282 research outputs found
Total thyroidectomy associated to chemotherapy in primary squamous cell carcinoma of the thyroid
Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignant disease with rapid fatal prognosis. The onset is generally characterized by sudden bilateral latero-cervical lymphadenopathy. The Authors report patient of 58-year-old who referred for evaluation of rapidly aggravating bilateral latero-cervical lymphadenopathy. The US highlighted the presence of a hypoechoic nodular lesion characterized by peri and intra-nodular vascularization. Multilayer CT showed diffused involvement of mediastinal and bilateral latero-cervical lymph nodes, with no evidence of primary pulmonary neoplasia or elsewhere. The patient underwent total thyroidectomy. The peri-isthmic tissue was removed due to the presence of a small roundish formation, that was due to lymph node metastasis at histological examination. Histological diagnosis: PSCCT. The immunohistochemical panel of the thyroid lesion was indispensable for the differential diagnosis between PSCCT, medullary carcinoma, anaplastic carcinoma, and thyroid metastasis of neoplasia with unknown primitiveness. The patient underwent chemotherapeutic treatment with Carboplatin and Paclitaxel with modest improvement of dysphagia symptoms and reduction of 10-15% of the target lesions. The clinical course was characterized by loco-regional progression of the disease with exitus in 10 months after diagnosis. Survival and quality of life after surgical therapy and chemotherapy were like that of patients undergoing only chemotherapy. Due to the extreme rarity of the neoplasia, 60 cases described in Literature, no exclusive guidelines are reported for PSCCT. More extensive case studies are needed to evaluate the effects of total thyroidectomy with intent R0/R1 on improving survival and quality of life of patients with PSCCT
Infinite Symmetry in the Fractional Quantum Hall Effect
We have generalized recent results of Cappelli, Trugenberger and Zemba on the
integer quantum Hall effect constructing explicitly a for
the fractional quantum Hall effect such that the negative modes annihilate the
Laughlin wave functions. This generalization has a nice interpretation in
Jain's composite fermion theory. Furthermore, for these models we have
calculated the wave functions of the edge excitations viewing them as area
preserving deformations of an incompressible quantum droplet, and have shown
that the is the underlying symmetry of the edge
excitations in the fractional quantum Hall effect. Finally, we have applied
this method to more general wave functions.Comment: 15pp. LaTeX, BONN-HE-93-2
CFT description of the Fully Frustrated XY model and phase diagram analysis
Following a suggestion given in Nucl. Phys. B 300 (1988)611,we show how the
U(1)*Z_{2} symmetry of the fully frustrated XY (FFXY) model on a square lattice
can be accounted for in the framework of the m-reduction procedure developed
for a Quantum Hall system at "paired states" fillings nu =1 (cfr. Cristofano et
al.,Mod. Phys. Lett. A 15 (2000)1679;Nucl. Phys. B 641 (2002)547). The
resulting twisted conformal field theory (CFT) with central charge c=2 is shown
to well describe the physical properties of the FFXY model. In particular the
whole phase diagram is recovered by analyzing the flow from the Z_{2}
degenerate vacuum of the c=2 CFT to the infrared fixed point unique vacuum of
the c=3/2 CFT. The last theory is known to successfully describe the critical
behavior of the system at the overlap temperature for the Ising and
vortex-unbinding transitions.Comment: 18 pages, 1 figure, to appear in JSTA
A late onset widespread skin rash in a previous Covid-19 infected patient. Viral or multidrug effect?
