scholarly journals Encoding function into polypeptide-oligonucleotide precision biopolymers

2018 ◽  
Vol 54 (83) ◽  
pp. 11797-11800 ◽  
Author(s):  
Weina Liu ◽  
Felix Boldt ◽  
Yu Tokura ◽  
Tao Wang ◽  
Bikram Keshari Agrawalla ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Molecular Weights ◽  
Novel Synthesis ◽  
Synthesis Strategy ◽  
Chain Lengths

We report a novel synthesis strategy to prepare precision polymers providing exact chain lengths, molecular weights and monomer sequences that allow post modifications by convenient DNA hybridization.

Immuno-compatibility of desaminotyrosine and desaminotyrosyl tyrosine functionalized star-shaped oligo(ethylene glycol)s with different molecular weights

2015 ◽  
Vol 1718 ◽  
pp. 97-102 ◽  
Author(s):  
Toralf Roch ◽  
Konstanze K. Julich-Gruner ◽  
Axel T. Neffe ◽  
Nan Ma ◽  
Andreas Lendlein
Keyword(s):  
Aqueous Solution ◽  
Ethylene Glycol ◽  
Average Molecular Weight ◽  
Molecular Weights ◽  
Immunological Effects ◽  
Microbial Products ◽  
Low Levels ◽  
Chain Lengths ◽  
Immunological Evaluation

ABSTRACTPolymer-based therapeutic strategies require biomaterials with properties and functions tailored to the demands of specific applications leading to an increasing number of newly designed polymers. For the evaluation of those new materials, comprehensive biocompatibility studies including cyto-, tissue-, and immunocompatibility are essential. Recently, it could be demonstrated that star-shaped amino oligo(ethylene glycol)s (sOEG) with a number average molecular weight of 5 kDa and functionalized with the phenol-derived moieties desaminotyrosine (DAT) or desaminotyrosyl tyrosine (DATT) behave in aqueous solution like surfactants without inducing a substantial cytotoxicity, which may qualify them as solubilizer for hydrophobic drugs in aqueous solution. However, for biomedical applications the polymer solutions need to be free of immunogenic contaminations, which could result from inadequate laboratory environment or contaminated starting material. Furthermore, the materials should not induce uncontrolled or undesired immunological effects arising from material intrinsic properties. Therefore, a comprehensive immunological evaluation as perquisite for application of each biomaterial batch is required. This study investigated the immunological properties of sOEG-DAT(T) solutions, which were prepared using sOEG with number average molecular weights of 5 kDa, 10 kDa, and 20 kDa allowing analyzing the influence of the sOEG chain lengths on innate immune mechanisms. A macrophage-based assay was used to first demonstrate that all DAT(T)-sOEG solutions are free of endotoxins and other microbial contaminations such as fungal products. In the next step, the capacity of the different DAT(T)-functionalized sOEG solutions to induce cytokine secretion and generation of reactive oxygen species (ROS) was investigated using whole human blood. It was observed that low levels of the pro-inflammatory cytokines interleukin(IL)-1β and IL-6 were detected for all sOEG solutions but only when used at concentrations above 250 µg·mL-1. Furthermore, only the 20 kDa sOEG-DAT induced low amounts of ROS-producing monocytes. Conclusively, the data indicate that the materials were not contaminated with microbial products and do not induce substantial immunological adverse effectsin vitro,which is a prerequisite for future biological applications.

The Use of Froth Flotation for Selective Separation of Plastic Wastes from Soil

2021 ◽  
Vol 6 (4) ◽  
pp. 135-138
Author(s):  
Kofi Moro ◽  
Dorothy A. Dechie
Keyword(s):  
Surface Properties ◽  
Polyethylene Terephthalate ◽  
Tannic Acid ◽  
Froth Flotation ◽  
Selective Separation ◽  
Composite Sample ◽  
Molecular Weights ◽  
Plastic Wastes ◽  
Chain Lengths ◽  
Selective Separations

  The Use of Froth Flotation for Selective Separation of Plastic Wastes from Soil   Kofi Moro and Dorothy A. Dechie   Abstract — In recycling of plastics, unless the goal is to form composites or materials having special properties, it is not advisable to mix plastics of different kinds because of the differences in their molecular weights and chain lengths. Hence, there is the need to separate these plastics when they are mixed before recycle can be done. This project investigated the selective separation of Polypropylene (PP), Polystyrene (PS) and Polyethylene terephthalate (PET) plastics out of soils using froth flotation. Pulverized samples were prepared from post-consumer plastic sources (PP, PS and PET) and soil and mixed uniformly to form a composite sample. The composite sample was subjected to froth flotation. Two tests were performed. A first test, where there was no addition of a depressant (tannic acid), and a second test, where there was addition of tannic acid to depress some of the plastics in order to selectively separate them. Recoveries from each test work indicated that, plastics are naturally hydrophobic and can be floated out of soils without modifying their surface properties. However, selective separations of the plastics were achieved when tannic acid was used to modify the surface properties of the plastic types.

