Photactivated adenylyl cyclase, a novel blue-light receptor flavoprotein, mediates photoavoidance in the unicellular flagellate Euglena gracilis

Iseki, Mineo,Matsunaga, Shigeru,Murakami, Akio,Ohno, Kaoru,Shiga, Kiyoshi,Yoshida, Kazuichi,Sugai, Michizo,Takahashi, Tetsuo,Hori, Terumitsu,Watanabe, Masakatsu Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

Euglena gracilis abruptly changes its swimming direction after a sudden increase or decrease in incident light intensity, that is, step-up or step-down photophobic responses, resulting in photoavoidance or photoaccumulation, respectively. To identify the photoreceptor molecules for these UV-A/blue-light type photobehaviors, we purified a flavoprotein from isolated putative photosencory organelles (PFBs) of Euglena. The purified flavoprotein, which noncovalently bound flavin adenine dinucleotide (FAD), seemed to be a heterotetramer of alpha- and beta-subunits. Predicted amino acid sequences of each of the subunits were similar to each other and contained two FAD-binding domains each followed by an adenylyl cyclase catalytic domain. The purified flavoprotein actually showed adenylyl cyclase activity, being drastically elevated by blue-light irradiation. Suppression of gene expression of the flavoprotein (Photoactivated Adenylyl Cyclase, PAC) by RNA interference (RNAi) caused loss of the step-up photophobic response, demonstrating that PAC actually mediates photoavoidance of Euglena.

MATHEMATICS ON TWO NORMED SPACES

ISEKI, KIYOSHI Korean Mathematical Society 1976 대한수학회보 Vol.13 No.2

Hydrogel-based Nanochannel Membrane Utilizing AAO for Concentration Gradient Power Generation

Tissasera Iseki,유성일 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

Nanofluidic channels has unique fluidic transport properties in the nanometer scale that can be utilized as a promising platform to improve the performance of conventional ion exchange membrane. In this regard, we fabricated poly(acrylic acid) (PAAc) hydrogel incorporated with anodic aluminum oxide (AAO) membrane as nano fluidics model system to utilize electric energy from the membrane. A commercialized AAO membrane with 20 nm pore diameter was functionalized by 3-(mercaptopropyl) trimethoxy silane (MPTS) silane coupling agent to promote interfacial adhesion and improve its properties. Then, PAAc hydrogel was synthesized onto the functionalized AAO membrane to build homogeneous nanochannel membrane structure. This model nanochannel system membrane utilizing hydrogel and AAO improve the energy harvesting performance in concentration cell application.

Local enhancement of concentration gradient through the hydrogel-functionalized anodic aluminum oxide membranes for osmotic power generation

Tissasera Iseki,Merreta Noorenza Biutty,박철호,유성일 한국고분자학회 2023 Macromolecular Research Vol.31 No.3

The salinity gradient between seawater and river water is a type of Gibbs energy that can be converted into electrical energy by an ion-exchange membrane. Although the salinity gradient between two aqueous solutions can be adjusted in a laboratory to improve the energy-harvesting performance, the salinity gradient in natural resources is rather constant, restricting the prospects of membrane-mediated power generation. To address this issue, we demonstrate the local enhancement of the salinity gradient through hydrogel-functionalized anodic aluminum oxide (AAO) membranes. In the composite structure, the surface-modified AAO membrane attracts the mobile counter ions from the hydrogels to increase the local concentration of mobile ions inside the nanopores of AAO membrane. Owing to the local concentration enhancement, the hydrogel-functionalized AAO membranes could extract electrical energy with improved efficiency, which could power small electronic devices.

Nutrition and quality of life in chronic kidney disease patients: a practical approach for salt restriction

( Kunitoshi Iseki ) 대한신장학회 2022 Kidney Research and Clinical Practice Vol.41 No.6

