bluuebunny/crossref_metadata_2025 huggingface dataset:
Disulfide Bonds versus Trp⋅⋅⋅Trp Pairs in Irregular β‐Hairpins: NMR Structure of Vammin Loop 3‐Derived Peptides as a Case Study
Authors: Mirassou Yasmina , Santiveri Clara M. , Pérez de Vega M. Jesús , González‐Muñiz Rosario , Jiménez M. Angeles
Published: March 2009

Where a noncovalent interaction is better than a covalent bond: The most stabilising cross‐strand pairs were incorporated into an irregular β‐hairpin, loop 3 of vammin. 1H and 13C NMR conformational analyses of these designed peptides indicated that an edge‐to‐face Trp⋅⋅⋅Trp interaction leads to a β‐hairpin that is more stable than a disulfide bond.

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Structural studies on model peptides have led to a good understanding of the rules behind the formation and stability of regular β‐hairpins. To test their applicability to the successful design of irregular β‐hairpins with long loops and/or β‐bulges at the strands, we mimicked loop 3 of vammin, a 4:6 β‐hairpin with a non‐Gly β‐bulge. The most stabilising cross‐strand pairs, disulfide bonds or/and Trp⋅⋅⋅Trp pairs, were incorporated at non‐hydrogen‐bonded sites in peptides spanning the 69–80 region of vammin. According to NMR data, these modified peptides adopt β‐hairpin conformations as intended by design. The Trp‐containing peptides reproduce even the unusual positive ϕ angle for the Gln residue, with the indole rings in the preferred edge‐to‐face orientation. For the first time the β‐hairpin‐stabilising capacities of a disulfide bond and a Trp⋅⋅⋅Trp pair are compared in the same model system. We found that the contribution to stability of the noncovalent indole–indole interaction is larger than that of the covalent disulfide bond, and that their combination gives rise to an even more stable β‐hairpin.
Localization of biogenic amines in the foregut of Aplysia californica: Catecholaminergic and serotonergic innervation
Authors: Martínez‐Rubio Clarissa , Serrano Geidy E. , Miller Mark W.
Published: March 2009

This study examined the catecholaminergic and serotonergic innervation of the foregut of Aplysia californica, a model system in which the control of feeding behaviors can be investigated at the cellular level. Similar numbers (15–25) of serotonin‐like‐immunoreactive (5HTli) and tyrosine hydroxylase‐like‐immunoreactive (THli) fibers were present in each (bilateral) esophageal nerve (En), the major source of pregastric neural innervation in this system. The majority of En 5HTli and THli fibers originated from the anterior branch (En2), which innervates the pharynx and the anterior esophagus. Fewer fibers were present in the posterior branch (En1), which innervates the majority of the esophagus and the crop. Backfills of the two En branches toward the central nervous system (CNS) labeled a single, centrifugally projecting serotonergic fiber, originating from the metacerebral cell (MCC). The MCC fiber projected only to En2. No central THli neurons were found to project to the En. Surveys of the pharynx and esophagus revealed major differences between their patterns of catecholaminergic (CA) and serotonergic innervation. Whereas THli fibers and cell bodies were distributed throughout the foregut, 5HTli fibers were present in restricted plexi, and no 5HTli somata were detected. Double‐labeling experiments in the periphery revealed THli neurons projecting toward the buccal ganglion via En2. Other afferents received dense perisomatic serotonergic innervation. Finally, qualitative and quantitative differences were observed between the buccal motor programs (BMPs) produced by stimulation of the two En branches. These observations increase our understanding of aminergic contributions to the pregastric regulation of Aplysia feeding behaviors. J. Comp. Neurol. 514:329–342, 2009. © 2009 Wiley‐Liss, Inc.
Postnatal development of synaptic structure proteins in pyramidal neuron axon initial segments in monkey prefrontal cortex
Authors: Cruz Dianne A. , Lovallo Emily M. , Stockton Steven , Rasband Matthew , Lewis David A.
Published: March 2009

In the primate prefrontal cortex (PFC), the functional maturation of the synaptic connections of certain classes of γ‐aminobutyric acid (GABA) neurons is very complex. For example, the levels of both pre‐ and postsynaptic proteins that regulate GABA neurotransmission from the chandelier class of cortical interneurons to the axon initial segment (AIS) of pyramidal neurons undergo marked changes during both the perinatal period and adolescence in the monkey PFC. In order to understand the potential molecular mechanisms associated with these developmental refinements, we quantified the relative densities, laminar distributions, and lengths of pyramidal neuron AIS immunoreactive for ankyrin‐G, βIV spectrin, or gephyrin, three proteins involved in regulating synapse structure and receptor localization, in the PFC of rhesus monkeys ranging in age from birth through adulthood. Ankyrin‐G‐ and βIV spectrin‐labeled AIS declined in density and length during the first 6 postnatal months, but then remained stable through adolescence and into adulthood. In contrast, the density of gephyrin‐labeled AIS was stable until approximately 15 months of age and then markedly declined during adolescence. Thus, molecular determinants of the structural features that define GABA inputs to pyramidal neuron AIS in monkey PFC undergo distinct developmental trajectories with different types of changes occurring during the perinatal period and adolescence. In concert with previous data, these findings reveal a two‐phase developmental process of GABAergic synaptic stability and GABA neurotransmission at chandelier cell inputs to pyramidal neurons that likely contributes to the protracted maturation of behaviors mediated by primate PFC circuitry. J. Comp. Neurol. 514:353–367, 2009. © 2009 Wiley‐Liss, Inc.
Synapse‐to‐synapse variation in mean synaptic vesicle size and its relationship with synaptic morphology and function
Authors: Qu Lei , Akbergenova Yulia , Hu Yunming , Schikorski Thomas
Published: March 2009

