bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of a Highly Efficient Alkylated Pincer Thioimido–Palladium(II) Complex as the Active Catalyst in Negishi Coupling
Authors: Liu Jing , Wang Haibo , Zhang Heng , Wu Xiaojun , Zhang Hua , Deng Yi , Yang Zhen , Lei Aiwen
Published: March 2009

PdII ate complex: A novel alkylated pincer thioimido–Pd complex generated from a catalyst precursor and basic organometallic reagents (RM) was observed by in situ IR, 1H NMR, and 13C NMR spectroscopies for the first time and proved to be the active catalyst in stoichiometric and catalytic reactions of aryl iodides with RM (see scheme). The catalyst, as an electron‐rich PdII species, promoted the Negishi coupling of aryl iodides and alkylzinc reagents with high efficiency, even at low temperatures (0 or −20 °C).

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The induction period of Negishi coupling catalyzed by pincer thioamide–palladium complex 1 was investigated. A heterogeneous mechanism was excluded by kinetic studies and comparison with Negishi coupling reactions promoted by Pd(OAc)2/Bu4NBr (a palladium–nanoparticle system). Tetramer 2 was isolated from the reaction of 1 and organozinc reagents. Dissociation of complex 2 by PPh3 was achieved, and the structure of resultant complex 8 was confirmed by X‐ray diffraction analysis. A novel alkylated pincer thioimido–PdII complex, 7, generated from catalyst precursor 1 and basic organometallic reagents (RM), was observed by in situ IR, 1H NMR, and 13C NMR spectroscopy for the first time. The reaction of 7 with methyl 2‐iodobenzoate afforded 74 % of the cross‐coupled product, methyl 2‐methylbenzoate, together with 60 % of PdII complex 2. Furthermore, the catalyst, as an electron‐rich PdII species, efficiently promoted the Negishi coupling of aryl iodides and alkylzinc reagents without an induction period, even at low temperatures (0 °C or −20 °C). To evaluate the influence of the catalyst structure upon the induction period, complex 9 was prepared, in which the nBu groups of 1 were displaced by more bulky 1,3,5‐trimethylphenyl groups. Trimer 10 was isolated from the reaction of complex 9 and basic organometallic reagents such as CyZnCl or CyMgCl (Cy: cyclohexyl); this is consistent with the result obtained with complex 1. The rate in the induction period of the model reaction catalyzed by 9 was faster than that with 1. Plausible catalytic cycles for the reaction, based upon the experimental results, are discussed.
Determination of the Catalytic Pathway of a Manganese Arginase Enzyme Through Density Functional Investigation
Authors: Leopoldini Monica , Russo Nino , Toscano Marirosa
Published: March 2009

The catalytic mechanism of dimanganese‐containing arginase enzyme has been investigated by DFT calculations. Two exchange‐correlation functionals, B3 LYP and MPWB1 K, have been used to construct the potential energy profiles for the hydrolysis of an arginine substrate performed by an arginase active site model system. Two reaction mechanisms have been investigated, one involving a water molecule (mechanism 1) and the other involving a hydroxide ion (mechanism 2) as nucleophilic agent. Results obtained in the gas phase and in the protein environment have indicated that mechanism 1 involving a water molecule entails structural features as well as an activation energy for the rate‐determining step that are inconsistent with experimental data available for the arginase enzyme. On the other hand, when a hydroxide ion is present at the Mn2 site, a lower activation energy and a structural arrangement closer to the experimental indication are obtained.
Well‐Defined Silica‐Supported Calcium Reagents: Control of Schlenk Equilibrium by Grafting
Authors: Gauvin Régis M. , Buch Frank , Delevoye Laurent , Harder Sjoerd
Published: March 2009

Bound to stay heteroleptic: Grafting of homoleptic benzyl and amide calcium reagents onto silica affords well‐defined supported heteroleptic species, catalytically active in hydrosilylation, hydroamination, and styrene polymerization. The fact that attempts to generate a molecular model were thwarted by the Schlenk equilibrium affording the homoleptic compound (see scheme) emphasizes the importance of immobilization as an approach for the syntheses of heteroleptic calcium complexes.

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Calcium reagents Ca(α‐Me3Si‐2‐Me2N‐benzyl)2⋅2 thf (1) and Ca[N(SiMe3)2]2⋅2 thf (2) reacted with silica partially dehydroxylated at 700 °C to afford materials that bear (SiO)Ca(α‐Me3Si‐2‐Me2N‐benzyl)⋅1.6 thf (SiO2‐1) and (SiO)Ca [N(SiMe3)2]⋅1.3 thf (SiO2‐2) fragments, respectively. Due to the bulk of the supported complexes, the silanol groups are only partially metalated: 50 % in SiO2‐1 and 70 % in SiO2‐2. In the case of SiO2‐2, a parallel SiMe3‐capping side reaction affords in fine a silanol‐free surface. The materials were characterized by IR spectroscopy, 1D and 2D solid‐state high‐field NMR spectroscopy, and elemental analysis. Reaction of 2 with one equivalent of the bulky silanol (tBuO)3SiOH, a silica‐surface mimic, afforded the homoleptic bis‐silyloxide calcium derivative through ligand exchange (Schlenk equilibrium), and a derivative was isolated and structurally characterized. Preliminary studies have shown that both grafted benzyl and amide derivatives are active in olefin hydrosilylation, intramolecular hydroamination, and styrene polymerization, with evidence showing that catalysis occurs through supported species. In styrene polymerization, a marked influence of the surface acting as a ligand on the stereoselectivity of the reaction was observed, as syndiotactic‐rich polystyrene (88 % of r diads) was obtained. These results illustrate that grafting of calcium benzyl or amide compounds on a silica surface is a new concept to prevent ligand exchange through the Schlenk equilibrium. Heteroleptic calcium complexes that cannot be synthesized as stable molecular species in solution can be obtained as silica‐supported species which have been shown to be catalytically active.
Flavonoid Dimers as Bivalent Modulators for P‐Glycoprotein‐Based Multidrug Resistance: Structure–Activity Relationships
Authors: Chan Kin‐Fai , Zhao Yunzhe , Chow Toby W. S. , Yan Clare S. W. , Ma Dik Lung , Burkett Brendan A. , Wong Iris L. K. , Chow Larry M. C. , Chan Tak Hang
Published: March 2009

Bivalent modulators of P‐glycoprotein: A small library of flavonoid homodimers and heterodimers was synthesized, and their in vitro activity in reversing paclitaxel resistance was evaluated along with structure–activity relationships. SAR trends indicate that flavonoid dimers with nonpolar, hydrophobic, less bulky substituents generally show more potent reversing activity. This will help guide future efforts in the search for more potent compounds.

