9,432 research outputs found
Nanoparticles-cell association predicted by protein corona fingerprints
In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a "protein corona" layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ≈ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells
Nanoparticles-cell association predicted by protein corona fingerprints
In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a "protein corona" layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ≈ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells
Firms’ Proactiveness During the Crisis: Evidence from European Data
none3This paper contributes to the literature on the entrepreneurial behavior of firms during the economic crisis by investigating the determinants of proactive behavior on a large sample of European companies during the 2008–2009 financial crisis. We explore various dimensions of proactive behavior, including: investments in innovation, expanding product offer, undergoing quality certification, investing in tangible assets and avoiding layoff. Our findings show a surprising heterogeneity of determinants in the case of different proactivity measures, especially when considering the impact of public policies which support entrepreneurship. We also provide some evidence supporting the organizational learning hypothesis with regard to proactiveness, as we show that the previous crisis experience matters in the case of the adoption of proactive or reactive strategy by a firm.openJan Brzozowski; Marco Cucculelli; Valentina PeruzziBrzozowski, Jan Pawel; Cucculelli, Marco; Peruzzi, Valentin
Family firms and regional entrepreneurship. The European evidence
none3noopenRICCARDO CAPPELLI, MARCO CUCCULELLI, VALENTINA PERUZZICappelli, Riccardo; Cucculelli, Marco; Peruzzi, Valentin
Finite element analysis applied to redesign of submerged entry nozzles for steelmaking
The production of steel by continuous casting is facilitated by the use of refractory hollow-ware components. A critical component in this process is the submerged entry nozzle (SEN). The normal operating conditions of the SEN are arduous, involving large temperature gradients and exposure to mechanical forces arising from the flow of molten steel; experimental development of the components is challenging in so hazardous an environment. The effects of the thermal stress conditions in relation to a well-tried design were therefore simulated using a finite element analysis approach. It was concluded from analyses that failures of the type being experienced are caused by the large temperature gradient within the nozzle. The analyses pointed towards a supported shoulder area of the nozzle being most vulnerable to failure and practical in-service experience confirmed this. As a direct consequence of the investigation, design modifications, incorporating changes to both the internal geometry and to the nature of the intermediate support material, were implemented, thereby substantially reducing the stresses within the Al2O3/graphite ceramic liner. Industrial trials of this modified design established that the component reliability would be significantly improved and the design has now been implemented in series production
Nuclear functions of the tyrosine kinase Src
Src is the representative member of the Src-family kinases (SFKs), a group of tyrosine kinases involved in several cellular processes. Its main function has been for long confined to the plasma membrane/cytoplasm compartment, being a myristoylated protein anchored to the cell membrane and functioning downstream to receptors, most of them lacking intrinsic kinase activity. In the last decades, new roles for some SFKs have been described in the nuclear compartment, suggesting that these proteins can also be involved in directly regulating gene transcription or nucleoskeleton architecture. In this review, we focused on those nuclear functions specifically attributable to Src, by considering its function as both tyrosine kinase and adapting molecule. In particular, we addressed the Src involvement in physiological as well as in pathological conditions, especially in tumors
Aortic regurgitation in athletes. Pieces of the puzzle we have so far omitted
The prevalence of valvular heart disease (VHD) rises with age, reaching 11.7% in individuals older than 75 years.1 In young individuals, VHD is usually related to the presence of a congenital valve abnormality, as bicuspid aortic valve (BAV) or mitral valve prolapse. This is also the case for athletes, where in the presence of these abnormalities few restrictions exist in eligibility
for competitive sports participation, even if a strict follow-up would be desirable. BAV is the most common congenital valve abnormality (1%) found in the general population and in athletes. BAV is more prevalent in males and it can lead to aortic regurgitation (AR), aortic stenosis and/or aortic root dilation. At present, no definitive studies have proved that intensive
sports participation could worsen the progression of BAV and limited data are available on athletes
Proof-of-principle of a new geometry for sampling calorimetry using inorganic scintillator plates
A novel geometry for a sampling calorimeter employing inorganic scintillators
as an active medium is presented. To overcome the mechanical challenges of
construction, an innovative light collection geometry has been pioneered, that
minimises the complexity of construction. First test results are presented,
demonstrating a successful signal extraction. The geometry consists of a
sampling calorimeter with passive absorber layers interleaved with layers of an
active medium made of inorganic scintillating crystals. Wavelength-shifting
(WLS) fibres run along the four long, chamfered edges of the stack,
transporting the light to photodetectors at the rear. To maximise the amount of
scintillation light reaching the WLS fibres, the scintillator chamfers are
depolished. It is shown herein that this concept is working for cerium fluoride
(CeF) as a scintillator. Coupled to it, several different types of
materials have been tested as WLS medium. In particular, materials that might
be sufficiently resistant to the High-Luminosity Large Hadron Collider
radiation environment, such as cerium-doped Lutetium-Yttrium Orthosilicate
(LYSO) and cerium-doped quartz, are compared to conventional plastic WLS
fibres. Finally, an outlook is presented on the possible optimisation of the
different components, and the construction and commissioning of a full
calorimeter cell prototype is presented.Comment: Submitted to Proceedings CALOR 2014, the 16th International
Conference on Calorimetry in High-Energy Physics, Giessen (Germany) 6 - 11
April 2014. To be published in Journal of Physics: Conference Series (10
pages, 15 figures
The influence of non-living mulch, mechanical and thermal treatments on weed population and yield of rainfed fresh-market tomato (Solanum lycopersicum L.)
