513 research outputs found
Four-wave mixing in a silicon microring resonator using a self-pumping geometry
We report on four-wave mixing in a silicon microring resonator using a
self-pumping scheme instead of an external laser. The ring resonator is
inserted in an external-loop cavity with a fibered semiconductor amplifier as a
source of gain. The silicon microring acts as a filter and we observe lasing in
one of the microring's resonances. We study correlations between signal and
idler generated beams using a Joint Spectral Density experiment
THE NEUTROPHIL ANTI-TUMORAL RESPONSE IN CANCER: ROLE OF ACKR2 AND CHEMOKINE RECEPTORS
Chemokines are key mediators of inflammation and are involved in both
extrinsic and intrinsic pathway of cancer. Their main function is to induce leukocyte
migration through the binding of specific seven transmembrane receptors. Beside
canonical chemokine receptor a smaller family of atypical chemokine receptors was
described. ACKR2 binds with high affinity a broad panel of CC inflammatory
chemokines mediating their internalization and intracellular degradation. Due to its
chemokine scavenging activity, ACKR2 plays a protective role in chronic
inflammation and in the extrinsic pathway of cancer.
The objective of my thesis was to investigate the role of ACKR2 in the intrinsic
pathway of cancer using the NeuT (HER2) murine model of oncogene-driven breast
cancer crossed with ACKR2 KO mice. In this model, we found that ACKR2 plays a
dual an opposite role. It slows the primary tumor development while it promotes lung
metastasis. We found the same phenotype on metastasis using the orthotopically
transplanted 4T1 mammary carcinoma and melanoma B16F10 cell lines were we
demonstrated that ACKR2 expression in the hematopoietic compartment acts as a
negative regulator of the mobilization of neutrophils with anti-metastatic function.
In the last part of my thesis we also investigated the phenotype of circulating
and tumor associated neutrophils (TANs) in glioma patients, a tumor context
characterized by blood neutrophilia and a general immunosuppressive state. We found
a higher grade of neutrophilia and an increased rate of immature neutrophils in high
grade comparing low grade glioma patients. Finally, we found that the relative
abundance of circulating neutrophils on total leukocytes positively correlates with
relative abundance of TANs.
Collectively taken, these results indicate that neutrophils are a heterogeneous
population with both pro and anti-tumoral functions. Targeting of neutrophils in cancer
context represent a potential therapeutic approach that limit their pro-tumoral role
unleashing the anti-tumoral and anti-metastatic potential
The occurrence of two morphologically similar Chaetozone (Annelida: Polychaeta: Cirratulidae) species from the Italian seas: Chaetozone corona Berkeley & Berkeley, 1941 and C. carpenteri McIntosh, 1911
The present study reports the spread of the cirratulids Chaetozone corona Berkeley & Berkeley, 1941 and Chaetozone carpenteri McIntosh, 1911 in the Western Central Adriatic Sea, off the coasts of Pescara (Italy). The two species were collected between 2014 and 2016 from soft bottom stations (at depths from 16.5 to 130 m) where the environment was more or less disturbed due to fishing activities. One specimen of C. corona was found also off the coast of Calafuria (Livorno, Italy), representing the first record of this species in the Tyrrhenian Sea. Chaetozone carpenteri could be a native species present in the Mediterranean for a long time but rarely recorded because of taxonomic confusion. Chaetozone corona was already known from the eastern Mediterranean Sea (except from the Adriatic Sea), where it is considered an established alien species. Our results extend the geographic range of these two cirratulid species, providing some information on their ecology and habitat preference. We also suggest a likely vector of spread of C. corona from the easternmost part of the Mediterranean towards the study area. The finding of reproducing specimens of C. corona and C. carpenteri supports the hypothesis that these two species have found a suitable habitat in the Western Central Adriatic Sea, and there will become well established. Although nothing suggests that C. corona would be invasive, it may, however, compete with native species. These findings also seem particularly relevant in order to improve the knowledge of Mediterranean biodiversity
Effects of miRNA-15 and miRNA-16 expression replacement in chronic lymphocytic leukemia : implication for therapy
This work was supported by: Associazione Italiana Ricerca sul Cancro (AIRC) Grant 5 x mille n.9980, (to M.F., F.M. A. N., P.T. and M.N.) ; AIRC I.G. n. 14326 (to M.F.), n.10136 and 16722 (A.N.), n.15426 (to F.F.). AIRC and Fondazione CaRiCal co-financed Multi Unit Regional Grant 2014 n.16695 (to F.M.). Italian Ministry of Health 5x1000 funds (to S.Z. and F.F). A.G R. was supported by Associazione Italiana contro le Leucemie-Linfomi-Mielomi (AIL) Cosenza - Fondazione Amelia Scorza (FAS). S.M. C.M., M.C., L.E., S.B. were supported by AIRC.Peer reviewedPostprin
Sediment contamination by heavy metals and PAH in the Piombino Channel (Tyrrhenian Sea).
