Optimal Polyethylene Glycol Concentration Research Articles

Optimasi Variasi Konsentrasi, Waktu Sentrifugasi Polyethylene Glycol (PEG), dan Modified Egg Yolk Lipemic Serum pada Enzim Serum Glutamic Pyruvic Transaminase (SGPT)

Examination of Serum Glutamic Pyruvic Transaminase (SGPT) enzymes can be disrupted due to the presence of fatty serum. The addition of Polyethylene Glycol (PEG) to fatty serum will lower the surface tension of the serum so that the fat will precipitate and eliminate error readings on the photometer. This study aims to determine the concentration and centrifugation time of the addition of Polyethylene Glycol (PEG) under optimal conditions. Serum modification was made to resemble fatty serum using egg yolks with three variations of triglyceride levels in ±500 mg/dL, ±600 mg/dL, ±700 mg/dL. Fatty serum is made using three concentrations of Polyethylene Glycol (PEG), namely 0.05%, 0.10%, 0.15%. Then incubated for 30 minutes at 40C and precipitation was carried out using centrifugation at 3000 rpm with three variations of centrifugation time, namely at 5, 10 and 15 minutes. Then the resulting supernatant was separated and measured to determine the Serum Glutamic Pyruvic Transaminase (SGPT) enzyme using a photometer. Then the data were analyzed using a two way ANOVA test followed by a Post Hoc test with a 95% confidence level. The conclusion of this study is that at 500 mg/dL fatty serum, the optimal concentration was obtained, namely 0.10% with a 10-minute centrifugation time, at 600 mg/dL fatty serum, the optimal concentration was obtained, namely 0.10% with a 10-minute centrifugation time, on fatty serum 700 mg/dL obtained the optimal PEG concentration and centrifugation time of 0.15% with a centrifugation time of 15 minutes.

Synthesis of a novel composite component inhibitor and its flame retardant effect on coal

In order to solve the problem of coal spontaneous combustion in the goaf, this paper used multi-component polymers as materials, and determined the optimal concentration of polyethylene glycol, carbonate and sodium polyacrylate was 13.7 wt%, 14.1 wt%, 0.03 wt% by response surface method. The water loss rate and surface tension of PAS-W were tested. The effect of PAS-W on functional groups was analyzed by infrared experiments. Thermogravimetric experiment was used to test the thermodynamic properties of PAS-W. The research showed that PAS-W had good applicability and stability. After treated with PAS-W, the content of aliphatic hydrocarbon and aromatic hydrocarbon in coal decreased by 49.5% and 39.7%, respectively. The oxidation rate of coal slowed down, and the ignition temperature also increased significantly. By analyzing the flame retardant mechanism of PAS-W, it was found that PAS-W had good flame retardant effect in physical and chemical properties.

Low concentration of polyethylene glycol facilitates separation of extracellular vesicles from bronchoalveolar lavage fluid.

Extracellular vesicles (EVs) in bodily fluids play an essential role in cell-cell cross talk and potentially serve as novel biomarkers in "liquid biopsy." It is crucial to have a consistent, efficient, and reliable method to separate EVs from bodily fluids. Currently, there is no universally accepted, "best" method to separate EVs. Besides differential ultracentrifugation (UC), polyethylene glycol (PEG) is among the commonly used methods for EV separation from bodily fluids. However, the optimal concentration of PEG to be used remains inadequately addressed. We initially observed that the concentration of PEG has a significant impact on the amount of separated EVs and EV-cargos, which are recovered from bronchoalveolar lavage fluid (BALF). To determine the optimal PEG concentration to be used in EV separation from BALF, we first separated the BALF and serum from wild-type C57BL/6 mice. Next, various concentrations of PEG (5%, 10%, and 15% PEG), a commercial kit, and UC were used to obtain EVs from BALF and serum. EVs were characterized, and EV-cargo protein, RNA, and miRNA levels were determined. We found that high concentration of PEG (10% and 15%) altered various EV parameters that are frequently used in EV studies, including EV yield, purity, and morphology. Using miR-15a, miR-142, and miR-223 as examples, we found that 10% and 15% PEG robustly reduced the detected levels of EV-cargo miRNAs compared with those in the EVs separated using UC or 5% PEG. Collectively, low concentration of PEG facilitates the optimal BALF EV separation.

