110 research outputs found
Retarding cement hydration by increasing temperature
Trabajo presentado a la 12th International Conference on Superplasticizers and Other Chemical Admixtures in Concrete, celebrada en Bejing (China) del 28 al 31 de octubre de 2018.Specific polymer structures at particular dosages have been identified to be able to delay cement hydration as temperature increases. The aim of the present work is to understand the underlying mechanisms involved behind this unexpected phenomenon. In particular, hydration kinetics of chemically admixed cement pastes at different temperatures have been related to the mineralogical changes in pastes, chemical composition of the pore solution and rheological properties. Results have demonstrated a dramatic increase in the low- concentration elements (Si, Al, Mg and Fe) in the pore solution of admixed samples hydrated at room temperature. At this temperature, nano-particles (polymer aggregates involving complexes and/or organoaluminates) have been detected. In contrast, nano-particles are not present at higher temperatures, when the delay of hydration is observed. This could lead to a higher amount of free polymer in the pore solution leading to a greater delay of silicates hydration.This research has been funded by the SP-SC 01-14 and SCCER-SoE projects
Melatonin regulates mesenchymal stem cells differentiation : a review
none10Among the numerous functions of melatonin, the control of survival and differentiation of mesenchymal stem cells (MSCs) has been recently proposed. MSCs are a heterogeneous population of multipotent elements resident in tissues such as bone marrow, muscle, and adipose tissue, which are primarily involved in developmental and regeneration processes, gaining thus increasing interest for tissue repair and restoration therapeutic protocols. Receptor-dependent and receptor-independent responses to melatonin are suggested to occur in these cells. These involve antioxidant or redox-dependent functions of this indolamine as well as secondary effects resulting from autocrine and paracrine responses. Inflammatory cytokines and adipokines, proangiogenic/mitogenic stimuli, and other mediators that influence the differentiation processes may affect the survival and functional integrity of these mesenchymal precursor cells. In this scenario, melatonin seems to regulate signaling pathways that drive commitment and differentiation of MSC into osteogenic, chondrogenic, adipogenic, or myogenic lineages. Common pathways suggested to be involved as master regulators of these processes are the Wnt/b-catenin pathway, the MAPKs and the, TGF-b signaling. In this respect melatonin emerges a novel and potential modulator of MSC lineage commitment and adipogenic differentiation. These and other aspects of the physiological and pharmacological effects of melatonin as regulator of MSC are discussed in this review.openLuchetti, Francesca; Canonico, Barbara; Bartolini, Desiree; Arcangeletti, Marcella; Ciffolilli, Silvia; Murdolo, Giuseppe; Piroddi, Marta; Papa, Stefano; Reiter, Russel J.; Galli, FrancescoLuchetti, Francesca; Canonico, Barbara; Bartolini, Desiree; Arcangeletti, Marcella; Ciffolilli, Silvia; Murdolo, Giuseppe; Piroddi, Marta; Papa, Stefano; Reiter, Russel J.; Galli, Francesc
Non-Hodgkin Lymphoma in Children and Adolescents: Progress Through Effective Collaboration, Current Knowledge, and Challenges Ahead
Non-Hodgkin lymphoma is the fourth most common malignancy in children, has an even higher incidence in adolescents, and is primarily represented by only a few histologic subtypes. Dramatic progress has been achieved, with survival rates exceeding 80%, in large part because of a better understanding of the biology of the different subtypes and national and international collaborations. Most patients with Burkitt lymphoma and diffuse large B-cell lymphoma are cured with short intensive pulse chemotherapy containing cyclophosphamide, cytarabine, and high-dose methotrexate. The benefit of the addition of rituximab has not been established except in the case of primary mediastinal B-cell lymphoma. Lymphoblastic lymphoma is treated with intensive, semi-continuous, longer leukemia-derived protocols. Relapses in B-cell and lymphoblastic lymphomas are rare and infrequently curable, even with intensive approaches. Event-free survival rates of approximately 75% have been achieved in anaplastic large-cell lymphomas with various regimens that generally include a short intensive B-like regimen. Immunity seems to play an important role in prognosis and needs further exploration to determine its therapeutic application. ALK inhibitor therapeutic approaches are currently under investigation. For all pediatric lymphomas, the intensity of induction/consolidation therapy correlates with acute toxicities, but because of low cumulative doses of anthracyclines and alkylating agents, minimal or no long-term toxicity is expected. Challenges that remain include defining the value of prognostic factors, such as early response on positron emission tomography/computed tomography and minimal disseminated and residual disease, using new biologic technologies to improve risk stratification, and developing innovative therapies, both in the first-line setting and for relapse
The Living and Working Together Perspective on Creativity in Organizations
