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PubMed2005

Effect of partially hydrolyzed guar gum (PHGG) on the bioaccessibility of fat and cholesterol.

The addition of a compound that lowers the intestinal uptake of fat and cholesterol might be an interesting strategy to reduce the risk of vascular disease. Partially hydrolyzed guar gum (PHGG) has been shown to have this effect in healthy volunteers after intake of a yogurt drink with 3 to 6% PHGG. In the present study a yogurt drink with 3% sunflower oil and 4% egg yolk was tested with 3% and 6% PHGG, and compared to a control without PHGG. Experiments were performed in a multi-compartmental model of the gastrointestinal tract, equipped to study the digestion and availability for absorption (bioaccessibility) of lipids. The results show that PHGG decreases the bioaccessibility of both fat and cholesterol in a dose-dependent manner. The bioaccessibility of fat was 79.4+/-1.7%, 70.8+/-2.5% and 60.1+/-1.1% for the control experiments and the experiments with 3% and 6% PHGG respectively. The bioaccessibility of cholesterol was 82.2+/-2.0%, 75.4+/-1.2% and 64.0+/-4.3% for the control and the experiments with 3% and 6% PHGG respectively. Additional experiments indicated that PHGG reduces bioaccessibility through the depletion flocculation mechanism. Depletion flocculation antagonizes the emulsification by bile salts and thus decreases lipolytic activity, resulting in a lower bioaccessibility of fat and cholesterol. Depletion flocculation with polymers might be an interesting mechanism, not described before, to reduce fat and cholesterol absorption.

Bile↗

PubMed1976

Changes in appearance of amniotic fluid during pregnancy - the macroscore.

During the first two trimesters of pregnancy the amniotic fluid is clear and yellow; during the third trimester the amniotic fluid becomes colourless; then, approximately from the 33rd-34rd week on, cloudiness and flocculation occur, at first very slowly, after the 36th-37th week steadily faster (Tab. I). At term, the amniotic fluid is moderately cloudy and contains a moderate number of flakes of vernix. The appearance of the amniotic fluid depending on the degree of cloudiness and on the number of flakes, has been expressed by means of a score system, the socalled macroscore (Tab. II). Relationships were observed: a) between the disappearance of the yellow colour (bilirubin) and the initial occurrence of cloudiness and flocculation; b) between the duration of pregnancy and the macroscore; from the 32nd-36th week of pregnancy the mean macroscore increases until the second half of the 40th week; then in the 41 st week there is a drop in the mean macroscore, after which a new increase occurs (Fig. 1,2 and 3). c) between the total gestation period at birth and the progression of the macroscore (Fig. 5); when birth takes place earlier (later), the macroscore will increase earlier (later). d) between the total duration of gestation at birth and the macroscore at the end of pregnancy; with an earlier (later) birth, the macroscore is lower (higher) (Fig. 5 and 6). With the macroscore it is possible to determine the duration of pregnancy (b) and the time before birth even more accurately (c). The fairly large standard deviation of the macroscore per pregnancy week (Fig. 1) also in case of a given duration of gestation at birth (Fig. 7) points to a fairly large interindividual variation in the appearance of the amniotic fluid at a certain duration of pregnancy. The macroscore is determined by elements originating from the fetal skin; the cloudiness and flocculation are caused by release of vernix and the flaking off of cells from the stratum corneum. Hence the macroscore reflects changes in the function of the fetal skin and is an indicator of the functional maturation of the fetal skin. The considerable variation of the macroscore at a given duration of pregnancy indicates a great variation of fetal maturation. The fetus that is maturing faster, will be delivered earlier; the fetus that is maturing slower, later (c). This points to a correlation between the degree of fetal maturation and the start of labour. The higher macroscore during the last days before birth in pregnancies of longer duration (d) (Fig. 5 and 6) may be explained by a less sensitive uterus, requiring a greater maturity of the fetus for delivery to start. The drop of the mean macroscore in the 41 st week of pregnancy is due to a sudden increase of lower scores in this week (Fig. 4). A lower score at a given stage of pregnancy means a later birth (Tab. VI and VII). Thus in the 41 st week of pregnancy a considerable group of pregnant women appears, that has a total duration of gestation that is, on the average, two weeks longer than normally...

