bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Evaluation of 1‐Amino‐6‐halo‐β‐carbolines as Antimalarial and Antiprion Agents
Authors: Thompson Mark J. , Louth Jennifer C. , Little Susan M. , Jackson Matthew P. , Boursereau Yohan , Chen Beining , Coldham Iain
Published: January 2012

Malaria is one of the world’s most devastating parasitic diseases, causing almost one million deaths each year. Growing resistance to classical antimalarial drugs, such as chloroquine, necessitates the discovery of new therapeutic agents for successful control of this global disease. Here, we report the synthesis of some 6‐halo‐β‐carbolines as analogues of the potent antimalarial natural product, manzamine A, retaining its heteroaromatic core whilst providing compounds with much improved synthetic accessibility. Two compounds displayed superior activity to chloroquine itself against a resistant Plasmodium falciparum strain, identifying them as promising leads for future development. Furthermore, in line with previous reports of similarities in antimalarial and antiprion effects of aminoaryl‐based antimalarial agents, the 1‐amino‐β‐carboline libraries were also found to possess significant bioactivity against a prion‐infected cell line.
Influence of the Number of Anchoring Groups on the Electronic and Mechanical Properties of Benzene‐, Anthracene‐ and Pentacene‐Based Molecular Devices
Authors: Martín‐Lasanta Ana , Miguel Delia , García Trinidad , López‐Villanueva Juan A. , Rodríguez‐Bolívar Salvador , Gómez‐Campos Francisco M. , Buñuel Elena , Cárdenas Diego J. , de Cienfuegos Luis Álvarez , Cuerva Juan M.
Published: January 2012

One of the central issues of molecular electronics (ME) is the study of the molecule–metal electrode contacts, and their implications for the conductivity, charge‐transport mechanism, and mechanical stability. In fact, stochastic on/off switching (blinking) reported in STM experiments is a major problem of single‐molecule devices, and challenges the stability and reliability of these systems. Surprisingly, the ambiguous STM results all originate from devices that bind to the metallic electrode through a one‐atom connection. In the present work, DFT is employed to study and compare the properties of a set of simple acenes that bind to metallic electrodes with an increasing number of connections, in order to determine whether the increasing numbers of anchoring groups have a direct repercussion on the stability of these systems. The conductivities of the three polycyclic aromatic hydrocarbons are calculated, as well as their transmission spectra and current profiles. The thermal and mechanical stability of these systems is studied by pulling and pushing the metal–molecule connection. The results show that molecules with more than one connection per electrode exhibit greater electrical efficiency and current stability.
Further Insight into the Photostability of the Pyrene Fluorophore in Halogenated Solvents
Authors: Aguilera‐Sigalat Jordi , Sanchez‐SanMartín Jaime , Agudelo‐Morales Carlos E. , Zaballos Elena , Galian Raquel E. , Pérez‐Prieto Julia
Published: January 2012

Pyrene fluorophores of pyrene‐functionalized CdSe quantum dots (QD@Py), as well as alkylpyrene and pyrene itself (Py), undergo fast degradation in aerated chloroform under ultraviolet‐A (UV‐A, 316<λ<400 nm) illumination. Steady‐state fluorescence studies of irradiated chloroform solutions of QD@Py show formation of new bands, red‐shifted compared to that of the pyrene moiety. Similar behaviour is observed for pyrene and the alkylpyrene system. Column chromatography of the pyrene photolysate in chloroform allowed us to isolate photoproducts arising from pyrene degradation, and to obtain information on the structure of the photoproducts responsible for the emission bands. The most predominant photoproducts were those originating from the reaction of pyrene with dichloromethyl radicals. The phototransformation of QD@Py and the alkylpyrene involves mainly detachment of the alkyl chain from the aromatic ring, induced also by dichloromethyl radicals, and oxidation of the alkyl chain at the benzylic position was detected as well. By contrast, these pyrene systems show a high photostability in aerated dichloromethane. Transient absorption measurements showed formation of both pyrene triplet and pyrene radical cation for all pyrene systems in these halogenated solvents. The yield of pyrene radical cations for Py is higher than for QD@Py and the alkylpyrene. In addition, pyrene radical cations were longer‐lived in dichloromethane than in chloroform. The reason for the pyrene photostability in dichloromethane is the different reactivity of chloromethyl and dichloromethyl radicals towards pyrene and oxygen. These studies show that the use of dichloromethane can be a suitable alternative to chloroform when the good solubility properties of these halogenated solvents are needed to dissolve pyrene when this chromophore is used as a fluorescent probe.
Reduced respiratory muscle strength and endurance in type 2 diabetes mellitus
Authors: Fuso Leonello , Pitocco Dario , Longobardi Anna , Zaccardi Francesco , Contu Chiara , Pozzuto Carmen , Basso Salvatore , Varone Francesco , Ghirlanda Giovanni , Antonelli Incalzi Raffaele
Published: January 2012

Background

A restrictive lung function pattern is frequently observed in patients with diabetes mellitus (DM) and has been related to respiratory muscle dysfunction in type 1 DM or in mixed population. We aimed to verify whether such a relationship applies also to type 2 DM patients.

Methods

The respiratory muscle function was explored in 75 non‐smoking patients with type 2 DM without pulmonary or cardiac diseases and compared with that of 40 healthy non‐smoking control subjects matched by age and sex. Maximal inspiratory and expiratory pressures (MIP, MEP) and maximum voluntary ventilation (MVV), which reflect respiratory muscle strength and endurance, respectively, were measured, and a complete respiratory function assessment was recorded.

