bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of fed‐batch production of the model recombinant protein GFP in Lactococcus lactis
Authors: Oddone Gian M. , Lan Christopher Q. , Rawsthorne Helen , Mills David A. , Block David E.
Published: November 2006

Optimization of recombinant protein production using lactic acid bacteria (LAB) remains an important obstacle on the road to realizing LAB as oral vaccine delivery vehicles. Despite this, there have been few published investigations to explore the higher limits of LAB recombinant protein expression in fed‐batch fermentations. In this study, results from response surface experiments suggested an optimal set of conditions for expression of green fluorescent protein (GFP), a model recombinant protein, in bench‐scale, fed‐batch Lactococcus lactis IL1403 fermentations. The 48 4‐L fed‐batch fermentations in this set of experiments, along with preliminary studies, investigated the effects of pH, temperature, hemin concentration, concentration of the nisin inducer per cell, and time of induction. Cell densities in this data set ranged from 2.9 to 7.4 g/L and maximum GFP expression per cell ranged from 0.1 to 4.4 relative fluorescence units (RFU)/g. The optimal 4‐L, fed‐batch fermentation process found here yields growth and protein expression values that dramatically improve upon results from traditional test tube and flask processes. Relative to the traditional process, the experimental optimum conditions yield 4.9 times the cell density, 1.6 times the protein per cell mass, and 8 times the total protein concentration. Unexpectedly, experiments also revealed that the compound hemin, known previously to improve growth and survival of Lactococcus lactis (L. lactis), negatively impacted recombinant protein production when added in concentrations from 5 to 20 µg/mL with this strain. The improvement in protein expression over traditional processes demonstrated here is an important step toward commercial development of LAB for oral delivery of recombinant vaccines and therapeutic proteins. Biotechnol. Bioeng. 2007;96:1127–1138. © 2006 Wiley Periodicals, Inc.
Long‐Range‐Distance NMR Effects in a Protein Labeled with a Lanthanide–DOTA Chelate
Authors: Vlasie Monica D. , Comuzzi Clara , van den Nieuwendijk Adrianus M. C. H. , Prudêncio Miguel , Overhand Mark , Ubbink Marcellus
Published: November 2006

A two‐thiol reactive lanthanide–DOTA (1,4,7,10‐tetraazacyclododecane‐N,N′,N′′,N′′′‐tetraacetic acid) chelate, CLaNP‐3 (CLaNP = caged lanthanide NMR probe), was synthesized for the rigid attachment to cysteine groups on a protein surface, and used to obtain long‐range‐distance information from the {15N,1H} HSQC spectra of the protein–lanthanide complex. The DOTA ring exhibits several isomers that are in exchange; however, single resonances were observed for most amide groups in the protein, allowing determination of a single, apparent magnetic‐susceptibility tensor. Pseudocontact shifts caused by Yb‐containing CLaNP‐3 were observed for atoms at 15–35 Å from the metal. By using Gd‐containing CLaNP‐3, relaxation effects were observed, allowing distances up to 30 Å from the paramagnetic center to be determined accurately. Similar results were obtained with a Gd–DTPA (diethylene‐triaminepentaacetic acid) chelate, CLaNP‐1, bound in the same bidentate manner to the protein. This study demonstrates that bidentate attachment of a paramagnetic probe enables determination of long‐range distances.
Characterizing Ionic Liquids as Reaction Media through a Chemical Probe
Authors: Dichiarante Valentina , Betti Cecilia , Fagnoni Maurizio , Maia Angelamaria , Landini Dario , Albini Angelo
Published: November 2006

The triplet N,N‐dimethylaminophenyl cation, a highly reactive but chemospecific electrophile, has been used as a probe for characterizing the properties of reaction media for a series of imidazolium ILs. With the N‐hexyl‐N‐methyl imidazolium derivatives (not with the N‐butyl analogues), hydrogen transfer leading to the aniline was the main process. Trapping by iodide occurred with an inverse dependence on viscosity. Trapping by π nucleophiles exhibited a more complex behavior. This was explained by the effect of both the bulk viscosity and the structure of the IL cation on both steps of the reaction, namely, initial electrophilic attack and ensuing cation elimination or nucleophile addition. However, with an excellent nucleophile, such as thiophene, or when the latter step was intramolecular, as with 4‐pentenol, the difference was obliterated and trapping became uniform. Incorporation of the probe into the IL cation (through insertion into the CH bond α to the imidazolium ring) was demonstrated, while no addition to the anion tested (including bis(trifluoromethanesulfonimide)) took place.
Mechanistic Insights into Stereoselective Catalysis—The Effects of Counterions in a CuII–Bissulfoximine‐Catalyzed Diels–Alder Reaction
Authors: Bolm Carsten , Martin Marc , Gescheidt Georg , Palivan Cornelia , Stanoeva Tsvetanka , Bertagnolli Helmut , Feth Martin , Schweiger Arthur , Mitrikas George , Harmer Jeffrey
Published: November 2006