Light driven growth of silver nanoplatelets on 2D MoS2 nanosheet templates

2015 ◽  
Vol 3 (18) ◽  
pp. 4771-4778 ◽  
Author(s):  
T. Daeneke ◽  
B. J. Carey ◽  
A. F. Chrimes ◽  
J. Zhen Ou ◽  
D. W. M. Lau ◽  
...  
Keyword(s):  
Metallic Silver ◽  
Direct Excitation ◽  
Novel Synthesis ◽  
Synthesis Strategy ◽  
Mos2 Nanosheet ◽  
Planar Growth

This work investigates a novel synthesis strategy for the functionalisation of 2D MoS2 nanosheets with silver. Direct excitation of the MoS2 bandgap was found to lead to the photodeposition and eventual planar growth of metallic silver on the 2D MoS2 nanosheet templates.

Identification of fatty acids from butterfat using a combined gas chromatograph-mass spectrometer

1967 ◽  
Vol 34 (2) ◽  
pp. 115-121 ◽  
Author(s):  
Ragnar Ryhage
Keyword(s):  
Fatty Acids ◽  
Mass Spectrometer ◽  
Methyl Esters ◽  
Acid Methyl Ester ◽  
Straight Chain ◽  
Molecular Weights ◽  
Acid Methyl ◽  
Branched Chain ◽  
Chain Lengths

SummaryThe identification and approximate quantitative determination of methyl esters of fatty acids from commercial butterfat was obtained with a combined gaschromatograph-mass spectrometer instrument. Fifty-two components, straight chain saturated and unsaturated, as well as branched chain compounds, were identified. Seven monomethyl saturated fatty acid methyl ester isomers were identified for both C15 and C17, i.e. with chain lengths of 14 and 16 carbon atoms, respectively. Multibranched fatty acids with molecular weights of 326 and 368 were found. The results were obtained in one day.

Physical characteristics of DNA from bacteriophages of Agrobacterium tumefaciens

1976 ◽  
Vol 22 (10) ◽  
pp. 1583-1585 ◽  
Author(s):  
R. J. Manasse ◽  
R. C. Staples
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Dna Hybridization ◽  
Physical Characteristics ◽  
Molecular Weights ◽  
Phage Dna

DNA was extracted from isolates of bacteriophages grown on virulent and avirulent strains of Agrobacterium tumefaciens. Molecular weights of DNA from phages isolated from the virulent A. tumefaciens (IIBV7) were about 41.5 × 106 daltons, while those from the avirulent A. tumefaciens (IIBNV6) were about 32.5 × 106 daltons. The buoyant densities of the four DNA's ranged from 1.7086 to 1.7089 g/cm3 values that were not significantly different. DNA–DNA hybridization studies also indicated that the four phages were closely related. Attempts to induce tumors with phage DNA were unsuccessful.

scholarly journals Analysis of Network Structures in Thiol-Ene UV Curing System Using Reworkable Resins

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 5 ◽  
Author(s):  
Haruyuki Okamura ◽  
Masashi Yamagaki ◽  
Kyohei Nakata
Keyword(s):  
Chain Length ◽  
Uv Curing ◽  
Size Exclusion ◽  
Network Structures ◽  
Thiol Compounds ◽  
Molecular Weights ◽  
Degraded Samples ◽  
Exclusion Chromatography ◽  
Chain Lengths ◽  
Acrylate Monomers

An analysis of the network structures in thiol-ene UV curing resins was carried out using reworkable resins composed of di(meth)acrylate monomers having tertiary ester linkages. The effect of the functionality of the thiols, the functional ratio of the thiol and ene functions, their conversions and curing atmosphere on the chain lengths was discussed. A mixture of (meth)acrylates, thiol compounds, a photoradical initiator, and a photoacid generator was cured by irradiation at 365 nm. The cured samples were degraded by heating after irradiation at 254 nm. Size exclusion chromatography (SEC) and 1H NMR analyses of the degraded samples were carried out after the methylation. The crosslinking conditions strongly affected the network structures. The degraded samples have molecular weights between 250 and 2700. The molecular weights of the degraded resins increased with the functionality of the thiol compounds. The chain length dependence suggests that thiol compounds with a high functionality have a low reactivity due to steric hindrance. The chain lengths of the degraded networks were nearly proportional to the concentration of the (meth)acrylate monomers. The addition of reactive diluents enhanced the reactivity and increased the chain length.

