1,101 research outputs found

    Ground state of antiferromagnetic Heisenberg two-leg ladder in terms of the valence-bond solid picture

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    We have proposed the plaquette-singlet solid (PSS) ground state for the spin-1 antiferromagnetic Heisenberg two-leg ladder. Based on the PSS picture, we discuss the correspondence of the PSS state to the valence-bond solid (VBS) state of the ground state of spin-2 chain by introducing an appropriate composite spin picture. When the bond alternation is introduced, there occur quantum phase transitions and each phase can be identified with that in the dimerized spin-2 chain. Furthermore, we argue that the VBS picture of spin-2S chain can be applied to the ground state of spin-S two-leg ladder.Comment: 2 pages, 1 eps figure, Proceedings for LT23; Proper citation added, Author list change

    Emission Credit Trading and Regional Inequalities

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    This paper examines how regional inequalities are affected by emission controls via credit trading and availability of absorption sources. We assume that homogeneous goods are costly traded without emission controls and that the rural areas have an advantage in terms of the availability of absorption sources. We especially focus on the long-term effects of firm relocation. Our two key findings are as follows. First, in the case where an emission control scheme is implemented without allowing for offsetting emissions with carbon absorption sources (carbon sinks), strengthening the emission controls drives firms to relocate from rural areas to urban areas, in the case that wage levels remain unchanged in both areas. As a result, regional inequalities in terms of both the number of firms and relative public welfare are enlarged by emission controls. Our second finding shows that in the case in which the emission control scheme allows for emissions-absorption offsetting, strengthening emission controls has mixed effects on the relative welfare of rural areas. Numerical simulations show that when the costs associated with transporting differentiated goods are relatively low, the introduction of emission controls with an offsetting system results in greater inequality across regions compared with introducing emission controls without such offsetting.

    Erbium-doped-fiber-based broad visible range frequency comb with a 30 GHz mode spacing for astronomical applications

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    Optical frequency combs have the potential to improve the precision of the radial velocity measurement of celestial bodies, leading to breakthroughs in such fields as exoplanet exploration. For these purposes, the comb must have a broad spectral coverage in the visible wavelength region, a wide mode spacing that can be resolved with a high dispersion spectrograph, and sufficient robustness to operate for long periods even in remote locations. We have realized a comb system with a 30 GHz mode spacing, 62 % available wavelength coverage in the visible region, and 40 dB spectral contrast by combining a robust erbium-doped-fiber-based femtosecond laser, mode filtering with newly designed optical cavities, and broadband-visible-range comb generation using a chirped periodically-poled LiNbO3 ridge waveguide. The system durability and reliability are also promising because of the stable spectrum, which is due to the use of almost all polarization-maintaining fiber optics, moderate optical power, and good frequency repeatability obtained with a wavelength-stabilized laser.Comment: 19 pages, 5 figure

    Total Vertebrectomy for Non-Small Cell Lung Cancer

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    We present a case who had left upper lobectomy with total vertebrectomy after arterial embolization in preparation for intraoperative bleeding. A 35-year-old man complained of left back pain. Chest CT revealed a tumor in S1+2 of the left lung, invading the third thoracic vertebra. As no nodal or distant metastasis was detected, we performed left upper lobectomy and lymph node dissection (ND2a-2) after embolization of the vessels feeding the tumor in order to reduce intraoperative bleeding. In addition, the team of orthopedics performed en bloc resection of the third thoracic vertebra and parts of the left third and fourth ribs. Histological examination of the tumor revealed pleomorphic carcinoma (pT4N0M0, stage IIIA)

    Cerebral Glycogen Distribution and Aging

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    In the brain, glycogen metabolism has been implied in synaptic plasticity and learning, yet the distribution of this molecule has not been fully described. We investigated cerebral glycogen of the mouse by immunohistochemistry (IHC) using two monoclonal antibodies that have different affinities depending on the glycogen size. The use of focused microwave irradiation yielded well‐defined glycogen immunoreactive signals compared with the conventional periodic acid‐Schiff method. The IHC signals displayed a punctate distribution localized predominantly in astrocytic processes. Glycogen immunoreactivity (IR) was high in the hippocampus, striatum, cortex, and cerebellar molecular layer, whereas it was low in the white matter and most of the subcortical structures. Additionally, glycogen distribution in the hippocampal CA3‐CA1 and striatum had a ‘patchy’ appearance with glycogen‐rich and glycogen‐poor astrocytes appearing in alternation. The glycogen patches were more evident with large‐molecule glycogen in young adult mice but they were hardly observable in aged mice (1–2 years old). Our results reveal brain region‐dependent glycogen accumulation and possibly metabolic heterogeneity of astrocytes

    The association between diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score and the outcome following mechanical thrombectomy of anterior circulation occlusion

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    Hashimoto H., Maruo T., Kimoto Y., et al. The association between diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score and the outcome following mechanical thrombectomy of anterior circulation occlusion. Interdisciplinary Neurosurgery: Advanced Techniques and Case Management 33, 101758 (2023); https://doi.org/10.1016/j.inat.2023.101758.Background: Although preoperative diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) is well known as a predictor of outcomes after mechanical thrombectomy (MT) for large-vessel occlusion (LVO), assessment of changes in DWI-ASPECT from before to after MT is rare. Therefore, we clarified the relationship between the change in DWI-ASPECTS and clinical outcomes. Methods: In this retrospective single-center study, we enrolled 63 cases of anterior LVOs treated with MT between April 2015 and March 2022. Preoperative and postoperative DWI-ASPECTSs were calculated. DWI-ASPECTSs were categorized into cortical-ASPECTSs (c-ASPECTSs) and subcortical ASPECTSs and assessed. Additionally, medical variables related to patients, such as sex, age, National Institutes of Health Stroke Scale (NIHSS) score, and premorbid modified Rankin Scale (mRS) score, were evaluated. A good outcome was defined as an mRS score of 0–2 at 3 months. Results: Forty-five patients met the inclusion criteria. Nine (20 %) had a good outcome. The good outcome group showed significantly higher postoperative DWI-ASPECTs (median 8 vs. 5, p = 0.012) and c-ASPECTSs (median 4 vs. 3, p = 0.020) than the poor outcome group. No difference in DWI-ASPECTSs and c-ASPECTSs from before to after MT were significantly associated with the good outcome (p = 0.017, p = 0.016, respectively). The cut-off values for the good outcome on receiver operating characteristic curve analysis for differences between DWI-ASPECTSs and c-ASPECTSs were 0 [area under the curve (AUC) 0.77] and 0 [AUC 0.74]. Logistic regression analyses showed that baseline NIHSS score (odds ratio, 0.69; 95 % confidence interval 0.48–1.00; p = 0.046) and postoperative DWI-ASPECTS (odds ratio, 2.27; 95 % confidence interval 1.02–5.04; p = 0.039) were independent factors for the good outcome. Conclusions: The good outcome of patients with anterior LVO was associated with no difference in DWI-ASPECTSs and c-ASPECTSs from before to after MT
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