Synthesis and electric properties of polyethylene glycol-modified fly ash floating bead/polyaniline composites

Fly ash floating bead (FAFB) was modified by the nonionic surfactant polyethylene glycol (PEG) under various concentrations to improve its hydrophobility, and then PEG modified FAFB composited with polyaniline (FAFB-PEG/PAn) by emulsion polymerization method using different feed ratios of FAFB-PEG. The chemical structure, phase structure, microstructure, conductivity, and dielectric properties were studied by FT-IR, XRD, SEM, four-probe technique, and LCR digital bridge, respectively. It was demonstrated that the optimal concentration of PEG was 1 mol/L and the corresponding grafting ratio was 1.42 %. The phase structure of FAFB was not destroyed after modification by PEG, while the surface became smoother and could be coated by PAn successfully according to SEM technique. Compared to that of dodecylbenzenesulfonic acid doped PAn (PAn-DBSA), the conductivity of FAFB-PEG/PAn was decreased by 10-100 times after introduction of various amounts of FAFB-PEG, especially the value could be decreased to 0.01 S cm-1 if 50 wt% of FAFB-PEG was provided. Additionally, the dielectric constant and loss factor of FAFB-PEG/PAn composites gradually decreased with increasing amount of FAFB-PEG in the frequency range of 100 KHz-2 MHz, namely, the dielectric constant could be still kept at 500 and correspondingly the loss factor decreased to 4.7 at 100 KHz if 50 wt% of FAFB-PEG was provided. The leaking current phenomenon derived from PAn-DBSA could also be weakened by FAFB-PEG.

A New Method of Using Polyethylene Glycol (PEG) Precipitation of Macroprolactin to Detect Genuine Hyperprolactinemia

The most commonly used method of polyethylene glycol (PEG) precipitation for macroprolactinemia (MP) screening has some significant drawbacks. The aim of this study was to establish a new method using PEG for precipitation of macroprolactin (macroPRL) to detect genuine hyperprolactinemia (genuine HP). The optimal PEG concentration for precipitation and the effect of PEG on the precipitation of PRL were analyzed to establish and optimize our PEG precipitation method. The PRL recovery rate and genuine HP detection rate were compared between our method and MP screening method. About 25% PEG6000 was determined to be the optimal PEG concentration for precipitation. Along with an increase in protein concentration in the PRL calibration solution, the PRL recovery rate after precipitation decreased gradually. The PRL recovery rate increased when the precipitation was carried out with diluted PRL calibration solution; the recovery rate reached greater than 90% after a 5-fold dilution of the calibration solution. The genuine HP detection rate and PRL recovery rate using our diluted serum PEG precipitation method were significantly higher than those obtained with the MP screening method. Our method successfully detected 31 cases of genuine HP, which was significantly higher than the detection rate obtained using the MP screening method (25 cases; P < 0.001). Precipitation using 5-fold diluted serum with 25% PEG6000 can effectively reduce the macroPRL concentration, increasing the PRL recovery rate and detection rate of genuine HP after precipitation, which is an effective and convenient method for the detection of genuine HP.

The Effects of Additives on the Properties of Non-Cyanide Electroless Gold Plating Deposition

In order to improve the non-cyanide electroless gold plating deposition performance, the effects of the kinds of additives as well as its concentration on the deposition performance were investigated. The appearance inspection, deposition rate, adhesive force, surface morphology and corrosion resistance were evaluated. The results showed that the introduction of appropriate additives did improve the coating properties. The optimal concentration of polyethylene glycol and polycrylamide were 0.6~1.0 g·L-1 and 1.0~1.5 g·L-1, respectively. The corrosion resistance of the coating deposited in baths containing polyacrylamide was best.

Characterization and magnetic properties of polyethylene glycol modified NiZn ferrite thin films

Polyethylene glycol (PEG) modified Ni 0.5Zn 0.5Fe 2.0O 4.0 ferrite thin films were deposited on Si (100) substrate by a sol–gel method. The crystal structure, surface morphology and magnetic properties of PEG-modified NiZn ferrite thin films (NZFs) were investigated by using the X-ray diffractometer (XRD), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). The FTIR spectrums showed that PEG molecules were on the surface of as-prepared particles, which effectively improved their dispersibility. The crystallization of NZFs improved and crystallite size increased with increasing PEG concentration. Optimal PEG concentration could improve the surface morphology and reduce the roughness. Magnetic properties measurement indicated that compared with the sample without PEG, PEG-modified NZFs showed excellent magnetic properties with higher saturation magnetization and lower coercive force. Finally, PEG-modified NZFs showed a high saturation magnetization 312 emu/cm 3 and low coercive force 90 Oe when PEG concentration was 40 g/L.

