353 research outputs found

    Surface doping in T6/ PDI-8CN2 Heterostructures investigated by transport and photoemission measurements

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    In this paper, we discuss the surface doping in sexithiophene (T6) organic field-effect transistors by PDI-8CN2. We show that an accumulation heterojunction is formed at the interface between the organic semiconductors and that the consequent band bending in T6 caused by PDI-8CN2 deposition can be addressed as the cause of the surface doping in T6 transistors. Several evidences of this phenomenon have been furnished both by electrical transport and photoemission measurements, namely the increase in the conductivity, the shift of the threshold voltage and the shift of the T6 HOMO peak towards higher binding energies.Comment: 5 pages, 5 figure

    Fast Likelihood-Based Change Point Detection

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    Change point detection plays a fundamental role in many real-world applications, where the goal is to analyze and monitor the behaviour of a data stream. In this paper, we study change detection in binary streams. To this end, we use a likelihood ratio between two models as a measure for indicating change. The first model is a single bernoulli variable while the second model divides the stored data in two segments, and models each segment with its own bernoulli variable. Finding the optimal split can be done in O(n) time, where n is the number of entries since the last change point. This is too expensive for large n. To combat this we propose an approximation scheme that yields (1 - epsilon) approximation in O(epsilon(-1) log(2) n) time. The speed-up consists of several steps: First we reduce the number of possible candidates by adopting a known result from segmentation problems. We then show that for fixed bernoulli parameters we can find the optimal change point in logarithmic time. Finally, we show how to construct a candidate list of size O(epsilon(-1) log n) formodel parameters. We demonstrate empirically the approximation quality and the running time of our algorithm, showing that we can gain a significant speed-up with a minimal average loss in optimality.Peer reviewe

    The Emerging Trends of Renewable Energy Communities’ Development in Italy

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    Increasing concerns over climate change and energy poverty have triggered the transition toward a decentralized energy system through the widespread adoption of renewable energy technologies. Although this transition was led, over past decades, mainly by major investors and large industrial players, citizens and local authorities are increasingly playing an active role in delivering clean energy investments. In particular, the current European Renewable Energy Directive introduced Renewable Energy Communities (RECs), which allow citizens to collectively organize their participation in the energy market, leading to a more distributed renewable energy system and new forms of sustainable, collaborative, and democratic economies. RECs currently under implementation show differences among European countries due to the different national contexts. A literature review exploring the peculiar Italian regulatory framework on RECs and its recent evolution has been carried out to identify available national and regional financial support mechanisms, barriers, and emerging trends in the diffusion of RECs across the country. The paper reviews and describes three main approaches that emerged in the development of RECs in Italy, discussing their strengths, and limitations. In addition, it provides a brief comparison of the regulatory framework in different European countries, highlighting the distinctive features of the Italian experience. Although the development of RECs in Italy involved a combination of both public and private initiatives, the leading role of local authorities as promoters and aggregators of RECs is evident. This role helps preserve the social impact of RECs but might slow down their implementation due to bureaucratic issues often linked to public procedures and procurement processes, as well as the lack of sufficient expertise within local authorities

    UBEM's archetypes improvement via data-driven occupant-related schedules randomly distributed and their impact assessment

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    In Urban Building Energy Models (UBEMs), buildings are usually modelled via archetypes describing occupants’ behaviour via fixed schedules. This research (i) creates data-driven schedules for electric use and occupancy from smart meter readings randomly distributed in the model to improve residential archetypes, (ii) assesses the impact of these schedules on UBEMs’ energy results at different temporal resolutions and spatial scales. The novel assessment procedure exploits integrated heat maps based on coefficients of variation of the root means square error (CVRMSE). The outcomes show that differences in energy needs, with randomized schedules, range based on temporal and spatial aggregation. Yearly, for the entire neighbourhood, heating and cooling energy needs, and electric uses are estimated -2%, +1%, and +18% compared to the base case. The outputs show that, when simulations are focused on the entire district, fixed schedules can be enough to describe energy patterns. However, if the simulation is focused on small groups of buildings (e.g., 5 or fewer), randomising the schedules can create variability in the model in terms of electric use and occupancy among buildings characterized by the same archetype. The followed methodology can be exploited also with larger databases and eventually verified with also other types of data

    Lymphatic endothelium stimulates melanoma metastasis and invasion via MMP14-dependent Notch3 and b1-integrin activation

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    Lymphatic invasion and lymph node metastasis correlate with poor clinical outcome in melanoma. However, the mechanisms of lymphatic dissemination in distant metastasis remain incompletely understood. We show here that exposure of expansively growing human WM852 melanoma cells, but not singly invasive Bowes cells, to lymphatic endothelial cells (LEC) in 3D co-culture facilitates melanoma distant organ metastasis in mice. To dissect the underlying molecular mechanisms, we established LEC co-cultures with different melanoma cells originating from primary tumors or metastases. Notably, the expansively growing metastatic melanoma cells adopted an invasively sprouting phenotype in 3D matrix that was dependent on MMP14, Notch3 and β1-integrin. Unexpectedly, MMP14 was necessary for LEC-induced Notch3 induction and coincident β1-integrin activation. Moreover, MMP14 and Notch3 were required for LEC-mediated metastasis of zebrafish xenografts. This study uncovers a unique mechanism whereby LEC contact promotes melanoma metastasis by inducing a reversible switch from 3D growth to invasively sprouting cell phenotype

