Swelling Degree of Carrageenan-Corncob Bead Gel in Various Media

Smart hydrogels which can change their swelling behavior and other properties in response to environmental stimuli such as temperature, pH, solvent composition and electric fields, have attracted great interest as chemical sensor material and controlled release system. The pH stimulus responsive hydrogels were synthesized by gamma-irradiation graft copolymerization of chitosan-acrylamide. In this research the influence of deacetylation process on the hydrogels characterization were investigated by measuring grafting efficiency, gel fraction, swelling degree, and crosslink density. Evidence of grafting was confirmed by FTIR spectroscopy. X-ray diffraction showed reduction in the crystallinity of chitosan with different deacetylation process also after the graft copolymerization reaction. The results showed that decreasing acetyl group of chitosan increase the grafting efficiency, gel fraction and swelling degree. While crystallinity decreased. The hydrogels indicated pH-dependent swelling behaviour.

Download Full-text

Celastrol Exerts Cardioprotective Effect in Rheumatoid Arthritis by Inhibiting TLR2/HMGB1 Signaling Pathway-Mediated Autophagy

International Archives of Allergy and Immunology ◽

10.1159/000517185 ◽

2021 ◽

pp. 1-10

Author(s):

Xiaohong Lu ◽

Sha Gong ◽

Xiaojun Wang ◽

Nan Hu ◽

Dan Pu ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Inflammatory Cytokines ◽

Rat Model ◽

Cell Apoptosis ◽

Signal Pathway ◽

Index Score ◽

Cardioprotective Effect ◽

Rat Cardiomyocytes ◽

Swelling Degree ◽

Collagen Iii

Objective: Rheumatoid arthritis (RA) is a kind of chronic inflammatory disease characterized by the release of inflammatory cytokines and cardiomyocyte apoptosis, which lead to increased riskfor heart diseases. This study aims to explore the possible effect and mechanism of Celastrol on RA induced cardiac impairments in rats. Methods: Collagen induced RA wistar rat models (CIA) were established for the measurement on secondary foot swelling degree, polyarthritis index score, spleen and thymus index. Pathological morphology was observed using H&E staining. Heart fibrosis was measured after Sirius red staining, while cell apoptosis was determined by TUNEL staining. For in vitro experiments, rat cardiomyocytes were isolated to determine the inflammatory cytokine secretion and cell apoptosis using ELISA and flow cytometry, respectively. Protein expressions of related index and autophagy were detected by Western blot and immunofluorescence. Results: CIA rat model was successfully established and characterized by severe secondary foot swelling degree, and increased polyarthritis index score and spleen and thymus index. Synovial hyperplasia, disordered cardiomyocytes, cell infiltration and fibrosis were also observed in CIA rat model. Compared with CIA model, Celastrol treatment could suppress the release of inflammatory cytokines, including TNF-α, IL-6, IL-1β, as well as inhibiting the expressions of Bax, cleaved caspase3, collagen I, collagen III and α-SMA. In addition to that, Celastrol treatment can attenuate cell apoptosis and fibrosis of cardiomyocytes and elevate Bcl-2 expression. RA induced cell autophagy can be suppressed by Celastrol through inhibiting the activation of TLR2/HMGB1 signal pathway. Conclusion: Celastrol can regulate TLR2/HMGB1 signal pathway to suppress autophagy and therefore exert cardioprotective effect in RA.

Download Full-text

STUDIES ON LOWERING OF SWELLING DEGREE OF RAYON

Sen i Gakkaishi ◽

10.2115/fiber.19.113 ◽

1963 ◽

Vol 19 (2) ◽

pp. 113-119 ◽

Cited By ~ 2

Author(s):

Kimio Inoue ◽

Saburo Okajima

Keyword(s):

Swelling Degree

Download Full-text

Preparation, Characterization and Swelling Studies of Carboxymethyl Sago Starch Hydrogel

10.21203/rs.2.12925/v1 ◽

2019 ◽

Author(s):

Normastura Sulta ◽

Norhazlin Zainuddin ◽

Mansor Bin Ahmad ◽

Mas Jaffri Masarudin

Keyword(s):

