402 research outputs found
Photoluminescence-Based Techniques for the Detection of Micro- and Nanoplastics
The growing numbers related to plastic pollution are impressive, with ca. 70 % of produced plastic (>350 tonnes/year) being indiscriminately wasted in the environment. The most dangerous forms of plastic pollution for biota and human health are micro- and nano-plastics (MNPs), which are ubiquitous and more bioavailable. Their elimination is extremely difficult, but the first challenge is their detection since existing protocols are unsatisfactory for microplastics and mostly absent for nanoplastics. After a discussion of the state of the art for MNPs detection, we specifically revise the techniques based on photoluminescence that represent very promising solutions for this problem. In this context, Nile Red staining is the most used strategy and we show here its pros and limitations, but we also discuss other more recent approaches, such as the use of fluorogenic probes based on perylene-bisimide and on fluorogenic hyaluronan nanogels, with the added values of biocompatibility and water solubility
Small Scale Systems of Galaxies. III. X-ray detected E+S galaxy pairs in low density environments
We present a comprehensive study of the local environments of four E+S galaxy
pairs with the main goal to investigate their formation/evolution histories.
New XMM-Newton data were obtained for two pairs (RR 143 and RR 242) that
complements existing ROSAT data for the other two (RR 210 and RR 216). The new
observations reveal diffuse X-ray emission in both pairs. The emission is
asymmetric in both cases and extends out to 120 kpc and 160 kpc in RR 143 and
RR 242 respectively. The nucleus of RR 242 hosts a low luminosity mildly
absorbed AGN. We find that the early-type components of pairs with diffuse hot
gas appear to be relaxed objects while those in RR 210 and RR 216, where no
diffuse emission has been found, display unambiguous signatures of ongoing
interaction. Wide-field V and R-band data are used to study the photometric
properties of the early-type components and to search for a candidate faint
galaxy populations around each of the pairs. While no diffuse optical light is
found for any of the pairs, all of the early-type members show very extended
and concentric luminous envelopes. We identify a faint galaxy sample in each
field and we consider whether they could be physically associated with the
luminous pairs based upon (V-R) colors and photometric properties. We find that
the distribution of r_e and M_R for the candidates are similar in three of the
fields (RR 143, 216 and 242). The same selection criteria applied to the field
of RR 210 suggest a fainter and more compact population possibly suggesting a
larger background fraction than in the other fields.Comment: 47 pages, 18 figures, Astron. J. in pres
The predictive and prognostic potential of plasma telomerase reverse transcriptase (TERT) RNA in rectal cancer patients
Background: Preoperative chemoradiotherapy (CRT) followed by surgery is the standard care for locally advanced rectal cancer,
but tumour response to CRT and disease outcome are variable. The current study aimed to investigate the effectiveness of plasma
telomerase reverse transcriptase (TERT) levels in predicting tumour response and clinical outcome.
Methods: 176 rectal cancer patients were included. Plasma samples were collected at baseline (before CRT\ubcT0), 2 weeks after
CRT was initiated (T1), post-CRT and before surgery (T2), and 4\u20138 months after surgery (T3) time points. Plasma TERT mRNA levels
and total cell-free RNA were determined using real-time PCR.
Results: Plasma levels of TERT were significantly lower at T2 (Po0.0001) in responders than in non-responders. Post-CRT TERT
levels and the differences between pre- and post-CRT TERT levels independently predicted tumour response, and the prediction
model had an area under curve of 0.80 (95% confidence interval (CI) 0.73\u20130.87). Multiple analysis demonstrated that patients with
detectable TERT levels at T2 and T3 time points had a risk of disease progression 2.13 (95% CI 1.10\u20134.11)-fold and 4.55 (95% CI
1.48\u201313.95)-fold higher, respectively, than those with undetectable plasma TERT levels.
Conclusions: Plasma TERT levels are independent markers of tumour response and are prognostic of disease progression in rectal
cancer patients who undergo neoadjuvant therapy
SPITZER IRS spectra of Virgo early type galaxies: detection of stellar silicate emission
We present high signal to noise ratio Spitzer Infrared Spectrograph
observations of 17 Virgo early-type galaxies. The galaxies were selected from
those that define the colour-magnitude relation of the cluster, with the aim of
detecting the silicate emission of their dusty, mass-losing evolved stars. To
flux calibrate these extended sources we have devised a new procedure that
allows us to obtain the intrinsic spectral energy distribution and to
disentangle resolved and unresolved emission within the same object. We have
found that thirteen objects of the sample (76%) are passively evolving galaxies
with a pronounced broad silicate feature which is spatially extended and likely
of stellar origin, in agreement with model predictions. The other 4 objects
(24%) are characterized by different levels of activity. In NGC 4486 (M 87) the
line emission and the broad silicate emission are evidently unresolved and,
given also the typical shape of the continuum, they likely originate in the
nuclear torus. NGC 4636 shows emission lines superimposed on extended (i.e.
