scholarly journals Biosynthesis of Saxitoxin in Marine Dinoflagellates: An Omics Perspective

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 103 ◽  
Author(s):  
Muhamad Afiq Akbar ◽  
Nurul Yuziana Mohd Yusof ◽  
Noor Idayu Tahir ◽  
Asmat Ahmad ◽  
Gires Usup ◽  
...  
Keyword(s):  
Biological Sciences ◽  
Sequence Length ◽  
Gene Environment ◽  
Genomic Landscape ◽  
Potential Applications ◽  
Unicellular Organisms ◽  
Marine Dinoflagellates ◽  
Systems View ◽  
First Time ◽  
Complex Genome

Saxitoxin is an alkaloid neurotoxin originally isolated from the clam Saxidomus giganteus in 1957. This group of neurotoxins is produced by several species of freshwater cyanobacteria and marine dinoflagellates. The saxitoxin biosynthesis pathway was described for the first time in the 1980s and, since then, it was studied in more than seven cyanobacterial genera, comprising 26 genes that form a cluster ranging from 25.7 kb to 35 kb in sequence length. Due to the complexity of the genomic landscape, saxitoxin biosynthesis in dinoflagellates remains unknown. In order to reveal and understand the dynamics of the activity in such impressive unicellular organisms with a complex genome, a strategy that can carefully engage them in a systems view is necessary. Advances in omics technology (the collective tools of biological sciences) facilitated high-throughput studies of the genome, transcriptome, proteome, and metabolome of dinoflagellates. The omics approach was utilized to address saxitoxin-producing dinoflagellates in response to environmental stresses to improve understanding of dinoflagellates gene–environment interactions. Therefore, in this review, the progress in understanding dinoflagellate saxitoxin biosynthesis using an omics approach is emphasized. Further potential applications of metabolomics and genomics to unravel novel insights into saxitoxin biosynthesis in dinoflagellates are also reviewed.

Preparation and Characterization of Chitosan-Casein Phosphopeptides Biocomposite Coatings on the Medical Titanium Alloy

2011 ◽  
Vol 480-481 ◽  
pp. 1065-1069
Author(s):  
Bin Liu ◽  
Lin Wang ◽  
Yin Zhong Bu ◽  
Sheng Rong Yang ◽  
Jin Qing Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Attenuated Total Reflectance ◽  
Ti Alloy ◽  
Force Microscopy ◽  
Implant Materials ◽  
Atomic Force ◽  
Casein Phosphopeptides ◽  
Potential Applications ◽  
First Time

Titanium (Ti) and its alloys have been applied in orthopedics as one of the most popular biomedical metallic implant materials. In this work, to enhance the bioactivity, the surface of Ti alloy pre-modified by silane coupling agent and glutaraldehyde was covalently grafted with chitosan (CS) via biochemical multistep self-assembled method. Then, for the first time, the achieved surface was further immobilized with casein phosphopeptides (CPP), which are one group of bioactive peptides released from caseins in the digestive tract and can facilitate the calcium adsorption and usage, to form CS-CPP biocomposite coatings. The structure and composition of the fabricated coatings were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscopy (AFM). As the experimental results indicated, multi-step assembly was successfully performed, and the CS and CPP were assembled onto the Ti alloy surface orderly. It is anticipated that the Ti alloys modified by CS-CPP biocomposite coatings will find potential applications as implant materials in biomedical fields.

scholarly journals Fabrication and Characterization of Lignin/Dendrimer Electrospun Blended Fiber Mats

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 518
Author(s):  
Somaye Akbari ◽  
Addie Bahi ◽  
Ali Farahani ◽  
Abbas S. Milani ◽  
Frank Ko
Keyword(s):  
Thermal Characteristics ◽  
Dendritic Polymers ◽  
Amino Groups ◽  
Fiber Mats ◽  
Potential Applications ◽  
Solution Electrospinning ◽  
Nanofiber Mats ◽  
Softwood Kraft Lignin ◽  
First Time

Blending lignin as the second most abundant polymer in Nature with nanostructured compounds such as dendritic polymers can not only add value to lignin, but also increase its application in various fields. In this study, softwood Kraft lignin/polyamidoamine dendritic polymer (PAMAM) blends were fabricated by the solution electrospinning to produce bead-free nanofiber mats for the first time. The mats were characterized through scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, zeta potential, and thermogravimetry analyses. The chemical intermolecular interactions between the lignin functional groups and abundant amino groups in the PAMAM were verified by FTIR and viscosity measurements. These interactions proved to enhance the mechanical and thermal characteristics of the lignin/PAMAM mats, suggesting their potential applications e.g. in membranes, filtration, controlled release drug delivery, among others.