Reaction Time ◽

Absorption Band ◽

Acid Solution ◽

Sago Starch ◽

Additional Absorption ◽

Sem Image ◽

Swelling Degree ◽

Swelling Studies ◽

Ft Ir ◽

Additional Absorption Band

Abstract Carboxymethyl sago starch (CMSS) hydrogel was prepared by dissolving CMSS in HCl solution under vigorous stirring to form gel. The parameter studied were the effect of the percentage of CMSS, concentration of the acid solution, reaction time and reaction temperature to identify the optimum condition of preparation of CMSS hydrogel. 60% of CMSS in 2.0M acid solution for 12 hours reaction time at room temperature were the optimum conditions for CMSS hydrogel. The hydrogel was characterized by using Fourier Transform Infrared (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). FTIR spectrum of CMSS shows an additional absorption band at 1597 cm-1 indicating the substitution of CH2COO-Na+ group on the starch molecular chain during carboxymethylation, while the spectrum of CMSS hydrogel shows an additional sharp absorption band at 1723 cm-1 indicating that the Na in CMSS being exchanged to H from hydrochloric acid solution. SEM image of CMSS hydrogel shows pores in structure and connected to each other to form networks. TGA curve shows that the maximum rate of thermal decomposition of CMSS hydrogel is higher than CMSS at 330.22 ºC with 60.22% major weight loss. This could be due to the presence of the cross-linkages in the CMSS hydrogel. CMSS hydrogel gives high swelling degree in PBS solution at pH 7 and low swelling degree in acidic medium.

Download Full-text

COMPOSITE OF CHITOSAN VANILIN / SULFONATED POLYSTYRENE AS POLYMER ELECTROLYTE MEMBRANES : CATIONIC EXCHANGE CAPACITY, SWELLING DEGREE AND THERMAL PROPERTIES

ALCHEMY Jurnal Penelitian Kimia ◽

10.20961/alchemy.10.2.55.116-129 ◽

2016 ◽

Vol 10 (2) ◽

pp. 116

Author(s):

Edi Pramono ◽

Candra Purnawan ◽

Yuniawan Hidayat ◽

Jati Wulansari ◽

Sayekti Wahyuningsih

Keyword(s):

Thermal Properties ◽

Composite Membranes ◽

Exchange Capacity ◽

Membrane Composition ◽

Sulfonated Polystyrene ◽

Swelling Degree ◽

Electrolyte Membranes ◽

Three Stages ◽

Cationic Exchange

Research on the preparation and characterization of sulfonated polystyrene (PST) /chitosan vanillin (KV) composite as electrolyte membranes has been conducted in order to investigate the effect of PST and KV composition to its chemical and physical properties. Polystyrene was modified by sulfonation reaction to produces PST, meanwhile chitosan was modified by schift base reaction to produces KV. The composite membranes were prepared by casting method and were characterized in order to identify the functional groups contained in the composite, the cation exchange capacity (CEC), the Swelling Degree (SD), the thermal properties and the morphology. The peak of imine vibration in the FTIR spectrum indicates that the chitosan vanilin was succesfully synthesized. Meanwhile, the peak of sulfonate vibration indicates the product of sulfonation on polystyrene. The result of CEC analysis shows that the addition of sulfonate groups on polystyrene and the addition of phenolic groups on chitosan increase the CEC value. The increasing of PST and KV concentration in membrane enhance the CEC value. However, the increasing of PST concentration in membrane composition even decrease the Swelling Degree of membranes. Meanwhile, the increasing of KV concentration increase the swelling degree of membranes. Thermal analysis shows that the thermal decomposition of membranes occurs in three stages i.e. the dehydration of water molecules, the degradation of the subtituen groups and the plasticizer and the degradation of the back bone of chitosan and polystyrene.

