bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Applications of Dewetting in Micro and Nanotechnology
Authors: Gentili Denis , Foschi Giulia , Valle Francesco , Cavallini Massimiliano , Biscarini Fabio
Published: August 2012

Review: 90 refs.
ChemInform Abstract: Self‐Disproportionation of Enantiomers via Achiral Chromatography: A Warning and an Extra Dimension in Optical Purifications
Authors: Soloshonok Vadim A. , Roussel Christian , Kitagawa Osamu , Sorochinsky Alexander E.
Published: August 2012

Review: about 50 refs.
ChemInform Abstract: Fuorescent Chemodosimeters Using “Mild” Chemical Events for the Detection of Small Anions and Cations in Biological and Environmental Media
Authors: Du Jianjun , Hu Mingming , Fan Jinagli , Peng Xiaojun
Published: August 2012

Review: 151 refs.
Determining the impact of US mammography screening guidelines on patient survival in a predominantly African American population treated in a public hospital during 2008
Authors: Habtes Imnett , Friedman Danielle , Raskind‐Hood Cheryl , Adams Kathleen , Becker Edmund R. , D'Orsi Carl , Birdsong George , Gundry Kathleen , O'Regan Ruth , Gabram Sheryl G. A.
Published: August 2012

BACKGROUND:

In November 2009, the US Preventive Service Task Force (USPSTF) published updated breast cancer screening guidelines. This marked a change from the 2002 recommendations and a significant divergence from the American Cancer Society (ACS) guidelines. In the current study, the potential effect of using the revised 2009 USPSTF guidelines on patient disease stage and survival were evaluated and compared with those actually observed and to predicted under ACS recommendations.

METHODS:

A retrospective chart review was performed for 84 patients who were diagnosed with stage I through III breast cancer at Grady Memorial Hospital during 2008. Previously published tumor volume doubling times were used to model an equation that would estimate tumor sizes. For each patient, a disease stage at diagnosis was predicted, and outcomes were modeled as though the patient had been screened according to the recommended versions of the ACS and USPSTF guidelines. Patient survival rates were then estimated based on prognostic data according to disease stage.

RESULTS:

The average age of patients in the study was 55 years, and 85% were African American. The USPSTF guidelines predicted later stages at diagnosis (14% stage I, 73% stage II), whereas the ACS guidelines predicted earlier stages (47% stage I, 53% stage II).

CONCLUSIONS:

A large stage migration was predicted, indicating significantly earlier diagnosis, when the ACS‐recommended screening guidelines were followed. The authors concluded that practitioners should understand how race and/or socioeconomic factors increase the risk of breast cancer and should be encouraged to prioritize discussions regarding the benefits and risks of annual mammographic screening, especially among women who have a potentially greater risk of developing breast cancer at a younger age. Cancer 2013. © 2012 American Cancer Society.
Production of Biobutanediols by the Hydrogenolysis of Erythritol
Authors: Amada Yasushi , Watanabe Hideo , Hirai Yuichirou , Kajikawa Yasuteru , Nakagawa Yoshinao , Tomishige Keiichi
Published: August 2012

The hydrogenolysis of erythritol using an Ir–ReOx/SiO2 catalyst was performed for the production of butanediols, which are widely used as a raw material of polymers. The activity and selectivity to butanediols on Ir–ReOx/SiO2 was much higher than that on conventional hydrogenolysis catalysts. The maximum selectivity to 1,4‐ and 1,3‐butanediols reached 33 and 12 % at 74 % conversion, respectively. The erythritol conversion and selectivity to butanediols was almost maintained during four repeating tests if small amounts of acid were added to the reaction and the catalyst was calcined again. The reaction kinetics, reactivity trends, and characterization results indicate a direct hydrogenolysis mechanism in which the hydride species on the Ir metal surface attacks the alkoxide species on the 3D ReOx clusters. Based on the production of erythritol by the fermentation of glucose and glycerol, erythritol hydrogenolysis may be a promising pathway for the production of biobutanediols.
A high‐order curvature‐corrected CMOS bandgap voltage reference with constant current technique
Authors: Geng Junfeng , Zhao Yiqiang , Zhao Hongliang
Published: August 2012

A high‐order curvature‐corrected complementary metal–oxide–semiconductor (CMOS) bandgap voltage reference (BGR), utilizing the temperature‐dependent resistor and constant current technique, is presented. Considering the process variation, a resistor trimming network is introduced in this work. The circuit is implemented in a standard 0.35‐µm CMOS process. The measurement results have confirmed that the proposed BGR operates with a supply voltage of 1.8 V, consuming 45 μW at room temperature (25 °C), and the temperature coefficient of the output voltage reference is about 5.5 ppm/°C from −40 °C to 125 °C. The measured power supply rejection ratio is −38.8 dB at 1 kHz. The BGR is compatible with low‐voltage and low‐power circuit design when the structure of operational amplifiers and all the devices in the proposed bandgap reference are properly designed. Copyright © 2012 John Wiley & Sons, Ltd.
Gate‐level body biasing technique for high‐speed sub‐threshold CMOS logic gates
Authors: Corsonello P. , Lanuzza M. , Perri S.
Published: August 2012

An efficient technique for designing high‐performance logic circuits operating in sub‐threshold region is proposed. A simple gate‐level body biasing circuit is exploited to change dynamically the threshold voltage of transistors on the basis of the gate status. Such an auxiliary circuit prepares the logic gate for fast switching while maintaining energy efficiency.