Results

Patients were in stable metabolic conditions and had, on average, normal total lung capacity and diffusing lung capacity for carbon monoxide. However, MIP and MVV were significantly reduced in comparison with those of control subjects. Both MIP/MEP and MVV significantly correlated with lung volumes and diffusing lung capacity for carbon monoxide. The multiple regression analysis identified age (beta coefficient = −0.238, p = 0.046), glycated haemoglobin (beta coefficient = −0.245, p = 0.047) and total lung capacity (beta coefficient = 0.430, p = 0.016) as independent correlates of MIP, whereas male sex (beta coefficient = 0.423, p = 0.004) and diabetic complications (beta coefficient = −0.248, p = 0.044) were independent correlates of MVV.

Conclusions

In type 2 DM, respiratory muscle strength was reduced and significantly related to lung volumes and quality of metabolic control, whereas impaired endurance of respiratory muscles prevailed in patients with microvascular complications. Copyright © 2012 John Wiley & Sons, Ltd.
Possible association of the DRD4 gene with a history of attention‐deficit/hyperactivity disorder in women with bulimia nervosa
Authors: Yilmaz Zeynep , Kaplan Allan S. , Levitan Robert D. , Zai Clement C. , Kennedy James L.
Published: January 2012

Objective:

Up to one‐third of patients with bulimia nervosa (BN) report a history of attention‐deficit/hyperactivity disorder (ADHD) symptoms, and the dopaminergic genes, especially the dopamine receptor D4 (DRD4), have been associated independently with both binge eating and ADHD.

Method:

The purpose of this study was to (1) compare the frequency of DRD4 exon III VNTR variants in 157 BN probands and equal number of healthy controls; (2) assess transmission of DRD4 alleles in 68 families of patients with BN; and (3) explore the possible role of DRD4 gene in childhood ADHD history in a subgroup of 81 women with BN.

Results:

Our results showed that the BN probands and controls did not differ in DRD4 allele frequency. We also did not find evidence for preferential transmission of any DRD4 variant to the affected offspring with BN. However, the presence of either the 2‐repeat or 7‐repeat allele was associated with a history of childhood ADHD in BN (p = .038, odds ratio = 3.2).

Discussion:

Our findings suggest that although DRD4 may not be associated with the diagnosis of BN, its variants are associated with a history of childhood ADHD in BN probands. This may have relevance for the understanding, prevention, and treatment of BN that evolves in the context of childhood ADHD. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2012)
Local Climate Action Plans in France: Emergence, Limitations and Conditions for Success
Authors: Yalçın Melike , Lefèvre Benoit
Published: January 2012

A growing number of local governments worldwide are addressing climate change by locally developed climate action plans (CAPs). In this paper, we analyse the first generation of voluntary and partnership‐based CAPs in France. On the basis of data collected from Grenoble Alpes Métropole and other French pioneer cities, we try to find out what the experiences of these pioneer cities teach us about the triggering factors, the scope, the limitations and the conditions for success of CAPs. Our study shows that CAPs help to raise awareness about climate and energy issues and to bring local stakeholders together to develop shared solutions suited to local specificities. However, they do not seem to launch ambitious operations conducted in a cross‐cutting manner. Their effective implementation depends on the resources available to authorities, as well as the incentives and support that they receive. Moreover, meeting the CAP targets requires the authorities' ability to promote and utilize partnerships to mobilize all local potential for energy efficiency and GHG emission reduction. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
Segment Solid‐Phase Total Synthesis of the Anthelmintic Cyclooctadepsipeptides PF1022A and Emodepside
Authors: Scherkenbeck Jürgen , Lüttenberg Sebastian , Ludwig Monika , Brücher Karin , Kotthaus Andreas
Published: January 2012

Cyclodepsipeptides of the enniation, PF1022 and verticilide families represent a diverse class of highly interesting natural products with respect to their manifold biological activities. However, until now, no practicable solid‐phase syntheses of these compounds have been accomplished, probably due to the problematic combination of N‐methyl amino acids and hydroxycarboxylic acids. We report herein an efficient synthesis of the anthelmintic PF1022A and its commercial analogue emodepside on Kaiser and Wang resins. Our protocol provides the basis for the solid‐phase synthesis of cyclodepsipeptide libraries with a high probability of anthelmintic, antibacterial or insecticidal activity.
Oxidative Homologation of Aldehydes to α‐Ketoaldehydes by using Iodoform, o‐Iodoxybenzoic Acid, and Dimethyl Sulf­oxide
Authors: Zall Andrea , Bensinger Dennis , Schmidt Boris
Published: January 2012

An efficient three‐step synthetic route to α‐ketoaldehydes starting from aryl aldehydes is reported. The aldehydes were treated with iPrMgCl and iodoform to obtain β‐diiodoalcohols, which were then oxidized with o‐iodoxybenzoic acid at room temperature to the corresponding β‐diiodoketones. Subsequent reaction of the β‐diiodoketone to the α‐ketoaldehyde occurred under oxygen transfer from dimethyl sulfoxide. These sensitive products were in situ cyclized with o‐phenylenediamine to form the stable monosubstituted quinoxalines, which could be characterized and isolated easily.
Intrinsic religiosity reduces intergroup hostility under mortality salience
Authors: Golec de Zavala Agnieszka , Cichocka Aleksandra , Orehek Edward , Abdollahi Abdolhossein
Published: January 2012