The initial steps of an enantioselective Diels–Alder reaction catalyzed by a CuII–bissulfoximine complex were followed by EXAFS (EXAFS=extended X‐ray absorption fine structure), EPR (EPR=electron paramagnetic resonance) spectroscopy (CW‐EPR, FID‐detected EPR, pulse ENDOR, HYSCORE; CW=continuous wave; ENDOR=electron nuclear double resonance; HYSCORE=hyperfine sublevel correlation; FID=free induction decay), and UV‐visible spectroscopy. The complexes formed between the parent CuX2 (X=Cl−, Br−, TfO−, SbF6−) salts, the chiral bissulfoximine ligand (S,S)‐1, and N‐(1‐oxoprop‐2‐en‐1‐yl)oxazolidin‐2‐one (2) as the substrate in CH2Cl2 were investigated in frozen and fluid solution. In all cases, penta‐ or hexacoordinated CuII centers were established. The complexes with counterions indicating high stereoselectivity (TfO− and SbF6−) reveal one unique species in which substrate 2 binds to pseudoequatorial positions (via O atoms), shifting the counterions to axial locations. On the other hand, those lacking stereoselectivity (X=Cl− and Br−) form two species in which the parent halogen anions remain at equatorial positions preventing the formation of geometries compatible with those found for X=TfO− and SbF6−.
Synthesis of polymer‐type chiral stationary phases and their enantioseparation evaluation by high‐performance liquid chromatography
Authors: Huang Shao‐Hua , Bai Zheng‐Wu , Yin Chuan‐Qi , Li Shi‐Rong , Pan Zhi‐Quan
Published: November 2006

Two new chiral polymers of different molecular weights were synthesized by the copolymerization of (1R,2R)‐(+)‐1,2‐diphenylethylenediamine, phenyl diisocyanate and terephthaloyl chloride. The polymers were immobilized on aminated silica gel to afford two chiral stationary phases. The polymers and the corresponding chiral stationary phases were characterized by Fourier transform‐IR, elemental analysis, 1H and 13C NMR. The surface coverages of chiral structural units on the chiral stationary phases were estimated as 0.27 and 0.39 mmol/g, respectively. The enantioseparation ability of these chiral stationary phases was evaluated with a variety of chiral compounds by high‐performance liquid chromatography. The effects of the organic additives, the composition of mobile phases, and the injection amount of sample on enantioseparation were investigated. A comparison of enantioseparation ability between these two chiral stationary phases was made. It was believed that the chain length of polymeric chiral selector significantly affected the enantioseparation ability of corresponding chiral stationary phase. Chirality, 2007. © 2006 Wiley‐Liss, Inc.
Enantioselective reduction of ketones with borane catalyzed by tridentate amino alcohols derived from salicylaldehyde
Authors: Lee Dong‐Sheng
Published: November 2006

In the presence of tridentate chiral ligand 4e, 99% e.e. value was obtained by asymmetric reduction of ethyl benzoylacetate with borane in toluene at 25°C. Various ligands and reaction conditions were investigated to develop a reasonable mechanism that explains the experimental outcomes. Chirality, 2007. © 2006 Wiley‐Liss, Inc.
Technologien für den Klimaschutz und ihre Anforderungen an Werkstoffe
Authors: Kranzmann A. , Hünert D.
Published: November 2006

Der Klimaschutz erfordert die Reduzierung des Ausstoßes von Kohlendioxid. Neue Kraftwerke mit Sauerstoffverbrennung und möglicherweise CO2‐Abscheidung sollen eine Reduktion des CO2 im Bereich der Energietechnik ermöglichen. Die heute üblichen Hochtemperaturwerkstoffe werden anderen Umgebungsbedingungen ausgesetzt, und es sind andere Korrosionsraten und Korrosionsreaktionen zu erwarten. In diesem Beitrag werden die Kraftwerkstechnologien kurz vorgestellt und an einem Beispiel erläutert, dass die Oxidation an Luft mit der Oxidation in Wasser nicht direkt vergleichbar ist.
Ein fotochromes Silberhalogenid/Gelatine‐System
Authors: Gahler S. , Harenburg J.
Published: November 2006

Durch Verwendung von niederwertigen Metallionen wie Kupfer(I)‐ und Eisen(II)‐ionen als Zusatz zu Silberhalogenid/Gelatine‐Emulsionen können fotochrome Schichten erzeugt werden. Entgegen den Erwartungen kann dabei die für die fotografischen Eigenschaften der Silberhalogenide unerlässliche Irreversibilität des Belichtungsvorganges in einen für die Fotochromie notwendigen reversiblen Vorgang umgewandelt werden. Durch Dotierung des Silberhalogenids mit weiteren Fremdionen können die Eigenschaften des fotochromen Systems, z. B. die Schichtfarbe, beeinflusst werden.
Neues Verfahren zur Reduzierung des Abwassers und Optimierung der Abwasserqualität bei der Herstellung von DNT
Authors: Winterbauer H.
Published: November 2006

Bei der Herstellung von Dinitrotoluol (DNT) fallen verschiedene Abwasserströme an, die unterschiedlich stark organisch und anorganisch verunreinigt sind und in der Regel aufwendig behandelt werden müssen. Daher gilt es die Abwasserströme. In dem vorgestellten neuen Verfahren werden verschiedene Prozessschritte eingeführt, um Abwässer unterschiedlicher Qualität zu erhalten, die an verschiedenen Stellen wieder in den Produktionsprozess zurückgefahren werden können. Zusätzlich senkt das Verfahren die Investitions‐ und Betriebskosten von Anlagen zur Herstellung von DNT beträchtlich.
Untersuchung von Konvektion und Segregation in Sandschüttungen bei harmonischen Schwingungen
Authors: Leschinski J. , Grochowski R. , Walzel P.
Published: November 2006

