Publications by authors named "T Usuda"

Objectives: To investigate the effectiveness of different holmium:yttrium-aluminum-garnet (Ho:YAG) laser modes for lithotripsy in the "dusting era" and identify the optimal laser mode for producing stone fragments measuring ≤0.5 mm.

Methods: We used plaster of Paris-made artificial stones crushed into 2-3 mm pieces, weighing 1 g in total.

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We propose an amplitude shift keying-type asymmetric quantum communication (AQC) system that uses an entangled state. As a first step toward development of this system, we evaluated and considered the communication performance of the proposed receiver when applied to the AQC system using a two-mode squeezed vacuum state (TSVS), the maximum quasi-Bell state, and the non-maximum quasi-Bell state, along with an asymmetric classical communication (ACC) system using the coherent state. Specifically, we derived an analytical expression for the error probability of the AQC system using the quasi-Bell state.

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In quantum information science, it is very important to solve the eigenvalue problem of the Gram matrix for quantum signals. This allows various quantities to be calculated, such as the error probability, mutual information, channel capacity, and the upper and lower bounds of the reliability function. Solving the eigenvalue problem also provides a matrix representation of quantum signals, which is useful for simulating quantum systems.

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Background: Thyroid function in asphyxiated newborns who received hypothermia therapy and its relation to neurological outcome are not well described.

Methods: We performed a prospective study to measure thyroid function in 12 asphyxiated newborns who received hypothermia therapy. We measured serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) on admission, at 24, 72, and 96 h after birth, and at discharge (range, 17-54 days).

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