If 200 aJ is the target total energy per operation consumption, a two input NAND (NOR) gate designed as described here shows a delay reduction between 20% (16%) and 40% (48%), with respect to previously proposed sub‐threshold approaches. Copyright 2012 John Wiley & Sons, Ltd.
Bleaching response of Symbiodinium (zooxanthellae): Determination by flow cytometry
Authors: Lee Co Sin , Wilson Yeo Yin Sheng , Sin Tsai Min
Published: August 2012

Coral bleaching is of increasing concern to reef management and stakeholders. Thus far, quantification of coral bleaching tends to be heavily reliant on the enumeration of zooxanthellae, with less emphasis on assessment of photosynthetic or physiological condition, these being often assessed separately by techniques such as liquid chromatography. Traditional methods of enumeration using microscopy are time consuming, subjected to low precision and great observer error. In this study, we presented a method for the distinction of physoiological condition and rapid enumeration of zooxanthellae using flow cytometry (FCM). Microscopy verified that healthy looking/live versus damaged/dead zooxanthellae could be reliably and objectively distinguished and counted by FCM on the basis of red and green fluorescence and light scatter. Excellent correlations were also determined between FCM and microscopy estimates of cell concentrations of fresh zooxanthellae isolates from Pocillopora damicornis. The relative intensities of chlorophyll and β‐carotene fluorescences were shown to be important in understanding the results of increased cell counts in freshly isolated zooxanthellae experimentally exposed to high temperatures (34, 36, and 38°C) over 24 h, with ambient temperature (29°C) used as controls. The ability to simultaneously identify and enumerate subpopulations of different physiological states in the same sample provides an enormous advantage in not just determining bleaching responses, but elucidating adaptive response and mechanisms for tolerance. Therefore, this approach might provide a rapid, convenient, and reproducible methodology for climate change studies and reef management programs. © 2012 International Society for Advancement of Cytometry
Evaluation of weight loss and adipocytokines levels after two hypocaloric diets with different macronutrient distribution in obese subjects with rs9939609 gene variant
Authors: de Luis Daniel Antonio , Aller Rocío , Izaola Olatz , de la Fuente Beatriz , Conde Rosa , Sagrado Manuel Gonzalez , Primo David
Published: August 2012

Background

Common polymorphisms of the fat mass and obesity associated gene (FTO) have been linked to obesity in some populations. One of these genetic variants (rs9939609) has been related to an increased risk of obesity.

Objective

Our aim was to evaluate weight loss and adipocytokine levels after two hypocaloric diets with different macronutrient distribution in obese subjects with RS9939609 gene variant.

Design

305 obese patients were enrolled in a prospective way. In the basal visit, patients were randomly allocated during 3 months to low carbohydrates and low fat.

Results

After treatment with both diets and in both genotypes, weight, fat mass, waist circumference and systolic blood pressures decreased. With the diet type I and in TT genotype, insulin (−6.6 ± 9.8 IU/L) and homeostasis model assessment (−2.9 ± 6.1 units) decreased. With the diet type II and in both genotypes (wild and mutant type), insulin (−5.2 ± 6.1 vs. −3.8 ± 6.1 IU/L; p < 0.05) and homeostasis model assessment (−2.4 ± 4.8 vs. −1.1 ± 3.8 kg; p < 0.05) decreased. In the A allele group, a significant decrease was detected in total cholesterol levels (−11.5 ± 20.1 mg/dL), low density lipoprotein cholesterol levels (−13.2 ± 20.9 mg/dL) and c‐reactive protein levels (−1.3 ± 3.8 mg/dL) secondary to weight loss after treatment with diet II. The decrease of leptin levels was higher in mutant type group than wild type group with low fat diet (−10.3 ± 36.1 vs. −28.6 ± 53.7 ng/mL; p < 0.05).

Conclusion

Metabolic improvement secondary to weight loss was better in A carriers with a low fat hypocaloric diet. Copyright © 2012 John Wiley & Sons, Ltd.
New transgenic reporters identify somatosensory neuron subtypes in larval zebrafish
Authors: Palanca Ana Marie S. , Lee Sung‐Ling , Yee Laura E. , Joe‐Wong Carlee , Trinh Le A. , Hiroyasu Elizabeth , Husain Majid , Fraser Scott E. , Pellegrini Matteo , Sagasti Alvaro
Published: August 2012

To analyze somatosensory neuron diversity in larval zebrafish, we identified several enhancers from the zebrafish and pufferfish genomes and used them to create five new reporter transgenes. Sequential deletions of three of these enhancers identified small sequence elements sufficient to drive expression in zebrafish trigeminal and Rohon‐Beard (RB) neurons. One of these reporters, using the Fru.p2x3‐2 enhancer, highlighted a somatosensory neuron subtype that expressed both the p2rx3a and pkcα genes. Comparison with a previously described trpA1b reporter revealed that it highlighted the same neurons as the Fru.p2x3‐2 reporter. To determine whether neurons of this subtype possess characteristic peripheral branching morphologies or central axon projection patterns, we analyzed the morphology of single neurons. Surprisingly, although these analyses revealed diversity in peripheral axon branching and central axon projection, PKCα/p2rx3a/trpA1b‐expressing RB cells did not possess obvious characteristic morphological features, suggesting that even within this molecularly defined subtype, individual neurons may possess distinct properties. The new transgenes created in this study will be powerful tools for further characterizing the molecular, morphological, and developmental diversity of larval somatosensory neurons. © 2012 Wiley Periodicals, Inc., 2013
Deacetylation of C/EBPβ is required for IL‐4‐induced arginase‐1 expression in murine macrophages
Authors: Serrat Neus , Pereira‐Lopes Selma , Comalada Mònica , Lloberas Jorge , Celada Antonio
Published: August 2012

