bluuebunny/crossref_metadata_2025 huggingface dataset:
An overview on controllability analysis of chemical processes
Authors: Yuan Zhihong , Chen Bingzhen , Zhao Jinsong
Published: June 2010

Controllability is one of the most important aspects of chemical process operability, because it can be used to assess the attainable operation of a given process and improve its dynamic performance. The purpose of this article is to outline the main methodologies that have been developed to deal with the assessment of process controllability and the improvement of its controllability characteristics. Several existing controllability assessment methods are reviewed and discussed. For improving the controllability characteristic of a process, there are two main design methods: the optimization‐based method and the controllability indices‐based anticipating sequential method. Advantages and disadvantages of these techniques are discussed. It has been emphasized that bifurcation analysis, as a powerful nonlinear analysis tool, could provide important guidance for making processes more controllable by eliminating or avoiding some undesirable behaviors of processes. Further challenges and developments in the field of process controllability are identified. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Parallel hydrogenation for the quantification of wetting efficiency and liquid–solid mass transfer in a trickle‐bed reactor
Authors: van Houwelingen Arie Jan , Nicol Willie
Published: June 2010

A novel method for the measurement of wetting efficiency in a trickle‐bed reactor under reaction conditions is introduced. The method exploits reaction rate differences of two first‐order liquid‐limited reactions occurring in parallel, to infer wetting efficiencies without any other knowledge of the reaction kinetics or external mass transfer characteristics. Using the hydrogenation of linear‐ and isooctenes, wetting efficiency is measured in a 50‐mm internal diameter, high‐pressure trickle‐bed reactor. Liquid–solid mass transfer coefficients are also estimated from the experimental conversion data. Measurements were performed for upflow operation and two literature‐defined boundaries of hydrodynamic multiplicity in trickle flow. Hydrodynamic multiplicity in trickle flow gave rise to as much as 10% variation in wetting efficiency, and 10–20% variation in the specific liquid–solid mass transfer coefficient. Conversions for upflow operation were significantly higher in trickle‐flow operation, because of complete wetting and better liquid–solid mass transfer characteristics. © 2010 American Institute of Chemical Engineers AIChE J, 2011.
An abnormal nonhyperdiploid karyotype is a significant adverse prognostic factor for multiple myeloma in the bortezomib era
Authors: Tan Daryl , Teoh Gerrard , Lau L.C. , Lim Alvin , Lim T.H. , Yap K.C. , Premalatha1 P. , Lao Z.T. , Wee Nelson , Choo Christine , Wee H.C. , Su S. , Lee Y.S. , Lee L.H. , Hwang William , Goh Y.T.
Published: June 2010

Multiple myeloma is clinically heterogeneous and risk stratification is vital for prognostication and informing treatment decisions. As bortezomib is able to overcome several high‐risk features of myeloma, the validity of conventional risk‐stratification and prognostication systems needs to be reevaluated. We study the survival data of 261 previously untreated myeloma patients managed at our institution, where bortezomib became available from 2004 for the treatment of relapse disease. Patient and disease characteristics, and survival data were evaluated overall, and with respect to bortezomib exposure. Overall, the international staging system (ISS), metaphase karyotyping and interphase fluorescence in situ hybridization (FISH) were discerning of survival outcomes, where the median for the entire cohort was 5.2 years. However, when stratified by bortezomib exposure, only metaphase karyotyping was still discriminating of long‐term prognosis. The presence of an abnormal nonhyperdiploid karyotype overrides all other clinical and laboratory parameters in predicting for a worse outcome on multivariate analysis (median survival 2.6 years,P= 0.001), suggesting that bortezomib used at relapse is better able to overcome adverse risk related to high tumor burden (as measured by the ISS) than adverse cytogenetics on conventional karyotyping. Metaphase karyotyping provides additional prognostic information on tumor kinetics where the presence of a normal diploid karyotype in the absence of any high‐risk FISH markers correlated with superior survival and could act as a surrogate for lower plasma cell proliferation. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
Thermal and mechanical properties of compression‐molded pMDI‐reinforced PCL/gluten composites
Authors: Mohamed Abdellatif , Finkenstadt Victoria L. , Gordon Sherald H. , Palmquist Debra E.
Published: June 2010

Many biopolymers and synthetic polymers composites were developed by different researchers for environmental protection and for cost reduction. One of these composites is polycaprolactone (PCL) and vital wheat gluten or wheat flour composites were prepared and compatibilized with polymeric diphenylmethane diisocyanate (pMDI) by blending and compression‐molding. PCL/pMDI blend exhibited glass transition (Tg) at −67°C (0.20 J/g/°C) and vital gluten at 63°C (0.45 J/g/°C), whereas no Tg was recorded for wheat flour. Although Tg was unmistakable for either PCL or gluten, all composite exhibited one Tg, which is strong indication of interaction between PCL and the fillers. Several samples amongst the blended or compression‐molded composites exhibited no Tg signifying another confirmation of interaction. The ΔH of the endothermic (melting) and the exothermic (crystallization) for PCL was decreased as the percentage of gluten or flour increased, whereas the overall ΔH was higher for all composites compared to the theoretical value. The presence of pMDI appeared to strengthen the mechanical properties of the composites by mostly interacting with the filler (gluten or flour) and not as much with PCL. The FTIR analysis ruled out covalent interaction between PCL, pMDI, or the fillers but suggested the occurrence of physical interactions. Based on the data presented here and the data published earlier, the presence of pMDI did not change the nature of interaction between PCL and gluten, but it improved the mechanical properties of the composite. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Residual stress and viscoelastic deformation of film insert molded automotive parts
Authors: Kim Seong Yun , Kim Sung Ho , Oh Hwa Jin , Lee Seung Hwan , Youn Jae Ryoun
Published: June 2010

