313 research outputs found

    Deflection and Friction Performance of Waste-Wooden Block Pavements

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    The use of waste wood for road light pavements is essential for environmental and economic sustainability.The paper investigates the mechanical performance of pavements built with waste wood elements discarded from Sardinia manufacture (Italy). Without structural value, mainly Sardinian wood is used for combustion and heating due to the characteristics of dimensional irregularity, non-homogeneity, and the presence of defects. Even small urban and forest furniture comes from foreign markets. Landscape reasons, emissions reduction, and environmental integration with the local context could encourage its use if reliable techniques are available.The study first analyzed the structural response of a portion of pavementmade with waste wood bricks (pine and Eucalyptus). Subsequently, a Finite Element simulation of the pavement has been validated with the tests' results. The experimental pavement was created with Interlocked Block Pavement (IBP) technique, using brick elements 13 x 6 x 10 cm. The behavior of the pavement was analyzed in situ with dynamic deflection tests using the Falling Weight Deflectometer test (FWD). Further tests performed in the laboratory investigated the friction of the wood pavement surface. The simulation results show that the wooden pavement elements do not differ substantially from the classic concrete IBP and HMA cracked pavement. The mean deflections are greater than 19%, while the vertical stress on the foundation layer is equivalent. As with the classic concrete IBP, the results largely depend on the bearing capacity of the substrate and the degree of interlocking.Friction tests show good values with mean values of 53 divided by 64 BPN. The most significant values were observed in the elements eucalyptus. The direction of the wood fibers also influences the results: about 3 points in the case of pine and over 7 points in the case of Eucalyptus. The study shows how the use of wood for the pavement with elements is sustainable and practicable due to the minor and low-traffic roads while also guaranteeing permeability and low-cost maintenance

    Exploring cell surface markers and cell-cell interactions of human breast milk stem cells

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    Background: Breakthrough studies have shown that pluripotent stem cells are present in human breast milk. The expression of pluripotency markers by breast milk cells is heterogeneous, relating to cellular hierarchy, from early-stage multi-lineage stem cells to fully differentiated mammary epithelial cells, as well as weeks of gestation and days of lactation. Design and methods: Here, we qualitatively analyze cell marker expression in freshly isolated human breast milk cells, without any manipulation that could influence protein expression. Moreover, we use electron microscopy to investigate cell-cell networks in breast milk for the first time, providing evidence of active intercellular communication between cells expressing different cellular markers. Results: The immunocytochemistry results of human breast milk cells showed positive staining in all samples for CD44, CD45, CD133, and Ki67 markers. Variable positivity was present with P63, Tβ4 and CK14 markers. No immunostaining was detected for Wt1, nestin, Nanog, OCT4, SOX2, CK5, and CD34 markers. Cells isolated from human breast milk form intercellular connections, which together create a cell-to-cell communication network. Conclusions: Cells freshly isolated form human breast milk, without particular manipulations, show heterogeneous expression of stemness markers. The studied milk staminal cells show "pluripotency" at different stages of differentiation, and are present as single cells or grouped cells. The adjacent cell interactions are evidenced by electron microscopy, which showed the formation of intercellular connections, numerous contact regions, and thin pseudopods

    Fast falling weight deflectometer method for condition assessment of rc bridges

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    In this paper, the use of Fast Falling Weight Deflectometer (Fast-FWD) is analyzed as a non-destructive and quick test procedure to evaluate the efficiency of short-span bridges. The FastFWD is an instrument that can produce a broadband dynamic force up to an impact value of 120 KN: The impact is constant and replicable, providing accurate action measures of bridge stiffness in a truly short period (30 ms). In this paper, a single-span reinforced concrete bridge is investigated, using the Fast-FWD. The considered bridge, approximately 12.0 m long and 15.5 m wide, was in critical condition. The bridge is in a suburban principal road near to the City of Cagliari in Sardinia (Italy), with an Annual Average Daily Traffic of 13,500 vehicles/day, and was suddenly closed, creating serious problems for urban mobility. In these conditions, the investigation through other standard techniques is time-consuming and labor intensive. For this reason, it is important to introduce methods that can be rapid, accurate and cost-efficient. In this paper, bridge stiffness values obtained during the in situ experimental campaign were compared with finite element models values. The Fast-FWD has the potential to provide engineering information that can help us to better understand bridge condition, in a rapid and cost-effective procedure

    Cell starvation increases uptake of extracellular Thymosin β4 and its complexes with calcium

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    Cell metastasis is the main cause of cancer mortality. Inhibiting early events during cell metastasis and invasion could significantly improve cancer prognosis, but the initial mechanisms of cell transition and migration are barely known. Calcium regulates cell migration, whilst Thymosin β4 is a G-actin and iron binding peptide associated with tumor metastasis and ferroptosis. Under normal cell growth conditions, intracellular free calcium ions and Thymosin β4 concentrations are strictly regulated, and are not influenced by extracellular supplementation. However, cell starvation decreases intracellular Thymosin β4 and increases extracellular peptide uptake above the normal range. Unexpectedly, cell starvation significantly increases internalization of extracellular Ca2+/Thymosin β4 complexes. Elucidating the role of Ca2+/Thymosin β4 in the early events of metastasis will likely be important in the future to develop therapies targeting metastasis

    Thymosin Beta 4 may translocate from the cytoplasm in to the nucleus in HepG2 cells following serum starvation. An ultrastructural study

