bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Temperature, Chemical, and Mineral Admixtures on the Electrical Conductivity of Concrete
Authors: Nokken Michelle , Boddy Adam , Wu Xiaorong , Hooton R. Douglas 
Published: May 2008

Abstract
ASTM C1202 has become a very common test method for prequalification purposes and for performance-based specifications in North America. Although the test neither directly determines the permeability or chloride resistance, it has often been shown to have good correlation to those properties since electrical conductivity is also related to the porosity and connectivity of the pore structure. The prevalence of the test is largely based on its ease of execution and its wide acceptance and use by many state and provincial DOTs. More recently, ASTM subcommittee C09.66 has discussed replacing the above test method with a more rapid method measuring conductivity. Several factors affect the conductivity of concrete, mixture design, inclusion of chemical and mineral admixtures, the temperature during testing and the age or maturity at test time. Research was carried out to investigate the magnitude of these variables on measured conductivity. Conductivity was measured using the same equipment as the ASTM C1202 method with changes in the magnitude and duration of the applied voltage as well as the solutions used in the test cell chamber. Conductivity was measured every three hours starting at one day after casting until seven days and weekly until 28 days. Conductivity was found to decrease with hydration as expected. It was determined that mixture design and temperature have significant effects on measured conductivity while chemical admixtures have less influence with the exception of corrosion inhibitors. The developed test method presents potential as a tool for prequalification and quality control that can be directly related to maturity and durability.
Electric conductance method to study the contact of injected liquid with fluidized particles
Authors: Portoghese Federica , House Peter , Berruti Franco , Briens Cedric , Adamiak Kazimierz , Chan Edward 
Published: May 2008

AbstractA sensitive and reliable experimental technique was developed to assess the performance of gas‐atomization nozzles injecting liquid into a gas‐solid fluidized bed. Gas atomizers are used to inject liquid feeds into industrial fluid cokers, fluid catalytic crackers, and gas‐phase polymerization reactors. In the fluid coking process, for example, both liquid yields and reactor operability are affected by how well the injected liquid contacts the fluidized particles. The new experimental method assesses the quality of the liquid‐solid contact from the electric conductance of the bed solids wetted with the injected liquid. The validity of the method was corroborated by direct comparison with the results provided by alternative experimental techniques, as well as by numerical modeling of the evolution of the bed conductance for various types of liquid distribution within the bed solids. The electric conductance technique can help optimize liquid injection into fluidized beds. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Individual strategy preferences and decisional fit
Authors: Betsch Cornelia , Kunz Justus J. 
Published: May 2008

AbstractThe present research introduces the concept of decisional fit. A decision maker experiences decisional fit when the individually preferred decision strategy fits the actually applied strategy. In accordance to other fit‐concepts in psychology (e.g., person–environment fit), we expected positive effects of decisional fit. Five studies examine the effects of a fit between the individual preference for intuition and deliberation (PID) and the actually used decision strategy (intuition or deliberation). A comparison of extreme types (according to participants' values on the PID scale) revealed that decisional fit enhances the perceived value of the chosen or evaluated object (Studies 1–3). In Studies 4 and 5, participants experienced less regret after decisional fit. The findings highlight the importance of considering individual differences when comparing intuitive and deliberate decision making, because strategy preferences interact with applied strategies. Copyright © 2008 John Wiley & Sons, Ltd.
Calcium phosphate transfection generates mammalian recombinant cell lines with higher specific productivity than polyfection
Authors: Chenuet Sebastien , Martinet Danielle , Besuchet‐Schmutz Nathalie , Wicht Marianne , Jaccard Nicolas , Bon Anne‐Charlotte , Derouazi Madiha , Hacker David L. , Beckmann Jacques S. , Wurm Florian M. 
Published: May 2008