Synaptic vesicle (SV) size is one parameter that controls the amount of neurotransmitter released from individual SVs and, therefore, is fundamental to our understanding of synaptic function. The recently discovered variability of mean SV size among excitatory hippocampal synapses—if actively regulated—is a potential mechanism for the regulation of transmitter release. Here, we investigated which parameters influence mean SV size. First, we revealed that synapse‐to‐synapse variability of SV size is a general phenomenon in several species and brain regions. In addition, we determined the relationship between mean SV size and synaptic morphology. In three‐dimensional reconstructions from serial ultrathin sections, we found that SV size did not correlate with the area of the postsynaptic density (a measure for synaptic size and synaptic cleft volume) nor with the total number of SVs within a bouton or bouton volume. We tested the long‐held hypothesis that a change in osmotic pressure (potentially caused by a change in neurotransmitter concentration) affects SV size. When we reduced the osmotic pressure, SVs became significantly smaller; however, an increase in osmotic pressure had no effect on SV size. Furthermore, we found that SV size does not adapt to chronic changes in activity and that the SV cycle is capable of providing constant SV size during long‐lasting, high‐frequency stimulation. J. Comp. Neurol. 514:343–352, 2009. © 2009 Wiley‐Liss, Inc.
Preparation, Characterization, and Electrocatalytic Properties of Mixed‐Valent Nickel Hexacyanoferrate/Phosphomolybdate Hybrid Film Electrodes Towards Oxidation of Ascorbic Acid and Reduction of S2O$\rm{ {_{8}^{2-}}}$
Authors: Chen Shen‐Ming , Liou Ching‐Yeoung , Balamurugan A. , Thangamuthu R.
Published: March 2009

Polynuclear mixed‐valent nickelhexacyanoferrate/phosphomolybdate (NiHCF/PMo), nickel/phosphomolybdate (Ni/PMo) hybrid films were prepared on glassy carbon electrode by multiple scan cyclic voltammetry. Combination of individual components gave the opportunity to fabricate hybrid film with tunable electrochemical and analytical properties compared to individual components. The film growth was monitored using electrochemical quartz crystal microbalance (EQCM). The cyclic voltammogram of the nickelhexacyanoferrate/phosphomolybdate film is characterized by four redox couple whereas nickel/phosphomolybdate hybrid film exhibits three redox couples. Cyclic voltammetric features suggest that the charge transfer process in both films resembles that of surface‐confined redox species. The voltammetric response of nickelhexacyanoferrate/phosphomolybdate film electrode was found to be depending on the pH of the contacting solution. Electrocatalytic behavior of nickel/phosphomolybdate hybrid film coated electrodes toward oxidation of ascorbic acid and reduction of sulfur oxoanion, S2O$\rm{ {_{8}^{2-}}}$, was investigated using cyclic voltammetry technique. Analytical application of nickel/phosphomolybdate hybrid film electrode was tested in amperometry and flow injection analysis.
Conformational dynamics of DNA‐electrophoresis on cationic membranes
Authors: Kahl Valentin , Hennig Martin , Maier Berenike , Rädler Joachim O.
Published: March 2009

The conformational dynamics of DNA molecules undergoing electrophoresis on a fluid substrate‐supported cationic lipid bilayer is investigated using fluorescence microscopy. At low electrophoretic velocities, drift of 2‐D random coils is observed. In contrast, at velocities larger than 0.3 μm/s, the DNA molecules stretch out and assume branched configurations. The cross‐over scenario is explained by the observation that cationic lipids segregate underneath the adsorbed DNA and confine the DNA to its counter charge imprint on time scales shorter than the relaxation time of the imprint. The concept of a tube‐like confinement of the DNA is corroborated by the observed 1/N size dependence of the electrophoretic mobility in analogy to the biased reptation model in gels. The role of membrane defects and possible applications of membrane‐based electrophoresis in microfluidic devices are discussed.
A new method for preparation of an etched porous joint for capillary electrophoresis and its pore‐size evaluation
Authors: Guo Longhua , Qiu Bin , Chen Mingxing , Chen Guonan
Published: March 2009

In this work, an improved approach was developed for the construction of a hydrofluoric acid etched capillary porous joint, and the pore size of the porous joint was investigated. Several etching factors such as reagents concentration and etching temperature were optimized. Results showed that moderate temperature with low hydrofluoric acid concentration was helpful for proportional etching. Low‐range protein molecular weight marker labeled with acridinium ester was used as pore‐size reference for pore‐size evaluation of the joint. A homemade CE with chemiluminescence detection system was used for the analysis of the acridinium ester labeled protein molecular weight marker, and the results showed that only the small molecular peptides can pass through the etched porous joint and the big size proteins cannot. The penetration of protein whose molecular mass was larger than 6500 Da was a signal of over‐etching.
Heritability of regional and global brain structure at the onset of puberty: A magnetic resonance imaging study in 9‐year‐old twin pairs
Authors: Peper Jiska S. , Schnack Hugo G. , Brouwer Rachel M. , Van Baal G. Caroline M. , Pjetri Eneda , Székely Eszter , van Leeuwen Marieke , van den Berg Stéphanie M. , Collins D. Louis , Evans Alan C. , Boomsma Dorret I. , Kahn René S. , Hulshoff Pol Hilleke E.
Published: March 2009

