210 research outputs found

    Text Entry Performance and Situation Awareness of a Joint Optical See-Through Head-Mounted Display and Smartphone System

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    Optical see-through head-mounted displays (OST HMDs) are a popular output medium for mobile Augmented Reality (AR) applications. To date, they lack efficient text entry techniques. Smartphones are a major text entry medium in mobile contexts but attentional demands can contribute to accidents while typing on the go. Mobile multi-display ecologies, such as combined OST HMD-smartphone systems, promise performance and situation awareness benefits over single-device use. We study the joint performance of text entry on mobile phones with text output on optical see-through head-mounted displays. A series of five experiments with a total of 86 participants indicate that, as of today, the challenges in such a joint interactive system outweigh the potential benefits.Comment: To appear in IEEE Transactions on Visualization and Computer Graphics On page(s): 1-17 Print ISSN: 1077-2626 Online ISSN: 1077-262

    Simultaneous pit generation and visualization of pit topography using combined atomic force-scanning electrochemical microscopy

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    Combined atomic force microscopy ā€“ scanning electrochemical microscopy (AFM-SECM) is for the first time used to generate single corrosion pits on passivating iron surfaces in the micrometer range. The AFM-SECM probe locally generates nitric acid during the oxidation of nitrite ions with the release of protons at selected sites on the surface of the otherwise passive metal. High confinement of passive film breakdown is achieved from the combination of a small probe size and the inhibiting properties of non-reacted nitrite ions on the surrounding passivated surface. Simultaneous visualization of pit nucleation and propagation can be obtained in the same solution without changing the probe by AFM

    In situ investigation of copper corrosion in acidic chloride solution using atomic force - scanning electrochemical microscopy

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    The anodic dissolution of pure copper surfaces in acidic chloride solution has been monitored in-situ using combined atomic force ā€“ scanning electrochemical microscopy (AFM-SECM). Here, the initial studies performed on model copper-modified substrates have been extended to the investigation of bulk copper samples used in industrial settings. The local release of Cu2+ ions was monitored through electrochemical reduction and deposition of the metal ions on the conductive frame of the AFM-SECM probe. Simultaneous monitoring of the topographical changes due to the corrosion process allowed the distinction and correlation of local passivation and pitting phenomena. The extent of the attack was estimated by anodic stripping of the copper metal deposited at the probe

    In situ monitoring of pit nucleation and growth at iron passive oxide layer using combined atomic force and scanning electrochemical microscopy

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    Generation of single corrosion pits and in situ monitoring of pit growth on iron exposed to 0.5 M NaCl solution was achieved using combined atomic force - scanning electrochemical microscopy (AFM-SECM). Pits as small as 2.7 Ī¼m in diameter were formed at arbitrary locations on the substrate by local generation of highly concentrated nitric acid in the vicinity of the AFM-SECM probe. Addition of nitrite ions to the environment, which act as corrosion inhibitors for iron, ensures passivation of the metal, and hinders metal corrosion despite exposure to the chloride-containing media. Localized acidification was achieved by oxidizing nitrite ions at the probe. Acidification in combination with the high chloride content in the solution leads to a local rapid attack at the surface and pit generation below the AFM-SECM probe. Besides improved spatial resolution and precise control of the pit nucleation site, combined AFM-SECM allows simultaneous imaging of the generated pits by the AFM tip

    Sigma-1 Receptor Positron Emission Tomography: A New Molecular Imaging Approach Using (S)-(āˆ’)-[18F]Fluspidine in Glioblastoma

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    Glioblastoma multiforme (GBM) is the most devastating primary brain tumour characterised by infiltrative growth and resistance to therapies. According to recent research, the sigma-1 receptor (sig1R), an endoplasmic reticulum chaperone protein, is involved in signaling pathways assumed to control the proliferation of cancer cells and thus could serve as candidate for molecular characterisation of GBM. To test this hypothesis, we used the clinically applied sig1R-ligand (S)-(āˆ’)-[18F]fluspidine in imaging studies in an orthotopic mouse model of GBM (U87-MG) as well as in human GBM tissue. A tumour-specific overexpression of sig1R in the U87-MG model was revealed in vitro by autoradiography. The binding parameters demonstrated target-selective binding according to identical KD values in the tumour area and the contralateral side, but a higher density of sig1R in the tumour. Different kinetic profiles were observed in both areas, with a slower washout in the tumour tissue compared to the contralateral side. The translational relevance of sig1R imaging in oncology is reflected by the autoradiographic detection of tumour-specific expression of sig1R in samples obtained from patients with glioblastoma. Thus, the herein presented data support further research on sig1R in neuro-oncology

    Sigma-1 receptor positron emission tomography: A new molecular imaging approach using (S)-(-)-[18F]fluspidine in glioblastoma

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    Glioblastoma multiforme (GBM) is the most devastating primary brain tumour characterised by infiltrative growth and resistance to therapies. According to recent research, the sigma-1 receptor (sig1R), an endoplasmic reticulum chaperone protein, is involved in signaling pathways assumed to control the proliferation of cancer cells and thus could serve as candidate for molecular characterisation of GBM. To test this hypothesis, we used the clinically applied sig1R-ligand (S)-(āˆ’)-[18F]fluspidine in imaging studies in an orthotopic mouse model of GBM (U87-MG) as well as in human GBM tissue. A tumour-specific overexpression of sig1R in the U87-MG model was revealed in vitro by autoradiography. The binding parameters demonstrated target-selective binding according to identical KD values in the tumour area and the contralateral side, but a higher density of sig1R in the tumour. Different kinetic profiles were observed in both areas, with a slower washout in the tumour tissue compared to the contralateral side. The translational relevance of sig1R imaging in oncology is reflected by the autoradiographic detection of tumour-specific expression of sig1R in samples obtained from patients with glioblastoma. Thus, the herein presented data support further research on sig1R in neuro-oncology