Results of three studies indicate that intrinsic religiosity and mortality salience interact to predict intergroup hostility. Study 1, conducted among 200 American Christians and Jews, reveals that under mortality salience, intrinsic (but not extrinsic or quest) religiosity is related to decreased support for aggressive counterterrorism. Study 2, conducted among 148 Muslims in Iran, demonstrates that intrinsic religiosity predicts decreased out‐group derogation under mortality salience. Study 3, conducted among 131 Polish Christians, shows that under mortality salience, priming of intrinsic religious concepts decreases support for aggressive counterterrorism. Copyright © 2012 John Wiley & Sons, Ltd.
Log‐jams and avulsions in the San Antonio River Delta, Texas
Authors: Phillips Jonathan D.
Published: January 2012

The San Antonio River Delta (SARD), Texas, has experienced two major avulsions in the past 80 years, and a number of other historical and Holocene channel shifts. The causes and consequences of these avulsions – one of which is ongoing – were examined using a combination of fieldwork, geographic information system (GIS) analysis, and historical information to identify active, semi‐active, and paleochannels and the sequence of shifting flow paths through the delta. The role of deposition patterns and antecedent morphology, large woody debris jams, and tectonic influences were given special attention. Sedimentation in the SARD is exacerbated by tectonic effects. Channel aggradation is ubiquitous, and superelevation of the channel bed above the level of backswamp areas on the floodplain is common. This creates ideal setup conditions for avulsions, and stable, cohesive fine‐grained banks favor avulsions rather than lateral migration. Flood basins between the alluvial ridges associated with the aggraded channels exist, but avulsions occur by re‐occupation of former channels found within or connected to the flood basins. Large woody debris and channel‐blocking log‐jams are common, and sometimes displace flow from the channel, triggering crevasses. However, a large, recurring log‐jam at the site of the ongoing avulsion from the San Antonio River into Elm Bayou is not responsible for the channel shift. Rather, narrow, laterally stable channels resulting from flow splits lead to accumulation of wood. Some aspects of the SARD avulsion regime are typical of other deltas, while others are more novel. These includes avulsions involving tributaries and subchannels within the delta as well as from the dominant channel; tectonic influences on delta backstepping and on channel changes within the delta; avulsions as an indirect trigger for log‐jam formation (as well as vice‐versa); and maintenance of a multi‐channel flow pattern distinct from classic anastamosing or distributary systems. Copyright © 2012 John Wiley & Sons, Ltd.
Alterations of Smad expression and activation in defining 2 subtypes of human head and neck squamous cell carcinoma
Authors: Xie Wen , Aisner Seena , Baredes Soly , Sreepada Gangadhar , Shah Rasesh , Reiss Michael
Published: January 2012

Background

We postulated that disruptions of the canonical transforming growth factor‐beta (TGF‐β)/Smad signaling pathway might contribute to the development of head and neck squamous cell carcinoma (HNSCC).

Methods

A cohort of 798 HNSCC tumor samples from 346 patients were analyzed by immunohistochemistry (IHC) to define the pattern of expression of (phospho)Smad2, (phospho)Smad3, and Smad4.

Results

We found that 19%, 40%, and 12% of HNSCC specimens failed to express pSmad2, pSmad3, or Smad4, respectively. Loss of Smad2/3 activation was observed in 8.5% of specimens. In addition, 4% of specimens failed to express only Smad4. Moreover, patients with pSmad2/3‐negative tumors had a significantly better overall survival than that of those whose tumors expressed activated Smad2/3. In contrast, loss of Smad4 expression did not have prognostic significance.

Conclusion

Our results indicate that HNSCC in which Smad2/3 are inactivated or in which Smad4 expression is lost represent 2 distinct tumor subtypes with different clinical outcomes. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
The chronic spleen injury of mice following long‐term exposure to titanium dioxide nanoparticles
Authors: Sang Xuezi , Zheng Lei , Sun Qingqing , Li Na , Cui Yaling , Hu Renping , Gao Guodong , Cheng Zhe , Cheng Jie , Gui Suxin , Liu Huiting , Zhang Zengli , Hong Fashui
Published: January 2012

To understand the chronic spleen injury induced by intragastric administrations with 2.5, 5, and 10 mg kg−1 body weight titanium dioxide nanoparticles (TiO2 NPs) for 90 consecutive days, histopathological and ultrastructure changes, hematological parameters, lymphocyte subsets, the inflammatory, and apoptotic cytokines in the mouse spleen were investigated. Our findings indicate that TiO2 NPs exposure results in the significant increase in the spleen indices, histopathological changes, and splenocyte apoptosis in spleen. Especially, in these TiO2 NPs‐treated mice, immunoglobulin, blood cells, platelets, hemoglobin, lymphocyte subsets (such as CD3, CD4, CD8, B cell, natural killer cell) of mice were significantly decreased. Furthermore, TiO2 NPs exposure can significantly increase the levels of nucleic factor‐κB, tumor necrosis factor‐α, macrophage migration inhibitory factor, interleukin‐2, interleukin‐4, interleukin‐6, interleukin‐8, interleukin‐10, interleukin‐18, interleukin‐1β, cross‐reaction protein, transforming growth factor‐β, interferon‐γ, Bax, and CYP1A1 expression, whereas decrease the levels of Bcl‐2 and heat shock protein 70 expression. These findings suggest that long‐term exposure to low dose TiO2 NPs may result in spleen injury and reduction of immune capacity, TiO2 NP‐induced injury in spleen may result from alteration of inflammatory and apoptotic cytokines expression, and workers and consumers should take great caution when handling nanomaterials. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Inhibition of IGF‐IR increases chemosensitivity in human colorectal cancer cells through MRP‐2 promoter suppression
Authors: Shen Ke , Cui Daling , Sun Liyun , Lu Yanhua , Han Mingquan , Liu Jianwen
Published: January 2012

