bluuebunny/crossref_metadata_2025 huggingface dataset:
Dust Ion‐Acoustic Shocks in a Q Machine Device
Authors: Popel S. I. , Losseva T. V. , Golub' A. P. , Merlino R. L. , Andreev S. N.
Published: September 2005

Dust ion‐acoustic shocks in a Q machine device are considered. For their description the so‐called hydrodynamic ionization source model is used. The model is appropriate for the description of the laboratory experiments in a Q machine device and contains the most important basic mechanisms responsible for the formation of the dust ion‐acoustic shocks. A comparative analysis of various dissipative processes occurring on ion‐acoustic time scales during the excitation and propagation of nonlinear dust ion‐acoustic perturbations in a complex (dusty) plasma is performed in terms of a purely kinetic approach and a hydrodynamic approach. It is found that the most important dissipative processes are the charging of dust grains, the absorption of ions by grains, the transfer of the ion momentum to the grains, and Landau damping. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Presheath in Fully Ionized Collisional Plasma in a Magnetic Field
Authors: Alterkop B. , Goldsmith S. , Boxman R. L.
Published: September 2005

The quasineutral presheath layer at the boundary of fully ionized, collisional, and magnetized plasma with an ambipolar flow to an adjacent absorbing wall was analyzed using a two fluid magneto‐hydrodynamic model. The plasma is magnetized by a uniform magnetic field B, imposed parallel to the wall. The analysis did not assume that the dependence of the particle density on the electric potential in the presheath is according to the Boltzmann equilibrium, and the dependence of the mean collision time τ on the varying plasma density within the presheath was not neglected. Based on the model equations, algebraic expressions were derived for the dependence of the plasma density, electron and ion velocities, and the electrostatic potential on the position within the presheath. The solutions of the model equations depended on two parameters: Hall parameter (β ), and the ratio (γ ), where γ = ZTe /(ZTe + Ti ), and Te , Ti and Z are the electron and ion temperatures and ionicity, respectively. The characteristic scale of the presheath extension is several times ri /β , where ri is the ion radius at the ion sound velocity. The electric potential could have a non monotonic distribution in the presheath. The ions are accelerated to the Bohm velocity (sound velocity) in the presheath mainly near the presheath‐sheath boundary, in a layer of thickness ∼ri /β . The electric field accelerates the ions in the whole presheath if their velocity in the wall direction exceeds their thermal velocity. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Calculated Electron Impact Ionization Cross Sections of Excited Ne Atoms Using the DM Formalism
Authors: Deutsch H. , Becker K. , Grum‐Grzhimailo A. N. , Probst M. , Matt‐Leubner S. , Märk T. D.
Published: September 2005

We used the semi‐classical Deutsch‐Märk (DM) formalism to calculate absolute electron‐impact ionization cross sections of excited Ne atoms from threshold to 1000 eV. Excited states of Ne where the outermost valence electron is excited to states with principal quantum numbers up to n = 7 and orbital angular momentum quantum numbers up to l = 2 have been considered and systematic trends in the calculated cross section data are discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stochastic Transport of Magnetic Field Lines in the Symmetric Tokamap
Authors: Wingen A. , Spatschek K. H. , Abdullaev S.
Published: September 2005

The topological structure and the statistical properties of stochastic magnetic fields are investigated on the basis of the so called tokamap. First, a monotonic safety factor (q‐profile) is assumed. As it is demonstrated, the transition from the continuous model to the discrete mapping in its symmetric form is essential, not only for the symplectic structure, but also for the precise values characterizing the transition to chaos (e.g. the break‐up of the KAM surfaces) in applications. Statistical properties of the symmetric tokamap, such as escape rates and anomalous diffusion properties, are being presented. By a systematic procedure the stable and unstable manifolds of the periodic hyperbolic fixed points and the resulting homoclinic tangles (stochastic layers) are determined. The latter are important for the magnetic field line transport. For a non‐monotonic q‐profile, the differences between the symmetric and non‐symmetric revtokamap become also significant. The symmetric revtokamap represents an open nonlinear dynamical system which is characterized here with the relevant tools. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PECVD of Carbon Nanostructures in Hydrocarbon‐Based RF Plasmas
Authors: Ostrikov K. , Tsakadze Z. , Rutkevych P. P. , Long J. D. , Xu S. , Denysenko I.
Published: September 2005

Different aspects of the plasma‐enhanced chemical vapor deposition of various carbon nanostructures in the ionized gas phase of high‐density, low‐temperature reactive plasmas of Ar+H2+CH4 gas mixtures are studied. The growth techniques, surface morphologies, densities and fluxes of major reactive species in the discharge, and effects of the transport of the plasma‐grown nanoparticles through the near‐substrate plasma sheath are examined. Possible growth precursors of the carbon nanostructures are also discussed. In particular, the experimental and numerical results indicate that it is likely that the aligned carbon nanotip structures are predominantly grown by the molecular and radical units, whereas the plasma‐grown nanoparticles are crucial components of polymorphous carbon films. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic Field Effect on the Volt‐Equivalent of Arc Spot Heat Flux
Authors: Essiptchouk A. M. , Marotta A. , Sharakhovsky L. I.
Published: September 2005

The results of an experimental study of the arc spot heat flux on the copper cathode of a coaxial Electric Arc Heaters (EAH), with magnetically driven arc, in air are presented. The three rings method was used for indirect separation of arc spot heat flux from total heat entering the electrode. As a result of joint generalizing new and previously published data, the linear dependence of the volt equivalent of arc spot heat flux on magnetic field was obtained for the range B = 0.01 – 1 Tesla and atmospheric pressure. A method, which allows to improve the measurement of the volt equivalent in highly unsteady arc spots, is proposed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Distinct patterns of MCM protein binding in nuclei of S phase and rereplicating SV40‐infected monkey kidney cells
Authors: Friedrich Thomas D. , Bedner Elzbieta , Darzynkiewicz Zbigniew , Lehman John M.
Published: September 2005

Background

Simian Virus 40 (SV40) infection of growth‐arrested monkey kidney cells stimulates S phase entry and the continued synthesis of both viral and cellular DNA. Infected cells can attain total DNA contents as high as DNA Index, DI = 5.0–6.0 (10–12C), with host cell DNA representing 70–80% of the total. In this study, SV40‐infected and uninfected control cells were compared to determine whether continued DNA replication beyond DI = 2.0 was associated with rebinding of the minichromosome maintenance (MCM) hexamer, the putative replicative helicase, to chromatin.

