214 research outputs found
Mass of the b-quark and B-decay constants from Nf=2+1+1 twisted-mass Lattice QCD
We present precise lattice computations for the b-quark mass, the quark mass
ratios mb/mc and mb/ms as well as the leptonic B-decay constants. We employ
gauge configurations with four dynamical quark flavors, up/down, strange and
charm, at three values of the lattice spacing (a ~ 0.06 - 0.09 fm) and for pion
masses as low as 210 MeV. Interpolation in the heavy quark mass to the bottom
quark point is performed using ratios of physical quantities computed at nearby
quark masses exploiting the fact that these ratios are exactly known in the
static quark mass limit. Our results are also extrapolated to the physical pion
mass and to the continuum limit and read: mb(MSbar, mb) = 4.26(10) GeV, mb/mc =
4.42(8), mb/ms = 51.4(1.4), fBs = 229(5) MeV, fB = 193(6) MeV, fBs/fB =
1.184(25) and (fBs/fB)/(fK/fpi) = 0.997(17).Comment: Version to appear in PRD. Added comments to simulation setup and
error budget discussion. 1+20 pages, 9 figure
Role and Efficacy of Intraoperative Evaluation of Resection Adequacy in Conservative Breast Surgery
In the present study we considered the histology of 51 patients who have undergone breast conservative surgery and the related 54 re-excisions that were performed in the same surgical procedure or in delayed procedures, in order to evaluate the role of intraoperative re-excisions in completing tumor removal. In 13% of the cases the re excision obtained the resection of the target lesion. In this study, the occurrence of residual neoplastic lesions in intraoperative re-excisions (24%) is lower than in delayed re-excisions (62%; P = .03).
The residual lesions that we could find with definitive histology of re excision specimens are related with lesions with ill defined profile. In 77% of the cases of re excision with tumoral residual the lesion was close to the new resection margin, thus the re-excisions couldn't achieve an adequate ablation of the neoplasm. Invasive or preinvasive nature of the main lesion resected for each case and the approach to the evaluation of the first resection specimen adequacy (surgical or radiological) don't affect the rate of tumoral residual in intraoperative re-excisions. In conclusion, our data are consistent with a low efficacy of intraoperative re excision in obtaining a complete removal of the tumor; intraoperative radiologic evaluation of the first resection specimen is however imperative in defining the effective removal of the target lesion
Up to 40 % reduction of the GaAs band gap energy via strain engineering in core/shell nanowires
The great possibilities for strain engineering in core/shell nanowires have
been explored as an alternative route to tailor the properties of binary III-V
semiconductors without changing their chemical composition. In particular, we
demonstrate that the GaAs core in GaAs/In(x)Ga(1-x)As or GaAs/In(x)Al(1-x)As
core/shell nanowires can sustain unusually large misfit strains that would have
been impossible in conventional thin-film heterostructures. The built-in strain
in the core can be regulated via the composition and the thickness of the
shell. Thick enough shells become almost strain-free, whereas the thin core
undergoes a predominantly-hydrostatic tensile strain, which causes the
reduction of the GaAs band gap energy. For the highest strain of 7 % in this
work (obtained for x=0.54), a remarkable reduction of the band gap by 40 % was
achieved in agreement with theoretical calculations. Such strong modulation of
its electronic properties renders GaAs suitable for near-infrared
nano-photonics and presumably high electron mobility nano-transistors.Comment: 12 pages, 4 figure
Bilateral optic neuritis in a 26-year-old man with common variable immunodeficiency: a case report
<p>Abstract</p> <p>Introduction</p> <p>Common variable immunodeficiency encompasses a group of heterogeneous conditions linked by a lack of immunoglobulin production and primary antibody failure. Although primary immunodeficiencies are typically characterized by recurrent infections, autoimmune manifestations have increasingly been recognized. Neurological complications are extremely rare and to the best of our knowledge optic neuritis has not been described previously. We report the case of a patient with common variable immunodeficiency who developed loss of vision secondary to bilateral optic neuritis.</p> <p>Case presentation</p> <p>A 26-year-old Caucasian man with a diagnosis of common variable immunodeficiency presented to our facility with loss of vision secondary to bilateral optic neuritis. Results of a thorough study for infectious, neoplastic and autoimmune diseases were negative. Our patient was treated with intravenous methylprednisolone with almost complete improvement and he remained asymptomatic at a 12-month follow-up.</p> <p>Conclusions</p> <p>Bilateral optic neuritis should be added to the list of autoimmune disorders related to common variable immunodeficiency. If a patient with common variable immunodeficiency experiences loss of vision, the possibility of bilateral optic neuritis should be considered as rapid initiation of high-dose corticosteroids may improve visual recovery.</p
Decision-making deficit in chronic migraine patients with medication overuse
