bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytological clues in the distinction between phyllodes tumor and fibroadenoma
Authors: El Hag Imad A. , Aodah A. , Kollur S. M. , Attallah A. , Mohamed A. A. E. , Al‐Hussaini H.
Published: January 2010

BACKGROUND:

Fine‐needle aspiration (FNA) sensitivity in discriminating between phyllodes tumor and its benign mimicker fibroadenoma (FA) remains low. Because a preoperative categorization of phyllodes tumor is crucial for their appropriate management, the authors undertook this study in an effort to improve the outcome of FNA by identifying reliable distinguishing features.

METHODS:

FNA smears from 15 and 12 histologically proven cases of phyllodes tumor and FA, respectively, were reviewed. The stromal and epithelial components were qualitatively and quantitatively analyzed. A group of cytological features that may distinguish between phyllodes tumor and FA were identified. Their value and reproducibility in categorizing phyllodes tumor cases were tested.

RESULTS:

Three major cytological features were exclusively seen in all of, or the vast majority of, the phyllodes tumor cases; fibromyxoid stromal fragments with spindle nuclei (90%), fibroblastic pavements (93%), and appreciable number of spindles cells of fibroblastic nature among dispersed cell population (100%). The identification of these features improved the pick‐up rate of phyllodes tumor from 40% to 100% and had substantial (κ = 0.56‐0.73) interobserver and almost perfect (κ = 0.83) intraobserver reproducibility. There was no significant difference in the epithelial component characteristics between phyllodes tumor and FA. The frequency and degree of atypia in the dispersed cell population correlated well to the histological grade of phyllodes tumor.

CONCLUSIONS:

FNA has proven to be a reliable test in differentiating between phyllodes tumor and FA with high sensitivity and good reproducibility. The importance of training and continuing education is emphasized. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.
Heterogeneous distribution of the serotonin 5‐HT1Areceptor mRNA in chemically identified neurons of the mouse rostral brainstem: Implications for the role of serotonin in the regulation of wakefulness and REM sleep
Authors: Bonnavion Patricia , Bernard Jean‐François , Hamon Michel , Adrien Joëlle , Fabre Veronique
Published: January 2010

The 5‐HT1Areceptor (5‐HT1AR) plays a key role in the inhibitory influence of serotonin (5‐HT) on rapid eye movement (REM) sleep in rodents. However, the neuronal networks mediating such influence are mostly unknown, notably in the mouse. This led us to map 5‐HT1AR mRNA, by in situ hybridization histochemistry (ISHH), and to characterize the neuronal phenotype of 5‐HT1AR mRNA‐positive neurons by dual ISHH and ISHH combined with immunohistochemistry, throughout the mouse rostral brainstem, a pivotal region for the generation of REM sleep and cortical activation. 5‐HT1AR mRNA was found in most 5‐HT neurons in the dorsal raphe (DR), the median raphe (MnR), the B9, and the interpeduncular (IP) nuclei. 5‐HT1AR mRNA‐positive neurons were also identified in individualized clusters of γ‐aminobutyric acid (GABA)ergic neurons in the DR and in neurons of an undetermined phenotype in the MnR. In addition, 1) GABAergic neurons of the ventral portion of Gudden's dorsal tegmental nucleus (DTg), the IP, and the caudal portion of the deep mesencephalic nucleus (DpMe), and 2) glutamatergic neurons scattered in the caudal pontine reticular nucleus (PnC) and densely packed in the internal lateral parabrachial subnucleus (PBil) also expressed 5‐HT1AR mRNA. In contrast, no specific 5‐HT1AR‐related ISHH signal was generally detected in brainstem cholinergic and catecholaminergic neurons. These results emphasize the role of 5‐HT1AR as an autoreceptor and the phenotypical heterogeneity of 5‐HT1AR‐expressing neurons within the DR and the MnR in the mouse brain. They also provide a neuroanatomical basis for understanding the influence of 5‐HT1AR on REM sleep and wakefulness. J. Comp. Neurol. 518:2744–2770, 2010. © 2010 Wiley‐Liss, Inc.
Generation of mice with a conditional null allele for Tbx2
Authors: Wakker Vincent , Brons Janynke F. , Aanhaanen Wim T.J. , van Roon Marian A. , Moorman Antoon F.M. , Christoffels Vincent M.
Published: January 2010

The T‐box transcription factor Tbx2 plays important roles in patterning and development, and has been implicated in cell‐cycle regulation and cancer. Conventional disruption of Tbx2 results in abnormalities of the heart, limbs, eye and other structures, and early fetal lethality. To gain insight into the role of Tbx2 in different tissues and at different stages of development, we have generated a conditional null allele of Tbx2 by flanking Exon 2 with loxP sites (Tbx2fl2). Homozygous Tbx2fl2 mice are viable and fertile, indicating that the Tbx2fl2 allele is a fully functional Tbx2 allele. Cre‐mediated recombination, using a ubiquitously active CMV‐Cre line, results in deletion of Exon 2 and loss of protein expression. Embryos homozygous for the recombined allele (Tbx2Δ2) show the same heart and limb defects as conventional Tbx2‐deficient embryos. This Tbx2 conditional null allele will be a valuable tool to uncover tissue‐specific roles of Tbx2 in development and disease. genesis 48:195–199, 2010. © 2010 Wiley‐Liss, Inc.
Towards Fluoride Sensing with Positively Charged Lanthanide Complexes
Authors: Tripier Raphaël , Platas‐Iglesias Carlos , Boos Anne , Morfin Jean‐François , Charbonnière Loïc
Published: January 2010

