bluuebunny/crossref_metadata_2025 huggingface dataset:
Donor‐Acceptor Oligomers and Polymers Composed of Benzothiadiazole and 3‐Hexylthiophene: Effect of Chain Length and Regioregularity
Authors: Wang Jintu , Ye Huaiying , Li Hongjiao , Mei Chongyu , Ling Jun , Li Weishi , Shen Zhiquan
Published: October 2013

A series of donor‐acceptor oligomer OBTThn (n=1–7) and polymer PBTTh1 and PBTTh2 composed of alternative 2,1,3‐benzothiadiazole and 3‐hexylthiophene have been designed and synthesized for the purpose of investigation on the effect of chain length and side‐chain regioregularity on their basic properties and photovoltaic performance. In the OBTThn oligomers and PBTTh1 polymer, all the hexyl side chains on thienyl units orient toward the same direction. Upon elongation of the chain length, the intramolecular charge transfer (ICT) absorption band in solution gradually redshifts from 398 nm for OBTTh1 to 505 nm for OBTTh7, then to 512 nm for PBTTh1 polymer. Meanwhile, the HOMO energy level increases from −5.45 eV (OBTTh1) to −5.08 eV (OBTTh7) and −5.09 eV (PBTTh1), and the LUMO energy level decreases from −3.11 eV (OBTTh1) to −3.30 eV (OBTTh7) and −3.33 eV (PBTTh1), thus giving a smaller and smaller energy bandgap for higher oligomers and polymers. Theoretical calculation suggests straight line‐like backbone geometry for this series of oligomers and polymer. On the other hand, polymer PBTTh2 possesses a different side‐chain regioregularity, in which every two neighbor hexyl side chains are arranged in different orienting direction. It is theoretically suggested to have curved line‐like backbone geometry. In solution, it shows similar photophysical and electrochemical properties as PBTTh1. However in film state, it displays a less redshift in the ICT band as refer to that in solution than PBTTh1. In combination with [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM), these oligomers and polymers were used as donor material to fabricate organic bulk heterojunction solar cells. Again, chain length‐dependent device photovoltaic performance was observed. The device based on OBTTh4 showed a power conversion efficiency of 0.16%, while it increased to 0.36% and 0.49% for the devices based on OBTTh6 and PBTTh1, respectively. However, the side‐chain regioregularity has less influence on the device photovoltaic output since the device based on PBTTh2 displayed an efficiency of 0.52%, comparable to that of PBTTh1.
Remote Monitoring of Implantable Pacemakers: In‐Office Setup Significantly Improves Successful Data Transmission
Authors: Ren Xiushui , Apostolakos Christina , Vo Thuy Hong , Shaw Richard E. , Shields Korey , Banki Nader M. , Zuckermann Douglas W. , Flint Alexander C. , Hongo Richard H. , Goldschlager Nora F.
Published: October 2013

Background

Remote wireless follow‐up of implanted pacemakers (PM) has become an attractive method of follow‐up. Although wireless PM follow‐up has several advantages compared with transtelephonic and office‐based follow‐up, its utility depends on successful transmission.

Hypothesis

Initial in‐office setup of wireless PM will improve transmission rate as compared with home setup.

Methods

A total of 202 consecutive patients from 2 medical centers were included in this retrospective study. Patients in the home setup group (N = 101) had traditional home setup of wireless PM, whereas patients in the in‐office group (N = 101) had setup of PMs by allied health professionals during the postoperative office visit. Successful transmission was defined as successful initial wireless transmission of PM data by 2 months postimplant.

Results

Of the 101 patients in the home setup group, 22 (22%) patients had successful transmission. Of the 101 patients in the in‐office group, 92 (91%) patients had successful transmission (P < 0.0001). Logistic regression analysis showed that that the in‐office group was independently associated with successful transmission (odds ratio: 114.5; 95% confidence interval: 32.1‐408.4; P < 0.0001).

Conclusions

In patients implanted with PM capable of remote wireless data transmission, initial home setup of the wireless monitoring device was frequently unsuccessful. In‐office PM setup was associated with a significantly higher rate of successful transmission.
Assessment of Heavy Metal Contamination in Soil and Groundwater at Leather Industrial Area of Kasur, Pakistan
Authors: Afzal Muhammad , Shabir Ghulam , Iqbal Samina , Mustafa Tanveer , Khan Qaiser Mahmood , Khalid Zafar Mahmood
Published: October 2013

Heavy metal contamination of soil and water caused by industrialization has become a major environmental issue in Pakistan. Therefore, it is important to determine the level of contamination of soil and water close to industrial areas. In the current study, we have assessed the heavy metal contamination of soil and groundwater at the leather industrial area of Kasur, Pakistan. Soil and groundwater samples were collected from the study area and analyzed for Cr, Fe, Ni, Cd, Pb, Zn, Co, and Mn by atomic absorption spectrophotometric method. The data revealed that soil and groundwater in the study area are highly contaminated with all tested heavy metals. In particular, chromium concentrations varied from 1970 to 2980 mg kg−1 and 0.82 to 2.25 mg L−1 in soil and groundwater, respectively. Correlation analysis has identified that the heavy metals in the groundwater and soil of the study area having a common source/origin, believed to be the leather industry of Kasur.
Acute cognitive impairment in patients with multiple myeloma undergoing autologous hematopoietic stem cell transplant
Authors: Jones Desiree , Vichaya Elisabeth G. , Wang Xin Shelley , Sailors Mary H. , Cleeland Charles S. , Wefel Jeffrey S.
Published: October 2013

BACKGROUND

Few studies have examined the acute effects of autologous hematopoietic stem cell transplantation (Au‐HSCT) on the neuropsychological functioning of patients with multiple myeloma (MM). The prevalence of cognitive deficits after induction chemotherapy (pre‐AuHSCT) was examined in patients with MM, clinically significant changes in cognitive function 1 and 3 months post‐AuHSCT were determined, and patients who may be vulnerable to cognitive decline during this period were identified.