Amniotic Fluid↗

PubMed2006

Nitrogen removal from the saline sludge liquor by electrochemical denitrification.

Sludge liquor from the sludge dewatering process has a high ammonia content. In the present study, a lab-scale electrochemical (EC) system with a pair of Ti electrode plates was used for treating the sludge centrate liquor of digested wastewater sludge with a NH4(+) - N content of around 500 mg/L. The sludge liquor had a high salinity due to seawater being used for toilet flushing in Hong Kong. The results show that the EC process is highly effective for denitrification of the saline sludge liquor. Complete nitrogen removal could be achieved within 1 hr or so. The rate of EC denitrification increased with the current intensity applied. The best current efficiency for nitrogen removal was obtained for a gap distance between the electrodes at 8 mm. Electro-chlorination was considered to be the major mechanism of EC denitrification. The formation of chlorination by-products (CBPs) appeared to be minimal with the total trihalomethanes (THM) detected at a level of 300 microg/L or lower. The power consumption for EC denitrification was around 23 kWh/kg N. Additional electro-flocculation with a pair of iron needle electrodes could enhance the flocculation and subsequent sedimentation of colloidal organics in the sludge liquor, increasing the organic removal from less than 30% to more than 70%. Therefore, the EC process including both electro-denitrification and electro-flocculation can be developed as the most cost-effective method for treatment of the saline sludge liquor.

Bioreactors↗

PubMed1994

Concentrated emulsions of perflubron in aqueous media.

Flocculation of o/w emulsions consisting of a perfluorochemical (PFC) emulsified by either phospholipids or decaglyceroldioleate (10-2-O) was assessed both by direct observation and through photon correlation spectroscopy (PCS) and viscoelasticity measurements in unsteady oscillatory flow. Flocculation gives rise to emulsion instability but can be prevented (a) by the addition of a negatively charged surfactant to either phosphatidylcholine (PC) or 10-2-O, respectively the zwitterionic phospholipid and the nonionic surfactant used as primary emulsifiers, or (b) by using a saccharide solution as the continuous phase. The study indicates that both electrostatic (Coulombic) repulsive forces and hydration (steric) forces play a role in preventing flocculation. Various minor components of the egg yolk phospholipids (EYP) used in commercial emulsion preparation probably stabilize the emulsion by increasing both electrostatic and hydration repulsion.

Drug Stability↗

PubMed2001

The effects of particle size distribution on the settleability of CSOs pollutants.

Over the past decades, flocculation and/or sedimentation processes have been adopted to remove pollutants from CSOs. It has been learned that major factors affecting settlement of pollutants are the particle size distribution, their settling velocities and their specific gravity. It is, therefore, a good idea to analyze the particle size distribution and settleability of CSOs pollutants in order to develop details in designing a process. Discussed in this study are pollutant characteristics of CSOs such as particle size distribution and settleability of pollutants. The power law function is applied and is found to be an effective and reliable index for expressing the particle size distribution of pollutants in CSOs. Based on the particle size spectrum analysis, the tendency toward settling and simultaneous flocculation-settling phenomenon of CSOs pollutants is described. Based on the regression analysis it is observed that the derived constants of curves representing settling velocity profile are proportional to the initial concentration of particles and to the beta-values of power law distributions. It is also revealed that the simultaneous flocculation-settling processes are effectively described by the changes of the average particle diameter and of the beta-values of power law distributions.

Geologic Sediments↗

PubMed2001

[Ultrasonic removal of organic pollutants in tannery waste water].

The effect of ultrasonic treatment on flocculating settling of tannery effluent was studied, removal of COD in particular was did. The influences of irradiation method and duration of ultrasonic as well prescription of coagulants on the efficiency of minimizing organic chemicals in waste water were investigated. The results show that: 1. when waste water was treated only by ultrasonic for 60s, the removal rate of COD was 40.6%; 2. when total concentration of coagulants increased to 100 mg/L, the highest removal rate of COD was achieved; 3. when waste water was firstly treated with ultrasonic for 60s, then flocculated with coagulants, the removal rate of COD came to 73.2%, 10% higher than the control without ultrasonic. Thus the treatment of tannery waste water with flocculating settling technology can be effectively strengthened by ultrasonic.