The amount of arginine available at inflammatory loci is a limiting factor for the growth of several cells of the immune system. IL‐4‐induced activation of macrophages produced arginase‐1, which converts arginine into ornithine, a precursor of polyamines and proline. Trichostatin A (TSA), a pan‐inhibitor of histone deacetylases (HDACs), inhibited IL‐4‐induced arginase‐1 expression. TSA showed promoter‐specific effects on the IL‐4‐responsive genes. While TSA inhibited the expression of arginase‐1, fizz1, and mrc1, other genes, such as ym,1 mgl1, and mgl2, were not affected. The inhibition of arginase‐1 occurred at the transcriptional level with the inhibition of polymerase II binding to the promoter. IL‐4 induced STAT6 phosphorylation and binding to DNA. These activities were not affected by TSA treatment. However, TSA inhibited C/EBPβ DNA binding. This inhibitor induced acetylation on lysine residues 215–216, which are critical for DNA binding. Finally, using macrophages from STAT6 KO mice we showed that STAT6 is required for the DNA binding of C/EBPβ. These results demonstrate that the acetylation/deacetylation balance strongly influences the expression of arginase‐1, a gene of alternative activation of macrophages. These findings also provide a molecular mechanism to explain the control of gene expression through deacetylase activity.
MKP‐1: A critical phosphatase in the biology of macrophages controlling the switch between proliferation and activation
Authors: Comalada Mònica , Lloberas Jorge , Celada Antonio
Published: August 2012

Macrophages play a central role in the immune response. These cells either proliferate in response to, for example, growth factors or become activated in response to, for example, LPS and develop functional activities. Experiments carried out in mice showed that macrophage proliferation requires a short period of ERK phosphorylation, while an extended period is required for macrophage activation. The length of phosphorylation is controlled by the MAPK phosphatase‐1 (MKP‐1), a nuclear‐localized dual‐specificity phosphatase that dephosphorylates the MAPKs ERK, p38, and c‐Jun NH2‐terminal kinase (JNK). MKP‐1 is induced in macrophages by growth factors, as well as by activators such as LPS, but with different kinetics; to achieve the different functional outcomes (proliferation versus activation), the inhibition of MKP‐1 by cytokines such as IFN‐γ blocks macrophage proliferation and induces activation. The data presented in this review show that this phosphatase is the switch between macrophage proliferation and activation.
Epithelial‐microbial crosstalk in polymeric Ig receptor deficient mice
Authors: Reikvam Dag Henrik , Derrien Muriel , Islam Rejoanoul , Erofeev Alexander , Grcic Vedrana , Sandvik Anders , Gaustad Peter , Meza‐Zepeda Leonardo A. , Jahnsen Frode L. , Smidt Hauke , Johansen Finn‐Eirik
Published: August 2012

Innate and adaptive mucosal defense mechanisms ensure a homeostatic relationship with the large and complex mutualistic gut microbiota. Dimeric IgA and pentameric IgM are transported across the intestinal epithelium via the epithelial polymeric Ig receptor (pIgR) and provide a significant portion of the first line of natural or adaptive antibody‐mediated immune defense of the intestinal mucosa. We found that colonic epithelial cells from pIgR KO mice differentially expressed (more than twofold change) more than 200 genes compared with cells from WT mice, and upregulated the expression of antimicrobial peptides in a commensal‐dependent manner. Detailed profiling of microbial communities based on 16S rRNA genes revealed differences in the commensal microbiota between pIgR KO and WT mice. Furthermore, we found that pIgR KO mice showed increased susceptibility to dextran sulfate sodium‐induced colitis, and that this was driven by their conventional intestinal microbiota. Thus, in the absence of pIgR, the stability of the commensal microbiota is disturbed, gut homeostasis is compromised, and the outcome of colitis is significantly worsened.
Indoleamine 2,3‐dioxygenase: From catalyst to signaling function
Authors: Fallarino Francesca , Grohmann Ursula , Puccetti Paolo
Published: August 2012

Control of tryptophan metabolism by indoleamine 2,3‐dioxygenase (IDO) in dendritic cells (DCs) is a highly versatile regulator of innate and adaptive immune responses. In acute reactions, the otherwise inflammatory cytokine interferon γ (IFN‐γ) acts in a feedback fashion to induce IDO's enzymatic function — and thus prevent potentially harmful, exaggerated responses — through the combined effects of tryptophan starvation and tryptophan catabolites acting via the aryl hydrocarbon receptor of T cells. IDO, however, is also involved in the maintenance of stable tolerance to self in noninflammatory contexts, thus restraining autoimmunity. Exposure, indeed, of mouse plasmacytoid DCs (pDCs) to transforming growth factor β (TGF‐β) provides IDO with regulatory effects that are distinct, in nature, from its enzymic activity. Once phosphorylated, IDO mediates signaling events culminating in self‐amplification and maintenance of a stably regulatory condition in pDCs. Therefore, IDO has dual immunoregulatory functions driven by distinct cytokines. Firstly, the IFN‐γ–IDO axis is crucial in generating and sustaining the function of regulatory T cells. Secondly, a nonenzymic function of IDO — as a signaling molecule — contributes to TGF‐β–driven tolerance. The latter function is part of a regulatory circuit in pDCs whereby — in response to TGF‐β — the kinase Fyn mediates tyrosine phosphorylation of IDO‐associated immunoreceptor tyrosine‐based inhibitory motifs, resulting in downstream effects that regulate gene expression and preside over a proper, homeostatic balance between immunity and tolerance. All these aspects are covered in this review.
Cross‐reactive responses to modified M158–66 peptides by CD8+T cells that use noncanonical BV genes can describe unknown repertoires
Authors: Petrova Galina V. , Gorski Jack
Published: August 2012