Puberty represents the phase of sexual maturity, signaling the change from childhood into adulthood. During childhood and adolescence, prominent changes take place in the brain. Recently, variation in frontal, temporal, and parietal areas was found to be under varying genetic control between 5 and 19 years of age. However, at the onset of puberty, the extent to which variation in brain structures is influenced by genetic factors (heritability) is not known. Moreover, whether a direct link between human pubertal development and brain structure exists has not been studied. Here, we studied the heritability of brain structures at 9 years of age in 107 monozygotic and dizygotic twin pairs (N = 210 individuals) using volumetric MRI and voxel‐based morphometry. Children showing the first signs of secondary sexual characteristics (N = 47 individuals) were compared with children without these signs, based on Tanner‐stages. High heritabilities of intracranial, total brain, cerebellum, and gray and white matter volumes (up to 91%) were found. Regionally, the posterior fronto‐occipital, corpus callosum, and superior longitudinal fascicles (up to 93%), and the amygdala, superior frontal and middle temporal cortices (up to 83%) were significantly heritable. The onset of secondary sexual characteristics of puberty was associated with decreased frontal and parietal gray matter densities. Thus, in 9‐year‐old children, global brain volumes, white matter density in fronto‐occipital and superior longitudinal fascicles, and gray matter density of (pre‐)frontal and temporal areas are highly heritable. Pubertal development may be directly involved in the decreases in gray matter areas that accompany the transition of our brains from childhood into adulthood. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Running exercise‐induced up‐regulation of hippocampal brain‐derived neurotrophic factor is CREB‐dependent
Authors: Chen Michael J. , Russo‐Neustadt Amelia A.
Published: March 2009

The past decade has witnessed burgeoning evidence that antidepressant medications and physical exercise increase the expression of hippocampal brain‐derived neurotrophic factor (BDNF). This phenomenon has gained widespread appeal, because BDNF is one of the first macromolecules observed to play a central role not only in the treatment of mood disorders, but also in neuronal survival‐, growth‐, and plasticity‐related signaling cascades. Thus, it has become critical to understand how BDNF synthesis is regulated. Much evidence exists that changes in BDNF expression result from the activation/phosphorylation of the transcription factor, cAMP‐response‐element binding protein (CREB) following the administration of antidepressant medications. Utilizing a mouse model genetically engineered with an inducible CREB repressor, our current study provides evidence that increases in BDNF expression and cellular survival signaling resulting from physical exercise are also dependent upon activation of this central transcription factor. The transcription and expression of hippocampal BDNF, as well as the activation of Akt, a key survival signaling molecule, were measured following acute exercise, and also following short‐term treatment with the norepinephrine reuptake inhibitor, reboxetine. We found that both interventions led to a marked increase in hippocampal BDNF mRNA, BDNF protein, and Akt phosphorylation (as well as CREB phosphorylation) in wild‐type mice. As expected, activation of the CREB repressor in mutant mice sharply decreased CREB phosphorylation. In addition, all measures noted above remained at baseline levels when mutant mice exercised or received reboxetine. Increases in BDNF and phospho‐Akt were also prevented when mutant mice received a combination of exercise and antidepressant treatment. The results are discussed in the context of what is currently known about BDNF signaling. © 2009 Wiley‐Liss, Inc.
Patterns of retrograde amnesia for recent and remote incidental spatial learning in rats
Authors: Gaskin Stephane , Tardif Marilyn , Mumby Dave G.
Published: March 2009

A non‐navigational test of incidental spatial learning was used to determine whether hippocampal damage causes temporally‐graded retrograde amnesia (TGRA) for allocentric‐spatial information. Rats were exposed to two identical objects in a circular open field for 7 min on seven consecutive days. In the 1–3 days after the last day of familiarization, rats received neurotoxic lesions of the hippocampal formation (HPC) or sham lesions. Another two groups received the same lesions 3 weeks after familiarization. The rats were then placed back in the open field with one object displaced, and the time spent in each of the quadrants as well as time spent exploring the objects was recorded. Rats that received HPC lesions 3 weeks but not 1–3 days after familiarization showed evidence of preserved remote spatial memory; however, their remote memory was expressed through different behavior than control rats. Rats with HPC lesions spent more time with the displaced object than with the object that remained in the same place, whereas control rats spent more time in the quadrant where the displaced object used to be. These results suggest that remote spatial memories may be preserved with a sufficiently long familiarization‐to‐surgery interval before HPC lesions, but that the nature of these memories may differ in quantity and/or quality from those of intact rats. © 2009 Wiley‐Liss, Inc.
Hydrological and sediment yield response to summer rainfall in a small high Arctic watershed
Authors: Dugan Hilary A. , Lamoureux Scott F. , Lafrenière Melissa J. , Lewis Ted
Published: March 2009

In cold regions, the response and related antecedent mechanisms that produce flood flows from rainfall events have received limited study. In 2007, a small watershed at Cape Bounty, Melville Island, Nunavut, was studied in detail during the melt season. Two rainfall events on June 30 and July 22, totalling 9·2 and 10·8 mm, respectively, represented significant contributions to seasonal discharge and sediment transport in a year with a low winter snowpack. The precipitation events elevated discharge and suspended sediment concentrations to twice the magnitude of the nival melt, and generated the only measurable downstream lacustrine turbidity current of the season. In two days, rainfall runoff transported 35% of the seasonal suspended sediment load, in contrast to 29% transported over the nival freshet. The magnitude and intensity of the rain events were not unusual in this setting, but the rainfall response was substantial in comparison with equivalent past events. Exceptional temperatures of July 2007 generated early, deep permafrost thaw, and ground ice melt. The resultant increase in soil moisture amplified the subsequent rainfall runoff and sediment transport response. These results demonstrate the importance of antecedent moisture conditions and the role of permafrost active layer development as an important factor in the rainfall runoff and sediment transport response to precipitation events. Copyright © 2009 John Wiley & Sons, Ltd.
Factors controlling the spatial variability of surface soil moisture within revegetated‐stabilized desert ecosystems of the Tengger Desert, Northern China
Authors: Pan Yan‐Xia , Wang Xin‐Ping
Published: March 2009

