The Experts below are selected from a list of 684 Experts worldwide ranked by ideXlab platform
S. Hirano - One of the best experts on this subject based on the ideXlab platform.
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structure of insect chitin isolated from beetle larva cuticle and silkworm bombyx mori pupa Exuvia
International Journal of Biological Macromolecules, 2000Co-Authors: Min Zhang, A Haga, H. Sekiguchi, S. HiranoAbstract:Abstract Chitin samples in a α-form structure were isolated from beetle larva cuticle and silkworm ( Bombyx mori ) pupa Exuvia by treatment with 1 N HCl and 1 N NaOH. Chitosan was prepared by treating them in 40% NaOH containing NaBH 4 . Chitin and chitosan were analyzed by X-ray, [ 13 C]CP/MAS NMR, [ 13 C]FT-NMR, and scanning electron microscopy (SEM) methods. Insect chitin degraded more readily than shrimp chitin when treated with 6 N HCl and the enzyme-chitinase. After treatment with 2 N HCl at 100°C, the insect chitin crystallinity increased. N -deacetylation of insect chitin was easier than that of crustaceous chitin, and about 94% of the N -acetyl groups were removed in one treatment with 40% NaOH for 4 h at 110°C. After treatment with 2 N HCl, 55% of the N -acetyl groups of silkworm chitin were removed under the same conditions. Beetle chitin showed a higher affinity for chitinase than shrimp chitin.
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structure of insect chitin isolated from beetle larva cuticle and silkworm bombyx mori pupa Exuvia
International Journal of Biological Macromolecules, 2000Co-Authors: Min Zhang, A Haga, H. Sekiguchi, S. HiranoAbstract:Chitin samples in a alpha-form structure were isolated from beetle larva cuticle and silkworm (Bombyx mori) pupa Exuvia by treatment with 1 N HCl and 1 N NaOH. Chitosan was prepared by treating them in 40% NaOH containing NaBH(4). Chitin and chitosan were analyzed by X-ray, [13C]CP/MAS NMR, [13C]FT-NMR, and scanning electron microscopy (SEM) methods. Insect chitin degraded more readily than shrimp chitin when treated with 6 N HCl and the enzyme-chitinase. After treatment with 2 N HCl at 100 degrees C, the insect chitin crystallinity increased. N-deacetylation of insect chitin was easier than that of crustaceous chitin, and about 94% of the N-acetyl groups were removed in one treatment with 40% NaOH for 4 h at 110 degrees C. After treatment with 2 N HCl, 55% of the N-acetyl groups of silkworm chitin were removed under the same conditions. Beetle chitin showed a higher affinity for chitinase than shrimp chitin.
Min Zhang - One of the best experts on this subject based on the ideXlab platform.
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structure of insect chitin isolated from beetle larva cuticle and silkworm bombyx mori pupa Exuvia
International Journal of Biological Macromolecules, 2000Co-Authors: Min Zhang, A Haga, H. Sekiguchi, S. HiranoAbstract:Abstract Chitin samples in a α-form structure were isolated from beetle larva cuticle and silkworm ( Bombyx mori ) pupa Exuvia by treatment with 1 N HCl and 1 N NaOH. Chitosan was prepared by treating them in 40% NaOH containing NaBH 4 . Chitin and chitosan were analyzed by X-ray, [ 13 C]CP/MAS NMR, [ 13 C]FT-NMR, and scanning electron microscopy (SEM) methods. Insect chitin degraded more readily than shrimp chitin when treated with 6 N HCl and the enzyme-chitinase. After treatment with 2 N HCl at 100°C, the insect chitin crystallinity increased. N -deacetylation of insect chitin was easier than that of crustaceous chitin, and about 94% of the N -acetyl groups were removed in one treatment with 40% NaOH for 4 h at 110°C. After treatment with 2 N HCl, 55% of the N -acetyl groups of silkworm chitin were removed under the same conditions. Beetle chitin showed a higher affinity for chitinase than shrimp chitin.
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structure of insect chitin isolated from beetle larva cuticle and silkworm bombyx mori pupa Exuvia
International Journal of Biological Macromolecules, 2000Co-Authors: Min Zhang, A Haga, H. Sekiguchi, S. HiranoAbstract:Chitin samples in a alpha-form structure were isolated from beetle larva cuticle and silkworm (Bombyx mori) pupa Exuvia by treatment with 1 N HCl and 1 N NaOH. Chitosan was prepared by treating them in 40% NaOH containing NaBH(4). Chitin and chitosan were analyzed by X-ray, [13C]CP/MAS NMR, [13C]FT-NMR, and scanning electron microscopy (SEM) methods. Insect chitin degraded more readily than shrimp chitin when treated with 6 N HCl and the enzyme-chitinase. After treatment with 2 N HCl at 100 degrees C, the insect chitin crystallinity increased. N-deacetylation of insect chitin was easier than that of crustaceous chitin, and about 94% of the N-acetyl groups were removed in one treatment with 40% NaOH for 4 h at 110 degrees C. After treatment with 2 N HCl, 55% of the N-acetyl groups of silkworm chitin were removed under the same conditions. Beetle chitin showed a higher affinity for chitinase than shrimp chitin.