AbstractTransfection with polyethylenimine (PEI) was evaluated as a method for the generation of recombinant Chinese hamster ovary (CHO DG44) cell lines by direct comparison with calcium phosphate‐DNA coprecipitation (CaPO4) using both green fluorescent protein (GFP) and a monoclonal antibody as reporter proteins. Following transfection with a GFP expression vector, the proportion of GFP‐positive cells as determined by flow cytometry was fourfold higher for the PEI transfection as compared to the CaPO4 transfection. However, the mean level of transient GFP expression for the cells with the highest level of fluorescence was twofold greater for the CaPO4 transfection. Fluorescence in situ hybridization on metaphase chromosomes from pools of cells grown under selective pressure demonstrated that plasmid integration always occurred at a single site regardless of the transfection method. Importantly, the copy number of integrated plasmids was measurably higher in cells transfected with CaPO4. The efficiency of recombinant cell line recovery under selective pressure was fivefold higher following PEI transfection, but the average specific productivity of a recombinant antibody was about twofold higher for the CaPO4‐derived cell lines. Nevertheless, no difference between the two transfection methods was observed in terms of the stability of protein production. These results demonstrated the feasibility of generating recombinant CHO‐derived cell lines by PEI transfection. However, this method appeared inferior to CaPO4 transfection with regard to the specific productivity of the recovered cell lines. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.
Ribosome display selection of a metal‐binding motif from an artificial peptide library
Authors: Wada Akira , Sawata Shinya Y. , Ito Yoshihiro 
Published: May 2008

AbstractA new ribosome display system was applied for the in vitro selection of a metal‐binding motif from an artificial peptide library. The display system consisted of an mRNA‐associating protein, a ribosome, and mRNA. The protein part of this display system was designed to provide a random peptide library and to stabilize the ribosome display. The random peptide library was newly designed to isolate stable metal‐binding motifs. We employed the system for in vitro selection and found several new proteins and peptides that bind Co(II)‐immobilized resin and Co(II)‐complex, respectively. This newly developed system can be conveniently applied to the in vitro selection of peptide aptamers. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.
Single‐cell analysis demonstrates how nutrient deprivation creates apoptotic and quiescent cell populations in tumor cylindroids
Authors: Kim Byoung‐jin , Forbes Neil S. 
Published: May 2008

AbstractUnderstanding how quiescent and apoptotic populations form in tumors is necessary because these cell types can considerably diminish therapeutic efficacy. Most cancer therapeutics are ineffective against quiescent cells because they target rapidly proliferating cells. Distinguishing apoptosis is important because apoptotic cells are committed to death and do not require treatment. Regrowth of quiescent cell can lead to tumor reoccurrence and metastasis, which are the leading causes of cancer mortality. We hypothesized that cylindroid cultures and acridine orange staining could be used to determine how nutrient diffusion creates apoptotic and quiescent regions in tumors. To test this hypothesis we developed a microscopy technique to measure cellular DNA and RNA content in single cells using thin cylindroids and acridine orange staining. Cell classification was compared to flow cytometry of cells grown in defined monolayer cultures. The presence of apoptosis was confirmed by morphological nuclear analysis. The effect of diffusion was determined by varying incubation time, cylindroid size, and exposing cylindroids to nutrient‐deficient media. Four overlapping regions were identified as a function of cylindroid radius: an outer viable/quiescent region; a second quiescent/apoptotic region; a third late‐stage apoptotic region; and an inner dead region. In monolayer cultures the absence of glutamine and growth factors induced apoptosis and hypoxia induced quiescence. Treating with nutrient‐deficient media suggested that cells became quiescent near the periphery because of glucose and oxygen limitations, and became apoptotic and died further from the edge because of glutamine and growth factor limitations. These results show that cellular microenvironments can be identified in cylindroids using simple acridine orange staining and that single cell florescence can be measured in three‐dimensional culture. The developed techniques will be useful for developing cancer therapies and determining how cell death and apoptosis are induced in three‐dimensional tumor tissue. Biotechnol. Bioeng. 2008;101: 797–810. © 2008 Wiley Periodicals, Inc.
Thermostability and molecular encapsulation within an engineered caged protein scaffold
Authors: Dalmau Mercè , Lim Sierin , Chen Helen C. , Ruiz Cesar , Wang Szu‐Wen 
Published: May 2008

AbstractSelf‐assembling biological complexes such as viral capsids have been manipulated to function in innovative nanotechnology applications. The E2 component of pyruvate dehydrogenase from Bacillus stearothermophilus forms a dodecahedral complex and potentially provides another platform for these purposes. In this investigation, we show that this protein assembly exhibits unusual stability and can be modified to encapsulate model drug molecules. To distill the E2 protein down to its structural scaffold core, we synthesized a truncated gene optimized for expression in Escherichia coli. The correct assembly and dodecahedral structure of the resulting scaffold was confirmed with dynamic light scattering and transmission electron microscopy. Using circular dichroism and differential scanning calorimetry, we found the thermostability of the complex to be unusually high, with an onset temperature of unfolding at 81.1 ± 0.9°C and an apparent midpoint unfolding temperature of 91.4 ± 1.4°C. To evaluate the potential of this scaffold for encapsulation of guest molecules, we made variants at residues 381 and 239 which altered the physicochemical properties of the hollow internal cavity. These mutants, yielding 60 and 120 mutations within this cavity, assembled into the correct architecture and exhibited high thermostability that was comparable to the wild‐type scaffold. To show the applicability of this scaffold, two different fluorescent dye molecules were covalently coupled to the cysteine mutant at site 381. We demonstrate that these mutations can introduce non‐native functionality and enable molecular encapsulation within the cavity while still retaining the dodecahedral structure. The unusually robust nature of this scaffold and its amenability to internal changes reveal its potential for nanoscale applications. Biotechnol. Bioeng. 2008;101: 654–664. © 2008 Wiley Periodicals, Inc.
Retail brand extension—perceived fit, risks and trust
Authors: Laforet Sylvie 
Published: May 2008