The spatial structure of surface soil moisture was investigated at a grid scale with 10 × 10 m intervals on a plot of 4500 m2 in a re‐vegetated desert area in Shapotou, the Tengger Desert. The site topography varies from dune crest to dune hollow, and again to dune crest. Volumetric soil moisture contents were measured 21 times over 6 months in 2006 by using Delta‐T Theta‐Probes in the 0–6 cm surface soil layer before and after rainfall. At the same time, soil texture, relative elevation, and plant coverage were measured, to examine (i) the spatial variability of surface soil moisture; (ii) the main factors controlling the spatial variability patterns; and (iii) how the importance of these factors varies with the seasonal variations in soil moisture content. The results indicated that the normal distribution of surface soil moisture was more obvious in wet conditions than in dry conditions; the spatial variability of surface soil moisture was inherent and decreased with increased soil moisture content; and precipitation increased the spatial dependence of surface soil moisture. The relative elevation of the landscape, the shrub coverage of the community, and the soil texture were the main factors influencing surface soil moisture variability, while the effect of soil texture strengthened gradually following the heavy precipitation events. The correlation between the spatial variability of surface soil moisture and the environmental factors, such as, the dry and wet conditions, the landscape coverage and the relative elevation suggests that increasing stability of the soil moisture resulted in a significant increase of soil moisture. Copyright © 2009 John Wiley & Sons, Ltd.
Religious coping among jews: development and initial validation of the JCOPE
Authors: Rosmarin David H. , Pargament, Kenneth I. , Krumrei Elizabeth J. , Flannelly Kevin J.
Published: March 2009

Numerous studies have underscored the importance of religious coping in psychological health and illness; however, the majority of research in this area has been conducted with Christian samples and knowledge about other religious groups is lacking. Although recent investigations have developed scales to measure religious coping among Hindus and Muslims, the potential for future research in Jewish populations remains limited as no measures of religious coping have been validated in the general Jewish community. This two‐part study reports on the development and validation of the 16‐item Jewish Religious Coping Scale (JCOPE). In Study 1, an exploratory factor analysis identified two factors reflecting positive and negative religious coping strategies, and the concurrent validity for the measure was evaluated by examining correlations with indices of Jewish beliefs and practices. In Study 2, a confirmatory factor analysis (CFA) verified the JCOPE's 2‐factor structure, and the scale's incremental validity was evaluated by examining Jewish religious coping as a predictor of psychological distress over and above significant covariates. Results suggest that the JCOPE has good psychometric properties, and that religious coping is a significant predictor of psychological distress among Jews. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65: 1–14, 2009.
Growth consulting: practical methods of facilitating growth through loss and adversity
Authors: Fazio Robert J.
Published: March 2009

The way that people lead themselves and others through crisis, loss, and adversity impacts their future and the future of those around them. Traditionally, mental health professionals have emphasized the negative consequences of crisis and loss. I present a story of how the simple act of holding the door for others on September 11th created a foundation for positive interventions. I offer the OTHERS(S) model and the process of growth consulting as practical means of creating growth as a result of loss or adversity. A case illustration and examples of clinical methods to facilitate Growth Through Loss and Adversity (GTLA) are provided. © 2009 Wiley Periodicals, Inc. J Clin Psychol: In Session 65: 1–12, 2009.
Production of α‐amylase under solid‐state fermentation utilizing coffee waste
Authors: Murthy Pushpa S. , Madhava Naidu M. , Srinivas Pullabhatla
Published: March 2009

Coffee industry substrates such as coffee pulp, coffee cherry husk, silver skin, spent coffee and mixtures of these coffee wastes (MC) were evaluated for their efficacy as sole carbon source for the synthesis of α‐amylase in solid‐state fermentation (SSF) using a fungal strain of Neurospora crassa CFR 308. For SSF with coffee pulp and with MC, α‐amylase activity of 3908 U g−1 ds (units per gram of dry substrate) and 3870 U g−1 ds, respectively, was observed. Parameters such as moisture (60%), pH (4.6), temperature (28 °C), particle size (1.0 mm), inoculum size (107 spores g−1 ds), and fermentation time (5 days) were optimized for enzyme synthesis, wherein 4981 and 4324 U g−1 U g−1 ds of α‐amylase activity was obtained in SSF with coffee pulp and MC, respectively. The enzyme production was further improved when the substrates were subjected to pre‐treatment by steaming. Accordingly, maximum α‐amylase activity of 7084 U g−1 ds and 6342 U g−1 ds was obtained with steam‐pretreated coffee pulp and MC, respectively, demonstrating them to be excellent sole carbon sources for synthesis of α‐amylase production. Copyright © 2009 Society of Chemical Industry
Gene expression study of Saccharomyces cerevisiae under changing growth conditions
Authors: Fu Pengcheng
Published: March 2009

BACKGROUND: DNA microarrays technology has been used to obtain expression profiles of thousands of genes at the same time for a given organism at relatively low costs. While gene expression approaches are being developed which allow holistic analysis of complex biological processes, there exist very few illustrative examples on the integration of large scale modeling and high throughput time course experiments to upgrade the information contents on yeast biology.

