Clear Supernatant Liquid Research Articles

A culture-free biphasic approach for sensitive and rapid detection of pathogens in dried whole-blood matrix

Blood stream infections (BSIs) cause high mortality, and their rapid detection remains a significant diagnostic challenge. Timely and informed administration of antibiotics can significantly improve patient outcomes. However, blood culture, which takes up to 5 d for a negative result, followed by PCR remains the gold standard in diagnosing BSI. Here, we introduce a new approach to blood-based diagnostics where large blood volumes can be rapidly dried, resulting in inactivation of the inhibitory components in blood. Further thermal treatments then generate a physical microscale and nanoscale fluidic network inside the dried matrix to allow access to target nucleic acid. The amplification enzymes and primers initiate the reaction within the dried blood matrix through these networks, precluding any need for conventional nucleic acid purification. High heme background is confined to the solid phase, while amplicons are enriched in the clear supernatant (liquid phase), giving fluorescence change comparable to purified DNA reactions. We demonstrate single-molecule sensitivity using a loop-mediated isothermal amplification reaction in our platform and detect a broad spectrum of pathogens, including gram-positive methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria, gram-negative Escherichia coli bacteria, and Candida albicans (fungus) from whole blood with a limit of detection (LOD) of 1.2 colony-forming units (CFU)/mL from 0.8 to 1 mL of starting blood volume. We validated our assay using 63 clinical samples (100% sensitivity and specificity) and significantly reduced sample-to-result time from over 20 h to <2.5 h. The reduction in instrumentation complexity and costs compared to blood culture and alternate molecular diagnostic platforms can have broad applications in healthcare systems in developed world and resource-limited settings.

Settling characteristics of coal preparation plant fine tailings using anionic polymers

The objective of solid-liquid separation in thickeners in coal preparation plants is to obtain both a clear supernatant liquid with a low turbidity for reuse and a dense slurry. It is important for the smooth operation of the plant to produce good-quality recirculation water. In this study, settling characteristics of coal tailings (d80=70 μm) taken from the thickener feed of Derekoy Coal Preparation Plant (Manisa, Turkey) were investigated with the use of anionic polymers. In the tests we determined the effects of the process parameters including polymer type, polymer dosage, temperature, suspension pH, and pulp density on the flocculation of the fine tailings of the coal preparation operation. Minefloc anionic polymer showed a better flocculation performance in comparison with other polymers. An optimum settling rate of 300 mm/min was reached at a dosage of 30 g/t-solids, a pulp density of 5%, pH 7.9, and temperature 25 °C using Minefloc polymer.

Effect of Saikosaponins-d on reversing malignant phenotype of HepG2 cells in vitro

To observe the effect of SSd on reversing the malignant phenotype of HepG2 cells and to investigate its mechanism in order to prove that SSd is a new choice to prevent and treat HCC. HepG2 cells were cultured and treated by different concentration (0 mg/L, 2.5 mg/L, 5.0 mg/L, 10.0 mg/L and 20.0 mg/L) of SSd for 24 h, and treated by 10 mg/L of SSd for 0 h, 6 h, 12 h, 24 h, 48 h and 72h respectively. The cell inhibition rates were measured by MTT assay. Then cells were treated by 10 mg/L SSd for 48 hr in experimental group and treated by no SSd as a control, their morphological changes were observed by contrast phase microscope. The concentrations of ALB and AFP in clear supernatant liquid of cells were detected by radio-immunity and chemiluminescence. The cell migration rates were observed by transwell method, the relative expression levels of p27 mRNA were measured by RT-PCR. The inhibitive effect of 10 mg/L SSd was the most significant among different concentrations ( F = 265.06, P less than 0.01). The shape of HepG2 from experimental group turned into small and round, and their volume ratios of nucleus to plasma decreased. ALB in supernatant liquid of HepG2 was higher ( t = 7.83, P less than 0.05, and its AFP was lower ( t = -10.72, P less than 0.01) as compared to control group. Cells migrated were fewer and p27 mRNA expression of HepG2 was higher in experimental group than that in control group (t = 22.00, P less than 0.05). SSd could reverse the malignant phenotype of HepG2 cells. It was suggested that the up-regulation of p27 mRNA expression play an important role in the differentiation of HepG2 cells treated by SSd.

