http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hironori Horiguchi,Shinichiro Hata,Yutaro Wada,Julien Richert,Yoshinobu Tsujimoto 한국유체기계학회 2019 International journal of fluid machinery and syste Vol.12 No.4
Rotordynamic fluid forces and a mechanism of their occurrence were examined in experiments and computations for a closed type centrifugal impeller in whirling motion. The rotordynamic fluid force on a front shroud was a main component of the rotordynamic fluid force. In a clearance between the front shroud and a casing, velocity disturbances were caused by an eccentricity of the impeller and a squeeze effect due to the whirling motion of the impeller. Appling the Bernoulli equation to disturbed swirling flow in the clearance in a relative coordinate fixed on the whirling motion, the pressure disturbance which generated the rotordynamic fluid force could be reasonably explained.
Richert, Julien,Nishiyama, Yumeto,Hata, Shinichiro,Horiguchi, Hironori,Tsujimoto, Yoshinobu Korean Society for Fluid machinery 2011 International journal of fluid machinery and syste Vol.4 No.2
The rotordynamic fluid forces acting on a closed type impeller in whirling motion were measured and the influence of the clearance geometry on the stability of the impeller was examined. At small positive whirling speed, the rotordynamic forces acted as destabilizing forces for all casings. A small clearance between the shroud of the impeller and the casing caused large fluid force, but did not change the destabilizing region. Radial grooves in the clearance were effective for reducing the fluid forces and destabilizing region due to the reduction of the circumferential velocity without the deterioration of the pump performance. A rotating phenomenon like a rotating stall of the impeller occurred at low flow rate and the resonance between it and the whirling motion led to a sudden increase in force at the whirling speed ratio of 0.7.
Firmicutes in Gut Microbiota Correlate with Blood Testosterone Levels in Elderly Men
Matsushita Makoto,Fujita Kazutoshi,Motooka Daisuke,Hatano Koji,Hata Junya,Nishimoto Mitsuhisa,Banno Eri,Takezawa Kentaro,Fukuhara Shinichiro,Kiuchi Hiroshi,Pan Yue,Takao Toshifumi,Tsujimura Akira,Yach 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.3
Purpose: In males, testosterone levels have been implicated in various diseases. Recently, the influence of gut microbialderived compounds on host metabolism has become evident, and it has been suggested that some gut bacteria may be involved in testosterone metabolism. In the present study, we examined the relationship between testosterone levels and gut microbiota in elderly Japanese men. Materials and Methods: We collected samples from Japanese male subjects suspected of having prostate cancer and underwent prostate biopsies and excluded patients with positive biopsies to avoid the effect of prostate cancer on the gut microbiota. In total, 54 Japanese males with negative biopsy results were included in our study. The gut microbiota was analyzed by 16S rRNA gene sequencing of bacterial DNA extracted from rectal swabs. Gut microbiota compositions were compared between the two groups according to the level of serum testosterone (above or below 3.5 ng /mL). Results: The median age of the cohort was 71 years, and the quartile range was 67 to 73 years. We observed no significant difference in alpha or beta diversity, but some bacteria belonging to the phylum Firmicutes (Clostridiales, Turicibacter, and Gemella) were increased in the high testosterone group. Serum testosterone levels positively correlated with the relative amount of Firmicutes (rS=0.3323, p=0.0141), and the amount of Firmicutes affected serum testosterone levels independent of host factors (age, body mass index, triglyceride, and total cholesterol; β=0.770, p=0.0396). Conclusions: Some intestinal bacteria belonging to the phylum Firmicutes were associated with testosterone levels in elderly males. Therefore, the gut microbiota could affect testosterone metabolism in elderly males.