Bringing Particle Scale Properties into Descriptions of Powder Behavior through the Enhanced Centrifuge Method

Inconsistent powder behavior introduces problems such as agglomeration, poor flowability, dust hazards, and segregation that decrease efficiency in powder processing environments. Understanding how a powder interacts with a surface at the particle scale provides insight into how to accommodate individual particle properties and avoid process deficiencies. This project uses an enhanced centrifuge technique to evaluate the adhesion between a stainless-steel surface and a powder comprised of fluorescent particles. Particles are deposited onto stainless steel plates which are rotated in a centrifuge. The adhesion properties are monitored by tracking the rotational speed at which particles of a known size are removed from the steel. To model the adhesion, a simulator was produced in MATLAB to map an ideal model to the experimental observations. In reality, the particles and steel are rough, and the particles are nonuniform in shape. The ideal case assumes the particles are smooth spheres and the steel is smooth. A modified van der Waals force model describes the observed forces. Within this model, a Hamaker constant, which usually describes only the effect of composition on the van der Waals force, is tuned to also describe the effects of the non-uniformity of the particles. This creates a distribution of ‘effective Hamaker constants’ that describes particle scale effects on the adhesion between the bulk powder and the stainless steel. This approach will allow industry to account for the effects of surface roughness, particle shape, and particle size when designing powder processing operations

Native cattle breeds of Southern Italy: karyological profile

Italian typical products of animal origin are strictly linked to native breeds. Their protection requires control of their reproductive and productive abilities. Hence the need for karyological studies to identify subjects with chromosome abnormalities linked to hypofertility or sterility. We report the results of karyological analyses carried out from January 2008 to December 2008 on 145 cattle of native breeds (Agerolese, Cinisara, Modicana and Podolica) reared in Southern Italy so as to evaluate and characterize the presence of chromosome abnormalities in subjects with normal phenotypes. Besides the 128 karyologically normal subjects (2n=60, XY and 2n=60, XX), 17 were carriers of rob (1;29) and one male was a carrier of cellular chimerism 2n=60, XX/XY. According to our data there is a high frequency of rob (1;29) in Cinisara and Podolica breeds while in Agerolese there was only one case of rob (1;29) and none in Modicana

a transverse and longitudinal mr imaging voxel based morphometry study in patients with primary cervical dystonia

BACKGROUND AND PURPOSE: Findings of standard MR imaging examinations are usually normal in primary CD. These findings are now increasingly challenged by studies using advanced neuroimaging techniques detecting abnormalities in brain areas that may be functionally involved in the pathophysiology of CD. Our purpose was to evaluate GM volumes in patients with CD at baseline and 5 years later. MATERIALS AND METHODS: We enrolled 19 patients (F/M = 15:4, mean age = 53.2 + 11.2 years), 12 of whom were studied at baseline and again approximately 5 years later. Twenty-eight healthy volunteers acted as controls (F/M = 17:11, mean age = 47.5 + 15.6 years). The subjects were imaged with a 1.5T scanner by using a 3D T1-weighted sequence on 150 contiguous axial 1-mm-thick sections to apply VBM. RESULTS: At entry, VBM analysis disclosed significantly lower GM volumes in the left caudate head and putamen and in the premotor and primary sensorimotor cortices bilaterally in patients than in controls. No correlation was found between decreased GM volumes and patient age, severity of dystonia, or disease duration. At the 5-year follow-up, GM volumes in the left primary sensorimotor cortex in patients had decreased significantly from baseline. CONCLUSIONS: The findings obtained at entry and after a 5-year follow-up consistently showed decreased caudate, putamen, and sensorimotor cortex GM volumes in patients with CD, and they probably play a pathophysiologic role in CD

Subclinical atherosclerosis in patients with psoriatic arthritis: a case-control study. Preliminary data

Objective: The aim of this study was to evaluate the prevalence of subclinical atherosclerosis in patients with psoriatic arthritis (PsA), correlated with some traditional risk factors of atherosclerosis and with PsA-related disease factors. Methods: Forty-one patients and 41 healthy subjects were evaluated for intima-media thickness (IMT) and flow-mediated dilation (FMD), using carotid duplex scanning. IMT values were expressed like IMT mean (cumulative mean of all the IMT mean) and M-MAX (cumulative mean of all the higher IMT). Subclinical atherosclerosis markers were correlated with age, body mass index (BMI) and blood pressure in both groups, with duration of arthritis, duration of psoriasis, tender and swollen joints, BASDAI (Bath Ankylosing Spondylitis Disease Activity Index), BASFI (Bath Ankylosing Spondylitis Functional Index), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in patients. Results: IMT mean and M-MAX were both higher in PsA patients compared with controls (0.7±0.15 vs 0.62±0.09 mm; p<0.01 and 0.86±0.21 vs. 0.74±0.13 mm; p<0.01 respectively). FMD was smaller in patients than in controls (5.9±2 vs 7.5±2.8%; p<0.01). Univariate analysis showed a correlation between IMT mean and SBP (r=0.217; p=0.05) and a correlation between M-MAX and age (r=0.392; p<0.001), BMI (r=0.252; p<0.05), SBP (r=0.446; p<0.001) in both groups. In PsA patients M-MAX resulted correlated with ESR (r=0.338; p<0.05) and BASDAI (r=0.322; p<0.05). Conclusions: PsA patients exhibited endothelial dysfunctions which is an early marker of subclinical atherosclerosis, as well as an higher IMT. An interesting correlation between M-MAX and PsA activity index (ESR and BASDAI) was found

