Biomacromolecules in recent phosphate-shelled brachiopods: identification and characterization of chitin matrix

Abstract Phosphate-shelled brachiopods differ in filter-feeding lifestyle, with Lingula anatina an active infaunal burrower, and Discinisca tenuis a shallow marine epibenthic animal. The shells of these animals are built of organophosphatic constituents, the organic fibres/sheets reinforced with calcium phosphate to provide a sophisticated ultrastructural robustness. This investigation examined the nature of the organic fibres in order to improve understanding of how living organisms produce hierarchically structured biomaterials. Unlike powdered samples commonly used in previous studies, organic fibres were isolated for the first time and the shell fractions were purified, in order to study the content and nature of the biopolymer fibres. Biochemical methods including Calcofluor staining revealed a chitin matrix. Ultrastructural analysis, thermal gravimetric analysis, and spectroscopic analyses show that the core polysaccharide framework is composed of layers of β-chitin sheets and/or fibrils that are coated with a fibrous organic matrix. There is more chitin matrix in the L. anatina shells (26.6 wt.%) compared to the D. tenuis shells (12.9 wt.%). Taken together, the data show that the chitin matrix contributes to increased skeletal strength, making L. anatina highly adapted for life as an active burrower. In comparison, D. tenuis contains less chitin and lives as attached epibenthos in a shallow marine environment. Graphical abstract First spectroscopic evidence of β-chitin sheets in recent organophosphatic brachiopods

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Chitin Matrix and Ultrastructure of Phosphate-Shelled Brachiopods

10.21203/rs.3.rs-129606/v1 ◽

2020 ◽

Author(s):

Oluwatoosin Agbaje ◽

Glenn Brock ◽

Zhifei Zhang ◽

Yue Liang ◽

Simon George ◽

...

Keyword(s):

Thermal Gravimetric Analysis ◽

Single Layer ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Protein Matrix ◽

Shallow Marine ◽

The Core ◽

Fibrous Protein ◽

Spectroscopic Analyses ◽

First Time

Abstract Phosphate-shelled brachiopods differ in filter-feeding lifestyle, with Lingula anatina an active infaunal burrower, and Discinisca tenuis a shallow marine epibenthic animal. The shells of these biomineralized organisms are built of organophosphatic constituents, the organic fibres/sheets reinforced with calcium phosphate (Ca-phosphate) to provide a sophisticated ultrastructural robustness. This investigation studied the nature of organic fibres in order to improve our understanding of how design principles are relevant to biominerals. Unlike the powdered samples that were commonly used in previous studies, for the first time organic fibres were isolated and the shell fractions were purified, in order to study the content and nature of the biopolymer fibres. Ultrastructural analysis, thermal gravimetric analysis and spectroscopic analyses reveal that the core polysaccharide framework is composed of layers of β-chitin sheets that are coated with a fibrous protein matrix. The chitin matrix in Lingula shells, 26.6 wt.%, is about two-fold higher wt.% compared to Discinisca shells,12.9 wt.%. After thermal gravimetric analysis, skeletal imaging of these shells shows important differences. Discinisca contains just a single layer that is ~21.0 µm thick. In contrast, Lingula exhibits two separate layers: the thicknesses of the primary- and secondary-layers are ~20.3 µm and ~8.1 µm, respectively. Taken together, the data shows that the chitin matrix contributes to increased skeletal strength, making Lingula highly adapted for life as an active burrower. In comparison, Discinisca contains less chitin and lives as attached epibenthos in a shallow marine environment.