Study on Proteinum in Clear Supernatant Liquid of Tongue Coating of Chronic Renal Failure Based on Protein Chip

This study aimed at screening proteinum markers of tongue coating related to chronic renal failure (CRF) and at establishing the predictive model by comparing differences of protein spectrum expression in clear supernatant liquid of tongue coating between CRF patients and normal controls in order to explore the significance of proteinum in clear supernatant liquid in the diagnosis of CRF. Clear supernatant liquid of tongue-coating samples collected from 67 CRF patients and 38 normal controls was used in the study. The proteinum markers of tongue coating were selected according to CRF with the SELDI-TOF-MS technique. The predictive model was established and verified by bioinformatics analysis. The tongue-coating samples of the 67 CRF patients and 38 normal samples in the control group were determined by the SELDI-TOF-MS technique. All 242 proteinum peaks were detected at 1000–20000 e/m. Overall, 13 distinct mass spectrum peaks were analyzed by bioinformatics and displayed statistical significance (P < 0.01). Seven distinct mass spectrum peaks, such as M/Z1092.68 and M/Z1508.26, show high expression in the CRF group. Six distinct mass spectrum peaks, such as M/Z13302.5 and M/Z14330.7, show low expression in the CRF group. Fuzzy-grouping algorithm was used in the fuzzy-grouping analysis and principal component analysis (PCA) between the CRF group and normal control group. The result showed discrimination, but was partly overlapping. The predictive model of CRF was analyzed and established by bioinformatics with biological markers that comprise seven distinct mass spectrum peaks, such as M/Z1049.61, M/Z1076.94, M/Z15295.7, and so on. The predictive model can be used in the sample classification between the CRF group and normal control group (The sensitivity of the predictive model is 61.4%; the specificity is 57.3%; and the predictive exactitude rate is 64.4%). It can be concluded that using the SELDI-TOF-MS technique, the proteinum markers of tongue coating of CRF have been preliminarily screened. The established predictive model provides objective evidence for the study on CRF diagnosis.

The expression of hepatitis B virus X protein and cyclooxygenase-2 in hepatitis B virus-related hepatocellular carcinoma: correlation with microangiogenesis and metastasis, and what is the possible mechanism

To investigate the expression of HBx and COX-2 in hepatitis B virus-related hepatocellular carcinoma, and Its correlation with microangiogenesis and metastasis, and possible mechanism. Immunohistochemistry was used to detect the expression of hepatitis B virus X, cyclooxygenase-2 and CD34 in hepatitis B virus related hepatic carcinoma and 22 non-HBV related hepatic carcinoma tissues. The expression of hepatitis B virus x protein and cyclooxygenase-2 in hepatitis B virus-related hepatocellular carcinoma correlated with microangiogenesis and metastasis was tested by Spearman correlation analysis. The expression of COX-2 in HepG2-X was detected by Western blot and RT-PCR. PGE2 was detected by ELISA in clear supernatant liquid of HepG2-X. Trypan blue exclusion was performed to examine the inhibitory effects of COX-2 selective inhibitor (celecoxib). In Hepatitis B carcinoma tissue, HBx and COX-2 were expressed at high level. The positive rate of COX-2 expression was 88.87% (55/62) in HBx positive expression group, which was significantly higher than that of the positive expression 31.82% (7/22, x2=27.188, P<0.01) in HBx negative expression group and 40.91% (9/22, x2=20.453, P<0.01) in non-HBV related hepatic carcinoma tissues, but it had no statistical difference (x2=0.393, P=0.531) between the HBx negative expression group and non-HBV related hepatic carcinoma tissue group. The expressions of HBx and COX-2 in metastasis group were higher than that in non-metastasis group (P<0.01), MVD in HBx or COX-2 positive expression group was significantly higher than that in negative expression group and non-HBV related hepatic carcinoma tissues (P is less than 0.01). MVD with metastasis was higher than that without metastasis (P<0.01) and MVD with portal vein invasion was higher than that without invasion (P<0.05). Spearman correlation analysis showed that the expression of COX-2 was significantly correlated with the expression of HBx (Rs=0.568, P<0.01). Celecoxib suppressed the growth of both cells in a dose-dependent manner. HepG2-X was significantly susceptible to celecoxib as compared to the HepG2-PC cells. COX-2 protein and mRNA were upregulated in HepG2-X cells than in HepG2-PC. Moreover, PGE2 was upregulated in clear supernatant liquid of HepG2-X than in HepG2-PC. The expressions of HBx and COX-2 were higher in HBV-related hepatocellular carcinoma. COX-2 was significantly correlated with HBx in HCC and it could be a key factor involved in HBx contributed hepatocellular carcinoma's microangiogenesis and metastasis. The possible mechanism of the dual effects might be through HBx, COX-2 and PGE2 pathways in infiltration involved metastasis and microangiogenesis involved metastasis.

