High Relative Viscosity Research Articles

Blood-cooling and hemostasis effects of Rehmanniae Radix before and after carbonizing

To compare the blood-cooling and hemostasis effects of Rehmanniae Radix before and after carbonizing on rats with blood heat and hemorrhage syndrome. The blood heat and hemorrhage syndrome rat model was established. Indexes including rectal temperature,whole blood viscosity,plasma viscosity,thrombin time(TT),activated partial thromboplastin time(APTT),prothrombin time(PT),fibrinogen content(FIB),red blood cell(RBC),hemoglobin(Hb),hematocrit(HCT),blood platelet count(PLT),mean platelet volume(MPV),serum IL-1,serum IL-6 and lung histopathology were detected to investigate the blood-cooling and hemostasis effects of Rehmanniae Radix and its carbonized products. Compared with the blank control group,the rectal temperature was significantly increased with rise of the high,middle and low whole blood viscosities and plasma viscosity(P<0.05); both the high and low whole blood restore viscosity and the high and low whole blood relative viscosity were increased significantly(P< 0.05); TT,APTT and PT were notably prolonged with the increase in FIB content(P<0.05); RBC,Hb and HCT increased significantly(P< 0.05); concentrations of serum IL-1 and IL-6 were also increased(P< 0.05) in model group. Additionally,obvious hemorrhages in lung and stomach were observed in rats of the model group. Rehmanniae Radix and its carbonized products can significantly reduce rectal temperature,high middle and low whole blood viscosities and plasma viscosity(P<0.05). TT and APTT were shortened,with lower expression of FIB in group of Rehmannia Radix and its carbonized products. Hemorrhages of lung and stomach were improved by Rehmannia Radix and its carbonized products. The results indicated that Rehmannia Radix before and after carbonizing had the hemostasis and blood-cooling effects by promoting coagulation,improving blood rheology and inhibiting expressions of IL-1 and IL-6.

A comparative study on the effect of structural variations of co-solvent on the Tetronic® micelles with widely different hydrophobicity

Here we report, a comparative study on the micellization and phase behavior of two commercially available ethylene oxide – propylene oxide (EO-PO) octablock copolymers, Tetronics® 1304 and 1307 (hereafter written as T1304 and T1307), in the presence of 2,2,2‑trifluoroethanol (TFE) and ethanol (EtOH) using cloud point (CP), dynamic light scattering (DLS), high sensitivity differential scanning calorimetry (HSDSC), relative viscosity and Langmuir film balance. These copolymers fabricated with almost the same PO block length vary in their EO chain lengths and hence display different characteristics. T1304 shows a more hydrophobic character and forms micelles at ambient temperature while T1307, due to longer EO chain length, exhibits high hydrophilicity and faces difficulty in forming micelles which results into high polydispersity in the aqueous system. In the presence of co-solvents TFE and EtOH, however a more interesting behavior is noted. T1304, as evident from DLS and viscosity measurements, displays micellar growth in the presence of TFE, while the presence of EtOH induces micellar breakdown. Though, in case of T1307, presence of TFE improves micellization and a single micellar peak becomes evident in the DLS stacks, no micellar growth can be noticed both through DLS and relative viscosity, which is possibly due to its highly hydrophilic character. Likewise, presence of TFE depresses the CMT in both the copolymers while EtOH increases it. A similar trend is also justified by π-A isotherms form Langmuir monolayers.

Physicochemical Characterization and Functional Analysis of the Polysaccharide from the Edible Microalga Nostoc sphaeroides.

Nostoc colonies have been used as food and medicine for centuries, and their main supporting matrix is polysaccharides, which help Nostoc cells resist various environmental stresses including oxidative stress. Here we isolated a polysaccharide, nostoglycan, from cultured Nostoc sphaeroides colonies and determined its physicochemical properties, which revealed a characteristic infrared absorption spectrum typical of polysaccharides and an amorphous morphology with rough surfaces. We also show that nostoglycan has strong moisture absorption and retention capacities and a high relative viscosity. Using Caenorhabditis elegans models, we then demonstrate that nostoglycan is capable of improving overall survival rate of the animals under increased oxidative stress caused by paraquat. Nostoglycan also reduces reactive oxygen species level, inhibits protein carbonyl formation and lipid peroxidation, and increases activities of superoxide dismutase and catalase in paraquat-exposed nematodes. As oxidative stress may drive tumor progression, we further demonstrate that nostoglycan can suppress the proliferation of several types of tumor cells and induce apoptosis of human lung adenocarcinoma A549 cells via caspase-3 activation. Together, our results yield important information on the physicochemical characteristics and demonstrate the antioxidant and anti-proliferative functions of nostoglycan, and thus provide an insight into its potential in food and health industries.