Abstract

This study examines consumer fit perception, risks and trust in retail brand extension in financial services. Respondents (324) living in Sheffield were involved in the consumer survey, conducted on three major British supermarkets. Mean scores were compared between four groups of respondents. Discriminant analysis was used to determine the factor(s) distinguishing the retailers. Retailers A and B were perceived as trusted brands with respect to financial services. Retailer A was perceived as a trusted brand regardless of the product category. Retailer B was seen as a trusted brand when product performance and financial risks were low while Retailer C was perceived unfit and risky by non‐users and the non‐intend‐to‐buy groups. Age, gender and income influenced fit, risks and trust perception. When consumers knew the store or were store loyal, they tended to trust the store brand extension whereas when consumers did not know or were new to the store, fit and risks were perceived. Implications for corporate branding, brand extension decision‐making and implementations are sought.
Copyright © 2008 John Wiley & Sons, Ltd.
Mitochondrial AIF protein involved in skeletal muscle regeneration
Authors: Qiu Xiao‐zhong , Yu Lei , Lai Gui‐hua , Wang Le‐yu , Chen Bing , Ouyang Jun 
Published: May 2008

AbstractThe mitochondrial flavoprotein apoptosis‐inducing factor (AIF) has proved to be either the main mediator of apoptosis or an anti‐apoptotic factor via its putative oxidoreductase and peroxide scavenging activities. We report here that 100 µM hydrogen peroxide (H2O2) induced the proliferation of C2C12 myoblasts and over‐expression of AIF simultaneously in vitro. Immunofluorescence showed that the over‐expression of AIF was located in the cytoplasm. The immunopositive AIF was detected in nuclei 27 days after denervation of skeletal muscle, but in the cytoplasm it was detected 27 days after fiber‐damaged skeletal muscle. AIF may be a factor involved in skeletal muscle regeneration. Copyright © 2008 John Wiley & Sons, Ltd.
4‐Amino‐3‐acetylquinoline‐induced apoptosis of murine L1210 leukemia cells involves ROS‐mitochondrial‐mediated death signaling and activation of p38 MAPK
Authors: Jantová S. , Repický A. , Letašiová S. , Čipák L. 
Published: May 2008

AbstractQuinolines are known to be multitarget agents with a broad spectrum of biological activity. In a previous study, we showed that newly prepared 4‐amino‐3‐acetylquinoline (AAQ) possesses strong anticancer activities. In this study, we investigated whether AAQ has cytotoxicity in murine L1210 leukemia cells. Results from cell proliferation assays showed that AAQ caused significant decrease in cell number in a dose‐dependent manner. The cell death induced by AAQ appeared to involve apoptosis, based on evidence from apoptotic DNA fragmentation, flow cytometry, fluorescence microscopy, and Western blot analyses. We found that AAQ‐treated cells had activated p38 MAPK and that apoptosis was processed through a reactive oxygen species (ROS)‐dependent mitochondrial pathway. In summary, our results suggest that AAQ can induce apoptosis, at least in part, through the activation of the p38 MAPK pathway in L1210 leukemia cells. Copyright © 2008 John Wiley & Sons, Ltd.
Reassembly of Anthramycin Biosynthetic Gene Cluster by Using Recombinogenic Cassettes
Authors: Hu Yunfeng , Phelan Vanessa V. , Farnet Chris M. , Zazopoulos Emmanuel , Bachmann Brian O. 
Published: May 2008

