scholarly journals Relationship between intrinsic viscosity, thermal and retrogradation properties of amylose and amylopectin

2014 ◽  
Vol 32 (No. 5) ◽  
pp. 514-520 ◽  
Author(s):  
S. Yu ◽  
J. Xu ◽  
Y. Zhang ◽  
N.K. Kopparapu
Keyword(s):  
Intrinsic Viscosity ◽  
Differential Scanning Calorimeter ◽  
Peak Temperature ◽  
Amylopectin Retrogradation ◽  
Ubbelohde Viscometer

The relationships between intrinsic viscosity and some properties of amylose and amylopectin were investigated. The intrinsic viscosities determined by Ubbelohde viscometer for rice, maize, wrinkled pea and potato amyloses were 46.28 &plusmn; 0.30, 123.94 &plusmn; 0.62, 136.82 &plusmn; 0.70, and 167.00 &plusmn; 1.10 ml/g, respectively; and the intrinsic viscosities of rice, maize, wrinkled pea and potato amylopectins were 77.28 &plusmn; 0.90, 154.50 &plusmn; 1.10, 162.56 &plusmn; 1.20 and 178.00 &plusmn; 1.00 ml/g, respectively. The thermal and retrogradation properties of amylose and amylopectin were investigated by differential scanning calorimeter (DSC). Results showed that the thermal enthalpy (&Delta;H<sub>g</sub>) was positively correlated with intrinsic viscosity, however, the onset and peak temperatures were not related to the intrinsic viscosity. The amylose and amylopectin retrogradation enthalpy values were negatively related to intrinsic viscosity, while the onset and peak temperature values of retrograded amylose and amylopectin were not related to the intrinsic viscosity during storage (except one-day storage). Furthermore, the onset and peak temperatures and retrogradation enthalpy of amylose and amylopectin changed slowly during storage at 4&deg;C. &nbsp; &nbsp;

Research on Structure and Properties of a Novel Type of Poly( Ester-Imide)

2011 ◽  
Vol 332-334 ◽  
pp. 231-234
Author(s):  
Shao Jian Lin ◽  
Jian Wu Lan ◽  
Si Die Wu ◽  
Si Chen
Keyword(s):  
Thermal Property ◽  
Intrinsic Viscosity ◽  
Chemical Resistance ◽  
Crystallization Rate ◽  
The Novel ◽  
Trimellitic Anhydride ◽  
Scanning Calorimetry ◽  
Ft Ir ◽  
Excellent Property ◽  
Ubbelohde Viscometer

A diacid monomer was prepared from trimellitic anhydride and aminobenzoic acid,and a novel poly(ester-imide) was synthesized through the diacid monomer and the 1, 4-butanediol.The structure and chemical resistance, intrinsic viscosity and thermal property and crystallization of the poly(ester -imide) were characterized by FT-IR spectra,various organic solvents,a capillary Ubbelohde viscometer,differental scanning calorimetry (DSC) and thermogravimetric analysis (TGA) and crystallization rate instrument.The results showed that the poly(ester-imide) has excellent chemical resistance and thermal property,its intrinsic viscosity is 0.46dL/g,it has high glass transition temperature (Tg) and relatively low melting temperature (Tm).Moreover,the novel poly(ester-imide) has obvious crystallization and excellent property to spin into fibers.

Bovine Platelet Proteins III. Some Properties of Platelet Fibrinogen

1969 ◽  
Vol 21 (03) ◽  
pp. 428-440 ◽  
Author(s):  
N. O Solum ◽  
S Łopaciuk
Keyword(s):  
Intrinsic Viscosity ◽  
Rabbit Antiserum ◽  
Disc Electrophoresis ◽  
Carbohydrate Content ◽  
Plasma Fibrinogen ◽  
Total Amino Acid ◽  
Electrophoretic Mobilities ◽  
Bovine Plasma ◽  
Starch Gel ◽  
The Difference