E0676 Value of serum adiponectin level in atrial fibrillation patients and clinical significance

ObjectiveTo investigate the level of plasma adiponectin (APN) in atrial fibrillation (AF) patients and clinical value.Methods1. 40 AF patients hospitalised in cardiology department in our hospital divided into two groups...

Application of depletion flocculation for prevention of formation of dilatant sediments

The flocculation of a pesticidal (ethirimol) suspension concentrate (stabilised using a graft copolymer) obtained by addition of free (non-adsorbing) polymer (hydroxyethylcellulose) was investigated. Three molecular weight polymers, namely Natrosol 250 LR ( M w=70 000), Natrosol 250 JR ( M w=124 000) and Natrosol 250 GR ( M w=223 000) were investigated. The volume fraction of the suspension was also varied (from 0.1 to 0.6). Flocculation was studied using three rheological techniques, namely steady state shear stress (τ) -shear rate (⋗g), shear wave and oscillatory measurements. This allowed one to obtain the Bingham yield stress τ β, Casson yield stress τ c; shear modulus G∞, complex modulus G*, storage modulus, G and loss modulus G″ as a function of φ p (the free polymer volume fraction). All results showed a rapid increase in rheological parameters above a critical φ p value, to be denoted φ + p. The latter depended on the polymer molecular weight and suspension volume fraction, φ s. For example, at δ s=0.4, φ p was found to be 0.0075; 0.0024 and 0.0018 for M w=70 000, 124 000 and 223 000 respectively. Moreover, for any given M w, φ p was found to decrease with increase in φ s as predicted theoretically. Sediment volume experiments showed weak flocculation of the suspension above a critical φ p value, resulting in the formation of a “loose” sediment with a clear supernatant liquid. With increase in φ s, the relative sediment volume increases, reaching values approaching 100% when φ s was increased above 0.3 and at high φ p value, such sediments can be easily redispersed and hence the phenomenon of depletion flocculation can be applied for prevention of formation of dilatant sediments on separation of the suspension concentrates. Optical photomicrographs showed a gradual change in the floc structure, with increase in φ p (below φ + p) but above ø + p there was a tendency of aggregation of the primary flocs, forming an interconnected structure which fills the whole volume. This is consistent with the rheological and sediment volume experiments which show a rapid increase with increase in φ p above φ + p.

The use of skim milk permeate in the preparation of spray dried beverages II. Beverage based on Strawberry

Concentrated permeate (27% TS) was prepared by ultrafltration of skim milk and concentrated by reverse osmosis and vacuum evaporation. The whole strawberry fruit was homogenized and added to concentrated permeate at the rate of 1:3 and left to settle, and the clear supernatant liquid was separated. Artificial colour was added and the mixture was spray-dried. Cane sugar and citric acid were added to the powder at the rate of 25:1:25 and product was packed in polyethylene bags and stored in air-tight containers. The changes in the physical properties, chemical composition and vitamin contents of the powdered beverage were followed when fresh and after 3 and 6 months of storage. Also organoleptic properties of the powder formed were assessed by a taste panel of the reconstituted beverage (15% TS). The results obtained clearly indicate the possibility of producing an acceptable beverage based upon strawberry permeate blends in dried form.

