bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow accelerates adhesion between functional polyethylene and polyurethane
Authors: Song Jie , Ewoldt Randy H. , Hu Wanli , Craig Silvis H. , Macosko Christopher W. 
Published: January 2011

AbstractPolyethylene (PE) has relatively poor adhesion with polar polymeric materials. In an effort to improve the adhesion between PE and thermoplastic polyurethane (TPU), maleic anhydride (MA), hydroxyl (OH), and secondary amine (NHR) functionalized PEs were blended into nonmodified PE. These functional groups will react with urethane linkages in TPU at the temperature of melt processing. We bonded these PEs to TPU via lamination and coextrusion. To compare the two processes, we determined the interfacial copolymer density Σ considering both advection and interfacial area generation. We found that the development of adhesion in coextrusion was much faster in comparison with lamination at the same temperature. This difference was attributed to the extensional and compressive flow in coextrusion overcoming the diffusion barrier at the interface and forcing reactive species to penetrate the interface. The effects of functional group reactivity and processing variables on adhesion were correlated with interfacial copolymer coverage. Amine functionalized PE showed dramatic adhesion improvement even at 1 wt %. © 2011 American Institute of Chemical Engineers AIChE J, 2011
Application of ultrasound for start‐up of evaporative batch crystallization of ammonium sulfate in a 75‐L crystallizer
Authors: Lakerveld Richard , Verzijden Nelleke G. , Kramer Herman , Jansens Peter , Grievink Johan 
Published: January 2011

AbstractA positive effect of ultrasound on crystallization has been shown for many applications especially on small scale. Predictable scale‐up of sonocrystallization is a challenge due to the inherent dependency of ultrasound on scale. The presented research discusses the experimental application of ultrasound to induce nucleation at low supersaturation for start‐up of evaporative batch‐wise crystallization of ammonium sulfate in a 75‐L draft tube (DT) crystallizer. A comparison is made with a conventional start‐up procedure using primary nucleation or seeding. Ultrasound is applied in two geometrically different vessels of 1.2‐L connected to a 75‐L DT crystallizer. Application of ultrasound for start‐up of a 75‐L DT crystallizer shows that an optimum amount of ground seeds is better capable to suppress nucleation. A challenge for future research is to improve the efficiency of ultrasound to produce a large number of nuclei for start‐up of batch crystallization at larger scale. © 2011 American Institute of Chemical Engineers AIChE J, 2011
Parametric analysis of Fischer‐tropsch synthesis in a catalytic microchannel reactor
Authors: Gumuslu Gamze , Avci Ahmet K. 
Published: January 2011

AbstractFischer‐Tropsch synthesis (FTS) involves highly exothermic conversion of syngas to a wide range of hydrocarbons, but demands isothermal conditions due to the strong dependence of product distribution on temperature. Running FTS in microchannel reactors is promising, as the sub‐millimeter dimensions can lead to significant intensification that inherently favors robust temperature control. This study involves computer‐based FTS simulations in a heat‐exchange integrated microchannel network composed of horizontal groups of square‐shaped cooling and wall‐coated, catalytic reaction channels. Effects of material type and thickness of the wall separating the channels, side length of the cooling channel, coolant flow rate, and channel wall texture on reaction temperature are investigated. Use of thicker walls with high thermal conductivities and micro‐baffles on the catalytic reaction channel wall favor near‐isothermal conditions. Response of reaction temperature against coolant flow rate is significant. Using cooling channels with smaller side lengths, however, is shown to be insufficient for temperature control. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Photochemical Reactions as Key Steps in Natural Product Synthesis
Authors: Bach Thorsten , Hehn Jörg P. 
Published: January 2011

AbstractPhotochemical reactions contribute in a significant way to the existing repertoire of carbon–carbon bond‐forming reactions by allowing access to exceptional molecular structures that cannot be obtained by conventional means. In this Review, the most important photochemical transformations that have been employed in natural product synthesis are presented. Selected total syntheses are discussed as examples, with particular attention given to the photochemical key step and its stereoselectivity. The structural relationship between the photochemically generated molecule and the natural product is shown, and, where necessary, the consecutive reactions in the synthesis are illustrated and classified.
Identification and functional consequences of a recurrent NLRP12 missense mutation in periodic fever syndromes
Authors: Jéru Isabelle , Le Borgne Gaëlle , Cochet Emmanuelle , Hayrapetyan Hasmik , Duquesnoy Philippe , Grateau Gilles , Morali Alain , Sarkisian Tamara , Amselem Serge 
Published: January 2011