Rheological Properties and Crosslinking Rheo-Kinetics of CMHEC/CTAB Synergistic Systems

Aiming at synergistic interaction between carboxymethyl hydroxyethyl cellulose (CMHEC) and cetyltrimethyl ammonium bromide (CTAB), mixtures of CMHEC and CTAB solutions were investigated, employing relative viscosity and rheological measurements. The effects of mass ratio of CMHEC and CTAB solutions, temperature, and polysaccharide concentration on relative viscosities of CMHEC/CTAB systems were studied. Rheological method was used to study rheo-kinetics of the isothermal crosslinking process for CMHEC/CTAB synergistic fracturing fluid, and the novel crosslinking rheo-kinetics equation was established. The results showed the strong synergism between CMHEC and CTAB, resulting in a higher relative viscosity, storage modulus G′, and loss modulus G″ than that of separate ones. CMHEC/CTAB systems behave as pseudoplastic fluids with considerable thixotropy and viscoelasticity, and the flow behavior can be well described by Carreau−Williamson model. The crosslinking rheo-kinetics equation can well describe the isothermal crosslinking process at different shear rates. The model parameters are well-defined and reasonable.

Liquid encapsulated electrostatic energy harvester for low-frequency vibrations

This article presents the modeling, fabrication, and testing of liquid encapsulated energy harvester using polyvinylidene fluoride electrets. Unlike harvesters reported in previous literature, this liquid encapsulated energy harvester uses flowing liquid rather than conventional resonating structures to induce variable capacitance and is more suitable for low-frequency applications. Prototypes injected with three types of liquid ( N-methyl-2-pyrrolidone, N, N-dimethylformamide, and glycerin) are tested in horizontal vibration and rotary motion mode, respectively. The results show that N, N-dimethylformamide–injected prototypes display the most desirable performance in horizontal vibration testing at 1–10 Hz due to high relative permittivity and low viscosity, with maximum output voltage of 2.32 V and power of 0.18 µW at 10 Hz. Glycerin-injected prototypes perform best at 0.1–1 Hz rotation due to effective movement and highest permittivity, with maximum output voltage of 11.46 V and power of 2.19 µW at 1 Hz.

Minerals, polysaccharides and antioxidant properties of aqueous solutions obtained from macroalgal beach-casts in the Noto Peninsula, Ishikawa, Japan

To clarify the useful properties of the macroalgal beach-casts for food, we determined mineral, water-soluble polysaccharide and total phenolic compound contents and antioxidant properties of aqueous solutions obtained from frond of eight brown and four green algae. These algae were washed ashore from the East Sea (the Sea of Japan) to the northeast beaches of the Noto Peninsula in autumn. There were fresh and large amounts of Ecklonia stolonifera (Es), Ecklonia kurome (Ek), Sargassum ringgoldianum subsp. coreanum (Sr) and Sargassum macrocarpum on the beaches. Potassium, magnesium and calcium ions were high in Sr-solution. High molecular weight water-soluble polysaccharide, mainly alginates, and relative viscosity were also high in Sr-solution. Both Es and Ek solutions showed high contents of total phenolic compounds and high antioxidant activities, including DPPH radical- and hydroxyl radical-scavenging and ferrous reducing power. On the other hand, the highest superoxide anion radical-scavenging activity was in the Sr solution. In the case of Sr, the same antioxidant properties were also found in the aqueous solution obtained from stem. These results suggest that some macroalgal beach-casts, especially Sr, can be utilised as new natural resources for functional foods, cosmetics, medical applications and fertilizer instead of being processed to landfill or incineration.