Method

Laser scanning cytometry was used to measure the total expression per cell and the chromatin/matrix‐association of two MCM subunits in relation to DNA content.

Results

MCM2 and MCM3 proteins that were associated with the chromatin/matrix fraction in G1 phase of both uninfected and SV40‐infected cells were gradually released during progression through S phase. However, in SV40‐infected cells that progressed beyond DI = 2.0, chromatin/matrix‐associated MCM2 and MCM3 remained at the low levels observed at the end of S phase. Rereplication was not preceded by an obvious rebinding of MCM proteins to chromatin, as was observed in G1 phase.

Conclusions

The rereplication of host cell DNA in the absence of the reassociation of MCM proteins with chromatin indicates that SV40 infection induces a novel mechanism of licensing cellular DNA replication. © 2005 International Society for Analytical Cytology
Characterization of cells with different mitochondrial membrane potential during apoptosis
Authors: Lugli Enrico , Troiano Leonarda , Ferraresi Roberta , Roat Erika , Prada Nicole , Nasi Milena , Pinti Marcello , Cooper Edwin L. , Cossarizza Andrea
Published: September 2005

Background

Until now, the simultaneous analysis of several parameters during apoptosis, including DNA content and mitochondrial membrane potential (ΔΨ), has not been possible because of the spectral characteristics of the commonly used dyes. Using polychromatic flow cytometry based upon multiple laser and UV lamp excitation, we have characterized cells with different ΔΨ during apoptosis.

Methods

U937 cells were treated with the flavonoid quercetin (Qu) and stained with JC‐1 to detect ΔΨ, propidium iodide (PI) for cell viability, Hoechst 33342 for DNA content, Annexin V conjugated with Alexa Fluor‐647 for detection of phosphatidilserine (PS) exposure, marker of early apoptosis, or Mitotracker Deep Red for the determination of mitochondrial mass.

Results

Treatment with Qu provoked the onset of three cell populations with different ΔΨ: (1) healthy cells, with normal ΔΨ, DNA content and physical parameters, high mitochondrial mass, PI‐ and Annexin V‐negative; (2) cells with intermediate ΔΨ and normal DNA content, but with physical parameters typical of apoptotic cells and low mitochondrial mass; most of them were PI+ and Annexin V+; (3) cells with collapsed ΔΨ that had low mitochondrial mass and were Annexin‐V+, PI+; half of them showed diminished DNA content. Similar results, i.e. the presence of cells with intermediate ΔΨ, were observed in other models of apoptosis.

Conclusions

During Qu‐induced apoptosis, loss of ΔΨ, PS exposure, and decrease of mitochondrial mass are early events that precede permeability to PI and loss of DNA. Populations of cells with different ΔΨ, as revealed by flow cytometry after JC‐1 staining, differed also for other parameters associated to apoptosis. Thus, the simultaneous analysis of several parameters by polychromatic flow cytometry permits a better identification of many stages of cell death, and, more in general, allows to evaluate the eventual heterogenic sensibility of the population under study to a given compound. © 2005 Wiley‐Liss, Inc.
A simplified flow cytometry method of CD4 and CD8 cell counting based on thermoresistant reagents: Implications for large scale monitoring of HIV‐infected patients in resource‐limited settings
Authors: Barbesti Silva , Soldini Laura , Carcelain Guisline , Guignet Angelique , Colizzi Vittorio , Mantelli Barbara , Corvaglia Alessandro , Tran‐Minh Thun , Dorigatti Fernanda , Autran Brigitte , Lazzarin Adriano , Beretta Alberto
Published: September 2005

Objective:

To validate a simplified flow cytometry assay for CD4 and CD8 T cell counting based on monoclonal antibodies which are made resistant to high temperatures (simplified thermoresistant assay (STRA)).

Method:

The STRA employs FITC‐conjugated anti‐CD4 and anti‐CD8 monoclonal antibodies, predispensed into test tubes and chemically treated to be resistant to high temperatures. Five correlation studies were performed in three different laboratories on a total of 560 blood samples from HIV‐1 infected patients. Each study correlated the STRA with either double or single platform assays currently available. Accelerated stability tests on the FITC‐conjugated monoclonal antibodies were performed to assess the resistance of the STRA to high temperatures.

Results:

Comparison of STRA with both single platform and double platform assays gave correlation coefficients ranging 0.957–0.987 for CD4+ T cells and 0.946–0.968 for CD8+ T cells. In all correlation studies there was a perfect data overlapping in the low‐pathological interval of CD4+ T cells (0–400 cells/ml). The FITC‐conjugated CD4 and CD8 monoclonal antibodies maintained intact binding activity and fluorescence brightness after storage for 4 weeks at 45°C and can be stored for up to 8 years in regular conditions (+4°C).