AbstractObjectiveTo gain insight into the molecular bases of genetically unexplained periodic fever syndromes (PFS) by screening NLRP12, a gene in which only a nonsense and a splice site mutation have so far been identified, and to assess the functional consequences of the identified missense variation.MethodsNLRP12 was screened for mutations by direct sequencing. Functional assays were performed in HEK 293T cells stably expressing the proapoptotic protein ASC and procaspase 1, in order to determine the effects of normal and mutated NLRP12 proteins on speck formation, caspase 1 signaling, and NF‐κB activation.ResultsA heterozygous NLRP12 missense mutation involving a CpG site (c.1054C>T; p.Arg352Cys) was identified in exon 3, which encodes the nucleotide‐binding site (NBS) of the protein, in 2 patients from different countries and carrying different NLRP12 haplotypes. The mutation, which does not alter the inhibitory effect of NLRP12 on NF‐κB activation, increases speck formation and activates caspase 1 signaling. To define this new class of PFS, we propose the term NLRP12‐associated disorders (NLRP12AD).ConclusionGiven the rarity of known NLRP12‐associated disorders, the identification of this NLRP12 molecular defect contributes to the delineation of the clinical spectrum associated with mutations in this gene and highlights the importance of screening NLRP12 in patients presenting with unexplained PFS. This study also demonstrates, by means of functional assays, the deleterious effect of this recurrent missense mutation; the gain of function for speck formation and caspase 1 signaling associated with this NBS mutation is consistent with the inflammatory phenotype of PFS.
In vivo effects of the anti–interleukin‐6 receptor inhibitor tocilizumab on the B cell compartment
Authors: Roll Petra , Muhammad Khalid , Schumann Mathias , Kleinert Stefan , Einsele Hermann , Dörner Thomas , Tony Hans‐Peter 
Published: January 2011

AbstractObjectiveInterleukin‐6 (IL‐6) receptor inhibition by tocilizumab was recently licensed for the treatment of rheumatoid arthritis (RA). IL‐6 induces in vitro differentiation of B cells into antibody‐forming cells; however, the in vivo effects of IL‐6 inhibition on the B cell compartment are currently not known. The purpose of this study was to examine this feature.MethodsSixteen patients with active RA were treated in an open‐label study with tocilizumab (8 mg/kg every 4 weeks). Immunophenotyping was performed at baseline, week 12, and week 24.ResultsMemory B cell subsets declined significantly during tocilizumab therapy. Preswitch memory B cells decreased from a median of 19.6% to 12.3% at week 24 and postswitch memory B cells declined from a median of 18.6% to 15.0% at week 24 (P = 0.04). In parallel, CD19+IgA+ and CD19+IgG+ B cells decreased significantly. The proportion of IgA‐expressing B cells fell from a median of 9.2% at baseline to 4.3% at week 12 and to 3.6% at week 24 (P = 0.01). IgG+ B cells declined from a median of 6.7% at baseline to 4.9% at week 12 (P = 0.007) and 2.8% at week 24 (P = 0.01). In parallel, serum levels of IgA and IgG were significantly diminished at week 24 (P < 0.05). There was a good correlation between relative and absolute numbers of IgA+ B cells with serum IgA at week 24.ConclusionTocilizumab induced a significant reduction in the frequency of peripheral preswitch and postswitch memory B cells. In addition, the number of IgG+ and IgA+ B cells declined and correlated well with reduced serum immunoglobulin levels. The data indicate that IL‐6 blockade affects the B cell hyperreactivity in RA patients.
Topic‐based PageRank on author cocitation networks
Authors: Ding Ying 
Published: January 2011