Extraction of native collagen from limed bovine split wastes through improved pretreatment methods

AbstractBACKGROUND: The large amount of limed bovine split wastes discharged by the leather industry has raised concerns regarding their environmental effect. The objective of this work was to perform pilot plant trials to extract high‐value native collagen from these wastes through improved pretreatment methods.RESULTS: EDTA‐ and HCl‐pretreatment gave similar removal percentages of inorganic substances. Owing to the open structure of fibers, the collagen yield of HCl‐pretreated splits (HPS) (41.31%) was higher than that of EDTA‐pretreated splits (EPS) (10.42%). Furthermore, HCl‐pretreated split collagen (HPC) had a more acidic isoelectric point, lower content of primary amino groups, larger Z‐average particle size and higher relative viscosity than EDTA‐pretreated split collagen (EPC). Electrophoretic analysis and circular dichroism spectra revealed the maintenance of polypeptide and triple helix conformation, respectively. In addition, the transition temperatures of EPC (34.7 °C) and HPC (34.6 °C) detected by differential scanning calorimetry (DSC) were close to that of commercial collagen from calfskin (CCC) (35.7 °C).CONCLUSION: A process of native collagen extraction from limed bovine split wastes was proposed. While both EPC and HPC represented similar physicochemical properties to those of CCC, the collagen yield of HPS was much higher than that of EPS. Copyright © 2008 Society of Chemical Industry

Fluid Shear Stress and Inner Curvature Remodeling of the Embryonic Heart. Choosing the Right Lane!

Cardiovascular development is directed or modulated by genetic and epigenetic factors. The latter include blood flow-related shear stress and blood pressure-related circumferential strain. This review focuses on shear stress and its effects on endothelial cells lining the inner surfaces of the heart and blood vessels. Flow characteristics of the embryonic blood, like velocity, viscosity and periodicity, are taken into account to describe the responses of endothelial cells to shear stress and the sensors for this friction force. The primary cilium, which is an integral part of the shear sensor, connects to the cytoskeletal microtubules and transmits information about the level and direction of blood flow into the endothelial cell. When the heart remodels from a more or less straight into a c-shaped tube the sharp curvature, in combination with the small vessel dimensions and high relative viscosity, directs the highest shear stress to the inner curvature of this pump. This proves to be an important epigenetic modulator of cardiac morphogenesis because when shear stress is experimentally altered inner curvature remodeling is affected which leads to the development of congenital cardiovascular anomalies. The best of both worlds, mechanics and biology, are used here to describe early cardiogenesis.

A clinical study of microcirculatory disturbance in Chinese patients with sudden deafness

Conclusion. Cochlear microcirculation disturbance is closely associated with sudden deafness. Objectives. To investigate the relationship between cochlear microcirculation and sudden deafness. Subjects and methods. Clinical laboratory parameters (clinical chemistry, hemorheology, hematology, and hemostasis determinations) were studied in 86 patients with sudden deafness and 30 healthy control subjects. Results. The levels of total cholesterol (TCH), triglyceride (TG), and lipoprotein A were significantly higher in patients with sudden deafness than in control subjects. Plasma viscosity, ratio viscosity of whole blood, reduced viscosity of whole blood, high and low shear relative viscosity of whole blood, index of red blood cells transmutation, and fibrinogen level in the plasma of patients with sudden sensorineural hearing loss (SSNHL) were also significantly elevated in comparison with those in control subjects. White-collar workers with psychological and behavioral abnormalities tend to suffer from sudden deafness.

On the behaviour of gelled fibre suspensions in steady shear

The shear rheological properties of suspensions of gelled agar fibres in a low viscosity Newtonian matrix fluid were investigated. Two classes of fibres, low aspect ratio fibres and high aspect ratio fibres with an aspect ratio of the order of 10 and 100 respectively were included in the investigations. For all fibre phase volumes investigated, from as low as 0.01 upwards, the flow curves are characterised by an apparent yield stress followed by shear-thinning which was independent of the fibre aspect ratio. Based on our analysis of the flow curves, we conclude that the high aspect ratio fibres behave like flexible threads in contrast to the low aspect ratio fibres whose high shear relative viscosity is successfully described by a relation for long rigid rods. These findings are supported by flow visualisation using an optical shearing stage coupled to a light microscope.

Rheological properties of organoclay suspensions in epoxy network precursors

This paper deals with the evolution of the state of dispersion of organically modified montmorillonites in epoxy or amine precursors. The epoxy prepolymer is a diglycidyl ether of bisphenol A (DGEBA) and the curing agent is an aliphatic diamine with a polyoxypropylene backbone (Jeffamine D2000). The clay dispersion is evaluated at the platelet scale (nanoscopic scale) from X-ray spectrometry [wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS)] and at the aggregates scale (microscopic scale) from rheological analysis. The organoclays used form gels in the monomers above the percolation threshold if no shear is applied and present a mechanical gel/sol transition when shear stress increases. Gel strength and viscosity at high shear rates are linked to the nanometric state of dispersion and reveal the existence of two different organizations depending on organoclay/monomer interactions: (i) When the clay shows good interactions with the monomer, a significant swelling of the clay galleries by the monomer is obtained. These swollen particles lead to formation of weak gels which after shearing give high relative viscosity fluids. (ii) When the clay develops poor interactions with the monomer, the clay tends to reduce its exchange surface with the monomer and leads to a strongly connected gel. Shear breaks down this physical network leading to a very low relative viscosity fluid composed of nonswollen particles keeping a high aspect ratio.