Complex automotive parts were produced by film insert molding and the ejected parts were annealed to investigate the viscoelastic deformation. Warpage of the part was predicted by numerical simulation of mold filling, packing, and cooling stages with non‐isothermal three‐dimensional flow analysis. The flow analysis results were transported to a finite element stress analysis program and the stress analysis was performed by using time‐temperature superposition principle to investigate viscoelastic deformation. Predicted residual stresses, viscoelastic deformation, and warpage showed good agreement with experimental results. Thermal shrinkage of the inserted film and relaxation of the residual stress affected the viscoelastic deformation of the part significantly during annealing. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Evolution of fiber morphology during electrospinning
Authors: Fang Jian , Wang Hongxia , Niu Haitao , Lin Tong , Wang Xungai
Published: June 2010

In this study, the morphological evolution of poly(acrylonitrile) (PAN) nanofibers during electrospinning was examined via immersion precipitation of newly electrospun filaments in ethanol, and subsequently associating the fiber morphologies with the electrospinning distances (2 to 10 cm). We have observed that an uneven fiber stretching happened throughout the electrospinning process. A massive filament‐thinning took place at the initial stage of whipping instability, and fiber stretching at the later whipping stage was mainly concentrated on the bead sections, leading to improved uniformity of the resultant fibers. This work has provided a new insight into the fiber formation mechanism in the electrospinning process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Metallic oxides as fire retardants and smoke suppressants in flexible poly(vinyl chloride)
Authors: Rodolfo Antonio , Innocentini Mei Lucia Helena
Published: June 2010

Combustion and smoke emission properties of PVC compounds, modified with copper (II), molybdenum, and zinc oxides, were studied using cone calorimeter, limiting oxygen index (LOI) and thermogravimetry coupled with mass spectrometry (TG/MS). Results showed that the metal oxides have a very significant effect on the combustion and smoke suppression properties of the PVC compounds. The results also confirmed the anticipation mechanisms of the dehydrochlorination reactions, reductive coupling, and elimination of benzene resulting from the presence of copper (II), molybdenum, and zinc, indicated by the increasing content of postcombustion char residue and the significant reduction in benzene production, indicated by the MS measurements performed. The results also provide indications that the combination of the copper (II) and molybdenum oxides is the one with the best balance of combustion properties, as it reduced the heat released and promoted the suppression of smoke more efficiently. The formulations containing ZnO, because of their strong Lewis acid character, indicated a less pronounced reduction of smoke released during the combustion process, when compared with copper (II) and molybdenum oxides. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Gelatin based pH‐sensitive hydrogels for colon‐specific oral drug delivery: Synthesis, characterization, and in vitro release study
Authors: Raafat Amany I.
Published: June 2010

Based on gelatin (Gltn) and acrylic acid (AAc), biodegradable pH‐sensitive hydrogel was prepared using gamma radiation as super clean source for polymerization and crosslinking. Incorporation of PAAc in the prepared hydrogel was confirmed by Fourier transform infrared spectroscopy (FTIR). The effect of PAAc content on the morphological structure of the prepared hydrogel swollen at pH 1, 5, and 7 was examined using scanning electron microscopy (SEM). The results showed the dependence of the porous structure of the prepared hydrogels on AAc content and the pH of the swelling medium. Swelling properties of gelatin/acrylic acid copolymer hydrogels with different AAc contents were investigated at different pH values. Swelling data showed that the prepared hydrogels possessed pronounced pH sensitivity. In vitro release studies were performed to evaluate the hydrogel potential as drug carrier using ketoprofen as a model drug. Experimental data showed that the release profile depends on both hydrogel composition and pH of the releasing medium. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and characterization of porous poly(vinylidene fluoride) membranes for dehumidification with poly(ethylene glycol) as an additive
Authors: Pei Lixia , Zhao Weijie , Zhang Lizhi
Published: June 2010

Porous poly(vinylidene fluoride) (PVDF) membranes for dehumidification were prepared from a PVDF/dimethylformamide/water system by phase inversion with poly(ethylene glycol) (PEG) as an additive at various concentrations (1.2, 1.8, and 2.4%) and with various molecular weights (1000, 2000, and 6000). The surface morphologies of the resultant membranes were characterized with scanning electron microscopy and atomic force microscopy, and the pore diameter, porosity, and pore size distribution of the membranes were also determined by a gas‐sorption method. The influence of the concentration and molecular weight of PEG on water‐vapor transport through the membranes was evaluated. The moisture‐transport property of the membranes was improved significantly with increases in the concentration and molecular weight of PEG, and a membrane with good moisture permeability was obtained with 2.4% PEG‐6000 as an additive. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Didecyl ester of 4‐sulfophthalic acid as a plast dopant and emulsifier in the chemical polymerization of aniline into polyaniline salt
Authors: Palaniappan Srinivasan , Ajit Singh
Published: June 2010

