117 research outputs found

    Some Factors Affecting the Diffusion of Actinide Elements in UO_2

    Get PDF
    In connection with the influences of the densification of sample, the evaporation of diffusant during diffusion annealing and the grain size of starting material on the diffusion of actinide elements in UO_2, three types of experiment were performed by the sectioning method using ^U and ^Pa as tracers. In all cases, the logarithm of the concentration in a deeper region varied linearly with penetration depth, as is characteristic of grain-boundary diffusion. Near the surface, the lattice diffusion or the evaporation made a considerable contribution to the concentration, thus showing a nonlinear concentration profile. The extent of this deviation increased with the increases of initial density of the pellet and of grain size of starting material. The concentration near the surface decreased with the approach to it in the presence of evaporation

    Effect of Aquaculture on Material Cycles in Otsuchi Bay, Japan

    Get PDF
    A numerical physical-biological coupled model is developed for the study of coastal material cycles including aquaculture. The model calculates spatial distributions of PON (Particulate Organic Nitrogen), POP (Particulate Organic Phosphorus), DON (Dissolved Organic Nitrogen), DOP (Dissolved Organic Phosphorus), Chl-a, zooplankton, NO_3-N, NH_4-N and PO_4-P using simulated current. It also takes into consideration the effects of shellfish feeding and excretion, seaweed photosynthesis, and the loading of DIN from rivers. The model is applied to Otsuchi Bay, in Iwate Pref., in Japan. The model elucidated the cycling of nitrogen among ecological compartments. If the amount of cultured shellfish is extremely increased, the feeding by shellfish is large enough to change the lower trophic level ecosystem, reducing concentration of phytoplankton and POM (Particulate Organic Matter) around the cultured region, while phytoplankton increases far from the culture due to the increase of recycled nutrient by the excretion of shellfish

    岩手医科大学歯学部口腔病理学教室における病理組織検査の報告 : 2002年度の集計

    Get PDF
    Pathological examinations undertaken in our department in 2002 were statistically reviewed. There were 602 examinations for 460 cases (Male 227, Female 233) Cases were most frequent in patients in their sixth decade (99 cases) According to histological classifications of the lesions (mean age±SD), odontogenic tumors consisted of 2 ameloblastomas (65 5±12 5), 4 odontomas (24 3±12 2) and 1 odontogenic ghost cell carcinoma (22) The non-odontogenic benign lesions were 29 fibrous hyperplasias (57 0±17 4), 23 hyperkeratoses (leukoplaskia) (57 3±16 2), 10 papillomas (62 1±143), 9 irritation fibromas (63 0±13 4), 8 hemangiomas (57 5±9 2), 6 papillary hyperplasias (65 7±13 7), 5 osteomas (exostosis, enostosis) (55 2±8 0), 4 epithelial dysplasias (60 8±13 3) and 4 penapical cemental dysplasias (45 3±5 7), 3 pleomorphic adenomas (44 3±5 7) Non-odontogenic malignant tumors consisted of 56 squamous cell carcinomas (658±126), 3 malignant lymphomas (68 7±20 1) The odontogenic cysts consisted of 37 radicular cysts (42 8± 15 7), 27 dentigerous cysts (42 9±186) and 16 primordial cysts (43 4±18 7) The non-odontogenic cysts consisted of 30 mucous retention cysts (mucoceles) (22 5±13 7), 18 postoperative maxillary cysts (56 7±9 1), 5 incisive canal cysts (49 8±3 7) and 2 simple bone cysts (13 0±1 4). Also found were 35 chronic inflammatory (granulation) tissues (54 7±14 1), 20 chronic localized hyperplastic gingivitises (epuhses) (50 4±16 8), 13 Sjogren syndromes (54 7±13 0), 10 sialohthiases (56 8±13 3), 7 lichen planuses (64 3±83), 7 dental granulomas (32 7±6 8) and 5 chronic (inflammatory) ulcers (61 0±7 5)