The clinical practice guidelines (CPGs) for nutrition in chronic kidney disease (CKD) were updated after 20 years from the previous guidelines by the Kidney Disease Outcomes Quality Initiative (KDOQI). During this period, the severity of CKD was defined by eGFR and albuminuria by the organization Kidney Disease: Improving Global Outcomes (KDIGO). Main risk factors for CKD such as hypertension, hyperlipidemia, obesity, metabolic syndrome, and diabetes mellitus are closely related to lifestyle. Nutritional management is important to prevent and retard the progression of CKD. Members of the International Society of Renal Nutrition and Metabolism (ISRNM) reviewed the KDOQI CPG draft. ISRNM is an international scientific society comprising members of multiple subspecialties. ISRNM proposed the medical term protein-energy wasting (PEW), which is a keyword in renal nutrition. The prevalence of PEW among dialysis patients is high. The success of dietary therapy depends on adherence to the diet. It has to be palatable, otherwise eating habits will not change. To prevent the development and progression of CKD and PEW, regular consultation with an expert dietitian is required, especially regarding salt and protein restriction. Our cluster-randomized trial showed that intervention by a dietician was effective at retarding the progression of stage 3 CKD. In this review, I focus on salt (sodium) restriction and introduce tips for salt restriction and Japanese kidney-friendly recipes. Due to the lack of randomized controlled trials, nutritional management of CKD inevitably relies on expert opinion. In this regard, well-designed observational studies are needed. Too strict salt restriction may decrease quality of life and result in PEW.

Preparation of Ion-Selective AAO Membranes for Concentration-Gradient Power Generation

Tissasera Iseki,유성일 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2

A concentration gradient is a promising source of energy that can be converted into electrical energy by an ion exchange membrane. The movement of charged ions through membrane channels generates an ionic current that flows down an electrochemical gradient. Since nanopores can substantially increase the ion transportation compared with non-structured membranes, anodic aluminum oxide (AAO) membrane has been previously employed as nanofluidic system. In this study, to enrich the charge density on the AAO, the surface of AAO membrane was functionalized with 3-(aminopropyl) triethoxysilane (APTES). Then, the APTES-modified AAO was filled with positively-charged hydrogel of poly(3-acrylamidopropyl) trimethylammonium chloride. By applying the prepared composite membranes to salted solutions, we investigated their energy harvesting performance.

Fabrication of Porous PDMS/Au Composites for Solar-based Thermoelectric Power Generation

이건석,Iseki Tissasera,김유빈,유성일 한국고분자학회 2020 한국고분자학회 학술대회 연구논문 초록집 Vol.45 No.2

Sessile Drop의 형상으로부터 수치계산에 의한 표면장력 측정

정영수,Takayoshi Iseki 한국세라믹학회 1996 한국세라믹학회지 Vol.33 No.12

Sessile drop method에 의해서 표면장력을 간단히 구하는 수치계산법을 계산프로그램과 같이 소개하였다. 이방법에 의하면 표명장력의 계산에 필요한 data는 sessile drop 표면상의 임의의 한 점에서의 좌표(X.Z)와 그 점에서의 접선의 각도${\theta}$, 그리고 밀도${\rho}$가 전부이다. 따라서 sessile drop의 형상으로부터 가장 정밀한 측정이 가능한 임의의점을 선정하여 그 점의 좌표, 접선의 각도를 측정하면 되므로 종래의 방법보다 정확한 값을 얻을 수 있다. 또한 4개의 data를 입력하는 것만으로 계산결과가 단시간에 나오므로 계산과정이 대단히 간단하다. Sessile drop의 크기, 접선의 각도, 밀도 등에 제한이 없으므로 응용범위가 넓다. 하나의 sessile drop에서 수개의 점으로부터 구한 각 표면장력의 값을 상호 비교하면 측정치 및 계산결과에 대하여 신뢰성을 높일 수 있다. 또한 이 수치계산법을 응용하면 pendant drop method에의 응용, 그외 sessile drop의 체적, 표면적, 접촉각의 계산 등에도 이용할 수 있다. A new numerical method for determining the surface tension of a liquid drop by experimental measurement of the contour of the sessile drop is explained. in the present method a very simple and short computer program enables the calculation of surface tension in a few seconds even by a low speed personal computer. It need not the use of any other numerical tables or complex techniques. X and Z-corrdinates at one point on the contour of a sessile drop and the tangential angle at that point are all the data needed when the density of the drop is known. The results were compared with the values derived by a conventional method. This method can be used for the confirmation of measuring accuracy. Also the same concepts can be applied for the pendant drop method by changing only the sign of Z-coordinate from "+" to "-"ot; to "-"ot;-"quot.

