Nuclear emulsions for the detection of micrometric-scale fringe patterns: an application to positron interferometry

Nuclear emulsions are capable of very high position resolution in the detection of ionizing particles. This feature can be exploited to directly resolve the micrometric-scale fringe pattern produced by a matter-wave interferometer for low energy positrons (in the 10-20 keV range). We have tested the performance of emulsion films in this specific scenario. Exploiting silicon nitride diffraction gratings as absorption masks, we produced periodic patterns with features comparable to the expected interferometer signal. Test samples with periodicities of 6, 7 and 20 {\mu}m were exposed to the positron beam, and the patterns clearly reconstructed. Our results support the feasibility of matter-wave interferometry experiments with positrons.Comment: 15 pages, 10 figure

Morphological distribution of μ chains and cd15 receptors in colorectal polyp and adenocarcinoma specimens.

BACKGROUND: We have recently investigated the localisation of immunoglobulin-producing cells (IPCs) in inflamed intestinal tissue samples from patients with inflammatory bowel disease (IBD), and identified two main patterns of B lymphocyte infiltration: one characterised by the moderate strong stromal localisation of small B1 cell-like IgM+/CD79+/CD20-/CD21-/CD23-/CD5 ± IPCs, and the other by the peri-glandular localisation of IPCs with irregular nuclei that had surface markers specific for a B cell subset (IgM and CD79), but quantitative differences in their λ and κ chains. The same patients were also tested for CD15+ receptors, which were localised on inflammatory cell surfaces or in the crypts of the intestinal epithelium. CD15+ receptor distribution in inflamed tissues was limited to the cell structures. The aim of the study was to analyse variations in IPCs and CD15+ cell morphology or distribution in bowel biopsy specimens taken from patients with pre-malignant polyps or adenocarcinomas. METHODS: IPCs were analysed by means of immunofluorescence using polyclonal goat anti-human μ chains. The pre-malignant polyp specimens were tested for B cell surface phenotype λ and κ chains, CD79, CD20, CD21 and CD23 using an immunoperoxidase method. CD15+ cells were evaluated using the immunoperoxidase method and monoclonal anti-CD15 IgM. RESULTS: The study involved 14 patients (four with pre-malignant polyps and 10 with colorectal adenocarcinomas). The distribution of μ chains and CD15 markers varied in all of the biopsies, but delineated normal cell structures in the pre-malignant polyp specimens. B cell surface phenotype analysis of μ chain-positive cells identified a subset of CD79+/CD20-/CD21-/CD23- IPCs. The IPCs in certain areas showed the sporadic disintegration of inflammatory cell membranes or the accumulation of fluorescence in individual cells. IPC membrane disintegration was particularly marked in all of the adenocarcinoma samples, in which the CD15 markers also showed epithelial cell involvement. Furthermore, six of the ten adenocarcinoma samples had atypical and reorganised membranes that expressed an excess of both receptors and isolated small portions of tissue within the tumour. CONCLUSION: The findings of this preliminary morphological study suggest the presence of membrane disintegration and remodelling mechanisms in the tumours. The newly-formed membranes expressed high concentrations of inflammatory cell receptors that can confer adhesive properties

Ordered array of Ga droplets on GaAs(001) by local anodic oxidation

The authors present a procedure to obtain uniform, ordered arrays of Ga droplets on GaAs(001) substrates. The growth process relies on an interplay between the substrate patterning, in form of a two dimensional array of nanoholes periodically modulated obtained via local anodic oxidation, and self-assembly of Ga droplets in a molecular beam epitaxy environment. The formation of site controlled Ga droplets, characterized by atomic force microscopy, is the outcome of the combined effects of capillary condensation and nucleation kinetics