Industrial Waste↗

PubMed2004

Development of a sensitive polymerase chain reaction method for the detection of Toxoplasma gondii in water.

Toxoplasma gondii is becoming a potential threat for public water supplies worldwide, as demonstrated by the occurrence of waterborne toxoplasmosis outbreaks in developing countries as well as industrialised countries. The aim of the present study was to develop a sensitive molecular approach (PCR) for the detection of Toxoplasma oocysts in water. Sporulated and unsporulated T. gondii oocysts (strains DX and AHC1) were isolated from faeces of laboratory-infected cats. After purification and enumeration, oocysts were spiked into 1 -L water replicates and concentrated using centrifugation, Al2(SO4)3 or Fe2(SO4)3 flocculation. DNA was extracted from the concentrated pellets, and a universal primer and a T. gondii-specific primer were selected to amplify a region at the small subunit ribosomal RNA gene. A theoretical detection limit of 0.1 oocysts was achieved for samples that had been concentrated using centrifugation or Al2(SO4)3 flocculation. No PCR products were generated for samples that had been pre-treated using Fe2(SO4)3 flocculation. The final target would be the development of a complete technique able to work as a diagnostic tool for the detection of Toxoplasma in environmental and drinking water.

Animals↗

PubMed2004

[Pilot test on oil field wastewater biotreatment with thermophilic microorganisms].

The thermophilic microorganisms (50-60 degrees C) are introduced and the contact oxidation technology is adopted to treat with the high temperature effluents from an oil field in this paper, which solves a problem that the effluents need to be cooled in routine biotreatment. The results of the pilot test show that the HRT of the biotreatment system adjusted to 8-18h can make CODCr of the effluents stable at 175-263mg/L and oil content under 10mg/L on condition that the temperature of the influents keeps at 60-65 degrees C, CODCr 300-590mg/L and the quality of the oil wastewater is greatly fluctuant. Flocculating process, then, can effectively flocculate and precipitate the suspending and residual chroma pollutant from the effluents of biotreatment and CODCr in the effluents of flocculating process can reduce to 136-229mg/L. And CODCr even reduces to under 150mg/L after flowing by sand and activated carbon filtration equipments. Under the high temperature condition, furthermore, combined stuffing is an ideal carrier for the thermophilic microorganisms.

Bacteria, Aerobic↗

PubMed2004

[Structural characteristics of infrared spectra for polyaluminum chloride in enhanced reactions of modification].

As an important preparation method of Inorganic Polymer Flocculants (IPFs) with all-round performance, the use of enhanced reactions of modification for Polyaluminum Chlorides (PAC) is a trend of application. In this paper, auctorial-made multicore oligomers as a complexing agent, polysilicate as a crosslinking agent and polyacrylamide as a compounding agent are respectively used to enhance PAC and prepared three kinds of IPFs, named CO-PAC, CR-PAC and PAM-PAC. The Fourier Transform Infrared spectra (FTIR) of the three flocculants show that there have been found new chemical bonds beyond Al-OH in their structures, and each characteristic band of primary group in PAC has a band shift to a lower frequency due to its structural aberration. These evidences suggested that enhanced reactions of modification for PAC are not at all a simple process of physical mix, but a chemical reaction to form other structural characteristics of inorganic polymers. The excellent coagulation behavior of these new flocculants depends mainly on the chemical actions, but there are a little physical effects between the modifiers and PAC.

English Abstract↗

PubMed1989

[The liver and rheumatoid arthritis].

The present paper deals with the relation of rheumatoid arthritis to hepatic diseases. Rheumatoid arthritis is regarded as a general disease though the predominant articular symptoms are also accompanied by changes in other organs. Rheumatoid arthritis includes distinct dysproteinemia conditioning the positivity of the flocculation tests. This dysproteinemia is not identical with that found in hepatic diseases. The level of serum mucoproteids in case of liver damage is always lower and in rheumatoid arthritis higher. The elevated mucoprotein level makes the serum more resistant to flocculation, but his protective influence is only restricted and the flocculation cannot even be prevented by the considerably higher mucoproteid level of pronounced dysproteinemia. The specific nature of hepatic involvement could not be proved so far.

