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Methods for the preparation of raw materials to produce leucosapphire are considered. It is shown that the main directions in the production of high-purity aluminum oxide raw materials are: electrochemical oxidation of aluminum, decomposition of alkoxides, high-temperature treatment of aluminum oxide in a halogen-containing atmosphere, and preliminary purification of aluminum-containing compounds followed by their decomposition. It is shown that methods of the purification of aluminum hydroxide and oxide obtained by the Bayer process are the most promising for industrial use. These methods include the complex purification and simultaneous preparation of ceramic preforms starting from aluminum hydroxides or oxides by their treatment in subcritical or supercritical steam and the following heat treatment in a halogen-containing medium. [ABSTRACT FROM AUTHOR]

The fraction of hydrophobic peptides was eluted with MeCN (70%) in trifluoroacetic acid (TFA) solution (0.05%). The antibacterial activity of the culture fluid (Table 1) and intermediate fractions in each purification step was determined by spotting on agar and estimating the diameter of the indicator culture growth inhibition zone [[6]]. Extension of tryptic fragment sequences of bacteriocin Mal from Lactobacillus plantarum strain Mal and known orthologs from similar strains. [Extracted from the article]

We developed a sample preparation method for the determination of polybrominated diphenyl ethers (PBDEs) with from one to ten bromine atoms in samples of feed and food products containing approximately 0.5 g of animal fat or vegetable oil. The method involves gas chromatography with high-resolution mass spectrometry or tandem mass spectrometry. A possibility of using various reagents for the purification of extracts by chemical reactions and fractionation is studied. The physicochemical properties of PBDEs and polychlorinated biphenyls (PCBs) have significant differences, and to determine the full range of PBDEs, it is necessary to use other methods of sample preparation than in the case of PCBs. The conditions selected for the purification of extracts in a column filled with potassium silicate, Florisil, and silica impregnated with sulfuric acid and for their fractionation using activated neutral alumina ensure the PBDE recoveries of at least 75%. Purification of the extracts can be carried out without the use of chlorinated organic solvents. Applied aspects of instrumental analysis and measurement quality assurance are also described. [ABSTRACT FROM AUTHOR]

A promising method was proposed for the first time for purification of animal bone tissue fragments from high-molecular weight compounds in biphase media containing high-pressure CO2 (solutions of carbonic and peroxycarbonic acids). The efficiency of this purification was confirmed by SEM and IR spectroscopy. It turned out that, during the exposure of bone fragments in solutions of carbonic and peroxycarbonic acids at high CO2 pressure, mineral phase components of bone tissue are also extracted, which can be used to obtain highly dispersed hydroxyapatite particles upon extract reprecipitation. The structure and composition of the extracts were investigated by X-ray diffraction and scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]

An efficient one-pot procedure has been proposed for the synthesis of 8-methyl-5-[(methylsulfanyl) methyl]-3-thiabicyclo[3.3.1]non-7-en-6-one from accessible natural raw materials. A stable complex of the title compound with gold(III) has been obtained by the extraction method, and the mode of its coordination to the metal ion has been determined by IR and NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Purification of berkelium-249 (249Bk) at Oak Ridge National Laboratory requires a multi-step process with Bk Finishing as the final step. The current multi-process takes 6-7 months, including ~ 3 months spent on Bk Finishing. Recent trials of using columns of either LN resin or MP-1 anion exchange resin adsorbing the tetravalent 249Bk4+ in 8M HNO3-0.5M NaBrO3, followed by eluting impurities (e.g. Ce4+, Cf3+) and stripping 249Bk resulted in a new dual column method of selectively separating 249Bk from other trans-curium elements and fission product impurities, which is proposed to replace the current Bk Finishing with higher Bk purification efficiency and shorter processing period. This paper displays the experimental results and describes the dual column method with relevant chemistry issues. [ABSTRACT FROM AUTHOR]

Saccharomyces boulardii was used for antimicrobial peptides production. Separation process of produced antimicrobial peptides was conducted using ultrafiltration technique through dialysis membranes with porous 10 (MWCO) kDa. The inhibition activity was determined against four bacterial isolates. As a result, higher inhibition zone against Bacillus cereus were 26, 29 and 33 mm after adding 50, 75 and 100 µL of concentrated peptide, respectively. After that, peptide passed through the Sephadex G-50 column to achieve purified peptide using gel filtration. The high activity of purified peptide was confirmed based on the second peak reaching to 37 mm of bacterial inhibition zone while other peaks did not show any inhibition against tested bacteria. Some of the important characteristics of purified bioactive peptide were applied. Antimicrobial peptides stability was studied and found to be stable at pH range from 5 to 7 values studied in addition to its inhibition activity reached to 100%. Regarding thermal stability, it was observed that the peptide was fully activity at a both 60-80 °C for 30 min. Moreover, molecular weight of a peptide was identified using electrophoresis technique with SDS measured at 5792 Dalton. [ABSTRACT FROM AUTHOR]