Significance of serum Il-9 levels in inflammatory bowel disease

IL-9, which may be an inflammatory or regulatory cytokine, can be experimentally produced in a Th17 or modified Th2 context in the presence of T cell receptor (TCR) stimulation. The primary aim of this study was to measure serum IL-9 levels in patients with inflammatory bowel disease (IBD), and evaluate their relationships with the patients' clinical characteristics. The secondary aim was to determine the levels of interferon-3 (IFN (interferon)-3), Th2 cytokines (IL-4, IL-5 and IL-13), and IL-6 in order to clarify the context of detectable peripheral cytokines in which IL-9 is produced. Venous blood samples of 43 IBD patients (20 with Crohn's disease [CD] and 23 with ulcerative colitis [UC]) were analysed by means of quantitative enzyme-linked immunosorbent assays using purified anti-human IL-4, IL-5, IL-13, IFN-3, IL-9 and IL-6 antibodies, and the laboratory findings were statistically correlated with their clinical expression. None of the patients showed the peripheral presence of IL-4, IL-5 and IL-13. Forty (93%) were positive for IFN-3, thus confirming the presence of Th1 in both UC and CD, and IFN-3 levels correlated with disease activity (P = 0.045). Eighteen patients (41%) were positive for IL-9, which was associated with a severe prognosis (P <0.001), and 72.2% of the IL-9-positive patients were also IL-6 positive. There was a significant correlation between disease severity and IL-9 in the CD patients (P <0.001), but not in the UC patients (P = 0.1). Our findings confirm the presence of common Th1 cytokines in UC and CD. However the IL-9 positivity indicates the presence of an alternative population of T cells that respond to antigen stimulation and condition the prognosis of IBD. The fact that the same serum IL-9 levels were differentially associated with clinical measures of CD and UC activity suggest that the same cytokine can be produced in different contexts

Morphological distribution of &#956; chains and cd15 receptors in colorectal polyp and adenocarcinoma specimens

Background: We have recently investigated the localisation of immunoglobulin-producing cells (IPCs) in inflamed intestinal tissue samples from patients with inflammatory bowel disease (IBD), and identified two main patterns of B lymphocyte infiltration: one characterised by the moderate strong stromal localisation of small B1 cell-like IgM+/CD79+/CD20-/CD21-/CD23-/CD5 \ub1 IPCs, and the other by the peri-glandular localisation of IPCs with irregular nuclei that had surface markers specific for a B cell subset (IgM and CD79), but quantitative differences in their \u3bb and \u3ba chains. The same patients were also tested for CD15+ receptors, which were localised on inflammatory cell surfaces or in the crypts of the intestinal epithelium. CD15+ receptor distribution in inflamed tissues was limited to the cell structures. The aim of the study was to analyse variations in IPCs and CD15+ cell morphology or distribution in bowel biopsy specimens taken from patients with pre-malignant polyps or adenocarcinomas. Methods. IPCs were analysed by means of immunofluorescence using polyclonal goat anti-human \u3bc chains. The pre-malignant polyp specimens were tested for B cell surface phenotype \u3bb and \u3ba chains, CD79, CD20, CD21 and CD23 using an immunoperoxidase method. CD15+ cells were evaluated using the immunoperoxidase method and monoclonal anti-CD15 IgM. Results: The study involved 14 patients (four with pre-malignant polyps and 10 with colorectal adenocarcinomas). The distribution of \u3bc chains and CD15 markers varied in all of the biopsies, but delineated normal cell structures in the pre-malignant polyp specimens. B cell surface phenotype analysis of \u3bc chain-positive cells identified a subset of CD79+/CD20-/CD21-/CD23- IPCs. The IPCs in certain areas showed the sporadic disintegration of inflammatory cell membranes or the accumulation of fluorescence in individual cells. IPC membrane disintegration was particularly marked in all of the adenocarcinoma samples, in which the CD15 markers also showed epithelial cell involvement. Furthermore, six of the ten adenocarcinoma samples had atypical and reorganised membranes that expressed an excess of both receptors and isolated small portions of tissue within the tumour. Conclusion: The findings of this preliminary morphological study suggest the presence of membrane disintegration and remodelling mechanisms in the tumours. The newly-formed membranes expressed high concentrations of inflammatory cell receptors that can confer adhesive propertie

Raman Spectroscopy for the Analysis of Temperature-Dependent Plastic Relaxation of SiGe Layers

