bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self‐Assembled Squalene‐based Fluorescent Heteronanoparticles
Authors: Borrelli Stella , Cartelli Daniele , Secundo Francesco , Fumagalli Gaia , Christodoulou Michael S. , Borroni Ambra , Perdicchia Dario , Dosio Franco , Milla Paola , Cappelletti Graziella , Passarella Daniele 
Published: October 2014

AbstractThe preparation of fluorescent nanoparticles containing squalenoyl–paclitaxel and a squalene‐based fluorescein derivative is presented. The formation of self‐assembled heteronanoparticles was confirmed by using the quasielastic light scattering (QELS) technique. The internalization in A549 human lung carcinoma cells was verified by microscopy analysis. Finally, paclitaxel in nanoassemblies maintains its ability to target microtubules.
Phosphorus‐based Bifunctional Organocatalysts for the Addition of Carbon Dioxide and Epoxides
Authors: Werner Thomas , Büttner Hendrik 
Published: October 2014

AbstractBifunctional phosphonium salts were synthesized and employed as organocatalysts for the atom efficient synthesis of cyclic carbonates from CO2 and epoxides for the first time. These catalysts were obtained in high yields by a modular, straightforward one‐step synthesis. The hydrogen‐bond donating alcohol function in the side chain leads to a synergistic effect accelerating the catalytic reaction. The desired cyclic carbonates are obtained in high yields and selectivity under solvent‐free reaction conditions without the use of any co‐catalyst. Under optimized reaction conditions various epoxides were converted to the corresponding cyclic carbonates in excellent yields. The products were obtained analytically pure after simple filtration over a silica gel pad. This protocol is even applicable for a multigram reaction scale. Moreover, the catalysts could be easily recovered and reused up to five times.
Carbon Dioxide Adsorption in Amine‐Functionalized Mixed‐Ligand Metal–Organic Frameworks of UiO‐66 Topology
Authors: Ethiraj Jayashree , Albanese Elisa , Civalleri Bartolomeo , Vitillo Jenny G. , Bonino Francesca , Chavan Sachin , Shearer Greig C. , Lillerud Karl Petter , Bordiga Silvia 
Published: October 2014

AbstractA series of mixed‐ligand [1,4‐benzenedicarboxylic acid (BDC)/2‐amino‐1,4‐benzenedicarboxylic acid (ABDC)] UiO‐66 metal–organic frameworks (MOFs) synthesized through two different methods (low (LT) and high temperature (HT)) have been investigated for their carbon dioxide adsorption properties from 0 to 1 bar to clarify the role of amino loading on carbon dioxide uptake. Volumetric CO2 isotherms show that the CO2 capacity (normalized to the Langmuir surface area) increases with a degree of functionalization of about 46 %; for similar NH2 contents, the same values are found for both synthetic procedures. Microcalorimetric isotherms reveal that amino‐functionalized materials have a larger differential heat of adsorption (qdiff) towards CO2; reaching 27(25) and 20(22) kJ mol−1 on HT(LT)‐UiO‐66‐NH2 and UiO‐66, respectively, at the lowest equilibrium pressures used in this study. All experimental results are supported by values obtained through quantum mechanical calculations.
Design and simulation of novel amplifier‐based mixer for ISM band wireless applications
Authors: Jin Jie , Wang Chunhua , Sun Jingru , Du Sichun 
Published: October 2014

SummaryThis letter describes a low‐voltage low‐power (LV‐LP) 2.4‐GHz mixer for Industrial, Scientific and Medical (ISM) band wireless applications. The approach is based on a two‐stage amplifier, and the Gilbert switch stage is inserted between the two amplifier stages. The proposed amplifier‐based mixer delivers a remarkable conversion gain of 13 dB with a local oscillator (LO) power of 7 dBm, while consuming only 1.05‐mW DC power from a 0.8‐V supply voltage. The input‐referred third‐order intercept point (IIP3) of the mixer is 3.82 dBm, and the chip area is only 0.429 mm2. The results indicate that this mixer is suitable for the low‐voltage low‐power applications. Copyright © 2014 John Wiley & Sons, Ltd.
900 MHZ radio‐frequency identification rectifier with optimization and reusing of electro‐static discharges protections in 180 nm digital CMOS technology
Authors: Boni Andrea , Bigi Marco 
Published: October 2014