METHODS

A total of 53 patients with MM were recruited pre‐AuHSCT. Neuropsychological tests measuring multiple cognitive domains (attention, psychomotor speed, learning/memory, language, executive function, motor function) were administered pre‐AuHSCT and 1 and 3 months post‐AuHSCT. A pretreatment assessment was not available. An Overall Cognitive Function Index was computed to determine cognitive impairment pre‐AuHSCT, and a practice‐effect–adjusted Reliable Change Index was used to determine cognitive change over time.

RESULTS

Overall, deficits were more frequent in learning/memory, executive function, motor function, and psychomotor speed. Before AuHSCT, 47% of patients (25/53) exhibited cognitive impairment as determined by the Overall Cognitive Function Index. One month post‐AuHSCT, 49% of patients (20/41) demonstrated clinically significant decline on 1 or more measures; 3 months post‐AuHSCT, 48% (14 of 29 patients) showed decline on 1 or more measures. Older patients, minorities, and those with advanced disease, more induction cycles, or postinduction deficits showed greater vulnerability to decline.

CONCLUSIONS

Nearly half of the patients showed vulnerability to impairment in learning/memory or executive function after receiving induction therapy, and the prevalence of impairment remained high post‐AuHSCT. Awareness of cognitive impairment and associated risk factors in actively treated patients is important for considering psychosocial or other support for patients with acute cognitive symptoms. Cancer 2013;119:4188–4195. ©2013 American Cancer Society.
Clinical effectiveness of seasonal influenza vaccine among adult cancer patients
Authors: Vinograd Inbal , Eliakim‐Raz Noa , Farbman Laura , Baslo Rina , Taha Ahmed , Sakhnini Ali , Lador Adi , Stemmer Salomon M. , Gafter‐Gvili Anat , Leibovici Leonard , Paul Mical
Published: October 2013

BACKGROUND

Patients with cancer are at increased risk of developing complications of influenza. In this study, the authors assessed the effectiveness of influenza vaccination among cancer patients.

METHODS

A prospective, noninterventional cohort study was conducted during the 2010 to 2011 influenza season. The cohort included adult cancer patients with solid malignancies who were receiving chemotherapy and hematologic patients who had active disease. Patients who died between October and November 2010 (N = 43) were excluded. A comparison was made between patients who received the 2011 seasonal influenza vaccine with those who did not. The primary outcome was a composite of hospitalizations for fever or acute respiratory infections, pneumonia, and/or infection‐related chemotherapy interruptions. All‐cause mortality was a secondary outcome. A propensity‐matched analysis was conducted based on the propensity for vaccination.

RESULTS

Of 806 patients who were included, 387 (48%) were vaccinated. Factors that were associated independently with vaccination included past influenza vaccination, past pneumococcal vaccination, >6 months since cancer diagnosis, country of birth, and cancer type/status. The primary outcome occurred in 111 of 387 (28.7%) vaccinated patients versus 112 of 419 (26.7%) unvaccinated patients (P = .54). No association was observed between vaccination and the primary outcome in a propensity‐matched analysis (N = 436) or during peak influenza activity. The mortality rate was 11.9% (46 of 387 patients) in vaccinated patients versus 19.1% (80 of 419 patients) in unvaccinated patients (P = .005). Vaccination retained a significant association with mortality on multivariable analysis (odds ratio, 2.31; 95% confidence interval, 1.4‐3.79) and in a propensity‐matched analysis (odds ratio, 2.39; 95% confidence interval, 1.32‐4.32).

CONCLUSIONS

Influenza vaccination was associated with lower mortality among cancer patients, although an association with infection‐related complications could not be demonstrated. The current results support efforts to promote influenza vaccination in patients with cancer. Cancer 2013;119:4028–4035. © 2013 American Cancer Society.
Use of imaging and biomarker tests for posttreatment care of early‐stage breast cancer survivors
Authors: Hahn Erin E. , Hays Ron D. , Kahn Katherine L. , Litwin Mark S. , Ganz Patricia A.
Published: October 2013

BACKGROUND

The American Society of Clinical Oncology (ASCO) recently released a “Top Five” list of opportunities to improve the quality of cancer care. Item 4 on the list advises against using advanced imaging and biomarkers for surveillance in patients with breast cancer who are treated with curative intent. This study examined concordance with ASCO follow‐up care guidelines for breast cancer survivors treated at an academic medical center.

METHODS

Claims data and medical records were reviewed and abstracted for early stage breast cancer survivors starting 1 year post diagnosis. A trained abstractor classified imaging tests as diagnostic or surveillance. Proportions and frequencies were generated for receipt of services. Multilevel logistic regression was used to estimate factors associated with receiving recommended and nonrecommended services and biomarker tests.

RESULTS

Records were available for 258 patients. Mean age at diagnosis was 58 years (standard deviation of 13 years), mean time since diagnosis was 6 years (standard deviation of 2 years), and 71% were stage 0/1. Only 47% of the sample received a mammogram within 1 year of diagnosis, and 55% of the sample received at least 1 nonrecommended imaging service for surveillance purposes. Seventy‐seven percent of the sample received at least 1 nonrecommended biomarker test. Regression results indicate that main treating physician, advanced disease stage, younger age at diagnosis, and greater number of years since diagnosis were associated with receiving nonrecommended services for surveillance.