Herein we report a series of [LnL(H2O)]Cl3 complexes, in which L is a 1,4,7,10‐tetrazacyclododecane framework (cyclen) functionalized with 2‐methylpyridyl pendants on the nitrogen atoms at the 1‐ and 7‐positions and with N‐[2‐(2‐hydroxyethoxy)ethyl]acetamide groups on those at the 4‐ and 10‐positions, and Ln stands for Eu, La, and Tb. The complexes were isolated and characterized by elemental analysis, mass spectrometry, infrared spectroscopy, and 1H NMR spectroscopy for the La and Eu complexes. 1H NMR spectroscopy indicates that the complexes display a major twisted square antiprismatic (TSAP) geometry in solution, which was confirmed by using DFT calculations. 1H and 13C variable‐temperature NMR spectroscopic experiments on the La complex provided an activation free energy of ΔG≠ = (58 ± 3) kJ mol–1 for the enantiomerization process of the TSAP isomer, which requires both the inversion of the five‐membered chelate rings formed upon coordination of the cyclen moiety and the rotation of the pendant arms. The photophysical properties of the complexes were studied by means of absorption, steady‐state, and time‐resolved luminescence spectroscopy. Upon ligand excitation, the Eu and Tb complexes displayed the typical lanthanide‐centered emission spectra with weak emission efficiencies (Φov = 0.11 and 0.68 %, respectively, for Eu and Tb in H2O). Luminescence lifetime measurements in water and heavy water allowed the determination of the hydration number of the complexes; these were (1.0 ± 0.2) for Eu and Tb. Spectrophotometric titrations of the [LnL(H2O)]Cl3 complexes (Ln = Eu and Tb) with F–, Cl–, and Br– anions (in buffered water solutions, 0.01 M tris(hydroxymethyl)aminomethane (TRIS)/HClO4, pH = 7.0) showed the complexes to interact selectively with fluoride anions, whereas no interactions were observed with Cl– and Br–. The interaction with F– was monitored by luminescence spectroscopy with [EuL(H2O)], which evidenced dramatic changes in the shape of the luminescence spectra, and an association constant of (2.86 ± 0.06) log units was determined. In the case of the Eu complex, time‐resolved and high‐resolution emission spectroscopy showed that the interaction resulted in the displacement of the coordinated water molecule, which led to an increase of the overall luminescence quantum yield, with almost no impact on the ligand‐to‐metal sensitization efficiency. Investigation of the Eu and La complexes by potentiometry (0.1 M NaCl) allowed the determination of the protonation constants of the complexes as well as the association constants with fluoride anions. DFT calculations on the fluoride adduct of the Eu complex confirmed the higher stability of the TSAP isomer and evidenced large structural changes upon F– binding, in agreement with spectrophotometric observations in solution.
Total Synthesis of (+)‐Brefeldin C, (+)‐nor‐Me Brefeldin A and (+)‐4‐epi‐nor‐Me Brefeldin A
Authors: Archambaud Sylvie , Legrand Frédéric , Aphecetche‐Julienne Karine , Collet Sylvain , Guingant André , Evain M.
Published: January 2010

A total synthesis of (+)‐brefeldin C (BFC) and two brefeldin A (BFA) analogues – (+)‐nor‐Me BFA and (+)‐4‐epi‐nor‐Me BFA – has been developed. Key features of the syntheses include desymmetrization of meso anhydrides, a Carreira reaction to control the absolute configuration at C4 of BFC, a Suzuki–Miyaura cross‐coupling reaction to create the C11–C12 bond and a Yamaguchi reaction to form the 13‐membered lactone ring.
Passive regulation of volume‐flow ratio for microfluidic streams with different hydrophilicity and viscosity
Authors: Kim Sung‐Jin , Lim Yong Taik , Yang Haesik , Kim Kyuwon , Kim Youn Tae
Published: January 2010

Biochemical solutions have a wide range of hydrophilicity (contact angle and surface tension) and viscosity. A critical challenge is that microfluidic systems typically need expensive or complex pumps to control the various parallel biochemical streams. In this study, without using any pumps, we present a simple scheme that controls the ratio of the volumetric flow rate (VFR) of the parallel streams that have highly different hydrophilicity and viscosity. We accomplish this process by using capillarity to drive and merge two streams, and by regulating relative flow resistance to control the VFR ratio. Our results will significantly simplify the control of the VFR ratio for the various biochemical solutions that are used in microfluidic applications.
The concept of minimized integrated exponential error for low dispersion and low dissipation schemes
Authors: Appadu A. R. , Dauhoo M. Z.
Published: January 2010

We devise two novel techniques to optimize parameters which regulate dispersion and dissipation effects in numerical methods using the notion that dissipation neutralizes dispersion. These techniques are baptized as the minimized integrated error for low dispersion and low dissipation (MIELDLD) and the minimized integrated exponential error for low dispersion and low dissipation (MIEELDLD).

These two techniques of optimization have an advantage over the concept of minimized integrated square difference error (MISDE), especially in the case when more than one optimal cfl is obtained, out of which only one of these values satisfy the shift condition. For instance, when MISDE is applied to the 1‐D Fromm's scheme, we have obtained two optimal cfl numbers: 0.28 and 1.0. However, it is known that Fromm's scheme satisfies shift condition only at r=1.0. Using MIELDLD and MIEELDLD, the optimal cfl of Fromm's scheme is computed as 1.0.

We show that like the MISDE concept, both the techniques MIELDLD and MIEELDLD are effective to control dissipation and dispersion. The condition ν2>4µ is satisfied for all these three techniques of optimization, where ν and µ are parameters present in the Korteweg‐de‐Vries‐Burgers equation.