Weed control is often a major limitation for vegetable crops, since compared to arable crops fewer herbicides are available and the crops are more sensitive to weeds. Field experiments were carried out in the province of Pisa (Central Italy) to determine the effect of two different mulches (black biodegradable plastic film and wheat straw) and mechanical and thermal treatments on weed population and yield of rain-fed fresh market tomato (Solanum lycopersicum L.). Rolling harrow, flaming machine and precision hoe for weed control, which were either built, enhanced or modified by the University of Pisa were used separately (mechanical-thermal strategy) or in combination with a straw mulch (mechanical-thermal-straw strategy). These two innovative strategies were compared with the traditional farming system, which uses a biodegradable plastic mulch film. The strategies were compared in terms of machine performance, weed density, total labour requirement, weed dry biomass, and crop fresh yield at harvest. The total operative time for weed control was on average ~25 h ha-1 for the two systems, which included mulching, and over 30 h ha-1 for the mechanical-thermal strategy. The three strategies controlled weeds effectively, with only 30 g m-2 in each treatment. Tomato yield, however, was 35% higher for strategies that included mulching (both biodegradable film and straw)
The use of different hot foam doses for weed control
Thermal weed control technology plays an important role in managing weeds in synthetic
herbicide-free systems, particularly in organic agriculture. The use of hot foam represents an evolution
of the hot water weed control thermal method, modified by the addition of biodegradable foaming
agents. The aim of this study was to test the weeding eect of dierent five hot foam doses, in two sites
of dierent weed composition fields [i.e., Festuca arundinacea (Schreb.), Taraxacum ocinale (Weber)
and Plantago lanceolata (L.)], by evaluating the devitalisation of weeds, their regrowth, the weed dry
biomass at the end of the experiment and the temperature of hot foam as aected by dierent foam
doses. The results showed that the eect of the hot foam doses diered with the dierent infested
weed species experiments. In the Festuca arundinacea (Schreb.) infested field, all doses from 3.33 L
m2 to 8.33 L m2 led to a 100% weed cover devitalisation and a lower weed dry biomass compared
to the dose of 1.67 L m2, whereas the weed regrowth was similar when all doses were applied. In the
Taraxacum ocinale (Weber) and Plantago lanceolata (L.) infested fields, doses from 5.00 L m2 to 8.33 L
m2 in site I and from 3.33 L m2 to 8.33 L m2 in site II led to 100% of weed cover devitalisation.
The highest doses of 6.67 L m2 and 8.33 L m2 led to a slower weed regrowth and a lower weed
dry biomass compared to the other doses. The time needed for weeds to again cover 50%, after
the 100% devitalisation, was, on average, one month when all doses were applied in the Festuca
arundinacea (Schreb.) infested field, whereas in the Taraxacum ocinale (Weber) and Plantago lanceolata
(L.) fields, this delay was estimated only when doses of 6.67 L m2 and 8.33 L m2 were used in site I
and a dose of 8.33 L m2 in site II. Thus, in the Festuca arundinacea (Schreb.) field experiments hot
foam doses from 3.33 L m2 to 8.33 L m2 were eective in controlling weeds, and the use of the
lowest dose (i.e., 3.33 L m2) is recommended. However, for Taraxacum ocinale (Weber) and Plantago
lanceolata (L.) the highest doses are recommended (i.e., 6.67 L m2 and 8.33 L m2), as these led to
100% weed devitalisation, slower regrowth, and lower weed dry biomass than other doses. A delay
in the regrowth of weeds by 30 days can lead to the hypothesis that the future application of hot foam
as a desiccant in no-till field bands, before the transplant of high-income vegetable crops, will provide
a competitive advantage against weeds
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