Postoperative change in patellofemoral alignment following closing-wedge distal femoral osteotomy performed for valgus osteoarthritic knees

Akaoka Yusuke,Nakayama Hiroshi,Iseki Tomoya,Kanto Ryo,Tensho Keiji,Yoshiya Shinichi 대한슬관절학회 2020 대한슬관절학회지 Vol.32 No.-

Purpose: To evaluate the postoperative change in patellar position after medial closed distal femoral osteotomy (DFO) performed for valgus osteoarthritic knees. Methods: The study included 21 consecutive knees in 20 patients undergoing DFO. A minimum of 2-year followup data was obtained for all subjects with a mean follow-up period of 42 months (range 31–59 months). The patellar position was evaluated on plain radiographs preoperatively, 1-year postoperatively, and 2-year postoperatively. For patellar height, the modified Insall–Salvati Index (mISI), modified Caton–Deschamps Index (mCDI) and modified Blackburne–Peel Index (mBPI) were measured on the standing lateral radiographs. Patellofemoral alignment on the axial plane was assessed on skyline views with 30° flexion based on the measurements for lateral patellar tilt (LPT) and lateral patellar shift (LPS). Measured values at pre- and postoperative phases were statistically compared using a two-way analysis of variance. Results: All indices including mISI, mCDI, mBPI, LPT and LPS showed no statistically significant postoperative changes. Conclusion: Medial closed-wedge DFO performed for valgus osteoarthritic knees did not significantly influence patellofemoral alignment either on the sagittal or axial plane. Therefore, to highlight the clinical relevance of our findings, medial closed-wedge DFO for the valgus knee does not adversely affect the patellofemoral joint.

일본의 코로나19 의료대응과 교훈: 보건의료체계 회복탄력성 관점에서

김명희,박지은,김다움,Tomotoshi Iseki 비판과 대안을 위한 사회복지학회/ 건강정책학회 2024 비판사회정책 Vol.0 No.83

다른 국가의 코로나19 대응 경험을 비판적으로 살펴보는 것은 국내 보건의료체계의 회복탄력성을 높이는 데 중요한 참고가 될 수 있다. 유행 초기 일본의 코로나19 대응은 부정적으로 평가되었지만 사망률과 초과사망 측면에서 일본의 성적은 한국과 비슷하거 나 더 양호하다. 이 연구는 보건의료체계의 회복탄력성 관점에서 일본의 코로나19 대응 특징과 그 맥락을 분석함으로써, 미래 공중보건 위기 대비에 유용한 교훈을 찾고자 한다. 일본의 코로나19 의료대응을 분석한 결과, 일본 지역의료기관들의 연계협력 경험, 요양 시설 감염예방 체계, 잘 확립된 재택.방문진료 서비스는 일본 코로나19 의료대응의 중요 한 대비역량으로 작동했다. 공공병원의 균등한 분포와 진료 역량은 유행 초기 흡수역량 이 적절히 작동하는 데 기여했고, 민간의료기관의 자발적 참여는 지역단위의 공동대응체 계 수립에 중요한 역할을 했다. 팬데믹 속성에 대한 이해를 토대로 한 의료대응 전략의 전환은 병상 부족을 완화하는 데 중요한 역할을 했으며, 코로나19 환자 대상 외래 진료 와 재택.방문진료는 적응 역량의 좋은 사례라 할 수 있다. 일본은 코로나19를 위한 별도 의 전담체계에 의존하기보다 기존의 의료체계를 활용했기 때문에 별도의 전환역량이 발 생하지는 않았다. 마지막으로 코로나19 대응에서 드러난 문제들에 대한 진단을 바탕으 로, 유연하게 병상.인력자원을 확보하고 신속한 재원 조달을 위해 관련 법령을 개정한 작업은 학습 및 환류 역량의 사례로 볼 수 있다. Reflecting on the COVID-19 response experiences of other countries can provide important lessons for enhancing the resilience of our own healthcare system. While Japan's response to COVID-19 was negatively perceived at the onset of the pandemic, its actual outcomes were similar to or even better than those of Korea. This study aims to analyze Japan's COVID-19 healthcare system responses, the context that led to those outcomes, and its impact from the perspective of resilience in order to identify insights that could be used to prepare for future public health crisis. The experience of local healthcare facilities in collaboration, infection prevention systems in nursing homes, and well-established home-based and home-visiting healthcare contributed to Japan's COVID-19 healthcare response preparedness. The even distribution and high medical capacity of public hospitals contributed to adequate absorptive capacity in the early stages of the pandemic. At the same time, the voluntary participation of private healthcare providers enabled the establishment of a coordinated response system at the local level. Shifts in healthcare response strategies based on understanding of the pandemic's characteristics helped alleviate bed shortages, and outpatient and home-based care for COVID-19 patients is a prominent example of adaptive capacity. Japan did not experience transformative capacity as it utilized the existing healthcare system rather than creating a dedicated delivery system. Lastly, based on a diagnosis of the problems that emerged from the COVID-19 response, the revision of laws and regulations to ensure flexible bed and staffing resources and rapid financing can be seen as an example of learning and reflexivity.