Polyaniline salt was synthesized through the chemical oxidation of aniline with sodium persulfate as the oxidant and didecyl ester of 4‐sulfophthalic acid via three different polymerization pathways (aqueous, emulsion, and interfacial). In these polymerization processes, the ester acted as a novel plast dopant and as an emulsifier. The yield, conductivity, and number of ester units present in the polyaniline salts were determined. A polyaniline salt prepared by emulsion polymerization was soluble in chloroform and showed excellent solution‐processing properties. Polyaniline samples prepared by aqueous or interfacial polymerization were not soluble in chloroform. A soluble polyaniline salt was successfully synthesized through the washing of an organic layer containing the polyaniline salt with water in emulsion polymerization. X‐ray diffraction spectra of polyaniline salts prepared by the three different methods showed an ordered, layer‐type supramolecular structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Removal of basic dyes from aqueous medium using novel poly(MAA)‐cross linked pregelled starch graft copolymer
Authors: Mostafa Kh. M. , Samarkandy Abdul Rahim , El‐Sanabary A. A.
Published: June 2010

Wastewater from textile industries may contain a variety of dyes that have to be removed before their discharge into waterways. For this purpose, pregelled starch (PG) as one of the most abundant biodegradable carbohydrate polymer was first cross linked with epichlorohydrin to obtain insoluble cross‐linked pregelled starch (CPS). The latter was graft copolymerized with different amounts of methacrylic acid (MAA) using potassium persulphate as initiator. This was done to obtain six levels of poly(MAA)‐cross linked pregelled starch graft copolymers (PMCPS) having different graft yields (expressed as meq COOH/100 g starch) with increasing order and designated as (PMCPS 1 to PMCPS 6). The latter copolymers were used to remove basic dyes namely (safranine T, methylene blue, crystal violet) from their solution and filtered to form polymer—dyes complex. Major factors affecting the dyes removal such as dye concentration, pH, polymer dose, treatment time, agitation speed, and extent of grafting were studied in detail. It was found from the obtained results that; the % dye removal increased by (a) increasing the dye concentration and pH within the range studied; (b) increasing the agitation speed until ≥ 40 rpm then leveled off thereafter; (c) increasing the polymer dosage from 0.25 to 3.0 g/L then leveled off thereafter; (c) increasing the time of the reaction up to 60 minute then leveled off after that; and (d) increasing the extent of grafting of PMCPS i.e., from PMCPS 1 to PMCPS 6. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Study on the properties of the epoxy‐matrix composites filled with thermally conductive AlN and BN ceramic particles
Authors: Zhu B. L. , Ma J. , Wu J. , Yung K. C. , Xie C. S.
Published: June 2010

To develop new composites with sufficiently high thermal conductivity and suitably controlled Dk value for PCBs application, the composites were prepared from epoxy and AlN or BN fillers, and the effects of content, size, size distribution, and morphology of two fillers on the thermal and dielectric properties of the composites were investigated. The results showed that either AlN or BN fillers can greatly increase Tg and thermal conductivity, decreasing CTE and Df, and suitably controlling the increase of Dk. At the same filler content, BN‐filled composites exhibit better thermal performance and dielectric properties compared to AlN‐filled composites. In the case of BN‐filled composites, it is found that platelet‐shaped micro‐BN filled composite has lower Tg and higher CTE compared with particle‐shaped nano‐BN filled composite, but its thermal conductivity is remarkably higher than that of nano‐BN filled composite. When hybrid BN fillers are used, thermal conductivity further increases. For micro‐ or nano‐BN filled composite, the composite shows decreased Tg and increased Dk at high fraction of BN, but hybrid BN‐filled composite still has high Tg and similar Dk with epoxy even if at high fraction of BN. Compared with single‐sized AlN‐filled composite, it is found that hybrid‐sized AlN‐filled composite has higher Tg and lower CTE, but has lower thermal conductivity. To predict thermal conductivity and Dk in the investigated materials system, different models reported in the literature were analyzed and compared with the experimental data. Finally, suitable models were recommended. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Life‐span phenotypes of elav and Rbp9 in Drosophila suggest functional cooperation of the two elav‐family protein genes
Authors: Toba Gakuta , Yamamoto Daisuke , White Kalpana
Published: June 2010

The ELAV family of RNA‐binding proteins is involved in various aspects of the post‐transcriptional regulation of gene expression, from alternative splicing to translation. The members of this family have been shown to interact with each other and have been suggested to function as homo‐ and/or hetero‐multimers. However, the functional interactions among them have not been demonstrated in vivo. In this study, we examined the genetic interaction between elav and Rbp9, two of the three genes encoding ELAV‐family proteins in Drosophila. Mutants of both elav and Rbp9 showed shorter life spans than the control, with elav showing a shorter life span than Rbp9. The survival curve of elav‐Rbp9 double‐mutant flies was indistinguishable from that of elav single‐mutant flies, suggesting that both mutations affect longevity through the same pathway. Considering the fact that both genes are co‐expressed in adult neurons, we hypothesize that ELAV and Rbp9 cooperate to maintain the functional integrity of the adult nervous system. © 2010 Wiley Periodicals, Inc.
Restricted and repetitive behaviors in toddlers and preschoolers with autism spectrum disorders based on the Autism Diagnostic Observation Schedule (ADOS)
Authors: Kim So Hyun , Lord Catherine
Published: June 2010