RESULTS: Saccharomyces cerevisiae cell culture experiments with perturbed growth conditions were designed so that the metabolic states would be shifted from one to another. Microarrays were used to explore changes in gene expression across the entire yeast genome during the perturbation experiments. Changes in transcript abundance in these growth periods were investigated to study the cellular response to different glucose and oxygen supply. Computational results and experimental observations representing the three characteristic metabolic states were compared on the S. cerevisiae metabolic pathways, as well as the visualization platform provided by the metabolic phenotypic phase plane (PhPP) for the gene regulation on cell metabolism and adaptation of cells to environmental changes.

CONCLUSIONS: The integrated expression study described reveals that S. cerevisiae cells respond to environmental changes mainly by down‐regulating a number of genes to alter the cell metabolism so that the cells adapt to the variations in their growth conditions. Copyright © 2009 Society of Chemical Industry
Volatile and non‐volatile acids of noni (Morinda citrifolia L.) fruit
Authors: Pino Jorge A , Márquez Eliosbel , Castro Déborah
Published: March 2009

BACKGROUND: Volatile and non‐volatile acids were analysed in noni (Morinda citrifolia L.) fruit by a combination of conventional sampling methods with gas chromatography/flame ionisation detection and gas chromatography/mass spectrometry.

RESULTS: A total of 34 volatile acids and 26 non‐volatile acids were identified in noni fruit. Octanoic acid (3.06 g kg−1) and hexanoic acid (0.33 g kg−1) were the major volatile acids, while malic acid (3.28 g kg−1), malonic acid (1.46 g kg−1) and fumaric acid (1.03 g kg−1) were the main non‐volatile acids.

CONCLUSION: The combination of conventional isolation methods and instrumental techniques provided the most representative information so far on noni fruit acids. Copyright © 2009 Society of Chemical Industry
Design of Experiment (DoE) as a Tool for the Optimization of Source Conditions in SEC‐ESI‐MS of Functional Synthetic Polymers Synthesized via ATRP
Authors: Gruendling Till , Guilhaus Michael , Barner‐Kowollik Christopher
Published: March 2009

Design of experiment (DoE) is applied to establish the optimum ionization conditions for analyzing synthetic polymers via coupled size exclusion chromatography electrospray ionization mass spectrometry (SEC‐ESI‐MS) yielding maximum ionization efficiency. The ion source conditions were optimized with regard to the ionization efficiency, the amount of fragmentation, as well as the formation of salt adducts. A D‐optimal experimental design was employed for this purpose and the recorded data were evaluated by a quadratic response surface model, accounting for possible interactions between the individual source settings. It was established that the ionization efficiency can be improved by up to one order of magnitude without compromising the softness of the ionization process and that optimal ionization conditions are found at similar source settings regardless of the charge state. The present optimization exercise therefore provides a hands‐on guide for the use of experimental design to determine optimum ionization conditions during the SEC‐ESI‐MS of functional polymers.

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Synthesis and ring‐opening polymerization of macrocyclic aryl ketone oligomers
Authors: Guo Q. Z. , Wang H. H. , Wu J. Y. , Guo D. , Chen T. L.
Published: March 2009

A series of macrocyclic aryl ketone oligomers were prepared by the reaction of phthaloyl dichloride or isophthaloyl dichloride with various bridge‐linking electron‐rich aromatic hydrocarbons 3a–d under pseudo‐high dilution conditions in the presence of Lewis base via Friedel–Crafts acylation reaction. Detailed structural characterization of these oligomers confirmed the cyclic nature by a combination of MALDI‐TOF‐MS, GPC, and 1H NMR analyses. These cyclic ketone oligomers have high solubility in organic solvents and the cyclic oligomers derived from phthaloyl dichloride are amorphous. The cyclic ketone oligomers readily undergo anionic ring‐opening polymerization in the melt by using potassium 4,4′‐biphenoxide as the initiator, producing linear, high molecular weight poly(ether ketone)s. Moreover, the isothermal chemorheology of the ring‐opening polymerization of cyclic oligomers 4a and 4b was also investigated. The results show that the shear viscosity of the molten reactive mixture is lower than 10 Pa · S at a constant shear rate of 0.05 rad/sec and increases slowly in the initial stage of ring‐opening polymerization. Copyright © 2009 John Wiley & Sons, Ltd.
Amniocentesis in the second trimester and congenital talipes equinovarus in the offspring: a population‐based record linkage study in Scotland
Authors: Cardy A. H. , Torrance N. , Clark D. , Miedzybrodzka Z. , Sharp L.
Published: March 2009

Background

To investigate whether amnniocentesis in the second trimester is associated with congenital talipes equinovarus (CTEV) in the offspring.

Methods

Case‐control study nested within a population‐based cohort, developed through linkage of the Scottish Congenital Anomalies Linked Database with records of amniocentesis from cytogenetics laboratories, including 564 299 singleton births 1992–2001. Odds ratios and 95% confidence intervals for CTEV in the offspring (isolated, non‐isolated, total) were calculated using logistic regression, adjusting for maternal age, year of birth and health board of birth.

Results

There was a modest positive association between total CTEV and amniocentesis at any time (OR = 1.27, 95% CI 0.99–1.65) and at ≥ 15 weeks (OR = 1.25, 95%CI 0.95–1.64). The association was strongest for non‐isolated CTEV (amniocentesis any time: OR = 1.68, 95%CI 1.08–2.61; amniocentesis ≥ 15 weeks: OR = 1.81, 95%CI 1.16–2.83). Amniocentesis at ≥ 20 weeks was associated with increased risk of total (OR = 5.87, 95% CI 3.38–10.21), non‐isolated (OR = 13.17, 95% CI 6.49–26.74) and isolated CTEV (OR = 3.10, 95% CI 1.28–7.49). There were no associations in mothers aged ≥ 35 years.

