425 research outputs found
Multicolor Licklider Transmission Protocol: An LTP Version for Future Interplanetary Links
The Licklider Transport Protocol (LTP) is the "convergence layer" of choice in Interplanetary networks based on Delay-/Disruption-Tolerant architecture. It was designed for long-delay scheduled-intermittent links, offering either a reliable or an unreliable service, with "red" and "green" parts, respectively. The aim of this article is to present multicolor LTP, an LTP version consisting in a series of enhancements of which the most significant are the use of monochrome sessions, the introduction of an additional orange color offering a "notified" service, and the definition of default link colors. After a thorough examination of basic LTP mechanisms for all color variants, this article discusses two scenarios where orange seems particularly appealing: video streaming and optical interplanetary links. Numerical results offer further insight into the complex LTP mechanisms and also highlight the difference between LTP retransmissions and bundle protocol retransmissions, the latter benefitting from routing reprocessing. Multicolor LTP has already been implemented as an interplanetary overlay network (ION) plug-in and its enhancements have been proposed to Consultative Committee for Space Data Systems Space Internetworking Services Delay-/Disruption-Tolerant Networking working group for a possible inclusion in the next version of LTP specifications (LTPv2)
MiR-205-5p inhibition by locked nucleic acids impairs metastatic potential of breast cancer cells
Mir-205 plays an important role in epithelial biogenesis and in mammary gland development but its role in cancer still remains controversial depending on the specific cellular context and target genes. We have previously reported that miR-205-5p is upregulated in breast cancer stem cells targeting ERBB pathway and leading to targeted therapy resistance. Here we show that miR-205-5p regulates tumorigenic properties of breast cancer cells, as well as epithelial to mesenchymal transition. Silencing this miRNA in breast cancer results in reduced tumor growth and metastatic spreading in mouse models. Moreover, we show that miR-205-5p knock-down can be obtained with the use of specific locked nucleic acids oligonucleotides in vivo suggesting a future potential use of this approach in therapy
The manufacture and products thereof of photo-sensitizing nanomaterials and their use in photodynamic treatments
A method for the manufacture of a photosensitizing nanoma
terial (40) and the products thereof are disclosed. The method
for the treatment of a biological target (50) is disclosed. The
photosensitizing nanomaterial (40) comprises a metal com
plex tetrapyrrole derivative (10). The metal complex tetrapy
rrole derivative (10) is attached by an axial covalent bond (60)
to the surface (25) of a solid nanomaterial (20). The solid
nanomaterial (20) has at least one dimension in the nanometer and/ or the micrometer range
From Connectivity to Advanced Internet Services: A Comprehensive Review of Small Satellites Communications and Networks
Recently the availability of innovative and affordable COTS (Commercial Off The Shelf) technological solutions
and the ever improving results of microelectronics and microsystems technologies have enabled the design of ever
smaller yet ever more powerful satellites. The emergence of very capable small satellites heralds an era of new
opportunities in the commercial space market. Initially applied only to scientific missions, earth observation and
remote sensing, small satellites are now being deployed to support telecommunications services. This review paper
examines the operational features of small satellites that contribute to their success. An overview of recent advances
and development trends in the field of small satellites is provided, with a special focus on telecommunication aspects
such as the use of higher frequency bands, optical communications, new protocols, and advanced architectures
The application of the Boolean Stochastic Generation Method to model seepage under levees in heterogeneous soils
Soil heterogeneity plays an important role in incrementing the uncertainty about the reliability of geotechnical engineering works, especially levees. The presence of thin layers of soils more permeable than the surrounding matrix significantly changes the seepage flow net below and within the dike. However, the detection of these layers is extremely difficult. Consequently, to evaluate the overall safety of dikes it may be useful to adopt stochastic computation methods. The paper presents the calibration of a seepage model of an operational river embankment subject to sand boils. The levee, located along the Adige River (South Tyrol, Italy), has been monitored since 2016. Piezometers and spot temperature sensors are installed in