Restricted and repetitive behaviors (RRBs) observed during the Autism Diagnostic Observation Schedule [ADOS: Lord et al., 2000] were examined in a longitudinal data set of 455 toddlers and preschoolers (age 8–56 months) with clinical diagnosis of Autism Spectrum Disorders (ASD; autism, n=121 and pervasive developmental disorders—not otherwise specified (PDD‐NOS), n=71), a nonspectrum disorder (NS; n=90), or typical development (TD; n=173). Even in the relatively brief semi‐structured observations, GEE analyses of the severity and prevalence of RRBs differentiated children with ASD from those with NS and TD across all ages. RRB total scores on the ADOS were stable over time for children with ASD and NS; however, typically developing preschoolers showed lower RRB scores than typically developing toddlers. Nonverbal IQ (NVIQ) was more strongly related to the prevalence of RRBs in older children with PDD‐NOS, NS, and TD than younger children under 2 years and those with autism. Item analyses revealed different relationships between individual items and NVIQ, age, diagnosis, and gender. These findings are discussed in terms of their implications for the etiology and treatment of RRBs as well as for the framework of ASD diagnostic criteria in future diagnostic systems.
Developmental microRNA expression profiling of murine embryonic orofacial tissue
Authors: Mukhopadhyay Partha , Brock Guy , Pihur Vasyl , Webb Cynthia , Pisano M. Michele , Greene Robert M.
Published: June 2010

BACKGROUND:Orofacial development is a multifaceted process involving precise, spatio‐temporal expression of a panoply of genes. MicroRNAs (miRNAs), the largest family of noncoding RNAs involved in gene silencing, represent critical regulators of cell and tissue differentiation. MicroRNA gene expression profiling is an effective means of acquiring novel and valuable information regarding the expression and regulation of genes, under the control of miRNA, involved in mammalian orofacial development.METHODS:To identify differentially expressed miRNAs during mammalian orofacial ontogenesis, miRNA expression profiles from gestation day (GD) ‐12, ‐13 and ‐14 murine orofacial tissue were compared utilizing miRXplore microarrays from Miltenyi Biotech. Quantitative real‐time PCR was utilized for validation of gene expression changes. Cluster analysis of the microarray data was conducted with the clValid R package and the UPGMA clustering method. Functional relationships between selected miRNAs were investigated using Ingenuity Pathway Analysis.RESULTS:Expression of over 26% of the 588 murine miRNA genes examined was detected in murine orofacial tissues from GD‐12–GD‐14. Among these expressed genes, several clusters were seen to be developmentally regulated. Differential expression of miRNAs within such clusters wereshown to target genes encoding proteins involved in cell proliferation, cell adhesion, differentiation, apoptosis and epithelial‐mesenchymal transformation, all processes critical for normal orofacial development.CONCLUSIONS:Using miRNA microarray technology, unique gene expression signatures of hundreds of miRNAs in embryonic orofacial tissue were defined. Gene targeting and functional analysis revealed that the expression of numerous protein‐encoding genes, crucial to normal orofacial ontogeny, may be regulated by specific miRNAs. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
A case–control study of the effects of pregnancy planning on neural tube defects and its primary preventive measures
Authors: Gong Rui , Wang Zhi‐Ping , Gao Li‐Jie , Lu Qing‐Bin , Sun Xi‐Hong , Zhao Zhong‐Tang
Published: June 2010

BACKGROUND: Measures for prevention of neural tube defects (NTDs) have been recommended for many years in China, but the compliance with these measures is unsatisfactory. This study aims to compare the effect differences between planned pregnancy and unplanned pregnancy in the compliance with these measures and analyze the interactions between pregnancy planning and these measures for NTD prevention. METHODS: A 1:1 matched case‐control study was conducted. We randomly selected 349 women who delivered or gestated babies/fetuses with NTDs in the last two years in two provinces and matched them with 349 women who delivered babies without obvious birth defects as controls. RESULTS: In the case group, 99 women reported that they had planned their pregnancies, accounting for 28.4%, and the proportion who received preconception examinations and took folic acid prior to conception was 13.8 and 8.6%, respectively. According to the multivariate analysis, health education (odds ratio [OR], 0.350), preconception examinations (OR, 0.497) and folic acid consumption prior to conception (OR, 0.257) all had preventative effects on NTDs (for all, p < 0.05). In both groups, the proportions of women who received preconception examinations and reported folic acid intake were much higher for those who reported planning their pregnancies compared to women with an unplanned pregnancy (for all, p < 0.01); and for NTD prevention, synergistic interactions existed between pregnancy planning and the other preventive measures. CONCLUSION: Folic acid consumption prior to conception, preconception examinations, and health education have preventive effects on NTDs. Pregnancy planning can significantly promote compliance with these preventive behaviors. In addition, there are synergistic interactions between pregnancy planning and these measures. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
Mosaic expression of Med12 in female mice leads to exencephaly, spina bifida, and craniorachischisis
Authors: Rocha Pedro P. , Bleiss Wilfrid , Schrewe Heinrich
Published: June 2010

