3,566 research outputs found

    Total thyroidectomy associated to chemotherapy in primary squamous cell carcinoma of the thyroid

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    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

    Study of the Fusion-Fission Process in the 35Cl+24Mg^{35}Cl+^{24}Mg Reaction

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    Fusion-fission and fully energy-damped binary processes of the 35^{35}Cl+24^{24}Mg reaction were investigated using particle-particle coincidence techniques at a 35^{35}Cl bombarding energy of Elab_{lab} \approx 8 MeV/nucleon. Inclusive data were also taken in order to determine the partial wave distribution of the fusion process. The fragment-fragment correlation data show that the majority of events arises from a binary-decay process with a relatively large multiplicity of secondary light-charged particles emitted by the two primary excited fragments in the exit channel. No evidence is observed for ternary-breakup processes, as expected from the systematics recently established for incident energies below 15 MeV/nucleon and for a large number of reactions. The binary-process results are compared with predictions of statistical-model calculations. The calculations were performed using the Extended Hauser-Feshbach method, based on the available phase space at the scission point of the compound nucleus. This new method uses temperature-dependent level densities and its predictions are in good agreement with the presented experimental data, thus consistent with the fusion-fission origin of the binary fully-damped yields.Comment: 30 pages standard REVTeX file, 10 eps Figures; to be published at the European Physical Journal A - Hadrons and Nucle

    Quantizing the damped harmonic oscillator

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    We consider the Fermi quantization of the classical damped harmonic oscillator (dho). In past work on the subject, authors double the phase space of the dho in order to close the system at each moment in time. For an infinite-dimensional phase space, this method requires one to construct a representation of the CAR algebra for each time. We show that unitary dilation of the contraction semigroup governing the dynamics of the system is a logical extension of the doubling procedure, and it allows one to avoid the mathematical difficulties encountered with the previous method.Comment: 4 pages, no figure

    Acute pancreatitis secondary to non-functioning pancreatic neuroendocrine tumor: uncommon clinical presentation. Clinical case and review of literature

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    I tumori neuroendocrini del pancreas (PNET) sono rari, e rappresentano <5% di tutte le neoplasie pancreatiche, suddivisi in PNET funzionanti con secrezione ormonale responsabile di sintomi specifici e PNET non funzionanti (nf-PNET) generalmente di diagnosi tardiva per la comparsa di metastasi o manifestazioni cliniche per effetti compressivi. L’approccio chirurgico è il trattamento di scelta per PNETs funzionanti, non-funzionanti di diametro superiore a 2 cm o sintomatici per disturbi da compressione. Osservazione personale. Donna di 76 anni ricoverata presso la UOC-Università-Chirurgia Ospedale “A. Fiorini” di Terracina per nausea e dolore ai quadranti addominali superiori con irradiazione dorso-lombare, insorti dopo un pasto serale. Dopo gli esami ematochimici e le indagini strumentali, è stata fatta la diagnosi di pancreatite acuta severa. Gli US convenzionali, CCT, CE-MRI ed EUS hanno mostrato una lesione di 2,8 cm di diametro nella giunzione testa-corpo del pancreas. L’esame citologico FNA non ha rilevato la presenza di cellule pancreatiche atipiche. La scintigrafia total body con Octreoscan® ha documentato un’area di ipercaptazione patologica situata in corrispondenza della neoformazione. La paziente è stata sottoposta a spleno-pancreasectomia corpo-coda. L’esame istologico ha dimostrato un nf-PNET di grado intermedio (G2) stenosante il vena lienale e stenosante il dotto di Wirsung, con pancreatite perilesionale. L’immunoistochimica ha mostrato un immunofenotipo positivo per CAM5.2, sinaptofisina (> 95%) e cromogranina (60%), con espressione di somatostatina intratumorale negativa. CONCLUSIONE: Sebbene raramente un nf-PNETS può essere la causa di grave pancreatite acuta non biliare da compressione del sistema duttale pancreatico. Nei casi in cui la PET / CT68Ga non può essere eseguita, la scintigrafia total body con Octreoscan® rimane il metodo più utilizzato per la diagnosi dei PNET e l’identificazione delle eventuali lesioni extra-pancreatiche. La cromogranina e la sinaptofisina sono confermate come marcatori specifici del differenziamento neuroendocrino.BACKGROUND: Pancreatic neuroendocrine tumors (PNETs) are uncommon, representing <5% of all pancreatic neoplasms, divided into functioning PNETs with secreted hormone cause of specific symptoms, and non-functioning PNETs (nf- PNETs) characterized by delayed diagnosis with metastases and clinical manifestations of compressive effects. Surgical approach is recommended for functioning and nf-PNETs >2 cm in diameter. CASE REPORT: A 76-year-old woman was admitted to the UOC-University-Surgery Hospital "A. Fiorini" in Terracina for nausea and pain in the upper abdominal quadrants with dorso-lumbar irradiation, arising after the evening meal. After the haematochemistry tests and the instrumental investigations, the diagnosis of acute, severe halitiasic pancreatitis was made. Conventional US, CCT, CE-MRI and EUS showed a 2.8cm diameter lesion in the head-body junction of the pancreas. FNA-cytological examination did not found the presence of atypical pancreatic cells. Total-body scintigraphy with Octreoscan® documented a pathological hypercaptation area located in correspondence with the neoformation. The patient underwent a body-tail spleno-pancreatectomy. The histological examination showed an intermediate grade (G2) nf-PNET infiltrating the lienal vein and stenosing the Wirsung duct, with perilesional pancreatitis. Immunohistochemistry showed CAM 5.2, Synaptophysin (>95%) and Chromogranin (60%) positive immunophenotype, with negative intratumoral Somatostatin expression. CONCLUSION: Although rarely, nf-PNETS may be the cause of severe non-biliary acute pancreatitis from pancreatic ductal system compression. In cases where PET/CT68Ga cannot be performed, total-body scintigraphy with Octreoscan® remains the most widely used method for the diagnosis of PNETs and the identification of extra-pancreatic lesions. Chromogranin and Synaptophysin are confirmed as specific markers of neuroendocrine differentiation. KEY WORDS: Acute pancreatitis, Chromogranin, Pancreatic neuroendocrine tumor, Synaptophysin, Somatostatin