Novel architectures for electronics and photonics are expected to be developed using the forthcoming Si 1−x Ge x technology. However, in Si 1−x Ge x -based heterostructures, materials and design issues rely on accurate control of strain and composition of the alloy. The Raman spectroscopy has rapidly emerged as a reliable technique for the quantitative determination of such parameters on a sub-micrometric scale. In this work we present an investigation of the effects of the growth conditions of Si 1−x Ge x graded layers on dislocation nucleation and interaction. In particular, we focus on the crucial role the deposition temperature plays in the dislocation kinetics. The analysis of threading dislocation densities is accompanied by a quantitative measurement of the residual strain in Si1−xGex/Si heterostructures, carried out by means of the Raman scattering. Our approach is effective in studying the physical mechanism governing dislocation multiplication and the sharp transition from a state of brittleness to a state of ductility within a narrow temperature window

Bovine Lactoferrin Prevents Invasive Fungal Infections in Very Low Birth Weight Infants: A Randomized Controlled Trial.

BACKGROUND: Lactoferrin is a mammalian milk glycoprotein involved in innate immunity. Recent data show that bovine lactoferrin (bLF) prevents late-onset sepsis in preterm very low birth weight (VLBW) neonates. METHODS: This is a secondary analysis of data from a multicenter randomized controlled trial where preterm VLBW neonates randomly received bLF (100 mg/day; group A1), bLF + Lactobacillus rhamnosus GG (10(6) colony-forming units per day; group A2), or placebo (group B) for 6 weeks. Here we analyze the incidence rates of fungal colonization, invasive fungal infection (IFI), and rate of progression from colonization to infection in all groups. RESULTS: This study included 472 neonates whose clinical, nutritional, and demographical characteristics were similar. Overall, the incidence of fungal colonization was comparable (17.6%, 16.6%, and 18.5% in A1, A2, and B, respectively; P = .89 [A1] and .77 [A2]). In contrast, IFIs were significantly decreased in A1 and A2 (0.7% and 2.0%, respectively) compared with B (7.7%; P = .002 [A1] and .02 [A2]), and this was significantly true both in <1000 g (0.9% [A1] and 5.6% [A2], vs 15.0%) and in 1001 to 1500 g infants (0% and 0% vs 3.7%). The progression rate colonization-infection was significantly lower in the bLF groups: 3.7% (A1) and 12% (A2), vs 41.9%; P < .001 (A1) and P = .02 (A2). No IFI-attributable deaths occurred in the treatment groups, versus 2 in placebo. No adverse effects or intolerances occurred. CONCLUSIONS: Prophylactic oral administration of bLF reduces the incidence of IFI in preterm VLBW neonates. No effect is seen on colonization. The protective effect on IFI is likely due to limitation of ability of fungal colonies to progress toward invasion and systemic disease in colonized infants

Size Evolution of Ordered SiGe Islands Grown by Surface Thermal Diffusion on Pit-Patterned Si(100) Surface

The ordered growth of self-assembled SiGe islands by surface thermal diffusion in ultra high vacuum from a lithographically etched Ge stripe on pit-patterned Si(100) surface has been experimentally investigated. The total surface coverage of Ge strongly depends on the distance from the source stripe, as quantitatively verified by Scanning Auger Microscopy. The size distribution of the islands as a function of the Ge coverage has been studied by coupling atomic force microscopy scans with Auger spectro-microscopy data. Our observations are consistent with a physical scenario where island positioning is essentially driven by energetic factors, which predominate with respect to the local kinetics of diffusion, and the growth evolution mainly depends on the local density of Ge atoms

Exposure to Gastric Acid Inhibitors Increases the Risk of Infection in Preterm Very Low Birth Weight Infants but Concomitant Administration of Lactoferrin Counteracts This Effect

