3,584 research outputs found

    Penetration depth study of LaOs4_4Sb12_{12}: Multiband s-wave superconductivity

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    We measured the magnetic penetration depth λ(T)\lambda(T) in single crystals of LaOs4_{4}Sb12_{12} (TcT_c=0.74 K) down to 85 mK using a tunnel diode oscillator technique. The observed low-temperature exponential dependence indicates a s-wave gap. Fitting the low temperature data to BCS s-wave expression gives the zero temperature gap value Δ(0)=(1.34±0.07)kBTc\Delta (0)= (1.34 \pm 0.07) k_B T_c which is significantly smaller than the BCS value of 1.76kBTck_B T_c. In addition, the normalized superfluid density ρ(T)\rho(T) shows an unusually long suppression near TcT_c, and are best fit by a two-band s-wave model.Comment: 5 pages, 2 figure

    The level of Marzano higher-order thinking skills among polytechnic students

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    This study aims to identify polytechnic students' level of Marzano Higher-Order Thinking Skills (HOTS) based on two dimensions, 'Extension and Refinement of Knowledge' and 'Meaningful Use of Knowledge,' and to analyze the difference in the students' level of Marzano HOTS based on these two dimensions depending on the students' demographic factors. This study design was a survey using quantitative methods. A total of 313 students were randomly selected as the survey sample. A questionnaire in the form of closed-ended questions was used as the research instrument. Data were analyzed using frequency percentage and MANOVA test. The findings showed no significant differences in the eight HOTS in the dimension of 'Extension and Refinement of Knowledge' with the gender and socio-economic status (SES) factors. However, there were significant differences in the eight HOTS with the academic achievement factor. Meanwhile, based on the dimension of 'Meaningful Use of Knowledge,' the findings showed no significant differences in the five HOTS in this dimension with the gender and academic achievement factors. The paper includes implications of the Higher-Order Thinking Skills (HOTS) for students to improve their academic performance. In future research, the authors can further identify university students' HOTS levels in the technical area

    Tapered microchannel for multi-particles passive separation based on hydrodynamic resistance

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    Researches on separation of multi-particles utilizing microfluidic have been flourishing in recent years with the aid from advancements in microfabrication design and technology. Generally, separation is beneficial for biomedical application especially involving heterogeneous samples. Due to inherent problems of samples isolation, a simple and efficient separation device is required. Here, we present a passive tapered microchannel for multi-particles separation using hydrodynamic principle. Our emphasis is on the effect of hydrodynamic resistance coupled with tapered microchannel design. In the experiment, successful multi-particles samples separation was observed. The results were further analyzed and were in agreement with the proposed concept. This method opens the route toward robust, low-cost and high-throughput, thus it may holds potential to be integrated as one functional module in Micro Total Analysis System (µTAS)

    Perspectives and experiences of community-dwelling older adults who experience falling: A qualitative meta-synthesis

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    Objectives: This study aimed to systematically review and synthesize the perspectives and experiences of community-dwelling older adults who experience falling, to inform the subsequent development of fall prevention and management interventions, and to provide recommendations for healthcare policy and practice. Methods: The review was a qualitative meta-aggregation study following the JBI qualitative systematic review methodology. Databases searched included Medline (through PubMed), CINAHL, PsycINFO, Embase, and the Web of Science. Peer-reviewed articles published in the English language from January 2010 to May 2023 were retrieved. The JBI Qualitative Assessment and Review Instrument (JBI-QARI) was used to assess the quality of the methodology. The ConQual ranking system was used to establish confidence in the synthesized findings. The protocol was registered with PROSPERO (CRD 42023421789). Results: This review included ten qualitative studies with an overall quality score of 60%–90%. Data extracted from eligible studies resulted in 59 findings, which were then aggregated into seven categories based on the similarity in meaning. Three synthesized findings were generated and rated as moderate for synthesized finding 2 and low for synthesized finding 1 and 3 on the ConQual score. Synthesized finding 1: Older adults experience physical injuries and pain, restricted daily activities, and limitations in social activities, reduction or loss of in independence, and have feelings of fear and helplessness. Synthesized finding 2: After experiencing a fall, older adults reflect on the cause of the fall and recognize and interpret the risk factors. Synthesized finding 3: Older adults’ reflections on the causes and impact of falls reveal both positive and negative reactions. They perceive a number of strategies for coping with falls and their consequences, such as using assistive devices, correcting risk factors, seeking medical help, and receiving ongoing physical and psychological attention. Conclusions: Healthcare providers should pay attention to the feelings and experiences of older adults after falling, as well as their reflection on the causes and impacts of falling, and develop tailored plans for intervention. There is also a need for longitudinal studies to examine the longer-term impact of falls on older adults to provide insights into the stability and changes in their reflections, perceptions, attitudes, and preventive behaviors over time

    Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe2_2As2_2

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    Resistivity, magnetization and microscopic 75^{75}As nuclear magnetic resonance (NMR) measurements in the antiferromagnetically ordered state of the iron-based superconductor parent material CaFe2_2As2_2 exhibit anomalous features that are consistent with the collective freezing of domain walls. Below T10T^*\approx 10 K, the resistivity exhibits a peak and downturn, the bulk magnetization exhibits a sharp increase, and 75^{75}As NMR measurements reveal the presence of slow fluctuations of the hyperfine field. These features in both the charge and spin response are strongly field dependent, are fully suppressed by H15H^*\approx 15 T, and suggest the presence of filamentary superconductivity nucleated at the antiphase domain walls in this material.Comment: 6pages, 6 figure

