333 research outputs found

    Biosorption of Uranium and Rare Earth Elements Using Biomass of Algae

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    In order to investigate the behavior of rare earth elements (REEs) and uranium (U) in marine organism, the concentrations of REEs and U in some brown algae samples taken on the coast of Niigata Prefecture were determined. In addition, laboratory model experiment to uptake these elements using living and dried algae (Undaria pinnatifida and Sargassum hemiphyllum) was also carried out to survey the uptake and bioaccumulation mechanism of REEs and U in algae. Consequently, the following matters have been mainly clarified. (1) The order of the concentration of REEs for each organ in Sargassum hemiphyllum is “main branch” > “leaf” > “vesicle,” however for U, the order is “leaf” > “vesicle” > “main branch.” (2) The concentration of REEs in Sargassum hemiphyllum may be strongly affected by suspended solid in seawater. (3) The uptake and/or accumulate mechanism of REEs in brown algae may be different from that of U

    Behavior and Distribution of Heavy Metals Including Rare Earth Elements, Thorium, and Uranium in Sludge from Industry Water Treatment Plant and Recovery Method of Metals by Biosurfactants Application

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    In order to investigate the behavior, distribution, and characteristics of heavy metals including rare earth elements (REEs), thorium (Th), and uranium (U) in sludge, the total and fractional concentrations of these elements in sludge collected from an industry water treatment plant were determined and compared with those in natural soil. In addition, the removal/recovery process of heavy metals (Pb, Cr, and Ni) from the polluted sludge was studied with biosurfactant (saponin and sophorolipid) elution by batch and column experiments to evaluate the efficiency of biosurfactant for the removal of heavy metals. Consequently, the following matters have been largely clarified. (1) Heavy metallic elements in sludge have generally larger concentrations and exist as more unstable fraction than those in natural soil. (2) Nonionic saponin including carboxyl group is more efficient than sophorolipid for the removal of heavy metals in polluted sludge. Saponin has selectivity for the mobilization of heavy metals and mainly reacts with heavy metals in F3 (the fraction bound to carbonates) and F5 (the fraction bound to Fe-Mn oxides). (3) The recovery efficiency of heavy metals (Pb, Ni, and Cr) reached about 90–100% using a precipitation method with alkaline solution

    Divergence of Evolutionary Ways Among Common sym Genes: CASTOR and CCaMK Show Functional Conservation Between Two Symbiosis Systems and Constitute the Root of a Common Signaling Pathway

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    In recent years a number of legume genes involved in root nodule (RN) symbiosis have been identified in the model legumes, Lotus japonicus (Lotus) and Medicago truncatula. Among them, a distinct set of genes has been categorized as a common symbiosis pathway (CSP), because they are also essential for another mutual interaction, the arbuscular mycorrhiza (AM) symbiosis, which is evolutionarily older than the RN symbiosis and is widely distributed in the plant kingdom. Based on the concept that the legume RN symbiosis has evolved from the ancient AM symbiosis, one issue is whether the CSP is functionally conserved between non-nodulating plants, such as rice, and nodulating legumes. We identified three rice CSP gene orthologs, OsCASTOR, OsPOLLUX and OsCCaMK, and demonstrated the indispensable roles of OsPOLLUX and OsCCaMK in rice AM symbiosis. Interestingly, molecular transfection of either OsCASTOR or OsCCaMK could fully complement symbiosis defects in the corresponding Lotus mutant lines for both the AM and RN symbioses. Our results not only provide a conserved genetic basis for the AM symbiosis between rice and Lotus, but also indicate that the core of the CSP has been well conserved during the evolution of RN symbiosis. Through evolution, CASTOR and CCaMK have remained as the molecular basis for the maintenance of CSP functions in the two symbiosis system

    Immunohistochemical Examination for the Distribution of Podoplanin-Expressing Cells in Developing Mouse Molar Tooth Germs

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    We recently reported the expression of podoplanin in the apical bud of adult mouse incisal tooth. This study was aimed to investigate the distribution of podoplanin-expressing cells in mouse tooth germs at several developing stages. At the bud stage podoplanin was expressed in oral mucous epithelia and in a tooth bud. At the cap stage podoplanin was expressed on inner and outer enamel epithelia but not in mesenchymal cells expressing the neural crest stem cell marker nestin. At the early bell stage nestin and podoplanin were expressed in cervical loop and odontoblasts. At the root formation stage both nestin and podoplanin were weakly expressed in odontoblasts generating radicular dentin. Podoplanin expression was also found in the Hertwig epithelial sheath. These results suggest that epithelial cells of developing tooth germ acquire the ability to express nestin, and that tooth germ epithelial cells maintain the ability to express podoplanin in oral mucous epithelia. The expression of podoplanin in odontoblasts was induced as tooth germ development advanced, but was suppressed with the completion of the primary dentin, suggesting that podoplanin may be involved in the cell growth of odontoblasts. Nestin may function as an intermediate filament that binds podoplanin in odontoblasts