Juan Diazcartelle - One of the best experts on this subject based on the ideXlab platform.
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effectiveness and safety of a paclitaxel eluting stent for superficial femoral artery lesions up to 190 mm one year outcomes of the single arm imperial long lesion substudy of the eluvia drug eluting stent
Journal of Endovascular Therapy, 2020Co-Authors: Jaafer Golzar, Yoshimitsu Soga, Anvar Babaev, Jeffery T Prem, Osamu Iida, Daizo Kawasaki, William Bachinsky, James Park, Frank Vermassen, Juan DiazcartelleAbstract:Purpose: To report the clinical effect of a drug-eluting stent on femoropopliteal occlusive disease in patients with long lesions. Materials and Methods: The global IMPERIAL Long Lesion substudy (ClinicalTrials.gov identifier NCT02574481) is a prospective, single-arm, multicenter trial of the Eluvia Drug-Eluting Vascular Stent for treating femoropopliteal lesions >140 mm and ≤190 mm in length. Fifty patients (mean age 68.2 years; 32 men) with long lesions (mean length 162.8±34.7 mm) were enrolled; 20 patients had diabetes. Fourteen of the lesions were severely calcified and 16 were occluded. Primary patency (duplex ultrasound peak systolic velocity ratio ≤2.4 in the absence of clinically-driven target lesion revascularization or bypass of the target lesion) and major adverse events [30-day all-cause death and 1-year target limb major amputation or target lesion revascularization (TLR)] were assessed at 12 months. Results: At 12 months, no deaths, target limb amputations, or stent thrombosis had occurred. The Kaplan-Meier estimate of primary patency was 91.0% (95% CI 82.5% to 99.6%). The MAE-free rate at 12 months was 93.5% due to 3 clinically-driven TLRs. The corresponding Kaplan-Meier estimate of freedom from TLR was 93.9% (95% CI 87.2% to 100%). Conclusion: The IMPERIAL Long Lesion substudy demonstrated excellent patency and safety through 1 year among patients with long femoropopliteal occlusive disease treated with the Eluvia stent.
Andreas Ziegler - One of the best experts on this subject based on the ideXlab platform.
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intracellular calcium phosphate deposits contribute to transcellular calcium transport within the hepatopancreas of porcellio scaber
Journal of Structural Biology, 2020Co-Authors: Ulrich Rupp, Paul Walther, Andreas ZieglerAbstract:Like in most Crustacea, the cuticle of terrestrial isopods is hardened by a calcareous mineral phase. This rigid cuticle is frequently shed during a process called moulting. To reduce calcium loss, Porcellio scaber eats the shed cuticle, the Exuviae, and absorb the calcium from it through large tubular diverticula of the intestine, called the mid gut glands or hepatopancreas. After moulting the absorbed calcium should be transported immediately into the hemolymph from which it is used to rapidly mineralize the new cuticle. This suggests that the hepatopancreas epithelium transports calcium from the lumen to the hemolymph. We used TEM, energy-filtered TEM and electron-probe X-ray microanalysis to analyse the distribution of elevated calcium within the hepatopancreas cells of P. scaber. We used animals in the postmoult stage that have eaten their Exuviae and, as a control, those that have not ingested the Exuviae. To minimize calcium loss within the samples, we used high pressure frozen and freeze substituted samples and propane-1-3-diol as floatation medium for thin-sectioning. The results reveal intracellular dense deposits containing calcium, phosphorus and oxygen at the apical microvillus membrane, within the cytoplasm, attached to vesicles and to the basolateral membrane, as well as extracellular between cells and the basal lamina. Control animals were devoid of these deposits. The results indicate that calcium from the Exuviae is absorbed and transported across the epithelium into the hemolymph. We propose that during transport, intracellular calcium is bound to phosphate avoiding toxic effects of high concentrations of ionized calcium.
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the effect of Exuviae ingestion on lysosomal calcium accumulation and the presence of exosomes in the hepatopancreas of porcellio scaber
Journal of Structural Biology, 2019Co-Authors: Ulrich Rupp, Andreas ZieglerAbstract:Abstract The hepatopancreas of isopods has major functions in food digestion and storage of carbohydrates and lipids. Also, it stores essential and accumulates xenobiotic metals in lysosomal granules within the two major cell types, the S- and B-cells of the tissue. A µCT study on moulting Porcellio scaber has shown mineral within the hepatopancreas lumen, when the animal has ingested their shed cuticle after moulting, suggesting recycling of mineral from the Exuviae. This study aims to reveal if the lysosomal metal containing granules store calcium originating from the ingested Exuviae. Therefore, we investigated the effect of cuticle ingestion on the elemental composition of the hepatopancreas granules of P. scaber, using electron probe X-ray microanalysis. For the preservation of diffusible elements, samples were high pressure frozen and freeze substituted in acetone and we used Propane-1,3-diol as a floatation medium for sections. We analyzed S- and B-cells of animals in the postmoult and intermoult stage that have ingested their Exuviae and, as a negative control, cells from postmoult animals that have not ingested their Exuviae. STEM and TEM were used for the investigation of the ultrastructure. Unexpectedly, the cryo-fixed samples contain numerous extracellular vesicles (exosomes) and many multivesicular bodies containing pro-exosomes. We show a significant increase of calcium, copper, zinc and sulphur within the metal granules upon Exuviae ingestion, and, after 9 days, a reduction of calcium and zinc. The results indicate transitory storage of calcium from the Exuviae within the metal granules and its subsequent utilization in cuticle mineralization.