Memory T‐cell repertoires are populated by clonotypes selected by an individual's history of antigen exposures. Our previous analysis of middle‐age CD8+ T‐cell memory repertoires to the influenza‐derived epitope M158–66, described a network of highly cross‐reactive BV19 clonotypes responding to M158–66 and at least one peptide with a conservative amino acid substitution at either of two TCR contact positions. Here, we report that some substitutions abrogate BV19 responses and favor responses with different BV. Cross‐reactive T cells using seven other BV families responded to 12 of 13 peptides tested. BV12 clonotypes define the most extensive cross‐reactive network that encompasses seven peptides. We generated 3D networks based on the peptides recognized and BV family used and observed a cluster of five peptides that includes M158–66 and another cluster of five peptides that does not include M158–66. The first cluster represents peptides structurally similar to M158–66, and the second represents peptides with more considerable changes in epitope recognition surface. We hypothesize that the second cluster represents the cross‐reactive network around another unknown epitope or epitopes. This data supports a model of stable CD8+ T‐cell memory networks that include a substantial contribution from cross‐reactive T cells.
Transcriptional control of innate lymphoid cells
Authors: Mjösberg Jenny , Bernink Jochem , Peters Charlotte , Spits Hergen
Published: August 2012

Cells that belong to the family of innate lymphoid cells (ILCs) not only form a first line of defense against invading microbes, but also play essential roles in tissue remodeling and immune pathology. Rorγt+ ILCs, producing the cytokines IL‐22 and IL‐17, include lymphoid tissue inducer (LTi) cells which are critical for the formation of lymphoid structures. Recently another ILC subset has been identified, which is dependent on RORα for its development and is dedicated to the production of the Th2 cytokines IL‐5 and IL‐13. These ILCs have been termed type 2 ILCs. All ILC subets are considered to belong to the same family that also includes natural killer cells because they all rely on the common γ‐chain (γc) of the IL‐2 receptor for their development and function, share a lymphoid morphology and depend on the transcriptional repressor Id2 for their development. Other transcription factors, including Notch, and the aryl hydrocarbon receptor (AhR) in RORγt+ ILCs and GATA3 in type 2 ILCs, also play roles in the development, survival, and function of these ILC subpopulations. Here we review the current knowledge with regard to the transcription factors involved in the development and functions of ILCs.
Synthesis of [MoS4]2––M (M = Cu and Cd) Clusters: Potential NMR Spectroscopic Structural Probes for the Orange Protein
Authors: Maiti Biplab K. , Avilés Teresa , Matzapetakis Manolis , Moura Isabel , Pauleta Sofia R. , Moura José J. G.
Published: August 2012

Two synthetic strategies of tetrathiomolybdate‐metal clusters with the potential to be used as NMR structural probes for the location of the metal cofactor in the orange protein (ORP) are described. The first strategy is based on the substitution reaction in which small organic ligands bind directly to the metal centre in a molybdenum–copper hetero‐dinuclear cluster. Interaction between [PPh4]2[MoS4CuCl] and either aliphatic [β‐mercaptoethanol (b‐me)] or aromatic [o‐aminobenzenethiol (abt)] thiols in the presence of a strong base resulted in the formation of [Ph4P]2[S2MoS2Cu(b‐me)] (1a) and [Et4N]2[S2MoS2Cu(abt)]·H2O·0.25DMF (1b), which can be used to obtain intermolecular NOEs. The compound 1a readily hydrolyzed to [Ph4P]2[OSMoS2Cu(b‐me)] (1ahydro) in contact with a protic solvent. The second strategy consisted of the incorporation of cadmium into tetrathiomolybdate ([MoS4]2–), which gives rise to the trinuclear cluster compound [PPh4]2[(MoS4)2Cd] (2). All clusters were characterized spectroscopically and their structure determined by X‐ray diffraction. The NMR spectroscopic data are consistent with the formation of a complex with a 1:1 ratio of {MoS4Cu} and thiol. The 113Cd NMR chemical shift of compound 2 is consistent with the cadmium having a tetrahedral geometry and coordinated by four sulfur ligands. The tetraphenylphosphonium cation in compound 1a was replaced by a tetramethylammonium countercation originating in the water‐soluble compound [Me4N‐1a]. Solubility in aqueous buffers is a requirement for incorporating this cluster into apo‐ORP. These compounds will be used to identify the exact location of the ORP heterometallic cluster using NMR methodologies.
Tuning the Electronics of Phosphorescent, Amide‐Functionalized, Cyclometalated IrIII Complexes: Syntheses, Structures, Spectroscopy and Theoretical Studies
Authors: Routledge Jack D. , Hallett Andrew J. , Platts James A. , Horton Peter N. , Coles Simon J. , Pope Simon J. A.
Published: August 2012

Iridium(III) complexes were synthesized with the general form [Ir(L1–6)2(bpy)]PF6 (bpy = 2,2′‐bipyridine), where ligands (LH1–6) are based on the N‐functionalization of 2‐phenyl‐N‐aryl/alkyl‐quinoline‐4‐carboxamides. Single crystal X‐ray diffraction studies were undertaken on two complexes, which show that each adopts a distorted octahedral coordination geometry with retention of the expected trans‐N, cis‐C arrangement of the cyclometalated ligands. Electrochemical studies confirmed the subtle perturbing of theIrIII/IV redox couple as a function of ligand structure. Scalar relativistic DFT studies provided qualitative descriptions of the HOMO and LUMO energy levels of the six complexes. The calculated HOMO is generally located over the Ir(5d) centre (about 45 %) and the amide‐substituted 2‐phenylquinoline ligand, whilst the LUMO is localized over the ancillary 2,2′‐bipyridine ligand. Similar calculations for [Ir(L6)2(bpy)]PF6 revealed a different HOMO depiction with locale on the pendant chromophores. A companion calculation, using an alternative relativistic approach (i.e. incorporating spin–orbit coupling effects) conducted on a simplified model compound, provided HOMO/LUMO depictions that are essentially identical to the non‐relativistic calculation, which predicts long‐lived phosphorescent emission from the HOMO–LUMO transition. Luminescence studies showed the predictable and tunable phosphorescent emission wavelengths between 585–627 nm. The experimental and theoretical studies suggest that the electronic nature of the pendant amide substituent influences the energy of the emitting state – the strongly electron‐withdrawing groups bathochromically shift the luminescence wavelength.
Synthesis, Structure and Properties of a Five‐Coordinate Oxophosphorus(V) meso‐Triphenylcorrole
Authors: Ghosh Avijit , Lee Way‐Zen , Ravikanth Mangalampalli
Published: August 2012