Effect of emulsion polymerization conditions of vinyl acetate on the viscosity fluctuation and gelation behavior of aqueous poly(vinyl alcohol) solution

AbstractPoly(vinyl alcohol) (PVA) was prepared by emulsion polymerization of vinyl acetate (VAc) at 40, 50, and 60°C. PVAs of various molecular parameters were dissolved in water at concentrations of 3, 5, and 7% (g/dL) and aged at 30 and 60°C. The effects of the molecular weight and polymerization temperature on the viscosity fluctuation and gelation behavior of aqueous PVA solutions were investigated. Viscosity was increased with increasing molecular weight when other parameters were held the same. PVA of superior molecular regularity due to the lower polymerization temperature of VAc had higher relative viscosity. Viscosity and its fluctuation of PVAs with aging time varied with the polymerization temperature of the precursors, concentration of the aqueous solutions, and aging time. For PVA with a number‐average degree of polymerization of 2800 prepared from poly(vinyl acetate) polymerized at 40°C, a sharp increase in viscosity was observed after 500 min of aging at a concentration of 7%. © 2001 John Wiley &amp; Sons, Inc. J Appl Polym Sci 82: 1897–1902, 2001

Phase separation properties of several aqueous alkyldimethylphosphine oxide/phospholipid mixtures and their potential use for protein purification

The phase separation properties of several aqueous alkyldimethylphosphine oxide/phospholipid mixtures were investigated. The addition of synthetic phospholipids with acyl residues ranging from 12 to 18 carbon atoms, a soybean phospholipid extract, and a red blood cell ghost extract lowered the temperature of phase separation below that of the surfactant alone. The high relative viscosity of the top layer suggests that asymmetric mixed micelles exist, whereas the relative viscosity of the bottom layer approached the value of 2.5 expected for spherical particles. The relative concentration of lipid in the top layer decreased with increasing molecular weight for the synthetic lecithins. The addition of 0.1 M univalent salts was investigated and no dependence of the cloud point on cation size was observed. However, a set of potassium halides exhibited a trend which followed the Hofmeister series. Finally, the composition of the top and bottom layers was investigated at 38, 42, 48 and 55°C for one DodDPO/DMPC mixture, and the solute was observed to be progressively concentrated in a smaller volume as the temperature was increased for each of five initial concentrations ranging from 12 to 53.6 mg/ml.

The nutritive value for broiler chickens of pelleting and enzyme supplementation of a diet containing barley, wheat and rye

A diet based on barley (40%), wheat (25%), and rye (7%) was given as a mash diet or as dry or steam pelleted diets to a total of 384 broiler chickens. Diets were given with or without the addition of a fibre-degrading enzyme preparation. Pelleting increased the water solubility (at 38°C) of starch and crude protein. There were, however, no notable effects on the solubility of dietary fibre components following pelleting or enzyme supplementation. Buffer extracts from pelleted diets had a high relative viscosity, while mash diets gave the lowest relative viscosity. Enzyme supplementation diminished the high viscosity obtained for pelleted diets and reduced sticky droppings. Pelleting increased weight gain for chickens receiving the unsupplemented diets by ∼ 30% and for those fed on the enzyme-supplemented diets by ∼ 20%. This improvement, which was similar at both 14 and 20 days of age, was mainly due to a greater feed intake, particularly with the steam pelleting. Enzyme supplementation improved weight gain by 11–24%, and was more effective in the unpelleted diets and at Day 14. This improvement was due to both a higher feed intake and a better feed conversion efficiency. Pelleting tended to increase ileal digestibility of the unsupplemented diet while enzyme supplementation had a similar effect on the unpelleted diet. The latter treatment also increased whole-tract digestibility.

The quaternary structure of bovine alpha-crystallin. Effects of variation in alkaline pH, ionic strength, temperature and calcium ion concentration.

