bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elektrische Charakterisierung von Hochfrequenz‐Niederdruck‐Gasentladungen
Authors: Schade K. , Suchaneck G. , Albert M. , Weber J. 
Published: July 2007

AbstractIn recent years there has emerged significant interest in low pressure radio frequency (rf) glow discharges which are used widely particulary in IC fabrication. Various parameters of the rf glow discharge have been found to be useful for its electrical characterization; however, there is no uniformity and agreement.Extensive experimental investigations on various discharge systems have shown, that the self‐bias on the rf driven electrode, the complex conductivity and the breakdown characteristic are preferable parameters of rf discharges. Advantageously the self‐bias and the complex conductivity should be presented in dependence on the pressure and the applied rf voltage. The discharge current cannot be measured quite accurately due to currents via leaky capacitors and the deviations from a sinusoidal form of the current due to nonlinearities.
Probe Measurements of Wave Fluctuations Excited in Glow Discharges
Authors: Ohe K. , Tsunoda K. 
Published: July 2007

AbstractFluctuations of the electric field, the charged particle density; the electron temperature and the plasma potential are simultaneously measured by a probe in the positive column of helium glow discharge at a few torr gas pressure by exciting a small amplitude ionization wave. It is proposed that these values can be determined by analyzing the probe current.
Arc Cathode Processes in the Transition Region between Vacuum Arcs and Gaseous Arcs
Authors: Anders S. , Jüttner B. 
Published: July 2007

AbstractThe cathode processes of electric ares on cleaned Cu cathodes were investigated in the transition region between vacuum and atmospheric pressure (argon). The plasma density in the cathode plane was estimated by probe measurements to be n = r are current, r – distance from the spot). It was observed that several cathode spot parameters have an extremum at p ∼ 104 Pa. The crater diameter has a minimum independently of the cathode temperature. The diffusion constant of the chaotic motion determined by framing photographs was found to have a maximum. Some additional, large displacements occurred at that pressure. The diameter of the bright plasma cloud obtained by open‐shutter photographs showed a maximum, the current per spot was found to decrease from 20 A in vacuum to 10 A at atmospheric pressure. It is thus concluded that the spot with the smallest crater radius and a low current per spot, occurring at ∼ 104 Pa, represents the single spot, whereas the spot at higher pressures, and probably also in vacuum, has a complicated nature where the large craters are formed by a cooperation of single spots.
A Study of Ionization Front Velocity in dc Pulsed Plasmas
Authors: Dengra A. , Hernandez M. A. , Colomer V. 
Published: July 2007

AbstractThe ionization front velocity in a de cylindrical plasma is reported. This parameter has been determined as the ratio between the distance separation of two Langmuir probes, Δz, and the time Δt which is needed for the ionization front to cover the distance Δz.A theoretical model which allows to obtain the functional relationship of ionization front velocity with the stationary electron density has been developed. A good agreement, both qualitatively and quantitatively, has been obtained.
Instabilities Propagated Along the External Magnetic Field in Magnetized Active Plasmas
Authors: Krstić S. R. , Milić B. S. 
Published: July 2007

AbstractThe conditions for spontaneous onset of instabilities propagated along the external (stationary or quasi‐stationary) magnetic field in cold and magnetized active plasmas are considered in collisionless approximation. Attention is given to non‐resonant cases, i.e. to situations in which the modal frequencies of the wave significantly differ from the frequency of coherent electromagnetic radiation arising due to the active particles. It is shown that instabilities are also possible in these non‐resonant cases and that, under certain specified conditions, they develop only in a very narrow wavelength band. The pertaining amplitude increments are evaluated.
Characterization of the Edge Plasma of the CASTOR‐Tokamak
Authors: Hildebrandt D. , Jüttner B. , Jakubka K. , Stöckel J. , Žáček F. , Groetzschel R. 
Published: July 2007

AbstractThe edge plasma of the CASTOR‐tokamak was investigated by Langmuir and collector probes. Te – values derived from both methods agree satisfactorily and are in the range from 15 eV to 45 eV, depending on the minor radius and the magnitude of the discharge current. However, the collector probe measurements indicate an anisotropic plasma and impurity flow in the edge plasma.
WHOMoVeS: An optimized broadband sensor network for military vehicle tracking
Authors: Hamdi Mohamed , Boudriga Noureddine , Obaidat Mohammad S. 
Published: July 2007

