Magnetic field-induced insulator-metal transition in transition metal oxides at ultrahigh magnetic fields

学位の種別: 課程博士審査委員会委員 : (主査)東京大学准教授 松田 康弘, 東京大学教授 廣井 善二, 東京大学准教授 貴田 徳明, 東京大学准教授 徳永 将史, 東京大学准教授 高木 紀明University of Tokyo(東京大学

Serum zinc deficiency could be associated with dementia conversion in Parkinson’s disease

BackgroundAssociation between heavy metals and Parkinson’s disease (PD) is well noted, but studies regarding heavy metal levels and non-motor symptoms of PD, such as PD’s dementia (PD-D), are lacking.MethodsIn this retrospective cohort study, we compared five serum heavy metal levels (Zn, Cu, Pb, Hg, and Mn) of newly diagnosed PD patients (n = 124). Among 124 patients, 40 patients were later converted to Parkinson’s disease dementia (PD-D), and 84 patients remained without dementia during the follow-up time. We collected clinical parameters of PD and conducted correlation analysis with heavy metal levels. PD-D conversion time was defined as the initiation time of cholinesterase inhibitors. Cox proportional hazard models were used to identify factors associated with dementia conversion in PD subjects.ResultsZn deficiency was significant in the PD-D group than in the PD without dementia group (87.53 ± 13.20 vs. 74.91 ± 14.43, p < 0.01). Lower serum Zn level was significantly correlated with K-MMSE and LEDD at 3 months (r = −0.28, p < 0.01; r = 0.38, p < 0.01). Zn deficiency also contributed to a shorter time to dementia conversion (HR 0.953, 95% CI 0.919 to 0.988, p < 0.01).ConclusionThis clinical study suggests that a low serum Zn level can be a risk factor for developing PD-D and could be used as a biological marker for PD-D conversion

Seeing Through the Conversation: Audio-Visual Speech Separation based on Diffusion Model

The objective of this work is to extract target speaker's voice from a mixture of voices using visual cues. Existing works on audio-visual speech separation have demonstrated their performance with promising intelligibility, but maintaining naturalness remains a challenge. To address this issue, we propose AVDiffuSS, an audio-visual speech separation model based on a diffusion mechanism known for its capability in generating natural samples. For an effective fusion of the two modalities for diffusion, we also propose a cross-attention-based feature fusion mechanism. This mechanism is specifically tailored for the speech domain to integrate the phonetic information from audio-visual correspondence in speech generation. In this way, the fusion process maintains the high temporal resolution of the features, without excessive computational requirements. We demonstrate that the proposed framework achieves state-of-the-art results on two benchmarks, including VoxCeleb2 and LRS3, producing speech with notably better naturalness.Comment: Project page with demo: https://mm.kaist.ac.kr/projects/avdiffuss

Algo más que una silla en la mesa: la participación de las personas refugiadas y la importancia de escuchar

El Foro Mundial sobre los Refugiados de 2019 fue significativo por la inclusión de representantes de las personas refugiadas. Se puede aprender mucho prestando atención a los discursos que pronunciaron, es decir, escuchando realmente sus voces

Disorder-dependent Li diffusion in Li6PS5Cl\mathrm{Li_6PS_5Cl} investigated by machine learning potential

Solid-state electrolytes with argyrodite structures, such as $\mathrm{Li_6PS_5Cl}$, have attracted considerable attention due to their superior safety compared to liquid electrolytes and higher ionic conductivity than other solid electrolytes. Although experimental efforts have been made to enhance conductivity by controlling the degree of disorder, the underlying diffusion mechanism is not yet fully understood. Moreover, existing theoretical analyses based on ab initio MD simulations have limitations in addressing various types of disorder at room temperature. In this study, we directly investigate Li-ion diffusion in $\mathrm{Li_6PS_5Cl}$ at 300 K using large-scale, long-term MD simulations empowered by machine learning potentials (MLPs). To ensure the convergence of conductivity values within an error range of 10%, we employ a 25 ns simulation using a $5\times5\times5$ supercell containing 6500 atoms. The computed Li-ion conductivity, activation energies, and equilibrium site occupancies align well with experimental observations. Notably, Li-ion conductivity peaks when Cl ions occupy 25% of the 4c sites, rather than at 50% where the disorder is maximized. This phenomenon is explained by the interplay between inter-cage and intra-cage jumps. By elucidating the key factors affecting Li-ion diffusion in $\mathrm{Li_6PS_5Cl}$, this work paves the way for optimizing ionic conductivity in the argyrodite family.Comment: 34 pages, 6 figure

Postoperative cervical length to predict success of repeat cerclage in singleton pregnancies with prolapsed membranes after prior cerclage

BackgroundThis study aimed to evaluate the outcome of repeat cerclage (RC) in singleton pregnancies with prolapsed membranes following a prior cerclage and analyze predictive factors for delivery at ≥26 weeks of gestation following RC.Materials and methodsPatients who underwent RC between 2010 and 2020 at the Hallym University Medical Center were reviewed. Women with singleton pregnancies with prolapsed membranes following prior cerclage were candidates for RC. We analyzed the characteristics, pregnancy outcomes, perioperative clinical and laboratory findings, and postoperative cervical length (CL) to identify the factors for predicting delivery at ≥26 weeks following RC.ResultsThirty-five women with RC were identified; the median gestational age (GA) at a prior cerclage was 14 weeks, the average GA at RC was 21 + 3 weeks, and the median GA at delivery following RC was 26 + 2 weeks. Patients were divided into two groups based on their delivery status at 26 weeks: 17 women delivered at <26 weeks (range, 18 + 4–25 + 6 weeks) (Group A) and 18 women delivered at ≥26 weeks (range, 26 + 2–40 + 3 weeks) (Group B). The median GA at delivery in group A was 22 + 4 weeks, whereas that in group B was 33 + 4 weeks (p < 0.001). No differences in preoperative clinical and laboratory findings were observed between the two groups. However, the postoperative CL in group A was significantly shorter than that in group B (12 mm vs. 21.5 mm, p < 0.001). The ROC curve of postoperative CL predicting delivery at ≥26 weeks showed an AUC of 0.843; a CL of 20 mm showed a sensitivity of 61.1% and a specificity of 100%.ConclusionRC may prolong singleton pregnancies with prolapsed membranes following prior cerclage. A postoperative CL ≥20 mm may predict the success of RC