The ability of Baculoviruses to hyper-express very late genes as polyhedrin, the major component of occlusion bodies (OBs) or polyhedra, has allowed the evolution of a system of great utility for biotechnology. The main function of polyhedra in nature is to protect Baculovirus in the environment. The possibility of incorporating foreign proteins into the crystal by fusing them to polyhedrin (POLH) opened novel potential biotechnological uses. In this review, we summarize different applications of Baculovirus chimeric OBs. Basically, the improvement of protein expression and purification with POLH as a fusion partner; the use of recombinant polyhedra as immunogens and antigens, and the incorporation of proteins into polyhedra to improve Baculoviruses as bioinsecticides. The results obtained in each area and the future trends in these topics are also discussed. [ABSTRACT FROM AUTHOR]

Modern technological approaches to ensuring the specific safety of human immunoglobulin and albumin preparations are analyzed. Introduction into human immunoglobulin preparation technology of donor screening for group- and rhesus-affiliations and chromatographic purification steps to reduce the contents of anti-A and anti-B hemagglutinins and anti-D antibodies are shown to be promising. Technological capabilities for reducing the anticomplementary activity and thrombogenic potential of immunoglobulin preparations and decreasing the contents of prekallikrein activator in human i.v. immunoglobulin and albumin preparations are discussed. [ABSTRACT FROM AUTHOR]

Pancreatic lipase inhibitors, such as tetrahydrolipstatin (orlistat), are used in anti-obesity treatments. Orlistat is the only anti-obesity drug approved by the European Medicines Agency (EMA). The drug is synthesized by saturation of lipstatin, a β-lactone compound, isolated from Streptomyces toxytricini and S. virginiae. To identify producers of novel pancreatic lipase inhibitors or microbial strains with improved lipstatin production and higher chemical purity remains still a priority. In this study, a high-throughput screening method to identify Streptomyces strains producing potent pancreatic lipase inhibitors was established. The assay was optimized and validated using S. toxytricini NRRL 15443 and its mutants. Strains grew in 24-well titer plates. Lipstatin levels were assessed directly in culture medium at the end of cultivation by monitoring lipolytic activity in the presence of a chromogenic substrate, 1,2-Di-O-lauryl-rac-glycero-3-glutaric acid 6-methylresorufin ester (DGGR). The lipase activity decreased in response to lipstatin production, and this was demonstrated by accumulation of red-purple methylresorufin, a product of DGGR digestion. The sensitivity of the assay was achieved by adding a lipase of high lipolytic activity and sensitivity to lipstatin to the reaction mixture. In the assay, the fungal lipase from Mucor javanicus was used as an alternative to the human pancreatic lipase. Many fungal lipases preserve high lipolytic activity in extreme conditions and are not colipase dependent. The assay proved to be reliable in differentiation of strains with high and low lipstatin productivity. [ABSTRACT FROM AUTHOR]

A new two-step procedure has been developed for the synthesis of 2,2′: 6′,2″-terpyridine and 4′-methylsulfanyl-2,2′: 6′,2″-terpyridine in more than 70% yield on the basis of Potts’ condensation. Efficient methods have been proposed for purification of all condensation products. [ABSTRACT FROM AUTHOR]

The ability of cobalt-, iron-, and zinc-containing framework compounds to take up impurities (free fatty acids and peroxide compounds) from linseed, false fl ax, and sunfl ower oil was studied. These framework structures improve the physicochemical properties and quality of the vegetable oils tested. The metal-organic frameworks surpass in performance the traditionally used industrial and natural sorbents. The sorbents tested preserve the performance for no less than five cycles. [ABSTRACT FROM AUTHOR]

Purpose: The emulsifiers in an exceedingly higher level are used in the preparation of drug loaded polymeric nanoparticles prepared by emulsification solvent evaporation method. This creates great problem to the formulator due to their serious toxicities when it is to be administered by parenteral route. The final product is therefore required to be freed from the used surfactants by the conventional purification techniques which is a cumbersome job. Methods: The solvent resistant stirred cell ultrafiltration unit (Millipore) was used in this study using polyethersulfone ultrafiltration membrane (Biomax®) having pore size of NMWL 300 KDa as the membrane filter. The purification efficiency of this technique was compared with the conventional centrifugation technique. Results: The flow rate of ultrafiltration was optimized for removal of surfactant (polyvinyl alcohol) impurities to the acceptable levels in 1-3.5 h from the nanoparticle dispersion of tamoxifen prepared by emulsification solvent evaporation method. Conclusions: The present investigations demonstrate the application of solvent resistant stirred cell ultrafiltration technique for removal of toxic impurities of surfactant (PVA) from the polymeric drug nanoparticles (tamoxifen) prepared by emulsification solvent evaporation method. This technique offers added benefit of producing more concentrated nanoparticles dispersion without causing significant particle size growth which is observed in other purification techniques, e.g., centrifugation and ultracentrifugation. [ABSTRACT FROM AUTHOR]