AbstractWith the advance of sensing technologies and their applications, advanced sensor networks are gaining increasing interest. For certain sensitive applications, heterogeneous sensors can be deployed in the monitored space to ensure scalability, high‐speed communication, and long network lifetime. Hybrid sensor networks have capabilities to combine the use of both resource‐rich and resource‐impoverished sensor nodes. This paper proposes a heterogeneous broadband sensor network architecture for military vehicle tracking. Powerful sensor devices with good bandwidth and energy capabilities are used as a communication backbone while energy sensors are used to track moving targets. Copyright © 2007 John Wiley & Sons, Ltd.
Generation of mice with a conditional Foxp2 null allele
Authors: French Catherine A. , Groszer Matthias , Preece Christopher , Coupe Anne‐Marie , Rajewsky Klaus , Fisher Simon E. 
Published: July 2007

AbstractDisruptions of the human FOXP2 gene cause problems with articulation of complex speech sounds, accompanied by impairment in many aspects of language ability. The FOXP2/Foxp2 transcription factor is highly similar in humans and mice, and shows a complex conserved expression pattern, with high levels in neuronal subpopulations of the cortex, striatum, thalamus, and cerebellum. In the present study we generated mice in which loxP sites flank exons 12–14 of Foxp2; these exons encode the DNA‐binding motif, a key functional domain. We demonstrate that early global Cre‐mediated recombination yields a null allele, as shown by loss of the loxP‐flanked exons at the RNA level and an absence of Foxp2 protein. Homozygous null mice display severe motor impairment, cerebellar abnormalities and early postnatal lethality, consistent with other Foxp2 mutants. When crossed to transgenic lines expressing Cre protein in a spatially and/or temporally controlled manner, these conditional mice will provide new insights into the contributions of Foxp2 to distinct neural circuits, and allow dissection of roles during development and in the mature brain. genesis 45:440–446, 2007. Published 2007 Wiley‐Liss, Inc.
Induction of immunosuppressive functions of dendritic cells in vivo by CD4+CD25+ regulatory T cells: Role of B7‐H3 expression and antigen presentation
Authors: Mahnke Karsten , Ring Sabine , Johnson Theron S. , Schallenberg Sonja , Schönfeld Kurt , Storn Volker , Bedke Tanja , Enk Alexander H. 
Published: July 2007

AbstractSuppressive functions of CD4+CD25+ regulatory T cells (Treg) are mainly studied by their interaction with conventional T cells. However, there is evidence that Treg also interact with antigen‐presenting cells (APC), leading to suppression of APC function in in vitro coculture systems. Studying the in vivo distribution of Treg after injection, we found that Treg are located in direct proximity to dendritic cells (DC) and affect their functional maturation status. After contact to Treg, DC up‐regulate the inhibitory B7‐H3 molecule and display reduced numbers of MHC–peptide complexes, leading to impaired T cell stimulatory function. When Treg‐exposed DC were used to immunize animals against antigens, the DC failed to produce a robust immune response as compared to control DC. Thus, these data indicate that Treg are able to inhibit DC activation and produce an inhibitory phenotype of DC. Accordingly, Treg may recruit DC for the amplification of immunosuppression by restraining their maturation in vivo and inducing an immunosuppressive phenotype of DC.
Hsp110 and Grp170, members of the Hsp70 superfamily, bind to scavenger receptor‐A and scavenger receptor expressed by endothelial cells‐I
Authors: Facciponte John G. , Wang Xiang‐Yang , Subjeck John R. 
Published: July 2007