    Surgical management of gynecomastia: Experience of a general surgery center

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    Aim. Gynecomastia is a common finding in male population of all ages. The aim of our study was to present our experience and goals in surgical treatment of gynecomastia. Patients and Methods. Clinical records of patients affected by gynecomastia referred to our Department of Surgery between September 2008 and January 2015 were analyzed. 50 patients were included in this study. Results. Gynecomastia was monolateral in 12 patients (24%) and bilateral in 38 (76%); idiopathic in 41 patients (82%) and secondary in 9 (18%). 39 patients (78%) underwent surgical operation under general anaesthesia, 11 (22%) under local anaesthesia. 3 patients (6%) presented recurrent disease. Webster technique was performed in 28 patients (56%), Davidson technique in 16 patients (32%); in 2 patients (4%) Pitanguy technique was performed and in 4 patients (8%) a mixed surgical technique was performed. Mean surgical time was 80.72±35.14 minutes, median postoperative stay was 1.46±0.88 days. 2 patients (4%) operated using Davidson technique developed a hematoma, 1 patient (2%) operated with the same technique developed hypertrophic scar. Conclusions. Several surgical techniques are described for surgical correction of gynecomastia. If performed by skilled general surgeons surgical treatment of gynecomastia is safe and permits to reach satisfactory aesthetic results

    On Coupling FCA and MDL in Pattern Mining

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    International audiencePattern Mining is a well-studied field in Data Mining and Machine Learning. The modern methods are based on dynamically updating models, among which MDL-based ones ensure high-quality pattern sets. Formal concepts also characterize patterns in a condensed form. In this paper we study MDL-based algorithm called Krimp in FCA settings and propose a modified version that benefits from FCA and relies on probabilistic assumptions that underlie MDL. We provide an experimental proof that the proposed approach improves quality of pattern sets generated by Krimp

    Rapid purification of yeast mitochondrial DNA in high yield

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    A procedure is presented for the rapid isolation of mitochondrial DNA (mtDNA) in high yield from Saccharomyces cerevisiae. Yeast cells, which may be grown to late stationary phase, are broken by a combination of enzymatic and mechanical means; mtDNA is then isolated from a crude mitochondrial lysate by a single cycle of bisbenzimide-CsCl buoyant density centrifugation. mtDNA so isolated is at least 99.5% pure, and has a mean duplex molecular weight of 24.5 [middle dot] 106. In addition to mtDNA and bulk nuclear DNA, several other yeast nucleic acid species, identified as ribosomal DNA and a mixture of duplex RNAs, form discrete bands in these gradients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23088/1/0000005.pd

    Up-regulation of 14-3-3sigma (Stratifin) is associated with high-grade CIN and high-risk human papillomavirus (HPV) at baseline but does not predict outcomes of HR-HPV infections or incident CIN in the LAMS study

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    To assess whether the potentially high-risk (HR) human papillomavirus (HPV)-related up-regulation of 14-3-3sigma (stratifin) has implications in the outcome of HPV infections or cervical intraepithelial neoplasia (CIN) lesions, cervical biopsy specimens from 225 women in the Latin American Screening Study were analyzed for 14-3-3sigma expression using immunohistochemical analysis. We assessed its associations with CIN grade and HR HPV at baseline and value in predicting outcomes of HR-HPV infections and the development of incident CIN 1+ and CIN 2+. Expression of 14-3-3sigma increased in parallel with the lesion grade. Up-regulation was also significantly related to HR-HPV detection (P = .004; odds ratio, 2.71; 95% confidence interval, 1.37-5.35) and showed a linear relationship to HR-HPV loads (P = .003). 14-3-3sigma expression was of no value in predicting the outcomes (incident, persistent, clearance) of HR-HPV infections or incident CIN 1+ and CIN 2+. 14-3-3sigma is not inactivated in cervical carcinoma and CIN but is up-regulated on transition from CIN 2 to CIN 3. Its normal functions in controlling G(1)/S and G(2)/M checkpoints are being bypassed by HR HPV.LAMS, Latin American Screening Study, funded by European Commission, INCO-DEV contract ICA4-CT-2001-10013

    Hormonal contraceptives and the length of their use are not independent risk factors for high-risk HPV infections or high-grade CIN

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    AIMS: To evaluate the role of hormonal contraceptives as a risk factor of high-risk human papillomavirus (HR-HPV), cervical intraepithelial lesions (CIN) and cervical cancer in our multi-center population-based LAMS (Latin American Screening) study. METHODS: A cohort study with >12,000 women from Brazil and Argentina using logistic regression to analyze the covariates of hormonal contraception (HOC - oral, injections, patches, implants, vaginal ring and progesterone intrauterine system) use followed by multivariate modeling for predictors of HR-HPV and CIN2+. RESULTS: HR-HPV infection was a consistent risk factor of high-grade CIN in all three groups of women. The length of HOC use was not significantly related to high-grade squamous intraepithelial lesions (HSIL)+ Pap (p = 0.069), LSIL+ Pap (p = 0.781) or ASCUS+ (p = 0.231). The same was true with the length of HOC use and histology CIN3+ (p = 0.115) and CIN2+ (p = 0.515). Frequently, HOC users have previously shown more HPV-related lesions, as well as lower HPV prevalence if they were current smokers. But HOC use and time of usage were not independent risk factors of either HR-HPV infection or high-grade CIN using multiple logistic regressions. CONCLUSIONS: No evidence was found for an association between the use of HOC with an increased risk for HR-HPV infection or high-grade CIN in this cohort.This study is a part of the ongoing LAMS (Latin American Screening) study, entitled: Improving Health Systems Towards Equality-Based Control of Cervical Cancer in Latin America, and is supported by the INCO-DEV Program of the European Commission (Project No. ICA4-CT-2001-10013). The generous contribution of Digene Corporation (USA) who donated the HCII tests at our disposal is gratefully acknowledged
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