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Koichi Tanaka

Bio: Koichi Tanaka is an academic researcher from Shimadzu Corp.. The author has contributed to research in topics: Mass spectrometry & Crystal structure. The author has an hindex of 48, co-authored 517 publications receiving 14427 citations. Previous affiliations of Koichi Tanaka include Ehime University & Okayama University.


Papers
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Journal ArticleDOI
08 Feb 2018-Nature
TL;DR: The measurement of high-performance plasma amyloid-β biomarkers by immunoprecipitation coupled with mass spectrometry demonstrates the potential clinical utility of plasma biomarkers in predicting brain amyloids-β burden at an individual level and shows cost–benefit and scalability advantages over current techniques.
Abstract: To facilitate clinical trials of disease-modifying therapies for Alzheimer's disease, which are expected to be most efficacious at the earliest and mildest stages of the disease, supportive biomarker information is necessary. The only validated methods for identifying amyloid-β deposition in the brain-the earliest pathological signature of Alzheimer's disease-are amyloid-β positron-emission tomography (PET) imaging or measurement of amyloid-β in cerebrospinal fluid. Therefore, a minimally invasive, cost-effective blood-based biomarker is desirable. Despite much effort, to our knowledge, no study has validated the clinical utility of blood-based amyloid-β markers. Here we demonstrate the measurement of high-performance plasma amyloid-β biomarkers by immunoprecipitation coupled with mass spectrometry. The ability of amyloid-β precursor protein (APP)669-711/amyloid-β (Aβ)1-42 and Aβ1-40/Aβ1-42 ratios, and their composites, to predict individual brain amyloid-β-positive or -negative status was determined by amyloid-β-PET imaging and tested using two independent data sets: a discovery data set (Japan, n = 121) and a validation data set (Australia, n = 252 including 111 individuals diagnosed using 11C-labelled Pittsburgh compound-B (PIB)-PET and 141 using other ligands). Both data sets included cognitively normal individuals, individuals with mild cognitive impairment and individuals with Alzheimer's disease. All test biomarkers showed high performance when predicting brain amyloid-β burden. In particular, the composite biomarker showed very high areas under the receiver operating characteristic curves (AUCs) in both data sets (discovery, 96.7%, n = 121 and validation, 94.1%, n = 111) with an accuracy approximately equal to 90% when using PIB-PET as a standard of truth. Furthermore, test biomarkers were correlated with amyloid-β-PET burden and levels of Aβ1-42 in cerebrospinal fluid. These results demonstrate the potential clinical utility of plasma biomarkers in predicting brain amyloid-β burden at an individual level. These plasma biomarkers also have cost-benefit and scalability advantages over current techniques, potentially enabling broader clinical access and efficient population screening.

1,049 citations

Journal ArticleDOI
TL;DR: This paper presents a new approach to solvent-free organic synthesis called “Solvent-free synthesis with real-time stoichiometry” that combines high-performance liquid chromatography and high-tech electronics.
Abstract: Solvent-free organic synthesis , Solvent-free organic synthesis , کتابخانه دیجیتال جندی شاپور اهواز

1,004 citations

Book
01 Jan 2003
TL;DR: In this paper, the authors proposed a Solvent Free Organic Synthesis (SOS) method for organic synthesis, which is a state-of-the-art method for solvent-free organic synthesis.
Abstract: Solvent-free organic synthesis , Solvent-free organic synthesis , کتابخانه دیجیتال جندی شاپور اهواز

828 citations

Patent
09 Dec 1997
TL;DR: In this article, an artificial intervertebral disk comprising a movable protrusion which is formed integrally with a base body of a first connecting body and which has an arc shape in cross section at the tip end of the protrusion is used to fix a vertebral column.
Abstract: An operation for fixing a vertebral column by an autogenetic or a spacer has no movability or motion property, leading to an impedance of everyday life functions and recurrence of damage at the treated part. An artificial intervertebral disk comprising a movable protrusion which is formed integrally with a base body of a first connecting body and which has an arc shape in cross section at the tip end thereof, a movable receiver part formed by depressing a base body of a second connecting body at an opposing inner surface thereof, and wherein the movable receiver part comprises a receiving surface which contacts the tip end of the movable protrusion and a bank protruding from the periphery of the receiving surface, and a vertical gap is defined between the first and second connecting bodies and a horizontal gap is defined between the outer periphery of the movable protrusion and the inner periphery of the bank, whereby the first and second connecting bodies of the artificial intervertebral disk mounted on the ailed part have movability such as turning and sliding to thereby give a motion property to the vertebral column so that the aforementioned problem is solved.