Production of no-carrier-added (NCA) Pd, which will decay to Rh, was experimented using the Nb(B, 3n)Pd reaction. The 36 MeV boron beam on natural niobium generated 1 MBq/µA.h yield of Pd along with minute contaminants. A chemical separation method based on the liquid-liquid-extraction (LLX) was developed for the separation of trace amount of Pd from the bulk Nb. Stable isotopes of Pd and Nb were used to simulate the reaction with the help of inductively coupled plasma-optical emission spectroscopy (ICP-OES). A high separation factor (~10) was achieved at the optimum separation condition. [ABSTRACT FROM AUTHOR]

Trends and methods of solving the problem of creating a complete technological chain from raw materials to high-purity rare-earth products in Russia have been considered. The need to create an information support system in the industry has been discussed and a possible way to implement one has been proposed. [ABSTRACT FROM AUTHOR]

Solvent extraction studies on the purification of uranium from zirconium rich sodium diuranate (SDU) feed was carried out using n-tri butyl phosphate (TBP) as extractant and n-decanol as phase modifier. The presence of Zr in SDU leached solution leads to the formation of third phase during liquid-liquid extraction of uranium which was successfully prevented by addition of n-decanol in 30% (v/v) TBP/ n-dodecane mixture. A seven stage counter current extraction of SDU feed solution followed by five stage stripping were carried out using optimum concentration of phase modifier 15% n-decanol-30% TBP in n-dodecane as solvent. Based on the findings a process flow-sheet has been developed for the purification of SDU to nuclear grade ammonium diuranate. [ABSTRACT FROM AUTHOR]

Isolation and purification of L-lactide to reach the polymerization purity level with removal of impurities by fractional melting was studied. The process implementation was suggested, and the influence of various parameters on the rate and degree of impurity removal was examined. The optimum conditions for removal of the main impurities from L-lactide were found. The method allows preparation of L-lactide of polymerization purity in approximately 50% yield. [ABSTRACT FROM AUTHOR]

This work presents a new and simple procedure for the shape selective purification of gold nanorods from a mixture of rods and spheres. Previously reported methods were time-consuming and revealed several drawbacks such as low yields and difficulty to recover the purified nanoparticles. Additionally, they were mostly applied to high aspect ratio (AR) nanorods. Our process is based on only simple and short centrifugation steps in order to precipitate specifically gold nanospheres. Samples containing low AR nanorods (AR < 6) were selected to perform the purification process. The supernatant content was followed by UV-Visible absorption spectroscopy after each centrifugation step. Then, transmission electron microscopy (TEM) allowed extract the purification efficiency thanks to shape analyses performed on more than 1000 nanoparticles. These results showed that our centrifugation process was applied successfully to three sizes of nanorods (2.4, 3.7, and 5.3). High purification yields of 72 and 78% were attained for AR = 3.7 and AR = 5.3 nanorods, respectively. [ABSTRACT FROM AUTHOR]

We have proposed and tested a combined process for ultrapurification of monoisotopic S and S sulfur, which comprises thermochemical treatment of sulfur vapor on silica and ceria packing, melting with aluminum, and distillation. The impurity composition of the purified sulfur has been determined by atomic emission and IR spectroscopy. We have obtained monoisotopic S and S sulfur samples comparable in chemical purity to high-purity sulfur of natural isotopic composition. [ABSTRACT FROM AUTHOR]

We have studied the wetting behavior of molten germanium on silica ceramics and amorphous silica coatings in vacuum at a pressure of 1 Pa and a temperature of 1273 K. The results demonstrate that the wetting of rough surfaces of ceramic samples and coatings by liquid Ge is significantly poorer than that of the smooth surface of quartz glass. The contact angle of polished glass is ~100°, and that of the ceramics and coatings increases from 112° to 137° as the total impurity content of the material decreases from 0.120 to 1 × 10 wt %. Using experimental contact angle data, we calculated the work of adhesion of molten Ge to the materials studied. Its value for the surface of the ceramics and coatings decreases from 0.45 to 0.20 J/m with decreasing impurity content, whereas the work of adhesion to a smooth glass surface is 0.55 J/m. We have fabricated fused silica test containers coated with high-purity amorphous silica. Using horizontal zone refining, we obtained germanium samples with a carrier concentration difference on the order of 10 cm. [ABSTRACT FROM AUTHOR]

Design of a flat-chamber type of electrobaromembrane device and procedure for calculating permeate flow rate and increased effective membrane area are developed for cleaning chemical, engineering, and food industry process solutions. [ABSTRACT FROM AUTHOR]

