Prediction of emergence period of overwintering Chironomid larvae (Diptera: Chironomidae) at lower reaches of the Kiso River, Central Japan.

Species composition and period of emergence were investigated for overwintering Chironomidae at the lower reaches of the Kiso River by rearing larvae to obtain fundamental information for drafting a plan to prevent outbreaks of nuisance midges. Adults of 9 species emerged from the substrate samples in February 2006. The four most abundant species, Stictochironomus akizukii, Hydrobaenus kondoi, Tanytarsus takahashii and Einfeldia dissidens, occupied 88.0% of the total abundance. Using effective accumulative temperature for emergence and in situ water temperatures, the in situ emergence periods of the overwintering generation in 2006 were predicted as until early March for H. kondoi, from the end of March to early May for S. akizukii and T. takahashii, and late April to mid-June for E. dissidens.Article衛生動物.58(3):183-190(2007)journal articl

Study protocol for a multi-center, randomized controlled trial to develop Japanese denture adhesive guidelines for patients with complete dentures : the Denture Adhesive Guideline trial : study protocol for a randomized controlled trial

Background: Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users. The null hypothesis is that the application of denture adhesives, including the cream and powder types, or a control (isotonic sodium chloride solution) would not produce different outcomes nor would they differentially improve the set outcomes between baseline and day 4 post-application. Methods: This ten-center, randomized controlled trial with parallel groups is ongoing. Three hundred edentulous patients with complete dentures will be allocated to three groups (cream-type adhesive, powder-type adhesive, and control groups). The participants will wear their dentures with the denture adhesive for 4 days, including during eight meals (three breakfasts, two lunches, and three dinners). The baseline measurements and final measurements for the denture adhesives will be performed on the first day and after breakfast on the fourth day. The primary outcome is a general satisfaction rating for the denture. The secondary outcomes are denture satisfaction ratings for various denture functions, occlusal bite force, resistance to dislodgement, masticatory performance, perceived chewing ability, and oral health-related quality of life. Between-subjects comparisons among the three groups and within-subjects comparisons of the pre- and post-intervention measurements will be performed. Furthermore, a multiple regression analysis will be performed. The main analyses will be based on the intention-to-treat principle. A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level. Discussion: This randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries

Prediction of the emergence period for overwintering chironomid larvae (Diptera: Chironomidae) at the lower reaches of the Kiso River, Central Japan

木曽川下流域における冬期の主なユスリカ幼虫相とその羽化期を調べるため,2006年2月に底質を採集し,その中に含まれる幼虫を飼育し羽化させた.その結果,9種が同定され,優占種はStictochironomus akizukii,Hydrobaenus kondoi,Tanytarsus takahashii,Einfeldia dissidensであった.これら4種はH. kondoi→S. akizukii,T. takahashii→E. dissidensの順で羽化した.羽化までに必要とした有効積算温度と採集地点付近の水温から,野外における越冬世代の羽化期は,H. kondoiは3月上旬まで,S. akizukiiおよびT. takahashiiは3月末から5月上旬,E. dissidensは4月下旬から6月中旬と推定された. / Species composition and period of emergence were investigated for overwintering Chironomidae at the lower reaches of the Kiso River by rearing larvae to obtain fundamental information for drafting a plan to prevent outbreaks of nuisance midges. Adults of 9 species emerged from the substrate samples in February 2006. The four most abundant species, Stictochironomus akizukii, Hydrobaenus kondoi, Tanytarsus takahashii and Einfeldia dissidens, occupied 88.0% of the total abundance. Using effective accumulative temperature for emergence and in situ water temperatures, the in situ emergence periods of the overwintering generation in 2006 were predicted as until early March for H. kondoi, from the end of March to early May for S. akizukii and T. takahashii, and late April to mid-June for E. dissidens.ArticleMedical Entomology and Zoology. 58(3):183-190 (2007)journal articl

Effect of denture adhesives on masticatory performance : Multicenter randomized controlled trial

Purpose: The purpose of this study is to investigate the effects of denture adhesives on masticatory performance via a 10-center, parallel, randomized, controlled trial of complete denture wearers in Japan. Methods: The trial was conducted between September 2013 and October 2016. The inclusion criteria were complete edentulism, willingness to undergo new complete denture treatment, and willingness to return for recall treatment. The exclusion criteria were age 90 years or older, presence of severe systemic illness, inability to understand the questionnaires, wearing metal base complete dentures, denture adhesive user, wearing prosthetics for maxillofacial defects, wearing complete dentures with tissue conditioners, and severe xerostomia. Randomization of the powder-type denture adhesive (powder), cream-type denture adhesive (cream), and control (saline) groups was performed using a sealed envelope system. Masticatory performance was measured using color-changeable chewing gum. Intervention blinding was not feasible. Results: Sixty-seven control, 69 powder, and 64 cream participants are analyzed using the intention-to-treat principle. The participants in all groups show significantly improved masticatory performance at post-intervention (paired t-test with Bonferroni correction P < 0.0001). However, no significant difference in masticatory performance is detected among the three groups (one-way analysis of variance). A significant negative correlation between pre- and post-changes in masticatory performance and intraoral condition scores is observed (Pearson’s correlation coefficient, P < 0.0001). Conclusions: Although denture adhesives improved the masticatory performance of complete denture wearers, their clinical effects are comparable to those of saline solution. The use of denture adhesives is more effective in complete denture wearers with unsatisfactory intraoral conditions

Effects of denture adhesives on denture retention and occlusal forces in complete denture wearers : A multicenter, randomized controlled trial

Purpose: This study aimed to determine the effects of denture adhesives on denture retention and occlusal force in complete denture wearers in a multicenter, randomized, parallel-group controlled trial. Methods: Two hundred edentulous patients wearing complete dentures were allocated to three groups: powder-type denture adhesive, cream-type denture adhesive, and control (saline solution). Denture adhesives and saline solution were applied to the dentures for 4 days. The retentive force of the dentures and occlusal force were measured using a force transducer occlusal force meter at baseline and after 4 days of intervention. In addition to between-group comparisons, subgroup analyses of denture retention and occlusal force were performed based on the level of difficulty of the edentulism treatment. The levels were ranked as I (easy), II, III, and IV (difficult). Results: Cream-type denture adhesives significantly improved the retentive force of the dentures (P<0.01) and occlusal force (P<0.05), with no significant differences between baseline and post-intervention forces in the powder-type denture adhesive and control groups. In within-group comparisons, cream-type denture adhesives improved both the retentive and occlusal forces at Level II (P<0.05), and powder-type denture adhesives improved the occlusal force at Level II (P<0.01). Conclusions: Application of cream-type denture adhesives effectively improves the denture retention and occlusal force in complete denture wearers with a moderate degree of difficulty during edentulism treatment

Experimental Challenges of the First Mass Measurement Campaign at the Rare-RI Ring

With the recent commissioning of the Rare-RI Ring (R3), nuclear mass measurement of rare isotopes (RIs) produced at the RI Beam Factory (RIBF) at RIKEN has become possible. The R3 spectrometer is based on the Isochronous Mass Spectrometry technique that allows for reaching a mass measurement precision of 10−6 within less than 1 ms. With the newly established self-triggered individual injection method, R3 specialized in mass measurements of extremely short-lived nuclei with low production yields. In this paper, we report the first mass measurement campaign conducted at the R3 addressing nuclei in the vicinity of N=50 and N=82 neutron magic numbers, with a particular focus on the challenges of this new facility