bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous determination of five active hydrolysis ingredients from Panax quinquefolium L. by HPLC‐ELSD
Authors: Zhang Xiangrong , Ma Xiaoning , Si Bingkun , Zhao Yuqing 
Published: August 2010

AbstractAn effective method for simultaneous determination of five hydrolysis products of 20 (R)‐dammarane‐3β,6α,12β,20,25‐pentol, 24(R)‐ocotillol, 20(R)‐protopanaxatriol, 20(S)‐panaxatriol and 20(R)‐dammarane‐3β,12β,20,25‐tetrol was developed using high‐performance liquid chromatography with evaporative light scattering detection (HPLC‐ELSD). The hydrolysis products from Panax quinquefolium L. in the stems and leaves, berries, flower buds and roots components were successfully separated on a Kromasil C18 column using methanol and water (83:17, v/v) as mobile phase in 18 min. The parameter for the ELSD was set to a probe temperature of 40°C and the nebulizer for nitrogen gas was adjusted to 3 L/min. All calibration curves showed good linear regression (r > 0.9975) within test ranges. The validation of the method included recovery, linearity, accuracy and precision (intra‐ and inter‐day variation). The accuracy and precision were satisfactory, with the overall intra‐ and inter‐day variation being less than 3.11%, and recoveries of this method were greater than 95.0%. This study developed an effective and rapid method for simultaneous determination of multiple hydrolysis components from Panax quinquefolium L. Copyright © 2010 John Wiley & Sons, Ltd.
Simultaneous quantification of total eicosapentaenoic acid, docosahexaenoic acid and arachidonic acid in plasma by high‐performance liquid chromatography–tandem mass spectrometry
Authors: Salm Paul , Taylor Paul J. , Kostner Karam 
Published: August 2010

AbstractA method for the simultaneous quantification of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) in human plasma by HPLC–tandem mass spectrometry (HPLC‐MS/MS) was developed and validated. Free and esterified forms of fatty acids were hydrolysed from plasma samples in the presence of an internal standard and subjected to liquid–liquid extraction. The chromatographic run time was 3.5 min per sample. The assay was linear from 0.5 to 300 mg/L (r2 > 0.997, n = 18). Based on matrix addition, accuracy deviation was <15%, except for AA at 10 mg/L (30–90%), whereas precision was <8% for all fatty acids studied. The method was applied to the measurement of these omega‐3 fatty acids in a fish oil supplement study with healthy volunteers. Healthy males (n = 4) were administered a supplement containing 465 mg EPA and 375 mg DHA per capsule (Omacor®). A dose of two capsules was given daily over a 4 week period. Pre‐treatment concentrations varied between subjects for EPA (17–68 mg/L), DHA (36–63 mg/L) and AA (121–248 mg/L). During the dosing period EPA increased 460–480% from the baseline concentration, while DHA increased 150–160%. The EPA–AA ratio increased from 0.07–0.56 to 0.3–3.1 after 4 weeks of dosing. In conclusion, the method described could be suitable for monitoring EPA, DHA and AA in clinical studies that may aid in achieving optimal concentrations of these fatty acids in patients who could be at risk of sudden cardiac death. Copyright © 2010 John Wiley & Sons, Ltd.
Indirect reversed‐phase high‐performance liquid chromatographic and direct thin‐layer chromatographic enantioresolution of (R,S)‐Cinacalcet
Authors: Bhushan Ravi , Dubey Rituraj 
Published: August 2010

AbstractEnantioresolution of the calcimimetic drug (R,S)‐Cinacalcet was achieved using both indirect and direct approaches. Six chiral variants of Marfey's reagent having l‐Ala‐NH2, l‐Phe‐NH2, l‐Val‐NH2, l‐Leu‐NH2, l‐Met‐NH2 and d‐Phg‐NH2 as chiral auxiliaries were used as derivatizing reagents under microwave irradiation. Derivatization conditions were optimized. Reversed‐phase high‐performance liquid chromatography was successful using binary mixtures of aqueous trifluoroacetic acid and acetonitrile for separation of diastereomeric pairs with detection at 340 nm. Thin silica gel layers impregnated with optically pure l‐histidine and l‐arginine were used for direct resolution of enantiomers. The limit of detection was found to be 60 pmol in HPLC while in TLC it was found to be in the range of 0.26–0.28 µg for each enantiomers. Copyright © 2010 John Wiley & Sons, Ltd.
Defense attorneys' concerns about the competence of adolescent defendants
Authors: Viljoen Jodi L. , McLachlan Kaitlyn , Wingrove Twila , Penner Erika 
Published: August 2010