Sediment contamination is of major concern in areas affected by heavy maritime traffic. The spatial variation and contamination of 11 trace elements and 17 PAHs in surface sediments were studied along a 31 km transect along the seaway from the port of Piombino (Tuscany) to the port of Portoferraio (Elba Island) in the Northern Tyrrhenian Sea. Heavy metal contamination was detected at sites near Piombino (Ni, Pb, Hg, Cu and Zn) and at sites near Portoferraio (Pb, Zn, Hg, Cr and Cd). Each of the 35 sampled sites showed PAH contamination, with the highest concentrations at sites near Portoferraio. The most abundant isomers detected were 2- and 4-ring PAHs. PAH ratio analysis showed a prevalence of PAHs of pyrolytic origin. High values of PAHs and heavy metals were related to high sediment water content, TOC, silt, and clay content. Arsenic increased with increasing depth. The correlation between concentrations of metals and PAHs suggests common anthropogenic sources and is of concern for possible synergistic adverse effects on the biota
Beyond two-point statistics: using the minimum spanning tree as a tool for cosmology
Cosmological studies of large-scale structure have relied on two-point statistics, not fully exploiting the rich structure of the cosmic web. In this paper we show how to capture some of this cosmic web information by using the minimum spanning tree (MST), for the first time using it to estimate cosmological parameters in simulations. Discrete tracers of dark matter such as galaxies, N-body particles or haloes are used as nodes to construct a unique graph, the MST, that traces skeletal structure. We study the dependence of the MST on cosmological parameters using haloes from a suite of COmoving Lagrangian Acceleration (COLA) simulations with a box size of 250 h−1Mpc, varying the amplitude of scalar fluctuations (As), matter density (Ωm), and neutrino mass (∑mν). The power spectrum P and bispectrum B are measured for wavenumbers between 0.125 and 0.5 hMpc−1, while a corresponding lower cut of ∼12.6 h−1Mpc is applied to the MST. The constraints from the individual methods are fairly similar but when combined we see improved 1σ constraints of ∼17 per cent (∼12 per cent) on Ωm and ∼12 per cent (∼10 per cent) on As with respect to P (P + B) thus showing the MST is providing additional information. The MST can be applied to current and future spectroscopic surveys (BOSS, DESI, Euclid, PSF, WFIRST, and 4MOST) in 3D and photometric surveys (DES and LSST) in tomographic shells to constrain parameters and/or test systematics
The effect of initial pH and retention time on boron removal by continuous electrocoagulation process
In this study, factors influencing boron removal via the continuous electrocoagulation process were investigated at lab-scale. Different influent pH values (4, 5, 6, 7.45 and 9) and contact times (10, 25, 50 and 100 min) were examined as variable parameters. Plate-type aluminium electrodes with 5 mm distance between them were used. All the experiments were conducted in continuous mode and the current density was kept constant at 5 A throughout the whole experimental period. The initial boron concentration was selected to be 1000 mg L-1. The first set of experiments concerning the influence of the influent pH showed that the highest boron removal (67%) was obtained at pH=6 since it was the optimal pH for boron precipitation through aluminium borate formation. Under the constant current density of the study and with the initial pH adjusted to 6, increasing the duration of the electrocoagulation process from 10 to 100 min resulted in raising the boron removal from 45 to 79% during the second set of experiments. The greater duration of the electrocagulation process enabled higher aluminium dissolution, thus allowing the existence of a higher number of coagulants within the reactor. Moreover, it enhanced boron precipitation because of the longer contact time between the boron ions and the coagulants. After optimizing significant parameters such as the influent pH and the electrocagulation duration, the continuous electrocoagulation process was found to constitute an effective alternative for boron removal
Risk of Recurrence of Chronic Subdural Hematomas After Surgery: A Multicenter Observational Cohort Study
Background: Chronic Subdural Hematoma (CSDH) is a common condition in the elderly population. Recurrence rates after surgical evacuation range from 5 to 30%. Factors predicting recurrence remain debated and unclear. Objective: To identify factors associated with increased risk of recurrence. Methods: Cases of CSDHs that underwent surgical treatment between 2005 and 2018 in the Neurosurgery Units of two major Italian hospitals were reviewed. Data extracted from a prospectively maintained database included demographics, laterality, antithrombotic therapy, history of trauma, corticosteroid therapy, preoperative and postoperative symptoms, type of surgical intervention, use of surgical drain, and clinical outcomes. Results: A total of 1313 patients was analyzed. The overall recurrence rate was 10.1%. The risk of recurrence was not significantly different between patients with unilateral or bilateral CSDH (10.4 vs. 8.8%, p = 0.39). The risk of recurrence was higher in patients that underwent surgical procedure without postoperative drainage (16.1 vs. 5.4%, p < 0.01). No relationship was found between recurrence rates and therapy with antithrombotic drugs (p = 0.97). The risk of recurrence was increasingly higher considering craniostomy, craniectomy, and craniotomy (9.3, 11.3, and 18.9%, respectively, p = 0.013). Lower recurrence rates following Dexamethasone therapy were recorded (p = 0.013). Conclusion: No association was found between the risk of recurrence of CSDH after surgical evacuation and age, use of antithrombotic medication, or laterality. Burr-hole craniostomy was found to be associated with lower recurrence rates, when compared to other surgical procedures. Placement of surgical drain and Dexamethasone therapy were significantly associated with reduced risk of recurrence of CSDHs
Long-term effects of intensive B cell depletion therapy in severe cases of IgG4-related disease with renal involvement
Biomarkers in post-reperfusion syndrome after acute lower limb ischaemia
Ischaemia reperfusion (I/R) injury refers to tissue damage caused when blood supply
returns to the tissue after a period of ischaemia. Matrix metalloproteinases (MMPs),
neutrophil gelatinase-associated lipocalin (NGAL) and cytokines are biomarkers
involved in several vascular complications. The aim of this study was to evaluate the
role of MMPs, NGAL and inflammatory cytokines in I/R syndrome. We conducted an
open label, multicentric, parallel group study, between January 2010 and December
2013. Patients with acute limb ischaemia were enrolled in this study and were divided
into two groups: (i) those subjected to fasciotomy and (ii) those not subjected to fasciotomy,
according to the onset of compartment syndrome. Plasma and tissue values
of MMPs and NGAL as well as plasma cytokines were evaluated. MMPs, NGAL and
cytokine levels were higher in patients with compartment syndrome. Biomarkers evaluated
in this study may be used in the future as predictors of I/R injury severity and its
possible evolution towards post-reperfusion syndrome
- …