1,426 research outputs found
Ultrasound-induced acoustophoretic motion of microparticles in three dimensions
We derive analytical expressions for the three-dimensional (3D)
acoustophoretic motion of spherical microparticles in rectangular
microchannels. The motion is generated by the acoustic radiation force and the
acoustic streaming-induced drag force. In contrast to the classical theory of
Rayleigh streaming in shallow, infinite, parallel-plate channels, our theory
does include the effect of the microchannel side walls. The resulting
predictions agree well with numerics and experimental measurements of the
acoustophoretic motion of polystyrene spheres with nominal diameters of 0.537
um and 5.33 um. The 3D particle motion was recorded using astigmatism particle
tracking velocimetry under controlled thermal and acoustic conditions in a
long, straight, rectangular microchannel actuated in one of its transverse
standing ultrasound-wave resonance modes with one or two half-wavelengths. The
acoustic energy density is calibrated in situ based on measurements of the
radiation dominated motion of large 5-um-diam particles, allowing for
quantitative comparison between theoretical predictions and measurements of the
streaming induced motion of small 0.5-um-diam particles.Comment: 13 pages, 8 figures, Revtex 4.
Multiple-crystal X-ray topographic characterization of periodically domain-inverted KTiOPO4 crystal
A periodically domain-inverted KTiOPO4 crystal has been characterized for the first time by multiple-crystal multiple-reflection x-ray topography. The striation contrast within the domain- inverted regions has been revealed in high strain-sensitivity reflection topographs. The origin of formation of the striation contrast and the mechanism of domain inversion in KTiOPO4 are discussed in terms of the structural characteristics of KTiOPO4
Nordic mcl2-3 trials: mirna-18b overexpression identifies a mantle cell lymphoma subgroup with poor survival and improves mipi-b prediction of prognosis
Plantando, colhendo, vendendo, mas não comendo: práticas alimentares e de trabalho associadas à obesidade em agricultores familiares do Bonfim, Petrópolis, RJ.
Objetivo: verificar a prevalência de obesidade entre adultos das 86 famílias agricultoras de um bairro de Petrópolis, RJ, e analisar seus determinantes socioculturais. Métodos: estudo quantitativo e qualitativo sobre nutrição, práticas alimentares e de trabalho realizado em 2008. Dados antropométricos foram coletados por inquérito nutricional domiciliar e o material qualitativo por observação participante e entrevistas. Resultados: a prevalência de obesidade foi baixa (9,3%) entre os homens, mas bastante elevada entre as mulheres (29,9%). A prática agrícola local implica em atividade física leve para mulheres e intensa para homens. Essa diferença não é acompanhada na dieta, semelhante para homens e mulheres, com predomínio de alimentos de alto valor calórico. A produção familiar objetiva essencialmente a venda. A agricultura mercantil e a decorrente especialização dos cultivos favorecem comprar alimentos no mercado em vez de produzir para autoconsumo. Conclusão: os aspectos socioculturais e ocupacionais estudados podem ter contribuído para elevar a prevalência de obesidade nas mulheres e podem ser úteis no estudo de outros grupos com características semelhantes. Esta pesquisa ratifica a importância de estudar a obesidade em nível local, integrando abordagens quantitativas e qualitativas para identificar possíveis limitações e portas de entrada para ações de intervenção localmente relevantes
Expression of CXCL10 is associated with response to radiotherapy and overall survival in squamous cell carcinoma of the tongue
Five-year survival for patients with oral cancer has been disappointingly stable during the last decades, creating a demand for new biomarkers and treatment targets. Lately, much focus has been set on immunomodulation as a possible treatment or an adjuvant increasing sensitivity to conventional treatments. The objective of this study was to evaluate the prognostic importance of response to radiotherapy in tongue carcinoma patients as well as the expression of the CXC-chemokines in correlation to radiation response in the same group of tumours. Thirty-eight patients with tongue carcinoma that had received radiotherapy followed by surgery were included. The prognostic impact of pathological response to radiotherapy, N-status, T-stage, age and gender was evaluated using Cox's regression models, Kaplan-Meier survival curves and chi-square test. The expression