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We recently described the modulatory activities of apigenin homodimers linked by ethylene glycol units in multidrug‐ resistant breast cancer and leukemic cells overexpressing ABCB1 (P‐glycoprotein, P‐gp). To further improve the potency of these dimers, a small library of flavonoid homodimers and heterodimers were synthesized, and their in vitro activity in reversing cellular resistance to paclitaxel, along with structure–activity relationships (SAR), were evaluated using a P‐gp‐expressing human breast cancer cell line. Among these synthesized homodimers, many showed more potent reversing activity than that of the parent compound and verapamil. Two compounds in particular showed promising reversing activity at sub‐micromolar concentrations with no cytotoxic effects. Regarding SAR trends, flavonoid dimers with nonpolar and hydrophobic substituents (e.g., methyl and ethyl groups) generally showed more potent resistance‐reversing activity than that of dimers with polar and hydrophilic substituents (e.g. hydroxy groups) at the C3, C6, and C7 positions, but not at C5. In terms of substituent steric bulk at C6, it was found that the flavonoid dimer with methyl groups was optimal, with bulkier substituents leading to lower reversing activity. Comparisons of flavonoid heterodimers with the corresponding homodimers revealed that the two binding sites on P‐gp for flavonoid moieties are quite similar to each other. Besides paclitaxel, these new compounds also increased drug accumulation and enhanced the cytotoxicity of other cancer drugs such as doxorubicin, vincristine, and vinblastine by decreasing the IC50values 4–45‐fold.
Phagocytosis and postphagocytic reaction of cord blood and adult blood monocyte after infection with green fluorescent protein‐labeled Escherichia coli and group B Streptococci
Authors: Gille Ch. , Leiber A. , Mundle I. , Spring B. , Abele H. , Spellerberg B. , Hartmann H. , Poets Ch. F. , Orlikowsky Th. W.
Published: March 2009

Background:

Neonatal sepsis is characterized by an excessive inflammatory response induced by immune cells (monocytes). We investigated the initial stage of monocyte‐pathogen interaction, i.e. bacterial ingestion and degradation at the single‐cell level, by comparing a new flow cytometric procedure with culture methods. We also examined the hypothesis that, in terms of phagocytosis‐induced cell death (PICD), phenotype, or cytokine production, cord blood monocytes (CBMO) differ from monocytes derived from adults (peripheral blood monocytes, PBMO).

Methods:

Phagocytosis and intracellular degradation were assessed by means of flow cytometry and bacterial cultures of green fluorescent protein‐labeled group B Streptococci (GBS) and Escherichia coli. The production of reactive oxygen species (ROS) was measured through luminol‐enhanced chemiluminescence. Apoptosis, phenotype, and cytokine production were assessed through flow cytometry.

Results:

Flow cytometry and bacterial cultures showed no difference between phagocytosis and degradation of GBS and E. coli by PBMO and CBMO. A high correlation between both methods was observed. No difference in ROS production was evident. In comparison with PBMO, CBMO apoptosis was lower after exposure to GBS and E. coli. Similarities were found between nonapoptotic monocytes and pro‐inflammatory monocytes.

Conclusions:

PICD is lower in CBMO during the early stages of monocyte‐pathogen interaction. Our results emphasize that monocyte apoptosis has a potential role in tailoring the immune response in neonatal sepsis. © 2009 Clinical Cytometry Society
Management implications of the relationships between water chemistry and fishes within channelized headwater streams in the midwestern United States
Authors: Smiley Peter C. , Gillespie Robert B. , King Kevin W. , Huang Chi‐hua
Published: March 2009

Many headwater streams in the midwestern United States were channelized for agricultural drainage. Conservation practices are implemented to reduce nutrient, pesticide, and sediment loadings within these altered streams. The impact of these practices is not well understood because their ecological impacts have not been evaluated and the relationships between water chemistry and fishes are not well understood. We evaluated relationships between water chemistry and fish communities within channelized headwater streams of Cedar Creek, Indiana, and Upper Big Walnut Creek, Ohio. Measurements of water chemistry, hydrology, and fishes have been collected from 20 sites beginning in 2005. Multiple regression analyses indicated that the relationships between water chemistry and fish communities were weak, but significant (P < 0·05). Fish communities exhibited negative relationships with ammonium and nitrate plus nitrite and positive relationships with dissolved oxygen, pH, and metolachlor. The strongest observed relationships occurred within those regression models that included a combination of nutrients, herbicides, and physicochemical variables. Multiple regression analyses also indicated that five water chemistry variables exhibited significant relationships (P < 0·05) with hydrology. Our results suggest that if water chemistry is the focus of a conservation plan, then the most effective conservation practices may be those that have a combined influence on nutrients, herbicides, and physicochemical variables. Additionally, the use of a combination of conservation practices to address physical habitat and water chemistry degradation is most likely to provide the greatest benefits for fish communities within channelized headwater streams. Copyright © 2009 John Wiley & Sons, Ltd.
Supercritical Hydrothermal Synthesis of Silicon‐Functional Metal and Metal Oxide Nanoparticles
Authors: Ogawa Takuya , Furudate Manabu , Oshima Yoshito
Published: March 2009

