17 research outputs found

    Expression analysis and functional characterization of the monosaccharide transporters, OsTMTs, involving vacuolar sugar transport in rice (Oryza sativa)

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    In Arabidopsis, the compartmentation of sugars into vacuoles is known to be facilitated by sugar transporters. However, vacuolar sugar transporters have not been studied in detail in other plant species. To characterize the rice (Oryza sativa) tonoplast monosaccharide transporters, OsTMT1 and OsTMT2, we analysed their subcellular localization using green fluorescent protein (GFP) and expression patterns using reverse-transcription polymerase chain reaction (RT-PCR), performed histochemical beta-glucuronidase (GUS) assay and in situ hybridization analysis, and assessed sugar transport ability using isolated vacuoles. Expression of OsTMT-GFP fusion protein in rice and Arabidopsis revealed that the OsTMTs localize at the tonoplast. Analyses of OsTMT promoter-GUS transgenic rice indicated that OsTMT1 and OsTMT2 are highly expressed in bundle sheath cells, and in vascular parenchyma and companion cells in leaves, respectively. Both genes were found to be preferentially expressed in the vascular tissues of roots, the palea/lemma of spikelets, and in the main vascular tissues and nucellar projections on the dorsal side of the seed coats. Glucose uptake studies using vacuoles isolated from transgenic mutant Arabidopsis (tmt1-2-3) expressing OsTMT1 demonstrated that OsTMTs are capable of transporting glucose into vacuoles. Based on expression analysis and functional characterization, our present findings suggest that the OsTMTs play a role in vacuolar glucose storage in rice

    Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

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    Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

    Ultra-Tough and Super-Swelling Poly(vinyl alcohol)/Poly(AAm- co-AA Sodium Salts) Double Network Hydrogels

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    The development of hydrogels and their application in various fields, such as in medical dilators and scaffolds for cartridge regeneration, are restricted by their low modulus because of the trade-off between the swelling ratio and mechanical properties. In this study, a new three-step strategy was developed to increase the mechanical strength as well as the swelling ratio of hydrogels. In stage I, polyacrylamide (PAAm) was cross-linked in the presence of poly(vinyl alcohol) (PVA). Acrylamide was selected as it can be easily polymerized in air, and PVA was selected as it is soluble only in hot water. In stage II, a crystallized PVA/cross-linked PAAm dual network was obtained by an acid treatment followed by drying. In stage III, the cross-linked PAAm in the dual network was converted into a polyelectrolyte, poly(AAm-co-acrylic acid sodium salts), by hydrolysis to increase the swelling ratio of the hydrogel. In this manner, stage III afforded excellent mechanical properties owing to the phase-separated PVA and remarkable swelling because of the extended chain conformation of poly(AAm-co-acrylic acid sodium salts) that is connected to the PVA through co-crystallization or esterification with the poly(AAm-co-acrylic acid salts) chain. In addition, by simply stretching the hydrogel, anisotropic swelling can be achieved, which allows controlling the compressive modulus along the swelling direction. © 2021 American Chemical Society.1

    Deriving Major Fire Risk Evaluation Items Utilizing Spatial Information Convergence Technology in Dense Areas of Small Obsolete Buildings

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    As small obsolete buildings are exposed to high fire risks, governments are trying to evaluate their fire risks and preferentially improve fire protection performance for high risk buildings, however, the evaluation manpower and time are insufficient compared to the rapidly increasing number of obsolete buildings. Therefore, this study aimed to derive major fire risk index (FRI) evaluation items as part of developing a platform to quickly and efficiently evaluate fire risks in dense areas of small obsolete buildings utilizing spatial information convergence technology. To this end, 20 preliminary evaluation items specifically tailored to dense areas of small obsolete buildings were derived through a field survey, investigation of FRI evaluation items from existing works, and expert pre-reviews. Based on the derived 20 preliminary items, an importance survey was conducted with a total of 181 fire safety experts including fire officers, university professors, researchers, industry experts, and fire insurers. As a result, a total of 12 major evaluation items (e.g., outdoor fire extinguisher, distance to 119 Safety Center, building structure, building cladding, illegal alterations, illegal parking, and liquefied natural gas cylinder) were derived. Results can help to evaluate the fast and efficient fire risks in dense areas of small obsolete buildings

    Optical Properties of Cyclic Amine Type Dyes, and Their Electronic Band Structures with Molecular Microstructure

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    Three different cyclic amine dyes, 9-(2-chlorophenyl)-9H-carbazole (CPCz; C18H12ClN), 10-(2-chlorophenyl)-10H-phenoxazine (CPPo; C18H12ClNO), and 10-(2-chlorophenyl)-10H-phenothiazine (CPPt; C18H12ClNS), were synthesized to systematically investigate their optical properties and electronic band structures with molecular microstructure. By the insertion of oxygen or sulfur atom into carbazole moiety, the absorption and photoluminescence (PL) spectra showed bathochromic shift, and the Stoke&apos;s shift was increased. Ionization potential of CPCz was measured as 5.75eV, on the other hand, CPPo and CPPt showed their ionization potentials of 5.37 and 5.39eV, respectively. The minute difference in chemical structure such as insertion of oxygen or sulfur atom caused huge change of optical property and electronic band structure.1

    Role of the Rice Hexokinases OsHXK5 and OsHXK6 as Glucose Sensors1[C][W]

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    The Arabidopsis (Arabidopsis thaliana) hexokinase 1 (AtHXK1) is recognized as an important glucose (Glc) sensor. However, the function of hexokinases as Glc sensors has not been clearly demonstrated in other plant species, including rice (Oryza sativa). To investigate the functions of rice hexokinase isoforms, we characterized OsHXK5 and OsHXK6, which are evolutionarily related to AtHXK1. Transient expression analyses using GFP fusion constructs revealed that OsHXK5 and OsHXK6 are associated with mitochondria. Interestingly, the OsHXK5ΔmTP-GFP and OsHXK6ΔmTP-GFP fusion proteins, which lack N-terminal mitochondrial targeting peptides, were present mainly in the nucleus with a small amount of the proteins seen in the cytosol. In addition, the OsHXK5NLS-GFP and OsHXK6NLS-GFP fusion proteins harboring nuclear localization signals were targeted predominantly in the nucleus, suggesting that these OsHXKs retain a dual-targeting ability to mitochondria and nuclei. In transient expression assays using promoter∷luciferase fusion constructs, these two OsHXKs and their catalytically inactive alleles dramatically enhanced the Glc-dependent repression of the maize (Zea mays) Rubisco small subunit (RbcS) and rice α-amylase genes in mesophyll protoplasts of maize and rice. Notably, the expression of OsHXK5, OsHXK6, or their mutant alleles complemented the Arabidopsis glucose insensitive2-1 mutant, thereby resulting in wild-type characteristics in seedling development, Glc-dependent gene expression, and plant growth. Furthermore, transgenic rice plants overexpressing OsHXK5 or OsHXK6 exhibited hypersensitive plant growth retardation and enhanced repression of the photosynthetic gene RbcS in response to Glc treatment. These results provide evidence that rice OsHXK5 and OsHXK6 can function as Glc sensors
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