47 research outputs found

    Time Dependent Inelastic Emission and Capture of Localized Electrons in Si n-MOSFETs Under Microwave Irradiation

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    Microwave irradiation causes voltage fluctuations in solid state nanodevices. Such an effect is relevant in atomic electronics and nanostructures for quantum information processing, where charge or spin states are controlled by microwave fields and electrically detected. Here the variation of the characteristic times of the multiphonon capture and emission of a single electron by an interface defect in submicron MOSFETs is calculated and measured as a function of the microwave power, whose frequency of the voltage modulation is assumed to be large if compared to the inverse of the characteristic times. The variation of the characteristic times under microwave irradiation is quantitatively predicted from the microwave frequency dependent stationary current generated by the voltage fluctuations itself. The expected values agree with the experimental measurements. The coupling between the microwave field and either one or two terminals of the device is discussed. Some consequences on nanoscale device technology are drawn.Comment: 8 Figure

    A Case of thyroid metastasis from pancreatic cancer: case report and literature review

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    Background: Thyroid metastases are clinically rare, and usually occur in patients with a history of prior malignancy and when there are metastases elsewhere. Metastases of pancreatic carcinoma to the thyroid are extremely rare, with only three cases reported in the literature. Case presentation: We report a patient who had a pancreatic carcinoma with metastasis to the thyroid as initial clinical presentation of the disease. A 63-year-old man with a history of weight loss and fatigue presented with cervical lymphadenopathies and a large nodule in the right lobe of the thyroid. A fine needle aspiration of the nodule gave inconclusive cytological results for the origin of the neoplastic cells. An ultrasound-guided core biopsy revealed the presence of a poorly differentiated adenocarcinoma infiltrating the thyroid with atrophic thyroid follicles. Immunohistochemical staining of the lesion was strongly positive for Cytokeratin 19 suggesting a pancreatic origin of the metastasis. A contrast CT scan demonstrated an enlargement of the pancreatic body, dilatation of the pancreatic duct, diffuse retroperitoneal, paraaortic and cervical lymphadenopathy and secondary lesions in the liver. Conclusion: Metastases to the thyroid from pancreatic carcinoma are extremely rare. A core biopsy of the lesion excluded a thyroid carcinoma and permitted the diagnosis of the primary neoplasm

    Effect of rhTSH on Lipids

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    Background: Subclinical hypothyroidism is associated with increased blood lipid levels. However, the exact role of thyrotropin (TSH) alone is not clear. In order to clarify this point, we analysed the acute effect of recombinant human TSH (rhTSH) administration on lipid levels. Methods: Sera of 27 premenopausal women with well-differentiated thyroid cancer were analysed. Patients that underwent a total thyroidectomy, ablation with I-131 (Iodine 131) and rhTSH administration as a part of routine follow-up American Thyroid Association guidelines were included. The protocol consists of 2 intramuscular injections of 0.9 mg of rhTSH, performed on day 1 day and day 2, with blood collection on day 1 (before rhTSH administration), and day 5. TSH, free thyroxine, total cholesterol, low-density lipoprotein cholesterol (LDLc), high density lipoprotein cholesterol (HDLc), and triglycerides were assessed in all the samples, before and four days after the first administration of rhTSH. Results: Total cholesterol and triglycerides significantly increased after stimulation of rhTSH (respectively, 192 +/- 33 vs. 207 +/- 26, p = 0.036 and 72 +/- 23 vs. 85 +/- 23, p = 0.016). LDLc and HDLc showed comparable concentrations before and after the test (respectively, 115 +/- 27 vs. 126 +/- 22, p = 0.066, and 62 +/- 15 vs. 64 +/- 15, p = 0.339), while non-HDLc increased after stimulation (130 +/- 30 vs. 143 +/- 25, p = 0.045). Conclusion: TSH has a direct effect on total cholesterol, triglycerides, and nonHDLc. Explanation of these phenomena will require additional studies

    Microwave Irradiation Effects on Random Telegraph Signal in a MOSFET

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    We report on the change of the characteristic times of the random telegraph signal (RTS) in a MOSFET operated under microwave irradiation up to 40 GHz as the microwave field power is raised. The effect is explained by considering the time dependency of the transition probabilities due to a harmonic voltage generated by the microwave field that couples with the wires connecting the MOSFET. From the dc current excited into the MOSFET by the microwave field we determine the corresponding equivalent drain voltage. The RTS experimental data are in agreement with the prediction obtained with the model, making use of the voltage data measured with the independent dc microwave induced current. We conclude that when operating a MOSFET under microwave irradiation, as in single spin resonance detection, one has to pay attention into the effects related to microwave irradiation dependent RTS changes.Comment: 3 pages, 4 figure

    Phenotypic heterogeneity of latent autoimmune diabetes in adults identified by body composition analysis

