152 research outputs found

    Silicon micromachined hollow microneedles for transdermal liquid transfer

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    This paper presents an improved design and fabrication process [ 13 for hollow micro needles with the proper mechanical strength and sharpness to be applied for painless transdermal transfer of liquids. Tests have shown that liquids like blood are drawn into the needle by capillary forces, reducing the need for active pumping. The fabrication method allows different needle shapes like blades and pencils, is robust enough to be applied for largerscale production, and enables the development of a complete micro-TAS for e.g. blood analysis

    A micro differential viscosity detector for polymer separation system

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    In this paper we present the first micromachined viscosity detector suitable for coupling to conventional, commercially available polymer separation systems. The μ-viscometer (viscochip) has a reduced dead volume compared to conventional viscometers. It is shown that this results in better chromatographic resolution

    Qualitative Evaluation of Common Quantitative Metrics for Clinical Acceptance of Automatic Segmentation:a Case Study on Heart Contouring from CT Images by Deep Learning Algorithms

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    Organs-at-risk contouring is time consuming and labour intensive. Automation by deep learning algorithms would decrease the workload of radiotherapists and technicians considerably. However, the variety of metrics used for the evaluation of deep learning algorithms make the results of many papers difficult to interpret and compare. In this paper, a qualitative evaluation is done on five established metrics to assess whether their values correlate with clinical usability. A total of 377 CT volumes with heart delineations were randomly selected for training and evaluation. A deep learning algorithm was used to predict the contours of the heart. A total of 101 CT slices from the validation set with the predicted contours were shown to three experienced radiologists. They examined each slice independently whether they would accept or adjust the prediction and if there were (small) mistakes. For each slice, the scores of this qualitative evaluation were then compared with the Sørensen-Dice coefficient (DC), the Hausdorff distance (HD), pixel-wise accuracy, sensitivity and precision. The statistical analysis of the qualitative evaluation and metrics showed a significant correlation. Of the slices with a DC over 0.96 (N = 20) or a 95% HD under 5 voxels (N = 25), no slices were rejected by the readers. Contours with lower DC or higher HD were seen in both rejected and accepted contours. Qualitative evaluation shows that it is difficult to use common quantification metrics as indicator for use in clinic. We might need to change the reporting of quantitative metrics to better reflect clinical acceptance

    Unidirectional relationship between heroin self-administration and impulsive decision-making in rats

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    Rationale: There is growing clinical evidence for a strong relationship between drug addiction and impulsivity. However, it is not fully clear whether impulsivity is a pre-existing trait or a consequence of drug abuse. Recent observations in the animal models show that pre-existing levels of impulsivity predict cocaine and nicotine seeking. Whether such relationships also exist with respect to non-stimulant drugs is largely unknown. Objective: We studied the relationship between impulsive choice and vulnerability to heroin taking and seeking. Materials and methods: Rats were selected in the delayed reward task based on individual differences in impulsive choice. Subsequently, heroin intravenous self-administration behaviour was analysed, including acquisition of heroin intake, motivation, extinction and drug- and cue-induced reinstatement. Throughout the entire experiment, changes in impulsive choice were monitored weekly. Results and discussion: High impulsivity did not predict measures of heroin taking. Moreover, high impulsive rats did not differ from low impulsive rats in extinction rates or heroin- and cue-induced reinstatement. However, both groups became more impulsive as heroin self-administration continued. During abstinence, impulsivity levels returned towards baseline (pre-heroin) levels. Our results indicate that, in contrast to psychostimulants, impulsive choice does not predict vulnerability to heroin seeking and taking. Conclusion: These data implicate that different neural mechanisms may underlie the vulnerability to opiate and psychostimulant dependence. Moreover, our data suggest that elevated impulsivity levels as observed in heroin-dependent subjects are a consequence of heroin intake rather than a pre-existing vulnerability trait. © 2011 The Author(s)

    The COGs (context, object, and goals) in multisensory processing

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    Our understanding of how perception operates in real-world environments has been substantially advanced by studying both multisensory processes and “top-down” control processes influencing sensory processing via activity from higher-order brain areas, such as attention, memory, and expectations. As the two topics have been traditionally studied separately, the mechanisms orchestrating real-world multisensory processing remain unclear. Past work has revealed that the observer’s goals gate the influence of many multisensory processes on brain and behavioural responses, whereas some other multisensory processes might occur independently of these goals. Consequently, other forms of top-down control beyond goal dependence are necessary to explain the full range of multisensory effects currently reported at the brain and the cognitive level. These forms of control include sensitivity to stimulus context as well as the detection of matches (or lack thereof) between a multisensory stimulus and categorical attributes of naturalistic objects (e.g. tools, animals). In this review we discuss and integrate the existing findings that demonstrate the importance of such goal-, object- and context-based top-down control over multisensory processing. We then put forward a few principles emerging from this literature review with respect to the mechanisms underlying multisensory processing and discuss their possible broader implications

    3 year report on activities for the Working Group on Phytoplankton and Microbial Ecology (WGPME)

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    The ICES Working Group on Phytoplankton and Microbial Ecology (WGPME) provides tools and expert perspectives on the sampling methods, ecology and diversity of phytoplankton and other planktonic microbes. The group set out terms of reference to improve access to data, crossdisciplinary approaches and to develop ecological interpretations of the changing phytoplankton seascape. The group published 16 papers between 2019–2021, including key tools, high-profile synthesis papers and science reports. Tools: The group has progressed efforts to collect images of commonly used Lugol’s-preserved phytoplankton, alongside live images to aid those in correctly identifying species. Members have noticed and published records of new phytoplankton species. The group aims to produce a New Records database to assist in notifying new or reoccurrence of a species. WGPME work, with other Expert Groups (EG) to improve access to molecular genetic tools and records. A multi-EG thematic session has been submitted for ICES ASC 2022 in cooperation with other EGs, whilst phytoplankton barcoding information will be incorporated into the Working Group on Integrated Morphological and Molecular Taxonomy (WGIMT) barcoding Atlas (https://metazoogene.org/atlas). Information and access: The group is gathering information on nano and picoplankton (small phytoplankton less than 10 and 2µm respectively) to incorporate into global datasets such as GLOMICON. Multiple data sources point to an increasing trend in picoplankton and few indicators exist in current EU or national legislation to measure their impact on marine ecology. Many members are involved in indicator development for governmental and pan-governmental organisations such as OSPAR. However, the number and level of indicators vary in each country. Long-term ecology: The cooperative zooplankton and phytoplankton report has been delayed but initial analysis has indicated ≥30 years of data reliably shows spatio-temporal trends in phytoplankton and the effects of temperature on key phytoplankton groups. Two research papers are being produced on climate change effects on key marine phytoplankton species with the additional aim of improving indicators of change using species-specific information

    Epidemiology of intra-abdominal infection and sepsis in critically ill patients: “AbSeS”, a multinational observational cohort study and ESICM Trials Group Project

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    Purpose: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). Methods: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. Results: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. Conclusion: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection
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