The optimal cfl number for some numerical schemes namely Lax–Wendroff, Beam–Warming, Crowley and Upwind Leap‐Frog when discretized by the 1‐D linear advection equation is computed. The optimal cfl number obtained is in agreement with the shift condition. Some numerical experiments in 1‐D have been performed which consist of discontinuities and shocks. The dissipation and dispersion errors at some different cfl numbers for these experiments are quantified. Copyright © 2010 John Wiley & Sons, Ltd.
Activation of an oncogenic TBC1D7 (TBC1 domain family, member 7) protein in pulmonary carcinogenesis
Authors: Sato Nagato , Koinuma Junkichi , Ito Tomoo , Tsuchiya Eiju , Kondo Satoshi , Nakamura Yusuke , Daigo Yataro
Published: January 2010

To develop novel biomarkers and therapeutic agents for lung cancers, we screened molecules that were highly expressed in lung cancers by means of cDNA microarray analysis and found an elevated expression of TBC1 domain family, member 7 (TBC1D7) in the majority of lung cancers. Northern‐blot analysis using mRNAs from 16 normal tissues detected its expression only in testis. Immunohistochemical staining using tumor tissue microarrays consisting of 261 archived non‐small cell lung cancer (NSCLC) specimens suggested an association of TBC1D7 expression with poor prognosis for NSCLC patients (P = 0.0063). Treatment of lung cancer cells using siRNA against TBC1D7, suppressed its expression and resulted in inhibition of the cell growth. Furthermore, the induction of exogenous expression of TBC1D7 conferred growth‐promoting activity at in vitro and in vivo conditions. We also identified TBC1D7 to interact with TSC1 protein in lung cancer cells. TSC1 introduction into cells increased the level of TBC1D7 protein, whereas knockdown of TSC1 expression decreased the level of TBC1D7 protein, suggesting that TBC1D7 is stabilized probably through interaction with TSC1. In addition, inhibition of the binding between TBC1D7 and TSC1 by a TBC1D7‐derived 20‐amino acid cell‐permeable peptide (11R‐TBC1D7152‐171), which corresponded to the binding domain to TSC1, effectively suppressed growth of lung cancer cells. Selective suppression of TBC1D7 and/or inhibition of the TBC1D7‐TSC1 complex formation could be promising therapeutic strategies for lung cancer therapy. © 2010 Wiley‐Liss, Inc.
FOXO1 and TCF7L2 genes involved in metastasis and poor prognosis in clear cell renal cell carcinoma
Authors: Kojima Takahiro , Shimazui Toru , Horie Ryo , Hinotsu Shiro , Oikawa Takehiro , Kawai Koji , Suzuki Hideaki , Meno Kohji , Akaza Hideyuki , Uchida Kazuhiko
Published: January 2010

The goal of this study was to identify genes related to the metastasis of clear cell renal cell carcinoma (CRCC). We analyzed copy number alterations in renal tissue specimens of patients with CRCC patients with or without metastasis by using high‐resolution single‐nucleotide polymorphism (SNP) arrays and then integrated these data with gene expression profiling data obtained using oligonucleotide microarrays. The expression levels of target genes were determined by quantitative real‐time RT‐PCR (qRT‐PCR) with an independent tumor set. An analysis of specimens from 23 CRCC cases with SNP arrays revealed that hemizygous deletions at 10q and 13q were found only in cases of metastatic disease. We found the homozygous deletion of TCF7L2 at 10q25.2 in an aggressive case that had hemizygous deletions at 10q. In addition, a qRT‐PCR analysis of TCF7L2 mRNA levels in tumor samples revealed significantly lower levels in patients with metastasis when compared with those without metastasis. FOXO1 was identified as a down‐regulated gene in the minimal overlapping region of the 13q hemizygous deletion in CRCC. Decreased FOXO1 expression was significantly correlated with metastasis and poor survival outcome. Knockdown of FOXO1 inhibited apoptosis after doxorubicin treatment in CRCC cells and reduced the expression of downstream genes involved in cell proliferation (CDKN1B) and survival (BCL2L11). Lower levels of FOXO1 expression were associated with decreased expression of CDKN1B and BCL2L11 in CRCC specimens. We conclude that FOXO1 and TCF7L2 are involved in metastasis and that molecules in these signaling pathways may be targets for diagnostic procedures and therapies for CRCC. © 2010 Wiley‐Liss, Inc.
Alterations of white matter tracts following neurotoxic hippocampal lesions in macaque monkeys: A diffusion tensor imaging study
Authors: Shamy J.L. , Carpenter D.M. , Fong S.G. , Murray E.A. , Tang C.Y. , Hof P.R. , Rapp P.R.
Published: January 2010

Diffusion tensor imaging (DTI) is a valuable tool for assessing presumptive white matter alterations in human disease and animal models. The current study used DTI to examine the effects of selective neurotoxic lesions of the hippocampus on major white matter tracts and anatomically related brain regions in macaque monkeys. Two years postlesion, structural MRI, and DTI sequences were acquired for each subject. Volumetric assessment revealed a substantial reduction in the size of the hippocampus in experimental subjects, averaging 72% relative to controls, without apparent damage to adjacent regions. DTI images were processed to yield measures of fractional anisotropy (FA), apparent diffusion coefficient (ADC), parallel diffusivity (lADC), and perpendicular diffusivity (tADC), as well as directional color maps. To evaluate potential changes in major projection systems, a region of interest (ROI) analysis was conducted including the corpus callosum, fornix, temporal stem, cingulum bundle, ventromedial prefrontal white matter, and optic radiations. Lesion‐related abnormalities in the integrity of the fiber tracts examined were limited to known hippocampal circuitry, including the fornix and ventromedial prefrontal white matter. These findings are consistent with the notion that hippocampal damage results in altered interactions with multiple memory‐related brain regions, including portions of the prefrontal cortex. © 2010 Wiley‐Liss, Inc.
Layered silicate epoxy nanocomposites: formation of the inorganic‐carbonaceous fire protection layer
Authors: Schartel B. , Weiß A. , Sturm H. , Kleemeier M. , Hartwig A. , Vogt C. , Fischer R. X.
Published: January 2010