AbstractRanking authors is vital for identifying a researcher's impact and standing within a scientific field. There are many different ranking methods (e.g., citations, publications, h‐index, PageRank, and weighted PageRank), but most of them are topic‐independent. This paper proposes topic‐dependent ranks based on the combination of a topic model and a weighted PageRank algorithm. The author‐conference‐topic (ACT) model was used to extract topic distribution of individual authors. Two ways for combining the ACT model with the PageRank algorithm are proposed: simple combination (I_PR) or using a topic distribution as a weighted vector for PageRank (PR_t). Information retrieval was chosen as the test field and representative authors for different topics at different time phases were identified. Principal component analysis (PCA) was applied to analyze the ranking difference between I_PR and PR_t.
Battery power loss compensated fractional order sliding mode control of a quadrotor UAV
Authors: Efe Mehmet Önder 
Published: January 2011

AbstractThis work considers the fractional order control of a lightweight quadrotor under loss in the battery voltage. Since the outdoor brushless motors are driven via a pulse width modulation (pwm) scheme, handshaking between the dynamic model and controller is established at the pwm level and this constitutes a major contribution of the paper. The attitude control is achieved via fractional order sliding mode control (FSMC) scheme. Necessary stability considerations are presented and it is seen that FSMC is a good alternative for the control of unmanned aerial vehicles.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Hydrogel embedding of precision‐cut liver slices in a microfluidic device improves drug metabolic activity
Authors: van Midwoud Paul M. , Merema Marjolijn T. , Verweij Niek , Groothuis Geny M.M. , Verpoorte Elisabeth 
Published: January 2011

AbstractA microfluidic‐based biochip made of poly‐(dimethylsiloxane) was recently reported for the first time by us for the incubation of precision‐cut liver slices (PCLS). In this system, PCLS are continuously exposed to flow, to keep the incubation environment stable over time. Slice behavior in the biochip was compared with that of slices incubated in well plates, and verified for 24 h. The goal of the present study was to extend this incubation time. The viability and metabolic activity of precision‐cut rat liver slices cultured in our novel microflow system was examined for 72 h. Slices were incubated for 1, 24, 48, and 72 h, and tested for viability (enzyme leakage (lactate dehydrogenase)) and metabolic activity (7‐hydroxycoumarin (phase II) and 7‐ethoxycoumarin (phase I and II)). Results show that liver slices retained a higher viability in the biochip when embedded in a hydrogel (Matrigel) over 72 h. This embedding prevented the slices from attaching to the upper polycarbonate surface in the microchamber, which occurred during prolonged (>24 h) incubation in the absence of hydrogel. Phase II metabolism was completely retained in hydrogel‐embedded slices when medium supplemented with dexamethasone, insulin, and calf serum was used. However, phase I metabolism was significantly decreased with respect to the initial values in gel‐embedded slices with medium supplements. Slices were still able to produce phase I metabolites after 72 h, but at only about ∼10% of the initial value. The same decrease in metabolic rate was observed in slices incubated in well plates, indicating that this decrease is due to the slices and medium rather than the incubation system. In conclusion, the biochip model was significantly improved by embedding slices in Matrigel and using proper medium supplements. This is important for in vitro testing of drug metabolism, drug–drug interactions, and (chronic) toxicity. Biotechnol. Bioeng. 2011; 108:1404–1412. © 2011 Wiley Periodicals, Inc.
Performance of a cutinase membrane reactor for the production of biodiesel in organic media
Authors: Badenes Sara M. , Lemos Francisco , Cabral Joaquim M.S. 
Published: January 2011

