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Essentials of Proteolytic Machineries in Chloroplasts

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Molecular Plant 2017年第1期10卷 4-19页

作者： Kenji Nishimura Yusuke Kato wataru Sakamoto Institute of Plant Science and Resources Okayama University 2-20-1 Chuo Kurashiki Okayama 710-0046 Japan

Plastids are unique organelles that can alter their structure and function in response to environmental and developmental stimuli. Chloroplasts are one type of plastid and are the sites for various metabolic pro- cesses, including photosynthesis. For optimal photosynthetic activity, the chloroplast proteome must be properly shaped and maintained through regulated proteolysis and protein quality control mechanisms. Enzymatic functions and activities are conferred by protein maturation processes involving consecutive proteolytic reactions. Protein abundances are optimized by the balanced protein synthesis and degrada- tion, which is depending on the metabolic status. Malfunctioning proteins are promptly degraded. Twenty chloroplast proteolytic machineries have been characterized to date. Specifically, processing peptidases and energy-driven processive proteases are the major players in chloroplast proteome biogenesis, remod- eling, and maintenance. Recently identified putative proteases are potential regulators of photosynthetic functions. Here we provide an updated, comprehensive overview of chloroplast protein degradation ma- chineries and discuss their importance for photosynthesis. Wherever possible, we also provide structural insights into chloroplast proteases that implement regulated proteolysis of substrate proteins/peptides.

关键词： chloroplast biogenesis protease protein homeostasis

Simulation of Stable Crack Growth for Welded Joints Including Strength Mismatching

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Journal of Materials Science & Technology 1999年第6期15卷 567-570页

作者： Jing, HY Luo, LX Zhang, YF minami, F Tianjin Univ Coll Mat Sci & Engn Tianjin 300072 Peoples R China Osaka Univ Osaka Japan

A 3-D computational method to simulate stable growth of a macroscopic crack under model condition is described in this paper. The Gurson-Tvergaard plasticity model for voided materials describes the damage process. Fixed-sized, computational cell elements (containing voids) defined over a thin layer at the crack plane simulate the ductile crack extension. Outside of this layer, the material remains undamaged by the void growth, follows the conventional J2 flow theory. The micromechanics parameters controlling crack growth are D, the thickness of computational cell layer and f(0), the initial void porosity. Calibration of these parameters proceeds through analyses of ductile tearing to match R-curve obtained from testing of deep notch bend specimens for welded joints. The effect of the strength mismatching on ductile crack growth for welded joints is simulated also.

关键词： Joints (structural components)

Numerical Investigation on Fracture Initiation Properties of Interface Crack in Dissimilar Steel Welded Joints

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Chinese Journal of Mechanical Engineering 2020年第3期33卷 142-149页

作者： Longfei Zhao Chendong Shao Yasuhito Takashima Fumiyoshi minami Fenggui Lu Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghaiChina Joining and Welding Research Institute Osaka UniversityOsakaJapan

Fracture toughness property is of significant importance when evaluating structural *** current research of fracture toughness mainly focused on crack in homogeneous material and experimental *** the crack is located in a welded joint with high-gradient microstructure and mechanical property distribution,it becomes difficult to evaluate the fracture toughness behavior since the stress distribution may be affected by various *** recent years,numerical method has become an ideal approach to reveal the essence and mechanism of fracture toughness *** study focuses on the crack initiation behavior and driving force at different interfaces in dissimilar steel welded *** stress and strain fields around the crack tip lying at the interfaces of ductile-ductile,ductile-brittle and brittle-brittle materials are analyzed by the numerical *** the interface of ductile-ductile materials,the strain concentration on the softer material side is responsible for ductile fracture *** the ductile-brittle interface,the shielding effect of the ductile material plays an important role in decreasing the fracture driving force on the brittle material *** the case of brittle-brittle interface,a careful matching is required,because the strength mismatch decreases the fracture driving force in one side,whereas the driving force in another side is *** results are deemed to offer support for the safety assessment of welded structures.