BACKGROUND: A precise temporal and spatial regulation of gene expression is necessary to achieve neural tube closure. Med12, a subunit of the mediator complex, can bind transcription factors and modulate expression of their target genes. Med12 is essential during early mouse development and is important for neural tube closure. METHODS: We have made use of a mouse line carrying a conditional null allele of the X‐linked Med12 gene to generate heterozygous female embryos that express Med12 in a mosaic fashion thus allowing the study of the role of Med12 during neural tube closure. RESULTS: Mosaic expression of Med12 causes a wide variety of embryonic phenotypes. Some embryos were unable to complete turning and were found with arrested development at embryonic day (ED) 9.5. Others were able to pass ED 12.5 and displayed defects in neural tube closure. These defects included exencephaly, spina bifida, craniorachischisis, split face, and curly tail. Histologic and skeletal analyses of these mutant females show that the neural plate is unable to elevate and is completely flat in the regions of the body axis where neural tube closure fails. CONCLUSIONS: We report examples of all known neural tube defects implying Med12 in the full process of neural tube closure along the complete body axis. Our work points to Med12 being an essential coregulator of transcription factors controlling neural tube closure. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
Chemiluminescence of non‐differentiated THP‐1 promonocytes: developing an assay for screening anti‐inflammatory milk proteins and peptides
Authors: Tompa Gorazd , Laine Aire , Pihlanto Anne , Korhonen Hannu , Rogelj Irena , Marnila Pertti
Published: June 2010

Human leukemic THP‐1 promonocytes are widely used as a model for peripheral blood monocytes. However, superoxide production during respiratory burst (RB) of non‐differentiated THP‐1 (nd‐THP‐1) cells is very low. Here we present a rapid and low‐cost method for measuring the chemiluminescence (CL) of opsonized zymosan (OZ) induced RB which allows detection of Escherichia coli lipopolysaccharide (LPS) induced priming of nd‐THP‐1 cells on the basis of CL reaction kinetics. Maximum CL intensity obtained was 2.20 ± 0.25 and 1.30 ± 0.11 relative light units, while CL peak time was achieved at 18.1 ± 2.6 and 28.7 ± 1.3 min in primed and non‐primed cells, respectively. The priming of nd‐THP‐1 cells with LPS evoked typical TNF‐α and IL‐6 production. We tested the effects of bovine lactoferrin and protein fractions from Lactobacillus helveticus BGRA43 fermented milk for potential anti‐inflammatory effects on LPS primed nd‐THP‐1 cells. Four fractions were found to inhibit the OZ‐induced CL in a dose‐dependent manner (IC50 3–30 µg/mL), while lactoferrin inhibited CL to a lesser extent (IC50 270 µg/mL). These results suggest that measuring CL response of nd‐THP‐1 cells can serve as a method for screening anti‐inflammatory compounds which could be used in reducing the risk of phagocyte‐mediated inflammatory diseases. Copyright © 2010 John Wiley & Sons, Ltd.
Endosome‐disruptive peptides for improving cytosolic delivery of bioactive macromolecules
Authors: Nakase Ikuhiko , Kobayashi Sachiko , Futaki Shiroh
Published: June 2010

Along with recent advances in therapeutic technologies based on biomacromolecules, including genes, oligonucleotides, and proteins, the development of technologies for improving the efficiency of the delivery of these therapeutic molecules into cells, more specifically into the cytosol and nucleus, is significantly required. Cell membranes are major impediments to the delivery of therapeutic macromolecules into cells. These macromolecules are usually taken up by the cells via endocytosis, and their translocation from endosomes to the cytosol is a critical step to determine their therapeutic effects. Many viruses and bacterial toxins use endocytic pathways to invade the host mammalian cells, and some of these pathogens have the ability to facilitate their endosomal escape into the cytosol by pH‐induced alteration in their component proteins that leads to the disruption of the endosomal membranes and the eventual membrane fusions. To simulating these functions, endosome‐disruptive peptides have been used for the intracellular delivery of biomacromolecules to accelerate their endosomal escape by sensing the endosomal acidification. In this review, current approaches for the intracellular delivery using these endosome‐disruptive peptides are surveyed. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94: 763–770, 2010.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Complete anaerobic mineralization of pentachlorophenol (PCP) under continuous flow conditions by sequential combination of PCP‐dechlorinating and phenol‐degrading consortia
Authors: Li Zhiling , Yang Suyin , Inoue Yasushi , Yoshida Naoko , Katayama Arata
Published: June 2010

