928 research outputs found

    Screening of external magnetic perturbation fields due to sheared plasma flow

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    Within the single fluid resistive magnetohydrodynamic model, systematic toroidal modelling efforts are devoted to investigate the plasma response induced screening of the applied external 3D magnetic field perturbations in the presence of sheared toroidal flow. One particular issue of interest is addressed, when the local flow speed approaches zero at the perturbation rational surface inside the plasma. Subtle screening physics, associated with the favourable averaged toroidal curvature effect (the GGJ effect (Glasser et al 1975 Phys. Fluids 7 875)), is found to play an essential role during slow flow near the rational surface by enhancing the screening at reduced flow. A strong cancellation effect between different terms of Ohm's law is discovered, leading to different screening physics in the GGJ regime, as compared to that of conventional screening of the typical resistive-inertial regime occurring at faster flow. These modelling results may be applicable to interpret certain mode locking experiments, as well as type-I edge localized mode suppression experiments, with resonant magnetic field perturbations being applied to tokamak plasmas at low input toroidal torque

    Characterization of high-resolution aerosol mass spectra of primary organic aerosol emissions from Chinese cooking and biomass burning

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    Aerosol mass spectrometry has proved to be a powerful tool to measure submicron particulate composition with high time resolution. Factor analysis of mass spectra (MS) collected worldwide by aerosol mass spectrometer (AMS) demonstrates that submicron organic aerosol (OA) is usually composed of several major components, such as oxygenated (OOA), hydrocarbon-like (HOA), biomass burning (BBOA), and other primary OA. In order to help interpretation of component MS from factor analysis of ambient OA datasets, AMS measurements of different primary sources is required for comparison. Such work, however, has been very scarce in the literature, especially for high resolution MS (HR-MS) measurements, which performs improved characterization by separating the ions of different elemental composition at each <i>m</i>/<i>z</i> in comparison with unit mass resolution MS (UMR-MS) measurements. In this study, primary emissions from four types of Chinese cooking (CC) and six types of biomass burning (BB) were simulated systematically and measured using an Aerodyne High-Resolution Time-of-Flight AMS (HR-ToF-AMS). The MS of the CC emissions show high similarity, with <i>m</i>/<i>z</i> 41 and <i>m</i>/<i>z</i> 55 being the highest signals; the MS of the BB emissions also show high similarity, with <i>m</i>/<i>z</i> 29 and <i>m</i>/<i>z</i> 43 being the highest signals. The MS difference between the CC and BB emissions is much bigger than that between different CC (or BB) types, especially for the HR-MS. The O/C ratio of OA ranges from 0.08 to 0.13 for the CC emissions and from 0.18 to 0.26 for the BB emissions. The UMR ions of <i>m</i>/<i>z</i> 43, <i>m</i>/<i>z</i> 44, <i>m</i>/<i>z</i> 57, and <i>m</i>/<i>z</i> 60, usually used as tracers in AMS measurements, were examined for their HR-MS characteristics in the CC and BB emissions. In addition, the MS of the CC and BB emissions are also compared with component MS from factor analysis of ambient OA datasets observed in China, as well as with other AMS measurements of primary sources in the literature. The MS signatures of cooking and biomass burning emissions revealed in this study can be used as important reference for factor analysis of ambient OA datasets, especially for the relevant studies in East Asia

    Migrânea com Aura, Qualidade de Vida e Tratamento: um relato de caso

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    A migrânea é uma cefaleia primária de etiologia multifatorial que acomete cerca de 15% da população. Afeta mais as mulheres do que os homens e gera um impacto significativo na qualidade de vida. A crise de cefaléia migranosa apresenta quatro fases: prodrômica, de aura, cefaléia e fase de recuperação. Um plano terapêutico para migrânea inclui tratamento agudo da crise para melhora da dor e do prejuízo funcional, e a terapia profilática de longo prazo para diminuir a frequência, a intensidade e a duração das crises. No presente trabalho, os autores correlacionaram o relato de caso de uma paciente do Hospital Universitário Sul Fluminense com a literatura atual