Although creativity represents a cornerstone for organizations that want to keep up with competitors, customers, and the current socio-economic context, there is a dearth in the literature of systemic and comprehensive models focused on the complexity and addressing several dimensions and factors. In this context, we propose the perspective of “working and living together in organizations” to enrich the scientific dialogue with a proposition that aims to hold together different variables of interaction and relationship between different parts of the organization (Gozzoli, 2016a,b). In fact, according to our previous studies (Frascaroli et al., 2016; Gorli et al., 2016; Marta et al., 2016; Saita et al., 2016; Tamanza et al., 2016), a generative living and working together environment is itself directly linked to creativity and innovative processes. This is because in a generative living and working together environment relationality – that is, the possibility of exchange among workers mediated by the object of work – is enabled. With this study, we intend to provide a contribution to the creativity study field, applying our perspective to an extensive level of analysis. The model was tested using the Exploratory Structural Equation Modeling methodology with EQS-6.3. Our results found some interesting elements in support of the theory behind this study
Trudne, bo nietypowe przypadki guzów litych u dzieci
Nietypowy obraz kliniczny nowotworów wieku dziecięcego niejednokrotnie stwarza trudności
diagnostyczne i staje się przyczyną opóźnień w ustaleniu rozpoznania. Poniżej
przedstawiamy troje dzieci z rozpoznaniami guzów litych o nietypowym przebiegu klinicznym,
leczonych w Klinice Pediatrii, Hematologii, Onkologii i Endokrynologii Akademii
Medycznej w Gdańsku
Recommended from our members
Prognostic Factors in Childhood Anaplastic Large Cell Lymphoma: Long Term Results of the International ALCL99 Trial
With the aim of describing the long-term follow-up and to define the prognostic role of the clinical/pathological/molecular characteristics at diagnosis for childhood, adolescent and young adults affected by anaplastic large cell lymphoma (ALCL), we analyzed 420 patients aged up to 22 years homogeneously treated within the international ALCL99 trial. The 10-year progression free survival (PFS) was 70% and overall survival was 90%, rare late relapses occurred but no secondary malignancies were reported. Among clinical/pathological characteristics, only patients presenting a small cell/lymphohistiocytic (SC/LH) pattern were independently associated with risk of failure (hazard ratio = 2.49). Analysis of minimal disseminated disease (MDD), available for 162 patients, showed that both SC/LH pattern (hazard ratio = 2.4) and MDD positivity (hazard ratio = 2.15) were significantly associated with risk of failure in multivariate analysis. Considering MDD and SC/LH results, patients were separated into three biological/pathological (bp) risk groups: a high-risk group (bpHR) including MDD-positive patients with SC/LH pattern; a low-risk group (bpLR) including MDD-negative patients without SC/LH pattern; and an intermediate-risk group (bpIR) including remaining patients. The 10-year PFS was 40%, 75% and 86% for bpHR, bpIR and bpLR, respectively (p 0.0001). These results should be considered in the design of future ALCL trials to tailor individual treatments
A Game-Theoretic approach to Fault Diagnosis of Hybrid Systems
Physical systems can fail. For this reason the problem of identifying and
reacting to faults has received a large attention in the control and computer
science communities. In this paper we study the fault diagnosis problem for
hybrid systems from a game-theoretical point of view. A hybrid system is a
system mixing continuous and discrete behaviours that cannot be faithfully
modeled neither by using a formalism with continuous dynamics only nor by a
formalism including only discrete dynamics. We use the well known framework of
hybrid automata for modeling hybrid systems, and we define a Fault Diagnosis
Game on them, using two players: the environment and the diagnoser. The
environment controls the evolution of the system and chooses whether and when a
fault occurs. The diagnoser observes the external behaviour of the system and
announces whether a fault has occurred or not. Existence of a winning strategy
for the diagnoser implies that faults can be detected correctly, while
computing such a winning strategy corresponds to implement a diagnoser for the
system. We will show how to determine the existence of a winning strategy, and
how to compute it, for some decidable classes of hybrid automata like o-minimal
hybrid automata.Comment: In Proceedings GandALF 2011, arXiv:1106.081
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
Simulation results for future measurements of electromagnetic proton form
factors at \PANDA (FAIR) within the PandaRoot software framework are reported.
The statistical precision with which the proton form factors can be determined
is estimated. The signal channel is studied on the basis
of two different but consistent procedures. The suppression of the main
background channel, , is studied.
Furthermore, the background versus signal efficiency, statistical and
systematical uncertainties on the extracted proton form factors are evaluated
using two different procedures. The results are consistent with those of a
previous simulation study using an older, simplified framework. However, a
slightly better precision is achieved in the PandaRoot study in a large range
of momentum transfer, assuming the nominal beam conditions and detector
performance
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