Complete mineralization of 50 µM of pentachlorophenol (PCP) was achieved anaerobically under continuous flow conditions using two columns connected in series with a hydraulic retention time of 14.2 days, showing the highest reported mineralization rate yet of 3.5 µM day−1. The first column, when injected with a reductive PCP dechlorinating consortium, dechlorinated PCP to mainly phenol and traces of 3‐chlorophenol (3‐CP) using lactate supplied continuously as an electron donor. The second column, with an anaerobic phenol degrading consortium, decomposed phenol and 3‐CP under iron‐reducing conditions with substantial fermentative degradation of organic compounds. When 20 mM of lactate was introduced into the first column, the phenol degradation activity of the second column was lost in a short period of time, because the amorphous Fe(III) oxide (FeOOH) that had been packed in the column before use was depleted by lactate metabolites, such as acetate and propionate, flowing into the second column from the first column. The complete mineralization of PCP was maintained for a long period by reducing the lactate concentration to 4 mM, effectively extending the longevity of second‐column activity with no depletion of FeOOH for more than 200 pore volumes (corresponding to 3,000 days). The carbon balance showed that 50 µM PCP and 4 mM lactate in the influent had transformed to CO2 (81%) and CH4 (3%) and had contributed to biomass growth (8%). A comparison of the microbial consortia introduced into the columns and those flowing out from the columns suggested that the introduced population did not flow out during the experiments, although the microbial composition of the phenol column was considered to be affected by the inflow of microbes from the PCP dechlorination column. These results suggest that a sequential combination of reductive dechlorinating and anaerobic oxidizing consortia is useful for anaerobic remediation of chlorinated aromatic compounds in a microbial permeable reactive barrier. Biotechnol. Bioeng. 2010;107: 775–785. © 2010 Wiley Periodicals, Inc.
Systematizing the generation of missing metabolic knowledge
Authors: Orth Jeffrey D. , Palsson Bernhard Ø.
Published: June 2010

Genome‐scale metabolic network reconstructions are built from all of the known metabolic reactions and genes in a target organism. However, since our knowledge of any organism is incomplete, these network reconstructions contain gaps. Reactions may be missing, resulting in dead‐ends in pathways, while unknown gene products may catalyze known reactions. New computational methods that analyze data, such as growth phenotypes or gene essentiality, in the context of genome‐scale metabolic networks, have been developed to predict these missing reactions or genes likely to fill these knowledge gaps. A growing number of experimental studies are appearing that address these computational predictions, leading to discovery of new metabolic capabilities in the target organism. Gap‐filling methods can thus be used to improve metabolic network models while simultaneously leading to discovery of new metabolic gene functions. Biotechnol. Bioeng. 2010;107: 403–412. © 2010 Wiley Periodicals, Inc.
Valorization of an industrial organosolv–sugarcane bagasse lignin: Characterization and use as a matrix in biobased composites reinforced with sisal fibers
Authors: Ramires Elaine C. , Megiatto Jackson D. , Gardrat Christian , Castellan Alain , Frollini Elisabete
Published: June 2010

In the present study, the main focus was the characterization and application of the by‐product lignin isolated through an industrial organosolv acid hydrolysis process from sugarcane bagasse, aiming at the production of bioethanol. The sugarcane lignin was characterized and used to prepare phenolic‐type resins. The analysis confirmed that the industrial sugarcane lignin is of HGS type, with a high proportion of the less substituted aromatic ring p‐hydroxyphenyl units, which favors further reaction with formaldehyde. The lignin–formaldehyde resins were used to produce biobased composites reinforced with different proportions of randomly distributed sisal fibers. The presence of lignin moieties in both the fiber and matrix increases their mutual affinity, as confirmed by SEM images, which showed good adhesion at the biocomposite fiber/matrix interface. This in turn allowed good load transference from the matrix to the fiber, leading to biobased composites with good impact strength (near 500 J m−1 for a 40 wt% sisal fiber‐reinforced composite). The study demonstrates that sugarcane bagasse lignin obtained from a bioethanol plant can be used without excessive purification in the preparation of lignocellulosic fiber‐reinforced biobased composites displaying high mechanical properties. Biotechnol. Bioeng. 2010;107:612–621. © 2010 Wiley Periodicals, Inc.
Mechanism of antibody reduction in cell culture production processes
Authors: Kao Yung‐Hsiang , Hewitt Daniel P. , Trexler‐Schmidt Melody , Laird Michael W.
Published: June 2010

We recently observed a significant disulfide reduction problem during the scale‐up of a manufacturing process for a therapeutic antibody using a CHO expression system. Under certain conditions, extensive reduction of inter‐chain disulfide bonds of an antibody produced by CHO cell culture may occur during the harvest operations and/or the protein A chromatography step, resulting in the observation of antibody fragments (light chain, heavy chain, and various combination of both) in the protein A pools. Although all conditions leading to disulfide reduction have not been completely identified, an excessive amount of mechanical cell lysis generated at the harvest step appears to be an important requirement for antibody reduction (Trexler‐Schmidt et al., 2010). We have been able to determine the mechanism by which the antibody is reduced despite the fact that not all requirements for antibody reduction were identified. Here we present data strongly suggesting that the antibody reduction was caused by a thioredoxin system or other reducing enzymes with thioredoxin‐like activity. The intracellular reducing enzymes and their substrates/cofactors apparently were released into the harvest cell culture fluid (HCCF) when cells were exposed to mechanical cell shear during harvest operations. Surprisingly, the reducing activity in the HCCF can last for a long period of time, causing the reduction of inter‐chain disulfide bonds in an antibody. Our findings provide a basis for designing methods to prevent the antibody reduction during the manufacturing process. Biotechnol. Bioeng. 2010;107:622–632. © 2010 Wiley Periodicals, Inc.
Characterization ofin vitrometabolism of capsazepine, a vanilloid transient receptor potential channel antagonist, by liquid chromatography quadrupole ion trap mass spectrometry
Authors: Douat Jennifer , Vachon Pascal , Beaudry Francis
Published: June 2010

Capsazepine is an antagonist of the transient receptor potential channel vanilloid 1 (TRPV1), which is known to play an important role in the regulation of pain and inflammation. A selective and sensitive quantitative method for the determination of capsazepine by HPLC‐ESI/MS/MS was developed. The method consisted of a protein precipitation extraction followed by analysis using liquid chromatography electrospray quadrupole ion trap mass spectrometry. The chromatographic separation was achieved using a 100 × 2 mm C18Waters Symmetry column combined with a gradient mobile phase composed of acetonitrile and 0.1% formic acid aqueous solution at a flow rate of 220 µL/min. The mass spectrometer was operating in full‐scan MS/MS mode using two‐segment analysis. An analytical range of 10–5000 ng/mL was used in the calibration curve constructed in rat plasma. The inter‐batch precision and accuracy observed were 10.1, 6.4 and 6.1% and 100.8, 98.5 and 106.2% at 50, 500 and 5 000 ng/mL, respectively. Anin vitrometabolic stability using rat, dog or mouse liver microsomes was performed to determine the intrinsic clearance of capsazepine. The results suggest a very rapid degradation withT1/2ranging from 2.6 to 4.3 min and a high clearance, suggesting that drug bioavailability is considerably reduced following extravascular administrations, consequently affecting drug response. Three metabolites were identified by HPLC‐MS/MS. S‐hydroxylation (M + 16), oxidative desulfuration (M − 16) and desulfuration (M − 32) metabolites of capsazepine were observed following exposure to rat, dog and mouse microsomes. Copyright © 2010 John Wiley & Sons, Ltd.
An analytical method for prohexadione in Chinese cabbage and apple
Authors: Choi Jeong‐Heui , Yoon Hae‐Jung , Do Jung‐Ah , Park Yong‐Chun , Kim Jae Hun , Choi Dongmi
Published: June 2010

A residual determination method as a regulatory residue method was developed using HPLC‐UVD for prohexadione residues in Chinese cabbage (Brassica pekinensis) and apple (Malus domestica). The developed method consisted of solid–liquid extraction with acidic acetonitrile and ion‐suppression liquid–liquid partitioning, followed by anion exchange cartridge cleanup. The limits of detection and quantitation for the method were 0.005 and 0.02 mg/kg, respectively. The method gave good linearity in the range of 0.02–2.5 mg/kg. Accuracy and precision ranged from 84.1 to 94.1% and from 2.4 to 6.9%, respectively. Additionally, the confirmative conditions of LC‐MS/MS for prohexadione were set in negative electrospray ionization mode with transitions of m/z 211.4 → 167.5 and m/z 211.4 → 123.5 in the selected reaction monitoring mode. The applicability of the method was demonstrated by analyzing real samples collected from local markets in Seoul, Republic of Korea. This developed method fully deserves consideration in accordance with its sensitivity, accuracy and precision required for residue analysis of prohexadione in Chinese cabbages and apples. Copyright © 2010 John Wiley & Sons, Ltd.
Usefulness of the simultaneous determination of serum levels of theophylline and its metabolites in patients medicated with theophylline preparation
Authors: Watanabe Yuko , Chohnabayashi Naohiko , Nasu Hideki , Nishimura Naoki , Uchiyama Noboru , Kizu Junko
Published: June 2010

Objective: Measurement of the serum level of theophylline is essential for its proper use; however, it is difficult to infer the metabolic ability of individual patients by only the serum theophylline level and to decide the appropriate medication. In this study, we simultaneously measured serum theophylline and metabolite levels in patients treated with theophylline, and investigated their usefulness.

Experimental: The subjects were asthma patients who visited the outpatient clinic of Respiratory Medicine, St Luke's International Hospital, between April and October 2003, and were medicated with sustained‐release theophylline tablets (Theodur®). The serum level of theophylline and its metabolites was measured by HPLC in patients who gave written consent.

Results: A strong correlation was noted between the serum theophylline (TP) and 1,3‐dimethyluric acid (DMU) levels of 52 patients (r = 0.670), and DMU/TP was about 0.04. In a patient whose the DMU/TP was 0.216, it was recognized that metabolic ability was promoted due to a history of smoking.

Discussion: In this study, it was shown that simultaneous measurement by HPLC of the serum level of theophylline and its metabolites and DMU/TP was useful to assess the metabolic ability of individual patients. Copyright © 2010 John Wiley & Sons, Ltd.
A novel enzymatic microreactor with Aspergillus oryzae β‐galactosidase immobilized on silicon dioxide nanosprings
Authors: Schilke Karl F. , Wilson Kelly L. , Cantrell Timothy , Corti Giancarlo , McIlroy David N. , Kelly Christine
Published: June 2010

The use of silicon dioxide (SiO2) nanosprings as supports for immobilized enzymes in a continuous microreactor is described. A nanospring mat (2.2 cm2 × 60 μm thick) was functionalized with γ‐aminopropyltriethoxysilane, then treated with N‐succinimidyl‐3‐(2‐pyridyldithio)‐propionate (SPDP) and dithiothreitol (DTT) to produce surface thiol (SH) groups. SPDP‐modified β‐galactosidase from Aspergillus oryzae was immobilized on the thiolated nanosprings by reversible disulfide linkages. The enzyme‐coated nanospring mat was placed into a 175‐μm high microchannel, with the mat partially occluding the channel. The kinetics and steady‐state conversion of hydrolysis of o‐nitrophenyl β‐D‐galactosylpyranoside at various substrate flow rates and concentrations were measured. Substantial flow was observed through the nanosprings, for which the Darcy permeability κ ≈ 3 × 10−6 cm2. A simple, one‐parameter numerical model coupling Navier‐Stokes and Darcy flow with a pseudo‐first‐order reaction was used to fit the experimental data. Simulated reactor performance was sensitive to changes in κ and the height of the nanospring mat. Permeabilities lower than 10−8 cm2 practically eliminated convective flow through the nanosprings, and substantially decreased conversion. Increasing the height of the mat increased conversion in simulations, but requires more enzymes and could cause sealing issues if grown above channel walls. Preliminary results indicate that in situ regeneration by reduction with DTT and incubation with SPDP‐modified β‐galactosidase is possible. Nanosprings provide high solvent‐accessible surface area with good permeability and mechanical stability, can be patterned into existing microdevices, and are amenable to immobilization of biomolecules. Nanosprings offer a novel and useful support for enzymatic microreactors, biosensors, and lab‐on‐chip devices. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Downstream antibody purification using aqueous two‐phase extraction
Authors: Mao Lisong Nathan , Rogers Jameson K. , Westoby Matthew , Conley Lynn , Pieracci John
Published: June 2010

The extraction of antibodies using a polyethylene glycol (PEG)‐citrate aqueous two‐phase system (ATPS) was investigated. Studies using purified monoclonal antibody (mAb) identified operating ranges for successful phase formation and factors that significantly affected antibody partitioning. The separation of antibody and host cell protein (HCP) from clarified cell culture media was examined using statistical design of experiments (DOE). The partitioning of antibody was nearly complete over the entire range of the operating space examined. A model of the HCP partitioning was generated in which both NaCl and citrate concentrations were identified as significant factors. To achieve the highest purity, the partitioning of HCP from cell culture fluid into the product containing phase was minimized using a Steepest Descent algorithm. An optimal ATPS consisting of 14.0% (w/w) PEG, 8.4% (w/w) citrate, and 7.2% (w/w) NaCl at pH 7.2 resulted in a product yield of 89%, an approximate 7.6‐fold reduction in HCP levels relative to the clarified cell culture fluid before extraction and an overall purity of 70%. A system consisting of 15% (w/w) PEG, 8% (w/w) citrate, and 15% (w/w) NaCl at pH 5.5 reduced product‐related impurities (aggregates and low molecular product fragments) from ∼40% to less than 0.5% while achieving 95% product recovery. At the experimental conditions that were optimized in the batch mode, a scale‐up model for the use of counter‐current extraction technology was developed to identify potential improvements in purity and recovery that could be realized in the continuous operational mode. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Modeling shear‐induced CHO cell damage in a rotary positive displacement pump
Authors: Kamaraju Hari , Wetzel Kenneth , Kelly William J.
Published: June 2010

Rotary lobe pumps are commonly used in the biotechnology industry for a variety of purposes. Shear damage to animal cells within the rotary lobe pump can adversely affect the product yield or purity during, for example, cell concentration via cross‐flow filtration. In this research, CHO cells grown in 20‐L bioreactors were fed to a rotary lobe pump in both single pass and recycle experiments were conducted at different RPMs and “slip” conditions. The results indicate that the slip flow rate more severely impacts the viability of the CHO cells than the pump RPM. A novel mathematical modeling approach is presented that predicts shear rates in all of the positive displacement pump's slip regions, and then predicts cell death vs. operating conditions. This model accounts for the complex flow situation that results from changes to RPM, backpressure and pump geometry (i.e., clearances). © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
A teaching tool for the state‐of‐the‐art probabilistic methods used in localization of mobile robots
Authors: Farrokhsiar M. , Krys D. , Najjaran H.
Published: June 2010

Probabilistic methods provide a powerful paradigm for modeling of robot motion and its environment; a precursor for autonomous navigation of mobile robots. As a graduate‐level engineering course, probabilistic robotics encompasses the techniques used in robot localization and mapping in unstructured environments. This article presents a simulation and animation software program developed mainly as a teaching tool that can help the students visualize different robot localization solutions through both parametric filters (viz., the Extended Kalman Filter, Unscented Kalman Filter) and nonparametric filters (viz., the histogram filter, Rao‐Blackwell particle filter). The program is also a powerful tool for performance analysis and tuning of such filters commonly used for robot localization, mapping, and autonomous navigation. The simulation features dead reckoning (e.g., INS), range‐only sensing (e.g., rangefinder), bearing‐only sensing (e.g., digital camera), or a combination of them. The program includes a simple graphical user interface that allows for changing both filtering and sensing parameters, and monitoring the effects of those changes on the animation of a unicycle in a 2D environment. The program animates the unicycle motion and shows the kinematic results in several graphs simultaneously to evaluate the performance of different methods in finding the robot pose. The program is available as an open‐source Matlab script to facilitate future modifications and improvements of the code by the students interested in robotics, mechatronics, and control engineering. This article presents the features of the program and briefly discusses the algorithms implemented in the software. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 721–727, 2012