458 research outputs found

    Apparatus for measuring thermal conductivity Patent

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    Development of apparatus for measuring thermal conductivit

    Low-level gas multicounter for C-14 dating of small samples: Electronic, numerical and shielding optimisation

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    Up to 14 methane samples can be dated simultaneously in our compact gas multicounter. Sample detectors are 10 ml (NTP) in volume each. They are made of copper and linked to form two 7 detector rigid assemblies which are filled in situ. Monitoring of the counting conditions is enabled through multichannel analysis of the cosmic pulse height spectrum, which shows the changes in gas amplification due to impurities or leakage. HV is set (and adjusted) automatically using the cosmic peak. All individual events are stored on disc, including pulse height (PH), risetime (RT) (both 256 Ch), time of arrival (TA), detector identification, anticoincidence status and elapsed and live time. Software programs analyse and validate data. Numerical discrimination and manipulations of counting parameters can be performed without destroying the original data set. Statistical quality control is based on chi-square and Poisson distribution of count rates around their mean in user defined energy regions as weil as time of arrival of pulses mode. TA analysis offers the user an early means for recognizing some types of system malfunction that otherwise might remain undetected for Jong periods of time. RT analysis is used to discriminate sample beta pulses from environmental radiation pulses, resulting in a low background with compact and relat ively inexpensive shielding. The automatic high voltage setting, PH, RT and TA electronics as weil as the liquid scintillation anticoincidence systems are applicable to all existing gas counting systems. Delivery of the gas multicounter to the Australian National University is to take place at the end of the year 1984

    Low-level liquid scintillation spectrometer for ß-counting

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    A new liquid scintillation (LS) spectrometer has been developed. lt improves the signal to noise ratio of C-14 assays by an order of magnitude compared to conventional LS systems. As a result, precision for a modern sample is 0.2 % and the dating limit is 64 Ky BP for a 15 ml sample of benzene. Sophisticated MCA facilities allow the use of Multiparameter Multichannel Analysis for data validation and age evaluation. Despite the high sophistication, the spectrometer, (named QUANTULUS) is seif contained, microprocessor controlled and user friendly. lt can be used with full advantage in a normal laboratory environment

    Molecular Differentiation of Mycobacterium tuberculosis Strains without IS6110 Insertions

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    By using standard restriction fragment length polymorphism, 6 zero-copy IS6110 Mycobacterium tuberculosis isolates were identified from 1,180 Maryland isolates as part of the National Tuberculosis Genotyping Surveillance Network Project. By using various genotyping methods, we demonstrated that this zero band cluster can be differentiated into six genotypes

    High Intake of Nonmilk Extrinsic Sugars Is Associated With Protein and Micronutrient Dilution in Home-Dwelling and Institutionalized Older People

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    Background: High dietary sugar intake may compromise protein and micronutrient intakes in people with low energy intakes. The results of micronutrient dilution studies in older people have been few and conflicting. We examined the nutritional status and nutrient intakes associated with nonmilk extrinsic sugars (NMES) intakes in older people representing a broad spectrum of both healthy and vulnerable older populations. Design and participants: This cross-sectional study combined five Finnish data sets covering homedwelling (n = 526) and institutionalized (n = 374) older people. Their nutritional status was assessed using Mini Nutritional Assessment (MNA) and nutrient intakes retrieved from 1- to 3-day food records. The participants were divided into quartiles corresponding to the proportions of energy received from NMES. Energy, nutrient, and fiber intakes were classified according to the NMES quartiles, and the participants were divided according to their places of residence (home, institution). Results: High NMES intakes were associated with older age, female sex, poor cognition, low MNA scores, immobility, and institutionalization. In all, 90% of the participants in the highest NMES quartile (Q4) were institutionalized. In the institutionalized individuals, low protein and micronutrient intakes were observed in both those with low energy intake (Q1) and in those with very high NMES intakes (Q4). In home-dwelling individuals, the nutrient intakes tended to decline linearly with increasing NMES intakes in protein and most micronutrients. Conclusions: Institutionalized older people consumed diets high in NMES, compared with those living at home, and their low energy and high NMES intakes were associated with low protein and micronutrient intakes. (C) 2016 AMDA - The Society for Post-Acute and Long-Term Care Medicine.Peer reviewe

    Molecular Typing of Mycobacterium tuberculosis Strains with a Common Two-Band IS6110 Pattern

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    We conducted a population-based molecular typing of all Mycobacterium tuberculosis isolates obtained in Alabama since 1994. Of 2,452 isolates, 1,013 (41%) had fewer than 6 bands of IS6110; 348 (14%) had a single two-band pattern (JH2). With conventional epidemiologic methods, we identified three groups of related patients with JH2 isolates. Spoligotyping and pattern of variable number of tandem repeats identified 10 molecular groups; two found by conventional methods were subdivided

    A Potential Biofilm Metabolite Signature for Caries Activity - A Pilot Clinical Study

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    BACKGROUND: This study's aim was to compare the dental biofilm metabolite-profile of caries-active (N=11) or caries-free (N=4) children by gas chromatography-mass spectrometry (GC/MS) analyses. METHODS: Samples collected after overnight fasting, with or without a previous glucose rinse, were combined for each child based on the caries status of the site, re-suspended in ethanol and analyzed by GC/MS. RESULTS: Biofilm from caries-active sites exhibited a different chromatographic profile compared to caries-free sites. Qualitative and quantitative analysis suggested a special cluster of branched alcohols and esters present at substantially higher intensity in biofilms of caries-active sites. CONCLUSIONS: This pilot study indicates that there are metabolites present in the biofilm which have the potential to provide a characteristic metabolomics signature for caries activity

    Laboratory-based surveillance of COVID-19 in the Greater Helsinki area, Finland, February-June 2020

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    Objectives: The aim was to characterise age-and sex-specific severe acute respiratory syndrome coronavirus disease-2 (SARS-CoV-2) RT-PCR sampling frequency and positivity rate in Greater Helsinki area in Finland during February & ndash;June 2020. We also describe the laboratory capacity building for these diagnostics. Methods: Laboratory registry data for altogether 80,791 specimens from 70,517 individuals was analysed. The data included the date of sampling, sex, age and the SARS-CoV-2 RT-PCR test result on specimens collected between 1 February and 15 June 2020. Results: Altogether, 4057/80,791 (5.0%) of the specimens were positive and 3915/70,517 (5.6%) of the individuals were found positive. In all, 37% of specimens were from male and 67% from female subjects. While the number of positive cases was similar in male and female subjects, the positivity rate was significantly higher in male subjects: 7.5% of male and 4.4% of female subjects tested positive. The highest incidence/100,000 was observed in those aged >80 years. The proportion of young adults in positive cases increased in late May 2020. Large dips in testing frequency were observed during every weekend and also during public holidays. Conclusions: Our data suggest that men pursue SARS-CoV-2 testing less frequently than women. Consequently, a subset of coronavirus disease-2019 infections in men may have gone undetected. People sought testing less frequently on weekends and public holidays, and this may also lead to missing of positive cases. The proportion of young adults in positive cases increased towards the end of the study period, which may suggest their returning back to social behaviour with an increased risk of infection. (c) 2020 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-ncnd/4.0/).Peer reviewe
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