3,922 research outputs found
Treatment responses to antiangiogenetic therapy and chemotherapy in nonsecreting paraganglioma (PGL4) of urinary bladder with SDHB mutation: a case report
Paraganglioma (PGL) is a rare neuroendocrine tumor. Currently, the malignancy is defined as the presence of metastatic spread at presentation or during follow-up. Several gene mutations are listed in the pathogenesis of PGL, among which succinate dehydrogenase (SDHX), particularly the SDHB isoform, is the main gene involved in malignancy. A 55-year-old male without evidence of catecholamine secretion had surgery for PGL of the urinary bladder. After 1 year, he showed a relapse of disease and demonstrated malignant PGL without evidence of catecholamine secretion with a germline heterozygous mutation of succinate dehydrogenase B (SDHB). After failure of a second surgery for relapse, he started medical treatment with sunitinib daily but discontinued due to serious side effects. Cyclophosphamide, vincristine, and dacarbazine (CVD) chemotherapeutic regimen stopped the disease progression for 7 months.
Conclusion: Malignant PGL is a very rare tumor, and SDHB mutations must be always considered in molecular diagnosis because they represent a critical event in the progression of the oncological disease. Currently, there are few therapeutic protocols, and it is often difficult, as this case demonstrates, to decide on a treatment option according to a reasoned set of choices.
Abbreviations: CVD = cyclophosphamide, vincristine and dacarbazine, HIF-1a = hypoxia inducible factor 1 alpha, PGL = paraganglioma, SDH = succinate dehydrogenase, VEGF = vasoendothelial growth factor
Constraints on new physics from the quark mixing unitarity triangle
The status of the Unitarity Triangle beyond the Standard Model including the
most recent results on Delta m_s, on dilepton asymmetries and on width
differences is presented. Even allowing for general New Physics loop
contributions the Unitarity Triangle must be very close to the Standard Model
result. With the new measurements from the Tevatron, we obtain for the first
time a significant constraint on New Physics in the B_s sector. We present the
allowed ranges of New Physics contributions to Delta F=2 processes, and of the
time-dependent CP asymmetry in B_s to J/Psi phi decays.Comment: 5 pages, 4 figures. v2: numerical error in Delta Gamma_s/Gamma_s
corrected. Plots and tables updated. v3: update after ICHEP06, final version
published in Phys Rev Letter
Dynamics of charge-displacement channeling in intense laser-plasma interactions
The dynamics of transient electric fields generated by the interaction of
high intensity laser pulses with underdense plasmas has been studied
experimentally with the proton projection imaging technique. The formation of a
charged channel, the propagation of its front edge and the late electric field
evolution have been characterised with high temporal and spatial resolution.
Particle-in-cell simulations and an electrostatic, ponderomotive model
reproduce the experimental features and trace them back to the ponderomotive
expulsion of electrons and the subsequent ion acceleration.Comment: 5 figures, accepted for publication in New Journal of Physic
Quantum SASE FEL with a laser wiggler
Quantum effects in high-gain FELs are ruled by the quantum FEL parameter, \u3c1 = pmcy/hkr, which is the ratio between the momentum spread at saturation and the one photon momentum recoil. It has been shown that when 3c\u3c1 64 1 the spectrum of the emitted radiation changes from the broad continuous and chaotic spectrum of the classical regime to a series of discrete and equally spaced very narrow lines, due to transitions between discrete momentum states. In this paper we show that the quantum regime can be achieved using Kilometers long magnetic wigglers or a laser wiggler. In this paper we state the scaling laws necessary to operate a Quantum SASE FEL in the Angstrom region with a laser wiggler. Specific example is given having in mind a high power Ti: Sa laser wiggler at \u3bb= 0.8 \u3bcm, in construction at LNF-INFN Laboratories, for the SPARC/PLASMON-X project
Update of the Unitarity Triangle Analysis
We present the status of the Unitarity Triangle Analysis (UTA), within the
Standard Model (SM) and beyond, with experimental and theoretical inputs
updated for the ICHEP 2010 conference. Within the SM, we find that the general
consistency among all the constraints leaves space only to some tension
(between the UTA prediction and the experimental measurement) in BR(B -> tau
nu), sin(2 beta) and epsilon_K. In the UTA beyond the SM, we allow for New
Physics (NP) effects in (Delta F)=2 processes. The hint of NP at the 2.9 sigma
level in the B_s-\bar B_s mixing turns out to be confirmed by the present
update, which includes the new D0 result on the dimuon charge asymmetry but not
the new CDF measurement of phi_s, being the likelihood not yet released.Comment: 4 pages, 2 figures, Proceedings of the 35th International Conference
of High Energy Physics - ICHEP2010 (July 22-28, 2010, Paris
Position Sense Deficits at the Lower Limbs in Early Multiple Sclerosis: Clinical and Neural Correlates