Topotactic route to synthesis of novel hydroxylated phases: I. Trioctahedral Micas

Clay Minerals ◽  
1986 ◽  
Vol 21 (2) ◽  
pp. 125-131 ◽  
Author(s):  
S. Komarneni ◽  
R. Roy
Keyword(s):  
Ion Exchange ◽  
Alkaline Earth ◽  
Water Molecules ◽  
Hydration Energy ◽  
Hydrothermal Conditions ◽  
Potential Applications ◽  
Clay Layers ◽  
First Time ◽  
Hydrolysis Of ◽  
Alkaline Earth Cations

AbstractK-depleted phlogopite mica was used as a topotactic precursor and treated with alkali (Li+, K+, , Rb+, Cs+), alkaline-earth (Mg2+, Ca2+, Sr2+, Ba2+) and trivalent (Al3+) cations under hydrothermal conditions of 200°C and 30 MPa pressure. K-, NH4-, Rb- and Cs-aluminosilicate micas were synthesised at 200°C in one day. The synthesis of Cs-aluminosilicate mica, with potential applications in the management of nuclear wastes, has been achieved for the first time by this approach. Ion exchange by Li+, Na+ and alkaline-earth cations under hydrothermal conditions did not produce anhydrous mica phases but resulted in hydrous phases with one or two layers of water molecules between the clay layers. The formation of hydrous phases may be attributed to the high hydration energy of the above cations compared to K+, , RB+ and Cs+. Ion exchange with Al3+ produced a chlorite-like phase because of the hydrolysis of Al3+ under these hydrothermal conditions. These studies are of relevance in the immobilization of wastes where hazardous ions can be fixed in highly stable insoluble phases like mica or chlorite.

scholarly journals MOF Decomposition and Introduction of Repairable Defects Using a Photodegradable Strut

2018 ◽  
Author(s):  
Jingjing Yan ◽  
John MacDonald ◽  
Shawn Burdette
Keyword(s):  
Drug Delivery ◽  
Porous Materials ◽  
New Method ◽  
Innovative Approach ◽  
Partial Decomposition ◽  
Multiple Defects ◽  
Potential Applications ◽  
Defect Repair ◽  
First Time ◽  
Interesting Area

Utilizing a photolabile ligand as MOF strut can make a framework undergo full or partial decomposition upon irradiation. For the first time, a nitrophenylacetate derivative has been incorporated into MOF as a backbone linker via PLSE method. The photo-induced decarboxylation of the NPDAC-MOF represents a novel way of degrading a MOF, which provides an innovative approach to formulating photoresponsive porous materials with potential applications in molecular release and drug delivery. When photoactive linker is mixed with non-photolabile linker via partial PLSE, the MOF structure can be retained after irradiation, but with the introduction of multiple defects, offering a new method to create vacancies in MOFs. Defect repair can be achieved by treatment with replacement ligands, the scope of which is an interesting area for developing customizable MOF contents.<br>

scholarly journals Virus-Like Microfossils in the 1.64 Ga Siliceous Rocks From Hogland Island, Russia

2021 ◽  
Author(s):  
Anatoly Belyaev
Keyword(s):  
Systematic Position ◽  
Base Pairs ◽  
Molecular Weights ◽  
Siliceous Rocks ◽  
Viral Particles ◽  
Unicellular Organisms ◽  
Giant Viruses ◽  
First Time ◽  
The Gulf Of Finland ◽  
Size Of Nuclei

Several varieties of virus-like microfossils, morphologically similar to modern giant viruses of the Mimiviridae family, have been identified in microquartzites in the 1.64 Ga volcanogenic-sedimentary strata in Hogland Island in the Gulf of Finland, Russia. Microquartzites contain graphite enriched in a light carbon isotope 12С, as is typical for the rocks forming with participation of living matter. Abundant remains of silificated and ferruginizated microfossils of planktonic microorganisms and virus-like structures were found in fragments of silificated biofilms. However, virus-like microfossils exceed modern giant viruses in linear dimensions by a factor of a thousand or more (Belyaev, 2018; 2019; Belyaev, Yukhalin, 2021) and contain structures similar to eukaryotic nuclei. In addition, data were obtained that can be interpreted as a fact of parasitic relationships of virus-like formations with microfossils of amoeba-like microorganisms. Inside, and in the immediate surroundings of some virus-like structures, small oval zonal formations occur, which, possibly, represent silificated viral particles, the most ancient obligate super parasites similar to "satellite" virophages in mimiviruses (La Scola, et al., 2008). Apatite grains found in the mineralized cytoplasm and nuclei of virus-like microfossils, most likely, crystallized from phosphoric acid residues of decayed nucleotides. This allowed for the first time to roughly estimate the size of the genomes of the most ancient virus-like structures, which exceeded the genomes of modern giant viruses and unicellular organisms by a factor of thousands (Belyaev, Yukhalin, 2021). The genome masses of eukaryotic microfossils and virus-like structures were also estimated following the principle of genomic-nuclear proportionality, according to which the molecular weights of genomes are directly proportional to the size of the nuclei. In this case, the size of genomes of virus-like structures estimated both form the enclosed apatite grains and the size of nuclei, averaged tens of thousands of picograms and, thus, could contain tens of thousands billions of base pairs. It is assumed that microfossils of virus-like structures from the group of unclear systematic position Dinoviridae Incertae sedis were representatives of the extinct family of unicellular facultative parasites or were the ancestors of giant viruses of the Mimiviridae family.