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Fabrication and characterization of hexadecyl acrylate cross-linked phase change microspheres

e-Polymers ◽

10.1515/epoly-2020-0008 ◽

2020 ◽

Vol 20 (1) ◽

pp. 69-75

Author(s):

Haoran Yun ◽

Xingxiang Zhang

Keyword(s):

Phase Change ◽

Smooth Surface ◽

Bone Conduction ◽

Cross Linking ◽

Gravimetric Analysis ◽

Orthopedic Implant ◽

Thermal Gravimetric ◽

Fabrication And Characterization ◽

Fast Release

AbstractMicrospheres with phase change properties were fabricated by polymerization of hexadecyl acrylate (HA) and different cross-linking agents. The samples were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA). The results show that, the samples that added cross-linking agents have a smooth surface and the latent heat of them is different. The experiments show that all of the cross-linked copolymer shells can be made into temperature controlled release microspheres. These materials can be potentially applied in the field of thermal energy storage. β-tricalcium phosphate was encapsulated in microspheres to obtain one with a fast release effect. It will effectively promote bone conduction when these microspheres were implanted into a bone defect. This microsphere can be used for orthopedic implant or coating of instrument in the future.

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Identification and Characterization of α-Glucosidase Inhibition Flavonol Glycosides from Jack Bean (Canavalia ensiformis (L.) DC

Molecules ◽

10.3390/molecules25112481 ◽

2020 ◽

Vol 25 (11) ◽

pp. 2481

Author(s):

Anita M. Sutedja ◽

Emiko Yanase ◽

Irmanida Batubara ◽

Dedi Fardiaz ◽

Hanifah N. Lioe

Keyword(s):

2D Nmr ◽

The Other ◽

Inhibition Activity ◽

Jack Bean ◽

Canavalia Ensiformis ◽

Kaempferol Glycosides ◽

Uv Visible ◽

First Time ◽

Identification And Characterization

Although the intake of jack bean (Canavalia ensiformis (L.) DC.), an underutilized tropical legume, can potentially decrease the risk of several chronic diseases, not much effort has been directed at profiling the polyphenolics contained therein. Hence, this work aimed to identify and quantify the dominant jack bean polyphenolics, which are believed to have antioxidant and other bioactivities. Four major compounds were detected and identified as kaempferol glycosides with three or four glycoside units. Their structures were established based on UV-visible, 1D, 2D NMR, and HR-ESI-MS analyses. Specifically, kaempferol 3-O-α-l-rhamnopyranosyl (1→6)- β-d-glucopyranosyl (1→2)-β-d-galactopyranosyl-7-O-[3-O-o-anisoyl]-α-l-rhamnopyranoside was detected for the first time, while the other three compounds have already been described in plants other than jack bean. This new compound was found to have a higher α-glucosidase inhibition activity compared to acarbose.

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Identification and characterization of cis-regulatory elements for photoreceptor type-specific transcription in zebrafish

10.1101/683284 ◽

2019 ◽

Author(s):

Wei Fang ◽

Yi Wen ◽

Xiangyun Wei

Keyword(s):

Core Promoter ◽

Regulatory Elements ◽

Specific Gene ◽

Protein Coding ◽

Core Promoters ◽

Protein Coding Genes ◽

The Core ◽

Cell Type Specific ◽

Identification And Characterization

AbstractTissue-specific or cell type-specific transcription of protein-coding genes is controlled by both trans-regulatory elements (TREs) and cis-regulatory elements (CREs). However, it is challenging to identify TREs and CREs, which are unknown for most genes. Here, we describe a protocol for identifying two types of transcription-activating CREs—core promoters and enhancers—of zebrafish photoreceptor type-specific genes. This protocol is composed of three phases: bioinformatic prediction, experimental validation, and characterization of the CREs. To better illustrate the principles and logic of this protocol, we exemplify it with the discovery of the core promoter and enhancer of the mpp5b apical polarity gene (also known as ponli), whose red, green, and blue (RGB) cone-specific transcription requires its enhancer, a member of the rainbow enhancer family. While exemplified with an RGB cone-specific gene, this protocol is general and can be used to identify the core promoters and enhancers of other protein-coding genes.