SummarySensitivity and electro‐static discharges (ESD) protection level are crucial parameters for any Ultra High‐Frequency (UHF) power rectifier–harvester designed for radio‐frequency identification (RFID) devices. While sensitivity limits the reading range of the interrogator‐to‐tag communication link, the requirement for an adequate protection against ESD is enforced in commercial devices connected to a printed antenna. Both resistive and capacitive parasitics of the protection circuits severely affect RF performance of the device. In the paper, a rectifier for UHF RFID embedding an ESD protection for 2 kV human‐body discharge model (HBM) level is proposed. The target of a low added parasitic capacitance is achieved by adapting the protection circuit to the RFID rectifier and reusing the ESD clamp for additional functions being mandatory in a UHF RFID front end. The layout of the ESD clamp has been optimized for minimum parasitic resistance without sacrificing the protection level. Two UHF harvesters were implemented in a 180 nm digital complementary metal‐oxide semiconductor (CMOS) technology, featuring a minimum sensitivity of −15.5 dBm with an ESD protection level of 2 kV HBM. Copyright © 2014 John Wiley & Sons, Ltd.
Langmuir Probe in Non‐Maxwellian Plasma: Correlation Between the Electron Energy Distribution Function, the Ion Energy at the Sheath Edge and the Floating Voltage
Authors: Jauberteau J. L. , Jauberteau I. 
Published: October 2014

AbstractThis work is devoted to the study of the Langmuir probe in non‐Maxwellian plasma, assuming mono‐energetic singly charged ions and a collisionless sheath. Using a general analytical equation for the Electron Energy Distribution Function (EEDF), we study the effect of the EEDF profile on: a) The ion energy at the sheath edge of a negatively biased collector, b) the I‐V probe characteristic and c) the floating voltage (Vp‐Vf). Different methods are used and compared to determine these parameters or characteristics. A correlation is given between the floating voltage, the ion energy at the sheath edge and the EEDF profile. The study is also extended to distribution functions with several components. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of a multiparametric score to predict left ventricular remodelling and prognosis after cardiac resynchronization therapy
Authors: Kydd Anna C. , Khan Fakhar Z. , Ring Liam , Pugh Peter J. , Virdee Munmohan S. , Dutka David P. 
Published: October 2014

AimsOptimal delivery of CRT requires appropriate patient selection and device implantation. Echocardiographic predictors of CRT response individually appear to enhance patient selection, but do not fully reflect the complex underlying myocardial dysfunction. We hypothesized that a multiparametric approach would offer greater predictive value and sought to derive a score incorporating baseline characteristics including: dyssynchrony, LV function, and LV lead position.Methods and resultsData were analysed from 294 patients undergoing CRT between June 2008 and December 2012. All patients were in sinus rhythm with QRS >120 ms, NYHA class II–IV, and LVEF <35%. Detailed clinical assessment including echocardiography was completed at baseline and 6 months after CRT. Response was defined as a ≥15% reduction in LV end‐systolic volume. Dyssynchrony (interventricular delay and radial strain delay), global longitudinal strain, and LV lead position were independent predictors of LV remodelling and were used to derive a predictive score which correlated with reduction in LV volume (r = − 0.5, P < 0.001) and was higher with QRS >150 ms and non‐ischaemic aetiology. A cut‐off score <0.6 offered the highest specificity and positive predictive value (100%) to determine non‐response. A score >3.28 offered high specificity (specificity 86%, sensitivity 70%) to predict response. Survival proportion at longer term follow‐up was low (21%) in the group with predictive score <0.6.ConclusionA multiparametric strategy, which defines anticipated probability of response to CRT, offers potential to predict non‐responders with poor long‐term survival following CRT. The value of this approach in avoiding unnecessary device implantation with potential for harm requires validation in large multicentre studies.
Micellar Polyaromatic Capsules: Enhanced Emissive Properties through Shell‐Functionalization
Authors: Kondo Kei , Suzuki Akira , Akita Munetaka , Yoshizawa Michito 
Published: October 2014