In the end of 2019, a series of pneumonia cases emerged in China, with clinical presentations greatly resembling viral pneumonia, caused by Covid-19 o SARS-CoV-2. Currently, several clinicians described an increasingly cases of coronavirus-positive patients reporting skin problems, either in early stage of infection or as late onset manifestation. Recently, Dr. Sebastiano Recalcati analyzed the cutaneous involvement in 148 COVID-19 patients hospitalized in the Lecco Hospital, Lombardy, Italy
Astrophysical structures from primordial quantum black holes
The characteristic sizes of astrophysical structures, up to the whole
observed Universe, can be recovered, in principle, assuming that gravity is the
overall interaction assembling systems starting from microscopic scales, whose
order of magnitude is ruled by the Planck length and the related Compton
wavelength. This result agrees with the absence of screening mechanisms for the
gravitational interaction and could be connected to the presence of Yukawa
corrections in the Newtonian potential which introduce typical interaction
lengths. This result directly comes out from quantization of primordial black
holes and then characteristic interaction lengths directly emerge from quantum
field theory.Comment: 11 page
Conformal field theory and edge excitations for the principal series of quantum Hall fluids
Motivated by recent experimental results, we reconsider the theory of the
edge excitations for the fractional Hall effect at filling factors
. We propose to modify the standard edge
theory for this series by introducing twist fields which change the boundary
conditions of the bosonic fields and simulate the effect of fractions of flux
quanta . This has the effect of removing the conserved charges
associated to the neutral modes while keeping the right statistics of the
particles. The Green function of the electron in presence of twists decays at
long distance with an exponent varying continuously with .Comment: 5 pages, latex; typos corrected and some references adde
Matrix Model Description of Laughlin Hall States
We analyze Susskind's proposal of applying the non-commutative Chern-Simons
theory to the quantum Hall effect. We study the corresponding regularized
matrix Chern-Simons theory introduced by Polychronakos. We use holomorphic
quantization and perform a change of matrix variables that solves the Gauss law
constraint. The remaining physical degrees of freedom are the complex
eigenvalues that can be interpreted as the coordinates of electrons in the
lowest Landau level with Laughlin's wave function. At the same time, a
statistical interaction is generated among the electrons that is necessary to
stabilize the ground state. The stability conditions can be expressed as the
highest-weight conditions for the representations of the W-infinity algebra in
the matrix theory. This symmetry provides a coordinate-independent
characterization of the incompressible quantum Hall states.Comment: 31 pages, large additions on the path integral and overlaps, and on
the W-infinity symmetr
Multiloop Calculations in the String-Inspired Formalism: The Single Spinor-Loop in QED
We use the worldline path-integral approach to the Bern-Kosower formalism for
developing a new algorithm for calculation of the sum of all diagrams with one
spinor loop and fixed numbers of external and internal photons. The method is
based on worldline supersymmetry, and on the construction of generalized
worldline Green functions. The two-loop QED -- function is calculated
as an example.Comment: uuencoded ps-file, 20 pages, 2 figures, final revised version to
appear in Phys. Rev.
Reduced biliverdin reductase-a expression in visceral adipose tissue is associated with adipocyte dysfunction and nafld in human obesity
Biliverdin reductase A (BVR-A) is an enzyme involved in the regulation of insulin signalling. Knockout (KO) mice for hepatic BVR-A, on a high-fat diet, develop more severe glucose impairment and hepato-steatosis than the wild type, whereas loss of adipocyte BVR-A is associated with increased visceral adipose tissue (VAT) inflammation and adipocyte size. However, BVR-A expression in human VAT has not been investigated. We evaluated BVR-A mRNA expression levels by real-time PCR in the intra-operative omental biopsy of 38 obese subjects and investigated the association with metabolic impairment, VAT dysfunction, and biopsy-proven non-alcoholic fatty liver disease (NAFLD). Individuals with lower VAT BVR-A mRNA levels had significantly greater VAT IL-8 and Caspase 3 expression than those with higher BVR-A. Lower VAT BVR-A mRNA levels were associated with an increased adipocytesâ size. An association between lower VAT BVR-A expression and higher plasma gamma-glutamyl transpeptidase was also observed. Reduced VAT BVR-A was associated with NAFLD with an odds ratio of 1.38 (95% confidence interval: 1.02â1.9; Ï2 test) and with AUROC = 0.89 (p = 0.002, 95% CI = 0.76â1.0). In conclusion, reduced BVR-A expression in omental adipose tissue is associated with VAT dysfunction and NAFLD, suggesting a possible involvement of BVR-A in the regulation of VAT homeostasis in presence of obesity
A novel germline mutation of PTEN associated with brain tumours of multiple lineages
We have identified a novel germline mutation in the PTEN tumour suppressor gene. The mutation was identified in a patient with a glioma, and turned out to be a heterozygous germline mutation of PTEN (Arg234Gln), without loss of heterozygosity in tumour DNA. The biological consequences of this germline mutation were investigated by means of transfection studies of the mutant PTEN molecule compared to wild-type PTEN. In contrast to the wild-type molecule, the mutant PTEN protein is not capable of inducing apoptosis, induces increased cell proliferation and leads to high constitutive PKB/Akt activation, which cannot be increased anymore by stimulation with insulin. The reported patient, in addition to glioma, had suffered from benign meningioma in the past but did not show any clinical signs of Cowden disease or other hereditary diseases typically associated with PTEN germline mutations. The functional consequences of the mutation in transfection studies are consistent with high proliferative activity. Together, these findings suggest that the Arg234Gln missense mutation in PTEN has oncogenic properties and predisposes to brain tumours of multiple lineages
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