Objective: To investigate whether exposure to inhibitors of gastric acidity, such as H2 blockers or proton pump inhibitors, can independently increase the risk of infections in very low birth weight (VLBW) preterm infants in the neonatal intensive care unit. Study design: This is a secondary analysis of prospectively collected data from a multicenter, randomized controlled trial of bovine lactoferrin (BLF) supplementation (with or without the probiotic Lactobacillus rhamnosus GG) vs placebo in prevention of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in preterm infants. Inhibitors of gastric acidity were used at the recommended dosages/schedules based on the clinical judgment of attending physicians. The distribution of days of inhibitors of gastric acidity exposure between infants with and without LOS/NEC was assessed. The mutually adjusted effects of birth weight, gestational age, duration of inhibitors of gastric acidity treatment, and exposure to BLF were controlled through multivariable logistic regression. Interaction between inhibitors of gastric acidity and BLF was tested; the effects of any day of inhibitors of gastric acidity exposure were then computed for BLF-treated vs -untreated infants. Results: Two hundred thirty-five of 743 infants underwent treatment with inhibitors of gastric acidity, and 86 LOS episodes occurred. After multivariate analysis, exposure to inhibitors of gastric acidity remained significantly and independently associated with LOS (OR, 1.03; 95% CI, 1.008-1.067; P = .01); each day of inhibitors of gastric acidity exposure conferred an additional 3.7% odds of developing LOS. Risk was significant for Gram-negative (P < .001) and fungal (P = .001) pathogens, but not for Gram-positive pathogens (P = .97). On the test for interaction, 1 additional day of exposure to inhibitors of gastric acidity conferred an additional 7.7% risk for LOS (P = .003) in BLF-untreated infants, compared with 1.2% (P = .58) in BLF-treated infants. Conclusion: Exposure to inhibitors of gastric acidity is significantly associated with the occurrence of LOS in preterm VLBW infants. Concomitant administration of BLF counteracts this selective disadvantage. Trial registration: isrctn.org: ISRCTN53107700

Is Lactoferrin More Effective in Reducing Late-Onset Sepsis in Preterm Neonates Fed Formula Than in Those Receiving Mother&apos;s Own Milk? Secondary Analyses of Two Multicenter Randomized Controlled Trials

Background: Lactoferrin is the major antimicrobial protein in human milk. In our randomized controlled trial (RCT) of bovine lactoferrin (BLF) supplementation in preterm neonates, BLF reduced late-onset sepsis (LOS). Mother's own milk (MM) contains higher concentrations of lactoferrin than donor milk or formula, but whether BLF is more effective in infants who receive formula or donor milk is uncertain. Aim: To evaluate the incidence of LOS in preterm infants fed MM and in those fed formula and/or donor milk. Study Design: This is a (A) post hoc subgroup analysis, in our RCT of BLF, of its effects in preterm infants fed MM, with or without formula, versus those fed formula and/or donor milk (no-MM) and (B) post hoc meta-analysis, in our RCT of BLF and in the ELFIN (Enteral Lactoferrin in Neonates) RCT, of the effect of BLF in subgroups not exclusively fed MM. Results (A) Of 472 infants in our RCT, 168 were randomized to placebo and 304 were randomized to BLF. Among MM infants, LOS occurred in 22/133 (16.5%) infants randomized to placebo and in 14/250 (5.6%) randomized to BLF (relative risk or risk ratio (RR): 0.34; relative risk reduction (RRR): 0.66; 95% confidence interval (95% CI) for RR: 0.18-0.64; p &lt; 0.0008). Among no-MM infants, LOS occurred in 7/35 (20.0%) randomized to placebo and in 2/54 (3.7%) randomized to BLF (RR: 0.19; RRR: 0.81; 95% CI for RR: 0.16-0.96; p = 0.026). In multivariable logistic regression analysis, there was no interaction between BLF treatment effect and type of feeding (p = 0.628). (B) In 1,891 infants not exclusively fed MM in our RCT of BLF and in the ELFIN RCT, BLF reduced the RR of LOS by 18% (RR: 0.82; 95% CI: 0.71-0.96; p = 0.01). Conclusion: Adequately powered studies should address the hypothesis that BLF is more effective in infants fed formula or donor milk than those fed MM. Such studies should evaluate whether a specific threshold of total lactoferrin intake can be identified to protect such patients from LOS