Arthritis, Rheumatoid↗

PubMed2002

Effect of sodium orthovanadate on glycosylation of the phosphopeptidomannans involved in the cell-cell aggregation of the yeast Kluyveromyces bulgaricus.

In studies of yeast flocculation it has been found that low concentrations of vanadium contained in sodium orthovanadate do not affect the growth and the cell-cell adhesion of the yeast Kluyveromyces bulgaricus, whereas high concentrations delay the growth of the yeasts and strongly inhibit flocculation. Moreover, higher sensitivity to Hygromycin B and calcofluor white was taken to imply altered cell wall integrity which is supported by compositional analysis of the extracted phosphopeptidomannans. Yeasts grown on sodium orthovanadate show a decrease in the percentage of phosphopeptidomannans and their compositions. It is proposed that the vanadium contained in sodium orthovanadate has a similar conformation to phosphorus and competes with phosphorus in phosphorylated compounds. The decrease of carbohydrate components and phosphorus linking to phosphopeptidomannans detected may alter their structure and modify ligand binding properties.

Cell Aggregation↗

PubMedDate not supplied

Improving primary treatment of urban wastewater with lime-induced coagulation.

The enhancement of primary treatment efficiency through the coagulation process may yield several advantages, including lower aeration energy in the subsequent biological unit and higher recovery of biogas from sludge digestion. In this work sewage coagulation with lime was studied at pilot plant level, using degritted sewage from the city of Rome. The work aimed at optimising the operating conditions (coagulant dosage or treatment pH, and mixing conditions in the coagulation and flocculation tanks), in order to maximise the efficiency of suspended Chemical Oxygen Demand (COD) removal and to minimise sludge production. Lime dosage optimisation resulted in an optimal treatment pH of 9. Lime addition up to pH 9 may increase COD removal rate in the primary treatment from typical 30-35% of plain sedimentation up to 55-70%. Within the velocity gradients experimented in this work (314-795 s(-1) for the coagulation tank and 13-46 s(-1) for the flocculation tank), mixing conditions did not significantly affect the lime-enhanced process, which seems to be controlled by slow lime dissolution. Sludge produced in the lime-enhanced process settled and compacted easily, inducing an average 36% decrease in sludge volume with respect to plain settling. However excess sludge was produced, which was not accounted for by the amount of suspended solids removed. This is probably due to incomplete dissolution of lime, which may be partially incorporated in the sludge.

Calcium Compounds↗

PubMed2003

Affinity selection of target cells from cell surface displayed libraries: a novel procedure using thermo-responsive magnetic nanoparticles.

Biotinylated thermo-responsive magnetic nanoparticles for use in affinity selection from yeast cell surface display libraries were prepared by coating magnetite nanoparticles with a thermo-responsive polymer consisting of N-isopropyl acrylamide and a biotin derivative. These particles showed a reversible transition between flocculation and dispersion at around the lower critical solution temperature of 30 degrees C, above which the flocculated particles--which absorbed a large amount of avidin due to their large surface area--were quickly separable by magnet. The model library was constructed by mixing control yeast cells with target yeast cells co-displaying IgG binding protein (ZZ) and enhanced green fluorescence protein. Biotinylated IgG and avidin were subsequently added to the model library, and target cells were efficiently enriched with the biotinylated magnetic nanoparticles by avidin-biotin sandwich and ZZ-IgG interaction. The few target cells (0.001%) in the model library were enriched by up to 100% in only 5 days by an affinity selection procedure repeated four times. This novel method based on magnetic nanoparticles and a yeast cell surface display system could fulfill a wide range of applications in the analysis of protein-protein interactions and rapid isolation of novel biomolecules.

Avidin↗

PubMed1989

M(III)-facilitated recovery and concentration of enzymes from mesophilic and thermophilic organisms.

Six enzymes isolated from organisms of widely differing thermal growth optima were flocculated from solution at constant pH by addition of Fe(III) solution. In all cases the enzyme concentration was 1 g.l-1 or less. Flocculation profiles were generated for each enzyme over a range of Fe(III) levels. The concentrated enzymes were recovered from the Fe(III)/protein complex by solubilisation with citrate and dithionite followed by precipitation with ammonium sulphate. In all cases approximately 70-80% enzyme recovery was achieved. Enzyme thermal stability did not appear to be important and protein concentration had no effect on the efficiency of enzyme recovery over the range of 0.01-1 g.l-1. Approximately 30 mmol Fe(III)/l of enzyme solution facilitated optimal enzyme recovery for all solutions studied. For protein concentrations up to 1 g.l-1 a 100-fold enzyme concentration factor can be expected.