Patients with chronic migraine developing medication-overuse headache (MOH) show dependency-like behaviors such as loss of control over analgesics despite adverse consequences on headaches, high rates of relapse after withdrawal from symptomatic medications, and compromised social functioning. Neuroimaging research suggests a common pathophysiology between substance-use disorders and MOH, which involves functional alterations in fronto-striatal networks, particularly in the orbitofrontal region of prefrontal cortex. These findings could explain the impaired decision-making observed in substance-use disorders. We hypothesize that MOH could share fronto-striatal circuit dysfunction and relative decision-making deficit with addiction. We further examine whether this deficit is a persistent cognitive trait or a reversible consequence of medication overuse. This study shows a dataset of 50 patients with MOH before the detoxification. All patients underwent a complete neurological and psychiatric examination. Psychiatric examination consisted of a clinical interview, Structured Clinical Interview for DSM-IV TR Axis II Personality Disorders, Anxiety and Depression Hamilton Scales, Severity of Dependence Scale. The neurological examination included the migraine disability assessment questionnaire. Neuropsychological assessment of fronto-striatal circuits was investigated using the Iowa gambling task (IGT). Twenty patients monitored for any relapse into medication overuse had 12 months of follow-up. Our sample, characterized by high rates of disability and dependency-like behaviors, exhibited a deficit in IGT performance, indicating an overall impairment in decision-making. All the 20 patients showed neurological and psychiatric improvement at 12-month follow-up, notwithstanding the overuse relapse, but a persistent IGT deficit was found. To our knowledge this is the first study that assesses this cognitive function in patients with MOH. Medication-overuse headache seems to share a persistent decision-making deficit with substance abuse that confirms the orbitofrontal cortex hypometabolism described in literature from a neuropsychological perspective. Looking at these shared neurocognitive features, our results suggest that MOH could belong to the addiction spectrum. Fronto-striatal dysfunction could be a premorbid psychobiological condition of vulnerability explaining the clinical onset of medication overuse and recurrent relapses. We propose that IGT could be used to identify chronic migraine patients with higher risk for medication overuse and relaps
Self-medication for migraine: a Nationwide cross-sectional study in Italy
Headache disorders are considered the second leading cause of years lived with disability worldwide, and 90% of people have a headache episode at least once a year, thus representing a relevant public health priority. As the pharmacist is often the first and only point of reference for people complaining of headache, we carried out a survey in a nationwide sample of Italian pharmacies, in order to describe the distribution of migraine or non-migraine type headaches and medicines overuse among people entering pharmacies seeking for self-medication; and to evaluate the association, in particular of migraine, with socio-demographic and clinical characteristics, and with the pathway of care followed by the patients. A 14-item questionnaire, including socio-demographic and clinical factors, was administered by trained pharmacists to subjects who entered a pharmacy requesting self-medication for a headache attack. The ID Migraine™ Screener was used to classify headache sufferers in four classes. From June 2016 to January 2017, 4424 people have been interviewed. The prevalence of definite migraines was 40%, significantly higher among women and less educated people. About half of all headache sufferers and a third of migraineurs do not consider their condition as a disease and are not cared by any doctor. Among people seeking self-medication in pharmacies for acute headache attacks, the rate of definite or probable migraine is high, and a large percentage of them is not correctly diagnosed and treated. The pharmacy can be a valuable observatory for the study of headaches, and the first important step to improve the quality of care delivered to these patients
Electrochemotherapy in the treatment of cutaneous metastases from breast cancer: a multicenter cohort analysis.
The management of breast cancer (BC) skin metastases represents a therapeutic challenge. Electrochemotherapy (ECT) combines the administration of bleomycin with temporary permeabilization induced by locally administered electric pulses. Preliminary experience with ECT in BC patients is encouraging.
METHODS: A total of 125 patients with BC skin metastases who underwent ECT between 2010 and 2013 were enrolled onto a multicenter retrospective cohort study. The treatment was administered following the European Standard Operative Procedures of Electrochemotherapy. Tumor response was clinically assessed adapting the Response Evaluation Criteria in Solid Tumors, and toxicity was evaluated according to Common Terminology Criteria for Adverse Events 4.0. Cox regression analysis was used to identify predictive factors.
RESULTS: Response was evaluable in 113 patients for 214 tumors (median 1 per patient, range 1-3). The overall response rate after 2 months was 90.2 %, while the complete response (CR) rate was 58.4 %. In multivariate analysis, small tumor size (P < 0.001), absence of visceral metastases (P = 0.001), estrogen receptor positivity (P = 0.016), and low Ki-67 index (P = 0.024) were significantly associated with CR. In the first 48 h, 10.4 % of patients reported severe skin pain. Dermatologic toxicity included grade 3 skin ulceration (8.0 %) and grade 2 skin hyperpigmentation (8.8 %). Tumor 1-year local progression-free survival was 86.2 % (95 % confidence interval 79.3-93.8) and 96.4 % (95 % confidence interval 91.6-100) in the subgroup of those with CR.
CONCLUSIONS: In this study, small tumor size, absence of visceral metastases, estrogen receptor positivity, and low Ki-67 index were predictors of CR after ECT. Patients who experienced CR had durable local control. ECT represents a valuable skin-directed therapy for selected patients with BC
Lattice QCD Study of -meson Decay Constants from ETMC
We discuss a lattice QCD computation of the -meson decay constants by the
ETM collaboration where suitable ratios allow to reach the bottom quark sector
by combining simulations around the charm-quark mass with an exactly known
static limit. The different steps involved in this ratio method are discussed
together with an account of the assessment of various systematic effects. A
comparison of results from simulations with two and four flavour dynamical
quarks is presented.Comment: 8 pages, 4 figures. Proceedings of the 8th International Workshop on
the CKM Unitarity Triangle (CKM 2014), Vienna, Austria, September 8-12, 201
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