294 citations


Cited by
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Journal ArticleDOI
30 Aug 2013-Science
TL;DR: Metal-organic frameworks are porous materials that have potential for applications such as gas storage and separation, as well as catalysis, and methods are being developed for making nanocrystals and supercrystals of MOFs for their incorporation into devices.
Abstract: Crystalline metal-organic frameworks (MOFs) are formed by reticular synthesis, which creates strong bonds between inorganic and organic units. Careful selection of MOF constituents can yield crystals of ultrahigh porosity and high thermal and chemical stability. These characteristics allow the interior of MOFs to be chemically altered for use in gas separation, gas storage, and catalysis, among other applications. The precision commonly exercised in their chemical modification and the ability to expand their metrics without changing the underlying topology have not been achieved with other solids. MOFs whose chemical composition and shape of building units can be multiply varied within a particular structure already exist and may lead to materials that offer a synergistic combination of properties.

10,934 citations

Journal ArticleDOI
TL;DR: This research framework seeks to create a common language with which investigators can generate and test hypotheses about the interactions among different pathologic processes (denoted by biomarkers) and cognitive symptoms and envision that defining AD as a biological construct will enable a more accurate characterization and understanding of the sequence of events that lead to cognitive impairment that is associated with AD.
Abstract: In 2011, the National Institute on Aging and Alzheimer's Association created separate diagnostic recommendations for the preclinical, mild cognitive impairment, and dementia stages of Alzheimer's disease. Scientific progress in the interim led to an initiative by the National Institute on Aging and Alzheimer's Association to update and unify the 2011 guidelines. This unifying update is labeled a "research framework" because its intended use is for observational and interventional research, not routine clinical care. In the National Institute on Aging and Alzheimer's Association Research Framework, Alzheimer's disease (AD) is defined by its underlying pathologic processes that can be documented by postmortem examination or in vivo by biomarkers. The diagnosis is not based on the clinical consequences of the disease (i.e., symptoms/signs) in this research framework, which shifts the definition of AD in living people from a syndromal to a biological construct. The research framework focuses on the diagnosis of AD with biomarkers in living persons. Biomarkers are grouped into those of β amyloid deposition, pathologic tau, and neurodegeneration [AT(N)]. This ATN classification system groups different biomarkers (imaging and biofluids) by the pathologic process each measures. The AT(N) system is flexible in that new biomarkers can be added to the three existing AT(N) groups, and new biomarker groups beyond AT(N) can be added when they become available. We focus on AD as a continuum, and cognitive staging may be accomplished using continuous measures. However, we also outline two different categorical cognitive schemes for staging the severity of cognitive impairment: a scheme using three traditional syndromal categories and a six-stage numeric scheme. It is important to stress that this framework seeks to create a common language with which investigators can generate and test hypotheses about the interactions among different pathologic processes (denoted by biomarkers) and cognitive symptoms. We appreciate the concern that this biomarker-based research framework has the potential to be misused. Therefore, we emphasize, first, it is premature and inappropriate to use this research framework in general medical practice. Second, this research framework should not be used to restrict alternative approaches to hypothesis testing that do not use biomarkers. There will be situations where biomarkers are not available or requiring them would be counterproductive to the specific research goals (discussed in more detail later in the document). Thus, biomarker-based research should not be considered a template for all research into age-related cognitive impairment and dementia; rather, it should be applied when it is fit for the purpose of the specific research goals of a study. Importantly, this framework should be examined in diverse populations. Although it is possible that β-amyloid plaques and neurofibrillary tau deposits are not causal in AD pathogenesis, it is these abnormal protein deposits that define AD as a unique neurodegenerative disease among different disorders that can lead to dementia. We envision that defining AD as a biological construct will enable a more accurate characterization and understanding of the sequence of events that lead to cognitive impairment that is associated with AD, as well as the multifactorial etiology of dementia. This approach also will enable a more precise approach to interventional trials where specific pathways can be targeted in the disease process and in the appropriate people.

5,126 citations

Journal ArticleDOI
TL;DR: Author(s): Livingston, Gill; Huntley, Jonathan; Sommerlad, Andrew ; Sommer Glad, Andrew; Ames, David; Ballard, Clive; Banerjee, Sube; Brayne, Carol; Burns, Alistair; Cohen-Mansfield, Jiska; Cooper, Claudia; Costafreda, Sergi G; Dias, Amit; Fox, Nick; Gitlin, Laura N; Howard, Robert; Kales, Helen C;

3,559 citations