scholarly journals Detection Probability Analysis of True Random Coding Photon Counting Lidar

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 545
Author(s):  
Yang Yu ◽  
Zhangjun Wang ◽  
Kuntai Ma ◽  
Chao Chen ◽  
Xiufen Wang ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Detection Probability ◽  
Effective Means ◽  
Photon Number ◽  
Photon Counting ◽  
Sequence Length ◽  
Random Coding ◽  
Working Principle ◽  
The Impact ◽  
First Time

With the wide application of lidar in the future, the problem of crosstalk between lidars will become more serious. True random coding photon counting lidar with high anti-crosstalk ability will play an important role in solving this problem. In this paper, based on the working principle of Gm-APD, the detection probability theoretical model of true random coding photon counting lidar is built, and the impact of jitter on detection probability is considered for the first time. The influence of mean echo photon number, mean pulse count density, sequence length and pulse width on detection probability is analyzed. Monte Carlo simulation and experimental results are highly consistent with the theoretical model, which proves the correctness of the detection probability theoretical model. This theoretical model provides an effective means to evaluate the system performance.

scholarly journals Evaluation of anthocyanin encapsulation efficiency into yeast cell by plasmolysis, ethanol, and ultrasound treatments using alone or in combination

Food Research ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 557-562
Author(s):  
M.D. Lieu ◽  
T.T.H. Hoang ◽  
H.N.T. Nguyen ◽  
T.K.T. Dang
Keyword(s):  
Yeast Cell ◽  
Encapsulation Efficiency ◽  
Color Stability ◽  
Water Soluble ◽  
Impact Factors ◽  
Time Treatment ◽  
Treated Sample ◽  
Potential Applications ◽  
The Individual ◽  
First Time

Anthocyanin is a water-soluble color compound of the flavonoid which was successfully encapsulation in Saccharomyces cerevisiae by plasmolysis, ethanol, and ultrasound treatments using alone or in combination in the first time. Treatment agents significantly enhanced the encapsulation efficiency of anthocyanin fluid. The encapsulation yield (EY) of the combined factors was higher than the individual impact factors. Ethanol 10% (v/v) and ultrasound 180 seconds for the highest EY 40.22±0.67%, then ethanol 10% (v/v) and NaCl 10% (w/v) for EY 36.45±0.35%, NaCl 10% and ultrasound for EY 32.14±0.98% lowest. The color stability evaluation of the capsules was carried out at 80°C for 30 minutes. The color lost rate was determined by the spectrometer. The color loss of samples with the un-treatment yeast was 20.45±1.21%, higher than the treated sample. This suggests that anthocyanin encapsulation by yeast cell is efficient in overcoming the effects of high temperatures and having potential applications in food processing.

scholarly journals Validation and characterization of a DNA methylation alcohol biomarker across the life course

2019 ◽  
Author(s):  
Paul Darius Yousefi ◽  
Rebecca Richmond ◽  
Ryan Langdon ◽  
Andrew Ness ◽  
Chunyu Liu ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Parents And Children ◽  
Average Alcohol ◽  
Alcohol Biomarker ◽  
Audit Score ◽  
Potential Applications ◽  
The Life Course ◽  
Offspring Generation ◽  
First Time