Aluminum↗

PubMed1993

Concentration of fish enveloped viruses from large volumes of water.

The validity of several concentration procedures for the detection of fish enveloped viruses present in large volumes of water was determined. Viral haemorrhagic septicaemia virus (VHSV) was used to evaluate adsorption/elution to positively-charged MK filter cartridges for the concentration of enveloped viruses. For fresh water, the efficiency of the procedure ranged from 12 to 100%, with a mean recovery of 57%. In seawater samples, the recoveries varied from 15 to 100%, with a mean recovery of 59%. The same virus was used in methods such as organic flocculation and ammonium sulphate flocculation with very poor recoveries of infectious virus, caused by the inactivation of VHSV in both procedures. Concentration of seawater samples from tanks housing sea bass or gilthead affected by viral erythrocytic infection and lymphocystis, respectively, were carried out. In both cases, the viruses responsible for the outbreaks were detected by electron microscopy in the concentrated water samples.

Adsorption↗

PubMed1977

On enzymatic clotting processes. I. Kinetics of enzyme-triggered coagulation reactions.

The kinetics of enzymatic clotting reactions such as the clotting of blood or milk, is analyzed. The appearance of a lag phase in the clotting is shown to be due to the difference in reaction order of enzymatic production and flocculation. The weight-average particle weight of the product formed is found to be a quadratic function of the reaction time. The condition for the clotting time is t square root of ksV/2 = C, where t is the clotting time, ks the flocculation rate constant, V the maximum rate of enzymatic product formation and C a constant. In agreement with this result double-logarithmic plots of t versus enzyme dilution are always observed to be linear over a wide range of enzyme concentrations. No statistical evidence could be produced for the widely held belief that the clotting time should be inversely proportional to the enzyme concentration. Varying exponents of the latter in its relation to the clotting time are discussed in terms of von Smoluchowski's theory of the slow coagulation of colloidal particles.

Animals↗

PubMed2006

Characterisation of solid and liquid fractions of dairy manure with regard to their component distribution and methane production.

Dairy manure with a total solids content of 77.2g TS/l was separated by means of screening and coagulation-flocculation treatments, using CaO as coagulant and a cationic polyacrylamide as flocculant, obtaining liquid and solid fractions. The solid fraction separated contained 33.4% of the initial total mass of dairy manure plus chemical solutions, containing also 75.2% of the TS, 80.4% of the VS, 58.5% of the total Kjeldahl nitrogen (TKN) and 87.4% of the total phosphorus (P(T)) present in the initial dairy manure. 83.7% of the liquid fraction chemical oxygen demand (COD) was anaerobically biodegradable (COD(BD)). Methane production for the separated liquid fraction was 0.604l CH4 NCTP/g VS added, being 0.307 and 0.371l CH4 NCTP/g VS added for dairy manure and screened dairy manure, respectively. The characteristics of this liquid fraction would allow its treatment in high loading anaerobic reactors having shorter hydraulic retention times, smaller reactor size and a higher methane volumetric production rate than conventional anaerobic reactors treating either manure or screened manure.

Anaerobiosis↗

PubMed2004

Selective separation of arsenopyrite from pyrite by biomodulation in the presence of Acidithiobacillus ferrooxidans.

Effective methods for selective separation using flotation or flocculation of arsenopyrite from pyrite by biomodulation using Acidithiobacillus ferrooxidans are presented here. Adhesion of the bacterium to the surface of arsenopyrite was very slow compared to that to pyrite, resulting in a difference in surface modification of the minerals subsequent to interaction with cells. The cells were able to effectively depress pyrite flotation in presence of collectors like potassium isopropyl xanthate and potassium amyl xanthate. On the other hand the flotability of arsenopyrite after conditioning with the cells was not significantly affected. The activation of pyrite by copper sulfate was reduced when the minerals were conditioned together, resulting in better selectivity. Selective separation could also be achieved by flocculation of biomodulated samples.

Absorption↗