Low molecular weight components in bovine semen diffusate and their effects on motility of bull sperm

1994 ◽  
Vol 6 (2) ◽  
pp. 165 ◽  
Author(s):  
N al-Somai ◽  
R Vishwanath ◽  
P Shannon ◽  
PC Molan
Keyword(s):  
Molecular Weight ◽  
Sperm Motility ◽  
Seminal Plasma ◽  
Detrimental Effect ◽  
Gel Permeation Chromatography ◽  
Low Molecular Weight ◽  
Small Molecular Weight ◽  
Bovine Semen ◽  
Molecular Weights ◽  
Sperm Survival

Dialysis of diluted semen before cryopreservation is beneficial to sperm survival. This is due to removal of low molecular weight components from seminal plasma that are damaging to sperm. The apparent molecular weights (M(r)) of these components range between 1000 and 12,000 as estimated by gel permeation chromatography and electrophoresis. The detrimental effect on sperm motility is greatest with the components of M(r) between 5000 and 12,000 and with those of M(r) < 1500. Their effect on sperm motility was dependent on concentration. The small molecular weight components were derived from the high molecular weight components of seminal plasma through disaggregation under prescribed conditions.

Comparison of Number—Average Molecular Weights Calculated by GPC and Membrane Osmometry

1973 ◽  
Vol 46 (1) ◽  
pp. 115-126
Author(s):  
M. R. Ambler ◽  
R. D. Mate
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Appreciable Amount ◽  
Diffusion Limit ◽  
Low Molecular Weight ◽  
Molecular Weights ◽  
True Value ◽  
Usual Manner ◽  
Gel Permeation ◽  
Polymer Species

Abstract Data are presented which show that when a polymer contains an appreciable amount of low molecular weight species below the diffusion limit of the osmometer membrane, the osmotic molecular weight, Mn, is generally higher than the Mn calculated from gel-permeation chromatography (GPC). Experiments were performed on samples of poly(vinylchloride) (PVC) and high-cis poly (butadiene) polymers. Osmotic data were obtained in the usual manner, while GPC data were obtained using the universal calibration approach. It was found that when all polymer species below approximately 10,000 molecular weight were excluded from the calculation of Mn by GPC, agreement in Mn was obtained between membrane osmometry and GPC. The data obtained suggest that the choice of Mn as measured by membrane osmometry in the calibration of the GPC should not be done casually, as the measured Mn may not reflect the “true” value of that sample, especially when the polymer sample contains an appreciable amount of low molecular weight material.

scholarly journals Synthesis, structure and thermogravimetric analysis of α,ω-telechelic polydimethylsiloxanes of low molecular weight

2017 ◽  
Vol 82 (12) ◽  
pp. 1395-1416 ◽  
Author(s):  
Aleksandra Tasic ◽  
Marija Pergal ◽  
Malisa Antic ◽  
Vesna Antic
Keyword(s):  
Molecular Weight ◽  
Thermogravimetric Analysis ◽  
Degradation Mechanism ◽  
Gel Permeation Chromatography ◽  
Polymer Chains ◽  
Low Molecular Weight ◽  
Dilute Solution ◽  
Molecular Weights ◽  
Dilute Solution Viscometry

A series of ?,?-telechelic polydimethylsiloxanes (PDMS), with predetermined molecular weights of about 2500 g mol-1, was synthesized by siloxane equilibration reaction. Syntheses were performed using octamethylcyclotetrasiloxane (D4) and various disiloxanes: hexamethyldisiloxane (HMDS), 1,1,3,3-tetramethyldisiloxane (TMDS), 1,3-divinyltetramethyldisiloxane (DVTMDS), 1,3-bis(3-carboxypropyl)tetramethyldisiloxane (DCPTMDS) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (DAPTMDS). The role of the disiloxane was to introduce terminal functional groups at the end of the polymer chains and to control the molecular weight of the polymers. Polymers with trimethyl, hydrido, vinyl, carboxypropyl and aminopropyl end-groups were obtained in this way. The structure of the ?,?-telechelic PDMSs was confirmed by NMR and IR spectroscopy. The molecular weights of the polymers were determined by 1H-NMR, gel permeation chromatography (GPC) and dilute solution viscometry. Thermogravimetric analysis (TGA) under nitrogen and air showed that the type of the terminal groups significantly influenced the thermal and thermo-oxidative stability, as well as the degradation mechanism of the ?,?-telechelic PDMSs.