Treatment of six‐coordinate (5,10,15‐triphenylcorrole)dihydroxyphosphorus(V) [P(TPC)(OH)2] with trifluoroacetic acid (TFA) in CH2Cl2 for 30 min at room temperature followed by recrystallization gave stable five‐coordinate (5,10,15‐triphenylcorrole)oxophosphorus(V) [P(TPC)O] in quantitative yield. The formation of [P(TPC)O] from [P(TPC)(OH)2] in the presence of TFA was also monitored by NMR, absorption and fluorescence spectroscopic titration studies. The structure of the isolated [P(TPC)O] was confirmed by X‐ray crystallography. In [P(TPC)O], the corrole ring is distorted, and the PV ion is displaced by 0.456 Å from the N4 plane towards the axial oxygen atom. This is unlike six‐coordinate (5,10,15‐triphenylcorrole)dimethoxyphosphorus(V) [P(TPC)(OCH3)2], in which the PV ion lies in the porphyrin plane. NMR, absorption and fluorescence spectroscopy and electrochemical studies indicate that [P(TPC)O] exhibits interesting and distinct properties, which differ from the six‐coordinate [P(TPC)(OCH3)2]. Attempts to reduce the PV complex [P(TPC)O] to its corresponding PIII complex by treating it with LiAlH4 resulted in the formation of six‐coordinate (5,10,15‐triphenylcorrole)dihydridophosphorus(V) [P(TPC)H2].
Structures and Antibacterial Activities of Minor Dolabellanes from the Brown Alga Dilophus spiralis
Authors: Ioannou Efstathia , Quesada Antonio , Rahman M. Mukhlesur , Gibbons Simon , Vagias Constantinos , Roussis Vassilios
Published: August 2012

Thirteen new minor diterpenes featuring the dolabellane skeleton (1–13) were isolated from the organic extracts of the brown alga Dilophus spiralis, collected in Elafonissos Island. The structures and relative configurations of the isolated natural products were elucidated on the basis of extensive analyses of their spectroscopic data (NMR, MS, IR). The absolute configuration of 1 was determined by using the modified Mosher's method, whereas the structure of 2 was confirmed by single‐crystal X‐ray diffraction analysis. The antibacterial activities of metabolites 1–9 and 13 were evaluated against six strains of Staphylococcus aureus, including multidrug‐ and methicillin‐resistant variants. Compounds 1 and 4 exhibited noteworthy levels of activity with MIC values in the range of 2–8 μg/mL.
Synthesis of SHIP1‐Activating Analogs of the Sponge Meroterpenoid Pelorol
Authors: Meimetis Labros G. , Nodwell Matt , Yang Lu , Wang Xiaoxia , Wu Joyce , Harwig Curtis , Stenton Grant R. , Mackenzie Lloyd F. , MacRury Thomas , Patrick Brian O. , Ming‐Lum Andrew , Ong Christopher J. , Krystal Gerald , Mui Alice L. ‐F. , Andersen Raymond J.
Published: August 2012

Two biomimetic approaches have been used to synthesize analogs of the SHIP1‐activating sponge meroterpenoid pelorol (1). One approach started from the chiral pool plant natural product sclareolide, which has the same absolute configuration as pelorol. The second approach utilized an enantioselective polyene cyclization to efficiently access both absolute configurations of the pelorol meroterpenoid skeleton and to prepare A‐ring functionalized compounds. Selected analogs have been evaluated for water solubility and biological activity. It was found that the undesirable catechol and ester functionalities in 1 could be removed to give MN100 (3), without a decrease in SHIP1‐activating ability. A further refinement led to the resorcinol analog 18, which is the most effective SHIP1‐activating pelorol analog made to date. The HCl salt of ent‐28, a C‐3 amino analog of 18, is about 500,000‐fold more soluble in water than MN100 (3). (±)‐28·HCl activates SHIP1 in vitro, inhibits Akt phosphorylation in stimulated MOLT‐4 (SHIP+) cells, and is active in a dose‐dependent manner in a mouse model of inflammation when administered by oral gavage (ED50 ≈ 0.1 mg/kg). Pelorol analogs ent‐28 or (±)‐28 are promising chemical tools for further preclinical in vivo evaluation of the potential of SHIP1 activators as therapeutics for treating hematopoietic diseases involving aberrant activation of PI3K cell signaling.
Synthesis, Properties and Applications of Biphenyl Functionalized 9,9‐Bis(4‐diphenylaminophenyl)fluorenes as Bifunctional Materials for Organic Electroluminescent Devices
Authors: Thangthong A‐monrat , Prachumrak Narid , Namuangruk Supawadee , Jungsuttiwong Siriporn , Keawin Tinnagon , Sudyoadsuk Taweesak , Promarak Vinich
Published: August 2012