The layered silicate (LS) modification and processing parameters applied control the morphology of the LS/polymer composites. Here, increasing the surface area of the LS particles by using alternative drying processes increases dispersion towards a more typical nanocomposite morphology, which is a basic requirement for promising flame retardancy. Nevertheless, the morphology at room temperature does not act itself with respect to flame retardancy, but serves as a prerequisite for the formation of an efficient surface protection layer during pyrolysis. The formation of this residue layer was addressed experimentally for the actual pyrolysis region of a burning nanocomposite and thus our results are valid without any assumptions or compromises on the time period, dimension, surrounding atmosphere or temperature. The formation of the inorganic‐carbonaceous residue is influenced by bubbling, migration, reorientation, agglomeration, ablation, and perhaps also delamination induced thermally and by decomposition, whereas true sintering of the inorganic particles was ruled out as an important mechanism. Multiple, quite different mechanisms are relevant during the formation of the residue, and the importance of each mechanism probably differs from one nanocomposite system to another. The main fire protection effect of the surface layer in polymer nanocomposites based on non‐charring or nearly non‐charring polymers is the increase in surface temperature, resulting in a substantial increase in reradiated heat flux (heat shielding). Copyright © 2010 John Wiley & Sons, Ltd.
The role of autocrine TGFβ1 in endothelial cell activation induced by phagocytosis of necrotic trophoblasts: a possible role in the pathogenesis of pre‐eclampsia
Authors: Chen Qi , Chen Limei , Liu Bonnia , Vialli Chez , Stone Peter , Ching Lai‐Ming , Chamley Lawrence
Published: January 2010

Pre‐eclampsia is a disorder of pregnancy characterized by hypertension and endothelial cell dysfunction. The causes of pre‐eclampsia are unclear but it is proposed that a factor released from the placenta triggers the maternal symptoms. One possible triggering factor is dead trophoblasts that are shed from the placenta, then deported to become trapped in the maternal pulmonary capillaries. It is hypothesized that trophoblasts die by apoptosis in normal pregnancy, but by necrosis in pre‐eclampsia. Deported trophoblasts may be phagocytosed by the pulmonary endothelial cells and we have previously shown that phagocytosis of necrotic trophoblasts leads to the activation of endothelial cells, accompanied by the release of interleukin‐6 from these cells. However, the mechanistic pathway linking phagocytosis of necrotic trophoblasts and endothelial cell activation is unknown. Here we show that, after phagocytosis of necrotic, but not apoptotic, trophoblasts, endothelial cells secrete TGFβ1. Using recombinant endoglin to inhibit the function of TGFβ1 we have shown that the TGFβ1 does not directly activate endothelial cells but rather it induces endothelial IL‐6 secretion. The IL‐6 then induces endothelial cell activation. Inhibiting either TGFβ1 or IL‐6 prevented endothelial cell activation in response to phagocytosing necrotic trophoblasts, but inhibiting IL‐6 did not prevent secretion of TGFβ1, confirming the order of signalling. IL‐6 also reduced endothelial cell‐surface endoglin but increased the amount of soluble endoglin released from placental explants. These interactions between the IL‐6 and TGFβ1 pathways in both the endothelium and placenta may help to regulate the maternal response to deported trophoblasts in pregnancy. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Cysteine‐free rop: A four‐helix bundle core mutant has wild‐type stability and structure but dramatically different unfolding kinetics
Authors: Hari Sanjay B. , Byeon Chang , Lavinder Jason J. , Magliery Thomas J.
Published: January 2010

Cysteine residues can complicate the folding and storage of proteins due to improper formation of disulfide bonds or oxidation of residues that are natively reduced. Wild‐type Rop is a homodimeric four‐helix bundle protein and an important model for protein design in the understanding of protein stability, structure and folding kinetics. In the native state, Rop has two buried, reduced cysteine residues in its core, but these are prone to oxidation in destabilized variants, particularly upon extended storage. To circumvent this problem, we designed and characterized a Cys‐free variant of Rop, including solving the 2.3 Å X‐ray crystal structure. We show that the C38A C52V variant has similar structure, stability and in vivo activity to wild‐type Rop, but that it has dramatically faster unfolding kinetics like virtually every other mutant of Rop that has been characterized. This cysteine‐free Rop has already proven useful for studies on solution topology and on the relationship of core mutations to stability. It also suggests a general strategy for removal of pairs of Cys residues in proteins, both to make them more experimentally tractable and to improve their storage properties for therapeutic or industrial purposes.
Lessons from the lysozyme of phage T4
Authors: Baase Walter A. , Liu Lijun , Tronrud Dale E. , Matthews Brian W.
Published: January 2010

