665 research outputs found

    Influence of Topological Edge States on the Properties of Al/Bi2Se3/Al Hybrid Josephson Devices

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    In superconductor-topological insulator-superconductor hybrid junctions, the barrier edge states are expected to be protected against backscattering, to generate unconventional proximity effects, and, possibly, to signal the presence of Majorana fermions. The standards of proximity modes for these types of structures have to be settled for a neat identification of possible new entities. Through a systematic and complete set of measurements of the Josephson properties we find evidence of ballistic transport in coplanar Al-Bi2Se3-Al junctions that we attribute to a coherent transport through the topological edge state. The shunting effect of the bulk only influences the normal transport. This behavior, which can be considered to some extent universal, is fairly independent of the specific features of superconducting electrodes. A comparative study of Shubnikov - de Haas oscillations and Scanning Tunneling Spectroscopy gave an experimental signature compatible with a two dimensional electron transport channel with a Dirac dispersion relation. A reduction of the size of the Bi2Se3 flakes to the nanoscale is an unavoidable step to drive Josephson junctions in the proper regime to detect possible distinctive features of Majorana fermions.Comment: 11 pages, 14 figure

    Sarcopenia is associated with reduced survival in patients with advanced hepatocellular carcinoma undergoing sorafenib treatment

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    Background: Sarcopenia has been associated with poor outcomes in patients with cirrhosis and solid tumours. Objective: Analyse the influence of sarcopenia on survival and treatment duration in patients with advanced hepatocellular carcinoma (HCC) treated with sorafenib. Methods: We conducted a multicentre, retrospective study on 96 patients with advanced HCC treated with sorafenib, all with available abdominal computed tomography (CT) scan within 30 days from treatment start. Anthropometric, laboratory, treatment and follow-up data were collected. Sarcopenia was defined by reduced skeletal muscle index calculated from an L3 section CT image. Results: Sarcopenia was present in 49% of patients. Patients were divided into two groups according to sarcopenia: age was significantly higher in the sarcopenic group (SG) (66 years (31–87) versus 72 years (30–84), p = 0.04], with no difference in other baseline characteristics. The SG showed shorter overall survival (OS) (39 (95% confidence interval (CI) 26–50) versus 61 (95% CI 47–77) weeks (p = 0,01)) and shorter time on treatment (12.3 (95% CI 8–19) versus 25.9 (95% CI 15–33) weeks (p = 0.0044)). At multivariate analysis, sarcopenia was independently associated to reduced OS (p = 0.03) and reduced time on treatment (p = 0.001). Conclusion: Sarcopenia is present in almost half of patients with advanced HCC, and is associated with reduced survival and reduced duration of oral chemotherapy

    Surveillance for Hepatocellular Carcinoma Also Improves Survival of Incidentally Detected Intrahepatic Cholangiocarcinoma Arisen in Liver Cirrhosis

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    Background: Due to its poor survival, intrahepatic cholangiocarcinoma (ICC) is held to be a much more aggressive cancer than hepatocellular carcinoma (HCC). In most published series, patients were diagnosed when symptomatic. However, ICC is now increasingly being discovered during the surveillance for HCC in cirrhosis. Whether this earlier detection of ICC is associated with an equally dismal prognosis or not is unknown. Methods: This is amulticenter retrospective study of consecutive ICC patients. Patients were stratified into subgroups according to the absence/presence of cirrhosis. A propensity score matching was performed to reduce the potential biases. Cirrhotic patients were further stratified according to their surveillance status. The lead-time bias and its potential effects were also estimated. Results: We gathered 184 patients. Eighty-five patients (46.2%) were cirrhotic. Liver cirrhosis was not related to a worse overall survival (33.0 vs. 32.0 months, p = 0.800) even after the propensity score analysis (43.0 in vs. 44.0 months in 54 pairs of patients, p = 0.878). Among the cirrhotic population, 47 (55.3%) patients had received a diagnosis of ICC during a surveillance programme. The 2 subgroups differed in maximum tumour dimensions (30 vs. 48 mm in surveyed and non-surveyed patients, respectively). Surveyed patients were more likely to receive surgical treatments (59.8 vs. 28.9%, p = 0.003). Overall survival was higher in surveyed patients (51.0 vs. 21.0 months, p 0.001). These benefits were confirmed after correcting for the lead-time bias. Conclusions: Cirrhotic patients have different clinical presentation and outcomes of ICC according to their surveillance status. In our series, ICC in cirrhosis was not associated with worse OS. Cirrhosis itself should not discourage either surgical or non-surgical treatments

