1,388 research outputs found

    The Role of Digital-Media-Based Pedagogical Aids in Elementary Entomology: An Innovative and Sustainable Approach

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    It has been challenging for city school pupils to learn about insects, given the lack of live insects. To overcome this challenge, the objective of this study is to propose the use of emerging digital media, namely three-dimensional printing (3DP) technologies, to create reusable, fake, “live” insects. In this study, we designed two 3D-printed pedagogical aids to support elementary entomology. The first aid was a set of cards showing photos of the 3D-printed insect prototype, which could help the learners in close observation of the insect body’s regions and parts, and the second 3D-printed aid was a construction kit mimicking physical insects, which were made of an enlarged 3D-printed insect prototype. The two aids were used in our field experiment to examine the effectiveness in learning and motivation. A total of 153 pupils were grouped into three groups (one using the existing multimedia e-book, one using the first 3DP aid, and one using the second aid). The results confirm that the digital media application—in this case, 3DP technologies—were able to compensate for the lack of the live insects. These results raised our confidence in using a customized size 3D-printed insect prototype to enhance rudimentary entomology inside the classroom. If the 3DP technologies are used properly, they could offer an innovative and sustainable solution

    Variability of the giant X-ray bump in GRB 121027A and possible origin

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    The particular giant X-ray bump of GRB 121027A triggered by \emph{Swift} is quite different from the typical X-ray flares in gamma-ray bursts. There exhibit four parts of the observed structural variabilities in the rise and decay phase of the bump. Considering the quality of four parts of the data, we can only analyze the data from about 5300 s to about 6100 s in the bump using the stepwise filter correlation method (Gao et al. 2012), and find that the 869.4+5.9 s86^{+5.9}_{-9.4}~\rm s periodic oscillation may exist, which is confirmed by the Lomb-Scargle method (Scargle 1982). Furthermore, a jet precession model (Liu et al. 2010) is proposed to account for such a variability.Comment: 5 pages, 3 figures, accepted for publication in MNRA

    Capacitive coupling study of the HERD SCD prototype: preliminary results

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    The Silicon Charge Detector (SCD) is a subdetector of the High Energy Cosmic Radiation Detection payload. The dynamic range of the silicon microstrip detector can be extended by the capacitive coupling effect, which is related to the interstrip capacitance and the coupling capacitance. A detector prototype with several sets of parameters was designed and tested in the ion beams at the CERN Super Proton Synchrotron. The capacitive coupling fractions with readout strip and floating strip incidences were studied using the beam test data and SPICE simulation

    Adaptation of a visualized loop-mediated isothermal amplification technique for field detection of Plasmodium vivax infection

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    <p>Abstract</p> <p>Background</p> <p>Loop-mediated isothermal amplification (LAMP) is a high performance method for detecting DNA and holds promise for use in the molecular detection of infectious pathogens, including <it>Plasmodium </it>spp. However, in most malaria-endemic areas, which are often resource-limited, current LAMP methods are not feasible for diagnosis due to difficulties in accurately interpreting results with problems of sensitive visualization of amplified products, and the risk of contamination resulting from the high quantity of amplified DNA produced. In this study, we establish a novel visualized LAMP method in a closed-tube system, and validate it for the diagnosis of malaria under simulated field conditions.</p> <p>Methods</p> <p>A visualized LAMP method was established by the addition of a microcrystalline wax-dye capsule containing the highly sensitive DNA fluorescence dye SYBR Green I to a normal LAMP reaction prior to the initiation of the reaction. A total of 89 blood samples were collected on filter paper and processed using a simple boiling method for DNA extraction, and then tested by the visualized LAMP method for <it>Plasmodium vivax </it>infection.</p> <p>Results</p> <p>The wax capsule remained intact during isothermal amplification, and released the DNA dye to the reaction mixture only when the temperature was raised to the melting point following amplification. Soon after cooling down, the solidified wax sealed the reaction mix at the bottom of the tube, thus minimizing the risk of aerosol contamination. Compared to microscopy, the sensitivity and specificity of LAMP were 98.3% (95% confidence interval (CI): 91.1-99.7%) and 100% (95% CI: 88.3-100%), and were in close agreement with a nested polymerase chain reaction method.</p> <p>Conclusions</p> <p>This novel, cheap and quick visualized LAMP method is feasible for malaria diagnosis in resource-limited field settings.</p

    DO INTERMEDIATE-MASS BLACK HOLES EXIST IN GLOBULAR CLUSTERS?