AbstractThe enzymatic transesterification of oils with an alcohol, using recombinant cutinase of Fusarium solani pisi microencapsulated in sodium bis(2‐ethylhexyl) sulfosuccinate (AOT)/isooctane reversed micelles, was performed in a membrane bioreactor (MBR). A tubular ceramic membrane with a nominal molecular weight cut off of 15,000 Da was used to retain the enzyme, and characterized in terms of rejection coefficients of the reaction components by transmission experiments. The performance of the MBR in a total recirculation‐batch mode was compared with results obtained in a stirred batch tank reactor. The continuous operation of the MBR was also evaluated and the influence of the alcohol type and permeate flow rate on conversion degree and productivity (up to 500 gproduct/day/genzyme was attained) were analyzed. Cutinase wild type and mutant T179C were tested for this process and the high long‐term operational stability of the cutinase mutant demonstrated its potential as biocatalyst for the enzymatic continuous production of biodiesel. Biotechnol. Bioeng. 2011; 108:1279–1289. © 2011 Wiley Periodicals, Inc.
Low temperature removal of inorganic sulfur compounds from mining process waters
Authors: Liljeqvist Maria , Sundkvist Jan‐Eric , Saleh Amang , Dopson Mark 
Published: January 2011

AbstractProcess water and effluents from mining operations treating sulfide rich ores often contain considerable concentrations of metastable inorganic sulfur compounds such as thiosulfate and tetrathionate. These species may cause environmental problems if released to downstream recipients due to oxidation to sulfuric acid catalyzed by acidophilic microorganisms. Molecular phylogenic analysis of the tailings pond and recipient streams identified psychrotolerant and mesophilic inorganic sulfur compound oxidizing microorganisms. This suggested year round thiosalt oxidation occurs. Mining process waters may also contain inhibiting substances such as thiocyanate from cyanidation plants. However, toxicity experiments suggested their expected concentrations would not inhibit thiosalt oxidation by Acidithiobacillus ferrivorans SS3. A mixed culture from a permanently cold (4–6°C) low pH environment was tested for thiosalt removal in a reactor design including a biogenerator and a main reactor containing a biofilm carrier. The biogenerator and main reactors were successively reduced in temperature to 5–6°C when 43.8% of the chemical oxidation demand was removed. However, it was found that the oxidation of thiosulfate was not fully completed to sulfate since low residual concentrations of tetrathionate and trithionate were found in the discharge. This study has demonstrated the potential of using biotechnological solutions to remove inorganic sulfur compounds at 6°C and thus, reduce the impact of mining on the environment. Biotechnol. Bioeng. 2011; 108:1251–1259. © 2011 Wiley Periodicals, Inc.
Consolidated bioprocessing (CBP) performance of Clostridium phytofermentans on AFEX‐treated corn stover for ethanol production
Authors: Jin Mingjie , Balan Venkatesh , Gunawan Christa , Dale Bruce E. 
Published: January 2011

AbstractConsolidated bioprocessing (CBP) is believed to be a potentially cost‐efficient and commercially viable way to produce cellulosic biofuels. In this study, we have evaluated the performance of the CBP organism Clostridium phytofermentans (ATCC 700394) on AFEX‐treated corn stover (AFEX‐CS). Fermentation conditions including temperature, inoculation size, nutrients, and initial pH were investigated. At optimal conditions with 0.5% (w/w) glucan loading of AFEX‐CS, C. phytofermentans hydrolyzed 76% of glucan and 88.6% of xylan in 10 days. These values reached 87% and 102% of those obtained by simultaneous saccharification and co‐fermentation (SSCF) using commercial enzymes and S. cerevisiae 424A. Ethanol titer for CBP was found to be 2.8 g/L which was 71.8% of that yielded by SSCF (3.9 g/L). Decomposition products from AFEX‐CS helped to increase ethanol yield somewhat during CBP. Particle size played a crucial role in the enhancement of sugar conversion by CBP. Biotechnol. Bioeng. 2011; 108:1290–1297. © 2011 Wiley Periodicals, Inc.
Computer‐based assessment of student performance in programing courses
Authors: Kalogeropoulos N. , Tzigounakis I. , Pavlatou E. A. , Boudouvis A. G. 
Published: January 2011