    Current clinical management of constitutional delay of growth and puberty

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    Feature- versus rule-based generalization in rats, pigeons and humans

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    Humans can spontaneously create rules that allow them to efficiently generalize what they have learned to novel situations. An enduring question is whether rule-based generalization is uniquely human or whether other animals can also abstract rules and apply them to novel situations. In recent years, there have been a number of high-profile claims that animals such as rats can learn rules. Most of those claims are quite weak because it is possible to demonstrate that simple associative systems (which do not learn rules) can account for the behavior in those tasks. Using a procedure that allows us to clearly distinguish feature-based from rule-based generalization (the Shanks-Darby procedure), we demonstrate that adult humans show rule-based generalization in this task, while generalization in rats and pigeons was based on featural overlap between stimuli. In brief, when learning that a stimulus made of two components ("AB") predicts a different outcome than its elements ("A" and "B"), people spontaneously abstract an opposites rule and apply it to new stimuli (e.g., knowing that "C" and "D" predict one outcome, they will predict that "CD" predicts the opposite outcome). Rats and pigeons show the reverse behavior-they generalize what they have learned, but on the basis of similarity (e.g., "CD" is similar to "C" and "D", so the same outcome is predicted for the compound stimulus as for the components). Genuinely rule-based behavior is observed in humans, but not in rats and pigeons, in the current procedure

    Properties of projectile-fragments in the 40^{40}Ar + 27^{27}Al reaction at 44 A MeV. Comparison with a multisequential decay model

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    GANIL-EXPResults on projectile fragment–fragment coincidences in the forward direction and for the reaction 40Ar + 27Al at 44 A MeV are presented and compared with the predictions of two different entrance channel models, a two-body and a three-body mechanism both followed by a binary multisequential decay including fission. This analysis shows that many features of the projectile decay products are well accounted for by the binary multisequential decay model. However the results depend critically upon the initial masses and excitation energies of the primary projectile fragments. In this respect, the three-body approach underestimates the excitation energy imparted to the primary fragments whereas the two-body scenario overestimates it. The present data put strong constraints on the initial excitation energy imparted to the primary fragments which appears to be intermediate between the predictions of the two models

    Alpha-particle clustering in excited expanding self-conjugate nuclei

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    The fragmentation of quasi-projectiles from the nuclear reaction 40Ca + 12C at 25 MeV/nucleon was used to produce alpha-emission sources. From a careful selection of these sources provided by a complete detection and from comparisons with models of sequential and simultaneous decays, strong indications in favour of α\alpha-particle clustering in excited 16O, 20Ne and 24}Mg are reported.Comment: 8 pages, 4 figures, 12th International Conference on Nucleus-Nucleus collisions (NN2015), 21-26 June 2015, Catania, Ital

    Production of α\alpha-particle condensate states in heavy-ion collisions

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    The fragmentation of quasi-projectiles from the nuclear reaction 40Ca^{40}Ca + 12C^{12}C at 25 MeV/nucleon was used to produce excited states candidates to α\alpha-particle condensation. The experiment was performed at LNS-Catania using the CHIMERA multidetector. Accepting the emission simultaneity and equality among the α\alpha-particle kinetic energies as experimental criteria for deciding in favor of the condensate nature of an excited state, we analyze the 02+0_2^+ and 22+2_2^+ states of 12^{12}C and the 06+0_6^+ state of 16^{16}O. A sub-class of events corresponding to the direct 3-α\alpha decay of the Hoyle state is isolated.Comment: contribution to the 2nd Workshop on "State of the Art in Nuclear Cluster Physics" (SOTANCP2), Universite Libre de Bruxelles (Belgium), May 25-28, 2010, to be published in the International Journal of Modern Physics
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