In der vorliegenden Arbeit sollen grundlegende Fragen zur Partikelbewegung und Entmischungsneigung granularer Stoffe geklärt werden. In der Vergangenheit wurden hier häufig ideale Systeme betrachtet, z. B. zweidimensionale Systeme oder Schüttungen aus Glas‐ oder Metallkugeln, die durch ihre regelmäßige Form sowie ihre niedrige Reibung nicht unbedingt den Eigenschaften realer Feststoffe mit unregelmäßiger Form, rauer Oberfläche und breiter Korngrößenverteilung entsprechen. Es wird untersucht, ob die gleichen Gesetzmäßigkeiten wie in idealen Systemen auch in technisch relevanten Systemen wieder zu finden sind und ob eine Beschreibung der Vorgänge mit den aus idealen Systemen hergeleiteten theoretischen Überlegungen möglich ist. In der hier betrachteten Behälterfüllung aus Sandpartikeln mit Korngrößen‐ und Formverteilung kommt es aufgrund von starken Konvektionsströmungen für alle betrachteten Maschinenkennziffern KV auch bei sehr großer Partikelgrößendifferenz zu keiner Entmischung. Ferner wird ein signifikanter Unterschied zwischen Form und Richtung der Konvektionsbewegung in der vorliegenden Schüttung und den Konvektionsströmungen in idealen Anordnungen beobachtet.
Lumineszenzmethode zur zeitlich und örtlich hochaufgelösten Messung von Temperaturverteilungen in einem beheizten welligen Flüssigkeitsfilm
Authors: Schagen A. , Modigell M.
Published: November 2006

Vorgestellt wird eine optische Messmethode, mit der erstmalig Temperaturverläufe in einer Einzelwelle einer laminar‐welligen dünnen Filmströmung experimentell ermittelt werden konnten. Mit den ermittelten Temperaturverteilungen wird der Verlauf des lokalen Wärmeübergangskoeffizienten erhalten. Dieser gibt genaueren Aufschluss, in welchen Bereichen der Wellen eine Transportverbesserung auftritt. Mit der Variation der Betriebsbedingungen lassen sich die Transportverhältnisse gezielt beeinflussen. Ebenso lassen sich kritische Zustände, wie Aufreißen der Filmströmung aufgrund lokaler Überhitzung, genauer abschätzen.
Der Walzengranulator, eine neuartige Kompaktier‐ und Granuliermaschine
Authors: Albers A.
Published: November 2006

Mit dem vorgestellten Walzengranulator steht jetzt ein neuartiges Verfahren für bisher nicht oder nur schwierig verarbeitbare Produkte zur Verfügung. Es lassen sich schwer fließfähige Schüttgüter kompaktieren und granulieren. Bisher nicht granulierbare, sehr temperaturempfindliche, chemisch reaktive oder lösungsmittelenthaltende Produkte können entgast, entfeuchtet oder gekühlt werden. Der Walzengranulator bewerkstelligt den Kompaktiervorgang und den Granulierprozess in einem Schritt.
Development of a fundamental‐solution‐less boundary element method for exterior wave problems
Authors: Song Chongmin , Bazyar Mohammad Hossein
Published: November 2006

A fundamental‐solution‐less boundary element method, the scaled boundary finite‐element method, has been developed recently for exterior wave problems. In this method, only the boundary is discretized yielding a reduction of the spatial dimension by one, but no fundamental solution is necessary. Seamless coupling with standard finite elements is straightforward. In this paper, the sparsity of the coefficient matrices of the scaled boundary finite‐element equation is exploited in performing the partial Schur decomposition to reduce the required computer memory and time. The Gauss–Lobatto–Legendre shape functions with nodal quadrature are applied to the elements on boundary, which leads to lumped coefficient matrices and high‐order elements. Numerical examples demonstrate that these advances, in combination with the Padé series solution for the dynamic stiffness matrix, increase significantly the computational efficiency of the scaled boundary finite‐element method. Copyright © 2006 John Wiley & Sons, Ltd.
Nitric oxide‐dependence of satellite stem cell activation and quiescence on normal skeletal muscle fibers
Authors: Wozniak Ashley C. , Anderson Judy E.
Published: November 2006

Satellite cells (quiescent precursors in normal adult skeletal muscle) are activated for growth and regeneration. Signaling by nitric oxide (NO) and hepatocyte growth factor (HGF) during activation has not been examined in a model that can distinguish quiescent from activated satellite cells. We tested the hypothesis that NO and HGF are required to regulate activation using the single‐fiber culture model. In normal fibers, HGF and inhibition of NO synthase (NOS) each increased activation without stretching, and NOS inhibition reduced stretch‐activation. Activation in unstretched mdx and NOS‐I(−/−) fibers was three‐ to fourfold higher than normal, and was reduced by stretching. Distinctions were not due to different pax7‐expressing populations on normal and mdx fibers. The population of c‐met–expressing satellite cells on normal fibers was increased by stretch, demonstrating functional heterogeneity among normal satellite cells. Cycloheximide did not prevent the stretch‐related increase in c‐met expression, suggesting c‐met may be an immediate–early gene in satellite cell activation. Results have important implications for designing new therapies that target the role of exercise in health, aging, and disease. Developmental Dynamics 236:240–250, 2007. © 2006 Wiley‐Liss, Inc.
BMP type I receptor ALK2 is essential for proper patterning at late gastrulation during mouse embryogenesis
Authors: Komatsu Yoshihiro , Scott Gregory , Nagy Andre , Kaartinen Vesa , Mishina Yuji
Published: November 2006