AbstractResearch indicates that a sizable proportion of adolescent defendants have difficulty understanding and participating in legal proceedings against them, and may be incompetent to stand trial. To examine attorneys' experience in defending adolescents with competence‐related difficulties, 214 juvenile attorneys were surveyed. Findings indicated that attorneys have doubts about the competence of approximately 10% of adolescent defendants, and that they find these cases particularly challenging to defend. Most attorneys appear to recognize that developmental factors may contribute to adolescents' competence‐related difficulties, and believe that the law should accept developmental immaturity as a basis for incompetence findings. In approximately half of the cases in which attorneys had doubts about competence, attorneys did not request a competence evaluation but instead made other efforts to address competence issues, such as by teaching adolescents about legal proceedings and further involving their parents. The implications of these findings are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Development of a process to manufacture PEGylated orally bioavailable insulin
Authors: Hazra Partha , Adhikary Laxmi , Dave Nitesh , Khedkar Anand , Manjunath H. S. , Anantharaman Ramya , Iyer Harish 
Published: August 2010

AbstractTo make insulin orally bioavailable, insulin was modified by covalent attachment (conjugation) of a short‐chain methoxy polyethylene glycol (mPEG) derivative to the ε‐amino group of a specific amino acid residue (LysB29). During the conjugation process, activated PEG can react with any of the free amino groups, the N‐terminal of the B chain (PheB1), the N‐terminal of the A chain (GlyA1), and the ε‐amino group of amino acid (LysB29), resulting in a heterogeneous mixture of conjugated products. The abundance of the desired product (Methoxy‐PEG3‐propionyl—insulin at LysB29:IN‐105) in the conjugation reaction can be controlled by changing the conjugation reaction conditions. Reaction conditions were optimized for maximal yield by varying the proportions of protein to mPEG molecule at various values of pH and different salt and solvent concentrations. The desired conjugated molecule (IN‐105) was purified to homogeneity using RP‐HPLC. The purified product, IN‐105, was crystallized and lyophilized into powder form. The purified product was characterized using multiple analytical methods including ESI‐TOF and peptide mapping to verify its chemical structure. In this work, we report the process development of new modified insulin prepared by covalent conjugation of short chain mPEG to the insulin molecule. The attachment of PEG to insulin resulted in a conjugated insulin derivative that was biologically active, orally bioavailable and that showed a dose‐dependent glucose lowering effect in Type 2 diabetes patients. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Optimization of ultrasound‐accelerated synthesis of enzymatic octyl hydroxyphenylpropionate by response surface methodology
Authors: Lee Chih‐Chen , Chen Hsiao‐Ching , Ju Hen‐Yi , Liu Yung‐Chuan , Chen Jiann‐Hwa , Shie Shiau‐Ying , Chang Cheng , Shieh Chwen‐Jen 
Published: August 2010

AbstractThe ultrasound‐accelerated enzymatic synthesis of octyl hydroxyphenylpropionate (OHPP) from p‐hydroxyphenylpropionic acid (HPPA) and octanol was investigated in this study. A commercially available immobilized lipase from Candida antarctica, Novozym® 435, was used as the biocatalyst. A three‐level‐three‐factor Box‐Behnken design experiment and response surface methodology were used to evaluate the effects of temperature, reaction time, and enzyme activity on percent yield of OHPP. The results indicated that temperature and enzyme activity significantly affected percent yield, whereas reaction time did not. A model for the synthesis of OHPP was established. Based on a ridge max analysis, the optimum conditions for OHPP synthesis were predicted to use a reaction temperature of 58.8°C, a reaction time of 14.6 h, and an enzyme activity of 410.5 PLU with a yield of 98.5%. A reaction was performed under these optimal conditions, and a yield of 97.5% ± 0.1% was obtained. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Towards an indirect screening technique facilitating detection of cellular populations bearing specific cell surface markers
Authors: Arora Sandeep K. , Sharma Rohit , Kaur Gagandeep , Bhoria Preeti , Sharma Maryada , Luthra‐Guptasarma Manni 
Published: August 2010