Summary1. Some properties of purified bovine platelet fibrinogen have been described and the data compared to those obtained by parallel analysis of purified bovine plasma fibrinogen.2. A close similarity was found between platelet and plasma fibrinogen as to sedimentation coefficients, electrophoretic mobilities in starch gel and polyacrylamide disc electrophoresis, light absorption spectra in the range 240 mμ to 330 mμ, ability to form immunoprecipitate with a rabbit antiserum against bovine plasma fibrinogen, total amino acid composition and in N-terminal amino acids.Differences between the fibrinogens were found as to intrinsic viscosity, carbohydrate content and behaviour upon clotting by thrombin. Intrinsic viscosity in 0.3 M NaCl at 25° was 0.48 dl/g for platelet fibrinogen as compared to 0.26 dl/g for plasma fibrinogen. The carbohydrate content of platelet fibrinogen was 0.56 ± 0.10% 1.56±0.10% and 1.37±0.09% for sialic acid (calculated as N-glycolyl neuraminic acid), hexose (galactose/mannose 1:2) and hexosamine (glucosamine), respectively. These values were 6, 54 and 26% higher than those found for plasma fibrinogen. The difference in clotting behaviour indicated a slower polymerization rate of the fibrin monomers formed from platelet fibrinogen than of those formed from plasma fibrinogen.

Application of pure, thermostable, alkali-tolerant xylanase in bleaching of oxygen-delignified pine kraft pulp

TAPPI Journal ◽  
2015 ◽  
Vol 14 (11) ◽  
pp. 689-694
Author(s):  
QINGZHI MA ◽  
QI WANG ◽  
CHU WANG ◽  
NIANJIE FENG ◽  
HUAMIN ZHAI
Keyword(s):  
Intrinsic Viscosity ◽  
Chlorine Dioxide ◽  
High Purity ◽  
Kraft Pulp ◽  
Alkaline Media ◽  
Industrial Scale ◽  
Elemental Chlorine ◽  
Effect Of Oxygen ◽  
Alkaline Tolerant ◽  
Ecf Bleaching

The effect of oxygen (O2)-delignified pine kraft pulp pretreatment by high-purity, thermostable, and alkaline-tolerant xylanases on elemental chlorine free (ECF) bleaching of O2-delignification kraft pulp was studied. The study found that xylanase pretreatment preserved the intrinsic viscosity and yield of O2-delignified pulp while causing about 7% of delignification with high delignification selectivity. The xylanases with high purity, higher thermostability (75°C~80°C) in highly alkaline media (pH 8.0~9.5) could be applied on an industrial scale. Pulp pretreatment by the high-purity, thermostable, and alkaline tolerant xylanases could improve pulp brightness or reduce the chlorine dioxide (ClO2) consumption. In a D0ED1D2 bleaching sequence using the same amount of ClO2, the xylanase-pretreated pulp obtained a higher brightness (88.2% vs. 89.7% ISO) at the enzyme dose of 2 U/g pulp; or for the same brightness as control (88.2% ISO), the ClO2 dosage in the D0 stage was reduced by 27%, which represents a 16% savings in total ClO2 used for bleaching.

Some Approaches to Viscometric Study of Chitosan in Acetic Acid Solution

2016 ◽  
Vol 10 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Valentina Chernova ◽  
◽  
Angela Shurshina ◽  
Elena Kulish ◽  
Gennady Zaikov ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Intrinsic Viscosity ◽  
Acetic Acid Solution ◽  
Conformational State ◽  
Macromolecular Coil ◽  
Degree Of Swelling ◽  
Current Value ◽  
Viscometric Study

Some ways of estimating the values of the intrinsic viscosity of chitosan were analyzed. It was shown that the method of Irzhak and Baranov for estimating the current value of the intrinsic viscosity allows to adequately estimates the conformational state of the macromolecular coil and its degree of swelling.