The use of hindered settling data to evaluate particle size or floc size, and the effect of particle-liquid association on such sizes

Above a certain concentration, a suspension settles “ en bloc” with a well-marked upper boundary; on one side of this boundary is a relatively clear supernatant liquid, below the boundary is the settling suspension. Theoretical and empirical relationships lead to a variety of methods for the calculation of the average particle (or floc) radius in the suspension; these relationships are all based on the observation of the rate of fall of the interface. A factor isolated from the theoretical treatment is termed by some the “size and shape” factor but is more correctly described as a “hindrance” factor. This, if correctly calculated, allows for an easy assessment of the average particle size. The various mathematical expressions are reviewed and assessed, with particular reference to that originally presented by Richardson and Zaki. The effect of particle-liquid association on sedimentation rates (and thus on calculated radii) is considered.

Infrared Spectrophotometry Method for Methazole Formulations: Collaborative Study

Abstract An infrared method was developed for the analysis of Probe 75% wettable powder formulation for methazole content. The procedure involves an extraction of the powder by agitation with acetone. The suspension is centrifuged, and the clear supernatant liquid is measured for absorbance at 755 cm−1. A collaborative study was conducted with 10 laboratories participating. One laboratory omitted the centrifugation, which resulted in a low assay. Statistical analysis of the data showed no significant variances. The coefficient of variation for 10 laboratories analyzing 2 samples in duplicate was 1.29%. The method has been adopted interim official first action.

Effect of Bentonites on Fluorometric Selenium Determination

Bentonites in feeds cause error in the analysis for Se by the AOAC (3.097-3.101) fluorometric method for Se in plants. The error apparently results from the binding of the piazselenol by insoluble residue from the bentonite. This effect is avoided by diluting digests to volume after reduction with HCl, centrifuging or allowing to stand, and analyzing a portion of the clear supernatant liquid. Insoluble residues present after digestion of plant materials do not appear to cause a similar error.

The pH Values of Soils Suspended in Dilute Salt Solutions

AbstractThe pH values of dilute solutions and soils were measured with the standard glass‐reference electrode combination and with the glass‐silver, silver chloride pair without liquid junction. At low ionic strengths, the pH values of the soils and solutions determined with the glass‐Ag, AgCl Combination were about 0.1 to 0.2 unit lower than those obtained using the standard reference electrode. With the soils, the differences were observed even when the KCl junction was kept in the clear supernatant liquid. Stirring the solutions and the soil suspensions and increasing the salt concentration decreased the pH values measured with the glass‐reference pair but not with the glass‐halide electrode combination. From these observations it was concluded that pH measurements made at low ionic strengths using the standard reference electrodes with restricted diffusion of KCl were subject to direct liquid junction errors. These liquid junction potentials were distinct from Donnan‐electromotive force (emf) effects caused by interaction of the charged soil particles with the KCl junction. Like the Donnan‐emf effects, they could be reduced by increasing the electrolyte concentration in solution.

The Adsorption of Carbohydrates and Related Compounds on Clay Minerals

AbstractStudies were made with the adsorption of carbohydrates on clay minerals. The carbohydrates utilized were ethyl cellulose, methylcellulose 15 cps, cellulose dextrin, starch dextrin, inulin, glycogen, corn polysaccharide, hydroxyethylcellulose, carboxy‐methylcellulose, corn starch, and sucrose.These carbohydrates were adsorbed on both a calcium and hydrogen saturated montmorillonitic type clay. A calcium saturated kaolinitic type clay was also used.Increasing increments of carbohydrates, ranging from 26 mg. to as much as 450 mg. in certain cases, were added to 1‐g. samples of the clays. Twenty ml. of water was added, and the materials were thoroughly mixed by mechanical shaking for 48 hours. The clays were allowed to stand 96 hours to attain equilibrium and were centrifuged. The clear supernatant liquid was then tested for carbohydrate by the anthrone reaction. The difference between the amount of carbohydrate added and the amount in the supernatant liquid was taken as the amount adsorbed on the clay.Adsorption on the calcium saturated kaolinitic clay ranged from 0.0% to 3.7%. The greatest amount of adsorption on bentonite, the montmorillonitic type clay, was with ethyl cellulose, starch, and cellulose dextrin, 20.5%, 21.6%, and 12.4% respectively. Little difference was noticed between the calcium and hydrogen saturated clays.X‐ray diffraction analyses demonstrated that the carbohydrate materials were adsorbed between the interplanar spacings of the montmorillonitic clay. Infrared spectra analysis suggests that hydrogen bonding plays a role in the adsorptive mechanism. Extractions with bases, acids, and salts suggest that cation and anion exchange are not involved in the adsorption of these carbohydrates.

