrass by providing the first-order rate constants of uptake, release, transpiration, and metabolism and formation of bound residues. These rate constants are used in calculating plant concentration factor (PCF). The ratios of trifluralin concentrations in ryegrass to its aqueous concentrations are between the PCF at thermodynamic equilibrium and the PCF at steady state, suggesting the utility of both PCF values.

Characterization of the cerebral distribution of general anesthetics in vivo by two-dimensional 19F chemical shift imaging.

The distribution of two fluorinated anesthetics, halothane and isoflurane, in rabbit brain was mapped during the course of their uptake using 19F NMR chemical shift imaging techniques. Use of a short phase-encoding time and free induction decay acquisition minimized T2-related signal losses in two-dimensional chemical shift imaging. Localization of the brain and exclusion of surrounding tissues was achieved by the use of a surface coil. The spatial distribution of halothane and isoflurane in the brain was nonuniform and both anesthetics were detected predominantly in the cerebral cortex. During the early stages of uptake, anesthetic concentration in the brain was extremely low, but it continued to increase for several hours with sustained anesthetic delivery. Time-dependent variations in anesthetic concentration were observed in different brain regions.

Characteristics of electronically desorbed negative ions from CO on Rh(111)

ESD of negative ions has been examined from the CO/Rh(111) system. The desorption yield of O − exhibits a behavior which is distinctly different from that observed for O + and CO +. Delayed onset of O − is observed in the early stages of uptake. Near saturation little decrease is observed, indicating that the resonance charge exchange process is not very effective in negative ion neutralization. The desorption energy of O − was observed to reflect the CO adsorbate structural change which occurs near 1 L CO exposure on the Rh(111) surface. An abrupt shift to higher desorption energy was observed at the exposure necessary to produce filling of bridge-bonded sites.

Characteristics of electronically desorbed negative ions from CO on Rh(111)

ESD of negative ions has been examined from the CO/Rh(111) system. The desorption yield of O − exhibits a behavior which is distinctly different from that observed for O + and CO +. Delayed onset of O − is observed in the early stages of uptake. Near saturation little decrease is observed, indicating that the resonance charge exchange process is not very effective in negative ion neutralization. The desorption energy of O + was observed to reflect the CO adsorbate structural change which occurs near 1 L CO exposure on the Rh(111) surface. An abrupt shift to higher desorption energy was observed at the exposure necessary to produce filling of bridge-bonded sites.

Early stages of uptake and transport of horseradish-peroxidase by cortical structures, and its use for the study of local neurons and their processes.

AbstractIt is well known that, when horseradish‐peroxidase (HRP) is injected into the central nervous system, it is taken up by nerve terminals and retrogradely transported to their cells of origin. We have now injected HRP into the visual cortex of cats in order to study light‐microscopically the pattern of its spread, the neural structures that take it up locally, and the initial steps of its retrograde descent towards the dorsal lateral geniculate nucleus (LGNd). Special attention was given to post‐injection times of ten minutes to eight hours, but animals with up tofive days' survival were also analyzed.It was found that the brown spot produced by the initial spread (primary diffusion) of HRP remains constant in size for about two hours and then spreads out (secondary diffusion) to involve neighboring visual cortical areas. Secondary diffusion, however, does not result in further retrograde labelling of LGNd neurons. Local nervous structures labelled during primary diffusion of HRP include a large number of infracortical axons, many of which show bifurcations directed towards the cortex. As HRP descends within these axons, fewer and deeper axonal branchings appear labelled, as though, after initial uptake, HRP were no longer taken up. The possible reasons for the lack of further HRP uptake, including observed local inflammatory reactions, are discussed. Intracortical labelled structures include neuron somata and processes. These resemble Golgi‐impregnated structures and, particularly at short survival times, show fine details such as dendritic spine necks, terminal bouton stalks, synaptic contacts, and a remarkable degree of axonal preterminal and terminal branching. Some of these structures were also examined electron‐microscopically.