AbstractIn this study, the score equivalence of computer‐based assessment (CBA) and paper‐and‐pencil testing (PPT) in an undergraduate course of introductory computer programing at the National Technical University of Athens' School of Chemical Engineering, was examined. The research was carried out with 211 students participating, and was realized by a specially constructed CBA platform as well as the classical PPT. Both types of assessment included the same questions of multiple‐choice type, completing and correcting code in Fortran, as well as writing Fortran code from scratch. The results showed that, in general, students performed better and received higher scores under CBA compared to PPT. In particular, the very good students benefited from the advantages that the computer compiler offers in debugging code and completing code exercises and, thus, received relatively higher scores in these parts of the test. Moreover, switching answers and devoting more time‐on‐task was found to be beneficial for the students' performance. Overall, the findings of this study revealed that the actual programing abilities of the students are better evaluated using such CBA tests. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 21: 671–683, 2013
Space flight affects motility and cytoskeletal structures in human monocyte cell line J‐111
Authors: Meloni Maria Antonia , Galleri Grazia , Pani Giuseppe , Saba Angela , Pippia Proto , Cogoli‐Greuter Marianne 
Published: January 2011

AbstractCertain functions of immune cells in returning astronauts are known to be altered. A dramatic depression of the mitogenic in vitro activation of human lymphocytes was observed in low gravity. T‐cell activation requires the interaction of different type of immune cells as T‐lymphocytes and monocytes. Cell motility based on a continuous rearrangement of the cytoskeletal network within the cell is essential for cell–cell contacts. In this investigation on the International Space Station we studied the influence of low gravity on different cytoskeletal structures in adherent monocytes and their ability to migrate. J‐111 monocytes were incubated on a colloid gold substrate attached to a cover slide. Migrating cells removed the colloid gold, leaving a track recording cell motility. A severe reduction of the motility of J‐111 cells was found in low gravity compared to 1g in‐flight and ground controls. Cell shape appeared more contracted, whereas the control cells showed the typical morphology of migrating monocytes, i.e., elongated and with pseudopodia. A qualitative and quantitative analysis of the structures of F‐actin, β‐tubulin and vinculin revealed that exposure of J‐111 cells to low gravity affected the distribution of the different filaments and significantly reduced the fluorescence intensity of F‐actin fibers. Cell motility relies on an intact structure of different cytoskeletal elements. The highly reduced motility of monocytes in low gravity must be attributed to the observed severe disruption of the cytoskeletal structures and may be one of the reasons for the dramatic depression of the in vitro activation of human lymphocytes. © 2011 Wiley‐Liss, Inc.
Discovery of Benzamide Analogues as a Novel Class of 5‐HT3 Receptor Agonists
Authors: Jørgensen Charlotte G. , Frølund Bente , Kehler Jan , Jensen Anders A. 
Published: January 2011

AbstractA 5‐HT3 receptor agonist based on a benzamide scaffold was identified in a screening of a small commercial compound library, and an elaborate SAR study originating from this hit was performed. The design, synthesis, and functional characterisation of benzamide analogues at the 5‐HT3A receptor yielded substantial information concerning the analogues as 5‐HT3 receptor agonists. However, the potencies of the derived analogues were not significantly improved over that of the initial hit. The benzamide scaffold constitutes a novel type of 5‐HT3 receptor agonist, as it does not possess a positively charged functionality, which is essential for the binding of all orthosteric ligands to the receptor. Preliminary investigations suggest that the compounds may exert their effects on 5‐HT3 receptors by binding to an allosteric site in the receptor complex.
A Versatile and Practical Synthesis toward the Development of Novel HIV‐1 Integrase Inhibitors
Authors: Rinaldi Marta , Tintori Cristina , Franchi Luigi , Vignaroli Giulia , Innitzer Anna , Massa Silvio , Esté José A. , Gonzalo Encarna , Christ Frauke , Debyser Zeger , Botta Maurizio 
Published: January 2011

AbstractAs a continuation of our previous work, which resulted in the identification of a new hit compound as an HIV‐1 integrase inhibitor, three novel series of salicylic acid derivatives were synthesized using three versatile and practical synthetic strategies and were assayed for their capacity to inhibit the catalytic activity of HIV‐1 integrase. Biological evaluations revealed that some of the synthesized compounds possess good inhibitory potency in enzymatic assays and are able to inhibit viral replication in MT‐4 cells at low micromolar concentrations. Finally, docking studies were conducted to analyze the binding mode of the synthesized compounds within the DNA binding site of integrase in order to refine their structure–activity relationships.