Bone morphogenetic proteins (BMPs) have multiple functions during vertebrate development. Previously, it was shown that BMP type I receptor ALK2 (also known as ACVRI, ActRI, or ActRIA) was important for normal mouse gastrulation by deleting exon 4 or exon 5 of Alk2. Recently, flanking exon 7 by loxP sites generated a conditional allele for Alk2. To assess whether the deletion of exon 7 causes functional null of ALK2, and does not produce a dominant negative form or a partially functional form of ALK2, we performed a comparative analysis between Alk2 homozygous mutant embryos with an exon 5 deletion (Alk2Δ5/Δ5) and embryos with an exon 7 deletion (Alk2Δ7/Δ7). Both Alk2Δ5/Δ5 and Alk2Δ7/Δ7 mutants showed identical morphological gastrulation defects. Histological examinations and molecular marker analyses revealed identical abnormal gastrulation phenotypes in Alk2Δ5/Δ5 and Alk2Δ7/Δ7 mutants. Although Fgf8 was expressed in the primitive streak of Alk2Δ5/Δ5 and Alk2Δ7/Δ7 mutants, Brachyury, Wnt3a, and Tbx6 were dramatically downregulated in Alk2Δ5/Δ5 and Alk2Δ7/Δ7 mutants. These results indicate that deletion of exon 7 for Alk2 leads to a functionally null mutation in vivo, and Alk2 is crucial for sustaining the proper gastrulation events in early mouse embryogenesis. Developmental Dynamics 236:512–517, 2007. Published 2006 Wiley‐Liss, Inc.
Inhibition of Sonic hedgehog signaling leads to posterior digit loss in Ambystoma mexicanum: Parallels to natural digit reduction in urodeles
Authors: Stopper Geffrey F. , Wagner Günter P.
Published: November 2006

Molecular mechanisms patterning the tetrapod limb, including anterior‐posterior axis determination involving Sonic hedgehog (Shh), have received much attention, particularly in amniotes. Anterior‐posterior patterning in urodele amphibians differs radically from that of amniotes in that it shows a pronounced anterior‐to‐posterior sequence of digit development. In contrast, amniotes develop their digits almost simultaneously with a slight posterior‐to‐anterior polarity. Here we use cyclopamine, an inhibitor of the Hedgehog signaling pathway, to investigate the role of Shh in anterior‐posterior patterning in the urodele limb. Inhibition of Shh signal transduction affects digit number long before their morphological appearance. In accordance with the apparently derived order of digit development in urodeles, exposure reproducibly removes digits in a posterior‐to‐anterior sequence, the inverse of their developmental sequence. This pattern of digit loss mimics the order of digit loss in natural variation. We suggest that variation in Shh expression and/or signal transmission may explain natural variation in digit number in urodeles. Developmental Dynamics 236:321–331, 2007. © 2006 Wiley‐Liss, Inc.
Studying drug–plasma protein interactions by two‐injector microchip electrophoresis frontal analysis
Authors: Liu Xiaojun , Liang Aiye , Shen Zheng , Liu Xin , Zhang Yu , Dai Zhongpeng , Xiong Bohui , Lin Bingcheng
Published: November 2006

We developed a simple, rapid, and sensitive two‐injector microchip electrophoresis frontal analysis (MCE‐FA) method for studying drug–plasma protein interactions. In this method, large volumes of a reference sample and drug–plasma protein mixture were simultaneously introduced into the respective sections of the microchannel through the separated injectors and then electrophoresed. Since the reference sample did not meet with the interacting species during migration, it could be used as an external standard. The interaction between heparin and HSA was quantitatively characterized as a model system. The binding constant was found to be (1.53 ± 0.01)×104 M&−1.
Micro freef‐low IEF enhanced by active cooling and functionalized gels
Authors: Albrecht Jacob W. , Jensen Klavs F.
Published: November 2006

Rapid free‐flow IEF is achieved in a microfluidic device by separating the electrodes from the focusing region with porous buffer regions. Moving the electrodes outside enables the use of large electric fields without the detrimental effects of bubble formation in the active region. The anode and cathode porous buffer regions, which are formed by acrylamide functionalized with immobilized pH groups, allow ion transport while providing buffering capacity. Thermoelectric cooling mitigates the effects of Joule heating on sample focusing at high field strengths (∼500 V/cm). This localized cooling was observed to increase device performance. Rapid focusing of low‐molecular‐weight pI markers and Protein G–mouse IgG complexes demonstrate the versatility of the technique. Simulations provide insight into and predict device performance based on a well‐defined sample composition.
Genotyping with microfluidic devices
Authors: Szántai Eszter , Guttman András
Published: November 2006

In the past few years, electrophoresis microchips have been increasingly utilized to interrogate genetic variations in the human and other genomes. Microfluidic devices can be readily applied to speed up existing genotyping protocols, in particular the ones that require electric field‐mediated separations in conjunction with restriction fragment analysis, DNA sequencing, hybridization‐based techniques, allele‐specific amplification, heteroduplex analysis, just to list the most important ones. As a result of recent developments, microfabricated electrophoresis devices offer several advantages over conventional slab‐gel electrophoresis, such as small sample volume requirement, low reagent consumption, the option of system integration and easy multiplexing. The analysis speed of microchip electrophoresis is significantly higher than that of any other electric field‐mediated separation techniques. State‐of‐the‐art microfluidic bioanalytical devices already claim their place in most molecular biology laboratories. This review summarizes the recent developments in microchip electrophoresis methods of nucleic acids, particularly for rapid genotyping, that will most likely play a significant role in the future of clinical diagnostics.
Optimizing the Production of Bacterial Cellulose in Surface Culture: Evaluation of Product Movement Influences on the Bioreaction (Part 2)
Authors: Hornung M. , Ludwig M. , Gerrard A. M. , Schmauder H.‐P.
Published: November 2006