An overview is presented of some of the major insights that have come from studies of the structure, stability, and folding of T4 phage lysozyme. A major purpose of this review is to provide the reader with a complete tabulation of all of the variants that have been characterized, including melting temperatures, crystallographic data, Protein Data Bank access codes, and references to the original literature. The greatest increase in melting temperature (Tm) for any point mutant is 5.1°C for the mutant Ser 117 → Val. This is achieved in part not only by hydrophobic stabilization but also by eliminating an unusually short hydrogen bond of 2.48 Å that apparently has an unfavorable van der Waals contact. Increases in Tm of more than 3–4°C for point mutants are rare, whereas several different types of destabilizing substitutions decrease Tm by 20°C or thereabouts. The energetic cost of cavity creation and its relation to the hydrophobic effect, derived from early studies of “large‐to‐small” mutants in the core of T4 lysozyme, has recently been strongly supported by related studies of the intrinsic membrane protein bacteriorhodopsin. The L99A cavity in the C‐terminal domain of the protein, which readily binds benzene and many other ligands, has been the subject of extensive study. Crystallographic evidence, together with recent NMR analysis, suggest that these ligands are admitted by a conformational change involving Helix F and its neighbors. A total of 43 nonisomorphous crystal forms of different monomeric lysozyme mutants were obtained plus three more for synthetically‐engineered dimers. Among the 43 space groups, P212121 and P21 were observed most frequently, consistent with the prediction of Wukovitz and Yeates.
The proline‐rich domain of TonB possesses an extended polyproline II‐like conformation of sufficient length to span the periplasm of Gram‐negative bacteria
Authors: Domingo Köhler Silvia , Weber Annemarie , Howard S. Peter , Welte Wolfram , Drescher Malte
Published: January 2010

TonB from Escherichia coli and its homologues are critical for the uptake of siderophores through the outer membrane of Gram‐negative bacteria using chemiosmotic energy. When different models for the mechanism of TonB mediated energy transfer from the inner to the outer membrane are discussed, one of the key questions is whether TonB spans the periplasm. In this article, we use long range distance measurements by spin‐label pulsed EPR (Double Electron–Electron Resonance, DEER) and CD spectroscopy to show that the proline‐rich segment of TonB exists in a PPII‐like conformation. The result implies that the proline‐rich segment of TonB possesses a length of more than 15 nm, sufficient to span the periplasm of Gram‐negative bacteria.
Structural basis for unfolding pathway‐dependent stability of proteins: Vectorial unfolding versus global unfolding
Authors: Yagawa Keisuke , Yamano Koji , Oguro Takaomi , Maeda Masahiro , Sato Takehiro , Momose Takaki , Kawano Shin , Endo Toshiya
Published: January 2010

Point mutations in proteins can have different effects on protein stability depending on the mechanism of unfolding. In the most interesting case of I27, the Ig‐like module of the muscle protein titin, one point mutation (Y9P) yields opposite effects on protein stability during denaturant‐induced “global unfolding” versus “vectorial unfolding” by mechanical pulling force or cellular unfolding systems. Here, we assessed the reason for the different effects of the Y9P mutation of I27 on the overall molecular stability and N‐terminal unraveling by NMR. We found that the Y9P mutation causes a conformational change that is transmitted through β‐sheet structures to reach the central hydrophobic core in the interior and alters its accessibility to bulk solvent, which leads to destabilization of the hydrophobic core. On the other hand, the Y9P mutation causes a bend in the backbone structure, which leads to the formation of a more stable N‐terminal structure probably through enhanced hydrophobic interactions.
Structural and dynamical characterization of tubular HIV‐1 capsid protein assemblies by solid state nuclear magnetic resonance and electron microscopy
Authors: Chen Bo , Tycko Robert
Published: January 2010

The wild‐type HIV‐1 capsid protein (CA) self‐assembles in vitro into tubular structures at high ionic strength. We report solid state nuclear magnetic resonance (NMR) and electron microscopy measurements on these tubular CA assemblies, which are believed to contain a triangular lattice of hexameric CA proteins that is similar or identical to the lattice of capsids in intact HIV‐1. Mass‐per‐length values of CA assemblies determined by dark‐field transmission electron microscopy indicate a variety of structures, ranging from single‐wall tubes to multiwall tubes that approximate solid rods. Two‐dimensional (2D) solid state 13C13C and 15N13C NMR spectra of uniformly 15N,13C‐labeled CA assemblies are highly congested, as expected for a 25.6 kDa protein in which nearly the entire amino acid sequence is immobilized. Solid state NMR spectra of partially labeled CA assemblies, expressed in 1,3‐13C2‐glycerol medium, are better resolved, allowing the identification of individual signals with line widths below 1 ppm. Comparison of crosspeak patterns in the experimental 2D spectra with simulated patterns based on solution NMR chemical shifts of the individual N‐terminal (NTD) and C‐terminal (CTD) domains indicates that NTD and CTD retain their individual structures upon self‐assembly of full‐length CA into tubes. 2D 1H‐13C NMR spectra of CA assemblies recorded under solution NMR conditions show relatively few signals, primarily from segments that link the α‐helices of NTD and CTD and from the N‐ and C‐terminal ends. Taken together, the data support the idea that CA assemblies contain a highly ordered 2D protein lattice in which the NTD and CTD structures are retained and largely immobilized.
Study of organic light emitting devices (OLEDs) with optimal emission effi‐ ciency
Authors: Singh Jai
Published: January 2010