the lateral banks while a distributed fiber optic sensors (FOS), buried in a 350 m long trench at the toe of the levee, is used to check temperature distribution in the subground. The Boolean Stochastic Generation (BoSG) method addresses the influence of layers of material with different properties with respect of the surrounding soil. 360 soil configurations were generated for a two-dimensional groundwater flow model of the levee and confronted with the monitoring data of two piezometers. This analysis permits to identify the configuration that has effects more congruent with piezometers data, which in this case is a configuration with a major presence of lenses on the waterside respect the field-side. This evidence could guide strategies for remedial works
Transport layer protocols and architectures for satellite networks
Designing efficient transmission mechanisms for advanced satellite networks is a demanding task, requiring the definition and the implementation of protocols and architectures well suited to this challenging environment. In particular, transport protocols performance over satellite networks is impaired by the characteristics of the satellite radio link, specifically by the long propagation delay and the possible presence of segment losses due to physical channel errors. The level of impact on performance depends upon the link design (type of constellation, link margin, coding and modulation) and operational conditions (link obstructions, terminal mobility, weather conditions, etc.). To address these critical aspects a number of possible solutions have been presented in the literature, ranging from limited modifications of standard protocols (e.g. TCP, transmission control protocol) to completely alternative protocol and network architectures. However, despite the great number of different proposals (or perhaps also because of it), the general framework appears quite fragmented and there is a compelling need of an integration of the research competences and efforts. This is actually the intent of the transport protocols research line within the European SatNEx (Satellite Network of Excellence) project. Stemming from the authors' work on this project, this paper aims to provide the reader with an updated overview of all the possible approaches that can be pursued to overcome the limitations of current transport protocols and architectures, when applied to satellite communications. In the paper the possible solutions are classified in the following categories: optimization of TCP interactions with lower layers, TCP enhancements, performance enhancement proxies (PEP) and delay tolerant networks (DTN). Advantages and disadvantages of the different approaches, as well as their interactions, are investigated and discussed, taking into account performance improvement, complexity, and compliance to the standard semantics. From this analysis, it emerges that DTN architectures could integrate some of the most efficient solutions from the other categories, by inserting them in a new rigorous framework. These innovative architectures therefore may represent a promising solution for solving some of the important problems posed at the transport layer by satellite networks, at least in a medium-to-long-term perspective. Copyright (c) 2006 John Wiley & Sons, Ltd
Rhenium complex as emitting material in highly efficient phosphorescent organic light-emitting diodes
Interest in luminescent materials able to efficiently emit in the solid state is continuously
growing, because in most applications the dyes are used as solid films. This is the case of the
Organic Light Emitting Diodes (OLEDs), where electroluminescent
metal complexes have been widely investigated as dopants, able to
increase their performances [1]. We present here a dinuclear Re(I)
complexes (1, see Scheme 1) whose emission is higher in solid state
and in PMMA matrix than in solution and is used as dopant in
OLEDs.
This complex belong to the family of neutral Re(I) complexes
with general formula [Re2(CO)6(\u3bc-1,2-diazine)(\u3bc-X)2], where X is halogen. Some of them
have recently gained interest for their intense yellow/green emission, occurring from triplet
metal-to-ligand charge transfer (3MLCT) states [2], showing a modulation effect of the
diazine substituents on wavelengths, lifetimes and quantum yields of the emission. \u3a6 up to
0.53 has been measured for the di-chloro complexes containing diazines bearing alkyl groups
in both the \u3b2 positions [3]. At variance with the chloro derivatives, the bromo analogue 1 is
almost not-emitting in solution (\u3a6em 0.002 in deareated toluene). We have now found that in
the solid state 1 shows intense yellow-orange emission (\u3a6em 0.50 in neat powder), blue
shifted with respect to the solution (560 nm vs. 620 nm). The emission is intense also in
PMMA matrix (\u3a6em 0.19 in PMMA at 10% w/w, 556 nm).