Electric‐field‐controlled synthesis of HPMA hydrogels containing self‐organized arrays of micro‐channels

AbstractWe report the synthesis of poly N‐(2‐hydroxypropyl)methacrylamide ordered arrays of fluid filled channels. The polymerization and crosslinking reactions are carried out under the influence of a constant electric field (60 V/cm). A charged comonomer, immobiline (pK 3.6), and porogen, polyethylene glycol (PEG) are added to the pregel solutions. Scanning electron microscopy reveals that the channels have a typical diameter of 2–25 μm and are oriented parallel to the electric field employed during synthesis. The self‐organization of channels occurs around an optimal PEG concentration of 8.6 wt/vol %, whereas significantly higher or lower concentrations yield random, isotropic pore structures. Moreover, tensile strength measurements show that the mechanical stability increases with decreasing concentration of PEG. Rheology experiments reveal that the swelling degree of these superabsorbant hydrogels increases with increasing PEG. Possible applications of these microstructured hydrogels as bidirectional scaffolds for regenerating neurons in the injured spinal cord are discussed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2593–2600, 2007

Transformation of Streptococcus bovis protoplasts by plasmid DNA.

The transformation and subsequent regeneration of ruminal strain Streptococcus bovis AO24/85 protoplasts by plasmid DNA was studied. The best stabilizer for regeneration of protoplasted cells was 5% sucrose in the regeneration medium and in the agar plates. Optimal concentration of polyethylene glycol 6000 in the transformation medium was 25% for both plasmids tested. Addition of Ca2+ and Mg2+ ions (2.5 mmol l-1) to the transformation medium increased the proportion of regenerated cells. Transformation frequencies were 3 x 10(3) transformants per microgram of pNZ12 and 2.4 x 10(2) per microgram of pJK108, respectively.

Plasmid transformation of Mycoplasma mycoides subspecies mycoides is promoted by high concentrations of polyethylene glycol

The recent isolation and characterization of two plasmids from Mycoplasma mycoides subspecies mycoides has opened up new possibilities for studying mycoplasmal genetics. In order to facilitate the development of a genetic system in M. mycoides subsp. mycoides, parameters of polyethylene glycol (PEG)-mediated transformation were examined, as existing protocols prove very inefficient in this organism. The effects of PEG concentration, DNA concentration, presence of Ca 2+ ions, and choice of buffers on the transformation of the Tn 916-containing plasmid pAM120 into M. mycoides subsp. mycoides were examined. The stability of Tn 916 in the M. mycoides subsp. mycoides chromosome was also evaluated. The optimal PEG concentration (53–62% ( w v )) in the transformation mixture was substantially higher than the PEG concentration reported to be optimal for transformation of other mycoplasmas (36% ( w v )). The PEG concentrations used here were also higher than the concentration used to promote transformation or fusion of gram-positive bacterial protoplasts. A necessity for the presence of Ca 2+ ions for optimal transformation was shown, as was the possible involvement of cell culture growth stage. Our results demonstrate the need for expanding current transformation techniques for mycoplasmas. Studies also indicate that once Tn 916 inserts into the M. mycoides subsp. mycoides chromosome, it can transpose to other sites at a relatively high frequency.

Effect of polyethylene glycol on transfection of Escherichia coli spheroplasts with bacteriophage .PHI.X174 single-stranded and double-stranded DNAs.

The efficiency of transfection of Escherichia coli spheroplasts increased when polyethylene glycol was used as an osmotic stabilizer instead of sucrose. Optimal concentration of polyethylene glycol was 0.5 to 1.0% for transfection with bacteriophage φX174 single-stranded DNA and 1.0 to 2.0% for that with φX174 double-stranded replicative form of DNA, and the efficiency of transfection increased 4 to 7-fold under these conditions. The extent of transfection of the spheroplasts prepared in the presence of polyethylene glycol was proportional to the number of phage DNA added. The effect of polyethylene glycol on transfection was independent of the presence of protamine sulfate.