AbstractThe reassembly and heterologous expression of complete gene clusters in shuttle vectors has enabled investigations of several large biosynthetic pathways in recent years. With a gene cluster in a mobile construct, the interrogation of gene functions from both culturable and nonculturable organisms is greatly accelerated and large pathway engineering efforts can be executed to produce “new” natural products. However, the genetic manipulation of complete natural product biosynthetic gene clusters is often complicated by their sheer size (10–200 kbp), which makes standard restriction/ligation‐based methods impracticable. To circumvent these problems, alternative recombinogenic methods, which depend on engineered homology‐based recombination have recently arisen as a powerful alternative. Here, we describe a new general technique that can be used to reconstruct large biosynthetic pathways from overlapping cosmids by retrofitting each cosmid with a “recombinogenic cassette” that contains a shared homologous element and orthogonal antibiotic markers. We employed this technique to reconstruct the anthramycin biosynthetic gene cluster of the thermotolerant actinomycete Streptomyces refuineus, from two >30 kbp cosmids into a single cosmid and integrate it into the genome of Streptomyces lividans. Anthramycin production in the heterologous Streptomyces host confirmed the integrity of the reconstructed pathway and validated the proposed boundaries of the gene cluster. Notably, anthramycin production by recombinant S. lividans was seen only during growth at high temperature—a property also shown by the natural host. This work provides tools to engineer the anthramycin biosynthetic pathway and to explore the connection between anthramycin production and growth at elevated temperatures.
Enantioselective Epoxidation of Electrophilic Olefins by Using Glycosyl Hydroperoxides
Authors: Kośnik Wioletta , Bocian Wojciech , Kozerski Lech , Tvaroška Igor , Chmielewski Marek 
Published: May 2008

AbstractAnomeric hydroperoxides derived from 3,4,6‐tri‐O‐benzyl‐galactose and glucose were used for enantioselective epoxidation of naphthoquinone (12), chalcone (13), (E)‐1,2‐dibenzoyl ethylene (14) and (E)‐iso‐butyryl‐phenyl ethylene (15). In the presence of sodium hydroxide, the epoxidations showed exceptional high asymmetric induction. The exchange of sodium by a potassium ion resulted in a low asymmetric induction. These results pointed to the crucial role of the counterion and strongly suggested that coordination of the alkaline ion occurs in the transition state of the epoxidation process by both reagents, hydroperoxide and the olefin. Theoretical studies of the reaction mechanism at the DFT B3LYP/6‐31G* level fitted very well with experimental results.
Untersuchungen zum Einfluss elektrokinetischer Wechselwirkungen auf die Adsorptionsmechanismen bei der Tiefenfiltration
Authors: Sartor M. , Kaschek M. , Mavrov V. , Chmiel H. 
Published: May 2008

AbstractDie Filtration von Biosuspensionen wird häufig durch das Biofouling an der Oberfläche des Filtermaterials limitiert. Um einen zufriedenstellenden Fluss zu ermöglichen, werden hohe Druckdifferenzen benötigt. Das Ziel dieser Arbeit ist es, den Einfluss elektrokinetischer Wechselwirkungen auf die Adsorptionsmechanismen zu untersuchen, die das Biofouling in Filterbetten verursachen. Verschiedene Filtermittel werden eingesetzt, um den Einfluss der elektrokinetischen Kräfte zu ermitteln. Es kann gezeigt werden, dass bei Wahl des geeigneten Filtermittels die suspendierten Partikel selektiv entweder mittels elektrokinetischer Abstoßungskräfte im Schüttbett zurückgehalten werden können oder auf der Oberfläche des Schüttbetts am Filtermittel adsorbieren. Durch die Berücksichtigung der elektrokinetischen Wechselwirkungen bei der Auswahl des geeigneten Filtermittels lässt sich die Tiefenfiltration für die selektive Entfernung von suspendierten Partikeln wie z. B. Mikroorganismen aus Biosuspensionen optimieren.
Überblick zur Gewinnung von Phytoextrakten
Authors: Ondruschka B. , Klemm W. 
Published: May 2008