The emergence of multidrug resistance (MDR) in cancer cells has made many of the currently available chemotherapeutic agents ineffective. However, the mechanism involved in mediating this effect is not yet fully understood. Here, we found the overexpression of type I insulin‐like growth factor receptor (IGF‐IR) in established colorectal MDR cells. Specific siRNA of IGF‐IR decreases cell proliferation, exert synergistic effect with anticancer drugs. The downstream signaling of IGF‐IR, PI3K/AKT pathway, was altered upon IGF‐IR silencing. The expression of multidrug‐resistance‐associated protein 2 (MRP‐2) was suppressed due to the nuclear translocation of nuclear factor‐like 2 (Nrf2). Then the intracellular drug concentration was increased and the drug‐resistant phenotype was reversed. Our findings improve current understanding of the biology of IGF‐IR and MDR and have significant therapeutic implications on colorectal MDR cancer. J. Cell. Biochem. 113: 2086–2097, 2012. © 2012 Wiley Periodicals, Inc.
EXTENDING ACCESS TO INFORMATION, EDUCATION AND ENTERTAINMENT IN THE DEVELOPING ECONOMIES: BROADCAST TECHNOLOGIES IN THE BRITISH EMPIRE, 1951 TO 1962
Authors: Bowden Sue , Clayton David , Pereira Alvaro
Published: January 2012

This paper builds on previous work published in this journal by considering the historical roots of poverty in relation to the denial or otherwise of access to the information made available by radio technology. The case study is that of the British Empire in the early post‐war years. New dimensions of access that are developing economy sensitive are presented and evaluated. We find that the colonial legacy of radio broadcast is significantly correlated with the diffusion and adoption of radio technologies in subsequent years and that this in terms was largely the reflection of geo‐political considerations. Differential access to information has its roots in the colonial historical past. Copyright © 2012 John Wiley & Sons, Ltd.
Bridging the gap between Gen X and Gen Y
Authors: Mhatre Ketan H. , Conger Jay A.
Published: January 2012

The implications of the generational diversity inherent in the fabric of the current workforce have been a topic of much discussion, exploration, and debate among organizational scholars and researchers. What are the leadership implications of this generational diversity, and what forms of leadership can be used constructively to achieve performance outcomes that foster a positive and constructive relationship between generations? We turn to the theoretical developments associated with the Authentic Leadership model to synthesize learning lessons from the theory, research, and practice of authentic leadership. We illustrate how the components of authentic leadership can help in overcoming some of the leadership challenges that result due to the differences between Gen Xers and Gen Yers.
Millennials and globalization
Authors: Perruci Gama
Published: January 2012

There is much discussion about the way Millennials are shaping organizations in the 21st century. We are cautioned to consider the implications of multiple generations working within the same organization. These discussions, however, tend to leave out the cross‐cultural dimensions of intragenerational leadership. Globalization is reshaping leadership not only at the vertical level (multiple generations working in the same organization) but also horizontally (communication and technology reshaping the way Millennials interact with other Millennials across national boundaries). This article offers a framework through which we can develop key questions for curricular development and scholarly research related to intragenerational leadership. This article presents a general definition of leadership, using five components (leaders, followers, goals, context, and cultural norms). This definition is then applied to the concept of globalization as the new context that the Millennials face. The article suggests possible curricular and research questions that may help us gain a deeper understanding of intragenerational leadership.
Response of cotton fiber quality to the carbohydrates in the leaf subtending the cotton boll
Authors: Xiangbin Gao , Youhua Wang , Zhiguo Zhou , Oosterhuis Derrick M.
Published: January 2012

This study investigated the effect of nitrogen (N) fertilization on leaf and boll N and carbohydrate concentrations in the development of fiber quality. A two‐year field study was conducted with two cotton (Gossypium hirsutum L.) cultivars, Kemian 1 (average fiber strength 35 cN tex–1) and NuCOTN 33B (average fiber strength 32 cN tex–1) at five (2008) and four (2009) N levels. The relationship between leaf and boll N and carbohydrate concentrations was assessed from measurements of N, carbohydrates, chlorophyll (based on SPAD readings), and free amino acids in the leaf subtending the boll, together with fiber carbohydrates and development of fiber quality. Results indicate that leaf N concentration more accurately reflected boll N status than the concentration of chlorophyll or free amino acids. Leaf sucrose and nonstructural carbohydrate had a quadratic relation with leaf N concentration (p < 1%). The optimal leaf N concentration ranged from 3.0% to 2.4%. During 24–38 d post‐anthesis (DPA), fiber sucrose was positively related to leaf sucrose and nonstructural carbohydrate (p < 5%), but was not correlated with leaf starch or total soluble carbohydrates. Fiber strength was positively correlated with fiber sucrose before 38 DPA, and it appeared to be more easily influenced by the fiber sucrose concentration than fiber length, fineness, or maturity. These results suggest that 24–38 DPA is a crucial period for fiber development which might be significantly influenced by physiological and ecological factors. In addition, sucrose or nonstructural carbohydrates in the subtending leaf could be used as a monitoring index to evaluate sucrose levels in the developing fiber, and also for predicting the final fiber strength.
Determination of phthalate esters in cow milk samples using dispersive liquid‐liquid microextraction coupled with gas chromatography followed by flame ionization and mass spectrometric detection
Authors: Farajzadeh Mir Ali , Djozan Djavanshir , Reza Mohammad , Mogaddam Afshar , Norouzi Jamal
Published: January 2012