    'You were quiet - I did all the marching': Research processes involved in hearing the voices of South Asian girls

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    This article is available open access through the publisher’s website at the link below. Copyright @ 2011 A B Academic Publishers.This article provides insights into the outcomes of reflection following two interview approaches used to explore narratives of the lived, individual experiences of South-Asian girls living in West London. In attempting to illuminate and re-present the cultural experiences as told by these girls, the choice of interview approach became critical in allowing the voices to be effectively heard (Rogers, 2005). This article therefore considers how a semi-structured interview approach offered valuable insights into the girls' experiences but became constraining for both researcher and participant in unveiling the complexity and depth of their lives. These constraints emerged through reflection by both participants and researcher. As a result of reflexivity during the research process, the researcher moved towards the use of research conversations during the second phase of the study. Ultimately the study revealed how the girls felt empowered by the opportunity to narrate their individual experiences and tell of their lives. In narrating their reflections on being part of the research, there was a clear recognition that the process facilitated the articulation of new voices and ‘multi-voicedness’ (Moen, 2006

    Cytotoxic prenylated xanthone and coumarin derivatives from Malaysian Mesua beccariana

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    Our recent research on the phytochemical constituents of the stem bark of Mesua beccariana gave one new xanthone, beccarixanthone T (1) and one new coumarin, beccamarin T (2) together with three known xanthones mesuarianone (3), mesuasinone (4), 1,5-dihydroxyxanthone (5) and four known terpenoids, friedelin (6), stigmasterol (7), beta-sitosterol (8) and gamma-sitosterol (9). The structures of these compounds were elucidated and determined using spectroscopic techniques such as NMR and MS. The cytotoxic activities of compounds 1-4 as well as the crude extracts were tested against two cancer cell lines, Hep G2 (liver cancer cell line) and HT-29 (colon cancer cell line) using MTT assays. Mesuarianone (3) gave a significant activity on the HT-29 cell line while mesuasinone (4) gave moderate activity against HT-29 cell line

    Radiation characteristic of cloud based magnetometer for vehicle detection

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    A traffic sensing and monitoring system based on a magnetometer is proposed to work with Arduino pro-mini and nRF24L01 to mitigate traffic congestion problems. As vehicles pass through the magnetometer buried underground, the microcontroller processes the magnetic field changes and transmits them by the nRF24L01 transceiver for data analysis. A MIFA antenna resonating at 2.4 GHz is incorporated in the transceiver module for transmission purposes. The performance of this antenna is simulated by using COMSOL commercial software. Approximate 7 dB of return loss enhancement is found when taper design is applied to the antenna. Since the antenna is designed to radiate at 2.4 GHz, its antenna gain is the highest (1.22 dBi) in this frequency too. The simulated 3D and 2D gain patterns have shown that this antenna is radiating omnidirectional, suitable for transmitting signals in all directions. This is further validated by the Received Signal Strength Indicator (RSSI) measurement, which indicates a similar trend of signal strength for all locations at a distance below 40 m (-87 dBm). When the distances increase beyond 40 m, the RSSI at the direction closer to the traffic flow drops significantly compared to the other directions where 30 dBm of variation is detected at 100 m

    Mendelian randomization study of B-type natriuretic peptide and type 2 diabetes: evidence of causal association from population studies

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    <p>Background: Genetic and epidemiological evidence suggests an inverse association between B-type natriuretic peptide (BNP) levels in blood and risk of type 2 diabetes (T2D), but the prospective association of BNP with T2D is uncertain, and it is unclear whether the association is confounded.</p> <p>Methods and Findings: We analysed the association between levels of the N-terminal fragment of pro-BNP (NT-pro-BNP) in blood and risk of incident T2D in a prospective case-cohort study and genotyped the variant rs198389 within the BNP locus in three T2D case-control studies. We combined our results with existing data in a meta-analysis of 11 case-control studies. Using a Mendelian randomization approach, we compared the observed association between rs198389 and T2D to that expected from the NT-pro-BNP level to T2D association and the NT-pro-BNP difference per C allele of rs198389. In participants of our case-cohort study who were free of T2D and cardiovascular disease at baseline, we observed a 21% (95% CI 3%-36%) decreased risk of incident T2D per one standard deviation (SD) higher log-transformed NT-pro-BNP levels in analysis adjusted for age, sex, body mass index, systolic blood pressure, smoking, family history of T2D, history of hypertension, and levels of triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. The association between rs198389 and T2D observed in case-control studies (odds ratio = 0.94 per C allele, 95% CI 0.91-0.97) was similar to that expected (0.96, 0.93-0.98) based on the pooled estimate for the log-NT-pro-BNP level to T2D association derived from a meta-analysis of our study and published data (hazard ratio = 0.82 per SD, 0.74-0.90) and the difference in NT-pro-BNP levels (0.22 SD, 0.15-0.29) per C allele of rs198389. No significant associations were observed between the rs198389 genotype and potential confounders.</p> <p>Conclusions: Our results provide evidence for a potential causal role of the BNP system in the aetiology of T2D. Further studies are needed to investigate the mechanisms underlying this association and possibilities for preventive interventions.</p&gt
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