Conclusions:

The STRA correlates well with both single‐platform and double‐platform flow‐cytometry assays currently used to assess CD4+ T cells. The test procedure is simple, rapid, and easy to perform. The reagents can be stored under unfavorable environmental conditions for long period of time. These features should facilitate access to flow cytometry testing in resource‐poor settings. © 2005 Wiley‐Liss, Inc.
Detection of Anisakis simplex‐induced basophil activation by flow cytometry
Authors: Gonzalez‐Muñoz Miguel , Luque Rosario , Nauwelaers Frans , Moneo Ignacio
Published: September 2005

Background:

Laboratory diagnosis of anisakidosis is based on specific serum IgE detection. Recently, detection of allergen‐induced basophil activation by flow cytometry has been proposed as a valuable tool for allergy diagnosis.

Objective:

To evaluate if detection of Anisakis‐induced basophil activation by flow cytometry is a useful tool in the diagnosis of Anisakis allergy.

Methods:

Patients with Anisakis allergy (A.s.+, n = 37), patients reporting chronic urticaria or abdominal pain unrelated to fish ingestion (A.s.−, n = 51), and healthy controls (n = 12) were studied. Specific IgE to Anisakis simplex (A. simplex) was quantified with CAP‐FEIA method, and basophil activation test was performed with three different concentrations of an Anisakis crude extract. Basophil gating was performed with CD123 and HLA‐DR, and cellular activation was measured with CD63.

Results:

A.s.+ patients showed significantly higher age and total IgE levels than did the A.s.− patients. Specific IgE to A. simplex correlated with the activated basophil percentages obtained with 15 μg/mL (r = 0.80; P < 0.001), 1.5 μg/mL (r = 0.84; P < 0.001), and 0.15 μg/mL (r = 0.82; P < 0.001) of A. simplex crude extract. Nine individuals (3 in the A.s.+ group and 6 in the A.s.− group) were nonresponders to basophil stimulation with anti‐IgE. Five A.s.− patients showed positive IgE values to A. simplex while the basophil activation test was negative.

According to the receiver operating characteristics curves performed between A.s.+ vs. A.s.− and A.s.+ vs. healthy controls, the cutoff for a positive basophil activation test was ≥21% (specificity = 96%, sensitivity = 100%), and 16% (sensitivity and specificity of 100%) respectively. When nonresponders were included in the A.s.+ vs. A.s.− analysis, sensitivity decreased to 95%. Multivariate logistic analysis showed that the specific basophil activation was a factor independently associated with clinical symptoms of A. simplex allergy.

Conclusions:

Detection of A. simplex‐induced basophil activation by flow cytometry is a useful laboratory technique for the diagnosis of anisakidosis, supplementing specific IgE determinations. © 2005 Wiley‐Liss, Inc.
Comparison of diagnostic and relapse flow cytometry phenotypes in childhood acute lymphoblastic leukemia: Implications for residual disease detection: A report from the children's oncology group
Authors: Borowitz Michael J , Pullen D Jeanette , Winick Naomi , Martin Paul L , Bowman W Paul , Camitta Bruce
Published: September 2005

Background:

Flow cytometric analysis of minimal residual disease (MRD) depends on detecting phenotypically abnormal populations. However, little is known about how phenotypic shifts between diagnosis and relapse affect MRD detection in childhood acute lymphoid leukemia (ALL).

Methods:

We compared diagnostic and relapse bone marrow specimens in 42 children with precursor B‐ALL studied with the two‐tube panel CD19‐APC/CD45‐PerCP/CD10‐PE/CD20‐FITC and CD19‐APC/CD45‐PerCP/CD9‐PE/CD34‐FITC.

Results:

At least 29 cases had phenotypic shifts of intensity or coefficient of variation of distribution of one or more markers. Shifts were complex and could not be explained by change in maturation stage. In the majority of cases MRD populations more closely resembled the diagnostic than the relapse specimen. In 6 of 7 MRD negative cases we did not identify an abnormal population that resembled diagnosis or relapse. In the remaining case, in which CD34 and CD10 were lost between diagnosis and relapse, it is possible that we could have missed an MRD population resembling relapse.

Conclusions:

Phenotypic shifts are common, but do not affect MRD recognition. At most 1 of 42 cases might have harbored an abnormal population undetected because of shift. However, MRD analysis with rigid gating (looking strictly for abnormal phenotypes at diagnosis) might have missed many positive cases, 8 of 22 (36%) in this series. © 2005 Wiley‐Liss, Inc.
Decision criteria for resolving isotype switching conflicts by B cells
Authors: Deenick Elissa K. , Hasbold Jhagvaral , Hodgkin Philip D.
Published: September 2005

Isotype switching by B cells is highly regulated by a group of cytokines including IL‐4, IFN‐γ and TGF‐β. A B cell can only express one isotype at a time; however, during an immune response it may be exposed to combinations of stimuli that provide it with conflicting switching instructions. To determine how such cytokine‐induced isotype switch conflicts would be resolved, the responses of B cells exposed to multiple cytokines were investigated. To eliminate complications arising from simultaneous effects of switching cytokines on proliferation, division number was used as a reference framework to monitor switching rate. The results show a clear hierarchy in which IFN‐γ is dominant over IL‐4, and both IL‐4 and IFN‐γ are dominant over TGF‐β. These studies reveal how B cells possess a set of logical decision criteria for dealing with pathogens that invoke a range of different stimuli.
TGF‐β1 production by CD4+CD25+ regulatory T cells is not essential for suppression of intestinal inflammation
Authors: Kullberg Marika C. , Hay Valerie , Cheever Allen W. , Mamura Mizuko , Sher Alan , Letterio John J. , Shevach Ethan M. , Piccirillo Ciriaco A.
Published: September 2005

