434 research outputs found

    Precise and highly-sensitive Doppler-free two-photon absorption dual-comb spectroscopy using pulse shaping and coherent averaging for fluorescence signal detection

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    We demonstrated Doppler-free two-photon absorption dual-comb spectroscopy of 5S1/2 - 5D5/2 and 5D3/2 transitions of Rb. We employed simple pulse-shaping of the dual-comb source and eliminated Doppler-broadening backgrounds, which cause fitting errors of the Doppler-free signals. Moreover, to improve sensitivity, we investigated the coherence in dual-comb fluorescence signals and the coherent averaging method was applied to fluorescence dual-comb detection for the first time. The detection sensitivity was significantly improved by coherent averaging to reduce the noise floor. Observed Doppler-free spectra was fitted to Voigt profiles and we performed absolute frequency determination with a precision of about 100 kHz

    Optical–optical double-resonance dual-comb spectroscopy with pump-intensity modulation

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    We apply an intensity-modulation technique to dual-comb spectroscopy to improve its detection sensitivity. The scheme is demonstrated via Doppler-free optical–optical double-resonance spectroscopy of Rb by modulating the intensity of a pump laser with frequencies set at rates 3 times lower and 50,000 times higher than the difference in the repetition rates of the two frequency combs. The signal-to-noise ratios are enhanced by 3 and 6 times for slow and fast modulations, respectively, compared to those of conventional dual-comb spectroscopy without any intensity modulation. The technique is widely applicable to pump-probe spectroscopy with dual-comb spectroscopy and provides high detection sensitivity

    Effects of mouse utricle stromal tissues on hair cell induction from induced pluripotent stem cells

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    BACKGROUND: Hair cells are important for maintaining our sense of hearing and balance. However, they are difficult to regenerate in mammals once they are lost. Clarification of the molecular mechanisms underlying inner ear disorders is also impeded by the anatomical limitation of experimental access to the human inner ear. Therefore, the generation of hair cells, possibly from induced pluripotent stem (iPS) cells, is important for regenerative therapy and studies of inner ear diseases. RESULTS: We generated hair cells from mouse iPS cells using an established stepwise induction protocol. First, iPS cells were differentiated into the ectodermal lineage by floating culture. Next, they were treated with basic fibroblast growth factor to induce otic progenitor cells. Finally, the cells were co-cultured with three kinds of mouse utricle tissues: stromal tissue, stromal tissue + sensory epithelium, and the extracellular matrix of stromal tissue. Hair cell-like cells were successfully generated from iPS cells using mouse utricle stromal tissues. However, no hair cell-like cells with hair bundle-like structures were formed using other tissues. CONCLUSIONS: Hair cell-like cells were induced from mouse iPS cells using mouse utricle stromal tissues. Certain soluble factors from mouse utricle stromal cells might be important for induction of hair cells from iPS cells

    Feeding Deterrence to Reticulitermes speratus (Kolbe) by Fibroporia radiculosa (Peck) Parmasto 1968

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    Brown rot fungus Fibroporia radiculosa (Peck) Parmasto grown in decayed wood and non-wood material, potato dextrose agar (PDA) media, deterred Reticulitermes speratus (Kolbe) feeding. Decayed wood and PDA media were extracted and tests were performed to assess termite feeding behavior towards the extracts. We found that the extract from PDA media also suppressed termite feeding, although it did not induce mortality. Using gas chromatography and mass spectrometry analysis, two bioactive compounds were detected from the decayed wood extract, and one was detected from the PDA extract. Based on National Institute of Science and Technology (USA) Mass Spectral library match and compound fragmentation, both of the compounds belong to the sesquiterpenes family

    Doppler-free dual-comb spectroscopy of Rb using optical-optical double resonance technique

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    We present a Doppler-free high-resolution dual-comb spectroscopy technique in which a dual-comb system is employed to perform optical-optical double-resonance (OODR) spectroscopy. In our experimental study, Doppler-free high-resolution and high-frequency-accuracy broadband measurements were realized using the proposed OODR dual-comb spectroscopic technique, which does not require high-power-per-mode frequency combs. We observed fully resolved hyperfine spectra of 5P3/2 - 4D5/2, 4D3/2 transitions of Rb at 1530 nm and precisely determined the absolute frequencies of the transitions, with an uncertainty of less than 1 MHz. The variations of the OODR spectral line shapes due to power broadening and alignment and the effects of polarization on the dual-comb OODR spectra were also analyzed. This study provides a widely applicable technique for Doppler-free dual-comb spectroscopy of various gaseous species

    Gross E esophageal atresia with unique course

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    The patient was a 15 months-old boy who had been diagnosed CHARGE syndrome, which is a multiple congenital anomaly syndrome caused by mutations in the CHD7 gene. Mechanical ventilation management was initiated 2 hours after birth for dysphagia and respiratory failure, and tracheotomy was performed 3 months after birth for dysphagia and failed extubation. He was repeatedly hospitalized due to pneuomoniae. Approximately 1 year after birth, the boy had two consecutive episodes of sudden ventilatory insufficiency while replacing the tracheotomy cannula. A bronchoscopic examination under general anesthesia revealed a tracheoesophageal fistula directly below the tracheostomy. The patient was diagnosed with Gross E esophageal atresia, and we speculated that the cannula migrated to the esophagus via the fistula during tracheostomy cannula replacement. Gross E esophageal atresia is a rare disease. Its diagnosis is often delayed, and it is discovered by recurrent pneumonia in many cases. A tracheoesophageal fistula may also be found in children with deformities of the respiratory system. Furthermore, tracheoesophageal fistulae are often found in the neck. Therefore, when sudden ventilatory insufficiency occurs in a child with a tracheostomy after replacing the tracheostomy cannula, caution must be exercised since the cannula may have migrated to the esophagus via a fistula

