73 research outputs found

    Buffer gas induced collision shift for the 88^{88}Sr 1S03P1\bf{^1S_0-^3P_1} clock transition

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    Precision saturation spectroscopy of the 88Sr1S03P1^{88}{\rm Sr} ^1S_0-^3P_1 is performed in a vapor cell filled with various rare gas including He, Ne, Ar, and Xe. By continuously calibrating the absolute frequency of the probe laser, buffer gas induced collision shifts of \sim kHz are detected with gas pressure of 1-20 mTorr. Helium gave the largest fractional shift of 1.6×109Torr11.6 \times 10^{-9} {\rm Torr}^{-1}. Comparing with a simple impact calculation and a Doppler-limited experiment of Holtgrave and Wolf [Phys. Rev. A {\bf 72}, 012711 (2005)], our results show larger broadening and smaller shifting coefficient, indicating effective atomic loss due to velocity changing collisions. The applicability of the result to the 1S03P0^1S_0-^3P_0 optical lattice clock transition is also discussed

    Deviance-related responses along the auditory hierarchy: combined FFR, MLR and MMN evidence

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    The mismatch negativity (MMN) provides a correlate of automatic auditory discrimination in human auditory cortex that is elicited in response to violation of any acoustic regularity. Recently, deviance-related responses were found at much earlier cortical processing stages as reflected by the middle latency response (MLR) of the auditory evoked potential, and even at the level of the auditory brainstem as reflected by the frequency following response (FFR). However, no study has reported deviance-related responses in the FFR, MLR and long latency response (LLR) concurrently in a single recording protocol. Amplitude-modulated (AM) sounds were presented to healthy human participants in a frequency oddball paradigm to investigate deviance-related responses along the auditory hierarchy in the ranges of FFR, MLR and LLR. AM frequency deviants modulated the FFR, the Na and Nb components of the MLR, and the LLR eliciting the MMN. These findings demonstrate that it is possible to elicit deviance-related responses at three different levels (FFR, MLR and LLR) in one single recording protocol, highlight the involvement of the whole auditory hierarchy in deviance detection and have implications for cognitive and clinical auditory neuroscience. Moreover, the present protocol provides a new research tool into clinical neuroscience so that the functional integrity of the auditory novelty system can now be tested as a whole in a range of clinical populations where the MMN was previously shown to be defectiv

    A phase I clinical trial for [131I]meta-iodobenzylguanidine therapy in patients with refractory pheochromocytoma and paraganglioma : a study protocol

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    Objective Pheochromocytoma and paraganglioma (PPGLs) are rare neuroendocrine tumors derived from the adrenal medulla or extra-adrenal paraganglioma from extra-adrenal chromaffin tissue. Although malignant PPGLs has miserable prognosis, the treatment strategy remains to be established. An internal radiation therapy using [131I]meta-iodobenzylguanidine (131I-mIBG) called MIBG therapy has been attempted as one of the systemic treatment of malignant PPGLs. The aim of this study is therefore to evaluate the safety and the efficacy of MIBG therapy for refractory PPGLs. Methods Patients with refractory PPGLs will be enrolled in this study. The total number of patients for registration is 20. The patients receive a fixed dose of 7,400 MBq of 131I-mIBG. Adverse events are surveyed during 20 weeks after 131I-mIBG injection and all severe adverse events will be documented and reported in detail in accordance with the Common Terminology Criteria for Adverse Events (CTCAE). Examination and imaging diagnosis are performed in 12 weeks after 131I-mIBG injection for the evaluation of therapeutic effect in accordance with the Response Evaluation in Solid Tumours (RECIST). Conclusion The current study is the first multi-institutional prospective study of MIBG therapy and thereby will play a significant role in improving the patients’ prognosis of refractory PPGLs

    Reliability of DWI and FLAIR for diagnosis of sporadic CJD

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    Objectives: To assess the utility of the display standardisation of diffusion-weighted MRI (DWI) and to compare the effectiveness of DWI and fluid-attenuated inversion recovery (FLAIR) MRI for the diagnosis of sporadic Creutzfeldte–Jakob disease (sCJD). Design: A reliability and agreement study. Setting: Thirteen MRI observers comprising eight neurologists and five radiologists at two universities in Japan. Participants: Data of 1.5-Tesla DWI and FLAIR were obtained from 29 patients with sCJD and 13 controls. Outcome measures: Standardisation of DWI display was performed utilising b0 imaging. The observers participated in standardised DWI, variable DWI (the display adjustment was observer dependent) and FLAIR sessions. The observers independently assessed each MRI for CJD-related lesions, that is, hyperintensity in the cerebral cortex or striatum, using a continuous rating scale. Performance was evaluated by the area under the receiver operating characteristics curve (AUC). Results: The mean AUC values were 0.84 (95% CI 0.81 to 0.87) for standardised DWI, 0.85 (95% CI 0.82 to 0.88) for variable DWI and 0.68 (95% CI 0.63 to 0.72) for FLAIR, demonstrating the superiority of DWI (p<0.05). There was a trend for higher intraclass correlations of standardised DWI (0.74, 95% CI 0.66 to 0.83) and variable DWI (0.72, 95% CI 0.62 to 0.81) than that of FLAIR (0.63, 95% CI 0.53 to 0.74), although the differences were not statistically significant. Conclusions: Standardised DWI is as reliable as variable DWI, and the two DWI displays are superior to FLAIR for the diagnosis of sCJD. The authors propose that hyperintensity in the cerebral cortex or striatum on 1.5-Tesla DWI but not FLAIR can be a reliable diagnostic marker for sCJD