AbstractHeat shock protein 110 (hsp110) and glucose‐regulated protein (grp170) act as anti‐cancer vaccines when complexed to tumor antigens by heat shock. It has been proposed that receptors on antigen‐presenting cells contribute to HSP‐mediated immune responses. Here, we show that hsp110 binds in a receptor‐mediated manner to RAW264.7 macrophages, as does grp170. This hsp110/grp170 binding is inhibited by scavenger receptor ligands, suggesting a role for scavenger receptors as binding structures. We examined scavenger receptor class A (SR‐A) and scavenger receptor expressed by endothelial cells‐I (SREC‐I). We show that hsp110/grp170 binds to both SR‐A‐ and SREC‐I‐expressing CHO cells in a saturable manner and scavenger receptor ligands inhibit binding. Hsp110 also saturably binds mouse bone marrow‐derived dendritic cells (bmDC) and is inhibited by scavenger receptor ligands. When an hsp110‐rat neu (intracellular domain) heat shock complex vaccine is used to pulse mouse bmDC in vitro, an induction of IFN‐γ secretion is observed by CD8+ T lymphocytes isolated from vaccine‐immunized mice. This immune response is inhibited by the application of scavenger receptor ligands to bmDC. Thus, SR‐A and SREC‐I appear to contribute to the binding of hsp110 and grp170 on APC. Scavenger receptors, in general, contribute to the cross‐presentation of hsp110‐chaperoned protein antigen.
Ultra‐Low Catalyst Loading as a Concept in Economical and Sustainable Modern Chemistry: The Contribution of Ferrocenylpolyphosphane Ligands
Authors: Hierso Jean‐Cyrille , Beaupérin Matthieu , Meunier Philippe 
Published: July 2007

AbstractThe challenge of sustainability in modern chemistry will be met with new technologies and processes provided significant progress is made in several key research areas, such as the expansion of chemistry from renewable feedstock, the design of environmentally benign chemicals and solvents, the minimization of depletive resources, and the development of high‐performance catalysis. In this prospect, ligand chemistry is a pivotal science that links modern‐organic,‐inorganic, ‐organometallic, and ‐coordination chemistry through a vast number of valuable applications, precisely associated to catalysis. We review in this article our recent work on catalysis promoted by original ferrocenyl tetra‐, tri‐, and diphosphane ligands. New concepts, taking advantages of this family of branched multidentate ligands, have led to progress in homogeneous catalysis. The search for catalyst longevity and ultra‐low catalyst loadings (high turnover numbers), on the basis of multidentarity effects and robustness of the ferrocenyl backbone were focused on high‐value palladium‐catalyzed C–C cross‐couplings, such as Heck, Suzuki, and Sonogashira reactions. Low catalyst loading was also explored for C–N cross‐coupling in the allylic amination of achiral substrates. The advantages of this newly born family of ligands in the class of multidentate compounds are discussed in light of the valuable information gathered up to now on their reactivity, structure, and mechanistic behavior.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Recent Progress in Asymmetric Catalysis Using Chiral Carbohydrate‐Based Ligands
Authors: Diéguez Montserrat , Claver Carmen , Pàmies Oscar 
Published: July 2007

AbstractThis review describes the use of the most representative carbohydrate derivative ligands in asymmetric catalysis between 1972 and 2006 (approximately). Particular emphasis is placed on the latest results published in the most active period of this area of research (1998 to January 2007). In the first sections we cover the results obtained using homodonor ligands, such as phosphanes, phosphinites, phosphites and dithioethers. In the next sections, we present the results of using heterodonor ligands, such as P–P′, P–S, P–N and N–S ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Selective Determination of Catechol in the Presence of Hydroquinone at Bare Indium Tin Oxide Electrodes via Peak‐Potential Separation and Redox Cycling by Hydrazine
Authors: Aziz Md. Abdul , Selvaraju Thangavelu , Yang Haesik 
Published: July 2007

AbstractThe electrochemical, selective determination of catechol (CT) in the presence of hydroquinone (HQ) is not readily achieved, because the formal potentials of two phenolic compounds are very close. Here, we have developed a simple electrochemical method for the selective determination of CT by using bare indium tin oxide electrodes and employing CT redox cycling by hydrazine. The cyclic voltammetry of CT and HQ was investigated in Tris buffer (pH 9.0), phosphate buffered saline buffer (pH 7.4), and acetate buffer (pH 4.5). Especially in Tris buffer, the anodic peak potential of CT is much lower than that of HQ, resulting in a large difference between two peak potentials (ca. 0.4 V). The difference allows the selective determination of CT in the presence of excess HQ. The anodic current of CT is amplified using CT redox cycling by hydrazine, which also helps to stabilize CT and HQ in Tris buffer for several hours. The detection limits of CT in Tris buffer containing 0.1 mM HQ are 1 μM and 10 μM in the presence and absence of hydrazine, respectively.
Adaptative Potential of Alkaliphilic Bacteria towards Chloroaromatic Substrates Assessed by a gfp‐tagged 2,4‐D Degradation Plasmid
Authors: Kiesel B. , Müller R. H. , Kleinsteuber R. 
Published: July 2007