On the basis of the universal Kennard-Stepanov-van Roosbroeck-Shockley relation, a general approach is proposed for separation of the contributions of homogeneous and inhomogeneous broadenings in the absorption and luminescence spectra of colloidal quantum dots. The applicability of the developed method is demonstrated on published experimental data. [ABSTRACT FROM AUTHOR]

Waste-generation schemes for β-lactam cephalosporin production were compared. It was shown that effluents from chemical transformation and purification steps are the most ecologically polluted and hazardous. Therefore, the issue of reduced environmental impact must be resolved first for these process steps. In general, the technogenic load from cephalothin sodium salt production was greater than that from cephalexin monohydrate production. [ABSTRACT FROM AUTHOR]

We demonstrate the possibility of obtaining high-purity aluminum oxide by successive processes of hydrothermal oxidation of aluminum and vacuum heat treatment of the solid oxidation product (boehmite). The results of studies of changes in the structural properties and chemical purity of alumina samples obtained in the different modes of vacuum heat treatment of boehmite are presented. Experiments have shown the ability to produce alumina with a purity of 99.997% (the total content of all impurities is approximately 30 ppm) of aluminum with a purity of 99.8%. It was shown that the chemical purity of the final product depends on not only the temperature and time of heat treatment but also a number of other parameters of the process. [ABSTRACT FROM AUTHOR]

Idaho National Laboratory (INL) produces Xe, Xe, Xe, and Xe standards for the calibration and testing of the collection equipment and analytical techniques used to monitor radioactive xenon emissions. At INL, xenon is produced and collected as one of several spontaneous fission products from a Cf source in a stagnant volume of pressurized helium. Solids are separated from gases by sintered steel filtration. Further chromatographic purification of the fission gases separates the xenon fraction for selective collection. An explanation of gas system, separation, and purification is presented. Xe and Xe activity ratio adjustments are explained. [ABSTRACT FROM AUTHOR]

Detector sensitivity and purification challenges have limited published Si sediment dating studies. The cosmogenic isotope Si can fill the sediment geochronology gap between Pb (<150 years) and C (>1000 years). Targeting this age range can provide geochronological reconstructions of paleoindicators that identify recent human and climate-induced shifts in coastal areas. We are preparing detectors and kilogram-scale sample preparation techniques for such a study of Puget Sound sediments. This work considers the impact of background on counting time and Si age-dating reach. Design and performance of new low-background, gas-proportional beta counters to measure Si (via P) are discussed. [ABSTRACT FROM AUTHOR]

Recently a Np-237 target (26 mg) was analyzed for trace Pu isotopes (approximately 300 ppb). This work describes the chemistry required for a Np/Pu separation sufficient for Thermal Ionization Mass Spectrometry (TIMS), as well as the Pu purification from other potential contaminants. A point source was prepared from the purified Pu fraction and the atom ratios were measured via TIMS. The Pu isotopics provide a picture of the Np target's irradiation history, which will also be discussed. [ABSTRACT FROM AUTHOR]

Saponins are secondary metabolites that are abundant and diversified in echinoderms. Mass spectrometry is increasingly used not only to identify saponin congeners within animal extracts but also to decipher the structure/biological activity relationships of these molecules by determining their inter-organ and inter-individual variability. The usual method requires extensive purification procedures to prepare saponin extracts compatible with mass spectrometry analysis. Here, we selected the sea star Asterias rubens as a model animal to prove that direct analysis of saponins can be performed on tissue sections. We also demonstrated that carboxymethyl cellulose can be used as an embedding medium to facilitate the cryosectioning procedure. Matrix-assisted laser desorption/ionization (MALDI) imaging was also revealed to afford interesting data on the distribution of saponin molecules within the tissues. We indeed highlight that saponins are located not only inside the body wall of the animals but also within the mucus layer that probably protects the animal against external aggressions. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Age of individual uranium-plutonium (U/Pu) mixed particles with various U/Pu atomic ratios (1-70) were determined by inductively coupled plasma mass spectrometry. Micron-sized particles were prepared from U and Pu certified reference materials. The Pu reference was stored for 4-6 years since the last purification (July 14, 2008). The Pu purification age was obtained from the Am/Pu ratio which was calculated from the product of three measured ratios of Pu and Am isotopes in the eluted fractions. These ratios were measured by a high-resolution inductively coupled plasma mass spectrometer equipped with a desolvation system. Femto-gram to pico-gram quantities of Am, U, and Pu in a sample solution were sequentially separated on a small anion-exchange column. The Am/Pu ratio was accurately determined by spiking pure Am into the sample solution. The average determined age for the particles for the five independent U/Pu ratios was in good agreement with the expected age with high accuracy (difference age 0.27 years) and high precision (standard deviation 0.44 years). The described analytical technique can serve as an effective tool for nuclear safeguards and environmental radiochemistry. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Crystals of E. coli purine nucleoside phosphorylase were grown in microgravity by the capillary counter-diffusion method through a gel layer. The X-ray diffraction data set suitable for the determination of the three-dimensional structure at atomic resolution was collected from one crystal at the Spring-8 synchrotron facility to 0.99 Å resolution. The crystals belong to sp. gr. P2 and have the following unit-cell parameters: a = 74.1 Å, b = 110.2 Å, c = 88.2 Å, α = γ = 90°, β = 111.08°. The crystal contains six subunits of the enzyme comprising a hexamer per asymmetric unit. The hexamer is the biological active form of E. coli. purine nucleoside phosphorylase. [ABSTRACT FROM AUTHOR]