AbstractFunctionalization of the polyaromatic shell of a micelle‐like molecular capsule was accomplished by simple functionalization of the amphiphilic subunits composed of a bent bis‐anthracene framework and two trimethylammonium groups. In aqueous solutions, functionalized subunits assemble spontaneously and quantitatively into spherical capsules providing anthracene shells with external diameters of 2–3 nm through hydrophobic and aromatic‐aromatic interactions. The shape and size of the functionalized capsules remain similar to the original, but the emissive intensities increase significantly (up to 5‐fold) by attaching cyano or phenylethynyl groups. Furthermore, the shell‐functionalization drastically enhances the host–guest photophysical properties (up to 8‐fold) in the cavities of the capsules, as estimated by emission intensities from the encapsulated fluorescent dyes.
DETACHED PARENTING AND TODDLER PROBLEM BEHAVIOR IN EARLY HEAD START FAMILIES
Authors: Jones Harden Brenda , Denmark Nicole , Holmes Allison , Duchene Melissa 
Published: October 2014

ABSTRACTThis study examined detached parenting among Early Head Start mothers, and associated maternal characteristics and child behavior. Participants included 81 mother–child dyads. Data were collected in participants' homes during two visits. Mothers reported on demographic factors, parenting stress, and children's problem behaviors. Children's neurodevelopment was assessed, and videotaped parent–child play interactions were coded. Path analyses indicated that demographic risk factors and parenting stress were associated with higher levels of detached parenting. As a mediator, detached parenting significantly predicted children's later problem behavior. There was a direct effect of parenting stress on children's behavior problems, but no direct effect of children's neurodevelopmental risk. Detached parenting partially mediated the influence of parenting stress on children's problem behavior. The final model moderately accounted for the variance in detached parenting and children's problem behaviors. The results suggest that parents who experience multiple risks and high levels of parenting stress are more likely to demonstrate detached parenting. In addition, detached parenting leads to higher levels of toddler problem behavior, and may increase the problem behavior displayed by toddlers of parents experiencing multiple risks and parenting stress. These findings are discussed in the context of infant mental health practice.
Use of FTIR‐PAS combined with chemometrics to quantify nutritional information in rapeseeds (Brassica napus)
Authors: Lu Yuzhen , Du Changwen , Yu Changbing , Zhou Jianmin 
Published: October 2014

AbstractFast acquisition of nutritional information of rapeseeds is important for rapeseed breeding programs, evaluation of soil nutrient conditions and even fertilization recommendations. Fourier transform mid‐infrared photoacoustic spectroscopy (FTIR‐PAS) was employed to determine nitrogen, phosphorus and potassium content in rapeseeds. Calibration models were developed using both partial least squares (PLS) and partial least squares combined with direct orthogonal signal correction (DOSC‐PLS). According to the values of RPD (ratio of prediction to deviation), the PLS models for nitrogen and phosphorus were acceptable, while the PLS model for potassium needed to be improved. By contrast, DOSC‐PLS models obtained the better predictive accuracy with RPD values of 2.54, 2.10 and 1.94 for nitrogen, phosphorus and potassium, respectively. This work demonstrates the good performance of FTIR‐PAS for rapid and non‐destructive quantification of nutritional information in rapeseeds.
Coarse soil can enhance the availability of nutrients from fine soil
Authors: Smaill Simeon J. , Clinton Peter W. , Allen Robert B. , Leckie Alan C , Davis Murray R. 
Published: October 2014

AbstractA recent trial found that the presence of coarse soil in fine soil increased nutrient uptake by two plant species (Smaill et al., 2014). To determine if the additional nutrient uptake was derived directly from the coarse soil, the changes in coarse soil nutrient stocks were assessed. In most cases nutrient stocks increased, despite being associated with greater plant nutrient uptake. This suggests coarse soil can promote nutrient release from fine soil through some currently unknown mechanism.
Nuclear magnetic resonance using electronic referencing: method validation and evaluation of the measurement uncertainties for the quantification of benzoic acid in orange juice
Authors: Garrido Bruno C. , de Carvalho Lucas J. 
Published: October 2014