    Use of FDG-PET in Radiation Treatment Planning for Thoracic Cancers

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    Radiotherapy plays an important role in the treatment for thoracic cancers. Accurate diagnosis is essential to correctly perform curative radiotherapy. Tumor delineation is also important to prevent geographic misses in radiotherapy planning. Currently, planning is based on computed tomography (CT) imaging when radiation oncologists manually contour the tumor, and this practice often induces interobserver variability. F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been reported to enable accurate staging and detect tumor extension in several thoracic cancers, such as lung cancer and esophageal cancer. FDG-PET imaging has many potential advantages in radiotherapy planning for these cancers, because it can add biological information to conventional anatomical images and decrease the inter-observer variability. FDG-PET improves radiotherapy volume and enables dose escalation without causing severe side effects, especially in lung cancer patients. The main advantage of FDG-PET for esophageal cancer patients is the detection of unrecognized lymph node or distal metastases. However, automatic delineation by FDG-PET is still controversial in these tumors, despite the initial expectations. We will review the role of FDG-PET in radiotherapy for thoracic cancers, including lung cancer and esophageal cancer

    La accesibilidad de las personas con discapacidad motriz en la Pontificia Universidad Católica del Perú

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    La presente investigación realiza el análisis de la accesibilidad de la Pontificia Universidad Católica del Perú para personas con discapacidad motriz. Debido al elevado número de personas con discapacidad en el Perú, se cuenta con la Ley General de la Persona con Discapacidad, la cual indica que, las instituciones públicas y privadas del país, deben incluir a personas con discapacidad. Por otro lado, la Ley Universitaria, indica que todos los estudiantes tienen derecho a contar con ambientes y equipos accesibles. Esta investigación, tiene como objetivo principal, analizar si la PUCP cumple con su deber, como institución educativa privada, de tener la accesibilidad adecuada para personas con discapacidad motriz. Por ello, se busca entender las necesidades de las personas con movilidad limitada, evaluando los espacios y servicios que brinda la universidad, y además, identificar las barreras de accesibilidad, desde el punto de vista de este grupo de personas. A partir de ello, se planea proponer ciertas adaptaciones en la infraestructura actual, promoviendo la equidad e inclusión de las personas con discapacidad motriz. Para lograr dichos objetivos, se utilizará una metodología de enfoque mixto puro concurrente en el contexto de estudio, el campus PUCP, haciendo uso herramientas cualitativas y cuantitativas Se encontraron distintas barreras de mobiliario e inmobiliario a las que se ven expuestas las personas con discapacidad motriz dentro de la PUCP. Asimismo, se calificó la accesibilidad del campus, desde el punto de vista de este grupo de personas, obteniendo como resultado, un nivel de accesibilidad Convertible. Los distintos pabellones tuvieron calificaciones que van desde el nivel Inaccesible, hasta el nivel Practicable o Básico. Finalmente, se propusieron adaptaciones para la mejora de la accesibilidad de la PUCP. Finalmente, se concluyó que las personas con discapacidad motriz necesitan adaptaciones en la infraestructura, como son el aumento y diseño adecuado de rampas y elevadores; y el uso de mobiliario adecuado, con las medidas necesarias. Asimismo, al ser calificada dentro del nivel Convertible, se concluye que, la PUCP, a pesar de no ser considerado un espacio inaccesible, presenta distintas barreras que impiden la inclusión de las personas con discapacidad motriz, encontrándose una gran problemática en los pabellones antiguos del campus, como son los edificios de las distintas especialidades de Ingeniería, los cuales fueron catalogados, en su totalidad, como Inaccesibles

    Effectiveness of Domain-Based Intervention for Language Development in Japanese Hearing-Impaired Children: A Multicenter Study

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    Objective: Decreasing language delay in hearing-impaired children is a key issue in the maintenance of their quality of life. Language training has been presented mainly by experience-based training; effective intervention programs are crucially important for their future. The aim of this study was to confirm the efficacy of 6-month domain-based language training of school-age, severe-to-profound hearing-impaired children. Methods: We conducted a controlled before-after study involving 728 severe-to-profound prelingual hearing-impaired children, including an intervention group (n = 60), control group (n = 30), and baseline study group (n = 638). Language scores of the participants and questionnaires to the caregivers/therapists were compared before and after the intervention. Average monthly increase in each language score of the control group and baseline study group were compared with those of the intervention group. Results: Language scores and the results of the questionnaire of the intervention group showed a significant improvement (P < .05). The average monthly language growth of the intervention group was twice that of the control group and 3 to 4 times that of the baseline study group (P < .05). The effect size was largest in communication (1.914), followed by syntax (0.931). Conclusion: Domain-based language training improved the language development and daily communication of hearing-impaired children without any adverse effects
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