84 research outputs found
Electrochemical remediation of synthetic and real marine sediments contaminated by PAHs, Hg and As under low electric field values
To date, remediation, protection, and restoration of contaminated sites is a global concern. The current technologies to restore sediments characterized by heterogeneous characteristics, several pollutants, fine grains, and low hydraulic permeability are poorly effective; hence their remediation is still challenging. A promising approach for the sediment's remediation could be the electrochemical route since it is a not-expensive, effective and noninvasive in situ technology. Electrochemical remediation (ER) is commonly studied under relatively high electric fields (E ≥ 1 V cm-1) and using costly processing fluids in a three compartments cell aiming to desorb and transport the contaminants into the processing fluids (secondary dangerous effluent). In this work, contaminated marine sediments were electrochemically treated focusing on the insertion of electrodes directly in the sediments and adopting, for the first time for real sediments, low E values (≤ 0.25 V cm-1) for 4-days period. It was observed that PAHs can be simultaneously transported and degraded in situ preventing the production of a secondary dangerous effluent and reducing the energy consumption. Firstly, clay marine sediments dragged from Capo Granitola Coast (Trapani, Italy) spiked with five PAHs congeners (5PAHs), Hg and As were used as a simplified model matrix and treated to simulate a real case study. A total PAHs removal efficiency of 57% was reached after 96 h of treatment under 0.05 V cm-1. Then, real polluted marine sediments from Augusta Bay (Syracuse) and Bagnoli-Coroglio Bay (Naples) in the southern Italy were treated as real contaminated sediments to be restored, to validate the proposed approach for real cases. A quite good removal efficiency of PAHs was reached after 96 h of electrochemical treatment coupled with a low energetic consumption due to the rather E values adopted. In addition, it was observed that this approach, under the adopted conditions, is unsuitable for the remediation of Hg and As
Zoonotic infectious diseases in transplanted immunocompromised patients
Background. Immunocompromised patients, like transplant recipients, are a particularly vulnerable group being at higher risk of developing several infectious diseases. Among them, zoonotic diseases, such as visceral leishmaniasis, bartonellosis, Q fever and leptospirosis are a growing concern in immunosuppressed patients as they are more susceptible to develop severe symptoms of the diseases. Objectives. The study aimed at the detection of Leishmania infantum, Bartonella spp., Leptospira spp. and Coxiella burnetii DNA in immunocompromised hosts through molecular methods
In vitro time-kill kinetics of dalbavancin against Staphylococcus spp. biofilms over prolonged exposure times
Abstract Staphylococcus aureus and Staphylococcus epidermidis are leading pathogens of biofilm-related infections and represent the most common cause of osteomyelitis and biomedical implants infections. Biofilm-related infections usually require long-term antibiotic treatment, often associated to surgical interventions. Dalbavancin is a newer lipoglycopeptide approved for the treatment of acute skin and skin-structure infections caused by Gram-positive pathogens. In addition, dalbavancin has recently been considered as a potential option for the treatment of staphylococcal osteomyelitis and orthopedic implant infections. In this study, time-kill kinetics of dalbavancin against S. aureus and S. epidermidis biofilms were determined over prolonged exposure times (up to 7 days), using both a standardized biofilm susceptibility model and biofilms grown onto relevant orthopedic biomaterials (i.e. titanium and cobalt-chrome disks). Dalbavancin (at concentrations achievable in bone and articular tissue) showed a potent activity against established staphylococcal biofilms in both tested models, and was overall superior to the comparator vancomycin
Au-Coated Ni80Fe20 Submicron Magnetic Nanodisks: Interactions With Tumor Cells
Effective interaction and accumulation of nanoparticles (NPs) within tumor cells is crucial for NP-assisted diagnostic and therapeutic biomedical applications. In this context, the shape and size features of NPs can severely influence the strength of adhesion between NPs and cell and the NP internalization mechanisms. This study proved the ability of the PT45 and A549 tumor cells to uptake and retain magnetic Au-coated Ni80Fe20 nanodisks (NDs) prepared by means of a bottom–up self-assembling nanolithography technique assisted by polystyrene nanospheres. The chosen geometrical parameters, i.e., diameter (≈650 nm) and thickness (≈30 nm), give rise to magnetic domain patterns arranged in vortex state at the magnetic remanence. PT45 and A549 cell lines were cultured in the presence of different concentrations of Au-coated Ni80Fe20 nanodisks, and their biocompatibility was evaluated by viability and proliferation tests. Electron microscopy techniques and a combined CARS (Coherent Anti-stokes Raman Scattering) and TPL (two-photon photoluminescence) microscopy allow localizing and distinguishing the NDs within or attached to the tumor cells, without any labeling. A quantitative measurement of ND amount retained within tumor cells as a function of ND concentrations was performed by the Instrumental Neutron Activation Analysis (INAA) characterization technique
De-Trending Time Series for Astronomical Variability Surveys
We present a de-trending algorithm for the removal of trends in time series.
Trends in time series could be caused by various systematic and random noise
sources such as cloud passages, changes of airmass, telescope vibration or CCD
noise. Those trends undermine the intrinsic signals of stars and should be
removed. We determine the trends from subsets of stars that are highly
correlated among themselves. These subsets are selected based on a hierarchical
tree clustering algorithm. A bottom-up merging algorithm based on the departure
from normal distribution in the correlation is developed to identify subsets,
which we call clusters. After identification of clusters, we determine a trend
per cluster by weighted sum of normalized light-curves. We then use quadratic
programming to de-trend all individual light-curves based on these determined
trends. Experimental results with synthetic light-curves containing artificial
trends and events are presented. Results from other de-trending methods are
also compared. The developed algorithm can be applied to time series for trend
removal in both narrow and wide field astronomy.Comment: Revised version according to the referee's second revie
Cancer cell metabolic plasticity allows resistance to NAMPT inhibition but invariably induces dependence on LDHA
Background: Inhibitors of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in NAD+
biosynthesis from nicotinamide, exhibit anticancer effects in preclinical models. However, continuous exposure
to NAMPT inhibitors, such as FK866, can induce acquired resistance.