A supercritical hydrothermal reaction was applied to synthesise silicon‐functional metal and metal oxide nanoparticles. The Si‐functionalised nanoparticles were formed by the hydrothermal reaction of metal salts and subsequent surface modification of the resultant particles by organofunctional silicon compounds. The metal salts studied were copper nitrate and acetate. Si‐functionalised copper nanoparticles with a size below 10 nm were formed when an epoxy‐functional silicone compound was used. The compositions, shapes and sizes of the resultant particles proved to be affected by the structures of the silicon compounds. As for the properties, the resultant particles were hydrophobic while nonfunctional particles were hydrophilic. This methodology can be potentially applied to the synthesis of Si‐based nanohybrid materials in which such surface‐modified nanoparticles are well dispersed in a polysiloxane matrix. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of the C11–C23 Fragment of the Potent Antitumor Agent Dictyostatin (Eur. J. Org. Chem. 10/2009)
Authors: Dias Luiz C. , Lima Dimas J. P. , Gonçalves Caroline C. S. , Andricopulo Adriano D.
Published: March 2009

The cover picture shows the intermolecular interactions between the marine‐derived dictyostatin and the β‐tubulin binding site, as well as some important molecular fragments of the required 15‐step sequence to produce the C11–C23 fragment (highlighted in blue) of dictyostatin in good overall yield. Dictyostatin, an unsaturated 22‐membered macrolactone containing 11 stereocenters, a (Z)‐alkene, and two diene systems, exhibits potent antitumoral activity as a consequence of its reversible and specific binding to the β‐tubulin cavity and modulation of microtubule function. Details of the synthesis and characterization of the C11–C23 fragment are reported in the Short Communication by L. C. Dias et al. on p. 1491 ff. The authors thank Ms. Lívia B. Salum for her contribution to the design of the cover picture.
Do schema processes mediate links between parenting and eating pathology?
Authors: Sheffield Alex , Waller Glenn , Emanuelli Francesca , Murray James , Meyer Caroline
Published: March 2009

Objective

Adverse parenting experiences are commonly linked to eating pathology. A schema‐based model of the development and maintenance of eating pathology proposes that one of the potential mediators of the link between parenting and eating pathology might be the development of schema maintenance processes—mechanisms that operate to help the individual avoid intolerable emotions.

Method

To test this hypothesis, 353 female students and 124 female eating‐disordered clients were recruited. They completed a measure of perceived parenting experiences as related to schema development (Young Parenting Inventory‐Revised (YPI‐R)), two measures of schema processes (Young Compensatory Inventory; Young–Rygh Avoidance Inventory (YRAI)) and a measure of eating pathology (Eating Disorders Inventory (EDI)).

Results

In support of the hypothesis, certain schema processes did mediate the relationship between specific perceptions of parenting and particular forms of eating pathology, although these were different for the clinical and non‐clinical samples.

Discussion

In those patients where parenting is implicated in the development of eating pathology, treatment might need to target the cognitive processes that can explain this link. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association.
Forest blowdown impacts of Hurricane Rita on fluvial systems
Authors: Phillips Jonathan D. , Park Lisa
Published: March 2009

Hurricane Rita, a category three hurricane which struck the US Gulf Coast near the Louisiana/Texas border in 2005, did not cause extensive river flooding. However, the storm did result in extensive forest damage and tree blowdown. High‐resolution post‐storm aerial photography allowed an inventory of river bank trees blown into the channel along the lower Neches and Sabine Rivers of southeast Texas and southwest Louisiana. Blowdowns directly into the channel averaged 9·3 per kilometer in the lower Neches and 13·4 in the lower Sabine River, but individual reaches 10 to 20 km in length had rates of 20 to 44 blowdowns per kilometer. Though large woody debris (LWD) from Hurricane Rita was widely perceived to reduce the capacity of channels to convey flow, no strong evidence exists of increased flooding or significant reductions in channel conveyance capacity due to LWD from the storm. The Rita blowdown inventory also allowed an assessment of whether similar blowdown events could account for major logjams and rafts on Red, Atchafalaya, and Colorado Rivers on the Gulf Coast, which blocked navigation from tens to hundreds of kilometers in the 1800s. Results from Hurricane Rita suggest that blowdown into channels alone – not withstanding blowdown elsewhere in the river valleys or along tributaries which could deliver LWD to the river – is sufficient to completely block channels, thus providing a plausible mechanism for initiating such (pre)historic log rafts. Copyright © 2009 John Wiley & Sons, Ltd.
Functional and effective connectivity of visuomotor control systems demonstrated using generalized partial least squares and structural equation modeling
Authors: Lin Fa‐Hsuan , Agnew John A. , Belliveau John W. , Zeffiro Thomas A.
Published: March 2009

Tasks employing parametric variation in movement rate are associated with predictable modulations in neural activity and provide a convenient context for developing new techniques for system identification. Using a multistage approach, we explored the functional and effective connectivity of a visuomotor control system by combining generalized partial least squares (gPLS) with subsequent structural equation modeling (SEM) to reveal the relationships between neural activity and finger movement rate in an experiment involving visually paced left or right thumb flexion. The gPLS in the first analysis stage automatically identified spatially distributed sets of BOLD‐contrast signal changes using linear combinations of sigmoidal basis functions parameterized by kinematic variables. The gPLS provided superior sensitivity in detecting task‐related functional activity patterns via a step‐wise comparison with both classical linear modeling and behavior correlation analysis. These activity patterns were used in the second analysis stage, which employed SEM to characterize the areal regional interactions. The hybrid gPLS/SEM procedure allowed modeling of complex regional interactions in a network including primary motor cortex, premotor areas, cerebellum, thalamus, and basal ganglia, with differential activity modulations with respect to rate observed in the corticocerebellar and corticostriate subsystems. This effective connectivity analysis of visuomotor control circuits showed that both the left and right corticocerebellar and corticostriate circuits exhibited movement rate‐related modulation. The identification of the functional connectivity among regions participating particular classes of behavior using gPLS, followed by the estimation of the effective connectivity using SEM is an efficient means to characterize the neural interactions underlying variations in sensorimotor behavior. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Functional abnormalities in the dyslexic brain: A quantitative meta‐analysis of neuroimaging studies
Authors: Richlan Fabio , Kronbichler Martin , Wimmer Heinz
Published: March 2009