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    Due to its actin-sequestering properties, thymosin beta-4 (Tβ4) is considered to play a significant role in the cellular metabolism. Several physiological properties of Tβ4 have been reported;, however, many questions concerning its cellular function remain to be ascertained. To better understand the role of this small peptide we have analyzed by means of transmission immunoelectron microscopy techniques the ultrastructural localization of Tβ4 in HepG2 cells. Samples of HepG2 cells were fixed in a mixture of 3% formaldehyde and 0.1% glutaraldehyde in 0.1 M cacodylate buffer and processed for standard electron microscopic techniques. The samples were dehydrated in a cold graded methanol series and embedded in LR gold resin. Ultrathin sections were labeled with rabbit antibodies to Tβ4, followed by gold-labeled goat anti-rabbit, stained with uranyl acetate and bismuth subnitrate, observed and photographed in a JEOL 100S transmission electron microscope. High-resolution electron microscopy showed that Tβ4 was mainly restricted to the cytoplasm of HepG2 growing in complete medium. A strong Tβ4 reactivity was detected in the perinuclear region of the cytoplasmic compartment where gold particles appeared strictly associated to the nuclear membrane. In the nucleus specific Tβ4 labeling was observed in the nucleolus. The above electron microscopic results confirm and extend previous observations at light microscopic level, highlighting the subcellular distribution of Tβ4 in both cytoplasmic and nuclear compartments of HepG2 cells. The meaning of Tβ4 presence in the nucleolus is not on the best of our knowledge clarified yet. It could account for the interaction of Tβ4 with nucleolar actin and according with this hypothesis, Tβ4 could contribute together with the other nucleolar acting binding proteins to modulate the transcription activity of the RNA polymeras

    Nurses’ behavior regarding pain treatment in an emergency department: A single-center observational study

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    Purpose: The aim of this prospective study was to assess the behavior of emergency department (ED) nurses with regard to pain and their role in pain management in a real-life clinical setting. Methods: A total of 509 consecutive patients were enrolled during a 6-week period. A case-report form was used to collect data on nurses’ approaches to pain, time to analgesia provision, and patient-perceived quality of analgesia. Results: Triage nurses actively inquired about pain in almost every case, but they did not estimate pain intensity in a third of patients. In the majority of cases, triage nurses did not report pain-related findings to the physician, who was the only professional that could prescribe analgesia to patients. The assignment of the color-coding of triage by nurses appears to be related to the perceived severity of the clinical case and a more comprehensive evaluation of pain. More than half of patients were at least fairly satisfied with analgesia. Conclusion: Pain is increasingly screened during triage, but its comprehensive assessment and management still lack systematic application. We believe that further education and implementation of analgesia protocols may empower nurses to manage ED patients’ pain more effectively and in a more timely manner

    Regulação emocional e memória de trabalho no desempenho acadêmico

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    The objective of this work was to analyze the relationship between emotional regulation strategies, cognitive reappraisal applied to home school tasks (CR-HST) and emotional management applied to home school tasks (EM-HST) on academic performance (AP) controlling working memory difficulties (WM-diff) in children who finished Primary Education. A self-report questionnaire to assess CR-HST and EM-HST was administered to 119 fourth, fifth and sixth grade children (9 to 11 years old) and two questionnaires to their teachers to assess their AP and WM difficulties. The results showed that EM-HST was associated with the success, academic productivity, mathematics and reading dimensions of AP, even when WM-diff was controlled. There were no significant associations between CR-HST and AP, or any of the strategies on impulse control in academic situations. The results are expected to deepen the understanding of the role of emotional regulation in AP and thus contribute to the content of programs for promoting emotional regulation designed for school contexts.El objetivo de este trabajo fue analizar la relación de las estrategias de regulación emocional reevaluación cognitiva aplicada a tareas escolares para el hogar (RC-TEH) y manejo emocional aplicado a tareas escolares para el hogar (ME-TEH) sobre el desempeño académico (DA) controlando dificultades de memoria de trabajo (dif-MT) en niños que finalizaban la Educación Primaria. Se administró un cuestionario de autoinforme para evaluar la RC-TEH y el ME-TEH a 119 de niños de cuarto, quinto y sexto grado (9 a 11 años de edad) y dos cuestionarios a sus maestros para evaluar su DA y dificultades de MT. Los resultados mostraron que el ME-TEH se asoció con las dimensiones éxito, productividad académica, matemáticas y lectura del DA, incluso cuando se controlaron dif-MT. No se observaron asociaciones significativas de la RC-TEH con el DA, ni de ninguna de las estrategias sobre el control del impulso en situaciones académicas. Se espera que los resultados profundicen en el conocimiento del rol de la regulación emocional en el DA y contribuyan así al contenido de programas de promoción de la regulación emocional diseñados para contextos escolares.O objetivo deste trabalho foi analisar a relação entre as estratégias de regulação emocional de reavaliação cognitiva aplicada ao dever de casa (RC-DDC) e a gestão emocional aplicada ao dever de casa (GE-DDE) sobre o desempenho acadêmico (DA) controlando as dificuldades de memória de trabalho (dif-MT) em crianças que terminam o Ensino Fundamental. Foi administrado um questionário de auto-relato para avaliar RC-DDC e GE-DDE a 119 crianças de quarto, quinto e sexto grau (9-11 anos), e dois questionários foram administrados a seus professores para avaliar suas dificuldades de DA e MT. Os resultados mostraram que a RC-DDC estava associada ao sucesso, produtividade acadêmica, matemática e leitura da DA, mesmo quando se controla a dif-MT. Não foram observadas associações significativas para RC-DDC com DA, nem para nenhuma das estratégias de controle de impulsos em situações acadêmicas. Espera-se que os resultados aprofundem a compreensão do papel da regulação emocional na DA e assim contribuam para o conteúdo de programas que promovam a regulação emocional projetada para ambientes escolares
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