840 research outputs found
Sum rules and spectral density flow in QCD and in superconformal theories
We discuss the signature of the anomalous breaking of the superconformal
symmetry in super Yang Mills theory and its manifestation in
the form of anomaly poles. Moreover, we describe the massive deformations of
the theory and the spectral densities of the corresponding
anomaly form factors. These are characterized by spectral densities which flow
with the mass deformation and turn the continuum contributions from the
two-particle cuts of the intermediate states into poles, with a single sum rule
satisfied by each component. The poles can be interpreted as signaling the
exchange of a composite axion/dilaton/dilatino (ADD) multiplet in the effective
Lagrangian. We conclude that global anomalous currents characterized by a
single flow in the perturbative picture always predict the existence of
composite interpolating fields.Comment: 8 pages. arXiv admin note: substantial text overlap with
arXiv:1402.636
Superconformal Sum Rules and the Spectral Density Flow of the Composite Dilaton (ADD) Multiplet in Theories
We discuss the signature of the anomalous breaking of the superconformal
symmetry in super Yang Mills theory, mediated by the
Ferrara-Zumino hypercurrent () with two vector ()
supercurrents and its manifestation in the anomaly action, in
the form of anomaly poles. This allows to investigate in a unified way both
conformal and chiral anomalies. The analysis is performed in parallel to the
Standard Model, for comparison. We investigate, in particular, massive
deformations of the theory and the spectral densities of the
anomaly form factors which are extracted from the components of this
correlator. In this extended framework it is shown that all the anomaly form
factors are characterized by spectral densities which flow with the mass
deformation. In particular, the continuum contributions from the two-particle
cuts of the intermediate states turn into into poles in the zero mass limit,
with a single sum rule satisfied by each component. Non anomalous form factors,
instead, in the same anomalous correlators, are characterized by non-integrable
spectral densities. These tend to uniform distributions as one moves towards
the conformal point, with a clear dual behaviour. As in a previous analysis of
the dilaton pole of the Standard Model, also in this case the poles can be
interpreted as signaling the exchange of a composite dilaton/axion/dilatino
(ADD) multiplet in the effective Lagrangian.[...]Comment: 51 pages, 13 figures. Revised final version. To appear on JHE
Can daily intake of aspirin and/or statins influence the behavior of non-muscle invasive bladder cancer? A retrospective study on a cohort of patients undergoing transurethral bladder resection
Background: This study aimed to evaluate the behavior of non-muscle-invasive bladder cancer (NMIBC) in patients
submitted to transurethral bladder resection (TURB) comparing subjects in chronic therapy with aspirin, statins, or
both drugs to untreated ones.
Methods: This retrospective study was conducted on 574 patients diagnosed with NMIBC who underwent TURB
between March 2008 and April 2013. The study population was divided into two main groups: treated (aspirin
and/or statins) and untreated. The treated group was further divided into three therapeutic subgroups: Group A
(100 mg of aspirin, daily for at least two years); Group B (20 mg or more of statins, daily for at least two years);
and Group C (100 mg of aspirin and 20 mg of statins together). The mean follow-up of patients was 45.06 months.
Results: No significant differences were observed among the different groups at baseline. On multivariate analysis,
statin treatment, smokers and high stage disease (T1) achieved the level of independent risk factor for the occurrence
of a recurrence. When patients were stratified according to the different treatment; patients treated with statins
(Group B) presented an higher rate of failure (56/91 patients; 61.5%) when compared to Group A (42/98 patients;
42.9%), Group C (56/98; 57.1%) and (133/287 patients; 46.3%). This difference corresponds to a significant difference
in recurrence failure free survival (p = 0.01).
Conclusions: Our results suggest that long-term treatment with aspirin in patients with NMIBC might play a role on
reducing the risk of tumor recurrence. In contrast, in our investigation data from statins and combination treatment
groups showed increased recurrence rates. A long-term randomized prospective study could definitively assess the
possible role of this widely used drugs in NMIBC
Neutrino and photon lensing by black holes: radiative lens equations and post-Newtonian contributions
We extend a previous phenomenological analysis of photon lensing in an
external gravitational background to the case of a massless neutrino, and
propose a method to incorporate radiative effects in the classical lens
equations of neutrinos and photons. The study is performed for a Schwarzschild
metric, generated by a point-like source, and expanded in the Newtonian
potential at first order. We use a semiclassical approach, where the
perturbative corrections to neutrino scattering, evaluated at one-loop in the
Standard Model, are compared with the Einstein formula for the deflection using
an impact parameter formulation. For this purpose, we use the renormalized
expression of the graviton/fermion/fermion vertex presented in previous
studies. We show the agreement between the classical and the semiclassical
formulations, for values of the impact parameter of the neutrinos of the
order of , measured in units of the Schwarzschild radius. The
analysis is then extended with the inclusion of the post Newtonian corrections
in the external gravity field, showing that this extension finds application in
the case of the scattering of a neutrino/photon off a primordial black hole.
