Isolation and Characterization of Human Gut Bacteria Capable of Extracellular Electron Transport by Electrochemical Techniques

Microorganisms are known to exhibit extracellular electron transfer (EET) in a wide variety of habitats. However, as for the human microbiome which significantly impacts our health, the role and importance of EET has not been widely investigated. In this study, we enriched and isolated the EET-capable bacteria from human gut microbes using an electrochemical enrichment method and examined whether the isolates couple EET with anaerobic respiration or fermentation. Upon the use of energy-rich or minimum media (with acetate or lactate) for electrochemical enrichment with the human gut sample at an electrode potential of +0.4 V [vs. the standard hydrogen electrode (SHE)], both culture conditions showed significant current production. However, EET-capable pure strains were enriched specifically with minimum media, and subsequent incubation using the δ-MnO2-agar plate with lactate or acetate led to the isolation of two EET-capable microbial strains, Gut-S1 and Gut-S2, having 99% of 16S rRNA gene sequence identity with Enterococcus avium (E. avium) and Klebsiella pneumoniae (K. pneumoniae), respectively. While the enrichment involved anaerobic respiration with acetate and lactate, further electrochemistry with E. avium and K. pneumoniae revealed that the glucose fermentation was also coupled with EET. These results indicate that EET couples not only with anaerobic respiration as found in environmental bacteria, but also with fermentation in the human gut

先秦思想史上の墨家

早大学位記番号:新8023早稲田大

The use of bone bridges in transtibial amputations

OBJETIVO: Descrever a técnica da osteoperiosteoplastia em adultos e apresentar a variação para a utilização em crianças, procurando demonstrar sua aplicabilidade como opção nas amputações transtibiais eletivas. CASUÍSTICA E MÉTODOS: O artigo apresenta um estudo prospectivo de 15 amputações transtibiais realizadas entre 1992 e 1995 em que se utilizou a técnica da osteoperiosteoplastia. A idade dos pacientes variou de 8 a 48 anos, com média de 22,53 anos. A técnica consistiu na confecção de um cilindro de periósteo retirado da tíbia, contendo fragmentos de osso cortical presos ao mesmo, para promover uma sinostose tibiofibular na extremidade distal do coto de amputação. Observou-se que os fragmentos de osso cortical eram dispensáveis quando a técnica foi empregada em crianças, pela maior capacidade osteogênica do periósteo. Isto levou a uma variação da técnica original, que consiste numa periosteoplastia sem a utilização de fragmentos de osso cortical. RESULTADOS: O tempo médio despendido com a técnica, sem variação significativa entre adultos e crianças, foi de 171 minutos. A adaptação da prótese definitiva dos pacientes foi obtida entre 20 e 576 dias, com média de 180 dias. Revisões da técnica empregada foram necessárias em três amputações (20%). CONCLUSÃO: A técnica encontra aplicação nas amputações transtibiais em que o comprimento final do coto seja próximo da transição musculotendínea do gastrocnêmio e nas revisões de cotos de amputação de crianças onde a técnica mostrou ser efetiva na prevenção das lesões decorrentes do excessivo crescimento ósseo.We sought to describe the bone bridge technique in adults, and present a variation for use in children, as well as to present its applicability as an option in elective transtibial amputations. This paper presents a prospective study of 15 transtibial amputations performed between 1992 and 1995 in which the bone bridge technique was employed. The patients' ages ranged from 8 to 48 years, with an average of 22.5 years. This technique consisted of the preparation of a cylinder of periosteum extracted from the tibia and with cortical bone fragments attached to it to promote a tibiofibular synostosis on the distal extremity of the amputation stump. We noted that the cortical bone fragments were dispensable when the technique was employed in children, due to the increased osteogenic capacity of the periosteum. This led to a variation of the original technique, a bone bridge without the use of the cortical bone fragments. RESULTS: The average time spent with this procedure, without any significant variation between adults and children, was 171 minutes. The adaptation to the definitive prosthesis was accomplished between 20 and 576 days, with an average of 180 days. Revision of the procedure was necessary in 3 amputations. CONCLUSIONS: This technique may be employed in transtibial amputations in which the final length of the stump lies next to the musculotendinous transition of the gastrocnemius muscle, as well as in the revision of amputation stumps in children, where the procedure has been shown to be effective in the prevention of lesions due to excessive bone growth

The K computer Operations: Experiences and Statistics

AbstractThe K computer, released on September 29, 2012, is a large-scale parallel supercomputer system consisting of 82,944 compute nodes. We have been able to resolve a significant number of operation issues since its release. Some system software components have been fixed and improved to obtain higher stability and utilization. We achieved 94% service availability because of a low hardware failure rate and approximately 80% node utilization by careful adjustment of operation parameters. We found that the K computer is an extremely stable and high utilization system