144 research outputs found

    L1CAM expression in endometrial carcinomas is regulated by usage of two different promoter regions

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    <p>Abstract</p> <p>Background</p> <p>The L1 cell adhesion molecule (L1CAM) was originally identified as a neural adhesion molecule involved in axon guidance. In many human epithelial carcinomas L1CAM is overexpressed and thereby augments cell motility, invasion and metastasis formation. L1CAM positive carcinomas are associated with bad prognosis. Recent data point out that L1CAM is regulated in a fashion similar to epithelial-mesenchymal transition (EMT). Previous studies have implied the transcription factors Slug and/or β-catenin in <it>L1CAM </it>transcriptional regulation. However, the regulation of human L1CAM expression at the transcriptional level is not well understood.</p> <p>Results</p> <p>To better understand the molecular basis of <it>L1CAM </it>transcriptional regulation, we carried out a detailed characterization of the human <it>L1CAM </it>promoter. We identified two transcription start sites, the first in front of a non-translated exon 0 (promoter 1) and the other next to the first protein-coding exon 1 (promoter 2). Both sites could be verified in endometrial carcinoma (EC) cell lines and appear to be used in a cell-type specific manner. The two identified promoter regions showed activity in luciferase reporter assays. Chromatin-IP analyses confirmed the <it>in silico </it>predicted E-boxes, binding sites for transcription factors Snail and Slug, as well as Lef-1 sites, which are related to β-catenin-mediated transcriptional regulation, in both promoters. Overexpression of β-catenin exclusively augmented activity of promoter 1 whereas Slug enhanced promoter 1 and 2 activity suggesting that both promoters can be active. Overexpression of β-catenin or Slug could upregulate L1CAM expression in a cell-type specific manner.</p> <p>Conclusions</p> <p>Our results, for the first time, provide evidence that the L1CAM gene has two functionally active promoter sites that are used in a cell-type specific manner. Slug and β-catenin are involved <it>L1CAM </it>transcriptional regulation. Nevertheless, Slug rather than β-catenin levels are correlated with L1CAM expression in EC cell lines. Our findings suggest that the <it>L1CAM </it>transcriptional regulation is more complex than anticipated and this study provides the basis for a better understanding of L1CAM regulation in non-neuronal/tumor cells.</p

    Анализ энергоэффективности использования древесной биомассы второго сорта для выработки тепловой и электрической энергии

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    Объектом исследования является древесная биомасса второго сорта и ее энергетическая эффективность. Цель работы – исследовать современное состояние литературных источников по процессу сушки и энергетической эффективности подготовки древесной биомассы для выработки тепловой и электрической энергии в России и других странах мира.The object of study is woody biomass of second grade and its energy efficiency. The aim of this work is to study the modern state of literature on the drying process and the energy efficiency of preparing woody biomass for generation of thermal and electric energy in Russia and other countries of the world

    A INSERÇÃO PROFISSIONAL E AS CONDIÇÕES DE TRABALHO DO ASSISTENTE SOCIAL NA ASSISTÊNCIA ESTUDANTIL DA UFSC

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    Anais III Seminário Nacional Serviço Social, Trabalho e Política SocialEste artigo trata do trabalho do/da assistente social na área da Assistência Estudantil na Universidade Federal de Santa Catarina (UFSC). As análises se construíram a partir de estudo dos documentos institucionais, da legislação e da bibliografia da área desenvolvidas durante processo de supervisão direta de estágio, envolvendo estagiário, supervisora de campo e supervisora acadêmica. Identificou-se elementos do Programa Nacional de Assistência Estudantil (PNAES); a forma como a política de Assistência Estudantil se organiza na UFSC; a constituição da equipe e as atribuições profissionais do Serviço Social; e ainda, traz observações acerca das condições de trabalho da equipe para o atendimento aos estudantes usuários da assistência estudantil na UFSC

    Annexin A1 Deficiency does not Affect Myofiber Repair but Delays Regeneration of Injured Muscles.