AbstractDie Gewinnung von Naturstoffen als qualitätsgerechte Komponenten für Produkte der Lebensmittel‐ sowie pharmazeutischen und kosmetischen Industrie hat in den letzten Jahren stark zugenommen. Aus wirtschaftlichen Gründen kommt den Extraktionsprozessen, zusammengefasst unter dem Begriff der Phytoextraktion, eine besondere Bedeutung zu. Hier soll über den gegenwärtigen Stand der Technologien zur Gewinnung von Naturstoffen berichtet werden, insbesondere über die Anwendung in der Industrie. Ein wesentlicher Gesichtspunkt ist dabei die Anwendung Mikrowellen‐assistierter Trennverfahren. In einer Übersicht über den Markt und die derzeit bevorzugt verwendeten Herstellungsverfahren sowie Anlagen wird die Zukunftsaussicht ihrer technischen Realisierung an Hand von Literaturrecherchen und persönlichen Anfragen an Hersteller von Produkten und Anlagen untersucht. Das Ergebnis ist, dass die Mikrowellen‐assistierte Technologie zwar für die Qualitäts‐ und Inhaltsstoffanalytik eine große Bedeutung gewonnen, aber aus technischen und daraus resultierenden wirtschaftlichen Gründen derzeit keine Aussicht auf eine Produktionseinführung hat.
Isolierung von Plasmid‐DNA durch inversmizellare Zweiphasensysteme – Optimierung der Rückextraktion
Authors: Streitner N. , Voß C. , Flaschel E. 
Published: May 2008

AbstractDie Verteilung von RNA und Plasmid‐DNA wurde in einem inversmizellaren Zweiphasensystem bestehend aus Trioctylmethylammoniumchlorid (TOMAC) und Isooctan untersucht. Die Auswirkung verschiedener Salze und Alkohole auf den Transfer der Nukleinsäuren wurde vor allem unter dem Gesichtspunkt einer hohen Wiederfindung der Plasmid‐DNA nach der Rückextraktion betrachtet. Systeme, die eine Trennung von Plasmid‐DNA und RNA ermöglichen, wurden eingesetzt, um RNA aus bakteriellem Klarlysat zu entfernen.
Gewinnung und Potenziale des Biopolymers Chitosan
Authors: Ondruschka J. , Trutnau M. , Bley T. 
Published: May 2008

AbstractIn der Natur konnte Chitosan bisher nur in den Zellwänden weniger Pilze (z. B. Mucorales) gefunden werden. Auf Grund struktureller Eigenschaften, der geringen Toxizität, Biokompatibilität und biologischen Abbaubarkeit besitzt Chitosan ein breites Anwendungspotenzial. Wegen entfallender Entsorgungs‐ und Umweltprobleme ist es zusätzlich als Rohstoff attraktiv. Chitosan wird bisher aus Chitin gewonnen, das überwiegend aus Schalenresten der Krabben‐ und Shrimpsherstellung stammt. Eigene Untersuchungen zeigen, dass sich Chitosan aus verschiedenen Pilzmycelien, die als Restprodukte bei biotechnologischen Prozessen (Enzymproduktion, Bierbrauerei) anfallen, besonders günstig gewinnen und aufarbeiten ließe. Unter Umständen ist sogar ein Fermentationsprozess mit Zygomycota rentabel, weil in der Zellwand dieser filamentösen Pilze bereits Chitosan in vivo enthalten ist und so auf den Aufarbeitungsschritt der Deacetylierung verzichtet werden kann. Analysen ergaben, dass Chitosan aus Pilzmycelien gleiche Eigenschaften wie Krabbenchitosan hinsichtlich des Deacetylierungsgrades und der Wasserlöslichkeit bei weniger Aufarbeitungsschritten zeigt. Außerdem lässt es sich protein‐ und schwermetallfrei herstellen, was für Anwendungen im medizinischen Bereich besonders wichtig ist.
Aptamere in der Biosensorik
Authors: Walter J.‐G. , Stahl F. 
Published: May 2008

AbstractIn der Biotechnologie und der Bioprozesstechnik wird es zukünftig verstärkt zum Vermessen von Zielsubstanzen des Proteoms kommen. Traditionell dienen dabei als Biorezeptoren in Biosensoren vor allem Antikörper. Die Empfindlichkeit von Antikörpern führt insbesondere bei der Vermessung komplexer Proben wie Fermentationsbrühen zu einer begrenzten Haltbarkeit der Sensoren. Durch den Einsatz von Aptameren als alternative Biorezeptoren lässt sich diese Limitierung umgehen. Im Vergleich zu Antikörpern sind diese funktionellen Nukleinsäuren wesentlich robuster und können zielgerichtet modifiziert werden, wodurch eine definierte Immobilisierung an festen Oberflächen möglich ist. Aufgrund dieser Vorteile eröffnen Aptamere in der Biosensorik neue Möglichkeiten. Dieser Übersichtsartikel beschreibt die Entwicklung von Aptameren und gibt einen Überblick über aptamerbasierte Biosensoren. Darüber hinaus wird der Einsatz von Aptameren in der Protein‐Microarray‐Technologie beschrieben.