15,394 research outputs found

    Modelling avalanches in martensites

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    Solids subject to continuous changes of temperature or mechanical load often exhibit discontinuous avalanche-like responses. For instance, avalanche dynamics have been observed during plastic deformation, fracture, domain switching in ferroic materials or martensitic transformations. The statistical analysis of avalanches reveals a very complex scenario with a distinctive lack of characteristic scales. Much effort has been devoted in the last decades to understand the origin and ubiquity of scale-free behaviour in solids and many other systems. This chapter reviews some efforts to understand the characteristics of avalanches in martensites through mathematical modelling.Comment: Chapter in the book "Avalanches in Functional Materials and Geophysics", edited by E. K. H. Salje, A. Saxena, and A. Planes. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-45612-6_

    Single-grasp detection based on rotational region CNN

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    Comprehensive workplace intervention for cancer prevention in China (WECAN): protocol for a stepped-wedge, cluster-randomised controlled trial.

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    INTRODUCTION: Cancer is the second leading cause of death across the globe with the majority of deaths occurring in low-income and middle-income countries. Evidence has shown that the cancer burden can be substantially reduced by avoiding behavioural risk factors through comprehensive intervention strategies, including workplace health promotion, which has shown to be cost-effective in developed countries while rarely conducted in developing countries. This study aims to explore a feasible and sustainable approach to the prevention and control of cancer in China by developing an evidence-based comprehensive workplace health model equipped with a smartphone application for implementation. METHODS AND ANALYSIS: This study is designed as a stepped-wedge, cluster-randomised controlled trial. We will recruit 15 workplaces from three cities in China. A total of 750 employees will be randomly selected for evaluation that includes five rounds of survey conducted every 6 months. After the second evaluation, workplaces will be randomly allocated to start the intervention sequentially every 6 months in three steps with five workplaces per step. A mobile application 'Healthy Workplace' will be developed to support the intervention. On-line and off-line health-related activities will be carried out among employees. Employers will provide supportive policies, environment and benefits to facilitate the adoption of healthy behaviours. The primary outcome is the change of Healthy Lifestyle Index Score, which consists of five components including smoking, alcohol drinking, physical activity, diet and body mass index. ETHICS AND DISSEMINATION: The study has been approved by Queen Mary University of London Ethics of Research Committee (QMERC22.257) and Chinese Centre for Disease Control and Prevention Institutional Review Board (202210). Written informed consent is required from all participants. Results will be disseminated through presentations, publications and social media. TRIAL REGISTRATION NUMBER: ChiCTR2200058680

    Repeatability of Corneal Elevation Maps in Keratoconus Patients Using the Tomography Matching Method

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    To assess repeatability of corneal tomography in successive measurements by Pentacam in keratoconus (KC) and normal eyes based on the Iterative Closest Point (ICP) algorithm. The study involved 143 keratoconic and 143 matched normal eyes. ICP algorithm was used to estimate six single and combined misalignment (CM) parameters, the root mean square (RMS) of the difference in elevation data pre (PreICP-RMS) and post (PosICP-RMS) tomography matching. Corneal keratometry, expressed in the form of M, J0 and J45 (power vector analysis parameters), was used to evaluate the effect of misalignment on corneal curvature measurements. The PreICP-RMS and PosICP-RMS were statistically higher (P < 0.01) in KC than normal eyes. CM increased significantly (p = 0.00), more in KC (16.76 ± 20.88 μm) than in normal eyes (5.43 ± 4.08 μm). PreICP-RMS, PosICP-RMS and CM were correlated with keratoconus grade (p < 0.05). Corneal astigmatism J0 was different (p = 0.01) for the second tomography measurements with misalignment consideration (−1.11 ± 2.35 D) or not (−1.18 ± 2.35 D), while M and J45 kept similar. KC corneas consistently show higher misalignments between successive tomography measurements and lower repeatability compared with healthy eyes. The influence of misalignment is evidently clearer in the estimation of astigmatism than spherical curvature. These higher errors appear correlated with KC progression