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    Background: In patients with Latent Autoimmune Diabetes in Adults (LADA) a lower body mass index was reported compared with classical type 2 diabetes (T2D), and was found to be associated with a faster progression to insulin-dependence. In this study we determined the body composition in a cohort of LADA patients from Sardinia, Italy, and compared it with age– and gender–matched patients diagnosed as having adult-onset type 1 diabetes (T1D) and non-autoimmune T2D. Methods: In 210 LADA patients, 210 T2D patients and 30 adult-onset T1D patients of Sardinian origin we assessed total and segmental body composition (weight-adjusted percent fat mass and lean mass) by using Dual Energy X-rays Absorptiometry (DXA). Results: In the whole cohort of LADA patients total fat mass was significantly smaller compared with T2D patients (p &lt; 0.0001), while no difference was found between LADA and T1D patients. In LADA men fat depletion involved all body segments, while in LADA women it was observed only in the truncal segment (p &lt; 0.0001), as in the upper and lower regions fat deposits were larger compared to T2D (p &lt; 0.0001). However, LADA women showed a significantly elevated truncal fat compared to T1D women (p &lt; 0.004), whereas no difference was detected in the extremities. Conclusions: Body composition in LADA patients shows substantial difference, in a gender-dependent way, compared to classic T2D. In women fat deposits tend to accumulate in peripheral regions rather than centrally, whereas in men the distribution is more homogeneous. In addition, central fat depletion in LADA women appears to be a significant predictor of faster progression to insulin dependence. Thus, routine assessment of body composition may help the physician identify LADA patients who require early insulin treatment in order to delay beta-cell exhaustion, as well those with increased CV risk due to excess truncal adiposity.</br

    Transient currents in HfO2 and their impact on circuit and memory applications

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    We investigate transient currents in HfO2 dielectrics, considering their dependence on electric field, temperature and gate stack composition. We show that transient currents remain an issue even at very low temperatures and irrespective of the HfO2/SiO2 bilayer properties. Finally, we assess their impact on the reliability of precision circuit and memory applications Transient currents in HfO2 and their impact on circuit and memory applications (PDF Download Available). Available from: http://www.researchgate.net/publication/224672970_Transient_currents_in_HfO2_and_their_impact_on_circuit_and_memory_applications [accessed Oct 22, 2015]

    Association between High Normal TSH Levels and Obesity in Women with Anti-Thyroid Autoantibodies (ATAs)

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    A positive correlation between Thyroid-Stimulating Hormone (TSH) and Body Mass Index (BMI) has been reported in many studies, but data on this topic remain controversial, especially when TSH values are in the normal range. Moreover, few studies have evaluated the co-existence of thyroid autoimmunity. This study investigated the role of thyroid autoimmunity in the interconnection between TSH, BMI, and waist circumference (WC) in euthyroid patients with overweight or obesity. We enrolled 902 patients (213 males; mean age +/- SD: 45 +/- 14 years; mean BMI +/- SD: 35.8 +/- 6.5 kg/m(2)), with normal serum TSH concentration; anti-thyroid autoantibodies (ATAs) were evaluated in 752 patients (186 males). Patients were divided into four BMI classes, based on WHO criteria, and the relationship between BMI, WC, and TSH was evaluated in the whole sample and compared to ATAs positivity, observed in 235 patients (44 males). No significant difference was found between TSH levels in the BMI classes. A statistically significant correlation between TSH and BMI was found only in ATAs-positive females (N = 191, Spearman rho: 0.149; p-value: 0.040). However, this finding was not confirmed when considering the WC. Our study shows a positive correlation only between TSH and BMI in obese women with positive ATAs, suggesting that in these patients, the high normal levels of TSH could be attributed to a mild thyroid failure with a possible worsening obesity-related effect, and both need a careful evaluation

    Proteasome inhibitors in medullary thyroid carcinoma: time to restart with clinical trials?

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    IntroductionMedullary thyroid cancer (MTC) is a rare thyroid tumour whose management in advanced stages is challenging, despite effective therapeutic options having expanded in recent years. Proteasome inhibitors (PrIn) have shown the ability to improve patient outcomes, including survival and quality of life, in several malignancies, due to their ability to impair cell proliferation and cause apoptosis through the inhibition of the proteasome activity. Consequently, these drugs could represent a useful tool, alone or in combination with other treatments, in MTC patients.Aim of the studyThis review aims to summarize the available in vitro and in vivo data about the role of PrIn in MTC.Materials and methodsWe performed an extensive search for relevant data sources, including full-published articles in international online databases (PubMed, Web of Science, Scopus), preliminary reports in selected international meeting abstract repositories, and short articles published as supplements of international meetings, by using the following terms: medullary thyroid carcinoma, proteasome inhibitors, bortezomib, carfilzomib, ixazomib, delanzomib, marizomib, oprozomib, and MG132. Additionally, we conducted with the same keywords, an in-depth search in registered clinical trials repositories.ResultsOur search revealed in vitro studies in human and murine MTC cell lines, based on the use of PrIns, both alone and in combination with other anticancer drugs, and two pertinent clinical trials.ConclusionWe found a strong discrepancy between the evidence of PrIns effects in preclinical studies, and the scarcity or early interruption of clinical trials. We might speculate that difficulties in enrolling patients, as happens in other rare diseases, may have discouraged trials’ implementation in favor of drugs already approved for MTC. However, given the concrete improvement in the comprehension of the molecular basis of PrIn effects in MTC, new clinical trials with accurate inclusion criteria of enrollment might be warranted, in order to ascertain whether this treatment, alone or in combination with other drugs, could indeed represent an option to enhance the therapeutic response, and to ultimately improve patients’ outcome and survival
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