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mineral in skeletal elements of the terrestrial crustacean porcellio scaber srμct of function related distribution and changes during the moult cycle
Arthropod Structure & Development, 2017Co-Authors: Andreas Ziegler, Frank Neues, Jiři Janacek, Felix Beckmann, Matthias EppleAbstract:Terrestrial isopods moult first the posterior and then the anterior half of the body, allowing for storage and recycling of CaCO3. We used synchrotron-radiation microtomography to estimate mineral content within skeletal segments in sequential moulting stages of Porcellio scaber. The results suggest that all examined cuticular segments contribute to storage and recycling, however, to varying extents. The mineral within the hepatopancreas after moult suggests an uptake of mineral from the ingested Exuviae. The total maximum loss of mineral was 46% for the anterior and 43% for the posterior cuticle. The time course of resorption of mineral and mineralisation of the new cuticle suggests storage and recycling of mineral in the posterior and anterior cuticle. The mineral in the anterior pereiopods decreases by 25% only. P. scaber has long legs and can run fast; therefore, a less mineralised and thus lightweight cuticle in pereiopods likely serves to lower energy consumption during escape behaviour. Differential demineralisation occurs in the head cuticle, in which the cornea of the complex eyes remains completely mineralised. The partes incisivae of the mandibles are mineralised before the old cuticle is demineralised and shed. Probably, this enables the animal to ingest the old Exuviae after each half moult.
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calcium translocations during the moulting cycle of the semiterrestrial isopod ligia hawaiiensis oniscidea crustacea
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2006Co-Authors: Andreas Ziegler, Monica Hagedorn, Gregory A Ahearn, Thomas H CarefootAbstract:Terrestrial isopods moult first the posterior and then the anterior half of the body. During the moulting cycle they retain a significant fraction of cuticular calcium partly by storing it in sternal CaCO3 deposits. We analysed the calcium content in whole Ligia hawaiiensis and the calcium distribution between the posterior, the anterior ventral, and the anterior dorsal cuticle during four stages of the moulting cycle. The results indicate that: (1) overall, about 80% of the calcium is retained and 20% is lost with the Exuviae, (2) in premoult 68% of the calcium in the posterior cuticle is resorbed (23% moved to the anterior ventral cuticle, 17% to the anterior dorsal cuticle, and the remaining 28% to internal tissues), (3) after the posterior moult 83% of the calcium in the anterior cuticle is shifted to the posterior cuticle and possibly to internal storage sites, (4) following the anterior moult up to 54% of the calcium in the posterior cuticle is resorbed and used to mineralise the new anterior cuticle. 45Ca-uptake experiments suggest that up to 80% of calcium lost with the anterior Exuviae may be regained after its ingestion. Whole body calcium of Ligia hawaiiensis is only 0.7 times that of the fully terrestrial isopods. These terrestrial species can retain only 48% of whole body calcium, suggesting that the amount of calcium that can be retained by shifting it between the anterior and posterior integument is limited. We propose that fully terrestrial Oniscidea rely to a larger degree on other calcium sources like internal stores and uptake from the ingested Exuviae.
Alexander Knyshov - One of the best experts on this subject based on the ideXlab platform.
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chemically mediated arrestment of the bed bug cimex lectularius by volatiles associated with Exuviae of conspecifics
PLOS ONE, 2016Co-Authors: Donghwan Choe, Hoeun Park, Alexander KnyshovAbstract:Extracts of the Exuviae (cast skins) of nymphal bed bugs (Cimex lectularius) were analyzed for volatile compounds that might contribute to arrestment of adult bed bugs. Four volatile aldehydes, (E)-2-hexenal, 4-oxo-(E)-2-hexenal, (E)-2-octenal, and 4-oxo-(E)-2-octenal were consistently detected in the headspace of freshly shed Exuviae regardless of the developmental stages from which the Exuviae were obtained. Quantification of the aldehydes in the solvent extracts of homogenized fresh, 45- or 99-d aged 5th instar Exuviae indicated that the aldehydes are present in the Exuviae and dissipate over time, through evaporation or degradation. Microscopic observation of the fifth instar Exuviae indicated that the dorsal abdominal glands on the Exuviae maintained their pocket-like structures with gland reservoirs, within which the aldehydes might be retained. Two-choice olfactometer studies with the volatiles from Exuviae or a synthetic blend mimicking the volatiles indicated that adult bed bugs tend to settle close to sources of the aldehydes. Our results imply that the presence and accumulation of bed bug Exuviae and the aldehydes volatilizing from the Exuviae might mediate bed bugs' interaction with their microhabitats.