Naturally occurring CD4+CD25+ regulatory T cells (Treg) are potent suppressors of CD4+ and CD8+ T cell responses in vitro and inhibit several organ‐specific autoimmune diseases. While most in vitro studies suggest that CD4+CD25+ Treg cells adopt a cytokine‐independent but cell contact‐dependent mode of T cell regulation, their precise mechanism of suppression in vivo remains largely unknown. Here we examine the functional contribution of Treg cell‐derived TGF‐β1 and effector T cell responsiveness to TGF‐β in CD4+CD25+ T cell‐mediated suppression of inflammatory bowel disease (IBD). We show that CD4+CD25+ Treg cells from either TGF‐β1+/+ or neonatal TGF‐β1–/– mice can suppress the incidence and severity of IBD as well as colonic IFN‐γ mRNA expression induced by WT CD4+CD25– effector T cells. Furthermore, TGF‐β‐resistant Smad3–/– CD4+CD25+ Treg cells are equivalent to WT Treg cells in their capacity to suppress disease induced by either WT or Smad3–/– CD4+CD25– effector T cells. Finally, anti‐TGF‐β treatment exacerbates the colitogenic potential of CD4+CD25– effector T cells in the absence of CD4+CD25+ Treg cells. Together, these data demonstrate that in certain situations CD4+CD25+ T cells are able to suppress intestinal inflammation by a mechanism not requiring Treg cell‐derived TGF‐β1 or effector T cell/Treg cell responsiveness to TGF‐β via Smad3.
A crucial role for macrophages in the pathology of K/B × N serum‐induced arthritis
Authors: Solomon Samuel , Rajasekaran Narendiran , Jeisy‐Walder Elvira , Snapper Scott B. , Illges Harald
Published: September 2005

Autoantibodies in the form of immune complexes are known to be crucial mediators in initiating inflammation in a variety of autoimmune diseases. This has been well documented in the anti‐collagen II antibody‐induced arthritis animal model for a long time now. Recently, in the K/B × N mouse model (the F1 of the TCR‐transgenic KRN and the diabetic NOD mice), anti‐glucose‐6‐phosphate isomerase (GPI) autoantibodies have been shown to induce arthritis. Experimental work in the K/B × N model demonstrated key roles of autoantigenic immune complexes activating the alternative pathway of complement, the subsequent association with C5aR and FcγRIII‐mediated cell activation and production of the inflammatory cytokines IL‐1 and TNF‐α, finally leading to joint destruction. The presence of high amounts of inflammatory cytokines and matrix‐degrading proteases at sites of inflammation obviously put the cytokine‐producing macrophages as the next target for investigation in this model. Here, we show that mice depleted of macrophages by clodronate liposome treatment are completely resistant to K/B × N serum‐induced arthritis. Reconstituting clodronate liposome‐treated mice with macrophages from naive animals could reverse this resistance. Also, we found that deficiencies in the Wiskott‐Aldrich syndrome protein and CD40, which are both implicated in macrophage activation, chemotaxis and phagocytosis, are not essential in serum‐induced arthritis. Mast cell degranulation was seen in arthritogenic serum‐treated mice even in the absence of macrophages, possibly suggesting that mast cell degranulation/activation acts hierarchically before macrophages in the inflammatory cascade of anti‐GPI antibody‐induced arthritis.
Role of mast cells in experimental anti‐glomerular basement membrane glomerulonephritis
Authors: Hochegger Kathrin , Siebenhaar Frank , Vielhauer Volker , Heininger Dorothea , Mayadas Tanya N. , Mayer Gert , Maurer Marcus , Rosenkranz Alexander R.
Published: September 2005

Recently, divergent reports on the role of mast cells (MC) in different glomerular diseases have brought our attention to their role in an accelerated model of anti‐glomerular basement membrane (GBM) glomerulonephritis (GN). Genetically MC‐deficient KitW/KitW‐v mice, MC‐reconstituted KitW/KitW‐v mice and Kit+/+ control mice were subjected to anti‐GBM GN. Kit+/+ mice developed moderate proteinuria and glomerular damage following the induction of anti‐GBM nephritis. In contrast, proteinuria and glomerular damage were dramatically increased in MC‐deficient KitW/KitW‐v mice. MC‐reconstituted KitW/KitW‐v mice showed proteinuria and glomerular damage comparable to Kit+/+ mice. A significant increase in infiltrating T cells and macrophages was detected in MC‐deficient KitW/KitW‐v mice as compared to Kit+/+ control mice and MC‐reconstituted KitW/KitW‐v mice. Accordingly, we observed an increase of TGF‐β1 mRNA in kidneys from KitW/KitW‐v mice. Interestingly, we did not detect MC in the kidney using either Giemsa staining or RT‐real‐time PCR, but MC were found in the regional lymph nodes. Finally, mortality of KitW/KitW‐v mice was significantly increased after the induction of anti‐GBM GN due to uremia. Our report provides the first direct evidence that MC are protective in anti‐GBM GN, possibly by modulating the influx of effector T cells and macrophages to inflammatory sites in the kidney.
The ratio between dendritic cells and T cells determines the outcome of their encounter: Proliferation versus deletion
Authors: Höpken Uta E. , Lehmann Insa , Droese Jana , Lipp Martin , Schüler Thomas , Rehm Armin
Published: September 2005

