105 research outputs found

    トウテイイ キフク ヲ トモナウ ロボット シエン シュジュツ ニ オケル ミャクハ デンパン ジカン ヲ モチイタ ヒシンシュウテキ シンハクシュツリョウケイ ノ シヨウ ケイケン

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    Background: Estimated continuous cardiac output(esCCO)is a non-invasive technique for monitoring continuous cardiac output(CCO)that is based on pulse-wave transit time. In this study, we report the use of CCO monitoring for patients undergoing robot-assisted surgery with pneumoperitoneum in a head-down position. Method: Thirteen patients undergoing radical robot-assisted prostatectomy under general anesthesia were enrolled. Intraoperatively, esCCO and arterial pressure-based cardiac output(APCO)were simultaneously recorded. The association between esCCO and APCO was then evaluated using correlation analysis and Bland-Altman analysis. The trending ability of esCCO was evaluated by 4-quadrant plot analysis. Results: The correlation coefficient between esCCO and APCO was 0.54(P < 0.0001). According to the Bland-Altman plot, the bias and precision values were 1.38 and 0.79 L/min, respectively. The concordance analysis showed the concordance rate of 92.3%. Conclusion: These results indicate that esCCO is capable of tracking hemodynamic changes associated with pneumoperitoneum in the head-down position

    Alterations in photosynthetic pigments and amino acid composition of D1 protein change energy distribution in photosystem II

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    AbstractThe marine cyanobacterium Prochlorococcus marinus accumulates divinyl chlorophylls instead of monovinyl chlorophylls to harvest light energy. As well as this difference in its chromophore composition, some amino acid residues in its photosystem II D1 protein were different from the conserved amino acid residues in other photosynthetic organisms. We examined PSII complexes isolated from mutants of Synechocystis sp. PCC 6803, in which chromophore and D1 protein were altered (Hisashi Ito and Ayumi Tanaka, 2011) to clarify the effects of chromophores/D1 protein composition on the excitation energy distribution. We prepared the mutants accumulating divinyl chlorophyll (DV mutant). The amino acid residues of V205 and G282 in the D1 protein were substituted with M205 and C282 in the DV mutant to mimic Prochlorococcus D1 protein (DV-V205M/G282C mutant). Isolated PSII complexes were analyzed by time-resolved fluorescence spectroscopy. Energy transfer in CP47 was interrupted in PSII containing divinyl chlorophylls. The V205M/G282C mutation did not recover the energy transfer pathway in CP47, instead, the mutation allowed the excitation energy transfer from CP43 to CP47, which neighbors in the PSII dimer. Mutual orientation of the subcomplexes of PSII might be affected by the substitution. The changes of the energy transfer pathways would reduce energy transfer from antennae to the PSII reaction center, and allow Prochlorococcus to acquire light tolerance

    The epidemiology of pediatric fractures in our hospital over the past 10 years

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    【Background】The epidemiology of fractures in children is not reported over the past 10 years in Japan. We investigated the epidemiology of pediatric fractures in our hospital over the past 10 years. 【Method】A retrospective analysis of fractures in children(0 to 15 years-old)between April 1, 2009, and March31,2019was undertaken. We excluded cranial and/or facial bone fractures. 【Results】We enrolled261children and297fractures. Mean age was8.9year-old, and70.8% was boys. The highest cause of fractures is sports(29.5%,77/261children), especially contact sports. Referred children were58.2%(152/261children)and operated children were 89%(233/261 children). 【Conclusion】Enlightment activities about fractures in sports and aggregation of children who needs a operation may be important

    Structure of a tetrameric photosystem I from a glaucophyte alga Cyanophora paradoxa

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    Photosystem I (PSI) is one of the two photosystems functioning in light-energy harvesting, transfer, and electron transfer in photosynthesis. However, the oligomerization state of PSI is variable among photosynthetic organisms. We present a 3.8-angstrom resolution cryo-electron microscopic structure of tetrameric PSI isolated from the glaucophyte alga Cyanophora paradoxa, which reveals differences with PSI from other organisms in subunit composition and organization. The PSI tetramer is organized in a dimer of dimers with a C2 symmetry. Unlike cyanobacterial PSI tetramers, two of the four monomers are rotated around 90 degrees, resulting in a completely different pattern of monomer-monomer interactions. Excitation-energy transfer among chlorophylls differs significantly between Cyanophora and cyanobacterial PSI tetramers. These structural and spectroscopic features reveal characteristic interactions and excitation-energy transfer in the Cyanophora PSI tetramer, suggesting that the Cyanophora PSI could represent a turning point in the evolution of PSI from prokaryotes to eukaryotes