AbstractWe describe and demonstrate a technique for detection of cell surface antigens, with potential use in tissue antigen research. Briefly, a small volume of wetted chromatographic beads (specifically, 100 μL of Nickel‐nitriloacetic acid (NTA) agarose) was bound to small quantities (specifically, ∼0.1–0.2 μg) of a single‐chain Fv antibody recognizing the Class I MHC heavy chain antigen. The beads were then used to capture and detect cells bearing this antigen, through SDS polyacrylamide gel electrophoresis of boiled bead–cell complexes. A key feature of this method is its use of “signal amplification.” Although the antibody‐mediated binding and immobilization of intact cells involves relatively small numbers of antibodies, and cells, what is being detected is simply the presence of cells. Each bound cell contains a number of abundant proteins that are present in millions of copies per cell, and the abundance of these proteins ensures that they are detectable on SDS‐PAGE, signaling cell‐binding. As few as 1010–1012 scFv antibodies immobilized on 100 μL of Ni‐NTA beads are thus enough for the trapping of enough cells to allow visualization of their abundant proteins. Conceptually, this method could be easily developed and applied to detection of cells bearing any other cell specific antigen. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
A plasmid display platform for the selection of peptides exhibiting a functional cell‐penetrating phenotype
Authors: Gao Shan , Simon Melissa J. , Morrison Barclay , Banta Scott 
Published: August 2010

AbstractCell‐penetrating peptides (CPPs) represent a promising nonviral platform for the delivery of therapeutic cargos to cells and tissues. However, these peptides are often nonspecific, and their mechanism of action is still a subject of debate, which hinders the design of new CPPs. The alternative to rational protein design is the combinatorial approach to protein engineering, whereby large libraries of peptides are created and a screening or selection procedure is used to identify members with the desired phenotype(s). Here we describe a novel procedure for selecting peptides with a CPP phenotype using a plasmid display (PD) platform to link the peptides to their encoding DNA sequences. The PD system is based on genetic fusions to a DNA binding domain. The plasmid was designed to concomitantly express a fluorescent reporter protein to serve as a mock therapeutic cargo indicating its functional delivery into a cell. We have demonstrated this selection strategy using a control CPP (the TAT peptide) in the PC12 neuronal‐like cell line. In the absence of transfection reagents, TAT was unable to deliver the protein/DNA complexes. The inclusion of the HA2 peptide from the hemagglutinin protein and the addition of polyethylenimine (PEI) were similarly ineffective. The addition of Lipofectamine, however, enabled the TAT‐mediated delivery of the protein/DNA complexes, which was significantly better than control experiments without a CPP. This new PD selection platform will be a valuable new approach for use in identifying unique CPPs from randomized libraries with novel abilities and specificities. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Improved recombinant protein yield using a codon deoptimized DHFR selectable marker in a CHEF1 expression plasmid
Authors: Westwood Amy D. , Rowe Daniel A. , Clarke Howard R. G. 
Published: August 2010

AbstractThe CHEF1® expression plasmid utilizes regulatory domains of the Chinese Hamster Elongation Factor 1 (CHEF1) housekeeping gene to drive stable recombinant protein expression in Chinese Hamster Ovary (CHO) cells. Rapid development of stable CHEF1 cell lines is possible, in part, because high titer pools are produced in the absence of methotrexate‐induced DHFR amplification. Inhibiting DHFR activity with methotrexate increases the selection pressure on transfected cells and can result in a compensatory event to ensure cell survival, such as dhfr gene amplification or integration into a transcriptionally active genomic site. Methotrexate amplification often results in improved cell line productivity but it is a time‐consuming process. Herein, we describe a novel mechanism to increase selection stringency via codon deoptimization of the mouse dhfr selectable marker utilizing hamster codon preference that results in improved expression of a linked recombinant protein compared to wild‐type DHFR selection. We show that deoptimizing the translatability of the dhfr gene reduces the expression level of the DHFR protein in CHO transfection pools and derived clones. Lower DHFR expression increases the transfection selection stringency, shown as lower transfection efficiency in pools, and correlates with increased recombinant protein expression in both pools and clones. These results demonstrate a new mechanism for increasing selection stringency and improving recombinant protein production during cell line development without time‐consuming gene amplification steps. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Selectivity and delignification kinetics for oxidative and nonoxidative lime pretreatment of poplar wood, part III: Long‐term
Authors: Sierra Rocio , Garcia Laura A. , Holtzapple Mark Thomas 
Published: August 2010