Four new bifunctional materials, namely BPTF, CBPTF, CMBPTF and BPVTF, having 9,9‐bis(4‐diphenylaminophenyl)fluorene as a molecular platform and biphenyl derivatives as end‐capping substituents were synthesized and characterized. Their optimized structures revealed that both triphenylamine moieties at the C‐9 position of the fluorene ring generated a bulky molecular structure. These molecules showed strong blue emission in both solution and in the solid state, and were thermally stable amorphous materials with glass transition temperatures up to 207 °C. The abilities of these materials to act as blue‐light‐emitting materials for blue OLEDs and hole‐transporting materials for green OLEDs in terms of device performance and thermal properties were superior to commonly used N,N′‐diphenyl‐N,N′‐bis(1‐naphthyl)‐(1,1′‐biphenyl)‐4,4′‐diamine (NPB). Efficient, and bright nondoped deep‐blue and Alq3‐based green OLEDs with maximum luminance efficiencies and CIE coordinates of 2.48 cd A–1 and x = 0.15 and y = 0.07, and 4.40 cd A–1 and x = 0.28 and y = 0.52 were achieved, respectively, with BPTF having two biphenyl substituents as active layers. Both devices showed low turn‐on voltages of 3.1 and 2.8 V, respectively. Notably, the color purities of these deep‐blue and green devices were close to the National Television Standards Committee blue (CIE coordinates of x = 0.14 and y = 0.08) and green (CIE coordinates of x = 0.26 and y = 0.65) standards.
Biosynthesis “debugged”: Novel bioproduction strategies
Authors: Guterl Jan‐Karl , Sieber Volker
Published: August 2012

The production of chemicals from biogenic resources is widely performed using microorganisms. These often do not meet the requirements of technical processes due to the narrow limits of microbial physiology. As a consequence, alternatives are sought. Cell‐free enzymatic reaction cascades were recently proposed as next‐generation bioproduction systems. Here, we address problems of microbial systems, show potential advantages of cell‐free concepts and give an overview over the state of the technology. Furthermore, we address current challenges of the cell‐free strategy and give an outlook on future developments.
Aluminum induces oxidative burst, cell wall NADH peroxidase activity, and DNA damage in root cells of Allium cepa L
Authors: Achary V. Mohan M. , Parinandi Narasimham L. , Panda Brahma B.
Published: August 2012

Plants under stress incur an oxidative burst that involves a rapid and transient overproduction of reactive oxygen species (ROS: O2•−, H2O2, •OH). We hypothesized that aluminum (Al), an established soil pollutant that causes plant stress, would induce an oxidative burst through the activation of cell wall‐NADH peroxidase (NADH‐PX) and/or plasma membrane‐associated NADPH oxidase (NADPH‐OX), leading to DNA damage in the root cells of Allium cepa L. Growing roots of A. cepa were treated with Al3+ (800 μM of AlCl3) for 3 or 6 hr without or with the pretreatment of inhibitors specific to NADH‐PX and NADPH‐OX for 2 hr. At the end of the treatment, the extent of ROS generation, cell death, and DNA damage were determined. The cell wall‐bound protein (CWP) fractions extracted from the untreated control and the Al‐treated roots under the aforementioned experimental conditions were also subjected to in vitro studies, which measured the extent of activation of peroxidase/oxidase, generation of •OH, and DNA damage. Overall, the present study demonstrates that the cell wall‐bound NADH‐PX contributes to the Al‐induced oxidative burst through the generation of ROS that lead to cell death and DNA damage in the root cells of A. cepa. Furthermore, the in vitro studies revealed that the CWP fraction by itself caused DNA damage in the presence of NADH, supporting a role for NADH‐PX in the stress response. Altogether, this study underscores the crucial function of the cell wall‐bound NADH‐PX in the oxidative burst‐mediated cell death and DNA damage in plants under Al stress. Environ. Mol. Mutagen., 2012. © 2012 Wiley Periodicals, Inc.
Channel network extent in the context of historical land use, flow generation processes, and landscape evolution in the North Carolina Piedmont
Authors: Jefferson Anne J. , McGee Ralph W.
Published: August 2012

Intensive agricultural land use in the 18th to early 20th centuries on the southeastern Piedmont resulted in substantial soil erosion and gully development. Today, many historically farmed areas have been abandoned and afforested, and such landscapes are an opportunity to study channel network recovery from disturbance by gullying. Channel initiation mapping, watershed area–slope relationships, and field monitoring of flow generation processes are used to identify channel network extent and place it in hydrologic, historical and landscape evolution context. In six study areas in the North Carolina Piedmont, 100 channel heads were mapped in fully‐forested watersheds, revealing a channel initiation relationship of 380 = AS1.27, whereAis contributing area (m2) andSis local slope (m/m). Flow in these channels is generated by subsurface and overland flow. The measured relative slope exponent is lower than expected based on literature values of ~2 for forested watersheds with subsurface and overland flow, suggesting that the channel network extent may reflect a former hydrological regime. However, geomorphic evidence of recovery in channel heads within fully forested watersheds is greater than those with present day pasture. Present day channel heads lie within hollows or downslope of unchanneled valleys, which may be remnants of historical gullies, and area–slope relationships provide evidence of colluvial aggradation within the valleys. Channel network extent appears to be sensitive to land use change, with recovery beginning within decades of afforestation. Channel initiation mapping and area–slope relationships are shown to be useful tools for interpreting geomorphic effects of land use change. Copyright © 2012 John Wiley & Sons, Ltd.
Combined effects of temperature and pyriproxyfen stress in a full life-cycle test with Chironomus riparius (Insecta)
Authors: Tassou Koffi Tcha , Schulz Ralf
Published: August 2012