    Stability Transfer between Two Clock Lasers Operating at Different Wavelengths for Absolute Frequency Measurement of Clock Transition in 87Sr

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    We demonstrated transferring the stability of one highly stable clock laser operating at 729 nm to another less stable laser operating at 698 nm. The two different wavelengths were bridged using an optical frequency comb. The improved stability of the clock laser at 698 nm enabled us to evaluate the systematic frequency shifts of the Sr optical lattice clock with shorter averaging time. We determined the absolute frequency of the clock transition 1S0 - 3P0 in 87Sr to be 429 228 004 229 873.9 (1.4) Hz referenced to the SI second on the geoid via International Atomic Time (TAI)

    Multicentre multiobserver study of diffusion-weighted and fluid-attenuated inversion recovery MRI for the diagnosis of sporadic Creutzfeldt–Jakob disease: a reliability and agreement study

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    Objectives: To assess the utility of the display standardisation of diffusion-weighted MRI (DWI) and to compare the effectiveness of DWI and fluid-attenuated inversion recovery (FLAIR) MRI for the diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). Design: A reliability and agreement study. Setting: Thirteen MRI observers comprising eight neurologists and five radiologists at two universities in Japan. Participants: Data of 1.5-Tesla DWI and FLAIR were obtained from 29 patients with sCJD and 13 controls. Outcome measures: Standardisation of DWI display was performed utilising b0 imaging. The observers participated in standardised DWI, variable DWI (the display adjustment was observer dependent) and FLAIR sessions. The observers independently assessed each MRI for CJD-related lesions, that is, hyperintensity in the cerebral cortex or striatum, using a continuous rating scale. Performance was evaluated by the area under the receiver operating characteristics curve (AUC). Results: The mean AUC values were 0.84 (95% CI 0.81 to 0.87) for standardised DWI, 0.85 (95% CI 0.82 to 0.88) for variable DWI and 0.68 (95% CI 0.63 to 0.72) for FLAIR, demonstrating the superiority of DWI (p<0.05). There was a trend for higher intraclass correlations of standardised DWI (0.74, 95% CI 0.66 to 0.83) and variable DWI (0.72, 95% CI 0.62 to 0.81) than that of FLAIR (0.63, 95% CI 0.53 to 0.74), although the differences were not statistically significant. Conclusions: Standardised DWI is as reliable as variable DWI, and the two DWI displays are superior to FLAIR for the diagnosis of sCJD. The authors propose that hyperintensity in the cerebral cortex or striatum on 1.5-Tesla DWI but not FLAIR can be a reliable diagnostic marker for sCJD

    Socioeconomic status, damage-related conditions, and PTSD following the Fukushima-daiichi nuclear power plant accident:The Fukushima Health Management Survey

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    The Great East Japan Earthquake severely damaged the Tohoku and Kanto districts, and Fukushima Prefecture faced a subsequent nuclear disaster. Few studies have reported the effects of socioeconomic stressors on individuals' mental status following disasters. We analyzed the responses of 60,704 adult residents of a designated restricted area to the PTSD Checklist-Stressor-Specific Version (PCL-S). The relationships between the PCL-S scores and demographic, socioeconomic, and damage-related variables were analyzed using regression analysis to predict participants' severity of PTSD symptoms. Approximately 14.1% of evacuees had severe PTSD symptoms (PCL-S ≥50) eighteen months post-earthquake. The PCL-S scores were higher among women, older adults, less educated people, those with a history of mental illness, and those living outside Fukushima Prefecture. The PCL-S scores increased with participants' scores on the Kessler Psychological Distress Scale. The number of trauma-exposure stressors and socioeconomic stressors were associated with 1.52 and 3.77 increases in the PCL-S score, respectively. Furthermore, psychological distress, unemployment, decreased income, house damage, tsunami experience, nuclear power plant accident experience, and loss of someone close due to the disaster were associated with the prevalence of severe PTSD symptoms. The complex triple disaster of a major earthquake, tsunami, and nuclear accident created significant socioeconomic changes that may be important determinants of PTSD among residents of restricted access areas in Fukushima
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