Fractionation of wheat straw Dioxane lignin reveals molar mass dependent structural differences

Summary The effect of hydrogen peroxide bleaching on the structure of thermomechanical (TMP) and chemothermomechanical (CTMP) wheat straw paper pulps was investigated. The results obtained by thioacidolysis indicated that the TMP treatment did not significantly affect the ß-0-4 structures of lignins whereas, the alkali conditions of sulfonation (CTMP) and bleaching induced the cleavage of the ß-0-4 bonds and an increase in the S/G ratio. Moreover, it was concluded that bleaching and sulfonation are responsible for the partial solubilisation of the p-coumaric and ferulic acid esters. The ethers of p-coumaric acid are not significantly affected by these treatments whereas, the ethers of ferulic acid are degraded, as shown by acidolysis data. These results underline the structural differences of wheat straw pulps compared to wood pulps.

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Molar mass dependent spatial distribution of form II to I transition inside spherulites of disentangled isotactic Poly(1-butene) revealed by scanning Confocal Raman microscopy

Polymer ◽

10.1016/j.polymer.2022.124529 ◽

2022 ◽

pp. 124529

Author(s):

Beibei Wu ◽

Yuqing Lai ◽

Yongfeng Men

Keyword(s):

Spatial Distribution ◽

Molar Mass ◽

Raman Microscopy ◽

Confocal Raman Microscopy ◽

Confocal Raman ◽

Mass Dependent

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High Resolution Observations of Ion-Milling Induced Transformation in Synthetic Hollandses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097259 ◽

1981 ◽

Vol 39 ◽

pp. 114-115 ◽

Cited By ~ 1

Author(s):

T. J. Headley

Keyword(s):

High Resolution ◽

Radioactive Waste Disposal ◽

Ion Milling ◽

Minor Elements ◽

Waste Forms ◽

Carbon Substrates ◽

Structural Differences ◽

Oxide Phases ◽

Argon Ions ◽

High Resolution Microscopy

Oxide phases having the hollandite structure have been identified in multiphase ceramic waste forms being developed for radioactive waste disposal. High resolution studies of phases in the waste forms described in Ref. [2] were initiated to examine them for fine scale structural differences compared to natural mineral analogs. Two hollandites were studied: a (Ba,Cs,K)-titan-ate with minor elements in solution that is produced in the waste forms, and a synthesized BaAl2Ti6O16 phase containing ∼ 4.7 wt% Cs2O. Both materials were consolidated by hot pressing at temperatures above 1100°C. Samples for high resolution microscopy were prepared both by ion-milling (7kV argon ions) and by crushing and dispersing the fragments on holey carbon substrates. The high resolution studies were performed in a JEM 200CX/SEG operating at 200kV.

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CHEMISTRY OF GONADOTROPHINS IN RELATION TO THEIR ANTIGENIC PROPERTIES

Acta Endocrinologica ◽

10.1530/acta.0.062s013 ◽

1969 ◽

Vol 62 (1_Suppl) ◽

pp. S13-S30 ◽

Cited By ~ 8

Author(s):

W. R. Butt

Keyword(s):

Biological Activity ◽

Guinea Pigs ◽

Complement Fixation ◽

Neuraminic Acid ◽

Fixation Technique ◽

Immunological Activity ◽

Antigenic Properties ◽

Specific Antisera ◽

Structural Differences

ABSTRACT Several chemical differences between FSH, LH and HCG have been reported: thus LH and HCG are richer in proline than FSH and FSH and HCG contain more N-acetyl neuraminic acid than LH. Sub-units of LH are formed by treatment with urea, guanidine or acid. HCG also may contain two sub-units. The sub-units from LH are biologically inert but retain their immunological activity: biological activity is restored when the sub-units are incubated together. There is much evidence from chemical and enzymic reactions that antigenic groups are distinct from those parts of the molecule essential for biological activity. N-acetyl neuraminic acid and probably other carbohydrates in FSH and HCG are not involved in immunological activity but are necessary for biological activity. Histidine, methionine and possibly cysteine appear to be essential for biological but not immunological activity of FSH, while tryptophan and possibly tyrosine are not essential for either. A few highly specific antisera to gonadotrophins have been prepared in rabbits and guinea pigs to crude antigens: there is no evidence that purified antigens are more likely to produce specific antisera. Differences in the immunological reactivities of urinary compared with pituitary gonadotrophins have been observed both by radioimmunoassay and by the complement fixation technique. The latter may be particularly useful for detecting structural differences in the hormones.

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