    Preclinical Incorporation Dosimetry of [18F]FACHā€”A Novel 18F-Labeled MCT1/MCT4 Lactate Transporter Inhibitor for Imaging Cancer Metabolism with PET

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    Overexpression of monocarboxylate transporters (MCTs) has been shown for a variety of human cancers (e.g., colon, brain, breast, and kidney) and inhibition resulted in intracellular lactate accumulation, acidosis, and cell death. Thus, MCTs are promising targets to investigate tumor cancer metabolism with positron emission tomography (PET). Here, the organ doses (ODs) and the effective dose (ED) of the first 18F-labeled MCT1/MCT4 inhibitor were estimated in juvenile pigs. Whole-body dosimetry was performed in three piglets (age: ~6 weeks, weight: ~13ā€“15 kg). The animals were anesthetized and subjected to sequential hybrid Positron Emission Tomography and Computed Tomography (PET/CT) up to 5 h after an intravenous (iv) injection of 156 Ā± 54 MBq [18F]FACH. All relevant organs were defined by volumes of interest. Exponential curves were fitted to the timeā€“activity data. Time and mass scales were adapted to the human order of magnitude and the ODs calculated using the ICRP 89 adult male phantom with OLINDA 2.1. The ED was calculated using tissue weighting factors as published in Publication 103 of the International Commission of Radiation Protection (ICRP103). The highest organ dose was received by the urinary bladder (62.6 Ā± 28.9 ĀµSv/MBq), followed by the gall bladder (50.4 Ā± 37.5 ĀµSv/MBq) and the pancreas (30.5 Ā± 27.3 ĀµSv/MBq). The highest contribution to the ED was by the urinary bladder (2.5 Ā± 1.1 ĀµSv/MBq), followed by the red marrow (1.7 Ā± 0.3 ĀµSv/MBq) and the stomach (1.3 Ā± 0.4 ĀµSv/MBq). According to this preclinical analysis, the ED to humans is 12.4 ĀµSv/MBq when applying the ICRP103 tissue weighting factors. Taking into account that preclinical dosimetry underestimates the dose to humans by up to 40%, the conversion factor applied for estimation of the ED to humans would rise to 20.6 ĀµSv/MBq. In this case, the ED to humans upon an iv application of ~300 MBq [18F]FACH would be about 6.2 mSv. This risk assessment encourages the translation of [18F]FACH into clinical study phases and the further investigation of its potential as a clinical tool for cancer imaging with PET

    Activation of Ventral Tegmental Area 5-HT2C Receptors Reduces Incentive Motivation

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    FUNDING AND DISCLOSURE The research was funded by Wellcome Trust (WT098012) to LKH; and National Institute of Health (DK056731) and the Marilyn H. Vincent Foundation to MGM. The University of Michigan Transgenic Core facility is partially supported by the NIH-funded University of Michigan Center for Gastrointestinal Research (DK034933). The remaining authors declare no conflict of interest. ACKNOWLEDGMENTS We thank Dr Celine Cansell, Ms Raffaella Chianese and the staff of the Medical Research Facility for technical assistance. We thank Dr Vladimir OrduƱa for the scientific advice and technical assistance.Peer reviewedPublisher PD

    Adenosine/A2B receptor signaling ameliorates the effects of ageing and counteracts obesity

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    The combination of aging populations with the obesity pandemic results in an alarming rise in non-communicable diseases. Here, we show that the enigmatic adenosine A2B receptor (A2B) is abundantly expressed in skeletal muscle (SKM) as well as brown adipose tissue (BAT) and might be targeted to counteract age-related muscle atrophy (sarcopenia) as well as obesity. Mice with SKM-specific deletion of A2B exhibited sarcopenia, diminished muscle strength, and reduced energy expenditure (EE), whereas pharmacological A2B activation counteracted these processes. Adipose tissue-specific ablation of A2B exacerbated age-related processes and reduced BAT EE, whereas A2B stimulation ameliorated obesity. In humans, A2B expression correlated with EE in SKM, BAT activity, and abundance of thermogenic adipocytes in white fat. Moreover, A2B agonist treatment increased EE from human adipocytes, myocytes, and muscle explants. Mechanistically, A2B forms heterodimers required for adenosine signaling. Overall, adenosine/A2B signaling links muscle and BAT and has both anti-aging and anti-obesity potential

    Wired for Her Face? Male Attentional Bias for Female Faces

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    Under conditions of inattention or deficits in orienting attention, special classes of stimuli (e.g. faces, bodies) are more likely to be perceived than other stimuli. This suggests that biologically salient visual stimuli automatically recruit attention, even when they are task-irrelevant or ignored. Here we report results from a behavioral experiment with female and male subjects and two magnetoencephalography (MEG) experiments with male subjects only, in which we investigated attentional capture with face and hand stimuli. In both the behavioral and MEG experiments, subjects were required to count the number of gender-specific targets from either face or hand categories within a block of stimuli. In the behavioral experiment, we found that male subjects were significantly more accurate in response to female than male face target blocks. There was no corresponding effect found in response to hand target blocks. Female subjects did not show a gender-based difference in response to face or hand target blocks. MEG results indicated that the male subjectsā€™ responses to face stimuli in primary visual cortex (V1) and the face-selective part of the fusiform gyrus (FG) were reduced when male face stimuli were not relevant to the task, whereas female faces maintained a strong response in these areas in both task-relevant and task-irrelevant conditions. These results suggest that within the male brain, female face stimuli are more resilient to suppression than male faces, once attention is drawn to the part of the visual field where the face appears
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