The common way for the production of bacterial cellulose in surface culture is to use culture boxes or beakers with vertical walls, where the maximum achievable thickness is around 4 cm. In order to improve this, it is necessary to study factors limiting the production. In part 1, the mass transfer influences of the substrate have been investigated. Now we look at a “wall effect”. It is noted that the growing cellulose is in contact with the wall of the box or beaker, and moves downwards into the nutrient broth as time proceeds. Experiments have been carried out where this wall contact was eliminated and a constant rate of production over several weeks was found. This indicates the importance of understanding the role of the wall in the usual surface culture.
Kinetic Traits and Enzyme Form Patterns of (R)‐2‐(2,4‐Dichlorophenoxy)propionate/α‐Ketoglutarate Dioxygenase (RdpA) after Expression in Different Bacterial Strains
Authors: Westendorf A. , Benndorf D. , Pribyl T. , Harms H. , Müller R. H.
Published: November 2006

The rdpA gene of strains Delftia acidovorans MC1, Rhodoferax sp. P230, and Sphingobium herbicidovorans MH proved to be identical. However, when RdpA [(R)‐2‐(2,4‐dichlorophenoxy)propionate/α‐ketoglutarate dioxygenase] was investigated after purification from the various strains, significant differences in the kinetics and some chemical properties of the enzymes were observed. The preference for substrates ranged in the order (R)‐2‐(2,4‐dichlorophenoxy)propionate (2,4‐DP) > (R)‐2‐(4‐chloro‐2‐methylphenoxy)propionate (MCPP) >> 2,4‐dichlorophenoxyacetate (2,4‐D) ∼ 4‐chloro‐2‐methylphenoxyacetate (MCPA), but detailed kinetic investigations revealed significant strain‐dependent differences in the kcat and KM values. While the KM values of RdpA from the various strains were low and their range rather narrow with 2,4‐DP (19–60 μM) and MCPP (35–64 μM), larger differences were observed with phenoxyacetates which were distinctly higher and spanned a wider range with 2,4‐D (237–935 μM) and MCPA (164–510 μM). The lowest KM values with 2,4‐D and MCPA were found for RdpA originating from strain P230. Investigation of the enzymes from the various sources by 2D gel electrophoresis revealed up to three monomeric enzyme forms which differed in the pI value. The 2D‐patterns were similar with RdpA from strains MC1 and MH, and after heterologous expression of the enzyme in Escherichia coli, but differed significantly from that of strain P230. The presence of enzyme forms and their different composition coincided apparently with the differences observed in the kinetic properties of RdpA in the various strains. The effects are discussed in terms of posttranslational modification of RdpA which appears to be different in extent and kind in the various strains.
Characterization of the native CREB3L2 transcription factor and the FUS/CREB3L2 chimera
Authors: Panagopoulos Ioannis , Möller Emely , Dahlén Anna , Isaksson Margareth , Mandahl Nils , Vlamis‐Gardikas Alexios , Mertens Fredrik
Published: November 2006

CREB3L2 was first identified as the 3′‐partner of FUS in a fusion gene that seems to be specific for low grade fibromyxoid sarcoma. In silico analyses suggest that the predicted CREB3L2 protein is a member of the CREB3 family of transcription factors, with its bZIP domain being highly similar to that in CREB3L1, CREB3L3, CREB3L4, CREB3, and Drosophila Bbf‐2. In the present study, the authors assessed various cellular outcomes after transfection of NIH3T3 and HEK‐293 cells with constructs containing full‐length and truncated versions of CREB3L2 and FUS/CREB3L2. Northern blot of CREB3L2 mRNA revealed a 7.4 kbp band that contains 0.4 kbp and 5.5 kbp untranslated 5′ and 3′ regions, respectively. CREB3L2 constructs containing the first 120 amino acids (aa) showed the highest transcriptional activation. Much stronger transcriptional activation was consistently seen for the FUS/CREB3L2 constructs than for the corresponding CREB3L2 constructs. Transcriptional activity was achieved through the box‐B element, ATF6 and CRE binding sites, as well as the GRP78 promoter. Proteins encoded by full‐length CREB3L2 and FUS/CREB3L2 were localized to reticular structures of the cytoplasm, whereas the corresponding, truncated proteins lacking the transmembrane domain and the carboxy‐terminal part of CREB3L2 resided within the nucleus. The results of the present study show that CREB3L2 is not only structurally, but also functionally very similar to CREB3L1. Thus, studies regarding the pathways influenced by wild‐type CREB3L2 should provide valuable clues to the pathogenetic significance of the FUS/CREB3L2 chimera in low grade fibromyxoid sarcoma. © 2006 Wiley‐Liss, Inc.
The spectrum of equitable, 4‐chromatic Steiner quadruple systems
Authors: Linek Vaclav
Published: November 2006

