Mineo Kobayashi

Ratchetting characteristics of 316FR steel at high temperature, part I: Strain-controlled ratchetting experiments and simulations

The paper is concerned with characteristics in ratchetting of 316FR steel at high temperature. In Part I, first, by discussing isothermal and nonisothermal “strain-controlled” ratchetting experiments, it is shown that 316FR steel exhibits the almost perfect closure of stress and strain hysteresis loops as well as the isotropic hardening depending on maximum plastic strain rather than accumulated plastic strain. Second, it is demonstrated that the experiments are simulated well using the nonlinear kinematic hardening model proposed in 1993 by Ohno and Wang (Int. J. Plasticity 9, 375–403) if the model is extended by taking account of the isotropic hardening depending on maximum plastic strain. On the basis of these findings, thermal ratchetting of 316FR steel cylinders subjected to the axial variation of temperature is analyzed in Part II.

Foods and nutrients in relation to bladder cancer risk : A case-control study in Aichi Prefecture, Central Japan

To elucidate the role of diet in the etiology of bladder cancer, we conducted a case-control study from 1996 to 1999 in Aichi Prefecture, Central Japan. Cases were patients newly diagnosed with bladder cancer, and one hospital control was selected for each case, matching gender, age, and hospital. A well-validated food frequency questionnaire was adopted to estimate intakes of nutrients and food groups. Odds ratios (ORs) adjusted for smoking and occupational history were computed using conditional logistic models. The analyses based on 297 cases and 295 controls revealed the following. 1) The more the intake of milk and dairy products, the lower the OR; the ORs across quartiles in all subjects were 1.02, 0.73, and 0.52. Fruit intake was negatively associated with the risk, particularly in men (ORs across quartiles = 0.76, 0.77, and 0.52). Green-yellow vegetables were associated with a decreased risk in the highest quartile of consumption in men (OR = 0.57). 2) Dietary intakes of retinol and saturated fatty acids were related to a reduced risk in all subjects (ORs across quartiles = 0.75, 0.54, and 0.66 and 0.55, 0.54, and 0.60, respectively). Monounsaturated fatty acids had an inverse association with bladder cancer risk in men.

A Randomized Study of Short-v ersus Long-Term Intravesical Epirubicin Instillation for Superficial Bladder Cancer

Objective: A prospective randomized study was undertaken to determine whether prophylactic maintenance instillation of epirubicin following induction treatment is beneficial in patients with superficial bladder cancer. Patients and Methods: One hundred and forty-eight patients with resectable superficial bladder cancer (Ta-1, single, multiple, primary or recurrent with, however, no recurrence during the last year) were enrolled in this study. In both arms, epirubicin (40 mg/ml in normal saline) was administered six times within 4 weeks after a transurethral resection of the bladder tumor(s). In arm A, the patients received 11 additional monthly instillations of epirubicin. Results: Of the 148 patients, 138 (93.2%) were eligible and followed for an average of 29.6 months. 93 (67.4%) had a solitary tumor. No significant difference in the recurrence-free curve was observed between the two arms (p = 0.62). The recurrence rate per year was 0.16 in arm A and 0.17 in arm B. Toxicity included vesical irritability in 10 (7.2%) and hematuria in 1 patient. No significant difference in the frequency or degree of toxicity was observed between the two arms. Conclusion: These data suggest that maintenance instillation of epirubicin does not reduce superficial bladder cancer recurrence.

Ratchetting characteristics of 316FR steel at high temperature, part II: Analysis of thermal ratchetting induced by spatial variation of temperature

Abstract On the basis of the material characteristics discussed in Part I, thermal ratchetting of 316FR steel cylinders subjected to the axial variation of temperature is analyzed by implementing in a finite element method three kinds of models, i.e. the elastic-perfectly plastic model, the Armstrong-Frederick model, and the first version of the Ohno-Wang model. The latter two models are specified in two forms, i.e. the combined hardening form verified in Part I and the kinematic hardening form with isotropic hardening neglected. It is shown that the analysis depends greatly on the models examined while it is influenced relatively little by the neglect of isotropic hardening, and that the Ohno-Wang model, which can express the closure of stress and strain hysteresis loops, gives good simulations to experiments in the two cases of long and short travel distances of temperature distributions.