Ultra-low-molecular-weight heparins: Precise structural features impacting specific anticoagulant activities

2013 ◽  
Vol 109 (03) ◽  
pp. 471-478 ◽  
Author(s):  
Marcelo Lima ◽  
Christian Viskov ◽  
Frederic Herman ◽  
Angel Gray ◽  
Eduardo de Farias ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Structural Data ◽  
Monosaccharide Composition ◽  
Structural Features ◽  
Therapeutic Agents ◽  
Resonance Spectroscopy ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Molecular Weights

SummaryUltra-low-molecular-weight heparins (ULMWHs) with better efficacy and safety ratios are under development; however, there are few structural data available. The main structural features and molecular weight of ULMWHs were studied and compared to enoxaparin. Their monosaccharide composition and average molecular weights were determined and preparations studied by nuclear magnetic resonance spectroscopy, scanning ultraviolet spectroscopy, circular dichroism and gel permeation chromatography. In general, ULMWHs presented higher 3-O-sulphated glucosamine and unsaturated uronic acid residues, the latter being comparable with their higher degree of depolymerisation. The analysis showed that ULMWHs are structurally related to LMWHs; however, their monosaccharide/oligosaccharide compositions and average molecular weights differed considerably explaining their different anticoagulant activities. The results relate structural features to activity, assisting the development of new and improved therapeutic agents, based on depolymerised heparin, for the prophylaxis and treatment of thrombotic disorders.

Molecular Weight Measurements of Low Molecular Weight Heparins by Gel Permeation Chromatography

1997 ◽  
Vol 77 (04) ◽  
pp. 668-674 ◽  
Author(s):  
B Mulloy ◽  
C Gee ◽  
S F Wheeler ◽  
R Wait ◽  
E Gray ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Molecular Weights ◽  
Calibration Table ◽  
Gel Permeation ◽  
Degraded Material

SummaryThe molecular weight profiles of low molecular weight heparin samples have been measured by high-performance gel permeation chromatography using as calibrant the heparinase-degraded material (90/686) now established as the 1st International Reference Preparation (IRP) Low Molecular Weight Heparin for Molecular Weight Calibration. Use of the calibrant as a broad molecular weight standard is described and a calibration table provided based on data collected over several years in one laboratory.In order to confirm the assignment of degree of polymerisation to resolved oligosaccharide peaks in the calibrant, molecular weights of oligosaccharides fractionated from the 1st IRP were independently determined by fast atom bombardment mass spectrometry (FAB MS).The molecular weight distributions of commercial low molecular weight heparins have been characterized. Measurements of molecular weight parameters of heparin molecular weight standards from several sources provide comparisons between the molecular weight scales of this and other studies.

scholarly journals Specific Seminal Plasma Fractions Are Responsible for the Modulation of Sperm–PMN Binding in the Donkey

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1388
Author(s):  
Jordi Miró ◽  
Jaime Catalán ◽  
Henar Marín ◽  
Iván Yánez-Ortiz ◽  
Marc Yeste
Keyword(s):  
Molecular Weight ◽  
Sperm Motility ◽  
Seminal Plasma ◽  
Potential Effect ◽  
Polymorphonuclear Neutrophils ◽  
Low Fertility ◽  
Plasma Fractions ◽  
Complex Fluid ◽  
First Time