A Steiner quadruple system of order v (briefly an SQS(v)) is a pair (X,$\cal B$) with |X| = v and $\cal B$ a set of quadruples taken from X such that every triple in X is in a unique quadruple in $\cal B$. Hanani [Canad J Math 12 (1960), 145–157] showed that an SQS(v) exists if and only if v is {admissible}, that is, v = 0,1 or v ≡ 2,4 (mod 6). Each SQS(v) has a chromatic number when considered as a 4‐uniform hypergraph. Here we show that a 4‐chromatic SQS(v) exists for all admissible v ≥ 20, and that no 4‐chromatic SQS(v) exists for v < 20. Each system we construct admits a proper 4‐coloring that is equitable, that is, any two color classes differ in size by at most one. © 2006 Wiley Periodicals, Inc. J Combin Designs 15: 369–392, 2007
A global time domain circuit simulation of a microwave rectenna
Authors: Essakhi Brahim , Akoun Gilles , Pichon Lionel
Published: November 2006

The paper presents a global time domain simulation of a microwave rectenna studied for wireless energy transfer. The novelty of the work is to take into account both distributed electromagnetic parts of the antenna and the rectifier circuit including lumped elements. From a 3D finite element time domain electromagnetic modelling of the structure an equivalent circuit of the antenna is deduced: the input impedance is obtained as a function of frequency over a broad band. Then a rational approximation gives a corresponding PSPICE representation. The electromotive force induced between the ports of the antenna during the microwave illumination is directly computed from the 3D transient scattering problem. The resulting equivalent circuit of the antenna is finally incorporated into the electronic simulator PSPICE, together with the lumped components of the rectenna (ideal diodes and load). Thus a global non‐linear time domain analysis of the whole structure becomes available. The results obtained with the methods presented in the paper are compared with those resulting from other techniques. The approach developed in the work could efficiently improve the design stage of rectennas devoted to microwave power transfer. Copyright © 2006 John Wiley & Sons, Ltd.
TLM node with arbitrary embedded objects
Authors: Biwojno Konrad , Smartt Chris , Sewell Phillip , Liu Yafang , Christopoulos Christos
Published: November 2006

This contribution is an extension of the authors' work in modelling multi‐scale systems which are of significant importance in many applications such as Electromagnetic Compatibility (EMC). By its very nature EMC analysis often requires consideration of systems characterized by many different physical scales, for example when thin wires, gaps and slots are present in otherwise physically large structures. For the Transmission Line Modelling (TLM) simulation method, nodes that explicitly embed fine structures smaller than the mesh size within them have previously been demonstrated for a number of special cases where the fields in close proximity to the object may be represented in terms of known local analytic solutions. This approach enables the presence of general sub cell objects to be correctly and efficiently modelled in coarse grids without incurring excessive computational effort. The work presented here differs in that it permits the use of purely numerical calculations of these local fields and therefore provides a powerful extension to more general structures for which local analytic field representations are unavailable. A full derivation of the formulation in terms of these local solutions is discussed as well as the procedure for linking them to the rest of the numerical network. Illustrative results are then obtained from an application to a canonical scattering problem. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of stationary phase polarity on the retention of ionic liquid cations in reversed phase liquid chromatography
Authors: Kowalska Sylwia , Buszewski Boguslaw
Published: November 2006

Chromatographic analysis of ionic liquids on different types of packings offers interesting possibility to determine their retention mechanism. As a consequence, the major interactions between stationary phase ligands and analyzed chemical entities can be defined. The main aim of this work was to analyze cations of ionic liquids on chemically bonded stationary phases with specific structural properties. The attempt to predict the main interactions between positive ions of ionic liquids and stationary phase ligands was undertaken. For that purpose, butyl, octyl, octadecyl, phenyl, aryl, mixed, alkylamide, and cholesterolic packings were chosen and applied to the analysis of six most commonly used ionic liquids' cations. Obtained results indicate mainly dispersive and π–π type of interaction part in the retention mechanism of analyzed compounds.
Compact bandpass filter using open‐loop resonators with capacitive loading
Authors: Zhang Xiu Yin , Chen Jian‐Xin , Xue Quan
Published: November 2006

A novel compact microstrip bandpass filter, based on open‐loop resonators with capacitive loading, is presented in this paper. The new filter has the advantages of compact size together with sharp rejection. Compared with the conventional filters using square open‐loop resonator, the proposed filter has a size reduction of 45%. A demonstration filter was designed, fabricated, and measured. Theoretical and experimental results are presented and show good agreement. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 83–84, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22035
CAD formula of microstrip line on two‐layer substrate with loss by synthetic asymptote
Authors: Tang Wanchun , Jiang Baozheng , Chow Y. Leonard
Published: November 2006

A simple CAD formula is obtained in this paper for microstrip line on lossy substrate of two layers (silicon‐oxide and silicon) by synthetic asymptote. The formulas are simple, accurate (error <2%) and therefore give good physical insights. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 52–55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22037
Novel compact bandpass filters with wide controllable fractional bandwidth
Authors: Mandal M. K. , Mondal P. , Sanyal S. , Chakrabarty A.
Published: November 2006

In this letter, a novel compact structure is proposed for bandpass filter (BPF) design. The structure is realized using only one resonator. The resonator is excited by two open microstrip stubs. Further, ground plane aperture technique is used to obtain wide bandwidth. 3‐dB fractional bandwidth can be varied between 1.0 and 90.0% with good in band as well as out of band filter characteristics. The filter has the advantages of compactness, wide bandwidth, low insertion loss (IL), and ease of fabrication. A prototype fabricated filter of FBW 45.1% and passband center frequency f0 = 3.795 GHz shows a maximum passband IL of 2.0 dB. The basic BPF occupying area is less than 0.22 λg × 0.23 λg, where λg is the guided wavelength at f0. A simple stub modification extends its upper stopband at least three times the upper cutoff frequency. Good agreement between measurements and simulations are obtained. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 29–31, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22039
New balanced UWB planar antenna
Authors: Guo Y. X. , Ruan Y. F. , Zhang Z. Y. , Ong L. C. , Shi X. Q.
Published: November 2006