CONCLUSIONS

Use of nonrecommended services for surveillance occurs frequently among early‐stage breast cancer survivors. There are opportunities to increase use of guideline concordant posttreatment care for breast cancer survivors. Cancer 2013;119:4316–4324. © 2013 American Cancer Society.
The Particle Size Dependence of the Oxygen Reduction Reaction for Carbon‐Supported Platinum and Palladium
Authors: Anastasopoulos A. , Davies J. C. , Hannah L. , Hayden B. E. , Lee C. E. , Milhano C. , Mormiche C. , Offin L.
Published: October 2013

Model carbon supported Pt and Pd electrocatalysts have been prepared using a high‐throughput physical vapor deposition method. For Pt, metal particle sizes are controlled between 1.5–5.5 nm over 100 electrodes of an electrochemical screening chip, allowing the oxygen reduction reaction (ORR) activity of the catalysts to be determined simultaneously. The ORR‐specific current density is observed to increase with increasing particle diameter up to approximately 4 nm, at which point the activity begins to level off. The reduction in ORR activity for particles below 4 nm is accompanied by a concomitant increase in the overpotential for surface reduction. The resulting mass activity exhibits a maximum for particles with diameters of approximately 3.5 nm. These results are consistent with results published recently for high area carbon‐supported Pt catalysts. For Pd particles, both the specific current density and the mass‐specific activity for the ORR are observed to increase with increasing particle diameter, with no distinct optimum observed. The implications for the optimization of Pt‐ or Pd‐based ORR catalysts for proton exchange membrane fuel cell (PEMFC) applications are discussed.
Comparison of Homogeneous and Heterogeneous Catalysts for Glucose‐to‐Fructose Isomerization in Aqueous Media
Authors: Choudhary Vinit , Pinar Ana B. , Lobo Raul F. , Vlachos Dionisios G. , Sandler Stanley I.
Published: October 2013

Herein, the first comparison of the mechanisms of glucose‐to‐fructose isomerization in aqueous media enabled by homogeneous (CrCl3 and AlCl3) and heterogeneous catalysts (Sn‐beta) by using isotopic‐labeling studies is reported. A pronounced kinetic isotope effect (KIE) was observed if the deuterium label was at the C2 position, thus suggesting that a hydrogen shift from the C2 to C1 positions was the rate‐limiting step with the three catalysts. 13C and 1H NMR spectroscopic investigations confirmed that an intra‐hydride‐transfer reaction pathway was the predominant reaction channel for all three catalysts in aqueous media. Furthermore, the deuterium atom in the labeled glucose could be mapped onto hydroxymethylfurfural and formic acid through reactions that followed the isomerization step in the presence of Brønsted acids. In all three catalysts, the active site appeared to be a bifunctional Lewis‐acidic/Brønsted‐basic site, based on a speciation model and first‐principles calculations. For the first time, a mechanistic similarities between the homogeneous and heterogeneous catalysis of aldose‐to‐ketose isomerization is established and it is suggested that learning from homogeneous catalysis could assist in the development of improved heterogeneous catalysts.
Crystal‐Plane‐Controlled Surface Chemistry and Catalytic Performance of Surfactant‐Free Cu2O Nanocrystals
Authors: Hua Qing , Cao Tian , Bao Huizhi , Jiang Zhiquan , Huang Weixin
Published: October 2013

Surfactant‐free Cu2O nanocrystals, including cubes exposing {100} crystal planes, octahedra exposing {111} crystal planes, and rhombic dodecahedra exposing {110} crystal planes, were used as model catalysts to study the effect of the crystal plane on the surface chemistry and catalytic performance for CO oxidation of Cu2O nanocrystals. The catalytic performance follows the order of octahedra≫rhombic dodecahedra>cubes; this suggests that Cu2O(111) is most active in catalyzing CO oxidation among Cu2O (111), (110), and (100) surfaces. CO temperature‐programmed reduction results demonstrate that Cu2O octahedra are the most easily reduced of the Cu2O cubes, octahedra, and rhombic dodecahedra. Diffuse reflectance FTIR spectra show that CO chemisorption on Cu2O nanocrystals depends on their shape and the chemisorption temperature. CO chemisorption is strongest on rhombic dodecahedra at 30 °C, but at 150 °C on octahedra. Both the reducibility and chemisorption ability of various Cu2O nanocrystals toward CO are consistent with their catalytic performance in CO oxidation. The observed surface chemistry and catalytic performance in CO oxidation of various Cu2O nanocrystals can be well correlated with their exposed crystal plane and surface composition/structure. Cu2O octahedra expose the {111} crystal plane with coordinated, unsaturated CuI sites, and thus, are most active in chemisorbing CO and catalyzing CO oxidation. These results nicely demonstrate the crystal‐plane‐controlled surface chemistry and catalytic performance of oxide catalysts.
Adsorption of HMF from Water/DMSO Solutions onto Hydrophobic Zeolites: Experiment and Simulation
Authors: Xiong Ruichang , León Marta , Nikolakis Vladimiros , Sandler Stanley I. , Vlachos Dionisios G.
Published: October 2013

The adsorption of 5‐hydroxymethylfurfural (HMF), DMSO, and water from binary and ternary mixtures in hydrophobic silicalite‐1 and dealuminated Y (DAY) zeolites at ambient conditions was studied by experiments and molecular modeling. HMF and DMSO adsorption isotherms were measured and compared to those calculated using a combination of grand canonical Monte Carlo and expanded ensemble (GCMC–EE) simulations. A method based on GCMC–EE simulations for dilute solutions combined with the Redlich–Kister (RK) expansion (GCMC–EE–RK) is introduced to calculate the isotherms over a wide range of concentrations. The simulations, using literature force fields, are in reasonable agreement with experimental data. In HMF/water binary mixtures, large‐pore hydrophobic zeolites are much more effective for HMF adsorption but less selective because large pores allow water adsorption because of H2O–HMF attraction. In ternary HMF/DMSO/water mixtures, HMF loading decreases with increasing DMSO fraction, rendering the separation of HMF from water/DMSO mixtures by adsorption difficult. The ratio of the energetic interaction in the zeolite to the solvation free energy is a key factor in controlling separation from liquid mixtures. Overall, our findings could have an impact on the separation and catalytic conversion of HMF and the rational design of nanoporous adsorbents for liquid‐phase separations in biomass processing.
Preparation of Sustainable Photocatalytic Materials through the Valorization of Industrial Wastes
Authors: Sugrañez Rafael , Cruz‐Yusta Manuel , Mármol Isabel , Morales Julián , Sánchez Luis
Published: October 2013