关键词： Dissimilar steel welded joint Fracture initiation Interface Strength mismatch Numerical simulation

Highly selective detection of copper(Ⅱ) by a “ligand-free” conjugated copolymer in nucleophilic solvents

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Frontiers of Chemical Science and Engineering 2020年第1期14卷 105-111页

作者： Weixing Deng Pengfei Sun Quli Fan Lei Zhang Tsuyoshi minami Key Laboratory for Organic Electronics and Information Displays&Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing University of Posts&TelecommunicationsNanjing 210023China Institute of Industrial Science The University of TokyoMeguro-kuTokyo 153-8505Japan

The synthesis of N-cyclohexyl carbamate-attached fluorene-alt-phenylene copolymer(PFPNCC)and the use of PFPNCC as a“ligand-free”fluorescent chemosensor for Cu(Ⅱ)are *** of Cu(Ⅱ)can efficiently quench the fluorescence of PFPNCC in nucleophilic solvents such as DMF and DMSO,but not in low nucleophilic solvents such as 1,4-dioxane and ***-visible spectra of the mixture of the conjugated polymer and Cu(Ⅱ)indicate the presence of a reduced Cu(Ⅰ)ion in the ***,fluorescence recovery of PFPNCC observed at low temperature suggests that the quenching and reducing mechanism is most probably due to a photo-induced electron transfer from excited PFPNCC to Cu(Ⅱ).Our findings provide a novel strategy for highly selective conjugated polymer-based chemosensors for various target analytes,albeit“ligand-free”.

关键词： ligand-free fluorescent chemosensor copper photo-induced electron transfer

BAYESIAN IMAGE SUPERRESOLUTION AND HIDDEN VARIABLE MODELING

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Journal of Systems Science & Complexity 2010年第1期23卷 116-136页

作者： Atsunori KANEMURA Shin-ichi MAEDA wataru FUKUDA ShinI SHII Graduate School of Informatics Kyoto University

Superresolution is an image processing technique that estimates an original high-resolutionimage from its low-resolution and degraded *** superresolution tasks,there have beenproblems regarding the computational cost for the estimation of high-dimensional *** are now being overcome by the recent development of fast computers and the developmentof powerful computational techniques such as variational Bayesian *** paper reviewsa Bayesian treatment of the superresolution problem and presents its extensions based on hierarchicalmodeling by employing hidden variables.

关键词： Bayesian estimation hidden variables image superresolution Markov random fields variational estimation.

Involvement of insulin receptor substrates in cognitive impairment and Alzheimer’s disease

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Neural Regeneration Research 2019年第8期14卷 1330-1334页

作者： Daisuke Tanokashira wataru Fukuokaya Akiko Taguchi Department of Integrative Aging Neuroscience National Center for Geriatrics and Gerontology Obu Aichi Japan Division of Neurology Endocrinology and Metabolism Faculty of Medicine University of Miyazaki Miyazaki Japan

Type 2 diabetes一associated with impaired insulin/insulin-like growth factor-1 (IGF1) signaling (IIS)一is a risk factor for cognitive impairment and dementia including Alzheimer's disease (AD). The insulin receptor substrate (IRS) proteins are major components of IIS, which transmit upstream signals via the insulin receptor and/or IGF1 receptor to multiple intracellular signaling pathways, including AKT/protein kinase B and extracellular-signal-regulated kinase cascades. Of the four IRS proteins in mammals, IRS1 and IRS2 play key roles in regulating growth and survival, metabolism, and aging. Meanwhile, the roles of IRS1 and IRS2 in the central nervous system with respect to cognitive abilities remain to be clarified. In contrast to IRS2 in peripheral tissues, inactivation of neural IRS2 exerts beneficial effects, resulting in the reduction of amyloid p accumulation and premature mortality in AD mouse models. On the other hand, the increased phosphorylation of IRS 1 at several serine sites is observed in the brains from patients with AD and animal models of AD or cognitive impairment induced by type 2 diabetes. However, these serine sites are also activated in a mouse model of type 2 diabetes, in which the diabetes drug metformin improves memory impairment. Because IRS1 and IRS2 signaling pathways are regulated through complex mechanisms including positive and negative feedback loops, whether the elevated phosphorylation of IRS1 at specific serine sites found in AD brains is a primary response to cognitive dysfunction remains unknown. Here, we examine the associations between IRS 1 /1 RS2-mediated signaling in the central nervous system and cognitive decline.