    Combination of Diclofenac and Sublingual Nitrates Is Superior to Diclofenac Alone in Preventing Pancreatitis After Endoscopic Retrograde Cholangiopancreatography

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    BACKGROUND & AIMS: Acute pancreatitis is a major adverse event of endoscopic retrograde cholangiopancreatography (ERCP). Rectal administration of nonsteroidal anti-inflammatory drugs (NSAIDs) decreases the incidence of post-ERCP pancreatitis (PEP). Little is known about the combined effects of sublingual nitrate and NSAIDs. We performed a randomized trial to assess whether the combination of NSAIDs and sublingual nitrate is more effective than NSAIDs alone in preventing PEP. METHODS: In a prospective superiority trial, eligible patients underwent ERCP at 12 endoscopic units in Japan, from March 2015 through May 2018. Patients were randomly assigned to groups given diclofenac suppositories (50 mg) within 15 minutes after the endoscopic procedure alone (diclofenac-alone group, n = 442) or in combination with sublingual isosorbide dinitrate (5 mg) 5 minutes before the endoscopic procedure (combination group, n = 444). The primary endpoint was the occurrence of PEP. RESULTS: PEP developed in 25 patients in the combination group (5.6%), and in 42 patients in the diclofenac-alone group (9.5%) (relative risk 0.59; 95% confidence interval 0.37-0.95; P = .03). Moderate to severe pancreatitis developed in 4 patients (0.9%) in the combination group, and 10 patients (2.3%) in the diclofenac-alone group (relative risk 0.12; 95% confidence interval 0.13-1.26; P = .12). There was no serious adverse event related to the additional administration of sublingual nitrate. CONCLUSIONS: In a randomized controlled trial, we found that prophylaxis with rectal diclofenac and sublingual nitrate significantly reduces the overall incidence of PEP compared with diclofenac suppository alone. ClinicalTrials.gov, no: UMIN 000016274

    A comprehensive survey on quantum computer usage: How many qubits are employed for what purposes?

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    Quantum computers (QCs), which work based on the law of quantum mechanics, are expected to be faster than classical computers in several computational tasks such as prime factoring and simulation of quantum many-body systems. In the last decade, research and development of QCs have rapidly advanced. Now hundreds of physical qubits are at our disposal, and one can find several remarkable experiments actually outperforming the classical computer in a specific computational task. On the other hand, it is unclear what the typical usages of the QCs are. Here we conduct an extensive survey on the papers that are posted in the quant-ph section in arXiv and claim to have used QCs in their abstracts. To understand the current situation of the research and development of the QCs, we evaluated the descriptive statistics about the papers, including the number of qubits employed, QPU vendors, application domains and so on. Our survey shows that the annual number of publications is increasing, and the typical number of qubits employed is about six to ten, growing along with the increase in the quantum volume (QV). Most of the preprints are devoted to applications such as quantum machine learning, condensed matter physics, and quantum chemistry, while quantum error correction and quantum noise mitigation use more qubits than the other topics. These imply that the increase in QV is fundamentally relevant, and more experiments for quantum error correction, and noise mitigation using shallow circuits with more qubits will take place.Comment: 14 pages, 5 figures, figures regenerate

    Structure of a cyanobacterial photosystem I surrounded by octadecameric IsiA antenna proteins

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    Iron-stress induced protein A (IsiA) is a chlorophyll-binding membrane-spanning protein in photosynthetic prokaryote cyanobacteria, and is associated with photosystem I (PSI) trimer cores, but its structural and functional significance in light harvesting remains unclear. Here we report a 2.7-angstrom resolution cryo-electron microscopic structure of a supercomplex between PSI core trimer and IsiA from a thermophilic cyanobacterium Thermosynechococcus vulcanus. The structure showed that 18 IsiA subunits form a closed ring surrounding a PSI trimer core. Detailed arrangement of pigments within the supercomplex, as well as molecular interactions between PSI and IsiA and among IsiAs, were resolved. Time-resolved fluorescence spectra of the PSI-IsiA supercomplex showed clear excitation-energy transfer from IsiA to PSI, strongly indicating that IsiA functions as an energy donor, but not an energy quencher, in the supercomplex. These structural and spectroscopic findings provide important insights into the excitation-energy-transfer and subunit assembly mechanisms in the PSI-IsiA supercomplex. Akita et al. present the latest approach to solve IsiA-PSI supercomplex molecular structure with increased resolution using cryo-EM and time-resolved fluorescence studies. With 2.7 angstrom resolution, they reveal molecular interactions between PSI and IsiA subunits and that IsiA functions as an energy donor in the supercomplex