Dendritic cells (DC) either induce T cell tolerance or contribute to the initiation and modulation of T and B cell responses. Since many of the variables determining the thresholds of naive T cell priming were defined in vitro using a homogeneously matured DC population, we here focused on partially mature DC which might reflect the occurrence of tumor‐infiltrating and thymic DC. To predict how those DC regulate the induction of antigen‐specific T cell proliferation and T cell tolerance, we co‐cultured ovalbumin‐pulsed murine DC at different ratios with antigen‐specific DO11.10 transgenic T cells. Whereas partially mature DC at a DC/T cell ratio of 1 : 10 supported proliferation, a DC/T cell ratio of 1 : 2 induced proliferation arrest in naive CD4+ T cells. The acquisition of the NK cell inhibitory markers NK1.1 and KLRG on T cells exposed to high numbers of DC suggests a role for these molecules in the protection of antigen‐responsive T cells from exhaustion by overstimulation. Mechanistically, abortive T cell proliferation upon encounter of high numbers of partially mature DC is caused by an apoptosis‐related pathway, suggesting that excessive antigen density without sufficient costimulation results in activation‐induced cell death.
Human splenic marginal zone B cells lack expression of activation‐induced cytidine deaminase
Authors: Willenbrock Klaus , Jungnickel Berit , Hansmann Martin‐Leo , Küppers Ralf
Published: September 2005

It has been speculated that somatic hypermutation of rearranged immunoglobulin variable (V) region genes does not only take place in the germinal center (GC) microenvironment, but also in the marginal zone (MZ) of the spleen, and that human peripheral blood IgM‐positive B cells with somatically mutated V region genes may derive from mutating MZ B cells. As somatic hypermutation is strictly dependent on the enzyme activation‐induced cytidine deaminase (AID), we used an AID‐specific monoclonal antibody that is suitable for immunohistochemical staining to analyze human splenic MZ cells for AID expression. Analysis of tissue sections from 29 spleens revealed only very rare MZ cells (approx. 0.05%) showing AID staining, whereas in 25 of the spleen samples strong AID staining of GC B cells was observed. Thus, there are virtually no AID‐expressing MZ B cells, indicating that somatic hypermutation does not take place at a significant level in the MZ. Consequently, it appears unlikely that the somatically mutated IgM B cells are generated in the splenic MZ. Moreover, the lack of AID‐positive MZ B cells questions the recent speculation that B cell chronic lymphocytic leukemias with mutated V genes are derived from mutating MZ B cells.

See accompanying commentary: http://dx.doi.org/10.1002/eji.200535446
Fluorine in Peptide Design and Protein Engineering
Authors: Jäckel Christian , Koksch Beate
Published: September 2005

The use of fluorine has become well established in the analysis of protein structure and function, e.g. in tools such as 19F NMR spectroscopy. The application of the unique electronic properties of this element for the structural and chemical modification of peptides and proteins emerged as a promising approach. However, the influences of amino acid fluorination on side‐chain interactions in proteins are still controversially discussed. The systematic investigation of the interaction properties of fluoroalkyl groups in a native polypeptide environment broadens the scope of fluorinated amino acids to the rational design of structural motifs and protein interfaces. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Nucleophilic Vinylic Substitution (SNV) of Activated Alkoxymethylene Derivatives with 6‐Aminoquinoxaline
Authors: Saloň Jozef , Milata Viktor , Gatial Anton , Prónayová Nadežda , Leško Ján , Černuchová Petra , Rappoport Zvi , Vo‐Thanh Giang , Loupy André
Published: September 2005

Treatment of 6‐aminoquinoxaline with β,β‐diactivated alkoxymethylene derivatives gave the corresponding N‐(quinoxalin‐6‐yl)enamines. A variant of the SNV reaction mechanism was proposed for substitution of the alkoxymethylene compounds, on the basis of the structures of the precursor enol ether and the vinylic substitution product and on computations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Ind2TiMe2‐Catalyzed Addition of Methyl‐ and Ethylamine to Alkynes
Authors: Marcseková Klaudia , Wegener Bernd , Doye Sven
Published: September 2005

We describe a very simple hydrogenation‐like experimental protocol for the addition of gaseous methyl‐ and ethylamine to alkynes in the presence of Ind2TiMe2 as the catalyst. For efficient hydroamination reactions it is sufficient to stir a mixture of the alkyne and the catalyst in toluene at temperatures between 80 °C (terminal alkynes) and 105 °C (internal alkynes) under a constant pressure of 1 atm of the corresponding amine. After subsequent reduction of the initially formed imines, methyl‐ and ethylamine derivatives are the final products of the described one‐pot reaction sequences. In the case of 2‐alkyl‐1‐phenylalkynes as starting materials, biologically interesting 2‐phenylethylamine derivatives possessing a small methyl or ethyl substituent at the N atom are easily accessible by the new reaction protocol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Electroreductive Radical Cyclization of Ethyl 2‐Bromo‐3‐allyloxy‐ and‐3‐(propargyloxy)propanoates Catalyzed by (Tetramethylcyclam)nickel(I) Electrogenerated at Carbon Cathodes in Dimethylformamide
Authors: Esteves Ana P. , Goken Danielle M. , Klein Lee J. , Leite Luis F. M. , Medeiros Maria J. , Peters Dennis G.
Published: September 2005

Reductive intramolecular cyclization of ethyl 2‐bromo‐3‐(3′,4′‐methylenedioxyphenyl)‐3‐(propargyloxy)propanoate(1) and ethyl 3‐allyloxy‐2‐bromo‐3‐(3′,4′‐dimethoxyphenyl)propanoate (2) promoted by (1,4,8,11‐tetramethyl‐1,4,8,11‐tetraazacyclotetradecane)nickel(I), [Ni(tmc)]+, electrogenerated at glassy‐carbon cathodes in dimethylformamide containing tetraalkylammonium salts, has been investigated. Cyclic voltammograms for reduction of [Ni(tmc)]2+ in the presence of 1 and 2 reveal that [Ni(tmc)]+ catalytically reduces these two compounds at potentials significantly more positive than those required for direct reduction of the bromo esters. During controlled‐potential electrolyses of solutions of [Ni(tmc)]2+ in the presence of 1 and 2, catalytic reduction of each substrate proceeds by one‐electron cleavage of the carbon–bromine bond to form a radical intermediate that undergoes cyclization to afford, respectively, ethyl 2‐(3′,4′‐methylenedioxyphenyl)‐4‐methylenetetrahydrofuran‐3‐carboxylate (3) and ethyl 2‐(3′,4′‐dimethoxyphenyl)‐4‐methyltetrahydrofuran‐3‐carboxylate (6). A mechanistic Scheme is proposed to account for the formation of each major product. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Expression analysis of 6p22 genomic gain in retinoblastoma
Authors: Orlic Marija , Spencer Clarellen E. , Wang Lisa , Gallie Brenda L.
Published: September 2005

