1,636 research outputs found

    Grazing-incidence small-angle X-ray scattering studies on templating nanopores in networked polymer thin films with a multi-armed porogen

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    The mechanism of thermal pore generation in organosilicate thin films loaded with a six-armed star-shaped poly(epsilon-caprolactone) porogen was quantitatively investigated by using in-situ grazing-incidence small-angle X-ray scattering and thermogravimetry. These analyses found that the blend components have a limited miscibility that depends on the compositionfor porogen loadings up to only 20 wt%, molecularly miscible blend films were obtained. Even for the miscible blend films, heating the films produced a curing reaction of the precursor matrix component, leading to the phase separation of the porogen component. This phase separation was found to begin at 393 K for 10 wt% porogen loaded films and at 373 K for 20 wt% porogen loaded films, and to continue for temperatures up to 423 K. The porogen aggregates remained and were confined within the matrix film without any further growth or movement until complete thermal decomposition above 564 K.ope

    Iron content in forage sorghum (Sorghum bicolor (L.) Moench) measured on different slit widths with atomic absorption spectrometry

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    Our objective was to know the right slit width for iron (Fe) concentration of forage sorghum, sorghum hybrid (Sorghum bicolor (L.) Moench), and also to discern which water treatment sludge (WTS) were good for ruminant's health with the feeding sorghum on the present study. The present experiment was carried out on a randomized block design with four treatments; Control, alum sludge compost, alum sludge + NPK (nitrogen, phosphorus, potassium fertilizers), alum sludge compost + NPK (nitrogen, phosphorus, potassium fertilizers). Sorghum hybrid was harvested, and iron content of it was analyzed with an atomic absorption spectrophotometer on background correction (BGC) mode. In order to analyze the iron (Fe) content of the sorghum with the spectrophotometer, three different slit widths conditions were used; 0.15, 0.20 and 0.25 nm. Absorbance and background values were obtained during the Fe analyses with the apparatus. When the background value is small, it is preferred for some trace metals’ analyses. Both (AM/BS) ratio (mean of the absorbance values<AM> to the standard deviation of back ground values<BS>) and (AS<standard deviation of the absorbance values>/BS) ratio, were larger on 0.25 nm slit than those on 0.15 and 0.20 nm slit, and, from our experiment, the condition seemed better on the 0.25 nm slit for the iron analysis with the spectrophotometer. Therefore, the sorghum hybrid grown on (Alum+NPK) and on (Compost only) might be dangerous for ruminants because of their higher values than 200 mg Fe/kg DM (dry matter).Key words: Absorbance, alum sludge, atomic absorption spectrophotometer, background, forage sorghum hybrid, iron, slit

    A Study of Problem Solving Using Blocks Vehicle in a STEAM Course for Lower Elementary Levels

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    STEAM education is currently one of the most important parts of the elementary school curriculum. If STEAM learning can cultivate good problem-solving ability, it will also help improve judgment and thinking abilities. Several voices in the literature have argued for cooperative learning in STEAM courses. Although the effectiveness of course learning often is evaluated using course feedback forms, there is comparatively little emphasis on whether a course succeeds in realizing cooperative learning. For a course involving self-propelled toy-brick cars, there is little research on the application of low-grade pupils. Therefore, based on the integration of STEAM courses into self-propelled toy-brick car learning, this study applied two learning strategies of cooperative learning and individual learning to low-grade pupils in the second grade in elementary schools. After completing the course problem-solving ability indicators were measured and analyzed using the problem-solving ability test. The results show that the mean score of the experimental group in the problem-solving ability test was higher than that of the control group. In the problem-solving ability test, the scores of the two groups were also significantly different, which suggests that cooperative learning is more effective than individual learning strategies.acceptedVersio

    Nasal-type NK/T cell lymphoma: clinical features and treatment outcome

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    Nasal-type NK/T cell lymphoma is an increasingly recognised disease entity of aggressive clinical behaviour. The objective of this study was to investigate clinical features and treatment outcomes in patients with nasal-type NK/T cell lymphoma. From January 1991 to December 2003, 26 patients diagnosed as nasal-type NK/T cell lymphoma were included in the analysis. One half of patients presented with poor performance status (ECOG ⩾2); 46% of patients were categorised as high intermediate or high-risk group according to IPI; and 46% of patients were diagnosed at advanced stage. The median survival for 26 patients with nasal-type NK/T cell lymphoma was 7.4 months (95% CI, 0.1, 16.9). The treatment outcome of primary anthracycline-based chemotherapy was poor: 60% CR rate in localised disease and 0% CR rate in advanced disease. After a median follow-up of 24.4 months (range 3.1–99.0) in patients with localised disease who had achieved a CR (range 29.6–165.7), three patients (50.0%) developed disease recurrence at 6.1, 21.8, and 52.1 months, respectively, and all patients presented with locoregional failure. The predictive factors for poor survival were of age greater than 60, advanced stage and poor performance in multivariate analysis. In conclusion, Nasal-type NK/T cell lymphomas showed a poor response to the conventional anthracycline-based chemotherapy, and thus an investigation for an innovative therapy is urgently needed to improve survival in these patients