A new value‐added material was developed from wastes to aim for appropriate waste management and sustainable development. This paper reports the valorization of industrial sandblasting operation wastes (SOWs) as new photocatalytic materials. This waste is composed of Fe2O3 (60.7 %), SiO2 (29.1 %), and Al2O3 (3.9 %) as the main components. The high presence of iron oxides was used to develop photocatalytic properties through their thermal transformation into α‐Fe2O3. The new product, SOW‐T, exhibited a good behavior towards the photochemical degradation of organic dyes. The preparation of advanced photocatalytic materials that exhibit self‐cleaning and depolluting properties was possible by the inclusion of SOW‐T and TiO2 in a cement‐based mortar. The synergy observed between both materials enhanced their photocatalytic action. To the best of our knowledge, this is the first report that describes the use of transformed wastes based on iron oxide for the photochemical oxidation of NOx gases.
Hollow AgI:Ag Nanoframes as Solar Photocatalysts for Hydrogen Generation from Water Reduction
Authors: An Changhua , Wang Jizhuang , Liu Junxue , Wang Shutao , Sun Yugang
Published: October 2013

A facile strategy based on the principle of the Kirkendall effect has been developed to synthesize hollow nanoframes and nanoshells of AgI:Ag composites through the controlled anion‐exchange reaction between I− ions and solid AgBr:Ag (or AgCl:Ag) nanoparticles that serve as templates. Regardless of the morphologies of the template nanoparticles, they can be chemically transformed to hollow AgI:Ag structures with morphologies similar to those of the templates. The synthesized hollow AgI:Ag nanostructures can be used as efficient photocatalysts for H2 generation from water reduction and the decomposition of organic pollutants owing to the enhanced absorption of visible light by the Ag components in the hybrid nanostructures. The hollow nanostructures exhibit a higher photocatalytic performance than the corresponding solid nanoparticles possibly because of the large surface area and unique AgI/Ag interfaces associated with the hollow nanostructures.
Controlled Synthesis of Nanosized Palladium icosahedra and Their Catalytic Activity towards Formic‐Acid Oxidation
Authors: Lv Tian , Wang Yi , Choi Sang‐Il , Chi Miaofang , Tao Jing , Pan Likun , Huang Cheng Zhi , Zhu Yimei , Xia Younan
Published: October 2013

Pd icosahedra with sizes controlled in the range of 5–35 nm were synthesized in high purity through a combination of polyol reduction and seed‐mediated growth. The Pd icosahedra were obtained with purity >94 % and uniform sizes controlled in the range of 5–17 nm by using ethylene glycol as both the reductant and solvent. The studies indicate that the formation of Pd nanocrystals with an icosahedral shape was very sensitive to the reaction kinetics. The success of this synthesis relies on the use of HCl to manipulate the reaction kinetics and thus control the twin structure and shape of the resultant nanocrystals. The size of the Pd icosahedra could be further increased up to 35 nm by seed‐mediated growth, with 17 nm Pd icosahedra serving as seeds. The multiply twinned Pd icosahedra could grow into larger sizes, and their shape and multiply twinned structure were preserved. Thanks to the presence of twin defects, the Pd icosahedra showed a catalytic current density towards formic‐acid oxidation that was 1.9 and 11.6 times higher than that of single‐crystal Pd octahedra, which were also fully covered by {111} facets, and commercial Pd/C, respectively.
Biomass‐Derived Chemicals: Synthesis of Biodegradable Surfactant Ether Molecules from Hydroxymethylfurfural
Authors: Arias Karen S. , Climent Maria J. , Corma Avelino , Iborra Sara
Published: October 2013

A new class of biodegradable anionic surfactants with structures based on 5‐alkoxymethylfuroate was prepared starting from 5‐hydroxymethylfurfural (HMF), through a one‐pot–two‐steps process which involves the selective etherification of HMF with fatty alcohols using heterogeneous solid acid, followed by a highly selective oxidation of the formyl group with a gold catalyst. The etherification step was optimized using aluminosilicates as acid catalysts with different pore topologies (H‐Beta, HY, Mordenite, ZSM‐5, ITQ‐2, and MCM‐41), different active sites (Bronsted or Lewis) and different adsorption properties. It was shown that highly hydrophobic defect‐free H‐Beta zeolites with Si/Al ratios higher than 25 are excellent acid catalysts to perform the selective etherification of HMF with fatty alcohols, avoiding the competitive self‐etherification of HMF. Moreover, the 5‐alkoxymethylfurfural derivatives obtained can be selectively oxidized to the corresponding furoic salts in excellent yield using Au/CeO2 as catalyst and air as oxidant, at moderated temperatures. Both H‐Beta zeolite and Au/CeO2 could be reused several times without loss of activity.
Angular Distribution Analysis of Nitrogen Ions in a Low Energy Dense Plasma Focus Device
Authors: Sohrabi M. , Habibi M. , Yousefi H.R. , Roshani G.H.
Published: October 2013

Angular distribution of nitrogen ions from a 4 kJ plasma focus device (PFD), as obtained by two detection methods was studied. The results obtained with two methods including consisting of (i) polycarbonate (PC) detectors (1 mm thick with about 15 cm diameter large etchable area) using electrochemical etching (ECE) at 50 Hz and 48 kV cm–1 field strenth and (ii) an array of five Faraday cups (FC) are analyzed, compared and discussed in this paper. The results obtained by the two detectors are quite different. A new concept is proposed in this paper for the ring‐shaped angular distribution of ions. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of Second Nonthermal Ion on the Characteristics of Dust Acoustic Solitary Waves in a Magnetized Dusty Plasma with Variable Dust Charge
Authors: Dezfuly S. Gh. , Dorranian D.
Published: October 2013