关键词： type 2 diabetes insulin/insulin^like growth factor-1 insulin receptor substrate Alzheimer's disease aging serine phosphorylation metformin neuroprotective effects high-fat-diet

Therapeutic response assessment of RFA for HCC:Contrast-enhanced US,CT and MRI

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World Journal of Gastroenterology 2014年第15期20卷 4160-4166页

作者： Yasunori minami Naoshi Nishida Masatoshi Kudo Department of Gastroenterology and Hepatology Kinki University Faculty of MedicineOsaka 589-8511Japan

Radiofrequency ablation (RFA) is commonly applied for the treatment of hepatocellular carcinoma (HCC) because of the facile procedure, and the safety and effectiveness for the treatment of this type of tumor. On the other hand, it is believed that HCC cells should spread predominantly through the blood flow of the portal vein, which could lead to the formation of intrahepatic micrometastases. Therefore, monitoring tumor response after the treatment is quite important and accurate assessment of treatment response is critical to obtain the most favorable outcome after the RFA. Indeed, several reports suggested that even small HCCs of ≤ 3 cm in diameter might carry intrahepatic micrometastases and/or microvascular invasion. From this point of view, for preventing local recurrences, RFA should be performed ablating a main tumor as well as its surrounding non-tumorous liver tissue where micrometastases and microvascular invasion might exist. Recent advancement of imaging modalities such as contrast-enhanced ultrasonic, computed tomography, and magnetic resonance imaging are playing an important role on assessing the therapeutic effects of RFA. The local recurrence rate tends to be low in HCC patients who were proven to have adequate ablation margin after RFA; namely, not only disappearance of vascular enhancement of main tumor, but also an adequate ablation margin. Therefore, contrast enhancement gives important findings for the diagnosis of recurrent HCCs on each imaging. However, hyperemia of non-tumorous liver surrounding the ablated lesion, which could be attributed to an inflammation after RFA, may well obscure the findings of local recurrence of HCCs after RFA. Therefore, we need to carefully address to these imaging findings given the fact that diagnostic difficulties of local recurrence of HCC. Here, we give an overview of the current status of the imaging assessment of HCC response to RFA.

关键词： Hepatocellular carcinoma Micrometastasis Microvascular invasion Radiofrequency ablation Safety margin

Contrast-enhanced ultrasonography with Sonazoid in hepatocellular carcinoma diagnosis

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Hepatoma Research 2020年第8期6卷 1-11页

作者： Yasunori minami Masatoshi Kudo Department of Gastroenterology and Hepatology Kindai University Faculty of MedicineOsaka 589-8511Japan.

With the development of second-generation contrast agents and advancement in contrast harmonic imaging,contrast-enhanced ultrasonography(CEUS)now has the capacity to sensitively and accurately show tumor ***,marked improvements have been achieved in the diagnosis of focal liver lesions(FLLs),including hepatocellular carcinoma(HCC),by *** contrast to other agents,Kupffer cells in liver sinusoids take up *** contrast enhancement phases occur in CEUS with Sonazoid:a vascular phase and Kupffer *** obtained in the Kupffer phase have higher diagnostic sensitivity for hepatic malignancies because the majority of these malignancies do not contain Kupffer *** images obtained in the vascular phase markedly narrow the clinical differential diagnoses of *** sustainable detection of inconspicuous HCC,adequate guidance of ablation therapy,and accurate assessment of treatment responses in HCC are all facilitated by *** principles,clinical applications,and techniques of CEUS with Sonazoid in the diagnosis of HCC will be reviewed herein.

关键词： Contrast-enhanced ultrasonography focal liver lesion hepatocellular carcinoma sonazoid

Adjuvant therapy after radical surgery for hepatocellular carcinoma: still an unmet need

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Hepatobiliary Surgery and Nutrition 2019年第4期8卷 414-416页

作者： Yasunori minami Masatoshi Kudo Department of Gastroenterology and Hepatology Kindai University Faculty of Medicine Osaka-Sayama Osaka Japan

Introduction Hepatocellular carcinoma(HCC)is one of the leading causes of cancer-related *** HCC typically occurs in patients with advanced liver disease,therapeutic decisions depend on the degree of underlying liver dysfunction and tumor *** treatment options,which result in 5-year survival rates of 60–80%(surgical resection)and 40–70%(local ablative therapies),are restricted to patients with early-stage HCC(1,2).However,surgical resection and local ablative therapies are limited by high tumor recurrence rates of 50%at 3 years and 70%at 5 years(1-6).Thus,monitoring treatment response is imperative for the clinical management of HCC patients(7),highlighting the need for adjuvant therapies.

关键词： mortality surgery clinical