867 research outputs found

    Electronic structure of silicon-based nanostructures

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    We have developed an unifying tight-binding Hamiltonian that can account for the electronic properties of recently proposed Si-based nanostructures, namely, Si graphene-like sheets and Si nanotubes. We considered the sp3ssp^3s^* and sp3sp^{3} models up to first- and second-nearest neighbors, respectively. Our results show that the Si graphene-like sheets considered here are metals or zero-gap semiconductors, and that the corresponding Si nanotubes follow the so-called Hamada's rule [Phys. Rev. Lett. {\bf 68}, 1579 1992]. Comparison to a recent {\it ab initio} calculation is made.Comment: 12 pages, 6 Figure

    Intravesical electromotive drug administration of mitomycin-C for non-muscle invasive bladder cancer

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    This article reviews intravesical application of electromotive drug administration (EMDA) for the treatment of bladder cancer and the evidence in support of intravesical passive diffusion chemotherapy in the management of non-muscle invasive bladder cancer. Two recently published randomised trials adopting protocols that use EMDA to enhance urothelial transport of intravesical mitomycin-C showed it provided a therapeutical advantage and suggested that intravesical passive diffusion administration of chemothera-peutic drugs may be suboptimal. Further studies are required to demonstrate feasibility and advantage of intravesical EMDA of mitomycin-C in the wider uro-oncological community

    Localised prostate cancer and hemophilia A (AHA): Case report and management of the disease.

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    Acquired Hemophilia A (AHA) is a rare bleeding diathesis characterized by the development of autoantibodies against factor VIII (FVIII). About half of the cases are idiopathic and the other half are associated with autoimmune diseases, postpartum problems, infections, inflammatory bowel disease, drugs, lymphoproliferative disorders or solid tumors . AHA is associated with malignancies in 7-15% of cases. We report a case of AHA in a 65 year old patient with prostatic carcinoma, who underwent retropubic radical prostatectomy (RP)

    Progressive fibrosing interstitial lung diseases: A current perspective

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    Interstitial lung diseases (ILDs) are a large and diverse group of rare and chronic respiratory disorders, with idiopathic pulmonary fibrosis (IPF) being the most common and best-studied member. Increasing interest in fibrosis as a therapeutic target and the appreciation that fibrotic mechanisms may be a treatable target of IPF prompted the development and subsequent approval of the antifibrotics, pirfenidone and nintedanib. The management of ILDs has changed considerably following an understanding that IPF and some ILDs share similar disease behavior of progressive fibrosis, termed “progressive fibrosing phenotype”. Indeed, antifibrotic treatment has shown to be beneficial in ILDs characterized by the progressive fibrosing phenotype. This narrative review summarizes current knowledge in the field of progressive fibrosing ILDs. Here, we discuss the clinical characteristics and pathogenesis of lung fibrosis and highlight relevant literature concerning the mechanisms underlying progressive fibrosing ILDs. We also summarize current diagnostic approaches and the available treatments of progressive fibrosing ILDs and address the optimization of treating progressive fibrosing ILDs with antifibrotics in clinical practice

    Band structure of hydrogenated Si nanosheets and nanotubes

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    The band structure of fully hydrogenated Si nanosheets and nanotubes are elucidated by the use of an empirical tight-binding model. The hydrogenated Si sheet is a semiconductor with indirect band gap of about 2.2 eV. The symmetries of the wave functions allow us to explain the origin of the gap. We predict that, for certain chiralities, hydrogenated Si nanotubes represent a new type of semiconductor, one with co-existing direct and indirect gaps of exactly the same magnitude. This behavior is different from the Hamada rule established for non-hydrogenated carbon and silicon nanotubes. Comparison to an ab initio calculation is made.Comment: 9 pages, 4 figures, to appear in J. Phys.: Condens. Matte

    Hexaminolevulinate hydrochloride in the detection of nonmuscle invasive cancer of the bladder

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    Clinical trials have shown that hexaminolevulinate (HAL) fluorescence cystoscopy improves the detection of bladder tumors compared with standard white-light cystoscopy, resulting in more efficacious treatment. However, some recent meta-analyses report controversially on recurrence-free rates with this procedure. A systematic review of literature was performed from December 2014 to January 2015 using the PubMed, Embase and Cochrane databases for controlled trials on photodynamic diagnosis (PDD) with HAL. A total of 154 publications were found up to January 2015. Three of the authors separately reviewed the records to evaluate eligibility and methodological quality of clinical trials. A total of 16 publications were considered eligible for analysis. HAL-PDD-guided cystoscopy increased overall tumor detection rate (proportion difference 19%, 95% confidence interval [CI] 0.152-0.236) although the benefit was particularly significant in patients with carcinoma in situ (CIS) lesion (proportion difference 15.7%, 95% CI 0.069-0.245) and was reduced in papillary lesions (Ta proportion difference 5.9%, 95% CI 0.014-0.103 and T1 proportion difference 1.2%, 95% CI 0.033-0.057). Moreover, there were 15% of patients (95% CI 0.098-0.211) with at least one additional tumor seen with PDD. With regard to recurrence rates, the data sample was insufficient for a statistical analysis, although the evaluation of raw data showed a trend in favor of HAL-PDD. This meta-analysis confirms the increased tumor detection rate by HAL-PDD with a most pronounced benefit for CIS lesion

    A variational method in the problem of screening an external charge in strongly correlated metals

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    We describe a variational calculation for the problem of screening of a point charge in a layered correlated metal for dopings close to the Mott transition where the screening is non-linear due to the proximity to the incompressible insulating state. We find that external charge can induce locally incompressible regions and that the non-linear dependence of the screening on density can induce overscreening in the nearest nearby layers while preserving overall charge neutrality.Comment: 7 pages, 1 figure, final version as publishe
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