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Synthesis, Structure, and Characterization of La1−xBax (0 ≤ x ≤ 1)

MRS Proceedings ◽

10.1557/proc-271-107 ◽

1992 ◽

Vol 271 ◽

Author(s):

Joseph E. Sunstrom ◽

Susan M. Kauzlarich

Keyword(s):

Magnetic Susceptibility ◽

Powder Diffraction ◽

Single Phase ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Temperature Dependent ◽

X Ray ◽

Early Transition Metal ◽

Arc Melting

ABSTRACTThe compounds La1−xBaxTiO3 (0 ≤ × ≤ 1) have been prepared by arc melting stoichiometric amounts of LaTiO3 and BaTiO3. Single phase samples can be made for the entire stoichiometry range. The polycrystalline samples have been characterized by thermal gravimetric analysis, X-ray powder diffraction, and temperature dependent magnetic susceptibility. This series of compounds has been studied as a possible candidate for an early transition metal superconductor.

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Crystallographic and spectroscopic characterization of a mixed actinide–lanthanide carbide cluster stabilized inside an Ih(7)-C80 fullerene cage

Chemical Communications ◽

10.1039/d0cc00133c ◽

2020 ◽

Vol 56 (27) ◽

pp. 3867-3870 ◽

Cited By ~ 4

Author(s):

Xiaomeng Li ◽

Yang-Rong Yao ◽

Wei Yang ◽

Jiaxin Zhuang ◽

Luis Echegoyen ◽

...

Keyword(s):

Spectroscopic Characterization ◽

Fullerene Cage ◽

Spectroscopic Analyses ◽

Carbide Cluster ◽

First Time

For the first time, crystallographic and spectroscopic analyses identified that a mixed actinide–lanthanide carbide cluster Sc2UC, with a very short UC bond, is stabilized inside an Ih(7)-C80 cage.

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Dispersal of linezolid-resistant enterococci carrying poxtA or optrA in retail meat and food-producing animals from Tunisia

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz263 ◽

2019 ◽

Vol 74 (10) ◽

pp. 2865-2869 ◽

Cited By ~ 22

Author(s):

Houyem Elghaieb ◽

Ana R Freitas ◽

Mohamed Salah Abbassi ◽

Carla Novais ◽

Mohamed Zouari ◽

...

Keyword(s):

Developed Countries ◽

Cow Milk ◽

Urban Wastewater ◽

Virulence Markers ◽

Linezolid Resistance ◽

Alternative Measures ◽

Retail Meat ◽

First Time ◽

Identification And Characterization

Abstract Objectives The epidemiology of Enterococcus resistant to priority antibiotics including linezolid has mainly been investigated in developed countries and especially in hospitals. We aimed to evaluate the contribution of different non-human reservoirs for the burden of MDR enterococci in Tunisia, where scarce data are available. Methods Samples (n = 287) were collected from urban wastewater (n = 57), retail meat (n = 29; poultry/bovine/ovine), milk (n = 89; bovine/ovine), farm animal faeces (n = 80; poultry/bovine/ovine) and pets (n = 32; rabbit/dogs/cats/birds) in different Tunisian regions (2014–17). They were plated onto Slanetz–Bartley agar after pre-enrichment without antibiotics. Standard methods were used for bacterial identification and characterization of antibiotic resistance and virulence genes (PCR), antibiotic susceptibility testing (disc diffusion/broth microdilution; EUCAST/CLSI) and clonality (SmaI-PFGE/MLST). Results All samples carried Enterococcus (n = 377 isolates) resistant to antibiotics considered to be critical or highly important by WHO. Even without antibiotic selection, 38% of Enterococcus faecalis (Efs) and 22% of Enterococcus faecium (Efm) were identified as MDR. Linezolid-resistant isolates (5%; MIC = 8 mg/L) comprised six poxtA-carrying Efm (cow milk), seven optrA-carrying Efs (chicken faeces/meat) and five Efm lacking cfr/optrA/poxtA (poultry/bovine/ovine/wastewater). Clinically relevant Efm clones (clade A1) were identified in animal/meat sources. Ampicillin resistance (1%) was confined to ST18/ST78-like MDR Efm clones from bovine meat/milk samples carrying relevant virulence markers (e.g. ptsD/IS16). Conclusions This study provides evidence of the contribution of livestock and foodstuffs to the dispersal of acquired linezolid resistance genes including poxtA and optrA. We report the first poxtA-carrying Efm in Tunisia, and for the first time in bovine samples, stressing the urgent need for alternative measures to counteract the spread of linezolid-resistant enterococci globally.