A simple and economic method for the analysis of phthalate esters, dimethyl phthalate, diethyl phthalate, di‐iso‐butyl phthalate, di‐n‐butyl phthalate, and di‐2‐ethylhexyl phthalate in cow milk samples by means of gas chromatography–flame ionization detection and gas chromatography–mass spectrometry has been developed. In this work, NaCl and ACN were added to 5 mL of the milk sample as the salting out agent and extraction solvent, respectively. After manual shaking, the mixture was centrifuged. In the presence of NaCl, a two‐phase system was formed: upper phase ‐ acetonitrile containing phthalate esters –and lower phase – aqueous phase containing soluble compounds and the precipitated proteins. After the extraction of phthalate esters from milk, a portion of supernatant phase (acetonitrile) was removed, mixed with 1,2‐dibromoethane at microliter level and injected by syringe into NaCl solution. After the extraction of the selected phthalate esters into 1,2‐dibromoethane, phase separation was performed by centrifugation and the enriched analytes in the sedimented phase were determined by gas chromatography‐flame ionization detection and gas chromatography–mass spectrometry. Under the optimum extraction conditions, low limits of detection and quantification between 1.5–3 and 2.5–11 ng/mL, respectively was observed. Enrichment factors were in the range of 397–499. The relative standard deviations for the extraction of 100 ng/mL of each phthalate ester were in the range of 3‐4% (n = 6). Finally, some milk samples were successfully analyzed using the proposed method and two analytes, di‐n‐butyl phthalate and di‐2‐ethylhyxel phthalate, were determined in them in nanogram per milliliter level.
High‐temperature rate constants for H/D + C2H6 and C3H8
Authors: Sivaramakrishnan R. , Michael J. V. , Ruscic B.
Published: January 2012

The reactions of H/D with C2H6 and C3H8 have been studied with both shock‐tube experiments and ab initio transition‐state theory calculations. Rate constants for the reactions of D with C2H6 and C3H8 have been measured in reflected shock wave experiments over the temperature range, 1128–1299 K, at pressures 0.3–1 atm. D atoms are detected using atomic resonance absorption spectrometry. The measured D‐atom profiles are sensitive to only the thermal dissociation of the D‐atom source molecule, C2D5I, and to the title reactions. Since the dissociation has been previously studied in this laboratory, modeling the temporal evolution of the D‐atom profiles allows determinations of the rate constants for the title reactions. Over the T range, 1128–1228 K, rate constants from the present experiments for D + C2H6 can be represented by the Arrhenius expression

equation image

The experimental total rate constants for D + C3H8 over the T range, 1128–1299 K, can be represented by the Arrhenius expression

equation image

The title reactions have been studied at the CCSD(T)/aug‐cc‐pv∞z level of theory using saddle point geometries at B3LYP/6‐311++G(d,p) and MP2/6‐311++G(d,p) levels of theory. The reaction endothermicities are in good agreement with current Active Thermochemical Tables values. Theoretical rate constants were estimated using transition state theory. The theoretical rate constants are in good agreement with the present experiments and lower temperature literature data. Over the T range of the present experiments, the theoretically predicted isotope effects are close to unity. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 194–205, 2012
A New Method for Mapping the Molecular Surface of a Protein Structure Using a Spherical Self‐Organizing Map
Authors: Hasegawa Kiyoshi , Funatsu Kimito
Published: January 2012

A spherical self‐organizing map (SSOM) was applied for mapping the molecular surface of a protein structure on a spherical structure. The active site of the X‐ray crystal structure of β2 receptor protein was used for this purpose. After mapping the molecular surface points and assigning the associated molecular electrostatic potential (MEP) values, the original 3D structure of the active site was well reproduced by the SSOM. In order to validate the geometrical transformation and the resulting MEP distribution, the molecular surfaces of twenty β2 ligands were mapped on the established SSOM sphere. The MEP values of two spheres derived from the ligand and the β2 receptor protein were compared. In almost all cases of strong ligands, the two spheres had a moderate negative correlation.
1H and 13C NMR characterization of new cycloartane triterpenes from Mangifera indica
Authors: Escobedo‐Martínez Carolina , Concepción Lozada M. , Hernández‐Ortega Simón , Villarreal María Luisa , Gnecco Dino , Enríquez Raúl G. , Reynolds William
Published: January 2012

From the stem bark of Mangifera indica, seven cycloartane‐type secondary metabolites were isolated. Compound 1 has been isolated for the first time from M. indica, whereas compounds 2 (2a and 2b, as an epimeric mixture), 3, and 4 are new triterpenoid‐type cycloartanes. Unambiguous 13C and 1H NMR assignments for these compounds and the known compounds mangiferonic acid (compound 5), isomangiferolic acid (compound 6), ambolic acid (compound 7), and friedelin (compound 8) are reported; the latter because full NMR data for these compounds are not available in the literature. Copyright © 2012 John Wiley & Sons, Ltd.
High‐resolution and high‐sensitivity 2D homonuclear J‐resolved NMR spectroscopy
Authors: Martinez Agathe , Bourdreux Flavien , Riguet Emmanuel , Nuzillard Jean‐Marc
Published: January 2012