    Risk Factors for Delirium After Spine Surgery in Extremely Elderly Patients Aged 80 Years or Older and Review of the Literature: Japan Association of Spine Surgeons with Ambition Multicenter Study

    Get PDF
    Study Design:Retrospective database analysis.Objective:Spine surgeries in elderly patients have increased in recent years due to aging of society and recent advances in surgical techniques, and postoperative complications have become more of a concern. Postoperative delirium is a common complication in elderly patients that impairs recovery and increases morbidity and mortality. The objective of the study was to analyze postoperative delirium associated with spine surgery in patients aged 80 years or older with cervical, thoracic, and lumbar lesions.Methods:A retrospective multicenter study was performed in 262 patients 80 years of age or older who underwent spine surgeries at 35 facilities. Postoperative complications, incidence of postoperative delirium, and hazard ratios of patient-specific and surgical risk factors were examined.Results:Postoperative complications occurred in 59 of the 262 spine surgeries (23%). Postoperative delirium was the most frequent complication, occurring in 15 of 262 patients (5.7%), and was significantly associated with hypertension, cerebrovascular disease, cervical lesion surgery, and greater estimated blood loss (P < .05). In multivariate logistic regression using perioperative factors, cervical lesion surgery (odds ratio = 4.27, P < .05) and estimated blood loss ≥300 mL (odds ratio = 4.52, P < .05) were significantly associated with postoperative delirium.Conclusions:Cervical lesion surgery and greater blood loss were perioperative risk factors for delirium in extremely elderly patients after spine surgery. Hypertension and cerebrovascular disease were significant risk factors for postoperative delirium, and careful management is required for patients with such risk factors

    Complications Associated With Spine Surgery in Patients Aged 80 Years or Older: Japan Association of Spine Surgeons with Ambition (JASA) Multicenter Study

    Get PDF
    Study Design:Retrospective study of registry data.Objectives:Aging of society and recent advances in surgical techniques and general anesthesia have increased the demand for spinal surgery in elderly patients. Many complications have been described in elderly patients, but a multicenter study of perioperative complications in spinal surgery in patients aged 80 years or older has not been reported. Therefore, the goal of the study was to analyze complications associated with spine surgery in patients aged 80 years or older with cervical, thoracic, or lumbar lesions.Methods:A multicenter study was performed in patients aged 80 years or older who underwent 262 spinal surgeries at 35 facilities. The frequency and severity of complications were examined for perioperative complications, including intraoperative and postoperative complications, and for major postoperative complications that were potentially life threatening, required reoperation in the perioperative period, or left a permanent injury.Results:Perioperative complications occurred in 75 of the 262 surgeries (29%) and 33 were major complications (13%). In multivariate logistic regression, age over 85 years (hazard ratio [HR] = 1.007, P = 0.025) and estimated blood loss ≥500 g (HR = 3.076, P = .004) were significantly associated with perioperative complications, and an operative time ≥180 min (HR = 2.78, P = .007) was significantly associated with major complications.Conclusions:Elderly patients aged 80 years or older with comorbidities are at higher risk for complications. Increased surgical invasion, and particularly a long operative time, can cause serious complications that may be life threatening. Therefore, careful decisions are required with regard to the surgical indication and procedure in elderly patients

    On the origin and evolution of the asteroid Ryugu: A comprehensive geochemical perspective

    Get PDF
    Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ18O, Δ17O, and ε54Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10’s of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

    Get PDF
    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

    A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu

    Get PDF
    Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe3+ to Fe2+ and dehydration developed. Space weathering probably contributed to dehydration by dehydroxylation of Ryugu surface phyllosilicates that had already lost interlayer water molecules and to weakening of the 2.7 µm hydroxyl (–OH) band in reflectance spectra. For C-type asteroids in general, this indicates that a weak 2.7 µm band can signify space-weathering-induced surface dehydration, rather than bulk volatile loss
    corecore