The external emission efficiency of organic light emitting devices (OLEDs) is analysed by studying the rate of spontaneous emission of both singlet and triplet excitons and their corresponding radiative lifetimes. Rates of spontaneous emissions are calculated from the first order perturbation theory using the newly discovered time‐dependent spin‐orbit‐exciton‐photon interaction operator as the perturbation operator. It is clearly shown how the new interaction operator is responsible for attracting triplet excitons to a phosphor (heavy metal atom) and then it flips the spins to a singlet configuration. Thus, the spin forbidden transition becomes spin allowed. Calculated rates agree with the experimental results qualitatively. Results are of general interests for OLED studies. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Measurements of thermal characteristics in silicon germanium un‐cooled micro‐bolometers
Authors: Moreno Mario , Ambrosio Roberto , Torres Alfonso , Kosarev Andrey , García Maria , Mireles Jose
Published: January 2010

We present a study of the thermal characteristics of an infrared detector (un‐cooled micro‐bolometer), based on an amorphous silicon germanium film (a‐SixGey:H), deposited by plasma at low temperature (∼ 300 °C) and compatible with the standard CMOS technology. These films have been studied due to their high performance characteristics as high activation energy (Ea≈ 0.37 eV), high temperature coefficient of resistance (TCR≈ ‐0.047 K‐1) and moderate room temperature conductivity (σRT≈ 2x10‐5Ω cm), which provides a moderate pixel resistance (Rcell≈3.5x108Ω). We have used two simple methods to calculate the thermal characteristics of the micro‐bolometer. The thermal conductance (Gth) has been obtained from the electrical I(U) characteristics in the range where self heating due to bias is not presented. The temperature dependence of the electrical resistance and as well the temperature dependence of the thermal resistance have been obtained by measuring the I(U) characteristics in the device at different temperature values. Finally the results of both methods have been compared. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parameter testing in bounded degree graphs of subexponential growth
Authors: Elek Gábor
Published: January 2010

Parameter testing algorithms are using constant number of queries to estimate the value of a certain parameter of a very large finite graph. It is well‐known that graph parameters such as the independence ratio or the edit‐distance from 3‐colorability are not testable in bounded degree graphs. We prove, however, that these and several other interesting graph parameters are testable in bounded degree graphs of subexponential growth. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 2010
MANET QoS support without reservations
Authors: Oh Soon Y. , Marfia Gustavo , Gerla Mario
Published: January 2010

An inelastic flow is a flow with an inelastic rate, i.e., the rate is fixed, and it cannot be dynamically adjusted to traffic and load condition as in elastic flows like TCP. Real time, interactive sessions, and video/audio streaming are typical examples of inelastic flows. Reliable support of inelastic flows in wirelessad hocnetworks is extremely challenging because flows and routes dynamically change and flows compete for the shared wireless channel. Bandwidth must be reserved for inelastic flows at session set up time. To avoid repeated attempts to set up reservations in a ‘volatile’ network and prevent serious network capacity degradation due to call set up overhead, a Call Admission Control strategy robust to mobility must be developed. In this paper we propose ProbeCast, a probe based call admission control scheme with QoS guarantees for inelastic flows. ProbCast was designed for multicast streams but can also work, by default, for unicast. In ProbeCast, a path (or a tree) is probed for capacity availability. If an intermediate link along the probed path fails to meet the QoS requirement, the flow is ‘pushed back’ via backpressure upstream to an intermediate branch or possibly to the source. The backpressure principle is simple; however, its implementation requires some care to avoid unfairness and eventual capture by one of the flows sharing a congested bottleneck. We show that proportional fairness among inelastic contenders will prevent capture. To achieve this, we have developed the Neighborhood Proportional Drop (N‐PROD) scheme. N‐PROD guarantees fair rejection of unfeasible flows and maintains the same proportional drop rate among surviving flows in the same contention domain. We demonstrate the efficacy and robustness of ProbeCast for unicast as well as multicast scenarios using the Qualnet simulation platform. Copyright © 2010 John Wiley & Sons, Ltd.
Well‐being Under chronic stress: is morningness an advantage?
Authors: Buschkens Jane , Graham Deborah , Cottrell David
Published: January 2010

This study investigated whether morningness was associated with better quality of life in individuals experiencing chronic stress. Thirty‐one informal primary carers and 35 non‐carers completed self‐report measures of time‐of‐day preference, stress and well‐being. The data were collected as part of a broader study of circadian rhythmicity under conditions of prolonged stress. There was a significant interaction between diurnal preference and caregiving, with morningness associated with better well‐being outcomes in those providing long‐term home care. It appears that chronic arousal, but not perceived stress, plays a role in this morningness–carer interaction, with lower arousal levels also evident in carers with a greater preference for morningness. These results point to a possible role for circadian influences in the relationship between stress and subjective well‐being. Copyright © 2010 John Wiley & Sons, Ltd.
Is Thymectomy Worthwhile in Central Lymph Node Dissection for Differentiated Thyroid Cancer?
Authors: Khatib Ziad El , Lamblin Julie , Aubert Sebastien , Arnalsteen Laurent , Leteurtre Emmanuelle , Caiazzo Robert , Pattou Francois , Carnaille Bruno
Published: January 2010

Background

Clinical guidelines edited in 2006 by the American Thyroid Association (ATA) and stated in the European Thyroid Association Consensus (ETA) recommend routine central lymph node dissection (level VI neck dissection) in addition to thyroidectomy for the surgical treatment of differentiated thyroid cancer. This central dissection increases the incidence of postoperative hypocalcemia, which is related to the resection or devascularization of the inferior parathyroids together with bilateral thymectomy. Some authors perform unilateral thymectomy in order to minimize this complication. Our aim was to study the benefit/risk (incidence of thymic lymph node metastases versus postoperative hypocalcemia) of both procedures.