    Cancer incidence in Italian contaminated sites

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    INTRODUCTION: The incidence of cancer among residents in sites contaminated by pollutants with a possible health impact is not adequately studied. In Italy, SENTIERI Project (Epidemiological study of residents in National Priority Contaminated Sites, NPCSs) was implemented to study major health outcomes for residents in 44 NPCSs. METHODS: The Italian Association of Cancer Registries (AIRTUM) records cancer incidence in 23 NPCSs. For each NPCSs, the incidence of all malignant cancers combined and 35 cancer sites (coded according to ICD-10), was analysed (1996-2005). The observed cases were compared to the expected based on age (5-year period,18 classes), gender, calendar period (1996-2000; 2001-2005), geographical area (North-Centre and Centre-South) and cancer sites specific rates. Standardized Incidence Ratios (SIR) with 90% Confidence Intervals were computed. RESULTS: In both genders an excess was observed for overall cancer incidence (9% in men and 7% in women) as well as for specific cancer sites (colon and rectum, liver, gallblad-der, pancreas, lung, skin melanoma, bladder and Non Hodgkin lymphoma). Deficits were observed for gastric cancer in both genders, chronic lymphoid leukemia (men), malignant thyroid neoplasms, corpus uteri and connective and soft-tissue tumours and sarcomas (women). DISCUSSION: This report is, to our knowledge, the first one on cancer risk of residents in NPCSs. The study, although not aiming to estimate the cancer burden attributable to the environment as compared to occupation or life-style, supports the credibility of an etiologic role of environmental exposures in contaminated sites. Ongoing analyses focus on the interpretation of risk factors for excesses of specific cancer types overall and in specific NPCSs in relation to the presence of carcinogenic pollutants

    Survival of patients with HCV cirrhosis and sustained virologic response is similar to the general population.

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    Background & Aims: Life expectancy of patients with compensated hepatitis C virus (HCV) cirrhosis achieving sustained virologic response (SVR) is limited by liver events as compared to the general population. Thus, survival benefit of SVR remains to be measured. Methods: The study includes prospective surveillance data from three cohorts of Italian patients with compensated HCV cirrhosis who achieved SVR on an interferon-based (IFN) regimen, compared to simultaneously observed non-SVR, untreated and decompensated patients. Overall survival was calculated from the date of start of IFN to death. The number of deaths expected during the at-risk period was determined by applying age- and sex-specific mortality rates recorded in Italy for person-years adequate for the enrolment period. The standardized mortality ratio (SMR) determined the relative risk of death over that of the age and sex matched general population. Results: Overall, 28/181 patients followed-up for a median period of 9.6 years (range 1–25 years) died. The 10 and 20-year overall survival rates for the whole series were 90.9% (95% CI, 84.3–94.8) and 62.9% (95% CI, 45.9–75.9), respectively. The number of expected deaths in the corresponding age and sex matched general population was 28.1, corresponding to a SMR = 1.00 (95% CI, 0.72–1.35), with an SMR for non-SVR patients of 3.85 (95% CI, 3.43–4.30), for untreated of 3.01 (95% CI, 2.64–3.42) and for decompensated of 6.70 (95% CI, 5.39–8.22). Conclusions: Patients with compensated HCV cirrhosis achieving SVR by IFN obtain a main benefit levelling their survival curve to that of the general population. Wider applicability of IFN-free regimens will possibly make this achievement more generalizable

    The health impact of hazardous waste landfills and illegal dumps contaminated sites: An epidemiological study at ecological level in Italian Region