We have investigated the mechanism for the reversible addition of ethylene to a periodic 2D network of square-planar nickel centers ([Ni(SC)]) using density functional theory. The mechanism is analogous to that for homogeneous olefin binding to metal bis(dithiolene) complexes. We considered periodic boundary calculations (PBC) as well as clusters containing up to 12 nickel atoms using a screened hybrid density functional to obtain accurate reaction barriers. Several different products were analyzed. The lowest-energy route begins with the addition of ethylene across the nickel-sulfur bond, which has previously not been considered for this system. The effect of the addition of several alkene molecules simultaneously on the surface was investigated to determine the potential efficiency of this material. This material is a candidate for alkene purification as it exhibits similar reactivity to its molecular analog in terms of the relative stability of products, energy barriers, and molecular efficiency while also providing the intrinsic technical benefits of heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

The leaf of Magnolia officinalis is abundant in natural resources as a novel potential antioxidant and has great commercial value. In this study, the contents of total phenolics, total flavonoids, magnolol and honokiol in different solvent extracts (acetone, methanol and water) were measured. Meanwhile, the antioxidant activity of extracts from M. officinalis leaves were evaluated using 1,1-diphenyl-2-picrylhydrazyl free radical scavenging assay, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt free radical scavenging assay, FRAP assays and β-carotene/linoleic acid system. In addition, the correlation between the antioxidant activity and the contents of the active compounds was analyzed. Experimental results indicated that three extracts exhibited antioxidant effects in a concentration-dependent manner, and acetone extracts had the highest antioxidant activity, next methanol and water. There was an intimate relativity between the contents of magnolol and honokiol in different solvent extracts and the antioxidant capability of them. So the magnolol and honokiol of M. officinalis leaves as a representative of the active compounds were extracted and purified by using the macroporous resin column. The purity of depurated sample could reach 82.6 %, which indicates the M. officinalis leaves have the potential to substitute the production of magnolol and honokiol in M. officinalis. The results of this study can provide theoretical and technical references for the reasonable use of the M. officinalis leaves and alleviate the shortage of M. officinalis resources. [ABSTRACT FROM AUTHOR]

A three-stage linear gradient strategy using reverse-phase high-performance liquid chromatography (HPLC) was optimized for rapid, high-quality, and simultaneous purification of the lipopeptide isoforms of iturin, fengycin, and surfactin, which may differ in composition by only a single amino acid and/or the fatty acid residue. Matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS/MS) was applied to detect the lipopeptides harvested from each reversed-phase HPLC peak. Amino acid analysis based on phenyl isothiocyanate derivatization was further used for confirmation of the amino acid species and molar ratio in a certain HPLC fraction. By this MALDI-TOF-MS/MS coupled with amino acid analysis, it was revealed that iturin at m/ z 1,043 consists of a circular Asn-Tyr-Asn-Gln-Pro-Asn-Ser peptide and C β-OH fatty acid. Surfactin homologs from Bacillus subtilis THY-7 at m/ z 1,030, 1,044, 1,058, and 1,072 possess a circular Glu-Leu-Leu-Val-Asp-Leu-Leu peptide and the β-OH fatty acid with a different length (C-C). Fengycin species at m/ z 1,463 and 1,477 are homologs possessing the circular peptide Glu-Orn-Tyr-Thr-Glu-Ala-Pro-Gln-Tyr-Ile linked to a C or C γ-OH fatty acid, whereas fengycin at m/ z 1,505 contains a Glu-Orn-Tyr-Thr-Glu-Val-Pro-Gln-Tyr-Ile sequence with a Val instead of Ala at position 6. The method developed in this work provided an efficient approach for characterization of diverse lipopeptide isoforms from the iturin, fengycin, and surfactin families. [ABSTRACT FROM AUTHOR]

A design diagram and simple asymptotic formulas are proposed for the supporting frame of a membrane device consisting of two covers in the form of open toroidal shells that mate with a ring along the outer perimeter, and an opening with a circular plate around the inner perimeter. The diagram and formulas make it possible to estimate the stress-strain state of basic components of the cover: toroidal shell, circular plate, and ring. An example of the procedure used to calculate the strength and stiffness of the cover of the device is given. [ABSTRACT FROM AUTHOR]