The nonlinear dust acoustic solitary waves in a magnetized dusty plasma with nonthermal ions and variable dust electric charge is studied analytically. Using reductive perturbation method the Zakharov‐Kuznetsov (ZK) equation is derived and effect of nonthermal coefficient, external magnetic field, and variable dust electric charge on the amplitude and width of soliton in dusty plasma is investigated. With increasing the rate of dust charge variation with respect of plasma potential, the amplitude of generated solitary waves in magnetized dusty plasma increases to a constant magnitude while its width decreases. Increasing the nonthermal ions coefficient leads to a noticeable decrease in the amplitude of solitons while the width of soliton increases. The amplitude of generated solitary waves in such a dusty plasma is independent of applied external magnetic field but we will have more localized solitons with increasing the external magnetic field strength. It is found that solitons are strongly influenced by the direction of external magnetic field. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Price‐based interference management in dense femtocell systems
Authors: Wang Xiaocheng , Han Qiaoni , Guan Xinping , Ma Kai
Published: October 2013

Femtocell technology has been drawing considerable attention as a cost‐effective means of improving cellular coverage and capacity. However, under co‐channel deployment, femtocell system in dense environment may incur high uplink interference to existing macrocells and experiences strong inter‐cell interference at the same time. To manage the uplink interference to macrocell, as well as the inter‐cell interference, this paper proposes a price‐based uplink interference management scheme for dense femtocell systems. Specifically, on the one hand, to guarantee the macrocell users' quality of service, the macrocell base station prices the interference from femtocell users (FUEs) subject to a maximum tolerable interference power constraint. On the other hand, the inter‐cell interference is also taken into consideration. Moreover, a Stackelberg game model is adopted to jointly study the utility maximization of the macrocell base station and FUEs. Then, in order to reduce the amount of information exchange, we design a distributed power allocation algorithm for FUEs. In addition, admission control is adopted to protect the active FUEs' performance. Numerical results show that the price‐based interference management scheme is effective. Meanwhile, it is shown that the distributed power allocation combined with admission control is capable of robustly protecting the performance of all the active FUEs. Copyright © 2013 John Wiley & Sons, Ltd.
Using data mining approaches to identify voice over IP spam
Authors: Su Ming‐Yang , Tsai Chen‐Han
Published: October 2013

With its rapid growth in popularity and attendant personal and commercial use of voice over Internet protocol (VoIP), spam over VoIP has emerged as a significant problem. In this paper, we first applied genetic algorithms to weight predetermined features of VoIP calls. Based on the weighting technique, we then proposed a mechanism for the online prevention of VoIP spam by the k‐nearest neighbor classification. Differing from the traditional k‐nearest neighbor algorithm, this paper used genetic algorithms to weight features to reflect the different degree of importance of each feature. VoIP is a real‐time communication service, as compared to off‐line e‐mail, and VoIP spam is also known as Spam over Internet telephony (SPIT). The system proposed in this paper has been named PSPIT that denotes Prevention of SPIT. Once spam is identified, the proposed PSPIT immediately updates the built‐in blacklist on the Session Initiation Protocol (SIP) server to block that specific user from sending SPIT again. The n‐fold cross‐validation was applied to evaluate PSPIT for unknown SPIT detection; in the case of n = 2, the best overall accuracy was 94.7%, whereas in the case of n = 4, the best overall accuracy was 93.1%. Copyright © 2013 John Wiley & Sons, Ltd.
Postsynaptic assembly: A role for Wnt signaling
Authors: Stamatakou Eleanna , Salinas Patricia C.
Published: October 2013

Synapse formation requires the coordinated formation of the presynaptic terminal, containing the machinery for neurotransmitter release, and the postsynaptic side that possesses the machinery for neurotransmitter reception. For coordinated pre‐ and postsynaptic assembly signals across the synapse are required. Wnt secreted proteins are well‐known synaptogenic factors that promote the recruitment of presynaptic components in diverse organisms. However, recent studies demonstrate that Wnts act directly onto the postsynaptic side at both central and peripheral synapses to promote postsynaptic development and synaptic strength. This review focuses on the role of Wnts in postsynaptic development at central synapses and the neuromuscular junction. © 2013 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 74: 818–827, 2014
Consequences of variation in foraging success among predators on numerical response
Authors: Okuyama Toshinori
Published: October 2013

The relationship between foraging success and reproduction is commonly assumed to be linear in theoretical investigations. Although the exact relationship (e.g., linear or nonlinear) does not influence qualitative conclusions of models under some assumptions, an inclusion of individual behavioral variation can make it otherwise due to Jensen's inequality. In particular, a mechanism that stabilizes food web dynamics is generated when two conditions are satisfied: (1) the reproduction of predators experiences diminishing returns from foraging success (i.e., concave down relationship between foraging success and reproduction) and (2) foraging success variation among predator individuals increases with the predator density. However, empirical results that confirm these conditions are scarce. This study describes the mechanism as a hypothesis for stability and discusses some important considerations for empirical verifications of the mechanism.
CreERT2 expression from within the c‐Kit gene locus allows efficient inducible gene targeting in and ablation of mast cells
Authors: Heger Klaus , Seidler Barbara , Vahl J. Christoph , Schwartz Christian , Kober Maike , Klein Sabine , Voehringer David , Saur Dieter , Schmidt‐Supprian Marc
Published: October 2013