Isolation of sodium hyaluronate.

DURING recent investigations for the development of new methods for the isolation and purification of hyaluronic acid from human umbilical cords, the following interesting observation was made. The cords, stored in acetone, were extracted with hot water (65°) and the aqueous extract allowed to ‘settle’ overnight. The clear supernatant liquid was kept under toluene for fourteen days, when it deposited a precipitate. This was removed, and the clear liquid was acidified with glacial acetic acid. Half the resulting mucin clot was stored in acetone for several weeks. Upon attempting to dissolve it at pH 8.0, it was found to be incompletely soluble, whereas the original clot was soluble. The ‘acetone-clot’ was extracted with water at pH. 8.0, the extract giving only a very faint cloudiness upon acidification to pH 4.0. It was poured into 3 vol. of alcohol and the precipitate re-extracted with water. Finally, a preparation of sodium hyaluronate was obtained having only 4.5 per cent nitrogen (on free acid) and 7.7 per cent ash (3.3 per cent sodium approximately); whereas the mucin clot, after reprecipitation, had 15 per cent nitrogen and negligible ash content. In fact, hyaluronic acid, containing only 6–10 per cent protein, had been extracted at pH 8.0 from the mucin clot after acetone treatment.

Comparative behavior of ammonia and ammonium salts in soils

does not appear. First page follows. Introduction Some years ago anhydrous ammonia (NH3) was introduced in California as a nitrogen fertilizer. This compound, sold as “Agricultural Ammonia” and “Shell NH3,” is available in the form of a liquefied gas compressed in strong steel cylinders that weigh about 150 pounds. Agricultural Ammonia is applied on the land during irrigation. The cylinders are connected to a simple metering device, and the ammonia is released as a gas into the irrigation water. Thus the ammonia is distributed in a very dilute solution (100 to 500 p. p.m.). In water ammonia (NH3) forms ammonium hydroxide (NH4OH). Every new method of fertilization unfolds problems for investigation. The mere fact that a new type of fertilizer initially produces good economic returns is no guarantee of lasting efficiency. Since the continued use of a given fertilizer may deteriorate the chemical and physical properties of a soil and impair the crop yields, it is, therefore, of utmost importance to acquire a clear understanding of the reactions that take place and the resulting changes in soil properties. In this paper are discussed certain fundamental problems of ammonia fertilization, especially those phases that require laboratory investigation. For the purpose of comparison with commonly used nitrogenous fertilizers, all experiments with ammonia (NH3) were accompanied by corresponding experiments with ammonium sulfate [(NH4)2SO4] or ammonium chloride (NH4Cl). The various topics investigated may be conveniently grouped as follows: (1) the extent and chemical nature of ammonia fixation in soils; (2) the availability of ammonia in soils to plants and microörganisms; (3) the influence of ammonia on physical soil characteristics, especially permeability. Fixation of Ammonium Compounds in Soils Experimental Procedure.—To 50-gram portions of air-dry soil were added electrolyte solutions containing 2 to 500 milliequivalents of NH4OH or (NH4)2SO4. All systems were brought to a volume of 1 liter. The suspensions were kept at room temperature for 24 hours and were shaken occasionally. Samples of clear supernatant liquid were obtained by centrifuging or by means of Pasteur-Chamberland filters. According to special tests, no NH3 was lost under the experimental conditions. The NH3 was determined by distillation with MgO into standard acid, using methyl red as an indicator.

Composition of Antigen-precipitin Precipitate.