This paper describes the implementation of the pure absorption ALPESTRE processing of 2D homonuclear J‐resolved NMR spectra. The method relies on the computation of the missing information at negative evolution times by means of backward linear prediction. The paper also shows that resolution can be improved by application of time‐symmetric apodization functions. The resulting spectra clearly display negative peaks at F2 chemical shifts that correspond to strong coupling artifacts, thus making it possible to identify them as such. The processing scripts are freely available for downloading, use and modification. Copyright © 2012 John Wiley & Sons, Ltd.
Skeletal muscle weakness caused by carrageenan‐induced inflammation
Authors: Pinniger Gavin J. , Lavin Tina , Bakker Anthony J.
Published: January 2012

Introduction: The skeletal muscle weakness associated with many chronic diseases has been attributed to the catabolic effect of pro‐inflammatory cytokines. We aimed to determine if local muscle inflammation has direct affects on contractile function and contributes to muscle weakness independent of muscle atrophy or mechanical injury. Methods: Local muscle inflammation was induced by injecting an algal‐derived polysaccharide, carrageenan (10 mg/kg), into the right tibialis anterior muscle in healthy ARC mice. The contralateral muscle was injected with sterile isotonic saline, and the muscles were removed after 24 h for measurement of contractile function and cytokine concentration. Results: Carrageenan significantly reduced maximum specific force, decreased the maximum rate of force development, altered the force‐frequency relationship, and increased intramuscular levels of pro‐inflammatory cytokines and chemokines. Conclusions: These results indicate that carrageenan directly affects contractile function and causes skeletal muscle weakness. Local muscle inflammation may contribute to the weakness observed in inflammatory related disorders. Muscle Nerve 46: 413–420, 2012
The effect of rectal distension on bladder function in patients with overactive bladder
Authors: Akl Mohamed N. , Jacob Kristina , Klauschie Jennifer , Crowell Michael D. , Kho Rosanne M. , Cornella Jeffrey L.
Published: January 2012

Aims

To investigate the effect of rectal distension on bladder sensation volumes and the number of detrusor contractions in patients with overactive bladder (OAB) symptoms.

Methods

A prospective randomized study included patients with OAB symptoms. Multichannel urodynamic studies were completed with and without rectal balloon distension. Bladder sensation volumes and detrusor contractions were compared.

Results

Twenty‐six patients were included in the study. The mean age was 67 years and mean BMI was 28.3 kg/m2. Bladder sensation volumes were lower with rectal distention as follows: normal desire to void (139 ml SD, ±114 vs. 197 ml SD ±150, P = 0.01), strong desire to void (260 ml SD ±171 vs. 330 ml SD ±172, P = 0.01), and maximum cystometric capacity (326 ml SD ±183 vs. 403 ml SD ±180, P = 0.0001). There was no difference in the number of detrusor contractions or the bladder volume at which the first detrusor contraction had occurred with and without rectal distension.

Conclusion

Rectal distention in patients with OAB symptoms significantly lowered bladder sensation volumes (normal desire, strong desire, and maximal capacity). Neurourol. Urodynam. 31:541–543, 2012. © 2012 Wiley Periodicals, Inc.
How does the urothelium affect bladder function in health and disease?: ICI‐RS 2011
Authors: Birder LA. , Ruggieri M. , Takeda M. , van Koeveringe G. , Veltkamp S. , Korstanje C. , Parsons B. , Fry CH.
Published: January 2012

The urothelium is a multifunctional tissue that not only acts as a barrier between the vesical contents of the lower urinary tract and the underlying tissues but also acts as a sensory organ by transducing physical and chemical stresses to the attendant afferent nervous system and underlying smooth muscle. This review will consider the nature of the stresses that the urothelium can transduce; the transmitters that mediate the transduction process; and how lower urinary pathologies, including overactive bladder syndrome, painful bladder syndrome and bacterial infections, are associated with alterations to this sensory system. In particular, the role of muscarinic receptors and the TRPV channels system will be discussed in this context. The urothelium also influences the contractile state of detrusor smooth muscle, both through modifying its contractility and the extent of spontaneous activity; potential pathways are discussed. The potential role that the urothelium may play in bladder underactivity is introduced, as well as potential biomarkers for the condition that may cross the urothelium to the urine. Finally, consideration is given to vesical administration of therapeutic agents that influence urinary tract function and how the properties of the urothelium may determine the effectiveness of this mode of delivery. Neurourol. Urodynam. 31:293–299, 2012. © 2012 Wiley Periodicals, Inc.
Polymerization of free secondary amine bearing monomers by RAFT polymerization and other controlled radical techniques
Authors: Janoschka Tobias , Teichler Anke , Krieg Andreas , Hager Martin D. , Schubert Ulrich S.
Published: January 2012