stellar) silicate emission, thus pushing the percentage of galaxies with
silicate emission to 82%. Finally, NGC 4550 and NGC 4435 are characterized by
polycyclic aromatic hydrocarbon (PAH) and line emission, arising from a central
unresolved region. A more detailed analysis of our sample, with updated models,
will be presented in a forthcoming paper.Comment: 6 pages; ApJ Letters, accepte
Integrin-Targeting Dye-Doped PEG-Shell/Silica-Core Nanoparticles Mimicking the Proapoptotic Smac/DIABLO Protein
Cancer cells demonstrate elevated expression levels of the inhibitor of apoptosis proteins (IAPs), contributing to tumor cell survival, disease progression, chemo-resistance, and poor prognosis. Smac/DIABLO is a mitochondrial protein that promotes apoptosis by neutralizing members of the IAP family. Herein, we describe the preparation and in vitro validation of a synthetic mimic of Smac/DIABLO, based on fluorescent polyethylene glycol (PEG)-coated silica-core nanoparticles (NPs) carrying a Smac/DIABLO-derived pro-apoptotic peptide and a tumor-homing integrin peptide ligand. At low \u3bcM concentration, the NPs showed significant toxicity towards A549, U373, and HeLa cancer cells and modest toxicity towards other integrin-expressing cells, correlated with integrin-mediated cell uptake and consequent highly increased levels of apoptotic activity, without perturbing cells not expressing the \u3b15 integrin subunit
Failure Physics and Reliability of GaN-Based HEMTs for Microwave and Millimeter-Wave Applications: A Review of Consolidated Data and Recent Results
Herein, the results are reviewed concerning reliability of high-electron mobility transistors (HEMTs) based on GaN, which currently represent the technology of choice for high-efficiency microwave and millimeter-wave power amplifiers. Several failure mechanisms of these devices are extensively studied, including converse piezoelectric effects, formation of conductive percolation paths at the edge of gate toward the drain, surface oxidation of GaN, time-dependent breakdown of GaN buffer, and of field-plate dielectric. For GaN HEMTs with scaled gate length, the simultaneous control of short-channel effects, deep-level dispersion, and hot-electron-induced degradation requires a careful optimization of epitaxial material quality and device design
Generalized Jacobi identities and ball-box theorem for horizontally regular vector fields
We consider a family of vector fields and we assume a horizontal regularity
on their derivatives. We discuss the notion of commutator showing that
different definitions agree. We apply our results to the proof of a ball-box
theorem and Poincar\'e inequality for nonsmooth H\"ormander vector fields.Comment: arXiv admin note: material from arXiv:1106.2410v1, now three separate
articles arXiv:1106.2410v2, arXiv:1201.5228, arXiv:1201.520
Fate of tebuthiuron herbicide in a recharge area of Guarany Aquifer in sugarcane field in Brazil.
Clinical and functional characterization of a novel mutation in lamin a/c gene in a multigenerational family with arrhythmogenic cardiac laminopathy.
none17noneAkinori Kimura;Cinzia Forleo;Monica Carmosino;Nicoletta Resta;Alessandra Rampazzo;Rosanna Valecce;Sandro Sorrentino;Massimo Iacoviello;Francesco Pisani;Giuseppe Procino;Andrea Gerbino;Arnaldo Scardapane;Cristiano Simone;Martina Calore;Silvia Torretta;Maria Svelto;Stefano FavaleAkinori, Kimura; Cinzia, Forleo; Monica, Carmosino; Nicoletta, Resta; Rampazzo, Alessandra; Rosanna, Valecce; Sandro, Sorrentino; Massimo, Iacoviello; Francesco, Pisani; Giuseppe, Procino; Andrea, Gerbino; Arnaldo, Scardapane; Cristiano, Simone; Calore, Martina; Silvia, Torretta; Maria, Svelto; Stefano, Faval
UPDATE ON THE JRA1 PROJECT RESULTS OF ELECTRO-POLISHING OF MULTI-CELL SUPER CONDUCTING RESONATORS
Abstract Under the contract RII3-CT-2003-506395 of the European Union improvement on the electro-polishing (EP) of multi cell resonators are made. Several methods to improve resonator performances are studied. Improvement of electrode shape, simulated by numerical computer codes and test set ups are presented. With respect to reproducible cavity performances and industrialization of the EP process, a study for quality control by acid management is started. An automated EP system is developed at INFN Legnaro / Italy and within the collaboration of Legnaro and DESY this automated steering will be integrated into the DESY EP facility. We will report on the status of the WP 5.2.2.and the progress of the transfer of the automated E
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