742 research outputs found
The key role of micrornas in self-renewal and differentiation of embryonic stem cells
NaĂŻve pluripotent embryonic stem cells (ESCs) and epiblast stem cells (EpiSCs) represent distinctive developmental stages, mimicking the pre-and the post-implantation events during the embryo development, respectively. The complex molecular mechanisms governing the transition from ESCs into EpiSCs are orchestrated by fluctuating levels of pluripotency transcription factors (Nanog, Oct4, etc.) and wide-ranging remodeling of the epigenetic landscape. Recent studies highlighted the pivotal role of microRNAs (miRNAs) in balancing the switch from self-renewal to differentiation of ESCs. Of note, evidence deriving from miRNA-based reprogramming strategies underscores the role of the non-coding RNAs in the induction and maintenance of the stemness properties. In this review, we revised recent studies concerning the functions mediated by miRNAs in ESCs, with the aim of giving a comprehensive view of the highly dynamic miRNA-mediated tuning, essential to guarantee cell cycle progression, pluripotency maintenance and the proper commitment of ESCs
Potential energy savings from circular economy scenarios based on construction and agri-food waste in Italy
In this study, our aim was to explore the potential energy savings obtainable from the recycling of 1 tonne of Construction and Demolition Waste (C&DW) generated in the Metropolitan City of Naples. The main fraction composing the functional unit are mixed C&DW, soil and stones, concrete, iron, steel and aluminium. The results evidence that the recycling option for the C&DW is better than landfilling as well as that the production of recycled aggregates is environmentally sustainable since the induced energy and environmental impacts are lower than the avoided energy and environmental impacts in the life cycle of recycled aggregates. This LCA study shows that the transition to the Circular Economy offers many opportunities for improving the energy and environmental performances of the construction sector in the life cycle of construction materials by means of internal recycling strategies (recycling C&DW into recycled aggregates, recycled steel, iron and aluminum) as well as external recycling by using input of other sectors (agri-food by-products) for the manufacturing of construction materials. In this way, the C&D sector also contributes to realizing the energy and bioeconomy transition by disentangling itself from fossil fuel dependence
Single-mode regime in large-mode-area rare-earth-doped rod-type PCFs
In this paper, large-mode-area, double-cladding, rare-earth-doped photonic crystal fibers are investigated in order to understand how the refractive index distribution and the mode competition given by the amplification can assure singlemode
propagation. Fibers with different core diameters, i.e., 35,60, and 100 ÎĽm, are considered. The analysis of the mode effective index, overlap, effective area, gain, and power evolution along the doped fiber provides clear guidelines on the fiber physical characteristics to be matched in the fabrication process to obtain a truly or effectively single-mode output beam
MicroRNA Roles in Cell Reprogramming Mechanisms
Cell reprogramming is a groundbreaking technology that, in few decades, generated a new paradigm in biomedical science. To date we can use cell reprogramming to potentially generate every cell type by converting somatic cells and suitably modulating the expression of key transcription factors. This approach can be used to convert skin fibroblasts into pluripotent stem cells as well as into a variety of differentiated and medically relevant cell types, including cardiomyocytes and neural cells. The molecular mechanisms underlying such striking cell phenotypes are still largely unknown, but in the last decade it has been proven that cell reprogramming approaches are significantly influenced by non-coding RNAs. Specifically, this review will focus on the role of microRNAs in the reprogramming processes that lead to the generation of pluripotent stem cells, neurons, and cardiomyocytes. As highlighted here, non-coding RNA-forced expression can be sufficient to support some cell reprogramming processes, and, therefore, we will also discuss how these molecular determinants could be used in the future for biomedical purposes
In-Line-Test of Variability and Bit-Error-Rate of HfOx-Based Resistive Memory
Spatial and temporal variability of HfOx-based resistive random access memory
(RRAM) are investigated for manufacturing and product designs. Manufacturing
variability is characterized at different levels including lots, wafers, and
chips. Bit-error-rate (BER) is proposed as a holistic parameter for the write
cycle resistance statistics. Using the electrical in-line-test cycle data, a
method is developed to derive BERs as functions of the design margin, to
provide guidance for technology evaluation and product design. The proposed BER
calculation can also be used in the off-line bench test and build-in-self-test
(BIST) for adaptive error correction and for the other types of random access
memories.Comment: 4 pages. Memory Workshop (IMW), 2015 IEEE Internationa
DTM-based morphometry of the Palinuro seamount (Eastern Tyrrhenian Sea): Geomorphological and volcanological implications
We present a high resolution DTM of the Palinuro Seamount (PS, Tyrrhenian Sea, Italy) resulting from the
processing of multibeam swath bathymetry records acquired during the second leg of the “Aeolian 2007”
cruise. PS consists of several superimposed volcanoes aligned along a N100°E strike and measures
55Ă—25 km. The western and the central sectors result from the coalescence of collapse structures (calderas)
with younger volcanic cones. The eastern sector reveals a more complex and articulated structure. In the
central sector, a volcanic crater with a well-preserved rim not obliterated by erosional events suggests a
volcanological rejuvenation of this sector. The presence of flat surfaces on the top of the seamount may be
due to the formation of marine terraces during the last sea-level lowering. Lateral collapses on the northern
and southern flanks of the seamount are probably related to slope instability, as suggested by the presence of
steep slopes (25–40°). The main fault affecting PS strikes N65°E and shows a right lateral component of
movement. E–W and N10°E striking faults are also present.
Assuming that theN100°E deep-seated fault,which is responsible for theemplacement of PS,movedwith sinistral
slips, we interpret the N65°E and the N10°E faults as right-lateral (second order) shear and left-lateral (third
order) shear, respectively. Due to the particular location of the Palinuro Seamount, the data presented here allow
us to better understand the volcanism and the geodynamic processes of the Tyrrhenian Sea
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