Traditional risk assessment guidelines employ acute or chronic toxicity tests for a maximum of one generation of organisms. These tests are usually performed in the laboratory at a constant standard temperature, although in the field organisms may experience different temperatures, which may be a source of additional stress. Climate change–related temperature shifts may have serious impacts on ectotherm populations that are key components of the aquatic food chains, particularly in combination with the exposure of pollutants affecting their development. Here, a chronic full life-cycle test with Chironomus riparius from the first-instar larvae in the parental (P) generation until emergence in the subsequent F1 generation was conducted at different temperatures (16 and 24°C), testing the effect of the insect growth regulator pyriproxyfen at 1, 3, 10, 30, and 100 µg/L. The emergence ratios were significantly affected by the interaction of temperature, chemical treatment, and generation, showing that, at lower temperatures, the negative effects of pyriproxyfen exposure were significantly greater in the F1 generation than in the P generation. The development rate showed that the effects of the interactions were significant in the F1 generation, underscoring the importance of extended exposure as a useful amendment to the risk assessment of those agrochemicals potentially influencing developmental and reproductive parameters in intact organisms. Moreover, results demonstrated that any difference from the standard temperature of 20°C might result in additional stress, leading to disruption of biological functions in C. riparius, highlighting the interaction among different global climate change-related variables. Environ. Toxicol. Chem. 2012; 31: 2384–2390. © 2012 SETAC
Accumulation of polychlorinated biphenyls from contaminated sediment by Atlantic cod (Gadus morhua): Direct accumulation from resuspended sediment and dietary accumulation via the polychaete Nereis virens
Authors: Ruus Anders , Daae Ingrid Aarre , Hylland Ketil
Published: August 2012

Bioaccumulation of sediment-associated polychlorinated biphenyls (PCBs) was examined in Atlantic cod (Gadus morhua) through direct diffusion from the sediment (via the water phase) and through the food chain (dietary exposure). To facilitate direct accumulation from the sediment, it was continuously resuspended. To study the dietary bioaccumulation of PCBs, cod were fed benthic polychaetes (Nereis virens) previously exposed to test sediments, which were naturally polluted sediments from the inner Oslofjord (Norway). Both exposure experiments had a duration of 129 d. Furthermore, the role of sediments as a source of PCBs accumulated in Oslofjord cod was elucidated, using results from environmental monitoring as a reference. Generally, the results suggest that the contaminated sediments of the inner Oslofjord are an important source of legacy PCBs for accumulation in resident cod, although additional contributions may also be important. Crude estimates of assimilation efficiency of ingested PCBs (through diet) were found to be 30 to 50%; the highest was for the lower chlorinated congeners (PCB-28 and -52). Challenges for applying trophic magnification factors for determining biomagnification in laboratory experiments, in terms of preventive environmental safety, are indicated. The results provide useful information for parameterization of models describing the behavior of hydrophobic persistent contaminants in the foodweb of the Oslofjord and elsewhere. Environ. Toxicol. Chem. 2012; 31: 2472–2481. © 2012 SETAC
OpenWSN: a standards‐based low‐power wireless development environment
Authors: Watteyne Thomas , Vilajosana Xavier , Kerkez Branko , Chraim Fabien , Weekly Kevin , Wang Qin , Glaser Steven , Pister Kris
Published: August 2012

The OpenWSN project is an open‐source implementation of a fully standards‐based protocol stack for capillary networks, rooted in the new IEEE802.15.4e Time Synchronized Channel Hopping standard. IEEE802.15.4e, coupled with Internet of Things standards, such as 6LoWPAN, RPL and CoAP, enables ultra‐low‐power and highly reliable mesh networks, which are fully integrated into the Internet. The resulting protocol stack will be cornerstone to the upcoming machine‐to‐machine revolution.

This article gives an overview of the protocol stack, as well as key integration details and the platforms and tools developed around it. The pure‐C OpenWSN stack was ported to four off‐the‐shelf platforms representative of hardware currently used, from older 16‐bit microcontroller to state‐of‐the‐art 32‐bit Cortex‐M architectures. The tools developed around the low‐power mesh networks include visualisation and debugging software, a simulator to mimic OpenWSN networks on a PC, and the environment needed to connect those networks to the Internet.

Experimental results presented in this article include a network where motes operate at an average radio duty cycle well below 0.1% and an average current draw of 68  μA on off‐the‐shelf hardware. These ultra‐low‐power requirements enable a range of applications, with motes perpetually powered by micro‐scavenging devices. OpenWSN is, to the best of our knowledge, the first open‐source implementation of the IEEE802.15.4e standard. Copyright © 2012 John Wiley & Sons, Ltd.
Influence of carbon nanotubes on fire behaviour and aerosol emitted during combustion of thermoplastics
Authors: Chivas‐Joly C. , Motzkus C. , Guillaume E. , Ducourtieux S. , Saragoza L. , Lesenechal D. , Lopez‐Cuesta J‐M. , Longuet C. , Sonnier R. , Minisini B.
Published: August 2012

Carbon nanotube‐based poly(methyl methacrylate) and polyamide‐6 nanocomposites have been investigated using various techniques within the framework of the NANOFEU project. Scanning transmission electron microscopy was used to characterize morphologies of composites, while fire properties were studied using cone calorimeter and pyrolysis combustion flow microcalorimeter. The study focused particularly on composition and microstructure of gaseous and aerosol products. Morphology of ultrafine particles released from the combustion of nanocomposites was studied using cascade impactor and atomic force microscopy. Fire behaviour has been interpreted in relation with the degradation mechanisms specifically induced by the presence of carbon nanotubes. Copyright © 2012 John Wiley & Sons, Ltd.
Nutritional‐rich and stress‐tolerant crops by saccharopine pathway manipulation
Authors: Arruda Paulo , Neshich Izabella Pena
Published: August 2012