Methods

We retrospectively reviewed the records of 138 patients who underwent total thyroidectomy with central neck lymph node dissection for differentiated thyroid cancer between 2004 and 2007. Bilateral thymectomy was performed in 45 patients (group 1, 15 males and 30 females) and unilateral thymectomy was performed in 93 patients (group 2, 27 males and 66 females). Forty‐two papillary and 3 medullary cancers were found in group 1, and 75 papillary, 2 follicular, and 17 medullary cancers were found in group 2. The presence of thymic metastases at pathology and the occurrence of postoperative hypocalcemia were reviewed.

Results

Two cases of papillary thymic metastases were found in group 1. These were lymph node micrometastases localized in the ipsilateral side of the primary tumor in both cases. Transient hypocalcemia was significantly more frequent (P < 0.001) in group 1 than in group 2: 16 patients (35.5%) versus 10 (10.7%). There was one case of permanent hypocalcemia in group 1 after the follow‐up period.

Conclusions

Bilateral thymectomy risk outweighs any likely carcinologic benefit. We do not recommend routine bilateral thymectomy during central neck dissection for differentiated thyroid cancer.
Pyrazole Derived Cationic Surfactants and their Tin and Copper Complexes: Synthesis, Surface Activity, Antibacterial and Antifungal Efficacy
Authors: Negm Nabel A. , Said Medhat M. , Morsy Salwa M. I.
Published: January 2010

Five membered heterocyclic cationic 3‐pyrazolium surfactants namely: 2‐[2‐(alkyloxy)‐2‐oxoethyl]‐3‐methyl‐5‐oxo‐1‐phenyl‐4, 5‐dihydro‐1H‐3‐pyrazolium bromide (decyl‐ dodecyl‐) and their copper and tin complexes were synthesized, their structures were confirmed using different spectroscopic tools. The IR spectra of the metal complexes showed that these compounds exhibit a tetrahedron structure with the transition metal ion (M2+) at the center and the cationic ligands arranged in the apexes, while the halide ions in the center. The synthesized compounds were evaluated as biocides against different types of bacteria and fungi. The biological activity data showed that the cationic surfactants exhibit moderate to high efficacy against the tested microorganisms (either bacteria or fungi). While, complexation of these cationic surfactants with Cu (II) and Sn (II) ions the antimicrobial activity was strongly increased. The surface activity of these compounds were discussed and correlated to their chemical structure and the type of substituents on the heterocyclic moiety. Meanwhile, the antimicrobial assay was correlated to the surface activities of the synthesized compounds.
Chemical Structure of Bacteriovorax stolpii Lipid A
Authors: Beck Sebastian , Müller Frederic D. , Strauch Eckhard , Brecker Lothar , Linscheid Michael W.
Published: January 2010

Bdellovibrionales is a phylogenetically diverse group of predatory prokaryotes, which consists of the two families Bdellovibrionaceae and Bacteriovoracaceae. We describe LPS and lipid A of the type strain Bacteriovorax stolpii DSM 12778, representing the first characterized endotoxin of a Bacteriovoracaceae member. It has a smooth form LPS, which was identified by SDS‐polyacrylamide gel electrophoresis. The lipid A structure was determined by combined gas chromatography–mass spectrometry, electrospray ionization mass spectrometry and NMR spectroscopy. Its backbone consists of two β‐(1 → 6)‐linked 2,3‐diamino‐2,3‐dideoxy‐d‐glucopyranoses (GlcpN3N) carrying a pyrophosphoethanolamine at O‐4′ of the non‐reducing sugar and a phosphate group linked to O‐1 of the reducing GlcpN3N. Positions 2, 3, 2′ and 3′ of the two GlcpN3N are acylated with primary 3‐hydroxy fatty acids and one of those carries a secondary fatty acid.
Can at‐risk young adolescents be popular and anti‐social? Sociometric status groups, anti‐social behaviour, gender and ethnic background
Authors: van de Schoot Rens , van der Velden Floor , Boom Jan , Brugman Daniël
Published: January 2010

This study aimed to extend the understanding of anti‐social behaviour and its association with popularity and sociometric status in a sample of at‐risk adolescents from diverse ethnic backgrounds (n = 1491, average age 14.7 years). Both overt and covert types of anti‐social behaviour were used to distinguish subgroups. These subgroups were created on the basis of anti‐social behaviour profile scores, using Latent Class Analysis. Moderator effects of gender and ethnic background were investigated using a log‐linear analysis. The main finding was that each sociometric status group consisted of subgroups that differed in terms of prevalence of self‐reported anti‐social behaviour. At‐risk young adolescents who reported involvement in anti‐social behaviour appeared in every status group, including the popular group. Implications for school prevention programmes for anti‐social behaviour are discussed.
Mitochondrial Ca2+ channels: Great unknowns with important functions
Authors: Malli Roland , Graier Wolfgang F.
Published: January 2010

Mitochondria process local and global Ca2+ signals. Thereby the spatiotemporal patterns of mitochondrial Ca2+ signals determine whether the metabolism of these organelles is adjusted or cell death is executed. Mitochondrial Ca2+ channels of the inner mitochondrial membrane (IMM) actually implement mitochondrial uptake from cytosolic Ca2+ rises. Despite great efforts in the past, the identity of mitochondrial Ca2+ channels is still elusive. Numerous studies aimed to characterize mitochondrial Ca2+ uniport channels and provided a detailed profile of these great unknowns with important functions. This mini‐review revisits previous research on the mechanisms of mitochondrial Ca2+ uptake and aligns them with most recent findings.
In vitro regulation of circadian phosphorylation rhythm of cyanobacterial clock protein KaiC by KaiA and KaiB
Authors: Nakajima Masato , Ito Hiroshi , Kondo Takao
Published: January 2010