    D139N mutation of PsbP enhances the oxygen-evolving activity of photosystem II through stabilized binding of a chloride ion

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    植物の光合成初期過程の酸素発生活性を向上させるアミノ酸変異を発見 --光合成・人工光合成の光エネルギー変換効率の向上へ期待--. 京都大学プレスリリース. 2022-08-18.Photosystem II (PSII) is a multi-subunit membrane protein complex that catalyzes light-driven oxidation of water to molecular oxygen. The chloride ion (Cl−) has long been known as an essential cofactor for oxygen evolution by PSII, and two Cl− ions (Cl-1 and Cl-2) have been found to specifically bind near the Mn4CaO5 cluster within the oxygen-evolving center (OEC). However, despite intensive studies on these Cl− ions, little is known about the function of Cl-2, the Cl− ion that is associated with the backbone nitrogens of D1-Asn338, D1-Phe339, and CP43-Glu354. In green plant PSII, the membrane extrinsic subunits—PsbP and PsbQ—are responsible for Cl− retention within the OEC. The Loop 4 region of PsbP, consisting of highly conserved residues Thr135–Gly142, is inserted close to Cl-2, but its importance has not been examined to date. Here, we investigated the importance of PsbP-Loop 4 using spinach PSII membranes reconstituted with spinach PsbP proteins harboring mutations in this region. Mutations in PsbP-Loop 4 had remarkable effects on the rate of oxygen evolution by PSII. Moreover, we found that a specific mutation, PsbP-D139N, significantly enhanced the oxygen-evolving activity in the absence of PsbQ, but not significantly in its presence. The D139N mutation increased the Cl− retention ability of PsbP and induced a unique structural change in the OEC, as indicated by light-induced Fourier transform infrared (FTIR) difference spectroscopy and theoretical calculations. Our findings provide insight into the functional significance of Cl-2 in the water-oxidizing reaction of PSII

    Role of a forward-viewing echoendoscope in fine-needle aspiration

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    AbstractA prototype forward-viewing echoendoscope has been developed for therapeutic endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The hard tip of the forward-viewing echoendoscope, which is shorter than that of the convex type echoendoscope, can be maneuvered flexibly. Using the forward-viewing echoendoscope, the gastrointestinal wall can be vertically punctured along the same axis as the scope, and this process is done more easily than with an oblique-viewing echoendoscope. The diagnostic accuracy of EUS-FNA with the forward-viewing echoendoscope is 97.4%, which is not significantly different to that of the oblique-viewing echoendoscope. The forward-viewing echoendoscope may be useful in situations where the location and procedure are difficult with the oblique-viewing scope, The forward-viewing echoendoscope is able to puncture the gastrointestinal wall vertically with minimal effort, therefore allowing therapeutic EUS procedures such as pseudocyst and abscess drainage, biliary drainage, and pancreatic duct drainage to be performed easily. However, a significant difference between the forward-viewing and oblique-viewing echoendoscopes in pseudocyst drainage has been reported recently. In the future, the forward-viewing and oblique-viewing echoendoscopes will probably be selectively used depending on not only lesion site but also the procedure required in individual patients, thereby facilitating various processes including puncture, tissue collection, and diagnosis, as well as therapeutic procedures

    Possibility of multivariate function composed of plasma amino acid profiles as a novel screening index for non-small cell lung cancer: a case control study

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    <p>Abstract</p> <p>Background</p> <p>The amino-acid balance in cancer patients often differs from that in healthy individuals, because of metabolic changes. This study investigated the use of plasma amino-acid profiles as a novel marker for screening non-small-cell lung cancer (NSCLC) patients.</p> <p>Methods</p> <p>The amino-acid concentrations in venous blood samples from pre-treatment NSCLC patients (<it>n </it>= 141), and age-matched, gender-matched, and smoking status-matched controls (<it>n </it>= 423), were measured using liquid chromatography and mass spectrometry. The resultant study data set was subjected to multiple logistic regression analysis to identify amino acids related with NSCLC and construct the criteria for discriminating NSCLC patients from controls. A test data set derived from 162 patients and 3,917 controls was used to validate the stability of the constructed criteria.</p> <p>Results</p> <p>The plasma amino-acid profiles significantly differed between the NSCLC patients and the controls. The obtained model (including alanine, valine, isoleucine, histidine, tryptophan and ornithine concentrations) performed well, with an area under the curve of the receiver-operator characteristic curve (ROC_AUC) of >0.8, and allowed NSCLC patients and controls to be discriminated regardless of disease stage or histological type.</p> <p>Conclusions</p> <p>This study shows that plasma amino acid profiling will be a potential screening tool for NSCLC.</p
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