395 research outputs found

    A peristomal plaque of sudden occurrence.

    Get PDF
    Koebner phenomenon regards the formation of a psoriatic lesion after a trauma, including tattoo, insect bite or other injuries. Although this manifestation is not specific for psoriasis, physicians should be aware because early recognition may be helpful in making the diagnosis when present

    A suspicious dark lesion in a boy.

    Get PDF
    The presence of history of hyperpigmented crust in a patient with a history of adequate hygiene is typical of terra firma\u2010forme dermatosis. The treatment is the rubbing of the skin with isopropyl alcohol (removal of the hyperpigmented brown crust, confirming the diagnosis). Physicians should be aware because early diagnosis avoid unnecessary treatment

    How many qubits are needed for quantum computational supremacy?

    Get PDF
    Quantum computational supremacy arguments, which describe a way for a quantum computer to perform a task that cannot also be done by a classical computer, typically require some sort of computational assumption related to the limitations of classical computation. One common assumption is that the polynomial hierarchy (PH) does not collapse, a stronger version of the statement that P \neq NP, which leads to the conclusion that any classical simulation of certain families of quantum circuits requires time scaling worse than any polynomial in the size of the circuits. However, the asymptotic nature of this conclusion prevents us from calculating exactly how many qubits these quantum circuits must have for their classical simulation to be intractable on modern classical supercomputers. We refine these quantum computational supremacy arguments and perform such a calculation by imposing fine-grained versions of the non-collapse assumption. Each version is parameterized by a constant aa and asserts that certain specific computational problems with input size nn require 2an2^{an} time steps to be solved by a non-deterministic algorithm. Then, we choose a specific value of aa for each version that we argue makes the assumption plausible, and based on these conjectures we conclude that Instantaneous Quantum Polynomial-Time (IQP) circuits with 208 qubits, Quantum Approximate Optimization Algorithm (QAOA) circuits with 420 qubits and boson sampling circuits (i.e. linear optical networks) with 98 photons are large enough for the task of producing samples from their output distributions up to constant multiplicative error to be intractable on current technology. In the first two cases, we extend this to constant additive error by introducing an average-case fine-grained conjecture.Comment: 24 pages + 3 appendices, 8 figures. v2: number of qubits calculation updated and conjectures clarified after becoming aware of Ref. [42]. v3: Section IV and Appendix C added to incorporate additive-error simulation

    Congenital cytomegalovirus related intestinal malrotation: a case report

    Get PDF
    Background: Cytomegalovirus is the most common cause of congenital infection in the developed countries. Gastrointestinal involvement has been extensively described in both adult and paediatric immunocompromised patients but it is infrequent in congenital or perinatal CMV infection. Case presentation: We report on a case of coexistent congenital Cytomegalovirus infection with intestinal malrotation and positive intestinal Cytomegalovirus biopsy. At birth the neonate showed clinical and radiological evidence of intestinal obstruction. Meconium passed only after evacuative nursing procedures; stooling pattern was irregular; gastric residuals were bile-stained. Laparatomy revealed a complete intestinal malrotation and contextually gastrointestinal biopsy samples of the appendix confirmed the diagnosis of CMV gastrointestinal disease. Intravenous ganciclovir was initiated for 2 weeks, followed by oral valgancyclovir for 6 month. Conclusion: CMV-induced proinflammatory process may be responsible of the interruption of the normal development of the gut or could in turn lead to a disruption in the normal development of the gut potentiating the mechanism causing malrotation. We suggest the hypothesis that an inflammatory process induced by CMV congenital infection may be responsible, in the early gestation, of the intestinal end-organ disease, as the intestinal malrotation. CMV infection should always be excluded in full-term infants presenting with colonic stricture or malrotation

    Quantitative comparison between different methods for the determination of the amplified spontaneous emission threshold in dye-polymer blends and perovskite thin films

    Get PDF
    Amplified Spontaneous Emission (ASE) properties and ASE threshold are usually investigated for the characterization of a candidate active material for laser applications. However, the comparison among different materials is often hampered by the use in literature of several different methods to estimate the ASE threshold. In this work we quantitatively compare the ASE threshold values obtained by using the most employed methods in dye-doped polymer and lead halide perovskite thin films, highlighting the dependence of the value obtained on the applied method
    corecore