AbstractChloroaromatics are important anthropogenic pollutants in many environmental systems. Knowledge on the microbial detoxification potential of such compounds in extreme environments is still limited. In pristine environments, horizontal gene transfer is the major mechanism for the adaptation of microbial communities to xenobiotic substrates. However, gene transfer mediated by plasmid conjugation from bacteria living in moderate environments to those thriving in extreme habitats might be limited by different growth requirements of donor and recipient cells. In order to assess the potential of alkaliphilic bacteria from a pristine ecosystem to adapt to chloroaromatic compounds, the host range of the 2,4‐D degradation plasmid pJP4 and the expression of the degradation pathway in alkaliphilic bacteria isolated from soda ponds in the South‐Hungarian Lowlands were investigated. Since most antibiotics are unstable under alkaline conditions, the Green Fluorescent Protein was used as a selective marker for monitoring plasmid transfer. The plasmid pJP4 was tagged by a Tn5::gfp cassette outside the catabolic region. The cassette was inserted into the korB gene without affecting replication, partitioning and transfer functions of pJP4. Escherichia coli was used as a donor of the gfp‐tagged pJP4, as its pH tolerance is higher than that of the natural host Cupriavidus necator JMP134. Additionally, alkaliphilic transconjugants were used as donors in a second mating experiment to enable plasmid transfer at higher pH values. Phylogenetic identification of transconjugants by 16S rRNA gene sequencing revealed that the host range of pJP4 among alkaliphilic bacteria comprises the proteobacterial genera of the β‐subdivision (Ralstonia), the γ‐subdivision (Pseudomonas, Halomonas, Idiomarina and other genera belonging to the Alteromonadales), the α‐subdivision (Devosia) and even the Gram‐positive bacteria of the genus Alkalibacterium (Firmicutes). While the majority of the transconjugants were unable to degrade 2,4‐D to a significant extent, five isolates identified as Halomonas sp. degraded 2,4‐D and 3‐chlorobenzoate in the presence of an additional carbon source but were unable to grow on chloroaromatics as the sole carbon and energy source. Enzyme assays after chemostat cultivation revealed that the degradation of chloroaromatics is limited by the low activity of chloromuconate cycloisomerase. The results indicate that the host range of plasmid pJP4 is broader than the range of bacteria capable to express the 2,4‐D degradation trait and that the Halomonadaceae are potential hosts to establish degradative traits for chloroaromatics in alkaline environments.
Enhancement of the NAD(P)(H) Pool in Escherichia coli for Biotransformation
Authors: Heuser F. , Schroer K. , Lütz S. , Bringer‐Meyer S. , Sahm H. 
Published: July 2007

AbstractIn pyridine nucleotide‐dependent, reductive whole cell biotransformation with resting cells of Escherichia coli, the availability of intracellular NAD(P)(H) is a pivotal point for an efficient and highly productive substrate conversion. The question whether an increase of the intracellular NAD(P)(H) concentration could increase the productivity was discussed controversially in the past. This is the first report on an E. coli strain with an increased NAD(P)(H) pool which was tested in a reductive biotransformation system for an increased productivity. Biotransformation was performed with a strain overexpressing a gene encoding an (R)‐specific alcohol dehydrogenase for the stereospecific, NADPH‐dependent reduction of methyl acetoacetate (MAA) to (R)‐methyl‐3‐hydroxybutanoate (MHB). Cofactor regeneration was implemented via glucose oxidation by coexpression of a gene encoding glucose dehydrogenase. The specific MHB productivity (mmol mg–1 cell dry weight–1h–1) enabled a comparison between the E. coli BL21(DE3) wild‐type and a genetically modified strain. The enhancement of the NAD(P)(H) pool was achieved by genetic manipulation of the NAD(H) biosynthetic pathways. After simultaneous overexpression of the pncB and nadE genes, encoding nicotinic acid phosphoribosyltransferase and NAD synthetase, measurements of the total NAD(P)(H) pool, sizes showed a 7‐fold and 2‐fold increased intracellular concentration of NAD(H) and NADP(H), respectively. However, the implementation of an E. coli strain carrying a genomically integrated pncB gene with an upstream T7 promoter for biotransformation did not result in reproducible increased specific cell productivity.
Intracystic hemorrhage in a mediastinal cystic adenoma causing parathyrotoxic crisis
Authors: Manouras Andreas , Toutouzas Konstantinos G. , Markogiannakis Haridimos , Lagoudianakis Emmanuel , Papadima Artemis , Antonakis Pantelis T. , Kafiri Georgia , Bramis Ioannis 
Published: July 2007