While artificial insemination (AI) with frozen-thawed sperm results in low fertility rates in donkeys, the addition of seminal plasma, removed during cryopreservation, partially counteracts that reduction. Related to this, an apparent inflammatory reaction in jennies is induced following AI with frozen-thawed sperm, as a high amount of polymorphonuclear neutrophils (PMN) are observed within the donkey uterus six hours after AI. While PMN appear to select the sperm that ultimately reach the oviduct, two mechanisms, phagocytosis and NETosis, have been purported to be involved in that clearance. Remarkably, sperm interacts with PMN, but the presence of seminal plasma reduces that binding. As seminal plasma is a complex fluid made up of different molecules, including proteins, this study aimed to evaluate how different seminal plasma fractions, separated by molecular weight (<3, 3–10, 10–30, 30–50, 50–100, and >100 kDa), affect sperm–PMN binding. Sperm motility, viability, and sperm–PMN binding were evaluated after 0 h, 1 h, 2 h, 3 h, and 4 h of co-incubation at 38 °C. Two seminal plasma fractions, including 30–50 kDa or 50–100 kDa proteins, showed the highest sperm motility and viability. As viability of sperm not bound to PMN after 3 h of incubation was the highest in the presence of 30–50 and 50–100 kDa proteins, we suggest that both fractions are involved in the control of the jenny’s post-breeding inflammatory response. In conclusion, this study has shown for the first time that specific fractions rather than the entire seminal plasma modulate sperm–PMN binding within the donkey uterus. As several proteins suggested to be involved in the control of post-AI endometritis have a molecular weight between 30 and 100 kDa, further studies aimed at determining the identity of these molecules and evaluating their potential effect in vivo are much warranted.

Probing the molecular weights of sweetgum and pine kraft lignin fractions

TAPPI Journal ◽  
2021 ◽  
Vol 20 (6) ◽  
pp. 381-391
Author(s):  
JULIANA M. JARDIM ◽  
PETER W. HART ◽  
LUCIAN LUCIA ◽  
HASAN JAMEEL
Keyword(s):  
Molecular Weight ◽  
Black Liquor ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Systematic Investigation ◽  
Kraft Pulping ◽  
Molecular Weights ◽  
Lignin Recovery ◽  
Lignin Reactivity ◽  
Kinetics Of

The present investigation undertook a systematic investigation of the molecular weight (MW) of kraft lignins throughout the pulping process to establish a correlation between MW and lignin recovery at different extents of the kraft pulping process. The evaluation of MW is crucial for lignin characterization and utilization, since it is known to influence the kinetics of lignin reactivity and its resultant physicochemical properties. Sweetgum and pine lignins precipitated from black liquor at different pHs (9.5 and 2.5) and different extents of kraft pulping (30–150 min) were the subject of this effort. Gel permeation chromatography (GPC) was used to deter- mine the number average molecular weight (Mn), mass average molecular weight (Mw), and polydispersity of the lignin samples. It was shown that the MW of lignins from both feedstocks follow gel degradation theory; that is, at the onset of the kraft pulping process low molecular weightlignins were obtained, and as pulping progressed, the molecular weight peaked and subsequently decreased. An important finding was that acetobromination was shown to be a more effective derivatization technique for carbohydrates containing lignins than acetylation, the technique typically used for derivatization of lignin.

scholarly journals Characterisation of Sequential Solvent Fractionation and Base-catalysed Depolymerisation of Treated Alkali Lignin

BioResources ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. 4137-4151 ◽  
Author(s):  
Aikfei Ang ◽  
Zaidon Ashaari ◽  
Edi Suhaimi Bakar ◽  
Nor Azowa Ibrahim
Keyword(s):  
Molecular Weight ◽  
Chemical Structure ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Solubility Parameters ◽  
Low Molecular Weight ◽  
Sequential Fractionation ◽  
Weight Average Molecular Weight ◽  
Solvent Fractionation ◽  
Alkali Lignin

An alkali lignin (OL) with a weight-average molecular weight (Mw) of 11646 g/mol was used to prepare low-molecular weight lignin for resin synthesis. The low-molecular weight lignin feedstock was obtained via base-catalysed depolymerisation (BCD) treatments at different combined severity factors. Sequential fractionation of the OL and BCD-treated lignins using organic solvents with different Hildebrand solubility parameters were used to alter the homogeneity of the OL. The yield and properties of OL itself and OL and BCD-treated OL dissolved in propan-1-ol (F1), ethanol (F2), and methanol (F3) were determined. Regardless of the treatment applied, a small amount of OL was dissolved in F1 and F2. The BCD treatment did not increase the yield of F1 but did increase the yields of F2 and F3. Gel permeation chromatography (GPC) showed that the repolymerization reaction occurred in F3 for all BCD-treated OL, so these lignins were not suitable for use as feedstocks for resin production. The GPC, 13Carbon-nuclear magnetic resonance, and Fourier transform infrared spectroscopy analyses confirmed that the F3 in OL exhibited the optimum yield, molecular weight distribution, and chemical structure suitable for use as feedstocks for resin synthesis.

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