A walking bout reveals altered foot thermodynamics associated with unilateral transtibial amputation among individuals with type 2 diabetes

2020 ◽  
pp. 030936462096864
Author(s):  
Kyle R Leister ◽  
Shane R Wurdeman
Keyword(s):  
Type 2 Diabetes ◽  
Temperature Change ◽  
Foot Ulcer ◽  
Diabetic Foot Ulcer ◽  
Rate Of Change ◽  
Peak Temperature ◽  
Cross Sectional ◽  
Contralateral Limb ◽  
Transtibial Amputation

Background: Increased foot temperature among individuals with type 2 diabetes can be predictive of diabetic foot ulcer development. A combination of physiological and mechanical deficiencies may contribute to elevations in intact foot temperature during gait for individuals with type 2 diabetes and transtibial amputation. Objective: This study evaluated plantar foot temperature differences between individuals with type 2 diabetes with and without transtibial amputation. We hypothesized that individuals with transtibial amputation maintain increased foot temperature compared to those without amputation. Study Design: Cross-sectional, case control. Methods: A sample of 16 participants with type 2 diabetes and transtibial amputation, and 16 age- and sex-matched participants with type 2 diabetes without amputation were recruited. Foot temperatures were measured during resting, walking, and cooldown periods. Peak temperature, mean temperature, and rate of temperature change were analyzed for each period, and compared between cohorts. Results: Participants with amputation exhibited increased mean foot temperature while at rest and during walking. Participants without amputation exhibited increased rate of change of foot temperature during walking. No differences in peak temperature or rate of temperature change were observed during the baseline or cooldown periods. Conclusion: The current findings of altered foot temperature for individuals with transtibial amputation and type 2 diabetes suggest a possible reason for the high rates of contralateral limb ulceration and amputation among this population.

scholarly journals Age-dependent and radial sectional differences in the dynamic viscoelastic properties of bamboo culms and their possible relationship with the lignin structures

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Yoko Okahisa ◽  
Keisuke Kojiro ◽  
Hatsuki Ashiya ◽  
Takeru Tomita ◽  
Yuzo Furuta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Viscoelastic Properties ◽  
Structural Variation ◽  
Thermal Softening ◽  
Peak Temperature ◽  
Outer Side ◽  
Phyllostachys Pubescens ◽  
Age Dependence ◽  
Age Dependent ◽  
S Peak

Abstract Age is an important factor that dictates bamboo’s mechanical properties. In Japan, bamboo plants aged 3–5 years are selected for use as materials because of their robustness and decorative or craft-friendly characteristics. In this study, the age-dependent and radial sectional differences in bamboo’s dynamic viscoelastic properties in relation to lignin structural variation, were evaluated. We used Phyllostachys pubescens samples at the current year and at 1.5, 3.5, 6.5, 9.5, 12.5, and 15.5 years of age. There was a clear age dependence in the peak temperature of tan δ and in the yield of thioacidolysis products derived from β-O-4 lignin structures. The highest peak temperature tan δ value was detected in 3.5-year-old bamboo, which contained the highest amount of the thioacidolysis products. Moreover, tan δ’s peak temperature was always higher on the outer side, and the ratio of S/G thioacidolysis products was always higher on the inner side of bamboo plants of all ages. These results suggest that changes in bamboo’s thermal softening properties from aging are caused by the maturation and degradation of lignin in bamboo.

scholarly journals Infecting dose and severity of typhoid: analysis of volunteer data and examination of the influence of the definition of illness used

1995 ◽  
Vol 115 (1) ◽  
pp. 23-30 ◽  
Author(s):  
J. R. Glynn ◽  
R. B. Hornick ◽  
M. M. Levine ◽  
D. J. Bradley
Keyword(s):  
Symptom Score ◽  
Salmonella Typhi ◽  
Peak Temperature ◽  
Challenge Dose ◽  
Severity Of Disease ◽  
Definition Of ◽  
The Relationship

SummaryData from volunteers challenged with Salmonella typhi were reanalysed to explore the relationship between challenge dose and severity of disease. Among 120 ill volunteers who received between 105 and 109 organisms, dose was weakly correlated with peak temperature (r = 0·22, 95% CI 0·04–0·39), duration of temperature above 103 °F (39·4 °C: r = 0·13, 95% CI –0·03 to 0·55) and symptom score (r = 0·27, 95% CI 0·09–0·43). The association with symptom score was lost after adjusting for year, and the findings depended on the definition of illness used: with stricter definitions the associations with temperature were also lost. The study shows the need for caution in interpreting the relationship between dose and severity of disease.

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