AbstractBackground.We report a case of intracystic hemorrhage in a mediastinal cystic parathyroid adenoma causing parathyrotoxic crisis.Methods and Results.A 30‐year‐old man presented with a large neck mass, dyspnea, and abdominal pain. The patient's serum calcium and parathormone levels were elevated. Radiography showed a right tracheal deviation, ultrasonography identified a thyroid nodular goiter extending to the mediastinum with a large (4.0 cm × 5.6 cm) cystic mass adjacent to the lower left thyroid pole. After IV fluid, pamidronate, and furosemide were administered, the patient underwent total thyroidectomy, and excision of the cyst and a small mass (2 cm × 2 cm) adjacent to the upper right thyroid lobe. Histopathologic examination revealed a double parathyroid adenoma and identified the mediastinal lesion as a cystic adenoma with intracystic hemorrhage.Conclusions.Intracystic hemorrhage in a functional mediastinal cystic parathyroid adenoma is an extremely rare cause of parathyrotoxic crisis. Aggressive medical treatment should be immediately instituted, and surgery should be performed as soon as hypercalcemia is controlled. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
Elective paratracheal neck dissection for lateral metastases from papillary carcinoma of the thyroid: Is it indicated?
Authors: Khafif Avi , Ben‐Yosef Rami , Abergel Avrum , Kesler Ada , Landsberg Roee , Fliss Dan M. 
Published: July 2007

AbstractBackground.Therapeutic paratracheal neck dissection for patients with papillary carcinoma of the thyroid is standard treatment. Its use as an elective procedure is controversial.Methods.Thirty‐seven patients with papillary carcinoma of the thyroid and evidence of positive adenopathy at levels II‐V underwent selective neck dissection and elective/therapeutic paratracheal neck dissection. Results of preoperative ultrasonography of the neck were compared with the dissection specimens.Results.Morbidity of the surgical procedure was minimal (1 permanent hypocalcemia). All specimens showed metastases from papillary thyroid carcinoma: 100% (37/37) in the jugular chain of lymphatics and 83.7% (31/37) in the paratracheal region. The rate of occult (negative physical examination and ultrasonography) metastases in the paratracheal region in the presence of metastases in the ipsilateral jugular chain was 83.3% (20/24).Conclusion.The high rate of occult metastases in the paratracheal region and the low rate of surgical morbidity speak in favor of elective paratracheal neck dissection in patients with metastatic papillary carcinoma of the thyroid. © 2007 Wiley Periodicals, Inc. Head Neck 2008
Dynamic survivin in head and neck cancer: Molecular mechanism and therapeutic potential
Authors: Lippert Burkhard M. , Knauer Shirley K. , Fetz Verena , Mann Wolf , Stauber Roland H. 
Published: July 2007

AbstractAlthough disease management of head and neck squamous cell carcinomas (HNSCC) has improved significantly, therapy resistance leading to tumor recurrence still counteracts improvement of long‐term survival. Consequently, identification of molecular markers that signal increased risk of treatment failure or, which can be exploited by targeted therapy, is urgently needed. Survivin is strongly expressed in HNSCC, and its proposed dual role as an apoptosis inhibitor and a mitotic effector positioned survivin in the front line of cancer research. Notably, survivin is detected as a cytoplasmic and as a nuclear protein in HNSCC patients, which stimulated numerous studies to investigate and to speculate on the functional and prognostic significance of its dynamic localization. This review focuses on our current understanding of the molecular mechanisms regulating survivin's intracellular localization and discusses its potential prognostic and therapeutic relevance for head and neck cancer. © 2007 Wiley‐Liss, Inc.