The energy dependence of the deflection, generated by the quantum corrections,
is then combined with the standard formulation of the classical lens equations.
We illustrate our approach by detailed numerical studies, using as a reference
both the thin lens and the nonlinear Virbhadra-Ellis lens
MicroRNAs in melanoma development and resistance to target therapy
microRNAs constitute a complex class of pleiotropic post-transcriptional regulators of gene expression involved in the control of several physiologic and pathologic processes. Their mechanism of action is primarily based on the imperfect matching of a seed region located at the 5' end of a 21-23 nt sequence with a partially complementary sequence located in the 3' untranslated region of target mRNAs. This leads to inhibition of mRNA translation and eventually to its degradation. Individual miRNAs are capable of binding to several mRNAs and several miRNAs are capable of influencing the function of the same mRNAs. In recent years networks of miRNAs are emerging as capable of controlling key signaling pathways responsible for the growth and propagation of cancer cells. Furthermore several examples have been provided which highlight the involvement of miRNAs in the development of resistance to targeted drug therapies. In this review we provide an updated overview of the role of miRNAs in the development of melanoma and the identification of the main downstream pathways controlled by these miRNAs. Furthermore we discuss a group of miRNAs capable to influence through their respective up- or down-modulation the development of resistance to BRAF and MEK inhibitors
Ultrasonic decontamination in smoked salmon experimentally contaminated with Listeria monocytogenes: Preliminary results
The purpose of this work was to evaluate the effects of ultrasound (sonication) and their combination with temperature (thermosonication) on the inactivation of Listeria monocytogenes (LM) in smoked salmon. The trial was conducted on smoked salmon samples experimentally contaminated with a cocktail of 4 strains of Listeria monocytogenes (LM ATCC 19114, LM ATCC 15313, LM ATCC 19111 and LM ATCC 7644) at a final concentration of 8 log cfu/g and kept at 4°C until its use. Thermosonication treatments between 40°C and 50°C for 5, 10 and 15 minutes proved to be more effective without altering the sensory characteristics of the food
The multi-epoch X-ray tale of I Zwicky 1 outflows
The narrow-line Seyfert 1 galaxy I Zwicky 1 shows a unique and complex system
of ionised gas in outflow, which consists of an ultra-fast wind and a
two-component warm absorber. In the last two decades, XMM-Newton monitored the
source multiple times enabling the study of the long-term variability of the
various outflows. Plasma in photoionisation equilibrium with the ionising
source responds and varies accordingly to any change of the ionising
luminosity. However, detailed modelling of the past RGS data has shown no
correlation between the plasma ionisation state and the ionising continuum,
revealing a complex long-term variability of the multi-phase warm absorber.
Here, we present a new observation of I Zwicky 1 by XMM-Newton taken in early
2020 characterised by a lower X-ray flux state. The soft X-ray spectrum from
the RGS reveals the two components of the warm absorber with and . Comparing our results with the previous
observations, the ionisation state of the two absorbing gas components is
continuously changing, following the same unpredictable behaviour. The new
results strengthen the scenario in which the ionisation state of the warm
absorber is driven by the density of the gas rather than the ionising
luminosity. In particular, the presence of a radiation driven, inhomogeneous
clumpy outflow may explain both the variability in ionisation throughout the
years and the line-locked N V system observed in the UV band. Finally, the
EPIC-pn spectrum reveals an ultra-fast wind with an outflow velocity of and ionisation parameter of .Comment: 16 pages, 11 figures, 3 tables, accepted for publication in MNRA
Secreted miR-210-3p as non-invasive biomarker in clear cell renal cell carcinoma
The most common subtype of renal cell carcinoma (RCC) is clear cell RCC (ccRCC).
It accounts for 70-80% of all renal malignancies representing the third most common
urological cancer after prostate and bladder cancer. The identification of non-invasive
biomarkers for the diagnosis and responsiveness to therapy of ccRCC may represent
a relevant step-forward in ccRCC management. The aim of this study is to evaluate
whether specific miRNAs deregulated in ccRCC tissues present altered levels also
in urine specimens. To this end we first assessed that miR-21-5p, miR-210-3p and
miR-221-3p resulted upregulated in ccRCC fresh frozen tissues compared to matched
normal counterparts. Next, we evidenced that miR-210-3p resulted significantly upregulated
in 38 urine specimens collected from two independent cohorts of ccRCC
patients at the time of surgery compared to healthy donors samples. Of note, miR-
210-3p levels resulted significantly reduced in follow-up samples. These results point
to miR-210-3p as a potential non-invasive biomarker useful not only for diagnosis
but also for the assessment of complete resection or response to treatment in ccRCC
management
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