AbstractLime pretreatment is an effective method for improving lignocellulose digestibility by removing lignin. For several weeks, mixtures of poplar wood, water, and calcium hydroxide (lime) were submitted to temperatures from 25 to 65°C, with and without aeration. Kinetic models for lignin and carbohydrate degradation were obtained as functions of temperature, time, and aeration using first‐order kinetics in lignin and carbohydrates. Model 1 considered two reacting moieties (slow and fast), and Model 2 considered three (slow, medium, and fast). Model 1 was statistically better and was employed to determine differential and integral selectivities, which measure the ability of pretreatment to retain carbohydrates while removing lignin. During the first 2 weeks, when lignin content ≥0.80 g/g lignin in raw biomass, both glucan and xylan differential and integral selectivities decreased rapidly. Afterwards, selectivities were nearly constant ranging between 0 and 3 g lignin removed/g carbohydrate degraded. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Achieving high mass‐throughput of therapeutic proteins through parvovirus retentive filters
Authors: Bolton Glen R. , Basha Jonida , LaCasse Daniel P. 
Published: August 2010

AbstractParvovirus retentive filters that assure removal of viruses and virus‐like particles during the production of therapeutic proteins significantly contribute to total manufacturing costs. Operational approaches that can increase throughput and reduce filtration area would result in a significant cost savings. A combination of methods was used to achieve high throughputs of an antibody or therapeutic protein solution through three parvovirus retentive filters. These methods included evaluation of diatomaceous earth or size‐based prefilters, the addition of additives, and the optimization of protein concentration, temperature, buffer composition, and solution pH. An optimum temperature of 35°C was found for maximizing throughput through the Virosart CPV and Viresolve Pro filters. Mass‐throughput values of 7.3, 26.4, and 76.2 kg/m2 were achieved through the Asahi Planova 20N, Virosart CPV, and Viresolve Pro filters, respectively, in 4 h of processing. Mass‐throughput values of 73, 137, and 192 kg/m2 were achieved through a Millipore Viresolve Pro filter in 4.0, 8.8, and 22.1 h of processing, respectively, during a single experiment. However, large‐scale parvovirus filtration operations are typically controlled to limit volumetric throughput to below the level achieved during small‐scale virus spiking experiments. The virus spike may cause significant filter plugging, limiting throughput. Therefore newer parvovirus filter spiking strategies should be adopted that may lead to more representative viral clearance data and higher utilization of large‐scale filter capacity. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Citrate and phosphate influence on green fluorescent protein thermal stability
Authors: de Lencastre Novaes Letícia C. , Mazzola Priscila G. , Pessoa Adalberto , Penna Thereza C. Vessoni 
Published: August 2010

AbstractProtein structure and function can be regulated by no specific interactions, such as ionic interactions in the presence of salts. Green fluorescent protein (GFP) shows remarkable structural stability and high fluorescence; its stability can be directly related to its fluorescence output, among other characteristics. GFP is stable under increasing temperatures, and its thermal denaturation is highly reproducible. The aim of this study was to evaluate the thermal stability of GFP in the presence of different salts at several concentrations and exposed to constant temperatures, in a range of 70–95°C. Thermal stability was expressed in decimal reduction time. It was observed that the D‐values obtained were higher in the presence of citrate and phosphate, when compared with that obtained in their absence, indicating that these salts stabilized the protein against thermal denaturation. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Accelerating glycolytic flux of Torulopsis glabrata CCTCC M202019 at high oxidoreduction potential created using potassium ferricyanide
Authors: Qin Yi , Liu Li‐Ming , Li Chang‐Hao , Xu Sha , Chen Jian 
Published: August 2010