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Synthesis and characterization of diaminomaleonitrile-functionalized polystyrene grafts for application in pervaporation separation

Chemical Papers ◽

10.2478/s11696-008-0037-8 ◽

2008 ◽

Vol 62 (4) ◽

Cited By ~ 4

Author(s):

Hamada Abdel-Razik

Keyword(s):

Chemical Structure ◽

Thermal Characteristics ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Optimum Conditions ◽

Scanning Calorimetry ◽

Phenol Water ◽

Pervaporation Separation ◽

Thermal Stability Of

AbstractSynthesis, characterization and application of diaminomaleonitrile (DAMN)-functionalized polystyrene grafts were studied. Dibenzoyle peroxide (BP) was used as an initiator. Optimum conditions for grafting were found to be c(DAMN) = 0.5 M, c(BP) = 0.016 M, θ = 85 °C and t = 4 h. Water uptake of the polystyrene graft membranes was found to increase with the increase of the grafting yield. The chemical structure, thermal characteristics and thermal stability of the obtained membranes were investigated by means of FTIR spectroscopy, differential scanning calorimetry, and thermal gravimetric analysis. Polystyrene graft membrane with the degree of grafting of up to 96 % was found to be useful for the pervaporation separation of phenol/water mixtures.

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A small mitochondrial protein present in myzozoans is essential for malaria transmission

Open Biology ◽

10.1098/rsob.160034 ◽

2016 ◽

Vol 6 (4) ◽

pp. 160034 ◽

Cited By ~ 9

Author(s):

Dennis Klug ◽

Gunnar R. Mair ◽

Friedrich Frischknecht ◽

Ross G. Douglas

Keyword(s):

Drug Targets ◽

Mitochondrial Protein ◽

Sister Group ◽

Developmental Defect ◽

Mitochondrial Mass ◽

First Time ◽

Potential Drug Targets ◽

Identification And Characterization

Myzozoans (which include dinoflagellates, chromerids and apicomplexans) display notable divergence from their ciliate sister group, including a reduced mitochondrial genome and divergent metabolic processes. The factors contributing to these divergent processes are still poorly understood and could serve as potential drug targets in disease-causing protists. Here, we report the identification and characterization of a small mitochondrial protein from the rodent-infecting apicomplexan parasite Plasmodium berghei that is essential for development in its mosquito host. Parasites lacking the gene mitochondrial protein ookinete developmental defect ( mpodd ) showed malformed parasites that were unable to transmit to mosquitoes. Knockout parasites displayed reduced mitochondrial mass without affecting organelle integrity, indicating no role of the protein in mitochondrial biogenesis or morphology maintenance but a likely role in mitochondrial import or metabolism. Using genetic complementation experiments, we identified a previously unrecognized Plasmodium falciparum homologue that can rescue the mpodd(−) phenotype, thereby showing that the gene is functionally conserved. As far as can be detected, mpodd is found in myzozoans, has homologues in the phylum Apicomplexa and appears to have arisen in free-living dinoflagellates. This suggests that the MPODD protein has a conserved mitochondrial role that is important for myzozoans. While previous studies identified a number of essential proteins which are generally highly conserved evolutionarily, our study identifies, for the first time, a non-canonical protein fulfilling a crucial function in the mitochondrion during parasite transmission.

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