This very high aggregated emission here is discussed in terms of the restriction of the
intramolecular roto-vibrational motions of the \u201cRe2(CO)6(\u3bc-Br)2\u201d scaffold imposed by the
rigid environment, as evidenced by the strong decrease of the knr. Moreover a parallel increase
of kr is noticed, which clearly shows the influence of the halides in determining not only the
energy of the excited state, but also the nature of the lowest (emitting) state.
These properties allowed its successful use as a phosphorescent dopant in OLEDs and
here we report the performances of OLED devices prepared both by solution- and vacuumprocessing.
The values of the external quantum efficiency are 1.7% (4.3 cd/A and 1.7 lm/W)
and 10% (29.1 cd/A and 22.1 lm/W) respectively and are the highest ever reported for
rhenium-based devices, comparable to state-of-the-art devices employing Ir(III)- and Pt(II)-
based metal complexes. The combination of synthetic strategy and encouraging results in
potential OLEDs applications should make these dinuclear Re(I) complexes highly attractive
to a broad spectrum of research fields.
1. \u201cHighly efficient OLEDs with Phosphorescent Materials\u201d H. Yersin Ed. Wiley-VCH, (2008).
2. D. Donghi, G. D\u2019Alfonso, M. Mauro, M. Panigati, P. Mercandelli, A. Sironi, P. Mussini, L. D\u2019Alfonso, Inorg.
Chem. 28 (2008) 4243-4255.
3. M. Mauro, E. Quartapelle Procopio, Y. Sun, C. H. Chien, D. Donghi, M. Panigati, P. Mercandelli, P. Mussini,
G. D\u2019Alfonso, L. De Cola, Adv. Funct. Mater. 19 (2009) 2607-2614
Climate change impacts on plant phenology: Grapevine (vitis vinifera) bud break in wintertime in southern italy
The effects of global warming on plants are not limited to the exacerbation of summer stresses; they could also induce dormancy dysfunctions. In January 2020, a bud break was observed in an old poly-varietal vineyard. Meteorological data elaboration of the 1951–2020 period confirmed the general climatic warming of the area and highlighted the particular high temperatures of the last winter. Phenological records appeared to be significantly correlated to wood hydration and starch reserve consumption, demonstrating a systemic response of the plant to the warm conditions. The eight cultivars, identified by single-nucleotide polymorphism (SNP) profiles and ampelographic description, grown in this vineyard showed different behaviors. Among them, the neglected Sprino, Baresana, Bianco Palmento, and Uva Gerusalemme, as well as the interspecific hybrid Seyve Villard 12.375, appeared to be the most interesting. Among the adaptation strategies to climate changes, the cultivar selection should be considered a priority, as it reduces the inputs required for the plant management over the entire life cycle of the vineyard. Hot Mediterranean areas, such as Salento, are a battlefront against the climate change impacts, and, thus, they represent a precious source of biodiversity for viticulture
p63 isoforms regulate metabolism of cancer stem cells
p63 is an important regulator of epithelial
development expressed in different variants containing (TA)
or lacking (\u394N) the N-terminal transactivation domain. The
different isoforms regulate stem-cell renewal and differentiation
as well as cell senescence. Several studies indicate
that p63 isoforms also play a role in cancer development;
however, very little is known about the role played by p63 in
regulating the cancer stem phenotype. Here we investigate the
cellular signals regulated by TAp63 and \u394Np63 in a model of
epithelial cancer stem cells. To this end, we used colon cancer
stem cells, overexpressing either TAp63 or \u394Np63 isoforms,
to carry out a proteomic study by chemical-labeling approach
coupled to network analysis. Our results indicate that p63 is
implicated in a wide range of biological processes, including metabolism. This was further investigated by a targeted strategy at
both protein and metabolite levels. The overall data show that TAp63 overexpressing cells are more glycolytic-active than \u394Np63
cells, indicating that the two isoforms may regulate the key steps of glycolysis in an opposite manner. The mass-spectrometry
proteomics data of the study have been deposited to the ProteomeXchange Consortium (http://proteomecentral.
proteomexchange.org) via the PRIDE partner repository with data set identifiers PXD000769 and PXD000768
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