To identify gene(s) targeted by 6p22 genomic gain, present in more than 50% retinoblastoma tumors, we used real‐time RT‐PCR to quantify the expression of seven genes in normal human retina and retinoblastoma. Six genes are located in the quantitative multiplex PCR‐defined 0.6 Mb minimal region of gain at 6p22 (DEK, AOF1, TPMT, NHLRC1, KIF13A, and NUP153), and E2F3 is 2 Mb away from the minimal region of gain on 6p22. E2F3, DEK, KIF13A, and NUP153 were most frequently overexpressed in retinoblastoma with 6p genomic gain, compared with the normal adult human retina. E2F3 and DEK mRNA levels were increased in all human tumors showing 6p22 gain, as well as in mouse retinoblastoma induced by SV40 large T antigen expression in developing retina, compared with the normal controls (adult human retina and 7‐day‐old mouse retina, respectively). Only DEK showed statistically significant correlation of expression and genomic copy number (P = 0.019). E2F3 and DEK, but not NUP153, showed developmental regulation. E2F3 and DEK mRNA overexpression was always associated with protein overexpression, determined by immunoblotting or immunofluorescent staining of primary tumors, relative to the adjacent normal retina. E2F3 was strongly expressed in actively proliferating cells, while DEK was overexpressed in all tumor cells. Taking into account the proliferation‐promoting role of E2F3, implication of E2F3 in bladder and prostate cancer, and the translocation and overexpression of DEK in leukemia, we conclude that either DEK or E2F3 (or both) are targeted by the 6p22 gain in retinoblastoma. © 2005 Wiley‐Liss, Inc.
Human reliability: A key to improved quality in manufacturing
Authors: Bubb Heiner
Published: September 2005

For one to learn, one must make mistakes. Human error can be defined on the basis of the definition of quality. Because quality is influenced by human actions, the so‐called performance shaping factors have an important influence on the human error probability. Different methods have been developed to predict human error probability. One of the most established and detailed methods is THERP (technique for human error rate prediction), which was originally developed for application in the nuclear power industry. Here this method is applied to a simple example of manufacturing. Further experimental research in the area of commission will be reported, where methods of error prediction were also applied. In both cases, measures of improving human reliability can be derived. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 353–368, 2005.
The integration of work process knowledge into human resources development
Authors: Fischer Martin
Published: September 2005

In this contribution the relationship between work process knowledge and human resources development is discussed. The concept of work process knowledge is described as it evolved as an outcome of a research network involving research institutions from 10 European countries (N. C. Boreham, R. Samurçay, & M. Fischer, 2002). Historical origins of the concept are mentioned and different dimensions of work process knowledge are depicted as a topic of ongoing research. How work process knowledge is considered within current research activities focusing on measures of organizational learning is also defined. In this respect, research results from the European research project OrgLearn (“Ways of Organisational Learning in the Chemical Industry and Their Impact on Vocational Education and Training,” funded under the Fifth Framework Programme of the European Union and coordinated by the author) are reported. Finally, the implications of the concept of work process knowledge are discussed, which have become apparent in recent developments within vocational education and training in Germany. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 369–384, 2005.
Human factors in manufacturing: New patterns of cooperation for company governance and the management of change
Authors: Erlicher Luisella , Massone Luciano
Published: September 2005

Innovation in manufacturing is driven by the globalization of competition, differentiation in demand, the shortening of the product lifecycle and the managerial innovations adopted by companies in response to the environment. Innovation has generated the new modular production system that allows greater product variety and variability. This new modular pattern in manufacturing determines a change in the priority list concerning human factors. Cognitive cooperation among all stakeholders in the manufacturing process, from suppliers to managers and workers, becomes the new focal point that must be developed and supported to ensure excellent performance of the modular factory and reasonable margins of identification for the persons performing the processes.

The authors argue that both change management practices of a prescriptive type and those based solely on commitment are bound to fail in the medium term, as they are unable to address the autogenous character of change. If long‐lasting change is to be generated, managers must understand and define the desires, intentions, and values denoting the subjective and collective identities of communities of persons at work; they must not be interested in direct self‐promotion of that particular type of change that fits in with their own original characters and their history. This pragmatic principle applies both to the internal processes of the modular factory and to those external processes that link the company to its suppliers.

