160 research outputs found

    Spin-orbit coupling inactivity of Co2+^{2+} ion in geometrically frustrated magnet GeCo2_2O4_4

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    We report single-crystal neutron diffraction studies on a spinel antiferromagnet GeCo2_2O4_4, which exhibits magnetic order with a trigonal propagation vector and tetragonal lattice expansion (c/a1.001c/a\simeq1.001) below TN=21T_{\rm N}=21 K. For this inconsistency between spin and lattice in symmetry, magnetic Bragg reflections with a tetragonal propagation vector were discovered below TNT_{\rm N}. We discuss spin and orbital states of Co2+^{2+} ion underlying the new magnetic component.Comment: 3 pages 2 figures, submitted to ICFCM proceeding (Journal of Physics: Conference Series, 2011

    Mental fatigue caused by prolonged cognitive load associated with sympathetic hyperactivity

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    <p>Abstract</p> <p>Background</p> <p>It is known that chronic fatigue is associated with sympathetic hyperactivity. However, the relationship between autonomic function and mental fatigue caused by a prolonged mental load in healthy humans is still unclear. Thus, in order to clarify the mechanisms underlying mental fatigue, we examined the association between mental fatigue and autonomic functions.</p> <p>Methods</p> <p>The study group comprised 10 healthy participants. To induce mental fatigue, participants performed mental tasks, which consisted of the advanced trail making test, <it>kana </it>pick-out test and mirror drawing test, for 8 hr, corresponding to a normal work day. Autonomic functions were measured by accelerated plethysmography before and after the fatigue-inducing mental tasks. As a control, the same participants completed an 8-hr relaxation session 4 weeks before the fatigue session.</p> <p>Results</p> <p>After the 8-hr relaxation session, low-frequency component power (LF), high-frequency component power (HF) and low-frequency component power/high-frequency component power ratio (LF/HF ratio) were not changed from baseline. In contrast, after the fatigue session, the HF and LF/HF ratio were significantly changed from baseline; specifically, the HF was lower and LF/HF ratio was higher as compared to those after the relaxation session.</p> <p>Conclusions</p> <p>Sympathetic hyperactivity based on decreased parasympathetic activity is associated with mental fatigue induced by prolonged cognitive load.</p

    Autonomic nervous alterations associated with daily level of fatigue

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    <p>Abstract</p> <p>Background</p> <p>Fatigue is a common symptom in both sick and healthy people. We examined autonomic nervous alterations associated with fatigue to clarify the mechanisms underlying fatigue.</p> <p>Methods</p> <p>The study group consisted of 19 healthy participants who performed a 2-back test for 30 min as a fatigue-inducing mental task session. Before and after the session, they completed the advanced trail making test (ATMT) for 30 min for mental fatigue evaluation, subjective scales to measure fatigue sensation, and underwent electrocardiography to allow assessment of autonomic nerve activities.</p> <p>Results</p> <p>After the fatigue-inducing task, the total error counts on the ATMT tended to increase (<it>P </it>= 0.076); the ATMT for total trial counts (<it>P </it>= 0.001), the subjective level of fatigue (<it>P </it>< 0.001), and the % low-frequency power (%LF) (<it>P </it>= 0.035) increased significantly; and the % high-frequency power (%HF) decreased compared with before the fatigue-inducing task although this did not reach the statistical significance (<it>P </it>= 0.170). Although LF measured in absolute units did not change significantly before and after the fatigue-inducing task (<it>P </it>= 0.771), and HF measured in absolute units decreased after the task (<it>P </it>= 0.020). The %LF and LF/HF ratio were positively associated with the daily level of fatigue evaluated using Chalder's fatigue scale. In addition, %HF was negatively associated with the fatigue score.</p> <p>Conclusions</p> <p>Increased sympathetic activity and decreased parasympathetic activity may be characteristic features of both acute and daily levels of fatigue. Our findings provide new perspectives on the mechanisms underlying fatigue.</p

    Verteilung der im Walzgut hervorgerufenen Spannungen beim Breitenabnahmenprozeß der Brammen

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    In dieser Arbeit wurde ein Modellversuch über die bei der Breitenabnahme im Walzgut entstehende Spannung anhand der Plasticine-Platten und gleichzeitig eine rechnerische Untersuchung darüber mit dem Finite-Elemente-Verfahren durchgeführt. Die berechneten Werte der Spannungen stimmten mit den gemessenen Werten im ganzen nicht nur qualitativ, sondern auch quantitativ gut überein. Daraus erklärte sich, wie die Walzbedingungen auf die Spannungsverteilung im Walzgut wirken, und gewonnene wichtige Kenntnis ist wie folgende: Beim Vertikalwalzen und auch beim nachfolgend durchgeführten Horizontalwalzen entsteht im allgemeinen eine Druckspannung, und ihre Größe ist am größten an den Breitenseiten der Bramme. Aber die Spannung in der Walzrichtung wendet sich mit Näherung zur Breitenmitte von Druckspannung zu Zugspannung. Dies bedeutet, daß die im Strangguß unerwartet in der Umgebung der Breitenmitte der Bramme erscheinenden Innenrisse durch die beim Walzen dort entstehende Zugspannung vergrößert werden können. Daher sollte die Entstehung von Innenrissen beim Stranggießverfahren völlig zurückgehalten werden

    Interploidy gene flow involving the sexual-asexual cycle facilitates the diversification of gynogenetic triploid Carassius fish