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    Background and aim: The implementation of idoneous management of hazardous waste, in contrast to illegal practices, is one of the environment and health priorities of the WHO. The aim of the present study, based on a collaborative agreement between the Italian National Health Institute and a Prosecution Office located in Naples North, was to evaluate the health effects of illegal landfills and burning of urban and hazardous waste in the territory of the Prosecution Office. Methods: The municipalities included in the study territory were investigated with respect to the regional population. Regression analyses were performed in the study area between four classes of an environmental municipal indicator of waste risk (MRI) previously defined, computing the relative risks (RRs) in 2–4 MRI classes, with respect to the first MRI class (the least impacted). The prevalence of reproductive outcomes and cause-specific mortality and hospitalization were analyzed in the general population and in the 0–19-year-old population using SAS software. Results: An increase of mortality and hospitalization risk in both the genders of the whole area, with respect to regional population, were found for overall all cancer cases, cancer of the stomach, the liver, the lung and the kidney, and ischemic heart diseases. An increase of mortality for leukemias in the 0-19-year-old population and in hospitalization risk for certain conditions originating in the perinatal period were observed. Correlation between MRI and the risk of mortality from breast tumors in women (MRI class 2: RR = 1.06; MRI class 3: RR = 1.15; MRI class 4: RR = 1.11) and between MRI and the risk of hospitalization from testis tumors (MRI class 2: RR = 1.25; MRI class 3: RR = 1.31; MRI class 4: RR = 1.32) were found. The hospitalization risk from breast tumors and asthma exceeded significantly in both genders of three and four MRI classes. Among the 0-19-year-old population, correlation between MRI and hospitalization from leukemias (MRI class 2: RR = 1.48; MRI class 3: RR = 1.60; MRI class 4: RR = 1.41) and between MRI and the prevalence of preterm birth (MRI class 2: RR = 1.17; MRI class 3: RR = 1.08; MRI class 4: RR = 1.25) were found. Conclusion: A correlation between health outcomes and the environmental pressure by uncontrolled waste sites was found. Notwithstanding the limitation of the study, the results promote implementing the actions of environmental remediation and the prosecution of illegal practices

    Memory for spatial locations in a patient with near space neglect and optic ataxia: Involvement of the occipitotemporal stream

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    Previous studies suggested that the occipitoparietal stream orients attention toward the near/lower space and is involved in immediate reaching, whereas the occipitotemporal stream orients attention toward the far/upper space and is involved in delayed reaching. In the present study, we investigated the role of the occipitotemporal stream in attention orienting and delayed reaching in a patient (GP) with bilateral damage to the occipitoparietal areas and optic ataxia. GP and healthy controls took part in three experiments. In the experiment 1, the participants bisected lines oriented along radial, vertical, and horizontal axes. GP bisected radial lines farther, and vertical lines more above, than the controls, consistent with an attentional bias toward the far/upper space and near/lower space neglect. The experiment 2 consisted of two tasks: (1) an immediate reaching task, in which GP reached target locations under visual control and (2) a delayed visual reaching task, in which GP and controls were asked to reach remembered target locations visually presented. We measured constant and variable distance and direction errors. In immediate reaching task, GP accurately reached target locations. In delayed reaching task, GP overshot remembered target locations, whereas the controls undershot them. Furthermore, variable errors were greater in GP than in the controls. In the experiment 3, GP and controls performed a delayed proprioceptive reaching task. Constant reaching errors did not differ between GP and the controls. However, variable direction errors were greater in GP than in the controls. We suggest that the occipitoparietal damage, and the relatively intact occipitotemporal region, produced in GP an attentional orienting bias toward the far/upper space (experiment 1). In turns, the attentional bias selectively shifted toward the far space remembered visual (experiment 2), but not proprioceptive (experiment 3), target locations. As a whole, these findings further support the hypothesis of an involvement of the occipitotemporal stream in delayed reaching. Furthermore, the observation that in both delayed reaching tasks the variable errors were greater in GP than in the controls suggested that in optic ataxia is present not only a visuo- but also a proprioceptivo-motor integration deficit
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