    Structural basis for different types of hetero-tetrameric light-harvesting complexes in a diatom PSII-FCPII supercomplex

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    Fucoxanthin chlorophyll (Chl) a/c-binding proteins (FCPs) function as light harvesters in diatoms. The structure of a diatom photosystem II-FCPII (PSII-FCPII) supercomplex have been solved by cryo-electron microscopy (cryo-EM) previously; however, the FCPII subunits that constitute the FCPII tetramers and monomers are not identified individually due to their low resolutions. Here, we report a 2.5 angstrom resolution structure of the PSII-FCPII supercomplex using cryo-EM. Two types of tetrameric FCPs, S-tetramer, and M-tetramer, are identified as different types of hetero-tetrameric complexes. In addition, three FCP monomers, m1, m2, and m3, are assigned to different gene products of FCP. The present structure also identifies the positions of most Chls c and diadinoxanthins, which form a complicated pigment network. Excitation-energy transfer from FCPII to PSII is revealed by time-resolved fluorescence spectroscopy. These structural and spectroscopic findings provide insights into an assembly model of FCPII and its excitation-energy transfer and quenching processes. Fucoxanthin chlorophyll a/c-binding proteins (FCPs) harvest light energy in diatoms. The authors analyzed a structure of PSII-FCPII supercomplex at high resolution by cryo-EM, which identified each FCP subunit and pigment network in the supercomplex

    Structural basis for the absence of low-energy chlorophylls in a photosystem I trimer from Gloeobacter violaceus

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    Photosystem I (PSI) is a multi-subunit pigment-protein complex that functions in light-harvesting and photochemical charge-separation reactions, followed by reduction of NADP to NADPH required for CO2 fixation in photosynthetic organisms. PSI from different photosynthetic organisms has a variety of chlorophylls (Chls), some of which are at lower-energy levels than its reaction center P700, a special pair of Chls, and are called low-energy Chls. However, the sites of low-energy Chls are still under debate. Here, we solved a 2.04-& ANGS; resolution structure of a PSI trimer by cryo-electron microscopy from a primordial cyanobacterium Gloeobacter violaceus PCC 7421, which has no low-energy Chls. The structure shows the absence of some subunits commonly found in other cyanobacteria, confirming the primordial nature of this cyanobacterium. Comparison with the known structures of PSI from other cyanobacteria and eukaryotic organisms reveals that one dimeric and one trimeric Chls are lacking in the Gloeobacter PSI. The dimeric and trimeric Chls are named Low1 and Low2, respectively. Low2 is missing in some cyanobacterial and eukaryotic PSIs, whereas Low1 is absent only in Gloeobacter. These findings provide insights into not only the identity of low-energy Chls in PSI, but also the evolutionary changes of low-energy Chls in oxyphototrophs

    Structural basis for the adaptation and function of chlorophyll f in photosystem I

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    Chlorophylls (Chl) play pivotal roles in energy capture, transfer and charge separation in photosynthesis. Among Chls functioning in oxygenic photosynthesis, Chl f is the most red-shifted type first found in a cyanobacterium Halomicronema hongdechloris. The location and function of Chl f in photosystems are not clear. Here we analyzed the high-resolution structures of photosystem I (PSI) core from H. hongdechloris grown under white or far-red light by cryo-electron microscopy. The structure showed that, far-red PSI binds 83 Chl a and 7 Chl f, and Chl f are associated at the periphery of PSI but not in the electron transfer chain. The appearance of Chl f is well correlated with the expression of PSI genes induced under far-red light. These results indicate that Chl f functions to harvest the far-red light and enhance uphill energy transfer, and changes in the gene sequences are essential for the binding of Chl f
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