    Scalp Metastasis After Breast Cancer Surgery: A Case Report

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    Jingxuan Wu,1,2,&ast; Wenzhu Zhang,1,2,&ast; Hong Zhang,1,2,&ast; Xingjia Lu,1,2,&ast; Biqing Luan,1,2,&ast; Qizhi Yang,1,2,&ast; Liang Chen,1,&ast; Wenlin Chen,3,&ast; Fei Ge1,&ast; 1Department of Breast Surgery, First Affiliated Hospital of Kunming Medical University, Kunming, 650000, People’s Republic of China; 2No. 1 School of Clinical Medicine, Kunming Medical University, Kunming, 650000, People’s Republic of China; 3Third Department of Breast Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, 650000, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Fei Ge, Department of Breast Surgery, First Affiliated Hospital of Kunming Medical University, Kunming, 650000, People’s Republic of China, Email [email protected] Wenlin Chen, Third Department of Breast Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, 650000, People’s Republic of China, Email [email protected]: Breast cancer is one of the most common malignant tumors affecting women worldwide. Breast cancer is a complex disease characterized by abnormal growth of cells in the breast tissue. Metastasis, the spread of cancer cells from the primary tumor site to distant organs, is a major challenge in the management of breast cancer. Although metastasis to distant sites is a well-known feature of breast cancer, scalp involvement is relatively rare. The occurrence of scalp metastasis signifies an advanced stage of the disease. The 51-year-old female discovered a firm, painless mass in her right breast that had been there for two years. It had been pricking for a month, and the biopsy revealed that the mass was invasive carcinoma of the right breast. Imaging tests suggested that the tumor was malignant. Adjuvant endocrine therapy and postoperative adjuvant chemotherapy were administered following a modified radical resection for breast cancer. Eleven months later, radiation treatment and replace endocrine therapy was used. 32 months following surgery, a scalp tumor was discovered; a pathology biopsy verified the origin of the breast cancer; three months later, bone, brain, and visceral metastases were discovered. After that, she received oral capecitabine treatment and was admitted into the hospital for advanced rescue treatment. She is currently in the disease stability state, her disease is effectively managed, and no new metastatic lesions have been discovered.Keywords: breast cancer, scalp metastasis, chemotherapy, radiotherapy, endocrine therapy, case repor

    Centralized Inverted Decoupling Control

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    This paper presents a new methodology of multivariable centralized control based on the structure of inverted decoupling. The method is presented for general nĂ—n processes, obtaining very simple general expressions for the controller elements with a complexity independent of the system size. The possible configurations and realizability conditions are stated. Then, the specification of performance requirements is carried out from simple open loop transfer functions for three common cases. As a particular case, it is shown that the resulting controller elements have PI structure or filtered derivative action plus a time delay when the process elements are given by first order plus time delay systems. Comparisons with other works demonstrate the effectiveness of this methodology through the use of several simulation examples and an experimental lab process

    MiR-31 promotes mammary stem cell expansion and breast tumorigenesis by suppressing Wnt signaling antagonists

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    MicroRNA-mediated post-transcriptional regulation plays key roles in stem cell self-renewal and tumorigenesis. However, the in vivo functions of specific microRNAs in controlling mammary stem cell (MaSC) activity and breast cancer formation remain poorly understood. Here we show that miR-31 is highly expressed in MaSC-enriched mammary basal cell population and in mammary tumors, and is regulated by NF-κB signaling. We demonstrate that miR-31 promotes mammary epithelial proliferation and MaSC expansion at the expense of differentiation in vivo. Loss of miR-31 compromises mammary tumor growth, reduces the number of cancer stem cells, as well as decreases tumor-initiating ability and metastasis to the lung, supporting its pro-oncogenic function. MiR-31 modulates multiple signaling pathways, including Prlr/Stat5, TGFβ and Wnt/β-catenin. Particularly, it activates Wnt/β-catenin signaling by directly targeting Wnt antagonists, including Dkk1. Importantly, Dkk1 overexpression partially rescues miR31-induced mammary defects. Together, these findings identify miR-31 as the key regulator of MaSC activity and breast tumorigenesis

    Dental and prosthodontic status of an over 40 year-old population in Shandong Province, China

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    Contains fulltext : 97791.pdf (postprint version ) (Open Access)BACKGROUND: This study aims to (1) describe the dental status using DMFT for the whole dentition and the anterior, premolar and molar regions; (2) determine associations of demographic variables and socio-economic status (SES) with DMFT and tooth replacement; (3) analyze to what extent the goal as proposed by the WHO -'the retention of not less than 20 teeth throughout life' is achieved. METHODS: DMFT and tooth replacement data of 1588 subjects over 40 years from urban and rural sites in Qingdao (Shandong Province, China) were collected. Relative D, M, and F scores per dental region were calculated and compared by paired T-tests. Multivariable logistic regression was used to determine relationships with age, gender, place of residence, and SES. RESULTS: Mean numbers of D and F were low (1.36 respectively 0.27) at all ages. Molars had highest chance for D and M. For the molar region every additional year of age gave significantly lower chance for D and higher chance for M (OR: 0.98 and 1.02 respectively; both p </= 0.01). Mean number of M was associated with age (approximately 1.5 in each jaw at 40 years and 6 at 80 years). Females had higher chance for D (OR: 1.34; p </= 0.05) and F (OR: 1.69; p </= 0.01), and lower chance for M (OR: 0.60; p </= 0.01). Urban and rural subjects had similar chance for D; urban subjects had approximately 5 times more chance for F (p </= 0.01). SES had no relationship with D and M, however SES low was associated with F (OR: 0.45; p </= 0.01). Replacements were significantly associated with age (all dental regions except anterior region), gender (all dental regions), place of residence (whole dentition and molar region), and SES (whole dentition and premolar and molar regions). CONCLUSIONS: The majority of subjects presented a reduced dentition. Molars were most frequently affected by D and M. D, M, F and replaced teeth were associated with the background variables, however differently for different dental regions. Above the age of 70 years, only 64% of the subjects presented 'not less than 20 natural teeth'
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