The stability of the native quaternary structure of bovine alpha-crystallin was studied, by sedimentation analysis and electron microscopy, as a function of pH (7--11), ionic strength (0.01--0.5), temperature (6--60 degrees C) and calcium ion concentration (0 and 10 mM). Three successive transitions are distinguished at 20 degrees C. Firstly, a slow transconformation step, which is independent of pH, ionic strength or calcium ions. Secondly, an irreversible primary dissociation step, favoured by increasing pH above 8 and/or a lower ionic strength, with formation of 'alkali-modified alpha-crystallin', which is spherically shaped like the native protein but has a smaller average diameter, sedimentation coefficient and molecular weight. Thirdly, with further increase of pH above 9, a rapidly reversible dissociation of alkali-modified alpha-crystallin characterized by a single reaction boundary in sedimentation velocity analysis. In the presence of calcium ions the quaternary structure is stabilized to the extent that no dissociation is observed up to at least pH 10.3. Upon increase of temperature, at pH 7.3, a slow irreversible dissociation and swelling run parallel until a limit is reached around 37 degrees C with formation of 'temperature-modified alpha-crystallin', which is indistinguishable from the native protein by electron microscopy, but has a higher relative viscosity and lower sedimentation coefficient and molecular weight. Calcium ions have little or no effect on this transition. Above 37 degrees C a reversal of this transition or aggregation is indicated. These findings, together with previous structural data on microheterogeneity, reassociation from urea, and aging of alpha-crystallin in vivo, are incorporated into a hypothetical scheme of transitions, based on a three-layer model for the quaternary structure.

Studies on Making Dissolving Pulp from Mangrove

We tried to make dissolving pulp from mangrove (Rhizophora sp.) grown in Southeast Asia. This paper is to illustrate the cooking behavior in Ca-base acid sulfite pulping process.Cooking speed of mangrove is slower than that of Japanese hard wood (Castanopsis mixed Quercus), but delignification is very easy. And we can get unbleached pulp with low lignin and high relative viscosity (1015).Compared with hard wood pulp of the same relative viscosity, unbleached pulp made from mangrove is not only excellent in permanganate number, α- and β- cellulose, but tailings are very small. And the pulp yield of each wood is almost the same.As the wood density of mangrove is high, it can be digested with small ratio of cooking liquor to wood. But when we think of synthetic quality of pulp, there is a limit at about 2.8 (1/kg of chip) in general liquor (T. A. 7.5%, C. A. 1.5%). At this ratio, CaO in combined acid is 30 g per bone dry chip kg.It is characteristic of mangrove that it admits a very low limit of combined acid in cooking, while Japanese hard wood needs CaO 35g/chip kg.In filterbility test of viscose, reactivity of mangrove pulp is better than hard wood pulp. Mangrove pulp made from unbleached pulp of relative viscosity 1014, is better in its reactivity than normal pulp of relative viscosity 78. And also in general cooking liquor (T.A. 7.5%, C.A. 1.5%), mangrove pulp made from combined acid containing CaO 3032g/chip kg, is the most reactive.

Separation of a hyaluronate-free lubricating fraction from synovial fluid.

THE lubricating qualities of synovial fluid from animal joints have been ascribed to the presence of large hyaluronate or hyaluronate–protein complexes1, although it has been questioned whether the protein was in fact an integral component of these macromolecules2. It is also uncertain whether the high relative viscosity of synovial fluid is important in building up a boundary layer of lubricant on the cartilage surface3. Some investigators suggest that the boundary layer is chemically bound, and that the viscosity of the lubricant is of little importance in the lubrication at the cartilage to cartilage interface4,5.

Solution properties of polygalacturonic acid.

1. The specimen of polygalacturonic acid used in these studies was shown to contain very little neutral sugar, methyl ester groups or ash, and only residues of galacturonic acid. Its electrophoretic homogeneity was examined in pyridine-acetic acid buffer at pH6.5 and in borate buffer at pH9.2. The distribution of effective particle weights was shown to be fairly narrow. 2. The pH-titration curve of the polymer gave a pK value of 3.7. 3. The interaction of the polymer with Ruthenium Red was studied and titration curves were obtained for the spectral shifts associated with the formation of a complex. 4. Optical-rotatory-dispersion studies showed that the Drude constant, lambda(c), was dependent on pH. 5. Polygalacturonic acid was shown to display non-Newtonian properties in solution and to have an anomalously high relative specific viscosity at low concentrations. 6. Studies were made of the pH-dependence of the sedimentation coefficient of the polymer. 7. These results are discussed in terms of the structure of the molecule and their relevance to the properties of pectic substances.