Download Full-text

PROTEIN INFLUENCE ON THE MECHANICAL PROPERTIES OF NR

Rubber Chemistry and Technology ◽

10.5254/rct.21.79916 ◽

2021 ◽

Author(s):

Yayoi Akahori ◽

Misao Hiza ◽

Soki Yamaguchi ◽

Seiichi Kawahara

Keyword(s):

Mechanical Properties ◽

Nmr Spectroscopy ◽

Sodium Dodecyl Sulfate ◽

Carbon Black ◽

Natural Rubber ◽

Hevea Brasiliensis ◽

Sodium Dodecyl ◽

Swelling Degree ◽

Deproteinized Natural Rubber ◽

Rubber State

ABSTRACT Protein effect on vulcanization of NR, obtained from Hevea brasiliensis, was investigated by analyzing the crosslinking structure of the resulting vulcanizates prepared from untreated NR, deproteinized natural rubber (DPNR), and protein-free natural rubber (PFNR) by swelling methods and rubber-state NMR spectroscopy. The proteins present in NR were removed by three methods: deproteinization with enzyme, urea, or urea–acetone in the presence of sodium dodecyl sulfate. The amount of proteins present in NR, approximately 0.238 w/w%, was reduced to 0.000 w/w% by urea–acetone deproteinization, whereas it was reduced to approximately 0.003 and 0.019 w/w% by enzyme and urea deproteinizations, respectively. Hardness, swelling degree, and crosslinking structure depended on the amount of proteins. Changes in mechanical properties for the vulcanizates prepared from not only non-filler compounds but also carbon black–filled and silica-filled compounds were attributed to the amount of proteins.

Download Full-text

Swelling degree prediction of polyhydroxybutyrate/chitosan matrices loaded with “ Arnica‐do‐Brasil”

Journal of Applied Polymer Science ◽

10.1002/app.47838 ◽

2019 ◽

Vol 136 (32) ◽

pp. 47838 ◽

Cited By ~ 2

Author(s):

Glauco Fonseca Silva ◽

Talita Goulart Silva ◽

Vinícius Guedes Gobbi ◽

Theresa Lomeu Portela ◽

Bruna Nunes Teixeira ◽

...

Keyword(s):

Swelling Degree

Download Full-text

Encapsulation and release of Beauveria bassiana from alginate–bentonite nanocomposite

RSC Advances ◽

10.1039/c7ra02185b ◽

2017 ◽

Vol 7 (42) ◽

pp. 26468-26477 ◽

Cited By ~ 6

Author(s):

D. P. C. Batista ◽

I. N. de Oliveira ◽

A. R. B. Ribeiro ◽

E. J. S. Fonseca ◽

N. S. Santos-Magalhães ◽

...

Keyword(s):

Beauveria Bassiana ◽

Release Kinetics ◽

Swelling Degree ◽

New Information ◽

Alginate Matrices

The present manuscript brings new information regarding the advantages of the encapsulation of B. bassiana in alginate matrices containing bentonite, such as conidia protection, swelling degree, and release kinetics.

Download Full-text

Effects of Wall Condition of a Plunging Body on Splash

ASME-JSME-KSME 2011 Joint Fluids Engineering Conference: Volume 1, Symposia – Parts A, B, C, and D ◽

10.1115/ajk2011-03076 ◽

2011 ◽

Author(s):

Masao Yokoyama ◽

Yoshihiro Kubota ◽

Osamu Mochizuki

Keyword(s):

Numerical Simulation ◽

Implicit Method ◽

Water Tank ◽

Air Cavity ◽

Slip Ratio ◽

Mps Method ◽

Swelling Degree ◽

Living Things ◽

Wall Condition ◽

Moving Particle

Splashes generated by hydrogel sphere were simulated numerically and experimentally for investigating the effects of slip like mucus of living things. Numerical simulation using MPS (Moving Particle Semi-implicit) method was carried out. We defined the slip ratio as the swelling degree of hydrogel and installed the slip ratio into the MPS method. The swelling degree is the ratio of the weight of water against that of hydrogel. We simulated the splashes generated by the hydrogel spheres which had the different swelling degree plunging into water. As the evaluation of swelling degree on the surface of actual hydrogel spheres we also tested by using the hydrogel spheres plunging into water experimentally. The height of splash as a result of reaction of the air cavity became higher according to the increase of the swelling degree. The speed of hydrogel sphere sinking in water tank was also quicker in the numerical simulation. The reason of these results was that the velocity of water around the hydrogel sphere became quicker due to the slip on the surface.

Download Full-text