Mast cells are abundantly situated at contact sites between the body and its environment, such as the skin and, especially during certain immune responses, at mucosal surfaces. They mediate allergic reactions and degrade toxins as well as venoms. However, their roles during innate and adaptive immune responses remain controversial and it is likely that major functions remain to be discovered. Recent developments in mast cell‐specific conditional gene targeting in the mouse promise to enhance our understanding of these fascinating cells. To complete the genetic toolbox to study mast cell development, homeostasis and function, it is imperative to inducibly manipulate their gene expression. Here, we report the generation of a novel knock‐in mouse line expressing a tamoxifen‐inducible version of the Cre recombinase from within the endogenous c‐Kit locus. We demonstrate highly efficient and specific inducible expression of a fluorescent reporter protein in mast cells both in vivo and in vitro. Furthermore, induction of diphtheria toxin A expression allowed selective and efficient ablation of mast cells at various anatomical locations, while other hematopoietic cells remain unaffected. This novel mouse strain will hence be very valuable to study mast cell homeostasis and how specific genes influence their functions in physiology and pathology.
Synthesis of Surface‐Functionalized Titania Particles with Organophosphorus Coupling Agents by Reactive Milling
Authors: Fischer Annika , Ney Christoph , Kickelbick Guido
Published: October 2013

We describe a top‐down approach for the synthesis of metal oxide particles with simultaneous surface modification. Functionalized titania particles were obtained by reactive milling together with phenylphosphonic acid in a high‐energy planetary ball mill. This process was accompanied by a tribochemical phase transition from the starting material anatase to the thermodynamically more stable rutile and a high‐pressure modification of titania, which was influenced by the presence of the coupling agent. The obtained products were characterized by X‐ray powder diffraction, IR and X‐ray fluorescence spectroscopy, thermal and elemental analysis as well as by scanning electron microscopy. The analysis showed final particle sizes of 100 to 300 nm, depending on the milling time and speed (rpm). Furthermore, the prepared particles showed a high degree of surface coverage with organophosphorus coupling agent, up to 1.4 mmol per gram. Coordination of the coupling agent to the surface resulted in a stabilization of the high‐pressure phase.
Zinc Thiocarboxylate Complexes as Precursors for Zinc Sulfide Nanoparticles under Aerobic Conditions
Authors: Vallejo‐Sánchez Daniel , Beobide Garikoitz , Castillo Oscar , Lanchas Mónica
Published: October 2013

Six new compounds with the formula [Zn(SCOR)2(N–N)] [R = –CH3 (TAc), –C6H5 (TBn); N–N = 2,2′‐bipyridine (BPY), 1,10‐phenanthroline (PHEN), 1,2‐bis(4‐pyridyl)ethylene (BPE), neocuproine (NEO)] have been obtained by the reaction of Zn(CH3COO)2·2H2O with the corresponding pyridine derivative and thiocarboxylate in methanol in the ratio Zn/SCOR/N–N = 1:2:1. In all compounds, the metal atom is bonded to sulfur atoms of two thiocarboxylato ligands and to two nitrogen atoms from one pyridine derivative imposing a distorted‐tetrahedral geometry. The use of chelating dipyridine ligands leads to discrete monomeric entities in compounds [Zn(TAc)2(BPY)] (1), [Zn(TBn)2(BPY)] (2), [Zn(TAc)2(NEO)] (3), and [Zn(TBn)2(PHEN)] (4). On the contrary, the bridging capability of the dipyridine BPE ligand gives rise to the polymeric chains observed in compounds [Zn(TAc)2(μ‐BPE)] (5) and [Zn(TBn)2(μ‐BPE)] (6). The occurrence of Zn···O weak interactions is rationalized on the basis of the νC=O shift and continuous shape measurements. Additionally, the present work demonstrates how ZnS nanoparticles can be obtained by dry thermolysis of the prepared thiocarboxylate complexes under aerobic conditions and moderate temperatures (300 °C). The analysis of the X‐ray diffraction pattern and SEM/TEM images reveals the presence of ZnS crystallites below 10 nm. The influence of the N‐heterocycle and thiocarboxylato ligands on the crystalline phase (blende or wurtzite), size, and purity of the resulting zinc sulfide nanoparticles is discussed.
Transformation of the [MnII2MnIII2(hmp)6]4+ Core into [CoIII2MnII2(hmp)6]4+ in the Reaction of the [Mn4(hmp)6(NO3)2(H2O)2] Cluster with [CoX4]2– (X = Cl, Br)
Authors: Kushch Lyudmila A. , Yagubskii Eduard B. , Simonov Sergey V. , Shibaeva Rimma P. , Suturina Elizaveta A. , Gritsan Nina P. , Sadakov Andrei V. , Sulimenkov Il'ya V.
Published: October 2013

The reactions of [Mn4(hmp)6(NO3)2(H2O)2](ClO4)2 with (Bu4N)2[CoX4] (X = Cl, Br) in CH3CN have been studied and the new heterometallic tetranuclear clusters [CoIII2MnII2(hmp)6Cl2(CH3CN)2]MnIICl4·3CH3CN and [CoIII2MnII2(hmp)6Br2(CH3CN)2]MnIIBr4·4CH3CN have been synthesized and characterized by TGA, electrospray ionization mass spectrometry, single‐crystal X‐ray diffraction, and magnetic measurements. The magnetic properties of the heterometallic clusters were analyzed by DFT and ab initio calculations.
Oxidation of Dodecanoate Intercalated Iron(II)–Iron(III) Layered Double Hydroxide to Form 2D Iron(III) (Hydr)oxide Layers
Authors: Huang Li‐Zhi , Ayala‐Luis Karina B. , Fang Liping , Dalby Kim N. , Kasama Takeshi , Bender Koch Christian , Hansen Hans Christian B.
Published: October 2013