of 23 CXC-chemokine ligands and their receptors were evaluated in all patients using microarray and qPCR and correlated with response to treatment using logistic regression. Pathological response to radiotherapy was independently associated to overall survival with a 2-year survival probability of 81 % for patients showing a complete pathological response, while patients with a non-complete response only had a probability of 42 % to survive for 2 years (p = 0.016). The expression of one CXC-chemokine, CXCL10, was significantly associated with response to radiotherapy and the group of patients with the highest CXCL10 expression responded, especially poorly (p = 0.01). CXCL10 is a potential marker for response to radiotherapy and overall survival in patients with squamous cell carcinoma of the tongue
Measured adiposity in relation to head and neck cancer risk in the European Prospective Investigation into Cancer and Nutrition
BACKGROUND: Emerging evidence from cohort studies indicates that adiposity is associated with greater incidence of head and neck cancer (HNC). However, most studies have used self-reported anthropometry which is prone to error. METHODS: Among 363 094 participants in the European Prospective Investigation into Cancer and Nutrition study (EPIC) with measured anthropometry, there were 837 incident cases of HNC. HNC risk was examined in relation to body mass index (BMI) [lean: 30 kg/m²], waist circumference (WC), hip circumference (HC) and waist to hip ratio (WHR) using Cox proportional hazards models. RESULTS: Among men, a BMI < 22.5 kg/m² was associated with higher HNC risk [hazard ratio (HR) 1.62, 95% confidence interval (CI) 1.23 - 2.12)]; BMI was not associated with HNC among women. WC and WHR were associated with greater risk of HNC among women, (WC per 5 cm: HR 1.08, 95% CI 1.02 - 1.15; WHR per 0.1 unit: HR 1.64, 95% CI 1.38 - 1.93). After stratification by smoking status, the association for WHR was present only among smokers (p interaction 0.004). Among men, WC and WHR were associated with HNC only upon additional adjustment for BMI (WC per 5 cm: HR 1.16, 95% CI 1.07 - 1.26; WHR per 0.1 unit: HR 1.42, 95% CI 1.21 - 1.65). CONCLUSION: Central adiposity, particularly among women, may have a stronger association with HNC risk than previously estimated. IMPACT: Strategies to reduce obesity may beneficially impact HNC incidence.The coordination of EPIC is financially supported by the European Commission (DG-SANCO) and the International Agency for Research on Cancer. The national cohorts are supported by Danish Cancer Society (Denmark); Ligue Contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l’Education Nationale, Institut National de la Santé et de la Recherche Médicale (INSERM) (France); German Cancer Aid, German Cancer Research Center (DKFZ), Federal Ministry of Education and Research (BMBF), Deutsche Krebshilfe, Deutsches Krebsforschungszentrum and Federal Ministry of Education and Research (Germany); the Hellenic Health Foundation (Greece); Associazione Italiana per la Ricerca sul Cancro-AIRC-Italy and National Research Council (Italy); Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); ERC- 2009-AdG 232997 and Nordforsk, Nordic Centre of Excellence programme on Food, Nutrition and Health (Norway); Health Research Fund (FIS), PI13/00061 to Granada; , PI13/01162 to EPIC-Murcia), Regional Governments of Andalucía, Asturias, Basque Country, Murcia and Navarra, ISCIII RETIC (RD06/0020) (Spain); Swedish Cancer Society, Swedish Research Council and County Councils of Skåne and Västerbotten (Sweden); Cancer Research UK (14136 to K.T. Khaw, N.J. Wareham; C570/A16491 to R.C. Travis and C8221/A19170 to Tim Key (EPIC-Oxford), Medical Research Council (1000143 to K.T. Khaw, N.J. Wareham, MR/M012190/1 to Tim Key (EPIC-Oxford)) (United Kingdom)
Copycats among underdogs - echoing the sharing economy business model
The sharing economy has gained traction in several industry sectors by establishing ever-new platforms, with digital intermediation and peer-to-peer exchanges at the heart of the business model. Most research on the sharing economy concerns the phenomenon level or focuses on the operations of single platforms. This paper connects various sharing economy platforms by asking: How has the sharing economy spread to new platforms? The purpose of the paper is to explain the pattern of spread of the sharing economy business model. Findings point out a seamless, unobtrusive pattern echoing characteristics of the sharing economy business model across distant sectors to avoid competition while reproducing activities in ever-new resource settings. The paper continues the exploration of the sharing economy related to industrial marketing through moving from the individual platforms to the way they lead to new ones while acknowledging how the innovative model for new platforms is highly based on mandates created through acknowledging oneself as a role model successor. Such a spread mechanism redefines innovation newness, adaptation and diffusion, and raises new insights to understand how current business landscapes would be under the possible transition into a new logic of operations