    Impact of the 2003 to 2018 Population Salt Intake Reduction Program in England A Modeling Study

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    The United Kingdom was among the first countries to introduce a salt reduction program in 2003 to reduce cardiovascular disease (CVD) incidence risk. Despite its initial success, the program has stalled recently and is yet to achieve national and international targets. We used age- and sex-stratified salt intake of 19 to 64 years old participants in the National Diet and Nutrition Surveys 2000 to 2018 and a multistate life table model to assess the effects of the voluntary dietary salt reduction program on premature CVD, quality-adjusted survival, and health care and social care costs in England. The program reduced population-level salt intake from 9.38 grams/day per adult (SE, 0.16) in 2000 to 8.38 grams/day per adult (SE, 0.17) in 2018. Compared with a scenario of persistent 2000 levels, assuming that the population-level salt intake is maintained at 2018 values, by 2050, the program is projected to avoid 83 140 (95% CI, 73 710–84 520) premature ischemic heart disease (IHD) cases and 110 730 (95% CI, 98 390–112 260) premature strokes, generating 542 850 (95% CI, 529 020–556 850) extra quality-adjusted life-years and £1640 million (95% CI, £1570–£1660) health care cost savings for the adult population of England. We also projected the gains of achieving the World Health Organization target of 5 grams/day per adult by 2030, which by 2050 would avert further 87 870 (95% CI, 82 050–88 470) premature IHD cases, 126 010 (95% CI, 118 600–126 460) premature strokes and achieve £1260 million (95% CI, £1180–£1260) extra health care savings compared with maintaining 2018 levels. Strengthening the salt reduction program to achieve further reductions in population salt intake and CVD burden should be a high priority

    Developmental definition of MSCs: New insights into pending questions

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    Mesenchymal stem cells (MSCs) are a rare heterogeneous population of multipotent cells that can be isolated from many different adult and fetal tissues. They exhibit the capacity to give rise to cells of multiple lineages and are defined by their phenotype and functional properties, such as spindle-shaped morphology, adherence to plastic, immune response modulation capacity, and multilineage differentiation potential. Accordingly, MSCs have a wide range of promising applications in the treatment of autoimmune diseases, tissue repair, and regeneration. Recent studies have shed some light on the exact identity and native distribution of MSCs, whereas controversial results are still being reported, indicating the need for further review on their definition and origin. In this article, we summarize the important progress and describe some of our own relevant work on the developmental definition of MSCs. © 2011 Mary Ann Liebert, Inc.published_or_final_versio

    Sodium content of restaurant dishes in China: a cross-sectional survey

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    BACKGROUND: Sodium intake in China is extremely high and eating in restaurants is increasingly popular. Little research has explored the sodium level of restaurant dishes. The present study aims to assess the content and sources of sodium in Chinese restaurants. METHODS: Cross-sectional data were obtained from the baseline survey of the Restaurant-based Intervention Study (RIS) in 2019. A total of 8131 best-selling restaurant dishes with detailed recipes from 192 restaurants in China were included. Sodium content per 100 g and per serving were calculated according to the Chinese Food Composition Table. The proportion of restaurant dishes exceeding the daily sodium reference intake level in a single serving and the major sources of sodium were determined. RESULTS: Median sodium content in restaurant dishes were 487.3 mg per 100 g, 3.4 mg per kcal, and 2543.7 mg per serving. For a single serving, 74.9% of the dishes exceeded the Chinese adults’ daily adequate intake for sodium (AI, 1500 mg per day), and 62.6% of dishes exceeded the proposed intake for preventing non-communicable chronic diseases (PI, 2000 mg per day). Cooking salt was the leading source of sodium in Chinese restaurant dishes (45.8%), followed by monosodium glutamate (17.5%), food ingredients (17.1%), soy sauce (9.4%), and other condiments/seasonings (10.2%). More types of salted condiments/seasonings use were related to higher sodium level. CONCLUSIONS: The sodium levels in Chinese restaurant dishes are extremely high and variable. In addition to cooking salt, other salted condiments/seasonings also contribute a large proportion of sodium. Coordinated sodium reduction initiatives targeting the main sources of sodium in restaurant dishes are urgently needed