Interfacial superassembly of MoSe2@Ti2N MXene hybrids enabling promising lithium-ion storage

CrystEngComm ◽  
2020 ◽  
Vol 22 (36) ◽  
pp. 5995-6002
Author(s):  
Hui Zong ◽  
Le Hu ◽  
Zhenguo Wang ◽  
Ke Yu ◽  
Shijing Gong ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Novel Synthesis ◽  
Synthesis Strategy ◽  
Ion Storage

Our work presents an interfacial superassembly by engineering MoSe2 nanoflowers coupled with ribbon-like Ti2N MXene frameworks. It can provide a novel synthesis strategy to improve the performance of LIBs.

scholarly journals Tailoring Performance, Damping, and Surface Properties of Magnetorheological Elastomers via Particle-Grafting Technology

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1411 ◽  
Author(s):  
Martin Cvek ◽  
Miroslav Mrlik ◽  
Jakub Sevcik ◽  
Michal Sedlacik
Keyword(s):  
Molecular Weight ◽  
Surface Roughness ◽  
Surface Properties ◽  
Carbonyl Iron ◽  
Magnetorheological Elastomers ◽  
Molecular Weights ◽  
Magnetorheological Effect ◽  
Novel Concept ◽  
Chain Lengths ◽  
Damping Capability

A novel concept based on advanced particle-grafting technology to tailor performance, damping, and surface properties of the magnetorheological elastomers (MREs) is introduced. In this work, the carbonyl iron (CI) particles grafted with poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) of two different molecular weights were prepared via surface-initiated atom transfer radical polymerization and the relations between the PHEMATMS chain lengths and the MREs properties were investigated. The results show that the magnetorheological performance and damping capability were remarkably influenced by different interaction between polydimethylsiloxane chains as a matrix and PHEMATMS grafts due to their different length. The MRE containing CI grafted with PHEMATMS of higher molecular weight exhibited a greater plasticizing effect and hence both a higher relative magnetorheological effect and enhanced damping capability were observed. Besides bulk MRE properties, the PHEMATMS modifications influenced also field-induced surface activity of the MRE sheets, which manifested as notable changes in surface roughness.

Controlling the nucleation process of InP/ZnS quantum dots using zeolite as a nucleation site

CrystEngComm ◽  
2020 ◽  
Vol 22 (20) ◽  
pp. 3474-3481
Author(s):  
Xiaopeng Zhou ◽  
Jiejun Ren ◽  
Xuan Dong ◽  
Xicheng Wang ◽  
Takatoshi Seto ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Nucleation Site ◽  
Emission Wavelength ◽  
Nucleation Process ◽  
Novel Synthesis ◽  
Synthesis Strategy

A novel synthesis strategy to adjust the emission wavelength of InP/ZnS quantum dots, using zeolite as a quantum dot nucleation template.

Isoprene and Rubber. Part 45. Viscosity Measurements of Solutions of Rubber and Hydrorubber in Various Solvents

1936 ◽  
Vol 9 (4) ◽  
pp. 579-584
Author(s):  
H. Staudinger ◽  
H. P. Mojen
Keyword(s):  
Carbon Tetrachloride ◽  
Chain Length ◽  
Homologous Series ◽  
Chlorinated Solvents ◽  
Cellulose Derivatives ◽  
Specific Viscosity ◽  
Molecular Weights ◽  
Rubber Part ◽  
Viscous Solutions ◽  
Chain Lengths

Abstract It has been observed many times that solutions of the same concentration of rubber in various solvents show marked differences in viscosity. For example, solutions of rubber in chlorinated solvents such as carbon tetrachloride have higher viscosities than do solutions of the same concentration in benzene or benzine. These differences in viscosity are attributable to the fact that the rubber molecules are solvated in different ways in the various solvents. It may be further assumed that in a particular homologous series of polymers, all members, i. e., substances of both high and low molecular weights, are solvated in the same solvent in the same way, for only in this way is it possible to believe that the specific viscosity of solutions of like concentration increases with increase in the chain length, as has been found to be true of cellulose derivatives. In the previous experiments with squalene and hydrosqualene (cf. preceding article), the constants necessary for calculating molecular weights and chain member indices n were determined. The constants for carbon tetrachloride are higher than those for benzene. In the case of squalene, therefore, as in the case of rubber, carbon tetrachloride gives more viscous solutions than does benzene. If, now, rubbers and hydrorubbers are solvated in the same way as squalene and hydrosqualene, then the same chain lengths of an homologous series of rubber polymers would be obtained by calculations using constants derived from the simple compounds of the chain member index, and from this the degrees of polymerization, are calculated by means of these constants in the formula:

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