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    Repair and regeneration of the injured skeletal myofiber involves fusion of intracellular vesicles with sarcolemma and fusion of the muscle progenitor cells respectively. In vitro experiments have identified involvement of Annexin A1 (Anx A1) in both these fusion processes. To determine if Anx A1 contributes to these processes during muscle repair in vivo, we have assessed muscle growth and repair in Anx A1-deficient mouse (AnxA1-/-). We found that the lack of Anx A1 does not affect the muscle size and repair of myofibers following focal sarcolemmal injury and lengthening contraction injury. However, the lack of Anx A1 delayed muscle regeneration after notexin-induced injury. This delay in muscle regeneration was not caused by a slowdown in proliferation and differentiation of satellite cells. Instead, lack of Anx A1 lowered the proportion of differentiating myoblasts that managed to fuse with the injured myofibers by days 5 and 7 after notexin injury as compared to the wild type (w.t.) mice. Despite this early slowdown in fusion of Anx A1-/- myoblasts, regeneration caught up at later times post injury. These results establish in vivo role of Anx A1 in cell fusion required for myofiber regeneration and not in intracellular vesicle fusion needed for repair of myofiber sarcolemma

    Enhanced Electrochemical Capacity of Spherical Co-Free Li1.2_{1.2}Mn0.6_{0.6}Ni0.2_{0.2}O2_{2} Particles after a Water and Acid Treatment and its Influence on the Initial Gas Evolution Behavior

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    Li-rich layered oxides (LRLO) with specific energies beyond 900 Wh kg1^{−1} are one promising class of high-energy cathode materials. Their high Mn-content allows reducing both costs and the environmental footprint. In this work, Co-free Li1.2_{1.2}Mn0.6_{0.6}Ni0.2_{0.2}O2_{2} was investigated. A simple water and acid treatment step followed by a thermal treatment was applied to the LRLO to reduce surface impurities and to establish an artificial cathode electrolyte interface. Samples treated at 300 °C show an improved cycling behavior with specific first cycle capacities of up to 272 mAh g1^{−1}, whereas powders treated at 900 °C were electrochemically deactivated due to major structural changes of the active compounds. Surface sensitive analytical methods were used to characterize the structural and chemical changes compared to the bulk material. Online DEMS measurements were conducted to get a deeper understanding of the effect of the treatment strategy on O2_2 and CO2_2 evolution during electrochemical cycling

    Origin of Aging of a P2-Nax_xMn3/4_{3/4}Ni1/4_{1/4}O2_2 Cathode Active Material for Sodium-Ion Batteries

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    Sodium-ion batteries (SIB) are currently being developed and commercialized as a promising new technology for cost-effective and powerful electrical energy storage. In this study, we investigate the origin of capacity fading in P2-type layered sodium cathode materials for SIBs using a micron-sized single-crystalline P2-Nax_xMn3/4_{3/4}Ni1/4_{1/4}O2_2 model cathode active material. Using various electrochemical techniques, we identify the following aging effects upon cycling: (i) a state of charge (SOC)-independent increase in polarization, (ii) a SOC-dependent increase in polarization at high voltage, and (iii) a loss of active material due to electronic disconnection after prolonged cycling. With high-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray (EDX) spectroscopy, we identify surface densification, resulting in 5–10 nm thick surface layers on cycled cathode active materials as the origin for SOC-independent increase of polarization. The corresponding oxygen loss is in accordance with gas evolution in differential electrochemical mass spectrometry (DEMS) measurements. Furthermore, with scanning electron microscopy (SEM) electrode cross sections, we identify (partly) reversible cracking at a high SOC as the cause for increased polarization depending on SOC. Operando X-ray diffraction (XRD) identifies significant anisotropic volume change, which suggests mechanical stress as the cause for cracking at a high SOC and loss of active material after prolonged cycling. We believe that the herein provided understanding on the aging of this highly attractive class of cathode active materials for SIBs will enable the development of future powerful and stable layered oxide cathode materials for SIBs

    Interleukin-6-dependent survival of multiple myeloma cells involves the Stat3-mediated induction of micro-RNA-21 through a highly conserved enhancer

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    Signal transducer and activator of transcription 3 (Stat3) is implicated in the pathogenesis of many malignancies and essential for IL-6–dependent survival and growth of multiple myeloma cells. Here, we demonstrate that the gene encoding oncogenic microRNA-21 (miR-21) is controlled by an upstream enhancer containing 2 Stat3 binding sites strictly conserved since the first observed evolutionary appearance of miR-21 and Stat3. MiR-21 induction by IL-6 was strictly Stat3 dependent. Ectopically raising miR-21 expression in myeloma cells in the absence of IL-6 significantly reduced their apoptosis levels. These data provide strong evidence that miR-21 induction contributes to the oncogenic potential of Stat3
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