Methods: We developed FK866-resistant CCRF-CEM (T cell acute lymphoblastic leukemia) and MDA MB231
(breast cancer) models, and by exploiting an integrated approach based on genetic, biochemical, and genome wide
analyses, we annotated the drug resistance mechanisms.
Results: Acquired resistance to FK866 was independent of NAMPT mutations but rather was based on a shift towards
a glycolytic metabolism and on lactate dehydrogenase A (LDHA) activity. In addition, resistant CCRF-CEM cells, which
exhibit high quinolinate phosphoribosyltransferase (QPRT) activity, also exploited amino acid catabolism as an alternative
source for NAD+ production, becoming addicted to tryptophan and glutamine and sensitive to treatment with the amino
acid transport inhibitor JPH203 and with L-asparaginase, which affects glutamine exploitation. Vice versa, in line with their
low QPRT expression, FK866-resistant MDA MB231 did not rely on amino acids for their resistance phenotype.
Conclusions: Our study identifies novel mechanisms of resistance to NAMPT inhibition, which may be useful to design
more rational strategies for targeting cancer metabolism
CT Perfusion as a Predictor of the Final Infarct Volume in Patients with Tandem Occlusion
Background: CT perfusion (CTP) is used in patients with anterior circulation acute ischemic stroke (AIS) for predicting the final infarct volume (FIV). Tandem occlusion (TO), involving both intracranial large vessels and the ipsilateral cervical internal carotid artery could generate hemodynamic changes altering perfusion parameters. Our aim is to evaluate the accuracy of CTP in the prediction of the FIV in TOs. Methods: consecutive patients with AIS due to middle cerebral artery occlusion, referred to a tertiary stroke center between March 2019 and January 2021, with an automated CTP and successful recanalization (mTICI = 2b - 3) after endovascular treatment were retrospectively included in the tandem group (TG) or in the control group (CG). Patients with parenchymal hematoma type 2, according to ECASS II classification of hemorrhagic transformations, were excluded in a secondary analysis. Demographic, clinical, radiological, time intervals, safety, and outcome measures were collected. Results: among 319 patients analyzed, a comparison between the TG (N = 22) and CG (n = 37) revealed similar cerebral blood flow (CBF) > 30% (29.50 +/- 32.33 vs. 15.76 +/- 20.93 p = 0.18) and FIV (54.67 +/- 65.73 vs. 55.14 +/- 64.64 p = 0.875). Predicted ischemic core (PIC) and FIV correlated in both TG (tau = 0.761, p < 0.001) and CG (tau = 0.315, p = 0.029). The Bland-Altmann plot showed agreement between PIC and FIV for both groups, mainly in the secondary analysis. Conclusion: automated CTP could represent a good predictor of FIV in patients with AIS due to TO
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Tristetraprolin/ZFP36 Regulates the Turnover of Autoimmune-Associated HLA-DQ mRNAs.
HLA class II genes encode highly polymorphic heterodimeric proteins functioning to present antigens to T cells and stimulate a specific immune response. Many HLA genes are strongly associated with autoimmune diseases as they stimulate self-antigen specific CD4+ T cells driving pathogenic responses against host tissues or organs. High expression of HLA class II risk genes is associated with autoimmune diseases, influencing the strength of the CD4+ T-mediated autoimmune response. The expression of HLA class II genes is regulated at both transcriptional and post-transcriptional levels. Protein components of the RNP complex binding the 3'UTR and affecting mRNA processing have previously been identified. Following on from this, the regulation of HLA-DQ2.5 risk genes, the main susceptibility genetic factor for celiac disease (CD), was investigated. The DQ2.5 molecule, encoded by HLA-DQA1*05 and HLA-DQB1*02 alleles, presents the antigenic gluten peptides to CD4+ T lymphocytes, activating the autoimmune response. The zinc-finger protein Tristetraprolin (TTP) or ZFP36 was identified to be a component of the RNP complex and has been described as a factor modulating mRNA stability. The 3'UTR of CD-associated HLA-DQA1*05 and HLA-DQB1*02 mRNAs do not contain canonical TTP binding consensus sequences, therefore an in silico approach focusing on mRNA secondary structure accessibility and stability was undertaken. Key structural differences specific to the CD-associated mRNAs were uncovered, allowing them to strongly interact with TTP through their 3'UTR, conferring a rapid turnover, in contrast to lower affinity binding to HLA non-CD associated mRNA
Recommendations for a safe restart of elective aerosol-generating oral surgery procedures following the COVID-19 pandemic outbreak: An Italian multicenter study
Among healthcare workers, oral and maxillofacial surgeons are some of the most exposed to coronavirus disease (COVID-19). The aim of this retrospective study was to develop suggestions for continuing the work of oral and maxillofacial surgeons using a safe protocol for elective and urgent aerosol-generating procedures that could prevent the onset of new clusters. Based on the results obtained and a guidelines review of those Asian countries that had promptly managed the current pandemic, the following safety protocol was developed
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