Lysine is a limiting essential amino acid in cereals, a major food source for humans and animals. Although cereals can synthesize lysine from aspartate, the pathway is feedback regulated in a manner that restricts lysine accumulation. Another step that restricts lysine accumulation in seeds is the saccharopine pathway for lysine catabolism. This pathway converts lysine to α‐aminoadipic‐δ‐semialdehyde (AASA) by the bifunctional enzyme lysine‐ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH). Then, AASA is converted to aminoadipic acid (AAA) by α‐aminoadipic‐δ‐semialdehyde dehydrogenase (AASADH). The downregulation of LKR/SDH in seeds results in the overaccumulation of free lysine to levels that meet human nutritional requirements. However, the saccharopine pathway is also involved in stress response in plants, animals, and bacteria. In these organisms, the gene encoding LKR/SDH is upregulated under osmotic, salt, and oxidative stress conditions. The role of the saccharopine pathway in stress response is not well understood, but the overexpression of AASADH results in stress‐tolerant plants and animal cells. The saccharopine pathway may thus act either by producing osmolytes, such as pipecolic acid and proline, or by signaling compounds that regulate stress‐response genes. In this review, we discuss the potential use of the saccharopine pathway to engineer nutritional‐rich and stress‐tolerant crops.
Glutathione peroxidase 1 activity dictates the sensitivity of glioblastoma cells to oxidative stress
Authors: Dokic Ivana , Hartmann Christian , Herold‐Mende Christel , Régnier‐Vigouroux Anne
Published: August 2012

The high intratumoral and intertumoral heterogeneity of glioblastoma (GBM) leads to resistance to different therapies, and hence, selecting an effective therapy is very challenging. We hypothesized that the antioxidant enzyme status is a significant feature of GBM heterogeneity. The most important reactive oxygen/nitrogen species (ROS/RNS) detoxification mechanisms include superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx). Expression and activity of these enzymes and the cellular response to induced oxidative stress were systematically analyzed and compared between GBM cells and nontransformed glial cells of both human and murine origin. Regardless of cell type or species, all tested cells expressed similar amount of catalase and MnSOD. All except one, GBM cell lines exhibited a deficiency in GPx1 expression and activity. Analysis of GBM tissue sections indicated a heterogeneous profile of weak to moderate expression of GPx1 in tumor cells. GPx1 deficiency led to an accumulation of ROS/RNS and subsequent death of GBM cells after induction of oxidative stress. Astrocytes, microglia/macrophages, and glioma stem cell lines expressed active GPx1 and resisted ROS/RNS‐mediated cell death. Pharmacological inhibition or siRNA silencing of GPx1 partially reverted this resistance in astrocytes, indicating the contribution of various antioxidant molecules besides GPx1. The GPx1‐expressing GBM cell line on the contrary, became extremely sensitive to oxidative stress after GPx1 inhibition. Altogether, these results highlight GPx1 as a crucial element over other antioxidant enzymes for oxidative stress regulation in GBM cells. Mapping the antioxidant enzyme status of GBM may prove to be a useful tool for personalized ROS/RNS inducing therapies. © 2012 Wiley Periodicals, Inc.
Induction of neuronal phenotypes from NG2+ glial progenitors by inhibiting epidermal growth factor receptor in mouse spinal cord injury
Authors: Ju Peijun , Zhang Si , Yeap Yeeshan , Feng Zhiwei
Published: August 2012

Besides neural stem cells, some glial cells, such as GFAP+ cells, radial glia, and oligodendrocyte progenitor cells can produce neuronal cells. Attractively, NG2+ glial progenitors exhibit lineage plasticity, and they rapidly proliferate and differentiate in response to central nervous system (CNS) injuries. These attributes of NG2+ glial progenitors make them a promising source of neurons. However, the potential of neuronal regeneration from NG2+ glial progenitors in CNS pathologies remains to be investigated. In this study, we showed that antagonizing epidermal growth factor receptor (EGFR) function with EGFR inhibitor caused a significant number of proliferative NG2+ glial progenitors to acquire neuronal phenotypes in contusive spinal cord injury (SCI), which presumably led to an accumulation of newly generated neurons and contributed to the improved neural behavioral performance of animals. In addition, the neuronal differentiation of glial progenitors induced by EGFR inhibitor was further confirmed with two different cell lines either in vitro or through ex vivo transplantation experiment. The inhibition of EGFR signaling pathway under the gliogenic conditions could induce these cells to acquire neuronal phenotypes. Furthermore, we find that the Ras‐ERK axis played a key role in neuronal differentiation of NG2+ glial progenitors upon EGFR inhibition. Taken together, our studies suggest that the EGFR inhibitor could promote neurogenesis post SCI, mainly from the NG2+ glial progenitors. These findings support the possibility of evoking endogenous neuronal replacement from NG2+ glial progenitors and suggest that EGFR inhibition may be beneficial to CNS trauma. © 2012 Wiley Periodicals, Inc.
Altered tissue electrical properties in squamous cell carcinoma in head and neck tumors: Preliminary observations
Authors: Małecka–Massalska Teresa , Smolen Agata , Morshed Kamal
Published: August 2012

Background

The purpose of this study was to investigate tissue electrical properties in patients with head and neck cancer.

Methods

In the cross‐sectional study direct bioimpedance measures (resistance, reactance, and phase angle) determined by bioelectrical impedance analysis (BIA) were performed on 31 patients with head and neck cancer and 31 healthy volunteers matched by age and sex as a control group.

Results

Phase angle at 50 kHz was found to be significantly lower (p = .000006) in patients with head and neck cancer than in the control group (4.69° ± 0.71 vs 5.59° ± 0.70, respectively). Resistance was significantly (p = .0002) greater in patients with head and neck cancer than in the control group (596.24 ± 96.31 ohm vs 513.73 ± 65.79 ohm, respectively).

Conclusion

Presurgical patients diagnosed with head and neck cancer have altered tissue electrical properties. Further observations would be valuable to calculate survival, validate the prognostic significance of phase angle, and monitor nutritional and therapeutic interventions in this patient population. © 2012 Wiley Periodicals, Inc. Head Neck, 2013