In sum, it is the authors' view that the new horizons of human factors in manufacturing no longer rely on the best match between people, technologies, and the organization, as the capability to create cognitive spaces to construct new meanings. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 403–419, 2005.
Human‐Centered design of engineering applications: Success factors from a case study in the automotive industry
Authors: Schulze Hartmut , Brau Henning , Haasis Siegmar , Weyrich Michael , Rhatje Tobias
Published: September 2005

The implementation of a so‐called “Digital Factory” is a tremendous challenge for automotive engineering. The technical task is to effect a seamless information backbone spanning three key departments: Design, Production Process Planning, and Manufacturing. Also suppliers such as machine and tool vendors have to be integrated into the information flow. Furthermore, there is the challenge of assimilating the human factor into the digital factory. New production planning tools will significantly change not only the contemporary production process planner's work but also the collaboration with suppliers. This raises one major issue: how to integrate different user groups into the design of complex engineering applications for production planning. The authors focus on a case study about the development of a computer‐aided planning (CAP) tool, which has been running since 1999 at DaimlerChrysler AG. The complexity of engineering processes and related information technology (IT) applications is examined and success factors for user involvement into IT development are identified. Finally, the article concludes with an adapted scenario‐based approach for the interdisciplinary and participative development of complex engineering applications. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 421–443, 2005.
From virtuality to reality: Individualized freeform model design and rapid manufacturing
Authors: Zhang Wei , Lin Heng , Zhang Weihan
Published: September 2005

Individuation, customer involvement, and rapid prototyping are crucial factors for developing a new product. A novel method addresses these issues by allowing both professional designers and general customers to freely express their design ideas for creating freeform product models and quickly developing physical prototypes. A virtual design environment is created to achieve natural human–computer interaction and multidesigners' collaboration via the Internet. Ray‐casting and other techniques are adopted to achieve real‐time calculation, stereo display, and haptic feedback. A design and manufacturing experiment is conducted to test feasibility and provide a preliminary understanding of how to improve this method. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 445–459, 2005.
Synthesis of Long‐Chain 3‐Alkylpyrroles Bearing Terminal Carboxy or Amino Groups
Authors: Freitas José M. , Abrantes Luísa M. , Darbre Tamis
Published: September 2005

Two new ω‐(1H‐pyrrol‐3‐yl)alkanoic acids 8a,b and the corresponding amines 9a,b were prepared on large scale in 41–51 and 27–39% overall yield, respectively, starting from N‐phenylsulfonyl‐protected pyrrole. The target compounds contain the desired functional groups for attachment of biomolecules such as proteins. During synthesis, an unprecedented partial reduction of the pyrrole ring with NaBH3CN in glacial AcOH was observed, for which a plausible mechanism is proposed (Scheme 3).
Solvothermal Synthesis and Crystal Structures of Alkali Molybdates
Authors: Michailovski Alexej , Willems Johannes B. , Stock Norbert , Patzke Greta R.
Published: September 2005

Within the frame of systematic morphological studies concerning the solvothermal formation of nanoscale and microscale molybdenum oxides from the interaction of a molybdenum‐based precursor such as MoO3⋅2 H2O with ionic additives such as alkali and earth alkali halides, we studied – with the aim to elaborate preparative guidelines – the influence of the precursor structure and the alkali halide upon the crystal structure of the emerging alkali polymolybdates in terms of solvothermal fields and high‐throughput solvothermal techniques. The discussion of the resulting crystal structures revealed a structure‐directing potential of the alkali cations that was explored for the synthesis of new mixed alkali polymolybdates.
Two‐Dimensional Holo‐ and Hemidirected Lead(II) Coordination Polymers: Synthetic, Spectroscopic, Thermal, and Structural Studies of [Pb(μ‐SCN)2(μ‐ebp)1.5]n and {[Pb(μ‐OAc)(μ‐ebp)](ClO4)}n (ebp=4,4′‐[(1E)‐Ethane‐1,2‐diyl]bis[pyridine]; OAc=Acetato)
Authors: Morsali Ali , Yilmaz Veysel T. , Kazak Canan , Zhu Long‐Guan
Published: September 2005

Two new coordination polymers of PbII complexes with bridging 4,4′‐[(1E)‐ethane‐1,2‐diyl]bis[pyridine] (ebp), thiocyanato, and acetato ligands, [Pb(μ‐SCN)2(μ‐ebp)1.5]n (1) and {[Pb(μ‐OAc)(μ‐ebp)](ClO4)}n (2), were synthesized and characterized by elemental analysis, FT‐IR, 1H‐ and 13C‐NMR, thermal analysis, and single‐crystal X‐ray diffraction. In 1, the Pb2+ ions are doubly bridged by both the ebp and the SCN− ligands into a two‐dimensional polymeric network. The seven‐coordinate geometry around the Pb2+ ion in 1 is a distorted monocapped trigonal prism, in which the Pb2+ ions have a less‐common holodirected geometry. In 2, the Pb2+ ions are bridged by AcO− ligands forming linear chains, which are also further bridged by the neutral ebp ligands into a two‐dimensional polymeric framework. The Pb2+ ions have a five‐coordinate geometry with two N‐atoms from two ebp ligands and three O‐atoms of AcO−. Although ClO$\rm{_{4}^{-}}$ acts as a counter‐ion, it also makes weak interactions with the Pb2+ center. The arrangement of the ligands in 2 exhibits hemidirected geometry, and the coordination gap around the Pb2+ ion is possibly occupied by a configurationally active lone pair of electrons.
Two New Aporphine Alkaloids from Litsea glutinosa
Authors: Yang Jing‐Hua , Li Liang , Wang Yun‐Song , Zhao Jing‐Feng , Zhang Hong‐Bin , Luo Shi‐De
Published: September 2005

Chemical examination of the BuOH extract of the leaves and twigs of Litsea glutinosa collected from Xishuangbanna resulted in the isolation of two new aporphine alkaloids, namely litseglutine A (1) and B (2), along with two known aporphine alkaloids, boldine (3) and laurolitsine (4). The structures of the new alkaloids have been elucidated on the basis of spectra analysis as 6‐demethyl‐9‐methoxy‐1,2‐(methylenedioxy)aporphin‐10‐ol (=6,7,7a,8‐tetrahydro‐10‐methoxy‐5H‐benzo[g]‐1,3‐benzodioxolo[6,5,4‐de]quinolin‐11‐ol; 1) and 1,10,11‐trimethoxyaporphin‐2‐ol (=5,6,6a,7‐tetrahydro‐1,10,11‐trimethoxy‐6‐methyl‐4H‐dibenzo[de,g]quinolin‐2‐ol; 2).
Indole Alkaloids from the Whole Plants of Ervatamia officinalis
Authors: Zhang Hua , Yue Jian‐Min
Published: September 2005