A planar trioctahedral iron(II)–iron(III) hydroxide (green rust, GR) intercalated with dodecanoate (GRC12) has been oxidized by dioxygen to produce the corresponding planar iron(III) (hydr)oxide. The formulae of GRC12 and the final iron(III) product (oxGRC12) were determined to be FeII2.00FeIII1.00(OH)5.31(C12H23O2)0.66(SO4)0.51 and FeIII3O2.18(OH)3.13(C12H23O2)0.56(SO4)0.47, respectively. oxGRC12 has the same planar layer structure as GRC12, as revealed by identical powder X‐ray diffraction patterns. The electrostatic interactions between the interlayer dodecanoate (C12) anions and the iron hydroxide planar layer were preserved during the oxidation, as shown by FTIR spectroscopy. The high positive charge in the hydroxide layer produced by the oxidation of iron(II) to iron(III) is partially compensated by the deprotonation of hydroxy groups, as shown by X‐ray photoelectron spectroscopy. The Mössbauer quadrupole splitting of the iron(III) doublet increased on oxidation of GRC12, which has been attributed to the distortion of the octahedral sites caused by deprotonation and changes in the coordination site geometry. oxGRC12 is stable in air for more than 2 years. The van der Waals interactions between the alkyl chains of the intercalated dodecanoate anions play a crucial role in stabilizing the structure and hindering the collapse of the iron(II)–iron(III) (hydr)oxide structure during oxidation. This is the first report describing the formation of a stable planar layered octahedral iron(III) (hydr)oxide. oxGRC12 shows promise as a sorbent and host for hydrophobic reagents, and as a possible source of single planar layers of iron(III) (hydr)oxide.
Crystal Structure and Enhanced Piezoelectric Properties of Scandium and Bismuth‐Excess Modified Aurivillius Oxides, Na0.5–xBi2.5+xNb2–xScxO9
Authors: Long Changbai , Fan Huiqing , Li Mengmeng , Li Qiang
Published: October 2013

Aurivillius piezoelectrics, Bi–Sc modified Na0.5–xBi2.5+xNb2–xScxO9 (x = 0.05 and 0.1) and Na‐deficient and Bi‐enriched Na0.5–xBi2.5+xNb2O9 (x = 0.05, 0.1, and 0.2), were prepared by using a solid‐state reaction process. The Rietveld refinement verified that Sc3+ and excess Bi3+ were incorporated into the layered perovskite structure and that they occupied the B and A sites, respectively. The Na0.45Bi2.55Nb1.95Sc0.05O9 [0.05(BiSc)‐modified] crystallized in the orthorhombic space group A21am [a = 5.49853(9) Å, b = 5.45976(9) Å, c = 24.98351(29) Å, and V = 750.021(20) Å3; Z = 4] at room temperature. The A‐site Bi3+ donor substitution induced no obvious increase in the Curie point (Tc), but a further Sc3+ modification at the B site gave rise to a significant increase in Tc. The movements of non‐180° domains contributed to the piezoelectric activities of the Bi‐excess polycrystalline materials, whereas the excellent piezoelectric properties of the Bi–Sc‐modified polycrystalline materials mostly originated from intrinsic lattice contributions, which are due to their single‐180°‐domain‐wall structures. The Na0.45Bi2.55Nb1.95Sc0.05O9 [0.05(BiSc)‐modified] polycrystalline materials have a high Tc of 811 °C and a high piezoelectric activity (d33) of 28 pC/N; interestingly, its d33 was very stable against temperature.
Magnetic and Stable H3PW12O40‐Based Core@shell Nanomaterial towards the Esterification of Oleic Acid with Methanol
Authors: Li Shi , Zhai Shang‐Ru , Zhang Jian‐Ming , Xiao Zuo‐Yi , An Qing‐Da , Li Ming‐Hui , Song Xiao‐Wei
Published: October 2013

A magnetically retrievable and stable composite, Fe3O4@SiO2–NH2/HPW@CS/HPW, in which H3PW12O40 (abbreviated as HPW hereafter) was successfully anchored onto the surface of a cross‐linked chitosan coating on magnetic Fe3O4 cores, has been prepared by means of chemical bonding between the amino and HPW components. The resultant composites were characterized by different physicochemical techniques, such as TEM, SEM, FTIR, and vibrating sample magnetometry (VSM). An improved synthesis of methyl oleate from oleic acid and methanol was observed with the as‐prepared material as catalyst with easy recovery by simply using an external magnet. A yield of 93.2 % of methyl oleate was achieved under the optimal reaction conditions, that is, a 20:1 molar ratio of methanol to oleic acid and 0.4 g catalyst at 60 °C for 4 h. It was demonstrated that improved catalytic performance and facilitated separation were simultaneously achieved in the esterification reactions as a result of the core@shell structures in which stabilized HPW and magnetic cores are integrated into one body.
Stability and Reactivity of Cyclometallated Naphthylamine Complexes in Pd–C Bond Insertion Reactions with Coordinated Alkynylphosphanes
Authors: Chen Shuli , Chiew Jun Xuan , Pullarkat Sumod A. , Li Yongxin , Leung Pak‐Hing
Published: October 2013

Phenylbis(phenylethynyl)phosphane PhP(C≡CPh)2 coordinates regiospecifically to the α‐methyl‐chiral ortho‐platinated and ‐palladated naphthylamine units at the positions trans to the nitrogen donors. The P→Pt coordination bond is kinetically inert, whereas the P→Pd bond is labile. Upon heating of these phosphane complexes at 70 °C, one of the C≡C bonds in the coordinated PhP(C≡CPh)2 was activated towards an intermolecular Pd–C bond insertion reaction with an external ortho‐palladated naphthylamine ring. No intramolecular insertion reaction occurred. In contrast to its palladium analogue, the ortho‐platinated ring is not reactive towards coordinated PhP(C≡CPh)2, although it can promote the Pd–C bond insertion reaction. However, despite the high kinetic stability of the P→Pt coordination, the organoplatinum unit is a noticeably weaker activator than its organopalladium counterpart. The chirality of the reacting ortho‐metallated naphthylamine ligand exhibited high stereochemical influence on the formation of the new stereogenic phosphorus center during the course of these C–C bond‐formation reactions. The coordination chemistry and the absolute stereochemistry of the dimetallic products were determined by single‐crystal X‐ray crystallographic analysis.
Binuclear Cage‐Like Copper(II) Silsesquioxane (“Cooling Tower”) – Its High Catalytic Activity in the Oxidation of Benzene and Alcohols
Authors: Bilyachenko Alexey N. , Dronova Marina S. , Yalymov Alexey I. , Korlyukov Alexander A. , Shul'pina Lidia S. , Arkhipov Dmitry E. , Shubina Elena S. , Levitsky Mikhail M. , Kirilin Alexey D. , Shul'pin Georgiy B.
Published: October 2013