This work describes the polymerization of the free secondary amine bearing monomer 2,2,6,6‐tetramethylpiperidin‐4‐yl methacrylate (TMPMA) by means of different controlled radical polymerization techniques (ATRP, RAFT, NMP). In particular, reversible addition‐fragmentation chain transfer (RAFT) polymerization enabled a good control at high conversions and a polydispersity index below 1.3, thereby enabling the preparation of well‐defined polymers. Remarkably, the polymerization of the secondary amine bearing methacrylate monomer was not hindered by the presence of the free amine that commonly induces degradation of the RAFT reagent. Subsequent oxidation of the polymer yielded the polyradical poly(2,2,6,6‐tetramethylpiperidinyloxy‐4‐yl methacrylate), which represents a valuable material used in catalysis as well as for modern batteries. The obtained polymers having a molar mass (Mn) of 10,000–20,000 g/mol were used to fabricate well‐defined, radical‐bearing polymer films by inkjet‐ printing. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Energy transfer from fluorene‐based conjugated polyelectrolytes to on‐chain and self‐assembled porphyrin units
Authors: Marques Ana T. , Pinto Sara M. A. , Monteiro Carlos J. P. , Seixas de Melo J. Sérgio , Burrows Hugh D. , Scherf Ullrich , Calvete Mário J. F. , Pereira Mariette M.
Published: January 2012

A new water soluble fluorene‐based polyelectrolyte containing on‐chain porphyrin units has been synthesized via Suzuki coupling, for use in optoelectronic devices. The material consist of a random copolymer of poly{1,4‐phenylene‐[9,9‐bis(4‐phenoxy butylsulfonate)]fluorene‐2,7‐diyl} (PBS‐PFP) and a 5,15‐diphenylporphyrin (DPP). The energy transfer process between the PBS‐PFP units and the porphyrin has been investigated through steady state and time‐resolved measurements. The copolymer PBS‐PFP‐DPP displays two different emissions one located in the blue region of the spectra, corresponding to the fluorene part and another in the red due to fluorescent DPP units either formed directly or by exciton transfer. However, relatively inefficient energy transfer from the PFP to the on‐chain porphyrin units was observed. We compare this with a system involving an anionic blue light‐emitting donor PBS‐PFP and a anionic red light‐emitting energy acceptor meso‐tetrakisphenylporphyrinsulfonate (TPPS), self‐assembled by electrostatic attraction induced by Ca2+. Based on previous studies related to chain aggregation of the anionic copolymer PBS‐PFP, two different solvent media were chosen to further explore the possibilities of the self‐assembled system: dioxane–water and aqueous nonionic surfactant n‐dodecylpentaoxyethylene glycol ether (C12E5). In contrast, with the on‐chain PBS‐PFP‐DPP system the strong overlap of the 0‐0 emission peak of the PBS‐PFP and the Soret absorption band of the TPPS results in an efficient Förster transfer. This is strongly dependent on the solvent medium used. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
An evaluation of stereo and laser‐based range sensing for rotorcraft unmanned aerial vehicle obstacle avoidance
Authors: Hrabar Stefan
Published: January 2012

We present an evaluation of stereo vision and laser‐based range sensing for rotorcraft unmanned aerial vehicle (RUAV) obstacle avoidance. Our focus is on sensors that are suitable for mini‐RUAV class vehicles in terms of weight and power consumption. The study is limited to the avoidance of large static obstacles such as trees. We compare two commercially available devices that are representative of the state of the art in two‐dimensional scanning laser and stereo‐based sensing. Stereo is evaluated with three different focal length lenses to assess the tradeoff between range resolution and field of view (FOV). The devices are evaluated in the context of obstacle avoidance through extensive flight trials with an RUAV. We discuss the merits and limitations of each sensor type, including sensing range, FOV, accuracy, and susceptibility to lighting conditions. We show that the stereo device fitted with 8‐mm lenses has a better sensing range and vertical FOV than the laser device; however, it relies on careful calibration and is affected by high‐contrast outdoor lighting conditions. The laser has a wider horizontal FOV and is more reliable at detecting obstacles that are within a 20‐m range. Overall the laser produced superior obstacle avoidance performance, with a success rate of 84% compared to 42% for 8‐mm stereo. © 2012 Wiley Periodicals, Inc.
Mental models of dynamic systems: taking stock and looking ahead
Authors: Groesser Stefan N. , Schaffernicht Martin
Published: January 2012

This paper deals with the representation of the conceptual structure of mental models of dynamic systems (MMDS). Heretofore, this structure has not been consistently defined. Consequently, studies about MMDS continue to use different conceptual structures to measure mental models. Even such properties as feedback loops and delays, which lie at the core of dynamic systems, are often not considered. This situation leads to incompatible findings and stagnating research. We review the literature about mental models in the field of system dynamics. In addition, we refer to dynamic systems theory as the mathematical basis for system dynamics to complement and validate our conceptual structure. One may conclude that most of the existing mental model studies measure only parts of the structure that we propose. The paper's contribution is to elaborate the conceptual structure of an MMDS and to use this structure to operationally enhance the definition of an MMDS. Copyright © 2012 System Dynamics Society
How knowledge affects radical innovation: Knowledge base, market knowledge acquisition, and internal knowledge sharing
Authors: Zhou Kevin Zheng , Li Caroline Bingxin
Published: January 2012