Sr was produced via Y(n, p) Sr using yttria as target in Fast Breeder Test Reactor (FBTR), Kalpakkam, India. A radiochemical procedure has been developed for the separation of bulk yttrium using TBP by solvent extraction followed by purification of Sr source by ion exchange chromatography using the cation exchange resin Dowex 50WX8 (100-200 mesh) and nitric acid of variable molarity as eluant. The present study establishes the purification of Sr source from the other radionuclidic impurities like Y, Zn, Mn, Co, Rb, Ir, Ru, Sn, Ce, Tb, Eu etc. produced during the irradiation of yttria by using the complexing agent tri-sodium tri-meta phosphate (SMP) in nitric acid medium instead of nitric acid alone as an eluant. The purification was achieved by using 0.1 M SMP as complexing agent which was optimized based on the distribution ratio data and final elution of Sr fraction was obtained in nitric acid medium. This resulted into a faster purification of Sr source in a smaller volume of eluant. Purity of Sr source from the cross contamination of the complexing agent SMP was also ensured. [ABSTRACT FROM AUTHOR]

A methodology to purify a Ho solution has been developed by a combination of activity and mass concentration measurements in order to further determine the Ho half-life. The isobaric interference at m/ q ≃ 166 requires Ho purification from non-natural Er with a high purification degree due to the large amount of Ho as opposed to Er. The Ho/Er separation was achieved using high-performance liquid chromatography on a semi-preparative column followed by purification on gravitational chromatography. The efficiency of the separation was evaluated after precise determination of the Er isotopic composition. The purification methodology enabled to separate Ho from Er. [ABSTRACT FROM AUTHOR]

The article discusses the study on the synthesis of monoisotopic 73GeH4 and 74GeH4 monogermanes with ≈99.9 percent isotope and chemical compounds' chemical elements of 10–5 mol %. The study involves monogermanes synthesis featuring their quantification of impurity composition and deep purification. Result shows that the content of impurities in the monogermanes does not surpass to 10–5 mol %.

This paper addresses the preparation, purification (removal of oxygen-containing impurities), and applications of fluoride glasses, with particular attention to the preparation of modified glasses for extending their transmission window. [ABSTRACT FROM AUTHOR]

Standard enthalpies of formation of ternary phases in the Cu-Ni-Sn system were determined along sections at 25, 41 and 45.5 at.% Sn applying tin solution drop calorimetry. Generally, the interaction of Ni with Sn is much stronger than that of Cu with Sn. Along all sections the enthalpy of formation changes almost linearly with the mutual substitution of Cu and Ni within the respective homogeneity ranges. Thus no additional ternary interaction promoting the formation of further Cu-Ni-Sn phases can be assumed. The results are discussed and compared with literature values relevant to this system. [ABSTRACT FROM AUTHOR]

Acid functionalization has been considered as an easy way to enhance the dispersion and biodegradation of carbon nanotubes (CNT). However, inconsistencies between toxicity studies of acid functionalized CNT remain unexplained. This could be due to a joint effect of the main physicochemical modifications resulting from an acid functionalization: addition of surface acid groups and purification from catalytic metallic impurities. In this study, the impact on CNT biotoxicity of these two physiochemical features was assessed separately. The in vitro biological response of RAW 264.7 macrophages was evaluated after exposure to 15-240 µg mL of two types of multi-walled CNT. For each type of CNT (small: 20 nm diameter, and big: 90 nm diameter), three different surface chemical properties were studied (total of six CNT samples): pristine, acid functionalized and desorbed. Desorbed CNT were purified by the acid functionalization but presented a very low amount of surface acid groups due to a thermal treatment under vacuum. A Janus effect of acid functionalization with two opposite impacts is highlighted. The CNT purification decreased the overall toxicity, while the surface acid groups intensified it when present at a specific threshold. These acid groups especially amplified the pro-inflammatory response. The threshold mechanism which seemed to regulate the impact of acid groups should be further studied to determine its value and potential link to the other physicochemical state of the CNT. The results suggest that, for a safer-design approach, the benefit-risk balance of an acid functionalization has to be considered, depending on the CNT primary state of purification. Further research should be conducted in this direction. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Antioxidant peptides were isolated from the leukocyte extract of the Siamese crocodile, Crocodylus siamensis. Crocodile leukocyte was extracted by a combination of methods including freeze-thawing, acetic acid extraction and homogenization. The peptides in the leukocyte extract were purified by anion exchange chromatography and reversed phase-high performance liquid chromatography. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay was used to evaluate the antioxidant activity of the elution peaks at each purification step. As a result, there were two purified peptides exhibiting strong antioxidant activity in reducing free radicals on DPPH molecules. The amino acid sequences of these peptides were determined by LC-MS/MS as TDVLGLPAK (912.5 Da) and DPNAALPAGPR (1,148.6 Da), and their IC values were 153.4 and 95.7 μM, respectively. The results of this study therefore indicate that leukocyte extract of C. siamensis contains peptides with antioxidant activity which could be used as a novel antioxidant. [ABSTRACT FROM AUTHOR]