A new method of metallasilsesquioxane synthesis is described for the first time. According to this method, a partial nucleophilic cleavage of polymeric copper phenylsilsesquioxane by the use of sym‐cis‐tetraphenylcyclotetrasiloxanolate nonaethanolate (1) gave previously unknown binuclear cage‐like copper silsesquioxane [(PhSiO1.5)10(CuO)2(NaO0.5)2·4EtOH] (2). The unprecedented structure of 2, the so called “Cooling Tower” structure, was confirmed by single‐crystal X‐ray diffraction analysis. Compound 2 was found to be an excellent catalyst in oxidation reactions of benzene and alcohols with peroxides in acetonitrile solution at 50–70 °C.
Palladium(II) Catalyzed Suzuki/Sonogashira Cross‐Coupling Reactions of Sulfonates: An Efficient Approach to C2‐Functionalized Pyrimidines and Pyridines
Authors: Quan Zheng‐Jun , Jing Fu‐Qiang , Zhang Zhang , Da Yu‐Xia , Wang Xi‐Cun
Published: October 2013

Pyrimidin‐2‐yl sulfonates, as a reaction partner, can be easily prepared from inexpensive commercial materials and are efficiently cross‐coupled with arylboronic acids and terminal alkynes by using Pd(OAc)2‐catalyzed Suzuki and Sonogashira reactions. A wide array of C2‐functionalized pyrimidines have been prepared in good to excellent yields. 2‐Arylpyridines and 2‐(oct‐1‐ynyl)pyridine were also synthesized.
Exploring a Multivalent Approach to α‐L‐Fucosidase Inhibition
Authors: Moreno‐Clavijo Elena , Carmona Ana T. , Moreno‐Vargas Antonio J. , Molina Lidia , Wright Daniel W. , Davies Gideon J. , Robina Inmaculada
Published: October 2013

To probe the utility of a multivalent approach for fucosidase inhibition, a series of di‐ and tri‐valent imino sugars based onL‐fuco‐configured 1,4‐imino‐ and 1,4‐bis(imino)‐cyclitol epitopes has been synthesized and analyzed for fucosidase inhibition with the best trivalent species yielding a modest improvement in binding constant. Structural analysis of a representative pair of mono‐ and tri‐valent imino sugars has been performed on a bacterial fucosidase,BtFuc2970. The 3D structures show binding of the imino‐cyclitol in the3Econformation, consistent with the known pathway for fucosidase action.
o‐Iodoxybenzoic Acid Mediated N‐Arylation of Aromatic Amines by Using Arylhydrazines as the Arylating Counterpart
Authors: Jadhav Ravindra R. , Huddar Sameerana N. , Akamanchi Krishnacharya G.
Published: October 2013

Through free‐radical trapping experiments we have established, for the first time, the combination of arylhydrazines with o‐iodoxybenzoic acid (IBX) for the generation of aryl free radicals. On the basis of this finding, a method was developed for the N‐arylation of aromatic amines under mild conditions (base‐free, –5 °C) by using arylhydrazines as the arylating counterpart and arylamines. The scope of this method was demonstrated by using a number of arylhydrazines and arylamines, which gave the N‐arylated amines in good yields.
5‐Alkenylthiazoles as In‐Out Dienes in Polar [4+2] Cycloaddition Reactions
Authors: Alajarin Mateo , Cabrera Jose , Sanchez‐Andrada Pilar , Bautista Delia , Pastor Aurelia
Published: October 2013

5‐Alkenyl‐2‐aminothiazoles react as in‐out dienes with a wide range of electron‐poor dienophiles leading to the corresponding cycloaddition products in good to excellent yields. The [4+2] cycloadditions of 5‐alkenyl‐2‐aminothiazoles can be classified as site‐selective because only the diene moiety incorporating the formal C–C double bond of the heterocycle and that of the side‐chain is involved. Calculations of the HOMO energy values of representative 5‐alkenyl‐2‐aminothiazoles are disclosed. The cycloadditions are endo‐selective with N‐phenylmaleimide or maleic anhydride and regioselective when the reactions are conducted with nonsymmetrical dienophiles. Completely oxidized cycloadducts are obtained in the reactions of 5‐alkenyl‐2‐aminothiazoles with naphthoquinone or dimethyl acetylenedicarboxylate (DMAD). Unexpectedly, the reactions with 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione (PTAD) are not stereospecific. A mechanism placed at the concerted/stepwise boundary is proposed.
A Two‐Step Sequence to Ethyl α‐Fluorocyclopropanecarboxylates Through MIRC Reaction of Ethyl Dichloroacetate and Highly Regioselective Fluorination
Authors: Zhang Min , Gong Yuefa , Wang Weizhou
Published: October 2013

A two‐step sequence to ethyl α‐fluorocyclopropanecarboxylates has been developed. Ethyl α‐chlorocyclopropanecarboxylates were first obtained through a Michael‐initiated ring closure reaction of terminal electron‐deficient olefins with ethyl 2,2‐dichloroacetate under mild basic conditions. Subsequent smooth conversion into the corresponding monofluorinated analogues in good yields was through a halogen exchange reaction with potassium bifluoride. Further investigation clearly demonstrated that potassium bifluoride in this reaction system played a dual role of base and nucleophilic reagent. This is the first successful example reported hitherto for producing ethyl α‐fluorocyclopropanecarboxylate directly through fluorination of its chlorinated analogue with alkali bifluoride.