Quantitative nuclear magnetic resonance measurements have become more popular over the last decade. The introduction of new methods and experimental parameters has been of fundamental importance in the development of new applications. Amongst these new developments is the introduction of electronic referencing for quantifications. The use of electronic referencing eliminates errors in the analyses as a result of weighting of internal standards as well as undesired problems as a result of the solubility of the standards in the analyte solution and chemical interactions between the analyte and the internal standard.In this work, we have studied the quantification of a very important analyte in a food matrix, benzoic acid in orange juice, as a model to the validation and measurement uncertainty estimation of electronic referencing using 1H NMR in food analyses. The referencing method applied was the pulse length‐based concentration measurement.Method was validated and showed good results for the precision and accuracy parameters evaluated. A certified reference material and a reference material candidate were analyzed, and extremely good results were obtained. Reported relative expanded uncertainties are in the 1.07–1.39% range that can be considered an extremely good performance for the analysis of a food complex matrix. Measurement uncertainty was evaluated by two different approaches, and the pulse calibrations for the samples and for the reference have been shown to account for approximately 80% of the total uncertainty of the measurement. Copyright © 2014 John Wiley & Sons, Ltd.
Electroluminescence of germanium LEDs on silicon: Influence of antimony doping
Authors: Schwartz Bernhard , Klossek André , Kittler Martin , Oehme Michael , Kasper Erich , Schulze Jörg 
Published: October 2014

AbstractAntimony‐doped Ge‐LEDs were subjected to electroluminescence studies at temperatures about 300 K and 80 K. The LEDs were grown on Si substrates by MBE. The thickness of the active layer was 300 nm. For the p+nn+‐LEDs the Sb concentrations were 1 × 1018, 1 × 1019, 3 × 1019, 4 × 1019, 7 × 1019 or 1 × 1020 cm–3, respectively. As reference a p+in+‐LED without intentional doping in the active layer was used. The investigated specimen exhibited dominance of the direct transition line at about 0.8 eV.Moreover, luminescence indirect transition was observed. In general, the spectra reveal higher EL intensities at room temperature as compared to 80 K. With decreasing temperature the direct peak was blue shifted. The highest EL intensity was found for the LED with Sb concentration of 3 × 1019 cm–3. With increasing Sb doping a red‐shift of the direct peak was observed, caused by band gap narrowing. In addition, a simulated curve of the direct transition was compared with our samples and fits well with the measured spectra. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Green light‐emitting CdTe nanocrystals: synthesis and optical characterizations
Authors: Algieri Luciana , Rosato Roberta , Mosca Maria Elena , Protopapa Maria Lucia , Scalone Anna Grazia , Di Benedetto Francesca , Bucci Luigi , Tapfer Leander 
Published: October 2014

AbstractIn this work, we report on the synthesis of CdTe nanocrystals (NCs) by using of two different saturated long‐chain capping ligands, oleic (OA) and myristic acids (MA), and investigate their influence on the nanocrystals optical properties. The main goal of our study is to identify the ligand that allows slowing down the growth rate of the NCs after nucleation, in order to obtain small enough nanocrystals emitting in the blue‐green part of the optical spectrum. Our results show clearly that oleic acid allows a good control on the CdTe NCs growth, finally leading to a fine‐tuning of the NCs size‐dependent emission from the green to the yellow part of the spectrum. Instead, a faster reaction kinetics, which arises in a lower possibility to produce small NCs emitting in the green part of the spectrum, was noticed using myristic acid. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhanced detection of the algal toxin PbTx‐2 in marine waters by atmospheric pressure chemical ionization mass spectrometry
Authors: Mead Ralph N. , Probst Emily E. , Helms John R. , Avery G. Brooks , Kieber Robert J. , Skrabal Stephen A. 
Published: October 2014

RATIONALEKarenia brevis, a marine dinoflagellate, biosynthesizes a unique class of polyether toxins called brevetoxins that produce significant health, environmental and economic impacts in and along coastal waters. Previous application of liquid chromatography/mass spectrometry for detection of the most common brevetoxin, PbTx‐2, has relied almost exclusively upon electrospray ionization (ESI). A different ionization source is proposed in this study with improved sensitivity ultimately leading to lower limit of detection compared to (+) ESI.METHODSBrevetoxin standards and samples (PbTx‐2) were analyzed by liquid chromatography/mass spectrometry using both (+) atmospheric pressure chemical ionization and (+) electrospray ionization sources.RESULTSLC/MS with (+) APCI exhibited an order of magnitude improvement in the limit of detection (7.7 × 10–4 pg mass on‐column) compared to the same method using (+) ESI (7.5 × 10–3 pg mass on‐column). The calibration sensitivity of (+) APCI (1.3 × 103) was also five times higher than positive mode (+) ESI (0.26 × 103).CONCLUSIONSPositive mode APCI represents a significant improvement in detection and quantification of PbTx‐2 by LC/MS allowing for smaller sample sizes compared to previous studies using (+) ESI. This in turn leads to higher throughput of samples during and after bloom events giving stakeholders detailed information on the fate of this potent marine toxin. Copyright © 2014 John Wiley & Sons, Ltd.
In situ identification and mapping of neuropeptides from the stomatogastric nervous system of Cancer borealis
Authors: Chen Ruibing , Ouyang Chuanzi , Xiao Mingming , Li Lingjun 
Published: October 2014