AbstractRecently, an alcohol predictor was developed using DNA methylation at 144 CpG sites (DNAm-Alc) as a biomarker for improved clinical or epidemiologic assessment of alcohol-related ill health. We validate the performance and characterize the drivers of this DNAm-Alc for the first time in independent populations. In N=1,049 parents from the Avon Longitudinal Study of Parents and Children (ALSPAC) Accessible Resource for Integrated Epigenomic Studies (ARIES) at midlife, we found DNAm-Alc explained 7.6% of the variation in alcohol intake, roughly half of what had been reported previously, and interestingly explained a larger 9.8% of AUDIT score, a scale of alcohol use disorder. Explanatory capacity in participants from the offspring generation of ARIES measured during adolescence was much lower. However, DNAm-Alc explained 14.3% of the variation in replication using the Head and Neck 5000 (HN5000) clinical cohort that had higher average alcohol consumption. To investigate whether this relationship was being driven by genetic and/or earlier environment confounding we examined how earlier vs. concurrent DNAm-Alc measures predicted AUDIT scores. In both ARIES parental and offspring generations, we observed associations between AUDIT and concurrent, but not earlier DNAm-Alc, suggesting independence from genetic and stable environmental contributions. The stronger relationship between DNAm-Alcs and AUDIT in parents at midlife compared to adolescents despite similar levels of consumption suggests that DNAm-Alc likely reflects long-term patterns of alcohol abuse. Such biomarkers may have potential applications for biomonitoring and risk prediction, especially in cases where reporting bias is a concern.

The effect of plasticization on the properties of poly(urethaneureas) based on oligoether diols, 2,4-toluenediisocyanate, and aromatic diamines

2018 ◽  
Vol 51 (4) ◽  
pp. 337-358 ◽  
Author(s):  
Vasiliy Tereshatov ◽  
Marina Makarova ◽  
Valeriy Senichev ◽  
Zhanna Vnutskikh ◽  
Tamara Oshchepkova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Arctic Climate ◽  
The Arctic ◽  
Aromatic Diamines ◽  
Plasticization Effect ◽  
Soft Segments ◽  
Potential Applications ◽  
Partial Crystallization ◽  
First Time

Segmented poly(urethaneureas) (SPUUs) modified with low glass transition temperature chemically inert liquids are of interest due to their controllable properties and potential applications under various environmental conditions. Investigation into the influence of plasticizers on the properties of SPUUs based on oligotetramethyleneoxide diol (polytetramethyleneoxide), oligopropyleneoxide diol (polypropyleneoxide), 2,4-toluenediisocyanate, Ethacure-300, and methylene-bis- o-chloroaniline was conducted. Partial crystallization of polytetramethyleneoxide segments was identified during cooling of some SPUU samples plasticized by di-(2-ethylhexyl)sebacate (DEHS) and tributyl phosphate. Polypropyleneoxide segments did not crystallize under the same conditions. A low crystallization temperature for the amorphous component of the polymer matrix in SPUU (−100°C to 103°C) was attained at a molecular mass ( Mn) of soft segments equal to 2000 g mol−1 and a DEHS concentration equal to 40–45%. A relationship between the mechanical properties of plasticized SPUU, microphase segregation, and dilution of the polymer matrix was found. For the first time, the effect of dilution with plasticizer on the strength of elastomers was considered. The plasticization effect on the mechanical properties of SPUU was investigated in the temperature diapason from 50°C to −70°C. The results of these investigations can be used in various technologies including the design of SPUUs with high elastic properties at temperatures as low as −70°C, typical of extreme conditions of the Arctic climate.

scholarly journals Saccharomyces paradoxus Transcriptional Alterations in Cells of Distinct Phenotype and Viral dsRNA Content

2020 ◽  
Vol 8 (12) ◽  
pp. 1902
Author(s):  
Bazilė Ravoitytė ◽  
Juliana Lukša ◽  
Vyacheslav Yurchenko ◽  
Saulius Serva ◽  
Elena Servienė
Keyword(s):  
Food Industry ◽  
Antifungal Agents ◽  
Acid Biosynthesis ◽  
Viral Dsrna ◽  
Saccharomyces Paradoxus ◽  
Distinct Phenotype ◽  
Transcriptional Alterations ◽  
Potential Applications ◽  
Dsrna Viruses ◽  
First Time

Killer yeasts are attractive antifungal agents with great potential applications in the food industry. Natural Saccharomyces paradoxus isolates provide new dsRNA-based killer systems available for investigation. The presence of viral dsRNA may alter transcriptional profile of S. paradoxus. To test this possibility, a high-throughput RNA sequencing was employed to compare the transcriptomes of S. paradoxus AML 15-66 K66 killer strains after curing them of either M-66 alone or both M-66 and L-A-66 dsRNA viruses. The S. paradoxus cells cured of viral dsRNA(s) showed respiration deficient or altered sporulation patterns. We have identified numerous changes in the transcription profile of genes including those linked to ribosomes and amino acid biosynthesis, as well as mitochondrial function. Our work advance studies of transcriptional adaptations of Saccharomyces spp. induced by changes in phenotype and set of dsRNA viruses, reported for the first time.

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