This study used foci from 17 original studies on functional abnormalities in the dyslexic brain to identify brain regions with consistent under‐ or overactivation. Studies were included when reading or reading‐related tasks were performed on visually presented stimuli and when results reported coordinates for group differences. Activation likelihood estimation (ALE) was used for quantification. Maxima of underactivation were found in inferior parietal, superior temporal, middle and inferior temporal, and fusiform regions of the left hemisphere. With respect to left frontal abnormalities, we found underactivation in the inferior frontal gyrus to be accompanied by overactivation in the primary motor cortex and the anterior insula. Tentative functional interpretations of the activation abnormalities are provided. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Functional interactions guiding adaptive processing of behavioral significance
Authors: Diekhof Esther Kristina , Falkai Peter , Gruber Oliver
Published: March 2009

The ability to quickly decide on the nature of unexpected environmental changes is vital for adaptive behavior. Converging evidence suggests that the orbitofrontal cortex plays an important role in the rapid assignment of motivational significance and goal relevance to environmental stimuli. However, its putative role as a central part of a network involved in the prioritization of attentional selection, particulary when significant environmental changes occur unexpectedly or outside of attentional focus, remains to be established. Therefore, we used functional magnetic resonance imaging with a subsequent psychophysiological interaction analysis to reveal the functional connectivity of the right posterior orbitofrontal cortex (pOFC) in a context, in which subjects had to adjust goal‐directed behavior to behaviorally relevant events presented outside of the current attentional focus. As expected, an increased functional interaction between pOFC and regions involved in the modulation of selective attention (pulvinar nucleus and inferior parietal lobule) and processing of “bottom‐up” salience (substantia nigra) could be observed when unattended, but significant changes were relevant for behavior. Moreover, a positive correlation between level of accuracy and an increased functional connectivity between pOFC and extrastriate cortex suggested that a motivationally‐triggered signal from pOFC may have increased visual processing of the relevant but currently unattended stimulus attribute. These data provide evidence that the interplay between the pOFC and these regions underlies a mechanism by which organisms rapidly achieve voluntary control of attentional resources to deal with behaviorally significant changes that occur outside of current attentional focus. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Estimating the effectiveness of a rotational irrigation delivery system: A case study from Pakistan
Authors: Zardari Noor ul Hassan , Cordery Ian
Published: March 2009

In this study, basic principles of the rotational irrigation water delivery system of Pakistan (i.e. the warabandi) and the performance of the warabandi system under current socio‐economic conditions have been investigated from a farmers' survey completed from 154 farmers located on five watercourses of the lower Indus River Basin. It is shown that irrigation water allocation based on very limited criteria does not give much incentive to the farmers for improving agricultural income. Also, the survey results suggest that the productivity of limited irrigation water could not be maximized under the warabandi system. We have therefore suggested the basic principles of the warabandi system should be revised by making them suitable for the current socio‐economic conditions. We propose that the existence or non‐existence of fresh groundwater resources along with other critical variables should be taken into consideration when making canal water allocation decisions. A framework to allow distribution equity and efficiency in water allocations – such as considering the gross area of a tertiary canal, sensitivity of crop growth stage to water shortage, crop value, bias of allocation towards most water use efficient areas, the potential losses from water deficiency, etc. – should be developed as a tool to improve water productivity for Pakistan and for individual farmers. The contribution of groundwater in the farmers' income from agriculture and the economic value of irrigation water have also been estimated. Copyright © 2009 John Wiley & Sons, Ltd.
Head ditch hydraulics and the variability of inflows to irrigation furrows
Authors: Smith R. J. , Gillies M. H.
Published: March 2009

The spatial variability and temporal variation of furrow inflows have a major impact on the performance of furrow irrigation, as indicated by the usual measures of application efficiency and uniformity. They also cause difficulties in determining the soil infiltration characteristic through inverse solution techniques and in selecting preferred values for the operational variables of flow rate and time to cut‐off to give maximum performance at the field scale.

In this paper a steady spatially varied flow analysis is performed to predict the steady water surface profiles in a typical head ditch and the subsequent spatial variability of the furrow inflows, for both pipe or siphon and sill or bankless‐type water application systems. The resulting patterns were very similar to those seen in the spatially varied pipe flow in gated pipe, with depths and outflows increasing toward the downstream end of the channel. It is shown that it is feasible to design head ditches to minimise the variability in outflows. An unsteady analysis of the same head ditch illustrated the variation of outflows with time caused by the time taken to fill the channel. Copyright © 2009 John Wiley & Sons, Ltd.
An AC electrokinetic method for enhanced detection of DNA nanoparticles
Authors: Krishnan Rajaram , Heller Michael J.
Published: March 2009

In biomedical research and diagnostics it is a challenge to isolate and detect low levels of nanoparticles and nanoscale biomarkers in blood and other biological samples. While highly sensitive epifluorescent microscope systems are available for ultra low level detection, the isolation of the specific entities from large sample volumes is often the bigger limitation. AC electrokinetic techniques like dielectrophoresis (DEP) offer an attractive mechanism for specifically concentrating nanoparticles into microscopic locations. Unfortunately, DEP requires significant sample dilution thus making the technology unsuitable for biological applications. Using a microelectrode array device, special conditions have been found for the separation of hmw‐DNA and nanoparticles under high conductance (ionic strength) conditions. At AC frequencies in the 3000–10 000 Hz range, 10 μm microspheres and human T lymphocytes can be isolated into the DEP low field regions, while hmw‐DNA and nanoparticles can be concentrated into microscopic high field regions for subsequent detection using an epifluorescent system. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Compartmentalization of epidermal growth factor receptor in liver plasma membrane
Authors: Wang Ye , Posner Barry I. , Balbis Alejandro
Published: March 2009