Quantitative determination revealed the presence of storage glucan (6.0%), fucoidan (19.2%) and alginate (12.7%) in the biomass of the brown alga Punctaria plantaginea collected from the Sea of Japan. The polysaccharides were isolated from the alga by fractional extraction followed by additional purification procedures. Unlike the well-known laminarans the storage polysaccharide from P. plantaginea was shown to be a linear (1→6)-β- d-glucopyranan, which is new for brown alga. The content of guluronic acid (G) residues in the alginate molecules exceeded the content of mannuronic acid residues (M), M/G = 0.5. Poly-G and poly-MG blocks were isolated from the products of partial hydrolysis of alginic acid; however, a heterogeneous mixture of polysaccharide fragments was obtained instead of the expected poly-M fraction. Preliminary data suggests that fucoidan from this alga is a new for brown algae type of sulfated polysaccharide (xylofucan) with a main backbone built of α- l-fucopyranose residues. This chain contains multiple sulfate groups and single non-sulfated β- d-xylopyranose residues as substituents. [ABSTRACT FROM AUTHOR]

This paper describes ultrapurification of isotopically enriched calcium and molybdenum compounds and CaMoO calcium molybdate growth charge in order to remove radioactive uranium, thorium, and radium impurities. CaMoO single crystals grown from such charges are needed for the fabrication of scintillator elements of the cryogenic detector for the AMoRE project: a search for Mo neutrino-less double-beta decay. [ABSTRACT FROM AUTHOR]

Two β-glucosidases (BGLs 1 and 2) were purified to homogeneity from the extracellular enzyme preparations of the ethanol-fermenting Mucor circinelloides NBRC 4572 statically grown on rice straw. BGLs 1 and 2 are monomeric glycoproteins whose apparent molecular masses ( Ms) are around 78 kDa, which decreased by approximately 10 kDa upon enzymatic deglycosylation. Both BGLs showed similar enzyme characteristics in optimal temperature and pH, stability, and inhibitors. They were active against a wide range of aryl-β-glucosides and β-linked glucose oligosaccharides. Their amino acid sequences shared 81 % identity and exhibited less than 60 % identity with the known family-3 BGLs. Considering properties such as reduced inhibition by ethanol, glucose, and cellobiose, low transglucosylation activity, wider substrate range, less binding affinity to lignocellulosic materials, and abundant expression, BGL1 is likely to be more suitable for bioethanol production than BGL2 via simultaneous saccharification and fermentation of rice straw with M. circinelloides. [ABSTRACT FROM AUTHOR]

In this work, we studied the effect of acid type in the final properties of CNTs as the resistance to air oxidation; for this, different techniques of characterization were used such as Raman spectroscopy, thermogravimetric analysis, and chemical analysis by ICP-AES. Through Raman spectroscopy, it is possible to monitor the structural changes induced by acids and this is reflected in changing of the activation energies for the different processes determined by thermogravimetric analysis; also by ICP-AES analysis, it was shown that the inorganic material was eliminated efficiently with the acid treatments used in this study. [ABSTRACT FROM AUTHOR]

Serine protease from kesinai leaves was purified for the first time by a surfactant-polymer aqueous micellar two-phase system. The effectiveness of different types and concentrations of non-ionic surfactants (Pluronic series and X-114) on the partitioning behaviour of the protease was evaluated. The results showed that the enzyme preferentially partitioned into the bottom surfactant-rich phase, while the hydrophilic amino acid preferred the top aqueous phase. This distribution of the enzyme is due to the hydrophobic interaction of the serine protease with the hydrophobic lid of the micelle core in the bottom phase. The influence of different types of salts (KSO, KHPO, KCl and KNO) on the purification and selectivity of the enzyme was determined. The protease partitioning in the bottom phase increased in the presence of KNO, which confirmed that the salt was able to improve the protein solubility in bottom phase and increase the hydrophobic interaction between the two phases. In addition, the protease from the bottom phase was re-extracted to a new aqueous phase solution to remove and recycle the surfactant. Addition of potassium thiocyanate led to the partitioning of the enzyme in top aqueous phase due to high ionic strength of SCN, which forced the lighter micellar phase toward the upper position of the system. A high purification factor (10.3) and yield of 92 % of the enzyme were achieved in a solution of 31 % of Pluronic L61 using 0.3 % KNO and 50 % crude feedstock at pH 7.0. [ABSTRACT FROM AUTHOR]