Children With Unstable Bladder: Clinical and Urodynamic Observation

A clinical analysis was done on 303 patients diagnosed by urodynamic study as having an unstable bladder, which was characterized by uninhibited contraction of the detrusor without any overt neurogenic lesions. An age distribution histogram demonstrated 2 peaks: children less than 10 years old and patients between 60 and 80 years old. Sex was not significant in the children but men predominated in the adults. There were 68 children less than 15 years old with the chief complaints of enuresis (54 per cent), urge incontinence (41 per cent) and fever (25 per cent). The objective findings were vesicoureteral reflux in 29 children, urinary tract infection in 20 and distal urethral stenosis in 8. An unstable bladder type I, the occurrence of uninhibited contractions during the filling phase of cystometry, was found in 53 children (78 per cent). We noted several postures that the children characteristically used to resist unheralded urgency and to prevent urine from leaking. The main therapeutic regimen consisted of anticholinergics with or without antimicrobials. Several children underwent surgical intervention. Once the antireflux operation was performed followup with anticholinergics was of primary importance. The unstable bladders of 63 of the 68 children (93 per cent) have been controlled satisfactorily. The etiology of bladder instability is discussed for both groups of patients.

Thermal ratchetting of a cylinder subjected to a moving temperature front: Effects of kinematic hardening rules on the analysis

When a cylinder is subjected to a temperature front moving cyclically in the axial direction, circumferential plastic strain may accumulate with the increase of the number of cycles. This is a thermal ratchetting problem induced by a liquid surface moving in a cylinder, which is important especially in designing fast breeder reactors. In the present paper, effects of kinematic hardening rules on the thermal ratchetting analysis are discussed by implementing in finite element analysis the following four kinds of kinematic hardening rules; the perfectly plastic model (PP), the linear kinematic hardening rule (LKH), the classical nonlinear kinematic hardening rule of Armstrong and Frederick (AF), and the rule proposed recently by Ohno and Wang (OW). It is shown that disregard of transient nonlinear hardening after yielding leads to overestimating the thermal ratchetting, that a rule predicting larger mechanical ratchetting makes the thermal ratchetting more serious, and that the Ohno and Wang rule may render the analysis most realistic among them.

Diagnosis and treatment of lower urinary tract symptoms in the elderly by general practitioners

Aim:  We investigated the diagnosis and treatment of lower urinary tract symptoms (LUTS) by general practitioners (GPs) according to the Practical Manual for LUTS Evaluation and Treatment in the Elderly For GPs.

Effect of prostaglandin on urethral resistance and micturition.

SummaryThe effect of four exogenous prostaglandins, PGA1, PG802, PGE2 and PGF2α, upon the lower urinary tract was investigated in female mongrel dogs without neurogenic lesions in vivo. The urethral resistance was studied by means of a urethral pressure profile, and the bladder function by evaluating whether or not the micturition was triggered. The reduction of urethral resistance in terms of the maximum urethral closure pressure was most significant with PGE2 given intraarterially. Micturition was most frequently provoked by the intravenous administration of PG802, a derivative of PGE1. PGE series seemed to be the most potent for the evacuation of urine in female dogs.

Radiation-induced urothelial carcinoma

Four cases of urothelial carcinoma following pelvic irradiation for carcinomas of the cervix uteri (n = 3) and the ovary (n = 1) are reported. The urothelial carcinomas developed 26.8 (mean) years after radiotherapy and invaded the bladder in 3 patients and the ureter in 1. Despite radical surgery, the patients died of metastatic cancer.

LONG-TERM EFFICACY OF A SELF-RETAINING INTRAURETHRAL CATHETER FOR THE TREATMENT OF PROSTATIC OBSTRUCTION

Background: