bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between Clostridium beijerinckii and Geobacter metallireducens in co‐culture fermentation with anthrahydroquinone‐2, 6‐disulfonate (AH2QDS) for enhanced biohydrogen production from xylose
Authors: Zhang Xinyu , Ye Xiaofeng , Finneran Kevin T. , Zilles Julie L. , Morgenroth Eberhard 
Published: August 2012

AbstractTo enhance biohydrogen production, Clostridium beijerinckii was co‐cultured with Geobacter metallireducens in the presence of the reduced extracellular electron shuttle anthrahydroquinone‐2, 6‐disulfonate (AH2QDS). In the co‐culture system, increases of up to 52.3% for maximum cumulative hydrogen production, 38.4% for specific hydrogen production rate, 15.4% for substrate utilization rate, 39.0% for substrate utilization extent, and 34.8% for hydrogen molar yield in co‐culture fermentation were observed compared to a pure culture of C. beijerinckii without AH2QDS. G. metallireducens grew in the co‐culture system, resulting in a decrease in acetate concentration under co‐culture conditions and a presumed regeneration of AH2QDS from AQDS. These co‐culture results demonstrate metabolic crosstalk between the fermentative bacterium C. beijerinckii and the respiratory bacterium G. metallireducens and suggest a strategy for industrial biohydrogen production. Biotechnol. Bioeng. 2013; 110: 164–172. © 2012 Wiley Periodicals, Inc.
Photoautotrophic cathodic oxygen reduction catalyzed by a green alga, Chlamydomonas reinhardtii
Authors: Liu Xian‐Wei , Sun Xue‐Fei , Huang Yu‐Xi , Li Dao‐Bo , Zeng Raymond J. , Xiong Lu , Sheng Guo‐Ping , Li Wen‐Wei , Cheng Yuan‐Yuan , Wang Shu‐Guang , Yu Han‐Qing 
Published: August 2012

AbstractBiofuel cells (BFCs) use enzymes and microbial cells to produce energy from bioavailable substrates and treat various wastewaters, and cathodic oxygen reduction is a key factor governing the efficiency of BFCs. In this study, we demonstrated that a green alga, Chlamydomonas reinhardtii, could directly mediate oxygen reduction. Cyclic voltammogram analysis revealed that the C. reinhardtii biofilm formed on a solid electrode was responsible for oxygen reduction without dosing of electron mediator. Furthermore, 4‐electron oxygen reduction pathway was found in this self‐sustained, light‐responded BFC. The results of this study could expand our understanding and viewpoints of biocathode catalysis, which is essential for novel catalyst design and development for BFCs. Biotechnol. Bioeng. 2013; 110: 173–179. © 2012 Wiley Periodicals, Inc.
Shear‐induced detachment of biofilms from hollow fiber silicone membranes
Authors: Huang Z. , McLamore E.S. , Chuang H.S. , Zhang W. , Wereley S. , Leon J.L.C. , Banks M.K. 
Published: August 2012

AbstractA suite of techniques was utilized to evaluate the correlation between biofilm physiology, fluid‐induced shear stress, and detachment in hollow fiber membrane aerated bioreactors. Two monoculture species biofilms were grown on silicone fibers in a hollow fiber membrane aerated bioreactors (HfMBR) to assess detachment under laminar fluid flow conditions. Both physiology (biofilm thickness and roughness) and nutrient mass transport data indicated the presence of a steady state mature biofilm after 3 weeks of development. Surface shear stress proved to be an important parameter for predicting passive detachment for the two biofilms. The average shear stress at the surface of Nitrosomonas europaea biofilms (54.5 ± 3.2 mPa) was approximately 20% higher than for Pseudomonas aeruginosa biofilms (45.8 ± 7.7 mPa), resulting in higher biomass detachment. No significant difference in shear stress was measured between immature and mature biofilms of the same species. There was a significant difference in detached biomass for immature vs. mature biofilms in both species. However, there was no difference in detachment rate between the two species. Biotechnol. Bioeng. 2013; 110: 525–534. © 2012 Wiley Periodicals, Inc.
Engineering of recombinant E. coli cells co‐expressing P450pyrTM monooxygenase and glucose dehydrogenase for highly regio‐ and stereoselective hydroxylation of alicycles with cofactor recycling
Authors: Pham Son Q. , Gao Pengfei , Li Zhi 
Published: August 2012

AbstractE. coli (P450pyrTM‐GDH) with dual plasmids, pETDuet containing P450pyr triple mutant I83H/M305Q/A77S (P450pyrTM) and ferredoxin reductase (FdR) genes and pRSFDuet containing glucose dehydrogenase (GDH) and ferredoxin (Fdx) genes, was engineered to show a high activity (12.7 U g−1 cdw) for the biohydroxylation of N‐benzylpyrrolidine 1 and a GDH activity of 106 U g−1 protein. The E. coli cells were used as efficient biocatalysts for highly regio‐ and stereoselective hydroxylation of alicyclic substrates at non‐activated carbon atom with enhanced productivity via intracellular recycling of NAD(P)H. Hydroxylation of N‐benzylpyrrolidine 1 with resting cells in the presence of glucose showed excellent regio‐ and stereoselectivity, giving (S)‐N‐benzyl‐3‐hydroxypyrrolidine 2 in 98% ee as the sole product in 9.8 mM. The productivity is much higher than that of the same biohydroxylation using E. coli (P450pyrTM)b without expressing GDH. E. coli (P450pyrTM‐GDH) was found to be highly regio‐ and stereoselective for the hydroxylation of N‐benzylpyrrolidin‐2‐one 3, improving the regioselectivity from 90% of the wild‐type P450pyr to 100% and giving (S)‐N‐benzyl‐4‐hydroxylpyrrolidin‐2‐one 4 in 99% ee as the sole product. A high activity of 15.5 U g−1 cdw was achieved and (S)‐4 was obtained in 19.4 mM. E. coli (P450pyrTM‐GDH) was also found to be highly regio‐ and stereoselective for the hydroxylation of N‐benzylpiperidin‐2‐one 5, increasing the ee of the product (S)‐N‐benzyl‐4‐hydroxy‐piperidin‐2‐one 6 to 94% from 33% of the wild‐type P450pyr. A high activity of 15.8 U g−1 cdw was obtained and (S)‐6 was produced in 3.3 mM as the sole product. E. coli (P450pyrTM‐GDH) represents the most productive system known thus far for P450‐catalyzed hydroxylations with cofactor recycling, and the hydroxylations with E. coli (P450pyrTM‐GDH) provide with simple and useful syntheses of (S)‐2, (S)‐4, and (S)‐6 that are valuable pharmaceutical intermediates and difficult to prepare. Biotechnol. Bioeng. 2013; 110: 363–373. © 2012 Wiley Periodicals, Inc.
A system of miniaturized stirred bioreactors for parallel continuous cultivation of yeast with online measurement of dissolved oxygen and off‐gas
Authors: Klein Tobias , Schneider Konstantin , Heinzle Elmar 
Published: August 2012

AbstractChemostat cultivation is a powerful tool for physiological studies of microorganisms. We report the construction and application of a set of eight parallel small‐scale bioreactors with a working volume of 10 mL for continuous cultivation. Hungate tubes were used as culture vessels connected to multichannel‐peristaltic pumps for feeding fresh media and removal of culture broth and off‐gas. Water saturated air is sucked into the bioreactors by applying negative pressure, and small stirrer bars inside the culture vessels allow sufficient mixing and oxygen transfer. Optical sensors are used for non‐invasive online measurement of dissolved oxygen, which proved to be a powerful indicator of the physiological state of the cultures, particularly of steady‐state conditions. Analysis of culture exhaust‐gas by means of mass spectrometry enables balancing of carbon. The capacity of the developed small‐scale bioreactor system was validated using the fission yeast Schizosaccharomyces pombe, focusing on the metabolic shift from respiratory to respiro‐fermentative metabolism, as well as studies on consumption of different substrates such as glucose, fructose, and gluconate. In all cases, an almost completely closed carbon balance was obtained proving the reliability of the experimental setup. Biotechnol. Bioeng. 2013; 110: 535–542. © 2012 Wiley Periodicals, Inc.
Chemometrics applications in biotechnology processes: Predicting column integrity and impurity clearance during reuse of chromatography resin
Authors: Rathore Anurag S. , Mittal Shachi , Lute Scott , Brorson Kurt 
Published: August 2012

AbstractSeparation media, in particular chromatography media, is typically one of the major contributors to the cost of goods for production of a biotechnology therapeutic. To be cost‐effective, it is industry practice that media be reused over several cycles before being discarded. The traditional approach for estimating the number of cycles a particular media can be reused for involves performing laboratory scale experiments that monitor column performance and carryover. This dataset is then used to predict the number of cycles the media can be used at manufacturing scale (concurrent validation). Although, well accepted and widely practiced, there are challenges associated with extrapolating the laboratory scale data to manufacturing scale due to differences that may exist across scales. Factors that may be different include: level of impurities in the feed material, lot to lot variability in feedstock impurities, design of the column housing unit with respect to cleanability, and homogeneity of the column packing. In view of these challenges, there is a need for approaches that may be able to predict column underperformance at the manufacturing scale over the product lifecycle. In case such an underperformance is predicted, the operators can unpack and repack the chromatography column beforehand and thus avoid batch loss. Chemometrics offers one such solution. In this article, we present an application of chemometrics toward the analysis of a set of chromatography profiles with the intention of predicting the various events of column underperformance including the backpressure buildup and inefficient deoxyribonucleic acid clearance. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Structure‐based replacement of methionine residues at the catalytic domains with serine significantly improves the oxidative stability of alkaline amylase from alkaliphilic Alkalimonas amylolytica
Authors: Yang Haiquan , Liu Long , Li Jianghua , Du Guocheng , Chen Jian 
Published: August 2012

AbstractThe alkaline amylase requires high resistance towards chemical oxidation for use in the detergent and textile industries. This work aims to improve the oxidative stability of alkaline amylase from alkaliphilic Alkalimonas amylolytica by site‐directed mutagenesis based on the enzyme structure model. Five mutants were created by individually replacing methionine at positions 145, 214, 229, 247, and 317 in the amino acid sequence of alkaline amylase with oxidative‐resistant serine. The pH stability of the mutant enzymes was almost the same as that of the wild‐type (WT) enzyme (pH 7.0–11.0). The stable temperature range of the mutant enzymes M145S and M247S decreased from <50°C of the WT to <40°C, while the thermal stability of the other three mutant enzymes (M214S, M229S, and M317S) was almost the same as that of the WT enzyme. The catalytic efficiency (kcat/Km) of all the mutant enzymes decreased when compared to WT enzyme. The mutant enzymes showed increased activity in the presence of surfactants Tween‐60 and sodium dodecyl sulfate. When incubated with 500 mM H2O2 at 35°C for 5 h, the WT enzyme retained only 13.3% of its original activity, while the mutant enzymes M145S, M214S, M229S, M247S, and M317S retained 55.6, 70.2, 54.2, 62.5, and 46.4% of the original activities, respectively. The results indicated that the substitution of methionine residues at the catalytic domains with oxidative‐resistant serine can significantly improve the oxidative stability of alkaline amylase. This work provides an effective strategy to improve the oxidative stability of amylase, and the high oxidation resistance of the mutant enzymes shows their potential applications in the detergent and textile industries. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Rare coronary anastomoses between the aorta, pulmonary trunk, left coronary artery, and subclavian artery
Authors: Takechi Masaki , Yan Jun , Hitomi Jiro 
Published: August 2012

AbstractWe report a rare case of coronary anastomoses in an 83‐year‐old male cadaveric heart. Anomalous vessels arose from the right sinus of the aorta, left main coronary artery, left anterior descending artery, left anterior medial atrial artery, and left subclavian artery. These vessels bifurcated and anastomosed, and finally connected to the pulmonary trunk. The present case is categorized as a multilateral coronary artery fistula in cardiology. Clin. Anat. 25:969–972, 2012. © 2012 Wiley Periodicals, Inc.
Venous architecture of the glabellar to the forehead region
Authors: Shimizu Yusuke , Imanishi Nobuaki , Nakajima Tatsuo , Nakajima Hideo , Aiso Sadakazu , Kishi Kazuo 
Published: August 2012

AbstractThe precise venous anatomy of the glabellar to the forehead region remains unknown. This study aimed to detail the venous architecture of the glabellar region to the forehead in conjunction with that of the supratrochlear artery to reduce the risk of venous congestion of flaps in this area. Fifteen fresh human cadavers were examined here. In five specimens, contrast medium was injected only into the venous system; in 10 specimens, two different types of contrast media were injected into the arterial and venous systems, respectively. A total of 30 hemifacial specimens were radiographed stereoscopically and observed microscopically. In all the cadavers, a distinct vein (termed as the “transverse nasal root vein”) connected the bilateral angular veins. One or two large ascending veins branched from the transverse nasal root or angular vein, coursing toward the forehead skin. Numerous small veins branched out from the large ascending vein(s), forming a subdermal polygonal venous network. Small ascending veins arose from this network and coursed toward the dermis, draining venous flow from the dermis. Three different‐sized valves prevented the reflux of blood in the venous pathway. The large ascending vein(s) and supratrochlear artery ran parallel only in the medial canthal area. Tiny venous vasa vasorum surrounded the adventitia of the supratrochlear artery and anastomosed with the polygonal venous network, while a few small veins from the vasa vasorum ascended toward the dermis. Understanding the venous architecture of this region is expected to facilitate the safe elevation of various flaps in the area. Clin. Anat. 2013. © 2012 Wiley Periodicals, Inc.
Analysis of neurosensory adverse events induced by FOLFOX4 treatment in colorectal cancer patients: a comparison between two Asian studies and four Western studies
Authors: Sugihara Kenichi , Ohtsu Atsushi , Shimada Yasuhiro , Mizunuma Nobuyuki , Gomi Katsushige , Lee Po‐Huang , de Gramont Aimery , Rothenberg Mace L. , André Thierry , Brienza Silvano , Goldberg Richard M. 
Published: August 2012

AbstractThe grades of neurosensory adverse events (NSAEs) induced by FOLFOX4 treatment were compared between Asian and Western colorectal cancer patients and correlated with cumulative oxaliplatin doses. A total of 3359 patients treated with FOLFOX4 were analyzed: 1515 from two Asian studies (Japanese Post Marketing Surveillance [J‐PMS] and MASCOT) and 1844 from four Western studies (EFC2962, N9741, EFC4584, and MOSAIC). The onset of NSAEs was analyzed in terms of treatment duration and cumulative dose of oxaliplatin. The incidence of grade ≥3 NSAEs ranged from 2.0% to 4.4% in Asian studies and 9.3% to 19% in Western studies. The cumulative doses of oxaliplatin that induced grade ≥3 NSAEs in 10% of patients were higher in Asian studies (1526 mg/m2 or not reached) than in Western studies (805–832 mg/m2). No significant correlations were noted between occurrence of grade ≥3 NSAEs and demographic/baseline characteristics. The frequency of escalation from grade 0 to 1 in J‐PMS was statistically significantly lower than that in EFC4584, and that from grade 0 to 1 and from grade 1 to 2 in MASCOT lower than that in MOSAIC. The cumulative oxaliplatin doses administered during grade escalation in J‐PMS were similar to those in EFC2962 or EFC4584. All grade‐3 NSAEs in MASCOT and 96% of those in MOSAIC improved to grade 2 or less within 12 months of follow‐up. The Asian populations accrued to these studies appear to be less susceptible to the neurotoxicity of oxaliplatin than the mainly Caucasian populations in the Western studies.
Modification of the siRNA Passenger Strand by 5‐Nitroindole Dramatically Reduces its Off‐Target Effects
Authors: Zhang Junbin , Zheng Jie , Lu Chang , Du Quan , Liang Zicai , Xi Zhen 
Published: August 2012

AbstractDuring the formation of RNA‐induced silencing complex (RISC), the passenger and guide strand of an siRNA duplex separate from each other to generate an active RISC complex. Accumulating evidence shows that an siRNA passenger strand can also assemble into a RISC complex and mediate RNA interference, thereby causing undesired off‐target effects. To reduce this effect, the so‐called “universal base” 5‐nitroindole nucleotides were incorporated into an siRNA passenger strand. Melting temperature and circular dichroism spectrum measurements showed no significant changes compared to the unmodified duplex, thus indicating the formation of normal A‐form conformation. Using a dual luciferase reporter assay, we have further shown that 5‐nitroindole modification at position 15 of the siRNA passenger strand drastically decreased the RNAi (RNA interfering) potency of this strand, whereas the potency of the RNA guide strand was not much affected. These results could provide a practical approach for reducing off‐target effects mediated by the siRNA passenger strand.
Tethering of Dinuclear Complexes to SBA‐15 and Their Application in CO2 Hydrogenation
Authors: Morgan Grace G. , Fennell Kevin , Kishore M. Jhansi L. , Sullivan James A. 
Published: August 2012

AbstractTwo bimetallic cryptates (containing Cu and Co), which have previously been shown to react with and activate atmospheric CO2, were tethered to modified mesoporous SiO2 and their activities in promoting the CO2+H2 reaction has been analysed. The cryptates were tethered to C3H6Cl‐modified SBA‐15 through a condensation reaction between surface alkyl chlorides and 2° amines of the ligands, which released HCl and formed 3° amine linkages. The materials were characterised using BET, thermogravimetric analysis, FTIR and elemental analysis and their activities in promoting the CO2+H2 reaction was tested under batch reactor conditions. Co ions appear to selectively populate the medal sites of the tethered ligands whereas Cu ions appear to deposit on the surface as Cu(BF4)2 salts. The composite materials generate CO and CH4 from the CO2+H2 mixtures. Co‐containing catalysts are more effective than their Cu analogues in promoting the reaction.
Click Chemistry of Alkyne–Azide Cycloaddition using Nanostructured Copper Catalysts
Authors: Jin Tienan , Yan Mei , Yamamoto Yoshinori 
Published: August 2012

AbstractWith increasing advances on nanotechnology, the nanostructured copper catalysts have attracted much attention in alkyne–azide click reaction in the last few years owing to their large surface area, tunable morphology and sustainable catalytic activities. Supported copper nanoparticles are most widely employed. The shape, size and dispersity of supported copper nanoparticles are highly controlled by the used supports, as these will determine the catalytic activity of the heterogeneous click reaction. On the other hand, nanoporous coppers with specific three‐dimensional open pore network structure was reported most recently, which can be fabricated with a tunable ligament or pore size without any supports, exhibiting high catalytic activity and reusability. This Minireview describes the state of the art with respect to the fabrication and catalytic application of both supported copper nanoparticles and nanoporous copper in click reaction.
Decentralized Control System Design for a Ternary Reactive Distillation with Inert Using Mixed Integer Optimization
Authors: Paramasivan G. , Kienle A. 
Published: August 2012

AbstractInferential control of ternary reactive distillation with inert is controversially discussed in recent literature. For further clarification, a systematic study based on mixed integer dynamic optimization is presented. Special emphasis is placed on robustness with respect to various disturbances arising in practice. This gives rise to a stochastic problem formulation which is extended step by step. Through this, significant improvements can be achieved and it is concluded that inferential control of ternary reactive distillation with inert is feasible.
NMR Spin–Spin Coupling Constants in Polymethine Dyes as Polarity Indicators
Authors: Murugan N. Arul , Aidas Kestutis , Kongsted Jacob , Rinkevicius Zilvinas , Ågren Hans 
Published: August 2012

AbstractHerein, we explore the use of spin–spin coupling constants (SSCCs) in merocyanine (MCYNE) dyes as indicators of polarity. For this purpose, we use Car–Parrinello hybrid quantum mechanics/molecular mechanics (QM/MM) to determine the structures of MCYNE in solvents of different polarity, followed by computations of the SSCCs by using QM/MM linear‐response theory. The molecular geometry of MCYNE switches between neutral, cyanine‐like, and zwitterionic depending on the polarity of the solvent. This structural variation is clearly reflected in the proton SSCCs in the polymethine backbone, which are highly sensitive to the dielectric nature of the environment; this mechanism can be used as a “polarity indicator” for different microenvironments. This result is highlighted by computing the SSCCs of the MCYNE probe in the cavity of the beta‐lactoglobulin protein. The computed SSCCs clearly indicate a non‐polar hydrophobic dielectric nature of this cavity.
Use of Melem as a Nucleophilic Reagent to Form the Triphthalimide C6N7(phthal)3—New Targets and Prospects
Authors: Schwarzer Anke , Böhme Uwe , Kroke Edwin 
Published: August 2012

AbstractMelem (1), as one of the most important representatives of the tri‐s‐triazine compounds, can be used as a nucleophilic reagent in reactions with phthalic acid derivatives. The synthesis of 2,5,8‐triphthalimido‐tri‐s‐triazine (C6N7(phthal)3, 2) was investigated starting from phthalic anhydride or phthalic dichloride in various solvents, at different temperatures as well as in the solid state. NMR measurements (solution and solid state), IR spectroscopy and elemental analysis indicated the formation of a cyclic imide. Single‐crystal structure analysis of a 1:1 adduct of 2 with nitromethane proved the molecular structure expected for a phthalimido‐s‐heptazine. DFT calculations were performed to obtain a better insight into the structural features of compound 2, especially the interaction of the carbonyl groups with the tri‐s‐triazine nitrogen atoms. The title compound 2 shows promising properties: it is thermally stable up to 500 °C in air and shows strong photoluminescence with a maximum emission at around 500 nm. The potential of the nucleophilic reaction of melem with other strong electrophiles provides new targets and prospects.
Incorporating Zn2SnO4 Quantum Dots and Aggregates for Enhanced Performance in Dye‐Sensitized ZnO Solar Cells
Authors: Li Yafeng , Wang Ya , Chen Caiyun , Pang Aiying , Wei Mingdeng 
Published: August 2012

AbstractThe performance of dye‐sensitized ZnO solar cells was improved by a facile surface‐treatment approach through chemical‐bath deposition. After the surface treatment, the quantum dots of Zn2SnO4 were deposited onto ZnO nanoparticles accompanied by the aggregations of Zn2SnO4 nanoparticles. The ZnO film displayed a better resistance to acidic dye solution on account of the deposited Zn2SnO4 nanoparticles. Meanwhile, the open‐circuit photovoltage was greatly enhanced, which can be ascribed to the increased conduction‐band edge of ZnO and inhibited interfacial charge recombination. Although the deposition of Zn2SnO4 decreased the adsorption amounts of N719 dye, the aggregates of Zn2SnO4 with a size of 350–450 nm acted as the effective light‐scattering layer, thereby resulting in an improved short‐circuit photocurrent. By co‐sensitizing 10 μm‐thick ZnO film with N719 and D131 dyes, a top efficiency of 4.38 % was achieved under the illumination of one sun (AM 1.5, 100 mW cm−2).