We have investigated epidermal growth factor (EGF)‐induced compartmentalization and activation of the EGF receptor (EGFR) in rat liver plasma membrane (PM) raft subfractions prepared by three different biochemical methods previously developed to characterize the composition of membrane rafts. Only detergent‐resistant membranes (DRMs) possessed the basic characteristics attributed to membrane rafts. Following the administration of a low dose of EGF (1 µg/100 g BW) the content of EGFR in PM–DRMs did not change significantly; whereas after a higher dose of EGF (5 µg/100 g BW) we observed a rapid and marked disappearance of EGFR (around 80%) from both PM and DRM fractions. Interestingly, following the administration of either a low or high dose of EGF, the pool of EGFR in the PM–DRM fraction became highly Tyr‐phosphorylated. In accordance with the higher level of EGFR Tyr‐Phosphorylation, EGF induced an augmented recruitment of Grb2 and Shc proteins to PM–DRMs compared with whole PM. Furthermore neither high nor low doses of EGF affected the caveolin content in DRMs and PM. These observations suggest that EGFR located in DRMs are competent for signaling, and non‐caveolae PM rafts are involved in the compartmentalization and internalization of the EGFR. J. Cell. Biochem. 107: 96–103, 2009. © 2009 Wiley‐Liss, Inc.
The perinucleolar compartment
Authors: Pollock Callie , Huang Sui
Published: March 2009

The perinucleolar compartment (PNC) is a distinct nuclear body that localizes to the nucleolar periphery. The PNC is predominantly found in cancer cells, and recent evidence suggests that PNC prevalence can be a pan‐cancer marker for tumors of solid tissue origin. The PNC is a heritable structure enriched with newly transcribed pol III RNAs and RNA‐binding proteins, which exchange rapidly with the surrounding nucleoplasm. The structural integrity of the PNC is dependent upon the continuous transcription of pol III RNA and an intact DNA structure. Although the complete structure and function of the PNC remains to be resolved, much progress has been made in the characterization of the PNC in recent years. Here we summarize our current understanding of the dynamics, structure and function of the PNC. J. Cell. Biochem. 107: 189–193, 2009. © 2009 Wiley‐Liss, Inc.
A high mobility group B‐1 box A peptide combined with an artery wall binding peptide targets delivery of nucleic acids to smooth muscle cells
Authors: Han Jee Seung , Kim Kyunghwa , Lee Minhyung
Published: March 2009

The TAT‐high mobility group box‐1 A box peptide (TAT‐HMGB1A) has been reported previously to be able to deliver DNA into cells without cytotoxicity. In this study, an artery wall smooth muscle cell‐targeting carrier was developed using TAT‐HMGB1A combined with an artery wall binding peptide (ABP). For the production of ABP linked TAT‐HMGB1A (TAT‐HMGB1A‐ABP), pET15b‐TAT‐HMGB1A‐ABP was constructed by inserting the ABP cDNA into pET15b‐TAT‐HMGB1A. TAT‐HMGB1A‐ABP was expressed in E. coli and purified by Nickel chelate chromatography. Gel retardation assays showed that TAT‐HMGB1A‐ABP formed a complex with the plasmid at or above a 5:1 weight ratio (peptide:plasmid). At a 20:1 weight ratio, the zeta‐potential was ∼25 mV and the particle size was ∼120 nm. TAT‐HMGB1A‐ABP had the highest transfection efficiency in A7R5 smooth muscle cells at a weight ratio of 20:1. TAT‐HMGB1A‐ABP exhibited higher transfection efficiency in A7R5 cells than PLL or TAT‐HMGB1A, while TAT‐HMGB1A‐ABP had lower transfection efficiencies in Hep3B hepatoma, 293 kidney, NIH3T3 fibroblast, and Raw264.7 macrophage cells compared with PLL. Together, these results suggest that the ABP moiety of the peptide increased transfection efficiency specifically in smooth muscle cells. In a competition assay, the transfection efficiency of TAT‐HMGB1A‐ABP in A7R5 cells was reduced by the addition of free ABP. MTT assays showed that TAT‐HMGB1A‐ABP did not produce any cytotoxicity in A7R5 cells. Therefore, TAT‐HMGB1A‐ABP may be useful for a targeting gene delivery to smooth muscle cells. J. Cell. Biochem. 107: 163–170, 2009. © 2009 Wiley‐Liss, Inc.
Global transcriptome analysis in mouse calvarial osteoblasts highlights sets of genes regulated by modeled microgravity and identifies a “mechanoresponsive osteoblast gene signature”
Authors: Capulli Mattia , Rufo Anna , Teti Anna , Rucci Nadia
Published: March 2009

Mechanical unloading is known to be detrimental for the skeleton, but the underlying molecular mechanisms are not fully elucidated. We performed global transcriptome analysis of mouse calvarial osteoblasts grown for 5 days at unit gravity (1g) or under modeled microgravity (0.008g) in the NASA‐developed rotating wall vessel (RWV) bioreactor. Elaboration of gene profiling data evidenced that, among the >20,000 gene probes evaluated, 45 genes were significantly up‐regulated (cut‐off >2) and 88 were down‐regulated (cut‐off <0.5) in modeled microgravity versus 1g. This set of regulated genes includes genes involved in osteoblast differentiation, function, and osteoblast–osteoclast cross‐talk, as well as new genes not previously correlated with bone metabolism. Microarray data were validated for subsets of genes by real‐time RT‐PCR, Western blot, or functional analysis. The significantly modulated genes were then clustered using the GOTM (Gene Ontology Tree Machine) software. This analysis evidenced up‐regulation of genes involved in the induction of apoptosis, in response to stress and in the activity of selected growth factors. Other molecular functions, such as extracellular matrix structural constituent, glycosaminoglycan/heparin‐binding activity, and other growth factor activity, were instead down‐regulated. We finally matched our transcriptome results with other public global gene profiles obtained in loading and unloading conditions, identifying 10 shared regulated genes which could represent an “osteoblast mechanoresponsive gene signature.” J. Cell. Biochem. 107: 240–252, 2009. © 2009 Wiley‐Liss, Inc.
On the density of 2‐colorable 3‐graphs in which any four points span at most two edges
Authors: Markström Klas , Talbot John
Published: March 2009