    The 'Harmonizing Optimal Strategy for Treatment of coronary artery stenosis - sAfety & effectiveneSS of drug-elUting stents & antiplatelet REgimen' (HOST-ASSURE) trial: study protocol for a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Second-generation drug-eluting stents (DES) have raised the bar of clinical performance. These stents are mostly made from cobalt chromium alloy. A newer generation DES has been developed from platinum chromium alloy, but clinical data regarding the efficacy and safety of the platinum chromium-based everolimus-eluting stent (PtCr-EES) is limited, with no comparison data against the cobalt chromium-based zotarolimus-eluting stent (CoCr-ZES). In addition, an antiplatelet regimen is an integral component of medical therapy after percutaneous coronary intervention (PCI). A 1-week duration of doubling the dose of clopidogrel (double-dose antiplatelet therapy (DDAT)) was shown to improve outcome at 1 month compared with conventional dose in acute coronary syndrome (ACS) patients undergoing PCI. However in Asia, including Korea, the addition of cilostazol (triplet antiplatelet therapy (TAT)) is used more commonly than doubling the dose of clopidogrel in high-risk patients.</p> <p>Methods</p> <p>In the 'Harmonizing Optimal Strategy for Treatment of coronary artery stenosis - sAfety & effectiveneSS of drug-elUting stents & antiplatelet REgimen' (HOST-ASSURE) trial, approximately 3,750 patients are being prospectively and randomly assigned in a 2 × 2 factorial design according to the type of stent (PtCr-EES vs CoCr-ZES) and antiplatelet regimen (TAT vs DDAT). The first primary endpoint is target lesion failure at 1 year for the stent comparison, and the second primary endpoint is net clinical outcome at 1 month for comparison of antiplatelet therapy regimen.</p> <p>Discussion</p> <p>The HOST-ASSURE trial is the largest study yet performed to directly compare the efficacy and safety of the PtCr-EES versus CoCr-ZES in an 'all-comers' population. In addition, this study will also compare the clinical outcome of TAT versus DDAT for 1-month post PCI.</p> <p>Trial registration</p> <p>ClincalTrials.gov number <a href="http://www.clinicaltrials.gov/ct2/show/NCT01267734">NCT01267734</a>.</p

    Strong constraints from COSINE-100 on the DAMA dark matter results using the same sodium iodide target

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    We present new constraints on dark matter interactions using 1.7 years of COSINE-100 data. The COSINE-100 experiment, consisting of 106 kg of tallium-doped sodium iodide [NaI(Tl)] target material, is aimed to test DAMA’s claim of dark matter observation using the same NaI(Tl) detectors. Improved event selection requirements, a more precise understanding of the detector background, and the use of a larger dataset considerably enhance the COSINE-100 sensitivity for dark matter detection. No signal consistent with the dark matter interaction is identified and rules out model-dependent dark matter interpretations of the DAMA signals in the specific context of standard halo model with the same NaI(Tl) target for various interaction hypotheses

    Searching for low-mass dark matter via the Migdal effect in COSINE-100

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    We report on the search for weakly interacting massive particle (WIMP) dark matter candidates in the galactic halo that interact with sodium and iodine nuclei in the COSINE-100 experiment and produce energetic electrons that accompany recoil nuclei via the the Migdal effect. The WIMP mass sensitivity of previous COSINE-100 searches that relied on the detection of ionization signals produced by target nuclei recoiling from elastic WIMP-nucleus scattering was restricted to WIMP masses above ∟5 GeV/c2 by the detectors' 1 keVee energy-electron-equivalent threshold. The search reported here looks for recoil signals enhanced by the Migdal electrons that are ejected during the scattering process. This is particularly effective for the detection of low-mass WIMP scattering from the crystals' sodium nuclei in which a relatively larger fraction of the WIMP's energy is transferred to the nucleus recoil energy and the excitation of its orbital electrons. In this analysis, the low-mass WIMP search window of the COSINE-100 experiment is extended to WIMP mass down to 200 MeV/c2. The low-mass WIMP sensitivity will be further improved by lowering the analysis threshold based on a multivariable analysis technique. We consider the influence of these improvements and recent developments in detector performance to re-evaluate sensitivities for the future COSINE-200 experiment. With a 0.2 keVee analysis threshold and high light-yield NaI(Tl) detectors (22 photoelectrons/keVee), the COSINE-200 experiment can explore low-mass WIMPs down to 20 MeV/c2 and probe previously unexplored regions of parameter space
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