A new balanced planar ultra‐wideband (UWB) antenna is proposed. First, a novel uniplanar broadband balun transition is presented. Then, a balanced UWB planar dipole antenna fed by the proposed balun is studied, and has a measured bandwidth from 2.8 to 11.2 GHz for the return loss better than −10 dB. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 114–118, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22040
A novel concept for reconfigurable frequency selective surfaces based on silicon switches
Authors: Liang Xiaotao , Werner Douglas H. , Weiner Brian
Published: November 2006

The authors describe a novel concept for reconfigurable frequency selective surfaces based on metallic dipole and cross‐dipole elements connected by switches on an exposed silicon substrate. As the conductivity of silicon can be varied over a large dynamic range by photonic excitation, it represents a good candidate substrate material for producing effective switches. The genetic algorithm was used to obtain optimal performance of the switch with respect to variations of the geometric and electrical parameters of the design for desired excitation frequencies. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 109–114, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22041
Novel distributed planar negative refractive index material
Authors: Karmakar N. C. , Balbin I.
Published: November 2006

A novel distributed microstrip negative refractive index material (NRI) is presented, which comprises of microstrip line sections loaded with interdigital capacitance and short‐circuited stub inductance. This new NRI removes the discrete lumped components and associated fabrication problems of conventional NRI. Simulation and experimental results show that the novel distributed NRI yields larger passbands and more distinct stopbands. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 48–51, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22044
The robust design for gapless microlens array fabrication using the incomplete developing and thermal reflow process
Authors: Hung Shih‐Yu , Chen Shih‐Nung , Lin Che‐Ping , Yang Hsiharng
Published: November 2006

A systematic approach to achieving high quality gapless microlens array fabrication using the incomplete developing and thermal reflow process was developed in this study. The experimental results proved that a hexagonal microlens array with a maximum 100% fill‐factor could be successfully produced. The major objective in using this robust design is to reduce the variations in microlens array focal length, allowing improved focus and enhanced illumination brightness. In this experiment, the Taguchi method was used first to perform an efficient experimental design and analyze the robustness of the microlens array fabrication process. Several parameters affect microlens array uniformity; the hexagonal column diagonal, spin coating revolution speed, exposure time, developing time, and reflow temperature. It is very important to control these parameters to decrease the sensitivity to noise. Therefore an artificial neural network (ANN) was used to minimize the variation and make the microlens array less sensitive to process variation. The L18orthogonal array was used as the learning data for the ANN to construct an ANN model that could predict the parameters at nondiscrete levels. The results showed the microlens array quality was significantly improved compared with the original design. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 23–29, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22046
An improved design of harmonic suppression for microstrip patch antennas
Authors: Mandal M. K. , Mondal P. , Sanyal S. , Chakrabarty A.
Published: November 2006

Harmonic suppression is an important factor for active microstrip patch antennas radiating harmonic frequencies. Here, a novel compact low pass filter (LPF) having high filter selectivity and wide stop band is used on the microstrip feed line of the patch antenna. The 15 dB LPF stopband exist over 10 GHz while implementing area is 0.1464λg × 0.1789λg at the cutoff frequency of 3.55 GHz. The fundamental antenna operating frequency falls in the passband of the LPF. The other harmonics falls in the LPF stopband and thus attenuated. An example shows up to fourth harmonic are suppressed while total occupying area remains compact. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 103–105, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22049
ASiGeHBT variable gain low noise amplifier with on‐chip active balun design
Authors: Yeh Ping‐Chun , Yang Tsung‐Yu , Liu Wei‐Cheng , Chiou Hwann‐Kaeo
Published: November 2006

A variable gain low noise amplifier (VGLNA) using a 0.35 μm SiGe HBT process is described. A VGLNA with linear gain control and high linearity has been developed for 2.4 GHz ISM band applications. The gain control circuit is achieved without degrading either the input or the output VSWR. This technique can also simultaneously realize low noise figure and high linearity. The designed VGLNA achieved a gain of 19 dB, a noise figure of 2.7 dB, a third‐order intercept point of −12 dBm, and a linear gain control range of 7.2 dB. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 42–45, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22052
Microstrip dual‐band bandpass filter using slow‐wave resonators for WLAN applications
Authors: Guan Xuehui , Ma Zhewang , Cai Peng , Anada Tetsuo , Hagiwara Gen
Published: November 2006

A dual‐band bandpass filter using microstrip slow‐wave resonators is developed for wireless local area network applications. The fundamental and higher order resonant harmonics of a microstrip open‐loop resonator are analyzed against the length of the loading open stub. Then a dual‐band bandpass filters is designed in the form of slow‐wave open‐loop resonators. A zero‐degree feed structure is employed to produce transmission zeros near the passband to increase the rate of attenuations, and a quarter‐wavelength feed line for impedance matching is added to get desired external quality factor at the input and output. The theoretical analysis and design procedures are successfully verified by experimental results. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 14–16, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22055
Comparison of switching properties between 10 Gb/s RZ and NRZ signal format utilizing 4 × 4 optical crosspoint switch matrix
Authors: Wang Zhuoran , Chi Nan , Yu Siyuan
Published: November 2006