Let ex2(n, K) be the maximum number of edges in a 2‐colorable K‐free 3‐graph (where K={123, 124, 134} ). The 2‐chromatic Turán density of K is \documentclass{article}\footskip=0pc\pagestyle{empty}\begin{document}$\pi_{2}({K}_{4}^-) =lim_{{n}\to \infty} {ex}_{2}({n}, {K}_{4}^-)/\left(_{3}^{n}\right)$\end{document}. We improve the previously best known lower and upper bounds of 0.25682 and 3/10−ε, respectively, by showing that

This implies the following new upper bound for the Turán density of K

In order to establish these results we use a combination of the properties of computer‐generated extremal 3‐graphs for small n and an argument based on “super‐saturation”. Our computer results determine the exact values of ex(n, K) for n≤19 and ex2(n, K) for n≤17, as well as the sets of extremal 3‐graphs for those n. © 2009 Wiley Periodicals, Inc. J Combin Designs 18: 105–114, 2010
Interleukin‐18 gene 105A/C genetic polymorphism is associated with the susceptibility of Kawasaki disease
Authors: Chen Shih‐Yin , Wan Lei , Huang Yu‐Chuen , Sheu Jim Jinn‐Chyuan , Lan Yu‐Ching , Lai Chih‐Ho , Lin Cheng‐Wen , Chang Jeng Sheng , Tsai Yuhsin , Liu Shih‐Ping , Lin Ying‐Ju , Tsai Fuu‐Jen
Published: March 2009

Interleukin‐18 (IL‐18)‐656T/G, ‐607A/C, and ‐137C/G promoter polymorphisms had been reported associated with Kawasaki disease (KD). An IL‐18 genetic A/C polymorphism at coding position 105 (rs549908) has been linked with asthma, rheumatoid, and systemic lupus erythematosus. We tested a hypothesis that the IL‐18 105A/C genetic polymorphism confers KD susceptibility. Study participants were Taiwanese KD patients and a healthy control group. Our data indicated that the frequency of C allele was significantly higher in the patient group (13.9%) than in the control group (2.7%; P<0.0001, odds ratio [OR]=5.93; 95% confidence interval [CI]=2.57–13.73). Therefore, persons with the C allele may have higher risk of deve loping KD. In addition, compared with the haplotype frequencies between case and control groups, the KD patients with TACC haplotype appeared to be a significant “at‐risk” haplotype compared with other haplotypes (OR: 4.62, 95% CI: 1.71–12.43; P=0.001). KD patient with the TAGA haplotype appeared to be a significant “protective” haplotype compared with other haplotypes (OR: 0.51, 95% CI:0.29–0.89; P=0.017). Our results suggest that 105A/C polymorphism and the haplotypes in IL‐18 gene are associated with the risk of KD in Taiwanese population. Clin. Lab. Anal. 23:71–76, 2009. © 2009 Wiley‐Liss, Inc.
Transferrin D protein variants in the diagnosis of congenital disorders of glycosylation (CDG)
Authors: Marklová Eliška , Albahri Ziad
Published: March 2009

Congenital disorders of glycosylation are a rapidly growing group of inherited (neuro)metabolic disorders characterized by defects in glycosylation of proteins and lipids. This study discusses an analytical problem in the differentiation between hypoglycosylation and transferrin (Tf) protein variants. Analysis of serum Tf by isoelectric focusing is used as a common method suitable for screening 19 out of a total of 22 types of glycosylation defects identified so far. In three members of a family, several indicators showed evidence of a Tf protein variant, however, routine neuraminidase‐based demonstration failed to confirm this result. On the assumption that we should be able to exclude Tf protein variants at the screening‐level of the diagnostic algorithm, our concern is a possible cause of our failure to confirm some of the Tf D variants (in contrast to the other C, B and D allelic combinations that are commonly well identified). Several explanations are discussed. J. Clin. Lab. Anal. 23:77–81, 2009. © 2009 Wiley‐Liss,Inc.
Effect of sample storage on stability of salivary glutathione, lipid peroxidation levels, and tissue factor activity
Authors: Emekli‐Alturfan Ebru , Kasikci Emel , Alturfan A. Ata , Pisiriciler Rabia , Yarat Aysen
Published: March 2009

Saliva samples are often required to be stored for longer periods of time either because of the project protocol or because of lack of funding for analysis. The effects of 6 months storage (fresh, 30, 60, 90 120, 150, and 180 d) on the stability of salivary reduced glutathione (GSH), lipid peroxidation (LPO) and 90 days of storage (fresh, 15, 30, 60, and 90 d) on the stability of salivary tissue factor (TF) activity and the stability of saliva imprint samples at −20°C were evaluated in this study. Salivary GSH, malondialdehyde (MDA) levels as an index of LPO, and TF activities were determined using the methods of Beutler, Yagi, and Quick, respectively. Saliva imprint samples were stained with Giemsa and microscopically examined. Salivary GSH levels and TF activities decreased, whereas MDA levels increased significantly after 6 months of storage at −20°C. Leucocyte, epithelium and bacterium cell counts did not significantly change at the end of 90 d of storage. Saliva samples may be stored up to 1 month at −20°C for LPO assay. For cytological examinations, saliva samples may be stored for 90 d at −20°C. Further studies are needed to determine the stability of salivary GSH, and salivary TF activity stored less than 30 days at −20°C. On the other hand, if saliva samples are required to be stored, to avoid the changes because of different storage periods, we recommend that they must be stored under the same circumstances and in the same time period. J. Clin. Lab. Anal. 23:93–98, 2009. © 2009 Wiley‐Liss, Inc.
Novel endotoxin assay by laser light‐scattering particle‐counting method
Authors: Mitsumoto Kotaro , Yabusaki Katsumi , Kobayashi Koji , Shirasawa Yoshiaki , Obata Toru
Published: March 2009