    Uptake of oxLDL and IL-10 production by macrophages requires PAFR and CD36 recruitment into the same lipid rafts

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    Macrophage interaction with oxidized low-density lipoprotein (oxLDL) leads to its differentiation into foam cells and cytokine production, contributing to atherosclerosis development. In a previous study, we showed that CD36 and the receptor for platelet-activating factor (PAFR) are required for oxLDL to activate gene transcription for cytokines and CD36. Here, we investigated the localization and physical interaction of CD36 and PAFR in macrophages stimulated with oxLDL. We found that blocking CD36 or PAFR decreases oxLDL uptake and IL-10 production. OxLDL induces IL-10 mRNA expression only in HEK293T expressing both receptors (PAFR and CD36). OxLDL does not induce IL-12 production. The lipid rafts disruption by treatment with βCD reduces the oxLDL uptake and IL-10 production. OxLDL induces co-immunoprecipitation of PAFR and CD36 with the constitutive raft protein flotillin-1, and colocalization with the lipid raft-marker GM1-ganglioside. Finally, we found colocalization of PAFR and CD36 in macrophages from human atherosclerotic plaques. Our results show that oxLDL induces the recruitment of PAFR and CD36 into the same lipid rafts, which is important for oxLDL uptake and IL-10 production. This study provided new insights into how oxLDL interact with macrophages and contributing to atherosclerosis development

    Observation of second-harmonic generation induced by pure spin currents

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    Extensive efforts are currently being devoted to developing a new electronic technology, called spintronics, where the spin of electrons is explored to carry information. [1,2] Several techniques have been developed to generate pure spin currents in many materials and structures. [3-10] However, there is still no method available that can be used to directly detect pure spin currents, which carry no net charge current and no net magnetization. Currently, studies of pure spin currents rely on measuring the induced spin accumulation with optical techniques [5, 11-13] or spin-valve configurations. [14-17] However, the spin accumulation does not directly reflect the spatial distribution or temporal dynamics of the pure spin current, and therefore cannot monitor the pure spin current in a real-time and real-space fashion. This imposes severe constraints on research in this field. Here we demonstrate a second-order nonlinear optical effect of the pure spin current. We show that such a nonlinear optical effect, which has never been explored before, can be used for the non-invasive, non-destructive, and real-time imaging of pure spin currents. Since this detection scheme does not rely on optical resonances, it can be generally applied in a wide range of materials with different electronic bandstructures. Furthermore, the control of nonlinear optical properties of materials with pure spin currents may have potential applications in photonics integrated with spintronics.Comment: 19 pages, 3 figures, supplementary discussion adde

    Evidence for Anthropogenic Surface Loading as Trigger Mechanism of the 2008 Wenchuan Earthquake

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    Two and a half years prior to China's M7.9 Wenchuan earthquake of May 2008, at least 300 million metric tons of water accumulated with additional seasonal water level changes in the Minjiang River Valley at the eastern margin of the Longmen Shan. This article shows that static surface loading in the Zipingpu water reservoir induced Coulomb failure stresses on the nearby Beichuan thrust fault system at <17km depth. Triggering stresses exceeded levels of daily lunar and solar tides and perturbed a fault area measuring 416+/-96km^2. These stress perturbations, in turn, likely advanced the clock of the mainshock and directed the initial rupture propagation upward towards the reservoir on the "Coulomb-like" Beichuan fault with rate-and-state dependent frictional behavior. Static triggering perturbations produced up to 60 years (0.6%) of equivalent tectonic loading, and show strong correlations to the coseismic slip. Moreover, correlations between clock advancement and coseismic slip, observed during the mainshock beneath the reservoir, are strongest for a longer seismic cycle (10kyr) of M>7 earthquakes. Finally, the daily event rate of the micro-seismicity (M>0.5) correlates well with the static stress perturbations, indicating destabilization.Comment: 22 pages, 4 figures, 3 table
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