Early signaling, referral, and treatment of adolescent chronic pain: a study protocol
<p>Abstract</p> <p>Background</p> <p>Chronic pain is prevalent among young people and negatively influences their quality of life. Furthermore, chronic pain in adolescence may persist into adulthood. Therefore, it is important early on to promote the self-management skills of adolescents with chronic pain by improving signaling, referral, and treatment of these youngsters. In this study protocol we describe the designs of two complementary studies: a signaling study and an intervention study.</p> <p>Methods and design</p> <p>The signaling study evaluates the Pain Barometer, a self-assessed signaling instrument for chronic pain in adolescents. To evaluate the feasibility of the Pain Barometer, the experiences of youth-health care nurses will be evaluated in semi-structured interviews. Also, we will explore the frequencies of referral per health-care provider. The intervention study evaluates Move It Now, a guided self-help intervention via the Internet for teenagers with chronic pain. This intervention uses cognitive behavioural techniques, including relaxation exercises and positive thinking. The objective of the intervention is to improve the ability of adolescents to cope with pain. The efficacy of Move It Now will be examined in a randomized controlled trial, in which 60 adolescents will be randomly assigned to an experimental condition or a waiting list control condition.</p> <p>Discussion</p> <p>If the Pain Barometer is proven to be feasible and Move It Now appears to be efficacious, a health care pathway can be created to provide the best tailored treatment promptly to adolescents with chronic pain. Move It Now can be easily implemented throughout the Netherlands, as the intervention is Internet based.</p> <p>Trial registration</p> <p>Dutch Trial Register NTR1926</p
Influence of final state interactions in attosecond photoelectron interferometry
Fano resonances are ubiquitous phenomena appearing in many fields of physics, e.g., atomic or molecular photoionization, or electron transport in quantum dots. Recently, attosecond interferometric techniques have been used to measure the amplitude and phase of photoelectron wave packets close to Fano resonances in argon and helium, allowing for the retrieval of the temporal dynamics of the photoionization process. In this work, we study the photoionization of argon atoms close to the 3s13p64p autoionizing state using an interferometric technique with high spectral resolution. The phase shows a monotonic 2π variation across the resonance or a nonmonotonic less than π variation depending on experimental conditions, e.g., the probe laser bandwidth. Using three different, state-of-the-art calculations, we show that the measured phase is influenced by the interaction between final states reached by two-photon transitionsThe authors acknowledge support from the Swedish Research Council (2013-8185, 2016-04907, 2018-03731, 2020-0520, 2020-03315, 2020-06384, 2023-04603), the European Research Council (advanced grant QPAP, 884900) and the Knut and Alice Wallenberg Foundation. This work was developed in the framework of the COST action CA18222 Attosecond Chemistry (AttoChem) supported by European Cooperation in Science and Technology. A.L. and M.A. are partly supported by the Wallenberg Center for Quantum Technology (WACQT) funded by the Knut and Alice Wallenberg Foundation. L.A. and C.M. acknowledge the NSF Grant No. PHY-1912507. R.Y.B. and F.M. acknowledge the Ministerio de Ciencia e Innovacien MICINN (Spain) through projects PID2022-138288NB-C31 and PID2022-138288NB-C32, the Severo Ochoa Programme for Centres of Excellence in R & D (CEX2020-001039-S) and the Maria de Maeztu Programme for Units of Excellence in R & D (CEX2018-000805-M). xchem calculations were performed at the Marenostrum Barcelona Supercomputer Center of the R
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