Exposure of Limulus amoebocyte lysate to endotoxin under stirring produced light‐reflective particles that appeared to be coagulin polymers. A laser light‐scattering particle counter, the PA‐200, detected these particles sensitively. The PA‐200 detected endotoxin at a concentration as low as 0.00015 EU/ml in 71 min, whereas the minimum endotoxin concentration measured by a turbidimeter, ET‐2000, was 0.0005 EU/ml in 138 min. Moreover, PA‐200 was much less affected by the presence of colored substances and refractive materials than was ET‐2000. We propose that the high sensitivity, speed, and high interference tolerance of the laser light‐scattering particle‐counting method make it more useful than the widely used turbidimetric method for quantitative endotoxin assay. J. Clin. Lab. Anal. 23:117–124 (2009). © 2009 Wiley‐Liss, Inc.
Ultrasound stimulates NF‐κB activation and iNOS expression via the Ras/Raf/MEK/ERK signaling pathway in cultured preosteoblasts
Authors: Hou Chun‐Han , Lin Jinn , Huang Shier‐Chieg , Hou Sheng‐Mou , Tang Chih‐Hsin
Published: March 2009

It has been shown that ultrasound (US) stimulation accelerates fracture healing in the animal models and non‐operatively clinical uses. Nitric oxide (NO) is a crucial early mediator in mechanically induced bone formation. Here we found that US‐mediated inducible nitric oxide synthase (iNOS) expression was attenuated by Ras inhibitor (manumycin A), Raf‐1 inhibitor (GW5074), MEK inhibitor (PD98059), NF‐κB inhibitor (PDTC), and IκB protease inhibitor (TPCK). US‐induced Ras activation was inhibited by manumycin A. Raf‐1 phosphorylation at Ser338by US was inhibited by manumycin A and GW5074. US‐induced MEK and ERK activation was inhibited by manumycin A, GW5074, and PD98059. Stimulation of preosteoblasts with US activated IκB kinase α/β (IKK α/β), IκBαphosphorylation, p65 phosphorylation at Ser276, p65, and p50 translocation from the cytosol to the nucleus, and κB‐luciferase activity. US‐mediated an increase of IKK α/β, IκBα, and p65 phosphorylation, κB‐luciferase activity and p65 and p50 binding to the NF‐κB element was inhibited by manumycin A, GW5074, and PD98059. Our results suggest that US increased iNOS expression in preosteoblasts via the Ras/Raf‐1/MEK/ERK/IKKαβ and NF‐κB signaling pathways. J. Cell. Physiol. 220: 196–203, 2009. © 2009 Wiley‐Liss, Inc.
The synthesis of isomeric naphthylethylcarbazole derivatives as reference compounds in coal‐derived products
Authors: Luo Jiann‐Kuan , Castle Raymond N. , Lee Milton L.
Published: March 2009

The synthesis of naphthylethylcarbazole derivatives is described.
Syntheses of 1,3,6,8,10,11,14‐heptaazapentaphene‐2,4,7,9(14H,3H,8H, ‐11H)‐tetrones (angular mixed flavins), 1,3,5,6,8,10,11,14‐octaazapentaphene‐2,4,7,9(14H,3H,8H,11H)‐tetrones (angular doubled flavins), and their related compounds
Authors: Yoneda Fumio , Koga Masakazu , Tanaka Kiyoshi , Yano Yumihiko
Published: March 2009

Cyclization of N, N′‐dialkyl‐N‐(3‐methyluracil‐6‐yl)‐N′‐(5‐nitro‐3‐methyluracil‐6‐yl)‐ p‐phenylenediamines with the Vilsmeier reagent gives the corresponding 1,3,6,8,10,11,14‐heptaazapentaphene‐2,4,7,9‐(14H,3H,8H,‐11H) ‐tetrones (angular mixed flavins) 2. Cyclization of N, N′‐di(5‐nitro‐3‐methyluracil‐6‐yl)‐p‐phenylenedi‐amines with the Vilsmeier reagent gives the corresponding 1,3,5,6,8,10,11,14‐octaazapentaphene‐2,4,7,9‐(14H,3H,8H,11H)‐tetrones (angular doubled flavins) 11 along with the angular mixed flavins 2.
Unexpected formation of a 11H‐pyrido[2,1‐b]quinazolin‐11‐one derivative from 5,11‐dihydro‐6H‐pyrido[2,3‐b]‐1,4‐benzodiazepin‐6‐one
Authors: Buděšínský Miloš , Symerský Jindřich , Podlaha Jaroslav , Podlahová Jana , Polívka Zdeněk , Protiva Miroslav
Published: March 2009

The unexpected formation of 11H‐pyrido[2,1‐b]quinazolin‐11‐one derivative 6 from 5,11‐dihydro‐6H‐pyrido[2,3‐b]‐1,4‐benzodiazepin‐6‐one (2) has been observed. Its structure 6 was determined by X‐ray crystallography. Detailed nmr study provided a complete set of proton and carbon‐13 nmr parameters of compound 6 in solution.
Synthesis of novel dihydrothiazolo[3,2‐a]pyrimidinone derivatives
Authors: Selby T. P. , Smith B. K.
Published: March 2009