ABSTRACT: We experimentally demonstrate optical packet switching with less than 8 ns switching speed for a 10 Gb/s return‐to‐zero (RZ) and non‐return‐to‐zero (NRZ) payload using a 4 × 4 optical crosspoint switch (OXS) matrix. Good waveforms and less than 0.8 dB power penalty show that RZ coding is better than NRZ. The wavelength dependence of the OXS is also investigated in terms of the receiver sensitivity and the output OSNR. Very good switching performance can be achieved from 1535 to 1561 nm. Our results suggest that the OXS can be a promising device for switching future high speed impulse coded signals. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 68–71, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22058
Compact designs of a shorted triangular patch antenna with a V slot
Authors: Sim Chow‐Yen‐Desmond , Han Tuan‐Yung
Published: November 2006

The compact designs of a shorted triangular patch antenna embedded with a V slot are proposed and studied. A broadband V‐slotted triangular patch antenna with one shorting wall is initially constructed as a reference. By inserting an additional shorting wall to this reference antenna, a new broadband operation can be obtained and its operating frequency is decreased by 22%, which corresponds to a reduction of 40% in the antenna area. The antenna area can be further reduced by symmetrically halving the patch size, and it is found that the impedance bandwidth of the broadband operation demonstrated no obvious variation and the operating frequency is only increased by around 8%. Details of the antenna designs and obtained results are presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 34–37, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22061
A self‐similar fractal electromagnetic band‐gap structure in the power plane with broadband suppression of ground bounce noise
Authors: Zhou Peng , Zhao Junming , Feng Yijun
Published: November 2006

In this paper, a self‐similar fractal electromagnetic band‐gap structure with “L‐Cross ” slots is proposed and designed in the power plane to suppress the ground bounce noise in high‐speed circuits. Both the simulation and the measured results with good agreement with each other show a low onset band stop frequency of 500 MHz and a broad stop band of about 4 GHz. When combining the structure with decoupling capacitor walls at the boundary of the power plane, a broadband GBN suppression from DC to 6 GHz can be obtained. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 190–192, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22063
A parallel coupled‐line bandpass filter with wide stopband using slotted ground structures
Authors: Weng Min‐Hang , Wu Hung‐Wei , Chang Yu‐Chi , Huang Chun‐Yueh , Su Yan‐Kuin
Published: November 2006

This letter proposes a parallel coupled‐line bandpass filter (BPF) using the folded slotted ground structures (SGSs) to improve the wide stopband. It is shown that the designed folded SGS has a very small area in comparison of previous works. The folded SGS exhibits a dual stopband characteristic owing to the bandgap resonant characteristic of SGS to suppress the harmonic frequency of the parallel coupled‐line BPF. Good agreement with electro‐magnetic simulation and measurement is demonstrated. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 159–162, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22065
Low‐phase‐noise transformer‐based top‐series QVCO using GaInP/GaAs HBT technology
Authors: Meng C. C. , Tseng S. C. , Chang Y. W. , Su J. Y. , Huang G. W.
Published: November 2006

The fully integrated GaInP/GaAs heterojunction bipolar transistor, transformer‐based top‐series quadrature voltage controlled oscillator (QVCO) is demonstrated at 4 GHz. The transformers on the semi‐insulating GaAs substrate possess good electrical properties at high frequencies. The QVCO at 4.1 GHz has phase noise of −120 dBc/Hz at 1 MHz offset frequency, output power of 2 dBm and the figure of merit −178 dBc/Hz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 215–218, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22067
The mathematical group of scattering matrices: Introduction of scattering matrix multiplication
Authors: Buccafusca Osvaldo
Published: November 2006

This paper provides a new step towards a mathematical foundation for S‐matrices. It introduces a new operation, the S‐matrix multiplication, and defines the mathematical group of S‐matrices, allowing the power of Group Theory to be applied to S‐parameter network analysis. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 179–183, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22070
Full‐wave analysis of a new designed wide band microstrip filter using the novel method of lines
Authors: Hashish Essam A. , Saker Hossam A.
Published: November 2006

A wide band small size microstrip filter is designed based on a full wave analysis achieved through a novel method of lines. Such a novel method enables the analysis of structures having either short or long interconnections between single discontinuities, and it reduces the discretization window through nonequidistant discretization. In the full‐wave analysis, the scattering parameters of the designed filter are computed, leading to an achievement of a bandwidth up to 23%. The designed filter is fabricated and tested, where good agreement is found between the numerical and experimental results. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 150–154, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22071
Microstrip‐fed slot antennas backed by a very thin cavity
Authors: Vallecchi Andrea , Gentili Guido Biffi
Published: November 2006

Slot antennas with a backing cavity for unidirectional radiation are investigated with the aim of achieving a thin structure capable of reasonably broadband operation. By tuning together the slot length and the cavity cross‐section, a very low‐profile cavity‐backed slot (CBS) is demonstrated. The cavity thickness of this slot antenna is about 10 times smaller than conventional one‐quarter wavelength cavities, which would allow constructing this antenna even with standard cost‐effective multilayer planar technology. The high gain and fairly wideband operation are the major advantages of the proposed configuration, which features a bandwidth of about 10% at a center frequency of 1.8 GHz with radiation efficiency in excess of 80%. Measured data are presented and compared with simulation results obtained by both the method of moments (MoM) and the finite integration technique (FIT). © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 247–250, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22073