Practically nothing is known about the composition of the antigen-precipitin precipitate beyond the fact that the amount of the precipitate produced may be much more than the amount of the antigen used. Just how much of the antigen is present in the precipitate does not seem to have been determined. This is due to the fact that there exists no chemical method of determining the antigen (protein) and the precipitin (protein) separately. One of us has worked out a method for the determination of minute amounts of hemoglobin. The method is based on the benzidine reaction, and as little as 0.02 mg. hemoglobin suffices for a quantitative determination. When hemoglobin is used as the antigen its amount in the antigen-precipitin precipitate can be determined directly by means of that method. The amount of the precipitin in the precipitate can be determined by the difference between the total protein and the hemoglobin. The assumption is here made that the precipitate contains only the antigen and the precipitin and no other protein. The word hemoglobin is used here in the generic sense, including oxyhemoglobin and its immediate derivatives. Oxyhemoglobin on standing is slowly converted into methemoglobin. This is, however, a matter of no consequence since oxyhemoglobin and methemoglobin have the same immunological properties as well as the same chemical properties utilized for their quantitative determination in the above mentioned method. Sheep oxyhemoglobin solution was prepared from washed cells by laking with 4 volumes of water and shaking with 2.5% suspension of freshly prepared aluminium hydroxide. The mixture was centrifuged and the clear supernatant liquid was filtered through a Seitz filter. Dog's oxyhemoglobin solution was prepared from crystals obtained by electrodialysis according to the method of Stadie. Alumina cream was also used. The final solutions contained about 5 % hemoglobin.

Correlation of Loaf Volume with Peptizing Action of Salts on Wheat Flour Proteins.

We have recently completed in this laboratory an extensive study of the peptizing action of certain salt solutions on a series of wheat flours.† The 12 wheat flours used were selected with the object of including flours from the various types of wheat grown extensively in the United States and Canada. The experimental procedure was to weigh out 6 grams of flour into a 100 cc. centrifuge tube, and to add 50 cc. of a salt solution of given concentration. This mixture was then shaken for 30 minutes in a mechanical shaker, and the flour residue tightly packed in the bottom of the tube by an electric centrifuge. The clear supernatant liquid was decanted into a Kjeldahl flask and the extraction repeated on the flour residue with 50 cc. of fresh salt solution, repeating the shaking, centrifuging and decanting, and following this with a third extraction of the residue, with a fresh portion of 50 cc. of the salt solution. Sulfuric acid was then added to these combined extracts, and the nitrogen dissolved by the sa...

A METHOD FOR THE DETERMINATION OF THE RELATIVE SURFACE AREAS OF POWDERED MATERIALS1

The ratios of the surfaces of powders of different degrees of fineness are obtained by determining the relative amounts of a radioactive substance, ThB, adsorbed on the surfaces of the powders. The ThB is dissolved in an ammonical solution of water or alcohol, and equal-weight samples of the various powders are placed in equal volumes of this radioactive solution. After adsorption equilibrium is complete, 10 cc. of the clear supernatant liquid of each sample are evaporated to dryness on watch glasses, and the relative radioactivities of the deposits are measured in an electroscope. Since, for a given concentration of radio-active solution, the degree of adsorption is not a straight-line function of the surface exposed, an adsorption curve must be determined for each material studied.

The butyric reaction for syphilis in man and in the monkey

In a preliminary communication1 I stated elsewhere that an increase in certain protein constituents of the blood serum and of the cerebro-spinal fluid of patients suffering from active or latent syphilis or parasyphilitic affections is a constant occurrence. I wish to describe here briefly the technique of employing butyric acid for the detection of this increase of protein.Cerebro-spinal fluid.—One or two parts2 of spinal fluid3 are mixed with five parts4 of 10 per cent. butyric acid solution5 and are heated over a flame to a brief boiling. One part1 of normal solution of NaOH is then added quickly to the heated mixture and the whole is boiled once more for a few seconds. The presence of an increased content of protein in a spinal fluid is indicated by the appearance of a granular or flocculent precipitate which gradually settles under a clear supernatant liquid. The intensity of the reaction varies greatly according to the amount of the protein which a given specimen contains, but the granular appearanc...