Conclusions

The modest association observed is most likely accounted for by amniocenteses conducted because of an earlier abnormal prenatal test. Thus, second trimester amniocentesis is unlikely to contribute to the development of CTEV in the offspring. Copyright © 2009 John Wiley & Sons, Ltd.
First‐trimester Down syndrome screening performance in the Dutch population; how to achieve further improvement?
Authors: Wortelboer E. J. , Koster M. P. H. , Stoutenbeek Ph. , Elvers L. H. , Loeber J. G. , Visser G. H. A. , Schielen P. C. J. I.
Published: March 2009

Objective

To study the performance of the first‐trimester combined test between 2004 and 2006 compared to a previous period to investigate changes in time and identify reasons for sub‐optimal performance.

Methods

Serum samples were analysed for pregnancy‐associated plasma protein A (PAPP‐A) and the free β subunit of human chorionic gonadotrophin (fβ‐hCG). Nuchal translucency (NT) was measured between 10 and 14 weeks. Tests were considered screen positive, if their calculated Down syndrome (DS) risk was at least 1 in 250 at term.

Results

A total of 20 293 singleton pregnancies were included in the analysis. The median maternal age fell from 35.7 to 34.3 years. The overall median weight‐corrected multiple of the median (MoM) values of PAPP‐A and fβ‐hCG were 1.12 and 1.03, respectively. The median MoM value of NT was 0.89 and increased from 0.82 to 0.96. Sixty‐six DS cases were detected by the screening test. The detection rate (DR) for DS was 75.9%, with a FPR of 3.3%.

Conclusion

The performance of the first‐trimester test has improved over the years. A better performance of the NT measurement was the main reason, although NT assessment should further be improved. In addition, a better setting of the medians for the biochemical parameters may contribute to a higher DR. Copyright © 2009 John Wiley & Sons, Ltd.
Quantitative analysis of cell signaling and drug action via mass spectrometry‐based systems level phosphoproteomics
Authors: Tedford Nathan C. , Hall Amy B. , Graham James R. , Murphy Cheryl E. , Gordon Neal F. , Radding Jeffrey A.
Published: March 2009

Protein phosphorylation is a primary form of information transfer in cell signaling pathways and plays a crucial role in regulating biological responses. Aberrant phosphorylation has been implicated in a number of diseases, and kinases and phosphatases, the cellular enzymes that control dynamic phosphorylation events, present attractive therapeutic targets. However, the innate complexity of signaling networks has presented many challenges to therapeutic target selection and successful drug development. Approaches in phosphoproteomics can contribute functional, systems‐level datasets across signaling networks that can provide insight into suitable drug targets, more broadly profile compound activities, and identify key biomarkers to assess clinical outcomes. Advances in MS‐based phosphoproteomics efforts now provide the ability to quantitate phosphorylation with throughput and sensitivity to sample a significant portion of the phosphoproteome in clinically relevant systems. This review will discuss recent work and examples of application data that demonstrate the utility of MS, with a particular focus on the use of quantitative phosphoproteomics and phosphotyrosine‐directed signaling analyses to provide robust measurement for functional biological interpretation of drug action on signaling and phenotypic outcomes.
Analysis of low molecular weight plasma proteins using ultrafiltration and large gel two‐dimensional electrophoresis
Authors: Jung Woon‐Won , Phark Sohee , Oh Sangnam , Khim Jin‐Young , Lee Juneyoung , Nam Myung Hee , Seo Jong Bok , Park So‐Young , Jo Eunkyung , Choi Seonyoung , Zheng Zhi , Lee Ji Young , Lee Min , Lee Eunil , Sul Donggeun
Published: March 2009

In this study, various solvent systems were applied to obtain a high and consistent recovery rate of low molecular weight plasma proteins (LMPP) from human plasma. A buffer system containing 7 M urea, 2 M thiourea, 25 mM NH4HCO3 + 20% ACN (pH 8.2) produced the highest recovery rate of LMPP. To validate the recovery of cut off membrane (COM) obtained using the urea buffer system, 27 different 30 kDa COMs were used to prepare the LMPP sample which were then subjected to 1‐D SDS‐PAGE. Statistical analysis showed that the buffer system with COM produced a consistent the recovery of LMPP. In addition, 2‐DE analysis was also conducted to determine the relative intensity of each protein spot. When molecular weight ranges over 30 kDa and under 30 kDa were evaluated, 953 and 587 protein spots were observed in the gels, respectively, resulting in a total of 1540 protein spots being resolved. Identification of the major proteins were then performed using a nano‐LC/MS system comprised of an HPLC system and an ESI‐quadrupole IT MS equipped with a nano‐ESI source.
Subproteome analysis of the neutrophil cytoskeleton
Authors: Xu Ping , Crawford Mark , Way Michael , Godovac‐Zimmermann Jasminka , Segal Anthony W. , Radulovic Marko
Published: March 2009

