Low Cycle Fatigue Damage of Mod.9Cr-1Mo Steel under Non-Proportional Multiaxial Loading

AbstractThis study discusses multiaxial low cycle fatigue damage of Mod.9Cr-1Mo steel under proportional and non-proportional loadings at room and high (823K) temperatures. Strain-controlled multiaxial low cycle fatigue tests were carried out using a hollow cylinder specimen including interruption tests. Strain paths employed were a push-pull straining, a reversed torsion straining and a circle straining. Behaviors of cyclic deformations and failure lives and an evaluation of the failure life are discussed. Surface cracks and microstructures in fatigued specimens are also observed by a digital microscope and a transmission electron microscope (TEM) in order to investigate mechanisms of cyclic deformation, failure and reduction in failure life due to non-proportional loading

Predictors of Hypotension after Adrenalectomy for Pheochromocytoma

The management of blood pressure is a significant concern for surgeons and anesthesiologists performing adrenalectomy for pheochromocytoma. We evaluated clinical factors in pheochromocytoma patients to identify the predictors of postoperative hypotension. The medical records of patients who underwent adrenalectomy for pheochromocytoma between 2001 and 2017 were retrospectively reviewed and clinical and biochemical data were evaluated. Of 29 patients, 13 patients needed catecholamine support in the perisurgical period while 16 patients did not. There were significant differences in median age, tumor size, and blood pressure drop (maxmin) between the 2 groups (68 vs 53 years old, p=0.045; 50 vs 32 mm diameter, p=0.022; 110 vs 71 mmHg, p=0.015 respectively). In univariate logistic analysis, age > 65.5 years, tumor size > 34.5 mm, urine metanephrine > 0.205 mg/day and urine normetanephrine > 0.665 mg/day were significant predictors of prolonged hypotension requiring postoperative catecholamine support. Tumor size and urine metanephrine and urine normetanephrine levels were correlated with postoperative hypotension. These predictors may help in the safe perioperative management of pheochromocytoma patients treated with adrenalectomy

多職種連携と患者特性に配慮したケアを行った高度肥満症の一例

A ４８-year-old man who weighed ２１６ kg was significantly overweight with a body mass index （BMI）of ７５．６kg/m２, and was unable to walk due to disuse syndrome. Because of the psychological and social problems in the background, a psychological examination was performed and the staff took time to build a trusting relationship with the patient, taking into account his characteristics. With diet and rehabilitation, he was able to lose weight to １２４kg and BMI ４３．９kg/m２ over ６００ days, and was able to walk with assistive devices and defecate by himself. The patient was discharged from our hospital after a series of multidisciplinary meetings with medical, nursing, welfare, and governmental agencies to create an environment for home recuperation. The reasons for the improvement to enable him to be discharged from the hospital were due to the multi-disciplinary meetings among the staff inside and outside the hospital, information sharing and advanced coordination, and smooth communication with the patient by taking into account his characteristics from a psychological standpoint

Role of Serotonergic System in the Antidepressant Actions of mGlu2/3 Receptor Antagonists: Similarity to Ketamine

Numerous studies have demonstrated the antidepressant effects of group II metabotropic glutamate (mGlu2/3) receptor antagonists in various rodent models. Importantly, it has been shown that the antidepressant effects of mGlu2/3 receptor antagonists in rodent models are similar to those of ketamine, which exerts rapid and long-lasting antidepressant effects in patients with major depressive disorders, including patients with treatment-resistant depression. In addition, the synaptic mechanisms underlying the effects of mGlu2/3 receptor antagonists are reported to be similar to those underlying the effects of ketamine. The roles of the serotonergic system in the antidepressant effects of mGlu2/3 receptor antagonists have recently been demonstrated. Moreover, it was investigated how mGlu2/3 receptor antagonists interact with the serotonergic system to exert antidepressant effects. Notably, the same neural mechanisms as those underlying the effects of ketamine may be involved in the antidepressant actions of the mGlu2/3 receptor antagonists. In this review, we shall summarize the antidepressant potential of mGlu2/3 receptor antagonists and their mechanisms of action in comparison with those of ketamine. In particular, we shall focus on the roles of the serotonergic system in the antidepressant actions of mGlu2/3 receptor antagonists

Potential of Glutamate-Based Drug Discovery for Next Generation Antidepressants

Recently, ketamine has been demonstrated to exert rapid-acting antidepressant effects in patients with depression, including those with treatment-resistant depression, and this discovery has been regarded as the most significant advance in drug development for the treatment of depression in over 50 years. To overcome unwanted side effects of ketamine, numerous approaches targeting glutamatergic systems have been vigorously investigated. For example, among agents targeting the NMDA receptor, the efficacies of selective GluN2B receptor antagonists and a low-trapping antagonist, as well as glycine site modulators such as GLYX-13 and sarcosine have been demonstrated clinically. Moreover, agents acting on metabotropic glutamate receptors, such as mGlu2/3 and mGlu5 receptors, have been proposed as useful approaches to mimicking the antidepressant effects of ketamine. Neural and synaptic mechanisms mediated through the antidepressant effects of ketamine have been being delineated, most of which indicate that ketamine improves abnormalities in synaptic transmission and connectivity observed in depressive states via the AMPA receptor and brain-derived neurotrophic factor-dependent mechanisms. Interestingly, some of the above agents may share some neural and synaptic mechanisms with ketamine. These studies should provide important insights for the development of superior pharmacotherapies for depression with more potent and faster onsets of actions

Targeting of Metabotropic Glutamate Receptors for the Development of Novel Antidepressants

Since discovering that ketamine has robust antidepressant effects, the glutamatergic system has been proposed as an attractive target for the development of novel antidepressants. Among the glutamatergic system, metabotropic glutamate (mGlu) receptors are of interest because mGlu receptors play modulatory roles in glutamatergic transmission, consequently, agents acting on mGlu receptors might not exert the adverse effects associated with ketamine. mGlu receptors have eight subtypes that are classified into three groups, and the roles of each mGlu receptor subtype in depression are being investigated. To date, the potential use of mGlu5 receptor antagonists and mGlu2/3 receptor antagonists as antidepressants has been actively investigated, and the mechanisms underlying these antidepressant effects are being delineated. Although the outcomes of clinical trials using an mGlu5 receptor negative allosteric modulator and an mGlu2/3 receptor negative allosteric modulator have not been encouraging, these trials have been inconclusive, and additional trials using other compounds with more appropriate profiles are needed. In contrast, the roles of group III mGlu receptors have not yet been fully elucidated because of a lack of suitable pharmacological tools. Nonetheless, investigations of the use of mGlu4 and mGlu7 receptors as drug targets for the development of antidepressants have been ongoing, and some interesting evidence has been obtained

マグネシア-アルミナ系酸化物の耐照射損傷性に関する研究

第1章 序論 第2章 改良型および従来型温度制御法による中性子照射セラミックス中の欠陥集合体形成過程と温度履歴効果 第3章 中性子照射したa-Al_2O_3およびMgO･Al_2O_3中における欠陥集合体の形成･成長過程 第4章 MgO･Al_2O_3中の欠陥集合体形成過程に及ぼす不純物および電子励起の効果 第5章 結論Made available in DSpace on 2012-07-10T06:35:35Z (GMT). No. of bitstreams: 2 fukumoto1.pdf: 8078229 bytes, checksum: 018d8969330f8619849c39535d1de7fe (MD5) fukumoto2.pdf: 10350614 bytes, checksum: 4bfe960f3347761fff1c00fe34d99ea7 (MD5) Previous issue date: 1994-03-25主1-参1工学_エネルギー量子_応用原子