380 research outputs found
Comparison of Monomethylhydrazine/Hydroxypropylcellulose and Hydrocarbon/Silica Gels
Experimental studies have been performed to investigate rheology and droplet burning with different types of gelled propellants. Monomethylhydrazine has been gelled with organic hydroxypropylcellulose. JP-8 and RP-1 hydrocarbon gels have been produced with inorganic fumed silica particles. Rheological characterization showed the differences in terms of viscosity and yield stress behavior due to different types of gelling agents. Herschel-Bulkley and Carreau-Yasuda models have been used to characterize the gels with inorganic and organic gelling agents, respectively. First experiments with the Monomethylhydrazine/hydroxypropylcellulose gels showed a typical swelling process during combustion with a flexible viscous droplet surface. Contrary to that, the hydrocarbon/silica gels burned while a rigid silica structure was built, which remained unburned. Burning drop measurements have been compared to the d^2-squared law
FOULING IN A CENTRITHERM EVAPORATOR WITH WHEY SOLUTIONS
Fouling caused by sweet cheese whey and reconstituted whey powder solutions was studied in a Centritherm evaporator, the behaviour being estimated by measuring the change in the overall heat transfer coefficients with the time. It was found that there was no fouling detectable for the reconstituted whey powder solution. For sweet cheese whey, the fouling rate was linked strongly with the evaporating temperature and temperature difference. Visual observation showed that the deposit layer on the evaporator surface was very thin and soft, and like the type A milk deposit described by other investigators. A high velocity of liquid film delayed the formation of deposit on the surface. Some interactions between the evaporation temperature, feed flow rate, rotating speed and temperature difference are discussed. The fouling is caused by denaturation of bovine serum albumin in a second order rate reaction
Thermo-mechanical behaviour of a compacted swelling clay
Compacted unsaturated swelling clay is often considered as a possible buffer
material for deep nuclear waste disposal. An isotropic cell permitting
simultaneous control of suction, temperature and pressure was used to study the
thermo-mechanical behaviour of this clay. Tests were performed at total
suctions ranging from 9 to 110 MPa, temperature from 25 to 80 degrees C,
isotropic pressure from 0.1 to 60 MPa. It was observed that heating at constant
suction and pressure induces either swelling or contraction. The results from
compression tests at constant suction and temperature evidenced that at lower
suction, the yield pressure was lower, the elastic compressibility parameter
and the plastic compressibility parameter were higher. On the other hand, at a
similar suction, the yield pressure was slightly influenced by the temperature;
and the compressibility parameters were insensitive to temperature changes. The
thermal hardening phenomenon was equally evidenced by following a
thermo-mechanical path of loading-heating-cooling-reloading
ODTN: Open Disaggregated Transport Network. Discovery and Control of a Disaggregated Optical Network through Open Source Software and Open APIs
ONOS discovers and manages a topology made of Transponders and a dedicated OLS, using standard protocols (NETCONF/RESTCONF) and models (OpenConfig/TAPI). The demo is a joint collaboration, towards production deployment, between 3 operators and 2 equipment vendors
Dielectric relaxations of nanocomposites composed of HEUR polymers and magnetite nanoparticles
We investigate the dynamics of nanocomposites composed of hydrophobically modified ethoxylated urethanes (HEUR) and magnetite nanoparticles (MNPs) as dry films. Weemployed dielectric relaxation spectroscopy (DRS) in combination with differential scanning calorimetry (DSC) and thermally stimulated depolarization currents (TSDC).The three techniques reveal a strong heterogeneity of the matrix of the nanocomposites, consisting of (i) a crystalline poly(ethyleneoxide) PEO bulk phase, (ii) an amorphous PEO portion, and (iii) small PEO crystallites which experience different constraints than the PEO bulk phase. TSDC and DRS reveal a very high direct current (DC)-conductivity of the pure matrix, which increases with MNPs concentration. The increase of the DCconductivity is not related to an increase of the segmental mobility, but most likely to the change of the morphology of the hydrophobic domains of the polymer matrix, due to the formation of large MNPs clusters. Indeed, the MNPs neither influence the segmental dynamics of the polymer nor the phase behavior of the polymer matrix. The addition of MNPs slightly increases the activation energy related to the γ-relaxation of the polymer. This effect might be related to the changes in nano-morphology as demonstrated by the slight increase of the degree of crystallinity. The analysis of the DRS data with the electrical modulus M’’(ω) and the derivative ε’’der formalism allow us to identify a low-frequency process in addition to the conductivity relaxation. This low-frequency dispersion is also revealed by TSDC. It is most likely related to the Maxwell-Wagner- Sillars relaxation, which typically occurs in systems which feature phase separation. The detailed investigation of the dielectric properties of these novel nanocomposites with increasing MNPs concentration will be useful for their practical application, for example as absorbers of electromagnetic waves
Low frequency of TERT promoter mutations in gastrointestinal stromal tumors (GISTs).
Somatic mutations in the promoter region of telomerase reverse transcriptase (TERT) gene, mainly at positions c. − 124 and
c. − 146 bp, are frequent in several human cancers; yet its presence in gastrointestinal stromal tumor (GIST) has not been
reported to date. Herein, we searched for the presence and clinicopathological association of TERT promoter mutations in
genomic DNA from 130 bona fide GISTs. We found TERT promoter mutations in 3.8% (5/130) of GISTs. The c. − 124C4T
mutation was the most common event, present in 2.3% (3/130), and the c. − 146C4T mutation in 1.5% (2/130) of GISTs.
No significant association was observed between TERT promoter mutation and patient’s clinicopathological features. The present
study establishes the low frequency (4%) of TERT promoter mutations in GISTs. Further studies are required to confirm our
findings and to elucidate the hypothetical biological and clinical impact of TERT promoter mutation in GIST pathogenesis.This project was partially supported by Barretos Cancer Hospital internal
research funds (PAIP) and CNPq Universal Grant (476192/2013-7) to RMR.
NCC is a recipient of an FAPESP Doctoral Fellowship (2013/25787-3). Further
funding from the project ‘Microenvironment, metabolism and cancer’ that was
partially supported by Programa Operacional Regional do Norte (ON.2—O
Novo Norte) under the Quadro de Referência Estratégico Nacional (QREN)
and the Fundo Europeu de Desenvolvimento Regional (FEDER). IPATIMUP is
an Associate Laboratory of the Portuguese Ministry of Science, Technology and
Higher Education that is partially supported by the FCT
A Deep Learning based Pipeline for Efficient Oral Cancer Screening on Whole Slide Images
Oral cancer incidence is rapidly increasing worldwide. The most important
determinant factor in cancer survival is early diagnosis. To facilitate large
scale screening, we propose a fully automated pipeline for oral cancer
detection on whole slide cytology images. The pipeline consists of fully
convolutional regression-based nucleus detection, followed by per-cell focus
selection, and CNN based classification. Our novel focus selection step
provides fast per-cell focus decisions at human-level accuracy. We demonstrate
that the pipeline provides efficient cancer classification of whole slide
cytology images, improving over previous results both in terms of accuracy and
feasibility. The complete source code is available at
https://github.com/MIDA-group/OralScreen.Comment: Accepted to ICIAR 202
Essential versus accessory aspects of cell death: recommendations of the NCCD 2015
Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death
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