Neutrophils play a key role in the early host‐defense mechanisms due to their capacity to migrate into inflamed tissues and phagocytose microorganisms. The cytoskeleton has an essential role in these neutrophil functions, however, its composition is still poorly understood. We separately analyzed different cytoskeletal compartments: cytosolic skeleton, phagosome membrane skeleton, and plasma membrane skeleton. Using a proteomic approach, 138 nonredundant proteins were identified. Proteins not previously known to associate with the skeleton were: n‐acetylglucosamine kinase, phosphoglycerate mutase 1, prohibitin, ficolin‐1, phosphogluconate dehydrogenase, glucosidase, transketolase, major vault protein, valosin‐containing protein, aldehyde dehydrogenase, and lung cancer‐related protein‐8 (LCRP8). The majority of these proteins can be classified as energy metabolism enzymes. Such a finding was interesting because neutrophil energy metabolism is unusual, mainly relying on glycolysis. The enrichment of phosphoglycerate mutase in cytosolic skeleton was additionally indicated by the use of Western blotting. This is the broadest subcellular investigation to date of the neutrophil cytoskeletal proteome and the first proteomic analysis in any cell type of the phagosome skeleton. The association of metabolic enzymes with cytoskeleton is suggestive of the importance of their localized enrichment and macromolecular organization in neutrophils.
7th HUPO World Congress: The Human Disease Glycomics/Proteomics Initiative (HGPI) Session 17 August 2008, Amsterdam, The Netherlands
Authors: Pierce J. Michael , Taniguchi Naoyuki
Published: March 2009

The Human Disease Glycomics/Proteomics Initiative (HGPI) Session was held on August 17, 2008, at the HUPO World Congress in Amsterdam. Reports were made on the progress of the first and second analytical pilot studies to profile N‐ and O‐linked glycan structures of standard glycoproteins utilizing laboratories from around the world. In addition, recent advances in glycan structural analyses were presented, including the use of O‐linked glycan libraries of standards, use of negative mode nano‐LC‐MS for O‐linked glycan analysis, and identification of aberrant O‐glycosylation of IgA1 as a cause of IgA nephropathy. A report was made of a newly discovered lectin, malectin, which appears to function in the folding/quality control of glycoproteins with N‐linked glycans and may regulate several human disorders whose etiology involves protein quality control in the ER. The major glycan ligand for malectin was identified using a novel printed glycan microarray. Advances in the analysis of the genes that are associated with glycan expression and recognition – the glycotranscriptome – were described, as well as technologies to determine the relative quantitation of N‐ and O‐linked glycans from as few as 2×106 cells. These technologies are being applied to identify potential biomarkers of stem and cancer cells.
Polymerization of Halogenophosphazenes in Capacitively Induced Plasma Discharges
Authors: Vorac Zbynek , Alberti Milan , Janca Jan
Published: March 2009

This work studies the products of plasma polymerized (NPCl2)3, (NPCl2)4 and (NPF2)3. Reaction products were examined by the 31P‐NMR, LDI‐TOF MS, DIP‐MS, IR and XPS. To achieve a successful reaction of (NPCl2)4 it is crucial that the phosphazene is carefully heated to a temperature of about 60 °C. Analysis demonstrated that products of plasma polymerization are similar for all halogenophosphazenes and mainly consist of branched chains. The best homogeneity, adhesion to substrate and also easiest substitution of halogen atoms by nucleophilic reagents was achieved with plasma polymerized (NPF2)3. Prepared polymers could be used for surface improvement and as flame‐retardants.

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Configuration of Plasma Processes for the Generation of a Chemical Triple Pattern for Cell‐Based RNA Arrays
Authors: Schröder Karsten , Busse Benedikt , Steffen Hartmut , Ohl Andreas , Quade Antje , Weltmann Klaus‐Dieter
Published: March 2009

A threefold chemical patterning of polymer surfaces has been investigated for cell‐based biomedical diagnostics. Therefore, plasma processes have to be configured to realize three different cytocompatible surface modifications without any deterioration of optical properties. Sufficient chemical contrasts of different surface zones were realized by the application of pulsed downstream microwave plasmas, which also allowed the reduction of thermal load to the substrate. Sufficient contrasts in subsequent processing steps were realized with good local definition using polymeric masks in tight contact with the polymeric surface.
NMR Study of Polyethylene‐Like Plasma Polymer Films
Authors: Hanuš Jan , Hanyková Lenka , Choukourov Andrei , Kousal Jaroslav , Polonskyi Oleksandr , Slavínská Danka , Biederman Hynek
Published: March 2009

Thermal decomposition (“evaporation”) of polyethylene (PE) was performed with or without an activation of volatile fragments in an rf glow discharge. Study of the deposition process via quadrupole mass spectrometry showed the presence of hydrocarbon fragments up to 100 amu. Properties of the resulting films were investigated by means of FTIR, XPS, and NMR spectroscopy. These analyses showed that the activation of polymeric fragments in plasma enhances cross‐linking and the films become hydrocarbon plasma polymers. However, these plasma polymers resemble much more the original PE. In addition, NMR technique enabled to assess the ratio of crystalline and amorphous phases in the films.
SiCx Layers Prepared by Hybrid Laser Deposition and PLD
Authors: Jelínek Miroslav , Kocourek Tomáš , Zemek Josef , Kadlec Jaromír
Published: March 2009

Thin SiC films were fabricated using hybrid laser‐magnetron deposition system and pulsed laser deposition (PLD). In the hybrid system, a KrF excimer laser was used for deposition of carbon and magnetron at the same time for sputtering of Si species. Films were fabricated in hydrogen/argon, or in argon ambient. Results were compared with SiC films created using PLD only. Substrate temperature (Ts) was changed from room temperature (RT) up to 800 °C. Film topology, crystallinity, composition and chemical bonds were studied. Polycrystalline SiC films were prepared by both deposition techniques, in argon atmosphere, for Ts > 600 °C.
Structural and Mechanical Study of Nanocomposite Ti–Zr–C–H Coatings Prepared by Reactive Magnetron Sputtering
Authors: Martínez‐Martínez Diego , Kubová Olga , Delplancke‐Ogletree Marie‐Paule
Published: March 2009