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    クローン繁殖フナは稀に有性生殖をしながら繁栄 --遺伝的に多様なクローンフナが存在する謎を解明--. 京都大学プレスリリース. 2021-11-19.Asexual vertebrates are rare and at risk of extinction due to their restricted adaptability through the loss of genetic recombination. We explore the mechanisms behind the generation and maintenance of genetic diversity in triploid asexual (gynogenetic) Carassius auratus fish, which is widespread in East Asian fresh waters and exhibits one of the most extensive distribution among asexual vertebrates despite its dependence on host sperm. Our analyses of genetic composition using dozens of genetic markers and genome-wide transcriptome sequencing uncover admixed genetic composition of Japanese asexual triploid Carassius consisting of both the diverged Japanese and Eurasian alleles, suggesting the involvement of Eurasian lineages in its origin. However, coexisting sexual diploid relatives and asexual triploids in Japan show regional genetic similarity in both mitochondrial and nuclear markers. These results are attributed to a unique unidirectional gene flow from diploids to sympatric triploids, with the involvement of occasional sexual reproduction. Additionally, the asexual triploid shows a weaker population structure than the sexual diploid, and multiple triploid lineages coexist in most Japanese rivers. The generated diversity via repeated interploidy gene flow as well as an increased establishment of immigrants is assumed to offset the cost of asexual reproduction and might contribute to the successful broad distribution of this asexual vertebrate

    Oral hypofunction in the older population : Position paper of the Japanese Society of Gerodontology in 2016

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    Background: There is growing international interest in identifying the effects of ageing on oral health and on appropriate strategies for managing oral disorders. The Japanese Society of Gerodontology (JSG), as the official representative of researchers and clinicians interested in geriatric dentistry in Japan, makes several recommendations on the concept of “oral hypofunction.” Aims: This study proposes diagnostic criteria and management strategies to reduce the risk of oral hypofunction among older people. Conceptual Framework: We define oral hypofunction as a presentation of 7 oral signs or symptoms: oral uncleanness; oral dryness; decline in occlusal force; decline in motor function of tongue and lips; decline in tongue pressure; decline in chewing function; and decline in swallowing function. The criteria of each symptom were determined based on the data of previous studies, and oral hypofunction was diagnosed if the criteria for 3 or more signs or symptoms were met. Conclusions: We recommend that more evidence should be gathered from clinical studies and trials to clarify our diagnostic criteria and management strategies

    Operative Procedure for Laparoscopy-Assisted Vagus Nerve and Pylorus-Preserving Gastrectomy (LAVNPPG) for Early Gastric Cancer

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    Laparosocpy-assisted pylorus-preserving gastrectomy (LAPPG) is a widely accepted surgical procedure for the treatment of early gastric cancer in the middle third of the stomach. We have been performing this operation since 2007. Compared with traditional distal gastrectomy, LAPPG has postoperative nutritional benefits for patients. However, this procedure preserves only the pyloric branch of the vagus nerve and not the celiac branch. We found that patients retain a large amount of residual food in the gastric remnant, which interferes with the detection of secondary cancer on endoscopic follow-up. To improve the pyloric function and postoperative gastrointestinal motility, we changed our procedure during 2009 to preserve both the pyloric and celiac branches of the vagus nerve, and we named this new procedure laparoscopy-assisted vagus nerve and pylorus-preserving gastrectomy (LAVNPPG). From 2009 to 2011, 11 patients underwent LAVNPPG at our hospital. Retrospective comparison of the safety of operation, postoperative complications, and condition of the gastric remnant between LAPPG (n = 13) and LAVNPPG (n = 11) found that the occurrence of postprandial stasis and food residue in the gastric remnant tended to be lower following LAVNPPG, though the differences were not significant. These findings indicate that LAVNPPG may be an operative procedure that could replace LAPPG

    血清TARC/CCL17値は薬剤性過敏症症候群(DIHS) の早期診断および病勢の指標となりうる。

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    BACKGROUND:Drug-induced hypersensitivity syndrome (DIHS)/drug rash with eosinophilia and systemic symptoms (DRESS) is a serious acute drug reaction with fever, cutaneous eruption, lymphadenopathy, and several visceral dysfunctions. Eosinophilia is a common hematological abnormality in DIHS/DRESS suggesting that the Th2-type immune response is involved. Thymus and activation-regulated chemokine (TARC/CCL17) is a family of CC chemokines known to play an important role in Th2-mediated immune-inflammatory processes. OBJECTIVE:We investigated the pathogenic role of TARC in patients with DIHS. METHODS:Sera were obtained from 8 patients with DIHS, 7 patients with Stevens-Johnson syndrome/Toxic epidermal necrolysis (SJS/TEN), and 14 patients with drug-induced maculopapular exanthema (MPE). Serum TARC levels were measured by ELISA. TARC levels were then compared with clinical symptoms and various hematological parameters. In addition, a biopsy was taken from the lesional skin of patients with DIHS and stained with anti-TARC Ab and anti-CD11c Ab. RESULTS:Serum TARC levels in patients with DIHS were significantly higher than those in patients with SJS/TEN and MPE during the acute phase. Serum TARC levels in DIHS patients correlated with skin eruptions, serum sIL-2R levels, eosinophil counts, and serum IL-5 levels. Immunohistochemical staining revealed that TARC was mainly expressed on CD11c+ dermal dendritic cells in patients with DIHS. CONCLUSION:Serum TARC levels may be associated with the initial presentation of DIHS as well as disease activity during the course. Thus, they could be useful as an indicator for early diagnosis and assessment of disease activity in DIHS. CD11c+ dendritic cells may be the main source of TARC in patients with DIHS.博士(医学)・甲第597号・平成25年3月15日Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved
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