Condensation of 2‐amino‐4‐hydroxy‐2‐mercaptopyrimidine (2) hydrate and ethyl 4‐bromocrotonate gave a mixture of ethyl 7‐amino‐2,3‐dihydro‐5‐oxo‐5H‐thiazolo[3,2‐a]pyrimidine‐3‐acetate (4) and 2a,3‐dihydro‐1‐thia‐5,8,8b‐triazaacenaphthylene‐4,7(2H)‐dione (5) whereas reaction of 2 with 4‐bromocrotononitrile afforded only 7‐amino‐2,3‐dihydro‐5‐oxo‐5H‐thiazolo[3,2‐a] pyrimidine‐3‐acetonitrile. Reaction of the tricycle 5 (which was isolated as a hemihydrate) with excess methyl iodide/potassium carbonate in dimethylformamide resulted in both ring hydrolysis and methylation to give 3,4‐dihydro‐1,7‐dimethyl‐4‐ [(methylthio)methyl]‐2H‐pyrimido[1,6‐a]pyrimidine‐2,6,8(1H,7H)‐trione (10). Methylating 5 with excess methyl iodide/sodium methoxide in methanol also resulted in ring fragmentation and methylation but instead afforded methyl 7‐methyl‐amino‐2,3‐dihydro‐5‐oxo‐7H‐thiazolo[3,2‐a]pyrimidine‐3‐acetate. The mechanistic aspects of these reactions are discussed.
The autorecycling oxidation of benzylamine by synthetic 8‐hydroxy‐5‐deazaflavin derivatives
Authors: Hirayama Ryoichi , Kawase Masahiro , Kimachi Tetsutaro , Tanaka Kiyoshi , Yoneda Fumio
Published: March 2009

Various 8‐hydroxy‐5‐deazaflavin derivatives were synthesized as the model compounds of coenzyme F420‐These compounds oxidized benzylamine to benzaldehyde more efficiently than the corresponding 8‐unsubstituted 5‐deazaflavins.
Chemistry of thienopyridines. XXXVI. Further studies on nitration in the thieno[2,3‐b]‐ and thieno[3,2‐b]pyridine systems
Authors: Klemm L. H. , Johnstone Susan , Sur Sandip K. , Muchiri Daniel R.
Published: March 2009

Three compounds, thieno[3,2‐b]pyridine 4‐oxide, 7‐nitrothieno[3,2‐b]pyridine 4‐oxide (1c), and 6‐cyano‐thieno[2,3‐b]pyridine, undergo nitration by means of a mixture of nitric and sulfuric acids to yield 3,7‐dinitro‐thieno[3,2‐b]pyridine (3%), 3,7‐dinitrothieno[3,2‐b]pyridine 4‐oxide (1d) (26%), and 6‐carbamoyl‐5‐nitrothieno[2,3‐b]pyridine (6b) (11%), respectively. Structures of the products were ascertained by spectral means, notably infrared, 1H nmr, and 13C nmr. It is proposed that 1d exists (at least in part) as a tricyclic structure and that 6b may result from an intramolecular mechanism of nitration. An attempt to de‐N‐oxygenate 1c with excess triphenylphosphine removes more than one oxygen atom per molecule (as triphenylphosphine oxide) without producing an identified thienopyridine product.
Stereochemistry of the bucherer‐bergs reaction and a modified strecker reaction on tetrahydro‐2H‐pyran‐3‐ones
Authors: Haroutounian Serkos A. , Georgiadis Minas P. , Polissiou Moschos G.
Published: March 2009

The stereochemical aspects of the Bucherer‐Bergs reaction and a modified Strecker reaction on tetrahydro‐2H‐pyran‐3‐one derivatives have been studied in details through the use of several nmr techniques. It was found that, in both reactions, the orientation of the substituents introduced on C‐3 of the pyran ring, depends from the number and nature of the substituents on the neighbouring C‐2 atom.
The synthesis of 3H‐1,2,4‐thiadiazolo[3,4‐b]benzothiazoles
Authors: Potts Kevin T. , Kane John M.
Published: March 2009

2‐Aminobenzothiazole reacted with 1,1,1‐trichloromethanesulfenyl chloride yielding 1,1,1‐trichloro‐N‐(2‐benzothiazolyl)methanesulfenamide. Subsequent cyclization using either aromatic or heteroaromatic amines readily yielded derivatives of the 3H‐1,2,4‐thiadiazolo[3,4‐b]benzothiazole ring system. Spectral data and brominations of these benzothiazoles are described.
2‐benzazepines. 10 [1]. New d‐fused 2‐benzazepines
Authors: Walser Armin , Todaro Louis
Published: March 2009

Pyrano[3,2‐d][2]benzazepines were synthesized by reaction of the beta‐dimethylamino unsaturated ketone 1 with malonic ester or the anion of t‐butyl acetate. Conversion of the pyrano derivative to the pyrido[3,2‐d]‐[2]benzazepine was achieved in low yield. A pyrrolo[3,2‐d][2]benzazepine was prepared via an oxazepino‐[6,7‐d][2]benzazepine which was obtained by reaction of 1 with the anion of ethyl isocyanoacetate.
The willgerodt‐kindler reactions. 7. The mechanisms
Authors: Carmack Marvin
Published: March 2009

The mechanisms involved in various stages of the Kindler Reaction are discussed, with particular attention especially to its most unusual feature: the movement of a carbonyl group from methylene carbon to methylene carbon in an unbranched alkyl chain, or around a cycloalkyl ring. The first step is the reversible formation of an enamine, which is attacked by a catalyst generated from sulfur and the amine solvent to form a highly reactive intermediate with a sulfur‐containing heterocyclic ring. The natures of the catalytically active species and the reactive intermediates are proposed. Other steps involved in the Kindler Reaction are also discussed, as is the relationship of the Willgerodt Reaction to the Kindler Reaction.