RATIONALEThe crustacean stomatogastric nervous system (STNS) is a classic experimental model to derive basic knowledge about neuronal functions and how they coordinate with each other to generate neural circuits. To investigate the components of the neuromodulators and how they are distributed in such a system is essential to understand the underlying mechanism. In this study, in situ mass spectrometry based techniques were employed to fulfill this goal.METHODSOffline high‐performance liquid chromatography (HPLC) separation was coupled with matrix‐assisted laser desorption/ionization time‐of‐flight/time‐of‐flight (MALDI‐TOF/TOF) to analyze the neuropeptides in the stomatogastric ganglion (STG) tissue extract from the Jonah crab Cancer borealis. Direct tissue analysis was employed to investigate the neuropeptides present in the STNS. MALDI imaging was also applied to map the localization of multiple neuropeptide families in the STG and the upstream nerve fibers.RESULTSFifty‐seven neuropeptides were detected from a single desheathed STG using direct tissue analysis, and they were from eleven different neuropeptide families, including FaRP, AST‐A, AST‐B, etc. Differential neuropeptide profiles from three different types of ganglia and two types of nerve fiber tissues from the STNS were documented. The direct tissue analysis was shown better for studying neuropeptides from small neural organs like the STG as compared to the large‐scale HPLC/MALDI analysis. MALDI images were also acquired to study the distribution of neuropeptides in the STG.CONCLUSIONSIn this study, the components and distribution of neuropeptides have been analyzed in the STNS from C. borealis using direct tissue profiling and MALDI imaging. The results show that the direct tissue analysis of desheathed neural tissues can provide higher sensitivity for neuropeptide study compared to large‐scale HPLC/MALDI analysis of pooled tissues. The results are valuable for understanding the functions of neuropeptides in neural network generation. Copyright © 2014 John Wiley & Sons, Ltd.
Structural characterization of organic aerosol using Fourier transform ion cyclotron resonance mass spectrometry: Aromaticity equivalent approach
Authors: Yassine Mahmoud M. , Harir Mourad , Dabek‐Zlotorzynska Ewa , Schmitt‐Kopplin Philippe 
Published: October 2014

RATIONALEA challenge of atmospheric particulate matter (PM) analysis is the understanding of the sources and chemistry of complex organic aerosols, especially the water‐soluble organic compounds (WSOC) fraction, a key component of atmospheric fine PM (PM2.5). The sources of WSOC are not well understood and, thus, the molecular characterization of WSOC is important because it provides insight into aerosol sources and the underlying mechanisms of secondary organic aerosols formation and transformation.METHODSIn this study, molecular characterization of WSOC was achieved using Fourier transform ion cyclotron resonance mass spectrometry. The aromaticity equivalent (Xc), a new parameter calculated from the assigned molecular formula, is introduced to improve the identification and characterization of aromatic and condensed aromatic compounds in WSOC. Diesel PM (DPM) and atmospheric PM samples were used to study the applicability of the proposed method.RESULTSThreshold values of Xc ≥2.5000 and Xc ≥2.7143 are proposed as unambiguous minimum criteria for the presence of aromatics and condensed aromatics, respectively. By using these criteria, 36% of precursors were defined as aromatics and condensed aromatics in the DPM. For comparison, 21% of aromatic and condensed aromatic compounds were defined using the Aromaticity Index (AI) classification. The lower estimates by the AI approach are probably due to the failure to recognize aromatics and condensed aromatics with longer alkyl chains. The estimated aromatic and condensed aromatic fractions in the atmospheric aerosol samples collected in an industrial area affected by biomass burning events were 51.2 and 50.0%, respectively.CONCLUSIONSThe advantage of employing this parameter is that Xc would have a constant value for each proposed core structure regardless of the degree of alkylation, and thus visual representation and structural interpretations of the spectra become advantageous for characterizing and comparing complex samples. In addition, the proposed parameter complements the AI classification and identification of aromatic and condensed aromatic structures in complex matrices. Copyright © 2014 John Wiley & Sons, Ltd.