Three new ervatamine‐type indole alkaloids, 6‐oxo‐16,20‐episilicine (1), 16,20‐episilicine (2), and 6,16‐didehydro‐20‐episilicine (6), along with seven known alkaloids, were isolated from the whole plants of Ervatamia officinalis. Their structures were elucidated by spectroscopic methods.
Kinetic and Mechanistic Studies on the Oxidation of Nitrogen(III) (HNO2/$\rm{{{NO}}_2^ - }$) by the Tris(biguanide)manganese(IV) Ion in Aqueous Acidic Media
Authors: Das Amit , Mukhopadhyay Subrata
Published: September 2005

The kinetics of a net two‐electron transfer between an authentic MnIV complex, [Mn(bigH)3]4+ (Fig. 1; bigH = biguanide = C2N5H7), and nitrite in aqueous solution in the pH interval 2.00–3.60 is described. Stoichiometric data for the reaction clearly indicates Δ[MnIV]/Δ[NIII]T = 1.07 ± 0.10, and $\rm{{{NO}}_3^ - }$ is detected as the oxidized product of nitrite ([NIII]T = [HNO2] + [$\rm{{{NO}}_2^ - }$]). Though both HNO2 and $\rm{{{NO}}_2^ - }$ are found to be reactive, the latter is kinetically superior in reducing the fully protonated MnIV complex. Proton‐coupled electron transfer (PCET; 1e, 1H+) reduces the activation barrier for the thermodynamically unfavorable reaction of weakly oxidizing MnIV species. At the end of the redox process, the ligand bigH is released, and the high protonation constants of the ligand carry the overall reaction to completion.
Microstructural and crystallographic surface changes after grinding zirconia‐based dental ceramics
Authors: Denry I. L. , Holloway J. A.
Published: September 2005

The purpose of this study was to evaluate microstructural and crystallographic phase changes after grinding 3Y‐TZP dental ceramics. Ceramic blanks were sintered according to manufacturer's recommendations and divided into four groups: (A) as‐sintered control, (B) diamond‐ground manually under water, (C) ground and polished, and (D) ground and annealed at 1000°C for 1 h. Bulk specimens were analyzed by X‐ray diffraction to characterize the crystalline phases. The microstructure was investigated by SEM. XRD analyses showed that the control group and the group that was ground and annealed contained only tetragonal zirconia. However, after grinding or after grinding followed by polishing, rhombohedral zirconia and strained tetragonal zirconia were present, without any detectable amount of monoclinic zirconia. Annealing led to the disappearance of both residual lattice strain and the rhombohedral phase. The microstructure of the ground and polished specimens was characterized by significant residual surface damage associated with grain pullout to a depth of about 20 μm. This type of damage could have an impact on the long‐term fatigue behavior of 3Y‐TZP. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Microscopic observation of unworn siloxane–hydrogel soft contact lenses by atomic force microscopy
Authors: González‐Méijome José M. , López‐Alemany Antonio , Almeida José B. , Parafita Manuel A. , Refojo Miguel F.
Published: September 2005

In the present study, samples of lotrafilcon A, balafilcon A, and galyfilcon A contact lenses were observed by atomic force microscopy (AFM) in tapping mode at areas ranging from 0.25 to 400 μm2. Mean roughness (Ra), root‐mean‐square roughness (Rms) and maximum roughness (Rmax) in nanometers were obtained for the three lens materials at different magnifications. The three contact lenses showed significantly different surface topography. However, roughness values were dependent of the surface area to be analyzed. For a 1 μm2 area, statistics revealed a significantly more irregular surface of balafilcon A (Ra = 6.44 nm; Rms = 8.30 nm; Rmax = 96.82 nm) compared with lotrafilcon A (Ra = 2.40 nm; Rms = 3.19 nm; Rmax = 40.89 nm) and galyfilcon A (Ra = 1.40 nm; Rms = 1.79 nm; Rmax = 15.33 nm). Ra and Rms were the most consistent parameters, with Rmax presenting more variability for larger surface areas. The higher roughness of balafilcon A is attributed to the plasma oxidation treatment used to improve wettability. Conversely, galyfilcon A displays a smoother surface. Present observations could have implications in clinical aspects of siloxane–hydrogel contact lens wear such as lens spoliation, resistance to bacterial adhesion, or mechanical interaction with the ocular surface. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Calcium phosphate cement reinforced by polypeptide copolymers
Authors: Lin Jiaping , Zhang Suning , Chen Tao , Liu Changshen , Lin Shaoliang , Tian Xiaohui
Published: September 2005

Water‐based calcium phosphate with bone repairing capability was reinforced by polypeptide graft copolymers and micelles that were formed by polypeptide copolymers. The mechanical studies showed that the compression strength and fracture energy of the calcium phosphate cement (CPC)/polypeptide composites are appreciably higher than those of CPC. The molecular structure of the polypeptide graft copolymers and the association form of the polypeptide copolymers exhibit a marked effect on the mechanical properties of CPC/polypeptide composites. The polypeptide copolymers with more hydrophilic side chains and with core‐shell micelle forms have more effective reinforcement effect. The morphological studies based on the scanning electron microscope (SEM) observations revealed that both polypeptide graft copolymers and polypeptide copolymer micelles are well dispersed in CPC matrix. According to the obtained experimental results, reinforcement mechanism was suggested. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006