Two yeast strains, which have the ability to degrade biodegradable plastic films, were isolated from the larval midgut of a stag beetle, Aegus laevicollis. Both of them are most closely related to Cryptococcus magnus and could degrade biodegradable plastic (BP) films made of poly(butylene succinate) (PBS) and poly(butylene succinate- co-adipate) (PBSA) effectively. A BP-degrading enzyme was purified from the culture broth of one of the isolated strains employing a newly developed affinity purification method based on the binding action of the enzyme to the substrate (emulsified PBSA) and its subsequent degradative action toward the substrate. Partial amino acid sequences of this enzyme suggested that it belongs to the cutinase family, and thus, the enzyme was named CmCut1. It has a molecular mass of 21 kDa and a degradative activity for emulsified PBSA which was significantly enhanced by the simultaneous presence of Ca or Mg at a concentration of about 2.5 mM. Its optimal pH was 7.5, and the optimal temperature was 40 °C. It showed a broad substrate specificity for p-nitrophenyl (pNP)-fatty acid esters ranging from pNP-acetate (C2) to pNP-stearate (C18) and films of PBSA, PBS, poly( ε-caprolactone), and poly(lactic acid). [ABSTRACT FROM AUTHOR]

Granulysin is a cytolytic, proinflammatory protein produced by human cytolytic T-lymphocytes and natural killer cells. Granulysin has two stable isoforms with molecular weight of 9 and 15 kDa; the 9-kDa form is a result of proteolytic maturation of the 15-kDa precursor. Recombinant 9-kDa granulysin exhibits cytolytic activity against a variety of microbes, such as bacteria, parasites, fungi, yeast and a variety of tumor cell lines. However, it is difficult to produce granulysin in large quantities by traditional methods. In this study, we developed a simple and robust fed-batch fermentation process for production and purification of recombinant 9- and 15-kDa granulysin using Pichia pastoris in a basal salt medium at high cell density. The granulysin yield reaches at least 100 mg/l in fermentation, and over 95 % purity was achieved with common His-select affinity and ion exchange chromatography. Functional analysis revealed that the yeast-expressed granulysin displayed dose-dependent target cytotoxicity. These results suggest that fermentation in P. pastoris provides a sound strategy for large-scale recombinant granulysin production that may be used in clinical applications and basic research. [ABSTRACT FROM AUTHOR]

Photon upconverting nanophosphors (UCNPs) have the unique luminescent property of converting low-energy infrared light into visible emission which can be widely utilized in nanoreporter and imaging applications. For the use as reporters in these applications, the UCNPs must undergo a series of surface modification and bioconjugation reactions. Efficient purification methods are required to remove the excess reagents and biomolecules from the nanophosphor solution after each step to yield highly responsive reporters for sensitive bioanalytical assays. However, as the particle size of the UCNPs approaches the size of biomolecules, the handling of these reporters becomes cumbersome with traditional purification methods such as centrifugation. Here we introduce a novel approach for purification of bioconjugated 32-nm NaYF: Yb, Er-nanophosphors from excess unbound biomolecules utilizing high gradient magnetic separation (HGMS)-system constructed from permanent super magnets which produce magnetic gradients in a magnetizable steel wool matrix amplifying the magnetic field. The non-magnetic biomolecules flowed straight through the magnetized HGMS-column while the UCNPs were eluted only after the magnetic field was removed. In the UCNPs the luminescent centers, i.e., lanthanide-ion dopants are responsible for the strong upconversion luminescence, but in addition they are also paramagnetic. In this study we have shown that the presence of these weakly paramagnetic luminescent lanthanides actually also enables the use of HGMS to capture the UCNPs without incorporating additional optically inactive magnetic core into them. [ABSTRACT FROM AUTHOR]

Sarcoplasmic/endoplasmic reticulum (SR) and nuclear membranes contain two related cation channels named TRIC-A and TRIC-B. In many tissues, both subtypes are co-expressed, making it impossible to distinguish the distinct single-channel properties of each subtype. We therefore incorporated skeletal muscle SR vesicles derived from Tric-a-knockout mice into bilayers in order to characterise the biophysical properties of native TRIC-B without possible misclassification of the channels as TRIC-A, and without potential distortion of functional properties by detergent purification protocols. The native TRIC-B channels were ideally selective for cations. In symmetrical 210 mM K, the maximum (full) open channel level (199 pS) was equivalent to that observed when wild-type SR vesicles were incorporated into bilayers. Analysis of TRIC-B gating revealed complex and variable behaviour. Four main sub-conductance levels were observed at approximately 80 % (161 pS), 60 % (123 pS), 46 % (93 pS), and 30 % (60 pS) of the full open state. Seventy-five percent of the channels were voltage sensitive with Po being markedly reduced at negative holding potentials. The frequent, rapid transitions between TRIC-B sub-conductance states prevented development of reliable gating models using conventional single-channel analysis. Instead, we used mean-variance plots to highlight key features of TRIC-B gating in a more accurate and visually useful manner. Our study provides the first biophysical characterisation of native TRIC-B channels and indicates that this channel would be suited to provide counter current in response to Ca release from the SR. Further experiments are required to distinguish the distinct functional properties of TRIC-A and TRIC-B and understand their individual but complementary physiological roles. [ABSTRACT FROM AUTHOR]