Background/Objective. Position sense, defined as the ability to identify joint and limb position in space, is crucial for balance and gait but has received limited attention in patients with multiple sclerosis (MS). We investigated lower limb position sense deficits, their neural correlates, and their effects on standing balance in patients with early MS. Methods. A total of 24 patients with early relapsing-remitting MS and 24 healthy controls performed ipsilateral and contralateral matching tasks with the right foot during functional magnetic resonance imaging. Corpus callosum (CC) integrity was estimated with diffusion tensor imaging. Patients also underwent an assessment of balance during quiet standing. We investigated differences between the 2 groups and the relations among proprioceptive errors, balance performance, and functional/structural correlates. Results. During the contralateral matching task, patients demonstrated a higher matching error than controls, which correlated with the microstructural damage of the CC and with balance ability. In contrast, during the ipsilateral task, the 2 groups showed a similar matching performance, but patients displayed a functional reorganization involving the parietal areas. Neural activity in the frontoparietal regions correlated with the performance during both proprioceptive matching tasks and quiet standing. Conclusion. Patients with early MS had subtle, clinically undetectable, position sense deficits at the lower limbs that, nevertheless, affected standing balance. Functional changes allowed correct proprioception processing during the ipsilateral matching task but not during the more demanding bilateral task, possibly because of damage to the CC. These findings provide new insights into the mechanisms underlying disability in MS and could influence the design of neurorehabilitation protocols
Investigation of the impact of additive manufacturing techniques on the acoustic performance of a coiled-up resonator
Acoustic metamaterials (AMMs) offer innovative solutions for physics and engineering problems, allowing lighter, multiphysics, and sustainable systems. They are usually studied analytically or numerically and then tested on prototypes. For this reason, additive manufacturing (AM) techniques are a popular way of quickly realising AMMs' innovative geometrical designs. However, AM parameters are often standardised without considering the specific issues of each AMM geometrical shape, leading to a possible mismatch between the analytical (or numerical) and experimental results. In this study, a simple AMM-a coiled-up resonator-has been produced with different AM technologies [fused deposition modeling (FDM), stereolithography (SLA), and selective laser melting and materials (polylactic acid, polyethylene terephthalate glycol, resin, flexible resin, and stainless steel). The sound absorption performance of these samples has been measured in two research labs in Italy and compared with the analytical and numerical calculations. This permitted the identification of the best combinations of AM technologies, their setup, and materials matching the expected results. The SLA/resin combination performed better overall; however, cheaper and more easily manageable samples made with FDM and polyethylene terephthalate glycol can achieve the same acoustic performance through the optimal AM printing setup. It is expected that this methodology could also be replicated for other AMMs
Improved Determination of the CKM Angle alpha from B to pi pi decays
Motivated by a recent paper that compares the results of the analysis of the
CKM angle alpha in the frequentist and in the Bayesian approaches, we have
reconsidered the information on the hadronic amplitudes, which helps
constraining the value of alpha in the Standard Model. We find that the
Bayesian method gives consistent results irrespective of the parametrisation of
the hadronic amplitudes and that the results of the frequentist and Bayesian
approaches are equivalent when comparing meaningful probability ranges or
confidence levels. We also find that from B to pi pi decays alone the 95%
probability region for alpha is the interval [80^o,170^o], well consistent with
recent analyses of the unitarity triangle where, by using all the available
experimental and theoretical information, one gets alpha = (93 +- 4)^o. Last
but not least, by using simple arguments on the hadronic matrix elements, we
show that the unphysical region alpha ~ 0, present in several experimental
analyses, can be eliminated.Comment: 16 pages, 7 figure
Multitarget microangiopathy in a young healthy man with COVID-19 disease: A case report.
A 41‑year‑old man presented to the emergency department complaining of decrease of vision in his left eye. Initial examination was consistent with retrobulbar optic neuritis, and an intravenous drip of methylprednisolone was started. On the third day, the fundus examination revealed the appearance of multiple Purtscher‑like cotton‑wool spots in the posterior pole and nasally to the optic disc, slight retinal whitening around the fovea, and cherry‑red spot. The patient reported flu‑like symptoms, and he tested positive at PCR (polymerase chain reaction) test for 2019‑nCoV (2019 novel coronavirus) infection. Assuming possible 2019‑nCoV‑related vascular damage, we prescribed low‑molecular‑weight heparin. The lesions were regressing at follow‑up, and we registered a complete visual recovery
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