Nanocomposite structures formed by small crystallites embedded in a lubricant matrix present moderate–high hardness, good toughness, and low values of friction coefficient and wear rate, and they are a promising alternative for protective tasks. In this study, we have prepared Ti–Zr–C–H films as potential candidates as protective layers for biocompatible applications. The constituting elements were selected due to their proven good biocompatibility at the macroscale. The films were prepared by reactive dc magnetron sputtering, and further characterized by X‐ray photoelectron spectroscopy and X‐ray diffraction. Mechanical and tribological properties were also evaluated.
Thermal Stability and Phase Transformations of γ‐/Amorphous‐Al2O3 Thin Films
Authors: Eklund Per , Sridharan Madanagurusamy , Singh Gurvinder , Bøttiger Jørgen
Published: March 2009

Magnetron‐sputtered Al2O3 thin films were annealed in ambient air. The phase compositions of the as‐deposited Al2O3 films were (i) fully amorphous, (ii) nanocrystalline γ‐Al2O3 in an amorphous Al2O3 matrix, and (iii) fully crystalline γ. For all samples, annealing to 1 100–1 150 °C resulted in a transformation to α‐alumina. The transformation paths depend on the phase fraction of γ in the as‐deposited films. For amorphous films and films with low initial γ fraction, the intermediate phase θ‐Al2O3 appeared in the range of 1 000–1 100 °C. For predominantly crystalline γ‐Al2O3 as‐deposited films no intermediate Al2O3 phases were observed, indicating a direct γ‐to‐α phase transformation at ∼1 100 °C.
Industrialisation Study of Nanocomposite nc‐TiC/a‐C Coatings for Electrical Contact Applications
Authors: Lewin Erik , Olsson Erik , André Benny , Joelsson Torbjörn , Öberg Åke , Wiklund Urban , Ljungcrantz Henrik , Jansson Ulf
Published: March 2009

Nanocomposite nc‐TiC/a‐C coatings were prepared by non‐reactive magnetron sputtering in industrial scale equipment, under varying deposition conditions in order to investigate up‐scaling and possible industrialisation. The coatings were found to have similar microstructure and performance compared to previous laboratory scale experiments. The samples were characterised with XRD, XPS and SEM as well with ball‐on‐disc, nanoindentation and electrical measurements. Coatings containing a small fraction of a‐C matrix phase were found to have promising both electrical properties (ρ < 400 µΩcm and contact resistances down to 0.34 mΩ at 40 N) and tribological properties (f < 0.3 for 10 000 laps).
Method to Determine the Sticking Coefficient of O2 on Deposited Al During Reactive Magnetron Sputtering, Using Mass Spectrometry
Authors: Leroy Wouter P. , Mahieu Stijn , Persoons Rosita , Depla Diederik
Published: March 2009

Models describing the reactive sputtering process need experimental input for some important parameters as the knock‐on yield, the reaction rate constant, the sticking coefficient on the target and the sticking coefficient on the deposited material. Here, a method is described to calculate the sticking coefficient of O2 on the deposited material, during reactive magnetron sputtering. Mass spectrometry is used to measure local, effective O2 partial pressure during sputtering, at the position of the sample. Combined with electron probe microanalysis of the oxygen content in deposited layers, we calculate the sticking coefficient. At our conditions, a local, effective pressure of (5.26 ± 0.44) × 10−6 mbar was found and an average sticking coefficient of 0.107 ± 0.032 for O2 on deposited aluminium during reactive magnetron sputtering.
Effect of annealing for CuInS2 thin films prepared from Cu‐rich ternary compound
Authors: Akaki Yoji , Nakamura Shigeuki , Nomoto Keita , Yoshitake Tsuyoshi , Yoshino Kenji
Published: March 2009

Evaporated CuInS2 films using a single‐source were annealed in H2S atmosphere from 250 to 500 °C for 60 min. after the evaporation. Polycrystalline CuInS2 powder grown by a hot‐press method was employed as a source material. Cu/In ratios of the source were 1.0, 1.2 and 1.5. All the films annealed above 350 °C were of CuInS2 single phase regardless of the Cu/In ratio of the source material. The films prepared from the source material of the Cu/In ratio of 1.5 became Cu‐rich films, which had the Cu/In ratio of 1.37. Carrier concentrations, resistivities and mobilities of the films annealed above 350 °C prepared from the source material of the Cu/In ratio of 1.5 were approximately 1×1021 cm–3, 0.1 Ωcm and 0.1 cm2/Vs, respectively, at room temperature. The activation energy of the film annealed at 400 °C was evaluated to be 6.5 meV. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Market orientation, marketing capabilities, and firm performance
Authors: Morgan Neil A. , Vorhies Douglas W. , Mason Charlotte H.
Published: March 2009

Drawing on traditional resource‐based theory and its recent dynamic capabilities theory extensions, we examine both the possession of a market orientation and the marketing capabilities through which resources are deployed into the marketplace as drivers of firm performance in a cross‐industry sample. Our findings indicate that market orientation and marketing capabilities are complementary assets that contribute to superior firm performance. We also find that market orientation has a direct effect on firms' return on assets (ROA), and that marketing capabilities directly impact both ROA and perceived firm performance. Copyright © 2009 John Wiley & Sons, Ltd.