213 research outputs found
Borderline CD30+ Cutaneous Lymphoproliferative Disorder: Report of a Case with Expression of Cytotoxic Markers and Response to Clarithromycin
CD30+ cutaneous lymphoproliferative disorders (CLPDs) are usually characterized by a benign clinical course. The prognostic value of cytotoxic markers in these lymphomas has not been evaluated in large series. We describe a case of borderline CD30+ CLPD with cytotoxic phenotype, presenting in a 22-year-old male patient as an ulcer on the forearm. He reported having had similar ulcers on the buttock and thigh that spontaneously regressed over the course of 1 year. The lesion resolved with a single course of clarithromycin; a subsequent lesion, too, responded to clarithromycin, and no recurrences or systemic involvement have been documented in the 9-month follow-up. A conservative approach in the management of CD30+ CLPD is recommended. We believe that the anti-inflammatory and apoptotic effects of clarithromycin on T cells may have hastened the remission process
Gravitational echoes of lepton number symmetry breaking with light and ultralight Majorons
We formulate a version of the low-scale Majoron model equipped with an
inverse seesaw mechanism featuring lepton-number preserving dimension-6
operators in the scalar potential. Contrary to its dimension-4 counterpart, we
find that the model can simultaneously provide light and ultralight Majorons,
neutrino masses and their mixing, while featuring strong first-order
cosmological phase transitions associated to the spontaneous breaking of the
lepton number and the electroweak symmetries in the early Universe. We show by
a detailed numerical analysis that under certain conditions on the parameter
space accounted for in collider physics, the model can be probed via the
primordial gravitational wave spectrum potentially observable at LISA and other
planned facilities.Comment: 29 pages, 7 figure
Impact of SM parameters and of the vacua of the Higgs potential in gravitational waves detection
In this work we discuss two different phases of a complex singlet extension
of the Standard Model (SM) together with an extension that also includes new
fermion fields, in particular, a Majoron model equipped with an inverse seesaw
mechanism. All considered scenarios contain a global symmetry
and allow for first-order phase transitions while only two of them are strong
enough to favour the detection of primordial gravitational waves (GWs) in
planned experiments such as LISA. In particular, this is shown to be possible
in the singlet extension with a non vanishing real VEV at zero temperature and
also in the model with extra fermions. In the singlet extension with no
additional fermions, the detection of GWs strongly depends on the
symmetry breaking pattern of the scalar potential at zero
temperature. We study for the first time the impact of the precision in the
determination of the SM parameters on the strength of the GWs spectrum. It
turns out that the variation of the SM parameters such as the Higgs boson mass
and top quark Yukawa coupling in their allowed experimental ranges has a
notable impact on GWs detectability prospects.Comment: 28 pages, 13 figure
Gravitational-Wave Signatures of Chiral-Symmetric Technicolor
A chiral-symmetric technicolor model successfully reconciles the tension
between electroweak precision tests and traditional technicolor models.
Focusing on its simplest realization preserving the conventional Higgs
mechanism, we study its primordial gravitational wave signatures originating
from first order phase transitions in the early Universe. We found that
abundant phase transition patterns arise from a physically viable parameter
space. Besides, we have also found gravitational wave signals possibly visible
by future experiments, such as LISA, BBO and u-DECIGO. Our results stress the
importance of gravitational wave detectors in exploring new physics
complementary to ground colliders in the multi-messenger astronomy era.Comment: 9 pages, 6 figures, 3 table
How Many Nodes are Effectively Accessed in Complex Networks?
The measurement called accessibility has been proposed as a means to quantify
the efficiency of the communication between nodes in complex networks. This
article reports important results regarding the properties of the
accessibility, including its relationship with the average minimal time to
visit all nodes reachable after steps along a random walk starting from a
source, as well as the number of nodes that are visited after a finite period
of time. We characterize the relationship between accessibility and the average
number of walks required in order to visit all reachable nodes (the exploration
time), conjecture that the maximum accessibility implies the minimal
exploration time, and confirm the relationship between the accessibility values
and the number of nodes visited after a basic time unit. The latter
relationship is investigated with respect to three types of dynamics, namely:
traditional random walks, self-avoiding random walks, and preferential random
walks.Comment: 8 pages and 7 figure
From Bloch Oscillations to a Steady-State Current in Strongly Biased Mesoscopic Devices
It has long been known that quantum particles in a periodic lattice exhibit
an oscillatory motion that is solely driven by a constant and uniform force
field. In a strongly biased mesoscopic device, this would appear as an ongoing
time-dependent current oscillation (a Bloch oscillation) but, even when
electrons can move coherently and without scattering, a steady-state regime of
charge transport (a Landauer current) have been seen to quickly emerge. Here,
we theoretically investigate the non-equilibrium current dynamics of a strongly
biased two-terminal mesoscopic device, in order to show that such a system can
exhibit Bloch oscillations as a transient regime that relaxes into a Landauer
steady-state from charge being drained into the leads. Analytical results from
the one-dimensional Wannier-Stark ladder problem are combined with numerical
quantum time-evolution of a tight-binding toy model with finite leads to
characterize the decay times of transient Bloch oscillations and establish the
conditions under which they can occur.Comment: Preliminary Version (13 pages + 12 Figures). Comments and Suggestions
are Welcome
Kinin B1 receptors mediate depression-like behavior response in stressed mice treated with systemic E. coli lipopolysaccharide
<p>Abstract</p> <p>Background</p> <p>Kinin B<sub>1 </sub>receptors are inducible molecules up-regulated after inflammatory stimuli. This study evaluated the relevance of kinin B<sub>1 </sub>receptors in a mouse depression behavior model.</p> <p>Methods</p> <p>Mice were exposed to a 5-min swimming session, and 30 min later they were injected with <it>E. coli </it>lipopolysaccharide (LPS). Depression-like behavior was assessed by determining immobility time in a tail suspension test. Different brain structures were collected for molecular and immunohistochemical studies. Anhedonia was assessed by means of a sucrose intake test.</p> <p>Results</p> <p>Our protocol elicited an increase in depression-like behavior in CF1 mice, as assessed by the tail-suspension test, at 24 h. This behavior was significantly reduced by treatment with the selective B<sub>1 </sub>receptor antagonists R-715 and SSR240612. Administration of SSR240612 also prevented an increase in number of activated microglial cells in mouse hippocampus, but did not affect a reduction in expression of mRNA for brain-derived neurotrophic factor. The increased immobility time following LPS treatment was preceded by an enhancement of hippocampal and cortical B<sub>1 </sub>receptor mRNA expression (which were maximal at 1 h), and a marked production of TNFα in serum, brain and cerebrospinal fluid (between 1 and 6 h). The depression-like behavior was virtually abolished in TNF<it>α </it>p55 receptor-knockout mice, and increased B<sub>1 </sub>receptor mRNA expression was completely absent in this mouse strain. Furthermore, treatment with SSR240612 was also effective in preventing anhedonia in LPS-treated mice, as assessed using a sucrose preference test.</p> <p>Conclusion</p> <p>Our data show, for the first time, involvement of kinin B<sub>1 </sub>receptors in depressive behavioral responses, in a process likely associated with microglial activation and TNFα production. Thus, selective and orally active B<sub>1 </sub>receptor antagonists might well represent promising pharmacological tools for depression therapy.</p
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