Biochemical circadian oscillation of KaiC phosphorylation, by mixing three Kai proteins and ATP, has been proven to be the central oscillator of the cyanobacterial circadian clock. In vivo, the intracellular levels of KaiB and KaiC oscillate in a circadian fashion. By scrutinizing KaiC phosphorylation rhythm in a wide range of Kai protein concentrations, KaiA and KaiB were found to be “parameter‐tuning” and “state‐switching” regulators of KaiC phosphorylation rhythm, respectively. Our results also suggest a possible entrainment mechanism of the cellular circadian clock with the circadian variation of intracellular levels of Kai proteins.
Community‐based distribution of misoprostol for treatment or prevention of postpartum hemorrhage: Cost‐effectiveness, mortality, and morbidity reduction analysis
Authors: Sutherland Tori , Meyer Carinne , Bishai David M. , Geller Stacie , Miller Suellen
Published: January 2010

Objective

To compare the cost‐effectiveness of community‐based distribution of misoprostol for prevention with misoprostol for treatment of postpartum hemorrhage (PPH).

Methods

A Monte Carlo simulation depicted mortality and anemia‐related morbidity attributable to PPH among 3 scenarios of 10 000 women delivering at home in rural India: (1) standard management; (2) standard management plus 800 µg of sublingual misoprostol for PPH treatment; and (3) standard management plus 600 µg of prophylactic oral misoprostol. The model included costs of drugs, birth attendant training, and transport for women who did not respond to misoprostol.

Results

Misoprostol lowered mortality by 70% and 81% in scenarios 2 and 3, respectively. Scenarios 2 and 3 raise costs by 6% and 35%, respectively. Incremental cost per disability‐adjusted life year (DALY) saved is estimated at $6 and $170, respectively.

Conclusion

Both interventions were more effective at decreasing mortality and anemia than standard management. The most efficient scale‐up plan would focus initially on increasing coverage with the treatment strategy ($6 per DALY).
Failures in endoscopic surgery of the maxillary sinus
Authors: Albu Silviu , Baciut Mihaela
Published: January 2010

Objective

To assess the prognostic factors of recurrence after endoscopic sinus surgery for maxillary chronic rhinosinusitis without nasal polyps.

Study Design

Prospective.

Setting

Tertiary referral center.

Methods

A total of 411 patients were operated on for maxillary chronic rhinosinusitis without nasal polyps (307 rhinogenic rhinosinusitis, 74 odontogenic rhinosinusitis, and 30 oroantral fistula cases) in a single institution between 2002 and 2007. Ten parameters were analyzed to study their relationship with recurrence: etiology of rhinosinusitis, partial resection of middle turbinate, smoking history, allergy, asthma, gastroesophageal reflux, preoperative endoscopic score, CT stage, maxillary sinus mucosa score, and bleeding score. Preoperative characteristics and recurrence rates were compared with the analysis of variance test. Failure was analyzed as a time‐dependent variable by the Kaplan‐Meier method. Variables identified on univariate analysis were entered into a multivariate Cox proportional hazards model.

Results

Recurrent rhinosinusitis developed in 28 (6.8%) cases. In the univariate analysis, preoperative endoscopic score, CT stage, and bleeding score were associated with recidivism. However, the multivariate analysis suggested that only bleeding is an independent predictive factor of recurrence (P = 0.034, 95% confidence interval for odds ratio 0.92‐7.21).

Conclusion

Intraoperative bleeding may be a risk factor for failure in endoscopic surgery of maxillary rhinosinusitis, but there is substantial uncertainty and future research is needed.
Air quality improvement and the prevalence of frequent ear infections in children
Authors: Bhattacharyya Neil , Shapiro Nina L.
Published: January 2010

Objective

To determine whether air quality influences the prevalence of pediatric frequent ear infections and respiratory allergy.

Study Design

Case‐control study.

Setting

Academic medical center.

Subjects and Methods

The National Health Interview Survey child sample for the calendar years 1997 through 2006 was analyzed, extracting 12‐month prevalence data for the following three disease conditions: frequent (≥3 within 12 months) ear infections, respiratory allergy, and seizures (nonrespiratory control condition). Based on information from the Environmental Protection Agency, yearly historical data for the air quality criteria pollutants carbon monoxide, nitrous dioxide, sulfur dioxide, and particulate matter were tabulated. Graphical and linear regression analyses were conducted to determine the influence of air quality on each of the disease conditions.

Results

A total of 126,060 children were studied (51.4% male, mean age 8.6 yrs). Overall, the 12‐month prevalence for three or more ear infections, respiratory allergy, and seizures was 6.6%, 11.7%, and 0.7%, respectively. Air quality steadily improved over the study period. Statistically significant positive regression coefficients were obtained for each of the criteria pollutants with ear infections (all P < 0.001), with regression coefficients ranging from 0.007 (particulate matter) to 11.2 (sulfur dioxide). For respiratory allergies, nonstatistically significant regression coefficients for the criteria pollutants were obtained (range <0.001‐0.379, all P ≥ 0.409). For the nonrespiratory condition seizures, nonsignificant regression coefficients were again identified (all P ≥ 0.404).

Conclusions

Better air quality is significantly associated with lower prevalence of pediatric frequent ear infections but is not associated with the prevalence of pediatric respiratory allergy. Improvements in air quality may be implicated in the decreased rates of pediatric ear infections over time.