This paper examines how existing knowledge base (i.e., knowledge breadth and depth) interacts with knowledge integration mechanisms (i.e., external market knowledge acquisition and internal knowledge sharing) to affect radical innovation. Survey data from high technology companies in China demonstrate that the effects of knowledge breadth and depth are contingent on market knowledge acquisition and knowledge sharing in opposite ways. In particular, a firm with a broad knowledge base is more likely to achieve radical innovation in the presence of internal knowledge sharing rather than market knowledge acquisition. In contrast, a firm with a deep knowledge base is more capable of developing radical innovation through market knowledge acquisition rather than internal knowledge sharing. Copyright © 2012 John Wiley & Sons, Ltd.
In Situ Controlled Synthesis of Thermosensitive Poly(N‐isopropylacrylamide)/Au Nanocomposite Hydrogels by Gamma Radiation for Catalytic Application
Authors: Zhu Chun‐Hua , Hai Zi‐Bin , Cui Chun‐Hua , Li Hui‐Hui , Chen Jia‐Fu , Yu Shu‐Hong
Published: January 2012

Thermosensitive poly(N‐isopropylacrylamide) (PNIPAM)/Au nanoparticle (NP) nanocomposite hydrogels are synthesized by in situ γ‐radiation‐assisted polymerization of N‐isopropylacrylamide monomer aqueous solution in the presence of HAuCl4·4H2O. In this reaction, the PNIPAM hydrogels and the Au NPs are formed simultaneously, thus demonstrating an easy and straightforward synthetic strategy for the preparation of a uniform nanocomposite. The results suggest that increasing the monomer content during the preparation of nanocomposite materials can increase the sizes of Au NPs. The effects of irradiation dose and concentration of HAuCl4·4H2O on the optical and thermal properties of the hydrogel are also investigated. The PNIPAM/Au nanocomposite hydrogels act as an excellent catalyst for the conversion of o‐nitroaniline to 1,2‐benzenediamine, and the catalytic activity of the composite hydrogel can be tuned by the volume transition of PNIPAM. The in situ polymerization of monomer and reduction of metal ions initiated by a “clean” and “green” γ‐radiation technique can be extended to the efficient synthesis of other nanocomposite materials.
An information systems design product theory for the class of integrated requirements and release management systems
Authors: Käkölä Timo , Koivulahti‐Ojala Mervi , Liimatainen Jani
Published: January 2012

High‐tech companies conducting product development need to collect and analyze requirements effectively, plan and implement releases, and allocate requirements to appropriate releases. Requirements and release management are complicated because development activities typically are scattered across multiple sites, involve multiple partners in different countries, leverage various development methods and tools, and are realized through various organizational arrangements such as release projects in organizations structured around products and permanent release teams in organizations responsible for the long‐term development and maintenance of strategic software and hardware assets. Flexible, scalable, and secure groupware‐based support for the activities provides substantial payoffs. Yet, the extant literature provides little theoretical guidance for designing and using requirements and release management systems (RRMS) in multi‐site, multi‐partner environments. This article develops the meta‐requirements and a meta‐design of an Information Systems Design Product Theory for the class of RRMS based on a case study in a global company and a literature review. The theory is scalable to meet the needs of global companies but simple enough so that small and medium‐sized companies can also leverage it to implement requirements and release management solutions. Copyright © 2010 John Wiley & Sons, Ltd.
Cognitive linguistics
Authors: Evans Vyvyan
Published: January 2012

Cognitive linguistics is one of the fastest growing and influential perspectives on the nature of language, the mind, and their relationship with sociophysical (embodied) experience. It is a broad theoretical and methodological enterprise, rather than a single, closely articulated theory. Its primary commitments are outlined. These are the Cognitive Commitment—a commitment to providing a characterization of language that accords with what is known about the mind and brain from other disciplines—and the Generalization Commitment—which represents a dedication to characterizing general principles that apply to all aspects of human language. The article also outlines the assumptions and worldview which arises from these commitments, as represented in the work of leading cognitive linguists.WIREs Cogn Sci2012, 3:129–141. doi: 10.1002/wcs.1163

This article is categorized under:

Linguistics > Linguistic Theory
Neural crest migration: interplay between chemorepellents, chemoattractants, contact inhibition, epithelial–mesenchymal transition, and collective cell migration
Authors: Theveneau Eric , Mayor Roberto
Published: January 2012

Neural crest (NC) cells are induced at the border of the neural plate and subsequently leave the neuroepithelium during a delamination phase. This delamination involves either a complete or partial epithelium‐to‐mesenchyme transition, which is directly followed by an extensive cell migration. During migration, NC cells are exposed to a wide variety of signals controlling their polarity and directionality, allowing them to colonize specific areas or preventing them from invading forbidden zones. For instance, NC cells are restricted to very precise pathways by the presence of inhibitory signals at the borders of each route, such as Semaphorins, Ephrins, and Slit/Robo. Although specific NC chemoattractants have been recently identified, there is evidence that repulsive interactions between the cells, in a process called contact inhibition of locomotion, is one of the major driving forces behind directional migration. Interestingly, in cellular and molecular terms, the invasive behavior of NC is similar to the invasion of cancer cells during metastasis. NC cells eventually settle in various places and make an immense contribution to the vertebrate body. They form the major constituents of the skull, the peripheral nervous system, and the pigment cells among others, which show the remarkable diversity and importance of this embryonic‐stem cell like cell population. Consequently, several birth defects and craniofacial disorders, such as Treacher Collins syndrome, are due to improper NC cell migration. WIREs Dev Biol 2012, 1:435–445. doi: 10.1002/wdev.28

This article is categorized under:

Early Embryonic Development > Development to the Basic Body Plan