AbstractThis study aimed to increase the glycolytic flux of the multivitamin auxotrophic yeast Torulopsis glabrata by redirecting NADH oxidation from oxidative phosphorylation to membrane‐bound ferric reductase. We added potassium ferricyanide as electron acceptor to T. glabrata culture broth at 20% dissolved oxygen (DO) concentration, which resulted in: (1) decreases in the NADH content, NADH/NAD+ ratio, and ATP level of 45.3%, 60.3%, and 15.2%, respectively; (2) high activities of the key glycolytic enzymes hexokinase, phosphofructokinase, and pyruvate kinase, as well as high expression levels of the genes encoding these enzymes; and (3) increases in the specific glucose consumption rate and pyruvate yield of T. glabrata was by 45.5% and 23.1%, respectively. Our results showed that membrane‐bound ferric reductase offers an alternative and efficient NADH oxidation pathway at lower DO concentration, which increases the glycolytic flux of T. glabrata. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Supermacroporous polymer‐based cryogel bioreactor for monoclonal antibody production in continuous culture using hybridoma cells
Authors: Jain Era , Karande Anjali A. , Kumar Ashok 
Published: August 2010

AbstractCryogel matrices composed of different polymeric blends were synthesized, yielding a unique combination of hydrophilicity and hydrophobicity with the presence or absence of charged surface. Four such cryogel matrices composed of polyacrylamide–chitosan (PAAC), poly(N‐isopropylacrylamide)–chitosan, polyacrylonitrile (PAN), and poly(N‐isopropylacrylamide) were tested for growth of different hybridoma cell lines and production of antibody in static culture. All the matrices were capable for the adherence of hybridoma cell lines 6A4D7, B7B10, and H9E10 to the polymeric surfaces as well as for the efficient monoclonal antibody (mAb) production. PAAC proved to be relatively better in terms of both mAb production and cell growth. Further, PAAC cryogel was designed into three different formats, monolith, disks, and beads, and used as packing material for packed‐bed bioreactor. Long‐term cultivation of 6A4D7 cell line on PAAC cryogel scaffold in all the three formats could be successfully done for a period of 6 weeks under static conditions. Continuous packed‐bed bioreactor was setup using 6A4D7 hybridoma cell line in the three reactor formats. The reactors ran continuously for a period of 60 days during which mAb production and metabolism of cells in the bioreactors were monitored periodically. The monolith bioreactor performed most efficiently over a period of 60 days and produced a total of 57.5 mg of antibody in the first 30 days (in 500 mL) with a highest concentration of 115 μg mL−1, which is fourfold higher than t‐flask culture. The results demonstrate that appropriate chemistry and geometry of the bioreactor matrix for cell growth and immobilization can enhance the reactor productivity. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Bionanoconjugate‐based composites for decontamination of nerve agents
Authors: Borkar Indrakant V. , Dinu Cerasela Zoica , Zhu Guangyu , Kane Ravi S. , Dordick Jonathan S. 
Published: August 2010

AbstractWe have developed enzyme‐based composites that rapidly and effectively detoxify simulants of V‐ and G‐type chemical warfare nerve agents. The approach was based on the efficient immobilization of organophosphorus hydrolase onto carbon nanotubes to form active and stable conjugates that were easily entrapped in commercially available paints. The resulting catalytic‐based composites showed no enzyme leaching and rendered >99% decontamination of 10 g/m2 paraoxon, a simulant of the V‐type nerve agent, in 30 minutes and >95% decontamination of diisopropylfluorophosphate, a simulant of G‐type nerve agent, in 45 minutes. The formulations are expected to be environmentally friendly and to offer an easy to use, on demand, decontamination alternative to chemical approaches for sustainable material self‐decontamination. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Improved particle counting and size distribution determination of aggregated virus populations by asymmetric flow field‐flow fractionation and multiangle light scattering techniques
Authors: McEvoy Matt , Razinkov Vladimir , Wei Ziping , Casas‐Finet Jose R. , Tous Guillermo I. , Schenerman Mark A. 
Published: August 2010

AbstractA method using a combination of asymmetric flow field‐flow fractionation (AFFFF) and multiangle light scattering (MALS) techniques has been shown to improve the estimation of virus particle counts and the amount of aggregated virus in laboratory samples. The method is based on the spherical particle counting approach given by Wyatt and Weida in 2004, with additional modifications. The new method was tested by analyzing polystyrene beads and adenovirus samples, both having a well‐characterized particle size and concentration. Influenza virus samples were analyzed by the new AFFFF‐MALS technique, and particle size and aggregate state were compared with results from atomic force microscopy analysis. The limitations and source of possible errors for the new AFFFF‐MALS analysis are discussed. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010