Thermal neutron detection by means of Timepix3

Thermal neutron detection plays a crucial role in numerous scientific and technical applications such as nuclear reactor physics, particle accelerators, radiotherapy,materials analysis and space exploration. There are several challenges associated with the accurate identification and quantification of thermal neutrons. The present work proposes a detailed characterization of a Timepix3 (TPX3) detector equipped with a Lithium Fluoride (6LiF) converter in order to study its response to thermal neutrons that are identified through the 6Li(n,α)3H reaction. The TPX3-based test system has been installed at the HOTNES facility in ENEA and the analysis highlighted its excellent performance showing high effectiveness in the identification of neutrons through morphological analysis of tracks produced by alpha and triton particles, after accurate discrimination from the gamma background. With the use of Monte Carlo simulations, it has been demonstrated that the main contribution is due to tritons and its signal can be used effectively in the identification of thermal neutrons obtaining an efficiency of 0.9 % for 25 meV neutrons. This allows the TPX3 to have important applications as an environmental monitor for thermal neutrons. This monitoring system can be simply realized and is easy to manage because of its compact size and its digital acquisition that allows a real-time analysis

Inhibition of N-linked glycosylation impairs ALK phosphorylation and disrupts pro-survival signaling in neuroblastoma cell lines

<p>Abstract</p> <p>Background</p> <p>The Anaplastic Lymphoma Kinase (ALK) is an orphan receptor tyrosine kinase, which undergoes post-translational N-linked glycosylation. The catalytic domain of ALK was originally identified in the t(2;5) translocation that produces the unglycosylated oncogenic protein NPM-ALK, which occurs in Anaplastic Large Cell Lymphoma (ALCL). Recently, both germline and somatic activating missense mutations of ALK have been identified in neuroblastoma (NB), a pediatric cancer arising from neural crest cells. Moreover, we previously reported that ALK expression is significantly upregulated in advanced/metastatic NB. We hypothesized that ALK function may depend on N-linked glycosylation and that disruption of this post-translational modification would impair ALK activation, regardless the presence of either gene mutations or overexpression.</p> <p>Methods</p> <p>We employed tunicamycin to inhibit N-linked glycosylation. The following ALK-positive NB cell lines were used: SH-SY5Y and KELLY (ALK mutation F1174L), UKF-NB3 (ALK mutation R1275Q) and NB1 (ALK amplification). As a control, we used the NB cell lines LA1-5S and NB5 (no ALK expression), and the ALCL cell line SU-DHL1 (NPM-ALK).</p> <p>Results</p> <p>Tunicamycin treatment of ALK-positive NB cells resulted in a hypoglycosylated ALK band and in decreased amounts of mature full size receptor. Concomitantly, we observed a marked reduction of mature ALK phosphorylation. On the contrary, tunicamycin had no effects on NPM-ALK phosphorylation in SU-DHL1 cells. Moreover, phosphorylation levels of ALK downstream effectors (AKT, ERK1/2, STAT3) were clearly impaired only in ALK mutated/amplified NB cell lines, whereas no significant reduction was observed in both ALK-negative and NPM-ALK-positive cell lines. Furthermore, inhibition of N-linked glycosylation considerably impaired cell viability only of ALK mutated/amplified NB cells. Finally, the cleavage of the Poly-ADP-ribose-polymerase (PARP) suggested that apoptotic pathways may be involved in cell death.</p> <p>Conclusions</p> <p>In this study we showed that inhibition of N-linked glycosylation affects ALK phosphorylation and disrupts downstream pro-survival signaling, indicating that inhibition of this post-translational modification may be a promising therapeutic approach. However, as tunicamycin is not a likely candidate for clinical use other approaches to alter N-linked glycosylation need to be explored. Future studies will assess whether the efficacy in inhibiting ALK activity might be enhanced by the combination of ALK specific small molecule and N-linked glycosylation inhibitors.</p