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    National Basic Research Program (973 Program) of China [2014CB845800]; National Natural Science Foundation of China [11073015, 11103015, 11222328, 11233006, 11333004, U1331101]The existence of intermediate-mass black holes (IMBHs) in globular clusters (GCs) remains a crucial problem. Searching for IMBHs in GCs reveals a discrepancy between radio observations and dynamical modelings: the upper mass limits constrained by radio observations are systematically lower than that of dynamical modelings. One possibility for such a discrepancy is that, as we suggest in this work, there exist outflows in accretion flows. Our results indicate that, for most sources, current radio observations cannot rule out the possibility that IMBHs may exist in GCs. In addition, we adopt an (M)over dot - L-R relation to revisit this issue, which confirms the results obtained by the fundamental plane relation

    Changes of Constituents and Activity to Apoptosis and Cell Cycle During Fermentation of Tea

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    Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest

    Unveiling the additive-assisted oriented growth of perovskite crystallite for high performance light-emitting diodes.

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    Solution-processed metal halide perovskites have been recognized as one of the most promising semiconductors, with applications in light-emitting diodes (LEDs), solar cells and lasers. Various additives have been widely used in perovskite precursor solutions, aiming to improve the formed perovskite film quality through passivating defects and controlling the crystallinity. The additive's role of defect passivation has been intensively investigated, while a deep understanding of how additives influence the crystallization process of perovskites is lacking. Here, we reveal a general additive-assisted crystal formation pathway for FAPbI3 perovskite with vertical orientation, by tracking the chemical interaction in the precursor solution and crystallographic evolution during the film formation process. The resulting understanding motivates us to use a new additive with multi-functional groups, 2-(2-(2-Aminoethoxy)ethoxy)acetic acid, which can facilitate the orientated growth of perovskite and passivate defects, leading to perovskite layer with high crystallinity and low defect density and thereby record-high performance NIR perovskite LEDs (~800 nm emission peak, a peak external quantum efficiency of 22.2% with enhanced stability)

    Postpartum stress urinary incontinence: a clinical study of 6,302 cases in Jiangsu Province

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    Objectives: To investigate the prevalence and influencing factors of stress urinary incontinence (SUI) within 6–8 weeks postpartum in Jiangsu Province. Material and methods: We designed a multi-center cross-sectional study involving seven hospitals in Jiangsu province, and enrolled women who underwent postpartum examination at 6–8 weeks in these hospitals between July 2019 and June 2021. According to the presence or absence of SUI, the enrolled patients were divided into two groups: the SUI group and the non-SUI group, respectively. We assessed the general health status, noted the details of delivery, and checked the pelvic floor electromyographic parameters of the postpartum women in both groups. Results: Among 6,302 cases of postpartum women in Jiangsu province, there were 1,579 cases of SUI, with a prevalence of 25.06%. The prevalence of SUI increased significantly with age, BMI, increasing parity, coexisting constipation, organ prolapse, and diastasis recti abdominis. Compared to the non-SUI group, the SUI group had a lower mean value of the pre-baseline rest phase, shorter rise and fall times of fast muscle contractions, and a lower mean value of the endurance contraction phase. Multiple regression analysis revealed associations with weight (especially overweight and obesity), coexisting organ prolapse, constipation, parity, gestational week of delivery, mode of delivery, and mean value of endurance contraction phase. Conclusions: The prevalence of postpartum stress urinary incontinence in Jiangsu Province was 25.06%, and was linked to being overweight, parity &gt; 2, coexisting organ prolapse, constipation, and a decrease in the mean value of the endurance contraction phase of the electromyograph. In this report, we offer a theoretical basis for the effective prevention of postpartum SUI clinically
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